Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/23/13

AREA FORECAST DISCUSSION

NWS PHOENIX AZ

 935 AM MST SUN JUL 21 2013

.UPDATE...UPDATED AVIATION DISCUSSION...

...POTENTIAL FOR HEAVY RAINFALL TODAY...

.SYNOPSIS...
A LOW PRESSURE SYSTEM IN MEXICO WILL CONTINUE TO SUPPLY MOISTURE TO
THE DESERT SOUTHWEST TODAY. HUMID CONDITIONS WILL RESULT IN
WELL-ABOVE NORMAL RAIN CHANCES AND WELL-BELOW NORMAL TEMPERATURES. A
DRYING TREND WILL BEGIN MONDAY...CONTINUING INTO WEDNESDAY AS
HIGH PRESSURE BUILDS BACK OVER THE REGION. MONSOON MOISTURE MOVING
BACK NORTHWARD INTO THE REGION IS LIKELY TO ONCE AGAIN INCREASE RAIN
CHANCES FOR THE END OF THE WEEK AND INTO THE WEEKEND.

&&

.DISCUSSION...
A VERY MOIST AIRMASS IN PLACE IN COMBINATION WITH BROAD UPPER
DIFLUENCE ALOFT CENTERED OVER WESTERN ARIZONA IS CREATING A WET
MORNING ACROSS MUCH OF SOUTHWEST AZ AND AREAS ELSEWHERE. A
UNSEASONABLY STRONG UPPER LOW CENTERED JUST OFF THE WEST COAST OF
BAJA AND A FLATTENED UPPER RIDGE STRETCHING FROM NORTHERN CA INTO CO
HAS RESULTED IN MODEST DIFLUENCE ALOFT. AN OVERNIGHT MCS THAT
DEVELOPED ACROSS SOUTHERN AZ ON THE NORTHERN PERIPHERY OF THE UPPER
LOW CONTINUES TO TRACK NORTHWESTWARD ACROSS WESTERN MARICOPA AND
YUMA COUNTIES. WITH PWATS OF AROUND 2 INCHES...RAINFALL RATES HAVE
BEEN VERY IMPRESSIVE WITH THE STRONGEST THUNDERSTORMS. THE AUTOMATED
RAIN GAGE AT THE BENDER WASH JUST EAST OF GILA BEND REPORTED 2.24
INCHES OF RAIN IN AROUND 45 MINUTES. OTHER GAGES HAVE REPORTED LESS
THAN AN INCH OF RAINFALL...BUT RADAR ESTIMATES INDICATE SOME RURAL
AREAS OF EASTERN YUMA AND WESTERN MARICOPA COUNTIES HAVE RECEIVED 1
TO 2 INCHES OF RAINFALL SINCE 5 AM THIS MORNING.

HEAVY RAINFALL AND THE FLASH FLOOD POTENTIAL WILL BE THE MAIN AND
NEARLY THE ONLY THREAT TODAY. THE 12Z SOUNDING AT KPHX AND FORECAST
SOUNDINGS SHOW AN EXTREMELY MOIST PROFILE WITH NO SIGNIFICANT DRY
LAYERS ALOFT. CAN/T RULE OUT SOME STRONG WIND GUSTS ASSOCIATED
WITH A WET MICROBURST WITH THE STRONGEST STORMS TODAY...BUT GUSTS
WILL MOST DEFINITELY BE SUB-SEVERE. LATEST HRRR AND LOCAL WRF RUNS
SHOW A MIXED PICTURE FOR STORM ACTIVITY FOR THE REST OF TODAY. THE
MCS SHOULD CONTINUE IT/S TRACK NORTHWESTWARD LATE THIS MORNING INTO
THE EARLY AFTERNOON BEFORE EITHER DISSIPATING OR MOVING OUT OF THE
CWA. ADDITIONAL ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS HAVE
DEVELOPED ALONG AND JUST TO THE EAST OF THE MCS OVER CENTRAL
MARICOPA COUNTY SINCE 8 AM MST. CURRENT SATELLITE IMAGERY AND
OBJECTIVE ANALYSIS SHOWS MORE UNSTABLE AIR WITH MIXED LAYER CAPES OF
AROUND 1000 J/KG OVER SOUTH-CENTRAL AND SOUTHEAST AZ. GIVEN THE
SURFACE DEW POINTS IN THE LOWER 70S ACROSS THIS AREA...SHOULD SEE
REDEVELOPMENT OF STORMS EVEN BEFORE NOON TODAY AND MORE LIKELY
THROUGHOUT THE AFTERNOON HOURS. THESE STORMS WILL LIKELY CONTINUE TO
TRACK WESTWARD INTO PORTIONS OF SOUTHWEST AZ AND SOUTHEAST CA THIS
EVENING AND POSSIBLY DURING THE OVERNIGHT HOURS TONIGHT. THE FLASH
FLOOD THREAT SHOULD BE ISOLATED DUE TO THE FAIRLY WORKED OVER
ATMOSPHERE FROM THE PAST 24 HOURS...SO NO FLASH FLOOD WATCHES ARE
EXPECTED AT THIS TIME.

&&

.PREVIOUS DISCUSSION...
UPPER LOW CONTINUES TO SPIN WESTWARD INTO THE PACIFIC OCEAN JUST OFF
THE BAJA PENINSULA. FURTHER NORTH...THE MID-TROPOSPHERIC ANTICYCLONE
REMAINS POSITIONED ACROSS CA/NV. RESULTING MID-LEVEL EASTERLY FLOW
IS STRONGER THAN NORMAL (STANDARDIZED ANOMALY NEAR 1.0) AND
CONTINUES TO ADVECT DEEP SUB-TROPICAL MOISTURE INTO THE FORECAST
AREA. SURFACE DEWPOINTS ARE CURRENTLY IN THE LOWER 70S ACROSS THE
PHOENIX METRO AREA WHILE THE GPS-IPW REGISTERED AROUND 1.75
INCHES...WELL ABOVE NORMAL. LATEST RAP INDICATES THAT PWATS MAY BE
AS HIGH AS 2.0 TO 2.4 INCHES ACROSS THE SOUTHWEST DESERTS AND
TOWARDS PUERTO PENASCO.

LATEST WV IMAGERY SHOWS TWO MCS...ONE ACROSS THE MOJAVE DESERT AND
THE OTHER ACROSS SOUTHERN AZ...BEARING DOWN ON SW AZ AND SE CA.
STRONG LOW-LEVEL CONVERGENCE IS EXPECTED EARLY THIS MORNING AND POPS
WERE INCREASED IN THESE AREAS. ACROSS SOUTH-CENTRAL AZ...NMM AND
WRF-BASED GUIDANCE CONTINUES TO SUGGEST THAT SHOWERS WILL REDEVELOP
AS EARLY AS THIS MORNING. THIS SEEMS REASONABLE GIVEN THE AMPLE
MOISTURE AND IT WILL ONLY TAKE A MINIMAL AMOUNT OF HEATING FOR
CONVECTION TO INITIATE. MODELS ALSO SUGGEST THAT VORTICITY-FORCED
ASCENT WILL AID IN THE DEVELOPMENT OF STORMS THIS AFTERNOON ACROSS
SE CA. ANY STORMS THAT DEVELOP WILL HAVE THE POTENTIAL TO PRODUCE
HEAVY RAIN AND LOCALIZED FLOODING. THE COPIOUS AMOUNT OF MOISTURE
WILL ALSO RESULT IN CONSIDERABLE CLOUDINESS ACROSS MUCH OF THE
AREA...WHICH WILL KEEP TEMPERATURES WELL BELOW NORMAL. FORECAST HIGH
FOR PHOENIX IS 95 DEGREES. A MAX TEMP THIS LOW HAS NOT OCCURRED
SINCE MAY 27.

A SIGNIFICANT DRYING TREND WILL TAKE PLACE MONDAY AS THE UPPER LOW
LIFTS STEADILY NORTHWARD. SHOWERS AND THUNDERSTORMS ARE STILL
ANTICIPATED...THOUGH COVERAGE WILL BE NOTICEABLY LESS THAN WHAT HAS
OCCURRED THE PAST FEW DAYS. THE UPPER LOW WILL BE PICKED UP BY THE
WESTERLIES TUESDAY AS THE MONSOON HIGH BECOMES REPOSITIONED ACROSS
THE ROCKIES. GFS/ECMWF DIFFER ON THE AMOUNT OF MOISTURE LEFT OVER
ACROSS THE DESERT SOUTHWEST THOUGH THE CONSENSUS IS THAT IT SHOULD
BE SUFFICIENT FOR ISOLATED THUNDERSTORMS THROUGH THE WEEK. FLOW WILL
BE WEAK AS AN ANTICYCLONE BUILDS BACK ACROSS AZ AND CONVECTION WILL
MAINLY BE RELEGATED TO THE HIGHER TERRAIN. A WARMING TREND IS ALSO
EXPECTED WITH A RETURN TO ABOVE NORMAL TEMPERATURES BY THURSDAY.
MODELS ARE IN GENERALLY GOOD AGREEMENT THAT ANOTHER PVD WILL SLIDE
WESTWARD THROUGH SONORA LATE IN THE WEEK...RESULTING IN AN INFLUX OF
MOISTURE. FORECAST IS FOR BELOW CLIMO POPS THROUGH
MIDWEEK...FOLLOWED BY NEAR CLIMO POPS THURSDAY THROUGH SUNDAY.


&&

.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL...
THUNDERSTORMS ARE NOW DEVELOPING...AND MOVING NORTHWARD ACROSS THE
GREATER PHOENIX AREA. THESE STORMS ARE EXPECTED TO AFFECT THE
TERMINALS OVER THE NEXT COUPLE OF HOURS BEFORE SOMEWHAT DRIER AIR
MOVING IN FROM THE SOUTH REDUCES ACTIVITY THIS AFTERNOON AND
EVENING. GENERALLY LIGHT WINDS AND SCT-BKN CLOUD DECKS AOA 6-8KFT
ARE EXPECTED WITH PERIODS OF CIGS LOWERING TO 3-4KFT/VISIBILITIES
REDUCED DOWN TO 4SM IN HEAVIER SHOWERS AND THUNDERSTORMS.

SOUTHEAST CA AND SOUTHWEST AZ...INCLUDING KIPL AND KBLH...
ISOLATED SHOWER/THUNDERSTORM ACTIVITY WILL CONTINUE TO FILL IN OVER
SOUTHEAST CALIFORNIA THIS MORNING THROUGH AT LEAST 17Z...WITH GUSTY
OUTFLOWS TO 30KT POSSIBLE AT TIMES...ESPECIALLY NEAR KNYL. SCT-BKN
CLOUD DECKS WITH CIGS DOWN TO AROUND 6-8KFT IN HEAVIER SHOWERS AND
THUNDERSTORMS WITH SKIES/CIGS IMPROVING LATER THIS AFTERNOON. WINDS
S-SELY AROUND 10-15KT THROUGH MUCH OF THE TAF PERIOD ACROSS THE
LOWER COLORADO RIVER VALLEY/KBLH WITH LIGHTER SELY WINDS AT KIPL.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
A SWITCH TO A SOUTHERLY FLOW ALOFT WILL BRING DRYING CONDITIONS AND
ENDING PRECIPITATION CHANCES ACROSS SOUTHEAST CALIFORNIA AND
SOUTHWEST ARIZONA. SLIGHT CHANCES FOR STORMS WILL CONTINUE ACROSS
SOUTH-CENTRAL ARIZONA WITH BETTER CHANCES ACROSS HIGHER TERRAIN
LOCATIONS NORTH AND EAST OF PHOENIX. HUMIDITIES WILL REMAIN ELEVATED
THROUGH THE ENTIRE PERIOD WITH AFTERNOON HUMIDITIES ONLY DROPPING
INTO THE 20-30 PERCENT RANGE WITH GOOD OVERNIGHT RECOVERY.

$$

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...KUHLMAN
PREVIOUS DISCUSSION...HIRSCH
AVIATION...PERCHA/MEYERS
FIRE WEATHER...KUHLMAN






AREA FORECAST DISCUSSION

NWS PHOENIX AZ

 923 AM MST SUN JUL 21 2013

...POTENTIAL FOR HEAVY RAINFALL TODAY...

.SYNOPSIS...
A LOW PRESSURE SYSTEM IN MEXICO WILL CONTINUE TO SUPPLY MOISTURE TO
THE DESERT SOUTHWEST TODAY. HUMID CONDITIONS WILL RESULT IN
WELL-ABOVE NORMAL RAIN CHANCES AND WELL-BELOW NORMAL TEMPERATURES. A
DRYING TREND WILL BEGIN MONDAY...CONTINUING INTO WEDNESDAY AS
HIGH PRESSURE BUILDS BACK OVER THE REGION. MONSOON MOISTURE MOVING
BACK NORTHWARD INTO THE REGION IS LIKELY TO ONCE AGAIN INCREASE RAIN
CHANCES FOR THE END OF THE WEEK AND INTO THE WEEKEND.

&&

.DISCUSSION...
A VERY MOIST AIRMASS IN PLACE IN COMBINATION WITH BROAD UPPER
DIFLUENCE ALOFT CENTERED OVER WESTERN ARIZONA IS CREATING A WET
MORNING ACROSS MUCH OF SOUTHWEST AZ AND AREAS ELSEWHERE. A
UNSEASONABLY STRONG UPPER LOW CENTERED JUST OFF THE WEST COAST OF
BAJA AND A FLATTENED UPPER RIDGE STRETCHING FROM NORTHERN CA INTO CO
HAS RESULTED IN MODEST DIFLUENCE ALOFT. AN OVERNIGHT MCS THAT
DEVELOPED ACROSS SOUTHERN AZ ON THE NORTHERN PERIPHERY OF THE UPPER
LOW CONTINUES TO TRACK NORTHWESTWARD ACROSS WESTERN MARICOPA AND
YUMA COUNTIES. WITH PWATS OF AROUND 2 INCHES...RAINFALL RATES HAVE
BEEN VERY IMPRESSIVE WITH THE STRONGEST THUNDERSTORMS. THE AUTOMATED
RAIN GAGE AT THE BENDER WASH JUST EAST OF GILA BEND REPORTED 2.24
INCHES OF RAIN IN AROUND 45 MINUTES. OTHER GAGES HAVE REPORTED LESS
THAN AN INCH OF RAINFALL...BUT RADAR ESTIMATES INDICATE SOME RURAL
AREAS OF EASTERN YUMA AND WESTERN MARICOPA COUNTIES HAVE RECEIVED 1
TO 2 INCHES OF RAINFALL SINCE 5 AM THIS MORNING.

HEAVY RAINFALL AND THE FLASH FLOOD POTENTIAL WILL BE THE MAIN AND
NEARLY THE ONLY THREAT TODAY. THE 12Z SOUNDING AT KPHX AND FORECAST
SOUNDINGS SHOW AN EXTREMELY MOIST PROFILE WITH NO SIGNIFICANT DRY
LAYERS ALOFT. CAN/T RULE OUT SOME STRONG WIND GUSTS ASSOCIATED
WITH A WET MICROBURST WITH THE STRONGEST STORMS TODAY...BUT GUSTS
WILL MOST DEFINITELY BE SUB-SEVERE. LATEST HRRR AND LOCAL WRF RUNS
SHOW A MIXED PICTURE FOR STORM ACTIVITY FOR THE REST OF TODAY. THE
MCS SHOULD CONTINUE IT/S TRACK NORTHWESTWARD LATE THIS MORNING INTO
THE EARLY AFTERNOON BEFORE EITHER DISSIPATING OR MOVING OUT OF THE
CWA. ADDITIONAL ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS HAVE
DEVELOPED ALONG AND JUST TO THE EAST OF THE MCS OVER CENTRAL
MARICOPA COUNTY SINCE 8 AM MST. CURRENT SATELLITE IMAGERY AND
OBJECTIVE ANALYSIS SHOWS MORE UNSTABLE AIR WITH MIXED LAYER CAPES OF
AROUND 1000 J/KG OVER SOUTH-CENTRAL AND SOUTHEAST AZ. GIVEN THE
SURFACE DEW POINTS IN THE LOWER 70S ACROSS THIS AREA...SHOULD SEE
REDEVELOPMENT OF STORMS EVEN BEFORE NOON TODAY AND MORE LIKELY
THROUGHOUT THE AFTERNOON HOURS. THESE STORMS WILL LIKELY CONTINUE TO
TRACK WESTWARD INTO PORTIONS OF SOUTHWEST AZ AND SOUTHEAST CA THIS
EVENING AND POSSIBLY DURING THE OVERNIGHT HOURS TONIGHT. THE FLASH
FLOOD THREAT SHOULD BE ISOLATED DUE TO THE FAIRLY WORKED OVER
ATMOSPHERE FROM THE PAST 24 HOURS...SO NO FLASH FLOOD WATCHES ARE
EXPECTED AT THIS TIME.

&&

.PREVIOUS DISCUSSION...
UPPER LOW CONTINUES TO SPIN WESTWARD INTO THE PACIFIC OCEAN JUST OFF
THE BAJA PENINSULA. FURTHER NORTH...THE MID-TROPOSPHERIC ANTICYCLONE
REMAINS POSITIONED ACROSS CA/NV. RESULTING MID-LEVEL EASTERLY FLOW
IS STRONGER THAN NORMAL (STANDARDIZED ANOMALY NEAR 1.0) AND
CONTINUES TO ADVECT DEEP SUB-TROPICAL MOISTURE INTO THE FORECAST
AREA. SURFACE DEWPOINTS ARE CURRENTLY IN THE LOWER 70S ACROSS THE
PHOENIX METRO AREA WHILE THE GPS-IPW REGISTERED AROUND 1.75
INCHES...WELL ABOVE NORMAL. LATEST RAP INDICATES THAT PWATS MAY BE
AS HIGH AS 2.0 TO 2.4 INCHES ACROSS THE SOUTHWEST DESERTS AND
TOWARDS PUERTO PENASCO.

LATEST WV IMAGERY SHOWS TWO MCS...ONE ACROSS THE MOJAVE DESERT AND
THE OTHER ACROSS SOUTHERN AZ...BEARING DOWN ON SW AZ AND SE CA.
STRONG LOW-LEVEL CONVERGENCE IS EXPECTED EARLY THIS MORNING AND POPS
WERE INCREASED IN THESE AREAS. ACROSS SOUTH-CENTRAL AZ...NMM AND
WRF-BASED GUIDANCE CONTINUES TO SUGGEST THAT SHOWERS WILL REDEVELOP
AS EARLY AS THIS MORNING. THIS SEEMS REASONABLE GIVEN THE AMPLE
MOISTURE AND IT WILL ONLY TAKE A MINIMAL AMOUNT OF HEATING FOR
CONVECTION TO INITIATE. MODELS ALSO SUGGEST THAT VORTICITY-FORCED
ASCENT WILL AID IN THE DEVELOPMENT OF STORMS THIS AFTERNOON ACROSS
SE CA. ANY STORMS THAT DEVELOP WILL HAVE THE POTENTIAL TO PRODUCE
HEAVY RAIN AND LOCALIZED FLOODING. THE COPIOUS AMOUNT OF MOISTURE
WILL ALSO RESULT IN CONSIDERABLE CLOUDINESS ACROSS MUCH OF THE
AREA...WHICH WILL KEEP TEMPERATURES WELL BELOW NORMAL. FORECAST HIGH
FOR PHOENIX IS 95 DEGREES. A MAX TEMP THIS LOW HAS NOT OCCURRED
SINCE MAY 27.

A SIGNIFICANT DRYING TREND WILL TAKE PLACE MONDAY AS THE UPPER LOW
LIFTS STEADILY NORTHWARD. SHOWERS AND THUNDERSTORMS ARE STILL
ANTICIPATED...THOUGH COVERAGE WILL BE NOTICEABLY LESS THAN WHAT HAS
OCCURRED THE PAST FEW DAYS. THE UPPER LOW WILL BE PICKED UP BY THE
WESTERLIES TUESDAY AS THE MONSOON HIGH BECOMES REPOSITIONED ACROSS
THE ROCKIES. GFS/ECMWF DIFFER ON THE AMOUNT OF MOISTURE LEFT OVER
ACROSS THE DESERT SOUTHWEST THOUGH THE CONSENSUS IS THAT IT SHOULD
BE SUFFICIENT FOR ISOLATED THUNDERSTORMS THROUGH THE WEEK. FLOW WILL
BE WEAK AS AN ANTICYCLONE BUILDS BACK ACROSS AZ AND CONVECTION WILL
MAINLY BE RELEGATED TO THE HIGHER TERRAIN. A WARMING TREND IS ALSO
EXPECTED WITH A RETURN TO ABOVE NORMAL TEMPERATURES BY THURSDAY.
MODELS ARE IN GENERALLY GOOD AGREEMENT THAT ANOTHER PVD WILL SLIDE
WESTWARD THROUGH SONORA LATE IN THE WEEK...RESULTING IN AN INFLUX OF
MOISTURE. FORECAST IS FOR BELOW CLIMO POPS THROUGH
MIDWEEK...FOLLOWED BY NEAR CLIMO POPS THURSDAY THROUGH SUNDAY.


&&

.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL...
NEW STORMS WILL CONTINUE TO DEVELOP TO THE SOUTH AND WEST OF THE
PHOENIX AREA...WITH ACTIVITY SLOWLY BUILDING AROUND AND ENCROACHING
ON THE TERMINALS LATER THIS MORNING AFTER 15Z...PERSISTING INTO THE
AFTERNOON/EARLY EVENING. GENERALLY LIGHT WINDS AND SCT-BKN CLOUD
DECKS AOA 6-8KFT ARE EXPECTED WITH PERIODS OF CIGS LOWERING TO
3-4KFT/VISIBILITIES REDUCED DOWN TO 4SM IN HEAVIER SHOWERS AND
THUNDERSTORMS. STORMS DIMINISH AND SKIES EXPECTED TO IMPROVE AFTER
02Z MONDAY WITH SCT-BKN CLOUD DECKS SETTLING IN AOA 10KFT.

SOUTHEAST CA AND SOUTHWEST AZ...INCLUDING KIPL AND KBLH...
ISOLATED SHOWER/THUNDERSTORM ACTIVITY WILL CONTINUE TO FILL IN OVER
SOUTHEAST CALIFORNIA THIS MORNING THROUGH AT LEAST 17Z...WITH GUSTY
OUTFLOWS TO 30KT POSSIBLE AT TIMES...ESPECIALLY NEAR KNYL. SCT-BKN
CLOUD DECKS WITH CIGS DOWN TO AROUND 6-8KFT IN HEAVIER SHOWERS AND
THUNDERSTORMS WITH SKIES/CIGS IMPROVING LATER THIS AFTERNOON. WINDS
S-SELY AROUND 10-15KT THROUGH MUCH OF THE TAF PERIOD ACROSS THE
LOWER COLORADO RIVER VALLEY/KBLH WITH LIGHTER SELY WINDS AT KIPL.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
A SWITCH TO A SOUTHERLY FLOW ALOFT WILL BRING DRYING CONDITIONS AND
ENDING PRECIPITATION CHANCES ACROSS SOUTHEAST CALIFORNIA AND
SOUTHWEST ARIZONA. SLIGHT CHANCES FOR STORMS WILL CONTINUE ACROSS
SOUTH-CENTRAL ARIZONA WITH BETTER CHANCES ACROSS HIGHER TERRAIN
LOCATIONS NORTH AND EAST OF PHOENIX. HUMIDITIES WILL REMAIN ELEVATED
THROUGH THE ENTIRE PERIOD WITH AFTERNOON HUMIDITIES ONLY DROPPING
INTO THE 20-30 PERCENT RANGE WITH GOOD OVERNIGHT RECOVERY.

$$

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...KUHLMAN
PREVIOUS DISCUSSION...HIRSCH
AVIATION...MEYERS
FIRE WEATHER...KUHLMAN









AREA FORECAST DISCUSSION

NWS PHOENIX AZ

 540 AM MST SUN JUL 21 2013

.UPDATE...UPDATED AVIATION DISCUSSION.

&&

.SYNOPSIS...
A LOW PRESSURE SYSTEM IN MEXICO WILL CONTINUE TO SUPPLY MOISTURE TO
THE DESERT SOUTHWEST TODAY. HUMID CONDITIONS WILL RESULT IN
WELL-ABOVE NORMAL RAIN CHANCES AND WELL-BELOW NORMAL TEMPERATURES. A
DRYING TREND WILL BEGIN MONDAY...CONTINUING INTO WEDNESDAY AS
HIGH PRESSURE BUILDS BACK OVER THE REGION. MONSOON MOISTURE MOVING
BACK NORTHWARD INTO THE REGION IS LIKELY TO ONCE AGAIN INCREASE RAIN
CHANCES FOR THE END OF THE WEEK AND INTO THE WEEKEND.

&&

.DISCUSSION...
UPPER LOW CONTINUES TO SPIN WESTWARD INTO THE PACIFIC OCEAN JUST OFF
THE BAJA PENINSULA. FURTHER NORTH...THE MID-TROPOSPHERIC ANTICYCLONE
REMAINS POSITIONED ACROSS CA/NV. RESULTING MID-LEVEL EASTERLY FLOW
IS STRONGER THAN NORMAL (STANDARDIZED ANOMALY NEAR 1.0) AND
CONTINUES TO ADVECT DEEP SUB-TROPICAL MOISTURE INTO THE FORECAST
AREA. SURFACE DEWPOINTS ARE CURRENTLY IN THE LOWER 70S ACROSS THE
PHOENIX METRO AREA WHILE THE GPS-IPW REGISTERED AROUND 1.75
INCHES...WELL ABOVE NORMAL. LATEST RAP INDICATES THAT PWATS MAY BE
AS HIGH AS 2.0 TO 2.4 INCHES ACROSS THE SOUTHWEST DESERTS AND
TOWARDS PUERTO PENASCO.

LATEST WV IMAGERY SHOWS TWO MCS...ONE ACROSS THE MOJAVE DESERT AND
THE OTHER ACROSS SOUTHERN AZ...BEARING DOWN ON SW AZ AND SE CA.
STRONG LOW-LEVEL CONVERGENCE IS EXPECTED EARLY THIS MORNING AND POPS
WERE INCREASED IN THESE AREAS. ACROSS SOUTH-CENTRAL AZ...NMM AND
WRF-BASED GUIDANCE CONTINUES TO SUGGEST THAT SHOWERS WILL REDEVELOP
AS EARLY AS THIS MORNING. THIS SEEMS REASONABLE GIVEN THE AMPLE
MOISTURE AND IT WILL ONLY TAKE A MINIMAL AMOUNT OF HEATING FOR
CONVECTION TO INITIATE. MODELS ALSO SUGGEST THAT VORTICITY-FORCED
ASCENT WILL AID IN THE DEVELOPMENT OF STORMS THIS AFTERNOON ACROSS
SE CA. ANY STORMS THAT DEVELOP WILL HAVE THE POTENTIAL TO PRODUCE
HEAVY RAIN AND LOCALIZED FLOODING. THE COPIOUS AMOUNT OF MOISTURE
WILL ALSO RESULT IN CONSIDERABLE CLOUDINESS ACROSS MUCH OF THE
AREA...WHICH WILL KEEP TEMPERATURES WELL BELOW NORMAL. FORECAST HIGH
FOR PHOENIX IS 95 DEGREES. A MAX TEMP THIS LOW HAS NOT OCCURRED
SINCE MAY 27.

A SIGNIFICANT DRYING TREND WILL TAKE PLACE MONDAY AS THE UPPER LOW
LIFTS STEADILY NORTHWARD. SHOWERS AND THUNDERSTORMS ARE STILL
ANTICIPATED...THOUGH COVERAGE WILL BE NOTICEABLY LESS THAN WHAT HAS
OCCURRED THE PAST FEW DAYS. THE UPPER LOW WILL BE PICKED UP BY THE
WESTERLIES TUESDAY AS THE MONSOON HIGH BECOMES REPOSITIONED ACROSS
THE ROCKIES. GFS/ECMWF DIFFER ON THE AMOUNT OF MOISTURE LEFT OVER
ACROSS THE DESERT SOUTHWEST THOUGH THE CONSENSUS IS THAT IT SHOULD
BE SUFFICIENT FOR ISOLATED THUNDERSTORMS THROUGH THE WEEK. FLOW WILL
BE WEAK AS AN ANTICYCLONE BUILDS BACK ACROSS AZ AND CONVECTION WILL
MAINLY BE RELEGATED TO THE HIGHER TERRAIN. A WARMING TREND IS ALSO
EXPECTED WITH A RETURN TO ABOVE NORMAL TEMPERATURES BY THURSDAY.
MODELS ARE IN GENERALLY GOOD AGREEMENT THAT ANOTHER PVD WILL SLIDE
WESTWARD THROUGH SONORA LATE IN THE WEEK...RESULTING IN AN INFLUX OF
MOISTURE. FORECAST IS FOR BELOW CLIMO POPS THROUGH
MIDWEEK...FOLLOWED BY NEAR CLIMO POPS THURSDAY THROUGH SUNDAY.


&&

.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL...
NEW STORMS WILL CONTINUE TO DEVELOP TO THE SOUTH AND WEST OF THE
PHOENIX AREA...WITH ACTIVITY SLOWLY BUILDING AROUND AND ENCROACHING
ON THE TERMINALS LATER THIS MORNING AFTER 15Z...PERSISTING INTO THE
AFTERNOON/EARLY EVENING. GENERALLY LIGHT WINDS AND SCT-BKN CLOUD
DECKS AOA 6-8KFT ARE EXPECTED WITH PERIODS OF CIGS LOWERING TO
3-4KFT/VISIBILITIES REDUCED DOWN TO 4SM IN HEAVIER SHOWERS AND
THUNDERSTORMS. STORMS DIMINISH AND SKIES EXPECTED TO IMPROVE AFTER
02Z MONDAY WITH SCT-BKN CLOUD DECKS SETTLING IN AOA 10KFT.

SOUTHEAST CA AND SOUTHWEST AZ...INCLUDING KIPL AND KBLH...
ISOLATED SHOWER/THUNDERSTORM ACTIVITY WILL CONTINUE TO FILL IN OVER
SOUTHEAST CALIFORNIA THIS MORNING THROUGH AT LEAST 17Z...WITH GUSTY
OUTFLOWS TO 30KT POSSIBLE AT TIMES...ESPECIALLY NEAR KNYL. SCT-BKN
CLOUD DECKS WITH CIGS DOWN TO AROUND 6-8KFT IN HEAVIER SHOWERS AND
THUNDERSTORMS WITH SKIES/CIGS IMPROVING LATER THIS AFTERNOON. WINDS
S-SELY AROUND 10-15KT THROUGH MUCH OF THE TAF PERIOD ACROSS THE
LOWER COLORADO RIVER VALLEY/KBLH WITH LIGHTER SELY WINDS AT KIPL.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
A SWITCH TO A SOUTHERLY FLOW ALOFT WILL BRING DRYING CONDITIONS AND
ENDING PRECIPITATION CHANCES ACROSS SOUTHEAST CALIFORNIA AND
SOUTHWEST ARIZONA. SLIGHT CHANCES FOR STORMS WILL CONTINUE ACROSS
SOUTH-CENTRAL ARIZONA WITH BETTER CHANCES ACROSS HIGHER TERRAIN
LOCATIONS NORTH AND EAST OF PHOENIX. HUMIDITIES WILL REMAIN ELEVATED
THROUGH THE ENTIRE PERIOD WITH AFTERNOON HUMIDITIES ONLY DROPPING
INTO THE 20-30 PERCENT RANGE WITH GOOD OVERNIGHT RECOVERY.

$$

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...HIRSCH
AVIATION...MEYERS
FIRE WEATHER...KUHLMAN






AREA FORECAST DISCUSSION

NWS PHOENIX AZ

 250 AM MST SUN JUL 21 2013

.SYNOPSIS...
A LOW PRESSURE SYSTEM IN MEXICO WILL CONTINUE TO SUPPLY MOISTURE TO
THE DESERT SOUTHWEST TODAY. HUMID CONDITIONS WILL RESULT IN
WELL-ABOVE NORMAL RAIN CHANCES AND WELL-BELOW NORMAL TEMPERATURES. A
DRYING TREND WILL BEGIN MONDAY...CONTINUING INTO WEDNESDAY AS
HIGH PRESSURE BUILDS BACK OVER THE REGION. MONSOON MOISTURE MOVING
BACK NORTHWARD INTO THE REGION IS LIKELY TO ONCE AGAIN INCREASE RAIN
CHANCES FOR THE END OF THE WEEK AND INTO THE WEEKEND.

&&

.DISCUSSION...
UPPER LOW CONTINUES TO SPIN WESTWARD INTO THE PACIFIC OCEAN JUST OFF
THE BAJA PENINSULA. FURTHER NORTH...THE MID-TROPOSPHERIC ANTICYCLONE
REMAINS POSITIONED ACROSS CA/NV. RESULTING MID-LEVEL EASTERLY FLOW
IS STRONGER THAN NORMAL (STANDARDIZED ANOMALY NEAR 1.0) AND
CONTINUES TO ADVECT DEEP SUB-TROPICAL MOISTURE INTO THE FORECAST
AREA. SURFACE DEWPOINTS ARE CURRENTLY IN THE LOWER 70S ACROSS THE
PHOENIX METRO AREA WHILE THE GPS-IPW REGISTERED AROUND 1.75
INCHES...WELL ABOVE NORMAL. LATEST RAP INDICATES THAT PWATS MAY BE
AS HIGH AS 2.0 TO 2.4 INCHES ACROSS THE SOUTHWEST DESERTS AND
TOWARDS PUERTO PENASCO.

LATEST WV IMAGERY SHOWS TWO MCSS...ONE ACROSS THE MOJAVE DESERT AND
THE OTHER ACROSS SOUTHERN AZ...BEARING DOWN ON SW AZ AND SE CA.
STRONG LOW-LEVEL CONVERGENCE IS EXPECTED EARLY THIS MORNING AND POPS
WERE INCREASED IN THESE AREAS. ACROSS SOUTH-CENTRAL AZ...NMM AND
WRF-BASED GUIDANCE CONTINUES TO SUGGEST THAT SHOWERS WILL REDEVELOP
AS EARLY AS THIS MORNING. THIS SEEMS REASONABLE GIVEN THE AMPLE
MOISTURE AND IT WILL ONLY TAKE A MINIMAL AMOUNT OF HEATING FOR
CONVECTION TO INITIATE. MODELS ALSO SUGGEST THAT VORTICITY-FORCED
ASCENT WILL AID IN THE DEVELOPMENT OF STORMS THIS AFTERNOON ACROSS
SE CA. ANY STORMS THAT DEVELOP WILL HAVE THE POTENTIAL TO PRODUCE
HEAVY RAIN AND LOCALIZED FLOODING. THE COPIOUS AMOUNT OF MOISTURE
WILL ALSO RESULT IN CONSIDERABLE CLOUDINESS ACROSS MUCH OF THE
AREA...WHICH WILL KEEP TEMPERATURES WELL BELOW NORMAL. FORECAST HIGH
FOR PHOENIX IS 95 DEGREES. A MAX TEMP THIS LOW HAS NOT OCCURRED SINCE
MAY 27.

A SIGNIFICANT DRYING TREND WILL TAKE PLACE MONDAY AS THE UPPER LOW
LIFTS STEADILY NORTHWARD. SHOWERS AND THUNDERSTORMS ARE STILL
ANTICIPATED...THOUGH COVERAGE WILL BE NOTICEABLY LESS THAN WHAT HAS
OCCURRED THE PAST FEW DAYS. THE UPPER LOW WILL BE PICKED UP BY THE
WESTERLIES TUESDAY AS THE MONSOON HIGH BECOMES REPOSITIONED ACROSS
THE ROCKIES. GFS/ECMWF DIFFER ON THE AMOUNT OF MOISTURE LEFT OVER
ACROSS THE DESERT SOUTHWEST THOUGH THE CONSENSUS IS THAT IT SHOULD
BE SUFFICIENT FOR ISOLATED THUNDERSTORMS THROUGH THE WEEK. FLOW WILL
BE WEAK AS AN ANTICYCLONE BUILDS BACK ACROSS AZ AND CONVECTION WILL
MAINLY BE RELEGATED TO THE HIGHER TERRAIN. A WARMING TREND IS ALSO
EXPECTED WITH A RETURN TO ABOVE NORMAL TEMPERATURES BY THURSDAY.
MODELS ARE IN GENERALLY GOOD AGREEMENT THAT ANOTHER PVD WILL SLIDE
WESTWARD THROUGH SONORA LATE IN THE WEEK...RESULTING IN AN INFLUX OF
MOISTURE. FORECAST IS FOR BELOW CLIMO POPS THROUGH
MIDWEEK...FOLLOWED BY NEAR CLIMO POPS THURSDAY THROUGH SUNDAY.


&&

.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL...
VERY LOW CONFIDENCE AVIATION FORECAST FOR CNTRL ARIZONA THROUGH
SUNDAY AFTERNOON WITH THUNDERSTORM COVERAGE AND MOVEMENT COMPLETELY
DICTATING IMPACT TIMING AND DURATION. WHILE MOST TSTMS SHOULD
CONGEAL WEST OF THE TERMINALS...SCT ACTIVITY MOVING WEST FROM HIGHER
TERRAIN TO THE EAST COULD ARRIVE BETWEEN 02Z-06Z.
CONCURRENTLY...NUMEROUS OUTFLOW BOUNDARIES FROM CONVECTION
SURROUNDING THE AREA MAY CAUSE FREQUENTLY SHIFTING SFC WINDS
ORIENTED FROM MANY DIFFERENT DIRECTIONS. ATTEMPTED TO CAPTURE
GENERAL TRENDS IN THIS TAF PACKAGE...WITH THE EXPECTATION OF SEVERAL
AMENDMENTS BASED ON SHORT TERM TRENDS.

SEVERAL MODELS SUGGEST EXTENSIVE CLOUD COVER AND SHOWERS LINGERING
ACROSS CNTRL ARIZONA SUNDAY MORNING. HAVE ADDED A VCSH MENTION WITH
LOWERING CIGS...THOUGH KEPT HEIGHTS ABOVE 6K FT. THERE ARE
INDICATIONS CIGS COULD FALL BLO 6K FT FOR A PERIOD NECESSITATING
REDUCED ACCEPTANCE RATES...THOUGH CONFIDENCE WAS TOO LOW TO INCLUDE
AT THIS TIME.


SOUTHEAST CA AND SOUTHWEST AZ...INCLUDING KIPL AND KBLH...
SCATTERED SHOWERS AND THUNDERSTORMS SHOULD BEGIN TO APPROACH SERN
CALIFORNIA TERMINALS LATER THIS EVENING AND OVERNIGHT. OVERALL
FORECAST CONFIDENCE IS RATHER LOW REGARDING THE COVERAGE AND TIMING
OF TSTMS AND AVIATION IMPACTS. HAVE ATTEMPTED TO INDICATE A TRENDS
OF SHIFTING WINDS AND VCTS/VCSH INTO TERMINAL TOWARDS THE LATE
EVENING AND OVERNIGHT HOURS. SHOWERS COULD LINGER INTO SUNDAY
MORNING...BUT DID NOT INCLUDE ANY MENTION IN THIS TAF PACKAGE GIVEN
EXTREMELY LOW CONFIDENCE.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
A SWITCH TO A SOUTHERLY FLOW ALOFT WILL BRING DRYING CONDITIONS AND
ENDING PRECIPITATION CHANCES ACROSS SOUTHEAST CALIFORNIA AND
SOUTHWEST ARIZONA. SLIGHT CHANCES FOR STORMS WILL CONTINUE ACROSS
SOUTH-CENTRAL ARIZONA WITH BETTER CHANCES ACROSS HIGHER TERRAIN
LOCATIONS NORTH AND EAST OF PHOENIX. HUMIDITIES WILL REMAIN ELEVATED
THROUGH THE ENTIRE PERIOD WITH AFTERNOON HUMIDITIES ONLY DROPPING
INTO THE 20-30 PERCENT RANGE WITH GOOD OVERNIGHT RECOVERY.

$$

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...HIRSCH
AVIATION...MO
FIRE WEATHER...KUHLMAN






AREA FORECAST DISCUSSION

NWS PUEBLO CO

 305 PM MDT SUN JUL 21 2013

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 304 PM MDT SUN JUL 21 2013

DRIER AIR MASS HAS SPREAD OVER THE NORTHERN AND WESTERN PORTIONS OF
THE AREA THIS AFTERNOON...DROPPING DEW POINTS INTO THE 20S OVER THE
CENTRAL MOUNTAINS AND ACROSS TELLER COUNTY. LOW LEVEL MOISTURE STILL
LURKS ON THE PLAINS...WHERE DEWPOINTS IN THE 50S HAVE LED TO CAPES
IN EXCESS OF 2K J/KG EAST OF I-25. VERY LITTLE IN THE WAY OF
FORCING/UPWARD MOTION THIS AFTERNOON...WITH ONLY VERY SPARSE
MOUNTAIN CONVECTION MAINLY SOUTH OF HIGHWAY 50. HAVE ALSO SEEN A
COUPLE CELLS DEVELOP THEN DISSIPATE QUICKLY OVER EASTERN EL PASO
COUNTY...WHERE MOISTURE GRADIENT IS FAIRLY TIGHT AND RESIDUAL
BOUNDARY FROM LAST NIGHT`S CONVECTION REMAINS. LATEST HRRR HINTS AT
TSRA DEVELOPING EAST OF I-25 THIS EVENING....AND WHILE FORCING IS
WEAK...LARGE CAPES ARE HARD TO IGNORE...AND WILL THROW IN SOME LOW
POPS FOR THE PLAINS EARLY THIS EVENING. STILL EXPECT ANY STORMS TO
DISSIPATE QUICKLY AFTER SUNSET. ON MONDAY...AIR MASS CONTINUES TO
DRY...AND EVEN THE MOUNTAINS WILL BE HARD PRESSED TO SEE MORE THAN
SOME MODERATE CUMULUS BUILD-UP IN THE AFTERNOON. KEPT SOME VERY LOW
POPS IN PLACE OVER THE HIGHER PEAKS...BUT EVEN THESE MAY BE
OVERDONE. RISING HEIGHTS AND MID-LEVEL TEMPS SUGGEST A HOT DAY IS IN
STORE...AS READINGS ON THE PLAINS REACH 100F...WITH 80/90S
ELSEWHERE.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 304 PM MDT SUN JUL 21 2013

THE ENTIRE EXTENDED FORECAST PERIOD CAN BE SUMMED UP IN TWO
SENTENCES. AN UPPER RIDGE OF HIGH PRESSURE WILL REMAIN LOCKED INTO
PLACE ACROSS THE REGION. MINOR DISTURBANCES IN THE FLOW ALOFT
ROTATING AROUND THE RIDGE WILL KICK OFF ENHANCED CONVECTION TOWARDS
THE LATTER HALF OF THE WEEK. NOW FOR THE SPECIFICS...

MONDAY NIGHT THROUGH TUESDAY...EC...GFS AND EVEN THE NAM MODEL ARE
NOW INDICATING THAT IT SHOULD REMAIN FAIRLY DRY THROUGH MUCH OF
TUE...WITH ISOLATED TO LOW END SCATTERED POPS OVER THE HIGHER
TERRAIN. A COLD FRONT DROPS DOWN TO THE PALMER DVD ON TUE...BUT THE
LATEST RUNS INDICATE IT DOES NOT DROP SOUTH UNTIL LATE TUE...SETTING
THE STAGE FOR WED. LOOK FOR MAX TEMPS ACROSS THE E PLAINS TO BE
AROUND 100 DEG F ON TUE...AND IN THE MID TO UPPER 80S FOR THE HIGH
VALLEYS.

WEDNESDAY THROUGH FRIDAY...THE COLD FRONT WILL DROP SOUTH ACROSS THE
CWA LATE TUE...WITH WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY
EXPECTED FOR A MAJORITY OF THE FORECAST AREA BOTH WED AND THU. MAX
TEMPS ARE EXPECTED TO BE ABOUT 10 DEGREES COOLER WITH SCATTERED POPS
ALL AREAS BORDERING ON LIKELY. WED AFTN THROUGH THU AFTN LOOKS LIKE
IT WILL BE THE MOST PROBABLY TIME FRAME FOR FLASH FLOOD POTENTIAL
ACROSS AREA BURN SCARS. BY FRIDAY THE UPPER RIDGE AXIS STARTS TO
SHIFT SLIGHTLY TO THE EAST AS THE RIDGE AMPLIFIES...AND THOUGH THERE
IS STILL A GOOD CHANCE FOR CONVECTION FOR ALL AREAS...IT WILL BE DUE
TO A REINFORCED MONSOON PLUME AS OPPOSED TO FRONTAL/LLVL FORCING.
TEMPS ON FRI WILL BE AS COOL OR PERHAPS EVEN A COUPLE OF DEGREES
COOLER.

SATURDAY AND SUNDAY...EXTENDED MODELS ARE POINTING TO ANOTHER
STRONGER DISTURBANCE MOVING ACROSS THE DAKOTAS AND MIDWEST ON
SAT...PUSHING ANOTHER COOLD SURGE INTO EASTERN CO LATE SAT INTO SUN.
WHEREAS SAT IS FORECAST TO HAVE DIURNAL CONVECTIVE ACTIVITY TIED
MAINLY TO THE HIGHER TERRAIN...SUNDAY COULD BE ANOTHER ACTIVE DAY
WITH WIDESPREAD CONVECTION AND SLIGHTLY COOLER TEMPS. MOORE

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 304 PM MDT SUN JUL 21 2013

ISOLATED TSRA HAVE BEEN DEVELOPING JUST EAST OF KCOS ALONG A WEAK
BOUNDARY...AND WHILE CURRENT STORM MOTION SUGGESTS ACTIVITY WILL
STAY EAST OF THE TERMINAL...GUSTY AND ERRATIC OUTFLOW WINDS MAY
DEVELOP FOR A FEW HOURS AFTER 21Z. MAY ALSO SEE TSRA GET CLOSE
ENOUGH TO PRODUCE SOME GUSTY WINDS AT KPUB...ESPECIALLY AFTER 22Z.
AT KALS...MAY SEE SOME TSRA OVER THE SAN JUANS DRIFT INTO THE AREA
AFTER 22Z...THOUGH AGAIN STORMS MAY DISSIPATE BEFORE THEY REACH THE
TERMINAL. CONVECTION WILL DIMINISH AFTER SUNSET...AND VFR CONDITIONS
EXPECTED ALL TAF SITES AFTER 03Z THIS EVENING. ON MONDAY...TAF SITES
WILL STAY VFR WITH ONLY VERY SPARSE HIGH BASED CONVECTION EXPECTED
OVER THE MOUNTAINS.

&&

.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...PETERSEN
LONG TERM...MOORE
AVIATION...PETERSEN







AREA FORECAST DISCUSSION

NWS DENVER/BOULDER CO

 257 PM MDT SUN JUL 21 2013

.SHORT TERM...STRONG OUTFLOW FROM T-STORMS UP IN NEBRASKA LAST
NIGHT...BACKED ACROSS NORTHEAST COLORADO EARLIER TODAY. THIS
SHALLOW MOIST AIRMASS SIGNIFICANTLY INFLUENCED TEMPERATURES EAST
OF THE MOUNTAINS TODAY. CURRENT TEMPERATURES ARE RUNNING SEVERAL
DEGS BEHIND THOSE YESTERDAY AT THIS TIME...THEREBY CREATING A
STRONG CAP UP AROUND 750 MBS NEAR THE FOOTHILLS...AND UP AROUND
700 MBS FARTHER OUT OVER THE PLAINS ACCORDING RUC SOUNDINGS AND
CROSS SECTIONS. BENEATH THIS PSUEDO-FRONTAL INVERSION...BNDRY
LAYER CAPE VALUES ARE NOW NEAR 700 J/KG UP AGAINST THE FOOTHILLS
AND CLOSE TO 1500 J/KG IN THE FAR NORTHEAST. DO SEE THIS ENERGY
BEING TAPPED NEAR THE FOOTHILLS EVEN WITH ISOLATED LOW TOP
CONVECTION DRIFTING OFF THE FOOTHILLS WITH ALL OF THE CIN IN THIS
AREA. FARTHER OUT ON THE PLAINS...COULD SEE THE WEAK SHORTWAVE
DISTURBANCE NOW SWINGING OVER SERN WYOMING TAPPING INTO SOME OF
THIS PENNED UP ENERGY RESULTING IN A FEW T-STORMS IN THE FAR
NORTHEAST COUNTIES AFTER 5 PM MDT TODAY. MORE LIKELY WE/LL SEE
THIS CONVECTION DURING THE EVENING HOURS WITH THE LAST OF THE
CIN ERRODING AS THE SHORTWAVE PASSES BY. NOT LOOKING FOR ANY
SEVERE WX OUT OF THEM...JUST PERHAPS SOME SMALL HAIL...BRIEF HEAVY
RAIN AND GUSTY OUTFLOW WINDS TO AROUND 50 MPH. STORMS SHOULD END
EARLIER TONIGHT WITH ARRIVAL OF DRIER AND MORE STABLE AIR BEHIND
THIS SHORTWAVE. HOWEVER...LINGERING LOW LEVEL MOISTURE MAY AGAIN
RESULT IN AREAS OF LOW CLOUDS AND/OR PATCHY FOG IN THE FAR
NORTHEAST TOWARDS MORNING.

ON MONDAY...AIRMASS APPEARS MUCH DRIER AND WARMER. WITH THE UPPER
RIDGE STRENGTHENING TO OUR WEST..AND BARRING ANY UNFORESEEN MOIST
OUTFLOW FROM DOWNSTREAM STORMS...SHOULD SEE TEMPERATURES EASILY
CLIMBING INTO THE 90S ON THE PLAINS TOMORROW...WITH 70S AND 80S IN
THE MTNS. IT/S NOT OUT THE QUESTION WE COULD SEE LOW 90S POPPING
UP IN A FEW SPOTS ALONG THE UPPER COLORADO IN GRAND COUNTY.
DO NOT ANTICIPATE ANY PRECIPITATION/T-STORMS ON MONDAY.

.LONG TERM...OVERALL NO BIG CHANGES TO THE ONGOING TRENDS IN THE
FORECAST. THE UPPER LEVEL RIDGE WILL BE CENTERED NEAR THE GREAT
BASIN FOR MONDAY NIGHT INTO TUESDAY. AS A RESULT...A DRY AND
STABLE NORTHWESTERLY FLOW ALOFT WILL BE OVER THE CWFA. PLENTY OF
LOW LEVEL MOISTURE OVER THE NORTHEAST PLAINS...BUT TOO SUBSIDENT
IN THE MID LEVELS TO ALLOW THE INITIATION OF DEEP CONVECTION FOR
MOST OF THE FORECAST AREA. A WEAK SYSTEM PASSING ACROSS THE NRN
GREAT PLAINS AND INTO THE MID WEST COULD BE ENOUGH TO INITIATE
TSTMS OVER THE FAR NERN CORNER OF CO LATE TUESDAY. FOR THE REST OF
THE WEEK...THE CENTER OF RIDGE SHIFTS EASTWARD WHICH OPENS UP
WESTERN CO TO SUBTROPICAL MID MOISTURE FM THE SOUTH. BETTER TSTM
COVERAGE SHOULD HELP TO SHAVE A FEW DEGREES OF THE AFTN
TEMPERATURES AS WELL. THE ECMWF AND GFS BOTH SHOW BOTH DEVELOP
DECENT QPF OVER THE AREA LATE WEDNESDAY AND THURSDAY...WITH A BIT
OF DRYING ON FRIDAY. MDLS DIFFER AS TO HOW MUCH MOISTURE WILL BE
AVAILABLE OVER THE WEEKEND SO SLGT CHC SHOULD SUFFICE FOR NOW.


&&

.AVIATION...VFR CONDITIONS ANTICIPATED FOR THE NEXT 24 HOURS
UNDER NORTHWEST FLOW ALOFT. NORTH-NORTHEAST SURFACE WINDS UNDER
12 KTS AT MOST DENVER AREA AIRPORTS SHOULD GRADUALLY BECOME
EASTERLY AT SIMILAR SPEEDS AFTER 23Z AND LINGER THROUGH EARLY
EVENING...THEN GO TO A DRAINAGE WIND OVERNIGHT. DIA AND APA COULD
SEE GUSTY SOUTHERLY WINDS OF 10-20 KTS DEVELOPING IN THE EVENING
WITH THE FORMATION A TIGHT PRES GRADIENT JUST EAST OF THE METRO
AREA. AFTER SAY 08Z...SHOULD SEE WIND SPEEDS RELAX AND RESUME
MORE TYPICAL SPEEDS UNDER 12KS. ON MONDAY SOUTHERLY WINDS UNDER
12KS ARE FORECAST TO GO WEST-NORTHWEST BY LATE MORNING AT SIMILAR
SPEEDS. WITH FEW CLOUDS AROUND...SHOULD SEE DAYTIME TEMPERATURES
RETURNING TO THE 90S.

&&

.HYDROLOGY...NO CONCERNS AT THIS TIME.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...BAKER
LONG TERM....COOPER
AVIATION...BAKER




AREA FORECAST DISCUSSION

NWS PUEBLO CO

 1026 PM MDT SAT JUL 20 2013

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 230 PM MDT SAT JUL 20 2013

THE HIGHER LEVEL MSTR PLUME HAS SHIFTED SOUTH OF THE AREA
TODAY...BUT LOW LEVEL MSTR REMAINS IN PLACE WITH DEW POINTS MOSTLY
IN THE 50S OVR THE SERN PLAINS AND AROUND 50 IN THE SAN LUIS
VALLEY.  EXPECTING MOST OF THE CONVECTIVE ACTIVITY THIS EVENING TO
BE OVR AND NR THE MTS.  SO FAR TODAY...THE SHOWERS THAT HAVE
DEVELOPED WERE MOVING AROUND 10-12 MPH TO THE SE OR SSE.  THIS SLOW
MOVEMENT WL AGAIN LEAD TO THE CONCERN FOR LOCALLY HEAVY RAIN ON THE
BURN SCARS AND THE POTENTIAL FOR FLASH FLOODING IF A HEAVIER STORM
MOVES OVR OR DEVELOPS ON A BURN SCAR.  THE NAM AND HRRR MOVE SOME
STORMS OFF THE MTS AND ACRS THE I-25 CORRIDOR...MAINLY OVR EL PASO
AND NRN PUEBLO COUNTIES THIS EVENING.  A SHORTWAVE TROF MOVING ACRS
NERN AND EAST CENTRAL CO TONIGHT IS EXPECTED TO BRING SOME
CONVECTIVE ACTIVITY TO THOSE AREAS...BUT AT THIS TIME THE HI RES
MODELS ARE KEEPING THAT MAINLY NORTH OF THE CWA...BUT COULD SEE SOME
SHOWERS/TSTMS IN KIOWA COUNTY ASSOC WITH THE DISTURBANCE.  WE COULD
SEE A FEW LINGERING SHOWERS OVR THE MTS UNTIL MIDNIGHT OR A LITTLE
LATER...BUT THEN BY MORNING ALL AREAS SHOULD BE DRY.

ON SUN IT LOOKS LIKE SOME ISOLD TO SCT SHOWER/TSTMS COULD DEVELOP
OVR THE HYR TRRN AROUND NOON...WITH THE BEST CHANCES BEING OVR THE
SW MTS AND THE SRN SANGRES.  A WEAK DISTURBANCE IS EXPECTED TO MOVE
ACRS NERN CO IN THE AFTERNOON...AND THE NAM HAS SOME CONVECTIVE
ACTIVITY FIRING UP IN NORTHEAST AND EAST CENTRAL CO...INCLUDING
KIOWA AND CROWLEY COUNTIES BY EVENING.  THE GFS KEEPS THE CONVECTION
OVR NERN CO. FOR NOW WL GO WITH A DRY FORECAST FOR THE FAR SERN
PLAINS SUN AFTERNOON. HIGH TEMPS ON SUN LOOK A COUPLE OR FEW DEGREES
WARMER THAN TODAY.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 230 PM MDT SAT JUL 20 2013

HOT AND MAINLY DRY CONDITIONS EXPECTED MON AND TUESDAY AS UPPER
RIDGE RE-AMPLIFIES OVER THE WESTERN US. MOISTURE PLUME WILL REMAIN
SUPPRESSED TO THE SOUTH BOTH DAYS...THOUGH PERHAPS JUST ENOUGH
RESIDUAL LOW LEVEL MOISTURE WILL LINGER TO PRODUCE AN ISOLATED
HIGH BASED TSRA OVER THE MOUNTAINS...ESPECIALLY MON. WITH HEIGHTS
RISING AND 700 MB TEMPS CLIMBING TOWARD 20C...EXPECT MAX TEMPS
MON/TUE WILL REACH 100F PLUS OVER THE LOWER ARKANSAS VALLEY...WITH
80S/90S ELSEWHERE. FRONT DROPS THROUGH THE EASTERN PLAINS LATE TUE
NIGHT/EARLY WED...LEADING TO A RENEWED WESTWARD PUSH OF MOISTURE
BY WED AFTERNOON. ECMWF HAS TRENDED TOWARD THE GFS ON WED...AND
BOTH MODELS NOW SUGGEST INCREASED CHANCES FOR TSRA OVER THE
EASTERN MOUNTAINS AND PLAINS WED AFTERNOON/EVENING. WESTERN
MOUNTAINS AND VALLEYS SHOULD ALSO SEE AN UPSWING IN TSRA WED...AS
WEAK PUSH OF MID LEVEL MOISTURE WORKS NORTHWARD UNDERNEATH THE
UPPER RIDGE AXIS. FOR LATE WEEK INTO THE WEEKEND...STILL APPEARS
AN INCREASE IN CONVECTION IS POSSIBLE MANY AREAS THU-SAT...THOUGH
DIFFERENCES BETWEEN THE EUROPEAN AND GFS ARISE BEGINNING THU...AS
EURO BRINGS A STRONG TROUGH THROUGH THE AREA...WHILE GFS IS
WEAKER/SLOWER. GFS IS THUS RATHER DRY THU...THEN MOISTENS THE AREA
FRI/SAT...WHILE FASTER ECMWF IS WETTER THU/FRI BEFORE DRYING
SLIGHTLY ON SAT. HAVE FOLLOWED THE MORE CONSISTENT GFS AT THIS
POINT...BUT MAIN MESSAGE OF BOTH MODELS IS A RETURN OF FAIRLY
WIDESPREAD CONVECTION BY WEEK`S END.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1023 PM MDT SAT JUL 20 2013

A LIGHT -TSRA WILL BE POSSIBLE AT KPUB THROUGH 07 UTC TONIGHT. THE
OTHER TWO TAF SITES WILL SEE NO SIGNIFICANT WEATHER.

FOR TOMORROW...VFR CONDITIONS IS EXPECTED. ISOLD -TSRA COULD OCCUR
BUT THE PROBABILITY OF IT OCCURRING IS TOO LOW TO MENTION
EXPLICITLY IN THE TAF. IF TSRA DO OCCUR...THEY WILL BE CAPABLE OF
LOCALLY GUSTY DOWNBURST WINDS.

&&

.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...28
LONG TERM...PETERSEN
AVIATION...HODANISH







AREA FORECAST DISCUSSION

NWS MELBOURNE FL

 316 PM EDT SUN JUL 21 2013

.DISCUSSION...

CURRENTLY-TONIGHT...DEBRIS CLOUDINESS HAS JUST ABOUT EXITED THE
AREA BUT CONVECTION HAS BEEN DELAYED A BIT. EXPECT SCATTERED
SHOWERS/STORMS FORMING ALONG THE WEST COAST BOUNDARY TO MARCH
ACROSS THE PENINSULA AS THE LATEST RAP WAS SHOWING STEERING LEVEL
WINDS NEAR 15 KNOTS. WITH THE LIMITED SOLAR INSOLATION...THE EAST
COAST SEA BREEZE WILL ONLY HAVE LIMITED INLAND MOVEMENT...MAINLY
FROM THE CAPE SOUTHWARD. STILL THIS MAY CAUSE A FEW STRONGER
STORMS THERE THROUGH EARLY EVENING. SOME POCKETS OF INSTABILITY
MAY LINGER THROUGH EVENING SO WILL GO WITH CHANCE POPS IN ALL ZONES.

MON-TUE...MID LEVEL RIDGE WITH AXIS JUST SOUTH OF THE AREA WILL
BREAK DOWN AS A TROUGH BECOMES ESTABLISHED OVER THE EASTERN CONUS.
THE LATEST GFS INDICATES SOME DRIER MID LEVEL AIR BEING ADVECTED
IN FROM THE GULF SO POPS ARE EXPECTED TO DECREASE A LITTLE. HOWEVER
THE WESTERLY STEERING LEVEL FLOW SHOULD FAVOR POPS CLOSE TO CLIMO
(40 PERCENT) EXCEPT 50 PERCENT IN THE NORTH WHERE MOISTURE
CONVERGENCE WILL BE HIGHER (NORTH OF LOW LEVEL RIDGE AXIS).

WITH SURFACE RIDGE AXIS OVER THE SOUTHERN PENINSULA...THE
WESTERLY FLOW SHOULD INCREASE A LITTLE EACH DAY AND BY TUE THE
EAST COAST SEA BREEZE MAY BE INHIBITED ALL BUT THE FAR SOUTH. THIS
SHOULD BOOST MAX TEMPS...THOUGH WILL NOT GO AS HIGH AS THE LATEST
GFS WHICH HAS SOME 93-94 DEGREE HIGHS. THIS WOULD BE ESPECIALLY
TRUE IF SOME UPPER LEVEL DEBRIS CLOUDS PERSIST LIKE THE PAST FEW
DAYS.

PREVIOUS DISCUSSION...
WED-SAT...THE CENTER OF SURFACE HIGH PRESSURE OVER THE WESTERN
ATLANTIC RETREATS SEAWARD AS ITS WESTWARD EMANATING AXIS FULLY
ADJUSTS TO SOUTH FLORIDA AND PERHAPS EVEN AS FAR AS THE STRAITS.
THIS WILL KEEP CENTRAL FLORIDA IN THE LOW-LEVEL WESTERLIES THRU
THE PERIOD. TROUGHING HANGS UP OVER THE ATLANTIC SEABOARD BOTH
SURFACE AND ALOFT TO KEEP WEATHER MORE DISTURBED JUST NORTH OF THE
FORECAST AREA...WITH MINOR WAVES AND VORT MAXES MOVING AROUND THE
BASE OF THE UPPER TROUGH. LOOKS LIKE SOME DRYING WORKS ITS WAY IN
FROM THE GULF FOR SOUTH FLORIDA TO PROMPT POPS GREATER NORTH AND
SOMEWHAT LOWER SOUTH LATER IN THE PERIOD. POPS AROUND 40 PERCENT
NORTH AREA EACH DAY. FOR SOUTH AREA...40 PERCENT DROPPING BACK TO
30-35 PERCENT BY FRI.

&&

.AVIATION...
LATER DEVELOPING CONVECTION DUE TO DEBRIS CLOUDS BUT EXPECT
ACTIVITY ALONG WEST COAST BOUNDARY TO MARCH STEADILY ACROSS THE
PENINSULA...SO CHANCE POPS ARE IN ORDER THROUGH ABOUT 00Z. SOME
STRONG STORMS ARE STILL POSSIBLE ESPECIALLY KMLB-KSUA WHERE
BOUNDARY INTERACTIONS BECOME MORE NUMEROUS.

SURFACE TO MID LEVEL WESTERLY FLOW WILL FAVOR STORMS MARCHING
ACROSS THE PENINSULA FROM WEST TO EAST ON MON AFTERNOON AGAIN.

&&

.MARINE...
TONIGHT-MON...NEAR 15 KNOT SOUTHWEST WINDS EXPECTED CANAVERAL
NORTHWARD THIS EVENING THEN DIMINISHING TO 10 KNOTS OR LESS LATE
AND INTO MON MORNING. THE MAIN MARINER CONCERN WILL BE OFFSHORE
MOVING STORMS THROUGH THIS EVENING AND AGAIN MON AFTERNOON.

TUE-FRI...HIGH PRESSURE RIDGE AXIS WILL EXTEND SOUTH OF THE WATERS
AND RESULT IN SOUTH/SOUTHWEST FLOW THROUGH THE PERIOD. SPEEDS
SHOULD GENERALLY BE 10-15 KNOTS. EXPECT SCATTERED STORMS OVER THE
MAINLAND TO SWEEP OFFSHORE EACH AFTERNOON. THE RIDGE AND STEERING
LEVEL WINDS ARE FORECAST TO WEAKEN BY FRI WHICH MAY KEEP AFTERNOON
STORMS MAINLY OVER THE PENINSULA.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  73  89  75  90 /  30  50  30  50
MCO  74  92  74  91 /  20  40  20  40
MLB  74  89  72  90 /  30  40  20  40
VRB  72  90  73  90 /  20  40  20  40
LEE  75  91  75  91 /  20  40  30  50
SFB  76  92  75  91 /  20  40  30  40
ORL  75  92  76  91 /  20  40  30  40
FPR  73  89  72  90 /  20  40  20  40

&&

.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.

&&

$$

FORECASTS...RL
IMPACT WEATHER/RADAR...TES





AREA FORECAST DISCUSSION

NWS MIAMI FL

 956 AM EDT SUN JUL 21 2013

.UPDATE...
LATEST ANALYSIS SHOWS A LARGE DEEP LAYER RIDGE CENTERED ACROSS
SOUTH CENTRAL FLORIDA NEAR LAKE OKEECHOBEE. WITHIN THIS BOUNDARY,
A WEAKNESS EXISTS AS A WEAK MID LEVEL TROUGH IS LOCATED JUST EAST
OF THE MELBOURNE COAST. STREAMLINE ANALYSIS INDICATES STRONG UPPER
LEVEL DIFFLUENCE IS OCCURRING WHICH IS THE REAL CULPRIT IN
GENERATING STRONG CONVECTION ALONG THIS BOUNDARY. ORIGINAL
THINKING WAS THAT MOST AFTERNOON DEVELOPMENT WOULD BE OVER THE
INTERIOR PORTIONS OF SOUTH FLORIDA BENEATH THE RIDGE AND VERY
LITTLE STORM MOTION. THE TRICKY PART OF THE FORECAST FOR THIS
AFTERNOON IS GOING TO BE WHAT INFLUENCE THE TROUGH AND DIFFLUENCE
MIGHT HAVE ON THE CONVECTION. THERE IS ALSO ABUNDANT CLOUD COVER THAT
COULD LIMIT THE AMOUNT OF DIURNAL HEATING THAT TAKES PLACE.
EARLIER RUNS OF THE HRRR HAD SHOWN VERY LITTLE DEVELOPMENT THIS
AFTERNOON BUT THE 10Z AND 11Z RUNS HAVE TAKEN A BIT OF A DIFFERENT
TURN AND SHOW WIDESPREAD DEVELOPMENT WITH A SLOW DRIFT TOWARDS THE
EAST COAST BY LATE AFTERNOON BUT THEN THE 12Z RUN IS SHOWING
MAINLY SEA BREEZE DEVELOPMENT. SO LATER UPDATES WILL BASICALLY
TAKE ON THE PATTERN OF SUBTLE CHANGES THAT MAY CHANGE THE LOCATION
AND MOVEMENT OF ANY CONVECTIVE DEVELOPMENT THAT MAY TAKE PLACE.

KOB

&&

.PREV DISCUSSION... /ISSUED 708 AM EDT SUN JUL 21 2013/

AVIATION...
VFR CONDITIONS WILL PREVAIL. HIGH PRESSURE WILL CONTINUE TO BUILD
INTO SOUTH FLORIDA THROUGH THE END OF THE TAF PERIOD...BRINGING IN
DRIER LOW/MID LEVEL AIR TO THE REGION. LIGHT WINDS THIS MORNING WILL
BECOME SOUTHEAST AROUND 10 KNOTS FOR THE EAST COAST TAF SITES BY THE
AFTERNOON AS THE SEA BREEZE PUSHES INLAND. FOR KAPF...WINDS WILL
SHIFT TO THE SOUTHWEST AROUND 8-10 KNOTS AS THE SEA BREEZE PUSHES
INLAND. WITH THE DRIER AIR...EXPECT SHOWER AND THUNDERSTORM ACTIVITY
TO BE LIMITED AND REMAIN ACROSS THE INTERIOR. LIGHT WINDS ARE
EXPECTED AGAIN OVERNIGHT.

PREV DISCUSSION... /ISSUED 337 AM EDT SUN JUL 21 2013/

DISCUSSION...

THE WEAK TROPICAL WAVE THAT AFFECTED THE WEATHER ON SATURDAY WILL
CONTINUE TO PUSH WESTWARD ACROSS SOUTH FLORIDA THIS MORNING AND MOVE
INTO THE WESTERN GULF ON SUNDAY AFTERNOON. FOR SUNDAY...DRIER AIR
WILL BEGIN TO SPREAD NORTH INTO THE AREA AS THE RIDGE BEGINS TO
BUILD OVER FLORIDA AND THE WEAK TROUGH LIFTS AWAY FROM THE AREA.
HOWEVER...LINGERING MOISTURE OVER THE NORTHERN HALF OF THE CWA...OR
AROUND THE LAKE REGION...WITH PWAT VALUES AROUND 2" COMBINED WITH SW
LOW-LEVEL FLOW WILL BE ENOUGH TO THE KEEP THE AFTERNOON/EVENING
SHOWERS/TSTMS IN THE FORECAST. BETWEEN NOW AND SUNRISE SHOWERS AND
THUNDERSTORMS ARE FORECAST FOR PORTIONS OF THE ATLANTIC AND GULF
WATERS.

THE LARGE SCALE WEATHER PATTERN INDICATES THAT AN AREA OF HIGH
PRESSURE DEVELOPS OVER FLORIDA AS THE BERMUDA HIGH EXTENDS WESTWARD
FROM SUNDAY THROUGH TUESDAY. THIS IS FORECAST TO BRING A MORE
TYPICAL SUMMER PATTERN OF AFTERNOON AND EVENING CONVECTION DRIVEN BY
SEA BREEZE BOUNDARIES. FOR MONDAY AND TUESDAY IT CAN BE SEEN IN THE
SOUNDING FORECASTS AND NEMS GFS AND NRL AEROSOL MODELS THE PRESENCE
OF SOME SAHARAN DUST. FOR WEDNESDAY, THE SUBTROPICAL HIGH PRESSURE
STRENGHTENS IN THE MIDDLE PORTIONS OF THE ATLANTIC OCEAN CAUSING THE
TROUGH OVER THE EASTERN PORTIONS OF THE US TO AMPLIFY. THIS IS
EXPECTED TO COOL SOMEWHAT THE MID LEVEL TEMPERATURES WHICH COULD
POTENTIALLY INCREASE THE CONVECTION BY MID WEEK. THE COMBINATION OF
WEAK SOUTHWESTERLY FLOW AND A LITTLE BIT MORE MOISTURE IS EXPECTED TO
INCREASE THE SHOWERS AND THUNDERSTORMS OVER THE NORTHERN AND EASTERN
SECTIONS OF SOUTH FLORIDA, THE LAKE REGION AND IN GENERAL PALM BEACH
AND BROWARD COUNTIES.

BETWEEN WEDNESDAY AND FRIDAY THE EAST COAST TROUGH WEAKENS GRADUALLY
BUT IT STILL SHOWS A GENERAL WEAKNESS OVER FLORIDA. FOR FRIDAY, THE
RIDGE OVER NORTHERN MEXICO EXPANDS EASTWARD INCREASING THE 500 MB
TEMPERATURES OVER NORTH FLORIDA AND SOUTH GEORGIA TO -4C. FOR SOUTH
FLORIDA WE STAY IN THE -6 RANGE WHICH IS VERY UNFAVORABLE FOR ANY
WIDESPREAD CONVECTION TO OCCUR.

THE RISK OF RIP CURRENTS WILL BE SLIGHT FOR THE ATLANTIC BEACHES FOR
SUNDAY.

MARINE...

GENERAL EAST TO SOUTHEAST WIND IS EXPECTED THROUGH TUESDAY AT SPEEDS
OF LESS THAN 10 TO 12 KNOTS OUTSIDE OF SCATTERED SHOWERS
/THUNDERSTORMS. THE WIND WILL BEGIN TO VEER TO A SOUTH OR SOUTHWEST
DIRECTION LATER IN THE WEEK AS THE SURFACE RIDGE SHIFTS TO THE SOUTH
AND THE EAST COAST AMPLIFIES DUE TO A BLOCKING HIGH IN THE
ATLANTIC.

FIRE WEATHER...

NO FIRE WEATHER CONCERNS OR FOG IS ANTICIPATED THROUGHOUT THE
FORECAST PERIOD. THE TYPICAL AREA WITH LOWER RELATIVE HUMIDITIES,
GLADES AND HENDRY, WILL MAINTAIN VALUES ABOVE 50 PERCENT THIS
WEEKEND AND COMING WEEK.

&&

.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH  89  76  88  76 / 20 20 30 10
FORT LAUDERDALE  89  79  89  78 / 20 20 30 10
MIAMI            90  77  88  77 / 20 20 20 10
NAPLES           90  75  89  75 / 20 10 20 10

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&

$$






AREA FORECAST DISCUSSION

NWS TALLAHASSEE FL

 352 AM EDT Sun Jul 21 2013

.NEAR TERM [Today and Tonight]...
Rain coverage has diminished greatly between 04 and 06 UTC, with
much of the forecast area dry at the time this discussion was
composed (shortly after 06 UTC). GOES and RAP analyzed PWATs are
still around or just above 2" across much of our area, so we remain
in the midst of a plume of deep tropical moisture. Therefore, it is
unsurprising that the majority of model guidance indicates an early
start to showers today. Indications are that coverage may be higher
today to the north of an Apalachicola to Valdosta line, where
surface dewpoints and boundary layer mixing ratios (as analyzed by
the RAP) appear to be slightly higher. We expect low-topped
convective showers to increase in coverage in the western Florida
Panhandle 11-14 UTC and then gradually overspread the rest of the
area by 18/19 UTC. It appears to be more likely than not that most
people will see measurable rainfall, but the showers today should be
of a more scattered variety, and thus should not last very long at
individual locations. Still, when showers do occur, we should
continue to see heavy rain rates. PoPs were maintained ~60% over
much of the area. High temperatures may be slightly warmer today
with more breaks of sun - in the upper 80s in most locations.

&&

.SHORT TERM [Monday Through Tuesday]...
One item that keeps coming to mind if we are unable to shake this
wet and troughy pattern across the SE US (for the second consecutive
summer nonetheless), is that Tallahassee may soon become known as
the Seattle of the South, only with much more rainfall and higher
temps. Not really much else of value to add, other than that PoPs
will continue above climo and Max temps will continue below, and the
disturbed pattern and strong 1000-700mb Mean Layer Vector Winds will
make the Sea Breeze very difficult to develop.

&&

.LONG TERM [Tuesday Night through Friday]...
The GFS and ECMWF continue to agree that a broad long wave trough
will be the dominant large scale weather feature over the
Southeast. During this time there will likely be multiple minor
short waves rotating through the base of the trough, enhancing our
rain chances at times as both models forecast plenty of deep layer
moisture and CAPE. While the MOS PoP consensus is above
climatology, we will forecast a fairly diurnal cycle, with the
greatest PoP during the afternoon & evening hours (even though
sometimes MCS`s can affect our area overnight in this type of
pattern). Despite the above-climo PoPs, the MOS consensus high
temperatures are in the lower to mid 90s, which is near climo.
It`s interesting to note that the 1000-700mb lapse rates are
forecast to be steeper than normal (6-7 C/km) through much of this
period, with the GFS being the most unstable. While the mid
tropospheric winds are not expected to be very strong, the
thermodynamics may be more supportive of pulse severe storms than
what we have seen in recent days.

&&

.AVIATION [through 12 UTC Sunday]...
IFR or LIFR CIGS are expected at all of the terminals (ABY, DHN,
VLD, and TLH) except for ECP early this morning. Short term ensemble
guidance is in good agreement on that scenario. There may also be
some light fog, but most of the flight category reductions should be
due to low ceilings. The low CIGS should scatter out or lift to VFR
levels within a couple hours of sunrise. Expecting scattered +SHRA
today with a few TS. It should be an early start with morning rain
possible at ECP, DHN, and TLH, spreading to ABY and VLD in the
afternoon hours (with lingering SHRA possible at the other terminals
after 18z as well).


&&

.MARINE...
Light to moderate west to southwesterly winds and corresponding
seas are expected to continue through much of the period, as the
Synoptic scale pressure pattern remains a bit above normal from the
usual summer doldrums.

&&

.FIRE WEATHER...
Red flag conditions are not expected for the next several days.

&&

.HYDROLOGY...
Due to the recent heavy rainfall across the eastern Florida Big
Bend, area rivers are on the rise, and minor flooding could be
possible along parts of the Aucilla and Econfina rivers during the
next couple of days, although widespread additional heavy rainfall
is not expected at this time.


&&

.PRELIMINARY POINT TEMPS/POPS...
Tallahassee   89  73  89  73  90 / 60  20  60  40  60
Panama City   87  75  87  76  87 / 60  20  60  40  50
Dothan        88  72  89  72  91 / 60  30  70  40  60
Albany        89  73  89  73  91 / 60  30  60  40  60
Valdosta      89  72  90  73  90 / 60  20  60  40  60
Cross City    88  73  90  73  89 / 50  20  50  30  50
Apalachicola  86  75  87  76  86 / 50  20  50  30  50

&&

.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.

&&

$$

NEAR TERM...Lamers
SHORT TERM...Gould
LONG TERM...Fournier
AVIATION...Lamers
MARINE...Gould
FIRE WEATHER...Lamers
HYDROLOGY...Lamers/Gould






AREA FORECAST DISCUSSION

NWS MIAMI FL

 137 AM EDT SUN JUL 21 2013

.AVIATION...
A CONVERGENT LINE OF SHOWERS AND STORMS REMAINED TO THE EAST OF
KPBI EARLY THIS MORNING. SOME OF THESE SHOWERS MAY GET NEAR KPBI
OVERNIGHT...SO ADDED VCSH. OTHERWISE...HIGH PRESSURE WILL CONTINUE
TO BUILD INTO SOUTH FLORIDA THROUGH THE TAF PERIOD WITH DRIER
CONDITIONS. LIGHT WINDS ARE EXPECTED THROUGH THE OVERNIGHT HOURS
AND AGAIN TONIGHT. SEA BREEZE BOUNDARIES ARE FORECAST TO PUSH
INLAND AT BOTH COASTS THIS AFTERNOON. SHOWER AND THUNDERSTORM
ACTIVITY IS FORECAST TO REMAIN MAINLY ACROSS THE INTERIOR...BUT
SHOWERS OR STORMS COULD GET NEAR KPBI AND KAPF IN THE AFTERNOON.

&&

.PREV DISCUSSION... /ISSUED 1027 PM EDT SAT JUL 20 2013/

UPDATE...
ONLY A FEW CHANGES WERE NECESSARY THIS EVENING BASED ON THE LATEST
TRENDS AND OBSERVATIONS AROUND THE LOCAL AREA. OTHERWISE...THE
PREVIOUS FORECAST PACKAGE REMAINS ON TRACK. THE AFTERNOON/EARLY
EVENING CONVECTION THAT MOSTLY IMPACTED THE INTERIOR AREAS AROUND
THE LAKE REGION HAS DIMINISHED. THE LATEST HRRR RUN HAS LINED UP
WELL WITH THE CURRENT CONDITIONS AND GENERALLY INDICATES A QUIET
NIGHT WITH THE EXCEPTION OF SOME SHOWERS DEVELOPING OVER THE
ATLANTIC WATERS THROUGH THE OVERNIGHT HOURS. FOR SUNDAY...DRIER
AIR WILL BEGIN TO SPREAD NORTH INTO THE AREA AS THE RIDGE BEGINS
TO BUILD OVERHEAD AND THE WEAK TROUGH LIFTS AWAY FROM THE AREA.
HOWEVER...LINGERING MOISTURE OVER THE NORTHERN HALF OF THE
CWA...OR AROUND THE LAKE REGION...WITH PWAT VALUES AROUND 2"
COMBINED WITH SW LOW-LEVEL FLOW WILL BE ENOUGH TO THE KEEP THE
AFTERNOON/EVENING SHOWERS/TSTMS IN THE FORECAST.

PREV DISCUSSION... /ISSUED 723 PM EDT SAT JUL 20 2013/

AVIATION...
OUTFLOW FROM INTERIOR CONVECTION IS MEETING DECAYING SEA BREEZE
BOUNDARY OVER THE EASTERN METROPOLITAN AREAS THIS EVENING...THUS
VCSH/VCTS IN TAFS BROWARD AND PALM BEACH COUNTIES TERMINALS.
OUTFLOW BOUNDARY SHOULD BRING A BRIEF PERIOD OF WNW WINDS TO
MIAMI-DADE TERMINALS...SO HAVE INCLUDED A TEMPO GROUP NOTING THE
WIND SHIFT. OTHERWISE...LIGHT ESE WINDS WILL PREVAIL...AT SPEEDS
OF AROUND 5 KTS TONIGHT AND 10 KTS ON SUNDAY. HAVE REMOVED VCSH
BEYOND MIDNIGHT...AS POPS OVER THE TERMINALS ARE BELOW 30 PERCENT
THROUGH SUNDAY.

PREV DISCUSSION... /ISSUED 213 PM EDT SAT JUL 20 2013/

SHORT TERM (TONIGHT-MONDAY NIGHT)...
A STRONG MID LEVEL RIDGE OVER THE MID ATLANTIC STRETCHES WEST TO
ACROSS CENTRAL/SOUTH FLORIDA WITH MID LATITUDE TROUGHS MOVING ACROSS
THE NORTHERN TIER OF STATES AND CANADA. A TROPICAL WAVE IS CURRENTLY
MOVING THROUGH THE WESTERN CARIBBEAN SOUTHWEST OF JAMAICA AND THE
NORTHERN EXTENT OF THIS WAVE IS LOCATED FROM THE EASTERN FLORIDA
STRAITS AND INTO THE BAHAMAS. THIS HAS INCREASED CONVECTIVE ACTIVITY
IN THAT REGION WITH HIGHER PWAT VALUES MOVING INTO SOUTH FLORIDA
WHICH IN TURN IS HELPING TO ENHANCE CONVECTION. THE 12Z MFL SOUNDING
WAS QUITE IMPRESSIVE AS REGARDS TO THE AVAILABLE CAPE BUT SO FAR THE
STORMS HAVE BEEN SOMEWHAT SUPPRESSED DUE TO THE WEAK MID LEVEL LAPSE
RATES ASSOCIATED WITH THE RIDGE AXIS. THE LOW LEVELS WERE VERY
UNSTABLE HOWEVER AND THIS AIDED IN AN EARLY START TO THE CONVECTION
PROCESS WITH STORM MOTION TO THE NORTHWEST DUE TO THE LOW LEVEL
SOUTHEAST FLOW. THE FLOW BECOMES VERY WEAK TO LIGHT SOUTHWEST IN THE
MID LEVELS IN RESPONSE TO THE RIDGE SO AS THE STORMS CONTINUE TO
GROW, THE INTERIOR COULD GET QUITE ACTIVE LATER THIS AFTERNOON AS
THE STORM MOTION BECOMES LESS THAN 5 MPH.

THE WAVE WILL CONTINUE TO MOVE WEST OF THE AREA ON SUNDAY BUT AS
MOISTURE CONTINUES TO LINGER ACROSS THE REGION WITH A WEAK SURFACE
TROUGH BOUNDARY REMAINING IN PLACE, SCATTERED SHOWERS/THUNDERSTORMS
ARE EXPECTED AGAIN BY LATE SUNDAY MORNING INTO THE AFTERNOON. DUE TO
THE WAVE BEING FARTHER TO THE WEST, THE LOW LEVEL SOUTHEAST FLOW
WILL BECOME SHALLOWER SO STORM MOTION WILL GO EVEN LIGHTER AND SEA
BREEZE BOUNDARIES WILL LIKELY BE THE DOMINANT FOCUSING MECHANISM. AT
THE SAME TIME, A SURFACE RIDGE WILL BUILD BACK ACROSS SOUTH FLORIDA
BY SUNDAY AFTERNOON THROUGH MONDAY AND THIS COULD SUPPRESS
CONVECTIVE ACTIVITY EVEN FURTHER WITH SEA BREEZE BOUNDARIES AGAIN
BEING THE MAIN FOCUS FOR MONDAY AFTERNOON.

LONG TERM (TUESDAY-SATURDAY)...
THIS SAME TREND WILL LIKELY CONTINUE THROUGH THE MIDDLE OF THE WEEK
AS A DEEP LAYER RIDGE BECOMES FIRMLY ESTABLISHED AND FORECAST
SOUNDINGS SHOW STORM MOTION 2 MPH OR LESS. A STRONG MID LEVEL TROUGH
WILL BEGIN TO DEEPEN INTO THE EASTERN STATES BY THURSDAY INTO THE
END OF THE WEEK AND INTO THE FIRST PART OF NEXT WEEKEND FOR A SLOW
RETURN TO STORM MOTION STEERING STORMS BACK TOWARDS THE EAST COAST.
FORECAST SOUNDINGS HOWEVER ARE NOT SHOWING A STRONG MOTION SO THE
ENTIRE WEEK LOOKS AS IF VERY SLOW STORM MOTION WILL CONTINUE A
THREAT FOR LOCALLY HEAVY RAINS WHERE EVER THE CONVECTION CAN SET UP.

MARINE...
GENERAL EAST TO SOUTHEAST WIND IS EXPECTED THROUGH TUESDAY AT
SPEEDS OF LESS THAN 15 KNOTS OUTSIDE OF SCATTERED
SHOWERS/THUNDERSTORMS. THE WIND WILL BEGIN TO VEER TO A SOUTH OR
SOUTHWEST DIRECTION LATER IN THE WEEK AS THE SURFACE RIDGE SHIFTS
TO THE SOUTH.

FIRE WEATHER...
NO PROBLEMS WITH PLENTY OF TROPICAL MOISTURE IN PLACE.

&&

.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH  89  76  88  77 / 20 20 30 10
FORT LAUDERDALE  89  79  89  79 / 20 20 30 10
MIAMI            90  77  88  79 / 20 20 20 10
NAPLES           91  75  89  75 / 20 10 20 10

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&

$$

DISCUSSION/MARINE/FIRE...71/JE
AVIATION/RADAR...84/AK






AREA FORECAST DISCUSSION

NWS LINCOLN IL

 910 PM CDT MON JUL 22 2013

.DISCUSSION...
ISSUED 900 PM CDT MON JUL 22 2013

THE LINE OF STORMS IS JUST ABOUT TO ENTER INTO NW IL FROM
IOWA. THE RADAR TRENDS AND STORM REPORTS UPSTREAM SHOW THE LINE TO
GENERALLY BE LOSING SOME OF ITS INTENSITY. THE LIGHTNING STRIKES
HAVE DIMINISHED IN THE NORTHERN WAVE HEADING TOWARD OUR NORTHERN
COUNTIES AS WELL. CLOUD TOP TEMPS IN THAT AREA WERE NOT
PARTICULARLY COLD THROUGH THE LIFE-CYCLE OF THE COMPLEX...BUT THEY
HAVE GENERALLY MAINTAINED IN THE -53C TO -55C RANGE. WE DO NOT
EXPECT SEVERE WEATHER IN OUR COUNTIES...BUT WILL MAINTAIN A CLOSE
WATCH ON ANY UPDRAFTS THAT BECOME INTENSE.

TIMING THE LINE INTO CENTRAL ILLINOIS HAS IT REACHING FROM HAVANA
TO BLOOMINGTON BY MIDNIGHT...AND EVENTUALLY SOUTHEAST OF
LAWRENCEVILLE BY 10Z. THE FORWARD PROGRESSION OF THE LINE MAY SLOW
DOWN ONCE THE COLD POOL LOSES FORWARD MOMENTUM AND DOWNDRAFTS
DIMINISH WITH WEAKENING INSTABILITY. WE HAVE INCREASED POPS TO
LIKELY NW OF THE IL RIVER AS THE STORMS ARRIVE IN KNOX COUNTY
BY 03Z...AND EXPANDED HIGHER CHANCE POPS FARTHER TO THE EAST AND
SOUTH AHEAD OF THE LINE. WE INCREASED CLOUD COVER AS WELL.

SOME CLEARING BEHIND THE LINE OF STORMS MAY ADD TO THE FOG
POTENTIAL LATER TONIGHT...BUT GUSTY NORTHWEST WINDS MAY BE TIMED
JUST RIGHT BEHIND THE FRONT TO KEEP FOG FROM FORMING. STEADIER
WINDS AROUND SUNRISE WOULD HELP TO PRECLUDE MUCH IN THE WAY OF
FOG. ADDITIONAL CLOUDS LAGGING WELL BEHIND THE FRONT MAY BE AN
INDICATION WE WILL SEE THAT LOW LEVEL MOISTURE ARRIVE HERE IN C IL
TOMORROW. WE DID INCREASE CLOUDS ACROSS THE NORTH...BUT DID NOT
HIT CLOUDS TOO HARD YET FOR TUESDAY.

LOW TEMPS SHOULD GENERALLY REMAIN 70-73...DEPENDING ON TIMING OF
THE FRONT. COLDER AIR LAGS FAR ENOUGH BEHIND THAT TONIGHTS LOWS
SHOULD REMAIN MUGGY...WITH DEWPOINTS IN THE UPPER 60S IN THE NW
AND LOW TO MID 70S IN SE THROUGH SUNRISE.

UPDATED INFO WILL BE AVAILABLE SHORTLY.

SHIMON
&&

.AVIATION...
ISSUED 649 PM CDT MON JUL 22 2013

THE COLD FRONT IS MAKING PROGRESS ACROSS IOWA AND SE
WISCONSIN...WITH THE STRONGEST STORMS IN EASTERN IOWA MOVING EAST-
SOUTHEAST TOWARD IL. HRRR AND NCEP 4KM OUTPUT SHOW THE LINE OF
STORMS GENERALLY WEAKENING AS THEY MOVE INTO CENTRAL IL. THE
TIMING LOOKS TO BE LATE EVENING FOR PIA AND ADVANCING TO CMI/DEC BY
09Z OR SO. WE KEPT ONLY A VCTS FOR A FEW HOURS AROUND THE FRONTAL
PASSAGE...SINCE COVERAGE AND INTENSITY OF THE STORMS LATER TONIGHT
WILL BE LESS/WEAKER. AS THE STORMS APPROACH...A TEMPO FOR IFR
VIS/CIGS MAY BE NEEDED IF ANY STORMS TRACK TOWARD ANY TERMINAL
SITES.

WINDS WILL START OUT SOUTHWEST THIS EVENING...THEN SHIFT TO THE
NORTHWEST AFTER THE FRONTAL PASSAGE. MUCH OF THE DAY TOMORROW
SHOULD SEE SUSTAINED NW WINDS AT 10-15KT. WINDS MAY VEER TO THE
NORTH LATER TOMORROW AFTERNOON AS SURFACE HIGH BEGINS TO BUILD
INTO ILLINOIS.

SHIMON
&&

.PREV DISCUSSION...
ISSUED 300 PM CDT MON JUL 22 2013

MAIN CONCERN IN THE SHORT TERM PACKAGE INCLUDES PCPN CHANCES
TONIGHT THROUGH TOMORROW AND COOLER TEMPS. LONG TERM CONCERNS ARE
WITH PCPN CHANCES AT END OF THE WEEK AND INTO THE WEEKEND.

MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THE NEXT FRONT COMING
INTO THE AREA TONIGHT AND THROUGH THE CWA BY TOMORROW MORNING. ALL
MODELS AGREE THAT THE FRONT WILL BE AROUND I-70 BY 18Z TOMORROW.
MOST MODELS EVEN SEEM TO PUSH THE FRONT INTO THE SOUTHEASTERN AND
SOUTHERN US BY WEDNESDAY EVENING. EXTENDED MODELS SEEM SIMILAR TOO
BUT HAVE THEIR DIFFERENCES AS FAR AS LOCATION AND TIMING OF THE
NEXT FRONT FOR LATE IN THE WEEK. HOWEVER...THIS DIFFERENCE DOESN`T
SEEM TO AFFECT THE PCPN CHANCES DURING THE PERIOD. SO
OVERALL...GOOD AGREEMENT IN THE SHORT AND LONG TERM MODELS...WHICH
GIVES GOOD CONFIDENCE IN FORECAST.

SHORT TERM...TONIGHT THROUGH THURSDAY

AS MENTIONED IN ABOVE SECTION...FRONT WILL MOVE INTO THE AREA
TONIGHT AND SHOULD REACH TO AROUND I-70 BY NOON. SO APPEARS MOST
OF THE PCPN CHANCES WILL BE CONFINED TO AROUND THE FRONT AND OCCUR
LATE TONIGHT THROUGH TOMORROW MORNING. CHANCES WILL START IN THE
NORTHWEST THIS EVENING BUT THEN PROGRESS SOUTHEAST THROUGH
TOMORROW. TOMORROW AFTERNOON POPS WILL BE MAINLY IN SOUTHEAST
ILLINOIS. MID LEVEL LAPSE RATES WILL BECOME STEEP TOMORROW
AFTERNOON...AND THOUGH AGREE WITH SPC SLIGHT RISK OF SEVERE
WEATHER OUTLOOK FOR TOMORROW...BELIEVE IT IS A LITTLE NORTH AND
PROBABLY WILL AFFECT ONLY SOUTHERN IL TOMORROW AFTERNOON...WHICH
INCLUDES SOUTHEAST ILLINOIS. BEHIND THIS SYSTEM...DRY AND COOLER
WEATHER WILL PUSH INTO THE AREA AS HIGH PRSS BUILDS INTO THE
REGION FOR MOST OF THE WEEK. NORTHWEST FLOW WILL BE THE RULE AS
THE MID LEVEL RIDGE BUILDS IN THE WEST AND A TROUGH SITS TO OUR
EAST.

TEMPS WILL BE WARM TOMORROW AHEAD OF THE FRONT...REMAINING IN THE
80S THROUGH THE AREA. HOWEVER...ONCE THE FRONT COMES
THROUGH...TEMPS WILL DECREASE. AFTERNOON HIGHS WILL BE IN THE MID
70S TO AROUND 80 WITH OVERNIGHT LOWS AROUND 60. GUIDANCE LOOKS
TOO WARM IN THE SOUTHEAST FOR TOMORROW AND THURSDAY. WED GUIDANCE
NUMBERS LOOKS OK.

LONG TERM...THURSDAY NIGHT THROUGH MONDAY

DRY WEATHER WILL CONTINUE FOR THURSDAY NIGHT...BUT A SFC LOW WILL
MOVE TOWARD THE GRT LKS REGION AND DRAG A COLD FRONT DOWN INTO THE
AREA BEGINNING FRIDAY AND CONTINUING INTO FRIDAY NIGHT AND SOME
SATURDAY. PCPN COULD BE ENDING SATURDAY...BUT TIMING IN THE MODELS
COULD CHANGE BETWEEN AND THEN...SO TOO SOON TO GET THAT SPECIFIC.
BEHIND THIS FRONT ANOTHER AREA OF HIGH PRESSURE WILL BUILD INTO
THE REGION FOR THE REST OF THE WEEKEND AND THE BEGINNING OF NEXT WEEK.

TEMPS WILL REMAIN ON THE COOL SIDE AS NORTHWEST FLOW CONTINUES
THROUGH THE PERIOD.

AUTEN

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$









AREA FORECAST DISCUSSION

NWS LINCOLN IL

 649 PM CDT MON JUL 22 2013

.DISCUSSION...
ISSUED 300 PM CDT MON JUL 22 2013

MAIN CONCERN IN THE SHORT TERM PACKAGE INCLUDES PCPN CHANCES
TONIGHT THROUGH TOMORROW AND COOLER TEMPS. LONG TERM CONCERNS ARE
WITH PCPN CHANCES AT END OF THE WEEK AND INTO THE WEEKEND.

MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THE NEXT FRONT COMING
INTO THE AREA TONIGHT AND THROUGH THE CWA BY TOMORROW MORNING. ALL
MODELS AGREE THAT THE FRONT WILL BE AROUND I-70 BY 18Z TOMORROW.
MOST MODELS EVEN SEEM TO PUSH THE FRONT INTO THE SOUTHEASTERN AND
SOUTHERN US BY WEDNESDAY EVENING. EXTENDED MODELS SEEM SIMILAR TOO
BUT HAVE THEIR DIFFERENCES AS FAR AS LOCATION AND TIMING OF THE
NEXT FRONT FOR LATE IN THE WEEK. HOWEVER...THIS DIFFERENCE DOESN`T
SEEM TO AFFECT THE PCPN CHANCES DURING THE PERIOD. SO
OVERALL...GOOD AGREEMENT IN THE SHORT AND LONG TERM MODELS...WHICH
GIVES GOOD CONFIDENCE IN FORECAST.

SHORT TERM...TONIGHT THROUGH THURSDAY

AS MENTIONED IN ABOVE SECTION...FRONT WILL MOVE INTO THE AREA
TONIGHT AND SHOULD REACH TO AROUND I-70 BY NOON. SO APPEARS MOST
OF THE PCPN CHANCES WILL BE CONFINED TO AROUND THE FRONT AND OCCUR
LATE TONIGHT THROUGH TOMORROW MORNING. CHANCES WILL START IN THE
NORTHWEST THIS EVENING BUT THEN PROGRESS SOUTHEAST THROUGH
TOMORROW. TOMORROW AFTERNOON POPS WILL BE MAINLY IN SOUTHEAST
ILLINOIS. MID LEVEL LAPSE RATES WILL BECOME STEEP TOMORROW
AFTERNOON...AND THOUGH AGREE WITH SPC SLIGHT RISK OF SEVERE
WEATHER OUTLOOK FOR TOMORROW...BELIEVE IT IS A LITTLE NORTH AND
PROBABLY WILL AFFECT ONLY SOUTHERN IL TOMORROW AFTERNOON...WHICH
INCLUDES SOUTHEAST ILLINOIS. BEHIND THIS SYSTEM...DRY AND COOLER
WEATHER WILL PUSH INTO THE AREA AS HIGH PRSS BUILDS INTO THE
REGION FOR MOST OF THE WEEK. NORTHWEST FLOW WILL BE THE RULE AS
THE MID LEVEL RIDGE BUILDS IN THE WEST AND A TROUGH SITS TO OUR
EAST.

TEMPS WILL BE WARM TOMORROW AHEAD OF THE FRONT...REMAINING IN THE
80S THROUGH THE AREA. HOWEVER...ONCE THE FRONT COMES
THROUGH...TEMPS WILL DECREASE. AFTERNOON HIGHS WILL BE IN THE MID
70S TO AROUND 80 WITH OVERNIGHT LOWS AROUND 60. GUIDANCE LOOKS
TOO WARM IN THE SOUTHEAST FOR TOMORROW AND THURSDAY. WED GUIDANCE
NUMBERS LOOKS OK.

LONG TERM...THURSDAY NIGHT THROUGH MONDAY

DRY WEATHER WILL CONTINUE FOR THURSDAY NIGHT...BUT A SFC LOW WILL
MOVE TOWARD THE GRT LKS REGION AND DRAG A COLD FRONT DOWN INTO THE
AREA BEGINNING FRIDAY AND CONTINUING INTO FRIDAY NIGHT AND SOME
SATURDAY. PCPN COULD BE ENDING SATURDAY...BUT TIMING IN THE MODELS
COULD CHANGE BETWEEN AND THEN...SO TOO SOON TO GET THAT SPECIFIC.
BEHIND THIS FRONT ANOTHER AREA OF HIGH PRESSURE WILL BUILD INTO
THE REGION FOR THE REST OF THE WEEKEND AND THE BEGINNING OF NEXT WEEK.

TEMPS WILL REMAIN ON THE COOL SIDE AS NORTHWEST FLOW CONTINUES
THROUGH THE PERIOD.

AUTEN

&&

.AVIATION...
ISSUED 649 PM CDT MON JUL 22 2013

THE COLD FRONT IS MAKING PROGRESS ACROSS IOWA AND SE
WISCONSIN...WITH THE STRONGEST STORMS IN EASTERN IOWA MOVING EAST-
SOUTHEAST TOWARD IL. HRRR AND NCEP 4KM OUTPUT SHOW THE LINE OF
STORMS GENERALLY WEAKENING AS THEY MOVE INTO CENTRAL IL. THE
TIMING LOOKS TO BE LATE EVENING FOR PIA AND ADVANCING TO CMI/DEC BY
09Z OR SO. WE KEPT ONLY A VCTS FOR A FEW HOURS AROUND THE FRONTAL
PASSAGE...SINCE COVERAGE AND INTENSITY OF THE STORMS LATER TONIGHT
WILL BE LESS/WEAKER. AS THE STORMS APPROACH...A TEMPO FOR IFR
VIS/CIGS MAY BE NEEDED IF ANY STORMS TRACK TOWARD ANY TERMINAL
SITES.

WINDS WILL START OUT SOUTHWEST THIS EVENING...THEN SHIFT TO THE
NORTHWEST AFTER THE FRONTAL PASSAGE. MUCH OF THE DAY TOMORROW
SHOULD SEE SUSTAINED NW WINDS AT 10-15KT. WINDS MAY VEER TO THE
NORTH LATER TOMORROW AFTERNOON AS SURFACE HIGH BEGINS TO BUILD
INTO ILLINOIS.

SHIMON
&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$








AREA FORECAST DISCUSSION

NWS LINCOLN IL

 1150 PM CDT SAT JUL 20 2013

.DISCUSSION...
ISSUED 858 PM CDT SAT JUL 20 2013

SOMEWHAT COMPLICATED SCENARIO FOR THE OVERNIGHT AS OPPOSED TO THE
LAST SEVERAL NIGHTS. CONVECTION ALONG THE I-64 CORRIDOR HAS BEEN
PERSISTENT THE LAST FEW HOURS. ALTHOUGH THE HEAVIEST RAIN IS NOW
WELL SOUTH OF OUR AREA...THE EXTREME SOUTHEAST CWA HAS SEEN LIGHT
TO MODERATE RAIN CONTINUING. THE FRONTAL BOUNDARY HAS BEGUN TO
RETROGRADE WESTWARD...WITH IT APPEARING FAIRLY NICELY ON RADAR
IMAGERY FROM JERSEYVILLE TO DECATUR TO JUST WEST OF CHAMPAIGN.
LATEST RAP AND HRRR GUIDANCE DOES NOT SHOW MUCH IN THE WAY OF
STEERING CURRENTS WHICH WOULD FULLY PUSH IT BACK SOUTHEAST OF THE
AREA...BUT THEY INDICATE THAT IT SHOULD NOT GET TOO MUCH FURTHER
NORTHWEST. WITH LIGHT WINDS...POOLING DEW POINTS NEAR 70 AND THE
MOISTURE FROM THE HEAVIER RAIN POCKETS FROM EARLIER TODAY... HAVE
SOME CONCERNS WITH FOG DEVELOPMENT ACROSS THE SOUTHEAST THIRD OF
THE CWA DESPITE THE AMOUNT OF CLOUDS. HAVE ADDED SOME PATCHY FOG
FOR THIS AREA OVERNIGHT. DID NOT REALLY CHANGE THE LOW
TEMPERATURES...BUT HAD TO MAKE SOME SIGNIFICANT ADJUSTMENTS TO THE
HOURLY TRENDS...ESPECIALLY IN THE SOUTHEAST DUE TO THE RAIN.

UPDATED GRIDS HAVE BEEN SENT. EARLIER ZONE ISSUANCE AT 7 PM
ALREADY TOOK INTO ACCOUNT MOST OF THE UPDATES...BUT WILL FRESHEN
THIS AS WELL TO ADD THE FOG MENTION.

GEELHART

&&

.AVIATION...
ISSUED 1150 PM CDT SAT JUL 20 2013

MAIN CONCERN IS WITH FOG POTENTIAL OVERNIGHT...MAINLY IN EASTERN
ILLINOIS. HAVE ALREADY BEEN SEEING SOME CEILINGS BELOW 500 FEET AT
TIMES IN AREAS SOUTH AND SOUTHEAST OF KCMI. THIS IS EAST OF THE
FRONTAL BOUNDARY...WHERE TEMPERATURE/DEW POINT SPREADS ARE
MINIMAL...AND IN LOCATIONS THAT SAW POCKETS OF 1 TO 3 INCHES OF
RAIN ON SATURDAY. LATEST GUIDANCE FROM THE RAP/HRRR/LAMP MODELS
SHOWING AN EXPANDING AREA OF FOG OVER THE NEXT FEW HOURS IN EAST
CENTRAL ILLINOIS. HAVE HIT KCMI THE HARDEST WITH LIFR CONDITIONS
DEVELOPING BY AROUND 08Z AND PERSISTING INTO EARLY MORNING. KDEC
ALSO SHOWING SOME IFR POTENTIAL AND INCLUDED TEMPO PERIODS THERE
AS WELL. FORECAST SOUNDINGS AT KPIA/KBMI/KSPI ARE DRIER...AND HAVE
ONLY MENTIONED SOME 4SM VISIBILITIES AT TIMES.

LATER ON...CONVECTION CONCERNS PREVAIL FROM ABOUT 21Z ONWARD.
LATEST MODEL GUIDANCE IS EASING OFF SOME ON COVERAGE AND TIMING IN
MUCH OF CENTRAL ILLINOIS...WITH MORE OF A FOCUS JUST SOUTH OF THE
TAF SITES. HAVE MAINTAINED SOME VCTS MENTION AT KPIA/KSPI...BUT
LEFT OUT THUNDER MENTION ELSEWHERE FOR NOW DUE TO THE UNCERTAINTY.

GEELHART

&&

.PREV DISCUSSION...
ISSUED 248 PM CDT SAT JUL 20 2013

MODELS LOOK IN VERY GOOD AGREEMENT IN THE SHORT TERM PERIOD...AS
MAIN CONCERN IS PCPN CHANCES AND TEMPS. EXTENDED MODELS HAVE SOME
DIFFERENCES BUT THEY ARE MINOR AND DO NOT CHANGE THE OVERALL
FORECAST THAT MUCH...EXCEPT TO BRING IN SOME DRIER PERIODS DURING
MIDDLE OF THE WEEK. SO OVERALL CONFIDENCE IN FORECAST IS GOOD.

SHORT TERM...TONIGHT THROUGH TUESDAY

FRONT HAS BEEN MOVING SOUTH THROUGH THE AREA TODAY AND WILL
CONTINUE TO MOVE SOUTH LATE THIS AFTERNOON AND EVENING.
THUNDERSTORMS HAVE DEVELOPED ALONG THE FRONT AS IT HAS INTERACTED
WITH JUICY AIR WITH LOWER TO MIDDLE 70S DEWPOINTS. WITH
THUNDERSTORMS THAT HAVE NOW DEVELOPED JUST NORTH OF I-70...WILL
HAVE A LATE AFTERNOON PERIOD IN THE WORDED FORECAST ONCE IT IS
ISSUED. OTHERWISE...TONIGHT THUNDERSTORMS WILL JUST BE IN THE
SOUTHEAST JUST FOR THIS EVENING AND THEN DRY FOR AFTER MIDNIGHT.

AS CAN BE SEEN ON VISIBLE SATELLITE AND RADAR IMAGES OUT
WEST...THE FRONT EXTENDS BACK TO THE NORTHWEST WITH MORE SHOWERS
AND THUNDERSTORMS. THIS FRONT WILL BE THE FOCUS FOR MORE
DEVELOPMENT TOMORROW THAT WILL ADVECT TOWARD WESTERN ILLINOIS
TOMORROW MORNING AND CENTRAL ILLINOIS TOMORROW AFTERNOON.
THUNDERSTORM CHANCES WILL CONTINUE INTO TOMORROW NIGHT AS A SHORT
WAVE MOVES ACROSS THE AREA AS WELL. POPS WILL BE HIGHEST TOMORROW
NIGHT DUE TO THIS SHORT WAVE AS WELL. PCPN CHANCES WILL CONTINUE
INTO MONDAY...THOUGH LOWER...AS THE SHORT WAVE MOVES EAST OF THE
AREA.

A SECOND WAVE OR MCS WILL THEN DEVELOP OUT WEST AND MOVE INTO THE
AREA FOR MON NIGHT INTO TUESDAY. THIS WILL BRING CONTINUED
THUNDERSTORM CHANCES FROM WEST TO EAST. CHANCES THEN DIMINISH FROM
THE WEST TUE INTO TUE NIGHT.

TEMP WILL REMAIN WARM AND WITH HIGH DEWPOINTS...MUGGY CONDITIONS
WILL CONTINUE. AFTERNOON HIGHS ARE EXPECTED TO STILL REACH INTO
THE MIDDLE TO UPPER 80S WITH NEAR 90 DEGREES IN THE SOUTHEAST ON
MONDAY.

LONG TERM...TUESDAY NIGHT THROUGH SATURDAY

AS THE SECOND WAVE MOVES THROUGH THE AREA...THUNDERSTORMS WILL
PROBABLY STILL BE POSSIBLE IN THE SOUTHEAST SECTIONS FOR TUE
NIGHT...SO WILL KEEP CHC POPS THERE. THIS SECOND WAVE SHOULD BE
STRONG ENOUGH TO PUSH THE FRONT WELL SOUTH AND BRING A PERIOD OF
DRY WEATHER TO THE AREA. UPPER LEVEL FLOW WILL ALSO BE OUT OF THE
NORTHWEST...SO CONDITIONS SHOULD BE A TAD COOLER DURING THE DAY.
CURRENT EXTENDED MODELS INDICATE THAT DRY WEATHER WILL PREVAIL
THROUGH THURSDAY NIGHT AS MODELS DO NOT SHOW ANY SHORT WAVES
MOVING THROUGH THE AREA DURING THAT PERIOD. HOWEVER...MODELS DO
NOT DO WELL WITH SMALL WEAK FEATURES IN NORTHWEST FLOW SO DON`T BE
SURPRISED IF THIS CHANGES OVER THE NEXT COUPLE OF DAYS. THE NEXT
REAL CHANCE OF SHOWERS AND THUNDERSTORMS APPEARS NOT TO BE UNTIL
FRIDAY THROUGH SATURDAY AS A MID LEVEL TROUGH MOVES TOWARD THE
AREA. CURRENTLY THIS SYSTEM LOOKS TO REMAIN WEST OF THE AREA BUT
STILL BRING PCPN TO ALL OF CENTRAL AND SOUTHEAST ILLINOIS FOR END
OF THE WEEK.

TEMPS WILL REMAIN AROUND NORMAL BUT THEN BECOME COOLER...
POSSIBLY...AT THE END OF THE WEEK AND BEGINNING OF THE WEEKEND.

AUTEN


&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$








AREA FORECAST DISCUSSION

NWS QUAD CITIES IA IL

 1252 PM CDT SUN JUL 21 2013

.SYNOPSIS...
ISSUED AT 252 AM CDT SUN JUL 21 2013

A QUIET NIGHT ACROSS THE AREA WHILE THUNDERSTORMS RAIN OVER THE
CENTRAL PLAINS. THE SURFACE AND 850 MB FRONTAL BOUNDARIES RESIDE
TO OUR SOUTH IN NORTHERN MISSOURI AND ARE ASSOCIATED WITH
WEAKENING STORMS. ANOTHER BOUNDARY TO OUR NORTH ACROSS MINNESOTA AND
WISCONSIN IS ASSOCIATED WITH ACTIVE STORMS.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 252 AM CDT SUN JUL 21 2013

MAIN CONCERN IN THIS TIME FRAME IS THUNDERSTORM CHANCES TODAY AND
THIS EVENING. MODELS OTHER THAN THE RAP AND HRRR HAVE A WEAK
HANDLE ON THE PLAINS CONVECTION. AND THIS SYSTEM WITH ITS ASSOCIATED
SHORT WAVE TROUGH/MCV WILL BE OUR WEATHER MAKER FOR TODAY.

OVERALL CURRENT CONVECTIVE TRENDS IN THE PLAINS ARE WEAKENING
EXCEPT FOR REDEVELOPING STORMS ON THE TAIL OF THE MCS WHICH IS
REACHING THE MISSOURI RIVER. TIMING OF THE SHORT WAVE INTO OUR
AREA IS SUCH THAT THE ATMOSPHERE SHOULD DESTABILIZE THROUGH THE
MORNING...ALBEIT WITH SUNSHINE FILTERED BY MID AND HIGH CLOUDS.

MODELS SEEM TO WEAKEN THE WAVE...AND THE NAM EVEN TAKES IT SOUTH
OF THE CWA. BUT THE ATMOSPHERE SHOULD BE PRIMED FOR CONVECTION...
AND IF THE SURFACE AND 850MB FRONTS ARE PULLED NORTH WITH THE
TROUGH...WE WILL HAVE A FOCAL POINT FOR STORM INITIATION. SINCE
FLOW IS WEAK AND MODEL FORECASTS ARE DIVERGENT ON THIS ISSUE...
HAVE GENERALLY HELD POPS IN THE HIGH CHANCE RANGE. SLOW MOVING
STORMS COULD PRODUCE LOCALLY HEAVY RAIN...AND THE ENVIRONMENT
SUPPORTS AN ISOLATED RISK OF DOWNBURSTS.

MAX TEMPS TODAY RELATIVE TO YESTERDAY WILL BE HINDERED SOME BY
CLOUD COVER. OVERNIGHT LOWS WILL BE MORE REFLECTIVE OF THE WARM
SECTOR IN MISSOURI AS WINDS SHIFT TO THE SOUTH TONIGHT. WOLF

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 252 AM CDT SUN JUL 21 2013

THE DEEP MOIST AIR MASS AHEAD OF AN EARLY TUE FROPA WILL CONTINUE
THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS MONDAY INTO MONDAY
NIGHT. DEVELOPING NW ALOFT AND HIGH PRESSURE TO THEN PROVIDE DRY
WEATHER AND SLIGHTLY COOLER TEMPERATURES FOR MOST OF THE UPCOMING
WORKWEEK. RAIN CHANCES RETURN LATE WEEK INTO THE WEEKEND WITH
TEMPERATURES POSSIBLY TRENDING WELL BELOW NORMAL BY SUNDAY.

MONDAY...WEAK MID LEVEL SUBSIDENCE AND LACK OF SIGNIFICANT SURFACE
BOUNDARIES WILL BE UNFAVORABLE FOR ANYTHING BEYOND ISOLATED
CONVECTION OVER MOST OF THE AREA AND HAVE LOWERED POPS TO SLIGHT
CHANCES FOR MOST OF THE DAY. THE EXCEPTION IS ACROSS THE FAR
NW...WHERE DEVELOPING LIFT AHEAD OF AN APPROACHING SHORTWAVE AND
SURFACE COLD FRONT MAY LEAD TO THUNDERSTORMS DURING LATE DAY PEAK
HEATING AND HAVE CHANCE POPS. PREFRONTAL WARMING AND WEDGE OF WARM
AIR AT 850 MB WILL SUPPORT HIGHS FROM THE MID 80S NORTH TO AROUND 90
SOUTH. DEW POINTS IN THE UPPER 60S TO LOWER 70S MAY DRIVE HEAT
INDEX READINGS INTO THE UPPER 90S ACROSS THE SOUTH.

MONDAY NIGHT INTO EARLY TUESDAY...THERE IS A SIGNIFICANT SPREAD
AMONG THE MODELS WITH THE TIMING OF THE SURFACE COLD FRONT. THE GFS
HAS TRENDED THE SLOWEST...NOT BRINGING THE FRONT THROUGH UNTIL MID
MORNING...WHILE THE ECMWF HAS THE SURFACE WIND SHIFT WELL BEFORE
SUNRISE. WILL STAY CLOSER TO A FASTER CONSENSUS KEEPING CHANCE POPS
FOCUSED ON THE OVERNIGHT PERIOD...FOLLOWED BY SLIGHT CHANCES OVER
MAINLY THE EAST TUESDAY MORNING. WILL CONTINUE TO HAVE A THREAT FOR
LOCALLY HEAVY RAINFALL DUE TO THE HIGH PW VALUES IN PLACE MONDAY
NIGHT. KEPT MINS FROM THE MID 60S NORTH TO THE LOWER 70S SOUTH.

TUESDAY THROUGH THURSDAY...CANADIAN HIGH PRESSURE BUILDS SOUTH INTO
GREAT LAKES UNDER A NW FLOW ALOFT TO PROVIDE A PERIOD OF SEASONABLY
MILD AND LESS HUMID CONDITIONS. WED LOOKS TO BE THE COOLEST AS THE
POSITIONING OF THE PASSING HIGH WILL PROVIDE A LOW LEVEL NORTHEAST
FETCH AND THE COOLEST TEMPERATURES AT 850 MB. THIS MAY RESULT IN
HIGHS LIMITED TO THE 70S ACROSS THE CENTRAL AND NORTH...WHILE BOTH
TUE AND THU WILL LIKELY SEE WIDESPREAD LOWER TO MID 80S. THIS
SEASONABLY DRY AIR MASS WILL SUPPORT LOWS IN THE 60S WITH SOME
POCKETS OF 50S POSSIBLE THU MORNING.

GULF MOISTURE RETURNS TO THE REGION THU NIGHT INTO FRIDAY. THIS AND
A COLD FRONT SHOWN PUSHING THROUGH FRIDAY NIGHT OR SATURDAY WILL
BRING THUNDERSTORM CHANCES BACK TO THE AREA. THE LATEST GFS AND
ECMWF THEN DEVELOP A SIGNIFICANT UPPER TROUGH OVER THE EASTERN U.S.
THAT ALLOWS HIGH PRESSURE TO SPILL INTO THE MID MS VALLEY. THIS
COULD LIMIT HIGHS TO THE 70S OVER THE WEEKEND WITH LOWS IN THE 50S.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1232 PM CDT SUN JUL 21 2013

UPPER LEVEL WAVE ROLLING EASTWARD ACRS WEST CENTRAL INTO NORTH
CENTRAL IA ATTM...KICKING UP SHOWERS ON IT/S EASTWARD FLANK AND
THUNDERSTORMS ON IT/S SOUTHERN FLANK ACRS SOUTH CENTRAL IA INTO SW
IA. AHEAD OF IT FOR THE TERMINALS JUST VFR LEVEL DEBRIS CLOUDS AND
SOUTHEAST BREEZE OF 5-10 KTS. THE SCTRD SHOWERS TO GET INTO THE
VCNTY OF CID AND DBQ BY MID AFTERNOON AND LAST THROUGH EARLY
EVENING. SOME EMBEDDED THUNDER EXPECTED IN THAT ACTIVITY AS WELL
AS THE AFTERNOON PROGRESSES. THUS SOME POCKETS OF MVFR AND
VARIABLE WIND GUSTS POSSIBLE THROUGH 7-8 PM THIS EVENING. HEAVIER
RAIN MAY PRODUCE BOUTS OF IFR VSBYS AFTER 3 PM CDT. THESE
CONDITIONS POSSIBLE FOR MLI AS WELL FROM LATE AFTERNOON THROUGH MID
EVENING...BUT A CHANCE MLI COULD REMAIN IN BETWEEN THE ACTION
ZONES TO THE NORTH AND SOUTH. THE SOUTHERN ACTION ZONE...THE
ACTIVITY NOW ACRS SOUTH CENTRAL IA COULD BE A IMPACT AT BRL BY LATE
AFTERNOON WITH BOUTS OF HEAVY RAIN/IFR VSBYS...LOWERED CIGS DOWN TO
MVFR AND POSSIBLE VARIABLE GUSTY WINDS UP TO 45 KTS PRODUCED BY
THE THUNDERSTORMS. CURRENT EXTRAPOLATION HAS THE BRL UNDER THE GUN
OF THE SOUTH CENTRAL IA STORMS FROM 3 PM THROUGH 6 PM...WITH
ADDITIONAL DEVELOPMENT LINGERING IN THAT AREA THROUGH MID EVENING.
AFTER PRECIP CLEARS LATER THIS EVENING AND INTO THE OVERNIGHT...SOME
MVFR AND POSSIBLE IFR FOG AT ALL TERMINALS TOWARD SUNRISE
ESPECIALLY AT THE TERMINALS THAT DO MANAGE TO GET IN ON SOME RAIN
THIS AFTERNOON/EVENING. WINDS BECOMING LIGHT AND VARIABLE OVERNIGHT
OR LIGHT EAST-SOUTHEAST.    ..12..

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&

$$

SYNOPSIS...WOLF
SHORT TERM...WOLF
LONG TERM...SHEETS
AVIATION...12







AREA FORECAST DISCUSSION

NWS QUAD CITIES IA IL

 318 AM CDT SUN JUL 21 2013

.SYNOPSIS...
ISSUED AT 252 AM CDT SUN JUL 21 2013

A QUIET NIGHT ACROSS THE AREA WHILE THUNDERSTORMS RAIN OVER THE
CENTRAL PLAINS. THE SURFACE AND 850 MB FRONTAL BOUNDARIES RESIDE
TO OUR SOUTH IN NORTHERN MISSOURI AND ARE ASSOCIATED WITH
WEAKENING STORMS. ANOTHER BOUNDARY TO OUR NORTH ACROSS MINNESOTA AND
WISCONSIN IS ASSOCIATED WITH ACTIVE STORMS.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 252 AM CDT SUN JUL 21 2013

MAIN CONCERN IN THIS TIME FRAME IS THUNDERSTORM CHANCES TODAY AND
THIS EVENING. MODELS OTHER THAN THE RAP AND HRRR HAVE A WEAK
HANDLE ON THE PLAINS CONVECTION. AND THIS SYSTEM WITH ITS ASSOCIATED
SHORT WAVE TROUGH/MCV WILL BE OUR WEATHER MAKER FOR TODAY.

OVERALL CURRENT CONVECTIVE TRENDS IN THE PLAINS ARE WEAKENING
EXCEPT FOR REDEVELOPING STORMS ON THE TAIL OF THE MCS WHICH IS
REACHING THE MISSOURI RIVER. TIMING OF THE SHORT WAVE INTO OUR
AREA IS SUCH THAT THE ATMOSPHERE SHOULD DESTABILIZE THROUGH THE
MORNING...ALBEIT WITH SUNSHINE FILTERED BY MID AND HIGH CLOUDS.

MODELS SEEM TO WEAKEN THE WAVE...AND THE NAM EVEN TAKES IT SOUTH
OF THE CWA. BUT THE ATMOSPHERE SHOULD BE PRIMED FOR CONVECTION...
AND IF THE SURFACE AND 850MB FRONTS ARE PULLED NORTH WITH THE
TROUGH...WE WILL HAVE A FOCAL POINT FOR STORM INITIATION. SINCE
FLOW IS WEAK AND MODEL FORECASTS ARE DIVERGENT ON THIS ISSUE...
HAVE GENERALLY HELD POPS IN THE HIGH CHANCE RANGE. SLOW MOVING
STORMS COULD PRODUCE LOCALLY HEAVY RAIN...AND THE ENVIRONMENT
SUPPORTS AN ISOLATED RISK OF DOWNBURSTS.

MAX TEMPS TODAY RELATIVE TO YESTERDAY WILL BE HINDERED SOME BY
CLOUD COVER. OVERNIGHT LOWS WILL BE MORE REFLECTIVE OF THE WARM
SECTOR IN MISSOURI AS WINDS SHIFT TO THE SOUTH TONIGHT. WOLF

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 252 AM CDT SUN JUL 21 2013

THE DEEP MOIST AIR MASS AHEAD OF AN EARLY TUE FROPA WILL CONTINUE
THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS MONDAY INTO MONDAY
NIGHT. DEVELOPING NW ALOFT AND HIGH PRESSURE TO THEN PROVIDE DRY
WEATHER AND SLIGHTLY COOLER TEMPERATURES FOR MOST OF THE UPCOMING
WORKWEEK. RAIN CHANCES RETURN LATE WEEK INTO THE WEEKEND WITH
TEMPERATURES POSSIBLY TRENDING WELL BELOW NORMAL BY SUNDAY.

MONDAY...WEAK MID LEVEL SUBSIDENCE AND LACK OF SIGNIFICANT SURFACE
BOUNDARIES WILL BE UNFAVORABLE FOR ANYTHING BEYOND ISOLATED
CONVECTION OVER MOST OF THE AREA AND HAVE LOWERED POPS TO SLIGHT
CHANCES FOR MOST OF THE DAY. THE EXCEPTION IS ACROSS THE FAR
NW...WHERE DEVELOPING LIFT AHEAD OF AN APPROACHING SHORTWAVE AND
SURFACE COLD FRONT MAY LEAD TO THUNDERSTORMS DURING LATE DAY PEAK
HEATING AND HAVE CHANCE POPS. PREFRONTAL WARMING AND WEDGE OF WARM
AIR AT 850 MB WILL SUPPORT HIGHS FROM THE MID 80S NORTH TO AROUND 90
SOUTH. DEW POINTS IN THE UPPER 60S TO LOWER 70S MAY DRIVE HEAT
INDEX READINGS INTO THE UPPER 90S ACROSS THE SOUTH.

MONDAY NIGHT INTO EARLY TUESDAY...THERE IS A SIGNIFICANT SPREAD
AMONG THE MODELS WITH THE TIMING OF THE SURFACE COLD FRONT. THE GFS
HAS TRENDED THE SLOWEST...NOT BRINGING THE FRONT THROUGH UNTIL MID
MORNING...WHILE THE ECMWF HAS THE SURFACE WIND SHIFT WELL BEFORE
SUNRISE. WILL STAY CLOSER TO A FASTER CONSENSUS KEEPING CHANCE POPS
FOCUSED ON THE OVERNIGHT PERIOD...FOLLOWED BY SLIGHT CHANCES OVER
MAINLY THE EAST TUESDAY MORNING. WILL CONTINUE TO HAVE A THREAT FOR
LOCALLY HEAVY RAINFALL DUE TO THE HIGH PW VALUES IN PLACE MONDAY
NIGHT. KEPT MINS FROM THE MID 60S NORTH TO THE LOWER 70S SOUTH.

TUESDAY THROUGH THURSDAY...CANADIAN HIGH PRESSURE BUILDS SOUTH INTO
GREAT LAKES UNDER A NW FLOW ALOFT TO PROVIDE A PERIOD OF SEASONABLY
MILD AND LESS HUMID CONDITIONS. WED LOOKS TO BE THE COOLEST AS THE
POSITIONING OF THE PASSING HIGH WILL PROVIDE A LOW LEVEL NORTHEAST
FETCH AND THE COOLEST TEMPERATURES AT 850 MB. THIS MAY RESULT IN
HIGHS LIMITED TO THE 70S ACROSS THE CENTRAL AND NORTH...WHILE BOTH
TUE AND THU WILL LIKELY SEE WIDESPREAD LOWER TO MID 80S. THIS
SEASONABLY DRY AIR MASS WILL SUPPORT LOWS IN THE 60S WITH SOME
POCKETS OF 50S POSSIBLE THU MORNING.

GULF MOISTURE RETURNS TO THE REGION THU NIGHT INTO FRIDAY. THIS AND
A COLD FRONT SHOWN PUSHING THROUGH FRIDAY NIGHT OR SATURDAY WILL
BRING THUNDERSTORM CHANCES BACK TO THE AREA. THE LATEST GFS AND
ECMWF THEN DEVELOP A SIGNIFICANT UPPER TROUGH OVER THE EASTERN U.S.
THAT ALLOWS HIGH PRESSURE TO SPILL INTO THE MID MS VALLEY. THIS
COULD LIMIT HIGHS TO THE 70S OVER THE WEEKEND WITH LOWS IN THE 50S.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1142 PM CDT SAT JUL 20 2013

WINDS WILL REMAIN LIGHT EAST OR SOUTHEAST TONIGHT AND SUNDAY WITH
WEAK HIGH PRESSURE REMAINING OVER THE WESTERN GREAT LAKES. WITH
THE RAINS AT KDBQ THIS AFTERNOON AND WITH SCATTERED CLOUDS AND
LIGHT WINDS OVERNIGHT THE MVFR VSBYS IN FOG WERE MAINTAINED FOR KDBQ
LATE TONIGHT. TONIGHT SHOULD BE DRY FOR MOST OF THE THE FORECAST
AREA. THERE IS A LOW CHANCE OF SOME SHRA/TSRA MOVING INTO THE
HIGHWAY 20 CORRIDOR INCLUDING KDBQ EARLY SUNDAY MORNING OTHERWISE
THE REST OF THE AREA SHOULD BE DRY THROUGH MUCH OF THE MORNING.
SHRA/TSRA SHOULD DEVELOP OR SPREAD INTO THE AREA BY LATE MORNING
WITH THE BEST CHANCE OF PRECIPITATION LATE SUNDAY AFTERNOON AND EVENING.
FOR NOW HAVE JUST MENTIONED MVFR CONDITIONS IN TSRA LATE SUNDAY
AFTERNOON.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&

$$

SYNOPSIS...WOLF
SHORT TERM...WOLF
LONG TERM...SHEETS
AVIATION...DLF







AREA FORECAST DISCUSSION

NWS TOPEKA KS

 603 PM CDT MON JUL 22 2013

.UPDATE...
ISSUED AT 603 PM CDT MON JUL 22 2013

23Z OBJECTIVE ANALYSIS SHOWS THE FRONTAL BOUNDARY STILL WELL NORTH
OF THE FORECAST AREA FROM NORTH CENTRAL IA...NORTH OF OMA INTO
CENTRAL NEB. WHILE LAPS ANALYSIS SUGGESTS CAPE VALUES ON THE ORDER
OF 4000 J/KG...RECENT VISIBLE IMAGERY DOES NOT SHOW MUCH IN THE
WAY OF A CU FIELD ACROSS THE AREA IN SPITE OF SEVERAL OUTFLOW
BOUNDARIES IN THE AREA. ADDITIONALLY WATER VAPOR SHOWS MID LEVEL
DRYING OVERSPREADING THE FORECAST AREA FROM THE WEST AND NORTHWEST
SUGGESTING THE MAIN VORT MAX IS CURRENTLY OVERHEAD AND MOVING
SOUTHEAST. THE 18Z NAM LOOKS TO BE A LITTLE TO FAR SOUTH WITH THE
FRONTAL BOUNDARY AND PREFER THE RUC13 DEPICTION OF THE LARGE
SCALE PRESSURE FIELD WHICH KEEPS THE MAIN FRONT MAINLY TO THE
NORTH. SO IN GENERAL THINKING IS ANY CONVECTION EARLY THIS
EVENING IS LIKELY TO REMAIN ISOLATED. WITH THE AVAILABLE
INSTABILITY...ANY STORM THAT FORMS WILL HAVE THE POTENTIAL TO
DEVELOP RAPIDLY. HOWEVER THINK THE BETTER CHANCES FOR SCATTERED TO
NUMEROUS STORMS COULD BE DURING THE DAY TUESDAY AS THE BOUNDARY
SETS UP ACROSS KS. WITH MODELS SHOWING THE LOW LEVEL JET FOCUSING
ACROSS SOUTHEAST KS OVERNIGHT...THINK BEST CHANCES FOR STORMS IN
THE EARLY MORNING MAY COME FROM CONVECTION CURRENTLY DEVELOPING
OVER THE HIGH PLAINS OF WY. THE RAP AND HRRR SHOW SIGNS OF THIS
PRECIP HOLDING TOGETHER AND MOVING INTO THE AREA BEFORE DAWN. WILL
MONITOR TRENDS BUT MAY ADJUST THE FORECAST TO LOWER POPS THIS
EVENING.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 248 PM CDT MON JUL 22 2013

STORMS AND CLOUD COVER FROM EARLIER IN THE DAY HAVE LIKELY DELAYED
THUNDERSTORM START TO THESE LATER AFTERNOON HOURS...AND A FEW OF THE
RESIDENT OUTFLOW BOUNDARIES ARE STARTING TO GENERATE CONNECTION.
STORM TO THE NORTH WENT UP QUICKLY...LIKELY IN RESPONSE TO STEEP MID
LEVEL LAPSE RATES AND AMPLE INSTABILITY.  WILL BE DIFFICULT TO SAY
WHERE STORMS WILL FROM IN PARTICULAR THIS AFTERNOON AS THEY REMAIN
BOUNDARY DRIVEN.  MAIN FRONT STILL PROGGED TO COME THROUGH IN THE
0-3Z WINDOW...AND EXPECT THAT THE BETTER SHEAR MORE ORGANIZED
FORCING THAT COMES WITH IT WILL STILL BRING A CHANCE FOR STORM OR
SMALL COMPLEX TO MOVE ACROSS THE CWA THIS EVENING INTO THE EARLY
MORNING HOURS.  PRIMARY CONCERNS ARE WINDS AND LOCALLY HEAVY
RAINFALL...ALTHOUGH ENVIRONMENT MAY BRING SOME MARGINALLY SEVERE
HAIL AS WELL.

WHERE BOUNDARY ENDS UP COMPLICATES SENSIBLE WEATHER AND RAINFALL
CHANCES FOR TUESDAY...WITH NORTHEAST COUNTIES LIKELY COOLER AND
MOISTURE POOLING WESTWARD SHIFTS AFTERNOON RAIN CHANCES TOWARD
WESTERN COUNTIES.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 248 PM CDT MON JUL 22 2013

TUESDAY EVENING THROUGH THURSDAY...

BY 7 PM ON TUESDAY EVENING ISOLATED THUNDERSTORMS MAY BE ONGOING IN
THE VICINITY OF THE SURFACE FRONT OVER EAST CENTRAL AREAS.
THUNDERSTORM COVERAGE IS EXPECTED TO INCREASE ACROSS THE AREA
TOWARDS THE EVENING AS A STRONGER SHORTWAVE EMBEDDED WITHIN THE
UPPER RIDGE TRANSLATES SOUTHEAST ACROSS EASTERN NEBRASKA INTO MISSOURI.
MODELS HAVE BEEN CONSISTENT THE PAST FEW DAYS WITH THIS SCENARIO AND
FEEL CONFIDENT TO BOOST POPS UP TO LIKELY ESPECIALLY IN THE EAST
CENTRAL AREAS. AS FAR AS STORM TYPE GOES...BEST CHANCE OF SEEING
STRONGER STORMS WILL BE CLOSER TO THE 00Z PERIOD WHERE ML CAPE
VALUES ARE PROGGED ANYWHERE FROM 1000 TO 3000 J/KG WITH THE NAM AT
12Z SHOWING 0-6 KM BULK SHEAR INCREASING UP TO 50 KTS. HIGH PRESSURE
WILL BE QUICK TO USHER SOUTHWARD BEHIND THIS SYSTEM WITH CAPE VALUES
STEADILY DECREASING AFT 06Z. GRADUALLY TRENDED POPS DOWNWARD AFT 06Z
WITH MOST OF THE AREA DRY BY WEDNESDAY MORNING. SUBSIDENCE IN PLACE
ON WEDNESDAY SHOULD BRING A TEMPORARILY LULL IN PRECIPITATION
WITH MOSTLY SUNNY SKIES AND COOLER HIGHS IN THE LOW TO MIDDLE 80S.

DURING THE AFTERNOON ON THURSDAY...THE UPPER RIDGE OVER THE
SOUTHWEST CONUS BREAKS DOWN SLIGHTLY AS A  DEVELOPING A LEE TROUGH
TRACKS ACROSS THE INTER-MOUNTAIN WEST AND INTO THE CENTRAL PLAINS. THE
ECMWF AND GFS ARE STILL IN RELATIVE AGREEMENT IN BRINGING A SWATH OF
SHOWERS AND THUNDERSTORMS THURSDAY EVENING INTO FRIDAY FOR NORTHEAST
KANSAS. SLIGHT CHANCES FOR THUNDER INCREASE ON THURSDAY AFTERNOON
WITH GOOD CONFIDENCE TO ADD LIKELY CHANCES FOR THE EVENING HOURS
OVER NORTH CENTRAL KS.

TEMPERATURES DURING THIS PERIOD WILL DEPEND ON LINGERING
PRECIPITATION AND CLOUD COVER ESPECIALLY WEDNESDAY. MADE LITTLE
ADJUSTMENTS WITH WARMEST TEMPERATURES OVER NORTH CENTRAL AREAS IN
THE UPPER 80S WITH COOLER TEMPS OVER EAST CENTRAL WHERE LINGERING
SHOWERS AND CLOUD COVER MAY PERSIST. THE INCREASING CLOUD COVER AS
THE TROF APPROACHES THURSDAY WILL BE A RELATIVELY COOLER BUT HUMID
DAY WITH HIGHS IN THE LOW TO MID 80S.

THURSDAY EVENING THROUGH MONDAY...

BULK OF THE AFOREMENTIONED LOW PRESSURE SYSTEM IMPACTS THE AREA
THURSDAY EVENING INTO FRIDAY. 12Z ECMWF IS STILL TRENDING A TAD
SLOWER THAN THE 12Z GFS WITH THE CENTER OF THE TROF AXIS AND ITS
POSITION BUT OVERALL HAS BEEN IN CONSISTENT AGREEMENT SO HAVE
CARRIED CHANCES FOR THUNDERSTORMS THROUGH FRIDAY AND TAPERING OFF TO
THE EAST FRIDAY EVENING. UPPER RIDGE AMPLIFIES ONCE AGAIN HEADING
INTO THE WEEKEND WITH A QUIET PERIOD FOR SATURDAY. MODELS STILL
DIFFERING BY THE END OF THE PERIOD BUT APPEARS PATTERN STARTS TO
CHANGE TRANSITIONING TO A WESTERLY FLOW PATTERN AND ATTEMPTING TO
BRING ADDITIONAL TROFS THROUGH THE REGION SUNDAY INTO MONDAY.
DECIDED TO LOWER PRECIPITATION CHANCES TO SLIGHT AS MODEL OUTPUT IS
STILL TOO NOISY TO DISCERN ANY MAIN SOURCES OF ENERGY. TEMPERATURES ARE
ON TRACK TO REMAIN IN THE LOW 80S FOR HIGHS WITH THIS ACTIVE PATTERN
IN PLACE.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 603 PM CDT MON JUL 22 2013

BASED ON THE UPDATED DISCUSSION ABOVE...THE LIKELY HOOD OF A STORM
MOVING INTO A TERMINAL APPEARS TO BE RATHER SMALL. THEREFORE WILL
NOT CONTINUE WITH THE VCTS THIS EVENING OR OVERNIGHT. MAY NEED TO
WATCH STORMS FROM WY. HIRES MODELS SUGGEST IT COULD MOVE INTO THE
AREA AFT 08Z. OTHERWISE THINK STORMS WILL REMAIN RATHER ISOLD TO
MENTION IN THE TAFS AT THIS TIME.

THERE IS A SMALL CONCERN FOR SOME MVFR VSBY DEVELOPING AROUND 11Z
SINCE DEWPOINTS ARE FORECAST TO REMAIN IN THE LOWER 70S. OBJECTIVE
GUIDANCE DOES NOT SEEM TO BE PICKING UP ON VSBY RESTRICTIONS SO
WILL MONITOR TRENDS THIS EVENING.

WINDS ARE LIKELY TO REMAIN SOUTHERLY OR SOUTHWESTERLY WITH A MESO
HIGH TO THE SOUTHWEST...THEN BECOME VARIABLE BY DAWN TUESDAY AS
THE SFC TROUGH APPROACHES.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

UPDATE...WOLTERS
SHORT TERM...67
LONG TERM...BOWEN
AVIATION...WOLTERS








AREA FORECAST DISCUSSION

NWS TOPEKA KS

 353 AM CDT SUN JUL 21 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT SUN JUL 21 2013

TODAY AND TONIGHT...A LONGER WAVE LENGTH UPPER LEVEL TROUGH WILL
CONTINUE TO AMPLIFY ACROSS THE UPPER MIDWEST AND GREAT LAKES STATES.
THIS WILL CAUSE THE UPPER FLOW ACROSS THE PLAINS TO BECOME
NORTHWESTERLY. SHORTER WAVE LENGTH UPPER LEVEL TROUGHS WILL ROUND
THE UPPER RIDGE AXIS ACROSS THE WESTERN CONUS AND DIG SOUTHEAST
ACROSS THE CENTRAL PLAINS THROUGH TONIGHT. A WEAK FRONTAL BOUNDARY
WAS LOCATED FROM SOUTHWEST KS...NORTHEAST TO NEAR TOP...THEN
NORTHEAST ACROSS NORTHERN MO. WEAK ISENTROPIC LIFT NORTH OF THE
BOUNDARY MAY CAUSE A FEW SHOWERS TO DEVELOP THIS MORNING ACROSS EAST
CENTRAL KS.

MOST NUMERICAL MODELS SHOW AN H5 TROUGH DIGGING SOUTHEAST ACROSS
CENTRAL HIGH PLAINS DURING THE AFTERNOON HOURS. THE ASCENT AHEAD OF
THE H5 TROUGH COMBINED WITH UPSLOPE FLOW WILL CAUSE A COMPLEX OF
THUNDERSTORMS TO DEVELOP ACROSS WESTERN NE LATE THIS AFTERNOON AND
EARLY EVENING...THEN MOVE SOUTHEAST ACROSS EASTERN KS LATER TONIGHT.
ISOLATED TO WIDELY SCATTERED THUNDERSTORMS MAY ALSO DEVELOP ALONG
THE NORTHWARD MOVING FRONTAL BOUNDARY ACROSS THE CWA DURING THE LATE
AFTERNOON AND EARLY EVENING HOURS. THE 00Z NAM AND RAP MODELS WERE
SHOWING 1500-2500 J/KG OF MLCAPE. HOWEVER...THE SFC-6KM EFFECTIVE
SHEAR WILL ONLY BE 15 TO 20 KTS DURING THE AFTERNOON AND EARLY
EVENING HOURS. DUE TO THE WEAKER VERTICAL WINDSHEAR UPDRAFTS WILL
PROBABLY NOT BE ABLE TO SUSTAIN THEIR INTENSITY FOR MORE THAN 15 TO
20 MINUTES. THE STRONGER THUNDERSTORMS MAY PRODUCE SMALL HAIL AND 40
TO 50 MPH WINDS GUSTS. A STORM OR TWO MAY BRIEFLY PRODUCE QUARTER
SIZE HAIL AND 58 MPH WINDS GUSTS.

THE INSTABILITY AND VERTICAL WIND SHEAR AND INSTABILITY LOOKS TOO
WEAK FOR THE COMPLEX OF THUNDERSTORMS LATE TONIGHT TO BE
SEVERE...SOME OF THE STRONGER STORMS MAY PRODUCE GUSTY WINDS AND
THERE COULD BE HEAVY RAINFALL ALONG THE TRACK OF THE THUNDERSTORM
COMPLEX. I KEPT LIKELY POPS FOR THE NORTHERN AND EASTERN COUNTIES OF
THE CWA AFTER MIDNIGHT. THIS MAY CHANGE DEPENDING TO WHERE THE MCS
ACROSS NE FORMS AND HOW IT TRACKS THROUGH THE NIGHT. ATTM...MOST
MODELS HAVE THE COMPLEX OF STORMS MOVING SOUTHEAST ACROSS SOUTH
CENTRAL NE AND ACROSS THE EASTERN CWA LATE TONIGHT AND THROUGH THE
MORNING HOURS OF SUNDAY.

BROKEN TO SCATTED CLOUD COVER AND LIGHT SOUTHEAST WINDS WILL KEEP
HIGH TEMPERATURES TODAY IN THE LOWER TO MID 90S ACROSS THE CWA.
HIGHER SURFACE DEWPOINTS IN THE MID TO UPPER 60S WILL CAUSE HEAT
INDICES TO RISE INTO THE UPPER 90S.


.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 345 AM CDT SUN JUL 21 2013

SHORTWAVE TROUGHS EMBEDDED IN THE WEST TO NORTHWEST FLOW ALOFT
WILL CONTINUE TO MOVE ACROSS THE AREA MAINTAINING A RATHER
UNSETTLED PATTERN FOR PERIODIC CHANCES FOR THUNDERSTORMS. ALTHOUGH
MONDAY MORNING MAY START DRY...MODELS ARE CONSISTENT WITH BACKING
THE LLVL FLOW IN RESPONSE TO THE NEXT UPSTREAM WAVE. AS THIS
OCCURS ISENTROPIC LIFT AND CONVERGENCE BEGIN TO INCREASE ACROSS
MAINLY EAST CENTRAL AND NORTHEAST KS THROUGH THE DAY...SO THE
POTENTIAL IS THERE FOR SOME ISOLATED DEVELOPMENT AS THE DAY
PROGRESSES. INSTABILITY WILL BE VERY HIGH...SO ANY STORM THAT DOES
DEVELOP COULD BE STRONG. LINGERING CLOUDS/ISOLATED CONVECTION MAY
COMPLICATE STRONG WARM AIR ADVECTION AND HIGHS EAST. STILL EXPECT
A WARM AND HUMID DAY WITH HIGHS IN THE MIDDLE TO UPPER 90S AND
HEAT INDICES AROUND 100 DEGREES. BETTER COVERAGE OF THUNDERSTORMS
IS EXPECTED INTO THE EVENING AND OVERNIGHT AS CONVECTION INCREASES
ALONG THE FRONT TO THE NORTH IN RESPONSE TO THE SHORTWAVE TROUGH
APPROACHING FROM THE NORTHWEST. WITH INCREASING FLOW ALOFT...SHEAR
PROFILES WILL BE MORE SUPPORTIVE OF STRONGER CONVECTION WITH HAIL
AND STRONG WINDS AS THE CONVECTION DEVELOPS/SPREADS SOUTHEASTWARD.
HIGHS IN THE WAKE OF THE CONVECTION FOR TUESDAY WILL BE SIMILAR OR
ONLY SLIGHTLY COOLER THAN MONDAY WITH READINGS IN THE LOW TO
MIDDLE 90S AND LINGERING SLIGHT CHANCE FOR THUNDERSTORMS.

A STRONGER SHORTWAVE WILL THEN MOVE THROUGH THE AREA TUESDAY
NIGHT/EARLY WEDNESDAY WITH A BETTER CHANCE FOR MORE WIDESPREAD
SHOWERS AND THUNDERSTORMS. IT WILL ALSO PROVIDE A STRONGER PUSH
TO THE FRONT SOUTHWARD THROUGH THE CWA...SO COOLER HIGHS IN THE
MIDDLE TO UPPER 80S ON TRACK FOR WEDNESDAY. CONVECTION SHOULD MOVE
SOUTH AND EAST OF THE CWA BY WEDNESDAY AFTERNOON AND NIGHT BEFORE
ANOTHER WAVE MOVES OUT OF THE ROCKIES AND INTO THE PLAINS IN THE
THURSDAY NIGHT/FRIDAY TIMEFRAME WITH THE NEXT SIGNIFICANT CHANCE
FOR THUNDERSTORMS. WILL KEEP A LINGERING LOW CHANCE FOR
THUNDERSTORMS INTO SATURDAY...BUT BETTER CHANCES FOR PRECIP AT
THAT TIME MAY OCCUR FURTHER TO THE WEST IN UPSLOPE FLOW OVER THE
HIGH PLAINS. HIGHS WILL REMAIN GENERALLY IN THE 80S THROUGH THE
END OF THE WEEK.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1156 PM CDT SAT JUL 20 2013

FOR THE 06Z TAFS...MAIN FOCUS IS ON THE POTENTIAL FOR ADDITIONAL
SHOWERS AND THUNDERSTORMS TO DEVELOP NEAR THE TAF SITES. A COMPLEX
OF THUNDERSTORMS WAS TRACKING SOUTHEAST ACROSS CENTRAL
NEBRASKA...AND IF THIS ACTIVITY HOLDS TOGETHER IT IS EXPECTED TO
PROGRESS INTO THE REGION DURING THE OVERNIGHT HOURS WITH SCATTERED
PRECIPITATION PERSISTING THROUGH THE MORNING HOURS. HOWEVER...THERE
IS STILL A UNCERTAINTY WITH REGARDS TO THE TIMING AND LOCATION OF
ANY PRECIPITATION THAT DEVELOPS OVERNIGHT AND THROUGH THE DAY ON
SUNDAY. CURRENTLY HAVE DRY CONDITIONS FOR THE AFTERNOON AND EVENING
HOURS...BUT SOME MODELS SUGGEST SCATTERED ACTIVITY WILL PERSIST SO
WILL CONTINUE TO MONITOR THIS POTENTIAL WITH FURTHER UPDATES. IN
GENERAL...WINDS THROUGH THE PERIOD WILL BE OUT OF THE SOUTH AND
SOUTHEAST...HOWEVER VARIABLE WINDS CAN BE EXPECTED IN AREAS OF
THUNDERSTORM DEVELOPMENT.


&&

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...GARGAN
LONG TERM...63
AVIATION...HENNECKE







AREA FORECAST DISCUSSION

NWS PADUCAH KY

 456 PM CDT SUN JUL 21 2013

.UPDATE...
ISSUED AT 456 PM CDT SUN JUL 21 2013

AFTER LOOKING AT NEW HRRR MODEL REFLECTIVITY DATA AND 18Z NAM...IT
APPEARS HEAVY RAIN IS MORE LIKELY IN SW INDIANA...SE ILLINOIS...AND
NW KENTUCKY LATE TONIGHT INTO EARLY MONDAY. 850 MB LOW LEVEL FLOW IS
FORECAST TO STRENGTHEN TO AROUND 20 KNOTS...WITH STRONG INDICATIONS
OF A BACKBUILDING MCS. RAISED POPS FOR THE OVERNIGHT HOURS TO
CATEGORICAL OR LIKELY IN NE COUNTIES. THE ENSEMBLE MEANS OF THE SREF
AND GFS ALSO SHOW QPF BULLSEYES IN THAT AREA OVERNIGHT. SURFACE TO
850 MB CONVERGENCE AXIS IS FORECAST TO BE IN THAT AREA WITH A 500 MB
SHORTWAVE TROUGH JUST UPSTREAM.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 215 PM CDT SUN JUL 21 2013

MAIN FORECAST CONCERN TONIGHT IS HEAVY RAIN POTENTIAL. LOTS OF
MOISTURE AND INSTABILITY IS IN PLACE...ALONG WITH A BROAD AREA OF
WEAK LIFT. THE PRIMARY LIFTING MECHANISM IS A 500 MB SHORTWAVE
ADVANCING EAST/SOUTHEAST ACROSS CENTRAL MISSOURI. CONVECTION HAS
BEEN SLOWLY INCREASING THIS AFTERNOON ALONG AND SOUTH OF A WEAK WARM
FRONT THAT EXTENDS FROM THE LOWER OHIO VALLEY TO NORTHWEST
ARKANSAS.

THE STORMS WILL CONTINUE TO INCREASE THROUGH THE EARLY EVENING
HOURS...AIDED BY THE APPROACHING SHORTWAVE AND WARM FRONTAL
CONVERGENCE. WILL MENTION HEAVY RAIN IN GRIDS AND ZONES. LOW LEVEL
WIND SPEEDS ARE CURRENTLY A LITTLE LOWER THAN OPTIMUM FOR AN
ORGANIZED FLOODING THREAT. HOWEVER...RAP MODEL RUNS INDICATE SOME
INCREASE AND BACKING OF LOW LEVEL WINDS LATE TODAY AND THIS EVENING.
POTENTIAL FOR EXCESSIVE RAINFALL AND LOCAL FLOODING WILL NEED TO BE
MONITORED THROUGH EVENING.

LATER TONIGHT AND MONDAY MORNING...WEAKENING INSTABILITY AND
DECREASING UPPER SUPPORT SHOULD BRING A GRADUAL DECREASE IN COVERAGE
AND INTENSITY OF THE PRECIP. TEMPS ON MONDAY WILL DEPEND ON TIMING
OF PARTIAL CLEARING...WHICH SHOULD TAKE PLACE FROM WEST TO EAST AS
THE DAY GOES ON. WILL CONTINUE WITH PREVIOUS FORECASTS THAT ARE
CLOSER TO GFS MOS THAN THE COOLER NAM MOS. A RELATIVE LULL IN PRECIP
CHANCES IS EXPECTED MONDAY NIGHT.

ON TUESDAY...A COLD FRONT WILL MOVE SOUTHEAST INTO SOUTHERN ILLINOIS
AND SE MISSOURI BY LATE IN THE DAY. THE FRONT SHOULD ARRIVE DURING
PEAK HEATING AND INSTABILITY...SO WILL CONTINUE WITH POPS ABOVE MOS
GUIDANCE. PRECIP WATER VALUES WILL BE SOMEWHAT LOWER DUE TO A MORE
VEERED /WEST TO NORTHWEST/ DEEP LAYER FLOW...WHICH IS WHY POPS WILL
BE KEPT BELOW THE LIKELY CATEGORY. FLOW FIELDS WILL BE SOMEWHAT
STRONGER WITH THIS SYSTEM...SO THE POTENTIAL FOR ISOLATED SEVERE
STORMS EXISTS. CONVECTION SHOULD DIMINISH WITH THE PASSAGE OF THE
COLD FRONT ACROSS THE LOWER OHIO VALLEY LATE TUESDAY NIGHT.

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
ISSUED AT 215 PM CDT SUN JUL 21 2013

THE MODELS ARE IN GENERAL AGREEMENT WITH FRONT ALONG OUR SOUTHERN
BORDER BY 12Z WED. HOWEVER THE GFS AND THE NAM PUSH IT ON THROUGH
LIMITING ANY PRECIP CHC AFTER 12Z WED. THE 00Z SUNDAY ECMWF LINGERS
PRECIP OVER THE AREA ALL DAY WED. CURRENT GRIDS REFLECT HIGHEST PROB
WOULD BE OVER SEMO AND LATEST RUNS SUPPORT THAT. HOWEVER WILL TRY TO
LOWER POPS NORTH AND EAST AS PREVIOUS SHIFT DID AND CONTINUE THE
TREND TOWARD A DRIER WED. IF THE 12Z ECMWF FOLLOWS THAT TREND THE
MID SHIFT WILL BE ABLE TO BETTER DEFINE THE CHC. SO THIS TIME FRAME
REMAINS A LITTLE SUSPECT FOR NOW WITH EITHER NORTH WINDS VIA NAM GFS
OR STALLED FRONT ECMWF. THE 12Z UKMET SHOWS THE FRONT ALONG THE
SOUTHERN BORDER AS WELL BUT THE RUN ENDS AT 12Z BUT APPEARS TO FAVOR
THE WETTER ECMWF.

FOR THE LATE WEEK CHC THE THE GFS BRINGS A FRONT THROUGH BUT THE
ECMWF AND DGEX BRING AN MCS OUT OF THE CENTRAL PLAINS FRIDAY WITH A
COLD FRONT IN ITS WAKE SATURDAY. THE GFS IS A LITTLE VOID OF THE MCS
FEATURE AND WILL LEAN TOWARD THE ECMWF AND DGEX SOLUTION...BUT USE
THE SLOWER TIMING OF THE ECMWF FOR THIS FEATURE. WILL MAINTAIN A
SLGT CHC SAT NGT IN THE EAST. WILL KEEP SUNDAY DRY WITH MUCH COOLER
AND DRIER AIR COMING INTO THE REGION.

AS FOR TEMPS IF THE EXTENDED INIT COMES TO FRUITION IT WILL BE A
MUCH COOLER AND WE COULD SEE SOME RECORD OR NEAR RECORD COOL TEMPS
EARLY NEXT WEEK. THE OPPOSITE OF LAST SUMMER RECORD SETTING HEAT.

&&

.AVIATION...
ISSUED AT 1230 PM CDT SUN JUL 21 2013

AREAS OF LOW CLOUDS WILL CONTINUE TO LIFT THIS AFTERNOON...WITH
LINGERING POCKETS OF MVFR CIGS BECOMING VFR EARLY. WITH DIURNAL
HEATING AND DESTABILIZATION...SHOWERS AND STORMS WILL SLOWLY
INCREASE IN COVERAGE AND INTENSITY THIS AFTERNOON. EXPECT PEAK
COVERAGE TO OCCUR EARLY THIS EVENING...ENHANCED BY AN UPPER LEVEL
DISTURBANCE APPROACHING FROM THE WEST. IT IS TOO EARLY TO PINPOINT
THE TIMING OF STORMS...BUT IT APPEARS LIKELY EACH TAF SITE WILL
RECEIVE AT LEAST SOME RAIN THIS AFTERNOON OR EVENING. BRIEF IFR
CONDITIONS ARE POSSIBLE IN ANY STORMS.

CONVECTION SHOULD FADE WITH LOSS OF HEATING...AND MAINLY DRY
CONDITIONS ARE EXPECTED OVERNIGHT. SOME LIGHT FOG OR PATCHY LOW
CLOUDS ARE POSSIBLE LATE AT NIGHT AND MONDAY MORNING. DIURNAL CU
WILL FORM AGAIN BY MIDDAY MONDAY.


&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&

$$

UPDATE...MY
SHORT TERM...MY
LONG TERM...KH
AVIATION...MY
















AREA FORECAST DISCUSSION

NWS JACKSON KY

 546 PM EDT SUN JUL 21 2013

.UPDATE...
ISSUED AT 544 PM EDT SUN JUL 21 2013

A CONTINUED LINE OF SCT TRAINING STORMS EXTENDS ACROSS THE NORTHERN
HALF OF THE CWA ALONG SOME WEAK HORIZONTAL BOUNDARY. PREVIOUS
FORECAST HAD SHOWERS ENDING OVER THE NW...BUT SO LONG AS THIS
BOUNDARY REMAINS IN PLACE...EXPECT ISOLATED TO SCT SHOWERS AND
THUNDERSTORMS TO CONTINUE OVER THIS AREA FOR THE NEXT COUPLE HOURS.
ALSO ADDED IN SOME ISOLATED POPS FOR SOME AREAS OVERNIGHT...MAINLY
BEFORE MIDNIGHT...BASED ON LATEST HI RES MODEL RUNS AND CURRENT
FORECAST TRENDS. ADDED CURRENT OBSERVATIONS INTO ONGOING FORECAST AS
WELL.

&&

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 325 PM EDT SUN JUL 21 2013

MORNING SHOWERS AND THUNDERSTORMS HAVE SHIFTED OFF TO THE SOUTH...BUT
THANKS TO SOME HEATING ACROSS THE EAST...ADDITIONAL SHOWERS AND
THUNDERSTORMS HAVE DEVELOPED TO THE EAST OF JACKSON...TOWARDS
PRESTONSBURG AND INEZ. THIS ACTIVITY WILL SLOWLY PUSH EAST THROUGH
THE REST OF THE AFTERNOON AND EVENING BEFORE EXITING EASTERN
KENTUCKY. IN THE WAKE OF THIS ACTIVITY IT LOOKS LIKE A FAIRLY QUIET
MID TO LATE EVENING IS ANTICIPATED AS SUBSIDENCE AHEAD OF THE
APPROACHING TROUGH AXIS ACROSS THE CENTRAL PLAINS TAKES HOLD. HRRR IS
IN LINE WITH CONDITIONS QUIETING DOWN THIS EVENING. WITH THE SYNOPTIC
FORCING OVERSPREADING THE AREA LATE TONIGHT INTO TOMORROW
MORNING...WILL BRING A PERIOD OF HIGH POPS BACK INTO THE FORECAST.
GIVEN THE RAIN THIS AFTERNOON...AND POTENTIAL HEAVY RAIN WITH THE
SYNOPTIC FEATURE LATE TONIGHT...GOING TO CONTINUE ON WITH THE FLASH
FLOOD WATCH. IN FACT...THE NAM SPITS OUT MORE THAN AN INCH OF RAIN
ACROSS A GOOD CHUNK OF THE AREA LATE TONIGHT AND TOMORROW...SO THE
POTENTIAL FOR HEAVY RAIN CONTINUES. THIS IS ESPECIALLY TRUE WITH
PWATS SITTING UP AROUND 1.8-2.0 INCHES. GOOD SHOWER AND THUNDERSTORM
COVERAGE SHOULD CONTINUE TOMORROW AS THE MID LEVEL WAVE PUSHES EAST
ACROSS THE AREA. COVERAGE SHOULD DIMINISH TOMORROW EVENING INTO THE
NIGHTTIME HOURS...ALTHOUGH SHOWERS AND THUNDERSTORMS COULD CONTINUE
THROUGH TOMORROW NIGHT AS WELL. CERTAINLY AN ACTIVE PERIOD SETTING
UP.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 325 PM EDT SUN JUL 21 2013

THE MODELS ESSENTIALLY AGREE ON THE GENERAL EVOLUTION OF MID LEVEL
TROUGHING OVER THE OHIO VALLEY AND GREAT LAKES THROUGH THE EXTENDED.
HOWEVER...THERE REMAINS MUCH DISAGREEMENT WITH RESPECT TO TIMING AND
TRACKS OF THE VARIOUS SHORTWAVES THAT WILL MOVE THROUGH THE AREA
LATER THIS WEEK AND INTO NEXT WEEKEND. THE ECMWF TAKES A KEY ONE OF
THESE INTO THE OHIO VALLEY ON WEDNESDAY HELPING TO BOTTOM OUT THIS
FIRST ITERATION OF A TROUGH. ANOTHER FOLLOWS...THOUGH...RIGHT ON THE
HEELS OF THE FIRST...THAT NIGHT WHICH WILL SERVE TO SHIFT THE TROUGH
EAST OF KENTUCKY ALLOWING SOME BRIEF HEIGHT RISES INTO THE CWA TO
CLOSE OUT THE WORK WEEK. HEIGHTS WILL START TO FALL AGAIN ON
SATURDAY WHEN A RATHER STRONG WAVE WILL MOVE DUE EAST OUT OF THE
CENTRAL PLAINS AND TOWARD THE OHIO VALLEY. UNLIKE YESTERDAY...THIS
FEATURE HAS GAINED SOME SUPPORT FROM THE GFS...JUST NOT AS STRONG.
IN CONJUNCTION WITH THIS SATURDAY WAVE...ANOTHER SWEEPS DOWN FROM
SOUTH CENTRAL CANADA LATER THAT NIGHT INTO EARLY SUNDAY RESTORING A
DEEP TROUGH OVER THE REGION. GIVEN THE SIMILARITIES IN THE OVERALL
PATTERN...WILL FAVOR A CONSENSUS OF THE OPERATIONAL GFS AND ECMWF
SOLUTIONS AS A STARTING POINT FOR THE EXTENDED GRIDS.

SENSIBLE WEATHER WILL FEATURE A CONTINUATION OF THE SOUPY AND
UNSETTLED CONDITIONS FROM THE SHORT TERM INTO THE DAY TUESDAY. THIS
WILL MEAN A THREAT OF CONVECTION AND POSSIBLY EXCESSIVE RAIN FALL.
A FRONTAL BOUNDARY WILL START TO MOVE SOUTH THROUGH THE AREA LATER
THAT NIGHT AND ON WEDNESDAY AS LOW PRESSURE CONSOLIDATES OVER THE
MID ATLANTIC COASTAL STATES. HIGH PRESSURE AND SOMEWHAT DRIER AIR
WILL MOVE INTO KENTUCKY ON THURSDAY AND PROVIDE A WELCOMED CHANGE OF
AIR MASS AND BREAK FROM THE SHOWER AND THUNDERSTORM THREATS. THIS
HIGH WILL MOVE EAST ON FRIDAY AND FRIDAY NIGHT AS A NEW AREA OF LOW
PRESSURE TAKES SHAPE OVER THE CENTRAL PLAINS LOOKING TO SLIP INTO
KENTUCKY ON SATURDAY. THIS WILL BRING RENEWED CHANCES OF SHOWERS AND
THUNDERSTORMS TO EAST KENTUCKY FOR THE WEEKEND...ALONG WITH SOMEWHAT
COOLER TEMPS. THE SFC LOW ASSOCIATED WITH THIS LOOKS TO PASS THROUGH
ON SUNDAY WITH THE BEST PCPN EXITING LATER IN THE DAY...WHILE THE
COOLER AIR REMAINS TO START THE NEW WORK WEEK.

THE CR GRID LOAD CAME IN REASONABLE CONSIDERING THE DIFFERENCES IN
THE SPECIFICS FROM THE MODELS. DID NUDGE DOWN POPS A BIT FROM
THURSDAY INTO FRIDAY NIGHT...MORE TOWARD THE 00Z OPERATIONAL ECMWF.
ALSO...ADJUSTED OVERNIGHT LOWS A TAD FOR WEDNESDAY AND THURSDAY
NIGHTS TO HIGHLIGHT RIDGE AND VALLEY TEMPERATURE DIFFERENCES.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 135 PM EDT SUN JUL 21 2013

A FRONTAL BOUNDARY DRAPED ACROSS THE AREA WILL CONTINUE TO PRODUCE
OCCASIONAL SHOWERS AND THUNDERSTORMS THROUGH THE REST OF TODAY. WHILE
A BREAK MAY OCCUR THIS EVENING...A SHORT WAVE TROUGH WILL PUSH ACROSS
THE AREA LATE TONIGHT INTO MONDAY BRINGING MORE WIDESPREAD RAIN TO
THE AREA. AS FOR THE REST OF THE DAY...BASED ON CURRENT RADAR
TRENDS...WOULD NOT ANTICIPATE MANY RESTRICTIONS AT THE TAF SITES AS
KLOZ AND SME ARE STUCK IN LIGHT RAIN AT THE MOMENT. BETTER
VISIBILITY/CEILING RESTRICTIONS WILL ARRIVE WITH THE SHORTWAVE LATE
TONIGHT AND DROPPED VISIBILITIES TO BETWEEN 1 AND 3 MILES WITH SOME
LOWER CIGS. WE WILL PROBABLY SEE A PERIOD OF LOWER VISIBILITIES AND
CEILINGS BUT WILL LET FUTURE TAF FORECAST HANDLE PERIOD.


&&

.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.

&&

$$

UPDATE...JMW
SHORT TERM...KAS
LONG TERM...GREIF
AVIATION...KAS







AREA FORECAST DISCUSSION

NWS JACKSON KY

 325 PM EDT SUN JUL 21 2013

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 325 PM EDT SUN JUL 21 2013

MORNING SHOWERS AND THUNDERSTORMS HAVE SHIFTED OFF TO THE SOUTH...BUT
THANKS TO SOME HEATING ACROSS THE EAST...ADDITIONAL SHOWERS AND
THUNDERSTORMS HAVE DEVELOPED TO THE EAST OF JACKSON...TOWARDS
PRESTONSBURG AND INEZ. THIS ACTIVITY WILL SLOWLY PUSH EAST THROUGH
THE REST OF THE AFTERNOON AND EVENING BEFORE EXITING EASTERN
KENTUCKY. IN THE WAKE OF THIS ACTIVITY IT LOOKS LIKE A FAIRLY QUIET
MID TO LATE EVENING IS ANTICIPATED AS SUBSIDENCE AHEAD OF THE
APPROACHING TROUGH AXIS ACROSS THE CENTRAL PLAINS TAKES HOLD. HRRR IS
IN LINE WITH CONDITIONS QUIETING DOWN THIS EVENING. WITH THE SYNOPTIC
FORCING OVERSPREADING THE AREA LATE TONIGHT INTO TOMORROW
MORNING...WILL BRING A PERIOD OF HIGH POPS BACK INTO THE FORECAST.
GIVEN THE RAIN THIS AFTERNOON...AND POTENTIAL HEAVY RAIN WITH THE
SYNOPTIC FEATURE LATE TONIGHT...GOING TO CONTINUE ON WITH THE FLASH
FLOOD WATCH. IN FACT...THE NAM SPITS OUT MORE THAN AN INCH OF RAIN
ACROSS A GOOD CHUNK OF THE AREA LATE TONIGHT AND TOMORROW...SO THE
POTENTIAL FOR HEAVY RAIN CONTINUES. THIS IS ESPECIALLY TRUE WITH
PWATS SITTING UP AROUND 1.8-2.0 INCHES. GOOD SHOWER AND THUNDERSTORM
COVERAGE SHOULD CONTINUE TOMORROW AS THE MID LEVEL WAVE PUSHES EAST
ACROSS THE AREA. COVERAGE SHOULD DIMINISH TOMORROW EVENING INTO THE
NIGHTTIME HOURS...ALTHOUGH SHOWERS AND THUNDERSTORMS COULD CONTINUE
THROUGH TOMORROW NIGHT AS WELL. CERTAINLY AN ACTIVE PERIOD SETTING
UP.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 325 PM EDT SUN JUL 21 2013

THE MODELS ESSENTIALLY AGREE ON THE GENERAL EVOLUTION OF MID LEVEL
TROUGHING OVER THE OHIO VALLEY AND GREAT LAKES THROUGH THE EXTENDED.
HOWEVER...THERE REMAINS MUCH DISAGREEMENT WITH RESPECT TO TIMING AND
TRACKS OF THE VARIOUS SHORTWAVES THAT WILL MOVE THROUGH THE AREA
LATER THIS WEEK AND INTO NEXT WEEKEND. THE ECMWF TAKES A KEY ONE OF
THESE INTO THE OHIO VALLEY ON WEDNESDAY HELPING TO BOTTOM OUT THIS
FIRST ITERATION OF A TROUGH. ANOTHER FOLLOWS...THOUGH...RIGHT ON THE
HEELS OF THE FIRST...THAT NIGHT WHICH WILL SERVE TO SHIFT THE TROUGH
EAST OF KENTUCKY ALLOWING SOME BRIEF HEIGHT RISES INTO THE CWA TO
CLOSE OUT THE WORK WEEK. HEIGHTS WILL START TO FALL AGAIN ON
SATURDAY WHEN A RATHER STRONG WAVE WILL MOVE DUE EAST OUT OF THE
CENTRAL PLAINS AND TOWARD THE OHIO VALLEY. UNLIKE YESTERDAY...THIS
FEATURE HAS GAINED SOME SUPPORT FROM THE GFS...JUST NOT AS STRONG.
IN CONJUNCTION WITH THIS SATURDAY WAVE...ANOTHER SWEEPS DOWN FROM
SOUTH CENTRAL CANADA LATER THAT NIGHT INTO EARLY SUNDAY RESTORING A
DEEP TROUGH OVER THE REGION. GIVEN THE SIMILARITIES IN THE OVERALL
PATTERN...WILL FAVOR A CONSENSUS OF THE OPERATIONAL GFS AND ECMWF
SOLUTIONS AS A STARTING POINT FOR THE EXTENDED GRIDS.

SENSIBLE WEATHER WILL FEATURE A CONTINUATION OF THE SOUPY AND
UNSETTLED CONDITIONS FROM THE SHORT TERM INTO THE DAY TUESDAY. THIS
WILL MEAN A THREAT OF CONVECTION AND POSSIBLY EXCESSIVE RAIN FALL.
A FRONTAL BOUNDARY WILL START TO MOVE SOUTH THROUGH THE AREA LATER
THAT NIGHT AND ON WEDNESDAY AS LOW PRESSURE CONSOLIDATES OVER THE
MID ATLANTIC COASTAL STATES. HIGH PRESSURE AND SOMEWHAT DRIER AIR
WILL MOVE INTO KENTUCKY ON THURSDAY AND PROVIDE A WELCOMED CHANGE OF
AIR MASS AND BREAK FROM THE SHOWER AND THUNDERSTORM THREATS. THIS
HIGH WILL MOVE EAST ON FRIDAY AND FRIDAY NIGHT AS A NEW AREA OF LOW
PRESSURE TAKES SHAPE OVER THE CENTRAL PLAINS LOOKING TO SLIP INTO
KENTUCKY ON SATURDAY. THIS WILL BRING RENEWED CHANCES OF SHOWERS AND
THUNDERSTORMS TO EAST KENTUCKY FOR THE WEEKEND...ALONG WITH SOMEWHAT
COOLER TEMPS. THE SFC LOW ASSOCIATED WITH THIS LOOKS TO PASS THROUGH
ON SUNDAY WITH THE BEST PCPN EXITING LATER IN THE DAY...WHILE THE
COOLER AIR REMAINS TO START THE NEW WORK WEEK.

THE CR GRID LOAD CAME IN REASONABLE CONSIDERING THE DIFFERENCES IN
THE SPECIFICS FROM THE MODELS. DID NUDGE DOWN POPS A BIT FROM
THURSDAY INTO FRIDAY NIGHT...MORE TOWARD THE 00Z OPERATIONAL ECMWF.
ALSO...ADJUSTED OVERNIGHT LOWS A TAD FOR WEDNESDAY AND THURSDAY
NIGHTS TO HIGHLIGHT RIDGE AND VALLEY TEMPERATURE DIFFERENCES.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 135 PM EDT SUN JUL 21 2013

A FRONTAL BOUNDARY DRAPED ACROSS THE AREA WILL CONTINUE TO PRODUCE
OCCASIONAL SHOWERS AND THUNDERSTORMS THROUGH THE REST OF TODAY. WHILE
A BREAK MAY OCCUR THIS EVENING...A SHORT WAVE TROUGH WILL PUSH ACROSS
THE AREA LATE TONIGHT INTO MONDAY BRINGING MORE WIDESPREAD RAIN TO
THE AREA. AS FOR THE REST OF THE DAY...BASED ON CURRENT RADAR
TRENDS...WOULD NOT ANTICIPATE MANY RESTRICTIONS AT THE TAF SITES AS
KLOZ AND SME ARE STUCK IN LIGHT RAIN AT THE MOMENT. BETTER
VISIBILITY/CEILING RESTRICTIONS WILL ARRIVE WITH THE SHORTWAVE LATE
TONIGHT AND DROPPED VISIBILITIES TO BETWEEN 1 AND 3 MILES WITH SOME
LOWER CIGS. WE WILL PROBABLY SEE A PERIOD OF LOWER VISIBILITIES AND
CEILINGS BUT WILL LET FUTURE TAF FORECAST HANDLE PERIOD.


&&

.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.

&&

$$

SHORT TERM...KAS
LONG TERM...GREIF
AVIATION...KAS







AREA FORECAST DISCUSSION

NWS JACKSON KY

 142 AM EDT SUN JUL 21 2013

.UPDATE...
ISSUED AT 142 AM EDT SUN JUL 21 2013

MADE A FEW TWEAKS TO THE FORECAST FOR THE 24 HOUR PERIOD BEGINNING
WITH 12Z TODAY. TRIED TO CAPTURE THE EVOLUTION OF ONGOING SHOWER AND
STORM ACTIVITY THAT IS MOVING ACROSS CENTRAL KENTUCKY. THE MODELS
HAVE ALL PRODUCED VERY DIFFERENT SOLUTIONS REGRADING TIMING OF SHOWER
AND STORM ACTIVITY AND OVERALL AREAL COVERAGE. IN THE END...DECIDED
TO GO WITH A MODIFIED VERSION OF THE LATEST NAM12 AND SREF MODEL
RUNS. OVERALL IT WILL BE QUITE CHALLENGING TO DETERMINE WHEN AND
WHERE SHOWERS AND STORMS WILL FORM ACROSS THE AREA AND HOW THEY WILL
PROGRESS ONCE THEY HAVE FORMED. MADE TWEAKS TO THE SKY
COVER...QPF...AND WEATHER GRIDS FROM 12Z ONWARD. WILL TAKE A LOOK AT
THE OTHER FORECAST ELEMENTS ONCE THE TAF DISCUSSION HAS BEEN ISSUED.
OVERALL IT APPEARS THAT SCATTERED TO NUMEROUS SHOWERS AND STORMS WILL
MOVE ACROSS EASTERN KENTUCKY DURING THE DAY TIME HOURS...WITH LOCALLY
HEAVY RAINFALL AND GUSTY WINDS POSSIBLE WITH SOME OF THE STORMS. THE
CULPRIT FOR ALL THIS WEATHER WILL BE A COLD FRONT THAT IS EXPECTED TO
MOVE SLOWLY SOUTHWARD ACROSS THE AREA TODAY.

UPDATE ISSUED AT 1025 PM EDT SAT JUL 20 2013

MOST SHOWERS AND THUNDERSTORMS HAVE DIMINISHED TO OUR NORTH AND EAST.
HOWEVER...A LARGE LINE OF WEAK CONVECTION HAS DEVELOPED TO OUR WEST
AND CONTINUES TO SLOWLY MAKE ITS WAY EASTWARD. EXPECT SOME CONTINUED
WEAKENING BY THE TIME IT REACHES EASTERN KY...THOUGH LOW END
CHANCES/SCT COVERAGE IS STILL WARRANTED BASED ON LATEST MODEL RUNS.
UPDATED POPS TO REFLECT THIS LATEST RADAR TREND...WITH SCT CHANCES
MOVING IN ACROSS THE WESTERN CWA IN THE NEXT COUPLE OF HOURS...AND
THEN SPREADING ACROSS THE REMAINING CWA BY LATE TONIGHT.

UPDATE ISSUED AT 527 PM EDT SAT JUL 20 2013

BASED ON CURRENT RADAR TRENDS...DIDN/T FEEL CONFIDENT IN NO POPS
ACROSS THE AREA THIS AFTERNOON/EVENING. WENT AHEAD AND ADDED IN SOME
SLIGHT CHANCES ALONG THE NORTHERN AND SOUTHEASTERN SECTIONS OF THE
CWA THROUGH THIS AFTERNOON IN CASE SOME SHORT LIVED CONVECTION
DEVELOPS. THEN HAVE ISOLATED CHANCES TAPERING OFF ACROSS THE
SOUTHEAST THIS EVENING AS BEST INSTABILITY BECOMES FOCUSED OVER THE
NORTHERN CWA WITH AN IMPOSING COLD FRONT AND AREA OF CONVECTION
MOVING INTO THE REGION.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 325 PM EDT SAT JUL 20 2013

CONTINUING TO WATCH SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS
DROPPING SOUTHWARD ACROSS THE OHIO RIVER VALLEY. A GAP IN THE LINE
HAS OPENED UP JUST TO OUR NORTH. WHILE SHOWERS AND STORMS ARE STILL
POSSIBLE THIS EVENING INTO TONIGHT...EVERY HRRR RUN OVER THE PAST
SEVERAL HOURS CONTINUES TO BACK OFF ON OVERALL COVERAGE ACROSS
EASTERN KENTUCKY THIS EVENING...WITH EVERYTHING FADING AWAY AROUND
SUNSET. THUS...HAVE DECREASED POPS INTO THIS EVENING AND THE
OVERNIGHT HOURS. THIS TREND MAY HAVE TO BE CONTINUED ON THE EVENING
SHIFT IF THE TRENDS CONTINUE THE WAY THEY ARE HEADING.
REGARDLESS...THE PROSPECTS FOR WIDESPREAD SHOWERS AND THUNDERSTORMS
IS DRASTICALLY LESS NOW. WILL MAINTAIN LOW 20-30 POPS THROUGH THE
OVERNIGHT HOURS. WITH THE BOUNDARY WASHED OUT OVER THE AREA
TOMORROW...DAYTIME HEATING SHOULD ALLOW FOR QUICK REDEVELOPMENT AFTER
SUNRISE. COVERAGE SHOULD BE DECENT TOMORROW...SO OPTED TO STAY WITH
OUR 60-70 POPS. THERE IS SOME QUESTION AS TO HOW MUCH ACTIVITY WILL
THEN LINGER INTO TOMORROW NIGHT AS THE QUASI BOUNDARY MAY SHIFT BACK
TO THE NORTH. LACK OF OVERNIGHT INSTABILITY MAY KEEP THINGS FAIRLY
LOW KEY FOR MUCH OF THE NIGHT. THERE IS A SHORTWAVE TROUGH PUSHING
ACROSS THE AREA LATE IN THE NIGHT THAT COULD ACT TO FIRE OFF SOME
SHOWERS AND THUNDERSTORMS...SO WILL INCREASE POPS THROUGH THE NIGHT.
TEMPERATURES ON SUNDAY SHOULD BE SLIGHTLY LOWER WITH THE INCREASED
CLOUD COVER AND PRECIPITATION.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 325 PM EDT SAT JUL 20 2013

THE MODELS BASICALLY AGREE ON THE GENERAL MID LEVEL PATTERN THROUGH
THE BULK OF THE EXTENDED FORECAST. A TROUGH WILL DEVELOP THROUGH THE
OHIO VALLEY INITIALLY AS ENERGY FROM THE NORTHERN PLAINS POOLS OVER
THE REGION. THIS TROUGH EVOLVES GRADUALLY AS A COUPLE OF CYCLES
OF WAVES MOVE THROUGH THE OHIO VALLEY...EACH DEPICTED SLIGHTLY
DIFFERENT BY THE MODELS. THIS SEMI-STATIONARY TROUGH BOTTOMS OUT ON
THURSDAY PER A CONSENSUS OF SOLUTIONS. EACH MODEL HAS ENOUGH OF A
DIFFERENT HANDLING OF THE INDIVIDUAL WAVES THAT A BLENDED APPROACH
IS PREFERRED FOR EXTENDED FORECASTING PURPOSES. IT DOES LOOK LIKE
HEIGHTS WILL RISE A BIT ON FRIDAY AS THE CORE OF THE TROUGH SHIFTS
TEMPORARILY EAST BUT THE ECMWF IS MOST AGGRESSIVE IN TAKING ANOTHER
DECENT WAVE FROM THE PLAINS EAST INTO THE OHIO VALLEY FOR THE
WEEKEND LIKELY RESTORING THE TROUGH FOR THE OHIO VALLEY. THE GFS HAS
A VERSION OF THIS THAT ALSO LOWERS HEIGHTS OVER THE OHIO VALLEY ON
SATURDAY...BUT DOES SO BY RELYING ON WAVES FURTHER NORTH THAN THE
ECMWF...MAINLY MOVING THEM THROUGH THE GREAT LAKES. AGAIN HERE...
WILL FAVOR A CONSENSUS SOLUTION FOR WEATHER DETAILS.

SENSIBLE WEATHER WILL FEATURE A VERY UNSETTLED SITUATION TO START
THE EXTENDED AS MID LEVEL WAVES ACTIVATE SHOWERS AND THUNDERSTORMS
ALONG AND SOUTH OF A FRONTAL BOUNDARY RUNNING JUST NORTH OF THE OHIO
RIVER. THERE WILL BE PLENTY OF HIGH PW AIR IN PLACE TO SUPPORT THE
STORMS AND THUS A HEAVY RAIN POTENTIAL WILL EXIST THROUGH THE
DAY...MONDAY. THE NEXT SFC BOUNDARY WILL APPROACH THE AREA ON
TUESDAY CONTINUING OUR CHANCES OF SHOWERS AND THUNDERSTORMS. THIS
CONVECTION IS EXPECTED TO LINGER INTO THE NIGHT WHEN THE BOUNDARY
DROPS THROUGH THE CWA IN THE FORM OF A COLD FRONT. FOR THURSDAY AND
FRIDAY...ANY CONVECTION SHOULD BE AT A MINIMUM IN THE WAKE OF THE
SFC FRONT AND SLIGHTLY HIGHER HEIGHTS ALOFT. HOWEVER...THE NEXT SFC
SYSTEM LOOKS TO BRING A RENEWED CHANCE OF CONVECTION TO THE AREA ON
SATURDAY...SPURRED ON BY FALLING HEIGHTS AND MORE INBOUND MID-LEVEL
ENERGY.

THE CR GRID LOAD CAME IN PRETTY GOOD CONSIDERING THE SMALLER SCALE
DIFFERENCES AMONG THE MODELS WITH RESPECT TO WEATHER DETAILS THROUGH
THE EXTENDED. DID NUDGE DOWN POPS A BIT LATE IN THE FORECAST...MORE
TOWARD THE OPERATIONAL ECMWF. ALSO...ADJUSTED OVERNIGHT LOWS A TAD
FOR WEDNESDAY AND THURSDAY NIGHT TO BETTER EMPHASIZE RIDGE AND
VALLEY TEMPERATURE DIFFERENCES.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 142 AM EDT SUN JUL 21 2013

A WEAK COLD FRONT WILL PUSH SOUTHEAST AND STALL OVER NORTHERN
KENTUCKY THROUGH THE REMAINDER OF THE OVERNIGHT. SCATTERED SHOWERS
AND STORMS CONTINUE TO FIRE IN WESTERN AND CENTRAL TENNESSEE AND
CENTRAL KENTUCKY. THESE SHOWERS AND STORMS WILL GRADUALLY MAKE THERE
WAY INTO THE FORECAST AREA OVERNIGHT...AND SHOULD INCREASE IN
COVERAGE ONCE THE SUN COMES UP AND A COLD FRONT SITUATED TO OUR NORTH
BEGINS TO MOVE SOUTHWARD OUT OF THE OHIO VALLEY. SHOWERS AND STORMS
ARE EXPECTED TO PERSIST THROUGH THE AFTERNOON AND EVENING HOURS
TODAY...AS THE AFOREMENTIONED COLD FRONT EVOLVES INTO A WARM FRONT
AND BEGINS TO DRIFT NORTHWARD ACROSS THE AREA. IN GENERAL...VFR
CONDITIONS WILL PREVAIL AT THE TAF SITES FOR THE REST OF THE NIGHT.
CONDITIONS WILL BEGIN TO DETERIORATE A BIT AS SHOWERS AND STORMS
BECOME MORE NUMEROUS DURING THE DAY...WITH MVFR CONDITIONS POSSIBLE
AT TIMES.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...AR
SHORT TERM...KAS
LONG TERM...GREIF
AVIATION...AR







AREA FORECAST DISCUSSION...UPDATED

NWS PADUCAH KY

 1200 AM CDT SUN JUL 21 2013

.UPDATE...
ISSUED AT 1155 PM CDT SAT JUL 20 2013

UPDATED THE AVIATION SECTION FOR THE 06Z TAF ISSUANCE.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 200 PM CDT SAT JUL 20 2013

18Z MESOANALYSIS SHOWS A COLD FRONT EXTENDING WESTWARD ACROSS
CENTRAL INDIANA TO A WEAK SURFACE LOW OVER CENTRAL ILLINOIS. A
SURFACE TROUGH EXTENDS SOUTHWEST FROM THE LOW CENTER TO NEAR KFAM
AND THEN BETWEEN KUNO/KPOF. DEW POINTS POOLING INTO THE LOWER AND
MID 70S ALONG THE TROUGH AND COLD FRONT HAVE CONTRIBUTED TO VERY
UNSTABLE CAPES LOCALLY OVER 3000 J/KG. ISOLATED STORMS HAVE POPPED
UP ALONG THE SURFACE TROUGH OVER MISSOURI...WHILE LARGER CLUSTERS OF
STORMS ARE EAST OF THE SURFACE LOW CENTER IN INDIANA/EAST CENTRAL IL.

THROUGH THE EVENING HOURS...THE COLD FRONT IS FORECAST TO DRIFT
SOUTH TO THE INTERSTATE 64 CORRIDOR WHILE THE SURFACE TROUGH REMAINS
STATIONARY OVER THE MISSOURI OZARKS. THE LATEST HRRR MODEL
REFLECTIVITY INDICATES THAT CLUSTERS OF STORMS /POSSIBLE MCS/ WILL
PROPAGATE SOUTH ALONG THE WABASH VALLEY...REACHING THE PENNYRILE
REGION OF WESTERN KY THIS EVENING. THIS SCENARIO IS SUPPORTED BY THE
12Z HIGH RES NMM. OTHER ISOLATED STORMS MAY DEVELOP EASTWARD FROM
THE SURFACE TROUGH OVER MISSOURI. VERY LIMITED SHEAR MAGNITUDE WILL
LIMIT SEVERE POTENTIAL TO ISOLATED PULSE EVENTS...THOUGH AN
ORGANIZED COLD POOL COULD DEVELOP WITH THE WABASH VALLEY MCS.
ACTIVITY WILL WEAKEN SIGNIFICANTLY BY 06Z AS THE BOUNDARY LAYER
COOLS AND STABILIZES.

ON SUNDAY...THE SURFACE FRONT IS FORECAST TO SLOWLY LIFT BACK NORTH
AS A WARM FRONT. A MINOR 500 MB SHORTWAVE WILL MOVE EAST/SOUTHEAST
ACROSS THE MISSISSIPPI VALLEY. THIS SHORTWAVE WILL HELP REJUVENATE
CONVECTION ALONG AND SOUTH OF THE FRONT...ESPECIALLY DURING THE
WARMER AND MORE UNSTABLE AFTERNOON HOURS. HIGH TEMPS WILL STRUGGLE
TO REACH THE UPPER 80S DUE TO ABUNDANT CLOUDINESS AND CONVECTION.

ON SUNDAY NIGHT...A RATHER WELL DEVELOPED 500 MB SHORTWAVE FOR MID
SUMMER WILL APPROACH FROM THE CENTRAL PLAINS. THIS SHORTWAVE WILL
TAP A VERY MOIST AND UNSTABLE SOUTHWEST WIND FLOW. SHOWERS AND
STORMS ARE LIKELY OVERNIGHT INTO MONDAY MORNING...UNTIL THE PASSAGE
OF THE SHORTWAVE. ONCE AGAIN...SEASONABLY WEAK SHEAR PROFILES WILL
LIMIT THE POTENTIAL HAZARDS TO MAINLY HEAVY RAIN AND FREQUENT
LIGHTNING.

ON MONDAY AFTERNOON AND MONDAY NIGHT...PRECIP COVERAGE WILL
GRADUALLY DECREASE WITH THE PASSAGE OF THE SHORTWAVE. 850 MB WARM
ADVECTION WILL BE COUNTERED BY EXTENSIVE CLOUD COVER AND PRECIP...
SO DAYTIME HIGHS ON MONDAY WILL ONLY BE NEAR SEASONAL NORMS.
OVERNIGHT LOWS WILL BE NEAR SURFACE DEW POINTS IN THE LOWER 70S.

.LONG TERM /TUESDAY THROUGH SATURDAY/...
ISSUED AT 200 PM CDT SAT JUL 20 2013

THE MODELS ARE IN A LITTLE BETTER AGREEMENT WITH THE TIMING OF THE
MID WEEK FRONT. THIS FRONT WILL PROVIDE THE FOCUS FOR THUNDERSTORMS
TUESDAY THEN TAPERING OFF INTO WEDNESDAY. WEAK HIGH PRESSURE WILL
DRY US OUT FOR AT LEAST THURSDAY AND FRIDAY WITH AT LEAST A CHANCE
RETURNING FRIDAY NIGHT INTO SATURDAY AS YET ANOTHER COLD FRONT
ENTERS THE PICTURE AT THE SAME TIME A WARM FRONT TRIES TO LIFT OUT
OF THE PLAINS INTO THE REGION. THE LATEST RUNS WOULD HAVE THE COLD
FRONT WINNING OUT AND SUPPRESSING THE WARM FRONT TO THE SOUTHWEST.
HOWEVER...THE SIGNALS ARE VERY WEAK AND MAY FLIP FLOP WITH LATER
RUNS. THIS WOULD ALSO RESULT IN A SIGNIFICANT CHANGE FOR TEMPS THIS
WEEKEND. EITHER WAY ONE SYSTEM OR THE OTHER WILL PROVIDE A CHANCE
FOR THUNDERSTORMS.

AS FOR TEMPS FOLLOWED THE ONGOING TREND WITH THE WARMEST DAY TUESDAY
THEN COOLING AND A BIT DRIER LATE IN THE WEEK. TEMPS BEGIN TO SOAR
BACK TO AROUND 90 LATE IN THE WEEK AHEAD OF THE APPROACHING COLD
FRONT. IF THE WEEKEND COLD FRONT MAKES IT THROUGH THE AREA WE WILL
COOL BACK INTO THE 80S AGAIN HOWEVER SHOULD THE WARM FRONT OVERTAKE
THE REGION WILL HAVE TO ADJUST TEMPS UP FROM CURRENT FORECAST.

&&

.AVIATION...
ISSUED AT 1155 PM CDT SAT JUL 20 2013

POSSIBLE MVFR FOG BETWEEN 08-12Z...OTHERWISE VFR CONDITIONS
SHOULD PREVAIL THROUGH MOST OF THE PERIOD. VCSH/VCTS POSSIBLE AFT
13Z. POSSIBLE MVFR CIGS/VSBYS IN TSRA AFT 00Z. LIGHT AND VARIABLE
WINDS WILL BECOME SOUTHWEST AOB 10 KTS AFT 13Z.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&

$$

PUBLIC...DB
AVIATION...JP







AREA FORECAST DISCUSSION

NWS CARIBOU ME

 1041 PM EDT MON JUL 22 2013

.SYNOPSIS...
A WARM FRONT WILL APPROACH FROM THE SOUTH OVERNIGHT. THE FRONT WILL
LIFT ONTO THE COAST TUESDAY WHILE A WEAK WAVE OF LOW PRESSURE
MOVES ALONG THE FRONT. A COLD FRONT WILL APPROACH TUESDAY NIGHT
THEN CROSS THE REGION WEDNESDAY.

&&

.NEAR TERM /THROUGH TUESDAY/...
1027 PM UPDATE: PRECIP CHANCES WERE PUSHED BACK MORE FROM EARLIER
THINKING AS HIGH PRES RIDGE IS HOLDING STRONG KEEPING RAINFALL
WELL S OF THE STATE ATTM. REGIONAL RADAR LOOP SHOWED THE BULK OF
SHOWERS AND EMBEDDED TSTMS MOVING ACROSS ERN NYS INTO VT AND MA.
NOT EXPECTING ANY MEASURABLE RAFL TO ARRIVE INTO CENTRAL AND DOWNEAST
AREAS UNTIL EARLY MONDAY MORNING. THE LATEST RUC AND CANADIAN GEM
PICKED UP ON THIS WELL. GFS AS WELL AS THE NAM APPEAR TO BE HAVING
SOME CONVECTIVE FEEDBACK ISSUES AS RAINFALL NOT AS HEAVY AS THESE
MODELS INDICATED AT THEIR 12 & 18Z RUNS. DEWPOINTS CLIMBING WELL
INTO THE 50S W/LOW TO MID 60S BACK ACROSS S AND SW ME. THIS AREA
OF HIGHER DEWPOINTS IS EXPECTED TO PUSH NE OVERNIGHT. THIS WILL
HELP TO MOISTEN LLVLS.

DID NOT INCLUDE ANY MENTION OF TSTMS OVERNIGHT AS AIRMASS LOOKS TO
REMAIN STABLE ABOVE 925MB. AIRMASS LOOKS TO DESTABILIZE MORE ON
TUESDAY PER THE GFS AND NAM SOUNDINGS. PWATS FCST TO PUSH 2+
INCHES COULD LEAD TO HEAVY RAFL AS FLOW THROUGH THE COLUMN IS SSW
W/POTENTIAL TO TRAINING CELLS.

PREVIOUS DISCUSSION...
SHOWERS AND POSSIBLE TSTMS FOR TUESDAY INCLUDING NORTHERN MAINE
W/THE HEAVIEST AXIS OF QPF ACROSS EASTERN AND DOWNEAST AREAS.
TEMPERATURES WILL BE DEPENDENT ON CLOUD COVER AND RAIN. THEREFORE,
TUESDAY COULD A BE A COLL DAY W/DAYTIME HIGHS NOT MAKING IT OUT OF
THE UPPER 60S W/THE EXCEPTION OF FAR NORTHERN MAINE. TEMPERATURES
THERE COULD REACH INTO THE LOWER 70S BEFORE CLOUDS THICKEN UP.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
A DISTURBANCE WILL MOVE ALONG A FRONT ALONG THE DOWNEAST COAST
TUESDAY NIGHT...WITH A COLD FRONT APPROACHING NORTHWEST MAINE
LATE. AN AREA OF RAIN WILL MOVE ACROSS THE REGION WITH THE
DISTURBANCE TUESDAY NIGHT. THIS AREA OF RAIN WILL MOVE EAST
OVERNIGHT...WITH PRECIPITATION TAPERING TO SHOWERS LATE. SHOWER
CHANCES WILL THEN BEGIN TO INCREASE ACROSS NORTHWESTERN AREAS
LATER TUESDAY NIGHT IN ADVANCE OF THE APPROACHING COLD FRONT.
SHOWERS AND THUNDERSTORMS WILL CROSS THE REGION IN ADVANCE OF THE
COLD FRONT WEDNESDAY...THEN END IN THE WAKE OF THE COLD FRONT
THROUGH THE AFTERNOON. HIGH PRESSURE WILL BUILD EAST WEDNESDAY
NIGHT THEN CROSS THE REGION THURSDAY THROUGH THURSDAY NIGHT WITH
PARTLY CLOUDY/MOSTLY CLEAR SKIES. TEMPERATURES WILL BE AT NEAR
NORMAL...TO SLIGHTLY BELOW NORMAL...LEVELS WEDNESDAY THROUGH
THURSDAY.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE EXTENDED MODELS ARE IN GOOD AGREEMENT THROUGH THE PERIOD. A
WEAK HIGH PRESSURE RIDGE WILL BE BUILT OVER THE AREA AT THE START
OF THE PERIOD. THERE WILL BE A LOW PRESSURE SYSTEM ALONG THE
COAST OF VA...A SECOND LOW PRESSURE SYSTEM OVER LAKE SUPERIOR. FRI
EVNG THE LOW ALONG THE COAST OF VA WILL MOVE NORTH. THE GFS AND
ECMWF DIFFER ON THE SOLUTION. THE ECMWF BRINGS THE LOW NORTH ALONG
THE COAST CENTERED AROUND LONG ISLAND..WITH A WARM FRONT EXTENDING
NE INTO THE GULF OF MAINE. THE GFS MOVES THE LOW NORTH BUT KEEPS
IT WELL EAST OF THE COAST...AND MAINTAINS THE HIGH PRESSURE RIDGE
ACROSS THE AREA. THESE DIFFERENCE CONTINUE INTO SAT MRNG. THE
ECMWF MOVES THE LOW NORTH TO BAR HARBOR...EXTENDS THE WARM FRONT
EAST INTO NEW BRUNSWICK. THE GFS CONTINUES TO MAINTAIN THE HIGH
PRESSURE RIDGE. BOTH MODELS DEEPEN THE LOW OVER LAKE SUPERIOR AND
MOVE IT NORTH TO JAMES BAY. BOTH MODELS ALSO SHOW SEVERAL
SECONDARY LOWS ALONG A BOUNDARY EXTENDING THROUGH THE GREAT
LAKES...THROUGH THE CENTRAL US...TO TEXAS. BY SUN MRNG BOTH MODELS
MOVE THE RIDGE EAST OF THE AREA...AS THE FRONT PUSHES INTO VT/NH.
BY SUN EVNG THE GFS MOVES THE FRONT INTO WRN MAINE...THE ECMWF
INTO NH. MON MRNG THE GFS TO ERN ME...ECMWF WRN ME. MON EVNG THE
GFS MOVES THE FRONT THROUGH...THE ECMWF TO ERN ME. BY THE END OF
THE PERIOD THE GFS INDICATES THAT MAINE WILL BE INFLUENCED BY WRAP
AROUND PRECIP...THE ECMWF MAINTAINS THE LOW OVER MAINE.

LOADED MODEL BLEND FOR MAX/MIN TEMP...WND/SKY/POP. ADDED 15
PERCENT TO WINDS FOR GUSTS OVER LAND...20 PERCENT OVER COASTAL
WATERS.

&&

.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: VFR CONDITIONS THIS EVENING ARE EXPECTED TO LOWER TO
IFR DOWNEAST LATE TONIGHT AND IFR TO MVFR ACROSS THE NORTH TUESDAY
MORNING. IFR CONDITIONS IN LOW CLOUDS ARE EXPECTED ON TUESDAY.

SHORT TERM: MVFR/IFR...WITH OCCASIONAL LIFR...CONDITIONS ARE
EXPECTED ACROSS THE REGION TUESDAY NIGHT INTO WEDNESDAY.
CONDITIONS WILL BEGIN TO IMPROVE LATER WEDNESDAY IN THE WAKE OF
THE COLD FRONT. GENERALLY VFR CONDITIONS ARE EXPECTED ACROSS THE
REGION WEDNESDAY NIGHT THROUGH SATURDAY.

&&

.MARINE...
NEAR TERM: WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA THROUGH
TUESDAY. HUMID AIR LIFTING NORTH WITH THE WARM FRONT WILL LIKELY
RESULT IN SOME FOG OVER THE WATERS LATE TONIGHT INTO TUESDAY.

SHORT TERM: SMALL CRAFT ADVISORY LEVEL SEAS ARE POSSIBLE WEDNESDAY
INTO WEDNESDAY NIGHT. OTHERWISE...WINDS/SEAS ARE EXPECTED TO BE
BELOW SMALL CRAFT ADVISORY LEVELS TUESDAY NIGHT THROUGH THURSDAY
NIGHT. VISIBILITIES WILL BE REDUCED IN RAIN AND FOG TUESDAY NIGHT
AND WEDNESDAY...WITH A CHANCE OF THUNDERSTORMS WEDNESDAY AFTERNOON.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.

&&

$$
NEAR TERM...HEWITT








AREA FORECAST DISCUSSION...UPDATED

NWS GRAY ME

 757 PM EDT MON JUL 22 2013

.SYNOPSIS...
LOW PRESSURE WILL SLOWLY LIFT NORTHEAST OUT OF THE OHIO VALLEY
TONIGHT AND WILL MOVE INTO SOUTHERN NEW ENGLAND ON TUESDAY. LOW
PRESSURE WILL CONTINUE NORTHEAST INTO NEW BRUNSWICK TUESDAY NIGHT
AND WILL DRAG A TRAILING COLD FRONT THROUGH THE REGION ON
EARLY WEDNESDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST
WEDNESDAY NIGHT AND THURSDAY. HIGH PRESSURE WILL CREST OVER THE
REGION THURSDAY NIGHT AND FRIDAY. HIGH PRESSURE WILL SHIFT
OFFSHORE ON SATURDAY AS A COLD FRONT APPROACHES FROM THE WEST. THE
COLD FRONT WILL SLOWLY CROSS THE REGION ON SUNDAY AND SUNDAY
NIGHT.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
.UPDATE....
HAVE ADJUSTED POP GRIDS TO REFLECT DECREASE IN SHOWER ACTIVITY AS
THE LOSS OF DAYTIME HEATING CONTINUES. HRRR SHOWING SHOWER
ACTIVITY RETURNING MUCH LATER TONIGHT/TOMORROW MORNING AS WARM
FRONT LIFTS ACROSS THE AREA. POPS WERE TWEAKED SLIGHTLY WITH
LATEST RUN. QPF AMOUNTS WERE ALSO ADJUSTED FOR HIGHER TERRAIN AND
INCLUDED MODERATE RAIN IN THE WORDING.

&&

STRATUS DECK IS FINALLY BEGINNING TO SCT OUT WITH PEAK IN DAYTIME
HEATING. THIS IS ALSO LEADING TO WIDELY SCT SHRA DEVELOPING ACROSS
THE CENTRAL PART OF THE CWFA. THESE SHRA WILL LIKELY DEVELOP OVER
THE HIGHER TERRAIN...DUE TO LACK OF STRONG FORCING...AND TRACK EWD
FROM THERE AS THEY GROW IN HEIGHT. LOSS OF DIURNAL HEATING SHOULD
BRING A QUICK END TO REMAINING SHRA...AS SFC WARM FNT WILL REMAIN
TO OUR S.

CONTINUED WAA AND INCREASINGLY MOIST AIR MASS RETURNING NWD
TONIGHT WILL BRING ABOUT MORE STRATUS INTO TUE. MANY OF THE SAME
AREAS THAT WERE SOCKED IN LAST NIGHT WILL BECOME SO AGAIN
TONIGHT...WITH AREAS OF FOG PSBL. AS OHIO VALLEY S/WV LIFTS
NEWD...AN INCREASE IN FORCING FOR ASCENT WILL BRING SHRA INTO SWRN
ZONES LATE TONIGHT.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
RNFL EVENT LOOKS ON TRACK FOR MOST OF TUE...AS S/WV TROF AND WARM
FNT IN THE VICINITY COMBINE TO PROVIDE A SWATH OF 1 INCH PLUS QPF
AMOUNTS. THERE REMAIN TIMING DIFFERENCES AMONG AVAILABLE MODEL
GUIDANCE...BUT CONSENSUS IS GROWING ON HEAVIEST QPF AXIS. DEEP
SELY FLOW WILL HIGHLIGHT FAVORED SELY UPSLOPE AREAS FOR POTENTIAL
HEAVY QPF...ROUGHLY A KLEB TO KIZG TO KWVL LINE. HERE AMOUNTS OF 1
TO 1.5 INCHES ARE PSBL...WHERE SREF GUIDANCE HINTS THAT ISOLD 2
INCH AMOUNTS AREN/T OUT OF THE QUESTION. ADDED SOME HEAVY RNFL
WORDING TO WHITE MTNS...BUT OPTED TO LEAVE THAT OUT OF MOST OF WRN
ME ATTM. PWATS CLIMB AGAIN TO 2 OR 3 SD ABOVE NORMAL...SO HEAVY
RNFL AND PSBL FLASH FLOODING ARE A CONCERN GIVEN ELEVATED
INSTABILITY AND BOUNDARY TO PROVIDE PCPN FOCUS.

THE 12Z/22 GFS STILL LOOK A LITTLE QUICK ON TIMING BASED OFF
LATEST SATELLITE TRENDS...BUT THE 22/00Z ECMWF APPEARED A LITTLE
CLOSER TO REALITY. TRACKING THE APPROACHING S/WV AND FRONTAL
BOUNDARY ON IR SATELLITE PLACES LIKELY SHRA INTO THE SRN NH ZONES
BETWEEN 06 AND 09Z. USED A 2/3 ECMWF AND 1/3 GFS BLEND TO TIME
PCPN INTO THE AREA.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
A COLD FRONT WILL CROSS THE REGION EARLY WEDNESDAY...TRIGGERING
SCATTERED SHOWERS AND THUNDERSTORMS AS IT PROGRESSES FROM WEST TO
EAST. THE OPERATIONAL GFS IS THE MOST PROGRESSIVE WITH THE TIMING
IN THE FRONTAL PASSAGE OFF THE NEW ENGLAND COASTLINE.

THEREAFTER...HIGH PRESSURE BEGINS TO BUILD OVER NEW ENGLAND FROM
THE GREAT LAKES REGION...BRINGING COOLER AND MUCH DRIER AIR FOR
MAINE AND NEW HAMPSHIRE THURSDAY.

ON FRIDAY...MODELS DIVERGE SOMEWHAT AS TO THE LOCATION OF A WAVE
OF LOW PRESSURE OFF THE EASTERN SEABOARD. THE GFS APPEARS TO BE A
GOOD COMPROMISE WITH THE EURO AND GGEM...KEEPING A WEAK SYSTEM
WELL OFFSHORE. THIS STILL MAY BE IN CLOSE ENOUGH PROXIMITY TO
BRING THE POSSIBILITY OF A SHOWER TO SOUTHERN LOCATIONS AS A WEAK
UPPER LEVEL TROUGH CROSSES THE AREA.

A LARGE SCALE UPPER LEVEL TROUGH APPROACHES FROM THE WEST OVER THE
WEEKEND. THIS MAY BRING A COOLING TREND TO THE REGION AFTER THIS
WEEKS HEAT...WITH AN INCREASE IN DIURNALLY DRIVEN SHOWERS.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...WIDESPREAD MVFR CONDS INTO THIS EVENING...WITH LOCAL
IFR CONDS PSBL IN SCT SHRA. AS WARM FNT LIFTS INTO THE
AREA...EXPECT CONDS TO DETERIORATE BACK TO IFR OR LOWER TONIGHT
AND LINGER INTO TUE.

LONG TERM...
MVFR AND IFR CONDITIONS EARLY WEDNESDAY FOLLOWED BY LIFTING
CEILINGS AND VISIBILITIES. CONDITIONS WILL REMAIN MAINLY VFR UNTIL
SUNDAY.

&&

.MARINE...
SHORT TERM...WINDS AND SEAS EXPECTED TO REMAIN BLO SCA THRESHOLDS.
DEVELOPING FOG WILL LIMIT VSBYS STARTING TONIGHT INTO TUE.

LONG TERM...
WINDS/SEAS MAINLY BELOW SCA CRITERIA.

&&

.TIDES/COASTAL FLOODING...
ABNORMALLY HIGH ASTRONOMICAL TIDES COMBINED WITH A LIGHT EASTERLY
FLOW WILL RESULT IN MINOR COASTAL FLOODING OVERNIGHT ACROSS
PORTIONS OF THE SOUTHWEST COAST OF MAINE AND THE NEW HAMPSHIRE
SEACOAST TONIGHT. HIGH TIDE IN PORTLAND HARBOR IS 1128 PM. THE
TIDE WILL LIKELY REACH ITS 12 FOOT FLOOD STAGE LATE THIS EVENING.

MINOR FLOODING MAY OCCUR ALONG PORTIONS OF THE WHARFS IN PORTLAND
AS WELL AS IMMEDIATE SHORELINE ROADS IN BIDDEFORD AND HAMPTON.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...COASTAL FLOOD ADVISORY FROM 11 PM THIS EVENING TO 2 AM EDT
     TUESDAY FOR MEZ023-024.
NH...COASTAL FLOOD ADVISORY FROM 11 PM THIS EVENING TO 2 AM EDT
     TUESDAY FOR NHZ014.
MARINE...NONE.

&&

$$

UPDATE...HANES







AREA FORECAST DISCUSSION

NWS CARIBOU ME

 108 AM EDT SUN JUL 21 2013

.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE REGION OVERNIGHT. A DRIER AND
COOLER CANADIAN AIR MASS WILL THEN BUILD INTO THE AREA ON SUNDAY
AND HOLD OVER THE REGION THROUGH MONDAY. THE NEXT LOW PRESSURE
FROM THE GREAT LAKES WILL APPROACH THE REGION LATE MONDAY NIGHT
INTO TUESDAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
105 AM UPDATE...NO SIGNIFICANT CHANGES WERE NEEDED FOR THIS
UPDATE. DRIER AIR CONTINUES TO SPILL INTO THE FORECAST AREA, WITH
DEWPOINTS DROPPING INTO THE 40S AND 50S. AS SUCH, TONIGHT WILL BE
A MUCH COOLER AND MORE COMFORTABLE NIGHT. SKIES HAVE BECOME CLEAR
OVER ALL BUT THE FAR DOWNEASTERN AREAS, AND THESE CLOUDS SHOULD
PUSH OFFSHORE BY DAWN. THE GOING FORECAST HAS THIS ALL COVERED, SO
ONLY MADE SLIGHT ADJUSTMENTS TO MIN TEMPS TO MATCH CURRENT OBS.

PREVIOUS DISCUSSION...
A COLD FRONT WILL MOVE THROUGH THE REGION
OVERNIGHT FOLLOWED BY CANADIAN HIGH PRES FOR SUNDAY. THIS HIGH
WILL REMAIN IN CONTROL THROUGH EARLY NEXT WEEK.

SOME CONVECTION HAS FIRED UP MAINLY ACROSS NORTHERN AND WESTERN
AREAS(SUB-SEVERE) AS SOME UPPER LEVEL DIVERGENCE SEEN ON THE SATL
WV IMAGERY AND 12Z UA. THE BEST SHOT FOR ANY STRONGER STORMS WILL
BE ACROSS THE DOWNEAST AND COAST INTO THE EVENING AND THEN
ACTIVITY WILL WEAKEN. THE BEST FORCING AND INSTABILITY WILL SHIFT
TO THE EAST. ADDED SOME FOG TO THE GRIDS FOR TONIGHT INTO EARLY
SUNDAY MORNING BASED ON ANTICIPATED CLEARING AND COOLER TEMPERATURES
W/A WET GROUND. ADJUSTED THE OVERNIGHT LOW USING A BLEND OF THE NAM12
AND ECMWF. POPS ARE A BLEND OF THE RUC AND DOWNSCALED NAM WHICH
SHOW PRECIP CHANCES WINDING DOWN AFTER 00Z.

SUNDAY LOOKS TO BE SUNNY AND PLEASANT W/HIGH PRES BUILDING IN FROM
CANADA. THINKING ATTM IS TO TAKE W/CONSISTENCY AND KEEP THE
MIDNIGHT CREW`S MAXES OF LOWER 70S NORTHERN CWA AND MID TO UPPER
70S CENTRAL AND DOWNEAST.

&&

.SHORT TERM /TONIGHT THROUGH 6 PM MONDAY/...
HIGH PRESSURE WILL SETTLE OVER THE AREA SUNDAY NIGHT. WITH LIGHT
WINDS...CLEAR SKIES AND RELATIVELY DRY AIR THE NIGHT WILL BE COOL
WITH LOWS DROPPING INTO THE 40S NORTH TO NEAR 50 DOWNEAST. THIS
WILL BE FOLLOWED BY A MOSTLY SUNNY AND SEASONABLE DAY ON MONDAY.
CLOUDS WILL BEGIN TO INCREASE FROM THE SOUTHWEST LATE IN THE DAY
AS MOISTURE LIFTS NORTH FROM LOW PRESSURE TRACKING INTO SOUTHERN
NEW ENGLAND. CLOUDS WILL CONTINUE TO INCREASE MONDAY NIGHT AND
SOME RAIN MAY SPREAD INTO THE AREA LATE. THE BEST CHANCE FOR RAIN
WILL BE ALONG THE FRONTAL BOUNDARY WHICH WILL BE NEAR THE COAST.
THE LOW WILL TRACK JUST OFFSHORE ON TUESDAY BRINGING A CHANCE OF
RAIN TO THE AREA. THE BEST CHANCE FOR RAIN WILL BE ALONG COASTAL
AREAS. A COLD FRONT WILL APPROACH THE WEST LATE IN THE DAY. WARM
AND HUMID AIR MOVING NORTH AHEAD OF THE FRONT BENEATH RELATIVELY
COOLER AIR ALOFT MAY PRODUCE SOME THUNDERSTORMS IN WESTERN AREAS
LATE IN THE DAY.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
A WEAK LOW WILL BE TRACKING OFF THE COAST TUESDAY NIGHT AS A COLD
FRONT APPROACHES FROM THE WEST. THE LOW MAY BRING SOME RAIN TO
COASTAL AREAS EARLY TUESDAY NIGHT WHILE THE APPROACHING FRONT
BRINGS SOME SHOWERS AND POSSIBLY THUNDERSTORMS TO FAR WESTERN
AREAS. THE FRONT IS EXPECTED TO CROSS THE AREA EARLY WEDNESDAY
BRINGING SOME SHOWERS AND ISOLATED THUNDERSTORMS MAINLY TO THE
DOWNEAST REGION. HIGH PRESSURE SHOULD THEN BRING DRIER AIR WITH
CLEARING LATER WEDNESDAY INTO THURSDAY. ANOTHER FRONT MAY APPROACH
LATER FRIDAY INTO SATURDAY WITH INCREASED HUMIDITY FRIDAY INTO
SATURDAY.

&&

.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: VFR THROUGH SUNDAY.

SHORT TERM: VFR CONDITIONS ARE EXPECTED SUNDAY NIGHT INTO MONDAY
WITH HIGH PRESSURE AND MOSTLY CLEAR SKIES. CONDITIONS WILL LIKELY
BEGIN VFR MONDAY NIGHT BUT MAY LOWER TO MVFR OR IFR LATE AS LOW
CLOUDS AND SHOWERS MOVE IN. MVFR CONDITIONS ARE EXPECTED TUESDAY
NIGHT INTO EARLY WEDNESDAY. HIGH PRESSURE MAY THEN BRING AN
IMPROVEMENT TO VFR WEDNESDAY INTO EARLY FRIDAY. LOWERING CLOUDS
AND SHOWERS MAY LOWER CONDITIONS TO MVFR FRIDAY NIGHT INTO
SATURDAY AS THE NEXT FRONT MOVES IN.

&&

.MARINE...
NEAR TERM: SEAS RUNNING AROUND 4 FT AT THE EASTERN MAINE SHELF
THIS EVENING. WINDS ARE EXPECTED TO BECOME GUSTY W/THE COLD FRONT
TONIGHT W/SPEEDS OF 25 KT BRIEFLY. THE WINDS WILL SUBSIDE ON
SUNDAY DOWN TO 10 KT AS HIGH PRES PUSHES E.

SHORT TERM: WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA THIS
WEEKEND INTO EARLY NEXT WEEK. HIGH PRESSURE SHOULD BRING CLEAR AND
PLEASANT CONDITIONS SUNDAY INTO MONDAY. LOWER CLOUDS...FOG AND
SOME RAIN MAY MOVE OVER THE WATERS ON TUESDAY.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.

&&

$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...BLOOMER
LONG TERM...BLOOMER
AVIATION...HASTINGS/HEWITT/BLOOMER
MARINE...HASTINGS/HEWITT/BLOOMER









AREA FORECAST DISCUSSION

NWS WAKEFIELD VA

 401 PM EDT SUN JUL 21 2013

.SYNOPSIS...
HIGH PRESSURE REMAINS ANCHORED OFF THE SOUTHEAST COAST DURING THE
EARLY PORTION OF THIS WEEK...AS A COLD FRONT BECOMES NEARLY
STATIONARY FROM THE OHIO VALLEY TO THE NORTHERN MID ATLANTIC STATES.
MEANWHILE...AN UPPER LEVEL TROUGH OF LOW PRESSURE WILL PERSIST
ACROSS THE REGION.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
CURRENT SATELLITE IMAGERY AND REGIONAL RADAR MOSAIC INDICATE AN
ORGANIZED LINE OF THUNDERSTORMS EXTENDING FROM NORTHERN VA SW ALONG
THE PIEDMONT AND MOVING EAST. THIS LINE OF STORMS IS BEGIN DRIVEN BY
THE TAIL END OF A SHORTWAVE TROUGH MOVING ACROSS THE NORTHERN MID
ATLANTIC...INTERACTING WITH A SURFACE TROUGH OVER THE AREA...AND
FEEDING OFF AN AXIS OF >2500 J/KG OF MLCAPE PER SPC HRRR BASED
MESOANALYSIS. ADDITIONAL SEA/BAY BREEZE CONVECTION IS DEVELOPING
ACROSS THE LOWER BAY AND MD ATLANTIC COAST.

THE PRIMARY LINE SHOULD PROGRESS EAST ACROSS CENTRAL/S-CENTRAL VA
THROUGH THE LATE AFTERNOON AND EARLY EVENING. INITIALLY...0-6KM BULK
SHEAR VALUES ARE PROGGED TO BE ~25KT BEFORE DECAYING BY EARLY
EVENING. THEREFORE...THE BEST CHANCE OF AN ISOLATED SEVERE STORM
(MAINLY WIND GUST) WOULD BE ACROSS THE NORTHERN PORTION OF THE AREA
THROUGH THE REMAINDER OF THE AFTERNOON. THE SOUTHERN END OF THE LINE
SHOULD EVENTUALLY DISSIPATE THIS EVENING DUE TO THE LOSS OF SURFACE
HEATING AND A LACK OF LARGE SCALE FORCING AS THE SHORTWAVE ENERGY
PULLS TOWARD NEW ENGLAND. FARTHER NE IN THE LOCAL AREA...SCT POPS
WILL BE MAINTAINED THROUGH THE EVENING/EARLY OVERNIGHT IN CLOSER
PROXIMITY TO THE SHORTWAVE. WARM AND HUMID CONDITIONS WILL PERSIST
OVERNIGHT WITH LOWS IN THE LOW/MID 70S.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
THE OVERALL PATTERN REMAINS UNSETTLED MONDAY AS A SURFACE
BOUNDARY/WEAK LOW STALL OVER THE AREA. ADDITIONALLY...A VIGOROUS
TROUGH CARVES OVER THE GREAT LAKES. A LEADING SHORTWAVE EJECTS OUT
OF THE TROUGH ACROSS THE OHIO VALLEY TOWARD THE APPALACHIANS MONDAY
AFTERNOON/EVENING. HENCE...HIGH CHANCE/LOW-END LIKELY POPS ARE
FORECAST MONDAY AFTN/EVENING. AFTERNOON HIGHS WILL TREND DOWN
SLIGHTLY DUE TO INCREASED CLOUD COVER AND A HIGHER PROBABILITY OF
SHOWERS/TSTMS (AND SHIFTING WIND DIRECTION MAINLY N)...ALTHOUGH
DEWPOINTS WILL REMAIN IN THE LOW/MID 70S. HIGHS SHOULD RANGE FROM
THE MID/UPPER 80S TO AROUND 90 MONDAY. ANY SEVERE THREAT LOOKS
RATHER LIMITED MONDAY...WITH THE MAIN CONCERN AGAIN BEING HEAVY RAIN
FROM SLOW MOVING STORMS.

THE PARENT TROUGH PIVOTS N OF THE GREAT LAKES TUESDAY AS A SECONDARY
WAVE LIFTS ACROSS THE MID ATLANTIC. THE LATEST DATA BRINGS THE WAVE
THROUGH EARLIER IN THE DAY...FOLLOWED BY WESTERLY MID-LEVEL FLOW BY
LATER AFTERNOON. GIVEN THIS...POPS HAVE BEEN LOWERED...ESPECIALLY W.
HOWEVER..A WELL-DEFINED LEE SIDE TROUGH REMAINS OVER THE AREA...SO
WILL MAINTAIN 30 POPS W...TO 40 E. HIGHS SHOULD AVERAGE IN THE UPPER
80S TO LOW 90S.

THE 21/12Z GFS/NAM BRING YET ANOTHER SHORTWAVE TROUGH THROUGH THE
REGION WEDNESDAY. THE MAIN MOISTURE FEED MAY BE WELL OFF THE COAST
BY THIS TIME...SO WILL GO NO HIGHER THAN CHANCE POPS AT THIS TIME.
HIGHS SHOULD AGAIN RANGE FROM THE UPPER 80S TO LOW 90S. LOWS THROUGH
THE PERIOD SHOULD RANGE FROM 70-75.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
UPR TROF OVR THE ERN THIRD OF THE U.S. WED NGT THRU THU...WILL SHIFT
EWRD AND OFFSHR THU NGT THRU FRI. THIS WILL PUSH FRNTL BNDRY ALNG OR
JUST OFFSHR AT THE BEGINNING OF THE PERIOD...FARTHER OUT TO SEA.
WEAK HI PRES WILL BLD INTO AND OVR THE AREA FOR FRI NGT INTO SAT.
THEN...ANOTHER SHRTWV TROF AND ASSOCIATED COLD FRONT WILL APPROACH
AND MOVE INTO THE REGION LATE SAT NGT THRU SUN. AT THIS TIME...WILL
NOT BE GOING ANY HIGHER THAN 20% OR 30% THRU THE PERIOD...DUE TO LOW
CONFIDENCE OF COVERAGE. MIN TEMPS WILL BE IN THE UPR 60S TO MID 70S
THU MORNG...AND MAINLY IN THE MID 60S TO LWR 70S FRI...SAT AND SUN
MORNGS. MAX TEMPS WILL GENERALLY BE IN THE MID TO UPR 80S THRU THE
PERIOD.

&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
AFTER SEVERAL HOURS OF OCNL MVFR CIGS AT EACH OF THE TAF SITES...VFR
IS EXPECTED TO PREVAIL DURING THE AFTN. THE FOCUS WILL TURN TO
SCATTERED CONVECTION ACROSS MUCH OF THE AREA. THIS IS MOST LIKELY TO
OCCUR AT RIC AND SBY WHERE TEMPO GROUPS FOR TSTMS ARE IN PLACE
TOWARD EARLY EVENING. CONFIDENCE IN THE TIMING FOR THE OTHER THREE
SITES IS NOT HIGH ENOUGH TO INCLUDE TSTMS AT THIS TIME. SOME MVFR IS
EXPECTED TO DEVELOP AGAIN MONDAY MORNING SIMILAR TO THE LAST SEVERAL
MORNINGS.

LOW PRESSURE ASSOCIATED WITH AN APPROACHING COLD FRONT HAS WEAKENED
RESULTING IN DIMINISHING WINDS OVER THE AREA. WINDS WILL BE LIGHT
AND VARIABLE DURING MUCH OF THE TAF PERIOD.

OUTLOOK...SCATTERED MAINLY AFTN AND EARLY EVENING TSTMS CAN BE
EXPECTED MON THROUGH FRI WITH THE HIGHEST CHANCES MON AND WED.
AVIATION CONDS MAY LWR BRIEFLY IN HEAVIER PCPN. PATCHY IFR FOG NEAR
SUNRISE CANNOT BE RULED BUT NO WIDESPREAD IFR IS INDICATED THROUGH
MID WEEK.

&&

.MARINE...
SUB-SCA CONDS WILL PREVAIL OVER THE NEXT SEVERAL DAYS OVER AREA
WATERS. SWELLS WILL IMPACT THE COASTAL WATERS DUE TO STRONGER WINDS
ASSOCIATED WITH THE BERMUDA HIGH WELL OFF THE COAST. ADDED SOME
HEIGHT TO THE SEAS DUE TO THE SWELL...ESPECIALLY MONDAY NIGHT AND
EARLY TUESDAY...BUT KEPT THEM BELOW 5 FT FOR OUR COASTAL ZONES.
EXPECT LOCALLY STRONGER WNDS IN SHOWERS AND TSTMS THRU THE PERIOD.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...AJZ/LKB
NEAR TERM...AJZ
SHORT TERM...AJZ/LKB
LONG TERM...TMG
AVIATION...LSA
MARINE...LSA





SHORT TERM FORECAST DISCUSSION FOR DETAILS ON CONVECTIVE INITIATION

AND SUPPORTING SEVERE WX PARAMETERS/INDICES ON MONDAY AFTERNOON. A

 LOT OF WHAT HAPPENS MONDAY EVENING WILL BE DEPENDENT ON CONVECTIVE
EVOLUTION MONDAY AFTERNOON. THE BEST INSTABILITY APPEARS TO BE ALONG
A THETA-E AXIS JUST AHEAD OF THE SFC COLD FRONT OVER THE WESTERN
SHORE OF UPPER MI AT THE START OF THE PERIOD...SO DO NOT EXPECT
CONVECTION TO CLEAR OUT UNTIL THE FRONTAL PASSAGE. THE MAIN QUESTION
IS IF THE ENVIRONMENT ON MONDAY AFTERNOON REMAINS CAPPED ENOUGH TO
MAKE THE FIRST SUBTLE MID-LEVEL WAVE INERT AS IT PASSES OVERHEAD
EARLY MONDAY AFTERNOON. IF THIS IS THE CASE...EARLY MONDAY EVENING
COULD BE QUITE ACTIVE ALONG THE FRONT...ESPECIALLY NEAR THE WI
BORDER ONCE FRONTAL FORCING INITIATES MORE WIDESPREAD CONVECTION.
THE LACK OF MINIMAL AFTERNOON CONVECTION COULD ALLOW MLCAPE VALUES
TO REACH 1000 TO 1500 J/KG ACROSS THE WEST. WHILE THE BEST SHEAR
WILL HAVE DIMINISHED SOMEWHAT BY THIS POINT AS THE SFC FLOW VEERS TO
THE SW...40KTS OF 0-6KM SHEAR WILL BE MORE THAN ENOUGH TO SUPPORT
SUPERCELLS ALONG THE COLD FRONT. ALSO...WITH THE SHORTWAVE TROUGH
MOVING ESE...MID-LEVEL WESTERLY WINDS WILL CREATE ABOUT 60 DEGREES
OF SEPARATION BETWEEN THE SFC FRONT AND SHEAR VECTORS. SO...WOULD
NOT BE SURPRISED TO SEE A WINDOW OF DISCRETE SUPERCELLS ALONG THE WI
BORDER IN THE EARLY EVENING. AS FOR THE MAIN SEVERE THREAT...THINGS
GET A LITTLE TRICKY GIVEN VEERING SFC FLOW AND FREEZING LEVELS AOA
14KFT. WITH DOWNDRAFT CAPE APPROACHING 1000 J/KG ALONG THE BORDER
AMIDST DECENT MID-LEVEL DRY AIR...THINKING IS THAT STRONG WINDS WILL
BE THE MAIN THREAT. SMALL MICROBURSTS FROM RFD/S ON ANY SUPERCELLS
THAT FORM...AND SMALL BOWING SEGMENTS WILL BE OF MOST CONCERN.
OVERALL...STILL THINK SEVERE CONVECTION THREAT IS MARGINAL AND QUITE
CONDITIONAL...BUT PARAMETERS ARE LINING UP WELL ENOUGH TO AT LEAST
DISCUSS THE POTENTIAL.

THE 12Z NAM FORECAST HAS COMPLETE FRONTAL PASSAGE THROUGH THE CWA
AND COASTAL WATERS OF LAKE MI BY 09Z TUESDAY. THOUGH...A BIT OF
ELEVATED INSTABILITY COMBINED WITH A SECONDARY MID-LEVEL TROUGH
CROSSING THE CWA BEHIND THE FRONT SUGGEST KEEPING AT LEAST
SLIGHT CHANCE POPS ACROSS THE WEST AND CENTRAL UNTIL SUNRISE
TUESDAY. ANY OF THIS PRECIP WILL BE ENTIRELY SHORTWAVE-DRIVEN.

TUESDAY THROUGH WEDNESDAY...WEAK MID-LEVEL RIDGING ON NORTHWEST FLOW
WILL BRING QUIET AND DRY CONDITIONS BY MID-WEEK. TUESDAY AND
TUESDAY NIGHT LOOK TO BE A CARBON COPY OF YESTERDAY AND LAST NIGHT.
HAVE LOWERED TEMPS IN BOTH PERIODS GIVEN LIGHT WINDS AND DRY AIR.
PWAT VALUES UNDER 0.5 INCHES TUESDAY NIGHT WILL ALLOW FOR GOOD
RADIATIONAL COOLING. THE MODELS THAT HANDLED LAST NIGHTS COOL TEMPS
THE BEST ARE SHOWING LOW 40S ACROSS THE INTERIOR WEST.
THEREFORE...DROPPED TEMPS SEVERAL DEGREES. BRISK NNW FLOW BEHIND THE
COLD FRONT WILL ALSO BRING AN ELEVATED SWIM RISK EAST OF MARQUETTE
THROUGHOUT THE DAY. BY WEDNESDAY...A WEAK SHORTWAVE TROUGH WILL
BEGIN TRACKING SOUTHEAST ACROSS NORTH MANITOBA ON THE BACKSIDE OF
THE DEEP EASTERN CANADIAN TROUGH. THE GEM AND GFS ARE DEPICTING A
CONVECTIVELY-INDUCED SHORTWAVE DIGGING SOUTHEAST INTO WI WEDNESDAY
AFTERNOON...BUT FALLING APART AS IT RUNS INTO THE RIDGE. THIS
FOLLOWS THE TRACK OF WEAKLY COUPLED UPPER JETS OVER THE UPPER TO MID
MS VALLEY. KEPT ANY MENTION OF PRECIP OUT OF THE DAY ON
WEDNESDAY...BUT THE TREND OF THIS FORECAST WILL NEED TO BE MONITORED
OVER THE NEXT COUPLE DAYS.

THURSDAY AND FRIDAY...A FEW DIURNAL SHOWERS AND STORMS ARE POSSIBLE
THURSDAY AFTERNOON ACROSS THE INTERIOR WEST WITH RETURN SFC MOISTURE
ON THE BACKSIDE OF THE SFC HIGH. THE REST OF THE LAYER WILL REMAIN
SOMEWHAT DRY...SO WILL KEEP THE CHANCE POPS FOR NOW. USED CONSENSUS
POPS FOR FRIDAY AS THE MODELS BECOME DIFFERENT ON HOW THEY HANDLE
THE INCOMING TROUGH FROM MANITOBA. THE GFS HAS THE TROUGH BECOMING
QUITE AMPLIFIED AND BRINGS A SFC COLD FRONT THROUGH THE CWA THURSDAY
NIGHT. MEANWHILE...THE ECMWF IS FAR LESS-AMPLIFIED WITH THE TROUGH
AND DOES NOT PASS THE FRONT UNTIL FRIDAY MORNING. THE GEM IS EVEN
SLOWER...BRINGING THE FRONT THROUGH FRIDAY AFTERNOON.

SATURDAY AND SUNDAY...SHARP MID-LEVEL RIDGING DEVELOPING ACROSS THE
NORTHERN PLAINS WILL BEGIN TO WORK INTO THE UPPER GREAT LAKES BEHIND
THE DEPARTING TROUGH. BEING LESS AMPLIFIED...THE ECMWF TAKES LONGER
TO PASS THE TROUGH ACROSS THE REGION...AND ACTUALLY STALLS IT OVER
LAKE HURON AT THE VERY END OF THE PERIOD. GIVEN THE
UNCERTAINTIES...WILL MAINTAIN CONSENSUS POPS FOR NEXT WEEKEND.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 248 AM EDT MON JUL 22 2013

VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE PERIOD. EXPECT
INCREASING MID CLOUDS LATE TONIGHT INTO MONDAY MORNING AHEAD OF AN
APPROACHING DISTURBANCE. SOME SHRA ARE POSSIBLE AT ALL SITES MON
MORNING AND TRIED TO TIME THESE WITH EITHER PROB30 GROUPS OR
PREVAILING. FRONT COMES THROUGH BY EVENING AND SWITCHES THE WIND TO
THE NORTHWEST.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 410 PM EDT SUN JUL 21 2013

SRLY WINDS WILL INCREASE TO AROUND 20 KNOTS LATE TONIGHT AND MONDAY
AHEAD OF A LOW PRESSURE TROUGH MOVING THROUGH THE AREA. NORTH TO
NORTHWEST WINDS WILL THEN INCREASE TO 20-25 KNOTS BY LATE MONDAY NIGHT
INTO TUESDAY BEHIND THE TROUGH/COLD FRONT MOVING THROUGH THE REGION.
WINDS ARE THEN EXPECTED TO REMAIN BELOW 20 KNOTS TUE NIGHT THROUGH
THURSDAY.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...JLB
LONG TERM...KLUBER
AVIATION...07
MARINE...JLB







AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 155 PM EDT SUN JUL 21 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 450 AM EDT SUN JUL 21 2013

WV IMAGERY AND RUC ANALYSIS INDICATED A ZONAL FLOW OVER THE UPPER
GREAT LAKES. AT THE SFC...HIGH PRESSURE DOMINATES THE UPPER GREAT
LAKES. THE CLEAR SKIES AND LIGHT WINDS HAVE ALLOWED TEMPS EARLY THIS
MORNING TO FALL INTO THE 40S WITH EVEN A FEW LOCATIONS REACHING THE
MID TO UPPER 30S.

TODAY...AS THE SFC HIGH SHIFTS EAST OF THE AREA...SRLY FLOW AND WAA
WILL INCREASE AHEAD OF APPROACHING SHORTWAVE AND FRONTAL SYSTEM OVER
THE NRN PLAINS. TEMPS SHOULD CLIMB INTO THE LOWER TO MID 70S INLAND
WITH LOWER READINGS IN THE MID TO UPPER 60S ALONG THE GREAT LAKES.
MODELS INDICATE SOME INCREASE IN 305K ISENTROPIC ASCENT OVER FAR WRN
UPR MI LATE IN THE DAY ALTHOUGH BEST MOISTURE LIFT SHOULD STAY SOUTH
AND WEST. WILL MAINTAIN GOING FCST OF SLIGHT CHANCE POPS OVER THE
FAR WEST.

TONIGHT...INCREASING 925-700 MB THETA-E ADVECTION AND 305K
ISENTROPIC ASCENT SHOULD LEAD TO INCREASED CHCS FOR SHRA AND TSRA
ESPECIALLY AFT MIDNIGHT AS SHORTWAVE APPROACHED FM THE WEST.
LIMITING FACTOR FOR TSRA WILL BE LACK OF ELEVATED INSTABILITY AS
MUCAPES ONLY A FEW HUNDRED J/KG. WILL KEEP HIGHER CHC POPS OVER FAR
WEST AND TAPER TO LOW CHC 20-30 PCT POPS OVER CENTRAL COUNTIES.
EXPECT LOWS GENERALLY IN THE 50S.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 450 AM EDT SUN JUL 21 2013

MOST TIME SPENT ON LONG TERM WAS WITH PRECIP CHANCES MON/MON NIGHT
AND ASSESSING SEVERE STORM THREAT FOR MON AFTERNOON/EVENING.

LOOKING FIRST AT THE LARGE SCALE...AN UPPER TROUGH OVER THE ERN HALF
OF THE CONUS WILL BE STEMMING FROM A CLOSED LOW OVER NRN QUEBEC AND
AN UPPER RIDGE WILL BE OVER THE WRN CONUS AT 12Z MON. A PIECE OF
UPPER ENERGY WILL MOVE ACROSS THE REGION MON INTO EARLY MON
NIGHT...FOLLOWED BY OTHER SMALLER SCALE ENERGY THU NIGHT THROUGH
SAT...BUT THE OVERALL PATTERN REMAINS SIMILAR THROUGH THE EXTENDED.
THIS MEANS...FOR THE MOST PART...THAT COOLER WEATHER IS HERE TO STAY
FOR MUCH OF THE NEXT WEEK AT LEAST.

FOR THE SPECIFICS...

MON/MON NIGHT...THERE WILL BE PRECIP MOVING INTO THE WRN CWA EARLY
MON AS THE UPPER TROUGH AND SFC TROUGH/COLD FRONT MOVE IN. THINK THE
BEST PRECIP CHANCES WILL BE DURING THE AFTERNOON/EARLY EVENING AS
THE COLD FRONT MOVES THROUGH A POTENTIALLY UNSTABLE AIRMASS.
QUESTIONS IS HOW MUCH CLEARING WILL RESULT AFTER MORNING
RAIN...WHICH WILL EFFECT HOW MUCH INSTABILITY EXISTS IN THE
AFTERNOON. IF WE CAN GET GOOD CLEARING...SBCAPE VALUES MAY BE
800-1200J/KG /HIGHEST OVER SCENTRAL UPPER MI/...AND STRONGLY VEERING
WINDS THROUGH THE ATMOSPHERE WILL LEAD TO AROUND 40KTS OF 0-6KM BULK
SHEAR. IF OPTIMAL CONDITIONS FOR CONVECTION DO MATERIALIZE...THEN
SEVERE THUNDERSTORMS WITH LARGE HAIL AND DAMAGING WINDS WOULD BE
POSSIBLE...WITH THE BEST CHANCES OVER SCENTRAL UPPER MI.
HOWEVER...AT THIS TIME...THINK THE COVERAGE OF ANY SEVERE WEATHER
WILL BE MORE LIMITED DUE TO DRY AIR. FOR NOW WILL CONTINUE MENTION
OF SEVERE CHANCES IN HWO/EHWO BUT STILL TOO UNCERTAIN TO PUT IN
GRIDS. MON LOOKS LIKE THE WARMEST DAY IN THE NEXT WEEK AHEAD OF THE
COLD FRONT...WITH HIGHS IN THE 70S TO MID 80S.

POSTFRONTAL TUESDAY SHOULD BE COOLER AND SIMILAR TO YESTERDAY...WITH
HIGHS AROUND 60 NEAR LAKE SUPERIOR TO THE LOW 70S SOUTH CENTRAL.
SKIES SHOULD BE CLEARING BY THE AFTERNOON.

WED WILL BE SLIGHTLY WARMER THAN TUESDAY AS TEMPS RECOVER SOME FROM
THE COLD FRONT. SHOULD SEE SOME INCREASE IN CLOUDS FROM W TO E
DURING THE AFTERNOON/EVENING AS A MORE MILD PIECE OF UPPER ENERGY
SLIDES ACROSS THE CWA...BUT NO PRECIP IS EXPECTED.

THERE IS MORE UNCERTAINTY LATER IN THE WEEK WHEN LOOKING AT MORE
SIGNIFICANT UPPER ENERGY SLIDING INTO THE REGION...BUT PRECIP WILL
CERTAINLY BE POSSIBLE LATER INTO THE WEEK. TEMPERATURES WILL CLIMB
ANOTHER COUPLE OF DEGREES ON THURSDAY...BUT SHOULD AGAIN FALL INTO
THE WEEKEND AS THE UPPER TROUGH MOVES OVERHEAD. USED A GENERAL
CONSENSUS OF MODEL GUIDANCE FOR THIS PART OF THE FORECAST.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 154 PM EDT SUN JUL 21 2013

VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE FCST PERIOD.
EXPECT INCREASING MID CLOUDS LATE IN THE DAY AND TONIGHT AHEAD OF AN
APPROACHING DISTURBANCE. SOME SHRA ARE POSSIBLE AT KIWD AND KCMX LATE
TONIGHT. SOME LOWER CIGS NEAR MVFR MAY BE POSSIBLE LATE TONIGHT AND
MON MORNING AS LOW LEVEL MOISTURE ADVECTION INCREASES.
HOWEVER...CONFIDENCE WAS TOO LOW MENTION IN THE TAF AT THIS TIME. &&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 AM EDT SUN JUL 21 2013

HIGH PRESSURE WILL KEEP WINDS GENERALLY LIGHT TODAY OVER THE
NORTHERN GREAT LAKES. SRLY WINDS WILL INCREASE TO AROUND 20 KNOTS
LATE TONIGHT AND MONDAY AHEAD OF A LOW PRESSURE TROUGH MOVING
THROUGH THE AREA. NORTH TO NORTHWEST WINDS WILL THEN INCREASE TO 20
KNOTS BY LATE MONDAY NIGHT INTO TUESDAY BEHIND THE TROUGH/COLD FRONT
MOVING THROUGH THE REGION. WINDS ARE THEN EXPECTED TO REMAIN BELOW
20 KNOTS TUE NIGHT THROUGH THURSDAY.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...JLB
MARINE...VOSS







AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 743 AM EDT SUN JUL 21 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 450 AM EDT SUN JUL 21 2013

WV IMAGERY AND RUC ANALYSIS INDICATED A ZONAL FLOW OVER THE UPPER
GREAT LAKES. AT THE SFC...HIGH PRESSURE DOMINATES THE UPPER GREAT
LAKES. THE CLEAR SKIES AND LIGHT WINDS HAVE ALLOWED TEMPS EARLY THIS
MORNING TO FALL INTO THE 40S WITH EVEN A FEW LOCATIONS REACHING THE
MID TO UPPER 30S.

TODAY...AS THE SFC HIGH SHIFTS EAST OF THE AREA...SRLY FLOW AND WAA
WILL INCREASE AHEAD OF APPROACHING SHORTWAVE AND FRONTAL SYSTEM OVER
THE NRN PLAINS. TEMPS SHOULD CLIMB INTO THE LOWER TO MID 70S INLAND
WITH LOWER READINGS IN THE MID TO UPPER 60S ALONG THE GREAT LAKES.
MODELS INDICATE SOME INCREASE IN 305K ISENTROPIC ASCENT OVER FAR WRN
UPR MI LATE IN THE DAY ALTHOUGH BEST MOISTURE LIFT SHOULD STAY SOUTH
AND WEST. WILL MAINTAIN GOING FCST OF SLIGHT CHANCE POPS OVER THE
FAR WEST.

TONIGHT...INCREASING 925-700 MB THETA-E ADVECTION AND 305K
ISENTROPIC ASCENT SHOULD LEAD TO INCREASED CHCS FOR SHRA AND TSRA
ESPECIALLY AFT MIDNIGHT AS SHORTWAVE APPROACHED FM THE WEST.
LIMITING FACTOR FOR TSRA WILL BE LACK OF ELEVATED INSTABILITY AS
MUCAPES ONLY A FEW HUNDRED J/KG. WILL KEEP HIGHER CHC POPS OVER FAR
WEST AND TAPER TO LOW CHC 20-30 PCT POPS OVER CENTRAL COUNTIES.
EXPECT LOWS GENERALLY IN THE 50S.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 450 AM EDT SUN JUL 21 2013

MOST TIME SPENT ON LONG TERM WAS WITH PRECIP CHANCES MON/MON NIGHT
AND ASSESSING SEVERE STORM THREAT FOR MON AFTERNOON/EVENING.

LOOKING FIRST AT THE LARGE SCALE...AN UPPER TROUGH OVER THE ERN HALF
OF THE CONUS WILL BE STEMMING FROM A CLOSED LOW OVER NRN QUEBEC AND
AN UPPER RIDGE WILL BE OVER THE WRN CONUS AT 12Z MON. A PIECE OF
UPPER ENERGY WILL MOVE ACROSS THE REGION MON INTO EARLY MON
NIGHT...FOLLOWED BY OTHER SMALLER SCALE ENERGY THU NIGHT THROUGH
SAT...BUT THE OVERALL PATTERN REMAINS SIMILAR THROUGH THE EXTENDED.
THIS MEANS...FOR THE MOST PART...THAT COOLER WEATHER IS HERE TO STAY
FOR MUCH OF THE NEXT WEEK AT LEAST.

FOR THE SPECIFICS...

MON/MON NIGHT...THERE WILL BE PRECIP MOVING INTO THE WRN CWA EARLY
MON AS THE UPPER TROUGH AND SFC TROUGH/COLD FRONT MOVE IN. THINK THE
BEST PRECIP CHANCES WILL BE DURING THE AFTERNOON/EARLY EVENING AS
THE COLD FRONT MOVES THROUGH A POTENTIALLY UNSTABLE AIRMASS.
QUESTIONS IS HOW MUCH CLEARING WILL RESULT AFTER MORNING
RAIN...WHICH WILL EFFECT HOW MUCH INSTABILITY EXISTS IN THE
AFTERNOON. IF WE CAN GET GOOD CLEARING...SBCAPE VALUES MAY BE
800-1200J/KG /HIGHEST OVER SCENTRAL UPPER MI/...AND STRONGLY VEERING
WINDS THROUGH THE ATMOSPHERE WILL LEAD TO AROUND 40KTS OF 0-6KM BULK
SHEAR. IF OPTIMAL CONDITIONS FOR CONVECTION DO MATERIALIZE...THEN
SEVERE THUNDERSTORMS WITH LARGE HAIL AND DAMAGING WINDS WOULD BE
POSSIBLE...WITH THE BEST CHANCES OVER SCENTRAL UPPER MI.
HOWEVER...AT THIS TIME...THINK THE COVERAGE OF ANY SEVERE WEATHER
WILL BE MORE LIMITED DUE TO DRY AIR. FOR NOW WILL CONTINUE MENTION
OF SEVERE CHANCES IN HWO/EHWO BUT STILL TOO UNCERTAIN TO PUT IN
GRIDS. MON LOOKS LIKE THE WARMEST DAY IN THE NEXT WEEK AHEAD OF THE
COLD FRONT...WITH HIGHS IN THE 70S TO MID 80S.

POSTFRONTAL TUESDAY SHOULD BE COOLER AND SIMILAR TO YESTERDAY...WITH
HIGHS AROUND 60 NEAR LAKE SUPERIOR TO THE LOW 70S SOUTH CENTRAL.
SKIES SHOULD BE CLEARING BY THE AFTERNOON.

WED WILL BE SLIGHTLY WARMER THAN TUESDAY AS TEMPS RECOVER SOME FROM
THE COLD FRONT. SHOULD SEE SOME INCREASE IN CLOUDS FROM W TO E
DURING THE AFTERNOON/EVENING AS A MORE MILD PIECE OF UPPER ENERGY
SLIDES ACROSS THE CWA...BUT NO PRECIP IS EXPECTED.

THERE IS MORE UNCERTAINTY LATER IN THE WEEK WHEN LOOKING AT MORE
SIGNIFICANT UPPER ENERGY SLIDING INTO THE REGION...BUT PRECIP WILL
CERTAINLY BE POSSIBLE LATER INTO THE WEEK. TEMPERATURES WILL CLIMB
ANOTHER COUPLE OF DEGREES ON THURSDAY...BUT SHOULD AGAIN FALL INTO
THE WEEKEND AS THE UPPER TROUGH MOVES OVERHEAD. USED A GENERAL
CONSENSUS OF MODEL GUIDANCE FOR THIS PART OF THE FORECAST.
&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 729 AM EDT SUN JUL 21 2013

VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD. EXPECT INCREASING
MID CLOUDS LATE IN THE DAY AND TONIGHT AHEAD OF AN APPROACHING LOW
PRESSURE SYSTEM. SOME SHRA ARE POSSIBLE AT KIWD AND KCMX LATE
TONIGHT.

&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 AM EDT SUN JUL 21 2013

HIGH PRESSURE WILL KEEP WINDS GENERALLY LIGHT TODAY OVER THE
NORTHERN GREAT LAKES. SRLY WINDS WILL INCREASE TO AROUND 20 KNOTS
LATE TONIGHT AND MONDAY AHEAD OF A LOW PRESSURE TROUGH MOVING
THROUGH THE AREA. NORTH TO NORTHWEST WINDS WILL THEN INCREASE TO 20
KNOTS BY LATE MONDAY NIGHT INTO TUESDAY BEHIND THE TROUGH/COLD FRONT
MOVING THROUGH THE REGION. WINDS ARE THEN EXPECTED TO REMAIN BELOW
20 KNOTS TUE NIGHT THROUGH THURSDAY.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...VOSS
MARINE...VOSS







AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 451 AM EDT SUN JUL 21 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 450 AM EDT SUN JUL 21 2013

WV IMAGERY AND RUC ANALYSIS INDICATED A ZONAL FLOW OVER THE UPPER
GREAT LAKES. AT THE SFC...HIGH PRESSURE DOMINATES THE UPPER GREAT
LAKES. THE CLEAR SKIES AND LIGHT WINDS HAVE ALLOWED TEMPS EARLY THIS
MORNING TO FALL INTO THE 40S WITH EVEN A FEW LOCATIONS REACHING THE
MID TO UPPER 30S.

TODAY...AS THE SFC HIGH SHIFTS EAST OF THE AREA...SRLY FLOW AND WAA
WILL INCREASE AHEAD OF APPROACHING SHORTWAVE AND FRONTAL SYSTEM OVER
THE NRN PLAINS. TEMPS SHOULD CLIMB INTO THE LOWER TO MID 70S INLAND
WITH LOWER READINGS IN THE MID TO UPPER 60S ALONG THE GREAT LAKES.
MODELS INDICATE SOME INCREASE IN 305K ISENTROPIC ASCENT OVER FAR WRN
UPR MI LATE IN THE DAY ALTHOUGH BEST MOISTURE LIFT SHOULD STAY SOUTH
AND WEST. WILL MAINTAIN GOING FCST OF SLIGHT CHANCE POPS OVER THE
FAR WEST.

TONIGHT...INCREASING 925-700 MB THETA-E ADVECTION AND 305K
ISENTROPIC ASCENT SHOULD LEAD TO INCREASED CHCS FOR SHRA AND TSRA
ESPECIALLY AFT MIDNIGHT AS SHORTWAVE APPROACHED FM THE WEST.
LIMITING FACTOR FOR TSRA WILL BE LACK OF ELEVATED INSTABILITY AS
MUCAPES ONLY A FEW HUNDRED J/KG. WILL KEEP HIGHER CHC POPS OVER FAR
WEST AND TAPER TO LOW CHC 20-30 PCT POPS OVER CENTRAL COUNTIES.
EXPECT LOWS GENERALLY IN THE 50S.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 450 AM EDT SUN JUL 21 2013

MOST TIME SPENT ON LONG TERM WAS WITH PRECIP CHANCES MON/MON NIGHT
AND ASSESSING SEVERE STORM THREAT FOR MON AFTERNOON/EVENING.

LOOKING FIRST AT THE LARGE SCALE...AN UPPER TROUGH OVER THE ERN HALF
OF THE CONUS WILL BE STEMMING FROM A CLOSED LOW OVER NRN QUEBEC AND
AN UPPER RIDGE WILL BE OVER THE WRN CONUS AT 12Z MON. A PIECE OF
UPPER ENERGY WILL MOVE ACROSS THE REGION MON INTO EARLY MON
NIGHT...FOLLOWED BY OTHER SMALLER SCALE ENERGY THU NIGHT THROUGH
SAT...BUT THE OVERALL PATTERN REMAINS SIMILAR THROUGH THE EXTENDED.
THIS MEANS...FOR THE MOST PART...THAT COOLER WEATHER IS HERE TO STAY
FOR MUCH OF THE NEXT WEEK AT LEAST.

FOR THE SPECIFICS...

MON/MON NIGHT...THERE WILL BE PRECIP MOVING INTO THE WRN CWA EARLY
MON AS THE UPPER TROUGH AND SFC TROUGH/COLD FRONT MOVE IN. THINK THE
BEST PRECIP CHANCES WILL BE DURING THE AFTERNOON/EARLY EVENING AS
THE COLD FRONT MOVES THROUGH A POTENTIALLY UNSTABLE AIRMASS.
QUESTIONS IS HOW MUCH CLEARING WILL RESULT AFTER MORNING
RAIN...WHICH WILL EFFECT HOW MUCH INSTABILITY EXISTS IN THE
AFTERNOON. IF WE CAN GET GOOD CLEARING...SBCAPE VALUES MAY BE
800-1200J/KG /HIGHEST OVER SCENTRAL UPPER MI/...AND STRONGLY VEERING
WINDS THROUGH THE ATMOSPHERE WILL LEAD TO AROUND 40KTS OF 0-6KM BULK
SHEAR. IF OPTIMAL CONDITIONS FOR CONVECTION DO MATERIALIZE...THEN
SEVERE THUNDERSTORMS WITH LARGE HAIL AND DAMAGING WINDS WOULD BE
POSSIBLE...WITH THE BEST CHANCES OVER SCENTRAL UPPER MI.
HOWEVER...AT THIS TIME...THINK THE COVERAGE OF ANY SEVERE WEATHER
WILL BE MORE LIMITED DUE TO DRY AIR. FOR NOW WILL CONTINUE MENTION
OF SEVERE CHANCES IN HWO/EHWO BUT STILL TOO UNCERTAIN TO PUT IN
GRIDS. MON LOOKS LIKE THE WARMEST DAY IN THE NEXT WEEK AHEAD OF THE
COLD FRONT...WITH HIGHS IN THE 70S TO MID 80S.

POSTFRONTAL TUESDAY SHOULD BE COOLER AND SIMILAR TO YESTERDAY...WITH
HIGHS AROUND 60 NEAR LAKE SUPERIOR TO THE LOW 70S SOUTH CENTRAL.
SKIES SHOULD BE CLEARING BY THE AFTERNOON.

WED WILL BE SLIGHTLY WARMER THAN TUESDAY AS TEMPS RECOVER SOME FROM
THE COLD FRONT. SHOULD SEE SOME INCREASE IN CLOUDS FROM W TO E
DURING THE AFTERNOON/EVENING AS A MORE MILD PIECE OF UPPER ENERGY
SLIDES ACROSS THE CWA...BUT NO PRECIP IS EXPECTED.

THERE IS MORE UNCERTAINTY LATER IN THE WEEK WHEN LOOKING AT MORE
SIGNIFICANT UPPER ENERGY SLIDING INTO THE REGION...BUT PRECIP WILL
CERTAINLY BE POSSIBLE LATER INTO THE WEEK. TEMPERATURES WILL CLIMB
ANOTHER COUPLE OF DEGREES ON THURSDAY...BUT SHOULD AGAIN FALL INTO
THE WEEKEND AS THE UPPER TROUGH MOVES OVERHEAD. USED A GENERAL
CONSENSUS OF MODEL GUIDANCE FOR THIS PART OF THE FORECAST.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 141 AM EDT SUN JUL 21 2013

VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD AS HIGH
PRESSURE REMAINS OVER THE REGION.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 AM EDT SUN JUL 21 2013

HIGH PRESSURE WILL KEEP WINDS GENERALLY LIGHT TODAY OVER THE
NORTHERN GREAT LAKES. SRLY WINDS WILL INCREASE TO AROUND 20 KNOTS
LATE TONIGHT AND MONDAY AHEAD OF A LOW PRESSURE TROUGH MOVING
THROUGH THE AREA. NORTH TO NORTHWEST WINDS WILL THEN INCREASE TO 20
KNOTS BY LATE MONDAY NIGHT INTO TUESDAY BEHIND THE TROUGH/COLD FRONT
MOVING THROUGH THE REGION. WINDS ARE THEN EXPECTED TO REMAIN BELOW
20 KNOTS TUE NIGHT THROUGH THURSDAY.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...07
MARINE...VOSS







AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 141 AM EDT SUN JUL 21 2013

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 419 PM EDT SAT JUL 20 2013

WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW OVER NE
CANADA AND A WEAK RIDGE INTO MANITOBA RESULTING IN CONFLUENT WNW
FLOW THROUGH THE NRN GREAT LAKES. AT THE SFC...A RIDGE EXTENDED FROM
SRN MANTIOBA INTO NW ONTARIO TO NW LAKE SUPERIOR. ABUNDANT DIRUNAL
CU HAD DEVELOPED IN THE COOL AIR TO THE NORTH OF LAKE SUPERIOR WHERE
850 MB TEMPS WERE DOWN TO 2C-3C. FARTHER SOUTH...VIS LOOP SHOWED
ONLY SCT CU OVER THE W HALF OF UPPER MI.

TONIGHT...WITH CLEAR SKIES AND LIGHT WINDS TONIGHT...FAVORABLE
RADIATIONAL COOLING CONDITIONS IN THE DRY AIRMASS OVER THE REGION
(PWAT BELOW 0.50 INCH)WILL ALLOW TEMPS TO DROP TO NEAR THE LOW END
OF GUIDANCE...NEAR 40 OVER THE COLDER INLAND LOCATIONS.

SUN...AS THE SFC HIGH SHIFTS EAST OF THE AREA AND THE MID LEVEL
FLOW BECOMES MORE ZONAL...SRLY FLOW AND WAA WILL INCREASE AHEAD OF
APPROACHING SHORTWAVE AND FRONTAL SYSTEM OVER THE NRN PLAINS. TEMPS
SHOULD CLIMB INTO THE LOWER TO MID 70S INLAND WITH LOWER READINGS IN
THE MID TO UPPER 60S ALONG THE GREAT LAKES. MODELS SUGGEST THAT THE
GREATEST INCREASE IN MOISTURE AND STRONGER 300-310K ISENTROPIC LIFT
WILL REMAIN TO THE SOUTH AND WEST OF UPPER MI FROM SRN MN INTO
CNTRL WI LATE SUN AFTERNOON. SO...THE FCST MAINTAINS ONLY SLIGHT
CHANCE POPS INTO THE FAR WEST

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 419 PM EDT SAT JUL 20 2013

UPPER AIR PATTERN THROUGH NEXT WEEK DRIVEN BY TWO AREAS OF LOWER
HEIGHTS...ONE OVER GULF OF ALASKA/BRITISH COLUMBIA AND THE OTHER
VCNTY OF HUDSON BAY ACROSS QUEBEC. IN BTWN THESE TWO...WNW FLOW
HOLDS IN PLACE FROM WESTERN CANADA ACROSS GREAT LAKES. MOST
PERSISTENT RIDGING WILL BE LIMITED TO SOUTHWEST PART OF CONUS.
PATTERN DOES NOT LOOK APPRECIABLY WARM...ESPECIALLY COMPARED TO
THE RECENT HEAT WAVE THAT AFFECTED GREAT LAKES REGION. OVERALL
TEMPS THROUGH THE PERIOD WILL BE AT OR SLIGHTLY BLO NORMAL /NORMAL
HIGH TEMPS ON AVERAGE THIS TIME OF YEAR ARE IN THE UPR 70S NORTH TO
LOWER 80S SOUTH/. WARMEST DAY MOST LIKELY ON MONDAY AS WARM FRONT
LIFTS ACROSS UPPER LAKES RESULTING IN SW SFC WINDS. COLD FRONT
MOVES IN MONDAY NIGHT THOUGH...MAKING THIS STAY IN THE WARM SECTOR
VERY BRIEF. SHRA/TSRA POSSIBLE AS THESE FRONTAL BOUNDARIES AFFECT
THE AREA. ONLY OTHER CHANCE OF RAIN ARRIVES LATER THURSDAY INTO
FRIDAY AS ANOTHER SFC TROUGH CROSSES THE REGION. WEAK HIGH PRESSURE
AND DRY WEATHER WILL DOMINATE THE WEATHER PATTERN REST OF THE LONG
TERM.

FIRST FOCUS IN LONGER TERM IS SHORTWAVE PRESSING INTO SCNTRL CANADA
ON SUNDAY NIGHT AND SFC LOW/TROUGH MOVING ACROSS NORTHERN PLAINS.
SLIGHT H85 TEMP/MOISTURE ADVECTION OVER UPR MICHIGAN AHEAD OF THE
WAVE AND SFC TROUGH...BUT INSTABILITY IS PRETTY MINIMAL WITH MUCAPES
1-6KM A FEW HUNDRED J/KG AT BEST...MAINLY OVER FAR WEST LK SUPERIOR
CLOSER TO STRONGEST H85-H7 MOISTURE TRANSPORT. FCST SOUNDINGS SHOW
INCREASE OF H8-H7 MOISTURE BUT HINT AT DRY AIR BLO AND ABOVE THIS
LAYER. WITH LACK OF INSTABILITY AND DEEP MOISTURE AND LARGER SCALE
FORCING...THINK COVERAGE TO ANY SHRA/TSRA WILL BE LIMITED SUN NIGHT
BUT CANNOT COMPLETELY RULE IT OUT.

SEEMS THAT BETTER CHANCES FOR SHRA/TSRA OCCUR ON MONDAY IN THE
MORNING DUE TO CLOSER PROXIMITY OF SHORTWAVE/H85 TROUGH AND
RESULTING SHARPER WARM AIR ADVECTION AND INCREASING H85 MOISTURE
TRANSPORT. EXPECT THIS WARM AIR ADVECTION SHRA/ISOLD TSRA TO SHIFT
NORTH BY AFTN ALONG SFC WARM FRONT AND THEN...PROVIDED THERE IS
ENOUGH CLEARING OF MORNING CLOUDS/SHRA/TSRA...THERE SHOULD BE PERIOD
OF BUILDING INSTABILITY DURING PEAK HEATING AS TEMPS WARM INTO THE
UPR 70S/LWR 80S. MLCAPES TOP OUT AROUND 800-1200J/KG...HIGHEST
ALONG WI BORDER. DEEP LAYER SHEAR INCREASES IN WARM SECTOR OUT
AHEAD OF COLD FRONT TO 30-40 KTS AS SHORTWAVE CROSSES NORTHERN
ONTARIO AND ADJACENT LK SUPERIOR. SOUNDINGS SHOW A BIT OF CAPPING
AROUND H8 AND THIS ADDS UNCERTAINTY TO INITIATION. BASED ON CAPE AND
SHEAR BALANCE...THERE SEEMS TO BE AT LEAST SMALL POTENTIAL FOR ISOLD
SVR STORMS. SUPERCELLS POSSIBLE AS WINDS SHOW SUFFICIENT VEERING WITH
HEIGHT. HAIL/WIND PRIMARY HAZARDS WITH LOWER WBZERO HEIGHTS AROUND
11KFT AND DCAPE UP TO 1000J/KG. ALL THIS IS CONDITIONAL ON HOW MUCH
INSTABILITY CAN MATERIALIZE. SINCE SPC DAY 3 DID INDICATE SEE TEXT
OVER THE AREA...THINK IT IS WORTH AN HWO MENTION.

COLD FRONT BLOWS THROUGH CWA PRETTY QUICKLY MONDAY EVENING/EARLY
OVERNIGHT. TRENDED TOWARD LOWER POPS 6Z-12Z ON TUESDAY WITH DRYING
NOTED IN SOUNDINGS AND GFS/ECMWF SHOWING LITTLE IF ANY QPF IN THAT
TIME FRAME THE LAST FEW MODEL RUNS. IN WAKE OF THE COLD FRONT ON
TUESDAY...COULD END UP WITH NEARLY CARBON COPY OF TODAY...COOL TEMPS
ALONG LK SUPERIOR/HIGHER SWIM RISK AND READINGS INTO LOWER 70S TOWARD
WI BORDER. CUT GUIDANCE TEMPS FOR TUESDAY NIGHT WITH HIGH CENTER
OVERHEAD. FAVORED COLD SPOTS OVER MAINLY WEST COULD REACH TO AROUND
40 DEGREES. STAYS QUIET THROUGH WEDNESDAY NIGHT AS HIGH PRESSURE
SLOWLY RETREATS.

NEXT CHANCE OF RAIN RETURNS THURSDAY INTO FRIDAY. MODELS HAVING
TOUGH TIME HANDLING SHORTWAVE TROUGH PUSHING THROUGH IN WNW FLOW
ALOFT. LATEST GFS AND ECMWF WOULD INDICATE SHORTWAVE PASSAGE
THURSDAY OR THURSDAY NIGHT. BLEND OF CONSENSUS SHOWS SLIGHT
CHANCE/LOW CHANCE POPS AS ANOTHER COLD FRONT CROSSES THE AREA
TIED TO THE WAVE. SATURDAY LOOKING PRETTY COOL YET AGAIN BEHIND
THIS COLD FRONT. PROBABLY WILL END UP SIMILAR TO WHAT IS OCCURRING
TODAY.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 141 AM EDT SUN JUL 21 2013

VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD AS HIGH
PRESSURE REMAINS OVER THE REGION.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 419 PM EDT SAT JUL 20 2013

AS HIGH PRESSURE BUILDS INTO THE NORTHERN GREAT LAKES...WINDS WILL
DIMINISH THIS EVENING TO LESS THAN 20 KNOTS. SRLY WINDS WILL
INCREASE TO AROUND 20 KNOTS AHEAD OF A LOW PRESSURE TROUGH MOVING
THROUGH THE AREA ON MONDAY. NORTH TO NORTHWEST WINDS WILL THEN INCREASE
TO 20 TO 30 KNOTS BY LATE MONDAY NIGHT INTO TUESDAY BEHIND A COLD
FRONT MOVING THROUGH THE REGION. WINDS ARE THEN EXPECTED TO REMAIN
BELOW 20 KNOTS THROUGH THURSDAY.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...JLB
LONG TERM...JLA
AVIATION...07
MARINE...JLB







AREA FORECAST DISCUSSION...UPDATED

NWS JACKSON MS

 933 PM CDT MON JUL 22 2013

.UPDATE...
H5 NW FLOW WILL KEEP UPPER S/WV DISTURBANCES MOVING INTO THE REGION
OVERNIGHT. WATER VAPOR IMAGERY DEPICTS A FEW DISTURBANCES MOVING
DOWN IN THE NW FLOW IN THE OZARKS AND CENTRAL PLAINS. GLOBAL/HI-RES
MODELS SEEM TO FOCUS MOST OF THE ACTIVITY OVERNIGHT IN THE NE
AREAS...MAINLY ALONG AND NORTHEAST OF A LINE FROM GREENVILLE TO
MERIDIAN. RAIN/STORM CHANCES WILL CONTINUE OVERNIGHT AS HRRR INDICATES
STORMS DEVELOPING TO THE NW AND MOVING SE INTO THE REGION...MAINLY
AFTER 6Z. MAINTAINED NEAR MAV POPS BUT DROPPED IN SW AS GLOBAL MODELS
FOCUS FARTHER NE. AREAS THAT RECEIVED RAINFALL TODAY COULD SEE SOME
PATCHY FOG BUT DUE TO STRONGER LOW LEVEL FLOW AND QUITE A BIT OF
CLOUD COVER AROUND OVERNIGHT...WILL LIKELY BE MORE STRATUS THAN ANY
PATCHY FOG. TEMPS TONIGHT WENT CLOSE TO MAVMOS. ALSO MODIFIED SKY
COVER GRIDS SLIGHTLY. REST OF THE FORECAST IS ON TRACK. /DC/

&&

.AVIATION...CONVECTION IS HANGING ON A BIT LONGER THIS EVENING
COMPARED TO THE PAST COUPLE AS A FEW OUTFLOW BOUNDARIES CONTINUE TO
MEANDER ABOUT THE FORECAST AREA.  STILL...VFR CONDITIONS CURRENTLY
PREVAIL AT MOST TAF SITES AND WILL CONTINUE THROUGH MUCH OF THE
NIGHT.  WHILE AT LEAST A SLIGHT CHANCE FOR CONVECTION EXISTS AT MOST
LOCATIONS OVERNIGHT...PARTICULARLY ALONG THE HIGHWAY 82 CORRIDOR
(KGLH...KGWO...KGTR) DUE TO IT`S CLOSE PROXIMITY TO SOME PASSING
UPPER LEVEL DISTURBANCES...MOST SITES WILL REMAIN DRY OVERNIGHT.
LOW STRATUS COULD AGAIN DEVELOP TOWARDS DAY BREAK TUESDAY...
RESULTING IN A PERIOD OF MVFR/IFR CEILINGS.  PATCHY FOG IS ALSO
POSSIBLE...MAINLY ACROSS EAST AND SOUTHEAST MISSISSIPPI (KMEI AND
KHBG)...WHICH COULD LEAD TO A BRIEF PERIOD OF MVFR VISIBILITIES
AROUND SUNRISE.  WINDS OVERNIGHT WILL AGAIN REMAIN UP A BIT THEY
STAY SOUTH SOUTHWESTERLY BETWEEN 3-8 KNOTS.  WINDS WILL BE WEST
SOUTHWESTERLY TUESDAY AROUND 10 KNOTS WITH SCATTERED CONVECTION
EXPECTED AGAIN FROM LATE-MORNING...THROUGH THE AFTERNOON...AND INTO
THE EARLY EVENING HOURS. /19/

&&

.PREV DISCUSSION... /ISSUED 322 PM CDT MON JUL 22 2013/

SHORT TERM...A SWATH OF CONVECTION HAS MOVED FROM NRN MS INTO
ECNTRL ZONES THIS AFTERNOON. ASSOCIATED OUTFLOW BOUNDARIES WILL
CONTINUE TO PUSH TO THE SOUTH AND MAINTAIN LIKELY COVERAGE OF
CONVECTION INTO THE EARLY EVENING. SCATTERED TO NUMEROUS ACTIVITY
THAT HAS DEVELOPED OVER CNTRL AND SRN ZONES IN AFTERNOON HEATING AND
SEA BREEZE INTERACTIONS WILL GRADUALLY DECREASE THIS EVENING AND
SHOULD GENERALLY END BY MIDNIGHT AT MOST LOCATIONS ALTHOUGH AN
ISOLATED SHWR OR TSTM CAN NOT BE RULED OUT OVERNIGHT IN THE SOUPY
AIR MASS CURRENTLY IN PLACE. INTERACTIONS BETWEEN THE DESCENDING
SWATH OF STORMS AND CONVECTION TO THE SOUTH MAY RESULT IN STRONG
STORMS OVER ECNTRL/SERN ZONES DURING THE LATE AFTERNOON AND EVENING
AND AN ISOLATED SEVERE STORM CAN NOT BE RULED OUT WITH THIS
ACTIVITY. MODELS ARE IN AGREEMENT THAT THE HIGHER RAIN CHANCES WILL
EXTEND ACROSS ERN ZONES TONIGHT...THIS REGION POSITIONED IN SLIGHTLY
BETTER MID LEVEL FLOW ON THE FRINGES OF UPPER TROUGHING TO OUR EAST.
ANOTHER WAVE EVIDENT IN SATELLITE AND RADAR IMAGES HEADING THIS WAY
INDICATES A CONTINUING CHANCE OF CONVECTION FOR NWRN ZONES INTO THE
NIGHTTIME PERIOD.

WAVES WILL DROP INTO THE REGION IN NWLY FLOW ALOFT TUESDAY AND THE
AIR MASS WILL REMAIN QUITE UNSTABLE WITH GENERALLY HIGH PRECIPITABLE
WATER VALUES IN PLACE. VERTICAL TOTALS AND LAPSE RATES LOOK MARGINAL
FOR STRONG...POSSIBLY SEVERE...CONVECTION BUT FORCING WILL BE
QUESTIONABLE AND WILL DEPEND ON THE PASSAGE OF WAVES IN UPPER NWLY
FLOW AND IN BOUNDARIES POSSIBLY LEFT FROM ACTIVITY OVERNIGHT. OF
INTEREST IS THE FACT THAT 850 MB DEWPOINTS AND MID LEVEL RH FIELDS
SUGGEST A SLIGHTLY DRIER AIR MASS BEGINNING TO WORK ITS WAY INTO
SWRN ZONES. THE OUTLOOK WILL REMAIN QUIET AS FAR AS STORMS GO FOR
TOMORROW UNTIL A BETTER HANDLE IS REACHED ON FORCING. WITH AFTERNOON
HEATING AND GOOD MOISTURE IN PLACE SCATTERED CONVECTION WILL BE LEFT
IN FOR MOST OF THE REGION WITH ISOLATED COVERAGE OVER SWRN ZONES.

THE UPPER TROUGH TO OUR EAST DIGS ENOUGH TO BEGIN TO INCREASE FLOW
FARTHER W INTO OUR AREA TUESDAY NIGHT. THE APPROACHING SURFACE
BOUNDARY ALSO EDGES FARTHER S INTO NRN MS BY SUNRISE WEDNESDAY. THE
MODELS ARE INDICATING AN INCREASE IN LAPSE RATES FOR TUESDAY NIGHT
INTO WEDNESDAY MORNING AND A POTENTIAL FOR SHWRS/TSTMS TO WORK INTO
THE AREA TUESDAY NIGHT AHEAD OF THE SURFACE TROUGH. THE BOUNDARY
WILL WORK ITS WAY SWD INTO THE REGION DURING THE DAY WEDNESDAY WITH
REMNANTS OF THE TROUGH STALLING ACROSS THE AREA WEDNESDAY NIGHT.
SCATTERED POPS WILL BE PAINTED ACROSS THE AREA WEDNESDAY BUT POPS
MAY BE INCREASED DURING LATER RUNS WHEN A MORE PRECISE PLACEMENT OF
LOW LEVEL CONVERGENCE CAN BE MADE.

HAVE MAINTAINED POPS FROM THE PREVIOUS FORECAST OVER THE LOWER
NUMBERS ADVERTISED BY THE LATEST MAV MOS RUN FOR ALL BUT TUESDAY
NIGHT. UNDERCUT MAV MOS HIGHS SLIGHTLY FOR THE SHORT
TERM...ESPECIALLY OVER ERN ZONES...WHILE INCREASING LOWS SLIGHTLY
FOR TUESDAY NIGHT AND WEDNESDAY NIGHT. /03/

LONG TERM...THE MAIN STORY FOR THE MED RANGE/LONG TERM (THU-MON)
WILL BE THE CONTINUATION OF THE NW FLOW PATTERN AND THE CHALLENGING
ASPECT OF TIMING DISTURBANCES AS THEY MOVE THROUGH THE FLOW AND SPARK
CONVECTION. ONE THING OF NOTE IS THAT BOTH THE GFS/EURO INDICATE THAT
THIS PATTERN SHOULD NOT EXIST THE ENTIRE TIME AS SOME RIDGING WILL
BRIEFLY MAKE AN APPEARANCE TO LIMIT PRECIP POTENTIAL FOR A COUPLE
PERIODS.

FOR THU-WED NGT...GLOBAL MODELS CONTINUE TO SHOW ANOTHER S/WV
IMPACTING THE FORECAST AREA IN OUR NW FLOW PATTERN. THIS WILL LIKELY
BE THE 3RD S/WV IN AS MANY DAYS AND DETERMINING DETAILS WILL BE VERY
TOUGH AS SPECIFICS FROM PREV DAYS ACTIVITY HAVE A LARGE BEARING ON
THE NEXT DAY.

BY THU...SOME S/WV RIDGING DEVELOPS AS THE LONG WAVE TROUGH AXIS
PUSHES EASTWARD. THIS LOOKS TO ALLOW FOR A PERIOD WHERE PRECIP
CHANCES WILL BE LIMITED...BUT SOME POPS WILL STILL EXIST AS
SURPRISES ARE A REAL POSSIBILITY IN SUCH A PATTERN.

FOR THE WEEKEND...BOTH THE EURO/GFS SHOW A RETURN TO THE NW FLOW
PATTERN AS STOUT SYSTEM HELPS CARVE OUT A LARGER TROUGH. TIMING ON
THIS IS A BIG QUESTION...BUT AT THIS POINT...FOLLOWING GUIDANCE IS
THE BEST COURSE. LOOK FOR ABOVE NORMAL PRECIP CHANCES TO EXIST
DURING THIS TIME.

AS FOR TEMPS...THE GFS CONTINUE TO BE THE MOST AGGRESSIVE WITH HIGH
TEMPS FOR THE ENTIRE EXTENDED. BASED ON TRENDS THIS SUMMER AND THE
FACT THAT THE AREA WILL SEE PRECIP ON SEVERAL OCCASION THIS
WEEK...LOWERING HIGH TEMPS A FEW DEGREES WAS DONE WHICH IS
CONSISTENT WITH PREV FORECASTS. /CME/

&&

.PRELIMINARY POINT TEMPS/POPS...
JACKSON       75  91  73  92 /  24  31  21  33
MERIDIAN      72  90  72  92 /  36  37  30  41
VICKSBURG     74  92  72  94 /  16  24  16  31
HATTIESBURG   73  92  74  93 /  34  40  17  23
NATCHEZ       73  93  72  92 /  13  24   9  20
GREENVILLE    76  94  74  92 /  31  32  29  37
GREENWOOD     73  93  72  91 /  33  40  36  38

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&

$$

DC/19/03/CME






AREA FORECAST DISCUSSION...UPDATED

NWS JACKSON MS

 123 PM CDT SUN JUL 21 2013

.UPDATE...
QUICK UPDATE TO ADJUST POPS FOR LATEST TRENDS...PRIMARILY TO RAISE TO
LIKELY CATEGORY S AND E AS CONVECTION CONTINUE TO BUILD/PROPAGATE N ALONG
N EDGE OF CONVECTIVE MASS TO OUR S. PER LAPS AND RUC ACTIVITY SHOULD
BE BUILDING INTO A MORE UNSTABLE AIRMASS WITH MAX OF SBLI NEAR -8
OVER EC MS. HENCE EXPECT ACTIVITY TO BECOME A BIT MORE ROBUST WITH
CONTINUED POTENTIAL FOR SOME STRONGER STORMS.

&&

.PREV DISCUSSION... /ISSUED 1028 AM CDT SUN JUL 21 2013/

UPDATE...
MAKING SOME ADJUSTMENTS TO THE FORECAST FOR THE FIRST COUPLE OF
PERIODS...INCLUDING ADJUSTING POPS A LITTLE FOR TODAY...CUTTING POPS
FOR TONIGHT...AND TWEAKING TEMPS UP A HAIR FOR THIS AFTERNOON.

SHORT TERM...
WATER VAPOR AND RUC STREAMLINE ANALYSIS SHOW REMNANT UPPER LEVEL LOW
CURRENTLY OVER THE LOWER DELTA REGION. SHORT TERM MODELS SHOW THIS
LOW OPENING UP AND DRIFTING EAST TODAY. BLENDED TOTAL PW PRODUCT
SHOWS BEST DEEP MOISTURE OVER S/E AREAS AHEAD OF UPPER LOW...BUT EVEN
RIGHT UNDER THE UPPER LOW WHERE A MIN IN MOISTURE EXISTS...PW VALUES
STILL AROUND 1.8 INCHES. CU IS BEGINNING TO FORM ACROSS THE
AREA...AND WITH CONTINUED HEATING AND SUPPORT FROM UPPER SYSTEM
EXPECT CONVECTIVE COVERAGE TO INCREASE THROUGH THE AFTERNOON. SHORT
TERM MESOSCALE MODELS AGREE ON BEST COVERAGE OVER S/E AREAS...AND
THIS GENERALLY SEEMS SUPPORTED BY LATEST TRENDS IN OBSERVATIONAL
DATA. DID TWEAK POPS UP A HAIR TO GET ALL AREAS TO AT LEAST 30 PCT
BUT OVERALL TREND OF GOING FORECAST LOOKS OK. MORNING SOUNDING
ANALYSIS AND LOCAL RUC MICROBURST PARAMETER SUGGEST THAT CURRENT
WORDING IN HWO AND GRAPHICAST OF SOME STRONG STORMS SEEMS REASONABLE.
RUC SHOWS 500 MB TEMPS COOLING A DEG OR TWO MOST OF AREA AS MID LEVEL
COLD POOL WITH UPPER LOW MOVES ACROSS...AND THIS SHOULD HELP ENHANCE
INSTABILITY AND LAPSE RATES A BIT. THUS WOULD CERTAINLY NOT RULE OUT
A COUPLE OF SEVERE STORMS THIS AFTERNOON...PARTICULARLY WITH ANY
CELL/BOUNDARY MERGERS. WITH PRETTY COMPLETE LACK OF CLOUDINESS BEFORE
BUILDING CU...TEMPS HAVE WARMED QUITE QUICKLY THIS MORNING. ADJUSTED
DIURNAL CURVE FOR MORE RAPID WARMUP AND TWEAKED MAXES UP A DEG OR
TWO.

WITH REGARD TO TONIGHT...THINKING THAT 00Z GFS MAY HAVE BEEN A WET
ANOMALY BASED ON GEFS GUIDANCE...LATEST 06Z GFS...AND 00Z ECMWF. MAIN
CONCERN FOR CONVECTION TONIGHT IS LIKELY WAVE THAT HAS BEEN PRODUCING
SOME CONVECTION OVER NE OK THIS MORNING...AND IT IS CERTAINLY
PLAUSIBLE THAT THIS SYSTEM COULD INCITE SOME OVERNIGHT CONVECTION
ESPECIALLY OVER NORTHERN AREAS. HOWEVER...HIGH CHANCE TO CATEGORICAL
POPS IN CURRENT FORECAST AS PROVIDED BY 00Z GFS SEEM A BIT
BULLISH...AND WILL REDUCE POPS BY 15-30 PCT AREA WIDE FOR TONIGHT.

&&

.AVIATION...

VFR CONDITIONS WERE BEING OBSERVED AT 14Z AND WILL PREVAIL AT ALL
SITES THROUGH 18Z. MODELS INDICATE GREATEST COVERAGE OF TSTMS THIS
AFTN/EVNG WL BE ACROSS THE SRN HALF OF THE AREA. BRIEF IFR CONDITIONS
CAN BE EXPECTED AROUND THE STORMS FROM 18Z-04Z. VFR CONDITIONS WL
RESUME AREAWIDE THIS EVNG AND CONTINUE THROUGH 09Z MON. AFTER
09Z...MVFR VSBYS WL BE PSBL MAINLY ACROSS THE SRN HALF OF THE AREA.
CONVECTION MAY GET AN EARLY START ACROSS THE NORTH MONDAY MORNING DUE
TO A DISTURBANCE IN THE NW FLOW ALOFT. /22/

&&

.PRELIMINARY POINT TEMPS/POPS...
JACKSON       73  92  76  94 /  33  48  27  29
MERIDIAN      72  91  72  96 /  35  61  38  41
VICKSBURG     73  93  75  94 /  30  41  21  21
HATTIESBURG   72  92  74  95 /  29  60  34  31
NATCHEZ       73  91  75  92 /  31  41  21  17
GREENVILLE    73  94  75  95 /  34  41  31  24
GREENWOOD     72  93  75  95 /  40  48  40  32

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&

$$

AEG







AREA FORECAST DISCUSSION...UPDATED

NWS JACKSON MS

 1028 AM CDT SUN JUL 21 2013

.UPDATE...
MAKING SOME ADJUSTMENTS TO THE FORECAST FOR THE FIRST COUPLE OF
PERIODS...INCLUDING ADJUSTING POPS A LITTLE FOR TODAY...CUTTING POPS
FOR TONIGHT...AND TWEAKING TEMPS UP A HAIR FOR THIS AFTERNOON.

&&

.SHORT TERM...
WATER VAPOR AND RUC STREAMLINE ANALYSIS SHOW REMNANT UPPER LEVEL LOW
CURRENTLY OVER THE LOWER DELTA REGION. SHORT TERM MODELS SHOW THIS
LOW OPENING UP AND DRIFTING EAST TODAY. BLENDED TOTAL PW PRODUCT
SHOWS BEST DEEP MOISTURE OVER S/E AREAS AHEAD OF UPPER LOW...BUT EVEN
RIGHT UNDER THE UPPER LOW WHERE A MIN IN MOISTURE EXISTS...PW VALUES
STILL AROUND 1.8 INCHES. CU IS BEGINNING TO FORM ACROSS THE
AREA...AND WITH CONTINUED HEATING AND SUPPORT FROM UPPER SYSTEM
EXPECT CONVECTIVE COVERAGE TO INCREASE THROUGH THE AFTERNOON. SHORT
TERM MESOSCALE MODELS AGREE ON BEST COVERAGE OVER S/E AREAS...AND
THIS GENERALLY SEEMS SUPPORTED BY LATEST TRENDS IN OBSERVATIONAL
DATA. DID TWEAK POPS UP A HAIR TO GET ALL AREAS TO AT LEAST 30 PCT
BUT OVERALL TREND OF GOING FORECAST LOOKS OK. MORNING SOUNDING
ANALYSIS AND LOCAL RUC MICROBURST PARAMETER SUGGEST THAT CURRENT
WORDING IN HWO AND GRAPHICAST OF SOME STRONG STORMS SEEMS REASONABLE.
RUC SHOWS 500 MB TEMPS COOLING A DEG OR TWO MOST OF AREA AS MID LEVEL
COLD POOL WITH UPPER LOW MOVES ACROSS...AND THIS SHOULD HELP ENHANCE
INSTABILITY AND LAPSE RATES A BIT. THUS WOULD CERTAINLY NOT RULE OUT
A COUPLE OF SEVERE STORMS THIS AFTERNOON...PARTICULARLY WITH ANY
CELL/BOUNDARY MERGERS. WITH PRETTY COMPLETE LACK OF CLOUDINESS BEFORE
BUILDING CU...TEMPS HAVE WARMED QUITE QUICKLY THIS MORNING. ADJUSTED
DIURNAL CURVE FOR MORE RAPID WARMUP AND TWEAKED MAXES UP A DEG OR
TWO.

WITH REGARD TO TONIGHT...THINKING THAT 00Z GFS MAY HAVE BEEN A WET
ANOMALY BASED ON GEFS GUIDANCE...LATEST 06Z GFS...AND 00Z ECMWF. MAIN
CONCERN FOR CONVECTION TONIGHT IS LIKELY WAVE THAT HAS BEEN PRODUCING
SOME CONVECTION OVER NE OK THIS MORNING...AND IT IS CERTAINLY
PLAUSIBLE THAT THIS SYSTEM COULD INCITE SOME OVERNIGHT CONVECTION
ESPECIALLY OVER NORTHERN AREAS. HOWEVER...HIGH CHANCE TO CATEGORICAL
POPS IN CURRENT FORECAST AS PROVIDED BY 00Z GFS SEEM A BIT
BULLISH...AND WILL REDUCE POPS BY 15-30 PCT AREA WIDE FOR TONIGHT.

&&

.AVIATION...
VFR CONDITIONS WERE BEING OBSERVED AT 14Z AND WILL PREVAIL AT ALL
SITES THROUGH 18Z. MODELS INDICATE GREATEST COVERAGE OF TSTMS THIS
AFTN/EVNG WL BE ACROSS THE SRN HALF OF THE AREA. BRIEF IFR CONDITIONS
CAN BE EXPECTED AROUND THE STORMS FROM 18Z-04Z. VFR CONDITIONS WL
RESUME AREAWIDE THIS EVNG AND CONTINUE THROUGH 09Z MON. AFTER
09Z...MVFR VSBYS WL BE PSBL MAINLY ACROSS THE SRN HALF OF THE AREA.
CONVECTION MAY GET AN EARLY START ACROSS THE NORTH MONDAY MORNING DUE
TO A DISTURBANCE IN THE NW FLOW ALOFT. /22/

&&

.PRELIMINARY POINT TEMPS/POPS...
JACKSON       93  72  90  75 /  31  43  55  36
MERIDIAN      92  72  91  72 /  40  47  62  45
VICKSBURG     94  74  92  73 /  32  44  49  29
HATTIESBURG   92  73  92  74 /  45  27  64  42
NATCHEZ       93  74  90  75 /  44  27  53  27
GREENVILLE    95  74  92  76 /  31  58  52  39
GREENWOOD     94  72  91  75 /  30  57  56  44

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&

$$

AEG/MME






AREA FORECAST DISCUSSION...UPDATED

NWS ST LOUIS MO

 956 PM CDT MON JUL 22 2013

.UPDATE...
ISSUED AT 948 PM CDT MON JUL 22 2013

MAIN ITEM OF INTEREST FOR THE REST OF NIGHT IS THE PROBABILITY OF
SHOWERS AND THUNDERSTORMS. THE GREATEST ATTENTION IS FOCUSED ON
THE LOOSELY ORGANIZED MCS ACROSS IOWA THAT IS OCCURRING AHEAD OF
THE ENCROACHING COLD FRONT. THE SYSTEM HAS DEVELOPED A DECENT COLD
POOL AND THERE IS SOME VIGOROUS CONVECTION ALONG THE WESTERN
FLANK. THE LOW LEVEL INFLOW INTO THE SYSTEM IS NOT PARTICULARILY
STRONG AT 20 KTS OR LESS AND FROM THE WEST...BUT THE AIR MASS
ACROSS EASTERN MO INTO WESTERN IL IS QUITE UNSTABLE WITH SBCAPE OF
2000-3000 J/KG. DEEP LAYER SHEAR VECTORS AND CFM VECTORS WOULD
SUGGEST THAT IF THE MCS CAN MAINTAIN SOME ORGANIZATION THAT IT
WOULD TEND TO MOVE SEWD...AND THE WESTERN FLANK OF THE SYSTEM
WOULD HAVE THE BEST CHANCE OF MAINTAINING SOME IDENTITY GIVEN THE
DIRECTION OF LOW LEVEL INFLOW. LOW LEVEL WAA IN ADVANCE OF THE
SYSTEM COULD ALSO GENERATE SOME SCATTERED ACTIVITY GIVEN THE MOIST
AND UNSTABLE AIR MASS IN PLACE. SOME OF THE EARLIER HRRR RUNS
DEPICTED THESE SCENARIOS WITH BOTH SOME SCATTERED WAA DEVELOPMENT
AND SOME DECAYING ELEMENTS OF THE MCS SINKING SEWD THRU ERN MO. AS
A RESULT I HAVE CHANGED THE CONFIGURATION OF THE POPS OVERNIGHT
INTO EARLY TUESDAY AND INCREASED THEM IN A FEW AREAS.

GLASS

&&

.SHORT TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 208 PM CDT MON JUL 22 2013

RELATIVELY QUIET DAY TODAY THANKS TO SUBSIDENCE IN THE WAKE OF THE
SHORTWAVE THAT MOVED ACROSS THE AREA LAST NIGHT. CURRENT SURFACE
ANALYSIS SHOWS A COLD FRONT STRETCHING FROM NEBRASKA...THROUGH
NORTHWEST IOWA AND THEN NORTH BISECTING MINNESOTA. MEANWHILE...
ACTIVE CONVECTION CONTINUES TO REINFORCE AN OUTFLOW BOUNDARY ACROSS
SOUTHWEST KANSAS...OKLAHOMA AND ARKANSAS.

TONIGHT...COLD FRONT IS FORECAST BY ALL MODEL GUIDANCE TO STEADILY
MARCH SOUTHEAST...ENTERING THE NORTHERN CWA BY 12Z. DESPITE THE
APPROACHING COLD FRONT...A SUBTLE SHORTWAVE RIPPLING SOUTHEAST FROM
THE PLAINS AND ABUNDANT LOW LEVEL MOISTURE...THE MODELS REMAIN
STINGY ON QPF TONIGHT. I BELIEVE THIS IS BECAUSE THE CONVECTION THAT
FIRES AHEAD OF THE FRONT WILL LIKELY DISSIPATE/WEAKEN AS IT MOVES
INTO THE NORTHERN CWA LATER THIS EVENING WITH LOSS OF DIURNAL
INSTABILITY...AND THAT ANY NOCTURNAL DEVELOPMENT MAY BE CONFINED
FURTHER WEST WHERE BETTER 850 MOISTURE CONVERGENCE APPEARS LIKELY TO
OCCUR TO THE NORTHEAST OF THE AFOREMENTIONED EFFECTIVE SURFACE
BOUNDARY.

TUESDAY...COLD FRONT WILL BE MOVING THROUGH THE CWA WITH BEST
CHANCES OF THUNDERSTORMS RE FIRING ALONG AND SOUTH OF INTERSTATE 70
BY LATE MORNING/EARLY AFTERNOON. SPC GENEROUSLY PLACED MUCH OF THE
CWA IN A SLIGHT RISK ON THEIR LATEST DAY2 OUTLOOK. PERSONALLY THE
LACK OF ANY SIGNIFICANT SHORTWAVE UPSTREAM HAS ME THINKING THAT
COVERAGE AND THEREFORE SEVERE THREAT MAY REMAIN ISOLATED TO
SCATTERED. HAVE MAINTAINED CHANCE POPS.

TUESDAY NIGHT AND WEDNESDAY...SYNOPTIC SCALE MODELS CONTINUE TO
TREND FURTHER SOUTHWEST WITH THE DEVELOPMENT OF AN MCS...AND HAVE
FOLLOWED SUIT AS HIGH PRESSURE BUILDS INTO THE CWA. GIVEN THE
POSITION OF THE EFFECTIVE BOUNDARY RIGHT NOW...AND THE FACT THAT THE
COLD FRONT WILL HAVE PUSHED IT FURTHER SOUTH...CAN`T IMAGINE MY CWA
BEING IMPACTED BY AN MCS DURING THIS PERIOD. MUCH COOLER
TEMPERATURES ARE EXPECTED ON WEDNESDAY WITH HIGHS IN THE LOWER 80S.

WEDNESDAY NIGHT AND THURSDAY...THE SURFACE RIDGE AXIS SHOULD BE IN
CONTROL OF THE CWA DURING THIS TIME PERIOD WITH BELOW AVERAGE
TEMPERATURES AND MOSTLY CLEAR SKIES.

CVKING

.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 208 PM CDT MON JUL 22 2013

ANOTHER STRONG SHORTWAVE TROF AND COLD FRONT WILL BRING A CHANCE OF
SHOWERS AND THUNDERSTORMS TO THE REGION FRIDAY THROUGH SATURDAY
MORNING. HIGH PRESSURE TAKES HOLD OF THE AREA BY SATURDAY AFTERNOON
AND DRY WEATHER WILL CONTINUE THROUGH SUNDAY NIGHT. TEMPERATURES
WILL BE BELOW NORMAL DURING THIS PERIOD WITH CLOUD COVER AND
PRECIPITATION ON FRIDAY AND THEN COLD ADVECTION THE REMAINDER OF THE
WEEKEND AS 850MB TEMPERATURES DROP INTO THE LOWER TEENS.

CVKING

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 637 PM CDT MON JUL 22 2013

THE PRIMARY CONCERN FOR TONIGHT IS THE POSSIBILITY OF
THUNDERSTORMS ACROSS THE AREA. A COLD FRONT IS DROPPING SLOWLY
SOUTH THROUGH IOWA...AND IT`S PRODUCING STORMS NORTH OF DES
MOINES. CURRENT THINKING IS THAT THESE STORMS WILL WEAKEN THIS
EVENING...BUT COULD EFFECT PARTS OF NORTHERN MISSOURI AND WEST
CENTRAL ILLINOIS. ANOTHER AREA OF STORMS MAY DEVELOP LATE THIS
EVENING/OVERNIGHT OVER PARTS OF CENTRAL/SOUTH CENTRAL MISSOURI AND
MOVE SOUTHEAST ON A WEAK LOW LEVEL JET. AM NOT VERY CONFIDENT IN
FORECASTING STORMS TONIGHT GIVEN THAT THE STORMS UP NORTH SHOULD
BE WEAKENING AS WE LOSE DAYTIME HEATING...AND THAT THE FORCING FOR
STORMS IN CENTRAL/SOUTH CENTRAL MISSOURI IS RATHER WEAK. ANY
STORMS THAT FORM COULD PRODUCE IFR VSBYS IN HEAVY RAIN AND
OCCASIONAL GUSTY WINDS. EXPECT VFR CONDITIONS OUTSIDE OF STORMS.

THE COLD FRONT WILL CONTINUE MOVING SLOWLY SOUTH ON TUESDAY. IT
WILL BE NEAR THE I-70 CORRIDOR FOR MUCH OF THE DAY DUE TO THIS
SLOW MOVEMENT...AND THUNDERSTORMS WILL AGAIN BE POSSIBLE ALONG AND
SOUTH OF THE FRONT.

SPECIFICS FOR KSTL...

THE PRIMARY CONCERN FOR TONIGHT IS THE POSSIBILITY OF
THUNDERSTORMS ACROSS THE AREA. A COLD FRONT IS DROPPING SLOWLY
SOUTH THROUGH IOWA...AND IT`S PRODUCING STORMS NORTH OF DES
MOINES. CURRENT THINKING IS THAT THESE STORMS WILL WEAKEN THIS
EVENING...AND ARE NOT LIKELY TO AFFECT LAMBERT. ANOTHER AREA OF
STORMS MAY DEVELOP LATE THIS EVENING/OVERNIGHT OVER PARTS OF
CENTRAL/SOUTH CENTRAL MISSOURI AND MOVE SOUTHEAST ON A WEAK LOW
LEVEL JET. SOME MODEL GUIDANCE IS HINTING THAT THIS AREA OF STORMS
COULD CLIP LAMBERT LATE THIS EVENING...BUT IN THE EVENT THAT
STORMS DO FORM IT LOOKS LIKE THE MAIN THRUST WILL BE SOUTHWEST OF
THE TERMINAL. THIS IS A LOW CONFIDENCE FORECAST GIVEN THE
UNCERTAINTIES. REGARDLESS...EXPECT VFR FLIGHT CONDITIONS TONIGHT UNLESS
STORMS TO AFFECT THE TERMINAL.

THE COLD FRONT WILL CONTINUE MOVING SLOWLY SOUTH ON TUESDAY. IT
WILL BE NEAR THE STL METRO AREA FOR MUCH OF THE DAY DUE TO THIS
SLOW MOVEMENT...AND THUNDERSTORMS WILL AGAIN BE POSSIBLE ALONG AND
SOUTH OF THE FRONT.

CARNEY

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&

$$

WFO LSX







AREA FORECAST DISCUSSION

NWS ST LOUIS MO

 400 AM CDT SUN JUL 21 2013

.SHORT TERM...(THROUGH LATE TONIGHT)
ISSUED AT 342 AM CDT SUN JUL 21 2013

EARLY THIS MORNING...A STALLED OUT AND WEAKLY-DEFINED SFC FRONTAL
BOUNDARY EXISTED JUST N OF THE INTERSTATE 70 CORRIDOR.  PCPN THAT
HAD DEVELOPED EARLIER IN THE NIGHT IN THE AIRMASS NEAR IT OR TO THE
S OF IT HAS SINCE DISSIPATED.  A NEARLY STATIONARY MCS EXISTED NEAR
THE INTERSECTION OF KS-MO-OK AND IF ANY MOVEMENT IS EXPECTED OF
IT...IT SHOULD BE A SLOW ONE TO THE SE.  FURTHER TO THE NW...A
WEAKENING COMPLEX OF TSRA WAS OVER THE MID MO VALLEY IN ERN NEBRASKA
MOVING E-SE WITH ANOTHER BATCH OF TSRA FURTHER TO THE W OVER THE HI
PLAINS OF WRN SD AND WRN NEBRASKA.  THIS SEWD MOVEMENT OF SYSTEMS IS
COURTESY OF WEAK NW UPPER LEVEL FLOW THANKS TO THE UPPER LEVEL RIDGE
RETREATING TO THE SWRN CONUS.  TEMPS AROUND THE AREA ARE IN THE LO
70S FOR MOST AREAS...WITH 60S IN THE FAR NRN FA.

THE MODELS TAKE THE FRONTAL BOUNDARY AND CONTINUE TO STALL IT IN ITS
CURRENT POSITION JUST N OF THE INTERSTATE 70 CORRIDOR THIS
MORNING...AND THEN RETREAT IT BACK TO THE N THIS AFTERNOON.  IF THE
AIRMASS IS ANYTHING LIKE THE PAST COUPLE OF DAYS...IT WILL BE
EASIEST TO GENERATE TSRA ALG-S OF THE FRONT WHERE CINH WILL BE CLOSE
TO NIL AND ENOUGH LOCALLY GENERATED LO LEVEL CONVERGENCE AND/OR
SMALL UPPER LEVEL DISTURBANCES WILL PROVIDE ALL THE FOCUS NEEDED TO
GET TSRA GOING.  TIMING-WISE...LOOK FOR NEW DEVELOPMENT FROM MIDDAY
ON WITH THE HEATING OF THE DAY AND REDUCTION OF CINH TO NEAR ZERO.

THE MORE ORGANIZED SYSTEM TO OUR SW IS NOT EXPECTED TO GET HERE
WHILE THE OTHER ORGANIZED SYSTEM TO OUR NW OVER NEBRASKA IS EXPECTED
TO WEAKEN AS IT MOVES INTO MORE STABLE AIR BEHIND THE SFC FRONT
ACROSS NE MO AND SE IA.  HOWEVER...SOME MEASURE OF REORGANIZATION IS
EXPECTED FROM THE REMNANT MCV OF THIS SYSTEM AS IT SLIDES THRU SRN
IA TODAY BUT TIMING-WISE...PROBABLY WON/T HAVE MUCH OF A SAY IN THE
FCST FOR OUR AREA UNTIL LATE IN THE DAY IN NE MO.  AND SO...HAVE
SLID POPS TODAY BACK TO HI-END CHC CATEGORY FROM LIKELYS EARLIER AS
THIS UPPER LEVEL SYSTEM FROM THE NW IS EXPECTED TO AFFECT OUR AREA
MORE SLOWLY THAN ORIGINALLY ANTICIPATED...WITH THE LIKELYS COMMUTED
FOR MOST AREAS TO TONIGHT WHEN THE UPPER LEVEL SYSTEM MOVES THRU.

VERY LITTLE CHANGE IN MAX TEMPS TODAY AND MIN TEMPS TONIGHT FROM
PREVIOUS FCST...WITH MOST LOCATIONS REMAINING IN THE 80S TODAY WITH
STL METRO AREA POSSIBLY REACHING 90F...AND MINS TONIGHT AROUND 70.

TES

.LONG TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 400 AM CDT SUN JUL 21 2013

NW UPPER LEVEL FLOW WILL PERSIST THRU THE PERIOD INTO NEXT WEEKEND.
THIS WILL ENSURE THE EXTREME HEAT WILL REMAIN AT BAY...OR IF IT DOES
INTRUDE IT WILL NOT LAST FOR LONG.  AND UNTIL SFC FRONTAL BOUNDARIES
CAN MAKE A DECENT PUSH THRU...THIS SETUP ALSO STRONGLY ALLUDES TO A
CONTINUATION OF THE ACTIVE WX PATTERN THAT WE HAVE SEEN IN RECENT
DAYS WITH A THREAT FOR TSRA.

WE WILL EITHER BE IN A WARM SECTOR SETUP OR HAVE THE PRESENCE OF A
FRONT OVER OUR AREA THRU TUESDAY NIGHT...AND THUS WILL HAVE THE
LINGERING CHC FOR TSRA DURING THAT TIME.  A CDFNT FINALLY LOOKS TO
PUSH THRU BY WEDNESDAY THEN SHUNTING THE BETTER RAIN CHCS TO THE S
AND SW AND PROVIDING A COUPLE OF MAINLY DRY DAYS WED AND THURS.

MODELS CONTINUE TO ZERO IN ON WHAT COULD BE A SIGNIFICANT WIDESPREAD
RAIN EVENT FOR LATE WEEK WITH APPROACH OF ANOTHER CDFNT AND WAVE OF
LO PRES ALONG THIS FRONT THANKS TO A STRONG MID LEVEL SHORTWAVE
TROF.  TIMING RIGHT NOW LOOKS TO BE FROM LATE FRIDAY THRU EARLY
SATURDAY AND HAS BEEN FAIRLY CONSISTENT RUN-TO-RUN THE PAST COUPLE
OF DAYS.

A BRIEF RETURN OF THE HEAT AND HUMIDITY IS ANTICIPATED FOR MUCH OF
OUR AREA MONDAY AND TUESDAY AS THE FRONT RIDES TO THE N MONDAY THEN
DROPS S AGAIN LATE TUESDAY.  AMBIENT TEMPS IN THE 90-95 RANGE SHOULD
YIELD HEAT INDEX VALUES AROUND 100 IN SPOTS...MAINLY STL METRO.

IF THE FRONT DOES MAKE A GOOD PUSH THRU ON WEDNESDAY...TEMPS WILL
STRUGGLE TO GET ABOVE 85 FOR THE REMAINDER OF THE PERIOD WITH A
REINFORCING SHOT OF COOLER AIR DUE ON EITHER FRIDAY OR SATURDAY.

TES

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1142 PM CDT SAT JUL 20 2013

LATEST CONVECTIVE TRENDS SHOW THAT CONVECTIVE CLUSTER EXTENDING
FROM SOUTH OF JEFFERSON CITY IS DEVELOPING NORTHWEST TOWARDS
SEDELIA MISSOURI AND WILL GRADUALLY MEET WITH DEVELOPING
CONVECTION OVER NORTHWEST MISSOURI. THE LATEST HRRR MESOSCALE
MODEL RUN SHOWS THE CONVECTIVE CLUSTER SOUTHWEST OF JEFFERSON CITY
HOWEVER THE LATEST RUN DOES NOT SHOW THE DEVELOPING CONVECTION
OVER NORTHWEST MISSOURI ATTM. THE AREA OF CONVECTION IS WTIHIN THE
AXIS OF HIGHEST MLCAPE WHICH EXTENDS NORTHWEST - SOUTHEAST ACROSS
NORTHWEST INTO SOUTH CENTRAL MISSOURI. CLUSTER OF THUNDERSTORMS
FROM SOUTHEAST SOUTH DAKOTA THROUGH CENTRAL NEBRASKA ASSOCIATED
WITH UPPER LEVEL DISTURBANCE OVER THE NORTHERN PLAINS. THIS
DISTURBANCE WILL MOVE EAST-SOUTHEAST ALONG THE MEAN NORTHWEST FLOW
AND BRING INCREASING THREAT TO SHOWERS AND THUNDERSTORMS OVER
CENTRAL MISSOURI BY ;ATE MORNING TO MID DAY AND MOVE INTO EASTERN
SECTIONS OF MISSOURI AND SOUTHWEST ILLINOIS BY NID TO LATE
AFTERNOON.

SPECIFICS FOR KSTL...WINDS WILL BE LIGHT AND VARIABLE THROUGH
DAYBREAK ON SUNDAY. THEN WINDS WILL BECOME SOUTHEAST AT 5 TO 8
KTS. ISOLATED SHOWERS ANDT HUNDERSTORMS ARE POSSIBLE BY LATE
MORNING FOR STL BUT HIGHER CHANCES INCREASE BY MID AFTERNOON.
CEILING WILL REMAIN AOA 10000 FT BUT LOWER CEILNGS ARE EXPECTED BY
EARLY TO MID AFTERNOON AS THUNDERSTORMS THREAT WILL INCREASE
DURING THE MID TO LATE AFTERNOON HOURS OVER STL. GUSTING SURFACE
WINDS UP TO 30 TO 35 KTS ARE POSSIBLE WITH THE STRONGER STORMS.

PRZYBYLINSKI

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&

$$

WFO LSX





AREA FORECAST DISCUSSION

NWS ST LOUIS MO

 342 AM CDT SUN JUL 21 2013

.SHORT TERM...(THROUGH LATE TONIGHT)
ISSUED AT 342 AM CDT SUN JUL 21 2013

EARLY THIS MORNING...A STALLED OUT AND WEAKLY-DEFINED SFC FRONTAL
BOUNDARY EXISTED JUST N OF THE INTERSTATE 70 CORRIDOR.  PCPN THAT
HAD DEVELOPED EARLIER IN THE NIGHT IN THE AIRMASS NEAR IT OR TO THE
S OF IT HAS SINCE DISSIPATED.  A NEARLY STATIONARY MCS EXISTED NEAR
THE INTERSECTION OF KS-MO-OK AND IF ANY MOVEMENT IS EXPECTED OF
IT...IT SHOULD BE A SLOW ONE TO THE SE.  FURTHER TO THE NW...A
WEAKENING COMPLEX OF TSRA WAS OVER THE MID MO VALLEY IN ERN NEBRASKA
MOVING E-SE WITH ANOTHER BATCH OF TSRA FURTHER TO THE W OVER THE HI
PLAINS OF WRN SD AND WRN NEBRASKA.  THIS SEWD MOVEMENT OF SYSTEMS IS
COURTESY OF WEAK NW UPPER LEVEL FLOW THANKS TO THE UPPER LEVEL RIDGE
RETREATING TO THE SWRN CONUS.  TEMPS AROUND THE AREA ARE IN THE LO
70S FOR MOST AREAS...WITH 60S IN THE FAR NRN FA.

THE MODELS TAKE THE FRONTAL BOUNDARY AND CONTINUE TO STALL IT IN ITS
CURRENT POSITION JUST N OF THE INTERSTATE 70 CORRIDOR THIS
MORNING...AND THEN RETREAT IT BACK TO THE N THIS AFTERNOON.  IF THE
AIRMASS IS ANYTHING LIKE THE PAST COUPLE OF DAYS...IT WILL BE
EASIEST TO GENERATE TSRA ALG-S OF THE FRONT WHERE CINH WILL BE CLOSE
TO NIL AND ENOUGH LOCALLY GENERATED LO LEVEL CONVERGENCE AND/OR
SMALL UPPER LEVEL DISTURBANCES WILL PROVIDE ALL THE FOCUS NEEDED TO
GET TSRA GOING.  TIMING-WISE...LOOK FOR NEW DEVELOPMENT FROM MIDDAY
ON WITH THE HEATING OF THE DAY AND REDUCTION OF CINH TO NEAR ZERO.

THE MORE ORGANIZED SYSTEM TO OUR SW IS NOT EXPECTED TO GET HERE
WHILE THE OTHER ORGANIZED SYSTEM TO OUR NW OVER NEBRASKA IS EXPECTED
TO WEAKEN AS IT MOVES INTO MORE STABLE AIR BEHIND THE SFC FRONT
ACROSS NE MO AND SE IA.  HOWEVER...SOME MEASURE OF REORGANIZATION IS
EXPECTED FROM THE REMNANT MCV OF THIS SYSTEM AS IT SLIDES THRU SRN
IA TODAY BUT TIMING-WISE...PROBABLY WON/T HAVE MUCH OF A SAY IN THE
FCST FOR OUR AREA UNTIL LATE IN THE DAY IN NE MO.  AND SO...HAVE
SLID POPS TODAY BACK TO HI-END CHC CATEGORY FROM LIKELYS EARLIER AS
THIS UPPER LEVEL SYSTEM FROM THE NW IS EXPECTED TO AFFECT OUR AREA
MORE SLOWLY THAN ORIGINALLY ANTICIPATED...WITH THE LIKELYS COMMUTED
FOR MOST AREAS TO TONIGHT WHEN THE UPPER LEVEL SYSTEM MOVES THRU.

VERY LITTLE CHANGE IN MAX TEMPS TODAY AND MIN TEMPS TONIGHT FROM
PREVIOUS FCST...WITH MOST LOCATIONS REMAINING IN THE 80S TODAY WITH
STL METRO AREA POSSIBLY REACHING 90F...AND MINS TONIGHT AROUND 70.

TES

.LONG TERM...(SUNDAY THROUGH NEXT SATURDAY)
ISSUED AT 252 PM CDT SAT JUL 20 2013

(SUNDAY THROUGH TUESDAY)

FOCUS THRU THE PERIOD CONTINUES TO BE PRECIP CHANCES.

MDLS ARE IN RELATIVELY GOOD AGREEMENT WITH RESPECT TO MASS FIELDS
AND IN GENERAL...HAVE A GENERAL CONSENSUS ON HOW THINGS WILL PAN
OUT THRU THIS PERIOD. THERE ARE SOME DIFFERENCES IN TIMING AS WELL
AS WHAT FEATURES WILL PRODUCE PRECIP AND WHICH MAY NOT.
OVERALL...HAVE TRENDED TWD A GFS/LOCAL WRF SOLN WHICH ARE IN BETTER
AGREEMENT THAN THE OTHER OPERATIONAL GUIDANCE.

NOT MUCH IN THE WAY OF CHANGES TO THE PREV FORECAST WRT POPS OR
TEMPS. LOWERED POPS ACROSS NRN PORTIONS OF THE CWA ON MON. THE S/W
IS NOW PROGD TO BE E OF THOSE AREAS BY MON MORNING...BUT WILL KEEP
LOW POPS FOR UNCERTAINTY IN TIMING.

(WEDNESDAY THROUGH SATURDAY)

NOT MUCH IN THE WAY OF CHANGES FROM THE PREV FORECAST THRU THIS
PERIOD. MDLS ARE IN GENERALLY GOOD AGREEMENT REGARDING MASS FIELDS.

EXPECT THIS PERIOD TO OVERALL BE COOLER WITH PRECIP CHANCES
CONTINUING THRU WED. THURS REMAINS DRY WITH THE SFC RIDGE SETTLED
OVER THE AREA. HOWEVER...MDLS TIMING THE NEXT S/W AND ASSOCIATED
PRECIP INTO THE AREA BY FRI AND REMAINING OVER PORTIONS OF THE CWA
INTO SAT. KEPT POPS ON THE LOWER SIDE DUE TO UNCERTAINTY IN TIMING
AND WILL INCREASE AS CONFIDENCE BUILDS AND TIME APPROACHES.

TILLY

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1142 PM CDT SAT JUL 20 2013

LATEST CONVECTIVE TRENDS SHOW THAT CONVECTIVE CLUSTER EXTENDING
FROM SOUTH OF JEFFERSON CITY IS DEVELOPING NORTHWEST TOWARDS
SEDELIA MISSOURI AND WILL GRADUALLY MEET WITH DEVELOPING
CONVECTION OVER NORTHWEST MISSOURI. THE LATEST HRRR MESOSCALE
MODEL RUN SHOWS THE CONVECTIVE CLUSTER SOUTHWEST OF JEFFERSON CITY
HOWEVER THE LATEST RUN DOES NOT SHOW THE DEVELOPING CONVECTION
OVER NORTHWEST MISSOURI ATTM. THE AREA OF CONVECTION IS WTIHIN THE
AXIS OF HIGHEST MLCAPE WHICH EXTENDS NORTHWEST - SOUTHEAST ACROSS
NORTHWEST INTO SOUTH CENTRAL MISSOURI. CLUSTER OF THUNDERSTORMS
FROM SOUTHEAST SOUTH DAKOTA THROUGH CENTRAL NEBRASKA ASSOCIATED
WITH UPPER LEVEL DISTURBANCE OVER THE NORTHERN PLAINS. THIS
DISTURBANCE WILL MOVE EAST-SOUTHEAST ALONG THE MEAN NORTHWEST FLOW
AND BRING INCREASING THREAT TO SHOWERS AND THUNDERSTORMS OVER
CENTRAL MISSOURI BY ;ATE MORNING TO MID DAY AND MOVE INTO EASTERN
SECTIONS OF MISSOURI AND SOUTHWEST ILLINOIS BY NID TO LATE
AFTERNOON.

SPECIFICS FOR KSTL...WINDS WILL BE LIGHT AND VARIABLE THROUGH
DAYBREAK ON SUNDAY. THEN WINDS WILL BECOME SOUTHEAST AT 5 TO 8
KTS. ISOLATED SHOWERS ANDT HUNDERSTORMS ARE POSSIBLE BY LATE
MORNING FOR STL BUT HIGHER CHANCES INCREASE BY MID AFTERNOON.
CEILING WILL REMAIN AOA 10000 FT BUT LOWER CEILNGS ARE EXPECTED BY
EARLY TO MID AFTERNOON AS THUNDERSTORMS THREAT WILL INCREASE
DURING THE MID TO LATE AFTERNOON HOURS OVER STL. GUSTING SURFACE
WINDS UP TO 30 TO 35 KTS ARE POSSIBLE WITH THE STRONGER STORMS.

PRZYBYLINSKI

&&

.PRELIMINARY POINT TEMPS/POPS...
SAINT LOUIS     88  73  93  75 /  50  60  40  40
QUINCY          86  70  90  72 /  50  60  20  30
COLUMBIA        85  70  92  72 /  60  60  30  50
JEFFERSON CITY  86  71  92  72 /  60  60  30  50
SALEM           87  72  88  71 /  50  50  40  30
FARMINGTON      85  70  91  72 /  50  50  50  50

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&

$$

WFO LSX





AREA FORECAST DISCUSSION...UPDATED AVIATION

NWS ST LOUIS MO

 1202 AM CDT SUN JUL 21 2013

.UPDATE...
ISSUED AT 937 PM CDT SAT JUL 20 2013
ISSUED AT 926 PM CDT SAT JUL 20 2013

DIURNAL CONVECTION AIDED BY A PLETHORA OF OUTFLOW BOUNDARIES AND A
WEAK COLD FRONT HAS REALLY BECOME LIMITED TO JUST A FEW STORMS
FROM THE LAKE OF THE OZARKS TO SULLIVAN MISSOURI. SHOULD SEE THIS
CONVECTION CONTINUE TO SLOWLY DISSIPATE AS IT SQUEEZES OUT THE
LAST OF THE SURFACE INSTABILITY. NEXT ROUND OF CONVECTION IS
LIKELY TO DEVELOP FURTHER NORTHWEST...AS NORTHWEST MISSOURI
REMAINS QUITE UNSTABLE WITH SPC MESOSCALE ANALYSIS SHOWING UPWARDS
OF 4000 J/KG OF MUCAPE. APPROACHING SHORTWAVE FROM THE UPPER
PLAINS SHOULD CAUSE THE LOW LEVEL JET TO INCREASE AND ACT UPON
THIS INSTABILITY WITH THUNDERSTORMS INCREASING AFTER
MIDNIGHT/SUNDAY MORNING.

CVKING

&&

.SHORT TERM...(THROUGH LATE TONIGHT)
ISSUED AT 319 PM CDT SAT JUL 20 2013

THE WEST-EAST ORIENTED SURFACE COLD FRONT IS MEANDERING SOUTHWARD
AND EXTENDED FROM JUST SOUTH OF KANSAS CITY TO JUST NORTH OF
COLUMBIA AND ST LOUIS TO LITCHFIELD AT 20Z. SCATTERED THUNDERSTORMS
HAVE DEVELOPED WITHIN THE LAST HOUR OR SO FROM JUST NORTH OF ST
LOUIS INTO CENTRAL IL ALONG THE FRONT...BUT THE GREATEST COVERAGE OF
STORMS IS ACROSS SOUTHEAST AND SOUTH CENTRAL MISSOURI ALONG AND
AHEAD OF A WEAK SURFACE TROF/CONVERGENCE ZONE WHERE THE ATMOSPHERE
IS VERY UNSTABLE. THESE SHOULD GENERALLY REMAIN THE FAVORED AREAS
THRU SUNSET...AHEAD OF THE VERY SLOW MOVING FRONT AND CONVERGENCE
ZONE. ALL OF THIS ACTIVITY WILL BE SLOW MOVING GIVEN WEAK FLOW AND
SHEAR ALOFT BUT THE GENERAL TENDENCY SHOULD BE FOR AN OVERALL SEWD
MOTION...ESPECIALLY WHERE MERGERS CAN LEAD TO GREATER ORGANIZATION.
THE DECREASE IN INSTABILITY WITH SUNSET SHOULD RESULT IN LARGE
DECREASE IN COVERAGE. THEN THE MAIN THREAT OF SHOWERS/STORMS FOR THE
REMAINDER OF THE NIGHT WILL BE ALONG AND SOUTH OF THE FRONT WHICH
WILL BECOME STATIONARY FROM SOUTHWEST ILLINOIS THRU MID MO INTO NRN
KS.

GLASS

.LONG TERM...(SUNDAY THROUGH NEXT SATURDAY)
ISSUED AT 252 PM CDT SAT JUL 20 2013

(SUNDAY THROUGH TUESDAY)

FOCUS THRU THE PERIOD CONTINUES TO BE PRECIP CHANCES.

MDLS ARE IN RELATIVELY GOOD AGREEMENT WITH RESPECT TO MASS FIELDS
AND IN GENERAL...HAVE A GENERAL CONSENSUS ON HOW THINGS WILL PAN
OUT THRU THIS PERIOD. THERE ARE SOME DIFFERENCES IN TIMING AS WELL
AS WHAT FEATURES WILL PRODUCE PRECIP AND WHICH MAY NOT.
OVERALL...HAVE TRENDED TWD A GFS/LOCAL WRF SOLN WHICH ARE IN BETTER
AGREEMENT THAN THE OTHER OPERATIONAL GUIDANCE.

NOT MUCH IN THE WAY OF CHANGES TO THE PREV FORECAST WRT POPS OR
TEMPS. LOWERED POPS ACROSS NRN PORTIONS OF THE CWA ON MON. THE S/W
IS NOW PROGD TO BE E OF THOSE AREAS BY MON MORNING...BUT WILL KEEP
LOW POPS FOR UNCERTAINTY IN TIMING.

(WEDNESDAY THROUGH SATURDAY)

NOT MUCH IN THE WAY OF CHANGES FROM THE PREV FORECAST THRU THIS
PERIOD. MDLS ARE IN GENERALLY GOOD AGREEMENT REGARDING MASS FIELDS.

EXPECT THIS PERIOD TO OVERALL BE COOLER WITH PRECIP CHANCES
CONTINUING THRU WED. THURS REMAINS DRY WITH THE SFC RIDGE SETTLED
OVER THE AREA. HOWEVER...MDLS TIMING THE NEXT S/W AND ASSOCIATED
PRECIP INTO THE AREA BY FRI AND REMAINING OVER PORTIONS OF THE CWA
INTO SAT. KEPT POPS ON THE LOWER SIDE DUE TO UNCERTAINTY IN TIMING
AND WILL INCREASE AS CONFIDENCE BUILDS AND TIME APPROACHES.


TILLY

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1142 PM CDT SAT JUL 20 2013

LATEST CONVECTIVE TRENDS SHOW THAT CONVECTIVE CLUSTER EXTENDING
FROM SOUTH OF JEFFERSON CITY IS DEVELOPING NORTHWEST TOWARDS
SEDELIA MISSOURI AND WILL GRADUALLY MEET WITH DEVELOPING
CONVECTION OVER NORTHWEST MISSOURI. THE LATEST HRRR MESOSCALE
MODEL RUN SHOWS THE CONVECTIVE CLUSTER SOUTHWEST OF JEFFERSON CITY
HOWEVER THE LATEST RUN DOES NOT SHOW THE DEVELOPING CONVECTION
OVER NORTHWEST MISSOURI ATTM. THE AREA OF CONVECTION IS WTIHIN THE
AXIS OF HIGHEST MLCAPE WHICH EXTENDS NORTHWEST - SOUTHEAST ACROSS
NORTHWEST INTO SOUTH CENTRAL MISSOURI. CLUSTER OF THUNDERSTORMS
FROM SOUTHEAST SOUTH DAKOTA THROUGH CENTRAL NEBRASKA ASSOCIATED
WITH UPPER LEVEL DISTURBANCE OVER THE NORTHERN PLAINS. THIS
DISTURBANCE WILL MOVE EAST-SOUTHEAST ALONG THE MEAN NORTHWEST FLOW
AND BRING INCREASING THREAT TO SHOWERS AND THUNDERSTORMS OVER
CENTRAL MISSOURI BY ;ATE MORNING TO MID DAY AND MOVE INTO EASTERN
SECTIONS OF MISSOURI AND SOUTHWEST ILLINOIS BY NID TO LATE
AFTERNOON.

SPECIFICS FOR KSTL...WINDS WILL BE LIGHT AND VARIABLE THROUGH
DAYBREAK ON SUNDAY. THEN WINDS WILL BECOME SOUTHEAST AT 5 TO 8
KTS. ISOLATED SHOWERS ANDT HUNDERSTORMS ARE POSSIBLE BY LATE
MORNING FOR STL BUT HIGHER CHANCES INCREASE BY MID AFTERNOON.
CEILING WILL REMAIN AOA 10000 FT BUT LOWER CEILNGS ARE EXPECTED BY
EARLY TO MID AFTERNOON AS THUNDERSTORMS THREAT WILL INCREASE
DURING THE MID TO LATE AFTERNOON HOURS OVER STL. GUSTING SURFACE
WINDS UP TO 30 TO 35 KTS ARE POSSIBLE WITH THE STRONGER STORMS.

PRZYBYLINSKI

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&

$$

WFO LSX







AREA FORECAST DISCUSSION...UPDATED

NWS NORTH PLATTE NE

 707 PM CDT MON JUL 22 2013

.SYNOPSIS...
ISSUED AT 340 PM CDT MON JUL 22 2013

SEVERAL BOUNDARIES ARE ACROSS THE HIGH PLAINS THIS AFTERNOON. A COOL
FRONT CONTINUES TO PUSH EAST...ACROSS EASTERN NEB...WITH
THUNDERSTORMS STARTING TO FIRE ACROSS NW IOWA AND INTO EASTERN NEB.
A SECONDARY...NEARLY STATIONARY...BOUNDARY EXISTS ACROSS THE SE
PANHANDLE INTO SW NEB. WINDS ON THE NORTH SIDE OF THE BOUNDARY ARE
OUT OF THE NORTH TO NORTHEAST AND SOUTHERLY TO THE SOUTH WINDS. A
THIRD BOUNDARY EXTENDS FROM THE NORTHERN PANHANDLE ACROSS CHERRY
COUNTY CURVING INTO CENTRAL NEB...WITH A LINE OF MID LEVEL CLOUDS.
TEMPS THIS AFTERNOON RANGE FROM THE MID 80S UNDERNEATH THE CLOUDS
ACROSS THE NORTH TO THE MID 90S ACROSS SW NEB.

&&

.UPDATE...
ISSUED AT 702 PM CDT MON JUL 22 2013

A LOOK AT THE HRRR MODEL FORECAST STORM MOTIONS ON THE SYSTEM
ACROSS NERN WY/WRN SD AND 850 MB MOISTURE ADVECTIONS IN THE RAP
MODEL SUGGEST THE DEVELOPING MCS UP NORTH COULD TURN SOUTH AND
SWEEP THE FCST ONCE IT MOVES EAST OF THE BLACK HILLS LATER THIS
EVENING. THE FORECAST HAS BEEN UPDATED FOR SCATTERED THUNDERSTORMS
OVERNIGHT THROUGH TUESDAY MORNING. THE HRRR SUGGESTS NORTH PLATTE
MIGHT BE THE WRN EDGE OF THE TSTM COMPLEX. THE FORECAST SHIFTS
THIS WEST A BIT TO NEAR OGALLALA.

GIVEN THE SHEAR PROFILES AND FCST STORM MOTION OF 10 KTS OR
LESS...WE WOULD LIKELY SEE A COLD POOL DRIVEN OUTFLOW DOMINANT RAIN
MAKER WITH GUSTY WINDS AND ISOLATED LARGE HAIL OVERNIGHT.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 340 PM CDT MON JUL 22 2013

TONIGHT WITH THE NUMEROUS BOUNDARIES ACROSS THE AREA...EXPECT A
COUPLE DIFFERENT AREAS OF THUNDERSTORMS. DECENT CU FIELD ACROSS
GARDEN COUNTY AND CAP HAS ERODED...WHILE GOOD CAPE. LIKELY GOING TO
SEE SOME STORMS DEVELOP OVER THE NEXT HOUR OR TWO...WITH MOVEMENT TO
THE SE. A SECOND AREA OF SHOWERS EXPECTED ACROSS THE FAR N...NEAR
THE S DAKOTA BORDER WITH THE AID OF AN UPPER LEVEL WAVE. THIS SHOULD
DIVE TOWARDS CENTRAL NEB.

BY TOMORROW MORNING FOCUS SHOULD BE THE STALLED MID LEVEL BOUNDARY
ACROSS NW INTO CENTRAL NEB. MODELS CONTINUE TO SHOW REDEVELOPMENT TO
THE NW...SIMILAR TO THIS MORNING...THEN DRIFTING SE. MODELS IN GOOD
AGREEMENT ALLOWING SOME MOISTURE TO POOL ALONG THE BOUNDARY AS PWATS
INCREASE TO AROUND 1.50 INCHES...AND SHOULD BE ENOUGH TO GET ISOLD
LATE MORNING AND EARLY AFTERNOON SHOWERS.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 340 PM CDT MON JUL 22 2013

UNSETTLED PERIOD EXPECTED...WITH SEVERAL UPPER LEVEL WAVES
FORECASTED TO ROTATE EAST ACROSS THE REGION ON NORTHERN PERIPHERY OF
SOUTHERN PLAINS UPPER LEVEL RIDGE. THE STRONGEST OF THESE SYSTEMS IS
FORECASTED TO ARRIVE THURSDAY INTO THURSDAY NIGHT...AND THIS PERIOD
WILL BE OUR BEST CHANCE FOR RAIN. MODELS HAVE STRUGGLED SLIGHTLY ON
EXACTLY WHERE THE NEXT FOCUS WILL BE...AND FOR THIS REASON WILL
LEAVE POPS CAPPED AT 40 PERCENT AT THIS TIME. LATER MODEL RUNS WILL
HELP DETERMINE WHERE THE HIGHER POPS /IF WARRANTED/ WILL BE
PLACED.

AFTER THE THURSDAY/THURSDAY NIGHT SYSTEM...STILL A SLIGHT CHANCE FOR
MORE RAIN INTO THE WEEKEND...AS WEAK WAVES CONTINUE TO CROSS THE
AREA. VERY HARD TO PIN DOWN EXACT TIMING AND LOCATION AT THIS
POINT...SO WILL ONLY KEEP CHANCES SLIGHT AT THIS TIME. THE OTHER
STORY WILL BE THE TEMPERATURES. A STRONG AREA OF LOW PRESSURE IS
EXPECTED TO FORM ACROSS SOUTHEAST CANADA FRIDAY INTO THE
WEEKEND...AND THIS SHOULD PUSH A FAIRLY STRONG COLD FRONT SOUTHWEST
INTO THE AREA. LOOKS LIKE THE FRONT WILL STALL IN CENTRAL
NEBRASKA...SO THE COOLER READINGS...WITH HIGHS AROUND 80...WILL BE
FOUND ALONG AND NORTHEAST OF A BROKEN BOW TO AINSWORTH LINE. AREAS
SOUTHWEST SHOULD GENERALLY SEE HIGHS IN THE 80S. HUMIDITY WILL ALSO
BE SCOURED OUT SOME...SO CONDITIONS LOOKING PLEASANT.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 624 PM CDT MON JUL 22 2013

THE MODEL CONSENSUS OF HRRR...RAP AND NAM SUGGEST THE CLUSTER OF
TSTMS ACROSS NERN WY WILL MOVE EAST THRU WRN SD AND THEN TURN
SOUTH INTO NEB AFFECTING KVTN AND KLBF WITH TSTMS BETWEEN 06Z-08Z.
THE STORMS MIGHT LINGER EAST OF HIGHWAY 83 NEAR KANW-KONL THROUGH
15Z. VFR IS EXPECTED THEREAFTER ALL AREAS.


&&

.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...CDC
SYNOPSIS...MASEK
SHORT TERM...MASEK
LONG TERM...TAYLOR
AVIATION...CDC







AREA FORECAST DISCUSSION

NWS OMAHA/VALLEY NE

 1154 AM CDT SUN JUL 21 2013

.AVIATION...
18Z TAFS FOR KOMA...KOFK...KLNK

A SCT TO BKN CU FIELD IS EXPECTED AT OMA/LNK THIS AFTERNOON WITH A
FEW CU AT OFK. THESE WILL LIKELY DISSIPATE QUICKLY THIS EVENING
WITH JUST SOME SCT MID AND HIGH LEVEL CLOUDS EXPECTED OVERNIGHT.
GIVEN THE INCREASE IN LOW-LEVEL MOISTURE WE MAY SEE SOME MVFR CIGS
WITH HZ/BR AT OMA AROUND SUNRISE ON MONDAY BUT IF THIS OCCURS IT
WILL BE SHORT LIVED. SFC CDFNT WILL BE MOVG TOWARD THE TAF SITES
ON MONDAY BUT WON`T MAKE IT PRIOR TO 18Z WITH JUST A GENERAL
SRLY/SWRLY SFC WIND EXPECTED THRU THE PERIOD.

&&

.PREV DISCUSSION... /ISSUED 1019 AM CDT SUN JUL 21 2013/

UPDATE...

UPDATED TO ADJUST MORNING AND AFTERNOON POPS

DISCUSSION...

12Z UPPER AIR ANALYSIS INDICATED THAT A SEASONABLY STRONG
SHORTWAVE TROUGH EXTNDD FM WRN MN INTO CNTRL NEB. THIS WAS
SPREADING LARGE-SCALE ASCENT ACROSS THE FA THIS MORNING. THE 12Z
KOAX RAOB INDCD AROUND 1400 J/KG OF MUCAPE WITH LITTLE CAPPING.
THUS THE COMBINATION OF THE FORCING AND WEAKLY CAPPED ATMOSPHERE
WAS LEADING TO SCT TSRA OVER FAR SE NEB AND SW IA. THIS SHOULD
CONT TO SHIFT EWD THIS MORNING ASSOCIATED WITH THE SHORTWAVE
TROUGH. WHAT HAPPENS IN THE WAKE OF THIS MORNING ACTIVITY IS A BIT
UNCLEAR. MODIFYING THE 12Z SOUNDING YIELDS LITTLE CAPPING AS
TEMPERATURES CLIMB INTO THE MID 80S WITH AROUND 2000 J/KG OF
MLCAPE. THE NEGATIVE THOUGH IS THE SUBSIDENCE THAT WILL BE SPREADING
INTO THE AREA LATER THIS MORNING IN THE WAKE OF THE MORNING
SHORTWAVE TROUGH. THIS IS LIKELY TO COMBINE WITH A LACK OF A SFC
BOUNDARY TO FOCUS CONVERGENCE TO MAKE REDEVELOPMENT THIS AFTERNOON
PRETTY UNLIKELY. WILL MAINTAIN A SCHC OF AFTERNOON STORMS OVER
THE ERN FA OTHERWISE WE FEEL IT WILL BE A PRETTY DRY AFTERNOON.
THE OTHER ELEMENTS OF THE FORECAST APPEAR ON TRACK ATTM.

PREV DISCUSSION... /ISSUED 301 AM CDT SUN JUL 21 2013/

DISCUSSION...

FORECASTING AREAL EXTENT OF CONVECTION THROUGH THE
FORECAST WILL BE A SIGNIFICANT CHALLENGE AS THE REGION REMAINS IN
NORTHWEST FLOW THIS WEEK.

FIRST ROUND OF CONVECTION IS MOVING INTO EASTERN NEBRASKA EARLY
THIS MORNING...BUT WILL ALSO HAVE TO OVERCOME A POCKET OF DRY AIR
AT H85. CONTINUED THETAE ADVECTION SHOULD HELP TO ERODE THIS DRY
POCKET AND CONTINUE TRIGGER STORMS THIS MORNING THAT WILL
CONTINUE TO MOVE EASTWARD THROUGH THE AREA INTO WESTERN IOWA
BEFORE DISSIPATING THROUGH MID TO LATE MORNING. WHILE HEAVY RAINS
ARE NOT WIDESPREAD...SOME VERY SPOTTY LOCATIONS WHERE LIGHTNING IS
OCCURRING ARE LIKELY PICKING UP SOME DECENT MEANINGFUL RAINFALL.

MEANWHILE...WATER VAPOR IMAGERY INDICATES ANOTHER SUBTLE WAVE IS
LIKELY MOVING THROUGH WESTERN SOUTH DAKOTA. ANOTHER CLUSTER OF
STORMS HAS REFIRED ACROSS THAT AREA...MOVING INTO NORTH CENTRAL
NEBRASKA. BOTH THE NAM AND RAP SEEM TO HAVE PICKED UP ON THIS
FEATURE AND MOVE IT THROUGH THE FORECAST AREA THIS AFTERNOON...WHICH
COULD BE THE TRIGGER FOR ADDITIONAL STORMS AS WE HEAD THROUGH PEAK
HEATING. FORWARD SPEED SUGGESTS THAT THIS MAY MOSTLY BE OUT OF THE
AREA BY EARLY THIS EVENING.

THE REMAINDER OF SUNDAY NIGHT AND MONDAY MORNING SHOULD BE DRY. A
FRONTAL BOUNDARY MOVING INTO THE REGION COULD TRIGGER ISOLATED
AFTERNOON STORMS IN NORTHEAST NEBRASKA. TEMPS AHEAD OF THE FRONT
WILL PROBABLY REACH THE LOWER 90S ONCE AGAIN. SHOULD ALSO SEE A
CHANCE OF THUNDERSTORMS MONDAY NIGHT AS THE FRONT MOVES THROUGH
THE AREA.

THE NEXT WAVE APPEARS ON THE HORIZON BY TUESDAY AFTERNOON THEN
MOVES THROUGH THE REGION TUESDAY NIGHT. WEDNESDAY AND WEDNESDAY
NIGHT SHOULD BE DRY...BUT ANOTHER WAVE MOVES INTO THE AREA ON
THURSDAY AND LINGERS THROUGH FRIDAY. THE GFS SUGGESTS THAT WE
MIGHT REMAIN DRY ON SATURDAY...BUT THE ECMWF HAS YET ANOTHER SURGE
OF MOISTURE MOVING THROUGH. NEVERTHELESS...CONFIDENCE DECREASES IN
SPECIFICS TOWARD THE END OF THE WEEK.

DEWALD

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.

&&

$$




AREA FORECAST DISCUSSION

NWS OMAHA/VALLEY NE

 1019 AM CDT SUN JUL 21 2013

.UPDATE...

UPDATED TO ADJUST MORNING AND AFTERNOON POPS

&&

.DISCUSSION...

12Z UPPER AIR ANALYSIS INDICATED THAT A SEASONABLY STRONG
SHORTWAVE TROUGH EXTNDD FM WRN MN INTO CNTRL NEB. THIS WAS
SPREADING LARGE-SCALE ASCENT ACROSS THE FA THIS MORNING. THE 12Z
KOAX RAOB INDCD AROUND 1400 J/KG OF MUCAPE WITH LITTLE CAPPING.
THUS THE COMBINATION OF THE FORCING AND WEAKLY CAPPED ATMOSPHERE
WAS LEADING TO SCT TSRA OVER FAR SE NEB AND SW IA. THIS SHOULD
CONT TO SHIFT EWD THIS MORNING ASSOCIATED WITH THE SHORTWAVE
TROUGH. WHAT HAPPENS IN THE WAKE OF THIS MORNING ACTIVITY IS A BIT
UNCLEAR. MODIFYING THE 12Z SOUNDING YIELDS LITTLE CAPPING AS
TEMPERATURES CLIMB INTO THE MID 80S WITH AROUND 2000 J/KG OF
MLCAPE. THE NEGATIVE THOUGH IS THE SUBSIDENCE THAT WILL BE SPREADING
INTO THE AREA LATER THIS MORNING IN THE WAKE OF THE MORNING
SHORTWAVE TROUGH. THIS IS LIKELY TO COMBINE WITH A LACK OF A SFC
BOUNDARY TO FOCUS CONVERGENCE TO MAKE REDEVELOPMENT THIS AFTERNOON
PRETTY UNLIKELY. WILL MAINTAIN A SCHC OF AFTERNOON STORMS OVER
THE ERN FA OTHERWISE WE FEEL IT WILL BE A PRETTY DRY AFTERNOON.
THE OTHER ELEMENTS OF THE FORECAST APPEAR ON TRACK ATTM.

&&

.PREV DISCUSSION... /ISSUED 611 AM CDT SUN JUL 21 2013/

AVIATION...
12Z TAFS FOR KOFK...KLNK AND KOMA.

FOR THE MAJORITY OF THE TAF PERIOD WE EXPECT VFR FLIGHT CONDITIONS
AND RELATIVELY QUIET WEATHER.  THE FORECAST CHALLENGE IS PREDICTING
WHEN AND WHERE SHOWERS AND THUNDERSTORMS MIGHT DEVELOP AND
CONSEQUENTLY EFFECT THE TAF SITES.  THIS TIME OF YEAR...IN THESE
WEATHER PATTERNS...THE PREDICTABILITY OF CONVECTION IS LOW AND THE
UNCERTAINTY IS HIGH.  GIVEN THAT...WILL KEEP SPECIFIC MENTION OF
TSRA OUT OF THE TAFS FOR NOW AND REFINE AS THE PATTERN BECOMES MORE
SUPPORTIVE OF THUNDERSTORM DEVELOPMENT.

THERE IS ONE CLUSTER OF SHOWERS AND THUNDERSTORMS CURRENTLY MOVING
THROUGH WESTERN NEBRASKA AND INTO CENTRAL NEBRASKA...BUT AT THIS
TIME THAT AREA APPEARS TO BE MOVING INTO SOUTH CENTRAL NEBRASKA AND
WILL NOT MOVE FAR ENOUGH EAST TO EFFECT THE TAF SITES.  ADDITIONAL
STORM DEVELOPMENT COULD OCCUR IN EASTERN NEBRASKA THIS AFTERNOON.

NIETFELD

PREV DISCUSSION... /ISSUED 301 AM CDT SUN JUL 21 2013/

DISCUSSION...

FORECASTING AREAL EXTENT OF CONVECTION THROUGH THE
FORECAST WILL BE A SIGNIFICANT CHALLENGE AS THE REGION REMAINS IN
NORTHWEST FLOW THIS WEEK.

FIRST ROUND OF CONVECTION IS MOVING INTO EASTERN NEBRASKA EARLY
THIS MORNING...BUT WILL ALSO HAVE TO OVERCOME A POCKET OF DRY AIR
AT H85. CONTINUED THETAE ADVECTION SHOULD HELP TO ERODE THIS DRY
POCKET AND CONTINUE TRIGGER STORMS THIS MORNING THAT WILL
CONTINUE TO MOVE EASTWARD THROUGH THE AREA INTO WESTERN IOWA
BEFORE DISSIPATING THROUGH MID TO LATE MORNING. WHILE HEAVY RAINS
ARE NOT WIDESPREAD...SOME VERY SPOTTY LOCATIONS WHERE LIGHTNING IS
OCCURRING ARE LIKELY PICKING UP SOME DECENT MEANINGFUL RAINFALL.

MEANWHILE...WATER VAPOR IMAGERY INDICATES ANOTHER SUBTLE WAVE IS
LIKELY MOVING THROUGH WESTERN SOUTH DAKOTA. ANOTHER CLUSTER OF
STORMS HAS REFIRED ACROSS THAT AREA...MOVING INTO NORTH CENTRAL
NEBRASKA. BOTH THE NAM AND RAP SEEM TO HAVE PICKED UP ON THIS
FEATURE AND MOVE IT THROUGH THE FORECAST AREA THIS AFTERNOON...WHICH
COULD BE THE TRIGGER FOR ADDITIONAL STORMS AS WE HEAD THROUGH PEAK
HEATING. FORWARD SPEED SUGGESTS THAT THIS MAY MOSTLY BE OUT OF THE
AREA BY EARLY THIS EVENING.

THE REMAINDER OF SUNDAY NIGHT AND MONDAY MORNING SHOULD BE DRY. A
FRONTAL BOUNDARY MOVING INTO THE REGION COULD TRIGGER ISOLATED
AFTERNOON STORMS IN NORTHEAST NEBRASKA. TEMPS AHEAD OF THE FRONT
WILL PROBABLY REACH THE LOWER 90S ONCE AGAIN. SHOULD ALSO SEE A
CHANCE OF THUNDERSTORMS MONDAY NIGHT AS THE FRONT MOVES THROUGH
THE AREA.

THE NEXT WAVE APPEARS ON THE HORIZON BY TUESDAY AFTERNOON THEN
MOVES THROUGH THE REGION TUESDAY NIGHT. WEDNESDAY AND WEDNESDAY
NIGHT SHOULD BE DRY...BUT ANOTHER WAVE MOVES INTO THE AREA ON
THURSDAY AND LINGERS THROUGH FRIDAY. THE GFS SUGGESTS THAT WE
MIGHT REMAIN DRY ON SATURDAY...BUT THE ECMWF HAS YET ANOTHER SURGE
OF MOISTURE MOVING THROUGH. NEVERTHELESS...CONFIDENCE DECREASES IN
SPECIFICS TOWARD THE END OF THE WEEK.

DEWALD

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.

&&

$$




AREA FORECAST DISCUSSION

NWS OMAHA/VALLEY NE

 611 AM CDT SUN JUL 21 2013

.AVIATION...
12Z TAFS FOR KOFK...KLNK AND KOMA.

FOR THE MAJORITY OF THE TAF PERIOD WE EXPECT VFR FLIGHT CONDITIONS
AND RELATIVELY QUIET WEATHER.  THE FORECAST CHALLENGE IS PREDICTING
WHEN AND WHERE SHOWERS AND THUNDERSTORMS MIGHT DEVELOP AND
CONSEQUENTLY EFFECT THE TAF SITES.  THIS TIME OF YEAR...IN THESE
WEATHER PATTERNS...THE PREDICTABILITY OF CONVECTION IS LOW AND THE
UNCERTAINTY IS HIGH.  GIVEN THAT...WILL KEEP SPECIFIC MENTION OF
TSRA OUT OF THE TAFS FOR NOW AND REFINE AS THE PATTERN BECOMES MORE
SUPPORTIVE OF THUNDERSTORM DEVELOPMENT.

THERE IS ONE CLUSTER OF SHOWERS AND THUNDERSTORMS CURRENTLY MOVING
THROUGH WESTERN NEBRASKA AND INTO CENTRAL NEBRASKA...BUT AT THIS
TIME THAT AREA APPEARS TO BE MOVING INTO SOUTH CENTRAL NEBRASKA AND
WILL NOT MOVE FAR ENOUGH EAST TO EFFECT THE TAF SITES.  ADDITIONAL
STORM DEVELOPMENT COULD OCCUR IN EASTERN NEBRASKA THIS AFTERNOON.

NIETFELD

&&

.PREV DISCUSSION... /ISSUED 301 AM CDT SUN JUL 21 2013/

.DISCUSSION...

FORECASTING AREAL EXTENT OF CONVECTION THROUGH THE
FORECAST WILL BE A SIGNIFICANT CHALLENGE AS THE REGION REMAINS IN
NORTHWEST FLOW THIS WEEK.

FIRST ROUND OF CONVECTION IS MOVING INTO EASTERN NEBRASKA EARLY
THIS MORNING...BUT WILL ALSO HAVE TO OVERCOME A POCKET OF DRY AIR
AT H85. CONTINUED THETAE ADVECTION SHOULD HELP TO ERODE THIS DRY
POCKET AND CONTINUE TRIGGER STORMS THIS MORNING THAT WILL
CONTINUE TO MOVE EASTWARD THROUGH THE AREA INTO WESTERN IOWA
BEFORE DISSIPATING THROUGH MID TO LATE MORNING. WHILE HEAVY RAINS
ARE NOT WIDESPREAD...SOME VERY SPOTTY LOCATIONS WHERE LIGHTNING IS
OCCURRING ARE LIKELY PICKING UP SOME DECENT MEANINGFUL RAINFALL.

MEANWHILE...WATER VAPOR IMAGERY INDICATES ANOTHER SUBTLE WAVE IS
LIKELY MOVING THROUGH WESTERN SOUTH DAKOTA. ANOTHER CLUSTER OF
STORMS HAS REFIRED ACROSS THAT AREA...MOVING INTO NORTH CENTRAL
NEBRASKA. BOTH THE NAM AND RAP SEEM TO HAVE PICKED UP ON THIS
FEATURE AND MOVE IT THROUGH THE FORECAST AREA THIS AFTERNOON...WHICH
COULD BE THE TRIGGER FOR ADDITIONAL STORMS AS WE HEAD THROUGH PEAK
HEATING. FORWARD SPEED SUGGESTS THAT THIS MAY MOSTLY BE OUT OF THE
AREA BY EARLY THIS EVENING.

THE REMAINDER OF SUNDAY NIGHT AND MONDAY MORNING SHOULD BE DRY. A
FRONTAL BOUNDARY MOVING INTO THE REGION COULD TRIGGER ISOLATED
AFTERNOON STORMS IN NORTHEAST NEBRASKA. TEMPS AHEAD OF THE FRONT
WILL PROBABLY REACH THE LOWER 90S ONCE AGAIN. SHOULD ALSO SEE A
CHANCE OF THUNDERSTORMS MONDAY NIGHT AS THE FRONT MOVES THROUGH
THE AREA.

THE NEXT WAVE APPEARS ON THE HORIZON BY TUESDAY AFTERNOON THEN
MOVES THROUGH THE REGION TUESDAY NIGHT. WEDNESDAY AND WEDNESDAY
NIGHT SHOULD BE DRY...BUT ANOTHER WAVE MOVES INTO THE AREA ON
THURSDAY AND LINGERS THROUGH FRIDAY. THE GFS SUGGESTS THAT WE
MIGHT REMAIN DRY ON SATURDAY...BUT THE ECMWF HAS YET ANOTHER SURGE
OF MOISTURE MOVING THROUGH. NEVERTHELESS...CONFIDENCE DECREASES IN
SPECIFICS TOWARD THE END OF THE WEEK.

DEWALD

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

$$




AREA FORECAST DISCUSSION

NWS OMAHA/VALLEY NE

 301 AM CDT SUN JUL 21 2013

.DISCUSSION...

FORECASTING AREAL EXTENT OF CONVECTION THROUGH THE FORECAST WILL
BE A SIGNIFICANT CHALLENGE AS THE REGION REMAINS IN NORTHWEST FLOW
THIS WEEK.

FIRST ROUND OF CONVECTION IS MOVING INTO EASTERN NEBRASKA EARLY
THIS MORNING...BUT WILL ALSO HAVE TO OVERCOME A POCKET OF DRY AIR
AT H85. CONTINUED THETAE ADVECTION SHOULD HELP TO ERODE THIS DRY
POCKET AND CONTINUE TRIGGER STORMS THIS MORNING THAT WILL
CONTINUE TO MOVE EASTWARD THROUGH THE AREA INTO WESTERN IOWA
BEFORE DISSIPATING THROUGH MID TO LATE MORNING. WHILE HEAVY RAINS
ARE NOT WIDESPREAD...SOME VERY SPOTTY LOCATIONS WHERE LIGHTNING IS
OCCURRING ARE LIKELY PICKING UP SOME DECENT MEANINGFUL RAINFALL.

MEANWHILE...WATER VAPOR IMAGERY INDICATES ANOTHER SUBTLE WAVE IS
LIKELY MOVING THROUGH WESTERN SOUTH DAKOTA. ANOTHER CLUSTER OF
STORMS HAS REFIRED ACROSS THAT AREA...MOVING INTO NORTH CENTRAL
NEBRASKA. BOTH THE NAM AND RAP SEEM TO HAVE PICKED UP ON THIS
FEATURE AND MOVE IT THROUGH THE FORECAST AREA THIS AFTERNOON...WHICH
COULD BE THE TRIGGER FOR ADDITIONAL STORMS AS WE HEAD THROUGH PEAK
HEATING. FORWARD SPEED SUGGESTS THAT THIS MAY MOSTLY BE OUT OF THE
AREA BY EARLY THIS EVENING.

THE REMAINDER OF SUNDAY NIGHT AND MONDAY MORNING SHOULD BE DRY. A
FRONTAL BOUNDARY MOVING INTO THE REGION COULD TRIGGER ISOLATED
AFTERNOON STORMS IN NORTHEAST NEBRASKA. TEMPS AHEAD OF THE FRONT
WILL PROBABLY REACH THE LOWER 90S ONCE AGAIN. SHOULD ALSO SEE A
CHANCE OF THUNDERSTORMS MONDAY NIGHT AS THE FRONT MOVES THROUGH
THE AREA.

THE NEXT WAVE APPEARS ON THE HORIZON BY TUESDAY AFTERNOON THEN
MOVES THROUGH THE REGION TUESDAY NIGHT. WEDNESDAY AND WEDNESDAY
NIGHT SHOULD BE DRY...BUT ANOTHER WAVE MOVES INTO THE AREA ON
THURSDAY AND LINGERS THROUGH FRIDAY. THE GFS SUGGESTS THAT WE
MIGHT REMAIN DRY ON SATURDAY...BUT THE ECMWF HAS YET ANOTHER SURGE
OF MOISTURE MOVING THROUGH. NEVERTHELESS...CONFIDENCE DECREASES IN
SPECIFICS TOWARD THE END OF THE WEEK.

DEWALD

&&

.AVIATION...06Z TAFS FOR KOMA...KLNK...AND KOFK. FORECAST
CONCERNS THROUGH THE PERIOD WILL BE CONVECTIVE CHANCES AND WHEN TO
INCLUDE IN THE TAF. CONVECTION IS ONGOING ACROSS PARTS OF SOUTH
DAKOTA AND WESTERN NEBRASKA AND IS ASSOCIATED WITH A SHORTWAVE
TROF MOVING SOUTHEAST ACROSS THE DAKOTAS AND NEBRASKA THROUGH
SUNDAY. THE LOW LEVEL JET WILL ALSO INCREASE OVER MISSOURI AND THE
SHOULD AID IN NEW DEVELOPMENT FARTHER SOUTH AND WITH DEEPER
MOISTURE RETURNING COULD SEE RE-DEVELOPMENT DURING THE DAY. SHOULD
SEE SOME SHOWERS...HOWEVER DUE TO TSRA BEING ISOLD WILL ONLY
MENTION SPARINGLY. COULD SEE SOME GUSTY WINDS NEAR SHOWERS/STORMS...
OTHERWISE WINDS WILL GENERALLY BE FROM THE SOUTHEAST

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

$$




AREA FORECAST DISCUSSION...UPDATED

NWS NORTH PLATTE NE

 113 AM CDT SUN JUL 21 2013

.SYNOPSIS...
ISSUED AT 253 PM CDT SAT JUL 20 2013

THE H5 ANALYSIS THIS MORNING...HAS AN ACTIVE NW FLOW
PATTERN ACROSS THE NRN CONUS. HIGH PRESSURE WAS ANCHORED ACROSS THE
CENTRAL VALLEY OF CA...WITH A PERSISTENT BERMUDA HIGH PRESENT ACROSS
THE WESTERN ATLANTIC. A BROAD TROUGH OF LOW PRESSURE EXTENDED FROM
NRN QUEBEC INTO THE MID ATLANTIC STATES. ACROSS THE NRN ROCKIES AND
CENTRAL PLAINS...NUMEROUS SHORTWAVES WERE EMBEDDED IN THE NWRLY
FLOW. ONE OVER NWRN WYOMING...AND A SECOND OVER THE IDAHO PANHANDLE.
ANOTHER DISTURBANCE WAS NOTED OVER NWRN IA AS WELL. AT THE
SURFACE...SHOWERS AND THUNDERSTORMS HAVE CONTINUED ACROSS NORTHERN
NEBRASKA THIS MORNING AND EARLY THIS AFTERNOON...ALONG A WEAK
SURFACE BOUNDARY. TEMPERATURES AS OF 2 PM CDT RANGED FROM 68 IN RAIN
COOLED AIR AT ONEILL...TO 87 AT OGALLALA...IMPERIAL AND NORTH PLATTE.

&&

.UPDATE...
ISSUED AT 111 AM CDT SUN JUL 21 2013

REDUCED CLOUD COVER WITH CLEARING SKIES SUBSIDENCE OVER WESTERN
NEBRASKA. THUNDERSTORM CHANCES DROPPED INTO ISOLATED CATEGORIES
AND QPF FIELDS DRASTICALLY REDUCED.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 253 PM CDT SAT JUL 20 2013

SCATTERED THUNDERSTORMS THIS AFTERNOON ARE EXPECTED TO DEVELOP OVER
THE NEBRASKA PANHANDLE AND NORTHWEST NEBRASKA AND COALESCE INTO A
CONVECTIVE SYSTEM BY EARLY THIS EVENING. WITH THE DEEP SHEAR VECTORS
DIAGONAL TO THE LOW LEVEL BOUNDARY...IT APPEARS TO FAVOR THE
DEVELOPMENT OF A LINEAR CONVECTIVE SYSTEM. ACCORDING TO THE SHORT
RANGE HRRR AND RAP13...THE SYSTEM WILL AFFECT A LARGE PART OF THE
SANDHILLS AND SOUTHWEST NEBRASKA BY 01Z AND FINALLY CLEARING CENTRAL
NEBRASKA BY 09Z. THEY DO INDICATE SOME LINGERING SHOWERS AND
THUNDERSTORMS EVEN INTO EARLY SUNDAY.

INSTABILITY CONTINUES OVER WESTERN NEBRASKA SUNDAY AND THERE IS A
CHANCE OF ANOTHER CONVECTIVE SYSTEM DEVELOPING IN SOUTH DAKOTA AND
NORTHWEST NEBRASKA LATE SUNDAY MORNING OR EARLY AFTERNOON...THEN
CROSSING WESTERN NEBRASKA THROUGH THE AFTERNOON.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 253 PM CDT SAT JUL 20 2013

MID RANGE...SUNDAY NIGHT THROUGH TUESDAY...A FAIRLY ACTIVE PATTERN
WILL CONTINUE INTO TUESDAY...THANKS TO NWLY FLOW AND THE PRESENCE OF
EMBEDDED SHORTWAVES WITHIN THAT FLOW. BEGINNING SUNDAY
NIGHT...ANOTHER UPPER LEVEL DISTURBANCE WILL TRACK FROM THE CENTRAL
AND NORTHERN ROCKIES...ACROSS WESTERN AND NORTH CENTRAL NEBRASKA.
CONVECTION WILL BE ONGOING BY SUNDAY AFTERNOON AND IS EXPECTED TO
IMPACT MOST OF THE FORECAST AREA DURING THE EVENING AND OVERNIGHT
HOURS. ATTM...WILL PAINT THE HIGHEST POPS IN THE CENTRAL AND
SOUTHWESTERN CWA...AS THESE LOCATIONS WILL SEE THE BEST DEEP LAYER
SHEAR OF 30 TO 40 KTS. SHEAR IN THE NERN ZONES WILL RUN 10 TO 20 KTS
SUNDAY EVENING...SO ANY TSRAS IN THESE AREAS WILL BE FEW AND FAR
BETWEEN. WILL CONTINUE MENTION OF THUNDERSTORMS IN THE FORECAST
OVERNIGHT IN THE SOUTHWESTERN ZONES AS THERE ARE INDICATIONS OF THE
DEVELOPMENT OF A LOW LEVEL JET...WHICH BECOMES FOCUSED ACROSS SWRN
AND CENTRAL NEBRASKA OVERNIGHT SUNDAY NIGHT. CONVECTION ALONG WITH
THE EXITING DISTURBANCE...WILL FORCE A FRONTAL BOUNDARY THROUGH THE
FORECAST AREA ON MONDAY...STALLING THIS FEATURE ACROSS CENTRAL AND
EASTERN NEBRASKA MONDAY EVENING. ONCE AGAIN...UPPER LEVEL ENERGY
WILL ENTER THE CENTRAL PLAINS FROM THE ROCKIES LATE IN THE DAY
MONDAY...LEADING TO THE DEVELOPMENT OF THUNDERSTORMS. THERE IS SOME
DISAGREEMENT AS TO WHERE THE UPPER LEVEL ENERGY WILL TRACK DURING
THIS PERIOD SO CONFIDENCE IN LOCATION OF POPS IS LACKING ATTM.
DECIDED TO CONFINE POPS INVOF OF THE FRONTAL BOUNDARY...IE...EASTERN
CWA FOR MONDAY NIGHT. ON TUESDAY...EASTERLY WINDS WILL BECOME
SOUTHERLY BY AFTERNOON AS HIGH PRESSURE DRIFTS EAST INTO THE UPPER
MIDWEST. THE FRONTAL BOUNDARY WILL WASH OUT WHILE NORTHWESTERLY FLOW
ALOFT CONTINUES. ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS WILL
TRACK ACROSS THE REGION TUESDAY AFTERNOON AND TUESDAY NIGHT AS
ANOTHER UPPER LEVEL DISTURBANCE TRACKS FROM THE CENTRAL AND NORTHERN
ROCKIES ONTO THE CENTRAL PLAINS.

LONG RANGE...TUESDAY NIGHT THROUGH SATURDAY...A FAIRLY ACTIVE
PATTERN WILL CONTINUE INTO THE EXTENDED PERIODS WITH ABUNDANT LOW
LEVEL MOISTURE AND PERSISTENT WESTERLY AND NORTHWESTERLY FLOW ALOFT.
NUMEROUS SHORTWAVES WILL TRACK ACROSS THE CENTRAL ROCKIES ACROSS THE
CENTRAL PLAINS THROUGH THE PERIOD...LEADING TO A GOOD CHANCE FOR
PRECIPITATION DURING THE PERIOD. TEMPERATURES WILL BE SEASONAL WITH
HIGHS IN THE 80S AND LOWS IN THE UPPER 50S AND LOWER 60S.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 111 AM CDT SUN JUL 21 2013

THUNDERSTORMS OVER SOUTH CENTRAL SOUTH DAKOTA HAVE PUT TEMPO GROUP
IN KVTN TAF EARLY THIS MORNING. WITH UNCERTAINTY IN FORECAST HAVE
LEFT THUNDERSTORMS OUT OF TAF FOR SUNDAY AFTERNOON. VFR CONDITIONS
OVER WESTERN NEBRASKA EARLY THIS MORNING WITH CLEARING SKIES
BEHIND THUNDERSTORMS MOVING INTO CENTRAL NEBRASKA.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...POWER
SYNOPSIS...CLB
SHORT TERM...SPRINGER
LONG TERM...CLB
AVIATION...POWER








AREA FORECAST DISCUSSION

NWS HASTINGS NE

 111 AM CDT SUN JUL 21 2013

.UPDATE...
ISSUED AT 942 PM CDT SAT JUL 20 2013

AS WAS THE CASE DURING THE PRECEDING DAY SHIFT...CONFIDENCE IN
THUNDERSTORM TRENDS/RAIN CHANCES THROUGH THE OVERNIGHT HOURS
CONTINUES TO RUN AT LESS-THAN-IDEAL LEVELS. FOR AT LEAST A SHORT
TIME LONGER...THE ENTIRE CWA CONTINUES IN A MULTI-HOUR LULL IN THE
WAKE OF AFTERNOON CONVECTION THAT HAS SINCE EXITED WELL SOUTHEAST
OF THE CWA. ALTHOUGH AREAS FROM THE TRI-CITIES AND WEST/NORTHWEST
ESSENTIALLY MISSED OUT ON THE EARLIER ROUND...SEVERAL SMALL
POCKETS ACROSS NORTH CENTRAL KS AND FAR SOUTHERN NEB RECEIVED A
QUICK 1-4 INCH DRENCHING PER OUR LOCAL STORM REPORTS. LOOKING
AHEAD...THE ONLY SHOW IN TOWN AT THE 9 PM HOUR IS A SMALL LINEAR
COMPLEX OF STRONG TO MARGINALLY SEVERE STORMS TRACKING SOUTH-
SOUTHEAST THROUGH THE WEST CENTRAL/NORTH CENTRAL NEB
SANDHILLS...BUT GRADUALLY APPROACHING THE FRINGES OF THE CWA.
FARTHER UPSTREAM...ADDITIONAL CLUSTERS OF STRONG-SEVERE STORMS
HAVE TAKEN OFF IN SOUTHERN SD.

ON THE LARGE SCALE ALOFT...SEASONABLY DECENT WEST-NORTHWEST FLOW
WILL PERSIST THROUGH THE NIGHT MAINLY AT/ABOVE 500
MILLIBARS...WHILE FAIRLY CHAOTIC AND LIGHT FLOW PERSISTS A BIT
LOWER AT 700MB...AND LOWER YET EVEN THE FLOW AT 850MB APPEARS
QUITE UNDERWHELMING...WITH THE PRIMARY EXIT REGION OF A FAIRLY
WEAK LOW LEVEL JET AIMED NORTH OF THE LOCAL AREA NEAR THE NEB/SD
BORDER. AS A RESULT...GIVEN THE LACK OF NOTABLE THETA-E
ADVECTION/CONVERGENCE IN AND NEAR THE CWA AT BOTH THE 850/700MB
LEVEL...OUR CURRENTLY-ADVERTISED 50+ PERCENT POPS ACROSS THE
MAJORITY OF THE CWA OVERNIGHT ARE COMING INCREASINGLY UNDER
QUESTION ESPECIALLY IN THE CENTRAL/SOUTHEAST COUNTIES. NOT
SURPRISINGLY...THE LATEST 00Z NAM AND HRRR ARE BOTH PRETTY PALTRY
WITH MEASURABLE RAIN POTENTIAL OVERNIGHT. BASED ON CURRENT RADAR
TRENDS...IT MAY VERY WELL END UP BEING THE CASE THAT THE BEST HOPE
FOR LEGITIMATE RAINFALL WILL HINGE ON HOW SUCCESSFULLY THE
ACTIVITY CURRENTLY DRIFTING TOWARD THE FAR NORTHWEST EDGES OF THE
CWA HOLDS TOGETHER OVER THE NEXT FEW HOURS. PER THE LATEST RAP
INSTABILITY TRENDS...THERE COULD BE AT LEAST A MODEST INCREASE IN
ELEVATED MUCAPE IN THE 850-700MB LAYER INTO THE 500-1000 J/KG
RANGE AS THE NIGHT WEARS ON...BUT MODEL SOUNDINGS SHOW THAT EVEN
MUCH OF THIS INSTABILITY MAY BE RATHER CAPPED. AS FOR ANY
OVERNIGHT SEVERE THREAT...THAT ALSO APPEARS TO BE ON A
DECLINE...UNLESS SOMEHOW THE CONVECTION CURRENTLY IN THE NORTH
PLATTE CWA RE-INTENSIFIES OR DEVELOPS A NEW VIGOROUS COLD POOL
OVER THE NEXT FEW HOURS. HAIL-WISE...IT MAY BE TOUGH TO GET
ANYTHING LARGER THAN DIMES-NICKELS GIVEN LATEST INSTABILITY
TRENDS.

IN SUMMARY...WILL CONTINUE TO EXAMINE THE LATEST TRENDS AND
POTENTIALLY DECREASE POPS ACROSS PARTS OF THE CWA IN A FORTHCOMING
EVENING UPDATE...BUT IN THE CONTINUED PRESENCE OF SUBTLE
NORTHWEST-FLOW FORCING...PROBABLY CANNOT EXCLUDE ANY LOCATION FROM
AT LEAST A TOKEN 20 PERCENT CHANCE OF SHOWERS/STORMS
OVERNIGHT...AS NORTHWEST FLOW IS NOTORIOUS FOR PROVIDING A FEW
SURPRISES. BY AND LARGE THOUGH...ITS STARTING TO LOOK LIKE THE 50+
POPS WE/VE BEEN ADVERTISING THE PAST FEW DAYS MAY PROVE OVERDONE
FOR A DECENT CHUNK OF THE AREA...ESPECIALLY FOR THOSE LOOKING FOR
MORE THAN A FEW TENTHS OF AN INCH. ALSO MAY BE MAKING A FEW
DOWNWARD TWEAKS TO OVERNIGHT LOW TEMPS BASED ON LATEST
OBSERVATIONAL TRENDS AND GUIDANCE. WILL BE DEFER TO ONCOMING
OVERNIGHT SHIFT TO MAKE CHANGES BEYOND 12Z SUNDAY MORNING...BUT IT
APPEARS IT COULD BE ANOTHER DAY/NIGHT OF FICKLE THUNDERSTORM
TRENDS. LOOK FOR NEXT ROUND OF FORECAST UPDATES TO BE OUT BETWEEN
10-1030 PM...

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 353 PM CDT SAT JUL 20 2013

ALOFT: QUASI-ZONAL WNW FLOW WILL CONT THRU 00Z/MON. WV IMAGERY SHOWS
A SUBTLE SHRTWV TROF MOVING INTO THE PANHANDLE FROM WY. THIS TROF IS
FCST TO DEEPEN TNGT...CROSS THE FCST AREA SUN MRNG...AND WILL BE
MOVING INTO NERN KS DURING PEAK HEATING. WHILE THIS TROF MAY AID
TSTM DEVELOPMENT TNGT...HAVE TO WONDER IF SUBSIDENCE IN ITS WAKE
WILL CAP OFF TSTM THREAT SUN AFTN.

SFC: NUMEROUS OUTFLOW BOUNDARIES WILL LINGER THRU SUN. THE LEE/HEAT
LOW WILL STRENGTHEN AND DRIFT INTO WRN KS. THIS SHOULD DROP DWPTS
SUBSTANTIALLY FROM MCK-PHG-RCP AND PROBABLY DID NOT GO LOW ENOUGH.

RAINFALL: PLEASE FOLLOW OUR LOCAL STORM REPORTS /LSR/. WE HAVE
SEEN SOME SUBSTANTIAL 2-3 INCH AMTS BUT IT HAS BEEN FEAST OR
FAMINE.

REST OF THIS AFTN: THE ATMS HAS APPARENTLY STABILIZED OVER MUCH OF
S-CNTRL NEB BASED ON THE LACK OF CU AND A WWD MOVING OUTFLOW
BOUNDARY W OF HWY 283. SCT TSTMS WILL GRADUALLY DIE OFF OVER N-CNTRL
KS.

TNGT: PROBABLY SOMEWHAT OF A BREAK THIS EVNG. WE WERE WATCHING
UPSTREAM TSTMS OVER THE PANHANDLE...WHICH THE MODELS SUGGESTED WOULD
PROPAGATE INTO S-CNTRL NEB. THOSE TSTMS HAVE DIED WHICH LOWERS
CONFIDENCE IN TNGT/S FCST...ESPECIALLY SINCE VIS SATPIX SHOW NO
AGITATED CU FIELDS.

SOME SEMBLANCE OF A COUPLED ULJ DEVELOPS TNGT...WHICH WILL ENHANCE
THE LLJ. SO THE ENVIRONMENT WILL REMAIN FAVORABLE FOR ADDITIONAL
TSTM DEVELOPMENT.

SUN: IT ALL HINGES ON WHAT HAPPENS TNGT. IF SCT TSTMS FORM AND MOVE
THRU THEN WE/LL SEE TSTMS DEPARTING DURING THE MRNG HRS WITH
CLEARING THEREAFTER.

FCST SOUNDINGS INDICATE DAYTIME HEATING SHOULD ERODE THE CAP.
LEFTOVER OUTFLOW BOUNDARIES WILL PROVIDE FOCI FOR TSTM DEVELOPMENT.
HOWEVER...IT APPEARS DOUBTFUL WE SEE ANYTHING MORE THAN AN ISOLATED
TSTM MAYBE TWO? LARGE-SCALE SUBSIDENCE COULD LIMIT OR MITIGATE THE
THREAT ALTOGETHER. IT/S POSSIBLE MODEL SOUNDINGS ARE NOT FULLY
DEPICTING THIS. QPF IS PRETTY MEAGER SO IT MAY BE OF LITTLE
CONSEQUENCE.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 353 PM CDT SAT JUL 20 2013

GUIDANCE SUGGESTS NORTHWESTERLY MID TO UPPER LEVEL FLOW WILL PERSIST
OVER THE CENTRAL PLAINS THROUGH MUCH OF THE EXTENDED FORECAST
PERIOD. THERE WILL BE THE POTENTIAL FOR MULTIPLE SMALL SCALE
PERTURBATIONS TO WORK THEIR WAY ACROSS THE REGION AS A RESULT...WITH
QPF FIELDS FROM THE NAM...OPERATIONAL GFS...EC AND SREF-MEAN
SUGGESTING PRECIPITATION WILL BE REALIZED OVER VARIOUS PORTIONS OF
OUR AREA DURING THE EXTENDED FORECAST PERIOD. AN EVEN AVERAGE OF THE
NAM...OPERATIONAL GFS...EC...AND SREF-MEAN WAS UTILIZED TO DERIVE
QPF FIELDS AND RESULTANT POPS FOR MONDAY AND TUESDAY...WHICH RESULTS
IN LOW POPS BEING PRESENTED TO MOST ALL OF THE CWA BOTH DAYS. THE
SAME PATTERN IS EXPECTED TO PERSIST THROUGH MUCH OF THE REST OF THE
WEEK AS WELL...WITH ALLBLEND PROVIDING 20-60% POPS TO THE CWA AS A
RESULT. THESE POPS WERE LEFT UNCHANGED FOR THE MOST PART.

AS FOR SEVERE WEATHER CHANCES DURING THE EXTENDED FORECAST
PERIOD...PERSISTENT LOW LEVEL MOISTURE SHOULD PRESENT DECENT CAPE
VALUES ACROSS THE AREA...WITH GUIDANCE SUGGESTING SUCH VALUES WILL
AVERAGE FROM 1500 TO 3000J/KG ON MOST DAYS. GIVEN THE UNCERTAINTY OF
PLACEMENT AND TIMING OF SEVERE WEATHER HOWEVER...WILL PROVIDE A
VAGUE SEVERE WEATHER MENTION IN THE HWO FOR MONDAY BUT LEAVE OUT ANY
MENTION OF SEVERE WEATHER THROUGH THE REMAINDER OF THE EXTENDED
FORECAST PERIOD.

LITTLE CHANGE IN THE LOW LEVEL AIRMASS SHOULD PRESENT AFTERNOON HIGH
TEMPERATURES IN THE 90S TO START THE EXTENDED FORECAST PERIOD...WITH
SLIGHTLY COOLER AIR PROVIDING AFTERNOON HIGHS IN THE 80S TO NEAR 90
BY THE END OF THE EXTENDED FORECAST PERIOD. OVERNIGHT LOW
TEMPERATURES IN THE 60S ARE EXPECTED FOR MOST PART DURING THE
EXTENDED FORECAST PERIOD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 102 AM  CDT SUN JUL 21 2013

A LINE OF SHOWERS AND THUNDERSTORMS NORTH AND WEST OF GRAND ISLAND
WILL SLIDE SOUTHEAST THROUGH KGRI OVER THE NEXT SEVERAL HOURS.
THESE THUNDERSTORMS HAVE WEAKENED SOME OVER THE LAST HOUR AND ARE
NON SEVERE. ODDS ARE GOOD THAT ANY PRECIPITATION WILL HAVE EXITED
KGRI PRIOR TO DAWN. THE WIND WILL GENERALLY BE LIGHT AND VARIABLE
TONIGHT...BUT COULD GUST TO AROUND 30 MPH IN AND AROUND
THUNDERSTORMS. A SLIGHT CHANCE OF THUNDERSTORMS WILL CONTINUE INTO
THE DAY ON SUNDAY...BUT THE CHANCE IS TOO LOW TO WARRANT INCLUSION
IN THE TAF. THE PREDOMINATE WIND DIRECTION ON SUNDAY SHOULD BE
SOUTHEAST.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

$$

UPDATE...PFANNKUCH
SHORT TERM...HALBLAUB
LONG TERM...BRYANT
AVIATION...WESELY







AREA FORECAST DISCUSSION...UPDATED

NWS NORTH PLATTE NE

 1133 PM CDT SAT JUL 20 2013

.SYNOPSIS...
ISSUED AT 253 PM CDT SAT JUL 20 2013

THE H5 ANALYSIS THIS MORNING...HAS AN ACTIVE NW FLOW
PATTERN ACROSS THE NRN CONUS. HIGH PRESSURE WAS ANCHORED ACROSS THE
CENTRAL VALLEY OF CA...WITH A PERSISTENT BERMUDA HIGH PRESENT ACROSS
THE WESTERN ATLANTIC. A BROAD TROUGH OF LOW PRESSURE EXTENDED FROM
NRN QUEBEC INTO THE MID ATLANTIC STATES. ACROSS THE NRN ROCKIES AND
CENTRAL PLAINS...NUMEROUS SHORTWAVES WERE EMBEDDED IN THE NWRLY
FLOW. ONE OVER NWRN WYOMING...AND A SECOND OVER THE IDAHO PANHANDLE.
ANOTHER DISTURBANCE WAS NOTED OVER NWRN IA AS WELL. AT THE
SURFACE...SHOWERS AND THUNDERSTORMS HAVE CONTINUED ACROSS NORTHERN
NEBRASKA THIS MORNING AND EARLY THIS AFTERNOON...ALONG A WEAK
SURFACE BOUNDARY. TEMPERATURES AS OF 2 PM CDT RANGED FROM 68 IN RAIN
COOLED AIR AT ONEILL...TO 87 AT OGALLALA...IMPERIAL AND NORTH PLATTE.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 253 PM CDT SAT JUL 20 2013

SCATTERED THUNDERSTORMS THIS AFTERNOON ARE EXPECTED TO DEVELOP OVER
THE NEBRASKA PANHANDLE AND NORTHWEST NEBRASKA AND COALESCE INTO A
CONVECTIVE SYSTEM BY EARLY THIS EVENING. WITH THE DEEP SHEAR VECTORS
DIAGONAL TO THE LOW LEVEL BOUNDARY...IT APPEARS TO FAVOR THE
DEVELOPMENT OF A LINEAR CONVECTIVE SYSTEM. ACCORDING TO THE SHORT
RANGE HRRR AND RAP13...THE SYSTEM WILL AFFECT A LARGE PART OF THE
SANDHILLS AND SOUTHWEST NEBRASKA BY 01Z AND FINALLY CLEARING CENTRAL
NEBRASKA BY 09Z. THEY DO INDICATE SOME LINGERING SHOWERS AND
THUNDERSTORMS EVEN INTO EARLY SUNDAY.

INSTABILITY CONTINUES OVER WESTERN NEBRASKA SUNDAY AND THERE IS A
CHANCE OF ANOTHER CONVECTIVE SYSTEM DEVELOPING IN SOUTH DAKOTA AND
NORTHWEST NEBRASKA LATE SUNDAY MORNING OR EARLY AFTERNOON...THEN
CROSSING WESTERN NEBRASKA THROUGH THE AFTERNOON.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 253 PM CDT SAT JUL 20 2013

MID RANGE...SUNDAY NIGHT THROUGH TUESDAY...A FAIRLY ACTIVE PATTERN
WILL CONTINUE INTO TUESDAY...THANKS TO NWLY FLOW AND THE PRESENCE OF
EMBEDDED SHORTWAVES WITHIN THAT FLOW. BEGINNING SUNDAY
NIGHT...ANOTHER UPPER LEVEL DISTURBANCE WILL TRACK FROM THE CENTRAL
AND NORTHERN ROCKIES...ACROSS WESTERN AND NORTH CENTRAL NEBRASKA.
CONVECTION WILL BE ONGOING BY SUNDAY AFTERNOON AND IS EXPECTED TO
IMPACT MOST OF THE FORECAST AREA DURING THE EVENING AND OVERNIGHT
HOURS. ATTM...WILL PAINT THE HIGHEST POPS IN THE CENTRAL AND
SOUTHWESTERN CWA...AS THESE LOCATIONS WILL SEE THE BEST DEEP LAYER
SHEAR OF 30 TO 40 KTS. SHEAR IN THE NERN ZONES WILL RUN 10 TO 20 KTS
SUNDAY EVENING...SO ANY TSRAS IN THESE AREAS WILL BE FEW AND FAR
BETWEEN. WILL CONTINUE MENTION OF THUNDERSTORMS IN THE FORECAST
OVERNIGHT IN THE SOUTHWESTERN ZONES AS THERE ARE INDICATIONS OF THE
DEVELOPMENT OF A LOW LEVEL JET...WHICH BECOMES FOCUSED ACROSS SWRN
AND CENTRAL NEBRASKA OVERNIGHT SUNDAY NIGHT. CONVECTION ALONG WITH
THE EXITING DISTURBANCE...WILL FORCE A FRONTAL BOUNDARY THROUGH THE
FORECAST AREA ON MONDAY...STALLING THIS FEATURE ACROSS CENTRAL AND
EASTERN NEBRASKA MONDAY EVENING. ONCE AGAIN...UPPER LEVEL ENERGY
WILL ENTER THE CENTRAL PLAINS FROM THE ROCKIES LATE IN THE DAY
MONDAY...LEADING TO THE DEVELOPMENT OF THUNDERSTORMS. THERE IS SOME
DISAGREEMENT AS TO WHERE THE UPPER LEVEL ENERGY WILL TRACK DURING
THIS PERIOD SO CONFIDENCE IN LOCATION OF POPS IS LACKING ATTM.
DECIDED TO CONFINE POPS INVOF OF THE FRONTAL BOUNDARY...IE...EASTERN
CWA FOR MONDAY NIGHT. ON TUESDAY...EASTERLY WINDS WILL BECOME
SOUTHERLY BY AFTERNOON AS HIGH PRESSURE DRIFTS EAST INTO THE UPPER
MIDWEST. THE FRONTAL BOUNDARY WILL WASH OUT WHILE NORTHWESTERLY FLOW
ALOFT CONTINUES. ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS WILL
TRACK ACROSS THE REGION TUESDAY AFTERNOON AND TUESDAY NIGHT AS
ANOTHER UPPER LEVEL DISTURBANCE TRACKS FROM THE CENTRAL AND NORTHERN
ROCKIES ONTO THE CENTRAL PLAINS.

LONG RANGE...TUESDAY NIGHT THROUGH SATURDAY...A FAIRLY ACTIVE
PATTERN WILL CONTINUE INTO THE EXTENDED PERIODS WITH ABUNDANT LOW
LEVEL MOISTURE AND PERSISTENT WESTERLY AND NORTHWESTERLY FLOW ALOFT.
NUMEROUS SHORTWAVES WILL TRACK ACROSS THE CENTRAL ROCKIES ACROSS THE
CENTRAL PLAINS THROUGH THE PERIOD...LEADING TO A GOOD CHANCE FOR
PRECIPITATION DURING THE PERIOD. TEMPERATURES WILL BE SEASONAL WITH
HIGHS IN THE 80S AND LOWS IN THE UPPER 50S AND LOWER 60S.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1129 PM CDT SAT JUL 20 2013

THE SCATTERED/NUMEROUS THUNDERSTORM ACTIVITY ACROSS SCNTL AND
NCNTL NEB SHOULD EXIT THE FCST AREA AROUND 06Z. OTHER ISOLATED
TSTM ACTIVITY ACROSS NRN NEB COULD CONTINUE OVERNIGHT. THE MODELS
SUGGEST THIS ACTIVITY WILL MOVE EAST.

OTHERWISE VFR IS EXPECTED THROUGH 20Z. THEREAFTER...SCATTERED
TSTMS SHOULD REDEVELOP ACROSS WRN AND NCNTL NEB. STORM MOTION WILL
BE EAST AND SOUTHEAST.

THE RISK TO THE FCST IS THAT THE MODELS ARE TOO FAST SUNDAY. THUS
ITS POSSIBLE THAT STORM DEVELOPMENT SUNDAY AFTN COULD HOLD OFF
UNTIL 22Z-23Z.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...CLB
SHORT TERM...SPRINGER
LONG TERM...CLB
AVIATION...CDC







AREA FORECAST DISCUSSION...CORRECTED

NWS WILMINGTON NC

 1033 PM EDT MON JUL 22 2013

.SYNOPSIS...
SEASONABLE AND WARM TEMPERATURES WILL CONTINUE WITH ISOLATED TO
AFTERNOON SHOWERS AS BERMUDA HIGH PRESSURE REACHES INTO THE AREA
FROM THE EAST . A FRONT WILL APPROACH FROM THE NORTHWEST WEDNESDAY
NIGHT AND STALL ACROSS THE AREA ON THURSDAY...PRODUCING MORE
UNSETTLED WEATHER THROUGH LATE WEEK. ANOTHER COLD FRONT WILL MOVE
INTO THE AREA EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM MONDAY...BERMUDA HIGH PRESSURE OVER A THOUSAND MILES
OFF THE COAST IS PRODUCING A SOUTHWEST FLOW ACROSS THE EASTERN
CAROLINAS. LOW PRESSURE MOVING EAST THROUGH THE CENTRAL APPALACHIANS
AND A PIEDMONT TROUGH STATIONARY ACROSS THE CENTRAL CAROLINAS INTO
EASTERN VIRGINIA ARE BOTH HELPING TO PINCH THE PRESSURE GRADIENT
TIGHTER. SINCE SUNSET...INLAND TEMPERATURES HAVE COOLED SUFFICIENTLY
TO SHIFT MOST OF THE WIND`S MOMENTUM UP INTO A LOW LEVEL JET WITH
1000 FT AGL WIND SPEED NEAR 30 KNOTS. OVER THE WARM OCEAN AND ALONG
PRIMARILY SOUTH-FACING BEACHES THESE STRONGER WINDS ARE MIXING DOWN
TO THE SURFACE WITH WIND GUSTS OVER 30 MPH RECENTLY REPORTED FROM
OAK ISLAND AND BALD HEAD ISLAND.

AS A LANDBREEZE HELPS ADVECT SOME OF THE COOLER AIR INLAND DOWN TO
THE COAST OVERNIGHT LOW-LEVEL LAPSE RATES SHOULD LESSEN ENOUGH TO
PREVENT THESE STRONGER WINDS FROM COMING DOWN TO THE SURFACE. UNTIL
THEN...HANG ONTO YOUR HAT ALONG THE BRUNSWICK COUNTY BEACHES.

A POCKET OF DRY AIR IN THE 800-500 MB LAYER WILL EXIT THE COAST
SHORTLY...WITH PRECIPITABLE WATER VALUES RISING FROM 1.7 INCHES TO
NEARLY 2 INCHES LATE TONIGHT. AN UPPER LEVEL DISTURBANCE PRODUCING
T-STORMS ACROSS THE MOUNTAINS AND FOOTHILLS WILL APPROACH THE
EASTERN CAROLINAS AROUND DAYBREAK. THIS IS TYPICALLY THE MOST
UNFAVORABLE TIME OF DAY FOR CONVECTION WITH INSTABILITY THE WEAKEST.
FORECAST SOUNDINGS SHOW TOO MUCH CAPPING TO OVERCOME GIVEN THE
MODEST LIFT AHEAD OF THE UPPER DISTURBANCE SO I HAVE MAINTAINED A
DRY FORECAST OVERNIGHT FOR MOST AREAS. AT THE BEACHES AND ESPECIALLY
OFFSHORE...ISOLATED TO SCATTERED SHOWERS MAY DEVELOP LATE WITHIN
WARMER...MORE UNSTABLE CONDITIONS.

NO SIGNIFICANT CHANGES HAVE BEEN MADE TO LOW TEMPERATURE FORECASTS
WHICH RANGE FROM 73-77...WARMEST AT THE BEACHES.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...A SHORTWAVE WILL RIDE THROUGH A VERY BROAD
TROUGH LOCATED OVER THE EASTERN CONUS. THIS WILL HELP TO PRODUCE
SOME CLOUDS AND A FEW SHOWERS EARLY MORNING ON TUES BUT THE
SHORTWAVE WILL SHIFT OFF THE COAST BY AFTERNOON WITH A DEEPER W-NW
FLOW OF DRIER AIR AND SUBSIDENCE DEVELOPING THROUGH TUES AFTN INTO
WED. THE WESTERLY DOWNSLOPE COMPONENT TO THE FLOW WILL ALSO AID IN
DRYING AND WARMING...ESPECIALLY INLAND THROUGH TUES AFTN. TEMPS
SHOULD REACH 90 OR SLIGHTLY ABOVE MOST PLACES TUES AND DROP TO
THE MID 70S OVERNIGHT.

THE DRIER AIR AND SUBSIDENCE THROUGH THE MID LEVELS WILL HOLD
THROUGH MUCH OF WEDNESDAY AS FRONT BEGINS TO ENTER INTO CAROLINAS
FROM THE NORTH AND WEST BY LATE DAY. BY WED NIGHT THE MID TO UPPER
TROUGH BECOMES MORE AMPLIFIED AS IT PUSHES A FRONT/TROUGH SOUTH
AND EAST INTO AREA. THIS WILL INCREASE CHANCES OF SHWRS/TSTMS
OVERNIGHT BUT MORE SO ON THURS. THE WESTERLY DOWNSLOPE WINDS IN
THE LOW LEVELS AND A GOOD DEAL OF SUNSHINE WILL AID IN PUSHING
TEMPS INTO THE 90S ON WED.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...A SERIES OF SHORTWAVE TROUGHS MOVING THROUGH THE
AMPLIFIED FLOW ALOFT WILL KEEP WEATHER ACTIVE DURING THE PERIOD.
BOTH SHORTWAVES WILL BE ACCOMPANIED BY A COLD FRONT THAT WILL TRY TO
PUSH ACROSS THE AREA. THE FIRST WILL BE MOVING INTO THE AREA AS THE
PERIOD BEGINS WITH A SECOND STRONGER FRONT ARRIVING MON. THE LARGE
SCALE 5H TROUGH AXIS REMAINS WEST OF THE AREA THROUGH AT LEAST THE
WEEKEND. THE FIRST FRONT ENDS UP LAYING PARALLEL TO THE STEERING
FLOW AND STALLS ACROSS OR JUST EAST OF THE AREA. SURFACE BOUNDARY IN
AIR MASS WITH DEEP MOISTURE AND DIURNAL INSTABILITY SHOULD PROVIDE A
FOCAL POINT FOR CONVECTION. SOME UNCERTAINTY WITH RESPECT TO THE
LOCATION OF THE FRONT AND AMOUNT OF DRY AIR ALOFT SPREADING OVER THE
AREA FRI/SAT SO WILL CARRY LOWER POP DURING THESE PERIODS THOUGH
STILL IN THE CHANCE CATEGORY DURING THE DAY.

PRECIP CHANCES INCREASE SUN/MON AS NEXT COLD FRONT APPROACHES FROM
THE WEST AND DEEP MOISTURE RETURNS. DIVERGENCE ALOFT WILL ENHANCE
BOTH LIFT ALONG THE FRONT AND DIURNAL INSTABILITY. TIMING...LOCATION
AND STRENGTH DIFFERENCE BETWEEN GFS/ECMWF DO ADD A LITTLE BIT OF
UNCERTAINTY EARLY NEXT WEEK SO FOR NOW WILL MAINTAIN CHANCE POP BUT
SHOW AN INCREASE OVER FRI/SAT.

HIGHS WILL BE NEAR TO SLIGHTLY BELOW CLIMO THROUGH THE PERIOD WITH
LOWS NEAR TO SLIGHTLY ABOVE CLIMO.

&&

.AVIATION /00Z TUESDAY THROUGH FRIDAY/...
AS OF 00Z...SYNOPTICALLY NOT MUCH HAS CHANGED IN THE PAST 24 HOURS.
AIR A BIT DRIER ALOFT...BUT SOME DEEPER MOISTURE MAY WORK ITS WAY IN
AFTER MIDNIGHT WITH A SLIGHT CHANCE OF SHOWERS. BASED MAINLY ON
CONTINUITY...WILL INTRODUCE NEAR IFR STRATUS AT THE INLAND
TERMINALS...WITH A MVFR CEILING FORMING NEAR SUNRISE. WINDS AT THE
BOUNDARY LAYER ARE TOO STRONG TO SUPPORT FOG...MVFR BEFORE SUNRISE
WORST CASE. TUESDAY...DAYTIME HEATING WILL KICK OFF SCATTERED
CONVECTION BY 17Z...FOCUSED FIRST ON THE SEA BREEZE BOUNDARY WITH
SCATTERED ACTIVITY INLAND AFTER 19Z.

EXTENDED OUTLOOK...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
ARE EXPECTED THROUGH THURSDAY...WITH BRIEF LOCALIZED PERIODS OF
MVFR/IFR POSSIBLE. OTHERWISE EXPECT VFR.

&&

.MARINE...
NEAR TERM/THROUGH TONIGHT/...
AS OF 1030 PM MONDAY...RECENT WIND GUSTS HAVE REACHED 31 KNOTS AT
THE OCEAN CREST PIER ON OAK ISLAND...28 KNOTS ON BALD HEAD
ISLAND...AND 27 KNOTS AT THE FRYING PAN SHOALS BUOY. THIS APPEARS TO
BE FROM A LOW-LEVEL JET DEVELOPING INLAND WHERE SURFACE TEMPERATURES
ARE COOLER. AS THIS JET BLOWS EAST TO THE COAST AND ENCOUNTERS A
WARMER MORE WELL-MIXED ENVIRONMENT THE MOMENTUM IS DISTRIBUTED
DOWNWARD IN STRONG GUSTS AS WE ARE SEEING. THIS ADDITIONAL INPUT OF
WIND ENERGY INTO THE OCEAN HAS PUSHED SEA HEIGHTS UP TO 5.5 FEET AT
THE WILMINGTON HARBOR BUOY JUST SOUTH OF SOUTHPORT...AND TO 6 FEET
AT THE FRYING PAN SHOALS BUOY. FOR THIS REASON I HAVE ISSUED A SMALL
CRAFT ADVISORY FOR THE NC WATERS THROUGH 3 AM...AND RETAINED THE
EXERCISE CAUTION HEADLINE FOR THE SC WATERS AS WELL.

THE LATEST SEVERAL RUNS OF THE HRRR AND THE 18Z NAM SHOW THIS
LOW-LEVEL JET FAIRLY WELL...WITH 975 MB (1000 FT AGL) WIND SPEEDS
HOLDING AROUND 30 KNOTS THROUGH 06Z (2 AM EDT) BEFORE VEERING
DIRECTIONS MORE WESTERLY WITH DECREASING SPEEDS LATE.

OUR SYNOPTIC WEATHER PATTERN FEATURES BERMUDA HIGH PRESSURE OVER A
THOUSAND MILES OFF THE CAROLINA COAST. LOW PRESSURE IS MOVING EAST
THROUGH THE CENTRAL APPALACHIANS...AND A PIEDMONT TROUGH IS
STATIONARY ACROSS THE CENTRAL CAROLINAS INTO EASTERN VIRGINIA. THE
PRESSURE GRADIENT SOUTH OF THE CENTRAL APPALACHIAN LOW IS PRODUCING
THE BREEZY SOUTHWEST WINDS...WHICH SHOULD VEER MORE WESTERLY
OVERNIGHT WITH A DEVELOPING LANDBREEZE. ALTHOUGH THE RADAR IS
CURRENTLY CLEAR...THE APPROACH OF AN UPPER LEVEL DISTURBANCE AFTER
MIDNIGHT COULD HELP IGNITE ISOLATED SHOWERS OR T-STORMS OVER THE
WATERS...BUT MAINLY FARTHER EAST AWAY FROM SHORE.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...SOUTHWEST WINDS WILL CONTINUE BETWEEN BERMUDA
HIGH TO THE EAST AND TROUGH ACROSS INLAND CAROLINAS. THE WINDS
WILL PICK UP SLIGHTLY TUES AFTN AS PINCHED GRADIENT DEVELOPS AS
TROUGH BECOMES MORE PRONOUNCED INLAND AND PUSHES EAST SLIGHTLY
IN COMBINATION WITH AFTN SEA BREEZE. BY WED NIGHT INTO EARLY
THURS A FRONT WILL MOVE DOWN FROM THE NORTH AND WEST WITH WINDS
SHIFTING TO THE N-NE TO THE NORTH OF THE BOUNDARY AND REMAINING SW
TO THE SOUTH OF THE BOUNDARY. OVERALL EXPECT SOUTHWEST WINDS OF
10-15 KNOTS THROUGH MUCH OF THE PERIOD. SEAS WILL RANGE FROM 2-4
FT.

LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3 PM MONDAY...SOUTHERLY FLOW THU WILL BECOME LIGHT AND
VARIABLE FRI AND SAT AS WEAK SURFACE BOUNDARY MOVES ACROSS THE
WATERS. MAY SEE SOME PERIODS OF LIGHT NORTHERLY FLOW BUT PROXIMITY
TO THE BOUNDARY WILL KEEP SPEEDS UNDER 10 KT. LATE IN THE PERIOD
REMNANTS OF BOUNDARY LIFT NORTH WITH LIGHT SOUTHERLY FLOW
DEVELOPING. WEAK GRADIENT THROUGH THE PERIOD KEEPING WINDS UNDER 10
KT WILL KEEP SEAS AROUND 2 FT FOR MUCH OF THE PERIOD...THOUGH SOME
ISOLATED 3 FT IS POSSIBLE AWAY FROM SHORE.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY FROM 9 PM THIS EVENING TO MIDNIGHT EDT
     TONIGHT FOR NCZ107.

MARINE...SMALL CRAFT ADVISORY THROUGH 3 AM TUESDAY FROM SURF CITY TO
         LITTLE RIVER INLET SC.

&&

$$

NEAR TERM...TRA
SHORT TERM...RGZ
LONG TERM...III
AVIATION...HDL






AREA FORECAST DISCUSSION

NWS WILMINGTON NC

 1031 PM EDT MON JUL 22 2013

.SYNOPSIS...
SEASONABLE AND WARM TEMPERATURES WILL CONTINUE WITH ISOLATED TO
AFTERNOON SHOWERS AS BERMUDA HIGH PRESSURE REACHES INTO THE AREA
FROM THE EAST . A FRONT WILL APPROACH FROM THE NORTHWEST WEDNESDAY
NIGHT AND STALL ACROSS THE AREA ON THURSDAY...PRODUCING MORE
UNSETTLED WEATHER THROUGH LATE WEEK. ANOTHER COLD FRONT WILL MOVE
INTO THE AREA EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM MONDAY...BERMUDA HIGH PRESSURE OVER A THOUSAND MILES
OFF THE COAST IS PRODUCING A SOUTHWEST FLOW ACROSS THE EASTERN
CAROLINAS. LOW PRESSURE MOVING EAST THROUGH THE CENTRAL APPALACHIANS
AND A PIEDMONT TROUGH STATIONARY ACROSS THE CENTRAL CAROLINAS INTO
EASTERN VIRGINIA ARE BOTH HELPING TO PINCH THE PRESSURE GRADIENT
TIGHTER. SINCE SUNSET...INLAND TEMPERATURES HAVE COOLED SUFFICIENTLY
TO SHIFT MOST OF THE WIND`S MOMENTUM UP INTO A LOW LEVEL JET WITH
1000 FT AGL WIND SPEED NEAR 30 KNOTS. OVER THE WARM OCEAN AND ALONG
PRIMARILY SOUTH-FACING BEACHES THESE STRONGER WINDS ARE MIXING DOWN
TO THE SURFACE WITH WIND GUSTS OVER 30 MPH RECENTLY REPORTED FROM
OAK ISLAND AND BALD HEAD ISLAND.

AS A LANDBREEZE HELPS ADVECT SOME OF THE COOLER AIR INLAND DOWN TO
THE COAST OVERNIGHT LOW-LEVEL LAPSE RATES SHOULD LESSEN ENOUGH TO
PREVENT THESE STRONGER WINDS FROM COMING DOWN TO THE SURFACE. UNTIL
THEN...HANG ONTO YOUR HAT ALONG THE BRUNSWICK COUNTY BEACHES.

A POCKET OF DRY AIR IN THE 800-500 MB LAYER WILL EXIT THE COAST
SHORTLY...WITH PRECIPITABLE WATER VALUES RISING FROM 1.7 INCHES TO
NEARLY 2 INCHES LATE TONIGHT. AN UPPER LEVEL DISTURBANCE PRODUCING
T-STORMS ACROSS THE MOUNTAINS AND FOOTHILLS WILL APPROACH THE
EASTERN CAROLINAS AROUND DAYBREAK. THIS IS TYPICALLY THE MOST
UNFAVORABLE TIME OF DAY FOR CONVECTION WITH INSTABILITY THE WEAKEST.
FORECAST SOUNDINGS SHOW TOO MUCH CAPPING TO OVERCOME GIVEN THE
MODEST LIFT AHEAD OF THE UPPER DISTURBANCE SO I HAVE MAINTAINED A
DRY FORECAST OVERNIGHT FOR MOST AREAS. AT THE BEACHES AND ESPECIALLY
OFFSHORE...ISOLATED TO SCATTERED SHOWERS MAY DEVELOP LATE WITHIN
WARMER...MORE UNSTABLE CONDITIONS.

NO SIGNIFICANT CHANGES HAVE BEEN MADE TO LOW TEMPERATURE FORECASTS
WHICH RANGE FROM 73-77...WARMEST AT THE BEACHES.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...A SHORTWAVE WILL RIDE THROUGH A VERY BROAD
TROUGH LOCATED OVER THE EASTERN CONUS. THIS WILL HELP TO PRODUCE
SOME CLOUDS AND A FEW SHOWERS EARLY MORNING ON TUES BUT THE
SHORTWAVE WILL SHIFT OFF THE COAST BY AFTERNOON WITH A DEEPER W-NW
FLOW OF DRIER AIR AND SUBSIDENCE DEVELOPING THROUGH TUES AFTN INTO
WED. THE WESTERLY DOWNSLOPE COMPONENT TO THE FLOW WILL ALSO AID IN
DRYING AND WARMING...ESPECIALLY INLAND THROUGH TUES AFTN. TEMPS
SHOULD REACH 90 OR SLIGHTLY ABOVE MOST PLACES TUES AND DROP TO
THE MID 70S OVERNIGHT.

THE DRIER AIR AND SUBSIDENCE THROUGH THE MID LEVELS WILL HOLD
THROUGH MUCH OF WEDNESDAY AS FRONT BEGINS TO ENTER INTO CAROLINAS
FROM THE NORTH AND WEST BY LATE DAY. BY WED NIGHT THE MID TO UPPER
TROUGH BECOMES MORE AMPLIFIED AS IT PUSHES A FRONT/TROUGH SOUTH
AND EAST INTO AREA. THIS WILL INCREASE CHANCES OF SHWRS/TSTMS
OVERNIGHT BUT MORE SO ON THURS. THE WESTERLY DOWNSLOPE WINDS IN
THE LOW LEVELS AND A GOOD DEAL OF SUNSHINE WILL AID IN PUSHING
TEMPS INTO THE 90S ON WED.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...A SERIES OF SHORTWAVE TROUGHS MOVING THROUGH THE
AMPLIFIED FLOW ALOFT WILL KEEP WEATHER ACTIVE DURING THE PERIOD.
BOTH SHORTWAVES WILL BE ACCOMPANIED BY A COLD FRONT THAT WILL TRY TO
PUSH ACROSS THE AREA. THE FIRST WILL BE MOVING INTO THE AREA AS THE
PERIOD BEGINS WITH A SECOND STRONGER FRONT ARRIVING MON. THE LARGE
SCALE 5H TROUGH AXIS REMAINS WEST OF THE AREA THROUGH AT LEAST THE
WEEKEND. THE FIRST FRONT ENDS UP LAYING PARALLEL TO THE STEERING
FLOW AND STALLS ACROSS OR JUST EAST OF THE AREA. SURFACE BOUNDARY IN
AIR MASS WITH DEEP MOISTURE AND DIURNAL INSTABILITY SHOULD PROVIDE A
FOCAL POINT FOR CONVECTION. SOME UNCERTAINTY WITH RESPECT TO THE
LOCATION OF THE FRONT AND AMOUNT OF DRY AIR ALOFT SPREADING OVER THE
AREA FRI/SAT SO WILL CARRY LOWER POP DURING THESE PERIODS THOUGH
STILL IN THE CHANCE CATEGORY DURING THE DAY.

PRECIP CHANCES INCREASE SUN/MON AS NEXT COLD FRONT APPROACHES FROM
THE WEST AND DEEP MOISTURE RETURNS. DIVERGENCE ALOFT WILL ENHANCE
BOTH LIFT ALONG THE FRONT AND DIURNAL INSTABILITY. TIMING...LOCATION
AND STRENGTH DIFFERENCE BETWEEN GFS/ECMWF DO ADD A LITTLE BIT OF
UNCERTAINTY EARLY NEXT WEEK SO FOR NOW WILL MAINTAIN CHANCE POP BUT
SHOW AN INCREASE OVER FRI/SAT.

HIGHS WILL BE NEAR TO SLIGHTLY BELOW CLIMO THROUGH THE PERIOD WITH
LOWS NEAR TO SLIGHTLY ABOVE CLIMO.

&&

.AVIATION /00Z TUESDAY THROUGH FRIDAY/...
AS OF 00Z...SYNOPTICALLY NOT MUCH HAS CHANGED IN THE PAST 24 HOURS.
AIR A BIT DRIER ALOFT...BUT SOME DEEPER MOISTURE MAY WORK ITS WAY IN
AFTER MIDNIGHT WITH A SLIGHT CHANCE OF SHOWERS. BASED MAINLY ON
CONTINUITY...WILL INTRODUCE NEAR IFR STRATUS AT THE INLAND
TERMINALS...WITH A MVFR CEILING FORMING NEAR SUNRISE. WINDS AT THE
BOUNDARY LAYER ARE TOO STRONG TO SUPPORT FOG...MVFR BEFORE SUNRISE
WORST CASE. TUESDAY...DAYTIME HEATING WILL KICK OFF SCATTERED
CONVECTION BY 17Z...FOCUSED FIRST ON THE SEA BREEZE BOUNDARY WITH
SCATTERED ACTIVITY INLAND AFTER 19Z.

EXTENDED OUTLOOK...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
ARE EXPECTED THROUGH THURSDAY...WITH BRIEF LOCALIZED PERIODS OF
MVFR/IFR POSSIBLE. OTHERWISE EXPECT VFR.

&&

.MARINE...
NEAR TERM/THROUGH TONIGHT/...
AS OF 1030 PM MONDAY...RECENT WIND GUSTS HAVE REACHED 31 KNOTS AT
THE OCEAN CREST PIER ON OAK ISLAND...28 KNOTS ON BALD HEAD
ISLAND...AND 27 KNOTS AT THE FRYING PAN SHOALS BUOY. THIS APPEARS TO
BE FROM A LOW-LEVEL JET DEVELOPING INLAND WHERE SURFACE TEMPERATURES
ARE COOLER. AS THIS JET BLOWS EAST TO THE COAST AND ENCOUNTERS A
WARMER MORE WELL-MIXED ENVIRONMENT THE MOMENTUM IS DISTRIBUTED
DOWNWARD IN STRONG GUSTS AS WE ARE SEEING. THIS ADDITIONAL INPUT OF
WIND ENERGY INTO THE OCEAN HAS PUSHED SEA HEIGHTS UP TO 5.5 FEET AT
THE WILMINGTON HARBOR BUOY JUST SOUTH OF SOUTHPORT...AND TO 6 FEET
AT THE FRYING PAN SHOALS BUOY. FOR THIS REASON I HAVE ISSUED A SMALL
CRAFT ADVISORY FOR THE NC WATERS THROUGH 3 AM...AND RETAINED THE
EXERCISE CAUTION HEADLINE FOR THE SC WATERS AS WELL.

THE LATEST SEVERAL RUNS OF THE HRRR AND THE 18Z NAM SHOW THIS
LOW-LEVEL JET FAIRLY WELL...WITH 975 MB (1000 FT AGL) WIND SPEEDS
INCREASING HOLDING AROUND 30 KNOTS THROUGH 06Z (2 AM EDT) BEFORE
VEERING DIRECTIONS MORE WESTERLY WITH DECREASING SPEEDS LATE.

OUR SYNOPTIC WEATHER PATTERN FEATURES BERMUDA HIGH PRESSURE OVER A
THOUSAND MILES OFF THE CAROLINA COAST. LOW PRESSURE IS MOVING EAST
THROUGH THE CENTRAL APPALACHIANS...AND A PIEDMONT TROUGH IS
STATIONARY ACROSS THE CENTRAL CAROLINAS INTO EASTERN VIRGINIA. THE
PRESSURE GRADIENT SOUTH OF THE CENTRAL APPALACHIAN LOW IS PRODUCING
THE BREEZY SOUTHWEST WINDS...WHICH SHOULD VEER MORE WESTERLY
OVERNIGHT WITH A DEVELOPING LANDBREEZE. ALTHOUGH THE RADAR IS
CURRENTLY CLEAR...THE APPROACH OF AN UPPER LEVEL DISTURBANCE AFTER
MIDNIGHT COULD HELP IGNITE ISOLATED SHOWERS OR T-STORMS OVER THE
WATERS...BUT MAINLY FARTHER EAST AWAY FROM SHORE.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...SOUTHWEST WINDS WILL CONTINUE BETWEEN BERMUDA
HIGH TO THE EAST AND TROUGH ACROSS INLAND CAROLINAS. THE WINDS
WILL PICK UP SLIGHTLY TUES AFTN AS PINCHED GRADIENT DEVELOPS AS
TROUGH BECOMES MORE PRONOUNCED INLAND AND PUSHES EAST SLIGHTLY
IN COMBINATION WITH AFTN SEA BREEZE. BY WED NIGHT INTO EARLY
THURS A FRONT WILL MOVE DOWN FROM THE NORTH AND WEST WITH WINDS
SHIFTING TO THE N-NE TO THE NORTH OF THE BOUNDARY AND REMAINING SW
TO THE SOUTH OF THE BOUNDARY. OVERALL EXPECT SOUTHWEST WINDS OF
10-15 KNOTS THROUGH MUCH OF THE PERIOD. SEAS WILL RANGE FROM 2-4
FT.

LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3 PM MONDAY...SOUTHERLY FLOW THU WILL BECOME LIGHT AND
VARIABLE FRI AND SAT AS WEAK SURFACE BOUNDARY MOVES ACROSS THE
WATERS. MAY SEE SOME PERIODS OF LIGHT NORTHERLY FLOW BUT PROXIMITY
TO THE BOUNDARY WILL KEEP SPEEDS UNDER 10 KT. LATE IN THE PERIOD
REMNANTS OF BOUNDARY LIFT NORTH WITH LIGHT SOUTHERLY FLOW
DEVELOPING. WEAK GRADIENT THROUGH THE PERIOD KEEPING WINDS UNDER 10
KT WILL KEEP SEAS AROUND 2 FT FOR MUCH OF THE PERIOD...THOUGH SOME
ISOLATED 3 FT IS POSSIBLE AWAY FROM SHORE.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY FROM 9 PM THIS EVENING TO MIDNIGHT EDT
     TONIGHT FOR NCZ107.

MARINE...SMALL CRAFT ADVISORY THROUGH 3 AM TUESDAY FROM SURF CITY TO
         LITTLE RIVER INLET SC.

&&

$$

NEAR TERM...TRA
SHORT TERM...RGZ
LONG TERM...III
AVIATION...HDL






AREA FORECAST DISCUSSION

NWS WILMINGTON NC

 714 PM EDT MON JUL 22 2013

.SYNOPSIS...
SEASONABLE AND WARM TEMPERATURES WILL CONTINUE WITH ISOLATED TO
AFTERNOON SHOWERS AS BERMUDA HIGH PRESSURE REACHES INTO THE AREA
FROM THE EAST AND A TROUGH REMAINS INLAND. A FRONT WILL APPROACH
FROM THE NORTHWEST WEDNESDAY NIGHT AND STALL ACROSS THE AREA ON
THURSDAY...PRODUCING MORE UNSETTLED WEATHER THROUGH LATE WEEK.
ANOTHER COLD FRONT WILL MOVE INTO THE AREA EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 730 PM MONDAY...MAJOR CHANGES ARE NEEDED TO WIND AND SKY COVER
FORECASTS THROUGH THE EVENING HOURS. A HEALTHY AFTERNOON SEABREEZE
HAS PUSHED WIND SPEEDS UP AS HIGH AS 20-25 KNOTS ALONG THE
BEACHES...AND 12-18 KNOTS FOR COASTAL CITIES LIKE WILMINGTON AND
MYRTLE BEACH. THESE STRONGER WINDS SHOULD DIE AWAY BY LATE EVENING
AS A DEVELOPING LANDBREEZE HELPS VEER WINDS AROUND FROM THE
SOUTHWEST TO A MORE WESTERLY DIRECTION. ALSO...SATELLITE IMAGERY AND
SURFACE OBSERVATIONS SHOW ONLY A SCATTERED CUMULUS DECK INLAND FROM
THE SEABREEZE BOUNDARY. MOSTLY CLEAR SKIES ARE ANTICIPATED THROUGH 9
PM BEFORE HIGH CLOUD COVER (BLOWOFF FROM EARLIER STORMS OVER
GEORGIA) INCREASES FROM THE SOUTHWEST. MODELS ARE ALSO SHOWING THE
POTENTIAL FOR LOW STRATUS CLOUDS LATE TONIGHT AS THE BOUNDARY LAYER
COOLS AND SATURATED LAYER DEVELOPS JUST ABOVE THE SURFACE. BOUNDARY
LAYER WIND SPEEDS SHOULD REMAIN STRONG ENOUGH TO FAVOR LOW CLOUDS
OVER FOG.

LATEST HRRR MODEL RUNS (19-21Z) APPEAR TO HAVE AN EXCELLENT HANDLE
ON THE DISTRIBUTION OF SHOWERS ACROSS THE EASTERN CAROLINAS.
ISOLATED SHOWER ACTIVITY SHOULD DIE AWAY OVER THE NEXT SEVERAL
HOURS...BUT AN APPROACHING SHORTWAVE TROUGH LATE TONIGHT WILL
INCREASE SHOWER CHANCES MAINLY OVER THE OCEAN. PREVIOUS DISCUSSION
FROM 300 PM FOLLOWS...

DESPITE THE IMPRESSIVELY HIGH AMOUNT OF MOISTURE CURRENTLY FOUND IN
THE ATMOSPHERE SHOWERS AND STORMS HAVE FAILED TO DEVELOP EVEN ALONG
WEAK SEABREEZE BOUNDARY EVIDENT ON KLTX. BEST GUESS AS TO WHY IS
THAT WV IMAGERY SHOWS A WEAK SENSE OF ANTICYCLONIC CIRCULATION JUST
OFF THE COAST. ALTHOUGH THIS FEATURE DOES NOT APPEAR TO SHOW UP WELL
IN ANY PARTICULAR MODEL GUIDANCE HAS BEEN HINTING ALL DAY OF VERY
LACKLUSTER ACTIVITY LEVELS OF CONVECTION AND THE FORECAST HAS BEEN
HEDGED DRYER IN ITS LAST FEW ITERATIONS. EVEN THE WELL DEFINED VORT
CROSSING INTO GA FROM AL HAS ONLY MANAGED TO GENERATE CONVECTION
ALONG ITS SOUTHERN FLANK...AND NOT EAST OF THE FEATURE WHERE THE
AFOREMENTIONED SUBSIDENCE SEEMS TO BE TAKING PLACE. THE GA VORT WILL
LARGELY SHEAR OUT AS IT APPROACHES DUE TO A MUCH BETTER DEFINED
UPPER PIECE OF ENERGY THAT ARRIVES OVER WESTERN ZONES BY END OF
PERIOD/12Z TUESDAY. GIVEN THE APPROACH OF BOTH FEATURES IT SEEMS
WARRANTED TO HAVE POPS CONTINUE ALL NIGHT...ALTHOUGH IN LIGHT OF
RELUCTANCE OF ANYTHING TO DEVELOP UP UNTIL THIS POINT THEY WILL BE
CAPPED AT ABOUT 30 THIS EVE AND SPEND THE NIGHT IN THE SCHC/20S
RANGE.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...A SHORTWAVE WILL RIDE THROUGH A VERY BROAD
TROUGH LOCATED OVER THE EASTERN CONUS. THIS WILL HELP TO PRODUCE
SOME CLOUDS AND A FEW SHOWERS EARLY MORNING ON TUES BUT THE
SHORTWAVE WILL SHIFT OFF THE COAST BY AFTERNOON WITH A DEEPER W-NW
FLOW OF DRIER AIR AND SUBSIDENCE DEVELOPING THROUGH TUES AFTN INTO
WED. THE WESTERLY DOWNSLOPE COMPONENT TO THE FLOW WILL ALSO AID IN
DRYING AND WARMING...ESPECIALLY INLAND THROUGH TUES AFTN. TEMPS
SHOULD REACH 90 OR SLIGHTLY ABOVE MOST PLACES TUES AND DROP TO
THE MID 70S OVERNIGHT.

THE DRIER AIR AND SUBSIDENCE THROUGH THE MID LEVELS WILL HOLD
THROUGH MUCH OF WEDNESDAY AS FRONT BEGINS TO ENTER INTO CAROLINAS
FROM THE NORTH AND WEST BY LATE DAY. BY WED NIGHT THE MID TO UPPER
TROUGH BECOMES MORE AMPLIFIED AS IT PUSHES A FRONT/TROUGH SOUTH
AND EAST INTO AREA. THIS WILL INCREASE CHANCES OF SHWRS/TSTMS
OVERNIGHT BUT MORE SO ON THURS. THE WESTERLY DOWNSLOPE WINDS IN
THE LOW LEVELS AND A GOOD DEAL OF SUNSHINE WILL AID IN PUSHING
TEMPS INTO THE 90S ON WED.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...A SERIES OF SHORTWAVE TROUGHS MOVING THROUGH THE
AMPLIFIED FLOW ALOFT WILL KEEP WEATHER ACTIVE DURING THE PERIOD.
BOTH SHORTWAVES WILL BE ACCOMPANIED BY A COLD FRONT THAT WILL TRY TO
PUSH ACROSS THE AREA. THE FIRST WILL BE MOVING INTO THE AREA AS THE
PERIOD BEGINS WITH A SECOND STRONGER FRONT ARRIVING MON. THE LARGE
SCALE 5H TROUGH AXIS REMAINS WEST OF THE AREA THROUGH AT LEAST THE
WEEKEND. THE FIRST FRONT ENDS UP LAYING PARALLEL TO THE STEERING
FLOW AND STALLS ACROSS OR JUST EAST OF THE AREA. SURFACE BOUNDARY IN
AIR MASS WITH DEEP MOISTURE AND DIURNAL INSTABILITY SHOULD PROVIDE A
FOCAL POINT FOR CONVECTION. SOME UNCERTAINTY WITH RESPECT TO THE
LOCATION OF THE FRONT AND AMOUNT OF DRY AIR ALOFT SPREADING OVER THE
AREA FRI/SAT SO WILL CARRY LOWER POP DURING THESE PERIODS THOUGH
STILL IN THE CHANCE CATEGORY DURING THE DAY.

PRECIP CHANCES INCREASE SUN/MON AS NEXT COLD FRONT APPROACHES FROM
THE WEST AND DEEP MOISTURE RETURNS. DIVERGENCE ALOFT WILL ENHANCE
BOTH LIFT ALONG THE FRONT AND DIURNAL INSTABILITY. TIMING...LOCATION
AND STRENGTH DIFFERENCE BETWEEN GFS/ECMWF DO ADD A LITTLE BIT OF
UNCERTAINTY EARLY NEXT WEEK SO FOR NOW WILL MAINTAIN CHANCE POP BUT
SHOW AN INCREASE OVER FRI/SAT.

HIGHS WILL BE NEAR TO SLIGHTLY BELOW CLIMO THROUGH THE PERIOD WITH
LOWS NEAR TO SLIGHTLY ABOVE CLIMO.

&&

.AVIATION /00Z TUESDAY THROUGH FRIDAY/...
AS OF 00Z...SYNOPTICALLY NOT MUCH HAS CHANGED IN THE PAST 24 HOURS.
AIR A BIT DRIER ALOFT...BUT SOME DEEPER MOISTURE MAY WORK ITS WAY IN
AFTER MIDNIGHT WITH A SLIGHT CHANCE OF SHOWERS. BASED MAINLY ON
CONTINUITY...WILL INTRODUCE NEAR IFR STRATUS AT THE INLAND
TERMINALS...WITH A MVFR CEILING FORMING NEAR SUNRISE. WINDS AT THE
BOUNDARY LAYER ARE TOO STRONG TO SUPPORT FOG...MVFR BEFORE SUNRISE
WORST CASE. TUESDAY...DAYTIME HEATING WILL KICK OFF SCATTERED
CONVECTION BY 17Z...FOCUSED FIRST ON THE SEA BREEZE BOUNDARY WITH
SCATTERED ACTIVITY INLAND AFTER 19Z.

EXTENDED OUTLOOK...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
ARE EXPECTED THROUGH THURSDAY...WITH BRIEF LOCALIZED PERIODS OF
MVFR/IFR POSSIBLE. OTHERWISE EXPECT VFR.

&&

.MARINE...
NEAR TERM/THROUGH TONIGHT/...
AS OF 730 PM MONDAY...MAJOR CHANGES WERE NEEDED TO THE FORECAST
BASED ON CURRENT OBSERVATIONS AND LATEST HIGH RESOLUTION MODELS.
FIRST OF ALL...THE DAYTIME SEABREEZE HAS PUSHED WIND SPEEDS UP TO A
SOLID 20 KNOTS ACROSS THE COASTAL WATERS WITH GUSTS 23-26 KNOTS AT
BOTH FRYING PAN SHOALS AND AT THE OCEAN CREST PIER ON OAK ISLAND.
THESE WINDS WILL SUBSIDE OVERNIGHT AS A LANDBREEZE HELPS VEER
WINDS FROM THE SOUTHWEST TO A MORE WESTERLY DIRECTION. AS A RESULT I
HAVE HAD TO INCREASE FORECAST WAVE HEIGHTS BY 1 FOOT AWAY FROM SHORE
AND 2 FEET NEARSHORE. SEAS AT OUR BUOYS AND WAVE GAUGES ALONG THE
BRUNSWICK COUNTY COAST ARE RUNNING 4-5 FT CURRENTLY. THIS...IN
ADDITION TO THE STRONG WINDS ONGOING NECESSITATE AN "EXERCISE
CAUTION" HEADLINE BE APPENDED TO THE FORECAST THROUGH 2 AM TUESDAY.

CURRENT SHOWER ACTIVITY IS VERY ISOLATED AND ALL INLAND BEHIND THE
SEABREEZE FRONT. MODELS SHOW AFTER MIDNIGHT SOME POTENTIAL FOR
SHOWER DEVELOPMENT OVER THE OCEAN...BUT NO WORSE THAN ISOLATED
COVERAGE. PREVIOUS DISCUSSION FROM 300 PM FOLLOWS...

SUBTLE LINGERING TROUGHINESS FOUND RUNNING SOUTH FROM THE MID
ATLANTIC AND ACRS NC SOUNDS AND INTO CAPE FEAR REGION. THIS FEATURE
IS PROGGED TO WASH OUT THIS EVENING...AT LEAST THIS FAR SOUTH. THIS
COULD ADD UP TO 5 KT OF WIND SPEED TO THE FORECAST AS THE WIND
DIRECTION SHOWS LITTLE VARIATION AS IT OFTEN DOES THIS TIME OF YEAR.
SOME CONCERN EARLIER THAT THIS COULD ALLOW SEAS TO BUILD
SUFFICIENTLY TO WHERE A SCEC HEADLINE MAY BE NEEDED. NOT CONFIDENT
ENOUGH TO SHOW THIS AT THIS TIME AS CURRENT FCST WHICH IS A BLEND OF
CONTINUITY WAVE WATCH AND SWAN DOES IN FACT BRING IN 5 FT SEAS BUT
WITH A RANGE OF 3 TO 5...WHICH USUALLY PRECLUDES SCEC.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...SOUTHWEST WINDS WILL CONTINUE BETWEEN BERMUDA
HIGH TO THE EAST AND TROUGH ACROSS INLAND CAROLINAS. THE WINDS
WILL PICK UP SLIGHTLY TUES AFTN AS PINCHED GRADIENT DEVELOPS AS
TROUGH BECOMES MORE PRONOUNCED INLAND AND PUSHES EAST SLIGHTLY
IN COMBINATION WITH AFTN SEA BREEZE. BY WED NIGHT INTO EARLY
THURS A FRONT WILL MOVE DOWN FROM THE NORTH AND WEST WITH WINDS
SHIFTING TO THE N-NE TO THE NORTH OF THE BOUNDARY AND REMAINING SW
TO THE SOUTH OF THE BOUNDARY. OVERALL EXPECT SOUTHWEST WINDS OF
10-15 KNOTS THROUGH MUCH OF THE PERIOD. SEAS WILL RANGE FROM 2-4
FT.

LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3 PM MONDAY...SOUTHERLY FLOW THU WILL BECOME LIGHT AND
VARIABLE FRI AND SAT AS WEAK SURFACE BOUNDARY MOVES ACROSS THE
WATERS. MAY SEE SOME PERIODS OF LIGHT NORTHERLY FLOW BUT PROXIMITY
TO THE BOUNDARY WILL KEEP SPEEDS UNDER 10 KT. LATE IN THE PERIOD
REMNANTS OF BOUNDARY LIFT NORTH WITH LIGHT SOUTHERLY FLOW
DEVELOPING. WEAK GRADIENT THROUGH THE PERIOD KEEPING WINDS UNDER 10
KT WILL KEEP SEAS AROUND 2 FT FOR MUCH OF THE PERIOD...THOUGH SOME
ISOLATED 3 FT IS POSSIBLE AWAY FROM SHORE.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY FROM 9 PM THIS EVENING TO MIDNIGHT EDT
     TONIGHT FOR NCZ107.

MARINE...NONE.

&&

$$

NEAR TERM...MBB/TRA
SHORT TERM...RGZ
LONG TERM...III
AVIATION...HDL






AREA FORECAST DISCUSSION

NWS RALEIGH NC

 310 PM EDT SUN JUL 21 2013

.SYNOPSIS...
A SURFACE TROUGH WILL PERSIST OVER THE REGION...IN A MOIST AIR
MASS...AT LEAST THROUGH THE MIDDLE OF THE WEEK...AS A TROUGH IN THE
UPPER LEVELS OF THE ATMOSPHERE MOVES INTO THE MID ATLANTIC AND THE
CAROLINAS.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 310 PM SUNDAY...

THE LATEST SURFACE ANALYSIS CONTINUED TO SHOW THE SURFACE TROUGH
OVER THE NORTHWEST PIEDMONT TOWARD THE UPSTATE OF SOUTH CAROLINA...
AND ALONG THIS TROUGH WHERE BETTER SURFACE CONVERGENCE
EXISTED...SCATTERED SHOWERS AND THUNDERSTORMS WERE OCCURRING OR
DEVELOPING. DOWNDRAFT CAPE AND LOW-LEVEL SHEAR REMAINED LIMITED...
BUT THE LATEST SPC MESOANALYSIS SHOWED MIXED-LAYER CAPE AROUND
2000J/KG NEAR THE SURFACE TROUGH. SCATTERED SHOWERS AND
THUNDERSTORMS SHOULD CONTINUE TO MOVE INTO THE WESTERN PIEDMONT
DURING THE LATE AFTERNOON...AND THE HRRR WRF HAS BEEN CONSISTENT
SHOWING SCATTERED SHOWERS AND THUNDERSTORMS SPREADING EAST TO ABOUT
U.S. 1 THROUGH 01Z BEFORE GENERALLY DIMINISHING. THROUGHOUT THE
DAY...THE RUC HAS BEEN PERSISTENT MAINTAINING SOME CHANCES FOR
SHOWERS ACROSS THE SANDHILLS AND CENTRAL AND SOUTHERN COASTAL
PLAIN...WHERE THE GFS HAS SLIGHTLY GREATER 850MB LIFT OVERNIGHT AND
WHERE THAT MODEL ALSO FORECASTS A RELATIVE MAXIMUM OF POTENTIAL
VORTICITY MOVING ACROSS THE AREA. GIVEN THIS...IT IS POSSIBLE THAT
SOME OF THE SHOWERS OVER WESTERN NORTH CAROLINA OR THE UPSTATE OF
SOUTH CAROLINA WILL PERSIST AS THEY DRIFT EAST NEAR AND JUST NORTH
OF THE SOUTH CAROLINA BORDER OVERNIGHT. WILL KEEP A SLIGHT CHANCE OF
SHOWERS FOR THE OVERNIGHT HOURS AFTER MIDNIGHT MAINLY EAST OF A LINE
FROM ABOUT KRWI TO KFAY. UNDER A PARTLY-TO-MOSTLY CLOUDY SKY...WITH
AREAS OF CLOUDS COURTESY OF DEEP CONVECTION AND THEN SOME HIGH
CLOUDS MOVING IN FROM THE WEST LATE...OVERNIGHT LOWS WILL AGAIN BE
70 TO 75 DEGREES. THE SREF SHOWS THE POTENTIAL FOR LOW CLOUDS TO BE
LESS THAN THE LAST COUPLE OF MORNINGS...HOWEVER...SOME OF THE
GUIDANCE MAINTAINS THE CHANCES FOR LOW CLOUDS PARTICULARLY TOWARD
KRDU...KFAY...AND KRWI...LESS TOWARD THE TRIAD. IF LOW CLOUDS INDEED
OCCUR...IT IS CURRENTLY THOUGHT THEY SHOULD BE LESS WIDESPREAD THAN
WHAT HAS OCCURRED THIS WEEKEND.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 310 PM SUNDAY...

MONDAY AND MONDAY NIGHT...
BOTH THE NAM AND THE GFS GRADUALLY MOVE THE WEAK UPPER LOW OVER THE
SOUTHERN MISSISSIPPI RIVER SLOWLY NORTHEAST...AND INDEED THE LATEST
WATER VAPOR IMAGERY SHOWS THIS WEAK LOW MOVING MORE INTO
MISSISSIPPI. BY THE TIME THE UPPER LOW GETS TO CENTRAL NORTH
CAROLINA...IT IS FORECAST TO WEAKEN FURTHER...AND FORECAST
PARAMETERS OF INSTABILITY...SHEAR...AND MOISTURE ARE SIMILAR TO WHAT
HAS RECENTLY OCCURRED. 850MB THETA-E IS PERSISTENT AROUND 340K AS
WELL...CURRENTLY SUGGESTIVE OF LITTLE OVERALL CHANGE IN ANTICIPATED
CONDITIONS. WITH THE WEAK UPPER LOW THE GFS DOES FORECAST A VERY
MODEST 35KT JETLET INTO CENTRAL NORTH CAROLINA AT 300MB MONDAY
AFTERNOON...BUT WITH MIXED-LAYER CAPE FROM ABOUT 1000J/KG TO
2000J/KG AND DOWNDRAFT CAPE REMAINING 500J/KG OR LESS...THINK
CONDITIONS WILL BE SIMILAR TO THE LAST COUPLE OF DAYS...MOSTLY
SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS...HIGHER
CHANCES RELATIVE TO THE REST OF CENTRAL NORTH CAROLINA TOWARD THE
WESTERN PIEDMONT AS THE WEAK LOW OR ITS REMNANTS APPROACHES...AND A
PARTLY SUNNY DAY ON AVERAGE WITH HIGHS AROUND 90. MONDAY
NIGHT...BOTH THE NAM AND THE GFS FORECAST ALMOST A WEAK PSEUDO FRONT
OR STRONG TROUGH MOVING INTO THE WESTERN PART OF CENTRAL NORTH
CAROLINA WITH DIMINISHING PRECIPITABLE WATER VALUES BEHIND IT TO
NEAR 1.5 INCHES LATE TOWARD THE YADKIN RIVER AND DEW POINTS FALLING
INTO THE UPPER 60S. BUFR SOUNDINGS BECOME SOMEWHAT MORE STABLE
OVERNIGHT IN CENTRAL NORTH CAROLINA...AND QPF IS CERTAINLY
LIMITED...BUT WITH THE APPROACH OF THIS TROUGH WILL MAINTAIN A
SLIGHT CHANCE OF A SHOWER THROUGH THE OVERNIGHT HOURS. OVERNIGHT
LOWS ABOUT A DEGREE OR TWO COOLER THAN WHAT SHOULD OCCUR
TONIGHT...BUT STILL 70 TO 75...MAYBE AN UPPER 60S LOW OR TWO TOWARD
THE FAR WESTERN PIEDMONT. -DJF

TUESDAY THROUGH WEDNESDAY NIGHT...
HEIGHTS WILL CONTINUE TO SLOWLY FALL ALOFT TUESDAY AND WEDNESDAY AS
A BROAD TROUGH BECOMES ESTABLISHED OVER THE EASTERN US.
MEANWHILE...A COLD FRONT TO OUR NORTH WILL SLOWLY SINK SOUTHEAST AND
EVENTUALLY MERGE WITH RELATIVELY STRONG LARGE SCALE LOW LEVEL TROUGH
EAST OF THE MOUNTAINS. ENERGY CURRENTLY MOVING OUT OF
MONTANA/WYOMING IS FORECAST MOVE THROUGH THE BASE OF THE UPPER
TROUGH TUESDAY...FOLLOWED BY ANOTHER SHORTWAVE ON WEDNESDAY.
HOWEVER...THE TIMING AND STRENGTH OF THESE WEAK WAVES AND OTHER
DISTURBANCES WITHIN THE FLOW ARE STILL NEBULOUS. FORECAST SOUNDINGS
DO INDICATE A BIT MORE WESTERLY FLOW ON TUESDAY...WITH PW
TEMPORARILY DROPPING TO 1.5" OR LESS OVER THE WESTERN CWA AND THE
INTRUSION OF DRIER MID LEVEL AIR.  HOWEVER...WITH THE MEAN TROUGH
AXIS STILL WEST OF OUR AREA... PROFILES MOISTEN BACK UP ON WEDNESDAY
WITH MORE ENERGY APPROACHING FROM THE WEST.  UNDER CYCLONIC FLOW
ALOFT AND MODERATE INSTABILITY...WE SHOULD SEE SCATTERED STORMS
BOTH DAYS BUT BETTER COVERAGE OVER THE EAST IN THE VICINITY OF
BETTER LOW LEVEL CONVERGENCE AND DEEP MOISTURE. HIGHS 88-92. LOWS IN
UPPER 60S AND LOWER 70S. -BLS

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 310 PM SUNDAY...

THE LAST IN A SERIES OF UPPER DISTURBANCES IS FORECAST TO PASS
THROUGH THE UPPER TROUGH ON THURSDAY...WITH MODELS HAVING TRENDED
DRIER FRIDAY AND SATURDAY AS THE REMNANT FRONTAL ZONE OVER THE EAST
COAST STATES SLIDES LITTLE FURTHER EAST TOWARD THE COAST.  THERE
SHOULD BE LESS COVERAGE IF STORMS THURSDAY AS THE MID LEVELS BEGIN
TO DRY OUT...BUT THE PASSAGE OF THE MEAN TROUGH AXIS AND SLIGHTLY
STRONGER MID-LEVEL FLOW MAY STILL SUPPORT SOME STRONG TO SEVERE
STORMS.  LOWER DEWPOINTS BEHIND THE FRONT/TROUGH SHOULD LIMIT
CONVECTION FRIDAY AND SATURDAY...PARTICULARLY IN THE WEST.
THICKNESSES FALL AS WELL...WITH HIGHS LIKELY TO BE MORE IN THE MID
AND UPPER 80S.

THE BROAD EASTERN US TROUGH IS EXPECTED TO RELOAD BY THE END OF THE
WEEKEND AS ENERGY CONTINUES TO ROTATE AROUND AN UPPER LOW NORTH OF
THE HUDSON BAY.  BOTH THE ECMWF AND GFS SHOW A MODEST LOW PRESSURE
SYSTEM MOVING OFF THE FRONT RANGE SATURDAY AND MOVING TOWARD THE
MID-ATLANTIC STATES BY SUNDAY/MONDAY...THOUGH WPC/S EXTENDED
DISCUSSION RAISES SOME DOUBT IN THE STRENGTH OF SUCH A FEATURE.
NONETHELESS...THERE IS ENOUGH AGREEMENT IN THE MODELS TO HAVE MEDIUM
CONFIDENCE IN TEMPS SLIGHTLY BELOW NORMAL OVER THE WEEKEND AND
ANOTHER CHANCE OF STORMS BY THE END OF THE WEEKEND.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 145 PM SUNDAY...

PERSISTENCE CONTINUES OVERALL THROUGH THE 18Z VALID TAF PERIOD.
SHOWERS AND THUNDERSTORMS MOSTLY IN A SCATTERED NATURE WILL OCCUR
WITH THE BETTER CHANCES EARLY IN THE TAF PERIOD TOWARD KGSO AND
KINT. OVERNIGHT...MODELS SHOW LIFT IS BETTER TOWARD THE SANDHILLS
AND SOUTHERN COASTAL PLAIN WHICH MAY KEEP A FEW SHOWERS GOING
PRIMARILY TOWARD KFAY AND JUST SOUTH OF KRWI. GUIDANCE OVERALL SHOWS
THE PROBABILITY OF LATE NIGHT AND EARLY MONDAY MORNING LOW CLOUDS TO
BE LESS THAN SATURDAY AND THIS SUNDAY MORNING. HOWEVER...INCLUDED
LOW CLOUDS FROM ABOUT 10Z TO 14Z AT KRDU...KFAY...AND KRWI WHERE THE
CHANCES RELATIVE TO THE TRIAD TAFS ARE GREATER. IT IS POSSIBLE THAT
ANY LOW CLOUDS THAT DEVELOP LATE TONIGHT ARE MORE SPOTTY IN COVERAGE
AS OPPOSED TO THE MORE WIDESPREAD COVERAGE THAT HAS OCCURRED OVER
THE WEEKEND.

BEYOND THE 18Z VALID TAF PERIOD...AVIATION INTERESTS SHOULD CONTINUE
TO BE PREPARED FOR GENERALLY SCATTERED AFTERNOON AND EVENING SHOWERS
AND THUNDERSTORMS...AND THEIR ASSOCIATED SUB-VFR CONDITIONS. CHANCES
OF THESE SHOWERS AND THUNDERSTORMS MAY SHIFT FROM BEING GREATER
TOWARD THE TRIAD TAFS MONDAY TO BEING GREATER EAST FOR THE MIDDLE
AND END OF THE WEEK. BASED ON THE LATEST FORECAST GUIDANCE...THE
NEXT DAY WITH THE POTENTIAL FOR MORE WIDESPREAD LOW CLOUDS IN THE
EARLY MORNING HOURS IS THURSDAY.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...DJF/BLS
LONG TERM...BLS
AVIATION...DJF






AREA FORECAST DISCUSSION

NWS RALEIGH NC

 146 PM EDT SUN JUL 21 2013

.SYNOPSIS...
A SURFACE TROUGH WILL PERSIST OVER THE REGION...IN A MOIST AIR
MASS...AT LEAST THROUGH THE MIDDLE OF THE WEEK...AS A TROUGH IN THE
UPPER LEVELS OF THE ATMOSPHERE MOVES INTO THE MID ATLANTIC AND THE
CAROLINAS.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1035 AM SUNDAY...

THE LATEST SURFACE ANALYSIS CONTINUED TO SHOW A WEAK GRADIENT OVER
CENTRAL NORTH CAROLINA...WITH A PERSISTENT SURFACE TROUGH WEST OF
THE YADKIN RIVER. THE MORNING UPPER-LEVEL ANALYSES SHOWED A FAIRLY
PRONOUNCED 850MB TROUGH OVER CENTRAL NORTH CAROLINA...CAPTURED BY
THE RUC AND FORECAST TO LINGER OVER THE AREA WHILE WEAKENING THROUGH
THE AFTERNOON. ON WATER VAPOR...IT SEEMED AS IF CENTRAL NORTH
CAROLINA WAS IN ALMOST SUBTLE RIDGING BETWEEN A WEAK UPPER LOW OVER
THE SOUTHERN MISSISSIPPI RIVER AND A WEAK WAVE MOVING EAST ACROSS
THE STATE.

IT WAS INTERESTING TO NOTE THAT THE PRECIPITABLE WATER VALUE ON THE
KRNK SOUNDING WAS BELOW 1.4 INCHES THIS MORNING. IT WAS HIGHER AT
KGSO COMPARED TO 12Z SATURDAY. DOWNDRAFT CAPE ON THE SPC
MESOANALYSIS WAS WEAKER THAN SATURDAY...AND OTHER PARAMETERS SUCH AS
THE MID-LEVEL LAPSE RATES AND THETA-E DIFFERENCE ALOFT WERE SLIGHTLY
LESS AS WELL. THE LATEST RUC FORECASTS NOTICEABLE 850MB SUBSIDENCE
OVER CENTRAL NORTH CAROLINA FOR THE AFTERNOON...WITH SOMEWHAT BETTER
LIFT MOVING IN OVER THE NORTHWEST PIEDMONT AND THE SANDHILLS LATE
TODAY AND THIS EVENING.

MOST OF THE CONVECTIVE-ALLOWING MODELS DEVELOP SCATTERED SHOWERS AND
THUNDERSTORMS OVER CENTRAL NORTH CAROLINA THIS AFTERNOON...AND FOR
THE MID-MORNING UPDATE OPTED TO CONCENTRATE THE BETTER CHANCES OVER
THE NORTHWEST PIEDMONT...NEAR WHAT MAY END UP BEING SOME
DIFFERENTIAL HEATING BASED ON THE LATEST VISIBLE IMAGES. A STORM OR
TWO COULD BECOME STRONG...BUT THE PREPONDERANCE OF THE CURRENT
EVIDENCE SUGGESTS THE POTENTIAL FOR A SEVERE STORM IS LIMITED. WILL
REVIEW LATER DATA TO TRY TO FOCUS BETTER CHANCES FOR THIS EVENING...
AS BASED ON THE LATEST RUC THIS WOULD BE MAINLY NORTH OF U.S. 64 AND
OVER THE SANDHILLS WHERE THE GREATER 850MB LIFT IS CONCENTRATED.
KEPT HIGH TEMPERATURES AS IS GIVEN AT LEAST SOME EXPECTED SUN...
THOUGH HIGHS ARE FORECAST BELOW FULL SUN 1000-850MB THICKNESS VALUES
WHICH WOULD SUGGEST HIGHS A CATEGORY WARMER. LOWS TONIGHT IN THE
LOWER 70S.

&&

.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 300 AM SUNDAY...

WEAK SHORT-WAVE ENERGY CURRENTLY OVER THE NORTHERN PLAINS WILL
UNDERGO SLIGHT AMPLIFICATION(ALONG WITH AMPLIFICATION OF THE LONG
WAVE TROUGH AS WELL)AS IT PROGRESSES EAST-SOUTHEASTWARD INTO THE
OHIO AND TN VALLEY ON MONDAY...REACHING THE CENTRAL-SOUTHERN BY
DAYBREAK TUESDAY. IN RESPONSE TO THE ATTENDANT UPSTREAM HEIGHT FALLS
ON THE ORDER OF 20 TO 30 METERS...A WEAK WAVE OF LOW PRESSURE IS
FORECAST TO DEVELOP ALONG THE SURFACE TROUGH OF LOW PRESSURE
BISECTING THE VIRGINIAS AND CAROLINAS...WHICH WILL SERVE TO
STRENGTHEN THE LOW-LEVEL MOISTURE CONVERGENCE AS A POOL OF +2.0
PWATS RESIDES OVER THE SOUTHEASTERN STATES. ADDITIONALLY...THERE IS
ALSO THE POTENTIAL THAT REMNANT CENTER ASSOCIATED WITH THE WEAK
UPPER LOW CURRENTLY OVER LOUISIANA COULD MOVE NORTHEASTWARD OVER THE
AREA LATE MONDAY AND INTO MONDAY NIGHT...FURTHER AUGMENTING ASCENT
OVER THE AREA. AS SUCH...CONVECTION MONDAY AFTERNOON IS EXPECTED TO
BE MORE ROBUST THAN IN PREVIOUS DAYS...WITH THE THREAT OF CONVECTION
PERSISTING THROUGH THE OVERNIGHT HOURS.

CONFIDENCE IN THE TIMING/IMPACTS OF THIS DISTURBANCE IS LOW AT THIS
POINT...ESPECIALLY WITH THE 00Z/21 GFS COMPLETELY SHEARING THE
DISTURBANCE COMPLETING APART OVER GEORGIA/SC. HOW THIS FEATURES
EVOLVES WILL LIKELY BE THE DIFFERENCE BETWEEN LIKELY OR CHANCE POPS
ACROSS CENTRAL NC MONDAY AFTERNOON/EVENING.

HIGH +2.0 PWATS COULD RESULT IN ONE OR TWO WET MICROBURSTS...MAINLY
DURING PEAK AFTERNOON HEATING/DESTABILIZATION...WITH A MORE
ORGANIZED SEVERE THREAT BEING IMPEDED BY WEAK SHEAR AND WEAK
MID-LEVEL LAPSE RATES. ALSO...WITH LOCAL RIVER....STREAMS AND CREEKS
STILL RUNNING HIGH...FLASH FLOODING WILL ALSO BE POSSIBLE.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 245 AM SUNDAY...

TUESDAY AND TUESDAY NIGHT:
WITH THE PERSISTENT SOUTHWEST FLOW...THE ATMOSPHERE WILL REMAIN
SUFFICIENTLY MOIST AND UNSTABLE. THE SURFACE TROUGH IS EXPECTED TO
STALL OVER THE MID ATLANTIC...WITH THE UPPER LEVEL TROUGH SLOWLY
DRIFTING EAST OVER THE AREA. THE 00Z RUN OF THE GFS PICKS UP ON A H3
DISTURBANCE MOVING THROUGH NC TUESDAY AFT/EVE...WHICH SHOULD HELP
ENHANCE THE DIURNALLY DRIVEN CONVECTION. BEST LIFT WILL TRANSLATE
FROM NW TO SE THROUGH CENTRAL NC AHEAD OF THE BACKDOOR COLD
FRONT...WHICH WPC PREDICTS WILL MOVE TROUGH THE AREA TUESDAY NIGHT
AND INTO WEDNESDAY...POTENTIALLY STALLING ALONG THE COAST. AS
SUCH...WILL SHOW BEST CHANCES FOR CONVECTION FROM THE TRIANGLE SE
BETWEEN 18Z TUESDAY AND 06Z WEDNESDAY. HIGH TEMPS IN THE UPPER 80S
TO LOW 90S AND OVERNIGHT LOWS IN THE LOW TO MID 70S EXPECTED.

WEDNESDAY THROUGH SATURDAY:
LOW LEVEL WINDS MAY TEMPORARILY BECOME MORE WNW BEHIND THE BACKDOOR
FRONT SHOULD IT INDEED MOVE THROUGH THE AREA AND STALL ALONG THE
COAST BY WEDNESDAY...WHICH WOULD YIELD A SUBSEQUENT DRYING OF THE
MID LEVELS. CURRENT MODEL AGREEMENT WITH REGARD TO THE TROUGH...AT
BOTH THE SURFACE AND ALOFT...LINGERING OVER THE AREA THROUGH THE END
OF THE WEEK IS GOOD. THE LOCATION OF THE TROUGH AXIS WILL PLAY A
ROLE IN WHERE THE BEST MOISTURE IS AVAILABLE...WHICH CURRENTLY IS
EXPECTED ALONG THE COAST. DEPENDING ON THEIR TIMING...A SERIES OF
UPPER LEVEL DISTURBANCES MOVING OVER THE AREA COULD ENHANCE DIURNAL
CONVECTIVE ACTIVITY THROUGH THE PERIOD. OF LESSER CERTAINTY IS THE
COVERAGE AND LOCATION OF THE ANTICIPATED AFT/EVE SHOWERS AND STORMS.
FOR NOW WILL CONTINUE TO INDICATE BEST PRECIP CHANCES DURING THE
AFT/EVE HOURS ACROSS THE AREA...WITH SLIGHTLY HIGHER CHANCES ACROSS
THE EAST WHERE THE BEST MOISTURE IS EXPECTED. ONLY SMALL CHANGES IN
TEMPS FROM DAY TO DAY THROUGH THE PERIOD...HIGHS MAINLY IN THE MID
80S TO AROUND 90 DEGREES WITH OVERNIGHT LOWS MAINLY IN THE UPPER 60S
TO LOW 70S.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 145 PM SUNDAY...

PERSISTENCE CONTINUES OVERALL THROUGH THE 18Z VALID TAF PERIOD.
SHOWERS AND THUNDERSTORMS MOSTLY IN A SCATTERED NATURE WILL OCCUR
WITH THE BETTER CHANCES EARLY IN THE TAF PERIOD TOWARD KGSO AND
KINT. OVERNIGHT...MODELS SHOW LIFT IS BETTER TOWARD THE SANDHILLS
AND SOUTHERN COASTAL PLAIN WHICH MAY KEEP A FEW SHOWERS GOING
PRIMARILY TOWARD KFAY AND JUST SOUTH OF KRWI. GUIDANCE OVERALL SHOWS
THE PROBABILITY OF LATE NIGHT AND EARLY MONDAY MORNING LOW CLOUDS TO
BE LESS THAN SATURDAY AND THIS SUNDAY MORNING. HOWEVER...INCLUDED
LOW CLOUDS FROM ABOUT 10Z TO 14Z AT KRDU...KFAY...AND KRWI WHERE THE
CHANCES RELATIVE TO THE TRIAD TAFS ARE GREATER. IT IS POSSIBLE THAT
ANY LOW CLOUDS THAT DEVELOP LATE TONIGHT ARE MORE SPOTTY IN COVERAGE
AS OPPOSED TO THE MORE WIDESPREAD COVERAGE THAT HAS OCCURRED OVER
THE WEEKEND.

BEYOND THE 18Z VALID TAF PERIOD...AVIATION INTERESTS SHOULD CONTINUE
TO BE PREPARED FOR GENERALLY SCATTERED AFTERNOON AND EVENING SHOWERS
AND THUNDERSTORMS...AND THEIR ASSOCIATED SUB-VFR CONDITIONS. CHANCES
OF THESE SHOWERS AND THUNDERSTORMS MAY SHIFT FROM BEING GREATER
TOWARD THE TRIAD TAFS MONDAY TO BEING GREATER EAST FOR THE MIDDLE
AND END OF THE WEEK. BASED ON THE LATEST FORECAST GUIDANCE...THE
NEXT DAY WITH THE POTENTIAL FOR MORE WIDESPREAD LOW CLOUDS IN THE
EARLY MORNING HOURS IS THURSDAY.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...DJF
NEAR TERM...CBL/DJF
SHORT TERM...CBL
LONG TERM...KMC
AVIATION...DJF






AREA FORECAST DISCUSSION

NWS RALEIGH NC

 1035 AM EDT SUN JUL 21 2013

.SYNOPSIS...
AN UPPER LEVEL TROUGH WILL SLOWLY AMPLIFY OVER THE REGION THROUGH
EARLY IN THE WEEK. MEANWHILE...A SURFACE TROUGH OF LOW PRESSURE
WILL REMAIN OVER THE AREA THROUGH MID TO LATE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1035 AM SUNDAY...

THE LATEST SURFACE ANALYSIS CONTINUED TO SHOW A WEAK GRADIENT OVER
CENTRAL NORTH CAROLINA...WITH A PERSISTENT SURFACE TROUGH WEST OF
THE YADKIN RIVER. THE MORNING UPPER-LEVEL ANALYSES SHOWED A FAIRLY
PRONOUNCED 850MB TROUGH OVER CENTRAL NORTH CAROLINA...CAPTURED BY
THE RUC AND FORECAST TO LINGER OVER THE AREA WHILE WEAKENING THROUGH
THE AFTERNOON. ON WATER VAPOR...IT SEEMED AS IF CENTRAL NORTH
CAROLINA WAS IN ALMOST SUBTLE RIDGING BETWEEN A WEAK UPPER LOW OVER
THE SOUTHERN MISSISSIPPI RIVER AND A WEAK WAVE MOVING EAST ACROSS
THE STATE.

IT WAS INTERESTING TO NOTE THAT THE PRECIPITABLE WATER VALUE ON THE
KRNK SOUNDING WAS BELOW 1.4 INCHES THIS MORNING. IT WAS HIGHER AT
KGSO COMPARED TO 12Z SATURDAY. DOWNDRAFT CAPE ON THE SPC
MESOANALYSIS WAS WEAKER THAN SATURDAY...AND OTHER PARAMETERS SUCH AS
THE MID-LEVEL LAPSE RATES AND THETA-E DIFFERENCE ALOFT WERE SLIGHTLY
LESS AS WELL. THE LATEST RUC FORECASTS NOTICEABLE 850MB SUBSIDENCE
OVER CENTRAL NORTH CAROLINA FOR THE AFTERNOON...WITH SOMEWHAT BETTER
LIFT MOVING IN OVER THE NORTHWEST PIEDMONT AND THE SANDHILLS LATE
TODAY AND THIS EVENING.

MOST OF THE CONVECTIVE-ALLOWING MODELS DEVELOP SCATTERED SHOWERS AND
THUNDERSTORMS OVER CENTRAL NORTH CAROLINA THIS AFTERNOON...AND FOR
THE MID-MORNING UPDATE OPTED TO CONCENTRATE THE BETTER CHANCES OVER
THE NORTHWEST PIEDMONT...NEAR WHAT MAY END UP BEING SOME
DIFFERENTIAL HEATING BASED ON THE LATEST VISIBLE IMAGES. A STORM OR
TWO COULD BECOME STRONG...BUT THE PREPONDERANCE OF THE CURRENT
EVIDENCE SUGGESTS THE POTENTIAL FOR A SEVERE STORM IS LIMITED. WILL
REVIEW LATER DATA TO TRY TO FOCUS BETTER CHANCES FOR THIS EVENING...
AS BASED ON THE LATEST RUC THIS WOULD BE MAINLY NORTH OF U.S. 64 AND
OVER THE SANDHILLS WHERE THE GREATER 850MB LIFT IS CONCENTRATED.
KEPT HIGH TEMPERATURES AS IS GIVEN AT LEAST SOME EXPECTED SUN...
THOUGH HIGHS ARE FORECAST BELOW FULL SUN 1000-850MB THICKNESS VALUES
WHICH WOULD SUGGEST HIGHS A CATEGORY WARMER. LOWS TONIGHT IN THE
LOWER 70S.

&&

.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 300 AM SUNDAY...

WEAK SHORT-WAVE ENERGY CURRENTLY OVER THE NORTHERN PLAINS WILL
UNDERGO SLIGHT AMPLIFICATION(ALONG WITH AMPLIFICATION OF THE LONG
WAVE TROUGH AS WELL)AS IT PROGRESSES EAST-SOUTHEASTWARD INTO THE
OHIO AND TN VALLEY ON MONDAY...REACHING THE CENTRAL-SOUTHERN BY
DAYBREAK TUESDAY. IN RESPONSE TO THE ATTENDANT UPSTREAM HEIGHT FALLS
ON THE ORDER OF 20 TO 30 METERS...A WEAK WAVE OF LOW PRESSURE IS
FORECAST TO DEVELOP ALONG THE SURFACE TROUGH OF LOW PRESSURE
BISECTING THE VIRGINIAS AND CAROLINAS...WHICH WILL SERVE TO
STRENGTHEN THE LOW-LEVEL MOISTURE CONVERGENCE AS A POOL OF +2.0
PWATS RESIDES OVER THE SOUTHEASTERN STATES. ADDITIONALLY...THERE IS
ALSO THE POTENTIAL THAT REMNANT CENTER ASSOCIATED WITH THE WEAK
UPPER LOW CURRENTLY OVER LOUISIANA COULD MOVE NORTHEASTWARD OVER THE
AREA LATE MONDAY AND INTO MONDAY NIGHT...FURTHER AUGMENTING ASCENT
OVER THE AREA. AS SUCH...CONVECTION MONDAY AFTERNOON IS EXPECTED TO
BE MORE ROBUST THAN IN PREVIOUS DAYS...WITH THE THREAT OF CONVECTION
PERSISTING THROUGH THE OVERNIGHT HOURS.

CONFIDENCE IN THE TIMING/IMPACTS OF THIS DISTURBANCE IS LOW AT THIS
POINT...ESPECIALLY WITH THE 00Z/21 GFS COMPLETELY SHEARING THE
DISTURBANCE COMPLETING APART OVER GEORGIA/SC. HOW THIS FEATURES
EVOLVES WILL LIKELY BE THE DIFFERENCE BETWEEN LIKELY OR CHANCE POPS
ACROSS CENTRAL NC MONDAY AFTERNOON/EVENING.

HIGH +2.0 PWATS COULD RESULT IN ONE OR TWO WET MICROBURSTS...MAINLY
DURING PEAK AFTERNOON HEATING/DESTABILIZATION...WITH A MORE
ORGANIZED SEVERE THREAT BEING IMPEDED BY WEAK SHEAR AND WEAK
MID-LEVEL LAPSE RATES. ALSO...WITH LOCAL RIVER....STREAMS AND CREEKS
STILL RUNNING HIGH...FLASH FLOODING WILL ALSO BE POSSIBLE.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 245 AM SUNDAY...

TUESDAY AND TUESDAY NIGHT:
WITH THE PERSISTENT SOUTHWEST FLOW...THE ATMOSPHERE WILL REMAIN
SUFFICIENTLY MOIST AND UNSTABLE. THE SURFACE TROUGH IS EXPECTED TO
STALL OVER THE MID ATLANTIC...WITH THE UPPER LEVEL TROUGH SLOWLY
DRIFTING EAST OVER THE AREA. THE 00Z RUN OF THE GFS PICKS UP ON A H3
DISTURBANCE MOVING THROUGH NC TUESDAY AFT/EVE...WHICH SHOULD HELP
ENHANCE THE DIURNALLY DRIVEN CONVECTION. BEST LIFT WILL TRANSLATE
FROM NW TO SE THROUGH CENTRAL NC AHEAD OF THE BACKDOOR COLD
FRONT...WHICH WPC PREDICTS WILL MOVE TROUGH THE AREA TUESDAY NIGHT
AND INTO WEDNESDAY...POTENTIALLY STALLING ALONG THE COAST. AS
SUCH...WILL SHOW BEST CHANCES FOR CONVECTION FROM THE TRIANGLE SE
BETWEEN 18Z TUESDAY AND 06Z WEDNESDAY. HIGH TEMPS IN THE UPPER 80S
TO LOW 90S AND OVERNIGHT LOWS IN THE LOW TO MID 70S EXPECTED.

WEDNESDAY THROUGH SATURDAY:
LOW LEVEL WINDS MAY TEMPORARILY BECOME MORE WNW BEHIND THE BACKDOOR
FRONT SHOULD IT INDEED MOVE THROUGH THE AREA AND STALL ALONG THE
COAST BY WEDNESDAY...WHICH WOULD YIELD A SUBSEQUENT DRYING OF THE
MID LEVELS. CURRENT MODEL AGREEMENT WITH REGARD TO THE TROUGH...AT
BOTH THE SURFACE AND ALOFT...LINGERING OVER THE AREA THROUGH THE END
OF THE WEEK IS GOOD. THE LOCATION OF THE TROUGH AXIS WILL PLAY A
ROLE IN WHERE THE BEST MOISTURE IS AVAILABLE...WHICH CURRENTLY IS
EXPECTED ALONG THE COAST. DEPENDING ON THEIR TIMING...A SERIES OF
UPPER LEVEL DISTURBANCES MOVING OVER THE AREA COULD ENHANCE DIURNAL
CONVECTIVE ACTIVITY THROUGH THE PERIOD. OF LESSER CERTAINTY IS THE
COVERAGE AND LOCATION OF THE ANTICIPATED AFT/EVE SHOWERS AND STORMS.
FOR NOW WILL CONTINUE TO INDICATE BEST PRECIP CHANCES DURING THE
AFT/EVE HOURS ACROSS THE AREA...WITH SLIGHTLY HIGHER CHANCES ACROSS
THE EAST WHERE THE BEST MOISTURE IS EXPECTED. ONLY SMALL CHANGES IN
TEMPS FROM DAY TO DAY THROUGH THE PERIOD...HIGHS MAINLY IN THE MID
80S TO AROUND 90 DEGREES WITH OVERNIGHT LOWS MAINLY IN THE UPPER 60S
TO LOW 70S.

&&

.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
AS OF 1035 AM SUNDAY...

24-HR TAF PERIOD:
MVFR CEILINGS WILL LIFT SLOWLY...EVENTUALLY BECOMING MOSTLY VFR BY
AFTERNOON. DIURNAL SCATTERED SHOWERS AND STORMS WILL BE POSSIBLE AT
ALL TAF SITES THIS AFTERNOON MAINLY FROM 20Z-02Z. -CBL/DJF

LOOKING AHEAD:
EXPECT AN ABOVE NORMAL CHANCE FOR SHOWERS AND THUNDERSTORMS MONDAY
THROUGH THURSDAY AS A SLOW MOVING UPPER LEVEL TROUGH DEVELOPS OVER
THE EASTERN UNITED STATES. THOUGH CONVECTION WILL BE POSSIBLE DURING
THE DAY AND AT NIGHT...THE BEST CHANCE EACH DAY WILL BE IN THE
TYPICAL 18-03Z TIME FRAME. SUB-VFR CONDITIONS ASSOCIATED WITH FOG OR
STRATUS WILL BE POSSIBLE EACH MORNING...PRIMARILY IN THE 08-14Z TIME
FRAME. -VINCENT

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...CBL
NEAR TERM...CBL/DJF
SHORT TERM...CBL
LONG TERM...KMC
AVIATION...CBL/VINCENT/DJF






AREA FORECAST DISCUSSION

NWS NEWPORT/MOREHEAD CITY NC

 646 AM EDT SUN JUL 21 2013

.SYNOPSIS...
A TYPICAL SUMMER PATTERN OF HIGH PRESSURE OFFSHORE AND A TROUGH
OF LOW PRESSURE INLAND WILL PERSIST THROUGH TUESDAY. A COLD
FRONT WILL APPROACH FROM THE NORTHWEST WEDNESDAY THEN STALL OVER
THE REGION THURSDAY AND FRIDAY BEFORE MOVING OFFSHORE SATURDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 635 AM SUNDAY...BAND OF SHOWERS PASSING SOUTH OF THE CRYSTAL
COAST AND THE BULK OF THE ACTIVITY LOOKS TO REMAIN NEAR THE COAST
OR OFFSHORE THROUGH MIDDAY AS MID-LEVEL ENERGY HAS PASSED TO OUR
NORTHEAST. THE 3 KM HRRR MODEL HAS DONE QUITE WELL WITH THE
PLACEMENT OF THE PRECIPITATION THUS FAR THIS MORNING AND PER THE
LATEST HRRR WITH AGREEMENT FROM THE RAP...EXPECT SCATTERED SHOWERS
AND THUNDERSTORMS TO REDEVELOP INLAND BY AROUND 18Z AND INCREASE
IN COVERAGE THROUGH THE AFTERNOON AND EVENING. POPS RAMP BACK UP
TO 30 TO 50 PCT AT THAT TIME WITH THE HIGHEST VALUES OVER AREAS
WEST OF HIGHWAY 17. WITH PRECIPITABLE WATER VALUES BACK NEAR 2
INCHES...ANY SHOWERS THAT DEVELOP COULD PRODUCE A QUICK DOWNPOUR
OF UP TO AN INCH OR SO. GIVEN MORE CLOUD COVER THAN RECENT
DAYS...MAXIMUM TEMPERATURES SHOULD REMAIN IN THE UPPER 80S FAIRLY
UNIFORM IN THE MIDDLE TO UPPER 80S AREA-WIDE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
AS OF 345 AM SUNDAY...BOTH THE GFS AND NAM SHOW SOME STRONG MID-
LEVEL VORTICITY RIDING UP THE COAST TONIGHT...COUPLED WITH A WEAK
UPPER LEVEL TROUGH SLIDING ACROSS THE REGION. THIS ALONG WITH A
VERY MOIST ATMOSPHERE WILL LEAD TO A CHANCE OF SHOWERS/TSTMS
LINGERING THROUGH THE NIGHT. GIVEN THE TREND FROM THE LAST FEW
NIGHTS...HAVE TRENDED THE BEST PRECIPITATION CHANCES NEAR THE
COAST...WITH LITTLE ACTIVITY INLAND AFTER MIDNIGHT. OVERNIGHT LOWS
TONIGHT SHOULD BE IN THE 73 TO 77 DEGREE RANGE.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 315 AM SUN...AN UPPER TROUGH OVER THE GREAT LAKES WILL DIG
SOUTH MON/TUES AND PERSIST OVER THE EASTERN CONUS THROUGH THE LONG
TERM...REINFORCING THE RAIN CHANCES THROUGH THE PERIOD. WEAK
PERTURBATIONS IN THE MID AND UPPER LEVELS WILL ALSO AID IN
DEVELOPING SHOWERS/TSTORMS DURING THE EXTENDED PERIOD...ESPECIALLY
DURING PEAK HEATING HOURS OF THE DAY. AT THE SURFACE...LONG FETCH SW
FLOW WILL TAP TROPICAL MOISTURE FROM THE GULF OF MEXICO AND WESTERN
ATLANTIC MON AND TUES...INCREASING PWATS TO AROUND 2 INCHES. A
WEAK COLD FRONT WILL APPROACH FROM THE NW MON INTO TUES...WHICH
WILL DISSIPATE WEST OF THE REGION PRIOR TO ANOTHER COLD FRONT
APPROACHING FROM THE NW WED INTO THURS. WITH DECENT MODEL
AGREEMENT THROUGH THE EXTENDED...HAVE INDICATED A WEAK FRONTAL
PASSAGE THURS NIGHT WITH BRIEF NORTHERLY FLOW/CAA ON FRI BEFORE
OFFSHORE RIDGE KICKS IN A SW FLOW AGAIN TAKES OVER.

HAVE CONTINUED THE TREND OF DIURNAL CONVECTION EACH DAY THROUGH
THURS WITH 40 TO 50 PERCENT POPS INLAND DURING THE AFTERNOON AND
25-30 PERCENT POPS OVERNIGHT. TRIED TO ADJUST TIMING OF POPS MON
AFTERNOON THROUGH TUES NIGHT TO ALSO COINCIDE WITH THE LOCATION OF
SEVERAL SHORTWAVE VORTMAX ALOFT THAT ROTATE AROUND THE BASE OF
THE BROAD UPPER TROUGH. SEVERE WEATHER IS NOT EXPECTED AS SHEAR
WILL BE MINIMAL...THOUGH WITH ANY PULSE STORM AN ISOLATED STRONG
TO SEVERE WIND GUST IS POSSIBLE. WITH OVERALL WEAK STEERING
FLOW...ANY ORGANIZED CONVECTION WILL HAVE HEAVY RAINFALL POTENTIAL
ESPECIALLY IF CELLS TRAIN OVER THE SAME AREA. POPS THURS NIGHT
THROUGH FRI NIGHT REMAIN PINNED NEAR THE COAST WITH SCATTERED
CONVECTION POSSIBLE AGAIN SAT AFTERNOON AS LIGHT SE/S FLOW RETURNS
TO THE AREA. TEMPS THROUGH THE LONG TERM PERIOD WILL BE NEAR CLIMO
WITH HIGHS IN THE UPPER 80S TO NEAR 90 WITH LOW/MID 70S FOR
OVERNIGHT LOWS.

&&

.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /TODAY AND TONIGHT/...
AS OF 1250 AM SUN...PER LATEST 11-3.9 MICRON SATELLITE IMAGERY
AND SURFACE OBSERVATIONS...THERE HAVE BEEN SOME MVFR CEILINGS WELL
INLAND AROUND KPGV AND KISO. WITH IMPROVED MIXING...WOULD EXPECT
THESE CEILINGS TO DISSIPATE BY 13Z OR 14Z. EXPECT SCATTERED
SHOWERS AND TSTMS TO DEVELOP BY AROUND 18Z AND CONTINUE INTO EARLY
EVENING WITH A FEW BRIEF REDUCTIONS IN CEILINGS AND VSBY. TONIGHT
WILL MOSTLY BE VFR BECAUSE OF SUFFICIENT WIND...BUT SCATTERED
SHOWERS AND TSTMS COULD AGAIN BRIEFLY LOWER CEILINGS AND VSBYS.

LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 315 AM SUN...SCT THUNDERSHOWERS POSSIBLE EACH DAY FOR THE
TERMINALS WITH MAINLY DRY CONDITIONS AT NIGHT AS PERSISTENT TROUGH
OF LOW PRESSURE REMAINS OVER THE REGION. GENERALLY VFR EXCEPT FOR
TEMPO RESTRICTIONS IN VSBY WITH THE SHOWERS/TSTORMS. COULD SEE
BRIEF EARLY MORNING MVFR/IFR VSBYS DURING THE LONG TERM AS
FORECAST SOUNDINGS INDICATE GOOD BOUNDARY LAYER MOISTURE TRAPPED
UNDER A WEAK SURFACE BASED INVERSION...ESPECIALLY FOR AREAS THAT
RECEIVE RAINFALL.

&&

.MARINE...
SHORT TERM /TODAY AND TONIGHT/...
AS OF 645 AM SUNDAY...HAVE ALLOWED THE SMALL CRAFT ADVISORY FOR
THE PAMLICO SOUND AND FOR THE COASTAL WATERS NORTH OF OREGON INLET
TO EXPIRE. WINDS ARE AT OR BELOW 20 KNOTS IN THESE LOCATIONS.
THE REMAINDER OF THE SMALL CRAFT ADVISORY REMAINS IN EFFECT INTO
TONIGHT. WINDS ARE CURRENTLY GENERALLY 15 TO 20 KNOTS AND NO BUOY
IS REPORTING MORE THAN 5 FEET NEAR SHORE...ALTHOUGH SOME AREAS ON
THE OUTER WATERS MAY BE AROUND 6 FEET...THUS THE SCA IS MARGINAL
CURRENTLY. HOWEVER...THE GUSTY SW WINDS WILL PERSIST BETWEEN
DEEPENING SURFACE TROUGH OVER THE PIEDMONT AND BERMUDA HIGH
PRESSURE TO THE EAST AND COULD BECOME GUSTY NEAR ANY CONVECTION
DURING THIS AFTERNOON. WINDS AND SEAS SUBSIDE LATER TONIGHT
BEFORE INCREASING AGAIN LATE MONDAY...THUS ANOTHER SCA WILL LIKELY
NEED TO BE ISSUED ONCE CURRENT ADVISORIES EXPIRE.


LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 320 AM SUN...HIGH PRESSURE OFF THE SE COAST WITH A THERMAL
TROUGH INLAND WILL BE THE DOMINANT PATTERN THROUGH MUCH OF THE LONG
TERM. EXPECT A BREAK IN THE GUSTY SW WINDS MON BEFORE REINFORCING
TROUGH/FRONT APPROACH TUES INTO LATE WEEK. MARGINAL SCA CONDITIONS
ARE EXPECTED ONCE AGAIN FROM OREGON INLET SOUTH TUES THROUGH TUES
NIGHT AS THE GRADIENT INCREASES A BIT. NO SIGNIFICANT CHANGES TO
THE MEDIUM AND LONG TERM. WINDS SHOULD BECOME LIGHT LATE IN THE
WEEK AS GRADIENT RELAXES WITH TROUGH AXIS OVER OR JUST EAST OF THE
WATERS.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EDT MONDAY FOR AMZ152-154-156-
     158.

&&

$$

SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...DAG
AVIATION...CTC/DAG
MARINE...CTC/DAG







AREA FORECAST DISCUSSION

NWS NEWPORT/MOREHEAD CITY NC

 351 AM EDT SUN JUL 21 2013

.SYNOPSIS...
A TYPICAL SUMMER PATTERN OF HIGH PRESSURE OFFSHORE AND A TROUGH
OF LOW PRESSURE INLAND WILL PERSIST THROUGH TUESDAY. A COLD
FRONT WILL APPROACH FROM THE NORTHWEST WEDNESDAY THEN STALL OVER
THE REGION THURSDAY AND FRIDAY BEFORE MOVING OFFSHORE SATURDAY.

&&

.NEAR TERM /TODAY/...
AS OF 335 AM SUNDAY...A FEW PATCHY SHOWERS ARE AFFECTING THE
CENTRAL PAMLICO SOUND AND CENTRAL OUTER BANKS REGION AND A COUPLE
OF STRAY SHOWERS ARE MOVING OFF OF CORE BANKS EARLY THIS MORNING.
THE 3 KM HRRR MODEL HAS HAD THE BEST DEPICTION OF THE
PRECIPITATION PLACEMENT THIS MORNING AND WILL FOLLOW ITS TREND
THROUGH THE MIDDAY HOURS. THERE WILL BE A LULL IN THE ACTIVITY
THROUGH ABOUT MID-MORNING WHEN SOME ADDITIONAL SHOWERS MAY SCRAPE
THE SOUTHERN COAST. MORE WIDESPREAD PRECIPITATION MOVES INTO THE
SOUTHERN COASTAL PLAINS BY 18Z OR SO WITH HIGH CHANCE POPS OVER
THE COASTAL PLAINS...TAPERING BACK TO CHC NEAR THE COAST. WITH
PRECIPITABLE WATER VALUES BACK NEAR 2 INCHES...ANY SHOWERS THAT
DEVELOP COULD PRODUCE A QUICK DOWNPOUR OF UP TO AN INCH OR SO.
GIVEN MORE CLOUD COVER THAN RECENT DAYS...MAXIMUM TEMPERATURES
SHOULD REMAIN IN THE UPPER 80S FAIRLY UNIFORM IN THE MIDDLE TO
UPPER 80S AREA-WIDE.

&&

.SHORT TERM /TONIGHT/...
AS OF 345 AM SUNDAY...BOTH THE GFS AND NAM SHOW SOME STRONG MID-
LEVEL VORTICITY RIDING UP THE COAST TONIGHT...COUPLED WITH A WEAK
UPPER LEVEL TROUGH SLIDING ACROSS THE REGION. THIS ALONG WITH A
VERY MOIST ATMOSPHERE WILL LEAD TO A CHANCE OF SHOWERS/TSTMS
LINGERING THROUGH THE NIGHT. GIVEN THE TREND FROM THE LAST FEW
NIGHTS...HAVE TRENDED THE BEST PRECIPITATION CHANCES NEAR THE
COAST...WITH LITTLE ACTIVITY INLAND AFTER MIDNIGHT. OVERNIGHT LOWS
TONIGHT SHOULD BE IN THE 73 TO 77 DEGREE RANGE.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 315 AM SUN...AN UPPER TROUGH OVER THE GREAT LAKES WILL DIG
SOUTH MON/TUES AND PERSIST OVER THE EASTERN CONUS THROUGH THE LONG
TERM...REINFORCING THE RAIN CHANCES THROUGH THE PERIOD. WEAK
PERTURBATIONS IN THE MID AND UPPER LEVELS WILL ALSO AID IN
DEVELOPING SHOWERS/TSTORMS DURING THE EXTENDED PERIOD...ESPECIALLY
DURING PEAK HEATING HOURS OF THE DAY. AT THE SURFACE...LONG FETCH SW
FLOW WILL TAP TROPICAL MOISTURE FROM THE GULF OF MEXICO AND WESTERN
ATLANTIC MON AND TUES...INCREASING PWATS TO AROUND 2 INCHES. A
WEAK COLD FRONT WILL APPROACH FROM THE NW MON INTO TUES...WHICH
WILL DISSIPATE WEST OF THE REGION PRIOR TO ANOTHER COLD FRONT
APPROACHING FROM THE NW WED INTO THURS. WITH DECENT MODEL
AGREEMENT THROUGH THE EXTENDED...HAVE INDICATED A WEAK FRONTAL
PASSAGE THURS NIGHT WITH BRIEF NORTHERLY FLOW/CAA ON FRI BEFORE
OFFSHORE RIDGE KICKS IN A SW FLOW AGAIN TAKES OVER.

HAVE CONTINUED THE TREND OF DIURNAL CONVECTION EACH DAY THROUGH
THURS WITH 40 TO 50 PERCENT POPS INLAND DURING THE AFTERNOON AND
25-30 PERCENT POPS OVERNIGHT. TRIED TO ADJUST TIMING OF POPS MON
AFTERNOON THROUGH TUES NIGHT TO ALSO COINCIDE WITH THE LOCATION OF
SEVERAL SHORTWAVE VORTMAX ALOFT THAT ROTATE AROUND THE BASE OF
THE BROAD UPPER TROUGH. SEVERE WEATHER IS NOT EXPECTED AS SHEAR
WILL BE MINIMAL...THOUGH WITH ANY PULSE STORM AN ISOLATED STRONG
TO SEVERE WIND GUST IS POSSIBLE. WITH OVERALL WEAK STEERING
FLOW...ANY ORGANIZED CONVECTION WILL HAVE HEAVY RAINFALL POTENTIAL
ESPECIALLY IF CELLS TRAIN OVER THE SAME AREA. POPS THURS NIGHT
THROUGH FRI NIGHT REMAIN PINNED NEAR THE COAST WITH SCATTERED
CONVECTION POSSIBLE AGAIN SAT AFTERNOON AS LIGHT SE/S FLOW RETURNS
TO THE AREA. TEMPS THROUGH THE LONG TERM PERIOD WILL BE NEAR CLIMO
WITH HIGHS IN THE UPPER 80S TO NEAR 90 WITH LOW/MID 70S FOR
OVERNIGHT LOWS.

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /THROUGH 00Z MONDAY/...
AS OF 1250 AM SUN...SHOWERS HAVE MOVED EAST OF THE TAF SITES AND
WITH A LIGHT SW BREEZE AND A 4 TO 6 DEGREE TEMPERATURE/DEWPOINT
SPREAD...NO ISSUES WITH LOW CEILINGS OR VSBYS THUS FAR. THERE
COULD BE SOME MVFR SCU CIGS PRIOR TO 12Z BUT THESE SHOULD BE
SHORT-LIVED. SCT TSTMS DURING THE DAY ALONG AND INLAND OF SEA
BREEZE.

LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 315 AM SUN...SCT THUNDERSHOWERS POSSIBLE EACH DAY FOR THE
TERMINALS WITH MAINLY DRY CONDITIONS AT NIGHT AS PERSISTENT TROUGH
OF LOW PRESSURE REMAINS OVER THE REGION. GENERALLY VFR EXCEPT FOR
TEMPO RESTRICTIONS IN VSBY WITH THE SHOWERS/TSTORMS. COULD SEE
BRIEF EARLY MORNING MVFR/IFR VSBYS DURING THE LONG TERM AS
FORECAST SOUNDINGS INDICATE GOOD BOUNDARY LAYER MOISTURE TRAPPED
UNDER A WEAK SURFACE BASED INVERSION...ESPECIALLY FOR AREAS THAT
RECEIVE RAINFALL.

&&

.MARINE...
SHORT TERM /TODAY AND TONIGHT/...
AS OF 350 AM SUNDAY...WILL CONTINUE SMALL CRAFT ADVISORY THROUGH 5
AM FOR THE PAMLICO SOUND AND FAR NORTHERN WATERS AND WILL MONITOR
FOR THE NEED TO EXTEND IT INTO MID-MORNING. GUSTY SW WINDS PERSIST
BETWEEN DEEPENING SURFACE TROUGH OVER THE PIEDMONT AND BERMUDA
HIGH PRESSURE TO THE EAST. THESE SW WINDS CONTINUE TO GUST INTO
THE MID 20S...BUT ANY 6 FOOT SEAS ARE ON THE OUTER PERIPHERY OF
THE MARINE ZONES. WINDS AND SEAS SUBSIDE LATER TONIGHT BEFORE
INCREASING AGAIN LATE MONDAY...THUS ANOTHER SCA WILL LIKELY NEED
TO BE ISSUED ONCE CURRENT ADVISORIES EXPIRE.


LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 320 AM SUN...HIGH PRESSURE OFF THE SE COAST WITH A THERMAL
TROUGH INLAND WILL BE THE DOMINANT PATTERN THROUGH MUCH OF THE LONG
TERM. EXPECT A BREAK IN THE GUSTY SW WINDS MON BEFORE REINFORCING
TROUGH/FRONT APPROACH TUES INTO LATE WEEK. MARGINAL SCA CONDITIONS
ARE EXPECTED ONCE AGAIN FROM OREGON INLET SOUTH TUES THROUGH TUES
NIGHT AS THE GRADIENT INCREASES A BIT. NO SIGNIFICANT CHANGES TO
THE MEDIUM AND LONG TERM. WINDS SHOULD BECOME LIGHT LATE IN THE
WEEK AS GRADIENT RELAXES WITH TROUGH AXIS OVER OR JUST EAST OF THE
WATERS.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EDT EARLY THIS MORNING FOR
     AMZ135-150.
     SMALL CRAFT ADVISORY UNTIL 1 AM EDT MONDAY FOR AMZ152-154-156-
     158.

&&

$$

SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...DAG
AVIATION...CTC/DAG
MARINE...CTC/DAG







AREA FORECAST DISCUSSION

NWS GRAND FORKS ND

 303 PM CDT SUN JUL 21 2013

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 303 PM CDT SUN JUL 21 2013

MAIN CHALLENGE CONTINUES TO BE TSTM CHANCES AND SEVERITY FOR
TONIGHT. LATEST MODEL GUIDANCE CONTINUES TO SUPPORT A THREAT FOR
PORTIONS OF THE FA BUT EARLY ON MAINLY FOR THE KDVL REGION AS IT
SHOULD TAKE A WHILE TO REACH THE RED RIVER VALLEY.

CURRENTLY HAVE A COLD FRONT WORKING INTO FAR NORTHWEST ND WITH AN
AREA OF LOW PRESSURE THERE AS WELL. A WARM FRONT EXTENDS SE FROM
THIS LOW DOWN TO NEAR KBIS AND KABR. IN THIS WARM SECTOR DEW
POINTS ARE GENERALLY IN THE LOW TO MID 60S WITH TEMPS IN THE 80S.
EAST OF THE WARM FRONT DEW POINTS HAVE BEEN SLOW TO RECOVER FROM
MORNING LOWS WITH 50S STILL COMMON. THERE HAS BEEN A WEAK TSTM
COMPLEX OVER SOUTHWEST MANITOBA RIDING AHEAD OF THE MAIN SHORT
WAVE. THIS SHOULD GET INTO THE FAR NW FA IN THE NEXT HOUR OR SO.
INSTABILITY IS WEAK OUT AHEAD OF THIS INITIAL COMPLEX BUT IT MAY
CONTINUE TO MOVE EAST ALONG THE BORDER WITH THE UPPER JET DYNAMICS
IN PLACE. THE SEVERE THREAT SHOULD BE BEHIND THIS COMPLEX CLOSER
TO THE COLD FRONT AND SFC LOW OVER WESTERN ND. INSTABILITY IS
BETTER HERE WITH THE ABOVE MENTIONED WARMER AND MOIST AIR. THE
MAIN SHORT WAVE ENERGY APPEARS TO BE LOCATED OVER SOUTHERN ALBERTA
WHICH IS NEARING THE SFC BOUNDARY. WITH THE WAVE AND THE UPPER JET
ENERGY A MORE ORGANIZED TSTM COMPLEX IS EXPECTED TO GET UNDERWAY
OUT WEST. SPC HAS ISSUED MCD 1456 AND A NEW TORNADO WATCH FOR
PORTIONS OF WESTERN AND CENTRAL ND. THERE HAVE BEEN A COUPLE OF
CELLS THAT HAVE POPPED UP NEAR KISN THAT MAY BE THE START OF SOME
STRONGER CELLS. NOT EXPECTING ANY STRONG STORMS TO APPROACH OUR
WESTERN FA FOR A FEW MORE HOURS YET SO WE WILL HAVE TIME TO WATCH
AND SEE HOW THINGS DEVELOP. LATEST RAP BRINGS SOME STORMS INTO
OUR WESTERN FA IN THE 01-02Z MON TIME FRAME. NSSL WRF IS A LITTLE
FASTER AND AS MENTIONED IN AN EARLIER AFD UPDATE IT DID BRING
TSTMS A LOT FURTHER SOUTH THAN WHAT IS ANTICIPATED. FOLLOWED MORE
CONTINUITY AND KEPT HIGHER PCPN CHANCES ACROSS THE NORTHERN HALF
OF THE FA TONIGHT WITH LOWER CHANCES ACROSS THE SOUTH. THE
COMBINATION OF THE LOW LEVEL JET UPPER JET AND THE WAVE SHOULD
KEEP SHOWERS AND TSTMS GOING AFTER DARK JUST NOT SURE HOW LONG THE
SEVERE POTENTIAL WILL GO.

LEFT SOME LINGERING LOW PCPN CHANCES ACROSS THE EAST ON MONDAY
MORNING WITH DRYING ACROSS THE WEST. SHOULD BE A FAIRLY NICE DAY
WITH DRIER AIR MOVING BACK IN WITH NORTHWEST WINDS. MON NIGHT WILL
BE A LITTLE COOL AGAIN ESPECIALLY ACROSS THE NORTH.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 303 PM CDT SUN JUL 21 2013

SHOULD REMAIN DRY TUE WITH FAIRLY LIGHT WINDS DUE TO THE PROXIMITY
OF THE SFC HIGH. CHANCES FOR PCPN RETURN BY TUE NIGHT AND WED
ALTHOUGH MODELS NOT IN VERY GOOD AGREEMENT ON THE DETAILS.

WEDNESDAY NIGHT-SUNDAY...12Z MODELS MAINTAIN SIMILAR IDEA AS
PREVIOUS RUNS. NORTHWEST FLOW ALOFT INTO FRIDAY WITH UPPER RIDGING
BUILDING INTO THE REGION FOR THE WEEKEND. THERE WILL BE SLIGHT
THUNDERSTORM CHANCES WITH ANY UPPER WAVE WITHIN THE NORTHWEST FLOW
ALOFT...WITH THESE CHANCES ENDING ONCE THE RIDGING BUILDS INTO THE
REGION. TEMPERATURES NEAR OR SLIGHTLY BELOW NORMAL VALUES.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1249 PM CDT SUN JUL 21 2013

THE MAIN CONCERN WILL BE TIMING OF THUNDERSTORMS. LATEST MODEL
GUIDANCE IN LINE WITH PREVIOUS THINKING AND NOT MUCH CHANGE NEEDED
TO PREVIOUS TAFS. ANTICIPATE A LINE OF STORMS TO MOVE INTO NORTHEAST
NORTH DAKOTA AROUND 00Z...AND INTO THE NORTHERN VALLEY AROUND
02Z...CONTINUING TO THE EAST. STILL NOT A LOT OF CONFIDENCE WITH HOW
FAR SOUTH THUNDER CHANCES WILL BE AND LEFT OUT OF THE KFAR FORECAST
(COVERAGE WILL BE SIGNIFICANTLY LESS TO THE SOUTH). SOUTHERLY WINDS
WILL SHIFT TO THE WEST/NORTHWEST TONIGHT.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&

$$

SHORT TERM...GODON
LONG TERM...GODON/TG
AVIATION...TG







AREA FORECAST DISCUSSION

NWS GRAND FORKS ND

 739 AM CDT SUN JUL 21 2013

.UPDATE...
ISSUED AT 735 AM CDT SUN JUL 21 2013

NO CHANGES NEEDED. LATEST HRRR SHOWS STORM THREAT INTO DVL 23-00Z
THEN SPREADING EAST.

&&

.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 329 AM CDT SUN JUL 21 2013

HIGH PRESSURE OVER NORTHWESTERN ONTARIO EARLY THIS MORNING WITH A
A CLEAR TO PARTLY CLOUDY SKY OVER MOST OF THE FCST AREA.
EXCEPTIONS ARE AN AREA OF STRATOCU AROUND RUGBY-CANDO NORTHWEST
INTO MANITOBA AND EASTERN SASK AND AN AREA OF MID LEVEL CLOUDS
OVER NE SD INTO CNTRL-SRN MN. A WEAK SHORT WAVE IS MOVING THRU
ECNTRL SD ATTM...CAUSING A FEW SHOWERS IN NE SD MOVING INTO
WCNTRL/SW MN JUST SOUTH OF THE FCST AREA. ALL MODELS INDICATE
THESE SHOWERS TO CONTINUE GENERALLY SOUTH OF OUR FCST AREA THRU
MID MORNING IN A WEAK 850 MB WARM ZONE.

MEANWHILE...NO TSTMS OUT IN WRN ND/ERN MT AT 08Z...SO STAGE IS SET
FOR A GENERALLY DRY DAY UNTIL A SIGNIFICANT SHORT WAVE MOVES FROM
SOUTHERN ALBERTA INTO NRN ND BY 00Z. THIS SHORT WAVE WILL SWING
THRU ERN ND TONIGHT INTO NRN MN AFTER 06Z.

QUESTION IS TSTM COVERAGE AND INTENSITY WITH SYSTEM. DID LIKE THE
SPC 4 KM WRF AND THE NSSL WRF AS THEY BOTH SHOWED REASONABLE
SCNERIOS IN THEIR REFLECTIVITY/PRECIP PATTERNS. STORMS IN ALBERTA
WILL MOVE INTO SRN SASK AND NW ND MIDDAY AND THEN LOOK FOR
INTENSIFICATION AS STORMS MOVE INTO SE SASK/SW MANITOBA AND CNTRL
ND MID TO LATE AFTN...WITH AREA OF STORMS MOVING THRU ERN ND 00Z-
03Z REACHING NW MN 03Z-06Z PERIOD. LOOKING AT VARIOUS SEVERE
WEATHER FIELDS IT WOULD INDICATE BEST CHC OF SFC BASED SEVERE
CONVECTION IN THE MOT-DVL REGION 22Z-00Z PERIOD...THEN MOVING EAST
AND INCREASINGLY INSTABILITY BECOMING MORE ELEVATED IN NATURE AND
AREA GROWING IN SIZE AS IT MOVE INTO THE NRN/CNTRL RRV TONIGHT. 40
KT LOW LEVEL JET PREDICTED WITH BEST COVERGENCE IN SRN MANITOBA
AND THUS MOST WIDESPREAD RAINS LIKELY ALONG OR NORTH OF THE
BORDER...BUT MODELS DO TAKE SFC LOW THRU NRN ND SO MORE DISCRETE
CELLS PSBL WITH THIS. SRN FCST AREA WHILE NOT CAPPED PER SE HAS A
BIT MORE CIN AND LESS COVERAGE OF STORMS.

ANY STORMS WILL EXIT MN FCST AREA BY 15Z MON AS HIGH PRESSURE
BUILDS IN WITH SOME CLEARING.

.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 329 AM CDT SUN JUL 21 2013

HIGH PRESSURE WILL GIVE DRY CONDITIONS MON NIGHT INTO
TUESDAY...WITH NEXT SHORT WAVE DUE TO ARRIVE LATER TUES NIGHT. GEM
APPEARS OVERDONE WITH PRECIP THOUGH.

WDNESDAY THROUGH SATURDAY NIGHT...00 UTC GFS/ECMWF BOTH SHOW
NORTHWEST FLOW ALOFT...AMPLIFYING BY LATE IN THE WEEK WITH A
BUILDING RIDGE ACROSS THE INTERMOUNTAIN WEST AND A LOBE OF THE POLAR
VORTEX DIGGING INTO ONTARIO. THIS LATTER FEATURE WILL BE THE PRIMARY
FOCUS FOR ANY PRECIPITATION...BUT MODELS DIFFER ON THE TIMING AND
LOCATION OF INDIVIDUAL BITS OF ENERGY. THE GFS IS MOST BULLISH WITH
PRECIPITATION WEDNESDAY NIGHT THROUGH THURSDAY...WHEREAS THE ECMWF
PAINTS THE MOST QPF ACROSS THE REGION FRIDAY NIGHT INTO SATURDAY.
POP FORECAST CONFIDENCE IS LOW...SO WILL STICK WITH ALL BLEND 20 TO
30 POPS FOR MUCH OF THE PERIOD. AT THIS TIME...FRIDAY LOOKS TO BE
THE DRIEST DAY. FORECAST AREA SHOULD REMAIN ON THE COOL SIDE OF
THE MID-LEVEL THERMAL GRADIENT...SO EXPECT TEMPERATURES SLIGHTLY
BELOW SEASONAL NORMALS WITH HIGHS IN THE 70S AND LOWS IN THE 50S.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 735 AM CDT SUN JUL 21 2013

MAIN ISSUE AVIATION WISE WILL BE TIMING ANY THUNDERSTORM THREATS.
GOT SOME VFR STRATOCU ADVANCING NORTHEAST THRU BJI-PKD REGION WITH
SCATTERED VFR STRAOCU ELSEWHERE. HIGH CLOUDS SPREADING SOUTHEAST
FROM CANADA WILL OVERSPREAD THE AREA THIS MORNING-MIDDAY. LATEST
MODEL GUIDANCE INDICATES LOW TO MOVE TOWARD MINOT AROUND 23Z THEN
EASTWARD FROM THERE WITH CHC OF TSTMS IN DVL 23Z-03Z...GFK 02-06Z
AND THEN AFTER 06Z IN BEMIDJI. THREAT FOR STORMS IN FARGO LOWER
AND THUS NOT INCLUDED IN TEMPO GROUP YET. WINDS WILL TURN SOUTH-
SOUTHEAST AT 15 KTS IN DVL WITH 5-15 KTS ELSEWHERE.


&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&

$$

UPDATE...RIDDLE
SHORT TERM...RIDDLE
LONG TERM...RIDDLE/ROGERS
AVIATION...RIDDLE







AREA FORECAST DISCUSSION...CORRECTED

NWS BISMARCK ND

 1237 AM CDT SUN JUL 21 2013

.UPDATE...
ISSUED AT 1221 AM CDT SUN JUL 21 2013

THE INHERITED FORECAST FOR THE REMAINDER OF TONIGHT IS ON TRACK
AND BLENDED TO THE 05 UTC OBSERVED TRENDS. THE FOCUS IS ON THE
SEVERE THUNDERSTORM THREAT FOR SUNDAY...WHICH NOW INCLUDES A
GREATER PORTION OF THE AREA COMPARED TO THE DAY 2 OUTLOOK FOR
SUNDAY. AREAS EAST OF HIGHWAY 85 HAVE THE GREATEST POTENTIAL FOR
SEVERE CONVECTION SUNDAY AFTERNOON AND EVENING. SEE THE NEW SPC
DAY 1 OUTLOOK FOR DETAILS.

UPDATE ISSUED AT 834 PM CDT SAT JUL 20 2013

LATEST REGIONAL RADAR SHOWS AN AREA OF SEVERE THUNDERSTORMS IN
EASTERN MONTANA MOVING SOUTHEAST WITH TIME. MONITORING FOR ANY
OUTFLOWS...WITH CURRENT MOVEMENT INDICATING THAT THIS AREA COULD
MOVE INTO OUR FAR SOUTHWESTERN COUNTIES OF GOLDEN VALLEY/SLOPE/BOWMAN
IN THE NEXT COUPLE OF HOURS. OTHERWISE EXPECT ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS OVERNIGHT...WITH INCREASING WARM AIR
ADVECTION ASSOCIATED WITH A WARM FRONT OVER EASTERN MONTANA. STILL
SOME ISOLATED CONVECTION IN NORTHWESTERN SOUTH DAKOTA BUT NOTHING
SEVERE AT THIS TIME. MINOR CHANGES FROM PREVIOUS FORECAST.

UPDATE ISSUED AT 559 PM CDT SAT JUL 20 2013

REGIONAL RADAR IMAGERY SHOWS A COUPLE OF AREAS TO WATCH THIS
EVENING. FIRST IS IN OUR SOUTHWEST...WITH A SEVERE THUNDERSTORM
WATCH BOX UP TO OUR SOUTHWEST BORDER FROM SOUTH DAKOTA.
THUNDERSTORMS CONTINUE TO REMAIN SOUTH OF THE BORDER...BUT COULD
DEVELOP A BIT FURTHER NORTH WITH AN AGITATED CUMULUS FIELD EVIDENT
NEAR BAKER AND ALONG OUR FAR SOUTHWESTERN ZONES. THE OTHER AREA
WAS SEEN OVER NORTHEASTERN MONTANA WITH SEVERE THUNDERSTORMS
ROLLING OUT OF SOUTHERN SASKATCHEWAN AND INTO NORTHERN MONTANA.
WILL CONTINUE TO MONITOR DEVELOPMENT OF THESE THUNDERSTORMS FURTHER
EAST THIS EVENING AND OVERNIGHT...AS WHAT IS BEING INDICATED BY
THE HRRR (HIGH RESOLUTION RAPID REFRESH MODEL)...AS WELL AS THE
OTHER SHORT TERM MODELS.

WARM AIR ADVECTION INCREASES OVERNIGHT AS NAM/GFS SOUNDINGS SHOW
MODERATE VEERING WIND PROFILES FROM THE SFC TO 750MB. EXPECTING AN
INCREASE IN THE AREAL COVERAGE OF SHOWERS/ELEVATED THUNDERSTORMS
THROUGH EARLY SUNDAY MORNING...AS THEY CONTINUE TO DEVELOP ALONG A
WARM FRONT IN EASTERN MONTANA. NAM/GFS SOUNDINGS SHOW DECENT
INSTABILITY/CAPE ABOVE 750MB OVERNIGHT...WITH SHOWALTER INDICES
SHOWING AN INCREASED POTENTIAL FOR ELEVATED THUNDERSTORMS WEST OF
MINOT THROUGH 12Z SUNDAY. THUS WILL CONTINUE TO MENTION ISOLATED
TO SCATTERED THUNDERSTORMS WEST...AND JUST INTO PORTIONS OF
CENTRAL NORTH DAKOTA OVERNIGHT. WILL MONITOR FOR ANY SEVERE
POTENTIAL DURING THE EVENING/OVERNIGHT. MOST OF WESTERN AND
CENTRAL NORTH DAKOTA GET INTO THE WARM SECTOR BY LATE MORNING AND
EARLY AFTERNOON SUNDAY...SETTING THE STAGE FOR SEVERE THUNDERSTORMS
ALONG AND AHEAD OF AN ADVANCING COLD FRONT. SEE PREVIOUS DISCUSSION
BELOW FOR MORE DETAILS.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 310 PM CDT SAT JUL 20 2013

MAIN CONCERNS THIS PERIOD WILL BE THUNDERSTORMS ASSOCIATED WITH A
WARM FRONT EXTENDED ACROSS EASTERN MONTANA THAT IS FORECAST TO
TRACK EAST ACROSS THE STATE LATE TONIGHT AND SUNDAY. SATELLITE
LOOPS SHOW CLOUD COVER ACROSS WESTERN NORTH DAKOTA IN LOW LEVEL
MOIST UP SLOPE FLOW. A BAND OF MID LEVEL SHOWERS AND ISOLATED
THUNDERSTORMS IS MOVING THROUGH SOUTH CENTRAL NORTH DAKOTA. THIS IS
EXPECTED TO DIMINISH AS IT MOVES EAST.

THE FOCUS FOR TONIGHT AND SUNDAY WILL BE THE WARM FRONT IN
EASTERN MONTANA THIS WILL BE PROVIDE LIFT AND WITH A SHORT WAVE
TROUGH SUPPORT THUNDERSTORMS ACROSS THE NORTHWEST...AND THEN THE
NORTH CENTRAL ON SUNDAY. ADDED THE MENTION OF SEVERE WHERE SPC HAS
DEFINED THE SLIGHT RISK SUNDAY AFTERNOON.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 315 PM CDT SAT JUL 20 2013

THE RISK OF SEVERE WEATHER CONTINUES FROM SUNDAY AFTERNOON INTO
THE NIGHT...MAINLY OVER THE CENTRAL AND EASTERN PARTS OF THE
FORECAST AREA.

LONG TERM MODELS ARE IN AGREEMENT THROUGH THE PERIOD ON THE BIG
PICTURE...NAMELY THAT THE H5 RIDGE OFF THE SOUTHWEST COAST BUILDS
EAST INTO THE DESERT SOUTHWEST AND EXPENDS NORTH INTO THE NORTHERN
ROCKIES AND AMPLIFIES. THIS KEEPS A WEAK NORTHWEST FLOW OVER NORTH
DAKOTA WITH CHANCES FOR THUNDERSTORMS COMING AS RIDGE RIDER SHORT
WAVES CREST THE RIDGE AND PASS THROUGH EVERY OTHER DAY. THIS
PATTERN IS ENHANCED AS AN H5 LOW CUTS OFF OVER ONTARIO AND SENDS A
TROUGH AXIS THROUGH DURING THE THURSDAY-FRIDAY TIME FRAME.
THAT...AS INDICATED IN THE PREVIOUS LONG TERM DISCUSSION...WILL BE
THE GREATEST CHANCES FOR STORMS IN THE LONG TERM...AFTER SUNDAY
NIGHT. BUT AGAIN...THERE ARE CHANCES ABOUT EVERY DAY AS TIMING OF
THE WAVES WILL LIKELY CHANGE FROM FORECAST TO FORECAST.

TEMPERATURES SHOULD BE FAIRLY STEADY IN THE PATTERN...AND NOT TOO
FAR FROM NORMAL...GENERALLY IN THE MID 70S NORTHEAST TO MID 80S
SOUTHWEST AND LOWS IN THE 50S TO LOWER 60S.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1221 AM CDT SUN JUL 21 2013

THE MAIN AVIATION HAZARD WITH THE 06 UTC TAF CYCLE WILL BE A
POSSIBLE ROUND OF SEVERE THUNDERSTORMS TO POTENTIALLY IMPACT
KBIS...KMOT AND KJMS POST 21 UTC. OTHERWISE...MVFR STRATUS IS
POSSIBLE ACROSS THE AREA TONIGHT WITH WEAK EASTERLY UPSLOPE FLOW
WITH SOME STATUS ALREADY FORMING ON SATELLITE.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...AYD
SHORT TERM...WAA
LONG TERM...JPM
AVIATION...AYD









AREA FORECAST DISCUSSION

NWS BISMARCK ND

 1221 AM CDT SUN JUL 21 2013

.UPDATE...
ISSUED AT 1221 AM CDT SUN JUL 21 2013

THE INHERITED FORECAST FOR THE REMAINDER OF TONIGHT IS ON TRACK
AND BLENDED TO THE 05 UTC OBSERVED TRENDS. THE FOCUS IS ON THE
SEVERE THUNDERSTORM THREAT FOR SUNDAY...WHICH NOW INCLUDES A
GREATER PORTION OF THE AREA COMPARED TO THE DAY 2 OUTLOOK FOR
SUNDAY. AREAS EAST OF HIGHWAY 85 HAVE THE GREATEST POTENTIAL FOR
SEVERE CONVECTION SUNDAY AFTERNOON AND EVENING. SEE THE NEW SPC
DAY 1 OUTLOOK FOR DETAILS.

UPDATE ISSUED AT 834 PM CDT SAT JUL 20 2013

LATEST REGIONAL RADAR SHOWS AN AREA OF SEVERE THUNDERSTORMS IN
EASTERN MONTANA MOVING SOUTHEAST WITH TIME. MONITORING FOR ANY
OUTFLOWS...WITH CURRENT MOVEMENT INDICATING THAT THIS AREA COULD
MOVE INTO OUR FAR SOUTHWESTERN COUNTIES OF GOLDEN VALLEY/SLOPE/BOWMAN
IN THE NEXT COUPLE OF HOURS. OTHERWISE EXPECT ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS OVERNIGHT...WITH INCREASING WARM AIR
ADVECTION ASSOCIATED WITH A WARM FRONT OVER EASTERN MONTANA. STILL
SOME ISOLATED CONVECTION IN NORTHWESTERN SOUTH DAKOTA BUT NOTHING
SEVERE AT THIS TIME. MINOR CHANGES FROM PREVIOUS FORECAST.

UPDATE ISSUED AT 559 PM CDT SAT JUL 20 2013

REGIONAL RADAR IMAGERY SHOWS A COUPLE OF AREAS TO WATCH THIS
EVENING. FIRST IS IN OUR SOUTHWEST...WITH A SEVERE THUNDERSTORM
WATCH BOX UP TO OUR SOUTHWEST BORDER FROM SOUTH DAKOTA.
THUNDERSTORMS CONTINUE TO REMAIN SOUTH OF THE BORDER...BUT COULD
DEVELOP A BIT FURTHER NORTH WITH AN AGITATED CUMULUS FIELD EVIDENT
NEAR BAKER AND ALONG OUR FAR SOUTHWESTERN ZONES. THE OTHER AREA
WAS SEEN OVER NORTHEASTERN MONTANA WITH SEVERE THUNDERSTORMS
ROLLING OUT OF SOUTHERN SASKATCHEWAN AND INTO NORTHERN MONTANA.
WILL CONTINUE TO MONITOR DEVELOPMENT OF THESE THUNDERSTORMS FURTHER
EAST THIS EVENING AND OVERNIGHT...AS WHAT IS BEING INDICATED BY
THE HRRR (HIGH RESOLUTION RAPID REFRESH MODEL)...AS WELL AS THE
OTHER SHORT TERM MODELS.

WARM AIR ADVECTION INCREASES OVERNIGHT AS NAM/GFS SOUNDINGS SHOW
MODERATE VEERING WIND PROFILES FROM THE SFC TO 750MB. EXPECTING AN
INCREASE IN THE AREAL COVERAGE OF SHOWERS/ELEVATED THUNDERSTORMS
THROUGH EARLY SUNDAY MORNING...AS THEY CONTINUE TO DEVELOP ALONG A
WARM FRONT IN EASTERN MONTANA. NAM/GFS SOUNDINGS SHOW DECENT
INSTABILITY/CAPE ABOVE 750MB OVERNIGHT...WITH SHOWALTER INDICES
SHOWING AN INCREASED POTENTIAL FOR ELEVATED THUNDERSTORMS WEST OF
MINOT THROUGH 12Z SUNDAY. THUS WILL CONTINUE TO MENTION ISOLATED
TO SCATTERED THUNDERSTORMS WEST...AND JUST INTO PORTIONS OF
CENTRAL NORTH DAKOTA OVERNIGHT. WILL MONITOR FOR ANY SEVERE
POTENTIAL DURING THE EVENING/OVERNIGHT. MOST OF WESTERN AND
CENTRAL NORTH DAKOTA GET INTO THE WARM SECTOR BY LATE MORNING AND
EARLY AFTERNOON SUNDAY...SETTING THE STAGE FOR SEVERE THUNDERSTORMS
ALONG AND AHEAD OF AN ADVANCING COLD FRONT. SEE PREVIOUS DISCUSSION
BELOW FOR MORE DETAILS.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 310 PM CDT SAT JUL 20 2013

MAIN CONCERNS THIS PERIOD WILL BE THUNDERSTORMS ASSOCIATED WITH A
WARM FRONT EXTENDED ACROSS EASTERN MONTANA THAT IS FORECAST TO
TRACK EAST ACROSS THE STATE LATE TONIGHT AND SUNDAY. SATELLITE
LOOPS SHOW CLOUD COVER ACROSS WESTERN NORTH DAKOTA IN LOW LEVEL
MOIST UP SLOPE FLOW. A BAND OF MID LEVEL SHOWERS AND ISOLATED
THUNDERSTORMS IS MOVING THROUGH SOUTH CENTRAL NORTH DAKOTA. THIS IS
EXPECTED TO DIMINISH AS IT MOVES EAST.

THE FOCUS FOR TONIGHT AND SUNDAY WILL BE THE WARM FRONT IN
EASTERN MONTANA THIS WILL BE PROVIDE LIFT AND WITH A SHORT WAVE
TROUGH SUPPORT THUNDERSTORMS ACROSS THE NORTHWEST...AND THEN THE
NORTH CENTRAL ON SUNDAY. ADDED THE MENTION OF SEVERE WHERE SPC HAS
DEFINED THE SLIGHT RISK SUNDAY AFTERNOON.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 315 PM CDT SAT JUL 20 2013

THE RISK OF SEVERE WEATHER CONTINUES FROM SUNDAY AFTERNOON INTO
THE NIGHT...MAINLY OVER THE CENTRAL AND EASTERN PARTS OF THE
FORECAST AREA.

LONG TERM MODELS ARE IN AGREEMENT THROUGH THE PERIOD ON THE BIG
PICTURE...NAMELY THAT THE H5 RIDGE OFF THE SOUTHWEST COAST BUILDS
EAST INTO THE DESERT SOUTHWEST AND EXPENDS NORTH INTO THE NORTHERN
ROCKIES AND AMPLIFIES. THIS KEEPS A WEAK NORTHWEST FLOW OVER NORTH
DAKOTA WITH CHANCES FOR THUNDERSTORMS COMING AS RIDGE RIDER SHORT
WAVES CREST THE RIDGE AND PASS THROUGH EVERY OTHER DAY. THIS
PATTERN IS ENHANCED AS AN H5 LOW CUTS OFF OVER ONTARIO AND SENDS A
TROUGH AXIS THROUGH DURING THE THURSDAY-FRIDAY TIME FRAME.
THAT...AS INDICATED IN THE PREVIOUS LONG TERM DISCUSSION...WILL BE
THE GREATEST CHANCES FOR STORMS IN THE LONG TERM...AFTER SUNDAY
NIGHT. BUT AGAIN...THERE ARE CHANCES ABOUT EVERY DAY AS TIMING OF
THE WAVES WILL LIKELY CHANGE FROM FORECAST TO FORECAST.

TEMPERATURES SHOULD BE FAIRLY STEADY IN THE PATTERN...AND NOT TOO
FAR FROM NORMAL...GENERALLY IN THE MID 70S NORTHEAST TO MID 80S
SOUTHWEST AND LOWS IN THE 50S TO LOWER 60S.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1221 AM CDT SUN JUL 21 2013

THE MAIN AVIATION HAZARD WITH THE 06 UTC TAF CYCLE WILL BE A
POSSIBLE ROUND OF SEVERE THUNDERSTORMS TO POTENTIALLY IMPACT
KBIS...KMOT AND KJMS POST 21 UTC. OUTSIDE OF THIS THREAT...VFR
CONDITIONS ARE EXPECTED.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...AYD
SHORT TERM...WAA
LONG TERM...JPM
AVIATION...AYD







AREA FORECAST DISCUSSION

NWS WILMINGTON OH

 1020 PM EDT MON JUL 22 2013

.SYNOPSIS...
A VIGOROUS UPPER LEVEL SYSTEM THAT BROUGHT HEAVY RAIN IS MOVING
EAST TONIGHT. A COLD FRONT WILL BRING THE LIKELIHOOD FOR MORE
SHOWERS AND THUNDERSTORMS ON TUESDAY...BEFORE HIGH PRESSURE
FINALLY BUILDS IN ON WEDNESDAY.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
MAIN UPDATES FOR THE EVENING WERE TO INCREASE FOG IN THE GRIDS AND
ADJUST POPS TO ACCOUNT FOR CURRENT TRENDS. IN GENERAL...MOST
LOCATIONS APPEAR SLATED FOR A DRY FORECAST TONIGHT...WITH SOME
SHOWERS REMAINING IN THE SOUTHERN AND SOUTHEASTERN CWA FOR THE
NEXT FEW HOURS. THE BIGGER CONCERN WILL BE FOG POTENTIAL. MANY OB
SITES IN THE CWA ARE ALREADY BELOW 5SM...WITH A FEW DROPPING BELOW
2SM ALREADY. HRRR VISIBILITY FORECASTS SUGGEST THAT CENTRAL OHIO
WILL HAVE THE GREATEST FOG POTENTIAL...WHICH DOES MAKE SOME SENSE
GIVEN THE HEAVY RAIN EXPERIENCED EARLIER TODAY.

PREVIOUS DISCUSSION >

WITH WIDESPREAD DOWNPOURS WEAKENING AND MOVING OUT...HAVE
CANCELLED FLASH FLOOD WATCH. SHOWERS AND THUNDERSTORMS WILL
CONTINUE TO MOVE OUT TONIGHT AS THE UPPER TROUGH WORKS EASTWARD.
FOG IS PROBABLE LATE TONIGHT IN VERY HUMID CONDITIONS NEAR THE
GROUND. OVERNIGHT LOWS WILL BE IN THE MID AND UPPER 60S.

WEAK CIRCULATIONS IN OUR PERSISTENTLY UNSTABLE AIRMASS WITH LOW
LIFTING CONDENSATION LEVELS HAVE GENERATED FUNNEL CLOUDS EARLY
THIS EVENING. THESE WEAKLY ROTATING PHENOMENA WILL DISAPPEAR WITH
LOSS OF DAYTIME HEATING.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
MORE SHOWERS AND THUNDERSTORMS WILL BE LIKELY ON TUESDAY AS
ANOTHER FRONTAL SYSTEM DROPS DOWN FROM THE NORTHWEST. MINOR HIGH
WATER PROBLEMS MAY DEVELOP DUE TO MOIST SOIL CONDITIONS BUT THE
PROGRESSIVE NATURE OF THE SYSTEM MAY PREVENT WIDESPREAD FLOODING.
HIGHS IN THE 80S ARE ANTICIPATED.

SHOWERS WILL END AND DRIER AIR WILL START TO ARRIVE ON A NORTHWEST
FLOW BEHIND THE FRONT ON TUESDAY NIGHT. LOWS WILL RANGE FROM UPPER
50S NORTHWEST UP TO THE UPPER 60S FAR SOUTHEAST.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
ACTIVE WEATHER PATTERN TO DRY OUT AT MID WEEK. MAIN WEATHER FEATURES
ARE A MID LEVEL RIDGE OVER THE WESTERN U.S. AND A MEAN TROF OVER THE
EAST.

FRONTAL BOUNDARY DROPPING SE WILL PROVIDE A LINGERING CHANCE FOR
PRECIPITATION OVER THE FAR SE EARLY WEDNESDAY. TEMPERATURES ARE
EXPECTED TO BE BELOW NORMAL WITH HIGHS RANGING FROM THE MID 70S
NORTHWEST TO NEAR 80 SE.

NORTHWEST FLOW PATTERN DEVELOPS WITH SFC HIGH PRESSURE BUILDING SE
ACRS THE REGION THRU THE END OF THE WEEK. THIS HIGH WILL PROVIDE
DRIER WEATHER THRU THE REMAINDER OF THE WEEK. BELOW NORMAL
TEMPERATURES TO CONTINUE WITH HIGHS ON THURSDAY RANGING FROM THE
UPPER 70S NW TO THE LOWER 80S SE. TEMPS WILL MODERATE A LTL ON
FRIDAY BUT STILL REMAIN BELOW NORMAL WITH HIGHS FROM THE LOWER 80S
NW TO THE MID 80S SE.

ENERGY DIGGING SE IN THE NORTHWEST FLOW WILL DEEPEN THE EASTERN U.S.
TROF. NUMERICAL MODEL SOLNS DIFFERENCES EXIST REGARDING TIMING...
PHASING AND DEPTH. ECMWF SOLN IS THE MOST AMPLIFIED WITH THIS FEATURE
ALTHOUGH DIFFERENCES EXIST MOST MODEL SOLNS ARE SIMILAR KEEPING MSTR
ASSOCIATED WITH REMNANTS OF CLOSED LOW TO OUR SOUTH. LATEST
OPERATIONAL GFS TAKES THE ASSOCIATED SFC WAVE THRU OHIO WILL COPIOUS
AMOUNTS OF PRECIPITATION NEXT WEEKEND. THIS WILL HAVE TO CONTINUE TO
BE MONITORED. EXPECT SFC COLD FRONT TO DROP SE THRU THE REGION
SAT/SAT NIGHT. WILL INDICATE CHANCE POPS WITH THIS FEATURE AND ALLOW
FOR LINGERING MENTION ON SUNDAY WITH THE BEST PROBABILITY ACRS THE
SE. BELOW NORMAL READINGS TO CONTINUE WITH HIGHS ON SATURDAY...UPPER
70S NW TO THE LOWER 80S SE.

NORTHWESTERLY FLOW ALOFT WITH SFC HIGH PRESSURE TO DRY US OUT LATER
SUNDAY INTO MONDAY. IN THE WAKE OF THIS COLD FRONT TEMPERATURES TO
RUN 5 TO 10 DEGREES BELOW NORMAL...WITH HIGHS SUNDAY FROM THE MID
70S NW TO NEAR 80 SE AND GENERALLY IN THE UPPER 70S TO NEAR 80
MONDAY.

&&

.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
AVIATION CONCERNS ARE MANY THROUGH THIS SET OF TAFS.

INITIALLY...CONVECTION IS GRADUALLY WEAKENING AND MOVING AWAY FROM
THE TAF SITES. A VCSH WILL COVER THE NEXT FEW HOURS...BUT CHANCES
FOR ADDITIONAL MVFR/IFR CONDITIONS DIRECTLY RELATED TO RAINFALL
ARE LOW.

OVERNIGHT...CONDITIONS BECOME VERY FAVORABLE FOR FOG AND STRATUS
DEVELOPMENT. LIGHT WINDS AND PLENTIFUL LOW-LEVEL MOISTURE WILL
ALLOW FOR THIS TO OCCUR...AND LIFR CONDITIONS ARE IN THE FORECAST
FOR ALL TAF SITES. THE COLUMBUS TAF SITES MAY BE IMPACTED THE
WORST...AS CENTRAL OHIO RECEIVED A SIGNIFICANT AMOUNT OF RAIN
TODAY.

CEILINGS AND VISIBILITIES WILL GRADUALLY (PERHAPS VERY GRADUALLY)
LIFT DURING THE MORNING HOURS. AN APPROACHING COLD FRONT WILL
GENERATE A CHANCE OF SHOWERS AND STORMS IN THE
AFTERNOON...REQUIRING A FOUR-HOUR WINDOW OF VCTS IN THE TAFS.
ULTIMATELY...DEPENDING ON HOW STORM COVERAGE ENDS UP APPEARING IN
LATER FORECAST UPDATES...SOME PREVAILING CONDITIONS WITH MVFR/IFR
AND GUSTY WINDS WILL BE POSSIBLE.

OUTLOOK...THUNDERSTORMS POSSIBLE SATURDAY.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.

&&

$$
SYNOPSIS...CONIGLIO
NEAR TERM...CONIGLIO/HATZOS
SHORT TERM...CONIGLIO
LONG TERM...AR
AVIATION...HATZOS







AREA FORECAST DISCUSSION

NWS CHARLESTON WV

 1008 PM EDT MON JUL 22 2013

.SYNOPSIS...
MID/UPPER DISTURBANCES MOVING UP THE OHIO VALLEY INTO WEDNESDAY WITH
ROUNDS OF CONVECTION. FLASH FLOOD HAZARD LINGERS.

&&

.NEAR TERM /THROUGH TUESDAY/...
10 PM UPDATE...TWEAKED POP GRIDS...AND DROPPED FLASH FLOOD WATCH
THIS EVENING. SOME LIGHT SHOWER/ISOLD THUNDERSTORM ACTIVITY
CONTINUES THIS EVENING...PARTICULARLY ACROSS EASTERN ZONES BUT
PRECIPITATION HAS BEEN LIGHT. WITH NO WIDESPREAD ADDITIONAL
DEVELOPMENT EXPECTED THIS EVENING...DECIDED TO DROP THE WATCH AREA WIDE.

STILL EXPECTING WIDESPREAD STRATUS DEVELOPMENT TONIGHT...AND IS ALREADY
STARTING TO DEVELOP WITH MANY SITES SOCKED IN WITH CIGS UNDER 1000
FEET.

PREVIOUS DISCUSSION FOLLOWS...
WILL BE TRACKING A POTENT UPR LVL SYS...LOCATED ACROSS W OH AND
KY...WITH A MESO VORTEX APPENDAGE MOVING NE INTO NE KY. USED LATEST
RUC AND HRRR FOR TIMING AND PLACEMENT OF POPS WITH THIS SYS WITH HVY
SHRA CURRENTLY MOVING BACK INTO NE KY AND SE OH AND INTO S WV/SW VA
BY 21Z. HAVE SCT SHRA IN GRIDS IN MEANTIME. LOW CLDS SCT OUT ACROSS
WV/SW VA RVR WHICH WILL HELP TO DESTABILIZE ATMOS FOR THIS SYS TO
WORK ON THIS AFTN. ROLLED WITH CATEGORICAL POPS MOST PLACES LATE
AFTN INTO EARLY THIS EVE AND INSERTED HVY RA WORDING IN COVERAGE
TERMS AS PWATS ON EITHER SIDE OF 2 INCHES. FLASH FLOOD WATCH CONT
THRU TONIGHT.

UPR TROF CROSSES TONIGHT WITH PERHAPS ADDITIONAL SHRA/TSRA MOVING
IN THIS EVE AFFECTING SE OH/NE KY/N WV. TROF AXIS SHOULD BE E OF
AREA AFTER 09Z WITH PCPN THREAT DIMINISHING.

THINK SOME LOW STRATUS AND FG DEVELOPS OVERNIGHT WHICH MAY TAKE
UNTIL MID MORNING TO SCT OUT. HAVE ISO TO SCT SHRA/TSRA BY
AFTN...WITH AN UPTICK LATE WITH A FAST MOVING SYS DROPPING IN NW
FLOW ALOFT.

ROLLED WITH WARMER GUIDANCE TONIGHT AND TOMORROW...THINKING AREA
SHOULD GET A DECENT SHOT OF SUN TOMORROW BEFORE SHRA/TSRA GET GOING.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
COLD FRONT SWINGS THROUGH TUESDAY NIGHT AS 5H TROF SWINGS THROUGH
AT THE MID LEVELS. CARRIED LIKELY POPS AS THERE WILL BE DECENT
DYNAMIC FORCING COUPLED WITH PLENTY OF A AVAILABLE MOISTURE.
HOWEVER...CHANCES FOR SEVERE WEATHER ASSOCIATED WITH THIS FEATURE
WILL BE LIMITED DUE TO THE LACK OF DAYTIME HEATING DURING THE
OVERNIGHT HOURS.

AS HIGH PRESSURE BUILDS IN WEDNESDAY...BULK OF MOISTURE WILL BE
SHUNTED TO THE EAST...LEADING TO A DRYING TREND. SHOULD SEE A
NOTICEABLE DECREASE IN CONVECTIVE ACTIVITY WEDNESDAY AND THURSDAY
AS LOW AND MID LEVEL COOL POOL HELPS TO STABILIZE THE ATMOSPHERE.
LEFT CHANCE POPS IN FOR MOUNTAINS AS HEATING IN ELEVATED TERRAIN
COULD STILL LEAD TO SOME CONVECTIVE DEVELOPMENT.

WILL SEE A COOLING TREND THIS PERIOD. GOING WITH MODEL BLEND FOR
TEMPERATURES THIS PERIOD.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
DRIER AIR MOVES IN TO CLOSE OUT THE WEEK AS TROUGH DIGS OVER THE
GREAT LAKES SATURDAY AND SUNDAY. GFS AND EURO MODELS HANDLING
FEATURES IN SEPARATE FASHION AND DEFERRED TO HPC GRIDS FOR
EXTENDED PERIOD. NO MAJOR CHANGES TO WPC MEDIUM RANGE GUIDANCE
TEMPERATURES.

&&

.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
00Z TUESDAY THRU 00Z WEDNESDAY...

SHOWER AND THUNDERSTORM ACTIVITY CONTINUES THIS EVENING...MAINLY
ACROSS WEST VIRGINIA AND SOUTHWEST VIRGINIA. STILL SOME ISOLATED
ACTIVITY ACROSS PARTS OF SOUTHEAST OHIO AND EASTERN KENTUCKY...BUT
COVERAGE NOT AS GREAT AS TO THE EAST. EXPECT BRIEF MVFR/IFR
CONDITIONS IN VICINITY OF SHOWERS/STORMS. OTHERWISE...EXPECT A LOW
STRATUS TO DEVELOP OVERNIGHT...WITH WIDESPREAD IFR AND LIFR
CONDITIONS. LOW STRATUS AND FG WILL LIFT AND SCT AFTER 15ZZ...INTO
LOW END VFR CU FOR AFTN. SCATTERED SHOWERS AND THUNDERSTORMS
DEVELOPING AGAIN AFTER 18-20Z...WITH MVFR/IFR CONDITIONS IN
VICINITY OF STORMS.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z WEDNESDAY...

FORECAST CONFIDENCE: LOW.

ALTERNATE SCENARIOS: TIMING/DENSITY OF FOG AND STRATUS MAY VARY
OVERNIGHT...AS WELL AS TIMING OF IMPROVEMENT TUESDAY MAY VARY FROM
CURRENT FORECAST.

EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH:   TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW:    TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.

DATE                                                  TUE 07/23/13
UTC 1HRLY       02   03   04   05   06   07   08   09   10   11   12   13
EDT 1HRLY       22   23   00   01   02   03   04   05   06   07   08   09
CRW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
HTS CONSISTENCY  M    M    M    L    L    L    L    L    L    L    H    L
BKW CONSISTENCY  H    H    H    M    M    H    M    H    H    H    H    H
EKN CONSISTENCY  H    H    H    H    M    H    H    H    H    M    H    H
PKB CONSISTENCY  M    M    M    L    L    L    M    L    L    H    H    M
CKB CONSISTENCY  H    H    H    M    H    H    H    H    M    M    M    H

AFTER 00Z WEDNESDAY...
IFR OR WORSE FOG POSSIBLE WEDNESDAY MORNING.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...KMC/30
NEAR TERM...SL/30
SHORT TERM...KMC
LONG TERM...KMC
AVIATION...SL









AREA FORECAST DISCUSSION

NWS CHARLESTON WV

 734 PM EDT MON JUL 22 2013

.SYNOPSIS...
MID/UPPER DISTURBANCES MOVING UP THE OHIO VALLEY INTO WEDNESDAY WITH
ROUNDS OF CONVECTION. FLASH FLOOD HAZARD LINGERS.

&&

.NEAR TERM /THROUGH TUESDAY/...
6PM UPDATE...TWEAKED POP GRIDS THIS EVENING BASED ON CURRENT RADAR
TRENDS. OTHERWISE...MADE NO MAJOR CHANGES TO THE FORECAST.

PREVIOUS DISCUSSION FOLLOWS...
WILL BE TRACKING A POTENT UPR LVL SYS...LOCATED ACROSS W OH AND
KY...WITH A MESO VORTEX APPENDAGE MOVING NE INTO NE KY. USED LATEST
RUC AND HRRR FOR TIMING AND PLACEMENT OF POPS WITH THIS SYS WITH HVY
SHRA CURRENTLY MOVING BACK INTO NE KY AND SE OH AND INTO S WV/SW VA
BY 21Z. HAVE SCT SHRA IN GRIDS IN MEANTIME. LOW CLDS SCT OUT ACROSS
WV/SW VA RVR WHICH WILL HELP TO DESTABILIZE ATMOS FOR THIS SYS TO
WORK ON THIS AFTN. ROLLED WITH CATEGORICAL POPS MOST PLACES LATE
AFTN INTO EARLY THIS EVE AND INSERTED HVY RA WORDING IN COVERAGE
TERMS AS PWATS ON EITHER SIDE OF 2 INCHES. FLASH FLOOD WATCH CONT
THRU TONIGHT.

UPR TROF CROSSES TONIGHT WITH PERHAPS ADDITIONAL SHRA/TSRA MOVING
IN THIS EVE AFFECTING SE OH/NE KY/N WV. TROF AXIS SHOULD BE E OF
AREA AFTER 09Z WITH PCPN THREAT DIMINISHING.

THINK SOME LOW STRATUS AND FG DEVELOPS OVERNIGHT WHICH MAY TAKE
UNTIL MID MORNING TO SCT OUT. HAVE ISO TO SCT SHRA/TSRA BY
AFTN...WITH AN UPTICK LATE WITH A FAST MOVING SYS DROPPING IN NW
FLOW ALOFT.

ROLLED WITH WARMER GUIDANCE TONIGHT AND TOMORROW...THINKING AREA
SHOULD GET A DECENT SHOT OF SUN TOMORROW BEFORE SHRA/TSRA GET GOING.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
COLD FRONT SWINGS THROUGH TUESDAY NIGHT AS 5H TROF SWINGS THROUGH
AT THE MID LEVELS. CARRIED LIKELY POPS AS THERE WILL BE DECENT
DYNAMIC FORCING COUPLED WITH PLENTY OF A AVAILABLE MOISTURE.
HOWEVER...CHANCES FOR SEVERE WEATHER ASSOCIATED WITH THIS FEATURE
WILL BE LIMITED DUE TO THE LACK OF DAYTIME HEATING DURING THE
OVERNIGHT HOURS.

AS HIGH PRESSURE BUILDS IN WEDNESDAY...BULK OF MOISTURE WILL BE
SHUNTED TO THE EAST...LEADING TO A DRYING TREND. SHOULD SEE A
NOTICEABLE DECREASE IN CONVECTIVE ACTIVITY WEDNESDAY AND THURSDAY
AS LOW AND MID LEVEL COOL POOL HELPS TO STABILIZE THE ATMOSPHERE.
LEFT CHANCE POPS IN FOR MOUNTAINS AS HEATING IN ELEVATED TERRAIN
COULD STILL LEAD TO SOME CONVECTIVE DEVELOPMENT.

WILL SEE A COOLING TREND THIS PERIOD. GOING WITH MODEL BLEND FOR
TEMPERATURES THIS PERIOD.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
DRIER AIR MOVES IN TO CLOSE OUT THE WEEK AS TROUGH DIGS OVER THE
GREAT LAKES SATURDAY AND SUNDAY. GFS AND EURO MODELS HANDLING
FEATURES IN SEPARATE FASHION AND DEFERRED TO HPC GRIDS FOR
EXTENDED PERIOD. NO MAJOR CHANGES TO WPC MEDIUM RANGE GUIDANCE
TEMPERATURES.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
00Z TUESDAY THRU 00Z WEDNESDAY...

SHOWER AND THUNDERSTORM ACTIVITY CONTINUES THIS EVENING...MAINLY
ACROSS WEST VIRGINIA AND SOUTHWEST VIRGINIA. STILL SOME ISOLATED
ACTIVITY ACROSS PARTS OF SOUTHEAST OHIO AND EASTERN KENTUCKY...BUT
COVERAGE NOT AS GREAT AS TO THE EAST. EXPECT BRIEF MVFR/IFR
CONDITIONS IN VICINITY OF SHOWERS/STORMS. OTHERWISE...EXPECT A LOW
STRATUS TO DEVELOP OVERNIGHT...WITH WIDESPREAD IFR AND LIFR
CONDITIONS. LOW STRATUS AND FG WILL LIFT AND SCT AFTER 15ZZ...INTO
LOW END VFR CU FOR AFTN. SCATTERED SHOWERS AND THUNDERSTORMS
DEVELOPING AGAIN AFTER 18-20Z...WITH MVFR/IFR CONDITIONS IN
VICINITY OF STORMS.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z WEDNESDAY...

FORECAST CONFIDENCE: LOW.

ALTERNATE SCENARIOS: TIMING/DENSITY OF FOG AND STRATUS MAY VARY
OVERNIGHT...AS WELL AS TIMING OF IMPROVEMENT TUESDAY MAY VARY FROM
CURRENT FORECAST.

EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH:   TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW:    TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.

DATE                                                            TUE 07/23/13
UTC 1HRLY       00   01   02   03   04   05   06   07   08   09   10   11
EDT 1HRLY       20   21   22   23   00   01   02   03   04   05   06   07
CRW CONSISTENCY  H    H    H    H    H    M    H    H    H    H    H    H
HTS CONSISTENCY  H    L    H    H    H    L    L    L    L    L    L    L
BKW CONSISTENCY  H    H    H    H    H    M    M    H    H    H    H    H
EKN CONSISTENCY  M    M    H    H    H    H    M    H    H    H    H    H
PKB CONSISTENCY  M    M    M    M    H    L    L    L    M    L    L    H
CKB CONSISTENCY  H    H    H    H    H    M    M    H    H    H    M    M

AFTER 00Z WEDNESDAY...
IFR OR WORSE FOG POSSIBLE WEDNESDAY MORNING.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLASH FLOOD WATCH UNTIL 6 AM EDT TUESDAY FOR WVZ005>011-
     013>020-024>040-046-047.
OH...NONE.
KY...NONE.
VA...FLASH FLOOD WATCH UNTIL 6 AM EDT TUESDAY FOR VAZ003-004.

&&

$$
SYNOPSIS...KMC/30
NEAR TERM...SL/30
SHORT TERM...KMC
LONG TERM...KMC
AVIATION...SL









AREA FORECAST DISCUSSION

NWS GREENVILLE-SPARTANBURG SC

 156 AM EDT SUN JUL 21 2013

.SYNOPSIS...
HIGH PRESSURE OVER THE SOUTHEAST WILL WEAKEN DURING THE REMAINDER OF
THE WEEKEND AS A COLD FRONT MOVES SOUTHWARD FROM THE GREAT LAKES.
THE FRONT WILL STALL NORTH OF THE AREA ON SUNDAY AND THEN DISSIPATE
OR RETURN NORTHWARD INTO MONDAY. AN UPPER LEVEL TROUGH OF LOW
PRESSURE WILL DEVELOP OVER THE EAST ON TUESDAY AND LINGER THROUGH
LATE WEEK. A SECOND WEAK COLD FRONT WILL ARRIVE FROM THE NORTHWEST
ON THURSDAY AND SETTLE JUST SOUTHEAST OF THE REGION THROUGH FRIDAY.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 200 AM...CONDITIONS REMAIN RATHER CALM ACROSS THE REGION AS
EARLIER CONVECTION HAS CEASED.  LOW CLOUDS CONTINUE TO PREVAIL
ACROSS MOST LOCATIONS WITH PATCHY FOG REMAINING LIKELY THROUGH
MORNING.  ADJUSTED TEMPERATURES AND DEWPOINTS TO REFLECT LATEST
OBSERVATIONS AND LEFT THE REMAINDER OF FORECAST AS IS.

PREVIOUS DISCUSSION...

1015 PM UPDATE...THUNDERSTORMS PERSIST AT THIS HOUR IN THE VICINITY
OF A REMNANT GUST FRONT EXTENDING ACROSS THE LOWER SC PIEDMONT AND
SOUTH SIDE OF THE CHARLOTTE METRO. LATEST SPC MESOANALYSIS SHOWS
NEARLY 2000 J OF SBCAPE STILL UNINHIBITED JUST SOUTH OF THIS
BOUNDARY...AS WELL AS A THERMAL GRADIENT IN THE SAME AREA THAT IS
LIKELY PROVIDING ENOUGH FORCING TO GET PARCELS GOING. LIGHT SLY FLOW
ON THE S SIDE OF THE BDY WILL CONTINUE TO REINFORCE THE GRADIENT AND
IT MAY TAKE SOME TIME FOR THE REMNANT INSTABILITY TO BE CONSUMED.
LATEST HRRR SUPPORTS THIS CONCEPT AS WELL AS THE SCHC POP WHICH HAS
BEEN MAINTAINED OVERNIGHT FOR MOST OF THE CWFA...AS IT FEATURES A
COUPLE OF ISOLATED CELLS HERE AND THERE...ESPECIALLY NEAR THE BLUE
RIDGE.

ON A FINAL NOTE...PATCHY FOG ALREADY DEVELOPING AT SOME
SITES...PRIMARILY SITES WHICH SAW HEAVY RAIN THIS AFTN. FOLLOWING
THAT THINKING THE MAIN AREA OF CONCERN WOULD BE THE FOOTHILLS AND
UPPER PIEDMONT. AT THIS TIME THE REPORTING SITES ARE TOO SCATTERED
TO NEED A DENSE FOG ADVY...AND NAM SOUNDINGS ARE NOT SUPPORTIVE OF
WIDESPREAD DENSE FOG ANYWAY. HOWEVER...IT BEARS MONITORING AND WILL
INFORM INCOMING SHIFT OF THIS CONCERN.

AT 230 PM EDT SATURDAY...AN UPPER LEVEL TROUGH WILL SLOWLY AMPLIFY
OVER THE EASTERN USA TONIGHT AND SUNDAY. A SHORTWAVE WILL MOVE INTO
THE BASE OF THIS TROUGH OVER THE TN RIVER VALLEY LATE SUNDAY. DEEP
GULF MOISTURE WILL BE TRANSPORTED NORTH INTO OUR AREA BY A GENTLE SW
LOW LEVEL FLOW  ON THE WEST SIDE OF A BERMUDA HIGH...WHILE A COLD
FRONT DROPS SOUTH INTO VA. WITH LOW LEVEL FLOW NEARLY PARALLEL THE
TO THE BLUE RIDGE...UPSLOPE FLOW WILL BE LIMITED...THOUGH STILL
PRESENT. WITH THE LOWE LEVELS STABILIZING LATE THIS EVENING...
CONVECTIVE COVER SHOULD DIMINISH. MODEL SOUNDINGS SHOW CAPE
SURPASSING 1000 J/KG AGAIN ON SUNDAY...AND CONVECTIVE TRENDS ARE
EXPECTED TO MIMIC TODAY...WITH THE GREATEST COVERAGE IN THE
MOUNTAINS...WITH ACTIVITY SPREADING EAST INTO THE FOOTHILLS AND
PIEDMONT WITH TIME. SHEAR WILL REMAIN WEAK HOWEVER...LIMITING STORM
ORGANIZATION. MINIMUM TEMPERATURES WILL BE SEVERAL DEGREES ABOVE
NORMAL TONIGHT IN A MOIST AIR MASS. MAXIMUM TEMPERATURES SUNDAY WILL
BE SLIGHTLY BELOW NORMAL...WITH CLOUDS...MOISTURE A FALLING HEIGHTS
ALOFT LIMITING WARMING.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
AT 230 PM SATURDAY... 500 MB HEIGHTS GRADUALLY LOWER OVER THE
SOUTHEAST MONDAY AND TUESDAY BUT SURFACE PATTERN CHANGES WILL BE
RATHER SUBTLE. DIURNAL CONVECTION WILL CONTINUE INTO THE FORECAST
PERIOD BEGINNING 00Z MONDAY THEN GRADUALLY DIMINISH DURING THE
NIGHT. MOIST AND MODERATELY UNSTABLE AIR MASS WILL CONTINUE OVER THE
REGION AND GFS DEPICTS SHORT WAVE TROUGH APPROACHING CWA BY 12Z
MONDAY... SO AT LEAST SLIGHT CHANCE POPS WILL CONTINUE WELL INTO THE
NIGHT. DURING DAYTIME MONDAY... CWA REMAINS IN AIRMASS CONDUCIVE TO
CONVECTIVE STORM DEVELOPMENT SO POPS WILL INCREASE WITH DAYTIME
HEATING INTO CHANCE CATEGORY WITH LIKELY POPS OVER HIGHER TERRAIN.
GFS HAS ANOTHER SHORT WAVE TROUGH DROPPING INTO LONG WAVE TROUGH
POSITION EARLY TUESDAY... SO CHANCE POPS WILL CONTINUE THROUGH THE
NIGHT AND INTO TUESDAY WHEN DIURNAL HEATING CYCLE ONCE AGAIN LEADS
TO HIGHER PROBABILITIES DURING AFTERNOON. NO SIGNIFICANT TEMPERATURE
CHANGES WILL OCCUR DURING MONDAY TUESDAY. HIGHS OUTSIDE THE
MOUNTAINS WILL BE IN THE UPPER 80S AND LOWER 90S WHILE MOUNTAIN
VALLEY TEMPERATURES WILL BE IN THE LOWER TO MIDDLE 80S. VERY WARM
LOW TEMPERATURES IN THE 60S AND LOWER 70S ARE EXPECTED TO CONTINUE.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 230 PM SATURDAY... FLOW PATTERN ACROSS U.S. DURING THE PERIOD
WILL CONSIST OF RIDGE IN THE WEST AND TROUGH OVER THE EASTERN
STATES. BOUNDARY LAYER WILL REMAIN WARM AND MOIST SO COOL
TEMPERATURES ALOFT ON WEDNESDAY WILL SUPPORT LAPSE RATES
SUFFICIENTLY STEEP TO PROMOTE CONVECTION WITH APPROACH AND PASSAGE
EARLY THURSDAY OF COLD FRONT. THEREAFTER DETAILS BECOME DIFFICULT TO
RESOLVE AS FRONT DRIFTS SLOWLY SOUTHEAST AND APPEARS IN CURRENT
GUIDANCE TO BECOME NEARLY STATIONARY JUST AFTER CROSSING CWA.
THUS... AIR MASS CHANGE WILL NOT BE SUFFICIENTLY SIGNIFICANT TO
ELIMINATE POPS BUT NUMBERS WILL BE IN THE LOWER END OF THE CHANCE
SPECTRUM AND WILL DISPLAY A DIURNAL TREND. NO SIGNIFICANT CHANGES IN
TEMPERATURE EXPECTED.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AT KCLT...CONTINUED WITH MOSTLY PERSISTENCE FORECAST FROM LAST
NIGHT.  EXPECTING MVFR FOG CONDITIONS TO DEVELOP IN THE NEXT HOUR OR
SO ACROSS THE NC PIEDMONT WITH CIGS LESS THAT 1K FT.
OTHERWISE...MVFR CONDITIONS WILL PREVAIL THROUGH MID MORNING THEN
FINALLY GIVE WAY TO LOW END VFR CIGS BY AROUND NOON.  AT THAT
TIME...INTRODUCED MVFR PROB30 IN THE TAF FOR POSSIBLE AFTERNOON
CONVECTION.  EXPECTING AS MUCH...IF NOT MORE COVERAGE ACROSS THE
REGION TODAY AS THE ATMOSPHERE CONTINUES TO MOISTEN.  AFTER
SUNSET EXPECTING CIGS TO LIFT ACROSS THE PIEDMONT TO SOLID VFR
LEVELS AND REMAIN THAT WAY THROUGH THE REMAINDER OF THE TAF CYCLE.
EXPECTING WINDS DURING THE PERIOD TO REMAIN LIGHT AND
SOUTHWESTERLY.

ELSEWHERE...RESTRICTIONS WILL CONTINUE...IF NOT WORSEN ACROSS
THE REGION IN THE NEXT FEW HOURS AS VERY MOIST BOUNDARY LAYER
SETTLES.  LIKELY A REPEAT OF LAST NIGHT WITH REGARDS TO MVFR/IFR
CIGS AT MOST SITES.  IN ADDITION...ADDED TEMPO GROUPS FOR VISB
RESTRICTIVE FOG AT ALL SITES WITH KAVL DROPPING DOWN TO AN IFR
VISB.  OTHERWISE...MUCH OF THE SAME AS KCLT ABOVE AS FAR AS MID
MORNING LOW END VFR CIGS OVERSPREADING MOST OF THE AREA.  BEYOND
THAT...ADDED PROB30 GROUPS AT ALL SITES FOR MVFR TSRA RESTRICTIONS
DURING THE LATE MORNING/AFTERNOON HOURS.  EXPECTING CONVECTION TO
INITIATE ACROSS THE HIGH TERRAIN FIRST...THEN SPREAD EASTWARD
THROUGH THE PIEDMONT.  CONDITIONS WILL IMPROVE THIS EVENING AS
DAYTIME HEATING IS LOST AFTER SUNSET...WHERE SOLID VFR CIGS WILL
RETURN.  WINDS THROUGH THE PERIOD WILL BE LIGHT AND SOUTHWESTERLY.

OUTLOOK...MOIST SOUTHWESTERLY FLOW CONTINUES INTO THE EARLY WEEK.
THIS WILL HELP DRIVE SHOWERS AND THUNDERSTORMS...MAINLY IN THE
AFTERNOON AND EVENING...AND LIKELY CAUSE RESTRICTIVE CIGS/VSBYS
EARLY EACH MORNING.

CONFIDENCE TABLE...

            06-12Z        12-18Z        18-24Z        00-06Z
KCLT       LOW   57%     MED   79%     HIGH 100%     HIGH 100%
KGSP       MED   69%     MED   77%     HIGH 100%     HIGH 100%
KAVL       MED   64%     LOW   58%     LOW   58%     HIGH 100%
KHKY       MED   67%     LOW   51%     HIGH  85%     MED   75%
KGMU       MED   71%     LOW   59%     HIGH  86%     HIGH 100%
KAND       LOW   56%     MED   77%     HIGH 100%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...PAT
NEAR TERM...CDG/JAT/WIMBERLEY
SHORT TERM...LGL
LONG TERM...LGL
AVIATION...CDG







AREA FORECAST DISCUSSION...UPDATED

NWS ABERDEEN SD

 1227 AM CDT SUN JUL 21 2013

.UPDATE...
SEE UPDATED AVIATION DISCUSSION BELOW.


&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH MONDAY NIGHT
SEVERAL WEAK SHORT WAVES EMBEDDED WITHIN THE NORTHWEST FLOW ALOFT
WILL BRING ISOLATED TO SCATTERED THUNDERSTORMS ACROSS THE REGION
THIS EVENING THOUGH SUNDAY. WITH HI-RES MODELS STRUGGLING TO
DEPICT THE AREAS OF CONVECTION...WITH MAINTAIN AT LEAST A LOW POP
THROUGH 18Z SUNDAY.

AS OF 19Z...A NARROW LINE OF SHOWERS ARE MOVING SE ACROSS
HYDE/HAND COUNTY. THESE STORMS SHOULD CONTINUE TO DISSIPATE AS THEY
EXIT THIS CWA. FARTHER WEST...A MORE PRONOUNCED SHORT WAVE HAS
CAUSED CONVECTION A DEVELOP OVER THE BLACK HILLS. THIS AREA IS
BASICALLY UNCAPPED WITH SB-CAPE VALUES AROUND 2000 J/KG. THESE
STORMS SHOULD CONTINUE TO GROW AS SOUTH TO EASTERLY LOW LEVEL FLOW
WILL FILTER MOISTURE INTO SW SOUTH DAKOTA. WOULD EXPECT THESE
STORM WILL REMAIN JUST SOUTH OF THE CWA AS THE LAYER STORM MOTION
OFF THE RUC SUGGEST A SE MOTION. THAT SAID...SEVERAL OUTFLOW
BOUNDARIES FROM EARLIER CONVECTION COULD RESULT IN A NORTHWARD
JOG.

CHANCES FOR THUNDERSTORMS IN THE EASTERN CWA TONIGHT/SUNDAY IS A
LITTLE UNCLEAR AT THIS TIME. HALF THE MODEL SUGGEST LLJ INDUCED
THUNDERSTORMS MOVING ACROSS THE EASTERN DAKOTAS BY 12Z. OTHERS
SUGGEST CONVECTION COULD BE SOUTH/EAST/OR NORTH OF THIS CWA. WITH
VERY LOW CONFIDENCE...WILL BROAD BRUSH MOST OF THE CWA WITH LOW
POPS FOR NOW ON SUNDAY.

AN AREA OF LOW PRESSURE AND SURFACE COLD FRONT WILL MOVE ACROSS
THE REGION ON SUNDAY NIGHT/MONDAY MORNING. WITH THE MAJORITY OF
THE PCPN FALLING POST FRONTAL...SEVERE STORMS DO NOT APPEAR
POSSIBLE. COOLER TEMPERATURES ARE EXPECTED ON MONDAY WITH HIGHS IN
THE UPPER 70S..IN THE NE...TO AROUND 90 IN THE SOUTHWEST CWA. A
BLEND OF CONSALL/ALLBLEND SHOWS HIGHS COULD BE SLIGHTLY COOLER
THAN CURRENTLY ADVERTISED.


.LONG TERM...TUESDAY THROUGH SATURDAY
NORTHWEST FLOW ALOFT WILL DOMINATE THROUGH THE EXTENDED. MAIN
FORECAST CHALLENGE WILL BE TIMING SHORTWAVE ACTIVITY. THE PATTERN
WILL REMAIN VERY ACTIVE THROUGH THURSDAY WITH A SERIES OF
SHORTWAVES. TIMING AND INTENSITY ARE VERY DIFFICULT TO DETERMINE
AT THIS TIME RANGE SO CONFIDENCE IN POPS IN ANY GIVEN PERIOD IS
LOW. THAT SAID TUESDAY NIGHT DOES SEEM TO HAVE MODEL AGREEMENT ON
BEING DRY WHILE THURSDAY HAS BEEN CONSISTENTLY STORMY. STUCK CLOSE
TO ALLBLEND POPS BECAUSE OF UNCERTAINTY. BY FRIDAY SFC HIGH
PRESSURE BEGINS TO DROP OUT OF CANADA AND NOSE INTO EASTERN SD.
THE START OF THE WEEKEND APPEARS DRY FOR NOW AS A RESULT.

TEMPERATURES WILL BE MUCH COOLER THROUGH THE PERIOD WITH HIGHS
RANGING FROM THE UPPER 70S IN THE EAST TO THE MID 80S IN THE
SOUTHWEST.


&&

.AVIATION...
06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS

VFR CONDITIONS ARE EXPECTED AT ALL TAF LOCATIONS THROUGH TONIGHT
AND SUNDAY. A FEW SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS
THE REGION TONIGHT AND SUNDAY AND MAY AFFECT THE TERMINALS AT OR
IN THE VICINITY. WILL WATCH FOR POSSIBLE AMENDMENTS.


&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&

$$
SHORT TERM...SD
LONG TERM...WISE
AVIATION...PARKIN

WEATHER.GOV/ABERDEEN






AREA FORECAST DISCUSSION

NWS MEMPHIS TN

 1113 AM CDT SUN JUL 21 2013

.UPDATE...

AN UPPER TROF IS BEGINNING TO PUSH INTO THE MIDSOUTH THIS MORNING.
LATEST MODELS INDICATE CHANCES FOR CONVECTION WILL MAINLY COME
FROM DIURNAL BASED STORMS THIS AFTERNOON. ALTHOUGH...A MINOR
SHORTWAVE WILL PUSH INTO NORTHEAST ARKANSAS LATE THIS AFTERNOON
WHICH COULD INCREASE COVERAGE. THE SHORTWAVE PRODUCED CONVECTION
ACROSS SE KANSAS AND NE OKLAHOMA OVERNIGHT. THE COMPLEX HAS SINCE
DIED OVER NW ARKANSAS. THIS IS A LOT QUICKER THAN WHAT THE LATEST HRRR
HAS SHOWN. THERE MAY BE SOME REDEVELOPMENT THIS AFTERNOON THUS
WILL KEEP 50-60 POPS ACROSS NE ARKANSAS OTHERWISE WILL REDUCE
CHANCES ACROSS THE REST OF THE CWA TO 30S.

KRM

&&

.DISCUSSION... /ISSUED 424 AM CDT SUN JUL 21 2013/

A WET WEATHER PATTERN WAS BEGINNING TO TAKE SHAPE ACROSS THE
MIDSOUTH THAT WILL LEAD TO SEVERAL DAYS WITH SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS. BY THURSDAY...MANY LOCATIONS ARE
EXPECTED TO HAVE RECEIVED TWO OR THREE OF RAIN...LOCALLY MORE.

EARLY THIS MORNING...A NEARLY STATIONARY FRONT STRETCHED TO THE
NORTH OF THE MIDSOUTH FROM CENTRAL MO TO SOUTHERN IN. OUTFLOW
BOUNDARIES FORMED IN ASSOCIATION WITH THUNDERSTORMS THAT DEVELOPED
SOUTH OF THIS FRONT WITH THESE BOUNDARIES PUSHING INTO EAST AR AND
NORTHWEST TN LAST EVENING. THIS SPARKED SCATTERED THUNDERSTORMS IN
PORTIONS OF THIS REGION DURING THE NIGHT BUT MOST HAVE NOW
DISSIPATED. A FEW SHOWERS AND THUNDERSTORMS DEVELOPED EARLY THIS
MORNING ACROSS PORTIONS OF NORTHEAST MS DUE TO A WEAK BUT LARGE LOW
PRESSURE SYSTEM ALOFT CENTERED ALONG THE NORTHEAST LA / CENTRAL MS
BORDER.

SEVERAL FACTORS WILL LEAD TO SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS ACROSS THE MIDSOUTH TODAY AND TONIGHT.
AN UPPER LEVEL SHORT WAVE WILL PUSH TOWARD THE MIDSOUTH FROM THE
NORTHWEST WITH UPPER LEVEL HEIGHTS CONTINUING TO DECREASE TO
UNSEASONABLY LOW VALUES ACROSS THE MIDSOUTH. THE UPPER LEVEL LOW TO
OUR SOUTH WILL PUSH EAST NORTHEASTWARD TO JUST SOUTH OF NORTHEAST
MS. A MOIST AND UNSTABLE ATMOSPHERE WILL EXIST ACROSS THE MIDSOUTH.
A FEW STRONG THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND TONIGHT
WITH WEAK MID LEVEL LAPSE RATES LIMITING THE THREAT FOR SEVERE
THUNDERSTORMS. WINDS GUSTS TO NEAR 50 MPH...SMALL HAIL...AND HEAVY
RAINFALL WITH LOCALIZED FLASH FLOODING MAY OCCUR. PRECIPITABLE
WATER VALUES WILL INCREASE TO BETWEEN 2 AND 2.25 INCHES ALONG AND
WEST OF THE MS RIVER. UPPER LEVEL HEIGHTS WILL CONTINUE TO LOWER
ACROSS THE MIDSOUTH TONIGHT AS THE SHORT WAVE EMBEDDED IN A BROAD
UPPER LEVEL TROUGH MOVES INTO THE MIDSOUTH RESULTING IN NUMEROUS
SHOWERS AND THUNDERSTORMS.

ON MONDAY...AN LARGE UPPER LEVEL TROUGH WILL DEEPEN OVER THE EASTERN
UNITED STATES. MID LEVEL LAPSE RATES WILL DECREASE ACROSS THE
MIDSOUTH LEADING TO INCREASED INSTABILITY. NUMEROUS SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS THE REGION. THIS WILL
PLAY HAVOC WITH HIGH TEMPERATURES SINCE IT IS DIFFICULT TO DETERMINE
HOW HOT IT WILL GET BEFORE THE SHOWERS AND STORMS DEVELOP.

A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS WILL CONTINUE MONDAY
NIGHT AND TUESDAY AS UPPER LEVEL SHORT WAVES EMBEDDED IN NORTHWEST
FLOW ALOFT CONTINUE TO INTERACT WITH A MOIST AND UNSTABLE
ATMOSPHERE.

FOR TUESDAY NIGHT AND WEDNESDAY...THE STORMY WEATHER PATTERN WILL
CONTINUE ALTHOUGH THE MODELS ARE NOT IN SYNC WITH THE DETAILS. THE
GFS PUSHES A COLD FRONT INTO THE REGION FROM THE NORTH QUICKER THAN
THE ECMWF DOES. HOWEVER...THE MODELS DO AGREE THAT A VERY UNSTABLE
AND MOIST ATMOSPHERE WILL BE LOCATED OVER THE MIDSOUTH INTO
WEDNESDAY.

KEPT THURSDAY RAINFREE AS DRIER AIR PUSHES INTO THE REGION FOLLOWING
THE PASSAGE OF A WEAK COLD FRONT. FRIDAY LOOKS RAINFREE ALSO WITH A
MILD START TO THE DAY BEFORE AFTERNOON TEMPERATURES WARM TO AROUND
THE NORMAL VALUES FOR THIS TIME OF THE YEAR.

LOOKING AT MODEL FORECAST CHARTS FOR FRIDAY NIGHT AND SATURDAY...YOU
WOULD NOT THINK IT WAS JULY. THE MODELS ARE IN FAIRLY GOOD AGREEMENT
FOR THAT FAR OUT. ANOTHER BROAD UNSEASONABLY DEEP UPPER LEVEL TROUGH
WILL DIG ALONG THE EASTERN UNITED STATES. THE GFS INDICATES A 1010
MB LOW NEAR THE MO BOOTHEEL 7 AM SATURDAY WITH A COLD FRONT
TRAILING TO THE SOUTHWEST WHILE THE ECMWF IS A LITTLE SLOWER AND
STRONGER INDICATING A 1006 MB LOW OVER SOUTH CENTRAL MO WITH A
TRAILING COLD FRONT TO THE SOUTHWEST. A CHANCE OF SHOWERS AND
THUNDERSTORMS WILL OCCUR AHEAD OF THIS SYSTEM FRIDAY NIGHT AND
SATURDAY. COOLER AND DRY HIGH PRESSURE IS FORECAST TO BEHIND INTO
THE REGION FROM THE NORTH WITH PASSAGE OF THE LOW PRESSURE SYSTEM
AND COLD FRONT.

JCL

&&

.AVIATION...

12Z TAFS

PRIMARY FORECAST CONCERN REMAINS TIMING AND LOCATION OF TSRA
ONSET. TSRA CHANCES WILL INCREASE AT ALL LOCATIONS AFTER 15Z.
PRESENCE OF ISOLATED SHRA/TSRA EARLY THIS MORNING INDICATES SOME
ELEVATED INSTABILITY...BUT THIS ACTIVITY HAS FAILED TO ORGANIZE
FOR ANY APPRECIABLE LENGTH OF TIME.

FOR THE 12Z TAFS...HAVE NARROWED TEMPOS DOWN TO NEAR PEAK HEATING
WITH RESPECT TO TSRA TIMING. OF CONCERN IS UPPER LEVEL LOW OVER
NORTHEAST LA...WHICH COULD HELP INITIATE TSRA BY LATE MORNING. GFS
LAMP GUIDANCE AND HRRR MODELS SHOWED LITTLE EFFECT OF THIS UPPER
LEVEL FEATURE FOR THE MORNING HOURS. BUT WILL SKIES TO START THE
DAY... AMPLE SURFACE HEATING OVER THE ARKLAMISS MAY TOUCH OFF
MID/LATE MORNING TSRA POSSIBLY EXTENDING UP TOWARD MEM.

PWB

&&




&&

.PRELIMINARY POINT TEMPS/POPS...
MEM  93  74  91  75 /  30  60  60  50
MKL  89  71  89  72 /  30  60  60  50
JBR  91  72  91  73 /  50  60  60  50
TUP  92  73  90  73 /  30  60  60  50

&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&

$$








AREA FORECAST DISCUSSION...UPDATED

NWS MEMPHIS TN

 646 AM CDT SUN JUL 21 2013

.UPDATE...
UPDATED FOR AVIATION.

&&

.PREV DISCUSSION... /ISSUED 424 AM CDT SUN JUL 21 2013/

DISCUSSION...

A WET WEATHER PATTERN WAS BEGINNING TO TAKE SHAPE ACROSS THE
MIDSOUTH THAT WILL LEAD TO SEVERAL DAYS WITH SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS. BY THURSDAY...MANY LOCATIONS ARE EXPECTED
TO HAVE RECEIVED TWO OR THREE OF RAIN...LOCALLY MORE.

EARLY THIS MORNING...A NEARLY STATIONARY FRONT STRETCHED TO THE
NORTH OF THE MIDSOUTH FROM CENTRAL MO TO SOUTHERN IN. OUTFLOW
BOUNDARIES FORMED IN ASSOCIATION WITH THUNDERSTORMS THAT DEVELOPED
SOUTH OF THIS FRONT WITH THESE BOUNDARIES PUSHING INTO EAST AR AND
NORTHWEST TN LAST EVENING. THIS SPARKED SCATTERED THUNDERSTORMS IN
PORTIONS OF THIS REGION DURING THE NIGHT BUT MOST HAVE NOW
DISSIPATED. A FEW SHOWERS AND THUNDERSTORMS DEVELOPED EARLY THIS
MORNING ACROSS PORTIONS OF NORTHEAST MS DUE TO A WEAK BUT LARGE LOW
PRESSURE SYSTEM ALOFT CENTERED ALONG THE NORTHEAST LA / CENTRAL MS
BORDER.

SEVERAL FACTORS WILL LEAD TO SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS ACROSS THE MIDSOUTH TODAY AND TONIGHT.
AN UPPER LEVEL SHORT WAVE WILL PUSH TOWARD THE MIDSOUTH FROM THE
NORTHWEST WITH UPPER LEVEL HEIGHTS CONTINUING TO DECREASE TO
UNSEASONABLY LOW VALUES ACROSS THE MIDSOUTH. THE UPPER LEVEL LOW TO
OUR SOUTH WILL PUSH EAST NORTHEASTWARD TO JUST SOUTH OF NORTHEAST
MS. A MOIST AND UNSTABLE ATMOSPHERE WILL EXIST ACROSS THE MIDSOUTH.
A FEW STRONG THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND TONIGHT
WITH WEAK MID LEVEL LAPSE RATES LIMITING THE THREAT FOR SEVERE
THUNDERSTORMS. WINDS GUSTS TO NEAR 50 MPH...SMALL HAIL...AND HEAVY
RAINFALL WITH LOCALIZED FLASH FLOODING MAY OCCUR. PRECIPITABLE
WATER VALUES WILL INCREASE TO BETWEEN 2 AND 2.25 INCHES ALONG AND
WEST OF THE MS RIVER. UPPER LEVEL HEIGHTS WILL CONTINUE TO LOWER
ACROSS THE MIDSOUTH TONIGHT AS THE SHORT WAVE EMBEDDED IN A BROAD
UPPER LEVEL TROUGH MOVES INTO THE MIDSOUTH RESULTING IN NUMEROUS
SHOWERS AND THUNDERSTORMS.

ON MONDAY...AN LARGE UPPER LEVEL TROUGH WILL DEEPEN OVER THE EASTERN
UNITED STATES. MID LEVEL LAPSE RATES WILL DECREASE ACROSS THE
MIDSOUTH LEADING TO INCREASED INSTABILITY. NUMEROUS SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS THE REGION. THIS WILL
PLAY HAVOC WITH HIGH TEMPERATURES SINCE IT IS DIFFICULT TO DETERMINE
HOW HOT IT WILL GET BEFORE THE SHOWERS AND STORMS DEVELOP.

A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS WILL CONTINUE MONDAY
NIGHT AND TUESDAY AS UPPER LEVEL SHORT WAVES EMBEDDED IN NORTHWEST
FLOW ALOFT CONTINUE TO INTERACT WITH A MOIST AND UNSTABLE
ATMOSPHERE.

FOR TUESDAY NIGHT AND WEDNESDAY...THE STORMY WEATHER PATTERN WILL
CONTINUE ALTHOUGH THE MODELS ARE NOT IN SYNC WITH THE DETAILS. THE
GFS PUSHES A COLD FRONT INTO THE REGION FROM THE NORTH QUICKER THAN
THE ECMWF DOES. HOWEVER...THE MODELS DO AGREE THAT A VERY UNSTABLE
AND MOIST ATMOSPHERE WILL BE LOCATED OVER THE MIDSOUTH INTO
WEDNESDAY.

KEPT THURSDAY RAINFREE AS DRIER AIR PUSHES INTO THE REGION FOLLOWING
THE PASSAGE OF A WEAK COLD FRONT. FRIDAY LOOKS RAINFREE ALSO WITH A
MILD START TO THE DAY BEFORE AFTERNOON TEMPERATURES WARM TO AROUND
THE NORMAL VALUES FOR THIS TIME OF THE YEAR.

LOOKING AT MODEL FORECAST CHARTS FOR FRIDAY NIGHT AND SATURDAY...YOU
WOULD NOT THINK IT WAS JULY. THE MODELS ARE IN FAIRLY GOOD AGREEMENT
FOR THAT FAR OUT. ANOTHER BROAD UNSEASONABLY DEEP UPPER LEVEL TROUGH
WILL DIG ALONG THE EASTERN UNITED STATES. THE GFS INDICATES A 1010
MB LOW NEAR THE MO BOOTHEEL 7 AM SATURDAY WITH A COLD FRONT
TRAILING TO THE SOUTHWEST WHILE THE ECMWF IS A LITTLE SLOWER AND
STRONGER INDICATING A 1006 MB LOW OVER SOUTH CENTRAL MO WITH A
TRAILING COLD FRONT TO THE SOUTHWEST. A CHANCE OF SHOWERS AND
THUNDERSTORMS WILL OCCUR AHEAD OF THIS SYSTEM FRIDAY NIGHT AND
SATURDAY. COOLER AND DRY HIGH PRESSURE IS FORECAST TO BEHIND INTO
THE REGION FROM THE NORTH WITH PASSAGE OF THE LOW PRESSURE SYSTEM
AND COLD FRONT.

JCL

&&

.AVIATION...
12Z TAFS

PRIMARY FORECAST CONCERN REMAINS TIMING AND LOCATION OF TSRA
ONSET. TSRA CHANCES WILL INCREASE AT ALL LOCATIONS AFTER 15Z.
PRESENCE OF ISOLATED SHRA/TSRA EARLY THIS MORNING INDICATES SOME
ELEVATED INSTABILITY...BUT THIS ACTIVITY HAS FAILED TO ORGANIZE
FOR ANY APPRECIABLE LENGTH OF TIME.

FOR THE 12Z TAFS...HAVE NARROWED TEMPOS DOWN TO NEAR PEAK HEATING
WITH RESPECT TO TSRA TIMING. OF CONCERN IS UPPER LEVEL LOW OVER
NORTHEAST LA...WHICH COULD HELP INITIATE TSRA BY LATE MORNING. GFS
LAMP GUIDANCE AND HRRR MODELS SHOWED LITTLE EFFECT OF THIS UPPER
LEVEL FEATURE FOR THE MORNING HOURS. BUT WILL SKIES TO START THE
DAY... AMPLE SURFACE HEATING OVER THE ARKLAMISS MAY TOUCH OFF
MID/LATE MORNING TSRA POSSIBLY EXTENDING UP TOWARD MEM.

PWB

&&

.PRELIMINARY POINT TEMPS/POPS...
MEM  93  74  91  75 /  50  60  60  50
MKL  90  71  89  72 /  50  60  60  50
JBR  92  72  91  73 /  60  60  60  50
TUP  92  73  90  73 /  50  60  60  50

&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&

$$








AREA FORECAST DISCUSSION

NWS SAN ANGELO TX

 1004 PM CDT MON JUL 22 2013

.UPDATE...
SHOWERS HAVE DISSIPATED ACROSS WEST CENTRAL TX WITH THE LOSS OF
DAYTIME HEATING. THE HRRR SUGGESTS WE MAY SEE A FEW MORE SHOWERS
DURING THE OVERNIGHT HOURS BUT WITH STABILITY INCREASING...I THINK
THAT IS A LONG SHOT. THE FORECAST IS DRY THROUGH THE REMAINDER OF
THE NIGHT WITH TEMPERATURES FALLING INTO THE LOWER 70S. MINOR
CHANGES WERE MADE TO WIND...DEWPOINT AND SKY FOR THE FIRST AND
SECOND PERIODS GRIDS BUT THE REMAINDER OF THE FORECAST REMAINS ON
TRACK.

JOHNSON

&&

.PREV DISCUSSION... /ISSUED 647 PM CDT MON JUL 22 2013/

DISCUSSION...
SEE AVIATION SECTION.

AVIATION...
WHILE AN ISOLATED SHOWER REMAINS POSSIBLE THIS EVENING BEFORE
SUNSET...THE CHANCE OF OCCURRENCE NEAR A TAF SITE IS REMOTE.
PLAN TO OMIT THE MENTION OF SHRA AFTER 00Z. THE CUMULUS FIELD
WILL DISSIPATE BY LATE EVENING WITH CLEAR SKIES FOR MUCH OF
TONIGHT. TOWARD MORNING...EXPECT A LOW CLOUD FIELD TO DEVELOP
ACROSS THE SOUTHEASTERN PART OF OUR AREA...WITH MVFR CEILINGS
AND BASES. CARRYING A LOW CLOUD MENTION MAINLY AT KJCT AND
KBBD...AND TO A LESSER EXTENT AT KSOA. KSJT MAY BRIEFLY HAVE
LOW CLOUDS IN THE VICINITY BY 13-14Z. THE LOW CLOUD FIELD WILL
ERODE BY MID-LATE MORNING. SHOULD HAVE A DIURNAL CUMULUS FIELD
ONCE AGAIN DURING THE DAY TUESDAY...BUT WITH LESS CLOUD COVERAGE
THAN WHAT OCCURRED TODAY. SOUTH-SOUTHEAST WINDS WILL CONTINUE
TONIGHT AND TUESDAY. BY MIDDAY TUESDAY EXPECT SOUTH WINDS 10-15 KT
OVERALL...WITH GUSTS AT TIMES TO 20 KT AT KABI AND KSJT.

19

PREV DISCUSSION... /ISSUED 350 PM CDT MON JUL 22 2013/

SHORT TERM...
/TONIGHT AND TUESDAY/

A WEAK UPPER LEVEL LOW CURRENTLY OVER NORTHERN CHIHUAHUA WILL
WEAKEN THROUGH TUESDAY AS HIGH PRESSURE ALOFT BEGINS TO BUILD
SOUTHEAST ACROSS THE AREA. WE ARE STILL SEEING AFFECTS FROM THE
UPPER LOW AS MOISTURE REMAINS HIGH AND ISOLATED TO WIDELY
SCATTERED CONVECTION HAS ONCE AGAIN DEVELOPED ACROSS THE AREA THIS
AFTERNOON. KEPT SLIGHT POPS GOING THROUGH EARLY EVENING ACROSS THE
SOUTHERN TWO THIRDS OF THE CWA WITH ISOLATED MENTION ACROSS A
PORTION OF THE BIG COUNTRY. BRIEF HEAVY RAINFALL WILL BE POSSIBLE
ALONG WITH A FEW CLOUD TO GROUND LIGHTNING STRIKES. CONVECTION
WILL DISSIPATE AFTER SUNSET WITH LOSS OF HEATING.

ANOTHER ROUND OF STRATUS WILL DEVELOP ACROSS MAINLY SOUTHERN
SECTIONS TOWARDS DAYBREAK...SCATTERING OUT BY MID MORNING. COULD
STILL SEE AN ISOLATED SHOWER DEVELOP ACROSS SOUTHERN SECTIONS
TUESDAY AFTERNOON BUT WITH HIGH PRESSURE BUILDING IN WILL LEAVE
POPS OUT OF THE FORECAST. LOWS TONIGHT WILL BE IN THE 70S WITH
HIGHS ON TUESDAY RANGING FROM THE LOW TO MID 90S SOUTH TO THE
UPPER 90S NORTH.

24

LONG TERM...
/TUESDAY NIGHT INTO MONDAY/

.HOT AND DRY MIDWEEK THEN A SLIGHT CHANCE OF THUNDERSTORMS FOR
THE BIG COUNTRY FRIDAY...

DISCUSSION...
UPPER RIDGE STRENGTHENS MIDWEEK...TEMPORARILY ENDING RAIN
CHANCES. GFS AND EC MODELS BRING A WEAK COLD FRONT INTO NORTHERN
TEXAS FRIDAY NIGHT. THE GFS MODEL BRINGS IT ALONG THE RED
RIVER... WHILE THE EC HAS BRINGS IT AS FAR SOUTH AS THE
INTERSTATE 20 CORRIDOR. WILL CONTINUE TO MAINTAIN A SLIGHT CHANCE
OF SHOWERS AND THUNDERSTORMS FOR THE BIG COUNTRY FRIDAY AND
FRIDAY NIGHT. HOWEVER...AS UPPER RIDGING WILL NOT BE WEAKENING...
THERE REMAINS CONSIDERABLE UNCERTAINTY IN STORM DEVELOPMENT.

HAVE TRENDED TOWARD A GRADUAL INCREASE IN TEMPERATURES MIDWEEK
WITH DECREASE IN CUMULUS. OVERNIGHT LOWS CONTINUE IN THE LOWER
TO MID 70S.

04

&&

.PRELIMINARY POINT TEMPS/POPS...
ABILENE  74  96  73  96  73 /   5  10   5   5   5
SAN ANGELO  74  96  73  96  72 /  10   5   0   5   0
JUNCTION  74  95  73  96  72 /  10   5   5   0   0

&&

.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

25







AREA FORECAST DISCUSSION

NWS SAN ANGELO TX

 1147 PM CDT SAT JUL 20 2013

.DISCUSSION...

SEE AVIATION DISCUSSION BELOW/

&&

.AVIATION...
MOSTLY VFR CONDITIONS ARE EXPECTED ACROSS THE FORECAST AREA THE
NEXT 24 HOURS.

SHOWERS EARLIER THIS EVENING HAVE DISSIPATED AS NIGHTTIME LAND
SURFACE COOLING HAS STABILIZED THE AIR MASS AND IS HELPING PREVENT
SHOWERS FROM DEVELOPING.

A MODEST SURGE OF SOUTH AND SOUTHEAST WINDS FROM THE GULF OF
MEXICO WILL ADVANCE INTO THE AREA LATE SUNDAY. SOUTH AND SOUTHEAST
WINDS ARE EXPECTED TO INCREASE TO 10 TO 15 MPH WITH A FEW HIGHER
GUSTS BY LATE AFTERNOON SUNDAY. THIS WIND AND MOISTURE SURGE MAY
INITIATE ISOLATED TO POSSIBLY SCATTERED SHOWERS...SPECIALLY
ACROSS AREAS SOUTH OF SAN ANGELO...INCLUDING CROCKETT...SUTTON...
KIMBLE...MASON...MENARD AND SCHLEICHER COUNTIES. THE PRIMARY
AVIATION HAZARD WILL BE THE POSSIBILITY OF LIGHTNING.

&&

.PREV DISCUSSION... /ISSUED 953 PM CDT SAT JUL 20 2013/

UPDATE...
DIURNALLY DRIVEN SHOWERS HAVE DISSIPATED ACROSS WEST CENTRAL TX
BUT WE CONTINUE TO SEE ECHOES ROTATING TO THE NORTHWEST AROUND
THE MID/UPPER LEVEL CYCLONE NEAR THE BIG BEND. POPS WERE REMOVED
ACROSS MOST OF THE FORECAST AREA THROUGH THE REMAINDER OF THE
OVERNIGHT PERIOD BUT I DID RETAIN A SLIGHT CHANCE OF SHOWERS IN
THE SOUTH...MAINLY CROCKETT AND SUTTON COUNTIES DUE TO THE
PROXIMITY OF THIS UPPER LOW. BOTH THE 3K TTU WRF AND HRRR DEPICT
WEAK CONVECTION MOVING INTO THIS AREA AFTER MIDNIGHT.
OTHERWISE...ONLY MINOR MODIFICATIONS WERE MADE TO THE INHERITED
FORECAST.

JOHNSON

PREV DISCUSSION... /ISSUED 633 PM CDT SAT JUL 20 2013/

DISCUSSION...
SEE AVIATION DISCUSSION BELOW/

AVIATION...
CURRENTLY ISOLATED SHOWERS HAVE DEVELOPED ACROSS
MASON...MCCULLOUGH...MENARD...COLEMAN...SHACKELFORD AND SUTTON
COUNTIES. AN ISOLATED SHOWER WAS NOTED JUST NORTH OF SAN ANGELO.
MOST OF THESE SHOWERS ARE EXPECTED TO DISSIPATE AFTER SUNSET.

ON SUNDAY THERE IS POTENTIAL FOR ISOLATED SHOWERS TO REDEVELOP...
CAUSED BY AFTERNOON HEATING THAT WILL CAUSE WARM AIR TO RISE
THROUGH A WEAKLY CAPPED ATMOSPHERE THAT HAS MOIST AIR IN THE
LOWEST 5K FEET. THE MOST LIKELY SHOWER AREAS WILL BE ACROSS
MASON...KIMBLE... SUTTON...MENARD AND SAN SABA COUNTIES.
HOWEVER...MOSTLY VFR CONDITIONS WILL PREVAIL THE NEXT 24 HOURS
ACROSS THE FORECAST AREA.

PREV DISCUSSION... /ISSUED 349 PM CDT SAT JUL 20 2013/

SHORT TERM...
/TONIGHT AND SUNDAY/

ISOLATED BRIEF SHOWERS AND THUNDERSTORMS INTO SUNDAY...

MOIST LOW LEVEL MOISTURE WILL CONTINUE WITH A WEAKLY OR UNCAPPED
ATMOSPHERE INTO SUNDAY. MOST STORMS EXPECTED TO DEVELOP MID AND
LATE AFTERNOON UNDER MAXIMUM HEATING...THEN DISSIPATE AFTER SUNSET.
HOWEVER...A FEW STORMS MAY LAST LONGER OVER SOUTHERN SECTIONS ALONG
THE I-10 CORRIDOR AT NIGHT WHERE THE THE UPPER RIDGE IS WEAKEST.
BRIEF HEAVY RAIN IS POSSIBLE IN SLOW MOVING STORMS.

LONG TERM...
THERE IS A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS
SOUTHERN SECTIONS ON MONDAY WITH DRY AND WARMER WEATHER FOR THE
REMAINDER OF NEXT WEEK.

A WEAK UPPER LEVEL LOW WILL BE SITUATED NEAR THE BIG BEND SUNDAY
EVENING AND WILL DRIFT SOUTHWEST INTO NORTHERN MEXICO BY TUESDAY
AFTERNOON. WE WILL STILL SEE A DECENT AMOUNT OF LOW AND MID LEVEL
MOISTURE AROUND...ESPECIALLY ACROSS SOUTHERN SECTIONS ON MONDAY.
KEPT INHERITED LOW POPS INTACT MAINLY OVER THE NORTHWEST HILL
COUNTRY AND NORTHERN EDWARDS PLATEAU MONDAY AND MONDAY EVENING
WHERE WIDELY SCATTERED SHOWERS AND FEW THUNDERSTORMS WILL BE
POSSIBLE. HIGHS ON MONDAY WILL BE MAINLY IN THE LOW TO MID 90S
WITH A FEW READINGS IN THE UPPER 90S ACROSS THE NORTHERN BIG
COUNTRY.

AN UPPER LEVEL RIDGE WILL BUILD SOUTHEAST ACROSS THE SOUTHERN
ROCKIES AND INTO CENTRAL TEXAS TUESDAY THROUGH THE END OF THE
WEEK. THE ECMWF DOES SHUNT THE RIDGE BACK TO THE WEST FRIDAY
INTO SATURDAY AS A SHORT WAVE DROPS SOUTHEAST FROM THE NORTHERN
ROCKIES...WITH AN ASSOCIATED WEAK COLD FRONT ENTERING THE AREA.
THE GFS MAINTAINS A STRONGER RIDGE WITH THE FRONT REMAINING NORTH
OF THE AREA. KEPT A DRY FORECAST GOING FOR NOW GIVEN THESE MODEL
DISCREPANCIES. HIGH TEMPERATURES WILL WARM FROM THE LOW TO MID 90S
ON TUESDAY...TO THE MID AND UPPER 90S WEDNESDAY THROUGH SATURDAY.
OVERNIGHT LOWS WILL MAINLY BE IN THE LOWER 70S THROUGH THE PERIOD.

&&

.PRELIMINARY POINT TEMPS/POPS...
ABILENE  71  93  72  94  74 /   5  10  10  10  10
SAN ANGELO  70  93  72  94  74 /  10  20  10  20  10
JUNCTION  70  92  72  93  73 /  10  30  20  20  10

&&

.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

99/99/99






AREA FORECAST DISCUSSION

NWS GREEN BAY WI

 1036 PM CDT MON JUL 22 2013

UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE

.UPDATE...
ISSUED AT 407 PM CDT MON JUL 22 2013

FORECAST UPDATED FOR THE SEVERE THUNDERSTORM WATCH WHICH COVERS
MUCH OF THE FORECAST AREA. WILL DEAL WITH THE FOX CITIES AND
LAKESHORE REGION AROUND MID EVENING IF NEEDED.
&&

.SHORT TERM...TONIGHT AND TUESDAY
ISSUED AT 220 PM CDT MON JUL 22 2013

LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A STRONG COLD
FRONT MOVING SOUTHEAST OVER WESTERN LAKE SUPERIOR...WESTERN
WISCONSIN TO NORTHWEST IOWA.  THOUGH UPPER SUPPORT IS LARGELY NORTH
OF LAKE SUPERIOR.  THERE MAY BE A WEAK IMPULSE OVER NORTHWEST
WISCONSIN THAT HELPED CONVECTION FIRE EARLIER THIS AFTERNOON.
THOUGH NOT THE 2500 ML CAPES THAT WERE EXPECTED EARLIER...ML CAPES
HAVE RISEN INTO THE 1500-2000 J/KG RANGE WHICH WILL BE MORE THAN
SUFFICIENT FOR SEVERE STORMS INTO NORTH-CENTRAL WISCONSIN LATER THIS
AFTERNOON...PROVIDED THAT THIS PESKY INHIBITION CAN GET WHITTLED
AWAY.  DESPITE 0-6KM SHEAR OF 35 KTS AND DECENT LOW LEVEL
SHEAR...THE FRONT IS STRUGGLING TO PRODUCE GOOD THUNDERSTORMS EVEN
WITH DEWPOINTS IN THE UPPER 60S AHEAD OF IT.  BUT POTENTIAL WILL
REMAIN FOR SEVERE STORMS TO DEVELOP AS INHIBITION IS FURTHER ERODED.
STORMS SHOULD BE ARRIVING INTO N-C WISCONSIN BY 21Z AND IRON
MOUNTAIN TO WAUSAU BY 00Z.  SEVERE WEATHER IS THE MAIN FORECAST
CONCERN.

TONIGHT...THE COLD FRONT WILL DRIVE SOUTHEAST ACROSS ALL BUT FAR
NORTH-CENTRAL WISCONSIN THIS EVENING...AND EXIT AROUND MIDNIGHT OR
SHORTLY THEREAFTER.  ASSUMING SEVERE STORMS DEVELOP...STORMS SHOULD
BE SURFACE BASED INTO THE EVENING WITH ML CAPES AROUND 1.5-2K J/KG
AND 0-6KM BULK SHEAR VALUES AROUND 30-35KTS.  STORMS SHOULD GROW
MORE ELEVATED WITH TIME THIS EVENING WITH CAPES FALLING AS A
RESULT.  DECENT 0-1KM HELICITY SHOULD BE ABLE TO SUPPORT ROTATING
UPDRAFTS THAT WILL KEEP A FEW STORMS ON THE STRONGER SIDE
THOUGH...SO THE SEVERE THREAT SHOULD CONTINUE INTO THE MID-EVENING
HOURS.  AS STORM INTENSITY GRADUALLY DIMINISHES...THE MAIN THREATS
WILL TRANSITION TO A DAMAGING WIND THREAT...WHICH SHOULD REACH INTO
THE EASTERN SECTIONS OF THE FORECAST AREA LATE IN THE EVENING.
BEHIND THE FRONT...PLENTY OF STRATO-CU UPSTREAM OVER MINNESOTA WILL
ARRIVE LATE TONIGHT.  WILL KEEP PARTLY TO MOSTLY CLOUDY CONDITIONS
GOING THROUGH LATE TONIGHT BEFORE MOISTURE THINS OUT.

TUESDAY...DRIER AIR WILL BE FILTERING SOUTH ACROSS MUCH OF CENTRAL
AND NORTHEAST WISCONSIN DURING THE MORNING...THOUGH LINGERING
MOISTURE OVER THE UPPER PENINSULA AND FAR NORTHERN WISCONSIN MAY
KEEP SCT-BKN STRATO-CU AROUND A LITTLE LONGER THAN FURTHER SOUTH.
NORTHERLY WINDS WILL BE DRIVING IN A COOLER AND LESS HUMID AIRMASS.
HIGH TEMPS WILL ONLY REACH FROM THE UPPER 60S TO MID 70S UNDER
MOSTLY SUNNY TO PARTLY CLOUDY SKIES.

.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
ISSUED AT 220 PM CDT MON JUL 22 2013

UPPER PATTERN DURING PERIOD CHARACTERIZED BY NW UPPER FLOW AND
OCNL SHORTWAVE TROFS MOVING THROUGH MEAN TROF POSITION. EACH
SHORTWAVE TROF--MID WEEK AND END OF THE WEEK--WILL BRING SCATTERED
CONVECTION AND COOLER AIR. STRONGEST OF THE SYSTEMS NEXT WEEKEND
WILL BRING CHILLY AIR INTO STATE ON SATURDAY. WHILE UPPER FLOW IS
CYCLONIC...SURFACE ANTICYCLONE AND DRY LOW-LEVELS SHOULD MINIMIZE
THREAT FOR WIDESPREAD INSTABILITY SHOWERS.

TEMP FORECAST THROUGH THE PERIOD GENERALLY A BLEND OF PREVIOUS
FORECAST AND BEST PERFORMING 22/12Z MODELS. MIN TEMPS WED AM COULD
SLIP TO 40 F IN THE BOGS OF NORTH-CENTRAL WISC.
&&

.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1036 PM CDT MON JUL 22 2013

SCATTERED STORMS ALONG AND NEAR A COLD FRONT WILL
CONTINUE TO PASS OVER PARTS OF EAST CENTRAL WISCONSIN THROUGH
EARLY TUESDAY MORNING. SCATTERED MVFR VSBYS AND CIGS ASSOCIATED
WITH THE SHOWERS AND STORMS. OTHERWISE VFR CONDITIONS TO PREVAIL
OVERNIGHT INTO TUESDAY. A PERIOD OF BKN VFR CIGS POSSIBLE ACROSS
NORTHERN WISCONSIN LATE TUESDAY MORNING INTO THE AFTERNOON.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE.........TDH
SHORT TERM.....MPC
LONG TERM......JKL
AVIATION.......TDH







AREA FORECAST DISCUSSION...UPDATED

NWS MILWAUKEE/SULLIVAN WI

 1027 PM CDT MON JUL 22 2013

.UPDATE...CURRENT CONVECTION ASSOCIATED WITH BOOKEND VORTEX OF
BROKEN LINE OF STORMS EXTENDING SOUTHWARD INTO NORTHERN ILLINOIS.
PASSING 500MB VORTICITY MAXIMUM ALSO LENDING SOME UPWARD VERTICAL
MOTION FOR THE CONVECTION AS WELL. THIS ACTIVITY WILL CONTINUE TO
BE STRONG TO SEVERE AS IT SHIFTS EAST SOUTHEAST ACROSS THE FAR
SOUTHERN COUNTIES NEAR THE ILLINOIS BORDER FOR THE NEXT HOUR OR
TWO...WITH LINGERING MEAN LAYER CAPES OF 1000 TO 2000 J/KG.

OTHER CONVECTION HAS WEAKENED ACROSS THE AREA...WITH SOME STILL
LINGERING AHEAD OF COLD FRONT TO THE NORTH OF THE AREA. COULD
STILL SEE SCATTERED SHOWERS AND A FEW STORMS BEFORE THE COLD FRONT
MOVES SOUTHEAST THROUGH THE AREA AFTER MIDNIGHT.

COLD AIR ADVECTION AFTER FRONTAL PASSAGE LATER TONIGHT WILL BRING
COOLER AND DRIER AIRMASS INTO THE AREA INTO TUESDAY. BRISK NORTH
WINDS WILL BRING TEMPERATURES BELOW SEASONAL NORMALS...ESPECIALLY
NEAR LAKE MICHIGAN.

&&

.AVIATION/06Z TAFS/...VFR CONDITIONS EXPECTED ACROSS TAF SITES
TONIGHT...TUESDAY INTO TUESDAY NIGHT. CURRENT THUNDERSTORM
ACTIVITY NEAR JANESVILLE MAY CLIP KENOSHA IN THE NEXT HOUR OR
TWO...BUT SOME UNCERTAINTY SO REMOVED THUNDER MENTION FOR NOW.
REST OF TAF SITES MAY SEE A FEW SHOWERS OR STORMS BEFORE COLD
FRONT PASSES THROUGH AFTER MIDNIGHT. MVFR/IFR VISIBILITIES ARE
POSSIBLE IN ANY STORMS...BUT KEPT MENTION OUT OF TAFS.

GUSTY NORTH WINDS ARE EXPECTED AFTER COLD FRONTAL PASSAGE LATER
TONIGHT INTO TUESDAY. GUSTS UP TO AROUND 20 KNOTS ARE EXPECTED...A
FEW HIGHER GUSTS ARE POSSIBLE. CLOUDS WILL GRADUALLY MOVE OUT
LATER TONIGHT...WITH SOME DIURNAL CUMULUS CLOUDS POSSIBLE TUESDAY
AFTERNOON. WINDS WILL WEAKEN TUESDAY EVENING...AS HIGH PRESSURE
MOVES INTO THE REGION.

&&

.MARINE...SMALL CRAFT ADVISORY REMAINS IN EFFECT FROM 09Z TUESDAY
UNTIL 21Z WEDNESDAY ACROSS THE NEARSHORE WATERS OF LAKE MICHIGAN.
TIGHT PRESSURE GRADIENT WILL BRING GUSTY NORTH TO NORTHEAST WINDS
ACROSS THIS AREA LATE TONIGHT/TUESDAY INTO TUESDAY EVENING. THE
WINDS WILL THEN SLOWLY WEAKEN. SUBSEQUENT HIGH WAVES ARE EXPECTED
TUESDAY INTO WEDNESDAY...BEFORE SUBSIDING WEDNESDAY AFTERNOON.

&&

.PREV DISCUSSION... /ISSUED 325 PM CDT MON JUL 22 2013/

VERY SHORT TERM...LATE THIS AFTERNOON...TONIGHT AND
TUESDAY...FORECAST CONFIDENCE IS MEDIUM.

MAIN FORECAST ISSUE CONTINUES TO BE AREAL COVERAGE OF STORMS AND
SEVERE RISK WITH PASSAGE OF COLD FRONT LATE THIS AFTERNOON AND THIS
EVENING. LATEST RUNS OF THE HRRR AND WRF 4KM WITH LAPS HIGH
RESOLUTION MODELS SHOW CONVECTION ASSOCIATED WITH THE FRONT MOVING
SOUTHEAST INTO THE NORTHWEST PORTIONS OF THE FORECAST AREA BY 00Z
TUESDAY...THEN FALLING APART AS THEY SHIFT FURTHER
SOUTHEAST...EXITING THE FAR SOUTHEAST COUNTIES BY 05Z TUESDAY.
NAM/GFS/ECMWF/CANADIAN MODELS ALL SHOW QPF WITH THE FRONTAL PASSAGE
THIS EVENING...THOUGH 18Z NAM CONTINUES TO BE SOMEWHAT SLOWER THAN
THE OTHER MODELS WITH ITS PROGRESSION.

SOME QUESTION WITH THE AREAL COVERAGE OF STORMS...AS UPWARD VERTICAL
MOTION WITH FRONT OVER THE AREA IS MODEST COMPARED TO THE NORTHEAST
AND SOUTHWEST. STILL...ENOUGH UPWARD MOTION WITH FRONT AND PASSING
MODEST 500MB VORTICITY MAXIMUM TO BRING SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS THROUGH THE AREA THIS EVENING...ENDING
SOON AFTER MIDNIGHT.

MEAN LAYER CAPES OF 1500 TO 2500 J/KG WITH 20 TO 25 KNOTS OF DEEP
LAYER SHEAR WILL BRING A RISK FOR LARGE HAIL AND DAMAGING WINDS WITH
MAINLY MULTICELL TYPE STRUCTURES. BEST CHANCES WILL REMAIN IN THE
SLIGHT RISK AREA FROM SPC...MAINLY NORTHWEST OF A FOND DU LAC TO
MADISON TO DARLINGTON LINE. THIS IS WHERE THE SOMEWHAT BETTER DEEP
LAYER SHEAR WILL BE LOCATED. LOCALLY HEAVY RAINFALL IS ALSO POSSIBLE
WITH DECENT PRECIPITABLE WATER VALUES.

BRISK NORTH WINDS WITH COLD AIR ADVECTION BEHIND FRONTAL PASSAGE
LATER TONIGHT INTO TUESDAY WILL BRING A COOLER AND DRIER AIRMASS
INTO THE REGION. THIS IS IN ADVANCE OF HIGH PRESSURE MOVING TOWARD
THE REGION FROM THE NORTHWEST. QUIET WEATHER WITH PARTLY CLOUDY
SKIES ARE EXPECTED. BREEZY NORTH WINDS WILL KEEP TEMPERATURES
SOMEWHAT BELOW SEASONAL NORMALS...ESPECIALLY NEAR THE LAKE.

TUESDAY NIGHT THROUGH THURSDAY...FORECAST CONFIDENCE MEDIUM TO HIGH

NW FLOW ALOFT WILL PREVAIL WITH HIGH PRESSURE CENTERED OVER WI FOR
TUE NT AND WED. A WEAK SHORTWAVE TROUGH MAY BRING SCT-BKN MID
LEVEL CLOUDS FOR A TIME WED AFTERNOON AND EVENING. AT MOST...A FEW
SPRINKLES TOWARD CENTRAL WI. THE HIGH THEN SHIFTS INTO THE ERN
GREAT LAKES FOR WED NT AND THU WHILE A SFC TROUGH MOVES INTO NW WI
ON THU. THIS IS AHEAD OF A LARGE UPPER TROUGH THAT IS DIGGING SEWD
INTO SRN MANITOBA AND ONTARIO CANADA. WEAK LOW LEVEL WARM
ADVECTION WILL DEVELOP LATE WED NT AND THU. 925 MB TEMPS YIELD SFC
TEMPS IN THE MID 70S ON WED AND UPPER 70S TO 80F FOR THU.

LONG TERM...

FRIDAY THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM

THE LARGE POLAR TROUGH WILL TRACK ALONG THE NRN GRTLKS AND
CANADIAN BORDER FOR THE WEEKEND. ITS COLD FRONT WILL BRING CHANCES
OF SHOWERS AND TSTORMS FOR FRI AND SAT. VERY PLEASANT AND DRY
SUMMER WX TO PREVAIL AFTERWARD.

AVIATION/00Z TAFS/...VFR CONDITIONS ARE EXPECTED THROUGH LATE THIS
AFTERNOON ACROSS TAF SITES. SOME DIURNAL CUMULUS CLOUDS WILL LINGER
DURING THIS TIME. LAKE BREEZE WILL SHIFT WINDS TO THE SOUTHEAST AT
MILWAUKEE AND KENOSHA BY 21Z TO 22Z MONDAY. MADISON SHOULD SEE LIGHT
SOUTHWEST WINDS.

COLD FRONT WILL SLIDE SOUTHEAST THROUGH TAF SITES BETWEEN 02Z AND
06Z TUESDAY. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE
EXPECTED WITH THE FRONT. A FEW MAY CONTAIN LARGE HAIL AND GUSTY
WINDS...WITH BETTER CHANCE AT MADISON...LOWER CONFIDENCE AT THE
EASTERN SITES. MVFR/IFR VISIBILITIES ARE POSSIBLE WITH ANY STORMS.

VFR CONDITIONS ARE THEN EXPECTED AFTER FRONTAL PASSAGE INTO
TUESDAY. WINDS WILL SHIFT NORTH NORTHWEST AFTER THE FRONTAL
PASSAGE...AND BECOME NORTH NORTHEAST THROUGH TUESDAY. WINDS WILL
BECOME GUSTY WITH COOLER AND DRIER AIR MOVING INTO THE REGION
DURING THIS TIME. GUSTS INTO THE 20 TO 25 KNOT RANGE ARE POSSIBLE.

$$

MARINE...A TIGHT PRESSURE GRADIENT WILL DEVELOP LATE TONIGHT INTO
TUESDAY...AFTER THE COLD FRONTAL PASSAGE. THIS WILL RESULT IN BREEZY
NORTH TO NORTHEAST WINDS ACROSS THE NEARSHORE WATERS. FREQUENT GUSTS
TO 25 KNOTS ARE POSSIBLE LATE TONIGHT INTO TUESDAY NIGHT. THIS
SHOULD CAUSE WAVES TO BECOME HIGH...WITH ONSHORE FLOW AT TIMES. THE
WAVES SHOULD REMAIN HIGH INTO WEDNESDAY BEFORE SUBSIDING WITH WEAKER
WINDS. THUS...A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR LATE
TONIGHT INTO WEDNESDAY.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 4 AM TUESDAY TO 4 PM CDT WEDNESDAY FOR
     LMZ643>646.

&&

$$

UPDATE...WOOD
TONIGHT/TUESDAY AND AVIATION/MARINE...WOOD
TUESDAY NIGHT THROUGH MONDAY...GEHRING







AREA FORECAST DISCUSSION

NWS GREEN BAY WI

 608 PM CDT MON JUL 22 2013

UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE

.UPDATE...
ISSUED AT 407 PM CDT MON JUL 22 2013

FORECAST UPDATED FOR THE SEVERE THUNDERSTORM WATCH WHICH COVERS
MUCH OF THE FORECAST AREA. WILL DEAL WITH THE FOX CITIES AND
LAKESHORE REGION AROUND MID EVENING IF NEEDED.
&&

.SHORT TERM...TONIGHT AND TUESDAY
ISSUED AT 220 PM CDT MON JUL 22 2013

LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A STRONG COLD
FRONT MOVING SOUTHEAST OVER WESTERN LAKE SUPERIOR...WESTERN
WISCONSIN TO NORTHWEST IOWA.  THOUGH UPPER SUPPORT IS LARGELY NORTH
OF LAKE SUPERIOR.  THERE MAY BE A WEAK IMPULSE OVER NORTHWEST
WISCONSIN THAT HELPED CONVECTION FIRE EARLIER THIS AFTERNOON.
THOUGH NOT THE 2500 ML CAPES THAT WERE EXPECTED EARLIER...ML CAPES
HAVE RISEN INTO THE 1500-2000 J/KG RANGE WHICH WILL BE MORE THAN
SUFFICIENT FOR SEVERE STORMS INTO NORTH-CENTRAL WISCONSIN LATER THIS
AFTERNOON...PROVIDED THAT THIS PESKY INHIBITION CAN GET WHITTLED
AWAY.  DESPITE 0-6KM SHEAR OF 35 KTS AND DECENT LOW LEVEL
SHEAR...THE FRONT IS STRUGGLING TO PRODUCE GOOD THUNDERSTORMS EVEN
WITH DEWPOINTS IN THE UPPER 60S AHEAD OF IT.  BUT POTENTIAL WILL
REMAIN FOR SEVERE STORMS TO DEVELOP AS INHIBITION IS FURTHER ERODED.
STORMS SHOULD BE ARRIVING INTO N-C WISCONSIN BY 21Z AND IRON
MOUNTAIN TO WAUSAU BY 00Z.  SEVERE WEATHER IS THE MAIN FORECAST
CONCERN.

TONIGHT...THE COLD FRONT WILL DRIVE SOUTHEAST ACROSS ALL BUT FAR
NORTH-CENTRAL WISCONSIN THIS EVENING...AND EXIT AROUND MIDNIGHT OR
SHORTLY THEREAFTER.  ASSUMING SEVERE STORMS DEVELOP...STORMS SHOULD
BE SURFACE BASED INTO THE EVENING WITH ML CAPES AROUND 1.5-2K J/KG
AND 0-6KM BULK SHEAR VALUES AROUND 30-35KTS.  STORMS SHOULD GROW
MORE ELEVATED WITH TIME THIS EVENING WITH CAPES FALLING AS A
RESULT.  DECENT 0-1KM HELICITY SHOULD BE ABLE TO SUPPORT ROTATING
UPDRAFTS THAT WILL KEEP A FEW STORMS ON THE STRONGER SIDE
THOUGH...SO THE SEVERE THREAT SHOULD CONTINUE INTO THE MID-EVENING
HOURS.  AS STORM INTENSITY GRADUALLY DIMINISHES...THE MAIN THREATS
WILL TRANSITION TO A DAMAGING WIND THREAT...WHICH SHOULD REACH INTO
THE EASTERN SECTIONS OF THE FORECAST AREA LATE IN THE EVENING.
BEHIND THE FRONT...PLENTY OF STRATO-CU UPSTREAM OVER MINNESOTA WILL
ARRIVE LATE TONIGHT.  WILL KEEP PARTLY TO MOSTLY CLOUDY CONDITIONS
GOING THROUGH LATE TONIGHT BEFORE MOISTURE THINS OUT.

TUESDAY...DRIER AIR WILL BE FILTERING SOUTH ACROSS MUCH OF CENTRAL
AND NORTHEAST WISCONSIN DURING THE MORNING...THOUGH LINGERING
MOISTURE OVER THE UPPER PENINSULA AND FAR NORTHERN WISCONSIN MAY
KEEP SCT-BKN STRATO-CU AROUND A LITTLE LONGER THAN FURTHER SOUTH.
NORTHERLY WINDS WILL BE DRIVING IN A COOLER AND LESS HUMID AIRMASS.
HIGH TEMPS WILL ONLY REACH FROM THE UPPER 60S TO MID 70S UNDER
MOSTLY SUNNY TO PARTLY CLOUDY SKIES.

.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
ISSUED AT 220 PM CDT MON JUL 22 2013

UPPER PATTERN DURING PERIOD CHARACTERIZED BY NW UPPER FLOW AND
OCNL SHORTWAVE TROFS MOVING THROUGH MEAN TROF POSITION. EACH
SHORTWAVE TROF--MID WEEK AND END OF THE WEEK--WILL BRING SCATTERED
CONVECTION AND COOLER AIR. STRONGEST OF THE SYSTEMS NEXT WEEKEND
WILL BRING CHILLY AIR INTO STATE ON SATURDAY. WHILE UPPER FLOW IS
CYCLONIC...SURFACE ANTICYCLONE AND DRY LOW-LEVELS SHOULD MINIMIZE
THREAT FOR WIDESPREAD INSTABILITY SHOWERS.

TEMP FORECAST THROUGH THE PERIOD GENERALLY A BLEND OF PREVIOUS
FORECAST AND BEST PERFORMING 22/12Z MODELS. MIN TEMPS WED AM COULD
SLIP TO 40 F IN THE BOGS OF NORTH-CENTRAL WISC.
&&

.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 608 PM CDT MON JUL 22 2013

LINE OF STORMS DEVELOPING ALONG AND AHEAD OF A COLD
FRONT WHICH AT 430 PM THIS AM EXTENDS FROM AROUND ASHLAND TO
LACROSSE. ISOLATED SEVERE STORMS POSSIBLE OVER CENTRAL AND NORTH
CENTRAL WISCONSIN THROUGH EARLY EVENING. STORMS WILL BE PASSING
OVER NORTH CENTRAL AND CENTRAL WISCONSIN THROUGH 8 PM AND THEN
TOWARD EAST CENTRAL WISCONSIN INCLUDING THE LAKESHORE TOWARD 10
PM. VFR CONDITIONS IN THE FRONTS WAKE AS DRIER AIR ON NORTHWEST
WINDS POUR INTO THE REGION. LATER TUESDAY MORNING...VFR CIGS WILL
WRAP INTO NORTHWEST WISCONSIN AND MAY REACH NORTH CENTRAL
WISCONSIN.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE.........TDH
SHORT TERM.....MPC
LONG TERM......JKL
AVIATION.......TDH







AREA FORECAST DISCUSSION

NWS GREEN BAY WI

 532 PM CDT SUN JUL 21 2013

UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE

.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 330 PM CDT SUN JUL 21 2013

LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A COUPLE
SHORTWAVES UPSTREAM...ONE OVER WESTERN WISCONSIN WHICH IS
RESPONSIBLE FOR THE CLUSTER OF SHOWERS AND STORMS MOVING OVER
CENTRAL WISCONSIN...AND ANOTHER OVER IOWA.  MAINLY THE SOUTHERN
PORTION OF THE FORECAST AREA WILL BE IMPACTED WITH THESE STORMS FOR
THE REST OF THE AFTERNOON...BUT NO SEVERE WEATHER IS EXPECTED.
FURTHER UPSTREAM...THE NEXT SHORTWAVE IS PRODUCING STORMS OVER FAR
SOUTH-CENTRAL CANADA AND NORTHERN NORTH DAKOTA WHICH WILL ARRIVE
TOMORROW.  PRECIP CHANCES FOR THE REST OF TODAY AND SEVERE WEATHER
CHANCES TOMORROW ARE THE MAIN FORECAST CONCERNS.

TONIGHT...SHORTWAVE IMPULSES MOVING EAST ACROSS THE REGION WILL TAKE UNTIL
MID TO LATE EVENING TO EXIT.  AS A RESULT...POTENTIAL WILL BE THERE
FOR ISOLATED TO SCATTERED THUNDERSTORMS UNTIL THEN OVER THE SOUTHERN
FORECAST AREA...EVEN THOUGH THE MAIN CLUSTER WILL HAVE PROBABLY
EXITED BY THE START OF THE EVENING.  PLENTY OF CLEARING OCCURRING
UPSTREAM OF THE SHORTWAVES...THOUGH MODELS DEPICT WEAK ISENTROPIC
ASCENT CONTINUING THROUGH THE NIGHT.  AM THINKING WILL SEE A PERIOD
OF SUBSIDENCE BEHIND THE WAVE...WHICH COULD LEAD TO A SEVERAL HOURS
OF MOSTLY CLEAR TO PARTLY CLOUDY CONDITIONS.  NOT SURE HOW LONG THIS
WILL LAST...BUT 850MB THETAE ADVECTION DOES RAMP UP LATE AHEAD OF
THE SHORTWAVE CURRENTLY MOVING INTO NORTHERN NORTH DAKOTA.  NOT OUT
OF THE QUESTION THAT CONVECTION COULD APPROACH N-C WISCONSIN LATE
TONIGHT.  SO WILL SHOW INCREASING CLOUDS AFTER MIDNIGHT ALONG WITH
SLIGHT CHANCE TO CHANCE POPS OVER CENTRAL AND NORTH-CENTRAL
WISCONSIN.  LOWS MAINLY IN THE MID 50S TO LOW 60S.

MONDAY...THE NORTH DAKOTA SHORTWAVE WILL MOVE ACROSS NORTHERN
WISCONSIN DURING THE MORNING.  BOTH THE NAM AND GFS SHOW A DECENT
WIND SHIFT OCCURRING AT 700MB SO WOULD NOT BE SURPRISED TO SEE SOME
CONVECTION MOVE ACROSS THE NORTH.  THEN A STRONG SHORTWAVE OVER
WESTERN ONTARIO WILL DRIVE A COLD FRONT ACROSS NORTHWEST WISCONSIN
DURING THE AFTERNOON.  DEPENDING UPON IF PRECIP OCCURS OVER NORTHERN
WISCONSIN AND HOW MUCH DESTABILIZATION CAN OCCUR WITH AMPLE CLOUD
COVER...MODIFYING PROGGED SOUNDINGS NEAR RHINELANDER FOR AN 80F/64F
PARCEL YIELDS 1700 J/KG OF ML CAPE AT 21Z.  WITH 0-6KM BULK SHEAR
VALUES OF 30-35KTS...POTENTIAL WILL BE THERE FOR SEVERE STORMS
TOMORROW AFTERNOON OVER N-C AND POSSIBLY CENTRAL WISCONSIN TOO. WARM
ADVECTION AHEAD OF THE FRONT WILL PUSH HIGHS TO THE UPPER 70S AND MID
80S.

.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 330 PM CDT SUN JUL 21 2013

NOT MUCH CHANGE IN THE OVERALL FORECAST FOR THIS PERIOD AS
SHORTWAVE TROFS MOVE THROUGH MEAN TROF POSITION ACROSS GREAT
LAKES. LATEST GFS AND ECMWF IN GENERAL AGREEMENT THROUGH MOST OF
PERIOD ON STRENGTH AND TIMING OF SYSTEMS.

TEMPS WILL BE AOB NORMAL FOR MUCH OF WEEK...AFTER MONDAY. IN
FACT...HIGHS NEXT WEEKEND MAY STRUGGLE TO REACH 70 ACROSS PARTS OF
THE NORTH AS NW FLOW IS REINFORCED BEHIND LATE WEEK SYSTEM.
&&

.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 516 PM CDT SUN JUL 21 2013

AREAS OF MVFR CIGS WILL SPREAD INTO CENTRAL AND NORTH CENTRAL
WISCONSIN THROUGH THIS EVENING AND POSSIBLY OVER EAST CENTRAL
WISCONSIN OVERNIGHT AS A SHORT WAVE TRACKS SOUTHEAST OF SOUTHEAST
WISCONSIN. RETURN FLOW DEVELOPS OVERNIGHT WHICH COULD LEAD TO MORE
MVFR CIGS OVER THE REGION. IF THESE MVFR CIGS BECOME MORE WIDESPREAD
OVERNIGHT...MAY LINGER INTO MONDAY MORNING UNTIL MIXING LIFTS
CIGS TO VFR LEVELS AHEAD OF AN APPROACHING COLD FRONT. SCATTERED MVFR
CIGS AND VSBYS DUE TO SHOWERS AND STORMS LIKELY ALONG THIS FRONT
STARTING MONDAY AFTERNOON OVER NORTHWEST WISCONSIN BEFORE REACHING
SOUTHEAST WISCONSIN MONDAY NIGHT.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM.....MPC
LONG TERM......JKL
AVIATION.......TDH








FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE



 .SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 330 PM CDT SUN JUL 21 2013

LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A COUPLE
SHORTWAVES UPSTREAM...ONE OVER WESTERN WISCONSIN WHICH IS
RESPONSIBLE FOR THE CLUSTER OF SHOWERS AND STORMS MOVING OVER
CENTRAL WISCONSIN...AND ANOTHER OVER IOWA.  MAINLY THE SOUTHERN
PORTION OF THE FORECAST AREA WILL BE IMPACTED WITH THESE STORMS FOR
THE REST OF THE AFTERNOON...BUT NO SEVERE WEATHER IS EXPECTED.
FURTHER UPSTREAM...THE NEXT SHORTWAVE IS PRODUCING STORMS OVER FAR
SOUTH-CENTRAL CANADA AND NORTHERN NORTH DAKOTA WHICH WILL ARRIVE
TOMORROW.  PRECIP CHANCES FOR THE REST OF TODAY AND SEVERE WEATHER
CHANCES TOMORROW ARE THE MAIN FORECAST CONCERNS.

TONIGHT...SHORTWAVE IMPULSES MOVING EAST ACROSS THE REGION WILL TAKE UNTIL
MID TO LATE EVENING TO EXIT.  AS A RESULT...POTENTIAL WILL BE THERE
FOR ISOLATED TO SCATTERED THUNDERSTORMS UNTIL THEN OVER THE SOUTHERN
FORECAST AREA...EVEN THOUGH THE MAIN CLUSTER WILL HAVE PROBABLY
EXITED BY THE START OF THE EVENING.  PLENTY OF CLEARING OCCURRING
UPSTREAM OF THE SHORTWAVES...THOUGH MODELS DEPICT WEAK ISENTROPIC
ASCENT CONTINUING THROUGH THE NIGHT.  AM THINKING WILL SEE A PERIOD
OF SUBSIDENCE BEHIND THE WAVE...WHICH COULD LEAD TO A SEVERAL HOURS
OF MOSTLY CLEAR TO PARTLY CLOUDY CONDITIONS.  NOT SURE HOW LONG THIS
WILL LAST...BUT 850MB THETAE ADVECTION DOES RAMP UP LATE AHEAD OF
THE SHORTWAVE CURRENTLY MOVING INTO NORTHERN NORTH DAKOTA.  NOT OUT
OF THE QUESTION THAT CONVECTION COULD APPROACH N-C WISCONSIN LATE
TONIGHT.  SO WILL SHOW INCREASING CLOUDS AFTER MIDNIGHT ALONG WITH
SLIGHT CHANCE TO CHANCE POPS OVER CENTRAL AND NORTH-CENTRAL
WISCONSIN.  LOWS MAINLY IN THE MID 50S TO LOW 60S.

MONDAY...THE NORTH DAKOTA SHORTWAVE WILL MOVE ACROSS NORTHERN
WISCONSIN DURING THE MORNING.  BOTH THE NAM AND GFS SHOW A DECENT
WIND SHIFT OCCURRING AT 700MB SO WOULD NOT BE SURPRISED TO SEE SOME
CONVECTION MOVE ACROSS THE NORTH.  THEN A STRONG SHORTWAVE OVER
WESTERN ONTARIO WILL DRIVE A COLD FRONT ACROSS NORTHWEST WISCONSIN
DURING THE AFTERNOON.  DEPENDING UPON IF PRECIP OCCURS OVER NORTHERN
WISCONSIN AND HOW MUCH DESTABILIZATION CAN OCCUR WITH AMPLE CLOUD
COVER...MODIFYING PROGGED SOUNDINGS NEAR RHINELANDER FOR AN 80F/64F
PARCEL YIELDS 1700 J/KG OF ML CAPE AT 21Z.  WITH 0-6KM BULK SHEAR
VALUES OF 30-35KTS...POTENTIAL WILL BE THERE FOR SEVERE STORMS
TOMORROW AFTERNOON OVER N-C AND POSSIBLY CENTRAL WISCONSIN TOO. WARM
ADVECTION AHEAD OF THE FRONT WILL PUSH HIGHS TO THE UPPER 70S AND MID
80S.

.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 330 PM CDT SUN JUL 21 2013

NOT MUCH CHANGE IN THE OVERALL FORECAST FOR THIS PERIOD AS
SHORTWAVE TROFS MOVE THROUGH MEAN TROF POSITION ACROSS GREAT
LAKES. LATEST GFS AND ECMWF IN GENERAL AGREEMENT THROUGH MOST OF
PERIOD ON STRENGTH AND TIMING OF SYSTEMS.

TEMPS WILL BE AOB NORMAL FOR MUCH OF WEEK...AFTER MONDAY. IN
FACT...HIGHS NEXT WEEKEND MAY STRUGGLE TO REACH 70 ACROSS PARTS OF
THE NORTH AS NW FLOW IS REINFORCED BEHIND LATE WEEK SYSTEM.
&&

.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1223 PM CDT SUN JUL 21 2013

A SHOWER AND THUNDERSTORM COMPLEX WILL MARCH EAST ACROSS
CENTRAL AND EAST-CENTRAL WISCONSIN THIS AFTERNOON.  VSBYS AND CIGS
TO FALL TO MVFR LEVELS WITHIN THE THUNDERSTORMS...BUT STRONG GUSTY
WINDS OR LARGE HAIL WILL NOT OCCUR.  BEHIND THE THUNDERSTORM
COMPLEX...SATELLITE IMAGES SHOW MOSTLY CLEAR CONDITIONS UNTIL YOU
REACH NORTH DAKOTA.  AS A RESULT...THINK WILL SEE A PERIOD OF MOSTLY
CLEAR TO SCT SKY CONDITIONS AFTER THE THUNDERSTORMS DEPART...UNTIL
CLOUDS INCREASE LATE TONIGHT.  THE DISTURBANCE JUST NORTH OF NORTH
DAKOTA COULD BRING THUNDER TO NORTH-CENTRAL WISCONSIN TOMORROW
MORNING...BUT CONFIDENCE IS NOT THERE TO INCLUDE IN THE TAFS AT THIS
TIME.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM.....MPC
LONG TERM......JKL
AVIATION.......MPC







AREA FORECAST DISCUSSION

NWS LA CROSSE WI

 105 PM CDT SUN JUL 21 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 300 AM CDT SUN JUL 21 2013

CURRENTLY AS OF 08Z...
WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS LOOKED VERY SIMILAR
TO THIS TIME YESTERDAY...CONSISTING OF NORTHWEST FLOW FROM BRITISH
COLUMBIA INTO THE GREAT LAKES REGION...NUMEROUS SHORTWAVES RIDING
THROUGH THE FLOW...AND TROUGHING OVER SOUTHEAST CANADA. MOST OF THE
SHORTWAVES ARE WEAK EXCEPT FOR A MORE IMPRESSIVE ONE OVER CENTRAL
ALBERTA. THE MAIN SHORTWAVE OF INTEREST IN THE SHORT TERM IS
ORIGINATING OUT OF CONVECTION OVER SOUTHEAST SD AND EASTERN
NEBRASKA. AIRMASS OVER THE FORECAST AREA VARIES GREATLY FROM SOUTH
TO NORTH WITH I-94 BEING A GREAT DIVIDING LINE. TO THE NORTH...DRIER
AIR CHARACTERIZED BY SURFACE DEWPOINTS IN THE 40S AND LOW 50S WAS
PRESENT. FARTHER UP TO THE NORTH...THE 00Z INL SOUNDING REPORTED A
PRECIPITABLE WATER VALUE OF 0.49 INCHES. NOW...SOUTH AND WEST OF
I-94...DEWPOINTS ARE IN THE 60S. THE 00Z SOUNDINGS FROM MPX AND DVN
HAD PRECIPITABLE WATER VALUES AROUND 1.15 INCHES. SEPARATING THESE
TWO AIRMASSES IS A STATIONARY FRONTAL BOUNDARY. ISOLATED
SHOWERS/STORMS HAVE BEEN POPPING UP ALONG/NORTH OF THE BOUNDARY ALL
NIGHT.

SYNOPTIC OVERVIEW...
NORTHWEST FLOW CONTINUES THROUGH THE SHORT TERM PERIOD. THE
CONVECTIVELY INDUCED SHORTWAVE TROUGH APPROACHING SIOUX CITY IA AT
08Z MODELS ARE STRUGGLING WITH GREATLY. MOST MODELS...INCLUDING HI
RESOLUTION RUNS SUCH AS THE HRRR AND HIRES-ARW ARE TOO SLOW.
EXTRAPOLATION HAS THE MCV CROSSING MUCH OF IOWA THIS MORNING.
POTENTIAL THEN EXISTS FOR SOME VERY WEAK RIDGING IN ITS WAKE FOR
THIS AFTERNOON AND TONIGHT...AHEAD OF THE CURRENT ALBERTA SHORTWAVE
WHICH DIGS INTO NORTHERN MN AND WESTERN ONTARIO BY 12Z MONDAY.

TODAY...
DESPITE THIS PERIOD BEING THE BEGINNING OF THE FORECAST...THE
UNCERTAINTY IS QUITE HIGH. MUCH OF THIS UNCERTAINTY STEMS FROM THE
TOO SLOW HANDLING FROM ALL MODELS REGARDING THE MCV APPROACHING
SIOUX CITY IA AS OF 08Z. GENERALLY FOLLOWED AN EXTRAPOLATION
APPROACH COMBINED WITH A SOMEWHAT SPED UP 21.05Z HRRR FORECAST TO
COME UP WITH THE FORECAST TODAY. THE PLAN IS THAT THE MCV SHOULD
TRACK ACROSS DES MOINES AND DAVENPORT THIS MORNING...WITH THE
FORECAST AREA ON THE NORTH SIDE. SHOWERS AND A FEW EMBEDDED
THUNDERSTORMS APPEAR LIKELY...PRIMARILY WEST OF THE MISSISSIPPI
RIVER DURING THE MORNING HOURS. CONCERNED THAT THE DIURNAL EFFECTS
ON LOW LEVEL MOISTURE TRANSPORT MAY CAUSE THE SHOWERS TO WEAKEN SOME
AS WE APPROACH MID-DAY...THUS THE HIGHER CHANCES TO THE WEST. DURING
THE AFTERNOON...IT IS HARD TO SAY WHATS GOING TO OCCUR. WE COULD
EASILY BE IN SUBSIDENCE IN THE WAKE OF THE MCV...PREVENTING MUCH IN
THE WAY OF ADDITIONAL PRECIPITATION.  ON THE OTHER HAND...THE
AFTERNOON IS PEAK HEATING AND WITH HIGHER DEWPOINTS TODAY...WE
SHOULD BE ABLE TO BUILD 500-1500 J/KG OF CAPE AS SUGGESTED BY THE
RAP. ANY SHORTWAVE COMING THROUGH THE NORTHWEST FLOW THATS HARD TO
DISCERN AT THIS TIME COULD KICK OFF SHOWERS AND STORMS. ADDITIONALLY
WE SHOULD STILL HAVE THAT STATIONARY FRONTAL BOUNDARY IN THE
FORECAST AREA TO PROVIDE WEAK LOW LEVEL CONVERGENCE. THEREFORE...
HAVE MAINTAINED AT LEAST 40-50 PERCENT CHANCES FOR THE AFTERNOON.
REGARDING TEMPERATURES...ASSUMING SOME SUN TODAY WHICH SHOULD
OCCUR...925MB TEMPS IN THE 18-20C RANGE SUPPORTS HIGHS IN THE 70S TO
NEAR 80.

TONIGHT...
ANY CONVECTION THAT OCCURS THIS AFTERNOON WILL LIKELY HAVE A STRONG
DIURNAL COMPONENT TO IT. THEREFORE...HAVE PRECIPITATION CHANCES
DIMINISHING THROUGH THE EVENING HOURS. HOWEVER...850MB MOISTURE
TRANSPORT DOES INCREASE THROUGH THE NIGHT AHEAD OF THE STRONGER
SHORTWAVE DROPPING INTO NORTHERN MN. CONVECTION WILL LIKELY FORM ON
THE NOSE OF THIS MOISTURE TRANSPORT...WHICH IS FORECAST FROM
NORTHERN MN INTO NORTHERN WI. KEPT SOME 20 PERCENT CHANCES OVERNIGHT
BOTH OVER TAYLOR/CLARK COUNTIES FOR THE NOSE OF THIS MOISTURE
TRANSPORT. ALSO KEPT THE 20 PERCENT CHANCES OVERNIGHT FOR THE
EASTERN HALF OF THE FORECAST AREA...IN THE EVENT ANY DIURNAL
CONVECTION CAN SURVIVE...THOUGH AS THE CHANCE STATES THE CONFIDENCE
IS LOW.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 300 AM CDT SUN JUL 21 2013

SYNOPTIC OVERVIEW...
20.00Z ECMWF/GFS/CANADIAN ALL CONTINUE THE NORTHWEST FLOW PATTERN
THROUGH THE ENTIRE LONG TERM PERIOD. WHAT LOOKED TO BE A POSSIBILITY
OF RIDGING BUILDING TOWARDS THE AREA BRIEFLY THURSDAY INTO FRIDAY IS
NOW COMPLETELY GONE. PART OF THE REASON WE STAY IN NORTHWEST FLOW IS
THE DEVELOPMENT OF AN OMEGA BLOCK OVER WESTERN CANADA BETWEEN
TUESDAY AND WEDNESDAY...WHICH DOES NOT SHOW ANY SIGNS OF BREAKING
DOWN FOR AWHILE. ADDITIONALLY...THERE APPEARS TO BE SOME MODEL
STRUGGLES HANDLING SHORTWAVE TROUGHING COMING DOWN THE EAST SIDE OF
THE OMEGA BLOCK...WHICH PUTS MORE UNCERTAINTY FOR THE FORECAST
THURSDAY AND BEYOND. ONE THING THAT IS STARTING TO BECOME A LITTLE
MORE EVIDENT IS FOR DEEPER TROUGHING OVER THE GREAT LAKES REGION AT
THE END OF NEXT WEEKEND. 500MB STANDARDIZED ANOMALIES FOR 12Z SUNDAY
FROM THE ECMWF/GFS ARE 1.5-2 BELOW NORMAL.

HAZARDS...
THERE COULD BE SOME ISOLATED SEVERE WEATHER LATE MONDAY AFTERNOON
INTO THE EVENING HOURS...ASSOCIATED WITH A COLD FRONT COMING
THROUGH...BUT CONFIDENCE IS LOW AS DESCRIBED BELOW.

MONDAY THROUGH TUESDAY NIGHT...
MUCH OF THE FOCUS HERE IS ON THE MONDAY/MONDAY NIGHT PERIOD.
SHORTWAVE TROUGH OVER NORTHERN MN AND WESTERN ONTARIO AT 12Z MONDAY
MODELS ALL AGREE ON SLIDING IT ACROSS NORTHERN ONTARIO. AS THIS
OCCURS...A COLD FRONT ASSOCIATED WITH IT APPROACHES THE FORECAST
AREA. TIMING ON THIS FRONT VARIES GREATLY. AT 00Z TUESDAY...TIMING
VARIES FROM THE 21.00Z HIRES-ARW HAVING IT WEST OF MINNEAPOLIS TO
THE 21.00Z ECMWF/GFS OVER MINNEAPOLIS AND THE 21.00Z
CANADIAN/NAM/UKMET WHICH ARE OVER LA CROSSE. TRENDS AT LEAST FROM
THE ECMWF/GFS SUGGEST A SLOWER APPROACH MAY BE THE WAY TO GO. THERE
STILL REMAINS UNCERTAINTY ON CONVECTIVE CHANCES WITH THIS
FRONT...

1. A WARM SURGE OF AIR AT 800MB IS STILL INDICATED TO COME OVER THE
FRONT TO PROVIDING POTENTIAL CAPPING
2. THE SHORTWAVE TROUGH SLIDING ACROSS NORTHERN ONTARIO COULD END UP
PUTTING RIDGING OVER THE FRONT FOR THE AFTERNOON AS SUGGESTED BY THE
21.00Z HIRES-ARW.
3. LOW LEVEL CONVERGENCE ON THE FRONT REMAINS IN QUESTION.
4. NOW THE FRONT BEING SLOWER...NOT COMING ACROSS THE FORECAST AREA
AT PEAK HEATING...COULD BE A NEGATIVE FOR PRECIP.

TO ACCOUNT FOR THE SLOWER TREND HAVE LOWERED PRECIPITATION CHANCES
SOME MONDAY AFTERNOON. LEFT THE 40-60 PERCENT CHANCES FOR MONDAY
EVENING AS THAT IS STILL FAIRLY WELL AGREED UPON BY GUIDANCE...THEN
CHANCES DIMINISHING AFTER MIDNIGHT WITH LOSS OF HEATING AND THE
FRONT PROGRESSING THROUGH THE AREA. DRY WEATHER FOLLOWS IN THE WAKE
OF THE FRONT FOR TUESDAY AND TUESDAY NIGHT WHILE HIGH PRESSURE
BUILDS IN AT THE SURFACE. 925MB TEMPS CLIMBING TO 21-24C AHEAD OF
THE FRONT ON MONDAY PLUS SUNSHINE WILL ALLOW HIGHS TO CLIMB INTO THE
80S. MAY EVEN SEE 90 IN A FEW SPOTS IF MORE SUN OCCURS. MONDAY LOOKS
HUMID AS WELL AS NEAR 70 DEGREE DEWPOINTS ADVECT IN AT THE SURFACE.
COOLER HIGHS ON THE WAY FOR TUESDAY AS 925MB TEMPS TUMBLE TO 17-20C.
TUESDAY NIGHT LOWS HAVE POTENTIAL TO GET INTO THE 40S AT THE TYPICAL
COLDER SPOTS...DUE TO LIGHT WINDS AND PRECIPITABLE WATER VALUES
FALLING TO 0.5-0.75 INCHES.

WEDNESDAY THROUGH SATURDAY NIGHT...
20.00Z ECMWF/GFS/CANADIAN ARE SUGGESTING NUMEROUS WEAK SHORTWAVES
DROP SOUTHEAST ACROSS THE FORECAST AREA WEDNESDAY THROUGH THURSDAY
IN THE NORTHWEST FLOW ALOFT. HARD TO SAY IF ANY OF THESE ARE GOING
TO DO ANYTHING PRECIP WISE. 20.00Z CANADIAN AND 19.12Z ECMWF WANT TO
BRING SOME SHOWERS ACROSS WEDNESDAY NIGHT AND THURSDAY...THOUGH THE
20.00Z ECMWF BACKED OFF. WOULD THINK A DRIER SCENARIO IS MORE LIKELY
GIVEN THE DRY AIRMASS COMING IN TUESDAY NIGHT/WEDNESDAY WITH
CANADIAN HIGH PRESSURE IN PLACE. NEVERTHELESS...DID HONOR A 20
PERCENT CHANCE MAINLY ON THURSDAY JUST IN CASE. CHANCES INCREASE A
LITTLE FOR THURSDAY NIGHT AND FRIDAY WHERE IT APPEARS A COLD FRONT
WILL CROSS THE AREA...ASSOCIATED WITH A POTENT UPPER TROUGH DROPPING
OVER MANITOBA AND NORTHERN ONTARIO. SOME OF THIS UPPER TROUGH LOOKS
TO SWING ACROSS THE FORECAST AREA FRIDAY NIGHT AND SATURDAY...THUS
STILL NEED TO CONTINUE AT LEAST 20 PERCENT CHANCES. BEING IN THIS
NORTHWEST FLOW PATTERN COMBINED WITH EVEN DEEPER TROUGHING FORMING
OVER THE WEEKEND SUGGESTS BELOW NORMAL TEMPERATURES. BY 12Z
SUNDAY...BOTH THE 20.00Z ECMWF AND GFS DEPICT 850MB TEMPS FALLING TO
6-9C...CHILLY RELATIVELY SPEAKING FOR THE END OF JULY.

&&

.AVIATION...THROUGH 18Z MONDAY
105 PM CDT SUN JUL 21 2013

MESOSCALE VORTICITY MAX SPINNING INTO NORTHEAST IA EARLY THIS
AFTERNOON AND HELPING TO ENHANCE SHOWERS AND THUNDERSTORMS ACROSS
THE LOCAL AREA. LOOKS LIKE THUNDER WILL REMAIN NORTH OF BOTH TAF
LOCATIONS FOR THE MOST PART. CANNOT COMPLETELY RULE OUT A RUMBLE
OF THUNDER...BUT CHANCE IS SO SMALL THAT IT WAS NOT INCLUDED IN
THE TAFS. ONCE THE MCV MOVES PAST...ANTICIPATE THAT THE SHOWER
ACTIVITY WILL DISSIPATE. SOME MODELS DO INDICATE THAT ADDITIONAL
DEVELOPMENT WILL OCCUR...BUT DO NOT FEEL THIS WILL IMPACT EITHER
TAF LOCATION.

WITH RAIN TODAY...AND GENERALLY WEAK FLOW OVERNIGHT...ANTICIPATE
SOME LIGHT FOG/MIST TO FORM. MAINTAINED MENTION IN THE FORECASTS.

NEXT DISTURBANCE AND ASSOCIATED COLD FRONT WILL MOVE THROUGH
DURING THE AFTERNOON HOURS ON MONDAY. LATER TAF ISSUANCES WILL
HAVE TO ACCOUNT FOR CONVECTIVE POTENTIAL NEAR AND AHEAD OF THE
FRONT.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.

&&

$$

SHORT TERM...AJ
LONG TERM...AJ
AVIATION...MW







AREA FORECAST DISCUSSION

NWS LA CROSSE WI

 622 AM CDT SUN JUL 21 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 300 AM CDT SUN JUL 21 2013

CURRENTLY AS OF 08Z...
WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS LOOKED VERY SIMILAR
TO THIS TIME YESTERDAY...CONSISTING OF NORTHWEST FLOW FROM BRITISH
COLUMBIA INTO THE GREAT LAKES REGION...NUMEROUS SHORTWAVES RIDING
THROUGH THE FLOW...AND TROUGHING OVER SOUTHEAST CANADA. MOST OF THE
SHORTWAVES ARE WEAK EXCEPT FOR A MORE IMPRESSIVE ONE OVER CENTRAL
ALBERTA. THE MAIN SHORTWAVE OF INTEREST IN THE SHORT TERM IS
ORIGINATING OUT OF CONVECTION OVER SOUTHEAST SD AND EASTERN
NEBRASKA. AIRMASS OVER THE FORECAST AREA VARIES GREATLY FROM SOUTH
TO NORTH WITH I-94 BEING A GREAT DIVIDING LINE. TO THE NORTH...DRIER
AIR CHARACTERIZED BY SURFACE DEWPOINTS IN THE 40S AND LOW 50S WAS
PRESENT. FARTHER UP TO THE NORTH...THE 00Z INL SOUNDING REPORTED A
PRECIPITABLE WATER VALUE OF 0.49 INCHES. NOW...SOUTH AND WEST OF
I-94...DEWPOINTS ARE IN THE 60S. THE 00Z SOUNDINGS FROM MPX AND DVN
HAD PRECIPITABLE WATER VALUES AROUND 1.15 INCHES. SEPARATING THESE
TWO AIRMASSES IS A STATIONARY FRONTAL BOUNDARY. ISOLATED
SHOWERS/STORMS HAVE BEEN POPPING UP ALONG/NORTH OF THE BOUNDARY ALL
NIGHT.

SYNOPTIC OVERVIEW...
NORTHWEST FLOW CONTINUES THROUGH THE SHORT TERM PERIOD. THE
CONVECTIVELY INDUCED SHORTWAVE TROUGH APPROACHING SIOUX CITY IA AT
08Z MODELS ARE STRUGGLING WITH GREATLY. MOST MODELS...INCLUDING HI
RESOLUTION RUNS SUCH AS THE HRRR AND HIRES-ARW ARE TOO SLOW.
EXTRAPOLATION HAS THE MCV CROSSING MUCH OF IOWA THIS MORNING.
POTENTIAL THEN EXISTS FOR SOME VERY WEAK RIDGING IN ITS WAKE FOR
THIS AFTERNOON AND TONIGHT...AHEAD OF THE CURRENT ALBERTA SHORTWAVE
WHICH DIGS INTO NORTHERN MN AND WESTERN ONTARIO BY 12Z MONDAY.

TODAY...
DESPITE THIS PERIOD BEING THE BEGINNING OF THE FORECAST...THE
UNCERTAINTY IS QUITE HIGH. MUCH OF THIS UNCERTAINTY STEMS FROM THE
TOO SLOW HANDLING FROM ALL MODELS REGARDING THE MCV APPROACHING
SIOUX CITY IA AS OF 08Z. GENERALLY FOLLOWED AN EXTRAPOLATION
APPROACH COMBINED WITH A SOMEWHAT SPED UP 21.05Z HRRR FORECAST TO
COME UP WITH THE FORECAST TODAY. THE PLAN IS THAT THE MCV SHOULD
TRACK ACROSS DES MOINES AND DAVENPORT THIS MORNING...WITH THE
FORECAST AREA ON THE NORTH SIDE. SHOWERS AND A FEW EMBEDDED
THUNDERSTORMS APPEAR LIKELY...PRIMARILY WEST OF THE MISSISSIPPI
RIVER DURING THE MORNING HOURS. CONCERNED THAT THE DIURNAL EFFECTS
ON LOW LEVEL MOISTURE TRANSPORT MAY CAUSE THE SHOWERS TO WEAKEN SOME
AS WE APPROACH MID-DAY...THUS THE HIGHER CHANCES TO THE WEST. DURING
THE AFTERNOON...IT IS HARD TO SAY WHATS GOING TO OCCUR. WE COULD
EASILY BE IN SUBSIDENCE IN THE WAKE OF THE MCV...PREVENTING MUCH IN
THE WAY OF ADDITIONAL PRECIPITATION.  ON THE OTHER HAND...THE
AFTERNOON IS PEAK HEATING AND WITH HIGHER DEWPOINTS TODAY...WE
SHOULD BE ABLE TO BUILD 500-1500 J/KG OF CAPE AS SUGGESTED BY THE
RAP. ANY SHORTWAVE COMING THROUGH THE NORTHWEST FLOW THATS HARD TO
DISCERN AT THIS TIME COULD KICK OFF SHOWERS AND STORMS. ADDITIONALLY
WE SHOULD STILL HAVE THAT STATIONARY FRONTAL BOUNDARY IN THE
FORECAST AREA TO PROVIDE WEAK LOW LEVEL CONVERGENCE. THEREFORE...
HAVE MAINTAINED AT LEAST 40-50 PERCENT CHANCES FOR THE AFTERNOON.
REGARDING TEMPERATURES...ASSUMING SOME SUN TODAY WHICH SHOULD
OCCUR...925MB TEMPS IN THE 18-20C RANGE SUPPORTS HIGHS IN THE 70S TO
NEAR 80.

TONIGHT...
ANY CONVECTION THAT OCCURS THIS AFTERNOON WILL LIKELY HAVE A STRONG
DIURNAL COMPONENT TO IT. THEREFORE...HAVE PRECIPITATION CHANCES
DIMINISHING THROUGH THE EVENING HOURS. HOWEVER...850MB MOISTURE
TRANSPORT DOES INCREASE THROUGH THE NIGHT AHEAD OF THE STRONGER
SHORTWAVE DROPPING INTO NORTHERN MN. CONVECTION WILL LIKELY FORM ON
THE NOSE OF THIS MOISTURE TRANSPORT...WHICH IS FORECAST FROM
NORTHERN MN INTO NORTHERN WI. KEPT SOME 20 PERCENT CHANCES OVERNIGHT
BOTH OVER TAYLOR/CLARK COUNTIES FOR THE NOSE OF THIS MOISTURE
TRANSPORT. ALSO KEPT THE 20 PERCENT CHANCES OVERNIGHT FOR THE
EASTERN HALF OF THE FORECAST AREA...IN THE EVENT ANY DIURNAL
CONVECTION CAN SURVIVE...THOUGH AS THE CHANCE STATES THE CONFIDENCE
IS LOW.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 300 AM CDT SUN JUL 21 2013

SYNOPTIC OVERVIEW...
20.00Z ECMWF/GFS/CANADIAN ALL CONTINUE THE NORTHWEST FLOW PATTERN
THROUGH THE ENTIRE LONG TERM PERIOD. WHAT LOOKED TO BE A POSSIBILITY
OF RIDGING BUILDING TOWARDS THE AREA BRIEFLY THURSDAY INTO FRIDAY IS
NOW COMPLETELY GONE. PART OF THE REASON WE STAY IN NORTHWEST FLOW IS
THE DEVELOPMENT OF AN OMEGA BLOCK OVER WESTERN CANADA BETWEEN
TUESDAY AND WEDNESDAY...WHICH DOES NOT SHOW ANY SIGNS OF BREAKING
DOWN FOR AWHILE. ADDITIONALLY...THERE APPEARS TO BE SOME MODEL
STRUGGLES HANDLING SHORTWAVE TROUGHING COMING DOWN THE EAST SIDE OF
THE OMEGA BLOCK...WHICH PUTS MORE UNCERTAINTY FOR THE FORECAST
THURSDAY AND BEYOND. ONE THING THAT IS STARTING TO BECOME A LITTLE
MORE EVIDENT IS FOR DEEPER TROUGHING OVER THE GREAT LAKES REGION AT
THE END OF NEXT WEEKEND. 500MB STANDARDIZED ANOMALIES FOR 12Z SUNDAY
FROM THE ECMWF/GFS ARE 1.5-2 BELOW NORMAL.

HAZARDS...
THERE COULD BE SOME ISOLATED SEVERE WEATHER LATE MONDAY AFTERNOON
INTO THE EVENING HOURS...ASSOCIATED WITH A COLD FRONT COMING
THROUGH...BUT CONFIDENCE IS LOW AS DESCRIBED BELOW.

MONDAY THROUGH TUESDAY NIGHT...
MUCH OF THE FOCUS HERE IS ON THE MONDAY/MONDAY NIGHT PERIOD.
SHORTWAVE TROUGH OVER NORTHERN MN AND WESTERN ONTARIO AT 12Z MONDAY
MODELS ALL AGREE ON SLIDING IT ACROSS NORTHERN ONTARIO. AS THIS
OCCURS...A COLD FRONT ASSOCIATED WITH IT APPROACHES THE FORECAST
AREA. TIMING ON THIS FRONT VARIES GREATLY. AT 00Z TUESDAY...TIMING
VARIES FROM THE 21.00Z HIRES-ARW HAVING IT WEST OF MINNEAPOLIS TO
THE 21.00Z ECMWF/GFS OVER MINNEAPOLIS AND THE 21.00Z
CANADIAN/NAM/UKMET WHICH ARE OVER LA CROSSE. TRENDS AT LEAST FROM
THE ECMWF/GFS SUGGEST A SLOWER APPROACH MAY BE THE WAY TO GO. THERE
STILL REMAINS UNCERTAINTY ON CONVECTIVE CHANCES WITH THIS
FRONT...

1. A WARM SURGE OF AIR AT 800MB IS STILL INDICATED TO COME OVER THE
FRONT TO PROVIDING POTENTIAL CAPPING
2. THE SHORTWAVE TROUGH SLIDING ACROSS NORTHERN ONTARIO COULD END UP
PUTTING RIDGING OVER THE FRONT FOR THE AFTERNOON AS SUGGESTED BY THE
21.00Z HIRES-ARW.
3. LOW LEVEL CONVERGENCE ON THE FRONT REMAINS IN QUESTION.
4. NOW THE FRONT BEING SLOWER...NOT COMING ACROSS THE FORECAST AREA
AT PEAK HEATING...COULD BE A NEGATIVE FOR PRECIP.

TO ACCOUNT FOR THE SLOWER TREND HAVE LOWERED PRECIPITATION CHANCES
SOME MONDAY AFTERNOON. LEFT THE 40-60 PERCENT CHANCES FOR MONDAY
EVENING AS THAT IS STILL FAIRLY WELL AGREED UPON BY GUIDANCE...THEN
CHANCES DIMINISHING AFTER MIDNIGHT WITH LOSS OF HEATING AND THE
FRONT PROGRESSING THROUGH THE AREA. DRY WEATHER FOLLOWS IN THE WAKE
OF THE FRONT FOR TUESDAY AND TUESDAY NIGHT WHILE HIGH PRESSURE
BUILDS IN AT THE SURFACE. 925MB TEMPS CLIMBING TO 21-24C AHEAD OF
THE FRONT ON MONDAY PLUS SUNSHINE WILL ALLOW HIGHS TO CLIMB INTO THE
80S. MAY EVEN SEE 90 IN A FEW SPOTS IF MORE SUN OCCURS. MONDAY LOOKS
HUMID AS WELL AS NEAR 70 DEGREE DEWPOINTS ADVECT IN AT THE SURFACE.
COOLER HIGHS ON THE WAY FOR TUESDAY AS 925MB TEMPS TUMBLE TO 17-20C.
TUESDAY NIGHT LOWS HAVE POTENTIAL TO GET INTO THE 40S AT THE TYPICAL
COLDER SPOTS...DUE TO LIGHT WINDS AND PRECIPITABLE WATER VALUES
FALLING TO 0.5-0.75 INCHES.

WEDNESDAY THROUGH SATURDAY NIGHT...
20.00Z ECMWF/GFS/CANADIAN ARE SUGGESTING NUMEROUS WEAK SHORTWAVES
DROP SOUTHEAST ACROSS THE FORECAST AREA WEDNESDAY THROUGH THURSDAY
IN THE NORTHWEST FLOW ALOFT. HARD TO SAY IF ANY OF THESE ARE GOING
TO DO ANYTHING PRECIP WISE. 20.00Z CANADIAN AND 19.12Z ECMWF WANT TO
BRING SOME SHOWERS ACROSS WEDNESDAY NIGHT AND THURSDAY...THOUGH THE
20.00Z ECMWF BACKED OFF. WOULD THINK A DRIER SCENARIO IS MORE LIKELY
GIVEN THE DRY AIRMASS COMING IN TUESDAY NIGHT/WEDNESDAY WITH
CANADIAN HIGH PRESSURE IN PLACE. NEVERTHELESS...DID HONOR A 20
PERCENT CHANCE MAINLY ON THURSDAY JUST IN CASE. CHANCES INCREASE A
LITTLE FOR THURSDAY NIGHT AND FRIDAY WHERE IT APPEARS A COLD FRONT
WILL CROSS THE AREA...ASSOCIATED WITH A POTENT UPPER TROUGH DROPPING
OVER MANITOBA AND NORTHERN ONTARIO. SOME OF THIS UPPER TROUGH LOOKS
TO SWING ACROSS THE FORECAST AREA FRIDAY NIGHT AND SATURDAY...THUS
STILL NEED TO CONTINUE AT LEAST 20 PERCENT CHANCES. BEING IN THIS
NORTHWEST FLOW PATTERN COMBINED WITH EVEN DEEPER TROUGHING FORMING
OVER THE WEEKEND SUGGESTS BELOW NORMAL TEMPERATURES. BY 12Z
SUNDAY...BOTH THE 20.00Z ECMWF AND GFS DEPICT 850MB TEMPS FALLING TO
6-9C...CHILLY RELATIVELY SPEAKING FOR THE END OF JULY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 622 AM CDT SUN JUL 21 2013

SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL IMPACT THE TAF
SITES FROM LATE THIS MORNING THROUGH THIS AFTERNOON. MVFR STRATUS
HAS DEVELOPED ACROSS PORTIONS OF SOUTHWEST WISCONSIN...NEAR THE
MISSISSIPPI RIVER...AND IS JUST EDGING INTO KLSE. PLAN ON THE
MVFR STRATUS TO LINGER THROUGH 14Z THIS MORNING WITH CLOUD BASES
AROUND 1500 FT. A WARM FRONT SITUATED NEAR THE INTERSTATE 90
CORRIDOR WILL GRADUALLY LIFT NORTH THIS AFTERNOON INTO THIS
EVENING WITH MOIST SOUTHERLY FLOW SETTING UP OVER THE REGION IN
THE WAKE OF THE FRONT. WILL HAVE TO KEEP A CLOSE WATCH ON THE
POTENTIAL FOR SOME IFR/MVFR STRATUS TONIGHT AND AREAS OF BR.
CURRENT THINKING IS THAT THERE WILL BE ENOUGH MIXING TONIGHT TO
INHIBIT THE DEVELOPMENT OF THE LOW STRATUS. THERE SHOULD BE A
BREAK IN THE SHOWER AND THUNDERSTORM ACTIVITY LATE THIS EVENING
INTO EARLY MONDAY MORNING.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&

$$

SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP








AREA FORECAST DISCUSSION

NWS LA CROSSE WI

 300 AM CDT SUN JUL 21 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 300 AM CDT SUN JUL 21 2013

CURRENTLY AS OF 08Z...
WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS LOOKED VERY SIMILAR
TO THIS TIME YESTERDAY...CONSISTING OF NORTHWEST FLOW FROM BRITISH
COLUMBIA INTO THE GREAT LAKES REGION...NUMEROUS SHORTWAVES RIDING
THROUGH THE FLOW...AND TROUGHING OVER SOUTHEAST CANADA. MOST OF THE
SHORTWAVES ARE WEAK EXCEPT FOR A MORE IMPRESSIVE ONE OVER CENTRAL
ALBERTA. THE MAIN SHORTWAVE OF INTEREST IN THE SHORT TERM IS
ORIGINATING OUT OF CONVECTION OVER SOUTHEAST SD AND EASTERN
NEBRASKA. AIRMASS OVER THE FORECAST AREA VARIES GREATLY FROM SOUTH
TO NORTH WITH I-94 BEING A GREAT DIVIDING LINE. TO THE NORTH...DRIER
AIR CHARACTERIZED BY SURFACE DEWPOINTS IN THE 40S AND LOW 50S WAS
PRESENT. FARTHER UP TO THE NORTH...THE 00Z INL SOUNDING REPORTED A
PRECIPITABLE WATER VALUE OF 0.49 INCHES. NOW...SOUTH AND WEST OF
I-94...DEWPOINTS ARE IN THE 60S. THE 00Z SOUNDINGS FROM MPX AND DVN
HAD PRECIPITABLE WATER VALUES AROUND 1.15 INCHES. SEPARATING THESE
TWO AIRMASSES IS A STATIONARY FRONTAL BOUNDARY. ISOLATED
SHOWERS/STORMS HAVE BEEN POPPING UP ALONG/NORTH OF THE BOUNDARY ALL
NIGHT.

SYNOPTIC OVERVIEW...
NORTHWEST FLOW CONTINUES THROUGH THE SHORT TERM PERIOD. THE
CONVECTIVELY INDUCED SHORTWAVE TROUGH APPROACHING SIOUX CITY IA AT
08Z MODELS ARE STRUGGLING WITH GREATLY. MOST MODELS...INCLUDING HI
RESOLUTION RUNS SUCH AS THE HRRR AND HIRES-ARW ARE TOO SLOW.
EXTRAPOLATION HAS THE MCV CROSSING MUCH OF IOWA THIS MORNING.
POTENTIAL THEN EXISTS FOR SOME VERY WEAK RIDGING IN ITS WAKE FOR
THIS AFTERNOON AND TONIGHT...AHEAD OF THE CURRENT ALBERTA SHORTWAVE
WHICH DIGS INTO NORTHERN MN AND WESTERN ONTARIO BY 12Z MONDAY.

TODAY...
DESPITE THIS PERIOD BEING THE BEGINNING OF THE FORECAST...THE
UNCERTAINTY IS QUITE HIGH. MUCH OF THIS UNCERTAINTY STEMS FROM THE
TOO SLOW HANDLING FROM ALL MODELS REGARDING THE MCV APPROACHING
SIOUX CITY IA AS OF 08Z. GENERALLY FOLLOWED AN EXTRAPOLATION
APPROACH COMBINED WITH A SOMEWHAT SPED UP 21.05Z HRRR FORECAST TO
COME UP WITH THE FORECAST TODAY. THE PLAN IS THAT THE MCV SHOULD
TRACK ACROSS DES MOINES AND DAVENPORT THIS MORNING...WITH THE
FORECAST AREA ON THE NORTH SIDE. SHOWERS AND A FEW EMBEDDED
THUNDERSTORMS APPEAR LIKELY...PRIMARILY WEST OF THE MISSISSIPPI
RIVER DURING THE MORNING HOURS. CONCERNED THAT THE DIURNAL EFFECTS
ON LOW LEVEL MOISTURE TRANSPORT MAY CAUSE THE SHOWERS TO WEAKEN SOME
AS WE APPROACH MID-DAY...THUS THE HIGHER CHANCES TO THE WEST. DURING
THE AFTERNOON...IT IS HARD TO SAY WHATS GOING TO OCCUR. WE COULD
EASILY BE IN SUBSIDENCE IN THE WAKE OF THE MCV...PREVENTING MUCH IN
THE WAY OF ADDITIONAL PRECIPITATION.  ON THE OTHER HAND...THE
AFTERNOON IS PEAK HEATING AND WITH HIGHER DEWPOINTS TODAY...WE
SHOULD BE ABLE TO BUILD 500-1500 J/KG OF CAPE AS SUGGESTED BY THE
RAP. ANY SHORTWAVE COMING THROUGH THE NORTHWEST FLOW THATS HARD TO
DISCERN AT THIS TIME COULD KICK OFF SHOWERS AND STORMS. ADDITIONALLY
WE SHOULD STILL HAVE THAT STATIONARY FRONTAL BOUNDARY IN THE
FORECAST AREA TO PROVIDE WEAK LOW LEVEL CONVERGENCE. THEREFORE...
HAVE MAINTAINED AT LEAST 40-50 PERCENT CHANCES FOR THE AFTERNOON.
REGARDING TEMPERATURES...ASSUMING SOME SUN TODAY WHICH SHOULD
OCCUR...925MB TEMPS IN THE 18-20C RANGE SUPPORTS HIGHS IN THE 70S TO
NEAR 80.

TONIGHT...
ANY CONVECTION THAT OCCURS THIS AFTERNOON WILL LIKELY HAVE A STRONG
DIURNAL COMPONENT TO IT. THEREFORE...HAVE PRECIPITATION CHANCES
DIMINISHING THROUGH THE EVENING HOURS. HOWEVER...850MB MOISTURE
TRANSPORT DOES INCREASE THROUGH THE NIGHT AHEAD OF THE STRONGER
SHORTWAVE DROPPING INTO NORTHERN MN. CONVECTION WILL LIKELY FORM ON
THE NOSE OF THIS MOISTURE TRANSPORT...WHICH IS FORECAST FROM
NORTHERN MN INTO NORTHERN WI. KEPT SOME 20 PERCENT CHANCES OVERNIGHT
BOTH OVER TAYLOR/CLARK COUNTIES FOR THE NOSE OF THIS MOISTURE
TRANSPORT. ALSO KEPT THE 20 PERCENT CHANCES OVERNIGHT FOR THE
EASTERN HALF OF THE FORECAST AREA...IN THE EVENT ANY DIURNAL
CONVECTION CAN SURVIVE...THOUGH AS THE CHANCE STATES THE CONFIDENCE
IS LOW.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 300 AM CDT SUN JUL 21 2013

SYNOPTIC OVERVIEW...
20.00Z ECMWF/GFS/CANADIAN ALL CONTINUE THE NORTHWEST FLOW PATTERN
THROUGH THE ENTIRE LONG TERM PERIOD. WHAT LOOKED TO BE A POSSIBILITY
OF RIDGING BUILDING TOWARDS THE AREA BRIEFLY THURSDAY INTO FRIDAY IS
NOW COMPLETELY GONE. PART OF THE REASON WE STAY IN NORTHWEST FLOW IS
THE DEVELOPMENT OF AN OMEGA BLOCK OVER WESTERN CANADA BETWEEN
TUESDAY AND WEDNESDAY...WHICH DOES NOT SHOW ANY SIGNS OF BREAKING
DOWN FOR AWHILE. ADDITIONALLY...THERE APPEARS TO BE SOME MODEL
STRUGGLES HANDLING SHORTWAVE TROUGHING COMING DOWN THE EAST SIDE OF
THE OMEGA BLOCK...WHICH PUTS MORE UNCERTAINTY FOR THE FORECAST
THURSDAY AND BEYOND. ONE THING THAT IS STARTING TO BECOME A LITTLE
MORE EVIDENT IS FOR DEEPER TROUGHING OVER THE GREAT LAKES REGION AT
THE END OF NEXT WEEKEND. 500MB STANDARDIZED ANOMALIES FOR 12Z SUNDAY
FROM THE ECMWF/GFS ARE 1.5-2 BELOW NORMAL.

HAZARDS...
THERE COULD BE SOME ISOLATED SEVERE WEATHER LATE MONDAY AFTERNOON
INTO THE EVENING HOURS...ASSOCIATED WITH A COLD FRONT COMING
THROUGH...BUT CONFIDENCE IS LOW AS DESCRIBED BELOW.

MONDAY THROUGH TUESDAY NIGHT...
MUCH OF THE FOCUS HERE IS ON THE MONDAY/MONDAY NIGHT PERIOD.
SHORTWAVE TROUGH OVER NORTHERN MN AND WESTERN ONTARIO AT 12Z MONDAY
MODELS ALL AGREE ON SLIDING IT ACROSS NORTHERN ONTARIO. AS THIS
OCCURS...A COLD FRONT ASSOCIATED WITH IT APPROACHES THE FORECAST
AREA. TIMING ON THIS FRONT VARIES GREATLY. AT 00Z TUESDAY...TIMING
VARIES FROM THE 21.00Z HIRES-ARW HAVING IT WEST OF MINNEAPOLIS TO
THE 21.00Z ECMWF/GFS OVER MINNEAPOLIS AND THE 21.00Z
CANADIAN/NAM/UKMET WHICH ARE OVER LA CROSSE. TRENDS AT LEAST FROM
THE ECMWF/GFS SUGGEST A SLOWER APPROACH MAY BE THE WAY TO GO. THERE
STILL REMAINS UNCERTAINTY ON CONVECTIVE CHANCES WITH THIS
FRONT...

1. A WARM SURGE OF AIR AT 800MB IS STILL INDICATED TO COME OVER THE
FRONT TO PROVIDING POTENTIAL CAPPING
2. THE SHORTWAVE TROUGH SLIDING ACROSS NORTHERN ONTARIO COULD END UP
PUTTING RIDGING OVER THE FRONT FOR THE AFTERNOON AS SUGGESTED BY THE
21.00Z HIRES-ARW.
3. LOW LEVEL CONVERGENCE ON THE FRONT REMAINS IN QUESTION.
4. NOW THE FRONT BEING SLOWER...NOT COMING ACROSS THE FORECAST AREA
AT PEAK HEATING...COULD BE A NEGATIVE FOR PRECIP.

TO ACCOUNT FOR THE SLOWER TREND HAVE LOWERED PRECIPITATION CHANCES
SOME MONDAY AFTERNOON. LEFT THE 40-60 PERCENT CHANCES FOR MONDAY
EVENING AS THAT IS STILL FAIRLY WELL AGREED UPON BY GUIDANCE...THEN
CHANCES DIMINISHING AFTER MIDNIGHT WITH LOSS OF HEATING AND THE
FRONT PROGRESSING THROUGH THE AREA. DRY WEATHER FOLLOWS IN THE WAKE
OF THE FRONT FOR TUESDAY AND TUESDAY NIGHT WHILE HIGH PRESSURE
BUILDS IN AT THE SURFACE. 925MB TEMPS CLIMBING TO 21-24C AHEAD OF
THE FRONT ON MONDAY PLUS SUNSHINE WILL ALLOW HIGHS TO CLIMB INTO THE
80S. MAY EVEN SEE 90 IN A FEW SPOTS IF MORE SUN OCCURS. MONDAY LOOKS
HUMID AS WELL AS NEAR 70 DEGREE DEWPOINTS ADVECT IN AT THE SURFACE.
COOLER HIGHS ON THE WAY FOR TUESDAY AS 925MB TEMPS TUMBLE TO 17-20C.
TUESDAY NIGHT LOWS HAVE POTENTIAL TO GET INTO THE 40S AT THE TYPICAL
COLDER SPOTS...DUE TO LIGHT WINDS AND PRECIPITABLE WATER VALUES
FALLING TO 0.5-0.75 INCHES.

WEDNESDAY THROUGH SATURDAY NIGHT...
20.00Z ECMWF/GFS/CANADIAN ARE SUGGESTING NUMEROUS WEAK SHORTWAVES
DROP SOUTHEAST ACROSS THE FORECAST AREA WEDNESDAY THROUGH THURSDAY
IN THE NORTHWEST FLOW ALOFT. HARD TO SAY IF ANY OF THESE ARE GOING
TO DO ANYTHING PRECIP WISE. 20.00Z CANADIAN AND 19.12Z ECMWF WANT TO
BRING SOME SHOWERS ACROSS WEDNESDAY NIGHT AND THURSDAY...THOUGH THE
20.00Z ECMWF BACKED OFF. WOULD THINK A DRIER SCENARIO IS MORE LIKELY
GIVEN THE DRY AIRMASS COMING IN TUESDAY NIGHT/WEDNESDAY WITH
CANADIAN HIGH PRESSURE IN PLACE. NEVERTHELESS...DID HONOR A 20
PERCENT CHANCE MAINLY ON THURSDAY JUST IN CASE. CHANCES INCREASE A
LITTLE FOR THURSDAY NIGHT AND FRIDAY WHERE IT APPEARS A COLD FRONT
WILL CROSS THE AREA...ASSOCIATED WITH A POTENT UPPER TROUGH DROPPING
OVER MANITOBA AND NORTHERN ONTARIO. SOME OF THIS UPPER TROUGH LOOKS
TO SWING ACROSS THE FORECAST AREA FRIDAY NIGHT AND SATURDAY...THUS
STILL NEED TO CONTINUE AT LEAST 20 PERCENT CHANCES. BEING IN THIS
NORTHWEST FLOW PATTERN COMBINED WITH EVEN DEEPER TROUGHING FORMING
OVER THE WEEKEND SUGGESTS BELOW NORMAL TEMPERATURES. BY 12Z
SUNDAY...BOTH THE 20.00Z ECMWF AND GFS DEPICT 850MB TEMPS FALLING TO
6-9C...CHILLY RELATIVELY SPEAKING FOR THE END OF JULY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1030 PM CDT SAT JUL 20 2013

MUDDLED WEATHER PICTURE WITH AN UNSTABLE AIRMASS INTERACTING WITH
VARIOUS MESOSCALE SFC BOUNDARIES AND A FEW PERTURBATIONS IN THE
UPPER LEVEL FLOW. THERE WILL BE PERIODS OF SHRA/TS ACROSS THE REGION
THROUGH SUNDAY NIGHT...BUT TRYING TO HIGHLIGHT WHEN THE TAF SITES
WOULD BE IMPACTED IS PROBLEMATIC AT BEST. CONFIDENCE IS LOW IN
REFINING THE PCPN FORECAST AND MIGHT HAVE TO WAIT UNTIL PCPN IS
ACTUALLY DEVELOPING TO FINE TUNE THE TAFS. THE MOST WIDESPREAD PCPN
SHOULD BE TIED WITH THE UPPER LEVEL SHORTWAVES. WILL CONTINUE TO
PAINT WITH A BROAD BRUSH AS A RESULT. OVERALL...EXPECT VFR
CONDITIONS TO DOMINATE...ALTHOUGH A BRIEF PERIOD OF MVFR COULD
ARISE WITH ANY THUNDERSTORM.

FOR MONDAY...A SFC FRONT IS EXPECTED TO DROP SOUTHWARD INTO THE
AREA. WITH UNSTABLE AIR TO WORK WITH...BELIEVE A LINE OF CONVECTION
WILL DEVELOP IN RESPONSE...AND THERE COULD BE SOME STRONGER STORMS
IN THE AFTERNOON/EARLY EVENING.


&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&

$$

SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....RIECK








AREA FORECAST DISCUSSION

NWS TOPEKA KS

 402 AM CDT TUE JUL 23 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM CDT TUE JUL 23 2013

FAIRLY STRONG NORTHWESTERLY H5 FLOW...CONSIDERING THE MID SUMMER
TIME PERIOD...CURRENTLY OVER THE FORECAST AREA BETWEEN THE MID
LEVEL HIGH OVER THE DESERT SOUTHWEST AND AN UPPER TROUGH LOCATED
NORTH OF THE GREAT LAKES REGION. TWO AREAS OF CONVECTION ARE
APPARENT ON RADAR...WITH AN AREA OF WEAK THUNDERSTORMS OVER
CENTRAL KANSAS...AND A MORE ORGANIZED COMPLEX OF STORMS CURRENTLY
IN C NEBRASKA. GENERALLY EXPECT THE WEAK THUNDERSTORMS OVER
CENTRAL KANSAS TO WEAKEN WHILE STAYING SLIGHTLY WEST OF THE
FORECAST AREA. THE FOCUS WOULD THEN SHIFT TO THE MCS DRIVING ESE
ACROSS C/S NEBRASKA. FORWARD PROPAGATING CORFIDI VECTORS WOULD
INDICATE THAT THE STORMS WILL CONTINUE THEIR PATH TO THE
ESE...PERHAPS BRINGING SOME EARLY MORNING THUNDERSTORMS TO THE
NORTHERN ROW OR TWO OF COUNTIES...WITH THE BEST CHANCES FOR
MORNING PRECIP BEING IN THE FAR NORTHEASTERN CORNER OF KANSAS.
MODELS HAVE BEEN HAVING TROUBLE RESOLVING MCS DEVELOPMENT THE
PREVIOUS COUPLE NIGHTS...SO WILL TAKE THEIR SOLUTIONS WITH A GRAIN
OF SALT. 4KM WRF-NMM WOULD SUGGEST THE COMPLEX WILL FALL APART AS
IT APPROACHES THE CWA...WHILE THE HRRR SUGGESTS IT WILL MAINTAIN
ITSELF IN SOME RESPECT TO THE NORTHERN TIER OF COUNTIES. CURRENTLY
WILL SIDE MORE WITH THE HRRR...AS RADAR TRENDS OVER THE PAST
COUPLE HOURS SHOW THE COMPLEX STILL STRONG AND ORGANIZED AS IT
MOVES ACROSS C NEBRASKA. IT ALSO SEEMS TO BE MAINTAINED ALONG THE
LEADING EDGE OF A 20 TO 30 KT 850 MB JET...WITH MAXIMIZED LOW
LEVEL CONVERGENCE RUNNING NW TO SE ACROSS C/S NEBRASKA. BETWEEN
THAT LINE OF MAXIMIZED LOW LEVEL CONVERGENCE AND THE
AFOREMENTIONED CORFIDI VECTORS...HAVE KEPT THE HIGHEST POPS
THROUGH THE MORNING HOURS ALONG AND NORTH OF INTERSTATE 70...WITH
POPS INCREASING TOWARD THE NORTHEAST PART OF KS.

EXACT THUNDERSTORM DEVELOPMENT FOR TUESDAY AFTERNOON IS SOMEWHAT
UNCERTAIN...AS THE DECAYING MCS WILL LIKELY LEAVE A REMNANT OUTFLOW
BOUNDARY ACROSS THE CWA AS IT CONTINUES ESE. THE REMNANT BOUNDARY
COULD BE THE IMPETUS FOR MORE THUNDERSTORM DEVELOPMENT LATER TODAY
WHERE LOW LEVEL CONVERGENCE IS MAXIMIZED. IN THE UNLIKELY CASE THAT
THE OFB SLIDES COMPLETELY THROUGH THE AREA AND SETS UP SOUTH OF THE
CWA IT COULD DECREASE CHANCES FOR RAIN LATER TODAY...HOWEVER THE
GENERAL THOUGHT IS THAT THAT BOUNDARY WILL REMAIN SOMEWHERE IN
NORTHEAST KANSAS. ASIDE FROM THE MAXIMIZED CONVERGENCE ALONG THE
BOUNDARY MODELS WOULD SUGGEST AN EMBEDDED VORTICITY MAXIMUM IN THE
NORTHWEST H5 FLOW. AS THIS VORT MAX SLIDES THROUGH THE AREA IT
SHOULD BRING INCREASED CHANCES FOR THUNDERSTORMS LATER THIS
AFTERNOON. GIVEN GOOD INSTABILITY IN THE FORM OF ROUGHLY 3000 J/KG
OF MIXED LAYER CAPE AND 0-6 BULK SHEAR VALUES OF PERHAPS 40
KTS...THE INGREDIENTS WILL BE PRESENT FOR SOME OF THESE AFTERNOON
THUNDERSTORMS TO BECOME STRONG TO SEVERE. THE MAIN HAZARDS WOULD BE
HAIL AND WIND...AS WELL AS HEAVY RAIN. EXPECT THESE STORMS TO FORM
INTO A COMPLEX BY SUNSET...AND MOVE SOUTHEASTWARD INTO WESTERN
MISSOURI DURING THE OVERNIGHT HOURS.

TEMPERATURE FORECAST FOR TUESDAY IS ALSO SOMEWHAT QUESTIONABLE AS
THAT OUTFLOW BOUNDARY FROM THE MORNING MCS WILL LIKELY DICTATE WHERE
THE WARMER TEMPS WILL BE LOCATED...VS COOLER TEMPS BEHIND THE
BOUNDARY. HAVE GONE WITH A FORECAST THE REFLECTS THE OFB ALONG WITH
ANY CLOUD DEBRIS FROM THE MCS TO REMAIN ALONG AND NORTH OF I
70...WITH WARMER TEMPS...INTO THE LOWER TO MID 90S ALONG AND SOUTH
OF THE INTERSTATE. THIS FORECAST COULD CHANGE BASED ON HOW
PROGRESSIVE THAT BOUNDARY AND ANY LINGERING CLOUD COVER MAY BE.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 356 AM CDT TUE JUL 23 2013

A LONGER WAVE LENGTH UPPER LEVEL TROUGH WILL REMAIN NEARLY
STATIONARY ACROSS THE EAST CENTRAL CONUS. THIS UPPER AIR PATTERN
WILL CAUSE THE FLOW AT MID AND UPPER LEVELS TO REMAIN
NORTHWESTERLY ACROSS THE PLAINS. A SERIES OF SHORTER WAVE-LENGTH
UPPER LEVEL TROUGHS WILL ROUND THE UPPER LEVEL RIDGE ACROSS THE
WESTERN CONUS AND DIG SOUTHEAST ACROSS THE CENTRAL PLAINS THROUGH
THE FORECAST PERIOD.

WEDNESDAY...THE FIRST H5 TROUGH WILL MOVE SOUTHEAST ACROSS NE INTO
MO WEDNESDAY MORNING. AN MCS OR COMPLEX OF THUNDERSTORMS MAY BE
ONGOING DURING THE MORNING HOURS. HOWEVER...THE STRONGER ASCENT
AHEAD OF THIS H5 TROUGH MAY REMAIN JUST NORTH AND EAST OF THE CWA. A
SURFACE OUTFLOW BOUNDARY/COLD FRONT SHOULD PUSH SOUTH AND SOUTHWEST
ACROSS THE CWA DURING THE MORNING HOURS. THE AFTERNOON MAY REMAIN
DRY AS THE BEST SURFACE CONVERGENCE WILL REMAIN SOUTH AND WEST OF
THE CWA DURING THE AFTERNOON HOURS. HIGHS WILL ONLY REACH THE MID
80S.

WEDNESDAY NIGHT THROUGH THURSDAY NIGHT....THE NEXT H5 TROUGH MAY
DIG SOUTHEAST ACROSS THE PLAINS THURSDAY INTO FRIDAY MORNING. BOTH
THE ECMWF AND GFS SHOW AN MCS DEVELOPING ACROSS THE HIGH PLAINS OF
EASTERN CO AND TRACKING SOUTHEAST ACROSS WESTERN KS INTO SOUTHERN KS
AND NORTHERN OK. THE CWA MAY REMAIN ON THE NORTH EDGE OF THIS MCS
TRACK. IF THE MCS DEVELOPS FARTHER NORTH...THEN THE CWA MAY SEE A
GREATER CHANCE FOR THUNDERSTORMS THURSDAY NIGHT INTO FRIDAY MORNING.
THIS WILL BE MORE OF A MESOSCALE FORECAST AND FOR NOW I JUST WENT
WITH CHANCE POPS. HIGHS MAY WARM BACK INTO THE UPPER 80S TO AROUND
90 DEGREES THURSDAY AFTERNOON.

FRIDAY THROUGH SUNDAY...OUTFLOW BOUNDARIES AND WEAK UPPER LEVEL
TROUGHS DIGGING SOUTHEAST ACROSS THE PLAINS MAY PROVIDE ENOUGH
ASCENT FOR AT LEAST ISOLATED SHOWERS AND THUNDERSTORMS THROUGH THE
PERIOD. HIGHS SHOULD REMAIN IN THE 80S.

SUNDAY NIGHT AND MONDAY...BOTH THE GFS AND ECMWF SHOW ANOTHER H5
TROUGH TRACKING EAST-SOUTHEAST ACROSS THE PLAINS. ASCENT AHEAD OF
THE TROUGH MAY LEAD TO AN MCS DEVELOPING ACROSS WESTERN KS AND
WESTERN NE THAT MAY TRACK EAST-SOUTHEAST ACROSS THE CWA SUNDAY NIGHT
INTO MONDAY MORNING. MONDAY HIGHS WILL ONCE AGAIN BE IN THE LOWER TO
MID 80S.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1128 PM CDT MON JUL 22 2013

WILL MAINTAIN A VFR FORECAST THROUGH THE NIGHT AS NO OBVIOUS
FORCING IS SEEN IN THE NEXT SEVERAL HOURS AND STEERING FLOW SHOULD
KEEP ONGOING CONVECTION MOVING AWAY FROM THE TERMINALS. THINK
THERE IS A CHANCE FOR SCATTERED CONVECTION BY TUESDAY AFTERNOON.
SEE UPDATED DISCUSSION ABOVE FOR FURTHER DETAILS. MAIN UNCERTAINTY
IS WHETHER PRECIP ACROSS NORTHWEST NEB CAN HOLD TOGETHER. IF IT
DOES...IT LOOKS TO MOVE INTO KS AFT 12Z. SO WILL LET THE NEXT
SHIFT MONITOR TRENDS. MAY INCLUDE A MENTION OF VCTS BY EARLY
AFTERNOON AS THIS LOOKS LIKE THE BEST TIMING FOR LIFT...INSTABILITY
AND FORCING TO COME TOGETHER.

SFC DEWPOINT TEMPS HAVE NOT RISEN MUCH...BUT AIR TEMPS HAVE COOLED
OFF MORE RAPIDLY THEN ANTICIPATED. BECAUSE OF THIS MAY PUT A TEMPO
GROUP IN FOR SOME GROUND FOG...ESPECIALLY AT MHK AND TOP.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...JL
LONG TERM...GARGAN
AVIATION...WOLTERS







AREA FORECAST DISCUSSION

NWS TOPEKA KS

 1128 PM CDT MON JUL 22 2013

.UPDATE...
ISSUED AT 1128 PM CDT MON JUL 22 2013

FORECAST THINKING HAS NOT CHANGED MUCH WITH THE 00Z MODEL RUNS
COMING IN. THE SYNOPTIC SCALE FRONT IS MAKING SLOW BUT STEADY
PROGRESS SOUTH. AND ALL SHORT TERM GUIDANCE SHOWS THE BOUNDARY
BISECTING THE FORECAST AREA THROUGH THE AFTERNOON TUESDAY.
MEANWHILE THE CONVECTION ONGOING SEEMS TO HAVE OCCURRED EVERYWHERE
BUT IN THE FORECAST AREA. BACKWARD PROPAGATING CORFIDI VECTORS
WOULD SUGGEST THE CONVECTION IN CENTRAL KS WILL MOVE SOUTH AND
SOUTHWEST WHILE THE CONVECTION NEAR THE IA/MO STATE LINE WOULD
PROPAGATE DUE SOUTH. WITH THIS IN MIND WILL MAINTAIN A SLIGHT
CHANCE POP DURING THE OVERNIGHT HOURS. THINK THAT CHANCES FOR
PRECIP WILL INCREASE THROUGH THE DAY TUESDAY AS A POSSIBLE MCV
FROM THE SD CONVECTION MOVES ACROSS THE FRONTAL BOUNDARY.
CONFIDENCE IN THE MODEL QPF SOLUTIONS IS STILL QUESTIONABLE...BUT
THERE SEEMS TO BE SOME LIFT AND FORCING MECHANISM AVAILABLE TO
ACT UPON THE VERY MOIST AIRMASS. BECAUSE OF THIS THERE COULD BE
SOME SCATTERED CONVECTION ACROSS NORTHEAST KS BY THE EARLY
AFTERNOON. CAN NOT RULE OUT THE CHANCE FOR SOME PRECIP MOVING INTO
NORTHERN KS BEFORE NOON IF STORMS OVER NORTHWEST NEB HOLD
TOGETHER. WITH SKIES REMAINING MOSTLY CLEAR...MAY HAVE TO LOWER
TEMPS A COUPLE DEGREES AS CONDITIONS FAVOR CONTINUED RADIATIONAL
COOLING.

UPDATE ISSUED AT 603 PM CDT MON JUL 22 2013

23Z OBJECTIVE ANALYSIS SHOWS THE FRONTAL BOUNDARY STILL WELL NORTH
OF THE FORECAST AREA FROM NORTH CENTRAL IA...NORTH OF OMA INTO
CENTRAL NEB. WHILE LAPS ANALYSIS SUGGESTS CAPE VALUES ON THE ORDER
OF 4000 J/KG...RECENT VISIBLE IMAGERY DOES NOT SHOW MUCH IN THE
WAY OF A CU FIELD ACROSS THE AREA IN SPITE OF SEVERAL OUTFLOW
BOUNDARIES IN THE AREA. ADDITIONALLY WATER VAPOR SHOWS MID LEVEL
DRYING OVERSPREADING THE FORECAST AREA FROM THE WEST AND NORTHWEST
SUGGESTING THE MAIN VORT MAX IS CURRENTLY OVERHEAD AND MOVING
SOUTHEAST. THE 18Z NAM LOOKS TO BE A LITTLE TO FAR SOUTH WITH THE
FRONTAL BOUNDARY AND PREFER THE RUC13 DEPICTION OF THE LARGE
SCALE PRESSURE FIELD WHICH KEEPS THE MAIN FRONT MAINLY TO THE
NORTH. SO IN GENERAL THINKING IS ANY CONVECTION EARLY THIS
EVENING IS LIKELY TO REMAIN ISOLATED. WITH THE AVAILABLE
INSTABILITY...ANY STORM THAT FORMS WILL HAVE THE POTENTIAL TO
DEVELOP RAPIDLY. HOWEVER THINK THE BETTER CHANCES FOR SCATTERED TO
NUMEROUS STORMS COULD BE DURING THE DAY TUESDAY AS THE BOUNDARY
SETS UP ACROSS KS. WITH MODELS SHOWING THE LOW LEVEL JET FOCUSING
ACROSS SOUTHEAST KS OVERNIGHT...THINK BEST CHANCES FOR STORMS IN
THE EARLY MORNING MAY COME FROM CONVECTION CURRENTLY DEVELOPING
OVER THE HIGH PLAINS OF WY. THE RAP AND HRRR SHOW SIGNS OF THIS
PRECIP HOLDING TOGETHER AND MOVING INTO THE AREA BEFORE DAWN. WILL
MONITOR TRENDS BUT MAY ADJUST THE FORECAST TO LOWER POPS THIS
EVENING.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 248 PM CDT MON JUL 22 2013

STORMS AND CLOUD COVER FROM EARLIER IN THE DAY HAVE LIKELY DELAYED
THUNDERSTORM START TO THESE LATER AFTERNOON HOURS...AND A FEW OF THE
RESIDENT OUTFLOW BOUNDARIES ARE STARTING TO GENERATE CONNECTION.
STORM TO THE NORTH WENT UP QUICKLY...LIKELY IN RESPONSE TO STEEP MID
LEVEL LAPSE RATES AND AMPLE INSTABILITY.  WILL BE DIFFICULT TO SAY
WHERE STORMS WILL FROM IN PARTICULAR THIS AFTERNOON AS THEY REMAIN
BOUNDARY DRIVEN.  MAIN FRONT STILL PROGGED TO COME THROUGH IN THE
0-3Z WINDOW...AND EXPECT THAT THE BETTER SHEAR MORE ORGANIZED
FORCING THAT COMES WITH IT WILL STILL BRING A CHANCE FOR STORM OR
SMALL COMPLEX TO MOVE ACROSS THE CWA THIS EVENING INTO THE EARLY
MORNING HOURS.  PRIMARY CONCERNS ARE WINDS AND LOCALLY HEAVY
RAINFALL...ALTHOUGH ENVIRONMENT MAY BRING SOME MARGINALLY SEVERE
HAIL AS WELL.

WHERE BOUNDARY ENDS UP COMPLICATES SENSIBLE WEATHER AND RAINFALL
CHANCES FOR TUESDAY...WITH NORTHEAST COUNTIES LIKELY COOLER AND
MOISTURE POOLING WESTWARD SHIFTS AFTERNOON RAIN CHANCES TOWARD
WESTERN COUNTIES.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 248 PM CDT MON JUL 22 2013

TUESDAY EVENING THROUGH THURSDAY...

BY 7 PM ON TUESDAY EVENING ISOLATED THUNDERSTORMS MAY BE ONGOING IN
THE VICINITY OF THE SURFACE FRONT OVER EAST CENTRAL AREAS.
THUNDERSTORM COVERAGE IS EXPECTED TO INCREASE ACROSS THE AREA
TOWARDS THE EVENING AS A STRONGER SHORTWAVE EMBEDDED WITHIN THE
UPPER RIDGE TRANSLATES SOUTHEAST ACROSS EASTERN NEBRASKA INTO MISSOURI.
MODELS HAVE BEEN CONSISTENT THE PAST FEW DAYS WITH THIS SCENARIO AND
FEEL CONFIDENT TO BOOST POPS UP TO LIKELY ESPECIALLY IN THE EAST
CENTRAL AREAS. AS FAR AS STORM TYPE GOES...BEST CHANCE OF SEEING
STRONGER STORMS WILL BE CLOSER TO THE 00Z PERIOD WHERE ML CAPE
VALUES ARE PROGGED ANYWHERE FROM 1000 TO 3000 J/KG WITH THE NAM AT
12Z SHOWING 0-6 KM BULK SHEAR INCREASING UP TO 50 KTS. HIGH PRESSURE
WILL BE QUICK TO USHER SOUTHWARD BEHIND THIS SYSTEM WITH CAPE VALUES
STEADILY DECREASING AFT 06Z. GRADUALLY TRENDED POPS DOWNWARD AFT 06Z
WITH MOST OF THE AREA DRY BY WEDNESDAY MORNING. SUBSIDENCE IN PLACE
ON WEDNESDAY SHOULD BRING A TEMPORARILY LULL IN PRECIPITATION
WITH MOSTLY SUNNY SKIES AND COOLER HIGHS IN THE LOW TO MIDDLE 80S.

DURING THE AFTERNOON ON THURSDAY...THE UPPER RIDGE OVER THE
SOUTHWEST CONUS BREAKS DOWN SLIGHTLY AS A  DEVELOPING A LEE TROUGH
TRACKS ACROSS THE INTER-MOUNTAIN WEST AND INTO THE CENTRAL PLAINS. THE
ECMWF AND GFS ARE STILL IN RELATIVE AGREEMENT IN BRINGING A SWATH OF
SHOWERS AND THUNDERSTORMS THURSDAY EVENING INTO FRIDAY FOR NORTHEAST
KANSAS. SLIGHT CHANCES FOR THUNDER INCREASE ON THURSDAY AFTERNOON
WITH GOOD CONFIDENCE TO ADD LIKELY CHANCES FOR THE EVENING HOURS
OVER NORTH CENTRAL KS.

TEMPERATURES DURING THIS PERIOD WILL DEPEND ON LINGERING
PRECIPITATION AND CLOUD COVER ESPECIALLY WEDNESDAY. MADE LITTLE
ADJUSTMENTS WITH WARMEST TEMPERATURES OVER NORTH CENTRAL AREAS IN
THE UPPER 80S WITH COOLER TEMPS OVER EAST CENTRAL WHERE LINGERING
SHOWERS AND CLOUD COVER MAY PERSIST. THE INCREASING CLOUD COVER AS
THE TROF APPROACHES THURSDAY WILL BE A RELATIVELY COOLER BUT HUMID
DAY WITH HIGHS IN THE LOW TO MID 80S.

THURSDAY EVENING THROUGH MONDAY...

BULK OF THE AFOREMENTIONED LOW PRESSURE SYSTEM IMPACTS THE AREA
THURSDAY EVENING INTO FRIDAY. 12Z ECMWF IS STILL TRENDING A TAD
SLOWER THAN THE 12Z GFS WITH THE CENTER OF THE TROF AXIS AND ITS
POSITION BUT OVERALL HAS BEEN IN CONSISTENT AGREEMENT SO HAVE
CARRIED CHANCES FOR THUNDERSTORMS THROUGH FRIDAY AND TAPERING OFF TO
THE EAST FRIDAY EVENING. UPPER RIDGE AMPLIFIES ONCE AGAIN HEADING
INTO THE WEEKEND WITH A QUIET PERIOD FOR SATURDAY. MODELS STILL
DIFFERING BY THE END OF THE PERIOD BUT APPEARS PATTERN STARTS TO
CHANGE TRANSITIONING TO A WESTERLY FLOW PATTERN AND ATTEMPTING TO
BRING ADDITIONAL TROFS THROUGH THE REGION SUNDAY INTO MONDAY.
DECIDED TO LOWER PRECIPITATION CHANCES TO SLIGHT AS MODEL OUTPUT IS
STILL TOO NOISY TO DISCERN ANY MAIN SOURCES OF ENERGY. TEMPERATURES ARE
ON TRACK TO REMAIN IN THE LOW 80S FOR HIGHS WITH THIS ACTIVE PATTERN
IN PLACE.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1128 PM CDT MON JUL 22 2013

WILL MAINTAIN A VFR FORECAST THROUGH THE NIGHT AS NO OBVIOUS
FORCING IS SEEN IN THE NEXT SEVERAL HOURS AND STEERING FLOW SHOULD
KEEP ONGOING CONVECTION MOVING AWAY FROM THE TERMINALS. THINK
THERE IS A CHANCE FOR SCATTERED CONVECTION BY TUESDAY AFTERNOON.
SEE UPDATED DISCUSSION ABOVE FOR FURTHER DETAILS. MAIN UNCERTAINTY
IS WHETHER PRECIP ACROSS NORTHWEST NEB CAN HOLD TOGETHER. IF IT
DOES...IT LOOKS TO MOVE INTO KS AFT 12Z. SO WILL LET THE NEXT
SHIFT MONITOR TRENDS. MAY INCLUDE A MENTION OF VCTS BY EARLY
AFTERNOON AS THIS LOOKS LIKE THE BEST TIMING FOR LIFT...INSTABILITY
AND FORCING TO COME TOGETHER.

SFC DEWPOINT TEMPS HAVE NOT RISEN MUCH...BUT AIR TEMPS HAVE COOLED
OFF MORE RAPIDLY THEN ANTICIPATED. BECAUSE OF THIS MAY PUT A TEMPO
GROUP IN FOR SOME GROUND FOG...ESPECIALLY AT MHK AND TOP.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

UPDATE...WOLTERS
SHORT TERM...67
LONG TERM...BOWEN
AVIATION...WOLTERS







AREA FORECAST DISCUSSION

NWS CARIBOU ME

 106 AM EDT TUE JUL 23 2013

.SYNOPSIS...
A WARM FRONT WILL APPROACH FROM THE SOUTH OVERNIGHT. THE FRONT WILL
LIFT ONTO THE COAST TUESDAY WHILE A WEAK WAVE OF LOW PRESSURE
MOVES ALONG THE FRONT. A COLD FRONT WILL APPROACH TUESDAY NIGHT
THEN CROSS THE REGION WEDNESDAY.

&&

.NEAR TERM /THROUGH TODAY/...
105 AM UPDATE...THE GOING FORECAST IS PRETTY MUCH ON TRACK. MADE
SOME ADJUSTMENTS TO EXPECTED MIN TEMPS TO MATCH CURRENT TRENDS. NO
OTHER CHANGES WERE NEEDED.

PREVIOUS DISCUSSION...PRECIP CHANCES WERE PUSHED BACK MORE FROM EARLIER
THINKING AS HIGH PRES RIDGE IS HOLDING STRONG KEEPING RAINFALL
WELL S OF THE STATE ATTM. REGIONAL RADAR LOOP SHOWED THE BULK OF
SHOWERS AND EMBEDDED TSTMS MOVING ACROSS ERN NYS INTO VT AND MA.
NOT EXPECTING ANY MEASURABLE RAFL TO ARRIVE INTO CENTRAL AND
DOWNEAST AREAS UNTIL EARLY MONDAY MORNING. THE LATEST RUC AND
CANADIAN GEM PICKED UP ON THIS WELL. GFS AS WELL AS THE NAM APPEAR
TO BE HAVING SOME CONVECTIVE FEEDBACK ISSUES AS RAINFALL NOT AS
HEAVY AS THESE MODELS INDICATED AT THEIR 12 & 18Z RUNS. DEWPOINTS
CLIMBING WELL INTO THE 50S W/LOW TO MID 60S BACK ACROSS S AND SW
ME. THIS AREA OF HIGHER DEWPOINTS IS EXPECTED TO PUSH NE
OVERNIGHT. THIS WILL HELP TO MOISTEN LLVLS.

DID NOT INCLUDE ANY MENTION OF TSTMS OVERNIGHT AS AIRMASS LOOKS TO
REMAIN STABLE ABOVE 925MB. AIRMASS LOOKS TO DESTABILIZE MORE ON
TUESDAY PER THE GFS AND NAM SOUNDINGS. PWATS FCST TO PUSH 2+
INCHES COULD LEAD TO HEAVY RAFL AS FLOW THROUGH THE COLUMN IS SSW
W/POTENTIAL TO TRAINING CELLS.

SHOWERS AND POSSIBLE TSTMS FOR TUESDAY INCLUDING NORTHERN MAINE
W/THE HEAVIEST AXIS OF QPF ACROSS EASTERN AND DOWNEAST AREAS.
TEMPERATURES WILL BE DEPENDENT ON CLOUD COVER AND RAIN. THEREFORE,
TUESDAY COULD A BE A COLL DAY W/DAYTIME HIGHS NOT MAKING IT OUT OF
THE UPPER 60S W/THE EXCEPTION OF FAR NORTHERN MAINE. TEMPERATURES
THERE COULD REACH INTO THE LOWER 70S BEFORE CLOUDS THICKEN UP.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY/...
A DISTURBANCE WILL MOVE ALONG A FRONT ALONG THE DOWNEAST COAST
TUESDAY NIGHT...WITH A COLD FRONT APPROACHING NORTHWEST MAINE
LATE. AN AREA OF RAIN WILL MOVE ACROSS THE REGION WITH THE
DISTURBANCE TUESDAY NIGHT. THIS AREA OF RAIN WILL MOVE EAST
OVERNIGHT...WITH PRECIPITATION TAPERING TO SHOWERS LATE. SHOWER
CHANCES WILL THEN BEGIN TO INCREASE ACROSS NORTHWESTERN AREAS
LATER TUESDAY NIGHT IN ADVANCE OF THE APPROACHING COLD FRONT.
SHOWERS AND THUNDERSTORMS WILL CROSS THE REGION IN ADVANCE OF THE
COLD FRONT WEDNESDAY...THEN END IN THE WAKE OF THE COLD FRONT
THROUGH THE AFTERNOON. HIGH PRESSURE WILL BUILD EAST WEDNESDAY
NIGHT THEN CROSS THE REGION THURSDAY THROUGH THURSDAY NIGHT WITH
PARTLY CLOUDY/MOSTLY CLEAR SKIES. TEMPERATURES WILL BE AT NEAR
NORMAL...TO SLIGHTLY BELOW NORMAL...LEVELS WEDNESDAY THROUGH
THURSDAY.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE EXTENDED MODELS ARE IN GOOD AGREEMENT THROUGH THE PERIOD. A
WEAK HIGH PRESSURE RIDGE WILL BE BUILT OVER THE AREA AT THE START
OF THE PERIOD. THERE WILL BE A LOW PRESSURE SYSTEM ALONG THE
COAST OF VA...A SECOND LOW PRESSURE SYSTEM OVER LAKE SUPERIOR. FRI
EVNG THE LOW ALONG THE COAST OF VA WILL MOVE NORTH. THE GFS AND
ECMWF DIFFER ON THE SOLUTION. THE ECMWF BRINGS THE LOW NORTH ALONG
THE COAST CENTERED AROUND LONG ISLAND..WITH A WARM FRONT EXTENDING
NE INTO THE GULF OF MAINE. THE GFS MOVES THE LOW NORTH BUT KEEPS
IT WELL EAST OF THE COAST...AND MAINTAINS THE HIGH PRESSURE RIDGE
ACROSS THE AREA. THESE DIFFERENCE CONTINUE INTO SAT MRNG. THE
ECMWF MOVES THE LOW NORTH TO BAR HARBOR...EXTENDS THE WARM FRONT
EAST INTO NEW BRUNSWICK. THE GFS CONTINUES TO MAINTAIN THE HIGH
PRESSURE RIDGE. BOTH MODELS DEEPEN THE LOW OVER LAKE SUPERIOR AND
MOVE IT NORTH TO JAMES BAY. BOTH MODELS ALSO SHOW SEVERAL
SECONDARY LOWS ALONG A BOUNDARY EXTENDING THROUGH THE GREAT
LAKES...THROUGH THE CENTRAL US...TO TEXAS. BY SUN MRNG BOTH MODELS
MOVE THE RIDGE EAST OF THE AREA...AS THE FRONT PUSHES INTO VT/NH.
BY SUN EVNG THE GFS MOVES THE FRONT INTO WRN MAINE...THE ECMWF
INTO NH. MON MRNG THE GFS TO ERN ME...ECMWF WRN ME. MON EVNG THE
GFS MOVES THE FRONT THROUGH...THE ECMWF TO ERN ME. BY THE END OF
THE PERIOD THE GFS INDICATES THAT MAINE WILL BE INFLUENCED BY WRAP
AROUND PRECIP...THE ECMWF MAINTAINS THE LOW OVER MAINE.

LOADED MODEL BLEND FOR MAX/MIN TEMP...WND/SKY/POP. ADDED 15
PERCENT TO WINDS FOR GUSTS OVER LAND...20 PERCENT OVER COASTAL
WATERS.

&&

.AVIATION /05Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: VFR CONDITIONS THIS EVENING ARE EXPECTED TO LOWER TO
IFR DOWNEAST LATE TONIGHT AND IFR TO MVFR ACROSS THE NORTH TUESDAY
MORNING. IFR CONDITIONS IN LOW CLOUDS ARE EXPECTED ON TUESDAY.

SHORT TERM: MVFR/IFR...WITH OCCASIONAL LIFR...CONDITIONS ARE
EXPECTED ACROSS THE REGION TUESDAY NIGHT INTO WEDNESDAY.
CONDITIONS WILL BEGIN TO IMPROVE LATER WEDNESDAY IN THE WAKE OF
THE COLD FRONT. GENERALLY VFR CONDITIONS ARE EXPECTED ACROSS THE
REGION WEDNESDAY NIGHT THROUGH SATURDAY.

&&

.MARINE...
NEAR TERM: WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA THROUGH
TUESDAY. HUMID AIR LIFTING NORTH WITH THE WARM FRONT WILL LIKELY
RESULT IN SOME FOG OVER THE WATERS LATE TONIGHT INTO TUESDAY.

SHORT TERM: SMALL CRAFT ADVISORY LEVEL SEAS ARE POSSIBLE WEDNESDAY
INTO WEDNESDAY NIGHT. OTHERWISE...WINDS/SEAS ARE EXPECTED TO BE
BELOW SMALL CRAFT ADVISORY LEVELS TUESDAY NIGHT THROUGH THURSDAY
NIGHT. VISIBILITIES WILL BE REDUCED IN RAIN AND FOG TUESDAY NIGHT
AND WEDNESDAY...WITH A CHANCE OF THUNDERSTORMS WEDNESDAY AFTERNOON.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.

&&

$$
NEAR TERM...BLOOMER/HASTINGS
SHORT TERM...NORCROSS
LONG TERM...NORTON
AVIATION...BLOOMER/HASTINGS/NORCROSS
MARINE...BLOOMER/HASTINGS/NORCROSS








AREA FORECAST DISCUSSION

NWS GAYLORD MI

 132 AM EDT TUE JUL 23 2013

.SYNOPSIS...
ISSUED AT 402 PM EDT MON JUL 22 2013

CHANCES FOR SHOWERS AND THUNDERSTORMS INCREASE TONIGHT...IN ADVANCE
OF A COLD FRONT THAT WILL SWEEP ACROSS NORTHERN MICHIGAN EARLY
TUESDAY. HIGH PRESSURE BUILDS BACK INTO THE GREAT LAKES TUESDAY AND
HOLDS INTO THE LATTER HALF OF THE WORK WEEK...BRINGING COOLER AND
LESS HUMID WEATHER BACK TO NORTHERN MICHIGAN.

&&

.UPDATE...
ISSUED AT 132 AM EDT TUE JUL 23 2013

NICE TO SEE CONVECTION CAN ACTUALLY DEVELOP ACROSS THE CWA -
HAVEN`T SEEN THAT IN SOME TIME. NICE VORT TAIL IN ADVANCE OF THE
INCOMING SURFACE FRONT...COMBINED WITH A NARROW PLUME OF ELEVATED
CAPE (MUCAPE VALUES UP TOWARD 1000J/KG PER LATEST RUC ANALYSIS)
HAS WORKED TO HELP POP ADDITIONAL SHOWERS/STORMS OVER NORTHERN
LAKE MICHIGAN. ACTIVITY IS BEING HELD WELL IN CHECK (I.E. NO
SEVERE) BY ONLY MARGINAL INSTABILITY AND MARGINAL MID LEVEL LAPSE
RATES...BUT NONETHELESS IS PROVIDING SOME NEEDED RAIN FOR PARTS OF
NORTHWEST LOWER. THIS ACTIVITY WILL LIKELY STAY NORTH OF M-72 FOR
MUCH OF THE NIGHT...TIED TO THE BEST FRONTAL FORCING AND SUPPORT
ALOFT...BUT CAN`T COMPLETELY RULE OUT SOMETHING SOUTH OF
HERE...WHERE WILL MAINTAIN SOME SMALL POPS. OTHERWISE...NO BIG
CHANGES OTHER THAN TIMING OF PRECIP. TEMPS STILL WARM AT THIS
HOUR...BUT WILL FALL LATER TONIGHT AS THE FRONT PROGRESSES THROUGH
THE CWA.

UPDATE ISSUED AT 1038 PM EDT MON JUL 22 2013

SO...IS IT GOING TO RAIN IN NORTHERN LOWER AT ALL? SOME STRONGER
CELLS CONTINUE IN NE WI...BUT THEY HAVEN/T COALESCED INTO ANYTHING
REMOTELY ORGANIZED. THE ONE WELL-DEFINED OUTFLOW BOUNDARY IS
MOVING OFF THE WI SHORE DUE WEST OF MBL...AND FEEL REASONABLY
CONFIDENT THAT MANISTEE CO AND SOME SURROUNDING AREAS WILL AT
LEAST SEE SOME SHRA. THE REST OF THE ACTIVITY OVER THERE WANTS TO
PROPAGATE SE-WARD WITH TIME.

TSRA IN CENTRAL UPPER MI BRIEFLY WAS QUASI-LINEAR...BUT HAS
DEVOLVED INTO SOMETHING MORE DISORGANIZED. ONE CAN SEE A SE-WARD
MOVING FEATURE WITHIN THIS CLUSTER...WHICH APPEARS TO BE THE
ACTUAL COLD FRONT. THERE IS SOMETHING LIKE 25KT OF SW/240 FLOW
NOT FAR OFF THE DECK...TO HELP CARRY THIS ALONG AS IT MOVES E OR
SE. BUT...THERE IS UPSTREAM CONVECTION ALONG THAT FETCH...SO SOME
OF OUR POTENTIAL INFLOW IS BEING STOLEN.

LIKELY TO CATEGORICAL POPS STILL CLEARLY IN ORDER IN EASTERN
UPPER. WILL ALSO KEEP POPS HIGH IN THE VERY TIP OF THE
MITT...WHERE THE COLD LAKE GETS NARROWER AND WILL ALLOW FOR SOME
SE-WARD PROPAGATION. MANISTEE AREA WILL HAS MENTIONED LIKELY GET
RAINDROPS...THOUGH THUNDER IS LESS CERTAIN. IN BETWEEN...WILL
LOWER POPS IN THE BULK OF NORTHERN LOWER TO CHANCY.

UPSTREAM CONVECTION CLEARLY ALREADY ENCOUNTERING DWINDLING
INSTABILITY. NEVER SAY NEVER WHEN IT COMES TO MAYBE SEEING AN
ISOLATED SVR...BUT THAT THREAT CERTAINLY LOOKS MINIMAL.

ONLY MINOR CHANGES TO TEMPS AND OTHER FORECAST ELEMENTS.

UPDATE ISSUED AT 831 PM EDT MON JUL 22 2013

A FEW SPRINKLES CONTINUE TO MOVE THRU NORTHERN LOWER MI...AS
HEIGHTS ALOFT JUST BEGIN TO FALL AND MID-LEVEL LAPSE RATES START
TO STEEPEN. LOOKING AT THE 00Z APX OBSERVED SOUNDING...WITH 1K
J/KG OF UNCAPPED SBCAPE...IT IS SOMEWHAT DIFFICULT TO SEE WHY
THESE AREN/T BEING MORE AMBITIOUS. A COUPLE OF WEAK SHRA HAVE ALSO
DEVELOPED IN THE NEWBERRY AREA...AHEAD OF THE MAIN AXIS OF
SHRA/TSRA FROM CENTRAL UPPER MI BACK INTO IOWA.

HAVE SLOWED DOWN THE ARRIVAL OF HIGHER POPS FOR A FEW HOURS.
FIDDLED WITH SHORT-TERM POP/SKY COVER GRIDS AS WELL.

UPDATE ISSUED AT 537 PM EDT MON JUL 22 2013

HAVE REDUCED EARLY EVENING POPS IN MOST OF NORTHERN LOWER...WHERE
CONVECTION IS GENERALLY REFUSING TO FIRE.

HOWEVER...IT WILL BE INTERESTING TO SEE IF AN INCOMING MID-LEVEL
MOIST BAND...SEEN ON RADAR FROM BEAVER ISL INTO EASTERN
UPPER...CAN INTERACT WITH MARGINAL OVERLAND INSTABILITY OVER FAR
NORTHERN LOWER. HAVE ADDED/INCREASED POPS OVER FAR NORTHERN
LOWER...ESPECIALLY FROM INDIAN RVR/CHEBOYGAN EAST TO APN...WHERE
A PRE-EXISTING CU FIELD EXISTS.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 402 PM EDT MON JUL 22 2013

EARLY AFTERNOON SURFACE ANALYSIS SHOWS A 998MB LOW OVER NORTHWEST
ONTARIO WITH A TRAILING COLD FRONT MOVING INTO FAR WESTERN LAKE
SUPERIOR/WESTERN UPPER/NORTHWEST WISCONSIN.  SURFACE LOW TRACKING
TOWARD A 3MB/3H PRESSURE FALL CENTER DIRECTLY TO ITS EAST...KEEPING
IT NORTH OF LAKE SUPERIOR.  SURFACE LOW SUPPORTED BY A SHORT WAVE
TROUGH ALSO MOVING THROUGH NORTHERN ONTARIO...WITH WATER VAPOR
IMAGERY HINTING AT ANOTHER VORTICITY CENTER AT THE TAIL END OF THIS
WAVE OVER SOUTHERN MINNESOTA/NORTHERN IOWA.  NICE CU FIELD HAS
SPROUTED ACROSS LOWER MICHIGAN THIS AFTERNOON...LATEST OBJECTIVE
ANALYSIS INDICATING 500-1500J/KG MLCAPE IN PLACE ACROSS NORTHERN
LOWER MICHIGAN.  NOT MUCH GOING JUST YET...THOUGH STARTING TO GET
SOME SCATTERED RADAR RETURNS OVER CENTRAL/SOUTHERN LOWER.  BROAD
AREA OF LOW LEVEL MOISTURE CONVERGENCE ACROSS THE LOWER PENINSULA
AND WATER VAPOR IMAGERY SUGGESTS STARTING TO GET UNDER SOME UPWARD
FORCING ASSOCIATED WITH TAIL END UP ONTARIO SHORT WAVE TROUGH.  ALSO
WATCHING FOR CONVECTIVE DEVELOPMENT FARTHER UPSTREAM ALONG COLD
FRONT OVER UPPER MISSISSIPPI VALLEY WHERE MLCAPE HAS INCREASED TO
2500-3500J/KG WITH SHRINKING MLCINH.

SURFACE LOW PASSING NORTH OF LAKE SUPERIOR THIS EVENING WILL DRAG
ITS ASSOCIATED COLD FRONT ACROSS NORTHERN MICHIGAN TONIGHT.  PUSH OF
COOLER AIR THEN ARRIVES TUESDAY AS WINDS SWING AROUND TO THE
NORTHWEST...AND SHOULD BE A BIT BREEZY AS WELL AS HIGH PRESSURE
SQUEEZES INTO THE UPPER LAKES BY TUESDAY NIGHT.  FORECAST CONCERNS
WILL DEAL INITIAL WITH CONVECTIVE TRENDS AHEAD OF THE APPROACHING
COLD FRONT TONIGHT...THEN SOME CLOUD/WIND ISSUES FOR TUESDAY.

TONIGHT/TUESDAY: WEATHER...EVEN WITHOUT ANY LATE AFTERNOON/EARLY
EVENING CONVECTIVE DEVELOPMENT LOCALLY...UPSTREAM COLD FRONT SHOULD
LIGHT UP WITH THUNDERSTORMS THAT SHOULD ARRIVE OVER THE FORECAST
AREA TOWARD LATE EVENING/MIDNIGHT.  PLAN TO MARCH A BAND OF LIKELY
POPS ACROSS THE FORECAST AREA IN 3 HOUR INCREMENTS...ENDING FROM
WEST TO EAST AFTER MIDNIGHT.  PRETTY EXTENSIVE AREA OF LOW CLOUDS
BEHIND THE COLD FRONT WHICH SHOULD DROP INTO SOUTHERN LOWER BY
DAYBREAK TUESDAY.  LOW LEVEL CYCLONIC FLOW AND COLD ADVECTION SHOULD
SUPPORT DIURNAL AUGMENTATION OF THIS CLOUD DECK...SO THOUGH THERE
MAY BE SOME EARLY BREAKS EXPECT THE FORECAST OVERALL TO TREND TOWARD
THE CLOUDIER SIDE.

WINDS...SOUTH/SOUTHWEST GENERALLY UNDER 10 MPH TO START THE NIGHT...
THEN SWINGING AROUND TO NORTHWEST WITH FRONTAL PASSAGE OVERNIGHT.
EXPECT COLD ADVECTION/MIXING TO RESULT IN GUSTY WINDS TUESDAY...
WITH 20-30MPH GUSTS FROM THE NORTHWEST EXPECTED.

TEMPERATURES...LOWS TONIGHT WILL BE DEPENDENT ON LOCATION RELATIVE
TO COLD FRONT...MID/UPPER 50S EASTERN UPPER...AROUND 60-MID 60S
ACROSS NORTHERN LOWER.  HIGHS TUESDAY WILL BE IMPACTED BY STRONG LOW
LEVEL COLD ADVECTION...PROBABLY GETTING STUCK IN THE 60S ACROSS
EASTERN UPPER/TIP OF THE MITT COUNTIES WITH LOWER-MID 70S ELSEWHERE.

&&

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 402 PM EDT MON JUL 22 2013

MAIN FORECAST CONCERN FOR THE EXTENDED PERIOD WILL BE THE NEXT FROPA
AROUND THE FRIDAY TIME FRAME.

LATEST HEMISPHERIC PATTER ANALYSIS SHOWS A RELATIVELY STABLE/
NON-PROGRESSIVE THREE WAVE PATTERN...WITH AN OMEGA BLOCK SEEN OVER
THE NORTH CENTRAL PACIFIC...SHORT WAVE RIDGING OVER THE WESTERN
STATES AND LARGER SCALE TROUGHING OVER EASTERN CANADA. THIS IS
LEAVING THE GREAT LAKES UNDER A WEST NORTHWEST FLOW REGIME WITH
THE FIRST OF TWO PASSING SHORT WAVES MOVING THROUGH THIS WEEK TO
BRING A FROPA TO THE REGION TONIGHT. GOING THROUGH THE WEEK
THE...FORECAST LOOKS RATHER BENIGN WEATHER WISE...WITH A VERY
BLOCKY PATTERN ON THIS SIDE OF THE NORTHERN HEMISPHERE. THE LOW
OVER THE GULF OF ALASKA AFFILIATED WITH THE NORTH PACIFIC OMEGA
BLOCK WILL MOVE SLOWLY TO THE B.C. COAST BY THE END OF THE WORK
WEEK. THE COMBINATION OF THIS AND A BUILDING RIDGE OVER THE NORTH
ATLANTIC WILL MAINTAIN GENERAL TROUGHINESS FOR THE EASTERN CONUS
RIGHT THROUGH THE END OF THE FORECAST PERIOD...WITH SIGNS THAT
THIS OVERALL PATTERN BREAKING DOWN JUST BEYOND THE FORECAST
PERIOD.

TUESDAY NIGHT THROUGH THURSDAY...THE FIRST OF TWO SHORTWAVES WILL
HAVE MOVED OFF WELL TO THE NORTHEAST TUESDAY NIGHT...WITH SURFACE
HIGH PRESSURE BUILDING INTO THE GREAT LAKES. THIS WILL PROMOTE VERY
COMFORTABLE AND SUNNY CONDITIONS FOR THE DAY ON WEDNESDAY WITH
SEASONABLE TEMPERATURES AND LOW AFTERNOON HUMIDITY. LOOKS LIKE A
GOOD RADIATIONAL COOLING SETUP FOR TUESDAY AND WEDNESDAY NIGHT WITH
THE HIGH IN CLOSE VICINITY TO NORTHERN MICHIGAN...ALLOWING FOR
MOSTLY CLEAR SKIES AND A DECOUPLING BOUNDARY LAYER WITH LOWS FALLING
INTO THE 40S BOTH NIGHTS. UNDERCUT MOST GUIDANCE BY SEVERAL
DEGREES...WITH TUESDAY NIGHT LOOKING TO BE THE CHILLIER OF THE TWO
DUE TO SOME RESIDUAL COLD AIR ADVECTION. RETURN FLOW LOOKS TO RETURN
FOR THURSDAY AS THE HIGH BEGINS TO SLIDE OFF TO THE EAST. THERE WILL
BE A SLIGHT UPTICK IN TEMPERATURES HUMIDITY...WITH THE ONLY REAL
DIFFERENCE IN SENSIBLE WEATHER JUST BEING SOME MID/HIGH LEVEL CLOUD
COVER AHEAD OF THE NEXT WEATHER SYSTEM AND PERHAPS SOME CU THURSDAY
AFTERNOON.

THURSDAY NIGHT THROUGH SATURDAY...THE NEXT SHORTWAVE WILL DROP OUT
OF SOUTH CENTRAL CANADA TOWARD THE GREAT LAKES THURSDAY NIGHT. THE
ASSOCIATED SURFACE LOW AND COLD FRONT LOOKS TO ENTER THE GREAT LAKES
SOMETIME IN THE THURSDAY NIGHT TO FRIDAY TIME FRAME...PROVIDING THE
NEXT CHANCE OF CONVECTION ACROSS THE GREAT LAKES. THE 12Z GEM IS
MOST AGGRESSIVE WITH THE FROPA...CLEARING NORTHERN MICHIGAN BY
FRIDAY AFTERNOON. FAVOR THE SLOWER GFS/ECMWF SOLUTIONS...ESPECIALLY
WITH THE MAIN UPPER WAVE SLOWING DOWN AND CLOSING OFF OVER EASTERN
ONTARIO BY SATURDAY. COULD SEE THE TIMING OF THE FROPA SLOWING DOWN
A BIT WITH THIS SETUP...AND MAINTAINED POPS IN THE FORECAST INTO
SATURDAY TO REFLECT THIS IDEA.

SUNDAY THROUGH MONDAY...HIGH PRESSURE BUILDS BACK INTO THE GREAT
LAKES...WITH A COOLISH PATTERN RETURNING ONCE AGAIN TO THE REGION.
SOME GUIDANCE EVEN SUGGESTING HIGHS IN THE 60S BY LATE THIS WEEKEND
AS COOL CANADIAN AIR MASS SETTLES IN. A BUILDING RIDGE LOOKS TO TAKE
SHAPE TOWARD THE END OF THE FORECAST PERIOD...WITH NEAR TO ABOVE
NORMAL TEMPS POTENTIAL RETURNING TOWARD THE MIDDLE OF NEXT WEEK.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 132 AM EDT TUE JUL 23 2013

UPDATED THINKING: NOT SO SURE WIDESPREAD LOWER CEILINGS WILL
DEVELOP BEHIND THE FRONT...AS DRIER AIR IS ALREADY BLEEDING
SOUTHWARD PRETTY QUICKLY. STILL NOT IMPOSSIBLE FOR SOME LOWER
STRATUS TO FOR A AN HOUR OR TWO BEHIND THE FRONT...BUT THINK THAT
STRONGER PUSH OF COLD ADVECTION WILL WORK TO ERADICATE THAT THREAT
QUICKLY.

EARLIER DISCUSSION BELOW:

SOME SHRA/TSRA OVERNIGHT...CIG RESTRICTIONS TOWARD DAWN.

A COLD FRONT WAS MOVING ACROSS EASTERN UPPER MI AND FAR NORTHERN
LAKE MI AT MIDNIGHT. THIS FRONT WILL CROSS NORTHERN LOWER MI
OVERNIGHT. MARGINAL LLWS WILL BE SEEN JUST AHEAD OF THE WARM
FRONT. SHRA/TSRA ALONG THE FRONT TO OUR WEST WILL MOVE IN
TONIGHT...WITH PLN MOST LIKELY TO SEE TS.

WITH THE EXTRA MOISTURE INPUT INTO THE LOW LEVELS...MVFR CIGS ARE
LIKELY JUST BEHIND THE COLD FRONT. THAT WILL QUICKLY LIFT TO VFR
TUESDAY MORNING.

LIGHT SW WINDS TONIGHT...VEERING NW LATE. RATHER GUSTY NW TO NNW
WINDS TUESDAY.

&&

.MARINE...
ISSUED AT 402 PM EDT MON JUL 22 2013

SOUTH/SOUTHWEST GRADIENT WINDS EARLY TONIGHT WILL SWING AROUND TO
NORTHWEST OVERNIGHT WITH PASSAGE OF A COLD FRONT...AND WILL BECOME
GUSTY TUESDAY GIVEN DECENT MIXING/DECREASING OVERWATER STABILITY
WITH COLD ADVECTION. GUSTS TO 30KTS LIKELY WITHIN MOST NEARSHORE
ZONES...SO WILL GO AHEAD AND ISSUE A PRE-EMPTIVE SMALL CRAFT
ADVISORY FOR TUESDAY. INCREASING SWIM RISK ALSO LIKELY TUESDAY
AFTERNOON ON LAKE MICHIGAN BEACHES SOUTH OF GRAND TRAVERSE LIGHT.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS
     EVENING FOR LHZ345-346.
     SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO MIDNIGHT EDT
     TONIGHT FOR LHZ347-348.
LM...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS
     EVENING FOR LMZ341.
     SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO MIDNIGHT EDT
     TONIGHT FOR LMZ323-342-344>346.
LS...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS
     EVENING FOR LSZ321-322.

&&

$$

UPDATE...LAWRENCE
SYNOPSIS...AJS
SHORT TERM...JPB
LONG TERM...NTS
AVIATION...JZ/LAWRENCE
MARINE...JPB






AREA FORECAST DISCUSSION

NWS KANSAS CITY/PLEASANT HILL MO

 422 AM CDT Tue Jul 23 2013

.SHORT TERM...(Today through Wednesday night)
Issued at 421 AM CDT TUE JUL 23 2013

Today through Tonight...Fickle northwest flow and muddled surface
boundaries will dictate our rain chances during this period. For the
past several days perturbations embedded within the northwest flow
have skirted by the bulk of the CWA with only the far northern and
northeastern counties receiving any beneficial rainfall. This may
change today as a relatively large convective complex continues to
track southeast through central NE.

A moderately strong mesohigh/cold pool and likely a developing MCV
are driving this feature. GFS/NAM/ECMWF have been pretty consistent
for the past few runs with this feature and maintain its strength
and resulting precipitation through the day and into the evening.
Only the HRRR has shown a tendency for the rain to fall apart
starting mid morning. This is a typical characteristic/phase of
convective systems which show a decided weakening from mid morning
through early afternoon before regenerating later in the afternoon.
Latest SPC meso page shows rather high MUCAPE of 3000-4000J/kg
downstream from this convection over northeast KS/northwest MO. Am
expecting the central NE convection to head for this better
instability and maintain its strength into mid morning. Surprisingly
there is moderately strong 0-6km shear of 40kts north of the MO
River so severe storms are possible. Have raised PoPs over the
western 1/2 of the CWA and adjusted them for the expected track of
this MCS. Will let day shift determine if this system will go
through the typical weakening/re-strengthening phases. Temperatures
will be problematic due to timing/location of cloud cover and
rain-cooled air. Have lowered them across the northern 1/2 of the
CWA.

Scattered convection expected to continue tonight with the northeast
third of the forecast area possibly missing out on the rain this
time.

Wednesday/Wednesday night...Could see lingering rain chances over
the far southern counties Wednesday morning as the convective
complex exists the CWA. Then expect dry, cooler and drier air to
spread into the region as high pressure settles in across IA through
IL and provides a northeast to easterly wind. Blended approach on
temperatures look reasonable with exceptionally pleasant weather for
Wednesday night/Thursday morning.


.LONG TERM...(Thursday through Monday)
Issued at 421 AM CDT TUE JUL 23 2013

The long range models are in better agreement with the 23/00Z runs
then in previous iterations. There is still however, a bit of
disagreement as to the timing of features that will affect the area
during this timeframe.

Thursday looks to be a very pleasant day with surface high pressure
over the area. Temperatures will be a few degrees below seasonal
averages with highs in the low to mid 80s. Thursday night there will
be two features of interest that will affect the area. The first is
a upper level trough moving through the Great Lakes region. This
will force a cold front into the Upper Midwest and back into the
Central Plains. Thunderstorms will develop out ahead of this front
and will move into northern Missouri Thursday night. Storms will
continue across northern Missouri on Friday as this front moves into
the area. The second feature of interest is an upper level shortwave
rounding an upper level ridge out west and dropping into the local
area on northwest flow on the lee side of the upper ridge. This
shortwave is actually remnant energy from the retrograding upper
level system that affected the region two weekends ago. The GFS/GEM
and ECMWF all depict a cluster of storms perhaps an MCS developing
across central Kansas Thursday night that will move into
central/southern Missouri either late Thursday night into Friday
(the faster GFS) or into Friday/Friday night (the slower EC and
GEM). In either case have chance POPs forecast for Thursday night
through Friday night.

Surface high pressure is advertised for the area behind the
departing cold front which should make for a very pleasant weekend
with highs in the upper 70s to lower 80s. Also, by the end of the
weekend there will be an overall pattern shift across the CONUS to a
more quasi-zonal pattern. This will be caused by a serious of
shortwaves moving through the Rockies which will suppress the
western CONUS ridge. The first of these shortwave is progged to
reach the area by Sunday night (still faster GFS) or early Monday
morning (the still slower EC). Either way, storms are expected to
linger into Monday across the area. That said have slight chance
POPs in for Sunday night to account for the faster GFS and have
chance POPs forecasted for Monday.


&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday Night)
Issued at 1243 AM CDT TUE JUL 23 2013

While VFR conditions will prevail outside of any convection the
forecast will be a challenging one. Scattered convection along/ahead
of a cold front dropping south across northern MO is likely to pass
northeast of the terminals overnight. However, TDWR radar from MCI
shows an outflow boundary from this convection will likely pass
through KSTJ at the start of the forecast with gusty winds.

Also watching a couple of convective complexes over the Northern and
Central High Plains which a couple of convective allowing models plus
the 00z GFS/NAM suggest this activity have the potential to affect
the terminals this afternoon. While confidence is boosted by all of
these models indicating convection for late Thursday
afternoon/evening best to go the conservative route as previous model
runs have had a poor track record.


&&

.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&

$$

SHORT TERM...MJ
LONG TERM...73
AVIATION...MJ







AREA FORECAST DISCUSSION...UPDATED AVIATION

NWS ST LOUIS MO

 1152 PM CDT MON JUL 22 2013

.UPDATE...
ISSUED AT 948 PM CDT MON JUL 22 2013

MAIN ITEM OF INTEREST FOR THE REST OF NIGHT IS THE PROBABILITY OF
SHOWERS AND THUNDERSTORMS. THE GREATEST ATTENTION IS FOCUSED ON
THE LOOSELY ORGANIZED MCS ACROSS IOWA THAT IS OCCURRING AHEAD OF
THE ENCROACHING COLD FRONT. THE SYSTEM HAS DEVELOPED A DECENT COLD
POOL AND THERE IS SOME VIGOROUS CONVECTION ALONG THE WESTERN
FLANK. THE LOW LEVEL INFLOW INTO THE SYSTEM IS NOT PARTICULARILY
STRONG AT 20 KTS OR LESS AND FROM THE WEST...BUT THE AIR MASS
ACROSS EASTERN MO INTO WESTERN IL IS QUITE UNSTABLE WITH SBCAPE OF
2000-3000 J/KG. DEEP LAYER SHEAR VECTORS AND CFM VECTORS WOULD
SUGGEST THAT IF THE MCS CAN MAINTAIN SOME ORGANIZATION THAT IT
WOULD TEND TO MOVE SEWD...AND THE WESTERN FLANK OF THE SYSTEM
WOULD HAVE THE BEST CHANCE OF MAINTAINING SOME IDENTITY GIVEN THE
DIRECTION OF LOW LEVEL INFLOW. LOW LEVEL WAA IN ADVANCE OF THE
SYSTEM COULD ALSO GENERATE SOME SCATTERED ACTIVITY GIVEN THE MOIST
AND UNSTABLE AIR MASS IN PLACE. SOME OF THE EARLIER HRRR RUNS
DEPICTED THESE SCENARIOS WITH BOTH SOME SCATTERED WAA DEVELOPMENT
AND SOME DECAYING ELEMENTS OF THE MCS SINKING SEWD THRU ERN MO. AS
A RESULT I HAVE CHANGED THE CONFIGURATION OF THE POPS OVERNIGHT
INTO EARLY TUESDAY AND INCREASED THEM IN A FEW AREAS.

GLASS

&&

.SHORT TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 208 PM CDT MON JUL 22 2013

RELATIVELY QUIET DAY TODAY THANKS TO SUBSIDENCE IN THE WAKE OF THE
SHORTWAVE THAT MOVED ACROSS THE AREA LAST NIGHT. CURRENT SURFACE
ANALYSIS SHOWS A COLD FRONT STRETCHING FROM NEBRASKA...THROUGH
NORTHWEST IOWA AND THEN NORTH BISECTING MINNESOTA. MEANWHILE...
ACTIVE CONVECTION CONTINUES TO REINFORCE AN OUTFLOW BOUNDARY ACROSS
SOUTHWEST KANSAS...OKLAHOMA AND ARKANSAS.

TONIGHT...COLD FRONT IS FORECAST BY ALL MODEL GUIDANCE TO STEADILY
MARCH SOUTHEAST...ENTERING THE NORTHERN CWA BY 12Z. DESPITE THE
APPROACHING COLD FRONT...A SUBTLE SHORTWAVE RIPPLING SOUTHEAST FROM
THE PLAINS AND ABUNDANT LOW LEVEL MOISTURE...THE MODELS REMAIN
STINGY ON QPF TONIGHT. I BELIEVE THIS IS BECAUSE THE CONVECTION THAT
FIRES AHEAD OF THE FRONT WILL LIKELY DISSIPATE/WEAKEN AS IT MOVES
INTO THE NORTHERN CWA LATER THIS EVENING WITH LOSS OF DIURNAL
INSTABILITY...AND THAT ANY NOCTURNAL DEVELOPMENT MAY BE CONFINED
FURTHER WEST WHERE BETTER 850 MOISTURE CONVERGENCE APPEARS LIKELY TO
OCCUR TO THE NORTHEAST OF THE AFOREMENTIONED EFFECTIVE SURFACE
BOUNDARY.

TUESDAY...COLD FRONT WILL BE MOVING THROUGH THE CWA WITH BEST
CHANCES OF THUNDERSTORMS RE FIRING ALONG AND SOUTH OF INTERSTATE 70
BY LATE MORNING/EARLY AFTERNOON. SPC GENEROUSLY PLACED MUCH OF THE
CWA IN A SLIGHT RISK ON THEIR LATEST DAY2 OUTLOOK. PERSONALLY THE
LACK OF ANY SIGNIFICANT SHORTWAVE UPSTREAM HAS ME THINKING THAT
COVERAGE AND THEREFORE SEVERE THREAT MAY REMAIN ISOLATED TO
SCATTERED. HAVE MAINTAINED CHANCE POPS.

TUESDAY NIGHT AND WEDNESDAY...SYNOPTIC SCALE MODELS CONTINUE TO
TREND FURTHER SOUTHWEST WITH THE DEVELOPMENT OF AN MCS...AND HAVE
FOLLOWED SUIT AS HIGH PRESSURE BUILDS INTO THE CWA. GIVEN THE
POSITION OF THE EFFECTIVE BOUNDARY RIGHT NOW...AND THE FACT THAT THE
COLD FRONT WILL HAVE PUSHED IT FURTHER SOUTH...CAN`T IMAGINE MY CWA
BEING IMPACTED BY AN MCS DURING THIS PERIOD. MUCH COOLER
TEMPERATURES ARE EXPECTED ON WEDNESDAY WITH HIGHS IN THE LOWER 80S.

WEDNESDAY NIGHT AND THURSDAY...THE SURFACE RIDGE AXIS SHOULD BE IN
CONTROL OF THE CWA DURING THIS TIME PERIOD WITH BELOW AVERAGE
TEMPERATURES AND MOSTLY CLEAR SKIES.

CVKING

.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 208 PM CDT MON JUL 22 2013

ANOTHER STRONG SHORTWAVE TROF AND COLD FRONT WILL BRING A CHANCE OF
SHOWERS AND THUNDERSTORMS TO THE REGION FRIDAY THROUGH SATURDAY
MORNING. HIGH PRESSURE TAKES HOLD OF THE AREA BY SATURDAY AFTERNOON
AND DRY WEATHER WILL CONTINUE THROUGH SUNDAY NIGHT. TEMPERATURES
WILL BE BELOW NORMAL DURING THIS PERIOD WITH CLOUD COVER AND
PRECIPITATION ON FRIDAY AND THEN COLD ADVECTION THE REMAINDER OF THE
WEEKEND AS 850MB TEMPERATURES DROP INTO THE LOWER TEENS.

CVKING

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1135 PM CDT MON JUL 22 2013

PROBABILITY FOR THUNDERSTORMS CONTINUES TO BE THE MAIN CHALLENGE
FOR THE REST OF TONIGHT AND INTO TUESDAY. AN OUTFLOW BOUNDARY
GENERATED BY A COMPLEX OF THUNDERSTORMS OVER IOWA EARLIER IN THE
EVENING IS MOVING THROUGH NORTHERN MISSOURI AND WEST CENTRAL
ILLINOIS AT THIS TIME. THIS BOUNDARY IS PRODUCING A WIND SHIFT
TO THE NORTH WITH GUSTS UP TO AROUND 20KTS...AND IS GENERATING
SCATTERED THUNDERSTORMS AS IT MOVES INTO OUR AREA. I EXPECT THIS
GENERAL TREND TO CONTINUE...WITH THE BOUNDARY MOVING SOUTH ACROSS
THE REGION GENERATING STORMS AS IT GOES. THINK COVERAGE OF STORMS
AND INTENSITY SHOULD GENERALLY DECREASE AS THE BOUNDARY MOVES FURTHER
SOUTHEAST...THO IT`S POSSIBLE THAT CENTRAL MO MAY SEE GREATER
COVERAGE AS THE AIR WILL BE MORE UNSTABLE FURTHER WEST.

EXPECT THE BOUNDARY TO STALL SOMEWHERE NEAR THE I-70 CORRIDOR ON
TUESDAY MORNING UNLESS THERE ARE MORE STORMS THAN EXPECTED TO
PUSH IT FURTHER SOUTH. EXPECT MORE THUNDERSTORMS TO FORM DURING
THE AFTERNOON TUESDAY ALONG AND SOUTH OF THE FRONT.

SPECIFICS FOR KSTL...

PROBABILITY FOR THUNDERSTORMS CONTINUES TO BE THE MAIN CHALLENGE
FOR THE REST OF TONIGHT AND INTO TUESDAY. AN OUTFLOW BOUNDARY
GENERATED BY A COMPLEX OF THUNDERSTORMS OVER IOWA EARLIER IN THE
EVENING IS MOVING THROUGH NORTHERN MISSOURI AND WEST CENTRAL
ILLINOIS AT THIS TIME. THIS BOUNDARY IS PRODUCING A WIND SHIFT
TO THE NORTH WITH GUSTS UP TO AROUND 20KTS...AND IS GENERATING
SCATTERED THUNDERSTORMS AS IT MOVES INTO OUR AREA. WILL INTRODUCE
A VCTS AT THE TERMINAL STARTING AT 08Z WHICH IS ABOUT THE TIME THE
OUTFLOW BOUNDARY WILL MOVE INTO THE AREA. THINK COVERAGE OF
STORMS AND INTENSITY SHOULD GENERALLY DECREASE AS THE BOUNDARY
MOVES INTO THE METRO AREA...BUT THE LIKELIHOOD OF A STORM LOOKS
HIGHER THAN IT DID EARLIER THIS EVENING.

EXPECT THE BOUNDARY TO STALL SOMEWHERE NEAR THE I-70 CORRIDOR ON
TUESDAY MORNING UNLESS THERE ARE MORE STORMS THAN EXPECTED TO
PUSH IT FURTHER SOUTH. EXPECT MORE THUNDERSTORMS TO FORM DURING
THE AFTERNOON TUESDAY ALONG AND SOUTH OF THE FRONT.

CARNEY

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&

$$

WFO LSX







AREA FORECAST DISCUSSION

NWS GLASGOW MT

 339 AM MDT TUE JUL 23 2013

.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH THURSDAY...
ISOLATED SHOWERS CONTINUE TO TRAVERSE ACROSS THE CWA VERY EARLY
THIS MORNING. CURRENT RADAR OBSERVATIONS INDICATE SHOWERS AND
EMBEDDED THUNDER ENTERING SOUTHWESTERN SASKATCHEWAN FROM SOUTHERN
ALBERTA AT THIS TIME. RECENT HRRR RUNS BRING THIS ACROSS THE
NORTHERN ZONES DURING THE LATE MORNING AND INTO THE AFTERNOON
HOURS. THIS HAS ADDITIONAL SUPPORT FROM THE 23/00Z ECMWF/NAM/GFS
SOLUTIONS DESPITE SUBTLE DIFFERENCES IN PLACEMENT AND TIMING. WILL
KEEP POPS GOING THROUGH MOST OF THE CWA WITH HIGHEST POPS ACROSS
THE INTERNATIONAL BORDER AND FURTHER EAST CLOSER TO NORTH DAKOTA.
WILL OPT TO KEEP PETROLEUM COUNTY DRY FOR NOW ALTHOUGH A VERY
ISOLATED SHOWER CANNOT ENTIRELY BE RULED OUT. FORECAST SOUNDINGS
INDICATE ENOUGH INSTABILITY TO INSERT MENTION OF SMALL HAIL AND
GUSTY WINDS INTO THE GRIDS. NAM BUFKIT SOUNDINGS SHOWS HIGHEST
CAPE FURTHER EAST. WILL NOT ENTIRELY RULE OUT A VERY ISOLATED
SEVERE THUNDERSTORM...ESPECIALLY ACROSS THE FAR NORTHERN AND
EASTERN ZONES DURING THE LATE AFTERNOON AND EVENING HOURS. DID
LEAVE ENOUGH FLEXIBILITY HOWEVER THAT THE DAY SHIFT CAN HAVE SOME
WIGGLE ROOM IF THEY HAVE A DIFFERENT ASSESSMENT. THE UPPER LEVEL
SHORTWAVE IS ALREADY APPARENT ON WATER VAPOR IMAGERY AND AS THIS
INTERACTS WITH A SLOWLY EASTWARD MOVING FRONTAL BOUNDARY CURRENTLY
STRETCHING FROM NORTHWEST TO SOUTHEAST ACROSS THE CWA...CONFIDENT
THAT SHOWERS AND THUNDERSTORMS WILL BECOME MORE SCATTERED ACROSS
THE FORECAST REGION.

TUESDAY NIGHT INTO WEDNESDAY...UPPER LEVEL SHORTWAVE EXITS
NORTHEAST MONTANA AS HIGH PRESSURE SETTLES IN. THIS WILL LEAD TO
LARGE SCALE SUBSIDENCE AND MOSTLY DRY CONDITIONS ACROSS THE CWA.
ANOTHER SUBTLE SHORTWAVE WILL APPROACH BY WEDNESDAY AFTERNOON AND
DID INCLUDE MENTION OF SHOWERS AND THUNDERSTORMS WITH SLIGHT
CHANCE POPS AFTER 18Z ACROSS THE FAR NORTH...OVERSPREADING THE CWA
DURING THE EVENING AND AT NIGHT.

DIFFERENCES EXIST IN MODEL SOLUTIONS ON TIMING/TRACK OF NEXT UPPER
LEVEL SYSTEM PUSHING THROUGH NORTHWEST FLOW ALOFT FOR THURSDAY
WITH THE ECWMF/GFS LEANING TOWARDS A DRIER SOLUTION BUT THE NAM
MORE BULLISH. WILL KEEP SLIGHT CHANCE POPS IN THE GRIDS FOR
NOW...BUT MODELS SEEM TO BE CONVERGING TOWARDS DRIER CONDITIONS
WITH THE CWA TO THE RIGHT OF AN UPPER LEVEL RIDGE AXIS IN A
FAVORED REGION OF DEEP VERTICAL SUBSIDENCE. WITH THE UPPER LEVEL
RIDGE AMPLIFYING INTO SOUTHERN ALBERTA...FAVORED AREAS FOR ASCENT
MAY BE MUCH FURTHER TO THE WEST. HOWEVER...AGAIN...IT WILL BE
TRICKY TO TIME SUBTLE SHORTWAVE FEATURES IN THE NORTHWEST FLOW
ALOFT ESPECIALLY GIVEN MODEL DIFFERENCES...AS DISCUSSED...SO WILL NOT GO
COMPLETELY DRY JUST YET. AS FOR TEMPERATURES...WITH LITTLE CHANGES
IN 850MB TEMPERATURES AND 500MB HEIGHT PATTERN...EXPECT LITTLE IN
THE WAY OF TEMPERATURE SWINGS OVER THE NEXT SEVERAL DAYS. LOW
TEMPERATURES WILL GENERALLY  RANGE ACROSS THE CWA IN THE MID 50S
TO NEAR 60 WITH HIGHS IN THE LOWER TO MIDDLE 80S AS A RULE OF
THUMB. MALIAWCO


.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
CANADIAN HIGH PRESSURE BUILDS INTO NORTH DAKOTA THURSDAY NIGHT AND
FRIDAY. THIS WILL THE FRONT FAR ENOUGH TO THE WEST THAT NORTHEAST
MONTANA WILL SEE DRY WEATHER AND SOMEWHAT COOLER TEMPERATURES.

A SHORTWAVE UPPER RIDGE MOVES THROUGH THE AREA FRIDAY NIGHT AND
SATURDAY. THIS WILL BRING THE FRONTAL BOUNDARY BACK EAST AS A WARM
FRONT. WITH AIRMASS FORECASTED TO BECOME UNSTABLE DURING THE DAY
ON SATURDAY...AFTERNOON AND EVENING THUNDERSTORMS WILL BE
POSSIBLE. WILL MAINTAIN A SLIGHT CHANCE FOR NOW.

SUNDAY THROUGH TUESDAY...MODELS HANDLE A SLOW MOVING UPPER
LOW/TROUGH ACROSS THE CANADIAN PRAIRIES THAT GIVES THE FORECAST
AREA FREQUENT SHORTWAVES IN A NEARLY ZONAL WSW TO WNW FLOW ALOFT.
WILL BROADBRUSH A CHANCE/SLIGHT CHANCE OF THUNDERSTORMS EACH DAY.
FORRESTER


&&

.AVIATION...
MOSTLY VFR. SCATTERED THUNDERSTORMS WILL MOVE SOUTHEAST ACROSS THE
AREA TODAY AND TONIGHT THAT MAY IMPACT ANY OF THE FOUR TERMINALS
WITH MVFR FLIGHT CONDITIONS AT TIMES. CONFIDENCE IN TIMING ANY
INDIVIDUAL STORMS AT A TAF SITE IS LOW AT THIS TIME. WILL MENTION
CB IN THE TAFS. WILL SEE EAST TO NORTHEAST WINDS 5 TO 10 KNOTS.

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

WEATHER.GOV/GLASGOW






AREA FORECAST DISCUSSION

NWS NORTH PLATTE NE

 354 AM CDT TUE JUL 23 2013

.SYNOPSIS...
ISSUED AT 353 AM CDT TUE JUL 23 2013

A WEAK COLD FRONT EXTENDS FROM NEAR THE NEBRASKA/KANSAS BORDER THEN
NORTHWEST THROUGH THE NEBRASKA PANHANDLE. A SMALL MCS MOVING INTO
CENTRAL NEBRASKA. RAINFALL AMOUNTS AT THEDFORD AND BROKEN BOW HAVE
BEEN AROUND A HALF INCH. OUTFLOW WINDS AHEAD OF THE SYSTEM HAVE
GUSTED TO AS HIGH AS 40 MPH. BROAD OUTFLOW FROM THIS SMALL MCS
EXTENDS THROUGH KIMBALL...IMPERIAL...LEXINGTON AND ORD. ANOTHER
BATCH OF SHOWERS AND THUNDERSTORMS EXITING THE BLACK HILLS NOW
NEARLY INTO CHERRY COUNTY. RECENT CLOUD TOPS AND LIGHTNING STRIKE
COUNTS HAVE BEEN NEAR STEADY STATE.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 353 AM CDT TUE JUL 23 2013

ONGOING CONVECTION IN NORTH CENTRAL NEBRASKA WILL CONTINUE TO MOVE
INTO CENTRAL NEBRASKA THIS MORNING. A FEW WEAK DISTURBANCES UPSTREAM
IN WESTERN SOUTH DAKOTA AND EASTERN MONTANA WILL CONTINUE THE
POSSIBILITY FOR AT LEAST A SLIGHT CHANCE FOR ALL AREAS EXCEPT THE
WEST CENTRAL AND SOUTHWEST COUNTIES. MOST...IF NOT ALL THE ACTIVITY
MAY END BY EARLY AFTERNOON. HIGHS BEHIND THE FRONT TODAY TO BE
COOLER RANGING FROM THE UPPER 70S NORTHEAST TO NEAR 90 FAR
SOUTHWEST. AS THE COLD FRONT CONTINUES TO PUSH SOUTHWEST...THE FOCUS
FOR THUNDERSTORMS WILL BE MAINLY ACROSS CENTRAL KANSAS BY THIS
EVENING...AND POSSIBLY THE FRONT RANGE. KEPT A SLIGHT CHANCE IN FOR
THE EASTERN PANHANDLE EARLY THIS EVENING AND FOR FRONTIER COUNTY IN
SOUTHWEST NEBRASKA. OTHERWISE SKIES TO BE MOSTLY CLEAR OVERNIGHT
WITH LIGHT AND VARIABLE WINDS. LOWS UPPER 50S.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 353 AM CDT TUE JUL 23 2013

THE MAIN FOCUS IN THE EXTENDED PERIODS CONTINUES TO BE
PRECIPITATION CHANCES...WHICH REMAIN PROBLEMATIC GIVEN THE LOW RUN
TO RUN CONSISTENCY WITH THE PERTURBATIONS THAT ARE SHOWN TO CROSS
THE REGION. THERE IS HOWEVER INCREASING CONFIDENCE WEDNESDAY INTO
THURSDAY OF A SYSTEM BRINGING RAINFALL...POSSIBLY
WIDESPREAD...BACK ACROSS MUCH OF WESTERN AND SOUTHWEST NEBRASKA.
WITH NORTHWESTERLY FLOW ALOFT IN PLACE AND A SURFACE TROUGH TO OUR
WEST...STORMS SHOULD INITIATE OFF THE HIGHER TERRAIN OF EASTERN
WYOMING DURING THE AFTERNOON HOURS WEDNESDAY...AND THEN SHIFT OFF
TO THE SOUTHEAST THROUGH THE EVENING AND INTO THE OVERNIGHT. A
MODEST LOW LEVEL JET DOES DEVELOP OVER THE CENTRAL PLAINS...WHICH
WOULD HELP MAINTAIN ANY COMPLEX OF STORMS THAT SHOULD DEVELOP.
THERE/S DISAGREEMENT HOWEVER IN HOW FAR EAST THE POTENTIAL LATE
NIGHT COMPLEX WILL MOVE...WITH THE EC DROPPING THE MCS THROUGH
NORTHEAST COLORADO INTO WESTERN KANSAS. THE GFS IS A BIT MORE
OPTIMISTIC /FURTHER EAST/ WITH RAIN CHANCES FOR SOUTHWESTERN
PORTIONS OF THE CWA OVERNIGHT WEDNESDAY/THURSDAY MORNING. WITH THE
UNCERTAINTY...WILL LIMIT POPS TO 40 PERCENT OR LESS FOR LOCATIONS
WEST OF HIGHWAY 83...WITH THE HIGHEST PROBABILITIES ACROSS
SOUTHWEST NEBRASKA...I.E. NEAR IMPERIAL. RAIN CHANCES CONTINUE
INTO FRIDAY AND THROUGH THE EXTENDED AS THE UPPER PATTERN
UNDERGOES A TRANSITION FROM NORTHWESTERLY TO ZONAL. ADDITIONAL
DISTURBANCES ARE SHOWN TO PASS THROUGH THE TRANSITIONING
FLOW...BUT REMAIN DIFFICULT TO TRACK/TIME AT THIS JUNCTURE...THUS
WILL LIMIT POPS BEYOND 00Z SATURDAY AT 25 PERCENT OR LESS UNTIL
HIGHER CONFIDENCE IS NOTED.

AS FOR TEMPERATURES...THANKS TO THE EXPECTED CLOUDS...PRECIPITATION...AND
A COLD FRONT...TEMPERATURES SHOULD COOL BACK INTO THE LOW TO MID
80S THURSDAY AND BEYOND FOR MOST LOCATIONS. THE WARMEST READINGS
WILL ONCE AGAIN BE CONFINED TO OUR FAR WEST...AS WEAK WAA PUSHES
EAST OFF THE HIGH PLAINS...MID TO UPPER 80S COULD RETURN TO THE
AREA BY EARLY NEXT WEEK. THE WARMEST DAY OF THE EXTENDED PERIOD IS
EXPECTED WEDNESDAY IN ADVANCE OF THE SHORTWAVE AND COLD
FRONT...WIDESPREAD READINGS IN THE MID TO UPPER 80S ARE
ANTICIPATED. LOWS SHOULD REMAIN SEASONAL THROUGH THE PERIOD...60S
SHOULD BE THE NORM.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1108 PM CDT MON JUL 22 2013

BOTH THE HRRR AND RAP MODELS SUGGEST THE ONGOING CONVECTION ACROSS
NWRN NEB WILL SPREAD EAST TONIGHT...SQIRTING KLBF...AND MOVING
MOSTLY EAST THROUGH KVTN...KANW AND KONL. THE CONVECTION IS
EXPECTED TO WEAKEN TOWARD 12Z AROUND KANW BUT COULD LINGER ACROSS
KONL THROUGH 18Z TUESDAY. VFR IS EXPECTED AT KLBF FOR THE NEXT 24
HR WITH JUST AN ISOLATED TSTM POTENTIAL.


&&

.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...JACOBS
AVIATION...CDC









AREA FORECAST DISCUSSION...UPDATED

NWS NORTH PLATTE NE

 1111 PM CDT MON JUL 22 2013

.SYNOPSIS...
ISSUED AT 340 PM CDT MON JUL 22 2013

SEVERAL BOUNDARIES ARE ACROSS THE HIGH PLAINS THIS AFTERNOON. A COOL
FRONT CONTINUES TO PUSH EAST...ACROSS EASTERN NEB...WITH
THUNDERSTORMS STARTING TO FIRE ACROSS NW IOWA AND INTO EASTERN NEB.
A SECONDARY...NEARLY STATIONARY...BOUNDARY EXISTS ACROSS THE SE
PANHANDLE INTO SW NEB. WINDS ON THE NORTH SIDE OF THE BOUNDARY ARE
OUT OF THE NORTH TO NORTHEAST AND SOUTHERLY TO THE SOUTH WINDS. A
THIRD BOUNDARY EXTENDS FROM THE NORTHERN PANHANDLE ACROSS CHERRY
COUNTY CURVING INTO CENTRAL NEB...WITH A LINE OF MID LEVEL CLOUDS.
TEMPS THIS AFTERNOON RANGE FROM THE MID 80S UNDERNEATH THE CLOUDS
ACROSS THE NORTH TO THE MID 90S ACROSS SW NEB.

&&

.UPDATE...
ISSUED AT 702 PM CDT MON JUL 22 2013

A LOOK AT THE HRRR MODEL FORECAST STORM MOTIONS ON THE SYSTEM
ACROSS NERN WY/WRN SD AND 850 MB MOISTURE ADVECTIONS IN THE RAP
MODEL SUGGEST THE DEVELOPING MCS UP NORTH COULD TURN SOUTH AND
SWEEP THE FCST ONCE IT MOVES EAST OF THE BLACK HILLS LATER THIS
EVENING. THE FORECAST HAS BEEN UPDATED FOR SCATTERED THUNDERSTORMS
OVERNIGHT THROUGH TUESDAY MORNING. THE HRRR SUGGESTS NORTH PLATTE
MIGHT BE THE WRN EDGE OF THE TSTM COMPLEX. THE FORECAST SHIFTS
THIS WEST A BIT TO NEAR OGALLALA.

GIVEN THE SHEAR PROFILES AND FCST STORM MOTION OF 10 KTS OR
LESS...WE WOULD LIKELY SEE A COLD POOL DRIVEN OUTFLOW DOMINANT RAIN
MAKER WITH GUSTY WINDS AND ISOLATED LARGE HAIL OVERNIGHT.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 340 PM CDT MON JUL 22 2013

TONIGHT WITH THE NUMEROUS BOUNDARIES ACROSS THE AREA...EXPECT A
COUPLE DIFFERENT AREAS OF THUNDERSTORMS. DECENT CU FIELD ACROSS
GARDEN COUNTY AND CAP HAS ERODED...WHILE GOOD CAPE. LIKELY GOING TO
SEE SOME STORMS DEVELOP OVER THE NEXT HOUR OR TWO...WITH MOVEMENT TO
THE SE. A SECOND AREA OF SHOWERS EXPECTED ACROSS THE FAR N...NEAR
THE S DAKOTA BORDER WITH THE AID OF AN UPPER LEVEL WAVE. THIS SHOULD
DIVE TOWARDS CENTRAL NEB.

BY TOMORROW MORNING FOCUS SHOULD BE THE STALLED MID LEVEL BOUNDARY
ACROSS NW INTO CENTRAL NEB. MODELS CONTINUE TO SHOW REDEVELOPMENT TO
THE NW...SIMILAR TO THIS MORNING...THEN DRIFTING SE. MODELS IN GOOD
AGREEMENT ALLOWING SOME MOISTURE TO POOL ALONG THE BOUNDARY AS PWATS
INCREASE TO AROUND 1.50 INCHES...AND SHOULD BE ENOUGH TO GET ISOLD
LATE MORNING AND EARLY AFTERNOON SHOWERS.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 340 PM CDT MON JUL 22 2013

UNSETTLED PERIOD EXPECTED...WITH SEVERAL UPPER LEVEL WAVES
FORECASTED TO ROTATE EAST ACROSS THE REGION ON NORTHERN PERIPHERY OF
SOUTHERN PLAINS UPPER LEVEL RIDGE. THE STRONGEST OF THESE SYSTEMS IS
FORECASTED TO ARRIVE THURSDAY INTO THURSDAY NIGHT...AND THIS PERIOD
WILL BE OUR BEST CHANCE FOR RAIN. MODELS HAVE STRUGGLED SLIGHTLY ON
EXACTLY WHERE THE NEXT FOCUS WILL BE...AND FOR THIS REASON WILL
LEAVE POPS CAPPED AT 40 PERCENT AT THIS TIME. LATER MODEL RUNS WILL
HELP DETERMINE WHERE THE HIGHER POPS /IF WARRANTED/ WILL BE
PLACED.

AFTER THE THURSDAY/THURSDAY NIGHT SYSTEM...STILL A SLIGHT CHANCE FOR
MORE RAIN INTO THE WEEKEND...AS WEAK WAVES CONTINUE TO CROSS THE
AREA. VERY HARD TO PIN DOWN EXACT TIMING AND LOCATION AT THIS
POINT...SO WILL ONLY KEEP CHANCES SLIGHT AT THIS TIME. THE OTHER
STORY WILL BE THE TEMPERATURES. A STRONG AREA OF LOW PRESSURE IS
EXPECTED TO FORM ACROSS SOUTHEAST CANADA FRIDAY INTO THE
WEEKEND...AND THIS SHOULD PUSH A FAIRLY STRONG COLD FRONT SOUTHWEST
INTO THE AREA. LOOKS LIKE THE FRONT WILL STALL IN CENTRAL
NEBRASKA...SO THE COOLER READINGS...WITH HIGHS AROUND 80...WILL BE
FOUND ALONG AND NORTHEAST OF A BROKEN BOW TO AINSWORTH LINE. AREAS
SOUTHWEST SHOULD GENERALLY SEE HIGHS IN THE 80S. HUMIDITY WILL ALSO
BE SCOURED OUT SOME...SO CONDITIONS LOOKING PLEASANT.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1108 PM CDT MON JUL 22 2013

BOTH THE HRRR AND RAP MODELS SUGGEST THE ONGOING CONVECTION ACROSS
NWRN NEB WILL SPREAD EAST TONIGHT...SQIRTING KLBF...AND MOVING
MOSTLY EAST THROUGH KVTN...KANW AND KONL. THE CONVECTION IS
EXPECTED TO WEAKEN TOWARD 12Z AROUND KANW BUT COULD LINGER ACROSS
KONL THROUGH 18Z TUESDAY. VFR IS EXPECTED AT KLBF FOR THE NEXT 24
HR WITH JUST AN ISOLATED TSTM POTENTIAL.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...CDC
SYNOPSIS...MASEK
SHORT TERM...MASEK
LONG TERM...TAYLOR
AVIATION...CDC







AREA FORECAST DISCUSSION

NWS BINGHAMTON NY

 309 AM EDT TUE JUL 23 2013

.SYNOPSIS...
A COLD FRONT WILL BRING ADDITIONAL SHOWERS, AND A FEW
THUNDERSTORMS TO NY AND PA TODAY AND THIS EVENING. PLEASANTLY COOLER
AND DRIER WEATHER WILL SETTLE IN FOR WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPPER LEVEL SYSTEM WILL SLIDE EASTWARD TODAY, TAKING HIGHER PWATS
EAST OF FA. HOWEVER A COLD FRONT WILL SLIDE INTO NY AND PA TO SPUR
ADDITIONAL CONVECTION.

THE STRATIFORM RAIN CURRENTLY OVER FA WILL DIMINISH IN COVERAGE
AND SLIDE NORTHEAST TOWARD SUNRISE, AS FORECAST BY THE PREVIOUS
FEW HRRR RUNS. SKIES WILL BE MAINLY CLOUDY, THOUGH THERE IS POTENTIAL
FOR A FEW BREAKS OVER THE CENTRAL SOUTHERN TIER WHERE TEMPS MAY
PUSH INTO THE LOWER 80S.

SHOWERS AND A FEW THUNDERSTORMS WILL RETURN WITH THE COLD FRONT.
LACK OF WINDS AND MODEST INSTABILITY SUGGEST NO SVR THREAT. WILL
NEED TO MONITOR HEAVY RAINERS OVER AREAS WHICH RECEIVED COPIOUS
RAIN ON MONDAY. THESE ARE ISOLATED PROBLEMS, SO WILL NOT BE
ISSUING A FLASH FLOOD WATCH PER COORDINATION WITH NEIGHBORING
OFFICES.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
COLD FRONT WILL SCOUR OUT REMAINING MOISTURE THIS EVENING, WITH
PRECIP GRADUALLY ENDING OVERNIGHT. HIGH PRESSURE WILL FOLLOW IN
ITS WAKE, BRINGING STRONG DOWNWARD MOTION AND AN UNSEASONABLY COOL
AIRMASS.

850MB TEMPS PROGGED AROUND 8C FOR WEDNESDAY INTO EARLY THURSDAY.
WITH MOSTLY SUNNY SKIES, THIS SHOULD YIELD MAX TEMPS MAINLY IN THE
70S ON WEDNESDAY WITH A FEW 80S POSSIBLE FROM THE CENTRAL SOUTHERN
TIER DOWN INTO PA. OVERNIGHT MINS WILL DIP INTO THE LOW AND MIDDLE
50S...THE COOLEST TEMPS WE HAVE WITNESSED IN JULY 2013. A FEW
READINGS IN THE UPPER 40S ARE FORECAST IN THE SHELTERED RURAL
VALLEYS.

HIGH PRESSURE WILL REMAIN IN CONTROL INTO THURSDAY, THOUGH MODELS
SUGGEST POTENTIAL FOR SOME RETURN FLOW INTO OUR FAR SERN COUNTIES
LATE IN THE PERIOD WHERE WE HAVE ADDED A SLIGHT CHANCE FOR A
SHOWER.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
3 PM MON UPDATE...
AN UNSETTLED WEATHER PATTERN IS EXPECTED ACROSS THE AREA AS BROAD
TROUGHING AND SW FLOW ALOFT IS EXPECTED TO SETTLE OVER THE
NORTHEAST THROUGH NEXT WEEKEND. MULTIPLE VORT MAXES WILL TRAVEL
AROUND THE BASE OF THE TROUGH AND EJECT NORTHEASTWARD RESULTING IN
A CHANCE FOR SHOWERS AND THUNDERSTORMS EACH DAY THROUGH THE
EXTENDED. MODELS PROJECT A COLD FRONT MOVING INTO OUR REGION
SUNDAY WHICH WILL RESULT IN COOLER AND DRIER AIR FOR THE REGION.
AS THE DRY AIR FUNNELS IN FROM THE WEST...A BRIEF DRY PERIOD MAY
RETURN TO THE AREA.

&&

.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
SHRT WV ACTING ON DEEP MOISTURE BRINGING WIDESPREAD RAIN AND GNRL
MVFR CIGS AND VSBYS...WITH BRIEF IFR AT TIMES. WV WILL MVE EAST
THIS MRNG AND CLR THE AREA ARND OR SHRTLY AFT 12Z. THIS WILL ALLOW
SLOWLY IMPRVG CONDS THRU THE DAY TODAY AND A RETURN TO VFR AS
DRIER AIR MVES IN. VFR CONDS SHD CONT THRU THE END OF THE PD.

.OUTLOOK...

LATE TUE NGT...SCATTERED MVFR SHRA.

WED/THU/...VFR

FRI/SAT...CHANCE OF SCATTERED MVFR SHRA/TSRA

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.

&&

$$
SYNOPSIS...DJP
NEAR TERM...DJP
SHORT TERM...DJP
LONG TERM...KAH
AVIATION...DGM/DJN







AREA FORECAST DISCUSSION

NWS WILMINGTON NC

 116 AM EDT TUE JUL 23 2013

.SYNOPSIS...
SEASONABLE AND WARM TEMPERATURES WILL CONTINUE WITH ISOLATED TO
SCATTERED AFTERNOON SHOWERS AS BERMUDA HIGH PRESSURE REACHES INTO
THE AREA FROM THE EAST . A FRONT WILL APPROACH FROM THE NORTHWEST
WEDNESDAY NIGHT AND STALL ACROSS THE AREA ON THURSDAY...PRODUCING
MORE UNSETTLED WEATHER THROUGH LATE WEEK. ANOTHER COLD FRONT WILL
MOVE INTO THE AREA EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1:15 AM TUESDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:

BERMUDA HIGH PRESSURE OVER A THOUSAND MILES OFF THE COAST IS
PRODUCING A SOUTHWEST FLOW ACROSS THE EASTERN CAROLINAS. LOW
PRESSURE MOVING EAST THROUGH THE CENTRAL APPALACHIANS AND A
PIEDMONT TROUGH STATIONARY ACROSS THE CENTRAL CAROLINAS INTO
EASTERN VIRGINIA ARE BOTH HELPING TO PINCH THE PRESSURE GRADIENT
TIGHTER. SINCE SUNSET...INLAND TEMPERATURES HAVE COOLED
SUFFICIENTLY TO SHIFT MOST OF THE WIND`S MOMENTUM UP INTO A LOW
LEVEL JET WITH 1000 FT AGL WIND SPEED NEAR 30 KNOTS. OVER THE WARM
OCEAN AND ALONG PRIMARILY SOUTH-FACING BEACHES THESE STRONGER
WINDS ARE MIXING DOWN TO THE SURFACE WITH WIND GUSTS OVER 30 MPH
RECENTLY REPORTED FROM OAK ISLAND AND BALD HEAD ISLAND.

AS A LANDBREEZE HELPS ADVECT SOME OF THE COOLER AIR INLAND DOWN TO
THE COAST OVERNIGHT LOW-LEVEL LAPSE RATES SHOULD LESSEN ENOUGH TO
PREVENT THESE STRONGER WINDS FROM COMING DOWN TO THE SURFACE. UNTIL
THEN...HANG ONTO YOUR HAT ALONG THE BRUNSWICK COUNTY BEACHES.

A POCKET OF DRY AIR IN THE 800-500 MB LAYER WILL EXIT THE COAST
SHORTLY...WITH PRECIPITABLE WATER VALUES RISING FROM 1.7 INCHES TO
NEARLY 2 INCHES LATE TONIGHT. AN UPPER LEVEL DISTURBANCE PRODUCING
T-STORMS ACROSS THE MOUNTAINS AND FOOTHILLS WILL APPROACH THE
EASTERN CAROLINAS AROUND DAYBREAK. THIS IS TYPICALLY THE MOST
UNFAVORABLE TIME OF DAY FOR CONVECTION WITH INSTABILITY THE WEAKEST.
FORECAST SOUNDINGS SHOW TOO MUCH CAPPING TO OVERCOME GIVEN THE
MODEST LIFT AHEAD OF THE UPPER DISTURBANCE SO I HAVE MAINTAINED A
DRY FORECAST OVERNIGHT FOR MOST AREAS. AT THE BEACHES AND ESPECIALLY
OFFSHORE...ISOLATED TO SCATTERED SHOWERS MAY DEVELOP LATE WITHIN
WARMER...MORE UNSTABLE CONDITIONS.

NO SIGNIFICANT CHANGES HAVE BEEN MADE TO LOW TEMPERATURE FORECASTS
WHICH RANGE FROM 73-77...WARMEST AT THE BEACHES.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...A SHORTWAVE WILL RIDE THROUGH A VERY BROAD
TROUGH LOCATED OVER THE EASTERN CONUS. THIS WILL HELP TO PRODUCE
SOME CLOUDS AND A FEW SHOWERS EARLY MORNING ON TUES BUT THE
SHORTWAVE WILL SHIFT OFF THE COAST BY AFTERNOON WITH A DEEPER W-NW
FLOW OF DRIER AIR AND SUBSIDENCE DEVELOPING THROUGH TUES AFTN INTO
WED. THE WESTERLY DOWNSLOPE COMPONENT TO THE FLOW WILL ALSO AID IN
DRYING AND WARMING...ESPECIALLY INLAND THROUGH TUES AFTN. TEMPS
SHOULD REACH 90 OR SLIGHTLY ABOVE MOST PLACES TUES AND DROP TO
THE MID 70S OVERNIGHT.

THE DRIER AIR AND SUBSIDENCE THROUGH THE MID LEVELS WILL HOLD
THROUGH MUCH OF WEDNESDAY AS FRONT BEGINS TO ENTER INTO CAROLINAS
FROM THE NORTH AND WEST BY LATE DAY. BY WED NIGHT THE MID TO UPPER
TROUGH BECOMES MORE AMPLIFIED AS IT PUSHES A FRONT/TROUGH SOUTH
AND EAST INTO AREA. THIS WILL INCREASE CHANCES OF SHWRS/TSTMS
OVERNIGHT BUT MORE SO ON THURS. THE WESTERLY DOWNSLOPE WINDS IN
THE LOW LEVELS AND A GOOD DEAL OF SUNSHINE WILL AID IN PUSHING
TEMPS INTO THE 90S ON WED.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...A SERIES OF SHORTWAVE TROUGHS MOVING THROUGH THE
AMPLIFIED FLOW ALOFT WILL KEEP WEATHER ACTIVE DURING THE PERIOD.
BOTH SHORTWAVES WILL BE ACCOMPANIED BY A COLD FRONT THAT WILL TRY TO
PUSH ACROSS THE AREA. THE FIRST WILL BE MOVING INTO THE AREA AS THE
PERIOD BEGINS WITH A SECOND STRONGER FRONT ARRIVING MON. THE LARGE
SCALE 5H TROUGH AXIS REMAINS WEST OF THE AREA THROUGH AT LEAST THE
WEEKEND. THE FIRST FRONT ENDS UP LAYING PARALLEL TO THE STEERING
FLOW AND STALLS ACROSS OR JUST EAST OF THE AREA. SURFACE BOUNDARY IN
AIR MASS WITH DEEP MOISTURE AND DIURNAL INSTABILITY SHOULD PROVIDE A
FOCAL POINT FOR CONVECTION. SOME UNCERTAINTY WITH RESPECT TO THE
LOCATION OF THE FRONT AND AMOUNT OF DRY AIR ALOFT SPREADING OVER THE
AREA FRI/SAT SO WILL CARRY LOWER POP DURING THESE PERIODS THOUGH
STILL IN THE CHANCE CATEGORY DURING THE DAY.

PRECIP CHANCES INCREASE SUN/MON AS NEXT COLD FRONT APPROACHES FROM
THE WEST AND DEEP MOISTURE RETURNS. DIVERGENCE ALOFT WILL ENHANCE
BOTH LIFT ALONG THE FRONT AND DIURNAL INSTABILITY. TIMING...LOCATION
AND STRENGTH DIFFERENCE BETWEEN GFS/ECMWF DO ADD A LITTLE BIT OF
UNCERTAINTY EARLY NEXT WEEK SO FOR NOW WILL MAINTAIN CHANCE POP BUT
SHOW AN INCREASE OVER FRI/SAT.

HIGHS WILL BE NEAR TO SLIGHTLY BELOW CLIMO THROUGH THE PERIOD WITH
LOWS NEAR TO SLIGHTLY ABOVE CLIMO.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 06Z...SYNOPTICALLY NOT MUCH HAS CHANGED IN THE PAST 24 HOURS.
AIR A BIT DRIER ALOFT...BUT SOME DEEPER MOISTURE MAY WORK ITS WAY IN
AFTER MIDNIGHT WITH A SLIGHT CHANCE OF SHOWERS. ANY CONVECTION
TOWARD MORNING WILL LIKELY SET UP JUST OFFSHORE.

BASED MAINLY ON CONTINUITY...WILL INTRODUCE NEAR IFR STRATUS AT THE
INLAND TERMINALS...WITH A MVFR CEILING FORMING NEAR SUNRISE. WINDS
AT THE BOUNDARY LAYER ARE TOO STRONG TO SUPPORT FOG...MVFR BEFORE
SUNRISE WORST CASE. TUESDAY...DAYTIME HEATING WILL KICK OFF
SCATTERED CONVECTION BY 17Z...FOCUSED FIRST ON THE SEA BREEZE
BOUNDARY WITH SCATTERED ACTIVITY INLAND AFTER 19Z. CONVECTION WILL
WIND DOWN SEVERAL HOURS AFTER MAX HEATING.

EXTENDED OUTLOOK...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
ARE EXPECTED THROUGH THURSDAY...WITH BRIEF LOCALIZED PERIODS OF
MVFR/IFR POSSIBLE. OTHERWISE EXPECT VFR.

&&

.MARINE...
NEAR TERM/THROUGH TONIGHT/...AS OF 1:15 AM TUESDAY...NO CHANGES TO
THE FORECAST WITH THE LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:

RECENT WIND GUSTS HAVE REACHED 31 KNOTS AT THE OCEAN CREST PIER ON
OAK ISLAND...28 KNOTS ON BALD HEAD ISLAND...AND 27 KNOTS AT THE
FRYING PAN SHOALS BUOY. THIS APPEARS TO BE FROM A LOW-LEVEL JET
DEVELOPING INLAND WHERE SURFACE TEMPERATURES ARE COOLER. AS THIS
JET BLOWS EAST TO THE COAST AND ENCOUNTERS A WARMER MORE WELL-
MIXED ENVIRONMENT THE MOMENTUM IS DISTRIBUTED DOWNWARD IN STRONG
GUSTS AS WE ARE SEEING. THIS ADDITIONAL INPUT OF WIND ENERGY INTO
THE OCEAN HAS PUSHED SEA HEIGHTS UP TO 5.5 FEET AT THE WILMINGTON
HARBOR BUOY JUST SOUTH OF SOUTHPORT...AND TO 6 FEET AT THE FRYING
PAN SHOALS BUOY. FOR THIS REASON I HAVE ISSUED A SMALL CRAFT
ADVISORY FOR THE NC WATERS THROUGH 3 AM...AND RETAINED THE
EXERCISE CAUTION HEADLINE FOR THE SC WATERS AS WELL.

THE LATEST SEVERAL RUNS OF THE HRRR AND THE 18Z NAM SHOW THIS
LOW-LEVEL JET FAIRLY WELL...WITH 975 MB (1000 FT AGL) WIND SPEEDS
HOLDING AROUND 30 KNOTS THROUGH 06Z (2 AM EDT) BEFORE VEERING
DIRECTIONS MORE WESTERLY WITH DECREASING SPEEDS LATE.

OUR SYNOPTIC WEATHER PATTERN FEATURES BERMUDA HIGH PRESSURE OVER A
THOUSAND MILES OFF THE CAROLINA COAST. LOW PRESSURE IS MOVING EAST
THROUGH THE CENTRAL APPALACHIANS...AND A PIEDMONT TROUGH IS
STATIONARY ACROSS THE CENTRAL CAROLINAS INTO EASTERN VIRGINIA. THE
PRESSURE GRADIENT SOUTH OF THE CENTRAL APPALACHIAN LOW IS PRODUCING
THE BREEZY SOUTHWEST WINDS...WHICH SHOULD VEER MORE WESTERLY
OVERNIGHT WITH A DEVELOPING LANDBREEZE. ALTHOUGH THE RADAR IS
CURRENTLY CLEAR...THE APPROACH OF AN UPPER LEVEL DISTURBANCE AFTER
MIDNIGHT COULD HELP IGNITE ISOLATED SHOWERS OR T-STORMS OVER THE
WATERS...BUT MAINLY FARTHER EAST AWAY FROM SHORE.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...SOUTHWEST WINDS WILL CONTINUE BETWEEN BERMUDA
HIGH TO THE EAST AND TROUGH ACROSS INLAND CAROLINAS. THE WINDS
WILL PICK UP SLIGHTLY TUES AFTN AS PINCHED GRADIENT DEVELOPS AS
TROUGH BECOMES MORE PRONOUNCED INLAND AND PUSHES EAST SLIGHTLY
IN COMBINATION WITH AFTN SEA BREEZE. BY WED NIGHT INTO EARLY
THURS A FRONT WILL MOVE DOWN FROM THE NORTH AND WEST WITH WINDS
SHIFTING TO THE N-NE TO THE NORTH OF THE BOUNDARY AND REMAINING SW
TO THE SOUTH OF THE BOUNDARY. OVERALL EXPECT SOUTHWEST WINDS OF
10-15 KNOTS THROUGH MUCH OF THE PERIOD. SEAS WILL RANGE FROM 2-4
FT.

LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3 PM MONDAY...SOUTHERLY FLOW THU WILL BECOME LIGHT AND
VARIABLE FRI AND SAT AS WEAK SURFACE BOUNDARY MOVES ACROSS THE
WATERS. MAY SEE SOME PERIODS OF LIGHT NORTHERLY FLOW BUT PROXIMITY
TO THE BOUNDARY WILL KEEP SPEEDS UNDER 10 KT. LATE IN THE PERIOD
REMNANTS OF BOUNDARY LIFT NORTH WITH LIGHT SOUTHERLY FLOW
DEVELOPING. WEAK GRADIENT THROUGH THE PERIOD KEEPING WINDS UNDER 10
KT WILL KEEP SEAS AROUND 2 FT FOR MUCH OF THE PERIOD...THOUGH SOME
ISOLATED 3 FT IS POSSIBLE AWAY FROM SHORE.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 AM EDT EARLY THIS MORNING FOR
     AMZ250-252.

&&

$$

NEAR TERM...REK/TRA
AVIATION...DL
MARINE...REK/TRA





AREA FORECAST DISCUSSION

NWS CHARLESTON WV

 350 AM EDT TUE JUL 23 2013

.SYNOPSIS...
MID/UPPER DISTURBANCES MOVING UP THE OHIO VALLEY INTO WEDNESDAY WITH
ROUNDS OF CONVECTION.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
130 AM UPDATE...
NO SIGNIFICANT CHANGES TO ONGOING FORECAST. BACK EDGE OF PRECIP
APPROACHING THE OHIO RIVER AT THIS TIME.

PREVIOUS DISCUSSION FOLLOWS...
WILL BE TRACKING A POTENT UPR LVL SYS...LOCATED ACROSS W OH AND
KY...WITH A MESO VORTEX APPENDAGE MOVING NE INTO NE KY. USED LATEST
RUC AND HRRR FOR TIMING AND PLACEMENT OF POPS WITH THIS SYS WITH HVY
SHRA CURRENTLY MOVING BACK INTO NE KY AND SE OH AND INTO S WV/SW VA
BY 21Z. HAVE SCT SHRA IN GRIDS IN MEANTIME. LOW CLDS SCT OUT ACROSS
WV/SW VA RVR WHICH WILL HELP TO DESTABILIZE ATMOS FOR THIS SYS TO
WORK ON THIS AFTN. ROLLED WITH CATEGORICAL POPS MOST PLACES LATE
AFTN INTO EARLY THIS EVE AND INSERTED HVY RA WORDING IN COVERAGE
TERMS AS PWATS ON EITHER SIDE OF 2 INCHES. FLASH FLOOD WATCH CONT
THRU TONIGHT.

UPR TROF CROSSES TONIGHT WITH PERHAPS ADDITIONAL SHRA/TSRA MOVING
IN THIS EVE AFFECTING SE OH/NE KY/N WV. TROF AXIS SHOULD BE E OF
AREA AFTER 09Z WITH PCPN THREAT DIMINISHING.

THINK SOME LOW STRATUS AND FG DEVELOPS OVERNIGHT WHICH MAY TAKE
UNTIL MID MORNING TO SCT OUT. HAVE ISO TO SCT SHRA/TSRA BY
AFTN...WITH AN UPTICK LATE WITH A FAST MOVING SYS DROPPING IN NW
FLOW ALOFT.

ROLLED WITH WARMER GUIDANCE TONIGHT AND TOMORROW...THINKING AREA
SHOULD GET A DECENT SHOT OF SUN TOMORROW BEFORE SHRA/TSRA GET GOING.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... MODELS
INDICATED ANOTHER BROAD LOW PRESSURE SYSTEM OVER CANADA SPITTING
ENERGY IN FORM OF VORTICITY MAXES SOUTH ACROSS SOUTHEAST OH AND WV
WEDNESDAY. A COLD FRONT WILL EXIT THE EASTERN MOUNTAINS ON
WEDNESDAY. THEREFORE...KEPT THE PREVIOUS TREND OF DECREASING POPS
WITH CHANCES ACROSS THE WESTERN SLOPES AND HIGHER ELEVATIONS...TO
SLIGHT CHANCES ACROSS THE LOWLANDS...DIMINISHING TOWARDS WEDNESDAY
EVENING.

A HIGH PRESSURE BUILDS IN WEDNESDAY...TO PROVIDE DRY CONDITIONS
THROUGH THURSDAY NIGHT. THE EXCEPTION WILL BE AFTERNOON CLOUDS AND
ISOLATED SHOWERS. AREAS OF FOG CAN BE ANTICIPATED EARLY THURSDAY
MORNING OVER AREAS THAT RECEIVE RAIN FROM THE PASSING COLD FRONT.

BEHIND THE FRONT...RELATIVELY COOLER AIR FILTERS IN TO KEEP
COMFORTABLE TEMPERATURES WEDNESDAY...REACHING 80F ACROSS THE
LOWLANDS...RANGING TO THE LOWER 70S HIGHER TERRAIN. IT WILL FEW
DEGREES WARMER THURSDAY PER WEAK WARM ADVECTION FROM THE
SOUTHWEST...AND PLENTY OF SUNSHINE.

FOR MIN TEMPERATURES WENT COOLER ON WEDNESDAY NIGHT AS H850
TEMPERATURES DROP TO 9C...AND WITH CLEAR SKIES...EXPECT
RADIATIONAL COOLING FOR A COMFORTABLE NIGHT.

USED A BLEND OF BIAS CORRECTED SREF AND BIAS CORRECTED GMOS
THROUGH THE PERIOD.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
DRIER AIR MOVES IN TO CLOSE OUT THE WEEK AS TROUGH DIGS OVER THE
GREAT LAKES SATURDAY AND SUNDAY. GFS AND EURO MODELS HANDLING
FEATURES IN SEPARATE FASHION AND DEFERRED TO HPC GRIDS FOR
EXTENDED PERIOD. NO MAJOR CHANGES TO WPC MEDIUM RANGE GUIDANCE
TEMPERATURES.

&&

.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
06Z TUESDAY THRU 06Z WEDNESDAY...

SCATTERED SHOWERS CONTINUE PRIMARILY ACROSS THE EASTERN PART OF
THE AREA...WITH THE BACK EDGE OF THE PRECIPITATION CURRENTLY
APPROACHING THE OHIO RIVER. SHOULD A HEAVIER SHOWER DIRECTLY
IMPACT A TERMINAL...BRIEF MVFR VIS MAY RESULT. OTHERWISE EXPECT
SHOWERS TO END FROM WEST TO EAST OVERNIGHT. IFR AND SUB-IFR
CONDITIONS IN FOG AND LOW STRATUS STILL EXPECTED FOR MOST
LOCATIONS BY THE 09Z-12Z TIME FRAME. THIS WILL SCATTER/RISE BY THE
MID-MORNING HOURS WITH VFR CONDITIONS PREVAILING THROUGH THE
REMAINDER OF THE DAY. SCATTERED SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO FORM ONCE AGAIN LATE AFTERNOON AND EVENING WHICH MAY
RESULT IN INTERMITTENT MVFR/IFR VIS...WITH MORE GENERAL COVERAGE
OF PRECIP ARRIVING NEAR THE END OF THE VALID PERIOD WITH THE
APPROACH OF A COLD FRONT.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...

FORECAST CONFIDENCE: LOW.

ALTERNATE SCENARIOS: TIMING/DENSITY OF FOG AND STRATUS MAY VARY
OVERNIGHT AND EARLY THIS MORNING...AS WELL AS TIMING OF
IMPROVEMENT THIS MORNING.

EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH:   TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW:    TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.

DATE                    TUE 07/23/13
UTC 1HRLY       08   09   10   11   12   13   14   15   16   17   18   19
EDT 1HRLY       04   05   06   07   08   09   10   11   12   13   14   15
CRW CONSISTENCY  H    H    H    H    H    H    M    H    H    M    M    M
HTS CONSISTENCY  L    L    L    L    L    L    H    H    M    H    H    H
BKW CONSISTENCY  H    H    L    L    M    H    H    H    H    H    H    H
EKN CONSISTENCY  M    L    L    M    L    M    M    H    M    H    H    H
PKB CONSISTENCY  M    H    M    H    L    L    H    H    M    M    M    M
CKB CONSISTENCY  H    M    M    M    M    H    H    H    M    M    M    M

AFTER 06Z WEDNESDAY...
IFR OR WORSE FOG POSSIBLE WEDNESDAY MORNING.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...KMC/30
NEAR TERM...50/30
SHORT TERM...ARJ
LONG TERM...KMC
AVIATION...50









AREA FORECAST DISCUSSION

NWS CHARLESTON WV

 148 AM EDT TUE JUL 23 2013

.SYNOPSIS...
MID/UPPER DISTURBANCES MOVING UP THE OHIO VALLEY INTO WEDNESDAY WITH
ROUNDS OF CONVECTION. FLASH FLOOD HAZARD LINGERS.

&&

.NEAR TERM /THROUGH TODAY/...
130 AM UPDATE...
NO SIGNIFICANT CHANGES TO ONGOING FORECAST. BACK EDGE OF PRECIP
APPROACHING THE OHIO RIVER AT THIS TIME.

PREVIOUS DISCUSSION FOLLOWS...
WILL BE TRACKING A POTENT UPR LVL SYS...LOCATED ACROSS W OH AND
KY...WITH A MESO VORTEX APPENDAGE MOVING NE INTO NE KY. USED LATEST
RUC AND HRRR FOR TIMING AND PLACEMENT OF POPS WITH THIS SYS WITH HVY
SHRA CURRENTLY MOVING BACK INTO NE KY AND SE OH AND INTO S WV/SW VA
BY 21Z. HAVE SCT SHRA IN GRIDS IN MEANTIME. LOW CLDS SCT OUT ACROSS
WV/SW VA RVR WHICH WILL HELP TO DESTABILIZE ATMOS FOR THIS SYS TO
WORK ON THIS AFTN. ROLLED WITH CATEGORICAL POPS MOST PLACES LATE
AFTN INTO EARLY THIS EVE AND INSERTED HVY RA WORDING IN COVERAGE
TERMS AS PWATS ON EITHER SIDE OF 2 INCHES. FLASH FLOOD WATCH CONT
THRU TONIGHT.

UPR TROF CROSSES TONIGHT WITH PERHAPS ADDITIONAL SHRA/TSRA MOVING
IN THIS EVE AFFECTING SE OH/NE KY/N WV. TROF AXIS SHOULD BE E OF
AREA AFTER 09Z WITH PCPN THREAT DIMINISHING.

THINK SOME LOW STRATUS AND FG DEVELOPS OVERNIGHT WHICH MAY TAKE
UNTIL MID MORNING TO SCT OUT. HAVE ISO TO SCT SHRA/TSRA BY
AFTN...WITH AN UPTICK LATE WITH A FAST MOVING SYS DROPPING IN NW
FLOW ALOFT.

ROLLED WITH WARMER GUIDANCE TONIGHT AND TOMORROW...THINKING AREA
SHOULD GET A DECENT SHOT OF SUN TOMORROW BEFORE SHRA/TSRA GET GOING.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
COLD FRONT SWINGS THROUGH TUESDAY NIGHT AS 5H TROF SWINGS THROUGH
AT THE MID LEVELS. CARRIED LIKELY POPS AS THERE WILL BE DECENT
DYNAMIC FORCING COUPLED WITH PLENTY OF A AVAILABLE MOISTURE.
HOWEVER...CHANCES FOR SEVERE WEATHER ASSOCIATED WITH THIS FEATURE
WILL BE LIMITED DUE TO THE LACK OF DAYTIME HEATING DURING THE
OVERNIGHT HOURS.

AS HIGH PRESSURE BUILDS IN WEDNESDAY...BULK OF MOISTURE WILL BE
SHUNTED TO THE EAST...LEADING TO A DRYING TREND. SHOULD SEE A
NOTICEABLE DECREASE IN CONVECTIVE ACTIVITY WEDNESDAY AND THURSDAY
AS LOW AND MID LEVEL COOL POOL HELPS TO STABILIZE THE ATMOSPHERE.
LEFT CHANCE POPS IN FOR MOUNTAINS AS HEATING IN ELEVATED TERRAIN
COULD STILL LEAD TO SOME CONVECTIVE DEVELOPMENT.

WILL SEE A COOLING TREND THIS PERIOD. GOING WITH MODEL BLEND FOR
TEMPERATURES THIS PERIOD.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
DRIER AIR MOVES IN TO CLOSE OUT THE WEEK AS TROUGH DIGS OVER THE
GREAT LAKES SATURDAY AND SUNDAY. GFS AND EURO MODELS HANDLING
FEATURES IN SEPARATE FASHION AND DEFERRED TO HPC GRIDS FOR
EXTENDED PERIOD. NO MAJOR CHANGES TO WPC MEDIUM RANGE GUIDANCE
TEMPERATURES.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
06Z TUESDAY THRU 06Z WEDNESDAY...

SCATTERED SHOWERS CONTINUE PRIMARILY ACROSS THE EASTERN PART OF
THE AREA...WITH THE BACK EDGE OF THE PRECIPITATION CURRENTLY
APPROACHING THE OHIO RIVER. SHOULD A HEAVIER SHOWER DIRECTLY
IMPACT A TERMINAL...BRIEF MVFR VIS MAY RESULT. OTHERWISE EXPECT
SHOWERS TO END FROM WEST TO EAST OVERNIGHT. IFR AND SUB-IFR
CONDITIONS IN FOG AND LOW STRATUS STILL EXPECTED FOR MOST
LOCATIONS BY THE 09Z-12Z TIME FRAME. THIS WILL SCATTER/RISE BY THE
MID-MORNING HOURS WITH VFR CONDITIONS PREVAILING THROUGH THE
REMAINDER OF THE DAY. SCATTERED SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO FORM ONCE AGAIN LATE AFTERNOON AND EVENING WHICH MAY
RESULT IN INTERMITTENT MVFR/IFR VIS...WITH MORE GENERAL COVERAGE
OF PRECIP ARRIVING NEAR THE END OF THE VALID PERIOD WITH THE
APPROACH OF A COLD FRONT.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...

FORECAST CONFIDENCE: LOW.

ALTERNATE SCENARIOS: TIMING/DENSITY OF FOG AND STRATUS MAY VARY
OVERNIGHT AND EARLY THIS MORNING...AS WELL AS TIMING OF
IMPROVEMENT THIS MORNING.

EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH:   TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW:    TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.

DATE                              TUE 07/23/13
UTC 1HRLY       06   07   08   09   10   11   12   13   14   15   16   17
EDT 1HRLY       02   03   04   05   06   07   08   09   10   11   12   13
CRW CONSISTENCY  L    L    H    H    H    H    H    H    M    H    H    M
HTS CONSISTENCY  L    L    L    L    L    L    L    L    H    H    M    H
BKW CONSISTENCY  H    H    L    M    L    L    M    H    H    H    H    H
EKN CONSISTENCY  L    H    M    L    L    H    H    M    M    H    M    H
PKB CONSISTENCY  L    L    M    H    M    H    L    L    H    H    M    M
CKB CONSISTENCY  H    H    H    H    H    H    M    H    H    H    M    M

AFTER 06Z WEDNESDAY...
IFR OR WORSE FOG POSSIBLE WEDNESDAY MORNING.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...KMC/30
NEAR TERM...50/30
SHORT TERM...KMC
LONG TERM...KMC
AVIATION...50









AREA FORECAST DISCUSSION...UPDATED

NWS SAN ANGELO TX

 1144 PM CDT MON JUL 22 2013

.DISCUSSION...
SEE AVIATION SECTION FOR DISCUSSION ON THE 06Z TAF PACKAGE.

&&

.AVIATION...
SKIES WILL BE MOSTLY CLEAR ACROSS WEST CENTRAL TEXAS UNTIL LATE
TONIGHT. LOW CLOUDS...CURRENTLY DEVELOPING OVER THE HILL COUNTRY
REGION...WILL EXPAND/DEVELOP NORTH ACROSS THE SOUTHEASTERN PART
OF WEST CENTRAL TEXAS BETWEEN 09Z AND 11Z. EXPECTING MVFR CEILINGS
AND BASES WITH THESE LOW CLOUDS. CARRYING A LOW CLOUD MENTION
MAINLY AT KJCT...KBBD AND KSOA. KSJT MAY BRIEFLY HAVE LOW CLOUDS
IN THE VICINITY BY 13-14Z. THE LOW CLOUD FIELD WILL ERODE BY MID-
LATE MORNING. SHOULD HAVE A DIURNAL CUMULUS FIELD ONCE AGAIN
DURING THE DAY TUESDAY...BUT WITH LESS CLOUD COVERAGE THAN WHAT
OCCURRED TODAY. SOUTH-SOUTHEAST WINDS 4-7 KT ARE EXPECTED OVERNIGHT.
BY MIDDAY TUESDAY EXPECT SOUTH WINDS 10-15 KT OVERALL...WITH GUSTS
AT TIMES TO 20 KT AT KABI AND KSJT.

19

&&

.PREV DISCUSSION... /ISSUED 1004 PM CDT MON JUL 22 2013/

UPDATE...
SHOWERS HAVE DISSIPATED ACROSS WEST CENTRAL TX WITH THE LOSS OF
DAYTIME HEATING. THE HRRR SUGGESTS WE MAY SEE A FEW MORE SHOWERS
DURING THE OVERNIGHT HOURS BUT WITH STABILITY INCREASING...I THINK
THAT IS A LONG SHOT. THE FORECAST IS DRY THROUGH THE REMAINDER OF
THE NIGHT WITH TEMPERATURES FALLING INTO THE LOWER 70S. MINOR
CHANGES WERE MADE TO WIND...DEWPOINT AND SKY FOR THE FIRST AND
SECOND PERIODS GRIDS BUT THE REMAINDER OF THE FORECAST REMAINS ON
TRACK.

JOHNSON

PREV DISCUSSION... /ISSUED 647 PM CDT MON JUL 22 2013/

DISCUSSION...
SEE AVIATION SECTION.

AVIATION...
WHILE AN ISOLATED SHOWER REMAINS POSSIBLE THIS EVENING BEFORE
SUNSET...THE CHANCE OF OCCURRENCE NEAR A TAF SITE IS REMOTE.
PLAN TO OMIT THE MENTION OF SHRA AFTER 00Z. THE CUMULUS FIELD
WILL DISSIPATE BY LATE EVENING WITH CLEAR SKIES FOR MUCH OF
TONIGHT. TOWARD MORNING...EXPECT A LOW CLOUD FIELD TO DEVELOP
ACROSS THE SOUTHEASTERN PART OF OUR AREA...WITH MVFR CEILINGS
AND BASES. CARRYING A LOW CLOUD MENTION MAINLY AT KJCT AND
KBBD...AND TO A LESSER EXTENT AT KSOA. KSJT MAY BRIEFLY HAVE
LOW CLOUDS IN THE VICINITY BY 13-14Z. THE LOW CLOUD FIELD WILL
ERODE BY MID-LATE MORNING. SHOULD HAVE A DIURNAL CUMULUS FIELD
ONCE AGAIN DURING THE DAY TUESDAY...BUT WITH LESS CLOUD COVERAGE
THAN WHAT OCCURRED TODAY. SOUTH-SOUTHEAST WINDS WILL CONTINUE
TONIGHT AND TUESDAY. BY MIDDAY TUESDAY EXPECT SOUTH WINDS 10-15 KT
OVERALL...WITH GUSTS AT TIMES TO 20 KT AT KABI AND KSJT.

19

PREV DISCUSSION... /ISSUED 350 PM CDT MON JUL 22 2013/

SHORT TERM...
/TONIGHT AND TUESDAY/

A WEAK UPPER LEVEL LOW CURRENTLY OVER NORTHERN CHIHUAHUA WILL
WEAKEN THROUGH TUESDAY AS HIGH PRESSURE ALOFT BEGINS TO BUILD
SOUTHEAST ACROSS THE AREA. WE ARE STILL SEEING AFFECTS FROM THE
UPPER LOW AS MOISTURE REMAINS HIGH AND ISOLATED TO WIDELY
SCATTERED CONVECTION HAS ONCE AGAIN DEVELOPED ACROSS THE AREA THIS
AFTERNOON. KEPT SLIGHT POPS GOING THROUGH EARLY EVENING ACROSS THE
SOUTHERN TWO THIRDS OF THE CWA WITH ISOLATED MENTION ACROSS A
PORTION OF THE BIG COUNTRY. BRIEF HEAVY RAINFALL WILL BE POSSIBLE
ALONG WITH A FEW CLOUD TO GROUND LIGHTNING STRIKES. CONVECTION
WILL DISSIPATE AFTER SUNSET WITH LOSS OF HEATING.

ANOTHER ROUND OF STRATUS WILL DEVELOP ACROSS MAINLY SOUTHERN
SECTIONS TOWARDS DAYBREAK...SCATTERING OUT BY MID MORNING. COULD
STILL SEE AN ISOLATED SHOWER DEVELOP ACROSS SOUTHERN SECTIONS
TUESDAY AFTERNOON BUT WITH HIGH PRESSURE BUILDING IN WILL LEAVE
POPS OUT OF THE FORECAST. LOWS TONIGHT WILL BE IN THE 70S WITH
HIGHS ON TUESDAY RANGING FROM THE LOW TO MID 90S SOUTH TO THE
UPPER 90S NORTH.

24

LONG TERM...
/TUESDAY NIGHT INTO MONDAY/

HOT AND DRY MIDWEEK THEN A SLIGHT CHANCE OF THUNDERSTORMS FOR
THE BIG COUNTRY FRIDAY...

DISCUSSION...
UPPER RIDGE STRENGTHENS MIDWEEK...TEMPORARILY ENDING RAIN
CHANCES. GFS AND EC MODELS BRING A WEAK COLD FRONT INTO NORTHERN
TEXAS FRIDAY NIGHT. THE GFS MODEL BRINGS IT ALONG THE RED
RIVER... WHILE THE EC HAS BRINGS IT AS FAR SOUTH AS THE
INTERSTATE 20 CORRIDOR. WILL CONTINUE TO MAINTAIN A SLIGHT CHANCE
OF SHOWERS AND THUNDERSTORMS FOR THE BIG COUNTRY FRIDAY AND
FRIDAY NIGHT. HOWEVER...AS UPPER RIDGING WILL NOT BE WEAKENING...
THERE REMAINS CONSIDERABLE UNCERTAINTY IN STORM DEVELOPMENT.

HAVE TRENDED TOWARD A GRADUAL INCREASE IN TEMPERATURES MIDWEEK
WITH DECREASE IN CUMULUS. OVERNIGHT LOWS CONTINUE IN THE LOWER
TO MID 70S.

04

&&

.PRELIMINARY POINT TEMPS/POPS...
ABILENE  74  96  73  96  73 /   5  10   5   5   5
SAN ANGELO  74  96  73  96  72 /  10   5   0   5   0
JUNCTION  74  95  73  96  72 /  10   5   5   0   0

&&

.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$










AREA FORECAST DISCUSSION...UPDATED

NWS SAN ANGELO TX

 1141 PM CDT MON JUL 22 2013

.DISCUSSION...


&&

.AVIATION...
SKIES WILL BE MOSTLY CLEAR ACROSS WEST CENTRAL TEXAS UNTIL LATE
TONIGHT. LOW CLOUDS...CURRENTLY DEVELOPING OVER THE HILL COUNTRY
REGION...WILL EXPAND/DEVELOP NORTH ACROSS THE SOUTHEASTERN PART
OF WEST CENTRAL TEXAS BETWEEN 09Z AND 11Z. EXPECTING MVFR CEILINGS
AND BASES WITH THESE LOW CLOUDS. CARRYING A LOW CLOUD MENTION
MAINLY AT KJCT...KBBD AND KSOA. KSJT MAY BRIEFLY HAVE LOW CLOUDS
IN THE VICINITY BY 13-14Z. THE LOW CLOUD FIELD WILL ERODE BY MID-
LATE MORNING. SHOULD HAVE A DIURNAL CUMULUS FIELD ONCE AGAIN
DURING THE DAY TUESDAY...BUT WITH LESS CLOUD COVERAGE THAN WHAT
OCCURRED TODAY. SOUTH-SOUTHEAST WINDS 4-7 KT ARE EXPECTED OVERNIGHT.
BY MIDDAY TUESDAY EXPECT SOUTH WINDS 10-15 KT OVERALL...WITH GUSTS
AT TIMES TO 20 KT AT KABI AND KSJT.

19

&&

.PREV DISCUSSION... /ISSUED 1004 PM CDT MON JUL 22 2013/

UPDATE...
SHOWERS HAVE DISSIPATED ACROSS WEST CENTRAL TX WITH THE LOSS OF
DAYTIME HEATING. THE HRRR SUGGESTS WE MAY SEE A FEW MORE SHOWERS
DURING THE OVERNIGHT HOURS BUT WITH STABILITY INCREASING...I THINK
THAT IS A LONG SHOT. THE FORECAST IS DRY THROUGH THE REMAINDER OF
THE NIGHT WITH TEMPERATURES FALLING INTO THE LOWER 70S. MINOR
CHANGES WERE MADE TO WIND...DEWPOINT AND SKY FOR THE FIRST AND
SECOND PERIODS GRIDS BUT THE REMAINDER OF THE FORECAST REMAINS ON
TRACK.

JOHNSON

PREV DISCUSSION... /ISSUED 647 PM CDT MON JUL 22 2013/

DISCUSSION...
SEE AVIATION SECTION.

AVIATION...
WHILE AN ISOLATED SHOWER REMAINS POSSIBLE THIS EVENING BEFORE
SUNSET...THE CHANCE OF OCCURRENCE NEAR A TAF SITE IS REMOTE.
PLAN TO OMIT THE MENTION OF SHRA AFTER 00Z. THE CUMULUS FIELD
WILL DISSIPATE BY LATE EVENING WITH CLEAR SKIES FOR MUCH OF
TONIGHT. TOWARD MORNING...EXPECT A LOW CLOUD FIELD TO DEVELOP
ACROSS THE SOUTHEASTERN PART OF OUR AREA...WITH MVFR CEILINGS
AND BASES. CARRYING A LOW CLOUD MENTION MAINLY AT KJCT AND
KBBD...AND TO A LESSER EXTENT AT KSOA. KSJT MAY BRIEFLY HAVE
LOW CLOUDS IN THE VICINITY BY 13-14Z. THE LOW CLOUD FIELD WILL
ERODE BY MID-LATE MORNING. SHOULD HAVE A DIURNAL CUMULUS FIELD
ONCE AGAIN DURING THE DAY TUESDAY...BUT WITH LESS CLOUD COVERAGE
THAN WHAT OCCURRED TODAY. SOUTH-SOUTHEAST WINDS WILL CONTINUE
TONIGHT AND TUESDAY. BY MIDDAY TUESDAY EXPECT SOUTH WINDS 10-15 KT
OVERALL...WITH GUSTS AT TIMES TO 20 KT AT KABI AND KSJT.

19

PREV DISCUSSION... /ISSUED 350 PM CDT MON JUL 22 2013/

SHORT TERM...
/TONIGHT AND TUESDAY/

A WEAK UPPER LEVEL LOW CURRENTLY OVER NORTHERN CHIHUAHUA WILL
WEAKEN THROUGH TUESDAY AS HIGH PRESSURE ALOFT BEGINS TO BUILD
SOUTHEAST ACROSS THE AREA. WE ARE STILL SEEING AFFECTS FROM THE
UPPER LOW AS MOISTURE REMAINS HIGH AND ISOLATED TO WIDELY
SCATTERED CONVECTION HAS ONCE AGAIN DEVELOPED ACROSS THE AREA THIS
AFTERNOON. KEPT SLIGHT POPS GOING THROUGH EARLY EVENING ACROSS THE
SOUTHERN TWO THIRDS OF THE CWA WITH ISOLATED MENTION ACROSS A
PORTION OF THE BIG COUNTRY. BRIEF HEAVY RAINFALL WILL BE POSSIBLE
ALONG WITH A FEW CLOUD TO GROUND LIGHTNING STRIKES. CONVECTION
WILL DISSIPATE AFTER SUNSET WITH LOSS OF HEATING.

ANOTHER ROUND OF STRATUS WILL DEVELOP ACROSS MAINLY SOUTHERN
SECTIONS TOWARDS DAYBREAK...SCATTERING OUT BY MID MORNING. COULD
STILL SEE AN ISOLATED SHOWER DEVELOP ACROSS SOUTHERN SECTIONS
TUESDAY AFTERNOON BUT WITH HIGH PRESSURE BUILDING IN WILL LEAVE
POPS OUT OF THE FORECAST. LOWS TONIGHT WILL BE IN THE 70S WITH
HIGHS ON TUESDAY RANGING FROM THE LOW TO MID 90S SOUTH TO THE
UPPER 90S NORTH.

24

LONG TERM...
/TUESDAY NIGHT INTO MONDAY/

HOT AND DRY MIDWEEK THEN A SLIGHT CHANCE OF THUNDERSTORMS FOR
THE BIG COUNTRY FRIDAY...

DISCUSSION...
UPPER RIDGE STRENGTHENS MIDWEEK...TEMPORARILY ENDING RAIN
CHANCES. GFS AND EC MODELS BRING A WEAK COLD FRONT INTO NORTHERN
TEXAS FRIDAY NIGHT. THE GFS MODEL BRINGS IT ALONG THE RED
RIVER... WHILE THE EC HAS BRINGS IT AS FAR SOUTH AS THE
INTERSTATE 20 CORRIDOR. WILL CONTINUE TO MAINTAIN A SLIGHT CHANCE
OF SHOWERS AND THUNDERSTORMS FOR THE BIG COUNTRY FRIDAY AND
FRIDAY NIGHT. HOWEVER...AS UPPER RIDGING WILL NOT BE WEAKENING...
THERE REMAINS CONSIDERABLE UNCERTAINTY IN STORM DEVELOPMENT.

HAVE TRENDED TOWARD A GRADUAL INCREASE IN TEMPERATURES MIDWEEK
WITH DECREASE IN CUMULUS. OVERNIGHT LOWS CONTINUE IN THE LOWER
TO MID 70S.

04

&&

.PRELIMINARY POINT TEMPS/POPS...
ABILENE  74  96  73  96  73 /   5  10   5   5   5
SAN ANGELO  74  96  73  96  72 /  10   5   0   5   0
JUNCTION  74  95  73  96  72 /  10   5   5   0   0

&&

.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$








AREA FORECAST DISCUSSION

NWS TUCSON AZ

 853 AM MST TUE JUL 23 2013

.SYNOPSIS...AN IMPULSE FROM THE EAST WILL ENHANCE THUNDERSTORM
COVERAGE WEDNESDAY AND THURSDAY...OTHERWISE PLENTY OF MOISTURE
ACROSS SOUTHEAST ARIZONA WITH A CHANCE OF MAINLY AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS INTO THE WEEKEND.

&&

.DISCUSSION...THIS MORNINGS KTWC SOUNDING CONTINUED TO SHOW A VERY
MOIST AIRMASS IN PLACE...WITH A PRECIPITABLE WATER VALUE OF 1.6
INCHES. MODIFYING THE SOUNDING USING T=97;TD=58 YIELDS A LIFTED
INDEX OF AROUND MINUS 1 AND A CAPE OF AROUND 500 J/KG IF LIFTING THE
PARCEL USING THE MEAN TEMP METHOD...BUT A CAPE OF AROUND 1000 J/KG
IF LIFTED FROM THE SURFACE. THE FLOW ALOFT ON THIS MORNINGS SOUNDING
WAS MEAGER WITH VERY WEAK FLOW FROM THE SURFACE THROUGH AROUND
250MB. THAT SAID...THE STORMS THAT DEVELOP TODAY WILL STRUGGLE TO
SURVIVE WITHOUT ANY MEANS OF ORGANIZATION...SO BRIEF HEAVY RAINERS
THE MAIN CONCERN FOR TODAY...AND MOSTLY IN THE MOUNTAINS.

THE LATEST HRRR SHOWS THE ACTIVITY DEVELOPING ALONG THE NEW MEXICO
BORDER THIS AFTERNOON AND SLOWLY SPREADING WEST...BUT DISSIPATES
BEFORE MAKING IT TO THE TUCSON AREA. THE U OF A WRF NAM SHOWS A
SIMILAR SOLUTION...ALTHOUGH THE ACTIVITY IS NOT AS NUMEROUS AS THE
HRRR. THE WRF GFS HAS THE LEAST COVERAGE. BOTTOM LINE IS THE
ACTIVITY SHOULD BE FOCUSED EAST OF TUCSON TODAY...SO THE INHERITED
POPS LOOK GOOD AND NO CHANGES PLANNED AT THIS TIME.

TEMPS SEEM TO BE ON TRACK...BUT WILL CONTINUE TO MONITOR
OBSERVATIONS AND WILL MAKE CHANGES IF NEEDED.

&&

.AVIATION...VFR CONDITIONS WITH GENERALLY SCT050 SCT-BKN090.  ISOLD
SHRA / TSRA AFTER 24/18Z MAINLY EAST OF KTUS.  NORMAL DIURNAL WINDS
EXPECTED AND GENERALLY LESS THAN 10 KTS THROUGH EARLY WEDNESDAY OR
24/12Z. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...PLENTY OF MOISTURE ACROSS SOUTHEAST ARIZONA WITH A
SEASONABLE CHANCE OF SHOWERS AND THUNDERSTORMS INTO THE COMING
WEEKEND. STRONG AND ERRATIC THUNDERSTORM OUTFLOWS AT TIMES...
OTHERWISE NORMAL DIURNAL WIND TRENDS.

&&

.PREVIOUS DISCUSSION...NOT AS MUCH ACTIVITY OVER THE PAST 24 HOURS.
MOISTURE IS STILL THERE WITH PRECIPITABLE WATER VALUES IN THE FAIRLY
ROBUST 1.5 TO 1.6 INCH RANGE FOR MOST OF SOUTHEAST ARIZONA AND
SURFACE DEWPTS SOLIDLY IN THE 60S. MAIN PROBLEM IS LACK OF LARGER
SCALE FORCING AND CURRENTLY VERY WEAK SHEAR AND FLOW ALONG WITH A
LESS THAN FAVORABLE -4C AT H5. WET STORMS THAT TEND TO SIT AND RAIN
FOR A BIT WITH LITTLE ORGANIZATION AND LIMITED VALLEY SUPPORT. SOME
MID LEVEL DRYING AND MODEST SUBSIDENT FIELD IN WESTERN AREAS BEHIND
THE LOW THAT HAS EXITED TOWARD CENTRAL CALIFORNIA AND SOUTHERN
NEVADA TURNING THINGS OFF FOR A BIT OUT THERE.

THE VERY SLOW MOVING EASTERLY IMPULSE IN NORTHERN CHIHUAHUA THAT
HELPED FOCUS THE ABOVE MENTIONED COMPLEX THIS PAST EVENING SHOULD
PROVIDE THE FOCUS FOR OUR NEXT SHOT OF STRONG THUNDERSTORM ACTIVITY.
THE ECMWF HAS BEEN VERY CONSISTENT IN BRINGING IT INTO FAR SOUTHEAST
ARIZONA WEDNESDAY AFTERNOON INTO THURSDAY. AFTER ANOTHER RELATIVE
DOWN DAY TODAY FROM TUCSON WESTWARD...EXPECT A MARKED INCREASE IN
THUNDERSTORM COVERAGE SPREADING FARTHER WEST WITH SOME SUSTAINED
CONVECTION WEDNESDAY NIGHT INTO THURSDAY MORNING.

BY LATE IN THE WEEKEND STRONGER FLOW THROUGH NORTHERN TIER STATES
MAY SEE THE HIGH CENTER RECONSOLIDATE INTO A NEAR BLOCKING POSITION
AT LOWER LATITUDES AND EVEN AS DEEP AS NORTHWEST MEXICO. THIS WOULD
TEND TO BE A RATHER HOT AND RELATIVELY DRIER PATTERN FOR MUCH OF OUR
NECK OF THE WOODS.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

CURRENT DISCUSSION...MOLLERE
PREVIOUS DISCUSSION...MEYER/RASMUSSEN







AREA FORECAST DISCUSSION

NWS COLUMBIA SC

 1037 AM EDT TUE JUL 23 2013

.SYNOPSIS...
AN UPPER LEVEL TROUGH WILL CONTINUE DEEPENING AS IT MOVES OVER THE
EASTERN US THIS AFTERNOON. THE TROUGH WILL REMAIN OVER THE
FORECAST THROUGH THE WEEKEND RESULTING IN AN ACTIVE WEATHER
PATTERN.

&&

.NEAR TERM /UNTIL 8 PM THIS EVENING/...
UPEPR TROUGH OVER THE E CONUS. WEAK SURFACE TROUGH STRETCHES DOWN
THE EASTERN SEABOARD. AN UPPER DISTURBANCE WILL PUSH TO OUR
EAST...WITH SOME DRIER MID LEVEL AIR MOVING IN. HIGHEST PW VALUES
HAVE PUSHED TO NEAR THE COAST AND OFFSHORE AND ALSO TO OUR
WEST...WITH DRIER AIR AND PW VALUES 1.5 INCHES OR LESS PUSHING ESE
INTO MOST OF OUR FA TODAY. FORECAST SOUNDINGS INDICATE HIGH LFCS.
LATEST HIGH RESOLUTION MODELS KEEP CONVECTIVE ACTIVITY TO A
RELAITVE MINIMUM TODAY. LATEST HRRR WEAKENS THE CURRENT BATCH OF
CONVECTION THAT IS ACROSS N ALA/NW GA. LATE TODAY INTO THIS
EVENING...ANOTHER UPPER DISTURBANCE TO PUSH SE TOWARDS GA TODAY
WITH BETTER MOISTURE AVAILABLE IN THAT AREA COULD PROMOTE SOME
CONVECTION WHICH COULD PUSH TOWARDS THE CSRA. THINK SLIGHT CHANCE
POPS IN ORDER FOR MOST OF THE FA...BUT UPPED THEM SLIGHTLY TO LOW
CHANCE CSRA LATE TODAY AND THIS EVENING. DCAPE VALUES ARE
PROJECTED TO INCREASE TO 1000 TO 1300 J/KG CSRA...SO ANY STRONGER
STORMS THAT FORM COULD PRODUCE A WIND THREAT. ALSO MADE SLIGHT
ADJUSTMENTS TO TEMPS...DEWPOINTS AND WINDS TODAY BASED ON CURRENT
TRENDS AND LATEST GUIDANCE. GUIDANCE BRINGS DEWPOINTS DOWN INTO
THE UPPER 60S THIS AFTERNOON FOR MUCH OF THE FA...THOUGH RECENT
RAINS AND HIGH SOIL MOISTURE COULD KEEP THEM FROM GETTING DOWN
QUITE THAT LOW.

&&

.SHORT TERM /8 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
SHORT WAVE TROUGH WILL MOVE FURTHER OFFSHORE WITH DRY AIR REMAINING
IN THE MID AND UPPER LEVELS OVERNIGHT. EXPECT ANY CONVECTIVE
ACTIVITY WHICH DEVELOPS THIS AFTERNOON TO DISSIPATE THIS EVENING
WITH THE LOSS OF HEATING AND A DRY FORECAST THROUGH TONIGHT. ON
WEDNESDAY MOISTURE WILL BEGIN RETURNING TO THE COLUMN...HOWEVER
THIS IS NOT EXPECTED UNTIL LATE IN THE AFTERNOON. WITH THE UPPER
LEVEL TROUGH ALSO OVER THE REGION AND A SERIES OF WEAK SHORT WAVES
ROTATING THROUGH THE AXIS THERE WILL BE ENOUGH POTENTIAL TO
INCLUDE A LOW CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS.
WEDNESDAY NIGHT THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL
CONTINUE AS A FAIRLY VIGOROUS SHORT WAVE MOVES THROUGH THE AREA
OVERNIGHT. TEMPERATURES THROUGH THE SHORT TERM WILL BE IN THE
LOWER 70S FOR OVERNIGHT LOWS WITH HIGH TEMPERATURES WEDNESDAY
AFTERNOON IN THE LOWER TO MIDDLE 90S.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
MODELS ARE IN GOOD AGREEMENT THROUGH FRIDAY WITH DIFFERENCES
INCREASING THROUGH THE WEEKEND. UPPER LEVEL TROUGH WILL REMAIN
OVER THE REGION THROUGH THE WEEKEND BEFORE LIFTING OUT ON MONDAY
WHICH WILL KEEP THE ACTIVE WEATHER PATTERN OVER THE REGION. MODELS
INDICATE A SERIES OF SHORT WAVE CROSSING THE AREA THROUGH THE LONG
TERM...HOWEVER DIFFER ON THE TIMING OF SIGNIFICANT SHORT WAVES
WHICH WOULD GENERATE CONVECTION. AS SUCH CONFIDENCE IN THE LONG
TERM IS LOWER THAN DESIRED AND HAVE REMAINED WITH MAINLY DIURNAL
CHANCES OF SHOWERS AND THUNDERSTORMS INTO EARLY NEXT WEEK.
TEMPERATURES THROUGH THE LONG TERM WILL BE SLIGHTLY BELOW NORMAL
FOR DAYTIME HIGHS WITH OVERNIGHT LOWS NEAR NORMAL.

&&

.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
MVFR CIGS CURRENTLY STILL HANGING ON ACROSS THE SOUTHERN
FA...INCLUDING OGB. EXPECT VFR CONDITIONS THIS AFTERNOON. DRIER
MID LEVEL AIR ENTERING THE REGION...WITH GENERALLY ONLY A SLIGHT
CHANCE OF AN AFTERNOON THUNDERSTORM...THOUGH AN UPPER DISTURBANCE
MAY PROVIDE A BETTER CHANCE OF TS AT AGS/DNL LATE TODAY AND THIS
EVENING...BUT THUNDERSTORM CHANCES TOO LOW TO INCLUDE MENTION IN
THE TAFS AT THIS TIME.

EXTENDED AVIATION OUTLOOK...SCATTERED AFTERNOON AND EVENING
THUNDERSTORMS. LATE NIGHT/EARLY MORNING FOG/STRATUS POSSIBLE.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$





AREA FORECAST DISCUSSION

NWS TOPEKA KS

 615 AM CDT TUE JUL 23 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM CDT TUE JUL 23 2013

FAIRLY STRONG NORTHWESTERLY H5 FLOW...CONSIDERING THE MID SUMMER
TIME PERIOD...CURRENTLY OVER THE FORECAST AREA BETWEEN THE MID
LEVEL HIGH OVER THE DESERT SOUTHWEST AND AN UPPER TROUGH LOCATED
NORTH OF THE GREAT LAKES REGION. TWO AREAS OF CONVECTION ARE
APPARENT ON RADAR...WITH AN AREA OF WEAK THUNDERSTORMS OVER
CENTRAL KANSAS...AND A MORE ORGANIZED COMPLEX OF STORMS CURRENTLY
IN C NEBRASKA. GENERALLY EXPECT THE WEAK THUNDERSTORMS OVER
CENTRAL KANSAS TO WEAKEN WHILE STAYING SLIGHTLY WEST OF THE
FORECAST AREA. THE FOCUS WOULD THEN SHIFT TO THE MCS DRIVING ESE
ACROSS C/S NEBRASKA. FORWARD PROPAGATING CORFIDI VECTORS WOULD
INDICATE THAT THE STORMS WILL CONTINUE THEIR PATH TO THE
ESE...PERHAPS BRINGING SOME EARLY MORNING THUNDERSTORMS TO THE
NORTHERN ROW OR TWO OF COUNTIES...WITH THE BEST CHANCES FOR
MORNING PRECIP BEING IN THE FAR NORTHEASTERN CORNER OF KANSAS.
MODELS HAVE BEEN HAVING TROUBLE RESOLVING MCS DEVELOPMENT THE
PREVIOUS COUPLE NIGHTS...SO WILL TAKE THEIR SOLUTIONS WITH A GRAIN
OF SALT. 4KM WRF-NMM WOULD SUGGEST THE COMPLEX WILL FALL APART AS
IT APPROACHES THE CWA...WHILE THE HRRR SUGGESTS IT WILL MAINTAIN
ITSELF IN SOME RESPECT TO THE NORTHERN TIER OF COUNTIES. CURRENTLY
WILL SIDE MORE WITH THE HRRR...AS RADAR TRENDS OVER THE PAST
COUPLE HOURS SHOW THE COMPLEX STILL STRONG AND ORGANIZED AS IT
MOVES ACROSS C NEBRASKA. IT ALSO SEEMS TO BE MAINTAINED ALONG THE
LEADING EDGE OF A 20 TO 30 KT 850 MB JET...WITH MAXIMIZED LOW
LEVEL CONVERGENCE RUNNING NW TO SE ACROSS C/S NEBRASKA. BETWEEN
THAT LINE OF MAXIMIZED LOW LEVEL CONVERGENCE AND THE
AFOREMENTIONED CORFIDI VECTORS...HAVE KEPT THE HIGHEST POPS
THROUGH THE MORNING HOURS ALONG AND NORTH OF INTERSTATE 70...WITH
POPS INCREASING TOWARD THE NORTHEAST PART OF KS.

EXACT THUNDERSTORM DEVELOPMENT FOR TUESDAY AFTERNOON IS SOMEWHAT
UNCERTAIN...AS THE DECAYING MCS WILL LIKELY LEAVE A REMNANT OUTFLOW
BOUNDARY ACROSS THE CWA AS IT CONTINUES ESE. THE REMNANT BOUNDARY
COULD BE THE IMPETUS FOR MORE THUNDERSTORM DEVELOPMENT LATER TODAY
WHERE LOW LEVEL CONVERGENCE IS MAXIMIZED. IN THE UNLIKELY CASE THAT
THE OFB SLIDES COMPLETELY THROUGH THE AREA AND SETS UP SOUTH OF THE
CWA IT COULD DECREASE CHANCES FOR RAIN LATER TODAY...HOWEVER THE
GENERAL THOUGHT IS THAT THAT BOUNDARY WILL REMAIN SOMEWHERE IN
NORTHEAST KANSAS. ASIDE FROM THE MAXIMIZED CONVERGENCE ALONG THE
BOUNDARY MODELS WOULD SUGGEST AN EMBEDDED VORTICITY MAXIMUM IN THE
NORTHWEST H5 FLOW. AS THIS VORT MAX SLIDES THROUGH THE AREA IT
SHOULD BRING INCREASED CHANCES FOR THUNDERSTORMS LATER THIS
AFTERNOON. GIVEN GOOD INSTABILITY IN THE FORM OF ROUGHLY 3000 J/KG
OF MIXED LAYER CAPE AND 0-6 BULK SHEAR VALUES OF PERHAPS 40
KTS...THE INGREDIENTS WILL BE PRESENT FOR SOME OF THESE AFTERNOON
THUNDERSTORMS TO BECOME STRONG TO SEVERE. THE MAIN HAZARDS WOULD BE
HAIL AND WIND...AS WELL AS HEAVY RAIN. EXPECT THESE STORMS TO FORM
INTO A COMPLEX BY SUNSET...AND MOVE SOUTHEASTWARD INTO WESTERN
MISSOURI DURING THE OVERNIGHT HOURS.

TEMPERATURE FORECAST FOR TUESDAY IS ALSO SOMEWHAT QUESTIONABLE AS
THAT OUTFLOW BOUNDARY FROM THE MORNING MCS WILL LIKELY DICTATE WHERE
THE WARMER TEMPS WILL BE LOCATED...VS COOLER TEMPS BEHIND THE
BOUNDARY. HAVE GONE WITH A FORECAST THE REFLECTS THE OFB ALONG WITH
ANY CLOUD DEBRIS FROM THE MCS TO REMAIN ALONG AND NORTH OF I
70...WITH WARMER TEMPS...INTO THE LOWER TO MID 90S ALONG AND SOUTH
OF THE INTERSTATE. THIS FORECAST COULD CHANGE BASED ON HOW
PROGRESSIVE THAT BOUNDARY AND ANY LINGERING CLOUD COVER MAY BE.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 356 AM CDT TUE JUL 23 2013

A LONGER WAVE LENGTH UPPER LEVEL TROUGH WILL REMAIN NEARLY
STATIONARY ACROSS THE EAST CENTRAL CONUS. THIS UPPER AIR PATTERN
WILL CAUSE THE FLOW AT MID AND UPPER LEVELS TO REMAIN
NORTHWESTERLY ACROSS THE PLAINS. A SERIES OF SHORTER WAVE-LENGTH
UPPER LEVEL TROUGHS WILL ROUND THE UPPER LEVEL RIDGE ACROSS THE
WESTERN CONUS AND DIG SOUTHEAST ACROSS THE CENTRAL PLAINS THROUGH
THE FORECAST PERIOD.

WEDNESDAY...THE FIRST H5 TROUGH WILL MOVE SOUTHEAST ACROSS NE INTO
MO WEDNESDAY MORNING. AN MCS OR COMPLEX OF THUNDERSTORMS MAY BE
ONGOING DURING THE MORNING HOURS. HOWEVER...THE STRONGER ASCENT
AHEAD OF THIS H5 TROUGH MAY REMAIN JUST NORTH AND EAST OF THE CWA. A
SURFACE OUTFLOW BOUNDARY/COLD FRONT SHOULD PUSH SOUTH AND SOUTHWEST
ACROSS THE CWA DURING THE MORNING HOURS. THE AFTERNOON MAY REMAIN
DRY AS THE BEST SURFACE CONVERGENCE WILL REMAIN SOUTH AND WEST OF
THE CWA DURING THE AFTERNOON HOURS. HIGHS WILL ONLY REACH THE MID
80S.

WEDNESDAY NIGHT THROUGH THURSDAY NIGHT....THE NEXT H5 TROUGH MAY
DIG SOUTHEAST ACROSS THE PLAINS THURSDAY INTO FRIDAY MORNING. BOTH
THE ECMWF AND GFS SHOW AN MCS DEVELOPING ACROSS THE HIGH PLAINS OF
EASTERN CO AND TRACKING SOUTHEAST ACROSS WESTERN KS INTO SOUTHERN KS
AND NORTHERN OK. THE CWA MAY REMAIN ON THE NORTH EDGE OF THIS MCS
TRACK. IF THE MCS DEVELOPS FARTHER NORTH...THEN THE CWA MAY SEE A
GREATER CHANCE FOR THUNDERSTORMS THURSDAY NIGHT INTO FRIDAY MORNING.
THIS WILL BE MORE OF A MESOSCALE FORECAST AND FOR NOW I JUST WENT
WITH CHANCE POPS. HIGHS MAY WARM BACK INTO THE UPPER 80S TO AROUND
90 DEGREES THURSDAY AFTERNOON.

FRIDAY THROUGH SUNDAY...OUTFLOW BOUNDARIES AND WEAK UPPER LEVEL
TROUGHS DIGGING SOUTHEAST ACROSS THE PLAINS MAY PROVIDE ENOUGH
ASCENT FOR AT LEAST ISOLATED SHOWERS AND THUNDERSTORMS THROUGH THE
PERIOD. HIGHS SHOULD REMAIN IN THE 80S.

SUNDAY NIGHT AND MONDAY...BOTH THE GFS AND ECMWF SHOW ANOTHER H5
TROUGH TRACKING EAST-SOUTHEAST ACROSS THE PLAINS. ASCENT AHEAD OF
THE TROUGH MAY LEAD TO AN MCS DEVELOPING ACROSS WESTERN KS AND
WESTERN NE THAT MAY TRACK EAST-SOUTHEAST ACROSS THE CWA SUNDAY NIGHT
INTO MONDAY MORNING. MONDAY HIGHS WILL ONCE AGAIN BE IN THE LOWER TO
MID 80S.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 610 AM CDT TUE JUL 23 2013

ACTIVE WEATHER IN STORE FOR THE TERMINALS THROUGH THE NEXT 24
HOURS. THE FIRST ROUND OF ACTIVE WEATHER WILL ACCOMPANY AN OUTFLOW
BOUNDARY WHICH WILL FLOW THROUGH KMHK AROUND 12Z AND THE TOPEKA
TERMINALS AROUND 13Z. THESE WINDS WILL BE AROUND 20 TO 30 KTS OUT
OF THE N/NE. A FEW SCATTERED THUNDERSTORMS MAY FORM TO THE NORTH
OF THE SOUTHWARD MOVING BOUNDARY...AND MAY BRING BRIEF PERIODS OF
MODERATE TO HEAVY RAIN TO THE TERMINALS. ANOTHER ROUND OF SHOWERS
WILL FORM LATER THIS AFTERNOON...WITH BETTER CHANCES OF
THUNDERSTORMS AFFECTING THE TERMINALS. EXPECT THESE STORMS TO
PRODUCE STRONG GUSTY CHAOTIC OUTFLOW WINDS AT AND AROUND THE
TERMINALS. RAIN CHANCES WILL DIMINISH OVERNIGHT.

JL

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...JL
LONG TERM...GARGAN
AVIATION...LEIGHTON







AREA FORECAST DISCUSSION

NWS GRAND RAPIDS MI

 1137 AM EDT TUE JUL 23 2013

LATEST UPDATE...
UPDATE

.SYNOPSIS...
ISSUED AT 330 AM EDT TUE JUL 23 2013

A COLD FRONT MOVING THROUGH WESTERN LOWER MICHIGAN THIS MORNING WILL
BRING A FEW SHOWERS AND STORMS THAT WILL END TOWARD MID DAY.  BEHIND
THE FRONT MUCH MORE COMFORTABLE HUMIDITY LEVELS WILL MOVE IN THIS
AFTERNOON AND PREVAIL THROUGH MID WEEK.  WEDNESDAY AND THURSDAY WILL
SEE HIGH TEMPERATURES FROM 75 TO 80 WITH MOSTLY SUNNY SKIES.

THE NEXT CHANCE OF RAIN IS EXPECTED TO ARRIVE FOR FRIDAY AND
SATURDAY.  TEMPERATURES INTO THE WEEKEND ARE EXPECTED TO REMAIN
SLIGHTLY BELOW NORMAL...MAINLY IN THE 70S.

&&

.UPDATE...
ISSUED AT 1137 AM EDT TUE JUL 23 2013

QUICK TURNAROUND FROM THE PREVIOUS UPDATE. SHOWERS HAVE DEVELOPED
ALONG THE FRONT JUST SOUTH AND NORTHEAST OF GRAND RAPIDS. THIS
ACTUALLY WAS WELL ADVERTISED BY THE LAST FEW RUNS OF THE HRRR...
BUT SADLY WAS DISCOUNTED. HAVE UPDATED THE GRIDS AND FORECASTS
USING RECENT HRRR GUIDANCE...WHICH MOVES PRECIPITATION SOUTHEAST
OUT OF THE AREA THIS AFTERNOON. RAP FORECAST SOUNDINGS SHOW
SUFFICIENT INSTABILITY FOR THUNDERSTORMS /MLCAPE 1000 J PER KG
EXTENDING TO ABOVE THE -30C LEVEL/ EXISTS ALONG AND AHEAD OF THE
FRONT.


UPDATE ISSUED AT 1026 AM EDT TUE JUL 23 2013

HAVE REMOVED MENTION OF PRECIPITATION FOR THE REST OF THE DAY
BASED ON RADAR TRENDS. VISIBLE SATELLITE IMAGERY AND SHORT RANGE
MODEL GUIDANCE SUGGEST THAT WE WILL SEE A FEW HOURS OF CLOUDINESS
BEHIND THE COLD FRONT...WHICH AT 10 AM WAS LOCATED JUST SOUTH OF A
MOUNT PLEASANT TO MUSKEGON LINE. THIS FRONT IS EXPECTED TO MOVE
SOUTH OUT OF LOWER MICHIGAN THIS AFTERNOON. TEMPERATURES ARE A
LITTLE TRICKY...BUT SHOULD PEAK EARLY THIS AFTERNOON NEAR OR JUST
BEHIND THE FRONT AS IT PROGRESSES SOUTH.

&&

.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 330 AM EDT TUE JUL 23 2013

A COLD FRONT WILL CONTINUE TO SLIDE ACROSS THE CWA THIS MORNING.  A
DRY AND COOL AIR MASS WILL FILTER IN THROUGH THE AFTERNOON BEHIND
THE FRONT.  THE COLD ADVECTION WILL BRING INCREASINGLY DANGEROUS
WAVE ACTION ON THE LAKE AND A BEACH HAZARDS STATEMENT HAS BEEN
POSTED.  MORE ON THIS IN THE MARINE SECTION.  OTHERWISE THERE IS AN
OUTSIDE CHANCE OF A FEW SHOWERS AGAIN LATE WEDNESDAY NIGHT INTO
THURSDAY ACROSS THE NORTHERN CWA.

THE COLD FRONT EXTENDED FROM NEAR THE STRAITS TO MADISON WI EARLY
THIS MORNING.  IT WAS PRESSING STEADILY SE AND SHOULD BE NEAR A
MOP-GRR-LWA LINE BY 12Z THIS MORNING.  AREAS NORTHWEST OF THIS LINE
SHOULD REMAIN DRY AFTER 12Z...AND HAVE DROPPED POPS.  SE OF THIS
LINE WILL CARRY LOW CHC POPS AS ANY LEFTOVER PCPN SLOWLY WEAKENS
WITH THE LACK OF ANY SUSTAINABLE JET AND DIMINISHING INSTABILITY.
THE FRONT SHOULD CLEAR EAST OF THE ENTIRE CWA AROUND NOON TIME WHEN
ALL PCPN SHOULD BE TO OUR EAST.  DEW POINTS WILL FALL FROM THE MID
60S EARLY THIS MORNING TO AROUND 50 BY EVENING.  CERTAINLY A
REFRESHING AIR MASS FOR MID SUMMER.

HIGH PRESSURE FILLS IN FOR THE REST OF THE SHORT TERM INTO
THURSDAY.  WARM DAYS AND COOL NIGHT WILL BE SEEN.  LOWS FROM 50 TO
55 AND HIGHS IN THE MID AND UPPER 70S ARE EXPECTED.  ONE BRIEF
GLITCH...THE MODELS ARE ON THE SAME PAGE WITH BRINGING A WEAK SHORT
WAVE THROUGH LOWER MI THURSDAY MORNING.  SOME WEAK LIFT AND SOME
MOISTURE POOLS NEAR THIS WAVE...ESPECIALLY ACROSS CENTRAL LOWER.
HAVE ADDED A 20 POP FOR A THURSDAY MORNING SHOWER NORTH OF HIGHWAY
20.

.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 356 AM EDT TUE JUL 23 2013

WE CONTINUE TO WATCH FOR A STRONG COLD FRONT TO COME THROUGH THE
AREA FRIDAY NIGHT WITH STRONG THUNDERSTORMS POSSIBLE. BEHIND THE
COLD FRONT WE MAY SEE THE COOLEST TEMPERATURES THIS AREA HAS SEEN
SINCE THE MIDDLE OF JUNE.

THE LONG WAVE PATTERN HAS SHIFTED IN THAT THE LONG WAVE TROUGH IS NOW
OVER EASTERN CANADA AND THE EASTERN UNITED STATES. THIS PATTERN
SEEMS STABLE INTO NEXT WEEK. THAT BEING SO AN UPPER AIR SYSTEM
CURRENTLY OVER CENTRAL CANADA INTO WESTERN HUDSON BAY... ROTATES
SOUTHEAST INTO THE GREAT LAKES TOWARD FRIDAY. A CLOSED UPPER LOW
DEVELOPS WITH THE SYSTEM BY FRIDAY AFTERNOON AND THAT MOVES EAST
JUST NORTH OF LAKE SUPERIOR INTO SUNDAY. THE GFS...ECMWF AND
CANADIAN MODELS ARE ALL RATHER SIMILAR WITH THIS OUTCOME AND HAVE
HAD SIMILAR SOLUTIONS OVER THE PAST FEW RUNS (SINCE 22/00Z). SO THAT
LENDS CONFIDENCE TO THE FORECAST.

THERE IS 90 KNOT JET STREAK THAT ROTATES INTO THE WESTERN GREAT
LAKES FRIDAY EVENING WITH THAT DEEPENING UPPER LOW. THE LEFT
ENTRANCE REGION OF THAT JET STREAK CROSSES THE INTERSTATE 94 AREA
AROUND MIDNIGHT FRIDAY NIGHT. AS TYPICAL FOR THIS AREA LATELY... THE
LOW LEVEL JET SPEED MAX CROSSES LAKE HURON FRIDAY EVENING PUTTING
SOUTHWEST MICHIGAN IN THE SPEED DIVERGENCE AREA OF THE LOW LEVEL
JET... NOT SO GOOD FOR SEVERE STORMS. SO EVEN THROUGH THERE WOULD BE
SOME DECENT MID LEVEL LIFT... ELEVATED CAPE AND 40 TO 60 KNOTS OF
DEEP LAYER SHEAR... THAT THOSE STORMS WOULD BE COMING THROUGH
OVERNIGHT WITH THE LOW LEVEL JET NOT IN AN OPTIMUM POSITION TELLS ME
THIS WILL BE ANOTHER EVENT WITH A MORE GENERIC NIGHT TIME
THUNDERSTORMS THAN SEVERE STORMS.

ONCE THE FRONT COMES THROUGH 850 MB TEMPS FALL TO NEAR 5C BY SUNDAY
MORNING. THAT IS 15-20C BELOW THE LAKE TEMPERATURE... WHICH BY THE
WAY IS AROUND 2 STANDARD DEVIATIONS FROM NORMAL (850 MB TEMP) AND
WOULD BE COLD ENOUGH FOR LAKE EFFECT RAIN SHOWERS IF THE LOW LEVEL
AIR IS MOIST ENOUGH (IT LIKELY WILL NOT BE MOIST ENOUGH). HOWEVER
WITH THE CLOSED UPPER LOW NORTH OF LAKE SUPERIOR THAT PUT SOUTHWEST
MICHIGAN FAR ENOUGH SOUTH FROM THE DEEP COLD AIR SO THAT WE WILL
LIKELY HAVE HIGH PRESSURE AND DRY AIR FROM SATURDAY AFTERNOON INTO
MONDAY. GIVEN HOW COLD THAT AIR IS IT WOULD SEEM THERE IS SOME
POTENTIAL FOR AFTERNOON HEATING CONVECTION AS THE COLDEST AIR MOVES
THROUGH ON SUNDAY. SO I PUT LOW CHANCE POP SUNDAY AFTERNOON INLAND
FOR THE POTENTIAL FOR SHALLOW CONVECTION DUE TO DESTABILIZATION FROM
AFTERNOON HEATING. MODEL SOUNDING SHOW A STRONG INVERSION AROUND 700
MB SO WHAT CONVECTION DOES DEVELOP SUNDAY AFTERNOON WILL HAVE TO BE
RATHER SHALLOW. MORE SPRINKLES THAN ANYTHING.

GIVEN THOSE 850 MB TEMPS SATURDAY INTO SUNDAY WE SHOULD HAVE HIGHS
ONLY IN THE LOWER TO MID 70S... QUIET THE CHANGE FROM LAST WEEK.
WE GET TO SEE THE COOLER SIDE OF SUMMER THIS COMING WEEKEND.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 749 AM EDT TUE JUL 23 2013

MVFR CONDITIONS ARE THE MAIN CONCERN THIS MORNING. A DECK OF
STRATUS CLOUDS WILL QUICKLY MOVE OVER THE AREA THROUGH MID MORNING. THIS
SHOULD EXIT EAST AND MAY MIX OUT WITH HEATING THIS AFTERNOON. VFR
CONDITIONS THEN SETTLE IN WITH THE FOCUS THEN BECOMING
WINDS...WITH GUSTY CONDITIONS LIKELY THROUGH LATE EVENING.


&&

.MARINE...
ISSUED AT 330 AM EDT TUE JUL 23 2013

NORTHERLY WINDS AND COLD ADVECTION WILL LEADING TO BUILDING WAVES
TODAY INTO THIS EVENING.  THIS WILL RESULT IN HAZARDOUS BEACH
CONDITIONS AS WELL AS PRODUCE SMALL CRAFT ADVISORY CONDITIONS.

WAVES WILL BUILD BY MID MORNING...FIRST ACROSS THE POINTS REGION.
THEN AS THE FRONT CONTINUES TO MOVE SE HIGHER WAVES WILL BUILD DOWN
THE LENGTH OF THE LAKE BY MID DAY.  THE PERSISTENT NORTHERLY FLOW
WILL CONTINUE TO BUILD WAVES RIGHT INTO THIS EVENING.  MOST AREAS
WILL SEE 4 TO 6 FOOTERS.  MAX WAVES SHOULD BUILD TO AROUND 8 FEET
NEAR AND SOUTH OF SOUTH HAVEN BY EARLY EVENING PRODUCING HIGH RISKS
TO ALL SWIMMERS.  THESE CONDITIONS WILL PERSIST THROUGH TONIGHT.

AS HIGH PRESSURE BUILDS IN ON WEDNESDAY A DIMINISHING TREND IN THE
WINDS AND WAVES IS EXPECTED.  MUCH QUIETER CONDITIONS ARE EXPECTED
FOR WED NIGHT AND THU.


&&

.HYDROLOGY...
ISSUED AT 330 AM EDT TUE JUL 23 2013

SCATTERED SHOWERS THIS MORNING SHOULD ONLY ACCOUNT FOR A QUARTER
INCH OR LESS FOR MOST RIVER BASIN.  THIS WILL NOT CAUSE ANY HYDRO
ISSUES.  BEYOND THIS MORNING DRY WEATHER IS EXPECTED THROUGH
THURSDAY NIGHT.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT THROUGH WEDNESDAY EVENING FOR MIZ037-043-
     050-056-064-071.

LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT WEDNESDAY FOR LMZ844>849.

&&

$$

UPDATE...TJT
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...WDM
AVIATION...JAM
HYDROLOGY...JK
MARINE...JK







AREA FORECAST DISCUSSION

NWS KANSAS CITY/PLEASANT HILL MO

 643 AM CDT Tue Jul 23 2013

.SHORT TERM...(Today through Wednesday night)
Issued at 421 AM CDT TUE JUL 23 2013

Today through Tonight...Fickle northwest flow and muddled surface
boundaries will dictate our rain chances during this period. For the
past several days perturbations embedded within the northwest flow
have skirted by the bulk of the CWA with only the far northern and
northeastern counties receiving any beneficial rainfall. This may
change today as a relatively large convective complex continues to
track southeast through central NE.

A moderately strong mesohigh/cold pool and likely a developing MCV
are driving this feature. GFS/NAM/ECMWF have been pretty consistent
for the past few runs with this feature and maintain its strength
and resulting precipitation through the day and into the evening.
Only the HRRR has shown a tendency for the rain to fall apart
starting mid morning. This is a typical characteristic/phase of
convective systems which show a decided weakening from mid morning
through early afternoon before regenerating later in the afternoon.
Latest SPC meso page shows rather high MUCAPE of 3000-4000J/kg
downstream from this convection over northeast KS/northwest MO. Am
expecting the central NE convection to head for this better
instability and maintain its strength into mid morning. Surprisingly
there is moderately strong 0-6km shear of 40kts north of the MO
River so severe storms are possible. Have raised PoPs over the
western 1/2 of the CWA and adjusted them for the expected track of
this MCS. Will let day shift determine if this system will go
through the typical weakening/re-strengthening phases. Temperatures
will be problematic due to timing/location of cloud cover and
rain-cooled air. Have lowered them across the northern 1/2 of the
CWA.

Scattered convection expected to continue tonight with the northeast
third of the forecast area possibly missing out on the rain this
time.

Wednesday/Wednesday night...Could see lingering rain chances over
the far southern counties Wednesday morning as the convective
complex exists the CWA. Then expect dry, cooler and drier air to
spread into the region as high pressure settles in across IA through
IL and provides a northeast to easterly wind. Blended approach on
temperatures look reasonable with exceptionally pleasant weather for
Wednesday night/Thursday morning.

.LONG TERM...(Thursday through Monday)
Issued at 421 AM CDT TUE JUL 23 2013

The long range models are in better agreement with the 23/00Z runs
then in previous iterations. There is still however, a bit of
disagreement as to the timing of features that will affect the area
during this timeframe.

Thursday looks to be a very pleasant day with surface high pressure
over the area. Temperatures will be a few degrees below seasonal
averages with highs in the low to mid 80s. Thursday night there will
be two features of interest that will affect the area. The first is
a upper level trough moving through the Great Lakes region. This
will force a cold front into the Upper Midwest and back into the
Central Plains. Thunderstorms will develop out ahead of this front
and will move into northern Missouri Thursday night. Storms will
continue across northern Missouri on Friday as this front moves into
the area. The second feature of interest is an upper level shortwave
rounding an upper level ridge out west and dropping into the local
area on northwest flow on the lee side of the upper ridge. This
shortwave is actually remnant energy from the retrograding upper
level system that affected the region two weekends ago. The GFS/GEM
and ECMWF all depict a cluster of storms perhaps an MCS developing
across central Kansas Thursday night that will move into
central/southern Missouri either late Thursday night into Friday
(the faster GFS) or into Friday/Friday night (the slower EC and
GEM). In either case have chance POPs forecast for Thursday night
through Friday night.

Surface high pressure is advertised for the area behind the
departing cold front which should make for a very pleasant weekend
with highs in the upper 70s to lower 80s. Also, by the end of the
weekend there will be an overall pattern shift across the CONUS to a
more quasi-zonal pattern. This will be caused by a serious of
shortwaves moving through the Rockies which will suppress the
western CONUS ridge. The first of these shortwave is progged to
reach the area by Sunday night (still faster GFS) or early Monday
morning (the still slower EC). Either way, storms are expected to
linger into Monday across the area. That said have slight chance
POPs in for Sunday night to account for the faster GFS and have
chance POPs forecasted for Monday.

&&

.AVIATION...(For the 12Z TAFS through 12Z Wednesday Morning)
Issued at 633 AM CDT TUE JUL 23 2013

An outflow boundary preceding convection over NE will push through
the terminals early in the forecast. Expect to see gusty NNW winds
for an hour or two.

Shower and thunderstorm complex from eastern NE into north central KS
may not have much left to it by the time it reaches west central MO
by mid morning. Radar has shown an overall weakening trend since
10z. Could see the KS portion of the system strengthen as it moves
into the most unstable airmass. However, short range models suggest
this initial activity will pretty much dissipate before new activity
reforms. Thus, can only support VCTS until tonight when PROB30 will
be used.


&&

.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&

$$

SHORT TERM...MJ
LONG TERM...73
AVIATION...MJ







AREA FORECAST DISCUSSION...UPDATED

NWS GLASGOW MT

 948 AM MDT TUE JUL 23 2013

.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH THURSDAY...
A VERY SUBTLE DISTURBANCE IN THE UPPER FLOW WORKING ALONG THE
STATIONARY BOUNDARY IS PRODUCING SCATTERED GENERAL THUNDERSTORMS
AND SHOWERS THAT ARE CURRENTLY MOVING EAST ALONG THE NORTHERN
TIER THIS MORNING. THESE STORMS ARE EXPECTED TO SPREAD MORE TO THE
SOUTHEAST THIS AFTERNOON AND POSSIBLY BECOME STRONG ENOUGH TO GO
SEVERE. SPC THIS MORNING ADDED OUR SOUTHEAST COUNTIES TO ITS
CONVECTIVE OUTLOOK FOR SLIGHT RISK FOR SEVERE. THE GRID REFLECT
THIS PATTERN SO FEW CHANGES. SCT

PREVIOUS DISCUSSION...
ISOLATED SHOWERS CONTINUE TO TRAVERSE ACROSS THE CWA VERY EARLY
THIS MORNING. CURRENT RADAR OBSERVATIONS INDICATE SHOWERS AND
EMBEDDED THUNDER ENTERING SOUTHWESTERN SASKATCHEWAN FROM SOUTHERN
ALBERTA AT THIS TIME. RECENT HRRR RUNS BRING THIS ACROSS THE
NORTHERN ZONES DURING THE LATE MORNING AND INTO THE AFTERNOON
HOURS. THIS HAS ADDITIONAL SUPPORT FROM THE 23/00Z ECMWF/NAM/GFS
SOLUTIONS DESPITE SUBTLE DIFFERENCES IN PLACEMENT AND TIMING. WILL
KEEP POPS GOING THROUGH MOST OF THE CWA WITH HIGHEST POPS ACROSS
THE INTERNATIONAL BORDER AND FURTHER EAST CLOSER TO NORTH DAKOTA.
WILL OPT TO KEEP PETROLEUM COUNTY DRY FOR NOW ALTHOUGH A VERY
ISOLATED SHOWER CANNOT ENTIRELY BE RULED OUT. FORECAST SOUNDINGS
INDICATE ENOUGH INSTABILITY TO INSERT MENTION OF SMALL HAIL AND
GUSTY WINDS INTO THE GRIDS. NAM BUFKIT SOUNDINGS SHOWS HIGHEST
CAPE FURTHER EAST. WILL NOT ENTIRELY RULE OUT A VERY ISOLATED
SEVERE THUNDERSTORM...ESPECIALLY ACROSS THE FAR NORTHERN AND
EASTERN ZONES DURING THE LATE AFTERNOON AND EVENING HOURS. DID
LEAVE ENOUGH FLEXIBILITY HOWEVER THAT THE DAY SHIFT CAN HAVE SOME
WIGGLE ROOM IF THEY HAVE A DIFFERENT ASSESSMENT. THE UPPER LEVEL
SHORTWAVE IS ALREADY APPARENT ON WATER VAPOR IMAGERY AND AS THIS
INTERACTS WITH A SLOWLY EASTWARD MOVING FRONTAL BOUNDARY CURRENTLY
STRETCHING FROM NORTHWEST TO SOUTHEAST ACROSS THE CWA...CONFIDENT
THAT SHOWERS AND THUNDERSTORMS WILL BECOME MORE SCATTERED ACROSS
THE FORECAST REGION.

TUESDAY NIGHT INTO WEDNESDAY...UPPER LEVEL SHORTWAVE EXITS
NORTHEAST MONTANA AS HIGH PRESSURE SETTLES IN. THIS WILL LEAD TO
LARGE SCALE SUBSIDENCE AND MOSTLY DRY CONDITIONS ACROSS THE CWA.
ANOTHER SUBTLE SHORTWAVE WILL APPROACH BY WEDNESDAY AFTERNOON AND
DID INCLUDE MENTION OF SHOWERS AND THUNDERSTORMS WITH SLIGHT
CHANCE POPS AFTER 18Z ACROSS THE FAR NORTH...OVERSPREADING THE CWA
DURING THE EVENING AND AT NIGHT.

DIFFERENCES EXIST IN MODEL SOLUTIONS ON TIMING/TRACK OF NEXT UPPER
LEVEL SYSTEM PUSHING THROUGH NORTHWEST FLOW ALOFT FOR THURSDAY
WITH THE ECMWF/GFS LEANING TOWARDS A DRIER SOLUTION BUT THE NAM
MORE BULLISH. WILL KEEP SLIGHT CHANCE POPS IN THE GRIDS FOR
NOW...BUT MODELS SEEM TO BE CONVERGING TOWARDS DRIER CONDITIONS
WITH THE CWA TO THE RIGHT OF AN UPPER LEVEL RIDGE AXIS IN A
FAVORED REGION OF DEEP VERTICAL SUBSIDENCE. WITH THE UPPER LEVEL
RIDGE AMPLIFYING INTO SOUTHERN ALBERTA...FAVORED AREAS FOR ASCENT
MAY BE MUCH FURTHER TO THE WEST. HOWEVER...AGAIN...IT WILL BE
TRICKY TO TIME SUBTLE SHORTWAVE FEATURES IN THE NORTHWEST FLOW
ALOFT ESPECIALLY GIVEN MODEL DIFFERENCES...AS DISCUSSED...SO WILL
NOT GO COMPLETELY DRY JUST YET. AS FOR TEMPERATURES...WITH LITTLE
CHANGES IN 850MB TEMPERATURES AND 500MB HEIGHT PATTERN...EXPECT
LITTLE IN THE WAY OF TEMPERATURE SWINGS OVER THE NEXT SEVERAL
DAYS. LOW TEMPERATURES WILL GENERALLY RANGE ACROSS THE CWA IN THE
MID 50S TO NEAR 60 WITH HIGHS IN THE LOWER TO MIDDLE 80S AS A RULE
OF THUMB. MALIAWCO

.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
CANADIAN HIGH PRESSURE BUILDS INTO NORTH DAKOTA THURSDAY NIGHT AND
FRIDAY. THIS WILL THE FRONT FAR ENOUGH TO THE WEST THAT NORTHEAST
MONTANA WILL SEE DRY WEATHER AND SOMEWHAT COOLER TEMPERATURES.

A SHORTWAVE UPPER RIDGE MOVES THROUGH THE AREA FRIDAY NIGHT AND
SATURDAY. THIS WILL BRING THE FRONTAL BOUNDARY BACK EAST AS A WARM
FRONT. WITH AIRMASS FORECASTED TO BECOME UNSTABLE DURING THE DAY
ON SATURDAY...AFTERNOON AND EVENING THUNDERSTORMS WILL BE
POSSIBLE. WILL MAINTAIN A SLIGHT CHANCE FOR NOW.

SUNDAY THROUGH TUESDAY...MODELS HANDLE A SLOW MOVING UPPER
LOW/TROUGH ACROSS THE CANADIAN PRAIRIES THAT GIVES THE FORECAST
AREA FREQUENT SHORTWAVES IN A NEARLY ZONAL WSW TO WNW FLOW ALOFT.
WILL BROADBRUSH A CHANCE/SLIGHT CHANCE OF THUNDERSTORMS EACH DAY.
FORRESTER


&&

.AVIATION...
MOSTLY VFR. SCATTERED THUNDERSTORMS WILL MOVE SOUTHEAST ACROSS THE
AREA TODAY AND TONIGHT THAT MAY IMPACT ANY OF THE FOUR TERMINALS
WITH MVFR FLIGHT CONDITIONS AT TIMES. CONFIDENCE IN TIMING ANY
INDIVIDUAL STORMS AT A TAF SITE IS LOW AT THIS TIME. WILL MENTION
CB IN THE TAFS. WILL SEE EAST TO NORTHEAST WINDS 5 TO 10 KNOTS.

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

WEATHER.GOV/GLASGOW






AREA FORECAST DISCUSSION

NWS BINGHAMTON NY

 1019 AM EDT TUE JUL 23 2013

.SYNOPSIS...
A PAIR OF COLD FRONTS...ONE PASSING THROUGH TODAY AND ANOTHER
OVERNIGHT TONIGHT...WILL PRODUCE ADDITIONAL SCATTERED SHOWERS AND
PERHAPS ISOLATED THUNDERSTORMS. MUCH COOLER AND DRIER WEATHER
WILL SETTLE IN FOR WEDNESDAY AND THURSDAY COURTESY OF CANADIAN
HIGH PRESSURE.

&&

.NEAR TERM /THROUGH TONIGHT/...
1015 AM UPDATE...
PRECIPITABLE WATER VALUES ARE QUICKLY DECREASING...WITH MAIN UPPER
WAVE NOW HEADING EAST AND TAKING THE DEEPER MOISTURE WITH IT. WE
ARE NOW IN UNFAVORABLE LEFT ENTRANCE REGION OF JET AS WELL...SO
CURRENTLY ONLY A FEW SCATTERED SHOWERS IN ITS WAKE. LOOSELY-
DEFINED SURFACE LOW AND FRONTAL BOUNDARY WILL BE SHIFTING ITS WAY
THROUGH THE AREA THE REMAINDER OF TODAY...PROVIDING SOME HELP TO
CURRENT SCATTERED SHOWERS/ISOLATED THUNDERSTORMS...BUT OTHERWISE
FACTORS ABOVE WILL HINDER DEVELOPMENT AND MUCH OF THE AREA WILL BE
DRY THIS AFTERNOON. GRIDS UPDATED ACCORDINGLY. WE WILL NEED TO WATCH
THE LOCALIZED AREAS THAT RECEIVED HEAVY RAINFALL IN THE LAST 18
HOURS JUST IN CASE...BUT AT THIS POINT NOT EXPECTING WATER
PROBLEMS.

OVERNIGHT TONIGHT...SECONDARY COLD FRONT IN TANDEM WITH WAVE ALOFT
WILL PROBABLY YIELD A BAND OF ADDITIONAL SCATTERED SHOWERS.
DETAILS IN POPS HAVE BEEN ADJUSTED FOR TIMING OF THIS
FEATURE...BUT THERE IS UNCERTAINTY TO HOW MUCH COVERAGE BECAUSE OF
THE LOWER PWATS AND DIURNALLY UNFAVORABLE TIMING. THERE MAY BE
SIGNIFICANT GAPS BETWEEN INDIVIDUAL SHOWERS.

PREVIOUS DISCUSSION...
UPPER LEVEL SYSTEM WILL SLIDE EASTWARD TODAY, TAKING HIGHER PWATS
EAST OF FA. HOWEVER A COLD FRONT WILL SLIDE INTO NY AND PA TO SPUR
ADDITIONAL CONVECTION.

THE STRATIFORM RAIN CURRENTLY OVER FA WILL DIMINISH IN COVERAGE
AND SLIDE NORTHEAST TOWARD SUNRISE, AS FORECAST BY THE PREVIOUS
FEW HRRR RUNS. SKIES WILL BE MAINLY CLOUDY, THOUGH THERE IS POTENTIAL
FOR A FEW BREAKS OVER THE CENTRAL SOUTHERN TIER WHERE TEMPS MAY
PUSH INTO THE LOWER 80S.

SHOWERS AND A FEW THUNDERSTORMS WILL RETURN WITH THE COLD FRONT.
LACK OF WINDS AND MODEST INSTABILITY SUGGEST NO SVR THREAT. WILL
NEED TO MONITOR HEAVY RAINERS OVER AREAS WHICH RECEIVED COPIOUS
RAIN ON MONDAY. THESE ARE ISOLATED PROBLEMS, SO WILL NOT BE
ISSUING A FLASH FLOOD WATCH PER COORDINATION WITH NEIGHBORING
OFFICES.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
COLD FRONT WILL SCOUR OUT REMAINING MOISTURE THIS EVENING, WITH
PRECIP GRADUALLY ENDING OVERNIGHT. HIGH PRESSURE WILL FOLLOW IN
ITS WAKE, BRINGING STRONG DOWNWARD MOTION AND AN UNSEASONABLY COOL
AIRMASS.

850MB TEMPS PROGGED AROUND 8C FOR WEDNESDAY INTO EARLY THURSDAY.
WITH MOSTLY SUNNY SKIES, THIS SHOULD YIELD MAX TEMPS MAINLY IN THE
70S ON WEDNESDAY WITH A FEW 80S POSSIBLE FROM THE CENTRAL SOUTHERN
TIER DOWN INTO PA. OVERNIGHT MINS WILL DIP INTO THE LOW AND MIDDLE
50S...THE COOLEST TEMPS WE HAVE WITNESSED IN JULY 2013. A FEW
READINGS IN THE UPPER 40S ARE FORECAST IN THE SHELTERED RURAL
VALLEYS.

HIGH PRESSURE WILL REMAIN IN CONTROL INTO THURSDAY, THOUGH MODELS
SUGGEST POTENTIAL FOR SOME RETURN FLOW INTO OUR FAR SERN COUNTIES
LATE IN THE PERIOD WHERE WE HAVE ADDED A SLIGHT CHANCE FOR A
SHOWER.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
3 PM MON UPDATE...
AN UNSETTLED WEATHER PATTERN IS EXPECTED ACROSS THE AREA AS BROAD
TROUGHING AND SW FLOW ALOFT IS EXPECTED TO SETTLE OVER THE
NORTHEAST THROUGH NEXT WEEKEND. MULTIPLE VORT MAXES WILL TRAVEL
AROUND THE BASE OF THE TROUGH AND EJECT NORTHEASTWARD RESULTING IN
A CHANCE FOR SHOWERS AND THUNDERSTORMS EACH DAY THROUGH THE
EXTENDED. MODELS PROJECT A COLD FRONT MOVING INTO OUR REGION
SUNDAY WHICH WILL RESULT IN COOLER AND DRIER AIR FOR THE REGION.
AS THE DRY AIR FUNNELS IN FROM THE WEST...A BRIEF DRY PERIOD MAY
RETURN TO THE AREA.

&&

.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
WV MVG OUT THIS MRNG AND TAKING THE STEADY RAIN WITH IT. ISLTD
SHWRS WITH LINGERING LWRD CIGS AND VSBYS PSBL FOR A FEW HRS THIS
MRNG. LTR TODAY...LIMITED INSTABILITY WILL RESULT IN ISLTD
SHWRS...BUT NOT ENUF CVRG FOR INCLUSION IN THE TAFS ATTM. SO...
XPCT GNRL VFR CONDS WITH VFR CIGS THRU THE DAY INTO THE NGT. LATE
IN THE PD...COLD FNT WILL PASS THRU THE AREA INCRSG WINDS BUT ONCE
AGAIN CVRG OF PCPN WILL BE LIMTED DUE TO THE LATE NIGHT FNTL
PASSAGE.

.OUTLOOK...


WED/THU/...VFR

FRI/SAT...CHANCE OF SCATTERED MVFR SHRA/TSRA

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.

&&

$$
SYNOPSIS...DJP/MDP
NEAR TERM...DJP/MDP
SHORT TERM...DJP
LONG TERM...KAH
AVIATION...DGM







AREA FORECAST DISCUSSION

NWS BINGHAMTON NY

 640 AM EDT TUE JUL 23 2013

.SYNOPSIS...
A COLD FRONT WILL BRING ADDITIONAL SHOWERS, AND A FEW
THUNDERSTORMS TO NY AND PA TODAY AND THIS EVENING. PLEASANTLY COOLER
AND DRIER WEATHER WILL SETTLE IN FOR WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
620 AM UPDATE...
UPDATED MORNING POP GRIDS. MAJORITY OF PRECIP WITH FIRST WAVE HAS
MOVED NORTHEAST OF FA, WITH SCATTERED LIGHT SHOWERS LEFT OVER TO
THE SOUTHWEST. THIS COVERAGE IS FORECAST THROUGH MOST OF THE
MORNING, WITH ACTIVITY PICKING UP AHEAD OF AFTERNOON COLD FRONT.

3 AM UPDATE...
UPPER LEVEL SYSTEM WILL SLIDE EASTWARD TODAY, TAKING HIGHER PWATS
EAST OF FA. HOWEVER A COLD FRONT WILL SLIDE INTO NY AND PA TO SPUR
ADDITIONAL CONVECTION.

THE STRATIFORM RAIN CURRENTLY OVER FA WILL DIMINISH IN COVERAGE
AND SLIDE NORTHEAST TOWARD SUNRISE, AS FORECAST BY THE PREVIOUS
FEW HRRR RUNS. SKIES WILL BE MAINLY CLOUDY, THOUGH THERE IS POTENTIAL
FOR A FEW BREAKS OVER THE CENTRAL SOUTHERN TIER WHERE TEMPS MAY
PUSH INTO THE LOWER 80S.

SHOWERS AND A FEW THUNDERSTORMS WILL RETURN WITH THE COLD FRONT.
LACK OF WINDS AND MODEST INSTABILITY SUGGEST NO SVR THREAT. WILL
NEED TO MONITOR HEAVY RAINERS OVER AREAS WHICH RECEIVED COPIOUS
RAIN ON MONDAY. THESE ARE ISOLATED PROBLEMS, SO WILL NOT BE
ISSUING A FLASH FLOOD WATCH PER COORDINATION WITH NEIGHBORING
OFFICES.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
COLD FRONT WILL SCOUR OUT REMAINING MOISTURE THIS EVENING, WITH
PRECIP GRADUALLY ENDING OVERNIGHT. HIGH PRESSURE WILL FOLLOW IN
ITS WAKE, BRINGING STRONG DOWNWARD MOTION AND AN UNSEASONABLY COOL
AIRMASS.

850MB TEMPS PROGGED AROUND 8C FOR WEDNESDAY INTO EARLY THURSDAY.
WITH MOSTLY SUNNY SKIES, THIS SHOULD YIELD MAX TEMPS MAINLY IN THE
70S ON WEDNESDAY WITH A FEW 80S POSSIBLE FROM THE CENTRAL SOUTHERN
TIER DOWN INTO PA. OVERNIGHT MINS WILL DIP INTO THE LOW AND MIDDLE
50S...THE COOLEST TEMPS WE HAVE WITNESSED IN JULY 2013. A FEW
READINGS IN THE UPPER 40S ARE FORECAST IN THE SHELTERED RURAL
VALLEYS.

HIGH PRESSURE WILL REMAIN IN CONTROL INTO THURSDAY, THOUGH MODELS
SUGGEST POTENTIAL FOR SOME RETURN FLOW INTO OUR FAR SERN COUNTIES
LATE IN THE PERIOD WHERE WE HAVE ADDED A SLIGHT CHANCE FOR A
SHOWER.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
3 PM MON UPDATE...
AN UNSETTLED WEATHER PATTERN IS EXPECTED ACROSS THE AREA AS BROAD
TROUGHING AND SW FLOW ALOFT IS EXPECTED TO SETTLE OVER THE
NORTHEAST THROUGH NEXT WEEKEND. MULTIPLE VORT MAXES WILL TRAVEL
AROUND THE BASE OF THE TROUGH AND EJECT NORTHEASTWARD RESULTING IN
A CHANCE FOR SHOWERS AND THUNDERSTORMS EACH DAY THROUGH THE
EXTENDED. MODELS PROJECT A COLD FRONT MOVING INTO OUR REGION
SUNDAY WHICH WILL RESULT IN COOLER AND DRIER AIR FOR THE REGION.
AS THE DRY AIR FUNNELS IN FROM THE WEST...A BRIEF DRY PERIOD MAY
RETURN TO THE AREA.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...

WV MVG OUT THIS MRNG AND TAKING THE STEADY RAIN WITH IT. ISLTD
SHWRS WITH LINGERING LWRD CIGS AND VSBYS PSBL FOR A FEW HRS THIS
MRNG. LTR TODAY...LIMITED INSTABILITY WILL RESULT IN ISLTD
SHWRS...BUT NOT ENUF CVRG FOR INCLUSION IN THE TAFS ATTM. SO...
XPCT GNRL VFR CONDS WITH VFR CIGS THRU THE DAY INTO THE NGT. LATE
IN THE PD...COLD FNT WILL PASS THRU THE AREA INCRSG WINDS BUT ONCE
AGAIN CVRG OF PCPN WILL BE LIMTED DUE TO THE LATE NIGHT FNTL
PASSAGE.

.OUTLOOK...


WED/THU/...VFR

FRI/SAT...CHANCE OF SCATTERED MVFR SHRA/TSRA

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.

&&

$$
SYNOPSIS...DJP
NEAR TERM...DJP
SHORT TERM...DJP
LONG TERM...KAH
AVIATION...DGM







AREA FORECAST DISCUSSION

NWS BINGHAMTON NY

 624 AM EDT TUE JUL 23 2013

.SYNOPSIS...
A COLD FRONT WILL BRING ADDITIONAL SHOWERS, AND A FEW
THUNDERSTORMS TO NY AND PA TODAY AND THIS EVENING. PLEASANTLY COOLER
AND DRIER WEATHER WILL SETTLE IN FOR WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
620 AM UPDATE...
UPDATED MORNING POP GRIDS. MAJORITY OF PRECIP WITH FIRST WAVE HAS
MOVED NORTHEAST OF FA, WITH SCATTERED LIGHT SHOWERS LEFT OVER TO
THE SOUTHWEST. THIS COVERAGE IS FORECAST THROUGH MOST OF THE
MORNING, WITH ACTIVITY PICKING UP AHEAD OF AFTERNOON COLD FRONT.

3 AM UPDATE...
UPPER LEVEL SYSTEM WILL SLIDE EASTWARD TODAY, TAKING HIGHER PWATS
EAST OF FA. HOWEVER A COLD FRONT WILL SLIDE INTO NY AND PA TO SPUR
ADDITIONAL CONVECTION.

THE STRATIFORM RAIN CURRENTLY OVER FA WILL DIMINISH IN COVERAGE
AND SLIDE NORTHEAST TOWARD SUNRISE, AS FORECAST BY THE PREVIOUS
FEW HRRR RUNS. SKIES WILL BE MAINLY CLOUDY, THOUGH THERE IS POTENTIAL
FOR A FEW BREAKS OVER THE CENTRAL SOUTHERN TIER WHERE TEMPS MAY
PUSH INTO THE LOWER 80S.

SHOWERS AND A FEW THUNDERSTORMS WILL RETURN WITH THE COLD FRONT.
LACK OF WINDS AND MODEST INSTABILITY SUGGEST NO SVR THREAT. WILL
NEED TO MONITOR HEAVY RAINERS OVER AREAS WHICH RECEIVED COPIOUS
RAIN ON MONDAY. THESE ARE ISOLATED PROBLEMS, SO WILL NOT BE
ISSUING A FLASH FLOOD WATCH PER COORDINATION WITH NEIGHBORING
OFFICES.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
COLD FRONT WILL SCOUR OUT REMAINING MOISTURE THIS EVENING, WITH
PRECIP GRADUALLY ENDING OVERNIGHT. HIGH PRESSURE WILL FOLLOW IN
ITS WAKE, BRINGING STRONG DOWNWARD MOTION AND AN UNSEASONABLY COOL
AIRMASS.

850MB TEMPS PROGGED AROUND 8C FOR WEDNESDAY INTO EARLY THURSDAY.
WITH MOSTLY SUNNY SKIES, THIS SHOULD YIELD MAX TEMPS MAINLY IN THE
70S ON WEDNESDAY WITH A FEW 80S POSSIBLE FROM THE CENTRAL SOUTHERN
TIER DOWN INTO PA. OVERNIGHT MINS WILL DIP INTO THE LOW AND MIDDLE
50S...THE COOLEST TEMPS WE HAVE WITNESSED IN JULY 2013. A FEW
READINGS IN THE UPPER 40S ARE FORECAST IN THE SHELTERED RURAL
VALLEYS.

HIGH PRESSURE WILL REMAIN IN CONTROL INTO THURSDAY, THOUGH MODELS
SUGGEST POTENTIAL FOR SOME RETURN FLOW INTO OUR FAR SERN COUNTIES
LATE IN THE PERIOD WHERE WE HAVE ADDED A SLIGHT CHANCE FOR A
SHOWER.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
3 PM MON UPDATE...
AN UNSETTLED WEATHER PATTERN IS EXPECTED ACROSS THE AREA AS BROAD
TROUGHING AND SW FLOW ALOFT IS EXPECTED TO SETTLE OVER THE
NORTHEAST THROUGH NEXT WEEKEND. MULTIPLE VORT MAXES WILL TRAVEL
AROUND THE BASE OF THE TROUGH AND EJECT NORTHEASTWARD RESULTING IN
A CHANCE FOR SHOWERS AND THUNDERSTORMS EACH DAY THROUGH THE
EXTENDED. MODELS PROJECT A COLD FRONT MOVING INTO OUR REGION
SUNDAY WHICH WILL RESULT IN COOLER AND DRIER AIR FOR THE REGION.
AS THE DRY AIR FUNNELS IN FROM THE WEST...A BRIEF DRY PERIOD MAY
RETURN TO THE AREA.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
SHRT WV ACTING ON DEEP MOISTURE BRINGING WIDESPREAD RAIN AND GNRL
MVFR CIGS AND VSBYS...WITH BRIEF IFR AT TIMES. WV WILL MVE EAST
THIS MRNG AND CLR THE AREA ARND OR SHRTLY AFT 12Z. THIS WILL ALLOW
SLOWLY IMPRVG CONDS THRU THE DAY TODAY AND A RETURN TO VFR AS
DRIER AIR MVES IN. VFR CONDS SHD CONT THRU THE END OF THE PD.

.OUTLOOK...

LATE TUE NGT...SCATTERED MVFR SHRA.

WED/THU/...VFR

FRI/SAT...CHANCE OF SCATTERED MVFR SHRA/TSRA

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.

&&

$$
SYNOPSIS...DJP
NEAR TERM...DJP
SHORT TERM...DJP
LONG TERM...KAH
AVIATION...DGM/DJN







AREA FORECAST DISCUSSION

NWS BISMARCK ND

 1020 AM CDT TUE JUL 23 2013

.UPDATE...
ISSUED AT 1017 AM CDT TUE JUL 23 2013

THIS UPDATE FOR A BAND OF CLOUDINESS ACROSS TEH CENTRAL SECTIONS.
ADDED MORE CLOUDS TO THE MORNING AND EARLY AFTERNOON THAT ARE
ASSOCIATED WITH BROAD WARM ADVECTION UPLIFT.

UPDATE ISSUED AT 842 AM CDT TUE JUL 23 2013

EARLY MORNING CONVECTION ALONG THE DIURNALLY DRIVEN LOW LEVEL JET
AXIS AS DEPICTED BY THE RUC MODEL NOW DISSIPATING. WITH THIS TREND
IN MIND HAVE ELIMINATED THE THE MORNING CHANCE FOR THUNDERSTORMS.
NEXT CHANCE FOR PRECIPITATION WILL BE WITH THE AFTERNOON AND
EVENING SHORTWAVE EXPECTED TO BRING THUNDERSTORMS TO THE WEST.
WITH SPC ADDING SLIGHT RISK SEVERE TO THE SOUTHWEST HAVE ADDED
MENTION OF SEVERE STORMS LATE THIS AFTERNOON AND EVENING.

UPDATE ISSUED AT 642 AM CDT TUE JUL 23 2013

ONLY A FEW MINOR ISSUES WITH THE EARLY MORNING UPDATE. RAISED
CLOUD COVER OVER THE AREA FOR A FEW HOURS THIS MORNING WITH
SATELLITE INDICATING QUITE A BIT OF JET INDUCED MID LEVEL
CLOUDINESS OVER THE AREA THIS MORNING. ISOLATED SHOWERS IN THE FAR
EASTERN CWA SHOULD MOVE OUT OF THE AREA SHORTLY SO WILL NOT ADD
ANY MENTION OF SHOWERS HERE FOR THE REMAINDER OF THE MORNING. A
COUPLE REPORTING STATIONS INDICATING FOG ACROSS THE NORTH THIS
MORNING ON THE BACK SIDE OF A WEAK SURFACE HIGH OVER FAR SOUTHWEST
MANITOBA...SO ADDED A COUPLE HOURS OF PATCHY FOG OVER PORTIONS OF
THE FAR NORTH.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 402 AM CDT TUE JUL 23 2013

THE HIGHLIGHT OF THE SHORT TERM IS THE CONVECTIVE POTENTIAL THIS
AFTERNOON THROUGH TONIGHT.

WHILE THE 00 UTC DETERMINISTIC AND ENSEMBLE SUITE IS IN GOOD
AGREEMENT ON THE DEVELOPMENT OF AN INSTABILITY AXIS ACROSS EASTERN
MONTANA AND WESTERN NORTH DAKOTA ON THE WESTERN PERIPHERY OF
SURFACE HIGH PRESSURE...DIFFERENCES DO EXIST IN REGARDS TO HOW THE
CONVECTIVE SCENARIO WILL UNFOLD. IN GENERAL...ML CAPE OF 1000-1500
J/KG IS FORECAST TO DEVELOP ACROSS THE AFOREMENTIONED AREAS THIS
AFTERNOON...WITH DEEP LAYER SHEAR OF 30-40 KTS. THE CONVECTIVE
SCENARIOS OFFERED BY THE DETERMINISTIC MODELS RANGE FROM VERY
LITTLE CONVECTION ON THE ECMWF...TO A LINE OF STRONG TO SEVERE
THUNDERSTORMS ON THE 00 UTC 4 KM WRF ENTERING WESTERN NORTH DAKOTA
BETWEEN 20-22 UTC WITH THE ARRIVAL OF WEAK IMPULSES
ALOFT. THIS FORECAST CONVECTION THEN PROPAGATES INTO SOUTH CENTRAL
NORTH DAKOTA THROUGH THE EVENING...WHICH IS AT LEAST SUGGESTED ON
MOST OF THE DETERMINISTIC MODELS BY 06 UTC. YET HOW FAR PAST 06
UTC CONVECTION CAN REMAIN ORGANIZED WITH THE LACK OF A LOW LEVEL
JET IS UNCERTAIN. SPC DOES HAVE MUCH OF THE CWA IN A SEE TEXT WITH
5 PERCENT HAIL AND WIND CONTOURS. GIVEN UNCERTAINTY...LEFT THE
MENTION OF SEVERE OUT OF THE GRIDS FOR NOW.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 402 AM CDT TUE JUL 23 2013

MAIN FORECAST PROBLEM EARLY IN THE EXTENDED PERIOD WILL BE
PRECIPITATION CHANCES IN A PROGRESSIVE NORTHWEST FLOW. WEAK SURFACE
HIGH PRESSURE IS OVER THE AREA ON WEDNESDAY BUT DAYTIME HEATING AND
UPPER LEVEL JET OVER THE AREA WILL PROVIDE A CHANCE OF SHOWERS AND
THUNDERSTORMS. 00Z 23 JUN GFS FCST BUFR SOUNDINGS INDICATE
ATMOSPHERE BECOMES UNSTABLE ACROSS THE AREA WITH A STRONG NORTHWEST
FLOW ALOFT. WEDNESDAY NIGHT INTO THURSDAY A STRONGER UPPER LEVEL JET
DROPS SOUTH FROM CANADA AS A DEEP UPPER LEVEL LOW DROPS OVER THE
GREAT LAKES. KEEPING A CHANCE OF CONVECTION IN THE FORECAST UNTIL
DRIER AIR WORKS FROM NORTH TO SOUTH ACROSS THE AREA DURING THE
MORNING HOURS ON THURSDAY.

COOL SURFACE HIGH PRESSURE WILL PERSIST OVER THE AREA FRIDAY WITH
HIGHS MAINLY IN THE 70S. UPPER LEVEL RIDGING BUILDS OVER THE AREA
BEHIND THE EXITING GREAT LAKES CYCLONE OVER THE WEEKEND. BUT
SHORTWAVE ENERGY ROTATING AROUND ANOTHER UPPER LOW OVER WESTERN
CANADA WORKS TO BREAK DOWN THE RIDGE. THERE ARE DIFFERENCES BETWEEN
THE GFS/ECMWF IN HOW MUCH SHORTWAVE ENERGY CAN MAKE IT OVER THE
RIDGE...THUS SETTLED ON A MODEL BLEND WHICH KEEPS SATURDAY DRY AND
BRING SLIGHT CHANCE POPS INTO THE FAR WEST SATURDAY NIGHT...AND
PROGRESSING INTO THE CENTRAL ON SUNDAY. FLOW THEN BECOMES SOUTHWEST
BY EARLY NEXT WEEK...KEEPING A RISK OF THUNDERSTORMS IN THE FORECAST.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY AFTERNOON)
ISSUED AT 1017 AM CDT TUE JUL 23 2013

VFR CONDITIONS ARE EXPECTED FOR THE 12 UTC TAF CYCLE OUTSIDE OF
THUNDERSTORMS EXPECTED TO MOVE INTO WESTERN NORTH DAKOTA LATE THIS
AFTERNOON AFTER 21-22 UTC. THESE STORMS MAY PUSH INTO SOUTH
CENTRAL NORTH DAKOTA LATE THIS EVENING. GIVEN UNCERTAINTY IN EXACT
TIMING AND IMPACTS TO THE TERMINALS...CODED AS VCTS FOR NOW FOR
KBIS...KDIK AND KISN.


&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...WAA
SHORT TERM...AYD
LONG TERM...TWH
AVIATION...WAA







AREA FORECAST DISCUSSION

NWS BISMARCK ND

 850 AM CDT TUE JUL 23 2013

.UPDATE...
ISSUED AT 842 AM CDT TUE JUL 23 2013

EARLY MORNING CONVECTION ALONG THE DIURNALLY DRIVEN LOW LEVEL JET
AXIS AS DEPICTED BY THE RUC MODEL NOW DISSIPATING. WITH THIS TREND
IN MIND HAVE ELIMINATED THE THE MORNING CHANCE FOR THUNDERSTORMS.
NEXT CHANCE FOR PRECIPITATION WILL BE WITH THE AFTERNOON AND
EVENING SHORTWAVE EXPECTED TO BRING THUNDERSTORMS TO THE WEST.
WITH SPC ADDING SLIGHT RISK SEVERE TO THE SOUTHWEST HAVE ADDED
MENTION OF SEVERE STORMS LATE THIS AFTERNOON AND EVENING.

UPDATE ISSUED AT 642 AM CDT TUE JUL 23 2013

ONLY A FEW MINOR ISSUES WITH THE EARLY MORNING UPDATE. RAISED
CLOUD COVER OVER THE AREA FOR A FEW HOURS THIS MORNING WITH
SATELLITE INDICATING QUITE A BIT OF JET INDUCED MID LEVEL
CLOUDINESS OVER THE AREA THIS MORNING. ISOLATED SHOWERS IN THE FAR
EASTERN CWA SHOULD MOVE OUT OF THE AREA SHORTLY SO WILL NOT ADD
ANY MENTION OF SHOWERS HERE FOR THE REMAINDER OF THE MORNING. A
COUPLE REPORTING STATIONS INDICATING FOG ACROSS THE NORTH THIS
MORNING ON THE BACK SIDE OF A WEAK SURFACE HIGH OVER FAR SOUTHWEST
MANITOBA...SO ADDED A COUPLE HOURS OF PATCHY FOG OVER PORTIONS OF
THE FAR NORTH.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 402 AM CDT TUE JUL 23 2013

THE HIGHLIGHT OF THE SHORT TERM IS THE CONVECTIVE POTENTIAL THIS
AFTERNOON THROUGH TONIGHT.

WHILE THE 00 UTC DETERMINISTIC AND ENSEMBLE SUITE IS IN GOOD
AGREEMENT ON THE DEVELOPMENT OF AN INSTABILITY AXIS ACROSS EASTERN
MONTANA AND WESTERN NORTH DAKOTA ON THE WESTERN PERIPHERY OF
SURFACE HIGH PRESSURE...DIFFERENCES DO EXIST IN REGARDS TO HOW THE
CONVECTIVE SCENARIO WILL UNFOLD. IN GENERAL...ML CAPE OF 1000-1500
J/KG IS FORECAST TO DEVELOP ACROSS THE AFOREMENTIONED AREAS THIS
AFTERNOON...WITH DEEP LAYER SHEAR OF 30-40 KTS. THE CONVECTIVE
SCENARIOS OFFERED BY THE DETERMINISTIC MODELS RANGE FROM VERY
LITTLE CONVECTION ON THE ECMWF...TO A LINE OF STRONG TO SEVERE
THUNDERSTORMS ON THE 00 UTC 4 KM WRF ENTERING WESTERN NORTH DAKOTA
BETWEEN 20-22 UTC WITH THE ARRIVAL OF WEAK IMPULSES
ALOFT. THIS FORECAST CONVECTION THEN PROPAGATES INTO SOUTH CENTRAL
NORTH DAKOTA THROUGH THE EVENING...WHICH IS AT LEAST SUGGESTED ON
MOST OF THE DETERMINISTIC MODELS BY 06 UTC. YET HOW FAR PAST 06
UTC CONVECTION CAN REMAIN ORGANIZED WITH THE LACK OF A LOW LEVEL
JET IS UNCERTAIN. SPC DOES HAVE MUCH OF THE CWA IN A SEE TEXT WITH
5 PERCENT HAIL AND WIND CONTOURS. GIVEN UNCERTAINTY...LEFT THE
MENTION OF SEVERE OUT OF THE GRIDS FOR NOW.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 402 AM CDT TUE JUL 23 2013

MAIN FORECAST PROBLEM EARLY IN THE EXTENDED PERIOD WILL BE
PRECIPITATION CHANCES IN A PROGRESSIVE NORTHWEST FLOW. WEAK SURFACE
HIGH PRESSURE IS OVER THE AREA ON WEDNESDAY BUT DAYTIME HEATING AND
UPPER LEVEL JET OVER THE AREA WILL PROVIDE A CHANCE OF SHOWERS AND
THUNDERSTORMS. 00Z 23 JUN GFS FCST BUFR SOUNDINGS INDICATE
ATMOSPHERE BECOMES UNSTABLE ACROSS THE AREA WITH A STRONG NORTHWEST
FLOW ALOFT. WEDNESDAY NIGHT INTO THURSDAY A STRONGER UPPER LEVEL JET
DROPS SOUTH FROM CANADA AS A DEEP UPPER LEVEL LOW DROPS OVER THE
GREAT LAKES. KEEPING A CHANCE OF CONVECTION IN THE FORECAST UNTIL
DRIER AIR WORKS FROM NORTH TO SOUTH ACROSS THE AREA DURING THE
MORNING HOURS ON THURSDAY.

COOL SURFACE HIGH PRESSURE WILL PERSIST OVER THE AREA FRIDAY WITH
HIGHS MAINLY IN THE 70S. UPPER LEVEL RIDGING BUILDS OVER THE AREA
BEHIND THE EXITING GREAT LAKES CYCLONE OVER THE WEEKEND. BUT
SHORTWAVE ENERGY ROTATING AROUND ANOTHER UPPER LOW OVER WESTERN
CANADA WORKS TO BREAK DOWN THE RIDGE. THERE ARE DIFFERENCES BETWEEN
THE GFS/ECMWF IN HOW MUCH SHORTWAVE ENERGY CAN MAKE IT OVER THE
RIDGE...THUS SETTLED ON A MODEL BLEND WHICH KEEPS SATURDAY DRY AND
BRING SLIGHT CHANCE POPS INTO THE FAR WEST SATURDAY NIGHT...AND
PROGRESSING INTO THE CENTRAL ON SUNDAY. FLOW THEN BECOMES SOUTHWEST
BY EARLY NEXT WEEK...KEEPING A RISK OF THUNDERSTORMS IN THE FORECAST.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 842 AM CDT TUE JUL 23 2013

VFR CONDITIONS ARE EXPECTED FOR THE 12 UTC TAF CYCLE OUTSIDE OF
THUNDERSTORMS EXPECTED TO MOVE INTO WESTERN NORTH DAKOTA LATE THIS
AFTERNOON AFTER 21-22 UTC. THESE STORMS MAY PUSH INTO SOUTH
CENTRAL NORTH DAKOTA LATE THIS EVENING. GIVEN UNCERTAINTY IN EXACT
TIMING AND IMPACTS TO THE TERMINALS...CODED AS VCTS FOR NOW FOR
KBIS...KDIK AND KISN.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...WAA
SHORT TERM...AYD
LONG TERM...TWH
AVIATION...WAA







FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION

VISIT...

 HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)







SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION

NWS LOS ANGELES/OXNARD CA

 212 PM PDT TUE JUL 23 2013

.SYNOPSIS...

HIGH PRESSURE WILL SLOWLY BUILD BACK OVER THE REGION STARTING
MIDWEEK AND CONTINUE INTO SATURDAY...THIS WILL BRING FAIR SKIES TO
MOST AREAS WITH THE MARINE LAYER LIMITED TO THE COAST BY THE END OF
THE WEEK. A LOW WILL APPROACH THE REGION EARLY NEXT WEEK FOR AN
INCREASE IN CLOUD COVER. THE TEMPERATURES THROUGH THE PERIOD WILL
STAY AROUND NORMAL...WITH FRIDAY FORECASTED TO BE THE WARMEST.

&&

.SHORT TERM (TODAY-FRI)...HAVE MADE MINOR CHANGES THROUGH THE
PERIOD. GUIDANCE INITIALIZED A TROUGH UPSTREAM AND MOISTURE FIELD
OVER THE AREA REASONABLY WELL AND WAS CONSISTENT WITH PREVIOUS RUNS.
THE TROUGH UPSTREAM WILL PERSIST UPSTREAM WHILE A SUBTROPICAL LONG
WAVE RIDGE BUILDS OVER THE AREA THROUGH FRIDAY AND WARMING TREND IS
EXPECTED. INLAND TEMPERATURES WILL LIKELY WARM 3 TO 6 DEGREES ABOVE
SEASONAL NORMAL BY FRIDAY WHILE MARINE LAYER PERSISTS AT THE COAST
TEMPERATURES WILL REMAIN BELOW NORMAL. THE GOES SOUNDER AND RAP HAD
INDICATED DECREASING STABILITY OVER VENTURA/LOS ANGELES MOUNTAINS
AND DESERT AND ISOLATED CUMULUS FIELD HAD DEVELOPED EARLY THIS
AFTERNOON. STABILITY IS EXPECTED TO INCREASE AS MID LEVELS WARM AND
HEIGHTS RISE THROUGH THE EVENING. THE ISOLATED CUMULUS FIELD OVER
THE MOUNTAINS WILL LIKELY DISSIPATE LATE THIS AFTERNOON. ISOLATED
SHOWERS AND THUNDERSTORMS WERE DEVELOPING WELL EAST OF THE AREA
EARLY THIS AFTERNOON AND WERE SHORT LIVED. THE ACTIVITY WILL REMAIN
EAST OF THE AREA AS THE STORMS PROPAGATE GRADUALLY EAST. OTHERWISE
MOISTURE FIELD INITIALIZED OVER MEXICO THIS MORNING WILL GRADUALLY
PROPAGATE WEST THROUGH THE PERIOD.

.LONG TERM (SAT-TUE)...GFS ANALOG GUIDANCE INDICATED LITTLE OR NO
CHANCE OF PRECIPTITION OVER THE AREA SATURDAY. A TROUGH THAT WAS
UPSTREAM OF THE AREA IN THE SHORT TERM IS EXPECTED TO MOVE ASHORE
SATURDAY AND LIMIT THE WESTWARD PROPAGATION OF THE TROPICAL MOISTURE
THAT WILL ARRIVE SOUTHEAST OF THE AREA FRIDAY NIGHT. A COOLING TREND
IS EXPECTED SATURDAY THROUGH SUNDAY WITH TEMPERATURES 4 TO 8 DEGREES
BELOW SEASONAL NORMAL BY SUNDAY. THE MID/UPPER LEVEL TROUGH OF LOW
PRESSURE MAY MODIFY THE MARINE LAYER SUNDAY AND THE MARINE CLOUDS
MAY BECOME SCATTERED MONDAY THROUGH TUESDAY. OTHERWISE A LONG WAVE
SUBTROPICAL RIDGE EAST OF THE AREA WILL REBUILD WHILE SHIFTING WEST
AND A WARMING TREND IS EXPECTED OVER THE AREA MONDAY THROUGH TUESDAY
THOUGH TEMPERATURES ARE EXPECTED TO REMAIN A COUPLE DEGREES BELOW
SEASONAL NORMAL.


&&

.AVIATION...23/1800Z...
MODERATE CONFIDENCE IN 18Z TAFS WITH LITTLE CHANGE EXPECTED IN THE
MARINE LAYER CLOUD COVERAGE OVERNIGHT. FOR KSBA...WEAK OFFSHORE
TRENDS MAY BRING LESS OR LATER LOW CLOUD COVER TO THE SITE.
GENERALLY EXPECT IFR CONDS FOR COASTAL SITES N OF PT
CONCEPTION...KSBA AND KOXR...WITH IFR TO LOW MVFR FOR THE L.A.
COAST. THERE IS A 10-20% CHANCE THAT LOW CIGS WILL MOVE INTO THE SAN
FERNANDO VLY TONIGHT. GUSTY W-SW WINDS FOR THE ANTELOPE VALLEY THIS
AFTERNOON/EVENING.

KLAX...MODERATE TO HIGH CONFIDENCE IN 18Z TAF. HIGH CONFIDENCE IN
STRATUS RETURN TONIGHT...BUT LOWER CONFIDENCE IN FORECAST TIMING AND
HEIGHT OF CIGS. EXPECT A TRANSITION FROM HIGH IFR TO LOW MVFR
OVERNIGHT.

KBUR...MODERATE CONFIDENCE IN 18Z TAF. THERE IS A 20% CHANCE OF SOME
IFR/MVFR CIG/VSBYS RESTRICTIONS OVERNIGHT OR EARLY WED MORNING.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
NONE

&&

$$

PUBLIC...30
AVIATION...CS
SYNOPSIS...SS

WWW.WEATHER.GOV/LOSANGELES






AREA FORECAST DISCUSSION

NWS TAUNTON MA

 355 PM EDT TUE JUL 23 2013

.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO THE EARLY EVENING
HOURS GRADUALLY DISSIPATING. A RENEWED CHANCE OF WET WEATHER
ACTIVITY IS POSSIBLE WEDNESDAY AHEAD OF A SWEEPING COLD FRONT
WHICH WILL EXIT OUT INTO THE WATERS INTO WEDNESDAY NIGHT. THE COLD
FRONT STALLS WELL OFFSHORE THURSDAY...THEN MOVES BACK TOWARD
SOUTHERN NEW ENGLAND FRIDAY AND SATURDAY. ANOTHER COLD FRONT
SWINGS ACROSS FROM THE WEST ON MONDAY.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
*** FLASH FLOOD WATCH IS IN EFFECT TILL THIS EVENING***

AFTERNOON SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO THE EARLY
EVENING HOURS GRADUALLY DISSIPATING TOWARDS MIDNIGHT. STARTING TO
SEE DEVELOPING CONGEAL INTO A LINE ALONG A WEAK FRONTAL BOUNDARY
ATTENDANT TO A BROAD AREA OF LOW PRESSURE OVER SOUTHERN NEW
ENGLAND. SOME OF THE CELLS ARE REACHING UP TO 30-40 KFT WITH
SIGNIFICANT DBZ/S. SUBSEQUENTLY...WHILE GUSTY WINDS OF 20 TO 30
MPH ARE EXPECTED WITH STORMS...COULD SEE ISOLATED STRONGER WHICH
COULD LEAD TO WIND DAMAGE.

OTHERWISE THERE CONTINUES THE THREAT OF HEAVY RAIN /WITH HOURLY
RAINFALL RATES UP TO AROUND 1.5 INCHES/ AND FLASH FLOODING BUT
WITH THE THREAT BECOMING MORE ISOLATED...WILL ALLOW THE FLASH
FLOOD WATCH TO DROP AT 8 PM. HRRR MODEL IS STILL DOING WELL IN
INITIALIZING WITH THE CURRENT CONDITIONS AND FORECASTING
EXPECTATIONS. WILL FOLLOW IT CLOSELY FOR THE EVENING FORECAST.

SOUTHWEST WINDS GUSTING ACROSS THE SOUTHCOAST AND ACROSS THE CAPE
WITH GUSTS UP TO AROUND 20 TO 25 MPH. EXPECT WINDS TO DIMINISH
INTO THE EVENING. CLOUDS IN ABUNDANCE...BUT SOME CLEARING IS
POSSIBLE OVER THE WESTERN ZONES. NEVERTHELESS...ABUNDANCE OF
MOISTURE AND SOUTHERLY WIND FLOW PRESENTS THE THREAT OF SOME
PATCHY FOG...ESPECIALLY ALONG THE COASTS. LOWS DOWN TO THE MID-
TO UPPER-70S BY WEDNESDAY MORNING.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
WEDNESDAY...

COLD FRONT SWEEPS THROUGH THE REGION DURING THE MIDDAY HOURS...THE
PROXIMITY OF WHICH WILL BE ROUGHLY ALONG AND PARALLEL TO THE I-95
CORRIDOR AROUND MIDDAY. MAIN QUESTION IS WHETHER WE WILL SEE SOME
WET WEATHER AHEAD OF THE FRONT.

CONSIDERING AVAILABLE MOISTURE /PWATS AROUND 1.25 INCHES/ COUPLED
WITH SUFFICIENT DEEP-LAYER ASCENT AND UNI-DIRECTIONAL WEST-
SOUTHWEST WIND SHEAR /25-30 KTS/...EXPECT SHOWERS AND POSSIBLE
THUNDERSTORMS AHEAD OF THE COLD FRONT IN AN ENVIRONMENT FAVORABLE
FOR UPDRAFT SUSTAINMENT. SOME QUESTION OF AVAILABLE
INSTABILITY...IMPORTANTLY WHETHER CLOUD DECKS WILL BREAK ALLOWING
FOR SUNSHINE. CONFIDENT IN SEEING SUNSHINE WHICH WILL ALLOW HIGHS
AROUND THE MID 80S. WITH THAT FORECAST GUIDANCE SUPPORTS UP TO
1000 J/KG MUCAPE. CONSIDERING...NOT MUCH CONFIDENCE FOR SEVERE
WEATHER THREATS...BUT BELIEVE THERE WILL BE POCKETS OF HEAVY RAIN
WHICH COULD LEAD TO LOCALIZED FLOODING.

GREATEST CONFIDENCE WITH THE THE 23.0Z ECMWF WHICH INITIALIZED WELL
WITH THE MORNING OUTCOMES. 23.12Z HIGH-RES NAM AND 23.09Z SREF
SUPPORT THE ECMWF. NOTABLY DOWNSTREAM TOWARDS THE EASTERN GREAT
LAKES...JUST THE LOW-LEVEL FORCING AHEAD OF THE LEAD IMPULSE ALOFT
IS GENERATING SHOWER AND THUNDERSTORM ACTIVITY.

WEDNESDAY NIGHT...

HIGH PRESSURE BUILDS SOUTH AND EAST OUT OF CANADA. FEEL THE INTERIOR
WILL BE DRY...BUT SHOWERS WILL BE POSSIBLE ALONG THE SOUTH COAST AS
A MID-LEVEL IMPULSE ROTATING THROUGH THE BROADER TROUGH LIFTS
NORTHEAST ALONG THE OFFSHORE FRONTAL BOUNDARY AND DEEPER AXIS OF
MOISTURE. WITH CLEARING NORTH AND WEST...THIS WILL PERMIT LOWS TO
FALL TO AROUND 50 DEGREES...WHILE REMAINING MILD SOUTH AND EAST
TOWARDS THE CLOUDS AND ANTICIPATED SHOWERY WEATHER. NO EXPECTATION
FOR ANY FLOODING WITH SHOWERS.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...

BIG PICTURE/PREFERENCES...UPPER RIDGE OVER THE ATLANTIC AND TROUGH
FROM NORTHERN QUEBEC ACROSS THE GREAT LAKES.  THE UPPER RIDGE BUILDS
NORTH INTO NEWFOUNDLAND LATE WEEK...THEN DIMINISHES OVER THE
WEEKEND. SHORTWAVE FROM NORTHERN CANADA MOVES AROUND THE UPPER
TROUGH AND FORMS A CLOSED LOW OVER THE GREAT LAKES FOR FRIDAY AND
THE WEEKEND...THEN EJECTS THROUGH QUEBEC AND MAINTAINS A CYCLONIC
FLOW OVER THE NORTHEAST USA THROUGH EARLY NEXT WEEK.

THIS WILL MAINTAIN A SOUTHWEST FLOW ACROSS NEW ENGLAND THROUGH MOST
OF THE PERIOD...WHICH WILL MAKE IT TOUGH FOR THE OFFSHORE STALLED
FRONT TO MOVE FARTHER OFFSHORE. TWO SHORTWAVES MOVE THROUGH THE FLOW
AND ACROSS SOUTHERN NEW ENGLAND. MODEL TIMING HAS VARIED FROM RUN TO
RUN AND SO CONFIDENCE IN THIS TIMING IS REDUCED.  ONE SHORTWAVE
MOVES UP THE COAST FRIDAY-SATURDAY...THE OTHER MOVES THROUGH WITH
THE EJECTED LOW AXIS AROUND MONDAY.

CONFIDENCE IN THE BROAD PICTURE...BUT LOW CONFIDENCE IN THE DAY-
BY-DAY DETAILS. A BLEND OF HPC AND GMOS WAS PREFERRED.

THE DAILIES...

THURSDAY... SURFACE HIGH PRESSURE BUILDING TO OUR NORTH WHILE THE
STALLED FRONT REMAINS WELL OFFSHORE.  THE RESULT WILL BE A NORTHEAST
FLOW AT THE SURFACE...UNDERLYING THE SOUTHWEST FLOW ALOFT.  WE
EXPECT THIS WILL MAINTAIN LOW CLOUDS OVER THE COASTAL PLAIN WITH
PARTLY TO MOSTLY SUNNY SKIES IN THE CT VALLEY/WORCESTER
HILLS/MONADNOCKS.  THE AREA ALSO REMAINS IN THE RIGHT ENTRANCE
REGION OF THE UPPER JET AND STABILITY PARAMETERS ARE
MARGINAL...MAINLY ALONG THE SOUTH COAST/ISLANDS.  WE WILL MAINTAIN
SLIGHT CHANCE POPS OVER THE SOUTHEAST HALF OF OUR AREA...CHANCE POPS
CLIPPING THE CAPE AND ISLANDS.  TEMPS ARE A BLEND OF MAV/MET VALUES.

FRIDAY THROUGH SUNDAY... UPPER SHORTWAVE FROM THE MIDWEST REACHES
THE COAST THURSDAY NIGHT AND MOVES UP ACROSS NEW ENGLAND
FRIDAY/FRIDAY NIGHT.  WE WILL AGAIN BE IN THE RIGHT ENTRANCE REGION
OF THE SUPPORTING UPPER JET WHICH WILL PROVIDE VENTING. MODEL
AGREEMENT THAT THIS INDUCES A WAVE ALONG THE STALLED FRONT AND
BRINGS THE WAVE UP THE COAST AND PASSING CAPE COD FRIDAY NIGHT. A 40
KNOT LOW LEVEL JET IS ASSOCIATED WITH THIS WAVE...BUT PASSES WELL
EAST OF CAPE COD.  SO THE BULK OF THE LOW LEVEL LIFT WILL REMAIN
EAST OF NEW ENGLAND. EVEN SO...THE UPPER SUPPORT IS ENOUGH TO EXPECT
CHANCE POPS FROM AT LEAST THE CENTRAL HILLS EASTWARD.

THE WAVE MOVES OFF SATURDAY...BUT ANOTHER SURFACE WAVE MAY APPROACH
SUNDAY WHICH SHOULD KEEP A CHANCE OF SHOWERS IN THE NEIGHBORHOOD.
THE UPPER LOW PASSES TO OUR NORTH MONDAY WITH THE TROUGH AXIS MOVING
ACROSS NEW ENGLAND.  AT THE SAME TIME A COLD FRONT WILL MOVE THROUGH
THE REGION.  WILL CONTINUE CHANCE POPS IN PLACE THROUGH MONDAY.

TUESDAY... HIGH PRESSURE BUILDS IN FROM THE GREAT LAKES.  THIS
SHOULD DRY THINGS OUT AND BRING MOSTLY CLEAR SKIES.  TEMPS AT THE
TOP OF THE MIXED LAYER WILL BE IN THE MID TEENS...SO MAX TEMPS
SHOULD BE IN THE MID 80S...A FEW SPOTS IN THE UPPER 80S POSSIBLE.

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /INTO WEDNESDAY NIGHT/...MODERATE CONFIDENCE.

18Z UPDATE...

BANDS OF SHRA/TSRA DEVELOPING ACROSS SOUTHERN NEW ENGLAND WILL
PREVAIL INTO THE EARLY EVENING HOURS. HAVE GONE -RA VCTS WITH
EXPECTATION OF THREATS...BUT WITH ANY IMPACTS...ANTICIPATING
SOUTHWESTERLY WINDS AROUND 10G20KT ALONG WITH IFR VSBYS.

ACTIVITY SHOULD DISSIPATE TOWARDS THE EARLY EVENING HOURS BECOMING
QUIET FOR THE MOST PART OVERNIGHT. OVERNIGHT VSBYS A CHALLENGE
WITH EXPECTED WEST-SOUTHWEST FLOW. WILL PREVAIL MVFR. NEED TO
MONITOR FOR EITHER THE DEVELOPMENT OF IFR CIGS AND/OR VSBYS. WITH
FLOW PREVAILING 10 KTS...HAVE GREATER CONFIDENCE WITH LOW CIGS.

A COLD FRONT WILL SWEEP ACROSS THE TERMINALS WEDNESDAY ALONG AND
AHEAD OF WHICH SHRA/TSRA WILL BE POSSIBLE...BUT ISOLATED TO WIDELY
SCATTERED. PERHAPS TEMPO MVFR IMPACTS. ACTIVITY DIMINISHING INTO
EVENING AS THE FRONT MOVES OFFSHORE. COULD SEE SOME LOCALIZED
IMPACTS ALONG THE SOUTH SHORE DOWN TO MVFR WITH -SHRA.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. TSRA CONSTANTLY
DEVELOPING WEST WHICH WILL REQUIRE MULTIPLE AFTERNOON UPDATES.
AGAIN...STORMS PRODUCING TEMPO 10G20KT WITH MVFR/IFR IMPACTS.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. LINE OF SHRA/TSRA
DEVELOPING NORTH AND WEST. HAVE TIMED INTO TAF AS BEST AS
POSSIBLE. TEMPO MVFR/IFR IMPACTS WITH STORMS ANTICIPATED.

OUTLOOK...THURSDAY THROUGH SUNDAY...

THURSDAY-FRIDAY...VFR.  MORE CLOUDINESS IN RI/SOUTHEAST MASS WITH
LOWEST CLOUDS OVER THE CAPE AND ISLANDS. RAIN OR RAIN SHOWERS WILL
BE POSSIBLE...ESPECIALLY IN RI AND EASTERN MASS ON FRIDAY. IN-FLIGHT
CONCERN MAY BE DIRECTIONAL WIND SHEAR WITH A NORTHEAST WIND AROUND
10-15 KNOTS AT THE SURFACE AND A SOUTHWEST WIND AT 15-20 KNOTS ABOVE
5000 FEET.

SATURDAY-SUNDAY...COASTAL LOW PRESSURE WILL SPREAD LOW CLOUDS AND
MVFR CONDITIONS INTO THE COASTAL PLAIN.  THE BEST CHANCE OF LOW CIGS
WILL BE ON THE CAPE AND ISLANDS...THE SMALLEST CHANCE IN THE
CONNECTICUT VALLEY.  RAIN OR RAIN SHOWERS WILL ALSO BE A CONCERN
BOTH DAYS.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /INTO WEDNESDAY NIGHT/...MODERATE CONFIDENCE.

SHOWERS AND THUNDERSTORMS WILL IMPACT THE NEAR-COASTAL WATERS INTO
THE EARLY EVENING HOURS...GRADUALLY DISSIPATING INTO THE OUTER
WATERS. HEAVY RAIN WITH REDUCED VISIBILITIES ALONG WITH FREQUENT
LIGHTNING SHOULD BE ANTICIPATED WITH THESE STORMS. GUSTY WINDS
ANTICIPATED WHICH COULD EXCEED GALE FORCE.

OTHERWISE WHILE SOUTHWEST WINDS ARE GUSTING AROUND 20 KTS ACROSS
THE CAPE PRESENTLY...FEEL SUCH WINDS WILL DIMINISH THROUGH THE
EVENING HOURS. WILL HOLD WINDS AND SEAS BELOW SMALL CRAFT ADVISORY
THRESHOLDS. STILL CONCERNS FOR PATCHY FOG ALONG THE SOUTH COAST
WITH THE POTENTIAL FOR VISIBILITIES DOWN TO A QUARTER MILE OR
LESS...BUT HAVE LOW CONFIDENCE AT THIS TIME.

OUTLOOK...THURSDAY THROUGH SUNDAY...

ROUGH SEAS OF 5-6 FEET WILL BE A CONCERN ON THE OUTER WATERS
THURSDAY AND AGAIN SATURDAY. NORTHEAST WINDS WILL GUST 20 TO 25
KNOTS ON THE SOUTHERN AND CAPE COD WATERS THURSDAY THROUGH
SATURDAY. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR THESE
CONDITIONS. SHOWERS THURSDAY...RAIN THEN SPREADS NORTH ACROSS THE
WATERS FOR FRIDAY AND THE WEEKEND.

&&

.TIDES/COASTAL FLOODING...
ASTRONOMICAL TIDES WILL BE ABNORMALLY HIGH DURING THE HIGH TIDE
CYCLE NEAR MIDNIGHT TONIGHT. BOS TIDE IS AGAIN 12.1 FT. HOWEVER
WITH OFFSHORE FLOW...BELIEVE THE THREAT FOR COASTAL FLOODING WILL
BE LOW. THERE MAY BE POCKETS OF SPLASHOVER...BUT WITH LOW
CONFIDENCE HAVE HOLD OFF ON ANY ISSUING ANY STATEMENT AT THIS
TIME.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR CTZ002>004.
MA...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR MAZ002>021-
     026.
NH...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR NHZ011-012-
     015.
RI...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR RIZ001>007.
MARINE...NONE.

&&

$$
SYNOPSIS...WTB/SIPPRELL
NEAR TERM...SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...WTB
AVIATION...WTB/SIPPRELL
MARINE...WTB/SIPPRELL
TIDES/COASTAL FLOODING...




AREA FORECAST DISCUSSION

NWS TAUNTON MA

 338 PM EDT TUE JUL 23 2013

.SYNOPSIS...

SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO THE EARLY EVENING
HOURS GRADUALLY DISSIPATING. A RENEWED CHANCE OF WET WEATHER
ACTIVITY IS POSSIBLE WEDNESDAY AHEAD OF A SWEEPING COLD FRONT
WHICH WILL EXIT OUT INTO THE WATERS INTO WEDNESDAY NIGHT. COOLER
AND LESS HUMID WEATHER FOLLOWS THEREAFTER FOR THURSDAY AND
FRIDAY. WARMER AIR RETURNS NEXT WEEKEND BEFORE A COLD FRONT BRINGS
SCATTERED SHOWERS/THUNDERSTORMS SUNDAY...POSSIBLY LINGERING INTO
MONDAY

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...

*** FLASH FLOOD WATCH IS IN EFFECT TILL THIS EVENING***

AFTERNOON SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO THE EARLY
EVENING HOURS GRADUALLY DISSIPATING TOWARDS MIDNIGHT. STARTING TO
SEE DEVELOPING CONGEAL INTO A LINE ALONG A WEAK FRONTAL BOUNDARY
ATTENDANT TO A BROAD AREA OF LOW PRESSURE OVER SOUTHERN NEW
ENGLAND. SOME OF THE CELLS ARE REACHING UP TO 30-40 KFT WITH
SIGNIFICANT DBZ/S. SUBSEQUENTLY...WHILE GUSTY WINDS OF 20 TO 30
MPH ARE EXPECTED WITH STORMS...COULD SEE ISOLATED STRONGER WHICH
COULD LEAD TO WIND DAMAGE.

OTHERWISE THERE CONTINUES THE THREAT OF HEAVY RAIN /WITH HOURLY
RAINFALL RATES UP TO AROUND 1.5 INCHES/ AND FLASH FLOODING BUT
WITH THE THREAT BECOMING MORE ISOLATED...WILL ALLOW THE FLASH
FLOOD WATCH TO DROP AT 8 PM. HRRR MODEL IS STILL DOING WELL IN
INITIALIZING WITH THE CURRENT CONDITIONS AND FORECASTING
EXPECTATIONS. WILL FOLLOW IT CLOSELY FOR THE EVENING FORECAST.

SOUTHWEST WINDS GUSTING ACROSS THE SOUTHCOAST AND ACROSS THE CAPE
WITH GUSTS UP TO AROUND 20 TO 25 MPH. EXPECT WINDS TO DIMINISH
INTO THE EVENING. CLOUDS IN ABUNDANCE...BUT SOME CLEARING IS
POSSIBLE OVER THE WESTERN ZONES. NEVERTHELESS...ABUNDANCE OF
MOISTURE AND SOUTHERLY WIND FLOW PRESENTS THE THREAT OF SOME
PATCHY FOG...ESPECIALLY ALONG THE COASTS. LOWS DOWN TO THE MID-
TO UPPER-70S BY WEDNESDAY MORNING.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...

WEDNESDAY...

COLD FRONT SWEEPS THROUGH THE REGION DURING THE MIDDAY HOURS...THE
PROXIMITY OF WHICH WILL BE ROUGHLY ALONG AND PARALLEL TO THE I-95
CORRIDOR AROUND MIDDAY. MAIN QUESTION IS WHETHER WE WILL SEE SOME
WET WEATHER AHEAD OF THE FRONT.

CONSIDERING AVAILABLE MOISTURE /PWATS AROUND 1.25 INCHES/ COUPLED
WITH SUFFICIENT DEEP-LAYER ASCENT AND UNI-DIRECTIONAL WEST-
SOUTHWEST WIND SHEAR /25-30 KTS/...EXPECT SHOWERS AND POSSIBLE
THUNDERSTORMS AHEAD OF THE COLD FRONT IN AN ENVIRONMENT FAVORABLE
FOR UPDRAFT SUSTAINMENT. SOME QUESTION OF AVAILABLE
INSTABILITY...IMPORTANTLY WHETHER CLOUD DECKS WILL BREAK ALLOWING
FOR SUNSHINE. CONFIDENT IN SEEING SUNSHINE WHICH WILL ALLOW HIGHS
AROUND THE MID 80S. WITH THAT FORECAST GUIDANCE SUPPORTS UP TO
1000 J/KG MUCAPE. CONSIDERING...NOT MUCH CONFIDENCE FOR SEVERE
WEATHER THREATS...BUT BELIEVE THERE WILL BE POCKETS OF HEAVY RAIN
WHICH COULD LEAD TO LOCALIZED FLOODING.

GREATEST CONFIDENCE WITH THE THE 23.0Z ECMWF WHICH INITIALIZED WELL
WITH THE MORNING OUTCOMES. 23.12Z HIGH-RES NAM AND 23.09Z SREF
SUPPORT THE ECMWF. NOTABLY DOWNSTREAM TOWARDS THE EASTERN GREAT
LAKES...JUST THE LOW-LEVEL FORCING AHEAD OF THE LEAD IMPULSE ALOFT
IS GENERATING SHOWER AND THUNDERSTORM ACTIVITY.

WEDNESDAY NIGHT...

HIGH PRESSURE BUILDS SOUTH AND EAST OUT OF CANADA. FEEL THE INTERIOR
WILL BE DRY...BUT SHOWERS WILL BE POSSIBLE ALONG THE SOUTH COAST AS
A MID-LEVEL IMPULSE ROTATING THROUGH THE BROADER TROUGH LIFTS
NORTHEAST ALONG THE OFFSHORE FRONTAL BOUNDARY AND DEEPER AXIS OF
MOISTURE. WITH CLEARING NORTH AND WEST...THIS WILL PERMIT LOWS TO
FALL TO AROUND 50 DEGREES...WHILE REMAINING MILD SOUTH AND EAST
TOWARDS THE CLOUDS AND ANTICIPATED SHOWERY WEATHER. NO EXPECTATION
FOR ANY FLOODING WITH SHOWERS.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...

HEADLINES...

* LESS HUMID WEATHER ARRIVES LATER WED
* NORTHEAST/GRTLKS LONG WAVE TROUGH WILL YIELD SEASONABLE TEMPS
* ACTIVE WEATHER PATTERN WILL RESULT IN SEVERAL BOUTS OF CONVECTION

SYNOPTIC OVERVIEW...

GOOD MODEL AGREEMENT AMONG THE GFS AND ECMWF ENSEMBLES IN
MAINTAINING LONG WAVE TROUGH OVER THE NE/GREAT LKS AND EASTERN
CANADA THIS PERIOD. THIS WILL PRECLUDE EXCESSIVE HEAT/HUMIDITY FROM
ENTERING SOUTHERN NEW ENGLAND AND KEEPING TEMPS AT OR SLIGHTLY
COOLER THAN NORMAL. AS FOR PRECIP...THIS PATTERN WILL FAVOR AN
ACTIVE NORTHERN STREAM JET ACROSS THE NORTHEAST RESULTING IN SEVERAL
BOUTS OF CONVECTION. SO A BREAK FROM THE HEAT AND RELATIVELY DRY
WEATHER PATTERN OF THIS MONTH.

SENSIBLE WEATHER DETAILS...

WED...MAIN PLUME OF MOISTURE MOVES OFFSHORE TONIGHT WITH LEAD SHORT
WAVE TROUGH. HOWEVER SECONDARY/TRAILING SHORT WAVE TROUGH SWEEPS
ACROSS THE AREA WED. THIS FEATURE MAY TOUCH OFF A FEW TSTMS OVER
EASTERN MA AND RI WHERE INSTABILITY LINGERS AND LOW LEVEL
CONVERGENCE IS GREATEST. CAN/T RULE OUT ONE OR TWO STRONG STORMS
WITH CAPES OF 1000-1500J/KG ALONG WITH DEEP LAYER SHEAR OF 25-30 KT.
OTHERWISE BIG IMPROVEMENT FROM TODAY AS DEPARTING SHORT WAVE ADVECTS
MUCH DRIER AND LESS HUMID AIR OVERSPREADS THE REGION LATER WED
AND WED NGT FROM NW TO SE. COULD BE WARMEST DAY OF THE WEEK AS
COOLER AIRMASS LAGS UNTIL WED NGT/THU. THUS HIGHS 85-90 LIKELY.

THU/FRI... FRONT GETS HUNG UP OVER CAPE COD/ISLANDS OR JUST
OFFSHORE. THUS CLOUDS MAY LINGER ACROSS THIS AREA WITH MORE SUNSHINE
INLAND THU. BY FRI WEAK WAVE OF LOW PRES MAY TRAVERSE NE ALONG THE
FRONT AND MAY YIELD A LOW RISK OF RAIN FOR SOUTHEAST MA...WITH LOWER
PROBABILITY OF RAIN INLAND. 00Z NAM AND GFS MORE SUPPRESSED WITH THIS
FRONTAL WAVE. HOWEVER 00Z ECMWF MORE ROBUST AND BRINGS QPF ACROSS
MUCH OF SOUTHERN NEW ENGLAND. 00Z GEFS IS SOMEWHERE IN BETWEEN WITH
30-50% PROBS OF RAIN FRI/FRI NGT ACROSS SOUTHEAST MA. GIVEN
UNCERTAINTY WILL HANDLE THIS WITH CHANCE POPS CAPE COD AND
ISLANDS...SLIGHT CHANCE ELSEWHERE.

COULD BE A BIT BREEZY AND COOL THU/FRI ACROSS EASTERN MA WITH NE
WINDS AS FRONT LURKS JUST OFFSHORE AND HIGH PRES BUILDS INTO THE ST
LWRNC RVR VLY.

SAT/SUN/MON...DRY WEATHER APPEARS TO LINGER INTO SAT ALONG WITH
SEASONABLE TEMPS. HOWEVER NEXT TROUGH ARRIVES SUN/MON BRINGING THE
RISK OF ANOTHER ROUND OF SHOWERS/TSTMS.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /INTO WEDNESDAY NIGHT/...MODERATE CONFIDENCE.

18Z UPDATE...

BANDS OF SHRA/TSRA DEVELOPING ACROSS SOUTHERN NEW ENGLAND WILL
PREVAIL INTO THE EARLY EVENING HOURS. HAVE GONE -RA VCTS WITH
EXPECTATION OF THREATS...BUT WITH ANY IMPACTS...ANTICIPATING
SOUTHWESTERLY WINDS AROUND 10G20KT ALONG WITH IFR VSBYS.

ACTIVITY SHOULD DISSIPATE TOWARDS THE EARLY EVENING HOURS BECOMING
QUIET FOR THE MOST PART OVERNIGHT. OVERNIGHT VSBYS A CHALLENGE
WITH EXPECTED WEST-SOUTHWEST FLOW. WILL PREVAIL MVFR. NEED TO
MONITOR FOR EITHER THE DEVELOPMENT OF IFR CIGS AND/OR VSBYS. WITH
FLOW PREVAILING 10 KTS...HAVE GREATER CONFIDENCE WITH LOW CIGS.

A COLD FRONT WILL SWEEP ACROSS THE TERMINALS WEDNESDAY ALONG AND
AHEAD OF WHICH SHRA/TSRA WILL BE POSSIBLE...BUT ISOLATED TO WIDELY
SCATTERED. PERHAPS TEMPO MVFR IMPACTS. ACTIVITY DIMINISHING INTO
EVENING AS THE FRONT MOVES OFFSHORE. COULD SEE SOME LOCALIZED
IMPACTS ALONG THE SOUTH SHORE DOWN TO MVFR WITH -SHRA.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. TSRA CONSTANTLY
DEVELOPING WEST WHICH WILL REQUIRE MULTIPLE AFTERNOON UPDATES.
AGAIN...STORMS PRODUCING TEMPO 10G20KT WITH MVFR/IFR IMPACTS.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. LINE OF SHRA/TSRA
DEVELOPING NORTH AND WEST. HAVE TIMED INTO TAF AS BEST AS
POSSIBLE. TEMPO MVFR/IFR IMPACTS WITH STORMS ANTICIPATED.

OUTLOOK...THURSDAY THROUGH SATURDAY...

THU AND FRI...LOW CONFIDENCE REGARDING AREAL COVERAGE OF POSSIBLE
RAIN SHIELD AND ASSOCIATED MVFR CONDITIONS. ENE WINDS. RAIN MAY
IMPACT SOUTHEAST MA.

SAT...MODERATE CONFIDENCE. VFR. SCT PM SHOWERS/TSTMS MAINLY IN
WESTERN NEW ENGLAND.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /INTO WEDNESDAY NIGHT/...MODERATE CONFIDENCE.

SHOWERS AND THUNDERSTORMS WILL IMPACT THE NEAR-COASTAL WATERS INTO
THE EARLY EVENING HOURS...GRADUALLY DISSIPATING INTO THE OUTER
WATERS. HEAVY RAIN WITH REDUCED VISIBILITIES ALONG WITH FREQUENT
LIGHTNING SHOULD BE ANTICIPATED WITH THESE STORMS. GUSTY WINDS
ANTICIPATED WHICH COULD EXCEED GALE FORCE.

OTHERWISE WHILE SOUTHWEST WINDS ARE GUSTING AROUND 20 KTS ACROSS
THE CAPE PRESENTLY...FEEL SUCH WINDS WILL DIMINISH THROUGH THE
EVENING HOURS. WILL HOLD WINDS AND SEAS BELOW SMALL CRAFT ADVISORY
THRESHOLDS. STILL CONCERNS FOR PATCHY FOG ALONG THE SOUTH COAST
WITH THE POTENTIAL FOR VISIBILITIES DOWN TO A QUARTER MILE OR
LESS...BUT HAVE LOW CONFIDENCE AT THIS TIME.

OUTLOOK...WEDNESDAY THROUGH SATURDAY...

THURSDAY AND FRIDAY...LOW CONFIDENCE ON POTENTIAL RAIN SHIELD AND
ASSOCIATED VSBYS. ENE WINDS WITH FRONTAL BOUNDARY JUST OFFSHORE. LOW
PRES MAY RIDE ALONG THIS FRONT WITH ITS RAIN SHIELD POSSIBLY
IMPACTING THE SOUTHERN NEW ENGLAND WATERS.

SATURDAY...MODERATE CONFIDENCE.
S/SE FLOW GETS UNDERWAY AND SHOULD VEER TO SW LATE AS COLD FRONT
PUSHES INTO UPSTATE NY. WINDS AND SEAS SHOULD REMAIN BELOW SCA.

&&

.TIDES/COASTAL FLOODING...

ASTRONOMICAL TIDES WILL BE ABNORMALLY HIGH DURING THE HIGH TIDE
CYCLE NEAR MIDNIGHT TONIGHT. BOS TIDE IS AGAIN 12.1 FT. HOWEVER
WITH OFFSHORE FLOW...BELIEVE THE THREAT FOR COASTAL FLOODING WILL
BE LOW. THERE MAY BE POCKETS OF SPLASHOVER...BUT WITH LOW
CONFIDENCE HAVE HOLD OFF ON ANY ISSUING ANY STATEMENT AT THIS
TIME.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR CTZ002>004.
MA...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR MAZ002>021-
     026.
NH...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR NHZ011-012-
     015.
RI...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR RIZ001>007.
MARINE...NONE.

&&

$$

SYNOPSIS...WTB/SIPPRELL
NEAR TERM...SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...WTB
AVIATION...WTB/SIPPRELL
MARINE...WTB/SIPPRELL
TIDES/COASTAL FLOODING...




AREA FORECAST DISCUSSION

NWS TAUNTON MA

 146 PM EDT TUE JUL 23 2013

.SYNOPSIS...

SHOWERS AND THUNDERSTORMS WILL BECOME MORE NUMEROUS INTO THE
AFTERNOON HOURS AS AN AREA OF LOW PRESSURE WITH AN ATTENDANT WARM
FRONT SLOWLY LIFT ACROSS THE REGION. A COLD FRONT WILL SWEEP
ACROSS THE REGION WEDNESDAY FOLLOWED BY COOLER AND LESS HUMID
WEATHER THURSDAY AND FRIDAY. WARMER AIR RETURNS NEXT WEEKEND
BEFORE A COLD FRONT BRINGS SCATTERED SHOWERS/THUNDERSTORMS
SUNDAY...POSSIBLY LINGERING INTO MONDAY

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...

*** FLASH FLOOD WATCH IS IN EFFECT TILL THIS EVENING***

2 PM UPDATE...

CLEARING PROCEEDED DURING THE LATE MORNING INTO MIDDAY HOURS
ALLOWING FOR BOUNDARY LAYER DESTABILIZATION. SUBSEQUENTLY...THE
RICH MOISTURE PROFILE IS EASILY LIFTING WITH AMBIENT SUNSHINE IN
AN ENVIRONMENT OF FAVORABLE SHEAR CONSEQUENTIALLY RESULTING IN
BANDS OF SHOWERS AND THUNDERSTORMS CONTAINING HEAVY RAIN.

DEEP-LAYER LIFT COMBINED WITH THE FAVORABLE SHEAR SHOULD ALLOW
UPDRAFTS TO SUSTAIN INTO THE EARLY EVENING HOURS...THUS THE
THUNDERSTORM LIKELIHOOD WILL CONTINUE WITH THE THREAT OF HEAVY
RAIN AND FLASH FLOODING. HRRR MODELS THE PRESENT ACTIVITY AND
ANTICIPATED OUTCOMES INTO EARLY EVENING WELL. HOURLY RAINFALL
AMOUNTS OF UP TO 2 INCHES ARE POSSIBLE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...

TONIGHT...

MID-LEVEL DRYING WILL PUSH INTO THE REGION AS TROUGH AXIS MOVES
ACROSS THE REGION. COLD FRONT IS ALSO PROGGED TO MOVE ACROSS THE
REGION THIS EVENING AND INTO THE OVERNIGHT HOURS. BELIEVE THAT
PRECIP WILL SLOWLY COME TO AN END FROM WEST TO EAST INTO THE
OVERNIGHT HOURS. VERY LITTLE RELIEF IS EXPECTED AS MOISTURE STILL
LINGER ACROSS THE REGION. EXPECT TEMPS TO DROP ONLY INTO THE MID 60S
TO LOW 70S.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...

HEADLINES...

* LESS HUMID WEATHER ARRIVES LATER WED
* NORTHEAST/GRTLKS LONG WAVE TROUGH WILL YIELD SEASONABLE TEMPS
* ACTIVE WEATHER PATTERN WILL RESULT IN SEVERAL BOUTS OF CONVECTION

SYNOPTIC OVERVIEW...

GOOD MODEL AGREEMENT AMONG THE GFS AND ECMWF ENSEMBLES IN
MAINTAINING LONG WAVE TROUGH OVER THE NE/GREAT LKS AND EASTERN
CANADA THIS PERIOD. THIS WILL PRECLUDE EXCESSIVE HEAT/HUMIDITY FROM
ENTERING SOUTHERN NEW ENGLAND AND KEEPING TEMPS AT OR SLIGHTLY
COOLER THAN NORMAL. AS FOR PRECIP...THIS PATTERN WILL FAVOR AN
ACTIVE NORTHERN STREAM JET ACROSS THE NORTHEAST RESULTING IN SEVERAL
BOUTS OF CONVECTION. SO A BREAK FROM THE HEAT AND RELATIVELY DRY
WEATHER PATTERN OF THIS MONTH.

SENSIBLE WEATHER DETAILS...

WED...MAIN PLUME OF MOISTURE MOVES OFFSHORE TONIGHT WITH LEAD SHORT
WAVE TROUGH. HOWEVER SECONDARY/TRAILING SHORT WAVE TROUGH SWEEPS
ACROSS THE AREA WED. THIS FEATURE MAY TOUCH OFF A FEW TSTMS OVER
EASTERN MA AND RI WHERE INSTABILITY LINGERS AND LOW LEVEL
CONVERGENCE IS GREATEST. CAN/T RULE OUT ONE OR TWO STRONG STORMS
WITH CAPES OF 1000-1500J/KG ALONG WITH DEEP LAYER SHEAR OF 25-30 KT.
OTHERWISE BIG IMPROVEMENT FROM TODAY AS DEPARTING SHORT WAVE ADVECTS
MUCH DRIER AND LESS HUMID AIR OVERSPREADS THE REGION LATER WED
AND WED NGT FROM NW TO SE. COULD BE WARMEST DAY OF THE WEEK AS
COOLER AIRMASS LAGS UNTIL WED NGT/THU. THUS HIGHS 85-90 LIKELY.

THU/FRI... FRONT GETS HUNG UP OVER CAPE COD/ISLANDS OR JUST
OFFSHORE. THUS CLOUDS MAY LINGER ACROSS THIS AREA WITH MORE SUNSHINE
INLAND THU. BY FRI WEAK WAVE OF LOW PRES MAY TRAVERSE NE ALONG THE
FRONT AND MAY YIELD A LOW RISK OF RAIN FOR SOUTHEAST MA...WITH LOWER
PROBABILITY OF RAIN INLAND. 00Z NAM AND GFS MORE SUPPRESSED WITH THIS
FRONTAL WAVE. HOWEVER 00Z ECMWF MORE ROBUST AND BRINGS QPF ACROSS
MUCH OF SOUTHERN NEW ENGLAND. 00Z GEFS IS SOMEWHERE IN BETWEEN WITH
30-50% PROBS OF RAIN FRI/FRI NGT ACROSS SOUTHEAST MA. GIVEN
UNCERTAINTY WILL HANDLE THIS WITH CHANCE POPS CAPE COD AND
ISLANDS...SLIGHT CHANCE ELSEWHERE.

COULD BE A BIT BREEZY AND COOL THU/FRI ACROSS EASTERN MA WITH NE
WINDS AS FRONT LURKS JUST OFFSHORE AND HIGH PRES BUILDS INTO THE ST
LWRNC RVR VLY.

SAT/SUN/MON...DRY WEATHER APPEARS TO LINGER INTO SAT ALONG WITH
SEASONABLE TEMPS. HOWEVER NEXT TROUGH ARRIVES SUN/MON BRINGING THE
RISK OF ANOTHER ROUND OF SHOWERS/TSTMS.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /INTO WEDNESDAY NIGHT/...MODERATE CONFIDENCE.

18Z UPDATE...

BANDS OF SHRA/TSRA DEVELOPING ACROSS SOUTHERN NEW ENGLAND WILL
PREVAIL INTO THE EARLY EVENING HOURS. HAVE GONE -RA VCTS WITH
EXPECTATION OF THREATS...BUT WITH ANY IMPACTS...ANTICIPATING
SOUTHWESTERLY WINDS AROUND 10G20KT ALONG WITH IFR VSBYS.

ACTIVITY SHOULD DISSIPATE TOWARDS THE EARLY EVENING HOURS BECOMING
QUIET FOR THE MOST PART OVERNIGHT. OVERNIGHT VSBYS A CHALLENGE
WITH EXPECTED WEST-SOUTHWEST FLOW. WILL PREVAIL MVFR. NEED TO
MONITOR FOR EITHER THE DEVELOPMENT OF IFR CIGS AND/OR VSBYS. WITH
FLOW PREVAILING 10 KTS...HAVE GREATER CONFIDENCE WITH LOW CIGS.

A COLD FRONT WILL SWEEP ACROSS THE TERMINALS WEDNESDAY ALONG AND
AHEAD OF WHICH SHRA/TSRA WILL BE POSSIBLE...BUT ISOLATED TO WIDELY
SCATTERED. PERHAPS TEMPO MVFR IMPACTS. ACTIVITY DIMINISHING INTO
EVENING AS THE FRONT MOVES OFFSHORE. COULD SEE SOME LOCALIZED
IMPACTS ALONG THE SOUTH SHORE DOWN TO MVFR WITH -SHRA.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. TSRA CONSTANTLY
DEVELOPING WEST WHICH WILL REQUIRE MULTIPLE AFTERNOON UPDATES.
AGAIN...STORMS PRODUCING TEMPO 10G20KT WITH MVFR/IFR IMPACTS.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. LINE OF SHRA/TSRA
DEVELOPING NORTH AND WEST. HAVE TIMED INTO TAF AS BEST AS
POSSIBLE. TEMPO MVFR/IFR IMPACTS WITH STORMS ANTICIPATED.

OUTLOOK...THURSDAY THROUGH SATURDAY...

THU AND FRI...LOW CONFIDENCE REGARDING AREAL COVERAGE OF POSSIBLE
RAIN SHIELD AND ASSOCIATED MVFR CONDITIONS. ENE WINDS. RAIN MAY
IMPACT SOUTHEAST MA.

SAT...MODERATE CONFIDENCE. VFR. SCT PM SHOWERS/TSTMS MAINLY IN
WESTERN NEW ENGLAND.

&&

.MARINE...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

TODAY THROUGH TONIGHT...MODERATE CONFIDENCE.

WINDS/SEAS WILL REMAIN BELOW SCA THRESHOLDS. HAVE UNDERCUT WAVE
GUIDANCE FOR TODAY AS MODELS HAVE A HARD TIME WITH SOUTHERN SWELL.
LOW CONFIDENCE ON SCA SEAS DEVELOPING LATE THIS AFTERNOON. HOWEVER
CONFIDENCE INCREASES TONIGHT ACROSS THE SOUTHERN ATLANTIC WATERS
WITH PERSISTENT LONG SOUTHWEST FETCH AHEAD OF AN APPROACHING COLD
FRONT. ITS UNCERTAIN HOW HIGH SEAS WILL GET WITH AN INVERSION IN
PLACE...SO WITH LOW CONFIDENCE HAVE HOLD OFF ON ISSUING A SCA AT
THIS TIME. OTHER CONCERN WILL BE FOR AREAS OF FOG WHICH MAY BE
LOCALLY DENSE ACROSS SOME OF THE WATERS DURING THE OVERNIGHT
TONIGHT AND MORNING HOURS ON WED.

OUTLOOK...WEDNESDAY THROUGH SATURDAY...

WEDNESDAY...HIGH CONFIDENCE.
COLD FRONT PUSHES OFFSHORE DURING AFTERNOON/EVENING AND MAY
RESULT IN AN ISOLATED SHOWER/STORM NEAR SHORE. FRONT WILL BRING
GRADUAL WIND SHIFT TO W BUT WINDS/SEAS REMAIN BELOW SCA.

THURSDAY AND FRIDAY...LOW CONFIDENCE ON POTENTIAL RAIN SHIELD AND
ASSOCIATED VSBYS. ENE WINDS WITH FRONTAL BOUNDARY JUST OFFSHORE. LOW
PRES MAY RIDE ALONG THIS FRONT WITH ITS RAIN SHIELD POSSIBLY
IMPACTING THE SOUTHERN NEW ENGLAND WATERS.

SATURDAY...MODERATE CONFIDENCE.
S/SE FLOW GETS UNDERWAY AND SHOULD VEER TO SW LATE AS COLD FRONT
PUSHES INTO UPSTATE NY. WINDS AND SEAS SHOULD REMAIN BELOW SCA.

&&

.TIDES/COASTAL FLOODING...
ASTRONOMICAL TIDES WILL BE ABNORMALLY HIGH DURING THE HIGH TIDE
CYCLE NEAR MIDNIGHT TONIGHT. BOS TIDE IS AGAIN 12.1 FT. HOWEVER
WITH OFFSHORE FLOW...BELIEVE THE THREAT FOR COASTAL FLOODING WILL
BE LOW. THERE MAY BE POCKETS OF SPLASHOVER...BUT WITH LOW
CONFIDENCE HAVE HOLD OFF ON ANY ISSUING ANY STATEMENT AT THIS
TIME.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR CTZ002>004.
MA...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR MAZ002>021-
     026.
NH...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR NHZ011-012-
     015.
RI...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR RIZ001>007.
MARINE...NONE.

&&

$$
SYNOPSIS...NOCERA/DUNTEN
NEAR TERM...SIPPRELL
SHORT TERM...DUNTEN
LONG TERM...NOCERA
AVIATION...NOCERA/DUNTEN
MARINE...NOCERA/DUNTEN
TIDES/COASTAL FLOODING...




AREA FORECAST DISCUSSION

NWS MIAMI FL

 215 PM EDT TUE JUL 23 2013

.SHORT TERM (TONIGHT-THURSDAY NIGHT)...
A STRONG SUBTROPICAL DEEP LAYER RIDGE CURRENTLY LOCATED ACROSS SOUTH
FLORIDA AND THIS SUPPRESSING THE CONVECTION. THE 12Z MFL SOUNDING
SHOWED THE LOWEST LAYERS OF THE ATMOSPHERE HAD DESTABILIZED
SUBSTANTIALLY FROM 24 HOURS AGO SO CU DEVELOPED EARLIER WHICH HAS
LEAD TO EARLIER SHOWER DEVELOPMENT TOO ALONG WITH A FEW
THUNDERSTORMS. A SEA BREEZE LINE OF CONVECTION DEVELOPED RIGHT ALONG
THE COAST OF SOUTHERN BROWARD AND IT APPEARS THAT SOME ADDITIONAL
CONVERGENCE SET UP OTHER THAN JUST THE SEA BREEZE. LOOKING AT
VISIBLE SATELLITE IMAGES REVEALS A CONVERGENT BOUNDARY ASSOCIATED
WITH AN OUTFLOW/LAND BREEZE OFF THE EAST COAST WITH THIS BAND
EXTENDING WELL OUT INTO THE ATLANTIC. OUTSIDE OF THIS, THERE IS ALSO
A MID LEVEL TROUGH THAT IS DEEPENING OVER THE EASTERN STATES WITH
FORECAST SOUNDINGS INDICATING THE RIDGE WOULD BEGIN TO SHIFT SOUTH
THROUGH THIS AFTERNOON AND THIS APPEARS TO BE OCCURRING WITH LOW
TOPPED CONVECTION ALREADY DRIFTING TO THE EAST. HOWEVER, AS THE
DAY PROGRESSES AND DIURNAL HEATING CAN DESTABILIZE A DEEPER
PORTION OF THE ATMOSPHERE THE STEERING FLOW IS STILL VERY WEAK SO
STORM MOTION IS STILL EXPECTED TO BE SLOW AND POSSIBLY ERRATIC
ALTHOUGH THERE COULD BE A DRIFT TOWARDS THE EAST. SOME OF THE
SHORT RANGE HIGH RESOLUTION MODELS SUCH AS THE HRRR ARE SHOWING
MORE ROBUST CONVECTION FORMING OVER THE INTERIOR AROUND 17-18Z
(ALTHOUGH THIS NOT OCCURRING AS OF 1815Z) AND THEN SLOWLY MOVING
TOWARDS THE EAST BUT THEN AS THE HEATING CYCLE IS CUT OFF WITH A
LOWER SUN ANGLE, THE CONVECTION NEVER MAKES IT QUITE TO THE EAST
COAST AND THIS APPEARS REASONABLE GIVEN THE ABOVE REASONING.

THE RIDGE WILL CONTINUE TO SHIFT SOUTH TONIGHT AND BE OVER THE
FLORIDA STRAITS INCLUDING THE KEYS AS THE TROUGH CONTINUES TO
DEEPEN. THIS WILL ALLOW FOR A DEEP WESTERLY FLOW TO BECOME
ESTABLISHED ON WEDNESDAY AND THURSDAY WITH FORECASTING SOUNDINGS
SHOWING A STORM MOTION OF AROUND 5-7 MPH ON WEDNESDAY AND NEAR 10
MPH ON THURSDAY. NONE OF THE GLOBAL MODELS HOWEVER INDICATE AN
ABUNDANCE OF DEEP LAYER AVAILABLE MOISTURE NOR INSTABILITY SO
WIDESPREAD CONVECTION AT THIS TIME IS NOT EXPECTED. THE NAM, GFS AND
ECMWF ALL SHOW PWAT IN THIS TIME FRAME TO BE 1.5-1.7 INCHES WHICH IS
CLOSE TO OR SLIGHTLY BELOW THE AVERAGE FOR MID TO LATE JULY. BUT THE
SCATTERED STORMS THAT DO DEVELOP IN THIS PATTERN WILL FAVOR THE
INTERIOR AND EAST COAST METRO AREAS.

.LONG TERM (FRIDAY-TUESDAY)...
NOT MUCH CHANGE IS FORESEEN LOOKING TOWARDS THE END OF THE WEEK INTO
SATURDAY AS THE MAIN MID LEVEL TROUGH WILL REMAIN IN PLACE ACROSS
THE EASTERN STATES. THIS WILL MAINTAIN THE DEEP WESTERLY FLOW ACROSS
SOUTH FLORIDA WITH A FORECAST PWAT REMAINING NEAR NORMAL VALUES.
NONE OF THE MODELS SHOW ANY KIND OF MOISTURE INFLUX SO AT THIS TIME,
BY LATE IN THE WEEKEND AND INTO EARLY NEXT WEEK SCATTERED
THUNDERSTORMS ARE EXPECTED WITH THE PATTERN AGAIN REVERTING TO
MOSTLY INTERIOR AWAY FROM BOTH COASTS.

&&

.AVIATION...
DIFFUSE AXIS OF CONVERGENCE ALONG THE EAST COAST IS ACTING AS A
FOCUS FOR SHRA/TSRA DEVELOPMENT EARLY THIS AFTERNOON AND IS MAINLY
AFFECTING KMIA NORTHWARD TO KFLL. ACTIVITY IS BEGINNING TO WEAKEN AS
OUTFLOW RETREATS TO THE WEST. LATEST HRRR DEVELOPS ADDITIONAL
ACTIVITY LATER THIS AFTERNOON ACROSS THE INTERIOR AND PROPAGATES IT
EASTWARD TOWARD THE ATLANTIC COAST. KEPT VCSH MENTION IN AT ALL EAST
COAST SITES THROUGH 02Z WITH LIGHT SOUTHERLY FLOW BECOMING MORE
SOUTHWESTERLY OVERNIGHT.

&&

.MARINE...
LIGHT SOUTH TO SOUTHEAST WIND WILL VEER TO A SOUTH TO SOUTHWEST
DIRECTION ON WEDNESDAY AND CONTINUE THROUGH FRIDAY WITH SEAS LESS
THAN 4 FEET AS THE RIDGE SHIFTS SOUTH OF THE AREA. THE RIDGE WILL
THEN MOVE BACK NORTH OVER THE WEEKEND WITH A RETURN TO A LIGHT
SOUTHEAST WIND.

&&

.FIRE WEATHER...
NO PROBLEMS OR CONCERNS WITH AMPLE TROPICAL MOISTURE.

&&

.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH  75  90  75  91 / 20 40 20 40
FORT LAUDERDALE  77  90  77  91 / 20 40 20 30
MIAMI            77  90  76  91 / -  30 20 30
NAPLES           76  88  74  89 / -  20 10 20

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&

$$

DISCUSSION/MARINE/FIRE...30/KOB
AVIATION/RADAR...10/CD






AREA FORECAST DISCUSSION

NWS COLUMBIA SC

 250 PM EDT TUE JUL 23 2013

.SYNOPSIS...
AN UPPER LEVEL TROUGH WILL CONTINUE DEEPENING AS IT MOVES OVER THE
EASTERN US THIS AFTERNOON. THE TROUGH WILL REMAIN OVER THE
FORECAST THROUGH THE WEEKEND RESULTING IN AN ACTIVE WEATHER
PATTERN.

&&

.NEAR TERM /UNTIL 8 PM THIS EVENING/...
UPPER TROUGH OVER THE E CONUS. WEAK SURFACE TROUGH STRETCHES DOWN
THE EASTERN SEABOARD. AN UPPER DISTURBANCE WILL PUSH TO OUR
EAST...WITH SOME DRIER MID LEVEL AIR MOVING IN. HIGHEST PW VALUES
HAVE PUSHED TO NEAR THE COAST AND OFFSHORE AND ALSO TO OUR
WEST...WITH DRIER AIR AND PW VALUES 1.5 INCHES OR LESS PUSHING ESE
INTO MOST OF OUR FA TODAY. FORECAST SOUNDINGS INDICATE HIGH LFCS.
LATEST HIGH RESOLUTION MODELS KEEP CONVECTIVE ACTIVITY TO A
RELATIVE MINIMUM TODAY. LATEST HRRR WEAKENS THE CURRENT BATCH OF
CONVECTION THAT IS ACROSS N ALA/NW GA. LATE TODAY INTO THIS
EVENING...ANOTHER UPPER DISTURBANCE TO PUSH SE TOWARDS GA TODAY
WITH BETTER MOISTURE AVAILABLE IN THAT AREA COULD PROMOTE SOME
CONVECTION WHICH COULD PUSH TOWARDS THE CSRA. THINK SLIGHT CHANCE
POPS IN ORDER FOR MOST OF THE FA...BUT UPPED THEM SLIGHTLY TO LOW
CHANCE CSRA LATE TODAY AND THIS EVENING. DUE TO LIMITED
COVERAGE...LOWER PW...AND FASTER CELL MOVEMENT...THINK LOCALLY
HEAVY RAIN/FLOODING THREAT MINIMAL. HOWEVER...DCAPE VALUES ARE
PROJECTED TO INCREASE TO 1000 TO 1300 J/KG CSRA...SO ANY STRONGER
STORMS THAT FORM COULD PRODUCE A WIND THREAT. ALSO MADE SLIGHT
ADJUSTMENTS TO TEMPS...DEWPOINTS AND WINDS TODAY BASED ON CURRENT
TRENDS AND LATEST GUIDANCE. GUIDANCE BRINGS DEWPOINTS DOWN INTO
THE UPPER 60S THIS AFTERNOON FOR MUCH OF THE FA...THOUGH RECENT
RAINS AND HIGH SOIL MOISTURE COULD KEEP THEM FROM GETTING DOWN
QUITE THAT LOW.

&&

.SHORT TERM /8 PM THIS EVENING THROUGH THURSDAY NIGHT/...
SHORT WAVE TROUGH WILL MOVE FURTHER OFFSHORE WITH DRY AIR
REMAINING IN THE MID AND UPPER LEVELS OVERNIGHT. EXPECT ANY
CONVECTIVE ACTIVITY WHICH DEVELOPS THIS AFTERNOON TO DISSIPATE
THIS EVENING WITH THE LOSS OF HEATING AND A DRY FORECAST THROUGH
TONIGHT.

A WEAK COLD FRONT WILL MOVE INTO THE AREA WEDNESDAY. WITH THE UPPER
LEVEL TROUGH ALSO OVER THE REGION AND A SERIES OF WEAK SHORT WAVES
ROTATING THROUGH THE AXIS THERE WILL BE ENOUGH POTENTIAL TO INCLUDE
A CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS. GIVEN MODERATE
INSTABILITY AND SMALL SCALE BOUNDARY INTERSECTIONS...A FEW STORMS
COULD BE SEVERE. WEDNESDAY NIGHT THE CHANCE OF SHOWERS AND
THUNDERSTORMS WILL CONTINUE AS A FAIRLY VIGOROUS SHORT WAVE MOVES
THROUGH THE AREA OVERNIGHT.

THE FRONT IS FORECAST TO MOVE SOUTH OF THE AREA THURSDAY...BUT GIVEN
ITS PROXIMITY COMBINED WITH AND UNSTABLE AIR MASS AND  PERHAPS A
WEAK SHORT WAVE MOVING THOUGH THE LONG WAVE TROUGH...THE THREAT OF
CONVECTION CONTINUES.

WILL SEE HIGHS IN THE UPPER 80S TO LOWER 90S WITH LOWS IN THE
LOW/MID 70S.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
MEAN UPPER TROUGH WILL REMAIN ACROSS THE EASTERN CONUS THROUGH
THE WEEKEND...THEN BEGIN TO LIFT OUT MONDAY. MODELS INDICATE A
SERIES OF SHORT WAVES CROSSING THE AREA. HOWEVER...THEY DIFFER ON
THE TIMING OF SIGNIFICANT SHORT WAVES WHICH WOULD GENERATE
CONVECTION. A FRONTAL BOUNDARY WILL BE STALLED ACROSS THE GULF COAST
STATES FRIDAY THROUGH SUNDAY...THEN BEGIN TO LIFT NORTHWARD TOWARD
THE AREA EARLY NEXT WEEK. OUR ACTIVE WEATHER PATTERN WILL PERSIST.
SLIGHT CHANCE POPS FRIDAY INCREASE TO HIGH CHANCE OVER THE WEEKEND
INTO MONDAY.

TEMPERATURES THROUGH THE LONG TERM WILL BE SLIGHTLY BELOW NORMAL FOR
DAYTIME HIGHS WITH OVERNIGHT LOWS NEAR NORMAL.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
EXPECT VFR CONDITIONS THIS AFTERNOON. DRIER MID LEVEL AIR ENTERING
THE REGION...WITH ONLY A SLIGHT CHANCE OF A LATE AFTERNOON/EVENING
THUNDERSTORM. HOWEVER...AN UPPER DISTURBANCE AND BETTER MOISTURE TO
OUR WEST MAY PROVIDE A BETTER CHANCE OF TS AT AGS/DNL LATE TODAY AND
THIS EVENING...BUT THUNDERSTORM CHANCES TOO LOW TO INCLUDE MENTION
IN THE TAFS AT THIS TIME. WILL MONITOR RADAR TRENDS AND AMEND IF
NECESSARY. GUIDANCE INDICATING POTENTIAL FOR MVFR VSBYS IN FOG LATE
TONIGHT/EARLY WED. THIS WILL DEPEND ON EXTENT OF ANY LINGERING
MID/UPPER LEVEL DEBRIS CLOUDINESS THAT MAY STREAM IN FROM THE WEST.
SCATTERED CONVECTION EXPECTED WED...AFT 18Z.

EXTENDED AVIATION OUTLOOK...SCATTERED AFTERNOON AND EVENING
THUNDERSTORMS. LATE NIGHT/EARLY MORNING FOG/STRATUS POSSIBLE.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$







AREA FORECAST DISCUSSION

NWS COLUMBIA SC

 127 PM EDT TUE JUL 23 2013

.SYNOPSIS...
AN UPPER LEVEL TROUGH WILL CONTINUE DEEPENING AS IT MOVES OVER THE
EASTERN US THIS AFTERNOON. THE TROUGH WILL REMAIN OVER THE
FORECAST THROUGH THE WEEKEND RESULTING IN AN ACTIVE WEATHER
PATTERN.

&&

.NEAR TERM /UNTIL 8 PM THIS EVENING/...
UPEPR TROUGH OVER THE E CONUS. WEAK SURFACE TROUGH STRETCHES DOWN
THE EASTERN SEABOARD. AN UPPER DISTURBANCE WILL PUSH TO OUR
EAST...WITH SOME DRIER MID LEVEL AIR MOVING IN. HIGHEST PW VALUES
HAVE PUSHED TO NEAR THE COAST AND OFFSHORE AND ALSO TO OUR
WEST...WITH DRIER AIR AND PW VALUES 1.5 INCHES OR LESS PUSHING ESE
INTO MOST OF OUR FA TODAY. FORECAST SOUNDINGS INDICATE HIGH LFCS.
LATEST HIGH RESOLUTION MODELS KEEP CONVECTIVE ACTIVITY TO A
RELAITVE MINIMUM TODAY. LATEST HRRR WEAKENS THE CURRENT BATCH OF
CONVECTION THAT IS ACROSS N ALA/NW GA. LATE TODAY INTO THIS
EVENING...ANOTHER UPPER DISTURBANCE TO PUSH SE TOWARDS GA TODAY
WITH BETTER MOISTURE AVAILABLE IN THAT AREA COULD PROMOTE SOME
CONVECTION WHICH COULD PUSH TOWARDS THE CSRA. THINK SLIGHT CHANCE
POPS IN ORDER FOR MOST OF THE FA...BUT UPPED THEM SLIGHTLY TO LOW
CHANCE CSRA LATE TODAY AND THIS EVENING. DUE TO LIMITED
COVERAGE...LOWER PW...AND FASTER CELL MOVEMENT...THINK LOCALLY
HEAVY RAIN/FLOODING THREAT MINIMAL. HOWEVER...DCAPE VALUES ARE
PROJECTED TO INCREASE TO 1000 TO 1300 J/KG CSRA...SO ANY STRONGER
STORMS THAT FORM COULD PRODUCE A WIND THREAT. ALSO MADE SLIGHT
ADJUSTMENTS TO TEMPS...DEWPOINTS AND WINDS TODAY BASED ON CURRENT
TRENDS AND LATEST GUIDANCE. GUIDANCE BRINGS DEWPOINTS DOWN INTO
THE UPPER 60S THIS AFTERNOON FOR MUCH OF THE FA...THOUGH RECENT
RAINS AND HIGH SOIL MOISTURE COULD KEEP THEM FROM GETTING DOWN
QUITE THAT LOW.

&&

.SHORT TERM /8 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
SHORT WAVE TROUGH WILL MOVE FURTHER OFFSHORE WITH DRY AIR REMAINING
IN THE MID AND UPPER LEVELS OVERNIGHT. EXPECT ANY CONVECTIVE
ACTIVITY WHICH DEVELOPS THIS AFTERNOON TO DISSIPATE THIS EVENING
WITH THE LOSS OF HEATING AND A DRY FORECAST THROUGH TONIGHT. ON
WEDNESDAY MOISTURE WILL BEGIN RETURNING TO THE COLUMN...HOWEVER
THIS IS NOT EXPECTED UNTIL LATE IN THE AFTERNOON. WITH THE UPPER
LEVEL TROUGH ALSO OVER THE REGION AND A SERIES OF WEAK SHORT WAVES
ROTATING THROUGH THE AXIS THERE WILL BE ENOUGH POTENTIAL TO
INCLUDE A LOW CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS.
WEDNESDAY NIGHT THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL
CONTINUE AS A FAIRLY VIGOROUS SHORT WAVE MOVES THROUGH THE AREA
OVERNIGHT. TEMPERATURES THROUGH THE SHORT TERM WILL BE IN THE
LOWER 70S FOR OVERNIGHT LOWS WITH HIGH TEMPERATURES WEDNESDAY
AFTERNOON IN THE LOWER TO MIDDLE 90S.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
MODELS ARE IN GOOD AGREEMENT THROUGH FRIDAY WITH DIFFERENCES
INCREASING THROUGH THE WEEKEND. UPPER LEVEL TROUGH WILL REMAIN
OVER THE REGION THROUGH THE WEEKEND BEFORE LIFTING OUT ON MONDAY
WHICH WILL KEEP THE ACTIVE WEATHER PATTERN OVER THE REGION. MODELS
INDICATE A SERIES OF SHORT WAVE CROSSING THE AREA THROUGH THE LONG
TERM...HOWEVER DIFFER ON THE TIMING OF SIGNIFICANT SHORT WAVES
WHICH WOULD GENERATE CONVECTION. AS SUCH CONFIDENCE IN THE LONG
TERM IS LOWER THAN DESIRED AND HAVE REMAINED WITH MAINLY DIURNAL
CHANCES OF SHOWERS AND THUNDERSTORMS INTO EARLY NEXT WEEK.
TEMPERATURES THROUGH THE LONG TERM WILL BE SLIGHTLY BELOW NORMAL
FOR DAYTIME HIGHS WITH OVERNIGHT LOWS NEAR NORMAL.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...

EXPECT VFR CONDITIONS THIS AFTERNOON. DRIER MID LEVEL AIR ENTERING
THE REGION...WITH ONLY A SLIGHT CHANCE OF A LATE AFTERNOON/EVENING
THUNDERSTORM. HOWEVER...AN UPPER DISTURBANCE AND BETTER MOISTURE TO
OUR WEST MAY PROVIDE A BETTER CHANCE OF TS AT AGS/DNL LATE TODAY AND
THIS EVENING...BUT THUNDERSTORM CHANCES TOO LOW TO INCLUDE MENTION
IN THE TAFS AT THIS TIME. WILL MONITOR RADAR TRENDS AND AMEND IF
NECESSARY. GUIDANCE INDICATING POTENTIAL FOR MVFR VSBYS IN FOG LATE
TONIGHT/EARLY WED. THIS WILL DEPEND ON EXTENT OF ANY LINGERING
MID/UPPER LEVEL DEBRIS CLOUDINESS THAT MAY STREAM IN FROM THE WEST.
SCATTERED CONVECTION EXPECTED WED...AFT 18Z.

EXTENDED AVIATION OUTLOOK...SCATTERED AFTERNOON AND EVENING
THUNDERSTORMS. LATE NIGHT/EARLY MORNING FOG/STRATUS POSSIBLE.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$







AREA FORECAST DISCUSSION

NWS DODGE CITY KS

 400 PM CDT TUE JUL 23 2013

...UPDATED FOR LONG TERM DISCUSSION...

.SYNOPSIS...
ISSUED AT 925 AM CDT TUE JUL 23 2013

THE 23.12Z 250 HPA RAOB MAP SHOWED WESTERLY TO NORTHWESTERLY FLOW STRETCHING
FROM OREGON TO THE MIDWEST. MAGNITUDES WERE 50-75 KT. @ 500 HPA, AN
ELONGATED 592/593 DM ANTICYCLONE EXTENDED FROM NORTHERN NEVADA SE TO
NW NEW MEXICO. DOWNSTREAM, A BROAD TROF WAS MOVING ACROSS THE EASTERN
UNITED STATES. @ 700 HPA, 2 DEG C OF WARMING OCCURRED AT KDDC BETWEEN
22.12Z AND 23.12Z SYNOPTIC FLIGHTS AND AT A FAIRLY WARM TEMP OF 15
DEG C THIS MORNING. @ 850 HPA, KDDC WAS AT 26 DEG C, WHICH IS ABOVE
THE 75TH PERCENTILE. AT THE SFC, A LOW PRESSURE CENTER WAS LOCATED ACROSS
FAR SW KANSAS. AN OUTFLOW BOUNDARY WAS DRAPED ACROSS THE FORECAST AREA
OF RESPONSIBILITY. INVEST 98E WAS LOCATED 800 MILES SSW OF THE SOUTHERN
TIP OF BAJA CALIFORNIA. INVEST 98L WAS LOCATED A COUPLE HUNDRED MILES
SSE OF THE CAPE VERDE ISLANDS.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 200 PM CDT TUE JUL 23 2013

TONIGHT:

NEAR TERM FORECAST CONCERN IS CONVECTION THIS AFTERNOON/EVENING. WSR-
88D AND SURFACE OBSERVATIONS SHOW A FEW BOUNDARIES ACROSS THE REGION
THIS AFTERNOON. ONE IS A "COLD FRONT"/OUTFLOW BOUNDARY THIS IS ROUGHLY
LOCATED FROM NESS CITY SE TO PRATT. A NONDESCRIPT DRYLINE IS THE OTHER
BOUNDARY FARTHER WEST. THE INTERSECTION OF THESE TWO DENSITY GRADIENTS
SHOULD BE WHERE CONVECTION INITIATES. THE MOST RECENT HRRR IS SHOWING
AN ISOLATED STORM DEVELOPING JUST NORTHEAST OF DODGE CITY (MUCH LIKE
YESTERDAY) AND THEN INDICATING THIS ACTIVITY DRIFTING OFF TO THE SE AS THE
EARLY EVENING WEARS ON. THE NAM IS IN FAIR AGREEMENT WITH THIS SOLUTION.
THE STORMS MAY BECOME SEVERE AS WELL AS 1-8 KM BULK SHEAR IS STRONGER
THAN YESTERDAY...PLUS DEWPOINTS ARE STILL RUNNING FAIRLY HIGH, WHICH
WILL CREATE ABOUT 1500-2000 J/KG OF SBCAPE. MODELS ALSO SHOW SOME DCAPE
AS THE ATMOSPHERE BECOMES WELL MIXED. AS A RESULT, HAVE TWEAKED THE
HWO WITH THE THREATS OF QUARTER SIZE HAIL, 60 MPH OUTFLOW, AND LIGHTNING
AS THE MAIN CONCERNS. THIS ACTIVITY WILL CLEAR THE AREA LATER THIS EVENING
AS THE FRONT SINKS SOUTHWARD. OVERNIGHT LOWS WILL BE IN THE 60S DEG
F AND 70S DEG F. UPSLOPE STRATUS WILL BE POSSIBLE ON THE BACKSIDE OF
THE LOW LEVEL PRESSURE PERTURBATION WITH UPSLOPE WINDS IN THE SFC-850
HPA LAYER.

TOMORROW:

AN UPSLOPE FLOW PATTERN IS EXPECTED TOMORROW IN THE WAKE OF THE AFOREMENTIONED
BOUNDARY. MAXIMUMS WILL BE "COOLER" THAN COMPARED TO TODAY WITH VALUES
IN THE UPPER 80S DEG F TO LOWER 90S DEG F. 23.12Z NAM SOLUTION IS WARMER
COMPARED TO OTHER GUIDANCE, BUT THIS MIGHT BE A BIT OVERDONE. WILL USE
THE ECMWF FOR NOW. OROGRAPHIC CONVECTION IS POSSIBLE IN THE UPSLOPE
FLOW REGIME TOMORROW ACROSS EASTERN COLORADO. WILL CARRY SLIGHT PRECIPITATION
PROBABILITY PERCENTAGE POINTS FOR FAR WEST KANSAS THROUGH 00Z TOMORROW
NIGHT.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 353 PM CDT TUE JUL 23 2013

THE SYSTEM THAT MOVED WESTWARD ALONG THE SOUTHERN EDGE OF THE UPPER
LEVEL RIDGE LAST WEEK WAS LOCATED NEAR THE CALIFORNIA COAST TODAY AND
IS POISED TO MOVE BACK EASTWARD ON THE NORTHERN SIDE OF THE UPPER
LEVEL RIDGE. BY WEDNESDAY NIGHT AND THURSDAY, THIS SYSTEM WILL BE
APPROACHING FROM THE WEST. A STATIONARY FRONT WILL BE LOCATED
OVER THE SOUTHERN PLAINS, WITH UPSLOPE FLOW AND ABUNDANT LOW LEVEL
MOISTURE ON THE COOL SIDE OF THE FRONT OVER WESTERN KANSAS. WE ARE
EXPECTING THUNDERSTORMS TO DEVELOP OVER COLORADO AND THEN EXPAND
INTO A LARGER CLUSTER OF STORMS OVER THE PLAINS. THE EXACT
POSITIONING OF THIS STORM CLUSTER IS UNCERTAIN. SO FOR NOW, RAIN
CHANCES WERE KEPT AT 40-50% FOR LATE WEDNESDAY NIGHT INTO THURSDAY
NIGHT.

AFTER THE AFOREMENTIONED SYSTEM PASSES BY FRIDAY MORNING, A BREAK IN
PRECIPITATION IS EXPECTED FRIDAY AND SATURDAY, WITH CONTINUED
COOL WEATHER (HIGHS MAINLY IN THE 80S AND LOWS IN THE 60S). BY
THE WEEKEND, THE MID TO UPPER LEVEL FLOW WILL BECOME MORE
WEST-NORTHWESTERLY AGAIN, RESULTING IN RENEWED WEAK SURFACE LEE TROUGHING
AND WARM/MOIST ADVECTION INTO WESTERN KANSAS. THEREFORE, THERE
ARE CHANCES OF THUNDERSTORMS AGAIN BY SATURDAY NIGHT INTO MONDAY,
WITH CONTINUED COOL WEATHER (HIGHS MAINLY 80S).

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1200 PM CDT TUE JUL 23 2013

SOME WEATHER AND POSSIBLE REDUCTION IN FLIGHT CATEGORY IS PSBL THROUGH
TAF PD. FIRST IS CONVECTION LATE THIS AFTERNOON/EVENING. STORMS SHOULD
INITIATE ALONG FRONTAL BOUNDARY. DO NOT HAVE HIGH CONFIDENCE IN TEMPORAL
AND SPATIAL DISTRIBUTION OF ACTIVITY AND WILL LEAVE OUT OF TAFS FOR
NOW. SECOND CONCERN IS PSBL MVFR CIGS IN TOMORROW MORNING. OTHERWISE,
SOUTHERLY WIND VECTORS WILL BECOME NORTHEASTERLY WITH 10-20 KT MAGNITUDES.


&&

.PRELIMINARY POINT TEMPS/POPS...
DDC  67  91  69  86 /  20  10  40  50
GCK  67  90  68  86 /  10  10  50  50
EHA  67  91  68  87 /  10  20  50  50
LBL  69  93  69  89 /  20  10  40  50
HYS  66  88  68  84 /  20  10  40  50
P28  71  90  71  89 /  20  10  40  50

&&

.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...FINCH
AVIATION...SUGDEN







AREA FORECAST DISCUSSION

NWS DODGE CITY KS

 200 PM CDT TUE JUL 23 2013

...UPDATE TO SHORT TERM DISCUSSION...

.SYNOPSIS...
ISSUED AT 925 AM CDT TUE JUL 23 2013

THE 23.12Z 250 HPA RAOB MAP SHOWED WESTERLY TO NORTHWESTERLY FLOW STRETCHING
FROM OREGON TO THE MIDWEST. MAGNITUDES WERE 50-75 KT. @ 500 HPA, AN
ELONGATED 592/593 DM ANTICYCLONE EXTENDED FROM NORTHERN NEVADA SE TO
NW NEW MEXICO. DOWNSTREAM, A BROAD TROF WAS MOVING ACROSS THE EASTERN
UNITED STATES. @ 700 HPA, 2 DEG C OF WARMING OCCURRED AT KDDC BETWEEN
22.12Z AND 23.12Z SYNOPTIC FLIGHTS AND AT A FAIRLY WARM TEMP OF 15
DEG C THIS MORNING. @ 850 HPA, KDDC WAS AT 26 DEG C, WHICH IS ABOVE
THE 75TH PERCENTILE. AT THE SFC, A LOW PRESSURE CENTER WAS LOCATED ACROSS
FAR SW KANSAS. AN OUTFLOW BOUNDARY WAS DRAPED ACROSS THE FORECAST AREA
OF RESPONSIBILITY. INVEST 98E WAS LOCATED 800 MILES SSW OF THE SOUTHERN
TIP OF BAJA CALIFORNIA. INVEST 98L WAS LOCATED A COUPLE HUNDRED MILES
SSE OF THE CAPE VERDE ISLANDS.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 200 PM CDT TUE JUL 23 2013

TONIGHT:

NEAR TERM FORECAST CONCERN IS CONVECTION THIS AFTERNOON/EVENING. WSR-
88D AND SURFACE OBSERVATIONS SHOW A FEW BOUNDARIES ACROSS THE REGION
THIS AFTERNOON. ONE IS A "COLD FRONT"/OUTFLOW BOUNDARY THIS IS ROUGHLY
LOCATED FROM NESS CITY SE TO PRATT. A NONDESCRIPT DRYLINE IS THE OTHER
BOUNDARY FARTHER WEST. THE INTERSECTION OF THESE TWO DENSITY GRADIENTS
SHOULD BE WHERE CONVECTION INITIATES. THE MOST RECENT HRRR IS SHOWING
AN ISOLATED STORM DEVELOPING JUST NORTHEAST OF DODGE CITY (MUCH LIKE
YESTERDAY) AND THEN INDICATING THIS ACTIVITY DRIFTING OFF TO THE SE AS THE
EARLY EVENING WEARS ON. THE NAM IS IN FAIR AGREEMENT WITH THIS SOLUTION.
THE STORMS MAY BECOME SEVERE AS WELL AS 1-8 KM BULK SHEAR IS STRONGER
THAN YESTERDAY...PLUS DEWPOINTS ARE STILL RUNNING FAIRLY HIGH, WHICH
WILL CREATE ABOUT 1500-2000 J/KG OF SBCAPE. MODELS ALSO SHOW SOME DCAPE
AS THE ATMOSPHERE BECOMES WELL MIXED. AS A RESULT, HAVE TWEAKED THE
HWO WITH THE THREATS OF QUARTER SIZE HAIL, 60 MPH OUTFLOW, AND LIGHTNING
AS THE MAIN CONCERNS. THIS ACTIVITY WILL CLEAR THE AREA LATER THIS EVENING
AS THE FRONT SINKS SOUTHWARD. OVERNIGHT LOWS WILL BE IN THE 60S DEG
F AND 70S DEG F. UPSLOPE STRATUS WILL BE POSSIBLE ON THE BACKSIDE OF
THE LOW LEVEL PRESSURE PERTURBATION WITH UPSLOPE WINDS IN THE SFC-850
HPA LAYER.

TOMORROW:

AN UPSLOPE FLOW PATTERN IS EXPECTED TOMORROW IN THE WAKE OF THE AFOREMENTIONED
BOUNDARY. MAXIMUMS WILL BE "COOLER" THAN COMPARED TO TODAY WITH VALUES
IN THE UPPER 80S DEG F TO LOWER 90S DEG F. 23.12Z NAM SOLUTION IS WARMER
COMPARED TO OTHER GUIDANCE, BUT THIS MIGHT BE A BIT OVERDONE. WILL USE
THE ECMWF FOR NOW. OROGRAPHIC CONVECTION IS POSSIBLE IN THE UPSLOPE
FLOW REGIME TOMORROW ACROSS EASTERN COLORADO. WILL CARRY SLIGHT PRECIPITATION
PROBABILITY PERCENTAGE POINTS FOR FAR WEST KANSAS THROUGH 00Z TOMORROW
NIGHT.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 323 AM CDT TUE JUL 23 2013

THE UPPER LEVEL WEATHER PATTERN DURING THE EXTENDED PERIOD WILL
GENERALLY BE DEPICTED BY AN AREA OF HIGH PRESSURE ACROSS THE
SOUTHWEST UNITED STATES THROUGH SATURDAY SHIFTING TO THE SOUTHERN
PLAINS BY EARLY NEXT WEEK. THIS IS DUE TO A TROUGH OF LOW PRESSURE
MOVING INTO THE PACIFIC NORTHWEST. ALSO, AN UPPER LEVEL LONG WAVE
TROUGH WILL BE POSITIONED ACROSS THE EASTERN UNITED STATES. A
FEW SHORTWAVES ARE PROGGED TO MOVE AROUND THE PERIPHERY OF THE UPPER
LEVEL HIGH AND INTO THE CENTRAL PLAINS. THIS WILL ENHANCE LIFT
ACROSS WESTERN KANSAS AND PUSH A FEW SURFACE FEATURES THROUGH THE
AREA.

THE FIRST SHORTWAVE IS FORECASTED TO MOVE THROUGH THE AREA ON
THURSDAY. THIS FEATURE WILL COINCIDE WITH A STATIONARY FRONT AT THE
SURFACE LOCATED ACROSS OKLAHOMA AND OK/TX PANHANDLES CURLING
NORTHWARD ACROSS EASTERN COLORADO. WINDS WILL GENERALLY HAVE AN
EASTERLY COMPONENT WEDNESDAY THROUGH THURSDAY ALLOWING UPSLOPE FLOW
TO OCCUR ACROSS WESTERN KANSAS. THUNDERSTORMS ARE EXPECTED TO FORM
ACROSS EASTERN COLORADO WEDNESDAY AFTERNOON AND MOVE INTO WESTERN
KANSAS WEDNESDAY NIGHT. THUNDERSTORM CHANCES BECOME LIKELY ON
THURSDAY WITH COOLER TEMPERATURES.  PRECIPITATION CHANCES THEN END
FROM WEST TO EAST FRIDAY AS THE UPPER LEVEL DISTURBANCE MOVES
SOUTHEAST OF THE CWA. HIGHS WEDNESDAY WILL BE AROUND 90S DEGREES
DROPPING INTO THE 80S THURSDAY AND FRIDAY. LOWS THURSDAY AND FRIDAY
MORNING WILL GENERALLY BE IN THE MID TO UPPER 60S WITH THE EXCEPTION
OF SOUTH CENTRAL KANSAS WHERE LOWER 70S COULD OCCUR.

A LULL IN THE ACTION IS EXPECTED FRIDAY NIGHT INTO SATURDAY LEAVING
PARTLY CLOUDY SKIES AND DRY CONDITIONS. THIS WILL BE SHORT LIVED AS
MODELS SUGGEST A FEW WEAK UPPER LEVEL DISTURBANCES MOVING THROUGH THE
AREA SATURDAY NIGHT TO THE BEGINNING OF NEXT WEEK. WINDS DURING THIS
TIMEFRAME WILL GENERALLY BE FROM THE SOUTHEAST WITH MOSTLY CLOUDY
SKIES. I AM LESS CONFIDENT WITH THIS SYSTEM AS THURSDAY AND MAY NEED
TO BE TWEAKED DURING FUTURE FORECAST UPDATES. AS FOR TEMPERATURES,
HIGHS WILL CONTINUE TO BE IN THE 80S SATURDAY AND SUNDAY BEFORE
RISING INTO THE LOWER 90S ON MONDAY. LOWS SATURDAY AND SUNDAY
MORNING ARE FORECASTED TO BE IN THE 60S WITH UPPER 60S TO LOWER 70S
MONDAY MORNING.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1200 PM CDT TUE JUL 23 2013

SOME WEATHER AND POSSIBLE REDUCTION IN FLIGHT CATEGORY IS PSBL THROUGH
TAF PD. FIRST IS CONVECTION LATE THIS AFTERNOON/EVENING. STORMS SHOULD
INITIATE ALONG FRONTAL BOUNDARY. DO NOT HAVE HIGH CONFIDENCE IN TEMPORAL
AND SPATIAL DISTRIBUTION OF ACTIVITY AND WILL LEAVE OUT OF TAFS FOR
NOW. SECOND CONCERN IS PSBL MVFR CIGS IN TOMORROW MORNING. OTHERWISE,
SOUTHERLY WIND VECTORS WILL BECOME NORTHEASTERLY WITH 10-20 KT MAGNITUDES.


&&

.PRELIMINARY POINT TEMPS/POPS...
DDC  67  91  69  86 /  20  10  50  60
GCK  67  90  68  86 /  10  10  50  60
EHA  67  91  68  87 /  10  20  50  50
LBL  69  93  69  89 /  20  10  50  50
HYS  66  88  68  84 /  20  10  40  60
P28  71  90  71  89 /  20  10  40  50

&&

.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...HOVORKA_42
AVIATION...SUGDEN







AREA FORECAST DISCUSSION

NWS TOPEKA KS

 1220 PM CDT TUE JUL 23 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM CDT TUE JUL 23 2013

FAIRLY STRONG NORTHWESTERLY H5 FLOW...CONSIDERING THE MID SUMMER
TIME PERIOD...CURRENTLY OVER THE FORECAST AREA BETWEEN THE MID
LEVEL HIGH OVER THE DESERT SOUTHWEST AND AN UPPER TROUGH LOCATED
NORTH OF THE GREAT LAKES REGION. TWO AREAS OF CONVECTION ARE
APPARENT ON RADAR...WITH AN AREA OF WEAK THUNDERSTORMS OVER
CENTRAL KANSAS...AND A MORE ORGANIZED COMPLEX OF STORMS CURRENTLY
IN C NEBRASKA. GENERALLY EXPECT THE WEAK THUNDERSTORMS OVER
CENTRAL KANSAS TO WEAKEN WHILE STAYING SLIGHTLY WEST OF THE
FORECAST AREA. THE FOCUS WOULD THEN SHIFT TO THE MCS DRIVING ESE
ACROSS C/S NEBRASKA. FORWARD PROPAGATING CORFIDI VECTORS WOULD
INDICATE THAT THE STORMS WILL CONTINUE THEIR PATH TO THE
ESE...PERHAPS BRINGING SOME EARLY MORNING THUNDERSTORMS TO THE
NORTHERN ROW OR TWO OF COUNTIES...WITH THE BEST CHANCES FOR
MORNING PRECIP BEING IN THE FAR NORTHEASTERN CORNER OF KANSAS.
MODELS HAVE BEEN HAVING TROUBLE RESOLVING MCS DEVELOPMENT THE
PREVIOUS COUPLE NIGHTS...SO WILL TAKE THEIR SOLUTIONS WITH A GRAIN
OF SALT. 4KM WRF-NMM WOULD SUGGEST THE COMPLEX WILL FALL APART AS
IT APPROACHES THE CWA...WHILE THE HRRR SUGGESTS IT WILL MAINTAIN
ITSELF IN SOME RESPECT TO THE NORTHERN TIER OF COUNTIES. CURRENTLY
WILL SIDE MORE WITH THE HRRR...AS RADAR TRENDS OVER THE PAST
COUPLE HOURS SHOW THE COMPLEX STILL STRONG AND ORGANIZED AS IT
MOVES ACROSS C NEBRASKA. IT ALSO SEEMS TO BE MAINTAINED ALONG THE
LEADING EDGE OF A 20 TO 30 KT 850 MB JET...WITH MAXIMIZED LOW
LEVEL CONVERGENCE RUNNING NW TO SE ACROSS C/S NEBRASKA. BETWEEN
THAT LINE OF MAXIMIZED LOW LEVEL CONVERGENCE AND THE
AFOREMENTIONED CORFIDI VECTORS...HAVE KEPT THE HIGHEST POPS
THROUGH THE MORNING HOURS ALONG AND NORTH OF INTERSTATE 70...WITH
POPS INCREASING TOWARD THE NORTHEAST PART OF KS.

EXACT THUNDERSTORM DEVELOPMENT FOR TUESDAY AFTERNOON IS SOMEWHAT
UNCERTAIN...AS THE DECAYING MCS WILL LIKELY LEAVE A REMNANT OUTFLOW
BOUNDARY ACROSS THE CWA AS IT CONTINUES ESE. THE REMNANT BOUNDARY
COULD BE THE IMPETUS FOR MORE THUNDERSTORM DEVELOPMENT LATER TODAY
WHERE LOW LEVEL CONVERGENCE IS MAXIMIZED. IN THE UNLIKELY CASE THAT
THE OFB SLIDES COMPLETELY THROUGH THE AREA AND SETS UP SOUTH OF THE
CWA IT COULD DECREASE CHANCES FOR RAIN LATER TODAY...HOWEVER THE
GENERAL THOUGHT IS THAT THAT BOUNDARY WILL REMAIN SOMEWHERE IN
NORTHEAST KANSAS. ASIDE FROM THE MAXIMIZED CONVERGENCE ALONG THE
BOUNDARY MODELS WOULD SUGGEST AN EMBEDDED VORTICITY MAXIMUM IN THE
NORTHWEST H5 FLOW. AS THIS VORT MAX SLIDES THROUGH THE AREA IT
SHOULD BRING INCREASED CHANCES FOR THUNDERSTORMS LATER THIS
AFTERNOON. GIVEN GOOD INSTABILITY IN THE FORM OF ROUGHLY 3000 J/KG
OF MIXED LAYER CAPE AND 0-6 BULK SHEAR VALUES OF PERHAPS 40
KTS...THE INGREDIENTS WILL BE PRESENT FOR SOME OF THESE AFTERNOON
THUNDERSTORMS TO BECOME STRONG TO SEVERE. THE MAIN HAZARDS WOULD BE
HAIL AND WIND...AS WELL AS HEAVY RAIN. EXPECT THESE STORMS TO FORM
INTO A COMPLEX BY SUNSET...AND MOVE SOUTHEASTWARD INTO WESTERN
MISSOURI DURING THE OVERNIGHT HOURS.

TEMPERATURE FORECAST FOR TUESDAY IS ALSO SOMEWHAT QUESTIONABLE AS
THAT OUTFLOW BOUNDARY FROM THE MORNING MCS WILL LIKELY DICTATE WHERE
THE WARMER TEMPS WILL BE LOCATED...VS COOLER TEMPS BEHIND THE
BOUNDARY. HAVE GONE WITH A FORECAST THE REFLECTS THE OFB ALONG WITH
ANY CLOUD DEBRIS FROM THE MCS TO REMAIN ALONG AND NORTH OF I
70...WITH WARMER TEMPS...INTO THE LOWER TO MID 90S ALONG AND SOUTH
OF THE INTERSTATE. THIS FORECAST COULD CHANGE BASED ON HOW
PROGRESSIVE THAT BOUNDARY AND ANY LINGERING CLOUD COVER MAY BE.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 356 AM CDT TUE JUL 23 2013

A LONGER WAVE LENGTH UPPER LEVEL TROUGH WILL REMAIN NEARLY
STATIONARY ACROSS THE EAST CENTRAL CONUS. THIS UPPER AIR PATTERN
WILL CAUSE THE FLOW AT MID AND UPPER LEVELS TO REMAIN
NORTHWESTERLY ACROSS THE PLAINS. A SERIES OF SHORTER WAVE-LENGTH
UPPER LEVEL TROUGHS WILL ROUND THE UPPER LEVEL RIDGE ACROSS THE
WESTERN CONUS AND DIG SOUTHEAST ACROSS THE CENTRAL PLAINS THROUGH
THE FORECAST PERIOD.

WEDNESDAY...THE FIRST H5 TROUGH WILL MOVE SOUTHEAST ACROSS NE INTO
MO WEDNESDAY MORNING. AN MCS OR COMPLEX OF THUNDERSTORMS MAY BE
ONGOING DURING THE MORNING HOURS. HOWEVER...THE STRONGER ASCENT
AHEAD OF THIS H5 TROUGH MAY REMAIN JUST NORTH AND EAST OF THE CWA. A
SURFACE OUTFLOW BOUNDARY/COLD FRONT SHOULD PUSH SOUTH AND SOUTHWEST
ACROSS THE CWA DURING THE MORNING HOURS. THE AFTERNOON MAY REMAIN
DRY AS THE BEST SURFACE CONVERGENCE WILL REMAIN SOUTH AND WEST OF
THE CWA DURING THE AFTERNOON HOURS. HIGHS WILL ONLY REACH THE MID
80S.

WEDNESDAY NIGHT THROUGH THURSDAY NIGHT....THE NEXT H5 TROUGH MAY
DIG SOUTHEAST ACROSS THE PLAINS THURSDAY INTO FRIDAY MORNING. BOTH
THE ECMWF AND GFS SHOW AN MCS DEVELOPING ACROSS THE HIGH PLAINS OF
EASTERN CO AND TRACKING SOUTHEAST ACROSS WESTERN KS INTO SOUTHERN KS
AND NORTHERN OK. THE CWA MAY REMAIN ON THE NORTH EDGE OF THIS MCS
TRACK. IF THE MCS DEVELOPS FARTHER NORTH...THEN THE CWA MAY SEE A
GREATER CHANCE FOR THUNDERSTORMS THURSDAY NIGHT INTO FRIDAY MORNING.
THIS WILL BE MORE OF A MESOSCALE FORECAST AND FOR NOW I JUST WENT
WITH CHANCE POPS. HIGHS MAY WARM BACK INTO THE UPPER 80S TO AROUND
90 DEGREES THURSDAY AFTERNOON.

FRIDAY THROUGH SUNDAY...OUTFLOW BOUNDARIES AND WEAK UPPER LEVEL
TROUGHS DIGGING SOUTHEAST ACROSS THE PLAINS MAY PROVIDE ENOUGH
ASCENT FOR AT LEAST ISOLATED SHOWERS AND THUNDERSTORMS THROUGH THE
PERIOD. HIGHS SHOULD REMAIN IN THE 80S.

SUNDAY NIGHT AND MONDAY...BOTH THE GFS AND ECMWF SHOW ANOTHER H5
TROUGH TRACKING EAST-SOUTHEAST ACROSS THE PLAINS. ASCENT AHEAD OF
THE TROUGH MAY LEAD TO AN MCS DEVELOPING ACROSS WESTERN KS AND
WESTERN NE THAT MAY TRACK EAST-SOUTHEAST ACROSS THE CWA SUNDAY NIGHT
INTO MONDAY MORNING. MONDAY HIGHS WILL ONCE AGAIN BE IN THE LOWER TO
MID 80S.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1217 PM CDT TUE JUL 23 2013

VERY UNCERTAIN FORECAST IN TERMS OF LOCATION/TIMING/INTENSITY OF
THUNDERSTORM POTENTIAL. FOR THE NEAR TERM...APPEARS MORNING
CONVECTION WILL DELAY REDEVELOPMENT AND COULD SAVE STRONGER STORMS
FOR SOUTH OF THE TERMINALS. HAVE GONE WITH VCTS FOLLOWED BY VCSH
FOR THE OVERNIGHT HOURS AND WILL MONITOR FOR UPDATES. DID
INTRODUCE MVFR CIGS POST MAIN COLD FRONT FOR THE MORNING HOURS ALL
SITES BUT EXPECT THIS WOULD MIX OUT LATE MORNING.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...JL
LONG TERM...GARGAN
AVIATION...67







AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 412 PM EDT TUE JUL 23 2013

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 411 PM EDT TUE JUL 23 2013

WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A VIGOROUS SHORTWAVE OVER
JAMES BAY. PRES GRADIENT BTWN ITS ASSOCIATED SFC LOW E OF JAMES BAY
AND SFC HIGH PRES OVER NW MN/ERN DAKOTAS HAS RESULTED IN BREEZY N/NW
WINDS TODAY AND MUCH COOLER CONDITIONS COMPARED TO YESTERDAY. PER
WATER VAPOR IMAGERY...IN THE NW FLOW UPSTREAM...THERE ARE A COUPLE
OF SHORTWAVES EVIDENT...ONE OVER ERN MT/WRN ND AND ANOTHER OVER
CNTRL SASKATCHEWAN. THE NRN WAVE MAY BE A FACTOR IN THE WEATHER HERE
ON WED.

A QUIET...COOL NIGHT IS IN STORE TONIGHT AS SFC HIGH PRES SETTLES SE
INTO WI...BRINGING DIMINISHING WINDS FROM W TO E. WITH DECREASING
WINDS...CLEAR SKIES AND PRECIPITABLE WATER 50-70PCT OF NORMAL...
EXPECT A DECENT RADIATIONAL COOLING NIGHT...ESPECIALLY OVER W AND SW
UPPER MI AS WINDS SHOULD DIMINISH TO CALM IN THAT AREA...BEING
CLOSER TO SFC HIGH PRES CENTER. WILL CONTINUE TO SHOW LOWEST TEMPS
IN THAT AREA (40 TO THE LWR 40S). OTHERWISE...MIN TEMPS SHOULD BE IN
THE 40S IN THE INTERIOR TO MOSTLY AROUND 50F ALONG THE GREAT LAKES.

AFTER A QUIET NIGHT...ATTENTION ON WED SHIFTS TO POSSIBLE AFTN
CONVECTION. SUMMERTIME WNW/NW FLOW IS OFTEN A FAVORABLE PATTERN
FOR ISOLD/SCT AFTN CONVECTION AS EVEN THE MOST SUBTLE SHORTWAVES CAN
SPARK SOME PCPN. IF THERE WASN`T A SHORTWAVE PRESENT UPSTREAM...
WOULD HAVE DROPPED PCPN MENTION ON WED...BUT SINCE THERE IS AN
OBVIOUS WAVE CURRENTLY UPSTREAM IN CNTRL SASKATCHEWAN...IT LOOKS
LIKE THERE WILL PROBABLY BE SOME ISOLD AFTN CONVECTION AS THE WAVE
DROPS SE INTO THE AREA. WILL CONTINUE TO HIGHLIGHT SCHC POPS OVER
MAINLY THE INTERIOR W AND CNTRL WHERE THE LIMITED INSTABILITY IS
BEST. NAM/GFS MLCAPES ARE ONLY AS HIGH AS 200-300J/KG DURING THE MID
AFTN...SO THUNDER POTENTIAL APPEARS MINIMAL. HOWEVER...CANADIAN
RADARS CURRENTLY SHOW DECENT RETURNS IN THE VCNTY OF SHORTWAVE IN
SASKATCHEWAN AND SATELLITE IMAGERY SUGGESTS SOME DECENT
CONVECTION...SO THERE MAY BE SOME THUNDER OCCURRING WITH THE WAVE
THIS AFTN. FOR NOW...WILL LEAVE THUNDER MENTION IN THE FCST FOR WED
AND LET LATER SHIFTS REASSESS.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 411 PM EDT TUE JUL 23 2013

MUCH OF THE LONG TERM PERIOD WILL BE INFLUENCED BY A SHORTWAVE
DROPPING SOUTH-SOUTHEAST THROUGH CENTRAL CANADA ON WEDNESDAY AND
WEDNESDAY NIGHT...WHICH THEN MOVES INTO CENTRAL ONTARIO BY THURSDAY
NIGHT AND CLOSES OFF. THIS UPPER LOW WILL REMAIN IN CENTRAL ONTARIO
INTO SUNDAY BEFORE SHIFTING NORTHEAST INTO ONTARIO FOR THE START OF
THE WORK WEEK.

WEDNESDAY NIGHT WILL BE RELATIVELY QUIET AS ANY DIURNAL CLOUDS AND
SHOWERS DIMINISH FAIRLY QUICKLY DURING THE EVENING. THEN...EXPECT
MID-HIGH CLOUDS TO BE ON THE INCREASE THROUGH THE NIGHT AS THE
SHORTWAVE MOVES INTO SOUTHWEST ONTARIO AND AN ASSOCIATED 1008MB LOW
DEVELOPS EAST OF LAKE WINNIPEG AND SLIDES EAST. AS THE SHORTWAVE
AND SURFACE LOW CONTINUE TO THE EAST-SOUTHEAST ON LATE WEDNESDAY
NIGHT AND THURSDAY...AN ASSOCIATED COLD FRONT WILL SLIDE INTO
WESTERN UPPER MICHIGAN DURING THE AFTERNOON. THAT WILL BE THE AREA
WITH THE BEST OPPORTUNITY FOR SHOWERS/THUNDERSTORMS ON THURSDAY
AFTERNOON AND WILL CONTINUE TO HIGHLIGHT INCREASING POPS TO LIKELY
VALUES DURING THE AFTERNOON.

INSTABILITY LOOKS FAIRLY LIMITED OVER MOST OF THE AREA...WITH MLCAPE
VALUES AROUND 500 J/KG ALTHOUGH MUCAPE VALUES DO APPROACH 1500
J/KG IN SOME MODELS OVER THE WEST AND 09Z SREF ONLY INDICATES A 20
PERCENT CHANCE 1000 J/KG IS REACHED. CAPE IS FAIRLY TALL/SKINNY AS
SEEN IN NCAPE VALUES IN THE 0.05-0.1 RANGE. AS FOR SHEAR...0-6KM AND
EFFECTIVE VALUES ARE ALSO MARGINAL (AROUND 30-35KTS)...ALTHOUGH
THERE IS SOME LOW LEVEL VEERING TO THE WIND. THE STRENGTH OF THE
SHORTWAVE MAY HELP OVERCOME THE MARGINAL INSTABILITY/SHEAR...BUT
THINK THE STORMS WILL PRIMARILY BE SUB SEVERE. THEY WILL LIKELY BE
THE STRONGEST OVER THE FAR WEST...WHERE IT IS CLOSER TO THE
SYNOPTIC AND FRONTAL FORCING. NAM/GFS STORM MOTION VECTORS INDICATE
THE STORMS WILL MOVE FAIRLY QUICKLY TO THE EAST (AROUND 40KTS) AND
HAVE FOLLOWED SUIT WITH THE POPS. BUT THE OVERALL TREND WITH THE
FRONT HAS BEEN SLOWER...WITH IT NOW EXITING EASTERN UPPER MICHIGAN
BETWEEN 09Z-18Z FRIDAY.

MODELS DIFFER SOMEWHAT WITH THE POSITION OF THE SURFACE/UPPER
LOW...BUT THE GENERAL IDEA OF COOL...CYCLONIC FLOW AFFECTING THE
UPPER GREAT LAKES FRIDAY THROUGH SUNDAY MORNING SEEMS REASONABLE.
ANOTHER SHORTWAVE ROTATES AROUND THE UPPER LOW ON FRIDAY AND
PRECIPITATION CHANCES DEPEND ON HOW QUICKLY THE FRONT MOVES
EAST...THE DRY SLOT BEHIND IT...AND ADDITIONAL MOISTURE DROPPING
SOUTHEAST ACROSS WESTERN LAKE SUPERIOR. THESE FEATURES ARE STILL
VARIABLE IN THE MODELS...BUT THE MORNING LOOKS TO HAVE THE BEST
OPPORTUNITY FOR LINGERING SHOWERS OVER THE SE U.P. TRIED TO SHOW A
LITTLE MORE TIMING ON POPS FOR FRIDAY BUT CONFIDENCE WASN/T HIGH
ENOUGH TO SHOW DRY PERIODS UNDER THE DRY SLOT.

WITH THE MOISTURE WRAPPING AROUND THE UPPER LOW FRIDAY
NIGHT INTO SATURDAY NIGHT...EXPECT THERE TO BE PERIODS OF
CLOUDS...ESPECIALLY FRIDAY NIGHT INTO SATURDAY. MOST OF THE MOISTURE
IS FAIRLY SHALLOW...BUT THERE MAY BE ENOUGH AROUND FOR SOME LIGHT
RAIN SHOWERS/DRIZZLE ON FRIDAY NIGHT INTO SATURDAY AND WILL RETAIN
SLIGHT CHANCE POPS. TEMPERATURES THIS WEEKEND WILL VERY COOL FOR
LATE JULY STANDARDS...WITH LOW 60S ON SATURDAY (10-15 DEGREES BELOW
NORMAL) AND MID-UPPER 60S FOR SUNDAY.

THE UPPER LOW SHIFTS AWAY ON SUNDAY AFTERNOON AND THE AREA WILL BE
BACK UNDER WEST-NORTHWEST FLOW ALOFT. BOTH GFS/ECMWF ARE SHOWING A
SHORTWAVE AND ASSOCIATED WARM FRONT MOVING TOWARDS THE AREA
SOMETIME MONDAY TO TUESDAY AND HAVE SLOWLY BROUGHT POPS UP TO
CHANCES BY TUESDAY.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 139 PM EDT TUE JUL 23 2013

LINGERING MVFR CIGS AT KSAW WILL LIFT TO VFR OVER THE NEXT HR OR TWO
AS DAYTIME HEATING AND INFLUX OF DRIER AIR WORK TO RAISE CLOUD
BASES. OTHERWISE...WITH HIGH PRES BUILDING INTO THE AREA...EXPECT
VFR CONDITIONS TO DOMINATE THRU THIS FCST PERIOD AT KIWD/KCMX/KSAW.
IN FACT...LINGERING STRATOCU WILL SCATTER OUT/DISSIPATE FROM NW TO
SE THRU THE AFTN...LEAVING CLR/MCLR SKIES BY SUNSET. GUSTY WINDS AT
KCMX/KSAW WILL ALSO SLOWLY SUBSIDE THRU THE AFTN AS PRES GRADIENT
WEAKENS WITH HIGH PRES MOVING CLOSER.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 411 PM EDT TUE JUL 23 2013

AFTER A PERIOD OF STRONG WINDS TODAY ACROSS LAKE SUPERIOR IN THE
WAKE OF A COLD FRONT...LIGHTER WINDS UNDER 20KT WILL BE THE RULE
TONIGHT INTO WED AS HIGH PRES BUILDS INTO THE WRN GREAT LAKES. AS
THE HIGH SHIFTS E AND LOW PRES APPROACHES FROM THE NW...WINDS WILL
BECOME SOUTHERLY WED NIGHT/THU...BUT REMAIN UNDER 20KT. EVEN AFTER
THE LOW PASSES THRU THE UPPER GREAT LAKES/NRN ONTARIO...WINDS WILL
PROBABLY REMAIN 20KT OR LESS LATE WEEK AND THRU THE WEEKEND.
HOWEVER...WILL NEED TO WATCH FOR STRONGER SOUTHERLY WINDS THU NIGHT
JUST AHEAD OF THE LOW AND ASSOCIATED COLD FRONT AND THEN LATER FRI
INTO SAT BEHIND COLD FRONT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  BEACH HAZARDS STATEMENT UNTIL 10 PM EDT THIS EVENING FOR MIZ005-
     006.

LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...ROLFSON







AREA FORECAST DISCUSSION

NWS KANSAS CITY/PLEASANT HILL MO

 1219 PM CDT Tue Jul 23 2013

.SHORT TERM...(Today through Wednesday night)
Issued at 421 AM CDT TUE JUL 23 2013

Today through Tonight...Fickle northwest flow and muddled surface
boundaries will dictate our rain chances during this period. For the
past several days perturbations embedded within the northwest flow
have skirted by the bulk of the CWA with only the far northern and
northeastern counties receiving any beneficial rainfall. This may
change today as a relatively large convective complex continues to
track southeast through central NE.

A moderately strong mesohigh/cold pool and likely a developing MCV
are driving this feature. GFS/NAM/ECMWF have been pretty consistent
for the past few runs with this feature and maintain its strength
and resulting precipitation through the day and into the evening.
Only the HRRR has shown a tendency for the rain to fall apart
starting mid morning. This is a typical characteristic/phase of
convective systems which show a decided weakening from mid morning
through early afternoon before regenerating later in the afternoon.
Latest SPC meso page shows rather high MUCAPE of 3000-4000J/kg
downstream from this convection over northeast KS/northwest MO. Am
expecting the central NE convection to head for this better
instability and maintain its strength into mid morning. Surprisingly
there is moderately strong 0-6km shear of 40kts north of the MO
River so severe storms are possible. Have raised PoPs over the
western 1/2 of the CWA and adjusted them for the expected track of
this MCS. Will let day shift determine if this system will go
through the typical weakening/re-strengthening phases. Temperatures
will be problematic due to timing/location of cloud cover and
rain-cooled air. Have lowered them across the northern 1/2 of the
CWA.

Scattered convection expected to continue tonight with the northeast
third of the forecast area possibly missing out on the rain this
time.

Wednesday/Wednesday night...Could see lingering rain chances over
the far southern counties Wednesday morning as the convective
complex exists the CWA. Then expect dry, cooler and drier air to
spread into the region as high pressure settles in across IA through
IL and provides a northeast to easterly wind. Blended approach on
temperatures look reasonable with exceptionally pleasant weather for
Wednesday night/Thursday morning.

.LONG TERM...(Thursday through Monday)
Issued at 421 AM CDT TUE JUL 23 2013

The long range models are in better agreement with the 23/00Z runs
then in previous iterations. There is still however, a bit of
disagreement as to the timing of features that will affect the area
during this timeframe.

Thursday looks to be a very pleasant day with surface high pressure
over the area. Temperatures will be a few degrees below seasonal
averages with highs in the low to mid 80s. Thursday night there will
be two features of interest that will affect the area. The first is
a upper level trough moving through the Great Lakes region. This
will force a cold front into the Upper Midwest and back into the
Central Plains. Thunderstorms will develop out ahead of this front
and will move into northern Missouri Thursday night. Storms will
continue across northern Missouri on Friday as this front moves into
the area. The second feature of interest is an upper level shortwave
rounding an upper level ridge out west and dropping into the local
area on northwest flow on the lee side of the upper ridge. This
shortwave is actually remnant energy from the retrograding upper
level system that affected the region two weekends ago. The GFS/GEM
and ECMWF all depict a cluster of storms perhaps an MCS developing
across central Kansas Thursday night that will move into
central/southern Missouri either late Thursday night into Friday
(the faster GFS) or into Friday/Friday night (the slower EC and
GEM). In either case have chance POPs forecast for Thursday night
through Friday night.

Surface high pressure is advertised for the area behind the
departing cold front which should make for a very pleasant weekend
with highs in the upper 70s to lower 80s. Also, by the end of the
weekend there will be an overall pattern shift across the CONUS to a
more quasi-zonal pattern. This will be caused by a serious of
shortwaves moving through the Rockies which will suppress the
western CONUS ridge. The first of these shortwave is progged to
reach the area by Sunday night (still faster GFS) or early Monday
morning (the still slower EC). Either way, storms are expected to
linger into Monday across the area. That said have slight chance
POPs in for Sunday night to account for the faster GFS and have
chance POPs forecast for Monday.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 1213 PM CDT TUE JUL 23 2013

Rather difficult aviation forecast into the overnight hours. Decaying
showers from old MCV will approach the KC terminals within the
upcoming hour, with primary frontal boundary now well south across
southeastern portions of Kansas. Short term models have struggled to
resolve northwesterly mid-level flow, resulting in poor QPF placement
and unresolved surface boundaries. Through this afternoon, generally
feel that convective chances remain low, with stabilizing mid-level
clouds preventing much in the way of a warmup. Higher convective
chances will refocus over southern NE and western Iowa as well as
near surface and elevated boundary over central Kansas and into the
Ozark Plateau.

Later this evening, a secondary shortwave over the Dakotas will move
into the region, which could force redevelopment of elevated showers
and thunderstorms closer to the terminals along an 850 mb moisture
axis. This activity should be focused between 02z-06z before drifting
south into Wednesday morning. High pressure will bring dry conditions
and light winds for Wednesday.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&

$$

SHORT TERM...MJ
LONG TERM...73
AVIATION...Dux







AREA FORECAST DISCUSSION...UPDATED

NWS GLASGOW MT

 1147 AM MDT TUE JUL 23 2013

.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH THURSDAY...
A VERY SUBTLE DISTURBANCE IN THE UPPER FLOW WORKING ALONG THE
STATIONARY BOUNDARY IS PRODUCING SCATTERED GENERAL THUNDERSTORMS
AND SHOWERS THAT ARE CURRENTLY MOVING EAST ALONG THE NORTHERN
TIER THIS MORNING. THESE STORMS ARE EXPECTED TO SPREAD MORE TO THE
SOUTHEAST THIS AFTERNOON AND POSSIBLY BECOME STRONG ENOUGH TO GO
SEVERE. SPC THIS MORNING ADDED OUR SOUTHEAST COUNTIES TO ITS
CONVECTIVE OUTLOOK FOR SLIGHT RISK FOR SEVERE. THE GRID REFLECT
THIS PATTERN SO FEW CHANGES. SCT

PREVIOUS DISCUSSION...
ISOLATED SHOWERS CONTINUE TO TRAVERSE ACROSS THE CWA VERY EARLY
THIS MORNING. CURRENT RADAR OBSERVATIONS INDICATE SHOWERS AND
EMBEDDED THUNDER ENTERING SOUTHWESTERN SASKATCHEWAN FROM SOUTHERN
ALBERTA AT THIS TIME. RECENT HRRR RUNS BRING THIS ACROSS THE
NORTHERN ZONES DURING THE LATE MORNING AND INTO THE AFTERNOON
HOURS. THIS HAS ADDITIONAL SUPPORT FROM THE 23/00Z ECMWF/NAM/GFS
SOLUTIONS DESPITE SUBTLE DIFFERENCES IN PLACEMENT AND TIMING. WILL
KEEP POPS GOING THROUGH MOST OF THE CWA WITH HIGHEST POPS ACROSS
THE INTERNATIONAL BORDER AND FURTHER EAST CLOSER TO NORTH DAKOTA.
WILL OPT TO KEEP PETROLEUM COUNTY DRY FOR NOW ALTHOUGH A VERY
ISOLATED SHOWER CANNOT ENTIRELY BE RULED OUT. FORECAST SOUNDINGS
INDICATE ENOUGH INSTABILITY TO INSERT MENTION OF SMALL HAIL AND
GUSTY WINDS INTO THE GRIDS. NAM BUFKIT SOUNDINGS SHOWS HIGHEST
CAPE FURTHER EAST. WILL NOT ENTIRELY RULE OUT A VERY ISOLATED
SEVERE THUNDERSTORM...ESPECIALLY ACROSS THE FAR NORTHERN AND
EASTERN ZONES DURING THE LATE AFTERNOON AND EVENING HOURS. DID
LEAVE ENOUGH FLEXIBILITY HOWEVER THAT THE DAY SHIFT CAN HAVE SOME
WIGGLE ROOM IF THEY HAVE A DIFFERENT ASSESSMENT. THE UPPER LEVEL
SHORTWAVE IS ALREADY APPARENT ON WATER VAPOR IMAGERY AND AS THIS
INTERACTS WITH A SLOWLY EASTWARD MOVING FRONTAL BOUNDARY CURRENTLY
STRETCHING FROM NORTHWEST TO SOUTHEAST ACROSS THE CWA...CONFIDENT
THAT SHOWERS AND THUNDERSTORMS WILL BECOME MORE SCATTERED ACROSS
THE FORECAST REGION.

TUESDAY NIGHT INTO WEDNESDAY...UPPER LEVEL SHORTWAVE EXITS
NORTHEAST MONTANA AS HIGH PRESSURE SETTLES IN. THIS WILL LEAD TO
LARGE SCALE SUBSIDENCE AND MOSTLY DRY CONDITIONS ACROSS THE CWA.
ANOTHER SUBTLE SHORTWAVE WILL APPROACH BY WEDNESDAY AFTERNOON AND
DID INCLUDE MENTION OF SHOWERS AND THUNDERSTORMS WITH SLIGHT
CHANCE POPS AFTER 18Z ACROSS THE FAR NORTH...OVERSPREADING THE CWA
DURING THE EVENING AND AT NIGHT.

DIFFERENCES EXIST IN MODEL SOLUTIONS ON TIMING/TRACK OF NEXT UPPER
LEVEL SYSTEM PUSHING THROUGH NORTHWEST FLOW ALOFT FOR THURSDAY
WITH THE ECMWF/GFS LEANING TOWARDS A DRIER SOLUTION BUT THE NAM
MORE BULLISH. WILL KEEP SLIGHT CHANCE POPS IN THE GRIDS FOR
NOW...BUT MODELS SEEM TO BE CONVERGING TOWARDS DRIER CONDITIONS
WITH THE CWA TO THE RIGHT OF AN UPPER LEVEL RIDGE AXIS IN A
FAVORED REGION OF DEEP VERTICAL SUBSIDENCE. WITH THE UPPER LEVEL
RIDGE AMPLIFYING INTO SOUTHERN ALBERTA...FAVORED AREAS FOR ASCENT
MAY BE MUCH FURTHER TO THE WEST. HOWEVER...AGAIN...IT WILL BE
TRICKY TO TIME SUBTLE SHORTWAVE FEATURES IN THE NORTHWEST FLOW
ALOFT ESPECIALLY GIVEN MODEL DIFFERENCES...AS DISCUSSED...SO WILL
NOT GO COMPLETELY DRY JUST YET. AS FOR TEMPERATURES...WITH LITTLE
CHANGES IN 850MB TEMPERATURES AND 500MB HEIGHT PATTERN...EXPECT
LITTLE IN THE WAY OF TEMPERATURE SWINGS OVER THE NEXT SEVERAL
DAYS. LOW TEMPERATURES WILL GENERALLY RANGE ACROSS THE CWA IN THE
MID 50S TO NEAR 60 WITH HIGHS IN THE LOWER TO MIDDLE 80S AS A RULE
OF THUMB. MALIAWCO

.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
CANADIAN HIGH PRESSURE BUILDS INTO NORTH DAKOTA THURSDAY NIGHT AND
FRIDAY. THIS WILL THE FRONT FAR ENOUGH TO THE WEST THAT NORTHEAST
MONTANA WILL SEE DRY WEATHER AND SOMEWHAT COOLER TEMPERATURES.

A SHORTWAVE UPPER RIDGE MOVES THROUGH THE AREA FRIDAY NIGHT AND
SATURDAY. THIS WILL BRING THE FRONTAL BOUNDARY BACK EAST AS A WARM
FRONT. WITH AIRMASS FORECASTED TO BECOME UNSTABLE DURING THE DAY
ON SATURDAY...AFTERNOON AND EVENING THUNDERSTORMS WILL BE
POSSIBLE. WILL MAINTAIN A SLIGHT CHANCE FOR NOW.

SUNDAY THROUGH TUESDAY...MODELS HANDLE A SLOW MOVING UPPER
LOW/TROUGH ACROSS THE CANADIAN PRAIRIES THAT GIVES THE FORECAST
AREA FREQUENT SHORTWAVES IN A NEARLY ZONAL WSW TO WNW FLOW ALOFT.
WILL BROADBRUSH A CHANCE/SLIGHT CHANCE OF THUNDERSTORMS EACH DAY.
FORRESTER


&&

.AVIATION...
VFR CONDITIONS. SCATTERED THUNDERSTORMS WILL MOVE SOUTHEAST ACROSS
THE AREA THIS AFTERNOON AND EVENING THAT MAY IMPACT ANY OF THE FOUR
TERMINALS WITH MVFR FLIGHT CONDITIONS AT TIMES. CONFIDENCE IN TIMING
OF INDIVIDUAL STORMS IS LOW AT THIS TIME. WINDS WILL REMAIN EAST TO
NORTHEAST 5 TO 10 KNOTS. DWB

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

WEATHER.GOV/GLASGOW









AREA FORECAST DISCUSSION

NWS GREAT FALLS MT

 1120 AM MDT Tue Jul 23 2013

UPDATED AVIATION SECTION

.DISCUSSION...
Update forthcoming. Have made minor adjustments to sky and pop
grids. Generally dry forecast continues with the exception being the
Hi-Line. CAPE values approaching 2000 J/kg develop along the
international border this afternoon and HRRR analysis indicates
thunderstorms developing across northern Hill and Blaine counties
later this afternoon. Temperatures look good. Emanuel

&&

.AVIATION...
UPDATED 1720Z.
An upper level ridge of high pressure will keep much of the area
under light winds and clear skies through the TAF period. The
exception will be around the KCTB area this afternoon where
instability may result in the development of a few thunderstorms.
Quite a bit of uncertainty regarding the coverage of thunderstorms
so will limit mention of thunder to VCTS. Any storms that develop
should diminish after sunset. Langlieb

&&

.PREV DISCUSSION...Issued 500 AM MDT Tue Jul 23 2013

Today through Thursday...High pressure building over the Rocky
Mountains will keep the forecast area mostly dry with the
continued exception being along the Canadian border. Today
will be a copy of Monday with a few afternoon and evening
thunderstorms developing over portions of North Central Montana
near the border. Wednesday looks fairly similar to Tuesday with
the chances for thunderstorms dipping a bit further south,
especially during the evening. Instability over Montana itself
does not look overly impressive but the storms look to develop
over the Canadian Rockies, where conditions are much more
favorable, and move southeast into Montana. Moisture begins to
creep back in from Idaho Thursday and some scattered thunderstorms
may return to Southwest Montana. These may pose an issue with the
extremely dry conditions there of late. Expect winds to be light
through the period and temperatures to remain pretty warm.

Thursday night through Monday...The upper level high pressure ridge
will be centered over central Montana, while to the west, a low
pressure trof will be approaching the West Coast. The combination of
moisture creeping underneath the ridge from the south and falling
heights aloft will continue a chance of thunderstorms across the
forecast area into the evening. The airmass will remain quite dry
across the northern portions of the region Friday and most
convection will be over Southwest Montana. This pattern will
continue into Saturday although the trof from the west will be
approaching the Rockies and increasing instability across the area.
The trof will move through the region Saturday night, increase the
chance of showers and thunderstorms, and cool the airmass. The low
pressure center associated with the trof will remain over Alberta
and another trof will rotate across the West Coast. This will keep
the region underneath unsettled southwest flow aloft through the end
of the forecast period. However, the airmass will also remain quite
dry and convection will not be widespread. Temperatures will be well
above normals at the beginning of the forecast period. The airmass
will cool as the trof moves over the region Sunday and temperatures
will drop nearer to seasonal normals...yet most locations will still
remain slightly above normals. Zelzer

&&

.FIRE WEATHER...
Relative humidity will dip dangerously low again this afternoon
and evening but winds should be fairly light overall. The threat
for critical fire conditions will drop as a result, but things
will remain very dry across much of Central and Southwest Montana.
Scattered thunderstorms over North Central Montana today will be
in areas of higher relative humidity and will only pose a slight
risk of lightning fire starts. Conditions over Southwest Montana
are another story. Extremely dry weather looks to continue with
moisture and instability beginning to creep up from Idaho on
Thursday. This will result in a chance of elevated thunderstorms
that may produce little precipitation. This combination could
cause new fire starts later in the week. Fire weather highlights
are not anticipated today, but conditions will continue to be
closely monitored, especially over Southwest Montana.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  89  54  90  55 /   0   0   0  10
CTB  82  53  83  53 /  20  10  10  20
HLN  91  56  92  58 /   0   0   0  10
BZN  88  50  90  53 /   0   0  10  10
WEY  79  43  82  47 /   0   0  20  10
DLN  86  51  88  55 /   0   0  10  10
HVR  85  55  85  56 /  20  10  10  10
LWT  84  55  85  54 /   0   0  10  10

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

weather.gov/greatfalls












AREA FORECAST DISCUSSION

NWS GREAT FALLS MT

 1025 AM MDT Tue Jul 23 2013

.DISCUSSION...
Update forthcoming. Have made minor adjustments to sky and pop
grids. Generally dry forecast continues with the exception being the
Hi-Line. CAPE values approaching 2000 J/kg develop along the
international border this afternoon and HRRR analysis indicates
thunderstorms developing across northern Hill and Blaine counties
later this afternoon. Temperatures look good. Emanuel

&&

.AVIATION...
UPDATED 1108Z.
Isolated thunderstorms continue to track north of the Canadian
border but will drift south and cross northeast portions of the
region later this morning....in the vcnty and east of KHVR. This
area will also become unstable during the afternoon and a chance for
new thunderstorm development exists. Elsewhere, high pressure aloft
will keep the airmass dry and generally stable. Winds will remain
light through the period and VFR conditions will prevail through the
next 24 hours.

&&

.PREV DISCUSSION...Issued 500 AM MDT Tue Jul 23 2013

Today through Thursday...High pressure building over the Rocky
Mountains will keep the forecast area mostly dry with the
continued exception being along the Canadian border. Today
will be a copy of Monday with a few afternoon and evening
thunderstorms developing over portions of North Central Montana
near the border. Wednesday looks fairly similar to Tuesday with
the chances for thunderstorms dipping a bit further south,
especially during the evening. Instability over Montana itself
does not look overly impressive but the storms look to develop
over the Canadian Rockies, where conditions are much more
favorable, and move southeast into Montana. Moisture begins to
creep back in from Idaho Thursday and some scattered thunderstorms
may return to Southwest Montana. These may pose an issue with the
extremely dry conditions there of late. Expect winds to be light
through the period and temperatures to remain pretty warm.

Thursday night through Monday...The upper level high pressure ridge
will be centered over central Montana, while to the west, a low
pressure trof will be approaching the West Coast. The combination of
moisture creeping underneath the ridge from the south and falling
heights aloft will continue a chance of thunderstorms across the
forecast area into the evening. The airmass will remain quite dry
across the northern portions of the region Friday and most
convection will be over Southwest Montana. This pattern will
continue into Saturday although the trof from the west will be
approaching the Rockies and increasing instability across the area.
The trof will move through the region Saturday night, increase the
chance of showers and thunderstorms, and cool the airmass. The low
pressure center associated with the trof will remain over Alberta
and another trof will rotate across the West Coast. This will keep
the region underneath unsettled southwest flow aloft through the end
of the forecast period. However, the airmass will also remain quite
dry and convection will not be widespread. Temperatures will be well
above normals at the beginning of the forecast period. The airmass
will cool as the trof moves over the region Sunday and temperatures
will drop nearer to seasonal normals...yet most locations will still
remain slightly above normals. Zelzer

&&

.FIRE WEATHER...
Relative humidity will dip dangerously low again this afternoon
and evening but winds should be fairly light overall. The threat
for critical fire conditions will drop as a result, but things
will remain very dry across much of Central and Southwest Montana.
Scattered thunderstorms over North Central Montana today will be
in areas of higher relative humidity and will only pose a slight
risk of lightning fire starts. Conditions over Southwest Montana
are another story. Extremely dry weather looks to continue with
moisture and instability beginning to creep up from Idaho on
Thursday. This will result in a chance of elevated thunderstorms
that may produce little precipitation. This combination could
cause new fire starts later in the week. Fire weather highlights
are not anticipated today, but conditions will continue to be
closely monitored, especially over Southwest Montana.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  89  54  90  55 /   0   0   0  10
CTB  82  53  83  53 /  20  10  10  20
HLN  91  56  92  58 /   0   0   0  10
BZN  88  50  90  53 /   0   0  10  10
WEY  79  43  82  47 /   0   0  20  10
DLN  86  51  88  55 /   0   0  10  10
HVR  85  55  85  56 /  20  10  10  10
LWT  84  55  85  54 /   0   0  10  10

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

weather.gov/greatfalls










AREA FORECAST DISCUSSION

NWS HASTINGS NE

 401 PM CDT TUE JUL 23 2013

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 400 PM CDT TUE JUL 23 2013

THE MAIN FOCUS FOR THIS EVENING/TONIGHT IS ON TSTM POTENTIAL.
CONVECTION WAS ONGOING FOR MUCH OF THE DAY TODAY BUT IN THE LAST FEW
HOURS THIS ACTIVITY HAS DISSIPATED. THE CAP REMAINS STRONG ACROSS
OUR SOUTHERN ZONES WITH THE MAIN BOUNDARY/WARM FRONT ORIENTED ACROSS
SOUTHERN KANSAS.

THIS BEING SAID...REMNANT OUTFLOW BOUNDARIES/DIFFERENTIAL HEATING
BOUNDARIES RESIDE ACROSS OUR CWA WITH THE NORTHERN TWO THIRDS OF OUR
CWA REMAINING UNCAPPED. ONE SUCH BOUNDARY FOR OUR CWA IS ORIENTED
NEAR THE NEB/KS STATE LINE AND CANNOT RULE OUT STRONG/SEVERE STORMS
IN THIS AREA AS BOUNDARY SAGS SOUTH WITH INSTABILITY ON THE ORDER OF
2000 TO 3000 J/KG AND GOOD SHEAR IN OUR NW FLOW REGIME.  FARTHER
NORTH...A HIT OR MISS SHOWER/STORM CANNOT BE RULED OUT AS SUBTLE
SHORTWAVE TROUGHS TRANSLATE SE ACROSS THE INTERIOR CONUS.  FARTHER
UPSTREAM...NEW STORMS ARE DEVELOPING ACROSS WESTERN SOUTH DAKOTA IN
A SIMILAR MANNER AS 24HRS AGO...BUT CONFIDENCE IS NOT HIGH THAT
THESE STORMS WILL SUSTAIN INTO THE OVERNIGHT HOURS TO IMPACT OUR
REGION...BUT WILL NEED TO MONITOR.  THE HRRR TRACKS THIS ACTIVITY
TO THE WEST OF OUR CWA.

ASIDE FM THE HIT OR MISS STORM POTENTIAL...WE ARE LOOKING AT FAIRLY
SEASONAL CONDITIONS OR PERHAPS A FEW DEGREES COOLER THAN NORMAL BOTH
TONIGHT AND WEDNESDAY.  A SFC RIDGE AXIS WILL BUILD TO THE SOUTHWEST
FM THE UPPER MIDWEST AND COOLER AIR WILL BACK IN FM THE NORTHEAST.
SFC DPS DROP SEVERAL DEGREES AND OVERNIGHT LOWS SHLD AVERAGE IN THE
UPPER 50S TO LOW 60S.  MODELS INDICATE SOME POTENTIAL FOR SOME LOW
CLOUDS AROUND TONIGHT/EARLY WEDNESDAY...MAINLY IN KS.  THERE ARE
SOME MODEL DIFFERENCES ON HIGHS FOR WEDNESDAY BUT WITH THE AIRMASS
MORE SIMILAR TO TODAY...WILL AIM FOR HIGH TEMPS IN THE MID/UPPER 80S.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 400 PM CDT TUE JUL 23 2013

OVER THE PAST SEVERAL DAYS...MORE AND MORE OF THE CWA HAS
GRADUALLY RECEIVED AT LEAST MINIMAL AMOUNTS OF MEANINGFUL
MEASURABLE RAIN AFTER A VERY DRY START TO THE MONTH...AND THIS
TREND OF VARIOUS...HIT-AND-MISS RAIN CHANCES IN WHICH PARTS OF
THE AREA SEE DECENT PRECIPITATION WHILE OTHERS LARGELY MISS OUT IS
EXPECTED TO CONTINUE THROUGH THE FORECAST PERIOD. AT THIS
TIME...ALL RAIN CHANCES OVER THIS 6-DAY PERIOD HAVE BEEN CAPPED AT
NO MORE THAN 30-50 PERCENT...UNTIL/UNLESS CONFIDENCE INCREASES.
ALTHOUGH VERY SUBJECT TO CHANGE...THE THURS/THURS NIGHT AND SUN
NIGHT/MONDAY TIME FRAMES CURRENTLY CONTAIN THE OVERALL-HIGHEST
COVERAGE OF 30+ POPS. REGARDING SEVERE WEATHER PROSPECTS...ITS
AGAIN MUCH THE SAME STORY AS ALTHOUGH ITS QUITE POSSIBLE...IF NOT
LIKELY...THAT AT LEAST A FEW SEVERE STORMS FLARE UP FROM TIME TO
TIME...THERE IS NO DEFINITIVE SETUP OF HEIGHTENED CONCERN EVIDENT
AT THIS TIME...AND THUS HAVE REFRAINED FROM SPECIFYING ANY PERIODS
IN THE HAZARDOUS WEATHER OUTLOOK. ON A POSITIVE NOTE FOR MOST
FOLKS...THERE IS PRETTY HIGH CONFIDENCE IN A CONTINUED SLIGHTLY BELOW
NORMAL TEMPERATURE REGIME...WITH HIGHS ON MOST DAYS AVERAGING 3-8
DEGREES BELOW AVERAGE LATE-JULY VALUES.

STARTING OFF WEDNESDAY EVENING/NIGHT...SEASONABLY STRONG
NORTHWEST FLOW REMAINS IN PLACE OVER THE CENTRAL PLAINS...BETWEEN
RIDGING CENTERED OVER THE NV/CA/UT/AZ BORDER AREA...AND A BROAD
LONGWAVE TROUGH OVER THE EASTERN CONUS...WHILE A SHORTWAVE TROUGH
DIVES SOUTH-SOUTHEAST ACROSS MANITOBA/SASKATCHEWAN. WITHIN THE
LOCAL FLOW...A LOW-AMPLITUDE SHORTWAVE TROUGH IS PROGGED TO RIDE
EASTWARD ALONG THE KS/NE BORDER OUT OF NORTHEAST CO AS THE NIGHT
WEARS ON. ALTHOUGH INSTABILITY APPEARS PRETTY MINIMAL
LOCALLY...HAVE EXPANDED SLIGHT CHANCES FOR STORMS ACROSS MUCH OF
THE WESTERN HALF OF THE CWA POST-MIDNIGHT...WHILE LEAVING THE
EVENING HOURS DRY...AT LEAST FOR NOW. MADE LITTLE CHANGE OT LOW
TEMPS...WITH MID 60S MOST AREAS.

THURSDAY/THURSDAY NIGHT...POP-WISE MADE LITTLE CHANGE FROM
PREVIOUS FORECAST WITH A BROAD COVERAGE OF 30 POPS AND SOME 40S-
50S MAINLY FOCUSED IN SOUTHERN ZONES. ALOFT...ITS THE SAME OLD
THEME...WITH SUBTLE EMBEDDED SHORTWAVE TROUGHS WORKING OVER OR NEAR
THE CWA IN NORTHWEST FLOW...WHILE A STRONGER SHORTWAVE TROUGH
DROPS OUT OF CANADA INTO THE NORTHERN MN AREA. NOT
SURPRISINGLY...MODEL QPF FIELDS ARE OVER THE PLACE...WITH THE
ECMWF HITTING THE DAYTIME HOURS A LITTLE HARDER AND THE GFS THE
NIGHT. TEMP-WISE...WITH A RETURN TO MORE SOUTHERLY WINDS...NUDGED
UP HIGH TEMPS A LITTLE FROM PREVIOUS PER MET/MAV GUIDANCE BLEND...BUT
STILL ONLY MID 80S IN MOST AREAS.

FRIDAY/FRIDAY NIGHT...CONTINUED 20-30 POPS CWA-WIDE THIS ENTIRE
TIME...ALTHOUGH LARGE SCALE SUPPORT WANES A BIT FRIDAY NIGHT AS
THE AFOREMENTIONED GREAT LAKES REGION SHORTWAVE TROUGH CLOSES OFF
AND STARTS TO SLOWLY EDGE FARTHER EAST. IN THE WAKE OF A PASSING
COLD FRONT AND RETURN TO NORTHEAST BREEZES...HAVE HIGHS BACK DOWN
IN THE LOW 80S MOST NEB ZONES...AND MID 80S IN KS.

SATURDAY/SATURDAY NIGHT...CAME VERY CLOSE TO LEAVING THE CWA VOID
OF THUNDERSTORM MENTION DURING THE DAY PER PREVIOUS FORECAST...BUT
WENT AHEAD AND BROUGHT SOME SLIGHT POPS BACK INTO PARTS OF THE
SOUTHWEST 1/2 MAINLY PER THE 12Z ECMWF. SATURDAY NIGHT...HINTS OF
A SUBTLE SHORTWAVE TROUGH CONTINUE TO SUPPORT SLIGHT POPS AREA-
WIDE. HIGH TEMPS SATURDAY AGAIN LOW-MID 80S.

SUNDAY/SUNDAY NIGHT...THE LARGE-SCALE FLOW STARTS TO TURN
LEGITIMATELY MORE ZONAL VERSUS NORTHWESTERLY...IN THE WAKE OF THE
GREAT LAKES CLOSED LOW LIFTING BACK NORTHEAST INTO CANADA...BUT
THE TRAIN OF LOW AMPLITUDE DISTURBANCES INTO THE CENTRAL PLAINS
CONTINUES...AND HAVE SLIGHT POPS IN NEARLY ALL AREAS DURING THE
DAY...FOLLOWED BY 30-40 POPS SUNDAY NIGHT.

MONDAY/MONDAY NIGHT...CONTINUED QUASI-ZONAL FLOW WITH EMBEDDED
DISTURBANCES...AND HAVE AT LEAST SLIGHT POPS THROUGHOUT THIS 24
HOURS ALL AREAS...AND HIGHER VALUES CURRENTLY FOCUSED DURING THE
DAY. TEMP-WISE...LOW 80S NORTHEAST TO NEAR 90 SOUTHWEST.

TUESDAY...HAVE KEPT IT DRY FOR NOW...BUT ITS NO GUARANTEE TO STAY
THAT WAY...AS THERE IS OVERALL LITTLE CHANGE IN THE PATTERN.
POSSIBLY IN RESPONSE TO CLIMATOLOGY CARRYING MORE WEIGHT WITH
MODEL GUIDANCE AT THIS TIME RANGE...HIGHS TUESDAY ARE PRELIMINARILY
ADVERTISED TO BE A TOUCH WARMER THAN PREVIOUS DAYS...WITH MID 80S
NORTHEAST TO LOWER 90S SOUTHWEST.

&&

.AVIATION...(FOR THE 18Z KGRI TAF THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1200 PM CDT TUE JUL 23 2013

HIT OR MISS SHOWERS OR A STORM OR TWO WILL BE IN THE VCNTY OF KGRI
THRU THE AFTN...WITH CHCS DIMINISHING DURING THE EVENING/TONIGHT.
WINDS WILL GENERALLY BE FROM A NORTHEASTERLY DIRECTION AND MODELS
SUGGEST POTENTIAL FOR SOME LOW CLOUDS TONIGHT/EARLY WED NEAR OR
SOUTH OF KGRI AND INCLUDED SCATTERED MVFR CLOUDS.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

$$

SHORT TERM...FAY
LONG TERM...PFANNKUCH
AVIATION...FAY





AREA FORECAST DISCUSSION

NWS ELKO NV

 318 PM PDT TUE JUL 23 2013

.SYNOPSIS...MONSOON MOISTURE IS IMPACTING NEVADA TODAY AND
TOMORROW PROVIDING INCREASING CLOUDS...ENHANCED CHANCES FOR
THUNDERSTORMS. THUNDERSTORMS ARE LIKELY ACROSS CENTRAL NEVADA THIS
AFTERNOON AND EVENING WHERE SOME WILL PRODUCE HEAVY RAINFALL. MORE
CONVECTION IS POSSIBLE TOMORROW AFTERNOON.

&&

.SHORT TERM...THIS AFTERNOON THROUGH THURSDAY. A REMNANT UPPER
LOW OVER THE SILVER STATE AND DEEP MOISTURE NEARING 200 PERCENT OF
NORMAL NEAR LAS VEGAS ARE NEARLY COINCIDENT WITH VISIBLE SATELLITE
IMAGERY SHOWING CUMULUS CLOUDS. THE MOISTURE ALONG WITH DIFFERENTIAL
HEATING ZONES...WILL LEND ITSELF TOWARDS RIPE CONVECTION. THE
RADAR HAS ALREADY PINGED INTO A NUMBER OF THUNDERSTORMS TODAY
WHICH IS CONSISTENT WITH THE NAM12 AND THE HRRR FOR ENHANCED CAPE
AND LIFTED INDICES. MORE THUNDERSTORMS EXPECTED TOMORROW
AFTERNOON.

.LONG TERM...THURSDAY NIGHT THROUGH NEXT TUESDAY. THE MODELS ARE IN
FAIRLY GOOD AGREEMENT THROUGH TUESDAY. THE GENERAL SCENARIO IS FOR
ABOVE-NORMAL TEMPERATURES TO CONTINUE. THE RIDGE OF HIGH PRESSURE
RESPONSIBLE FOR THE LATEST STRING OF VERY WARM TEMPERATURES WILL
REMAIN STRONG THROUGH EARLY FRIDAY THEN BEGIN TO GET SUBDUED BY THE
INFUSION OF A LOW PRESSURE SYSTEM CROSSING EAST ACROSS THE SIERRAS
FOLLOWED BY A STRONGER UPPER LOW MOVING SOUTH FROM THE PACIFIC
NORTHWEST REGION. THE UPPER LOW WILL SLOWLY BEAR DOWN AND FLATTEN
THE RIDGE BY THE WEEKEND. SOME DAYTIME TEMPERATURES WILL FALL INTO
THE 80S OVER THE WEEKEND AND INTO EARLY NEXT WEEK. MODELS ARE
INDICATING A VERY UNSTABLE AIR MASS OVER CENTRAL NEVADA FOLLOWING
THE SURGE OF MOISTURE EXPECTED TODAY AND TOMORROW. DOWNDRAFT CAPE
VALUES SOUTH OF HIGHWAY 50 ARE GREATER THAN 1500 J/KG THROUGH
SATURDAY. PRECIPITABLE WATER VALUES ARE APPROACHING ONE INCH SOUTH
OF HIGHWAY 50. THE PROSPECT OF FLASH FLOODING FROM THUNDERSTORM
TRAINING ACROSS CENTRAL NEVADA MAY LINGER THROUGH SATURDAY DUE TO
THE LIGHT WINDS ALOFT...ESPECIALLY OVER THE RECENT BURN AREAS OF
NORTHERN NYE AND WHITE PINE COUNTIES...SPECIFICALLY THE WHITE PINE
FIRE AND THE BLACK FIRE. HUMBOLDT COUNTY WILL SEE THE LEAST AMOUNT
OF THUNDERSTORM ACTIVITY THROUGHOUT THE LONG TERM PERIOD AND
OVERNIGHT THUNDERSTORMS WILL BE PRIMARILY CONFINED TO THE SOUTHERN
HALF OF THE FORECAST AREA THROUGH FRIDAY NIGHT...THEN THE EASTERN
HALF SATURDAY AND SUNDAY AS A SHORTWAVE LOW TO THE NORTH NUDGES THE
MOISTURE AXIS EAST. THE SHOW MAY BE OVER BY TUESDAY AS THE
DEVELOPING PACIFIC TROUGH PROMISES TO SCOUR THE MOISTURE OUT OF THE
GREAT BASIN.


&&

.AVIATION...VFR CONDITIONS CAN BE EXPECTED THROUGH WEDNESDAY.
THUNDERSTORM ACTIVITY IS EXPECTED TO AFFECT KELY AND KTPH THROUGH
EARLY THIS EVENING. ISOLATED THUNDERSTORMS MAY AFFECT KELY AND KTPH
OVERNIGHT. THUNDERSTORM ACTIVITY IS EXPECTED TO AFFECT KWMC KEKO
KELY AND KTPH WEDNESDAY AFTERNOON AS THE MOISTURE FLUX INCREASES
ACROSS THE NORTH. BRIEF HEAVY RAINS AND STRONG GUSTY WINDS ARE
POSSIBLE WITH THESE STORMS.


&&

.FIRE WEATHER...A VERY UNUSUAL PATTERN HAS BEEN IN PLACE FOR THE
PAST TWO WEEKS. THIS UPPER LEVEL DISTURBANCE THAT IS CURRENTLY
OVER THE WESTERN GREAT BASIN...ORIGINALLY CAME FROM THE
MIDWEST...AKA...BACK EAST...WHERE A STRONG HIGH DEVELOPED CAUSING
THIS LOW TO RETROGRADE. THE SYSTEM HAS TAPPED INTO A FETCH OF MONSOON
MOISTURE. THE PWS OVER LAS VERY WERE ALMOST 200 PERCENT OF
NORMAL FROM THIS MORNINGS 12Z SOUNDING...REAL DATA NOT MODEL DATA.
TAKING THE GENESIS OF THIS PATTERN IN COMBINATION WITH AN UNSTABLE AIR
MASS WILL RESULT IN SCATTERED TO NUMEROUS THUNDERSTORMS CAPABLE OF
PRODUCING HEAVY RAIN ACROSS MUCH OF CENTRAL NEVADA. STORMS WILL BE
SLOW MOVING AND MAY TREK OVER THE SAME LOCATIONS...RESULTING IN
ENHANCED RAINFALL AMOUNTS.


&&

.LKN WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR NORTHEASTERN NYE
COUNTY...NORTHWESTERN NYE COUNTY...SOUTHERN LANDER COUNTY AND
SOUTHERN EUREKA COUNTY...WHITE PINE COUNTY.

&&

$$

97/98/98/97






AREA FORECAST DISCUSSION

NWS BINGHAMTON NY

 109 PM EDT TUE JUL 23 2013

.SYNOPSIS...
A PAIR OF COLD FRONTS...ONE PASSING THROUGH TODAY AND ANOTHER
TONIGHT...WILL PRODUCE ADDITIONAL SCATTERED SHOWERS AND PERHAPS
ISOLATED THUNDERSTORMS. MUCH COOLER AND DRIER WEATHER WILL SETTLE
IN FOR WEDNESDAY AND THURSDAY COURTESY OF CANADIAN HIGH PRESSURE.

&&

.NEAR TERM /THROUGH TONIGHT/...
1015 AM UPDATE...
PRECIPITABLE WATER VALUES ARE QUICKLY DECREASING...WITH MAIN UPPER
WAVE NOW HEADING EAST AND TAKING THE DEEPER MOISTURE WITH IT. WE
ARE NOW IN UNFAVORABLE LEFT ENTRANCE REGION OF JET AS WELL...SO
CURRENTLY ONLY A FEW SCATTERED SHOWERS IN ITS WAKE. LOOSELY-
DEFINED SURFACE LOW AND FRONTAL BOUNDARY WILL BE SHIFTING ITS WAY
THROUGH THE AREA THE REMAINDER OF TODAY...PROVIDING SOME HELP TO
CURRENT SCATTERED SHOWERS/ISOLATED THUNDERSTORMS...BUT OTHERWISE
FACTORS ABOVE WILL HINDER DEVELOPMENT AND MUCH OF THE AREA WILL BE
DRY THIS AFTERNOON. GRIDS UPDATED ACCORDINGLY. WE WILL NEED TO WATCH
THE LOCALIZED AREAS THAT RECEIVED HEAVY RAINFALL IN THE LAST 18
HOURS JUST IN CASE...BUT AT THIS POINT NOT EXPECTING WATER
PROBLEMS.

OVERNIGHT TONIGHT...SECONDARY COLD FRONT IN TANDEM WITH WAVE ALOFT
WILL PROBABLY YIELD A BAND OF ADDITIONAL SCATTERED SHOWERS.
DETAILS IN POPS HAVE BEEN ADJUSTED FOR TIMING OF THIS
FEATURE...BUT THERE IS UNCERTAINTY TO HOW MUCH COVERAGE BECAUSE OF
THE LOWER PWATS AND DIURNALLY UNFAVORABLE TIMING. THERE MAY BE
SIGNIFICANT GAPS BETWEEN INDIVIDUAL SHOWERS.

PREVIOUS DISCUSSION...
UPPER LEVEL SYSTEM WILL SLIDE EASTWARD TODAY, TAKING HIGHER PWATS
EAST OF FA. HOWEVER A COLD FRONT WILL SLIDE INTO NY AND PA TO SPUR
ADDITIONAL CONVECTION.

THE STRATIFORM RAIN CURRENTLY OVER FA WILL DIMINISH IN COVERAGE
AND SLIDE NORTHEAST TOWARD SUNRISE, AS FORECAST BY THE PREVIOUS
FEW HRRR RUNS. SKIES WILL BE MAINLY CLOUDY, THOUGH THERE IS POTENTIAL
FOR A FEW BREAKS OVER THE CENTRAL SOUTHERN TIER WHERE TEMPS MAY
PUSH INTO THE LOWER 80S.

SHOWERS AND A FEW THUNDERSTORMS WILL RETURN WITH THE COLD FRONT.
LACK OF WINDS AND MODEST INSTABILITY SUGGEST NO SVR THREAT. WILL
NEED TO MONITOR HEAVY RAINERS OVER AREAS WHICH RECEIVED COPIOUS
RAIN ON MONDAY. THESE ARE ISOLATED PROBLEMS, SO WILL NOT BE
ISSUING A FLASH FLOOD WATCH PER COORDINATION WITH NEIGHBORING
OFFICES.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
LONG STORY SHORT...LARGE CANADIAN HIGH PRESSURE BUILDS IN WITH DRY
AND COOL AIR MASS. THIS WILL INCLUDE THE COOLEST TEMPERATURES OF
JULY 2013 BY EARLY THURSDAY MORNING.

ON THE FRONT EDGE OF THE BUILDING HIGH...SOME LOW LEVEL MOISTURE
WILL BE TRAPPED UNDER DEVELOPING SUBSIDENCE INVERSION EARLY
WEDNESDAY. GIVEN THE FAIRLY SHALLOW NATURE OF IT...EXPECTING
CLOUDS AND PERHAPS A COUPLE SPRINKLES FOR A TIME EARLY WEDNESDAY
MORNING...BEFORE VERY DRY AIR MASS BECOMES FULLY REALIZED LATE
MORNING THROUGH WEDNESDAY AFTERNOON...ERADICATING CLOUDS VIA COLD
AIR ADVECTION AND MIXING DOWN OF VERY DRY AIR FROM MID LEVELS.
PRECIPITABLE WATER VALUES DIVE TO LESS THAN A HALF INCH BY LATE
WEDNESDAY AFTERNOON. THIS IS NEARLY 2 STANDARD DEVIATIONS BELOW
NORMAL FOR JULY. EXCEPT FOR PERHAPS THE LOWEST ELEVATIONS OF
DELAWARE VALLEY IN PIKE COUNTY PA...HIGHS WEDNESDAY SHOULD BE
LIMITED TO UPPER 60S TO MID 70S FOR CNY AND 70S FOR NEPA.

THE COOL FRESH DAY WITH NORTHWEST WINDS GUSTING TO 15-20 MPH...WILL
BE FOLLOWED BY QUICK DECOUPLING OF WINDS WEDNESDAY NIGHT AS CENTER
OF HIGH SHIFTS FROM WESTERN GREAT LAKES TO EASTERN GREAT
LAKES/QUEBEC/ONTARIO. RADIATIONAL COOLING WILL EASILY YIELD THE
COOLEST NIGHT OF THIS MONTH...UPPER 40S TO MID 50S...COOLEST IN
SHELTERED VALLEYS OF THE TWIN TIERS AND WESTERN CATSKILLS AND
MOHAWK VALLEY. CAVEAT ON THIS IS THAT WITH 850MB TEMPERATURES OF
ONLY 6-8 DEGREES CELSIUS...WE MAY ACTUALLY GET SOME LAKE EFFECT
CLOUDS COMING FROM LAKE ONTARIO TO SOME PARTS OF FINGER LAKES AND
CENTRAL SOUTHERN TIER REGIONS. TEMPERATURES WILL BE VERY SENSITIVE
TO RADIATIONAL COOLING SET UP AND THUS CLOUD LAYER DETAILS.

HIGH PRESSURE CENTER WILL TRAVEL ROUGHLY DOWN THE SAINT LAWRENCE
SEAWAY THURSDAY...THEN TO CANADIAN MARITIME PROVINCES FRIDAY...YET
OVERALL THE HIGH PRESSURE WILL REMAIN DOMINANT OF OUR WEATHER. I
WAS ABLE TO REMOVE LINGERING SLIGHT CHANCE OF A SHOWER THAT WAS IN
OUR FAR SOUTHEASTERN ZONES THURSDAY. BY FRIDAY...SOME EASTERLY LOW
LEVEL FLOW UNDER THE HIGH COULD POTENTIALLY ATTEMPT TO BRING IN
MARINE LAYER MOISTURE AGAINST THE POCONOS/CATSKILLS...SO I PLACE
A SLIGHT CHANCE OF A SHOWER THERE BUT OTHERWISE STILL DRY
AREAWIDE. OVERALL...AT LEAST A SURFACE RIDGE WILL KEEP CONTROL FOR
MOST OF THE REGION. HIGHS FRIDAY BACK UP TO NEAR CLIMATOLOGY...YET
WITH DEWPOINTS STILL VERY COMFORTABLE IN THE 50S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
3 PM MON UPDATE...
AN UNSETTLED WEATHER PATTERN IS EXPECTED ACROSS THE AREA AS BROAD
TROUGHING AND SW FLOW ALOFT IS EXPECTED TO SETTLE OVER THE
NORTHEAST THROUGH NEXT WEEKEND. MULTIPLE VORT MAXES WILL TRAVEL
AROUND THE BASE OF THE TROUGH AND EJECT NORTHEASTWARD RESULTING IN
A CHANCE FOR SHOWERS AND THUNDERSTORMS EACH DAY THROUGH THE
EXTENDED. MODELS PROJECT A COLD FRONT MOVING INTO OUR REGION
SUNDAY WHICH WILL RESULT IN COOLER AND DRIER AIR FOR THE REGION.
AS THE DRY AIR FUNNELS IN FROM THE WEST...A BRIEF DRY PERIOD MAY
RETURN TO THE AREA.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
WV MVG OUT THIS MRNG AND TAKING THE STEADY RAIN WITH IT. ISLTD
SHWRS WITH LINGERING LWRD CIGS AND VSBYS PSBL FOR A FEW HRS THIS
MRNG. LTR TODAY...LIMITED INSTABILITY WILL RESULT IN ISLTD
SHWRS...BUT NOT ENUF CVRG FOR INCLUSION IN THE TAFS ATTM. SO...
XPCT GNRL VFR CONDS WITH VFR CIGS THRU THE DAY INTO THE NGT. LATE
IN THE PD...COLD FNT WILL PASS THRU THE AREA INCRSG WINDS BUT ONCE
AGAIN CVRG OF PCPN WILL BE LIMTED DUE TO THE LATE NIGHT FNTL
PASSAGE.

.OUTLOOK...


WED/THU/...VFR

FRI/SAT...CHANCE OF SCATTERED MVFR SHRA/TSRA

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.

&&

$$
SYNOPSIS...DJP/MDP
NEAR TERM...DJP/MDP
SHORT TERM...MDP
LONG TERM...KAH
AVIATION...DGM







AREA FORECAST DISCUSSION

NWS GRAND FORKS ND

 309 PM CDT TUE JUL 23 2013

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 309 PM CDT TUE JUL 23 2013

MAIN FORECAST CHALLENGE REMAINS PCPN CHANCES OVER THE NEXT FEW
DAYS. MODELS SEEM TO BE IN BETTER AGREEMENT ON THE DETAILS THIS
TIME AROUND WHICH MATCH UP PRETTY WELL WITH FORECAST CONTINUITY.
THEREFORE DO NOT PLAN MANY CHANGES TO THE SHORT TERM.

QUITE A BIT OF CUMULUS FORMED ACROSS THE AREA AGAIN TODAY WHICH
LIKELY HELPED TO HOLD DOWN TEMPS A LITTLE. EXPECT THE CUMULUS TO
THIN OUT THIS EVENING. THE MID AND HIGH LEVEL CLOUDS ASSOCIATED
WITH AREA OF PCPN OVER NORTHWEST ND SHOULD DRIFT INTO PORTIONS OF
THE FA. ANY ACTUAL PCPN SHOULD TRACK FROM NORTHWEST ND DOWN INTO
NORTHEAST SD TONIGHT. LATEST VERSION OF THE RAP SEEMS TO SHOW THIS
WELL. WILL LEAVE INHERITED PCPN CHANCES ACROSS THE SOUTHWEST FOR
LATE TONIGHT BASICALLY AS IS. PRETTY DRY SFC DEW POINT READINGS
ESPECIALLY IN THE EAST SO CUT BACK A LITTLE ON MIN TEMPS THERE.

FOR WED THERE ARE NOT A LOT OF CHANGES FROM TODAY. STILL IN NW
FLOW WITH WEAK EMBEDDED IMPULSES. MODELS ALL SEEM CONSISTENT IN
SHOWING SOME LIGHT PCPN ACROSS THE AREA. THESE CHANCES SHOULD
SHIFT INTO NORTHWEST MN WED NIGHT.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 309 PM CDT TUE JUL 23 2013

BY THU THE NEXT SFC COLD FRONT WILL SWING THRU THE FA WITH A
LITTLE STRONGER UPPER LEVEL DISTURBANCE. THIS WILL PROBABLY BE THE
TIME PERIOD WITH THE BEST CHANCE FOR PCPN ALTHOUGH AMOUNTS WILL BE
PRETTY LIGHT. WILL LEAVE THU NIGHT DRY. STILL HAVE SOME QUESTIONS
ABOUT PCPN CHANCES AGAIN BY FRI. MODELS ARE INDICATING A
SUBSTANTIAL PIECE OF SHORTWAVE ENERGY DROPPING THROUGH WITH CHILLY
500MB TEMPS. LEFT SOME LOW CHANCES FOR PCPN IN THE EAST.

FOR FRI NIGHT THROUGH TUE...THE PERIOD WILL BEGIN WITH TEMPS
BELOW NORMAL AND DRY WEATHER...WITH COOL CANADIAN HIGH PRESSURE IN
CONTROL. TEMPS AND MOISTURE PROFILES WILL INCREASE BY EARLY NEXT
WEEK...WITH A CHANCE FOR SHOWERS AND STORMS WITH MORE ZONAL FLOW
ALOFT. MOST AREAS COULD REMAIN DRY THROUGH MONDAY...WITH DRY AIR
IN PLACE INITIALLY AND IT WILL TAKE TIME TO MOISTEN COLUMN.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1226 PM CDT TUE JUL 23 2013

EXPECT VFR CONDITIONS WITH SOME MID/HIGH LEVEL CLOUDS TODAY. WINDS
WILL BE LIGHT...UNDER 10 KT THROUGH THE PERIOD AS WELL. A CONVECTIVE
CLUSTER COULD SPREAD SOME SHOWERS OR PERHAPS A RUMBLE OF THUNDER
INTO THE AREA WED MORNING...MAINLY IN THE SOUTH. FOR NOW CONFIDENCE
NOT HIGH ENOUGH TO MENTION BUT SOMETHING TO MONITOR.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&

$$

SHORT TERM...GODON
LONG TERM...GODON/DK
AVIATION...DK







AREA FORECAST DISCUSSION

NWS BISMARCK ND

 1216 PM CDT TUE JUL 23 2013

.UPDATE...
ISSUED AT 1202 PM CDT TUE JUL 23 2013

DIURNAL LOW LEVEL JET CONTINUES TO MIX OUT WITH UPSTREAM MCS IN
NORTHEAST MONTANA GOING THROUGH ITS DIURNAL MINIMA AT THIS TIME.
QUESTION IS WHEN WILL THE THUNDERSTORMS INCREASE/REGENERATE.
CURRENT THINKING CONTINUES TO BE AROUND 21-23Z WITH SLIGHT RISK
SEVERE WEST CENTRAL AND SOUTHWEST LATE AFTERNOON AND EVENING.
INCREASED CLOUDINESS NORTH AND SOUTH CENTRAL WHERE WARM ADVECTION
UPLIFT/AFTERNOON HEATING EAST OF SURFACE TROUGH IN MONTANA SEEMS
TO BE SUSTAINING THE CLOUD AREA. ALSO LOWERED HIGHS IN THE CLOUDY
REGION 2 TO 3 DEGREES FOR THIS AFTERNOON.

UPDATE ISSUED AT 1017 AM CDT TUE JUL 23 2013

THIS UPDATE FOR A BAND OF CLOUDINESS ACROSS THE CENTRAL SECTIONS.
ADDED MORE CLOUDS TO THE MORNING AND EARLY AFTERNOON THAT ARE
ASSOCIATED WITH BROAD WARM ADVECTION UPLIFT.

UPDATE ISSUED AT 842 AM CDT TUE JUL 23 2013

EARLY MORNING CONVECTION ALONG THE DIURNALLY DRIVEN LOW LEVEL JET
AXIS AS DEPICTED BY THE RUC MODEL NOW DISSIPATING. WITH THIS TREND
IN MIND HAVE ELIMINATED THE THE MORNING CHANCE FOR THUNDERSTORMS.
NEXT CHANCE FOR PRECIPITATION WILL BE WITH THE AFTERNOON AND
EVENING SHORTWAVE EXPECTED TO BRING THUNDERSTORMS TO THE WEST.
WITH SPC ADDING SLIGHT RISK SEVERE TO THE SOUTHWEST HAVE ADDED
MENTION OF SEVERE STORMS LATE THIS AFTERNOON AND EVENING.

UPDATE ISSUED AT 642 AM CDT TUE JUL 23 2013

ONLY A FEW MINOR ISSUES WITH THE EARLY MORNING UPDATE. RAISED
CLOUD COVER OVER THE AREA FOR A FEW HOURS THIS MORNING WITH
SATELLITE INDICATING QUITE A BIT OF JET INDUCED MID LEVEL
CLOUDINESS OVER THE AREA THIS MORNING. ISOLATED SHOWERS IN THE FAR
EASTERN CWA SHOULD MOVE OUT OF THE AREA SHORTLY SO WILL NOT ADD
ANY MENTION OF SHOWERS HERE FOR THE REMAINDER OF THE MORNING. A
COUPLE REPORTING STATIONS INDICATING FOG ACROSS THE NORTH THIS
MORNING ON THE BACK SIDE OF A WEAK SURFACE HIGH OVER FAR SOUTHWEST
MANITOBA...SO ADDED A COUPLE HOURS OF PATCHY FOG OVER PORTIONS OF
THE FAR NORTH.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 402 AM CDT TUE JUL 23 2013

THE HIGHLIGHT OF THE SHORT TERM IS THE CONVECTIVE POTENTIAL THIS
AFTERNOON THROUGH TONIGHT.

WHILE THE 00 UTC DETERMINISTIC AND ENSEMBLE SUITE IS IN GOOD
AGREEMENT ON THE DEVELOPMENT OF AN INSTABILITY AXIS ACROSS EASTERN
MONTANA AND WESTERN NORTH DAKOTA ON THE WESTERN PERIPHERY OF
SURFACE HIGH PRESSURE...DIFFERENCES DO EXIST IN REGARDS TO HOW THE
CONVECTIVE SCENARIO WILL UNFOLD. IN GENERAL...ML CAPE OF 1000-1500
J/KG IS FORECAST TO DEVELOP ACROSS THE AFOREMENTIONED AREAS THIS
AFTERNOON...WITH DEEP LAYER SHEAR OF 30-40 KTS. THE CONVECTIVE
SCENARIOS OFFERED BY THE DETERMINISTIC MODELS RANGE FROM VERY
LITTLE CONVECTION ON THE ECMWF...TO A LINE OF STRONG TO SEVERE
THUNDERSTORMS ON THE 00 UTC 4 KM WRF ENTERING WESTERN NORTH DAKOTA
BETWEEN 20-22 UTC WITH THE ARRIVAL OF WEAK IMPULSES
ALOFT. THIS FORECAST CONVECTION THEN PROPAGATES INTO SOUTH CENTRAL
NORTH DAKOTA THROUGH THE EVENING...WHICH IS AT LEAST SUGGESTED ON
MOST OF THE DETERMINISTIC MODELS BY 06 UTC. YET HOW FAR PAST 06
UTC CONVECTION CAN REMAIN ORGANIZED WITH THE LACK OF A LOW LEVEL
JET IS UNCERTAIN. SPC DOES HAVE MUCH OF THE CWA IN A SEE TEXT WITH
5 PERCENT HAIL AND WIND CONTOURS. GIVEN UNCERTAINTY...LEFT THE
MENTION OF SEVERE OUT OF THE GRIDS FOR NOW.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 402 AM CDT TUE JUL 23 2013

MAIN FORECAST PROBLEM EARLY IN THE EXTENDED PERIOD WILL BE
PRECIPITATION CHANCES IN A PROGRESSIVE NORTHWEST FLOW. WEAK SURFACE
HIGH PRESSURE IS OVER THE AREA ON WEDNESDAY BUT DAYTIME HEATING AND
UPPER LEVEL JET OVER THE AREA WILL PROVIDE A CHANCE OF SHOWERS AND
THUNDERSTORMS. 00Z 23 JUN GFS FCST BUFR SOUNDINGS INDICATE
ATMOSPHERE BECOMES UNSTABLE ACROSS THE AREA WITH A STRONG NORTHWEST
FLOW ALOFT. WEDNESDAY NIGHT INTO THURSDAY A STRONGER UPPER LEVEL JET
DROPS SOUTH FROM CANADA AS A DEEP UPPER LEVEL LOW DROPS OVER THE
GREAT LAKES. KEEPING A CHANCE OF CONVECTION IN THE FORECAST UNTIL
DRIER AIR WORKS FROM NORTH TO SOUTH ACROSS THE AREA DURING THE
MORNING HOURS ON THURSDAY.

COOL SURFACE HIGH PRESSURE WILL PERSIST OVER THE AREA FRIDAY WITH
HIGHS MAINLY IN THE 70S. UPPER LEVEL RIDGING BUILDS OVER THE AREA
BEHIND THE EXITING GREAT LAKES CYCLONE OVER THE WEEKEND. BUT
SHORTWAVE ENERGY ROTATING AROUND ANOTHER UPPER LOW OVER WESTERN
CANADA WORKS TO BREAK DOWN THE RIDGE. THERE ARE DIFFERENCES BETWEEN
THE GFS/ECMWF IN HOW MUCH SHORTWAVE ENERGY CAN MAKE IT OVER THE
RIDGE...THUS SETTLED ON A MODEL BLEND WHICH KEEPS SATURDAY DRY AND
BRING SLIGHT CHANCE POPS INTO THE FAR WEST SATURDAY NIGHT...AND
PROGRESSING INTO THE CENTRAL ON SUNDAY. FLOW THEN BECOMES SOUTHWEST
BY EARLY NEXT WEEK...KEEPING A RISK OF THUNDERSTORMS IN THE FORECAST.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1202 PM CDT TUE JUL 23 2013

AT NOON CDT...A TROUGH OF LOW PRESSURE ACROSS EASTERN MONTANA WAS
ASSOCIATED WITH A WEAK SHORTWAVE TROUGH MOVING IN NORTHWEST FLOW
ALOFT. A DYING CLUSTER OF THUNDERSTORMS IN NORTHWEST MONTANA WILL
SLOWLY REGENERATE AS THUNDERSTORMS IN WESTERN NORTH DAKOTA LATE
TUESDAY AFTERNOON. VFR CONDITIONS ARE EXPECTED AT ALL TAF SITES
THROUGH THE 18Z TAF PERIOD. THE MAIN HAZARD TO AVIATION WILL BE
THE RISK OF THUNDERSTORMS AFTER 20Z AT KISN-KDIK. AT THIS TIME...
THREAT OF THUNDERSTORMS AT THE TAF SITES ARE STILL LOW SO WILL
CONTINUE TO EXPRESS THIS THREAT AS VCTS (VICINITY) AT KISN-KDIK.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...WAA
SHORT TERM...AYD
LONG TERM...TWH
AVIATION...WAA








AREA FORECAST DISCUSSION

NWS EL PASO TX/SANTA TERESA NM

 139 PM MDT TUE JUL 23 2013

.SYNOPSIS...
A MOIST WEATHER PATTERN WILL PERSIST WITH HUMID AIR TRAPPED BELOW
EXPANDING UPPER LEVEL HIGH PRESSURE. SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO DEVELOP EACH AFTERNOON OVER THE MOUNTAINS AND SPREAD
INTO THE LOWLANDS DURING THE EVENING THROUGH FRIDAY.

THE NUMBER AND INTENSITY OF THE STORMS MAY INCREASE OVER THE
WEEKEND AS A BACKDOOR COLD FRONT MOVES TOWARD THE REGION. IT IS
UNCERTAIN WHETHER THE FRONT WILL MOVE THROUGH THE AREA...BUT IT
SHOULD BE CLOSE ENOUGH TO DRAW IN ADDITIONAL MOISTURE AND INCREASE
THE RISK OF LOCALIZED FLOODING.

SOMEWHAT DRIER SURFACE AIR SHOULD FILTER INTO THE REGION BEGINNING
MONDAY WITH A CORRESPONDING REDUCTION IN THUNDERSTORMS.

WITH LOTS OF CLOUDS AROUND TEMPERATURES THROUGH THE PERIOD SHOULD
GENERALLY RUN NEAR NORMAL.

&&

.DISCUSSION...
NO LARGE CHANGES IN PATTERN WITH UPPER HIGH CONTINUING TO SPREAD
OVER THE CWA. THE FLY IN THE OINTMENT IS THE PERSISTING INVERTED
TROUGH MOVING SLOWLY WEST ACROSS NORTHERN MEXICO. THE TROUGH OR A
SMALL REMNANT WILL PERSIST NEAR/OVER THE CWA THROUGH SUNDAY KEEPING
A FAIRLY ACTIVE WEATHER PATTERN THROUGH THAT TIME.

ON THE SHORTER TERM...THE HIGH RES MODELS INCLUDING HRRR HAVE NOT
PERFORMED WELL SO FAR TODAY SHOWING EXTENSIVE PRECIP OVER SW NM
FOR THIS MORNING WHICH NEVER MATERIALIZED PROBABLY DUE TO TOO MUCH
LOW-LEVEL CIN. LATEST HRRR/12Z SPC WRF INDICATED AFTERNOON/EVENING
CONVECTION FOR THE SW ONCE AGAIN AND AN EVENING BATCH OF CONVECTION
MOVING ACROSS SOUTHERN TIER. HAVE ADJUSTED POPS TO REFLECT THESE
TRENDS HOPING THAT THE EARLIER PROBLEMS HAVE BEEN FLUSHED OUT OF
THE SYSTEM WITH LATER MODEL INITIALIZATIONS.

MODEL OMEGAS INCREASE TOMORROW SO I EXPECT A GREATER COVERAGE OF
STORMS THROUGHOUT THE AREA FOLLOWED BY A RETURN TO A BASELINE
COVERAGE FOR THURSDAY AND FRIDAY. SLOW MOVEMENT SHOULD
CHARACTERIZE STORMS THROUGH FRIDAY WHICH WILL MEAN A DECENT RISK
OF AT LEAST LOCALIZED FLOODING. HAVE NO INCLINATION TO ISSUE FFA
ATTM BUT IT IS SOMETHING THAT WILL NEED TO BE WATCHED EACH SHIFT
FOR THE NEXT SEVERAL DAYS.

THE WEEKEND REMAINS IN DOUBT REGARDING THE POSITIONING OF A
BACKDOOR COLD FRONT. CURRENT MODELS ARE HANGING THE FRONT ON THE
SACS FOR SATURDAY - I AM SKEPICAL. REGARDLESS WHETHER THE FRONT
ACTUALLY PENETRATES THE AREA...THERE SHOULD BE ENOUGH MOISTURE
CHANNELED INTO FRONT TO PRODUCE SCATTERED TO NUMEROUS STORMS FOR
SATURDAY AND SUNDAY. THE MAIN ISSUE WILL BE WHETHER WE SEE STRONG
TO SEVERE STORMS AND HEAVIER RAIN WITH ISENTROPIC LIFT.

IT APPEARS THAT THE UPPER LOW FINALLY MOVES OUT OF THE AREA MONDAY
AND SOME DRYING TAKES PLACE AT THE SURFACE SO POPS SHOULD DECREASE.


&&

.AVIATION...VALID 24/00Z-25/00Z.
SCATTERED TSRA OVER THE MOUNTAINS WITH ISOLATED TO WIDELY SCATTERED
TSRA IN THE LOWLANDS. STORMS WILL TEND TO DRIFT TOWARDS THE W OR
WSW. GNLY FEW-SCT050-070 SCT-BKN100-140 SCT-BKN200-250 WITH LCL 3SM
+TSRAGS BKN040CB OVC080 AND BRIEF MVFR IN STORMS GNLY 18Z-06Z. SVR
TURBC PSBL WITH 10 MI CB/TSTM. WNDS GNLY 21010KTS WITH VRB 30G40KTS
NR TSTMS.

&&

.FIRE WEATHER...
A WEAK TO MODERATE MONSOONAL PATTERN WILL CONTINUE FOR MOST OF REST
OF THE WEEK. WITH A SEMI STALLED LOW PRESSURE SYSTEM JUST SOUTH OF
THE BORDER...THIS PATTERN WILL FAVOR HEAVIER RAINFALL ESPECIALLY FOR
FOR AREAS WEST OF THE CONTINENTAL DIVIDE. HOWEVER AFTERNOON OR
NIGHTTIME SHOWERS AND THUNDERSTORMS ARE POSSIBLE JUST ABOUT ANYWHERE
WITH THIS MOIST UNSTABLE AIR MASS IN PLACE. BY THE WEEKEND...A
BACKDOOR COLD FRONT MAY APPROACH OUR AREA FROM THE NORTHEAST WHICH
COULD ALLOW FOR EVEN MORE ADDITIONAL TROPICAL MOISTURE INTO THE
REGION RESULTING IN AN INCREASED CHANCES OF SHOWERS AND THUNDERSTORMS.
MIN RH WILL RANGE FROM 30% TO 45% ALL AREAS TODAY AND WEDNESDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
EL PASO                 76  91  74  92  74 /  30  40  40  30  30
SIERRA BLANCA           71  90  70  93  71 /  40  40  40  30  30
LAS CRUCES              72  90  69  89  70 /  30  40  50  30  30
ALAMOGORDO              73  91  70  92  71 /  30  40  50  30  30
CLOUDCROFT              53  66  50  68  52 /  30  50  50  30  30
TRUTH OR CONSEQUENCES   71  89  68  88  69 /  30  40  50  40  30
SILVER CITY             64  83  63  81  63 /  40  50  60  40  40
DEMING                  71  90  68  87  68 /  30  40  50  40  30
LORDSBURG               69  90  67  87  68 /  40  40  50  40  30
WEST EL PASO METRO      76  90  74  91  75 /  30  40  40  30  30
DELL CITY               70  94  70  94  71 /  30  40  40  30  20
FORT HANCOCK            74  93  73  96  73 /  40  40  40  30  30
LOMA LINDA              68  85  67  87  68 /  30  40  40  30  30
FABENS                  74  91  73  92  74 /  40  40  40  30  30
SANTA TERESA            73  90  71  90  72 /  30  40  40  30  30
WHITE SANDS HQ          74  90  72  90  73 /  30  40  40  30  30
JORNADA RANGE           69  89  67  89  68 /  30  40  50  30  30
HATCH                   72  87  69  86  71 /  30  40  50  30  30
COLUMBUS                71  90  71  88  69 /  30  40  50  30  30
OROGRANDE               72  91  70  92  71 /  30  40  40  30  30
MAYHILL                 59  75  57  76  59 /  30  40  40  30  30
MESCALERO               57  78  55  79  57 /  30  50  50  30  30
TIMBERON                58  75  57  75  59 /  30  40  40  30  30
WINSTON                 62  81  60  80  61 /  40  40  50  40  40
HILLSBORO               68  85  65  83  66 /  30  50  60  40  30
SPACEPORT               70  89  68  87  69 /  30  40  50  30  30
LAKE ROBERTS            63  82  61  81  62 /  40  50  60  40  40
HURLEY                  65  85  64  82  64 /  40  40  60  40  40
CLIFF                   68  91  66  87  66 /  40  40  50  40  40
MULE CREEK              61  86  60  83  60 /  40  50  50  40  30
FAYWOOD                 67  84  65  81  66 /  30  40  60  40  30
ANIMAS                  68  88  68  85  68 /  40  40  50  30  30
HACHITA                 68  89  67  86  68 /  40  40  50  40  30
ANTELOPE WELLS          66  86  66  84  66 /  40  40  50  40  30
CLOVERDALE              65  82  64  80  64 /  40  50  60  40  40

&&

.EPZ WATCHES/WARNINGS/ADVISORIES...
NM...NONE.
TX...NONE.
&&

$$

02/20







FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE



 .SHORT TERM...TONIGHT AND WEDNESDAY
ISSUED AT 224 PM CDT TUE JUL 23 2013

LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW YESTERDAYS COLD
FRONT HEADED FOR THE OHIO VALLEY WHILE CANADIAN HIGH PRESSURE IS
MOVING SOUTHEAST OVER THE NORTHERN PLAINS. COLD ADVECTION IS
OCCURRING BEHIND THE FRONT OVER THE WESTERN GREAT LAKES AND THE
THERMAL TROUGHING IS CONTRIBUTING TO A WIDESPREAD STRATO-CU FIELD
ACROSS MOST OF THE STATE.  LOOKING UPSTREAM...A FEW SHORTWAVES NOTED
OVER SASKATCHEWAN AND CENTRAL MANITOBA...WHERE CU LOOKS RATHER
BUBBLY BUT NO LIGHTNING STRIKES SO FAR THIS AFTERNOON.  AS HIGH
PRESSURE BUILDS INTO THE REGION TONIGHT...CLOUDS AND TEMPS WILL BE
THE MAIN FORECAST CONCERNS FOLLOWED BY SHOWER CHANCES TOMORROW.

TONIGHT...HIGH PRESSURE WILL SHIFT SOUTHEAST TOWARDS WESTERN GREAT
LAKES.  GUSTY NORTH WINDS WILL PERSIST ALONG THE LAKE SHORE LONGER
THAN NORTH-CENTRAL WISCONSIN...BUT SHOULD ALSO DIMINISH LATE IN THE
NIGHT.  AS WINDS DROP OFF...GOOD RADIATIONAL COOLING CONDITIONS WILL
SETUP...THOUGH PATCHES OF MID-CLOUDS MAY ARRIVE AFTER LATE IN THE
EVENING OR AFTER MIDNIGHT.  THE COLD SPOTS COULD REACH THE LOWER
40S...WHILE MOST AREAS WILL RANGE FROM THE MID 40S TO LOW 50S.
PATCHY FOG WILL ALSO BE POSSIBLE LATE TONIGHT AS WELL.

WEDNESDAY...HIGH PRESSURE WILL REMAIN ACROSS THE AREA.  WEAK
SHORTWAVES WILL BE DIVING TOWARDS WISCONSIN WITHIN NORTHWEST FLOW
ALOFT.  CONVECTIVE TEMPS ARE PRETTY LOW TOMORROW...IN THE UPPER 60S
TO LOWER 70S.  COMBINED WITH WEAK FORCING ALOFT...THAT SHOULD BE
ENOUGH TO PRODUCE A GOOD CU FIELD BY LATE MORNING.  PROGGED
INSTABILITY TOMORROW AFTERNOON WILL BE AROUND 100 J/KG...BUT THERE
IS A SIZABLE CAP AROUND 625MB THAT WILL BE TOUGH TO OVERCOME.
STILL...CU SHOULD BE DEEP ENOUGH FOR A WIDELY SCT TO LOW END SCT OF
SHOWERS OVER THE HIGHER TERRAIN OF N-C WISCONSIN.  PERHAPS AN
ISOLATED RUMBLE OF THUNDER IS POSSIBLE.  HIGHS WILL BE RATHER
UNIFORM IN THE LOW TO MID 70S.

.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY
ISSUED AT 224 PM CDT TUE JUL 23 2013

UPPER AIR PATTERN CHARACTERIZED BY WESTERN RIDGE AND GREAT LAKES
TROF WILL DOMINATE THE WEATHER PATTERN DURING THE PERIOD.
SHORTWAVE TROFS WILL AMPLIFY MEAN TROF OVER GREAT LAKES LATER THIS
WEEK INTO WEEKEND. CLOSED LOW FORECAST TO DEVELOP WHICH WILL KEEP
COOL AIR IN PLACE INTO EARLY NEXT WEEK.

BEST CHANCE FOR RAIN WILL BE LATE THURSDAY INTO FRIDAY AS
STRONGEST OF THE SHORTWAVE TROFS MOVE ACROSS AREA. SURFACE LOW
PRESSURE AND COLD FRONT WILL PUSH ACROSS AREA WITH CONVECTION
EXPECTED GIVEN INSTABILITY AND SHEAR.

WARM AIR ADVECTION AHEAD OF APPROACHING SYSTEM COULD PUSH PRECIP
INTO AREA AS EARLY AS LATE WEDNESDAY NIGHT/EARLY THURSDAY.

TEMPS DURING MUCH OF PERIOD WILL REMAIN BELOW NORMAL. ON
SATURDAY...HIGHS ONLY IN THE 60S ACROSS MUCH OF AREA.
&&

.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1237 PM CDT TUE JUL 23 2013

COLD AIR FLOWING SOUTH OFF LAKE SUPERIOR IS CONTRIBUTING
TO A WIDESPREAD STRATO-CU FIELD ACROSS MUCH OF THE STATE.  CIGS HAVE
BEEN RISING WITH DAYTIME HEATING SO SHOULD REMAIN VFR THIS
AFTERNOON.  CLOUDS ARE RELATIVELY SHALLOW AND THEIR IS AMPLE DRY AIR
ALOFT...WHICH SHOULD MIX DOWN AND HELP DISSIPATE THE CLOUDS AROUND
MID-AFTERNOON.  NORTH WINDS WILL ALSO REMAIN GUSTY THROUGH LATE
AFTERNOON BEFORE DIMINISHING WITH THE APPROACH OF HIGH PRESSURE
TONIGHT.  MAINLY CLEAR SKIES TONIGHT WITH SOME PATCHY MID-LEVEL
CLOUDS ARRIVING LATE FROM THE WEST.  CLOUDS TO BUILD DURING THE LATE
MORNING TOMORROW WHICH COULD LEAD TO WIDELY SCT SHOWERS OVER
NORTHERN WISCONSIN TOMORROW AFTERNOON.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM.....MPC
LONG TERM......JKL
AVIATION.......MPC







AREA FORECAST DISCUSSION

NWS CHEYENNE WY

 346 PM MDT TUE JUL 23 2013

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 330 PM MDT TUE JUL 23 2013

AN INFLUX OF MONSOONAL MOISTURE WILL INDICATE A TURN TO A MUCH MORE
CLIMATOLOGICALLY NORMAL PERIOD OF UNSETTLED WEATHER BEGINNING
WEDNESDAY AND CONTINUING THROUGH MUCH OF THE LONGER TERM. BEFORE
THEN...AFTERNOON SATELLITE PIX SHOW SHALLOW CONVECTION BEGINNING TO
DEVELOP OVER THE NORTHERN LARAMIE RANGE. A RESULT OF LLVL
CONVERGENCE DUE TO A STATIONARY BOUNDARY DRAPED UP ALONG THE FRONT
RANGE. DEW POINTS WEST OF THIS BOUNDARY WERE BELOW 30F...WITH
RAWLINS REPORTING 11F. MORE AMPLE LLVL MOISTURE EAST OF THIS
BOUNDARY AS INDICATED BY 50 DEGREE DEW POINTS. IN FACT...THIS
BOUNDARY PUSHED EAST OF KCYS EARLY THIS MORNING DROPPING DEWPOINTS
BRIEFLY BACK INTO THE 20S. MOST OF THE CWA WILL REMAIN DRY THIS
EVENING...THESE EXCEPTION BEING THE FAR EASTERN ROW OF COUNTIES FROM
CHADRON TO BRIDGEPORT. AS HAS BEEN THE CASE THE PAST SEVERAL
DAYS...12Z MODEL OUTPUT CONTINUES TO SUGGEST CAP WILL HOLD AND THE
AREA WILL REMAIN DRY. EVEN THE LATEST HRRR DEVELOPS CONVECTION JUST
EAST OF THE CWFA. PERSISTENCE SAYS OTHERWISE HOWEVER...SO WILL KEEP
SLIGHT CHANCES GOING FROM CHADRON AND BRIDGEPORT. IF THE CAP DOES
MANAGE TO BREAK...SBCAPES OF 1000 TO 1500 J/KG WOULD BE REALIZED
WHICH COULD RESULT IN SOME SEVERE DEVELOPMENT. ANY THUNDERSTORMS
WILL WIND DOWN BY LATE EVENING.

ATTENTION THEN SHIFTS TO UPSTREAM MOISTURE AND SHORTWAVE EVIDENT ON
WV IMAGERY FROM NRN CA/SRN OR EAST INTO UTAH. THIS SUB-TROPICAL
MONSOON MOISTURE PLUME AND SHORTWAVE WILL SLOWLY MEANDER NORTH INTO
THE REGION ON WEDNESDAY. 12Z MODELS HAVE DELAYED ITS ARRIVAL BY A
FEW HOURS. ALTHOUGH THERE IS SOME POTENTIAL FOR DRY LIGHTNING EARLY
WEDNESDAY...AM NOT CONFIDENT ON ITS COVERAGE. SO FOR NOW...HAVE
MAINTAINED THE INHERITED COVERAGE...BUT HAVE CONFINED IT TO THE
SNOWY/SIERRA MADRE RANGES WEDNESDAY MORNING. BY MIDDAY
WEDNESDAY...CONVECTION WILL BE DEVELOPING OVER THE SE WYOMING
MOUNTAINS AND ADJACENT FOOTHILLS/VALLEY LOCATIONS. PROGD SBCAPES
WILL NOT BE PARTICULARLY HIGH (500-800 J/KG). HOWEVER PWATS RISING
ABOVE AN INCH ALONG WITH STORM MOTIONS OF 10 KNOTS OR LESS WILL
RESULT IN EFFICIENT RAIN PRODUCERS. CAN NOT RULE OUT THE POTENTIAL
FOR SMALL HAIL TOO...THOUGH THERMODYNAMIC PARAMETERS ARE NOT
FAVORABLE. SHORTWAVE WILL MEANDER ATOP THE CWA WEDNESDAY NIGHT WHICH
SHOULD AID IN THE CONTINUATION OF NOCTURNAL CONVECTION.

MID/UPPER-LEVEL FLOW WILL TURN NORTHWEST FOR THURSDAY BEHIND
DEPARTING SHORTWAVE. AT THE SFC...A WEAK COOL FRONT ALONG WITH
FAVORABLE UPSLOPE BEHIND FROPA WILL SET THE STAGE FOR ANOTHER ROUND
OF AFTERNOON AND EVENING SHOWERS/THUNDERSTORMS. AGAIN AMPLE MOISTURE
WILL ACT TO LIMIT SEVERE POTENTIAL...ONLY YIELDING SBCAPES OF
500-800 J/KG. STORM MOTIONS WILL AGAIN BE LESS THAN 10 KNOTS.

THE THICKER CLOUD CANOPY ALONG WITH WEAK COLD FROPA ON THURSDAY WILL
CAUSE TEMPERATURES TO COOL FROM THE UPPER 80S ON WEDNESDAY INTO THE
LOWER 80S ON THURSDAY.

.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 330 PM MDT TUE JUL 23 2013

MONSOONAL MOISTURE WILL CONTINUE TO STREAM INTO THE REGION ON
FRIDAY THROUGH THE WEEKEND. SHORTWAVE MOVES SOUTHWARD ACROSS THE
NORTHERN HIGH PLAINS ON THURSDAY NIGHT WITH RISING SFC PRESSURES
BEHIND IT OVER THE PLAINS. THIS RESULTS IN GOOD SOUTHEAST UPSLOPE
BY FRIDAY WITH PW VALUES OF 1.00-1.25 INCHES OVER MOST AREAS ALONG
AND EAST OF THE LARAMIE RANGE. WIDESPREAD QPF IS DEPICTED ON BOTH
THE GFS AND ECMWF BY FRIDAY AFTN/EVENING. WITH DEEP LAYER SHEAR OF
50 KTS AND CAPE VALUES OF 1250-1500 J/KG...A FEW STRONG TO SEVERE
STORMS COULD BE POSSIBLE OVER THE PLAINS. THE STEERING FLOW IS A
LITTLE TOO FAST FOR MAJOR FLASH FLOODING CONCERNS ON FRIDAY. UPPER
LEVEL RIDGE AXIS IS POSITIONED OVER WESTERN WY BY SATURDAY
AFTN...WITH NORTHWESTERLY MIDLEVEL FLOW PERSISTING IN THE CWA.
CONVECTIVE PARAMETERS APPEAR VERY SIMILAR TO FRIDAY...SO GENERALLY
CARRIED THE SAME POPS. RIDGE AXIS IS ALMOST DIRECTLY OVER THE CWA
BY SUNDAY WITH STEERING FLOW BECOMING MORE WESTERLY AND SOMEWHAT
SLOWER THAN THE PREVIOUS DAYS. SHORTWAVE ROTATES THROUGH THE AREA
DURING PEAK HEATING AND WITH PW VALUES REMAINING ABOVE
NORMAL...EXPECT ANOTHER DAY OF GOOD STORM COVERAGE. DRIER
700-500MB FLOW CREEPS INTO THE REGION BY MONDAY WHICH COULD RESULT
IN MORE ISOLATED TSTM CHANCES. TEMPS THROUGHOUT THE PERIOD WILL BE
SLIGHTLY BELOW AVERAGE WITH THE MOIST AIRMASS AND RATHER CLOUDY
CONDITIONS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY MORNING)
ISSUED AT 1146 AM MDT TUE JUL 23 2013

VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. CUMULUS WILL
LIKELY DEVELOP ACROSS THE PLAINS DURING THE AFTERNOON. ISOLATED
SHOWERS AND TSTMS WILL BE POSSIBLE MAINLY OVER THE NORTHERN
NEBRASKA PANHANDLE...SO INCLUDED VCTS AT KCDR DURING THE EVENING.
WINDS WILL GENERALLY BE BELOW 10-15 KTS.

&&

.FIRE WEATHER...
ISSUED AT 330 PM MDT TUE JUL 23 2013

MONSOONAL MOISTURE WILL RETURN TO THE DISTRICT IN EARNEST DURING THE
DAY ON WEDNESDAY. AS THIS OCCURS...WE MAY BE ABLE TO SEE SOME
HIGH-BASED SHOWER/THUNDERSTORM DEVELOPMENT MAINLY OVER THE SNOWY AND
SIERRA MADRE RANGES. AM NOT CONFIDENT OF WHETHER OR NOT THIS WILL
OCCUR...BUT IF IT DOES THE BEST TIME WILL BE BETWEEN 6AM AND NOON
WEDNESDAY. AFTER THAT...BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS
WILL RETURN TO THE DISTRICT BEGINNING WEDNESDAY AFTERNOON AND
CONTINUING INTO THE UPCOMING WEEKEND.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

SHORT TERM...HAHN
LONG TERM...FINCH
AVIATION...FINCH
FIRE WEATHER...HAHN