Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/15/14
AREA FORECAST DISCUSSION
NWS TUCSON AZ
910 AM MST WED AUG 13 2014
.SYNOPSIS...SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS THROUGH
THIS EVENING. SOME STORMS WILL GENERATE LOCALLY HEAVY RAIN AND
STRONG GUSTY WINDS. A DOWNWARD MOISTURE TREND AND WEAKER FLOW WILL
LEAD TO LESS THUNDERSTORM ACTIVITY FRIDAY AND SATURDAY.
&&
.DISCUSSION...IR/VISIBLE SATELLITE IMAGERY AND SURFACE OBSERVATIONS
INDICATE PARTLY CLOUDY SKIES TO MOSTLY CLOUDY SKIES ACROSS SE AZ AT
THIS TIME. DEWPOINTS AT LOWER ELEVATIONS VALID 16Z WERE IN THE
60S F...AND THESE TEMPS WERE GENERALLY 2-5 DEGS F HIGHER VERSUS 24
HOURS AGO. SURFACE TEMPS VALID 16Z WERE ABOUT 5-10 DEGS F COOLER
VERSUS THIS TIME TUE. 13/12Z KTWC SOUNDING TOTAL PRECIP WATER WAS
1.74 INCHES...AND THIS VALUE REMAINED ALMOST TWO STANDARD DEVIATIONS
ABOVE NORMAL. HAVE NOTED THAT THE STEERING FLOW FOR SHOWERS/TSTMS
HAS VEERED TO A MORE SWLY COMPONENT VERSUS 24 HOURS AGO. 13/12Z
UPPER AIR PLOTS INDICATED 587 DM LOW PRESSURE CENTERED OVER NWRN
AZ...RIDGE AXIS EXTENDED FROM WEST TEXAS NWD INTO THE NRN CONUS
PLAINS...AND A TROUGH WAS OVER THE PACIFIC NW. LIGHT SLY/SWLY FLOW
PREVAILED OVER SE AZ.
ABUNDANT MOISTURE WILL CONTINUE ACROSS SE AZ THRU TONIGHT AS THE
WEAK UPPER LEVEL LOW PRESSURE SYSTEM THAT ENHANCED SHOWER/TSTM
ACTIVITY TUE MOVES FROM NWRN AZ INTO WRN COLORADO. HOWEVER...HAVE
NOTED ANOTHER WEAK CYCLONIC CIRCULATION SYSTEM VIA WATER VAPOR
IMAGERY OVER NRN SONORA. DESPITE A GENERAL FLOW REGIME THAT WOULD
TEND TO SUPPRESS CONVECTIVE ACTIVITY TO SOME DEGREE...THIS WEAK
SONORAN SYSTEM IN COMBINATION WITH THE AMPLE MOISTURE SHOULD PROVIDE
SCATTERED TO NUMEROUS SHOWERS/TSTMS INTO THIS EVENING. THE 13/14Z
RUC HRRR AND 13/12Z UNIV OF AZ WRF-NAM SOLUTIONS SUPPORT THIS
SCENARIO.
THE MAIN IMPACT AGAIN TODAY WILL BE HEAVY RAIN WITH THE POTENTIAL
FOR FLASH FLOODING TO OCCUR. HOWEVER...LESS COVERAGE OF HEAVY
RAINFALL IS ANTICIPATED INTO THIS EVENING VERSUS TUE. SHOWERS/TSTMS
SHOULD WEAKEN IN INTENSITY AND LESSEN IN COVERAGE LATE THIS EVENING.
A SLIGHT CHANCE OF SHOWERS/TSTMS EXISTS MAINLY FROM TUCSON EWD LATE
TONIGHT INTO EARLY THUR MORNING.
THE INHERITED OFFICIAL FORECAST IS IN GREAT SHAPE AND NO UPDATES ARE
PLANNED AT THIS TIME. PLEASE REFER TO THE ADDITIONAL SECTIONS FOR
FURTHER DETAIL.
&&
.AVIATION...VALID THRU 14/18Z.
SCATTERED TO NUMEROUS -TSRA/-SHRA FROM LATE THIS MORNING INTO THIS
EVENING AS ABUNDANT MOISTURE CONTINUES ACROSS SOUTHEAST ARIZONA.
MVFR VISIBILITIES AND BRIEF WIND GUSTS MAINLY AROUND 40-45 KTS WILL
OCCUR WITH THE STRONGER TSRA. EXPECT THE COVERAGE OF -TSRA/-SHRA TO
DECREASE AFTER 14/04Z WITH ISOLATED -TSRA/-SHRA EAST OF KTUS LATE
TONIGHT INTO THURSDAY MORNING. OTHERWISE...CLOUD DECKS WILL MAINLY
BE AT 5-10K FT AGL AND SURFACE WIND WILL GENERALLY BE LESS THAN 10
KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...PLENTY OF MOISTURE WITH SCATTERED SHOWERS AND
THUNDERSTORMS TODAY AND THURSDAY. SOME DRYING WITH LESS THUNDERSTORM
COVERAGE OVER THE WEEKEND.
&&
.PREV DISCUSSION...STILL ENOUGH MOISTURE FOR AN AVERAGE THUNDERSTORM
DAY THURSDAY...HOWEVER WE START TO PICK UP A BRIEF WESTERLY
COMPONENT TO OUR FLOW AS THE RIDGE STARTS TO REORIENT INTO A LOWER
LATITUDE PARTIAL BLOCKING POSITION. WE SHOULD START TO LOSE THIS
LONG AND DEEP MOISTURE FETCH AT THAT POINT. THIS SHOULD THEN LEAD
INTO OUR DOWNTURN FRIDAY INTO THE WEEKEND EVEN AS THE RIDGE SHIFTS A
LITTLE FURTHER NORTH IN RESPONSE TO THE NORTHERN BASIN LOW LIFTING
TOWARD THE NORTHERN PLAINS. OUR BEST CHANCE OF THUNDERSTORMS WILL BE
TRIMMED BACK TO MAINLY NEAR THE INTERNATIONAL BORDER AND FAR EASTERN
AREAS. SOME RESPITE FROM THIS LATE SUNDAY OR MONDAY WITH THE RIDGE
AXIS TEMPORARILY TRANSITIONING INTO A HIGHER AMPLITUDE JUST EAST OF
US. THAT SHOULD OPEN US BACK UP FOR A DAY OR TWO OF BETTER MOISTURE.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
FRANCIS
PREVIOUS DISCUSSION...MEYER
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
526 AM PDT WED AUG 13 2014
.UPDATE...
WE JUST SENT A QUICK UPDATE TO THE FORECAST TO ACCOUNT FOR MORE
WIDESPREAD COVERAGE OF THE MARINE STRATUS DECKS...PUSHING INTO THE
INLAND EMPIRE ATTM. HAVE ALSO INCREASED COVERAGE FOR TONIGHT AND
THURSDAY MORNING AS WE EXPECT A VERY SIMILAR PATTERN. NO OTHER
CHANGES AT THIS TIME.
.SYNOPSIS...
A MOIST AND UNSTABLE ATMOSPHERE WILL PERSIST TODAY ALONG WITH
AFTERNOON SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE FOR THE
MOUNTAINS AND DESERTS. SOUTHWEST FLOW ALOFT SHOULD BRING DRY
WEATHER TO THE REGION THURSDAY THROUGH EARLY NEXT WEEK.
TEMPERATURES WILL BE MOSTLY NEAR SEASONAL NORMALS THROUGH EARLY
NEXT WEEK...AND NIGHT AND MORNING LOW CLOUDS WILL CONTINUE ALONG
THE COAST AND THE NEARBY VALLEYS.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
NOCTURNAL CONVECTION HAS PERSISTED OVERNIGHT ACROSS SOUTHEAST
CALIFORNIA AND OVER THE LAST COUPLE HOURS HAS BLOSSOMED SOUTHWEST
INTO THE EASTERN PORTIONS OF SAN DIEGO AND RIVERSIDE
COUNTIES...WHERE A MOIST ATMOSPHERE RESIDES AND CONSIDERABLE
INSTABILITY. THIS ACTIVITY WILL DIMINISH TOWARDS DAYBREAK AS THE
UPPER LOW QUICKLY SHIFTS NORTH.
THE LATEST HIGH RESOLUTION MODELS THEN SUGGEST DIURNALLY DRIVEN
CONVECTION WILL FIRE UP LATER THIS AFTERNOON WITH THE HRRR MODEL
INDICATING A POCKET OF CAPE VALUES APPROACHING 4000 J/KG OVER
EASTERN SAN DIEGO COUNTY. MODEL SOUNDINGS INDICATE PWAT VALUES
PERSISTING OR INCREASING SLIGHTLY TO NEARLY 2.0 INCHES IN THIS
REGION. FORCING WILL BE WEAK TO NON- EXISTENT AS THE SYNOPTIC
SCALE TROUGH EXITS TO NORTHERN ARIZONA...HOWEVER RESIDUAL OUTFLOW
BOUNDARIES AND TERRAIN FEATURES WILL HELP TO KICK THE CONVECTION
OFF AGAIN THIS AFTERNOON. WITH EXCESSIVE DEEP MOISTURE PERSISTING
HAVE ISSUED A FLASH FLOOD WATCH FOR THE EASTERN MOUNTAINS AND
DESERTS AND THE COACHELLA VALLEY WHERE ANY STRONGER...SLOW MOVING
THUNDERSTORMS COULD DROP HEAVY RAINFALL OF ONE INCH PER HOUR OR
HIGHER THIS AFTERNOON. THE THREAT FOR FLASH FLOODING WILL QUICKLY
DIMINISH AFTER 5 PM. BROAD SW FLOW ENSUES TONIGHT WHICH SHOULD
SHUNT THE MOISTURE AWAY FROM OUR REGION...WITH POPS DWINDLING.
BROAD UPPER LEVEL HIGH PRESSURE CENTERED OVER ARIZONA WILL BE THE
MAIN SYNOPTIC WEATHER FEATURE FROM FRIDAY THROUGH EARLY NEXT WEEK.
THIS WILL ALLOW A STRONGER MARINE LAYER TO DEVELOP AND BRING
A STRONG DIURNAL SPREAD OF LOW CLOUDS INTO THE COASTAL VALLEYS
AND INTO THE WESTERN INLAND EMPIRE. THE BROAD HIGH PRESSURE IS NOT
EXPECTED TO BE PARTICULARLY STRONG...SO INLAND TEMPERATURES WILL
NOT EXCEED NORMAL VALUES.
&&
.AVIATION...
130930Z...SCATTERED THUNDERSTORMS IN LOWER DESERTS AND DESERT SLOPES
OF MOUNTAINS THROUGH AROUND 12Z...TAPERING OFF AFTER SUNRISE. BASES
AROUND 5000-7000 FEET MSL UNDER THESE STORMS WITH TOPS TO 25000
FEET. GUSTY ERRATIC WINDS AND BRIEFLY REDUCED VIS IN RAINFALL IN AND
AROUND TSTORMS. LOW CLOUDS WILL CONTINUE MOVING INLAND THIS MORNING
APPROACHING KONT BY SUNRISE. BASES WILL BE AROUND 1500 FEET MSL WITH
TOPS TO 2500 FEET. LOCAL VIS 3-5SM ALONG INLAND EXTENT OF CLOUDS.
SCATTER OUT WILL BE AROUND 17-18Z. SOME TSTORMS THIS AFTERNOON IN
MOUNTAINS AND DESERTS. TSTORMS IN CB CLOUD BASES AROUND 8000 FEET
MSL WITH TOPS UP TO 35000 FEET. THEN MOSTLY CLEAR AFTER 01Z THIS
EVE. LOW CLOUDS WILL RETURN TO COASTAL AIRPORTS BETWEEN 00-04Z AND
MAY REACH KONT BY 11Z THURSDAY. BASES WILL BE AROUND 1500 FEET MSL.
&&
.MARINE...
200 AM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH SUNDAY.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR THE COACHELLA
VALLEY...RIVERSIDE COUNTY MOUNTAINS...SAN DIEGO COUNTY
DESERTS...SAN DIEGO COUNTY MOUNTAINS.
PZ...NONE.
&&
$$
PUBLIC...BROTHERTON
AVIATION/MARINE...MM
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
340 AM PDT WED AUG 13 2014
.SYNOPSIS...
A MOIST AND UNSTABLE ATMOSPHERE WILL PERSIST TODAY ALONG WITH
AFTERNOON SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE FOR THE
MOUNTAINS AND DESERTS. SOUTHWEST FLOW ALOFT SHOULD BRING DRY
WEATHER TO THE REGION THURSDAY THROUGH EARLY NEXT WEEK.
TEMPERATURES WILL BE MOSTLY NEAR SEASONAL NORMALS THROUGH EARLY
NEXT WEEK...AND NIGHT AND MORNING LOW CLOUDS WILL CONTINUE ALONG
THE COAST AND THE NEARBY VALLEYS.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
NOCTURNAL CONVECTION HAS PERSISTED OVERNIGHT ACROSS SOUTHEAST
CALIFORNIA AND OVER THE LAST COUPLE HOURS HAS BLOSSOMED SOUTHWEST
INTO THE EASTERN PORTIONS OF SAN DIEGO AND RIVERSIDE
COUNTIES...WHERE A MOIST ATMOSPHERE RESIDES AND CONSIDERABLE
INSTABILITY. THIS ACTIVITY WILL DIMINISH TOWARDS DAYBREAK AS THE
UPPER LOW QUICKLY SHIFTS NORTH.
THE LATEST HIGH RESOLUTION MODELS THEN SUGGEST DIURNALLY DRIVEN
CONVECTION WILL FIRE UP LATER THIS AFTERNOON WITH THE HRRR MODEL
INDICATING A POCKET OF CAPE VALUES APPROACHING 4000 J/KG OVER
EASTERN SAN DIEGO COUNTY. MODEL SOUNDINGS INDICATE PWAT VALUES
PERSISTING OR INCREASING SLIGHTLY TO NEARLY 2.0 INCHES IN THIS
REGION. FORCING WILL BE WEAK TO NON- EXISTENT AS THE SYNOPTIC
SCALE TROUGH EXITS TO NORTHERN ARIZONA...HOWEVER RESIDUAL OUTFLOW
BOUNDARIES AND TERRAIN FEATURES WILL HELP TO KICK THE CONVECTION
OFF AGAIN THIS AFTERNOON. WITH EXCESSIVE DEEP MOISTURE PERSISTING
HAVE ISSUED A FLASH FLOOD WATCH FOR THE EASTERN MOUNTAINS AND
DESERTS AND THE COACHELLA VALLEY WHERE ANY STRONGER...SLOW MOVING
THUNDERSTORMS COULD DROP HEAVY RAINFALL OF ONE INCH PER HOUR OR
HIGHER THIS AFTERNOON. THE THREAT FOR FLASH FLOODING WILL QUICKLY
DIMINISH AFTER 5 PM. BROAD SW FLOW ENSUES TONIGHT WHICH SHOULD
SHUNT THE MOISTURE AWAY FROM OUR REGION...WITH POPS DWINDLING.
BROAD UPPER LEVEL HIGH PRESSURE CENTERED OVER ARIZONA WILL BE THE
MAIN SYNOPTIC WEATHER FEATURE FROM FRIDAY THROUGH EARLY NEXT WEEK.
THIS WILL ALLOW A STRONGER MARINE LAYER TO DEVELOP AND BRING
A STRONG DIURNAL SPREAD OF LOW CLOUDS INTO THE COASTAL VALLEYS
AND INTO THE WESTERN INLAND EMPIRE. THE BROAD HIGH PRESSURE IS NOT
EXPECTED TO BE PARTICULARLY STRONG...SO INLAND TEMPERATURES WILL
NOT EXCEED NORMAL VALUES.
&&
.AVIATION...
130930Z...SCATTERED THUNDERSTORMS IN LOWER DESERTS AND DESERT SLOPES
OF MOUNTAINS THROUGH AROUND 12Z...TAPERING OFF AFTER SUNRISE. BASES
AROUND 5000-7000 FEET MSL UNDER THESE STORMS WITH TOPS TO 25000
FEET. GUSTY ERRATIC WINDS AND BRIEFLY REDUCED VIS IN RAINFALL IN AND
AROUND TSTORMS. LOW CLOUDS WILL CONTINUE MOVING INLAND THIS MORNING
APPROACHING KONT BY SUNRISE. BASES WILL BE AROUND 1500 FEET MSL WITH
TOPS TO 2500 FEET. LOCAL VIS 3-5SM ALONG INLAND EXTENT OF CLOUDS.
SCATTER OUT WILL BE AROUND 17-18Z. SOME TSTORMS THIS AFTERNOON IN
MOUNTAINS AND DESERTS. TSTORMS IN CB CLOUD BASES AROUND 8000 FEET
MSL WITH TOPS UP TO 35000 FEET. THEN MOSTLY CLEAR AFTER 01Z THIS
EVE. LOW CLOUDS WILL RETURN TO COASTAL AIRPORTS BETWEEN 00-04Z AND
MAY REACH KONT BY 11Z THURSDAY. BASES WILL BE AROUND 1500 FEET MSL.
&&
.MARINE...
200 AM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH SUNDAY.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR THE COACHELLA
VALLEY...RIVERSIDE COUNTY MOUNTAINS...SAN DIEGO COUNTY
DESERTS...SAN DIEGO COUNTY MOUNTAINS.
PZ...NONE.
&&
$$
PUBLIC...BROTHERTON
AVIATION/MARINE...MM
AREA FORECAST DISCUSSION
NWS PUEBLO CO
913 PM MDT THU AUG 14 2014
.UPDATE...
ISSUED AT 911 PM MDT THU AUG 14 2014
UPDATED FORECAST TO LOWER/REMOVE POPS OVER ALL BUT THE FAR
SOUTHEAST PLAINS.
UPDATE ISSUED AT 557 PM MDT THU AUG 14 2014
WITH HEAVY RAIN THREAT SHIFTING INTO NORTHEAST COLORADO THIS
EVENING...AND ONLY VERY ISOLATED STORMS ALONG THE CONTINENTAL
DIVIDE...WILL CANCEL FLASH FLOOD WATCH FOR ALL AREAS A LITTLE
EARLIER THAN SCHEDULED.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 310 PM MDT THU AUG 14 2014
SHORTWAVE CURRENTLY MOVING ACROSS NORTHERN CO HAS INITIATED
THUNDERSTORMS OVER THE PIKES PEAK REGION THIS AFTERNOON. HIGH
PRECIPITABLE WATERS RUNNING 150+% OF NORMAL IS ALLOWING FOR
EFFICIENT RAINFALL RATES AS EVIDENCED FROM RADAR KDP/S AND SPOTTER
REPORTS. THERE HAVE ALSO BEEN SOME PEA SIZE HAIL REPORTS WITH THE
STRONGER STORMS. AS THE SHORTWAVE CONTINUES TO DRAG ACROSS EASTERN
COLORADO...THUNDERSTORMS WILL CONTINUE TO SPREAD EASTWARD ACROSS
THE PLAINS. STORMS HAVE BEEN MOVING NORTHEAST AT 15 MPH...ENOUGH
TO ABATE SOME OF THE FLASH FLOOD RISK...BUT NOT ENTIRELY NEGATE IT
AS HEAVY RAINFALL RATES OF AROUND 2 INCHES PER HOUR CAN STILL
CAUSE PROBLEMS FOR THE BURN SCARS AND URBAN AREAS. THUS WILL KEEP
THE FLASH FLOOD WATCH GOING THROUGH 9 PM. BEEN A LITTLE HARDER TO
GET STRONGER CONVECTION GOING OUT WEST ALONG THE CONTINENTAL
DIVIDE AND SUSPECT THAT THREAT THERE IS RAPIDLY DIMINISHING AS
STABILITY HAS BEEN A FACTOR WITH THE CLOUD COVER AND EARLIER
RAINFALL. WILL KEEP THE WATCH GOING THROUGH THE PRIME HEATING
HOURS...BUT SUSPECT THAT WE MAY BE ABLE TO TAKE DOWN THE WATCH BY
6 PM FOR CHAFFEE/LAKE COUNTIES AND THE EASTERN SAN JUANS AND LA
GARITAS.
THUNDERSTORMS WILL SPREAD EASTWARD ACROSS THE PLAINS THROUGH THE
EVENING HOURS. LATEST HRRR SUGGESTS THAT THREAT FOR PIKES PEAK AREA
MAY BE ENDED BY 6-7 PM. HIGHEST POPS THROUGH THE EVENING HOURS WILL
BE ACROSS THE SOUTHEAST PLAINS AS THUNDERSTORMS DEVELOP ALONG
SOUTHWARD ADVANCING COLD FRONT. APPEARS BEST LIFT MAY BE ACROSS
NORTHWEST KANSAS AND EAST CENTRAL CO (KIOWA COUNTY) AS LOW LEVEL JET
IMPINGES ON THE FRONT...SO WILL KEEP HIGHEST POPS UP THAT WAY. MOST
OF THE ACTIVITY WILL BE DONE BY MIDNIGHT AS LINE OF THUNDERSTORMS
MOVES EAST INTO KANSAS.
A LITTLE LESS ACTIVE WEATHER IS EXPECTED TOMORROW. PRECIPITABLE
WATERS WILL DROP OFF BELOW 1 INCH FOR THE I-25 CORRIDOR AND
WESTWARD. STILL LOOKING AT SUFFICIENT MOISTURE FOR ISOLATED TO
SCATTERED THUNDERSTORMS...SO STILL CAN`T RULE OUT HEAVY RAIN ON BURN
SCARS AND POTENTIAL FOR FLASH FLOODING. BUT THREAT CERTAINLY LOOKS
LOWER DUE TO THE MORE ISOLATED NATURE OF THESE STRONGER CELLS.
GRIDS WILL CARRY MORE OF A DIURNAL POP TREND...WITH THUNDERSTORMS
FIRING OVER THE MOUNTAINS AROUND NOON...THEN DEVELOPING/SPREADING
EASTWARD ACROSS THE ADJACENT PLAINS DURING THE LATE AFTERNOON. -KT
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 310 PM MDT THU AUG 14 2014
FRIDAY NIGHT-THURSDAY...NOT MUCH CHANGE IN THE ONGOING FORECAST
THROUGH THE EXTENDED PERIOD WITH FLAT UPPER LEVEL RIDGING REMAINING
IN PLACE ACROSS THE GREAT BASIN THROUGH THE ROCKIES. THIS WILL KEEP
MONSOONAL MOISTURE PLUME SOUTH AND SOUTHWEST OF THE STATE WITH WEAK
WEST TO NORTHWEST FLOW ALOFT ACROSS THE STATE AND WEATHER SYSTEMS
MOVING ACROSS THE NORTHERN TIER OF STATES AND INTO THE UPPER
MIDWEST.
THERE LOOKS TO BE ENOUGH RESIDUAL MOISTURE IN PLACE TO WORK WITH
LATE SUMMER SOLAR HEATING TO KEEP ISOLATED TO SCATTERED AFTERNOON
AND EVENING STORMS IN THE FORECAST OVER AND NEAR THE HIGHER
TERRAIN...WITH A FEW STORMS POSSIBLY ROLLING ACROSS THE FAR SE
PLAINS THROUGH THE LATE EVENING AND OVERNIGHT HOURS. STORMS THAT DO
DEVELOP SHOULD BE GENERALLY HIGH BASED...THOUGH STILL CAN NOT RULE
OUT LOCALIZED HEAVY RAINFALL AND SMALL HAIL WITH STRONGER CELLS.
HARD TO PIN POINT BEST COVERAGE OF STORMS THOUGH COULD SEE INCREASED
COVERAGE SUNDAY THROUGH SUNDAY NIGHT AND AGAIN TUESDAY AND TUESDAY
NIGHT AS EMBEDDED DISTURBANCES MOVE ACROSS THE NORTHERN ROCKIES AND
INTO THE HIGH PLAINS. WITH RIDGING IN PLACE...TEMPERATURES ACROSS
THE AREA LOOK TO BE GENERALLY AT OR SLIGHTLY ABOVE LATE SUMMER
AVERAGES THROUGH THE PERIOD.
THERE COULD BE A CHANGE IN THE PATTERN INTO EARLY NEXT WEEKEND...AS
A BROAD UPPER TROUGH TRIES TO CARVE OUT ACROSS THE WEST COAST
OPENING THE DOOR TO INCREASING MOISTURE WITHIN DEVELOPING SOUTH TO
SOUTHWEST FLOW ALOFT ACROSS THE DESERT SOUTHWEST AND INTO THE
ROCKIES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 310 PM MDT THU AUG 14 2014
THUNDERSTORMS WILL CONTINUE THROUGH THROUGH THE EVENING HOURS FOR
THE MOUNTAINS AND I-25 CORRIDOR WITH THREAT FOR TSRA AT TERMINALS TO
CONTINUE UNTIL 00-01Z. CIGS COULD DROP INTO THE MVFR TO EVEN BRIEF
IFR CATEGORY UNDER THE STRONGER STORMS WITH HEAVY RAIN AND PEA SIZE
HAIL POSSIBLE. THUNDERSTORMS WILL END FROM WEST TO EAST AT THE
TERMINALS THROUGH THE EVENING WITH VFR CONDITIONS EXPECTED
OVERNIGHT. THREAT FOR THUNDERSTORMS WILL BE LESS TOMORROW AND
MAINLY CONFINED TO THE MOUNTAIN AREAS THOUGH THE AFTERNOON...THOUGH
A FEW MAY DRIFT INTO THE SOUTHEAST PLAINS DURING THE EVENING. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...PETERSEN
SHORT TERM...KT
LONG TERM...MW
AVIATION...KT/MW
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
853 PM MDT THU AUG 14 2014
.UPDATE...
ISSUED AT 848 PM MDT THU AUG 14 2014
INCREASED POPS OVER NORTHEAST CORNER TO KEEP THUNDERSTORMS LONGER
THROUGH EVENING. LOWERED TEMPERATURES AND ALSO INCREASED CLOUD
COVERAGE THROUGH THE PERIOD.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 323 PM MDT THU AUG 14 2014
WEATHER IS BEHAVING ABOUT AS EXPECTED THIS AFTERNOON. A FEW HEAVY
RAINERS HAVE DUMPED AROUND AN INCH IN SPOTS BUT NO MAJOR ISSUES
AS OF YET. THIS HEAVY RAIN THREAT WILL CONTINUE INTO THE EARLY
EVENING HOURS. MAIN LINE OF ACTIVITY IS JUST COMING OFF THE
FOOTHILLS AT 2030Z AND SHOULD SPREAD EAST ACROSS THE PLAINS OVER
THE NEXT SEVERAL HOURS. HRRR HAS ACTIVITY ENDING AROUND MIDNIGHT.
UPPER TROUGH IS OVER THE MOUNTAINS RIGHT NOW WITH QUASIGEOSTROPHIC
ASCENT HELPING THINGS OUT AHEAD OF IT AND TENDING TO SQUASH MOST
BUT NOT ALL CONVECTION OVER WESTERN COLORADO. THIS SUBSIDENCE WILL
BECOME MORE PREVALENT OVERNIGHT ACROSS THE AREA AND STRENGTHEN
TOMORROW. THIS SHOULD CLEAR TONIGHT /PER CIRA SYNTHETIC SATELLITE
IMAGERY/ AND WILL COUPLE WITH LESS MOISTURE AND LOW-LEVEL
DOWNSLOPE FLOW EAST OF THE MOUNTAINS TO LESSEN THE CONVECTIVE
ACTIVITY FRIDAY AFTERNOON. WITH LESS SHOWER/THUNDERSTORM/CLOUDS
MINIMUM TEMPERATURES SHOULD BE LOWER TONIGHT WITH MAXIMA TOMORROW
A FEW DEGREES WARMER.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 323 PM MDT THU AUG 14 2014
UPPER RIDGING WILL BUILD OVER COLORADO AND THE WESTERN U.S.
THROUGH THE WEEKEND...BRINGING AN EVENTUAL DECREASE IN AFTERNOON
AND EVENING THUNDERSTORM ACTIVITY. MOISTURE WILL LINGER OVER THE
REGION WHICH WILL BE AVAILABLE TO FUEL DIURNAL THUNDERSTORM
ACTIVITY EACH DAY...BUT RISING HEIGHTS MAY ALSO PRODUCE MID-LEVEL
INVERSIONS THAT CAP OFF CONVECTIVE DEVELOPMENT. FOR THE TIME BEING
WILL STICK WITH POPS IN THE 20-30 PERCENT RANGE...PRIMARILY OVER
THE MOUNTAINS AND FOOTHILLS. BY EARLY NEXT WEEK...BUILDING HIGH
PRESSURE OFF THE OREGON COAST WILL LEAVE COLORADO UNDER A WEAK
AND PERSISTENT NORTHWESTERLY FLOW ALOFT. THE GENERAL PATTERN
ACROSS THE COUNTRY WILL BE LOW AMPLITUDE AND PROGRESSIVE. THIS
SHOULD KEEP TEMPERATURES AROUND SEASONAL NORMALS AND PRECLUDE THE
ACCUMULATION OF EXCESSIVE MOISTURE OVER THE STATE. THE MIDDLE OF
NEXT WEEK MAY BE ENTIRELY DRY...BUT THE ABSENCE OF STRONGER
RIDGING IN THE MODEL SOLUTIONS WILL KEEP ME FROM PULLING AFTERNOON
THUNDERSTORMS OUT OF THE FORECAST.
&&
.AVIATION...(FOR THE TAFS THROUGH 06Z FRIDAY EVENING)
ISSUED AT 848 PM MDT THU AUG 14 2014
EXPECT CEILINGS TO REMAIN OVERNIGHT UNTIL TOMORROW AFTERNOON WITH
LINGERING STORMS. POSSIBLE WIND SHIFT TO THE NORTHWEST WITH STORM
CREATING OUTFLOW BOUNDARY BUT SHOULD RETURN SOUTHWESTERLY SHORTLY
AFTER BOUNDARY PASSAGE. SOME GUSTING COULD ACCOMPANY THIS BOUNDARY
PASSAGE AS WELL AND WILL NOTE IN AMENDED TAF IF REQUIRED.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BOWEN
SHORT TERM...ET
LONG TERM...DANKERS
AVIATION...BOWEN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
557 PM MDT THU AUG 14 2014
.UPDATE...
ISSUED AT 557 PM MDT THU AUG 14 2014
WITH HEAVY RAIN THREAT SHIFTING INTO NORTHEAST COLORADO THIS
EVENING...AND ONLY VERY ISOLATED STORMS ALONG THE CONTINENTAL
DIVIDE...WILL CANCEL FLASH FLOOD WATCH FOR ALL AREAS A LITTLE
EARLIER THAN SCHEDULED.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 310 PM MDT THU AUG 14 2014
...FLASH FLOOD POTENTIAL TO CONTINUE THROUGH THIS EVENING FOR THE
CONTINENTAL DIVIDE AND PIKES PEAK REGION...
SHORTWAVE CURRENTLY MOVING ACROSS NORTHERN CO HAS INITIATED
THUNDERSTORMS OVER THE PIKES PEAK REGION THIS AFTERNOON. HIGH
PRECIPITABLE WATERS RUNNING 150+% OF NORMAL IS ALLOWING FOR
EFFICIENT RAINFALL RATES AS EVIDENCED FROM RADAR KDP/S AND SPOTTER
REPORTS. THERE HAVE ALSO BEEN SOME PEA SIZE HAIL REPORTS WITH THE
STRONGER STORMS. AS THE SHORTWAVE CONTINUES TO DRAG ACROSS EASTERN
COLORADO...THUNDERSTORMS WILL CONTINUE TO SPREAD EASTWARD ACROSS THE
PLAINS. STORMS HAVE BEEN MOVING NORTHEAST AT 15 MPH...ENOUGH TO
ABATE SOME OF THE FLASH FLOOD RISK...BUT NOT ENTIRELY NEGATE IT AS
HEAVY RAINFALL RATES OF AROUND 2 INCHES PER HOUR CAN STILL CAUSE
PROBLEMS FOR THE BURN SCARS AND URBAN AREAS. THUS WILL KEEP THE
FLASH FLOOD WATCH GOING THROUGH 9 PM. BEEN A LITTLE HARDER TO GET
STRONGER CONVECTION GOING OUT WEST ALONG THE CONTINENTAL DIVIDE AND
SUSPECT THAT THREAT THERE IS RAPIDLY DIMINISHING AS STABILITY HAS
BEEN A FACTOR WITH THE CLOUD COVER AND EARLIER RAINFALL. WILL KEEP
THE WATCH GOING THROUGH THE PRIME HEATING HOURS...BUT SUSPECT THAT
WE MAY BE ABLE TO TAKE DOWN THE WATCH BY 6 PM FOR CHAFFEE/LAKE
COUNTIES AND THE EASTERN SAN JUANS AND LA GARITAS.
THUNDERSTORMS WILL SPREAD EASTWARD ACROSS THE PLAINS THROUGH THE
EVENING HOURS. LATEST HRRR SUGGESTS THAT THREAT FOR PIKES PEAK AREA
MAY BE ENDED BY 6-7 PM. HIGHEST POPS THROUGH THE EVENING HOURS WILL
BE ACROSS THE SOUTHEAST PLAINS AS THUNDERSTORMS DEVELOP ALONG
SOUTHWARD ADVANCING COLD FRONT. APPEARS BEST LIFT MAY BE ACROSS
NORTHWEST KANSAS AND EAST CENTRAL CO (KIOWA COUNTY) AS LOW LEVEL JET
IMPINGES ON THE FRONT...SO WILL KEEP HIGHEST POPS UP THAT WAY. MOST
OF THE ACTIVITY WILL BE DONE BY MIDNIGHT AS LINE OF THUNDERSTORMS
MOVES EAST INTO KANSAS.
A LITTLE LESS ACTIVE WEATHER IS EXPECTED TOMORROW. PRECIPITABLE
WATERS WILL DROP OFF BELOW 1 INCH FOR THE I-25 CORRIDOR AND
WESTWARD. STILL LOOKING AT SUFFICIENT MOISTURE FOR ISOLATED TO
SCATTERED THUNDERSTORMS...SO STILL CAN`T RULE OUT HEAVY RAIN ON BURN
SCARS AND POTENTIAL FOR FLASH FLOODING. BUT THREAT CERTAINLY LOOKS
LOWER DUE TO THE MORE ISOLATED NATURE OF THESE STRONGER CELLS.
GRIDS WILL CARRY MORE OF A DIURNAL POP TREND...WITH THUNDERSTORMS
FIRING OVER THE MOUNTAINS AROUND NOON...THEN DEVELOPING/SPREADING
EASTWARD ACROSS THE ADJACENT PLAINS DURING THE LATE AFTERNOON. -KT
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 310 PM MDT THU AUG 14 2014
FRIDAY NIGHT-THURSDAY...NOT MUCH CHANGE IN THE ONGOING FORECAST
THROUGH THE EXTENDED PERIOD WITH FLAT UPPER LEVEL RIDGING REMAINING
IN PLACE ACROSS THE GREAT BASIN THROUGH THE ROCKIES. THIS WILL KEEP
MONSOONAL MOISTURE PLUME SOUTH AND SOUTHWEST OF THE STATE WITH WEAK
WEST TO NORTHWEST FLOW ALOFT ACROSS THE STATE AND WEATHER SYSTEMS
MOVING ACROSS THE NORTHERN TIER OF STATES AND INTO THE UPPER
MIDWEST.
THERE LOOKS TO BE ENOUGH RESIDUAL MOISTURE IN PLACE TO WORK WITH
LATE SUMMER SOLAR HEATING TO KEEP ISOLATED TO SCATTERED AFTERNOON
AND EVENING STORMS IN THE FORECAST OVER AND NEAR THE HIGHER
TERRAIN...WITH A FEW STORMS POSSIBLY ROLLING ACROSS THE FAR SE
PLAINS THROUGH THE LATE EVENING AND OVERNIGHT HOURS. STORMS THAT DO
DEVELOP SHOULD BE GENERALLY HIGH BASED...THOUGH STILL CAN NOT RULE
OUT LOCALIZED HEAVY RAINFALL AND SMALL HAIL WITH STRONGER CELLS.
HARD TO PIN POINT BEST COVERAGE OF STORMS THOUGH COULD SEE INCREASED
COVERAGE SUNDAY THROUGH SUNDAY NIGHT AND AGAIN TUESDAY AND TUESDAY
NIGHT AS EMBEDDED DISTURBANCES MOVE ACROSS THE NORTHERN ROCKIES AND
INTO THE HIGH PLAINS. WITH RIDGING IN PLACE...TEMPERATURES ACROSS
THE AREA LOOK TO BE GENERALLY AT OR SLIGHTLY ABOVE LATE SUMMER
AVERAGES THROUGH THE PERIOD.
THERE COULD BE A CHANGE IN THE PATTERN INTO EARLY NEXT WEEKEND...AS
A BROAD UPPER TROUGH TRIES TO CARVE OUT ACROSS THE WEST COAST
OPENING THE DOOR TO INCREASING MOISTURE WITHIN DEVELOPING SOUTH TO
SOUTHWEST FLOW ALOFT ACROSS THE DESERT SOUTHWEST AND INTO THE
ROCKIES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 310 PM MDT THU AUG 14 2014
THUNDERSTORMS WILL CONTINUE THROUGH THROUGH THE EVENING HOURS FOR
THE MOUNTAINS AND I-25 CORRIDOR WITH THREAT FOR TSRA AT TERMINALS TO
CONTINUE UNTIL 00-01Z. CIGS COULD DROP INTO THE MVFR TO EVEN BRIEF
IFR CATEGORY UNDER THE STRONGER STORMS WITH HEAVY RAIN AND PEA SIZE
HAIL POSSIBLE. THUNDERSTORMS WILL END FROM WEST TO EAST AT THE
TERMINALS THROUGH THE EVENING WITH VFR CONDITIONS EXPECTED
OVERNIGHT. THREAT FOR THUNDERSTORMS WILL BE LESS TOMORROW AND
MAINLY CONFINED TO THE MOUNTAIN AREAS THOUGH THE AFTERNOON...THOUGH
A FEW MAY DRIFT INTO THE SOUTHEAST PLAINS DURING THE EVENING. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...PETERSEN
SHORT TERM...KT
LONG TERM...MW
AVIATION...KT/MW
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1034 AM MDT WED AUG 13 2014
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 334 AM MDT WED AUG 13 2014
EVERYTHING COMING TOGETHER AS EXPECTED WITH MONSOONAL MOISTURE
CONTINUING TO STREAM INTO THE AREA. OBSERVED PWATS IN GRAND
JUNCTION YESTERDAY EVENING REACHED 1.04 INCHES SO PLENTY OF
MOISTURE FOR ANY DISTURBANCES TO WORK WITH. EVEN AT THIS EARLY
HOUR...RADAR IS PICKING UP ON SOME LIGHT RETURNS WHICH NAM AND
HRRR ARE ALSO HIGHLIGHTING. HRRR ALSO SHOWING SOME CONVECTION
FIRING IN A FEW HOURS OVER DURANGO MUCH LIKE YESTERDAY MORNING SO
WILL BE INTERESTING TO SEE IF THIS PANS OUT.
ALL MODELS CONTINUE TO SHOW PLENTY OF PRECIP FOR OUR AREA TODAY
AS UPPER LEVEL SUPPORT IS MINIMAL AT BEST. ONE FLY IN THE OINTMENT
THOUGH IS A VERY WEAK JET STREAK THAT`S FORECAST TO MOVE OVER THE
UT/CO BORDER TODAY PRODUCING SOME FAIRLY NOTICEABLE DIVERGENCE
ALOFT. THE JET STREAK IS REALLY QUITE UNIMPRESSIVE...HOWEVER...A
SIMILAR JET STREAK MOVED OVERHEAD LAST WEEK BRINGING PLENTY OF
FLASH FLOODING AND STORMS TO THE REGION FOR THOSE THAT REMEMBER.
ON THE FLIP SIDE OF THAT...CLOUD COVER MAY INHIBIT STRONGER
CONVECTION TODAY DESPITE ANY UPPER LEVEL SUPPORT. LOOKING
UPSTREAM...SALT LAKE CITY HAD A GANGBUSTERS DAY YESTERDAY WITH
HEAVY RAIN AND STRONG WINDS BEING COMMON. GOING TO FOLLOW THAT LEAD
AND EXPECT THUNDERSTORMS AND SHOWERS TODAY WITH HEAVY
RAIN...STRONG WINDS EXCEEDING 45 MPH...AND HAIL. OBVIOUSLY...THE
FLASH FLOOD WATCH REMAINS IN PLACE. SPEAKING OF...EXTENDED THE WATCH
THROUGH EARLY FRIDAY MORNING AS BOTH THE GFS AND NAM CONTINUE TO
FORM A STRONG SHORTWAVE THAT WILL MOVE OVERHEAD WEDNESDAY NIGHT
INTO THURSDAY. SOME DIFFERENCES IN TIMING AND STRENGTH REMAIN BUT
THINK IT BETTER TO GET WORD OUT NOW.
PLUME OF HEAVY RAIN AND EMBEDDED THUNDERSTORMS ASSOCIATED WITH
THE ELONGATED H5 VORT MAX WILL CONTINUE TO TRACK EAST THROUGH
WESTERN COLORADO TONIGHT AND THURSDAY MORNING. 0-6 KM BULK SHEAR
OF 20-35 KTS IS STILL FORECAST SUGGESTING ORGANIZED MULTICELLS
WITH FLASH FLOODING STILL BEING THE MOST LIKELY IMPACT. STRONG
DOWNDRAFTS AND HAIL ALSO REMAIN POSSIBLE WITH THESE STORMS. THE WEAK
40KT JET ALOFT IS ALSO EXPECTED TO CONTINUE TO PROVIDE SUPPORT FOR
STORM TOP DIVERGENCE THROUGHOUT THE NIGHT. PRECIPITABLE WATER
VALUES WILL TOP OUT AROUND 1.25 INCHES TONIGHT BEFORE DRYING OUT
SLIGHTLY THURSDAY AFTERNOON BEHIND THE DISTURBANCE IN WESTERLY
FLOW. EXPECT A WET THURSDAY MORNING ACROSS MUCH OF WESTERN
COLORADO AS THE BULK OF THE MOISTURE CONTINUES TO TREK EAST. WEAK
RIDGING WILL MOVE INTO THE REGION BEHIND THE DISTURBANCE
PASSAGE...BUT CAPE VALUES THURSDAY AFTERNOON IN EASTERN UTAH
SUGGEST A BATCH OF CONVECTION INITIATING BEHIND THE MAIN AREA OF
RAIN AS SKIES CLEAR THROUGHOUT THE DAY. SEEMS PLAUSIBLE DUE TO
STEEP LAPSE RATES AND PLENTY OF MOISTURE STILL ACCESSIBLE FOR
QUICKLY DEVELOPING THUNDERSTORMS WITH THE BIGGEST THREAT STILL
BEING HEAVY RAIN.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 334 AM MDT WED AUG 13 2014
THURSDAY NIGHT SHOULD BE PRETTY QUIET AS HIGH PRESSURE RETURNS
OVER THE REGION. MOISTURE STUCK UNDER THE RIDGE WILL HELP TO
INITIATE OROGRAPHIC SHOWERS AND THUNDERSTORMS AGAIN ON FRIDAY
AFTERNOON BUT OF AN ISOLATED NATURE.
CONVECTION WILL DIE DOWN QUICKLY NEAR SUNSET FRIDAY EVENING AS
ZONAL FLOW SETS UP OVER THE AREA. HIGH PRESSURE ALSO GETS SET TO
REBUILD INTO THE DESERT SW. AS ANTICYCLONIC FLOW SETS UP OVER THE
CWA...NO MOISTURE IS EXPECTED TO INTRUDE INTO THE AREA ALLOWING
GARDEN VARIETY STORMS TO FIRE EACH AFTN/EVENING. THIS CONTINUES
THROUGH TUESDAY AS MOST AREAS WILL SEE SOME CU BUILD UP EACH AFTN
OVER HIGHER TERRAIN. VALLEYS SHOULD STAY DRY WITH NORMAL
TEMPERATURES EXPECTED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1034 AM MDT WED AUG 13 2014
SHOWERS AND THUNDERSTORMS WILL INCREASE THROUGH THIS AFTERNOON...
ESPECIALLY OVER THE SOUTH AND WEST. HEAVY RAIN...GUSTY OUTFLOW
WINDS EXCEEDING 40 MPH...AND HAIL WILL BE POSSIBLE. MVFR TO IFR
CIGS/VIS WILL OCCUR UNDER THE STRONGEST CELLS THAT FORM...AND MAY
AT TIMES IMPACT TAF SITES AND OTHER AREA AIRPORTS. THESE
CONDITIONS WILL CONTINUE FOR THE NEXT 24 HOURS THOUGH INTENSITY
SHOULD DECREASE SOMEWHAT AFTER 04Z.
&&
.HYDROLOGY...
ISSUED AT 334 AM MDT WED AUG 13 2014
FLASH FLOOD WATCH REMAINS IN EFFECT AND HAS BEEN EXTENDED THROUGH
06Z FRIDAY AS DEEP SUBTROPICAL MOISTURE ASSOCIATED WITH THE MONSOONAL
SURGE SLIDES OVER THE AREA. STORMS WILL HAVE SOME MOTION
TODAY BUT EVEN SO...DYNAMIC INPUT AND AMPLE MOISTURE WILL CAUSE
HEAVY RAIN FROM THUNDERSTORMS. RAINFALL OF 1 INCH OR MORE WILL BE
POSSIBLE. LOW LYING AREAS NEAR STEEP TERRAIN AND WILDFIRE BURN
SCARS...SLOT CANYONS AND SLICK ROCK AREAS...NORMALLY DRY
CREEKS...STREAMS AND ARROYOS HAVE THE HIGHEST THREAT OF FLASH
FLOODING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR COZ001>014-
017>019-022-023.
FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR COZ020-021.
UT...FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR UTZ023>025-027.
FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR UTZ022-028-029.
&&
$$
SHORT TERM...TGR/JAM
LONG TERM...JAM/TGR
AVIATION...EH
HYDROLOGY...TGJT
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
351 AM MDT WED AUG 13 2014
CORRECTED FOR FORMATTING ERRORS
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 334 AM MDT WED AUG 13 2014
EVERYTHING COMING TOGETHER AS EXPECTED WITH MONSOONAL MOISTURE
CONTINUING TO STREAM INTO THE AREA. OBSERVED PWATS IN GRAND
JUNCTION YESTERDAY EVENING REACHED 1.04 INCHES SO PLENTY OF
MOISTURE FOR ANY DISTURBANCES TO WORK WITH. EVEN AT THIS EARLY
HOUR...RADAR IS PICKING UP ON SOME LIGHT RETURNS WHICH NAM AND
HRRR ARE ALSO HIGHLIGHTING. HRRR ALSO SHOWING SOME CONVECTION
FIRING IN A FEW HOURS OVER DURANGO MUCH LIKE YESTERDAY MORNING SO
WILL BE INTERESTING TO SEE IF THIS PANS OUT.
ALL MODELS CONTINUE TO SHOW PLENTY OF PRECIP FOR OUR AREA TODAY
AS UPPER LEVEL SUPPORT IS MINIMAL AT BEST. ONE FLY IN THE OINTMENT
THOUGH IS A VERY WEAK JET STREAK THAT`S FORECAST TO MOVE OVER THE
UT/CO BORDER TODAY PRODUCING SOME FAIRLY NOTICEABLE DIVERGENCE
ALOFT. THE JET STREAK IS REALLY QUITE UNIMPRESSIVE...HOWEVER...A
SIMILAR JET STREAK MOVED OVERHEAD LAST WEEK BRINGING PLENTY OF
FLASH FLOODING AND STORMS TO THE REGION FOR THOSE THAT REMEMBER.
ON THE FLIP SIDE OF THAT...CLOUD COVER MAY INHIBIT STRONGER
CONVECTION TODAY DESPITE ANY UPPER LEVEL SUPPORT. LOOKING
UPSTREAM...SALT LAKE CITY HAD A GANGBUSTERS DAY YESTERDAY WITH
HEAVY RAIN AND STRONG WINDS BEING COMMON. GOING TO FOLLOW THAT LEAD
AND EXPECT THUNDERSTORMS AND SHOWERS TODAY WITH HEAVY
RAIN...STRONG WINDS EXCEEDING 45 MPH...AND HAIL. OBVIOUSLY...THE
FLASH FLOOD WATCH REMAINS IN PLACE. SPEAKING OF...EXTENDED THE WATCH
THROUGH EARLY FRIDAY MORNING AS BOTH THE GFS AND NAM CONTINUE TO
FORM A STRONG SHORTWAVE THAT WILL MOVE OVERHEAD WEDNESDAY NIGHT
INTO THURSDAY. SOME DIFFERENCES IN TIMING AND STRENGTH REMAIN BUT
THINK IT BETTER TO GET WORD OUT NOW.
PLUME OF HEAVY RAIN AND EMBEDDED THUNDERSTORMS ASSOCIATED WITH
THE ELONGATED H5 VORT MAX WILL CONTINUE TO TRACK EAST THROUGH
WESTERN COLORADO TONIGHT AND THURSDAY MORNING. 0-6 KM BULK SHEAR
OF 20-35 KTS IS STILL FORECAST SUGGESTING ORGANIZED MULTICELLS
WITH FLASH FLOODING STILL BEING THE MOST LIKELY IMPACT. STRONG
DOWNDRAFTS AND HAIL ALSO REMAIN POSSIBLE WITH THESE STORMS. THE WEAK
40KT JET ALOFT IS ALSO EXPECTED TO CONTINUE TO PROVIDE SUPPORT FOR
STORM TOP DIVERGENCE THROUGHOUT THE NIGHT. PRECIPITABLE WATER
VALUES WILL TOP OUT AROUND 1.25 INCHES TONIGHT BEFORE DRYING OUT
SLIGHTLY THURSDAY AFTERNOON BEHIND THE DISTURBANCE IN WESTERLY
FLOW. EXPECT A WET THURSDAY MORNING ACROSS MUCH OF WESTERN
COLORADO AS THE BULK OF THE MOISTURE CONTINUES TO TREK EAST. WEAK
RIDGING WILL MOVE INTO THE REGION BEHIND THE DISTURBANCE
PASSAGE...BUT CAPE VALUES THURSDAY AFTERNOON IN EASTERN UTAH
SUGGEST A BATCH OF CONVECTION INITIATING BEHIND THE MAIN AREA OF
RAIN AS SKIES CLEAR THROUGHOUT THE DAY. SEEMS PLAUSIBLE DUE TO
STEEP LAPSE RATES AND PLENTY OF MOISTURE STILL ACCESSIBLE FOR
QUICKLY DEVELOPING THUNDERSTORMS WITH THE BIGGEST THREAT STILL
BEING HEAVY RAIN.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 334 AM MDT WED AUG 13 2014
THURSDAY NIGHT SHOULD BE PRETTY QUIET AS HIGH PRESSURE RETURNS
OVER THE REGION. MOISTURE STUCK UNDER THE RIDGE WILL HELP TO
INITIATE OROGRAPHIC SHOWERS AND THUNDERSTORMS AGAIN ON FRIDAY
AFTERNOON BUT OF AN ISOLATED NATURE.
CONVECTION WILL DIE DOWN QUICKLY NEAR SUNSET FRIDAY EVENING AS
ZONAL FLOW SETS UP OVER THE AREA. HIGH PRESSURE ALSO GETS SET TO
REBUILD INTO THE DESERT SW. AS ANTICYCLONIC FLOW SETS UP OVER THE
CWA...NO MOISTURE IS EXPECTED TO INTRUDE INTO THE AREA ALLOWING
GARDEN VARIETY STORMS TO FIRE EACH AFTN/EVENING. THIS CONTINUES
THROUGH TUESDAY AS MOST AREAS WILL SEE SOME CU BUILD UP EACH AFTN
OVER HIGHER TERRAIN. VALLEYS SHOULD STAY DRY WITH NORMAL
TEMPERATURES EXPECTED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 334 AM MDT WED AUG 13 2014
THUNDERSTORMS AND RAINSHOWERS WILL INCREASE TODAY FROM THE SOUTH
AND WEST. HEAVY RAIN...GUSTY OUTFLOW WINDS EXCEEDING 40 MPH AT
TIMES...AND HAIL ARE POSSIBLE THIS AFTERNOON. MVFR TO IFR CIGS/VIS
WILL OCCUR UNDER THE STRONGEST CELLS THAT FORM. ALL AERODROMES
UNDER THE GUN TODAY AND THIS IS REFLECTED IN TAFS WITH MEDIUM TO
HIGH CONFIDENCE FOR SHOWERS AND STORMS. THESE CONDITIONS WILL
CONTINUE FOR THE NEXT 24 HOURS THOUGH INTENSITY SHOULD DECREASE
SOMEWHAT AFTER 03Z.
&&
.HYDROLOGY...
ISSUED AT 334 AM MDT WED AUG 13 2014
FLASH FLOOD WATCH REMAINS IN EFFECT AND HAS BEEN EXTENDED THROUGH
06Z FRIDAY AS DEEP SUBTROPICAL MOISTURE ASSOCIATED WITH THE MONSOONAL
SURGE SLIDES OVER THE AREA. STORMS WILL HAVE SOME MOTION
TODAY BUT EVEN SO...DYNAMIC INPUT AND AMPLE MOISTURE WILL CAUSE
HEAVY RAIN FROM THUNDERSTORMS. RAINFALL OF 1 INCH OR MORE WILL BE
POSSIBLE. LOW LYING AREAS NEAR STEEP TERRAIN AND WILDFIRE BURN
SCARS...SLOT CANYONS AND SLICK ROCK AREAS...NORMALLY DRY
CREEKS...STREAMS AND ARROYOS HAVE THE HIGHEST THREAT OF FLASH
FLOODING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...FLASH FLOOD WATCH FROM NOON MDT TODAY THROUGH THURSDAY EVENING
FOR COZ001>014-017>019-022-023.
FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR COZ020-021.
UT...FLASH FLOOD WATCH FROM NOON MDT TODAY THROUGH THURSDAY EVENING
FOR UTZ023>025-027.
FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR UTZ022-028-029.
&&
$$
SHORT TERM...TGR/JAM
LONG TERM...JAM/TGR
AVIATION...TGR
HYDROLOGY...TGJT
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
349 AM MDT WED AUG 13 2014
CORRECTED FOR FORMATTING ERROR
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 334 AM MDT WED AUG 13 2014
EVERYTHING COMING TOGETHER AS EXPECTED WITH MONSOONAL MOISTURE
CONTINUING TO STREAM INTO THE AREA. OBSERVED PWATS IN GRAND
JUNCTION YESTERDAY EVENING REACHED 1.04 INCHES SO PLENTY OF
MOISTURE FOR ANY DISTURBANCES TO WORK WITH. EVEN AT THIS EARLY
HOUR...RADAR IS PICKING UP ON SOME LIGHT RETURNS WHICH NAM AND
HRRR ARE ALSO HIGHLIGHTING. HRRR ALSO SHOWING SOME CONVECTION
FIRING IN A FEW HOURS OVER DURANGO MUCH LIKE YESTERDAY MORNING SO
WILL BE INTERESTING TO SEE IF THIS PANS OUT.
ALL MODELS CONTINUE TO SHOW PLENTY OF PRECIP FOR OUR AREA TODAY
AS UPPER LEVEL SUPPORT IS MINIMAL AT BEST. ONE FLY IN THE OINTMENT
THOUGH IS A VERY WEAK JET STREAK THAT`S FORECAST TO MOVE OVER THE
UT/CO BORDER TODAY PRODUCING SOME FAIRLY NOTICEABLE DIVERGENCE
ALOFT. THE JET STREAK IS REALLY QUITE UNIMPRESSIVE...HOWEVER...A
SIMILAR JET STREAK MOVED OVERHEAD LAST WEEK BRINGING PLENTY OF
FLASH FLOODING AND STORMS TO THE REGION FOR THOSE THAT REMEMBER.
ON THE FLIP SIDE OF THAT...CLOUD COVER MAY INHIBIT STRONGER
CONVECTION TODAY DESPITE ANY UPPER LEVEL SUPPORT. LOOKING
UPSTREAM...SALT LAKE CITY HAD A GANGBUSTERS DAY YESTERDAY WITH
HEAVY RAIN AND STRONG WINDS BEING COMMON. GOING TO FOLLOW THAT LEAD
AND EXPECT THUNDERSTORMS AND SHOWERS TODAY WITH HEAVY
RAIN...STRONG WINDS EXCEEDING 45 MPH...AND HAIL. OBVIOUSLY...THE
FLASH FLOOD WATCH REMAINS IN PLACE. SPEAKING OF...EXTENDED THE WATCH
THROUGH EARLY FRIDAY MORNING AS BOTH THE GFS AND NAM CONTINUE TO
FORM A STRONG SHORTWAVE THAT WILL MOVE OVERHEAD WEDNESDAY NIGHT
INTO THURSDAY. SOME DIFFERENCES IN TIMING AND STRENGTH REMAIN BUT
THINK IT BETTER TO GET WORD OUT NOW.
PLUME OF HEAVY RAIN AND EMBEDDED THUNDERSTORMS ASSOCIATED WITH
THE ELONGATED H5 VORT MAX WILL CONTINUE TO TRACK EAST THROUGH
WESTERN COLORADO TONIGHT AND THURSDAY MORNING. 0-6 KM BULK SHEAR
OF 20-35 KTS IS STILL FORECAST SUGGESTING ORGANIZED MULTICELLS
WITH FLASH FLOODING STILL BEING THE MOST LIKELY IMPACT. STRONG
DOWNDRAFTS AND HAIL ALSO REMAIN POSSIBLE WITH THESE STORMS. THE WEAK
40KT JET ALOFT IS ALSO EXPECTED TO CONTINUE TO PROVIDE SUPPORT FOR
STORM TOP DIVERGENCE THROUGHOUT THE NIGHT. PRECIPITABLE WATER
VALUES WILL TOP OUT AROUND 1.25 INCHES TONIGHT BEFORE DRYING OUT
SLIGHTLY THURSDAY AFTERNOON BEHIND THE DISTURBANCE IN WESTERLY
FLOW. EXPECT A WET THURSDAY MORNING ACROSS MUCH OF WESTERN
COLORADO AS THE BULK OF THE MOISTURE CONTINUES TO TREK EAST. WEAK
RIDGING WILL MOVE INTO THE REGION BEHIND THE DISTURBANCE
PASSAGE...BUT CAPE VALUES THURSDAY AFTERNOON IN EASTERN UTAH
SUGGEST A BATCH OF CONVECTION INITIATING BEHIND THE MAIN AREA OF
RAIN AS SKIES CLEAR THROUGHOUT THE DAY. SEEMS PLAUSIBLE DUE TO
STEEP LAPSE RATES AND PLENTY OF MOISTURE STILL ACCESSIBLE FOR
QUICKLY DEVELOPING THUNDERSTORMS WITH THE BIGGEST THREAT STILL
BEING HEAVY RAIN.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 334 AM MDT WED AUG 13 2014
THURSDAY NIGHT SHOULD BE PRETTY QUIET AS HIGH PRESSURE RETURNS
OVER THE REGION. MOISTURE STUCK UNDER THE RIDGE WILL HELP TO
INITIATE OROGRAPHIC SHOWERS AND THUNDERSTORMS AGAIN ON FRIDAY
AFTERNOON BUT OF AN ISOLATED NATURE.
CONVECTION WILL DIE DOWN QUICKLY NEAR SUNSET FRIDAY EVENING AS
ZONAL FLOW SETS UP OVER THE AREA. HIGH PRESSURE ALSO GETS SET TO
REBUILD INTO THE DESERT SW. AS ANTICYCLONIC FLOW SETS UP OVER THE
CWA...NO MOISTURE IS EXPECTED TO INTRUDE INTO THE AREA ALLOWING
GARDEN VARIETY STORMS TO FIRE EACH AFTN/EVENING. THIS CONTINUES
THROUGH TUESDAY AS MOST AREAS WILL SEE SOME CU BUILD UP EACH AFTN
OVER HIGHER TERRAIN. VALLEYS SHOULD STAY DRY WITH NORMAL
TEMPERATURES EXPECTED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 334 AM MDT WED AUG 13 2014
THUNDERSTORMS AND RAINSHOWERS WILL INCREASE TODAY FROM THE SOUTH
AND WEST. HEAVY RAIN...GUSTY OUTFLOW WINDS EXCEEDING 40 MPH AT
TIMES...AND HAIL ARE POSSIBLE THIS AFTERNOON. MVFR TO IFR CIGS/VIS
WILL OCCUR UNDER THE STRONGEST CELLS THAT FORM. ALL AERODROMES
UNDER THE GUN TODAY AND THIS IS REFLECTED IN TAFS WITH MEDIUM TO
HIGH CONFIDENCE FOR SHOWERS AND STORMS. THESE CONDITIONS WILL
CONTINUE FOR THE NEXT 24 HOURS THOUGH INTENSITY SHOULD DECREASE
SOMEWHAT AFTER 03Z.
&&
.HYDROLOGY...
ISSUED AT 334 AM MDT WED AUG 13 2014
FLASH FLOOD WATCH REMAINS IN EFFECT AND HAS BEEN EXTENDED THROUGH
06Z FRIDAY AS DEEP SUBTROPICAL MOISTURE ASSOCIATED WITH THE MONSOONAL
SURGE SLIDES OVER THE AREA. STORMS WILL HAVE SOME MOTION
TODAY BUT EVEN SO...DYNAMIC INPUT AND AMPLE MOISTURE WILL CAUSE
HEAVY RAIN FROM THUNDERSTORMS. RAINFALL OF 1 INCH OR MORE WILL BE
POSSIBLE. LOW LYING AREAS NEAR STEEP TERRAIN AND WILDFIRE BURN
SCARS...SLOT CANYONS AND SLICK ROCK AREAS...NORMALLY DRY
CREEKS...STREAMS AND ARROYOS HAVE THE HIGHEST THREAT OF FLASH
FLOODING.
&&
.HYDROLOGY...
ISSUED AT 334 AM MDT WED AUG 13 2014
FLASH FLOOD WATCH REMAINS IN EFFECT AND HAS BEEN EXTENDED THROUGH
06Z FRIDAY AS DEEP SUBTROPICAL MOISTURE ASSOCIATED WITH THE MONSOONAL
SURGE SLIDES OVER THE AREA. STORMS WILL HAVE SOME MOTION
TODAY BUT EVEN SO...DYNAMIC INPUT AND AMPLE MOISTURE WILL CAUSE
HEAVY RAIN FROM THUNDERSTORMS. RAINFALL OF 1 INCH OR MORE WILL BE
POSSIBLE. LOW LYING AREAS NEAR STEEP TERRAIN AND WILDFIRE BURN
SCARS...SLOT CANYONS AND SLICK ROCK AREAS...NORMALLY DRY
CREEKS...STREAMS AND ARROYOS HAVE THE HIGHEST THREAT OF FLASH
FLOODING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...FLASH FLOOD WATCH FROM NOON MDT TODAY THROUGH THURSDAY EVENING
FOR COZ001>014-017>019-022-023.
FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR COZ020-021.
UT...FLASH FLOOD WATCH FROM NOON MDT TODAY THROUGH THURSDAY EVENING
FOR UTZ023>025-027.
FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR UTZ022-028-029.
&&
$$
SHORT TERM...TGR/JAM
LONG TERM...JAM/TGR
AVIATION...TGR
HYDROLOGY...TGJT
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
334 AM MDT WED AUG 13 2014
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 334 AM MDT WED AUG 13 2014
EVERYTHING COMING TOGETHER AS EXPECTED WITH MONSOONAL MOISTURE
CONTINUING TO STREAM INTO THE AREA. OBSERVED PWATS IN GRAND
JUNCTION YESTERDAY EVENING REACHED 1.04 INCHES SO PLENTY OF
MOISTURE FOR ANY DISTURBANCES TO WORK WITH. EVEN AT THIS EARLY
HOUR...RADAR IS PICKING UP ON SOME LIGHT RETURNS WHICH NAM AND
HRRR ARE ALSO HIGHLIGHTING. HRRR ALSO SHOWING SOME CONVECTION
FIRING IN A FEW HOURS OVER DURANGO MUCH LIKE YESTERDAY MORNING SO
WILL BE INTERESTING TO SEE IF THIS PANS OUT.
ALL MODELS CONTINUE TO SHOW PLENTY OF PRECIP FOR OUR AREA TODAY
AS UPPER LEVEL SUPPORT IS MINIMAL AT BEST. ONE FLY IN THE OINTMENT
THOUGH IS A VERY WEAK JET STREAK THAT`S FORECAST TO MOVE OVER THE
UT/CO BORDER TODAY PRODUCING SOME FAIRLY NOTICEABLE DIVERGENCE
ALOFT. THE JET STREAK IS REALLY QUITE UNIMPRESSIVE...HOWEVER...A
SIMILAR JET STREAK MOVED OVERHEAD LAST WEEK BRINGING PLENTY OF
FLASH FLOODING AND STORMS TO THE REGION FOR THOSE THAT REMEMBER.
ON THE FLIP SIDE OF THAT...CLOUD COVER MAY INHIBIT STRONGER
CONVECTION TODAY DESPITE ANY UPPER LEVEL SUPPORT. LOOKING
UPSTREAM...SALT LAKE CITY HAD A GANGBUSTERS DAY YESTERDAY WITH
HEAVY RAIN AND STRONG WINDS BEING COMMON. GOING TO FOLLOW THAT LEAD
AND EXPECT THUNDERSTORMS AND SHOWERS TODAY WITH HEAVY
RAIN...STRONG WINDS EXCEEDING 45 MPH...AND HAIL. OBVIOUSLY...THE
FLASH FLOOD WATCH REMAINS IN PLACE. SPEAKING OF...EXTENDED THE WATCH
THROUGH EARLY FRIDAY MORNING AS BOTH THE GFS AND NAM CONTINUE TO
FORM A STRONG SHORTWAVE THAT WILL MOVE OVERHEAD WEDNESDAY NIGHT
INTO THURSDAY. SOME DIFFERENCES IN TIMING AND STRENGTH REMAIN BUT
THINK IT BETTER TO GET WORD OUT NOW.
PLUME OF HEAVY RAIN AND EMBEDDED THUNDERSTORMS ASSOCIATED WITH
THE ELONGATED H5 VORT MAX WILL CONTINUE TO TRACK EAST THROUGH
WESTERN COLORADO TONIGHT AND THURSDAY MORNING. 0-6 KM BULK SHEAR
OF 20-35 KTS IS STILL FORECAST SUGGESTING ORGANIZED MULTICELLS
WITH FLASH FLOODING STILL BEING THE MOST LIKELY IMPACT. STRONG
DOWNDRAFTS AND HAIL ALSO REMAIN POSSIBLE WITH THESE STORMS. THE WEAK
40KT JET ALOFT IS ALSO EXPECTED TO CONTINUE TO PROVIDE SUPPORT FOR
STORM TOP DIVERGENCE THROUGHOUT THE NIGHT. PRECIPITABLE WATER
VALUES WILL TOP OUT AROUND 1.25 INCHES TONIGHT BEFORE DRYING OUT
SLIGHTLY THURSDAY AFTERNOON BEHIND THE DISTURBANCE IN WESTERLY
FLOW. EXPECT A WET THURSDAY MORNING ACROSS MUCH OF WESTERN
COLORADO AS THE BULK OF THE MOISTURE CONTINUES TO TREK EAST. WEAK
RIDGING WILL MOVE INTO THE REGION BEHIND THE DISTURBANCE
PASSAGE...BUT CAPE VALUES THURSDAY AFTERNOON IN EASTERN UTAH
SUGGEST A BATCH OF CONVECTION INITIATING BEHIND THE MAIN AREA OF
RAIN AS SKIES CLEAR THROUGHOUT THE DAY. SEEMS PLAUSIBLE DUE TO
STEEP LAPSE RATES AND PLENTY OF MOISTURE STILL ACCESSIBLE FOR
QUICKLY DEVELOPING THUNDERSTORMS WITH THE BIGGEST THREAT STILL
BEING HEAVY RAIN.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 334 AM MDT WED AUG 13 2014
THURSDAY NIGHT SHOULD BE PRETTY QUIET AS HIGH PRESSURE RETURNS
OVER THE REGION. MOISTURE STUCK UNDER THE RIDGE WILL HELP TO
INITIATE OROGRAPHIC SHOWERS AND THUNDERSTORMS AGAIN ON FRIDAY
AFTERNOON BUT OF AN ISOLATED NATURE.
CONVECTION WILL DIE DOWN QUICKLY NEAR SUNSET FRIDAY EVENING AS
ZONAL FLOW SETS UP OVER THE AREA. HIGH PRESSURE ALSO GETS SET TO
REBUILD INTO THE DESERT SW. AS ANTICYCLONIC FLOW SETS UP OVER THE
CWA...NO MOISTURE IS EXPECTED TO INTRUDE INTO THE AREA ALLOWING
GARDEN VARIETY STORMS TO FIRE EACH AFTN/EVENING. THIS CONTINUES
THROUGH TUESDAY AS MOST AREAS WILL SEE SOME CU BUILD UP EACH AFTN
OVER HIGHER TERRAIN. VALLEYS SHOULD STAY DRY WITH NORMAL
TEMPERATURES EXPECTED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 334 AM MDT WED AUG 13 2014
THUNDERSTORMS AND RAINSHOWERS WILL INCREASE TODAY FROM THE SOUTH
AND WEST. HEAVY RAIN...GUSTY OUTFLOW WINDS EXCEEDING 40 MPH AT
TIMES...AND HAIL ARE POSSIBLE THIS AFTERNOON. MVFR TO IFR CIGS/VIS
WILL OCCUR UNDER THE STRONGEST CELLS THAT FORM. ALL AERODROMES
UNDER THE GUN TODAY AND THIS IS REFLECTED IN TAFS WITH MEDIUM TO
HIGH CONFIDENCE FOR SHOWERS AND STORMS. THESE CONDITIONS WILL
CONTINUE FOR THE NEXT 24 HOURS THOUGH INTENSITY SHOULD DECREASE
SOMEWHAT AFTER 03Z.
.HYDROLOGY...
ISSUED AT 334 AM MDT WED AUG 13 2014
FLASH FLOOD WATCH REMAINS IN EFFECT AND HAS BEEN EXTENDED THROUGH
06Z FRIDAY AS DEEP SUBTROPICAL MOISTURE ASSOCIATED WITH THE MONSOONAL
SURGE SLIDES OVER THE AREA. STORMS WILL HAVE SOME MOTION
TODAY BUT EVEN SO...DYNAMIC INPUT AND AMPLE MOISTURE WILL CAUSE
HEAVY RAIN FROM THUNDERSTORMS. RAINFALL OF 1 INCH OR MORE WILL BE
POSSIBLE. LOW LYING AREAS NEAR STEEP TERRAIN AND WILDFIRE BURN
SCARS...SLOT CANYONS AND SLICK ROCK AREAS...NORMALLY DRY
CREEKS...STREAMS AND ARROYOS HAVE THE HIGHEST THREAT OF FLASH
FLOODING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...FLASH FLOOD WATCH FROM NOON MDT TODAY THROUGH THURSDAY EVENING
FOR COZ001>014-017>019-022-023.
FLASH FLOOD WATCH FROM 6 AM MDT THIS MORNING THROUGH THURSDAY
EVENING FOR COZ020-021.
UT...FLASH FLOOD WATCH FROM NOON MDT TODAY THROUGH THURSDAY EVENING
FOR UTZ023>025-027.
FLASH FLOOD WATCH FROM 6 AM MDT THIS MORNING THROUGH THURSDAY
EVENING FOR UTZ022-028-029.
&&
$$
SHORT TERM...TGR/JAM
LONG TERM...JAM/TGR
AVIATION...TGR
HYDROLOGY...TGJT
AREA FORECAST DISCUSSION
NWS ALBANY NY
149 PM EDT WED AUG 13 2014
.SYNOPSIS...
AS AN OCCLUDED FRONT CROSSES THE AREA THIS AFTERNOON...THERE WILL BE
SOME LINGERING RAIN SHOWERS. MOST OF THE SHOWERS WILL TAPER OFF BY
THIS EVENING...ALTHOUGH AN UPPER LEVEL LOW WILL REMAIN ACROSS
SOUTHEAST CANADA...KEEPING SOMEWHAT COOL AND UNSETTLED CONDITIONS
THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 149 PM EDT...AN OCCLUDED FRONT IS CURRENTLY WORKING ACROSS
THE REGION...WITH A TRIPLE POINT LOW JUST SOUTHEAST OF THE REGION
OVER CONNECTICUT.
THE MAJORITY OF THE STEADY MODERATE-HEAVY RAIN IS NOW EAST OF OUR
AREA ACROSS CENTRAL NEW ENGLAND. SOME LINGERING RAIN SHOWERS
REMAIN OVER OUR AREA DUE TO OCCLUDED FRONT AND UPPER TROUGH AXIS...BUT
MOST OF THESE ARE RATHER LIGHT...WITH A FEW MODERATE BURSTS.
BECAUSE THE HEAVIEST RAINFALL SHOULD BE EAST OF OUR AREA...AND IR
SATELLITE IMAGERY SHOWS THE COLDEST/TALLEST CLOUD TOPS NOW
NORTH/EAST OF OUR AREA...WE HAVE CANCELLED THE FLASH FLOOD WATCH
FOR OUR ENTIRE AREA. WHILE RAIN SHOWERS WILL CONTINUE...RAIN RATES
WILL BE LOW ENOUGH TO PREVENT ANY FLASH FLOODING FROM OCCURRING.
THE LATEST 15Z 3KM HRRR SEEMS TO SHOW THIS IDEA AS WELL...HAVING
THE STRONGEST MODEL PREDICTED RADAR ECHOS EAST OF OUR AREA...AND
JUST LIGHT CELLULAR SHOWERS OVER OUR AREA THROUGH THE AFTN. WILL
INCLUDE A SLIGHT CHC FOR THUNDER IN CASE THERE IS A RUMBLE OR TWO
AROUND...BUT LIMITED INSTABILITY WILL PREVENT ANY STRONG/SEVERE
STORMS FROM OCCURRING.
STILL EXPECT MAX TEMPS TO REACH THE LOWER/MID 70S BY LATE
AFTERNOON IN MOST VALLEY AREAS...WITH POSSIBLY SOME UPPER 70S
ACROSS THE MID HUDSON VALLEY. MAX TEMPS SHOULD HOLD IN THE
LOWER/MID 60S ACROSS MUCH OF THE SOUTHERN ADIRONDACKS...AND SOME
HIGHER ELEVATIONS ACROSS WESTERN NEW ENGLAND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT-THU NT...AS THE MAIN OCCLUDED FRONT MOVES PAST...THE THREAT
FOR SHOWERS WILL GRADUALLY DIMINISH THIS EVENING FROM SW TO NE.
HOWEVER...THE COMBINATION OF COOL AIR ALOFT...CYCLONIC FLOW...AND
WEAK PIECES OF ENERGY POTENTIALLY ROTATING AROUND THE SOUTHERN
PERIPHERY OF THE CLOSED LOW NORTH OF THE GREAT LAKES SHOULD PROMOTE
THE CHANCES FOR SHOWERS ACROSS THE SOUTHERN ADIRONDACKS...AND
OCCASIONALLY INTO THE MOHAWK VALLEY AND LAKE GEORGE/SARATOGA REGIONS
AND SOUTHERN VT...WITH MORE LIMITED ACTIVITY EXPECTED FURTHER SOUTH
AND EAST WHERE MORE LOW LEVEL DOWNSLOPING AND SLIGHTLY WARMER TEMPS
ALOFT WILL REMAIN. SO...WILL KEEP CHC POPS FOR NORTHERN AREAS...WITH
SLIGHT CHC POPS OR LESS FURTHER SOUTH. TEMPS WILL FALL INTO THE
UPPER 40S TO MID 50S TONIGHT. THU MAX TEMPS SHOULD REACH 70-75 IN
MOST VALLEYS...BUT ONLY REACH THE 60S ACROSS MOST HIGHER ELEVATION
AREAS. LOWS THURSDAY NIGHT WILL BE IN THE MID 40S TO MID 50S.
ON FRIDAY THE COLD POOL WILL PERSIST WITH A GOOD CHANCE FOR SHOWERS
OVER THE ADIRONDACKS...WITH SLIGHT CHANCE OR LESS ELSEWHERE. HIGHS
WILL BE IN THE 60S OVER THE HIGHER ELEVATIONS...AND 70 TO 75 IN THE
VALLEYS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
THE PERIOD STARTS OUT FRIDAY NIGHT WITH AN UPPER LEVEL CLOSED LOW
LIFTING NORTHWARD THROUGH QUEBEC...AS CYCLONIC FLOW REGIME BECOMES
MORE NEUTRAL ACROSS OUR REGION. STILL RELATIVELY FAST FLOW ALOFT
INTO SATURDAY...WITH A POSSIBLE DISTURBANCE QUICKLY APPROACHING FROM
THE GREAT LAKES. MOST OF THE DAY LOOKS DRY WITH INCREASING AFTERNOON
CLOUDS. WILL INCREASE POPS ACROSS THE REGION SATURDAY NIGHT INTO
SUNDAY...AS A SHORT WAVE TROUGH MOVES THROUGH. WILL ONLY MENTION
SLIGHT CHANCE OF THUNDER ON SUNDAY...AS FORECAST INSTABILITY LOOKS
RATHER LIMITED. TEMPERATURES CONTINUE BELOW NORMAL THROUGH THE
WEEKEND.
A NORTHWEST FLOW REGIME LOOKS TO SET UP IN WAKE OF SUNDAY/S TROUGH
PASSAGE...WITH A RIDGE BUILDING UPSTREAM OVER THE GREAT LAKES. THIS
PATTERN SHOULD KEEP OUR REGION DRY MONDAY AND TUESDAY. TEMPERATURES
SHOULD MODERATE BACK TO NORMAL WITH INCREASING SUNSHINE. ANOTHER
UPPER LEVEL LOW ADVANCING EASTWARD ACROSS THE MIDWEST AND OHIO
VALLEY BRINGS THE NEXT CHANCE OF SHOWERS AND THUNDERSTORMS FOR THE
MID WEEK PERIOD.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
GENERALLY MVFR TO IFR CONDITIONS...ESP FOR CIGS...WILL PREVAIL
THROUGH AROUND 20Z-22Z/WED. THEREAFTER...CONDITIONS SHOULD GRADUALLY
IMPROVE TO VFR.
AREAS OF SHOWERS/DRIZZLE WILL MIGRATE ACROSS THE TAF SITES AT TIMES
THROUGH LATE AFTERNOON...AS A LOW PRESSURE SYSTEM TRACKS EAST OF THE
REGION ACROSS NEW ENGLAND.
WINDS WILL BECOME NORTH TO NORTHEAST EARLY THIS AFTERNOON AT 5-10
KT...WITH SOME GUSTS OF 15-20 KT POSSIBLE AT KPSF. WINDS WILL THEN
BACK INTO THE WEST/NORTHWEST AT 5-10 KT LATER THIS AFTERNOON INTO
TONIGHT...THEN MAY BACK SLIGHTLY INTO THE WEST BY MID MORNING ON THU
AT 8-12 KT...WITH SOME GUSTS OF 15-20 POSSIBLE TOWARD OR AFTER
18Z/THU.
OUTLOOK...
THURSDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
FRIDAY TO SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
SUNDAY NIGHT TO MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
WET FLAG CONDITIONS ACROSS THE REGION THROUGH TODAY...
THE COMBINATION OF A LOW PRESSURE SYSTEM LOCATED NORTH OF THE GREAT
LAKES...AND A SECONDARY LOW DEVELOPING ALONG THE NEW JERSEY
COAST...WILL BRING A WIDESPREAD SOAKING RAINFALL TO THE REGION
THROUGH EARLY AFTERNOON. RAIN WILL TAPER TO SHOWERS AND SCATTERED
THUNDERSTORMS DURING THIS AFTERNOON. THE LOW WILL MOVE INTO NORTHERN
NEW ENGLAND BY THIS EVENING...BUT AN UPPER LEVEL LOW WILL LINGER
ACROSS SOUTHEAST CANADA...KEEPING SOMEWHAT COOL AND UNSETTLED
CONDITIONS THROUGH THE END OF THE WEEK.
RAIN...HEAVY AT TIMES...WILL FALL ACROSS THE REGION THROUGH AROUND
MIDDAY AS A BAND OF RAIN ASSOCIATED WITH A FRONTAL BOUNDARY CROSSES
THE REGION FROM WEST TO EAST. TOTAL RAINFALL AMOUNTS ASSOCIATED WITH
THIS BAND OF RAIN MAY REACH ONE TO TWO INCHES.
&&
.HYDROLOGY...
RAIN...HEAVY AT TIMES...WILL FALL ACROSS THE REGION THROUGH AROUND
MIDDAY AS A BAND OF RAIN ASSOCIATED WITH A FRONTAL BOUNDARY CROSSES
THE REGION FROM WEST TO EAST. TOTAL RAINFALL AMOUNTS ASSOCIATED WITH
THIS BAND OF RAIN MAY REACH ONE TO TWO INCHES AND CAUSE LOCALIZED
URBAN AND SMALL STREAM FLOODING. HOWEVER...AN AREA OF TORRENTIAL
RAIN WITH RAINFALL RATES OF ONE TO TWO INCHES PER HOUR THAT WAS OVER
LONG ISLAND AS OF 400 AM...WILL LIKELY PASS TO THE SOUTH AND EAST OF
THE FLASH FLOOD WATCH AREA THIS MORNING. AS A RESULT...THE THREAT OF
FLASH FLOODING WILL BE REDUCED IF THIS AREA OF TORRENTIAL RAIN
REMAINS TO THE SOUTH AND EAST OF THE FORECAST AREA. WAS NOT
CONFIDENT ENOUGH EARLY THIS MORNING TO DROP ANY PORTION OF THE FLASH
FLOOD WATCH AREA...BUT IF THE CURRENT RADAR TRENDS CONTINUE...THEN
PORTIONS OR ALL OF THE FLASH FLOOD WATCH MAY NEED TO BE CANCELLED
EARLY. THE ONLY OTHER FLOODING THREAT THAT WILL NEED TO BE MONITORED
IS THE POTENTIAL FOR ADDITIONAL CONVECTION WITH HIGH RAINFALL RATES
TO FORM THIS AFTERNOON ALONG AND BEHIND THE FRONTAL BOUNDARY.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS/GJM
NEAR TERM...FRUGIS/KL/GJM
SHORT TERM...GJM
LONG TERM...JPV
AVIATION...KL
FIRE WEATHER...GJM
HYDROLOGY...GJM
AREA FORECAST DISCUSSION
NWS TAUNTON MA
310 AM EDT WED AUG 13 2014
.SYNOPSIS...
A STRONG LOW PRESSURE SYSTEM WILL BRING HEAVY RAIN ON WEDNESDAY.
AREAS OF URBAN AND LOCALIZED FLASH FLOODING ARE THE MAIN THREATS
WITH A LOW PROBABILITY FOR ISOLATED SEVERE WEATHER. ISOLATED SHOWERS
MAY DEVELOP ACROSS INLAND AREAS DURING THE DAYLIGHT HOURS LATE
THIS WEEK. EXPECT GENERALLY DRY CONDITIONS INTO EARLY THIS
WEEKEND...THEN ANOTHER SHOT FOR SHOWERS MOVES THROUGH THE REGION
SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
130 AM UPDATE...
LATEST MESOSCALE GUIDANCE INCLUDING THE HRRR AND RAP13 STRUGGLING
TO SIMULATE HEAVY RAIN ACROSS COASTAL NJ/NYC AND LONG ISLAND. 00Z
GFS APPEARS TO BE HANDLING THE ACTIVITY BEST. THE GFS PROPROGATES
THIS AREA OF HEAVY RAIN NORTHEAST INTO CT/RI AND SOUTH OF THE MASS
PIKE BY 12Z. THIS SEEMS REASONABLE AS LOW LEVEL JET BEGINS TO
INTENSIFY DURING THIS TIME SOUTH OF NEW ENGLAND. ONE AREA OF
CONCERN IS THE LACK OF RAIN/SHOWERS DOWNSTREAM OF THIS ACTIVITY
ACROSS PA INTO NY STATE. CONVECTION ACROSS COASTAL NJ/NYC AND LONG
ISLAND MAY BE PRECLUDING INSTABILITY AND MOISTURE FROM BEING
ADVECTED NORTHWARD. WILL HAVE TO WATCH HOW THIS EVOLVES AND SEE
HOW 00Z ECMWF AND OTHER GUID SIMULATE THIS CONVECTION. OTHERWISE
NO WHOLESALE CHANGES TO PREVIOUS FORECAST. EARLIER DISCUSSION
BELOW.
================================================================
TORRENTIAL RAINFALL/FLASH FLOODING BEGINNING TO COMMENCE OVER NJ
AS LOW LEVEL JET BEGINS TO FORM AND IS ALSO COLOCATED WITH AREA
OF BEST PRES FALLS AND ALONG WARM FRONTAL BOUNDARY. THIS HAS
INITIATED EMBEDDED CONVECTION WITHIN THIS AREA. MILLVILLE NJ IN
THE SOUTHERN PART OF THE STATE RECEIVED 3.39 INCHES OF RAINFALL
FROM 7 PM TO 9 PM! NONE OF THE HI RES MODEL GUID HANDLING THIS
PARTICULARLY WELL INCLUDING THE HRRR AND RAP13. THE GLOBAL GUID
/GFS AND ECMWF/ IS BETTER BUT IS TOO SLOW IN SPINNING UP
CONVECTION. THIS AREA OF EXCESSIVE RAINFALL IS TRACKING NNE TOWARD
NYC AND SHOULD ARRIVE INTO WESTERN NEW ENGLAND INCLUDING THE
GREATER HARTFORD/SPRINGFIELD AREA AROUND OR AFTER SUNRISE.
FARTHER EASTWARD MESO ANALYSIS CONTINUES TO INDICATE DEEP LAYER OF
DRY AIR ESPECIALLY AROUND 850 MB SOUTH OF NEW ENGLAND THAT STILL
HAS TO BE ADVECTED NORTHWARD. THIS IS ALSO EVIDENT ON THE 00Z OKX
UPPER AIR SOUNDING. THUS STEADY RAINS WILL NOT ARRIVE ACROSS MUCH
OF THE REGION UNTIL AFTER 12Z. HENCE HEAVIEST RAINFALL FOR MUCH OF
THE REGION ARRIVES LATE MORNING INTO EARLY AFTERNOON WED...
POSSIBLY LINGERING AND IMPACTING THE LATE DAY COMMUTE FOR THE
GREATER BOSTON AREA. PREVIOUS FORECAST CAPTURES THESE DETAILS
NICELY SO NO MAJOR CHANGES EXPECTED WITH THIS UPDATE. EARLIER
DISCUSSION BELOW.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
***FLASH FLOOD WATCH FOR THE POTENTIAL OF URBAN AND LOCALIZED FLASH
FLOODING IS THE MAIN CONCERN WEDNESDAY***
1) HEAVY RAIN - FLASH FLOOD THREAT
A LOW LEVEL JET 4 TO 5 STANDARD DEVIATIONS ABOVE NORMAL WILL
COMBINED WITH PWATS BETWEEN 1.75 AND 2 INCHES. THAT IS A CLASSIC
SETUP FOR A SUMMER TIME HEAVY RAIN AND LOCALIZED FLASH FLOOD EVENT.
THE MAIN UNCERTAINTY IS TRYING TO LOCATE WHERE THE HEAVIEST
RAIN/FLOOD THREAT WILL SET UP. GIVEN THAT WE HAVE SOUTH TO
SOUTHEAST FLOW...EXPECT TO SEE THE NORMALLY FAVORED UPSLOPE REGIONS
ALONG THE EAST SLOPES OF THE BERKSHIRES/WORCESTER HILLS AND
MONADNOCKS PERHAPS SEE LOCALLY HIGHER AMOUNTS. THERE MAY ALSO BE A
SECONDARY AREAS ACROSS EASTERN MA/RHODE ISLAND GIVEN A BETTER CHANCE
FOR EMBEDDED THUNDERSTORMS WITH HIGHER INSTABILITY.
OVERALL...EXPECT 1 TO 3 INCHES OF RAINFALL ACROSS MOST AREAS...WITH
LOCALIZED 4 OR 5 INCH AMOUNTS NOT OUT OF THE QUESTION. FORECASTING
QPF AMOUNTS IN THE SUMMER IS NO EASY TASK GIVEN CONVECTIVE FEEDBACK
ISSUES ETC. WE ARE NOT GOING TO BE ABLE TO PINPOINT EXACTLY WHERE
THE BEST CHANCE OF FLASH FLOODING MAY SETUP...OTHER THAN A GENERAL
OVERVIEW GIVEN IN THE PREVIOUS PARAGRAPH. THE MORE IMPORTANT THEME
IS THE POTENTIAL FOR SOME LOCALES TO RECEIVE 2+ INCHES OF RAIN IN
LESS THAN 1 HOUR...LEADING TO THE POTENTIAL FOR SOME URBAN AND
LOCALIZED FLASH FLOODING. THAT IS THE REASON A FLASH FLOOD WATCH IS
IN EFFECT FOR ALL BUT THE CAPE/ISLANDS ON WEDNESDAY.
2) SEVERE WEATHER THREAT
THE BEST SHEAR AND INSTABILITY DO NOT OVERLAP ON WEDNESDAY...SO
SEVERE WEATHER POTENTIAL APPEARS LIMITED. IN ADDITION...RAIN AND
CLOUD COVER WILL LIMIT THE AMOUNT OF INSTABILITY THAT IS ABLE TO
DEVELOP. HOWEVER...THERE IS STILL A LOW PROBABILITY FOR A FEW
STRONG TO SEVERE THUNDERSTORMS ACROSS NORTHERN CT/RHODE ISLAND AND
EASTERN MA. THIS WILL BE DEPENDENT ON WHETHER OR NOT WE CAN MUSTER
ENOUGH INSTABILITY AND HOW FAR NORTH THE SURFACE WARM FRONT MAKES IT
ACROSS THE REGION. ISOLATED STRONG WIND GUSTS WOULD BE THE MAIN
CONCERN. HOWEVER...GIVEN WE WILL HAVE A WARM FRONT TRYING TO LIFT
NORTH THERE IS A LOW PROBABILITY FOR A BRIEF TORNADO IN AN AREA OF
ENHANCED LOW LEVEL HELICITY.
AS A SIDE NOTE...THE LATEST SPC SREF SIGNIFICANT TORNADO PARAMETERS
DOES NOT INDICATE ANY PROBABILITIES IN OUR REGION...WHILE OUR AREA
WAS HIGHLIGHTED DURING THE REVERE DAY. NOW THAT CERTAINLY DOES NOT
MEAN WE CAN/T SEE A BRIEF TORNADO...BUT THE SETUP DOES NOT APPEAR AS
CONDUCIVE AS A FEW WEEKS AGO.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGHLIGHTS...
* SPOT SHOWERS POSSIBLE ACROSS INTERIOR ON FRIDAY
* COLD FRONT MOVES ACROSS SUNDAY INTO SUNDAY NIGHT
* BELOW NORMAL TEMPS LATE THIS WEEK WILL TREND CLOSER TO NORMAL BY
EARLY NEXT WEEK
MODELS AND CONFIDENCE...
OVERALL SYNOPTIC GUIDANCE IS IN AGREEMENT FOR THIS TIMEFRAME UNTIL
THE END OF THE PERIOD WHERE MODELS DIVERGE. MODELS IN DECENT
AGREEMENT WITH DEEP TROUGHING OVER THE NORTHEAST CENTERED BY A
SOUTHERN QUEBEC UPPER LOW. THIS CUTOFF LOW WILL REMAIN OVER THE
REGION UNTIL LIFTING NORTHEASTWARD OVER THE WEEKEND. ANTICIPATE A
SERIES OF WEAK SHORTWAVES TO ROTATE THROUGH THE REGION DURING THIS
TIMEFRAME. THERE IS SUBTLE DIFFERENCES IN TIMING BETWEEN THE GFS/EC
AS WELL AS MESO SCALE DIFFERENCES.
BY SUNDAY MODEL GUIDANCE BEGINS TO DIVERGE AS OPERATIONAL GUIDANCE
IS STRUGGLING TO HANDLE THE BREAKDOWN OF THE MORE ZONAL FLOW
OCCURRING OVER THE WEEKEND. REGARDLESS THEY BOTH SHOW SHORTWAVE
MOVING THROUGH ALLOWING FOR A WEAK COLD FRONT ON SUNDAY. HOWEVER BY
EARLY NEXT WEEK HAVE LOW CONFIDENCE ON THE FORECAST BECAUSE OF THE
AMOUNT OF SPREAD. OVERALL TRENDED FORECAST TOWARDS ENSEMBLES AND
PREV FORECAST.
MODERATE CONFIDENCE IN OVERALL FORECAST WITH LOW CONFIDENCE ON EXACT
TIMING OF ANY PRECIP DURING THIS TIMEFRAME. INCREASING CONFIDENCE IN
WARMING TREND FOR NEXT WEEK PER ENSEMBLE TRENDS.
DETAILS...
THURSDAY INTO FRIDAY...
SURFACE LOW PRESSURE SYSTEM WILL MOVE TOWARDS THE MARITIMES ON
THURSDAY LEADING TO A GOOD AMOUNT OF SUBSTANCE IN ITS WAKE. ALTHOUGH
THERE IS A COLD POOL ALOFT...ANTICIPATE A QUIET DAY AS MOISTURE IS
VERY LIMITED. ALTHOUGH CANNOT RULE OUT A FEW DIURNAL CU. EXPECT A
PLEASANT DAY WITH LOW HUMIDITY AND TEMPS BELOW AVERAGE DUE TO THE
COOLER TEMPS ALOFT.
DUE TO DIFFERENCE IN SHORTWAVE TIMING THERE IS LOW CONFIDENCE ON
PRECIP TIMING FOR THURSDAY NIGHT INTO FRIDAY. CUT OFF LOW WILL STILL
BE IN THE VICINITY WITH -12C TEMPS AT 500MB ALOFT. MOISTURE ALOFT
DOES INCREASE ON FRIDAY...HOWEVER THE STRONGER COLD POOL -16C IS
TO THE NORTH OF THE REGION. THEREFORE BELIEVE THAT LOCATIONS NORTH
OF ROUTE 2 HAS THE BEST SHOT OF SEEING A FEW ISOLATED STORMS. BEST
TIMING IS IN THE AFTERNOON AS DIURNAL HEATING WILL STEEPENING THE
LAPSE RATES AND LEAD TO ANOTHER RISK OF LOW TOP CONVECTION. PWAT
VALUES WILL BE AROUND AN INCH SO DO NOT EXPECT FLOODING BEING AN
ISSUE.
THE WEEKEND...
UPPER LEVEL LOW AND COLD POOL ALOFT MOVES NORTHWARD OUT OF THE
REGION LEADING TO A MORE TRANSITION PERIOD FOR THE REGION. AS
HEIGHTS ARE BUILDING APPEARS THAT SATURDAY WILL TREND TO MORE DRY
WEATHER. HOWEVER A NORTHERN STREAM SHORTWAVE AND COLD FRONT COULD
BRING THE NEXT CHANCE OF CONVECTIVE ACTIVITY ON SUNDAY. THERE ARE
MODELS DIFFERENCES ON THE TIMING OF THIS NORTHERN STREAM
SYSTEM...THEREFORE TRENDED TOWARDS A BLEND OF THE GUIDANCE AND WPC.
BELIEVE CONVECTION WILL BE MORE ON THE SUNDAY TIMEFRAME WITH RIDGING
SURFACE/ALOFT APPEARS TO BUILD IN ON MONDAY AND INTO TUESDAY WITH
WARMING TEMPERATURES.
NEXT WEEK...
QUITE A DIFFERENCE IN MODEL SOLUTIONS DURING THIS TIMEFRAME...AS
MENTIONED ABOVE. OVERALL KEPT MAINLY DRY FORECAST GOING HOWEVER
THERE ARE HINTS FOR ANOTHER SYSTEM MOVING THROUGH NEXT WEDNESDAY.
TEMPS LOOK TO BE CLOSE TO SEASONAL OR PERHAPS SLIGHTLY ABOVE DURING
THIS TIMEFRAME.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM...TODAY AND TONIGHT...
CIGS MAINLY BASED ON GFS AND ITS MAVMOS. WHILE VSBYS AN EVEN BLEND
OF NAM AND GFS.
THRU 12Z...HEAVY RAIN OVER COASTAL NJ-NYC AND LONG ISLAND AT 06Z
WILL TRACK NORTHEAST INTO CT/RI AND SOUTH OF THE MASS PIKE BY 12Z.
HOURLY RAINFALL RATES OF 1-2" WILL BE POSSIBLE IN THE HEAVIER
CONVECTION. SOUTHEAST WINDS WILL INCREASE TO 15-25 KT. CIGS AND
VSBYS TRENDING TOWARD IFR/MVFR TOWARD 12Z. LLWS ENTERING CT AS
STRONG SOUTHEAST LOW LEVEL JET APPROACHES FROM LONG ISLAND.
AFTER 12Z...HEAVY RAIN CONTINUES TO OVERSPREAD ALL OF CT/RI AND MA
BY LATE MORNING/EARLY AFTERNOON. LOW RISK OF STRONG TSTMS ACROSS
CT/RI AND SOUTHEAST MA 18Z-00Z FROM WEST TO EAST. GUSTY SE WINDS
OF 15-25 KT BEGIN TO RELAX AND SHIFT TO THE SW TOWARD 00Z.
WIDESPREAD IFR/MVFR IN NUMEROUS SHOWERS WITH EMBEDDED HEAVY
DOWNPOURS. LLWS AS STRONG LOW LEVEL SOUTHEAST JET MOVES ACROSS THE
AREA.
TONIGHT...IMPROVING TREND FROM IFR/MVFR TO VFR WITH TIME FROM WEST
TO EAST. RAIN EXITS EASTERN MA DURING THE EARLY EVENING WITH DRY
CONDITIONS ELSEWHERE. SOUTHEAST WINDS SHIFT TO SOUTHWEST.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. LOWER CONFIDENCE ON
HOW FAR NORTH POTENTIAL TSTMS WILL TRAVERSE THIS AFTERNOON AND
EARLY EVENING. TSTMS MOST LIKELY REMAIN SOUTH OF THE TERMINAL
AIRSPACE.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. LOW RISK OF A FEW
STRONG TSTMS EXITING THE NY HUDSON VALLEY INTO CT AFTER 18Z.
STRONG WINDS MAY CONCERN. OTHERWISE HEAVY RAIN MUCH OF TODAY WITH
SOME IMPROVEMENT LATER THIS AFTERNOON.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THURSDAY THROUGH SATURDAY...HIGH CONFIDENCE. VFR. POSSIBLE SEA
BREEZES ALONG THE COASTLINES.
SUNDAY...MODERATE CONFIDENCE. MVFR DUE TO SHOWERS AND ISO THUNDER.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM...TONIGHT AND WEDNESDAY...
TONIGHT AND WEDNESDAY...MODERATE TO HIGH CONFIDENCE. AN ANOMALOUS
SHORTWAVE FOR AUGUST STANDARDS WILL MOVE EAST FROM THE GREAT LAKES.
THIS WILL INDUCE A STRONG SOUTH TO SOUTHEAST LOW LEVEL JET LATE
TONIGHT AND WEDNESDAY. THE RESULT WILL BE SOUTHEAST SCA WIND GUSTS
OF 25 TO 30 KNOTS AND BUILDING SEAS. SCA HEADLINES ARE POSTED FOR
SOME AREAS BEGINNING LATE TONIGHT AND ALL LOCATIONS BY WEDNESDAY.
IN ADDITION...HEAVY RAIN/ISOLATED THUNDERSTORMS AND AREAS OF FOG
WILL REDUCE VISIBILITIES FOR MARINERS. ALSO...THERE REMAINS A LOW
PROBABILITY FOR A WATERSPOUT GIVEN HIGH SHEAR ON A NORTHWARD MOVING
WARM FRONT.
OUTLOOK...THURSDAY THROUGH SUNDAY...HIGH CONFIDENCE.
THURSDAY...WINDS AND SEAS START TO DIMINISH AS LOW PRESSURE MOVES
AWAY FROM THE WATERS. SMALL CRAFT ADVISORIES MAY STILL BE NECESSARY
DURING THIS TIME FOR LINGERING SEAS.
FRIDAY AND SATURDAY...QUIET BOATING WEATHER EXPECTED AS HIGH
PRESSURE STARTS TO BUILD OVER THE WATERS.
SUNDAY...COLD FRONT WILL PASS ACROSS THE WATERS. SEAS WILL INCREASE
BUT SHOULD REMAIN BELOW 5FT.
&&
.TIDES/COASTAL FLOODING...
A COASTAL FLOOD ADVISORY WAS ISSUED FOR THE EAST AND SOUTH COASTS
FOR THE WEDNESDAY HIGH TIDE CYCLE...THAT RUNS FROM LATE MORNING INTO
MID AFTERNOON. EAST TO SOUTHEAST FLOW AHEAD OF A WARM FRONT WILL
ALLOW FOR A 0.5 TO 1 FOOT STORM SURGE. THIS MAY BE ENOUGH TO
PRODUCE SOME POCKETS OF SPLASH OVER OR VERY MINOR COASTAL FLOODING
DURING THE WEDNESDAY NIGH TIDE. THE HEAVY RAIN MAY EXACERBATE THE
PROBLEM A BIT...SLOWING DOWN THE DRAINAGE AFTER THE HIGH TIDE.
OVERALL...THIS WILL BE A NUISANCE EVENT AT WORST BUT A FEW OF THE
MOST VULNERABLE SHORE ROADS COULD BE IMPACTED WITHIN AN HOUR OR TWO
OF HIGH TIDE.
&&
.EQUIPMENT...
THE KBOX RADAR IS CURRENTLY BACK IN SERVICE...BUT THE PART NEEDED TO
PERMANENTLY FIX THE RADAR WILL NOT BE IN UNTIL WEDNESDAY.
THEREFORE...ITS POSSIBLE THAT THE RADAR MAY GO DOWN AGAIN SO USE
WITH CAUTION.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...FLASH FLOOD WATCH THROUGH THIS EVENING FOR CTZ002>004.
MA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR MAZ002>021-026.
COASTAL FLOOD ADVISORY FROM 9 AM THIS MORNING TO 4 PM EDT THIS
AFTERNOON FOR MAZ007-015-016-019>022-024.
NH...FLASH FLOOD WATCH THROUGH THIS EVENING FOR NHZ011-012-015.
RI...FLASH FLOOD WATCH THROUGH THIS EVENING FOR RIZ001>007.
COASTAL FLOOD ADVISORY FROM 9 AM THIS MORNING TO 4 PM EDT THIS
AFTERNOON FOR RIZ006-007.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ231>234.
SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 6 PM EDT THIS
EVENING FOR ANZ230.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ236.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ235-237-
254>256.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ250-251.
&&
$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...NOCERA
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...NOCERA/DUNTEN
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...STAFF
EQUIPMENT...FRANK
AREA FORECAST DISCUSSION
NWS TAUNTON MA
148 AM EDT WED AUG 13 2014
.SYNOPSIS...
A STRONG LOW PRESSURE SYSTEM WILL BRING HEAVY RAIN ON WEDNESDAY.
AREAS OF URBAN AND LOCALIZED FLASH FLOODING ARE THE MAIN THREATS
WITH A LOW PROBABILITY FOR ISOLATED SEVERE WEATHER. ISOLATED SHOWERS
MAY DEVELOP ACROSS INLAND AREAS DURING THE DAYLIGHT HOURS LATE
THIS WEEK. EXPECT GENERALLY DRY CONDITIONS INTO EARLY THIS
WEEKEND...THEN ANOTHER SHOT FOR SHOWERS MOVES THROUGH THE REGION
SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
130 AM UPDATE...
LATEST MESOSCALE GUIDANCE INCLUDING THE HRRR AND RAP13 STRUGGLING
TO SIMULATE HEAVY RAIN ACROSS COASTAL NJ/NYC AND LONG ISLAND. 00Z
GFS APPEARS TO BE HANDLING THE ACTIVITY BEST. THE GFS PROPROGATES
THIS AREA OF HEAVY RAIN NORTHEAST INTO CT/RI AND SOUTH OF THE MASS
PIKE BY 12Z. THIS SEEMS REASONABLE AS LOW LEVEL JET BEGINS TO
INTENSIFY DURING THIS TIME SOUTH OF NEW ENGLAND. ONE AREA OF
CONCERN IS THE LACK OF RAIN/SHOWERS DOWNSTREAM OF THIS ACTIVITY
ACROSS PA INTO NY STATE. CONVECTION ACROSS COASTAL NJ/NYC AND LONG
ISLAND MAY BE PRECLUDING INSTABILITY AND MOISTURE FROM BEING
ADVECTED NORTHWARD. WILL HAVE TO WATCH HOW THIS EVOLVES AND SEE
HOW 00Z ECMWF AND OTHER GUID SIMULATE THIS CONVECTION. OTHERWISE
NO WHOLESALE CHANGES TO PREVIOUS FORECAST. EARLIER DISCUSSION
BELOW.
================================================================
TORRENTIAL RAINFALL/FLASH FLOODING BEGINNING TO COMMENCE OVER NJ
AS LOW LEVEL JET BEGINS TO FORM AND IS ALSO COLOCATED WITH AREA
OF BEST PRES FALLS AND ALONG WARM FRONTAL BOUNDARY. THIS HAS
INITIATED EMBEDDED CONVECTION WITHIN THIS AREA. MILLVILLE NJ IN
THE SOUTHERN PART OF THE STATE RECEIVED 3.39 INCHES OF RAINFALL
FROM 7 PM TO 9 PM! NONE OF THE HI RES MODEL GUID HANDLING THIS
PARTICULARLY WELL INCLUDING THE HRRR AND RAP13. THE GLOBAL GUID
/GFS AND ECMWF/ IS BETTER BUT IS TOO SLOW IN SPINNING UP
CONVECTION. THIS AREA OF EXCESSIVE RAINFALL IS TRACKING NNE TOWARD
NYC AND SHOULD ARRIVE INTO WESTERN NEW ENGLAND INCLUDING THE
GREATER HARTFORD/SPRINGFIELD AREA AROUND OR AFTER SUNRISE.
FARTHER EASTWARD MESO ANALYSIS CONTINUES TO INDICATE DEEP LAYER OF
DRY AIR ESPECIALLY AROUND 850 MB SOUTH OF NEW ENGLAND THAT STILL
HAS TO BE ADVECTED NORTHWARD. THIS IS ALSO EVIDENT ON THE 00Z OKX
UPPER AIR SOUNDING. THUS STEADY RAINS WILL NOT ARRIVE ACROSS MUCH
OF THE REGION UNTIL AFTER 12Z. HENCE HEAVIEST RAINFALL FOR MUCH OF
THE REGION ARRIVES LATE MORNING INTO EARLY AFTERNOON WED...
POSSIBLY LINGERING AND IMPACTING THE LATE DAY COMMUTE FOR THE
GREATER BOSTON AREA. PREVIOUS FORECAST CAPTURES THESE DETAILS
NICELY SO NO MAJOR CHANGES EXPECTED WITH THIS UPDATE. EARLIER
DISCUSSION BELOW.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
***FLASH FLOOD WATCH FOR THE POTENTIAL OF URBAN AND LOCALIZED FLASH
FLOODING IS THE MAIN CONCERN WEDNESDAY***
1) HEAVY RAIN - FLASH FLOOD THREAT
A LOW LEVEL JET 4 TO 5 STANDARD DEVIATIONS ABOVE NORMAL WILL
COMBINED WITH PWATS BETWEEN 1.75 AND 2 INCHES. THAT IS A CLASSIC
SETUP FOR A SUMMER TIME HEAVY RAIN AND LOCALIZED FLASH FLOOD EVENT.
THE MAIN UNCERTAINTY IS TRYING TO LOCATE WHERE THE HEAVIEST
RAIN/FLOOD THREAT WILL SET UP. GIVEN THAT WE HAVE SOUTH TO
SOUTHEAST FLOW...EXPECT TO SEE THE NORMALLY FAVORED UPSLOPE REGIONS
ALONG THE EAST SLOPES OF THE BERKSHIRES/WORCESTER HILLS AND
MONADNOCKS PERHAPS SEE LOCALLY HIGHER AMOUNTS. THERE MAY ALSO BE A
SECONDARY AREAS ACROSS EASTERN MA/RHODE ISLAND GIVEN A BETTER CHANCE
FOR EMBEDDED THUNDERSTORMS WITH HIGHER INSTABILITY.
OVERALL...EXPECT 1 TO 3 INCHES OF RAINFALL ACROSS MOST AREAS...WITH
LOCALIZED 4 OR 5 INCH AMOUNTS NOT OUT OF THE QUESTION. FORECASTING
QPF AMOUNTS IN THE SUMMER IS NO EASY TASK GIVEN CONVECTIVE FEEDBACK
ISSUES ETC. WE ARE NOT GOING TO BE ABLE TO PINPOINT EXACTLY WHERE
THE BEST CHANCE OF FLASH FLOODING MAY SETUP...OTHER THAN A GENERAL
OVERVIEW GIVEN IN THE PREVIOUS PARAGRAPH. THE MORE IMPORTANT THEME
IS THE POTENTIAL FOR SOME LOCALES TO RECEIVE 2+ INCHES OF RAIN IN
LESS THAN 1 HOUR...LEADING TO THE POTENTIAL FOR SOME URBAN AND
LOCALIZED FLASH FLOODING. THAT IS THE REASON A FLASH FLOOD WATCH IS
IN EFFECT FOR ALL BUT THE CAPE/ISLANDS ON WEDNESDAY.
2) SEVERE WEATHER THREAT
THE BEST SHEAR AND INSTABILITY DO NOT OVERLAP ON WEDNESDAY...SO
SEVERE WEATHER POTENTIAL APPEARS LIMITED. IN ADDITION...RAIN AND
CLOUD COVER WILL LIMIT THE AMOUNT OF INSTABILITY THAT IS ABLE TO
DEVELOP. HOWEVER...THERE IS STILL A LOW PROBABILITY FOR A FEW
STRONG TO SEVERE THUNDERSTORMS ACROSS NORTHERN CT/RHODE ISLAND AND
EASTERN MA. THIS WILL BE DEPENDENT ON WHETHER OR NOT WE CAN MUSTER
ENOUGH INSTABILITY AND HOW FAR NORTH THE SURFACE WARM FRONT MAKES IT
ACROSS THE REGION. ISOLATED STRONG WIND GUSTS WOULD BE THE MAIN
CONCERN. HOWEVER...GIVEN WE WILL HAVE A WARM FRONT TRYING TO LIFT
NORTH THERE IS A LOW PROBABILITY FOR A BRIEF TORNADO IN AN AREA OF
ENHANCED LOW LEVEL HELICITY.
AS A SIDE NOTE...THE LATEST SPC SREF SIGNIFICANT TORNADO PARAMETERS
DOES NOT INDICATE ANY PROBABILITIES IN OUR REGION...WHILE OUR AREA
WAS HIGHLIGHTED DURING THE REVERE DAY. NOW THAT CERTAINLY DOES NOT
MEAN WE CAN/T SEE A BRIEF TORNADO...BUT THE SETUP DOES NOT APPEAR AS
CONDUCIVE AS A FEW WEEKS AGO.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGHLIGHTS...
* SPOT SHOWERS POSSIBLE ACROSS INTERIOR BOTH THURSDAY AND FRIDAY
* COLD FRONT MOVES ACROSS SUNDAY INTO SUNDAY NIGHT
* BELOW NORMAL TEMPS LATE THIS WEEK WILL TREND CLOSER TO NORMAL
BY EARLY NEXT WEEK
OVERVIEW AND MODEL PREFERENCES...
MEDIUM RANGE MODELS CONTINUE TO SIGNAL COOLER THAN NORMAL
TEMPERATURES ACROSS THE REGION WITH AMPLIFIED NORTHERN STREAM
PATTERN IN PLACE ACROSS NORTH AMERICA. H5 CUTOFF LOW PRES/COLD POOL
SETS UP ACROSS NORTHERN NEW ENGLAND INTO QUEBEC LATE THIS WEEK INTO
THE WEEKEND. MODELS AND ENSEMBLES START TO FLATTEN OUT THIS PATTERN
LATER THIS WEEKEND...WITH UPPER LEVEL WINDS BECOMING MORE NW. WILL
START TO SEE CHANGES IN THE TIMING OF SYSTEMS ACROSS THE NORTHERN
STREAM FROM ABOUT SUNDAY ONWARD...WHICH THE LONGER RANGE OPERATIONAL
MODELS ARE NOT HANDLING WELL. GFS/EC ENSEMBLES TENDING TO LEAN
TOWARD THE LAST COUPLE OF EC OP SOLUTIONS...WHICH IS ON THE SLOWER
SIDE OF THE FORECAST GUIDANCE IN KEEPING A MORE AMPLIFIED UPPER
LEVEL PATTERN IN PLACE.
LEANED TOWARD A BLEND OF AVAILABLE GUIDANCE INTO THIS WEEKEND...
THEN TRENDED TOWARD THE GFS/EC ENSEMBLES WHICH WERE PRETTY CLOSE TO
WPC GUIDANCE.
DETAILS...
WEDNESDAY NIGHT...
EXPECT FRONTAL SYSTEM/LOW PRES TO PUSH NE INTO MAINE...WHICH WILL
PUSH THE PRECIP WITH IT. WILL SEE LEFTOVER SHOWERS/ISOLD TSTMS
UNTIL AROUND MIDNIGHT...WITH THE BEST CHANCE ACROSS CENTRAL AND
EASTERN AREAS. PRECIP WILL END FROM W-E AFTER MIDNIGHT...WITH
DRIER AND COOLER AIR WORKING IN. OVERNIGHT LOWS WILL FALL TO THE
LOWER-MID 50S ACROSS SW NH/N CENTRAL AND W MA...MAINLY OVER THE
HIGHER TERRAIN... RANGING TO THE MID 60S ACROSS THE MID AND OUTER
CAPE AND THE ISLANDS. DEWPTS WILL ALSO FALL BACK WELL
INLAND...DOWN TO THE MID 50S TOWARD DAYBREAK.
THURSDAY AND FRIDAY...
CUTOFF UPPER LOW WILL SLOWLY SPIN ACROSS NORTHERN NEW ENGLAND
INTO QUEBEC DURING THIS TIMEFRAME. WHILE SOME SURFACE SUBSIDENCE
WILL BE IN PLACE ON LIGHT W-NW WINDS...STILL CAN NOT RULE OUT A
FEW SPOTTY DIURNAL SHOWERS EACH DAY WITH THE COLD POOL ALOFT. DOES
LOOK LIKE BEST CHANCE FOR ANY ACTION WILL BE DURING
FRIDAY...THOUGH...AS THERE APPEARS TO BE A WEAK SHORT WAVE
ROTATING AROUND THE BASE OF THE UPPER TROUGH. ONLY CARRIED SLIGHT
CHANCE POPS MAINLY NEAR AND N OF ROUTE 2. DID NOT MENTION THUNDER
AT THIS TIME...BUT CAN NOT TOTALLY RULE OUT SOME LOW TOPPED
CONVECTION.
HOWEVER...DO EXPECT COMFORTABLE CONDITIONS AS DEWPTS CONTINUE TO
FALL BACK...MAINLY IN THE 50S THOUGH SOME INLAND SPOTS ACROSS S NH/N
CENTRAL AND W MA COULD SEE DEWPTS DOWN IN THE MID-UPPER 40S THU
NIGHT. DAYTIME HIGHS BOTH DAYS WILL MAINLY BE IN THE 70S...THOUGH
SOME SPOTS ON FRIDAY MAY NOT MAKE IT TO 70 ACROSS THE HIGHER TERRAIN
OF SW NH...RUNNING AROUND 5 DEGREES BELOW SEASONAL NORMS.
SATURDAY...
UPPER LEVEL CUTOFF/COLD POOL STUBBORN TO MOVE...BUT LOOKS LIKE IT
FINALLY BEGINS TO SHIFT E TOWARD THE MARITIMES LATER SAT/SAT
NIGHT...AT LEAST ON THIS MODEL SUITE. HAVE RUN WITH DRY CONDITIONS
DURING THE DAY WITH HIGHS AGAIN IN THE 70S REGIONWIDE. AS NW FLOW
TAKES OVER...MIGHT SEE A FEW SHOWERS BEGIN TO APPROACH AS WEAK
SHORT WAVE/SURFACE FRONT MOVES SE LATE SAT NIGHT. ONLY CARRIED
SLIGHT CHANCE POPS AFTER 06Z OVER SW NH.
SUNDAY...
COLD FRONT IN THE UPPER FLOW MOVES ACROSS THE REGION...BUT TIMING
IN QUESTION AS GFS AND EC AT ODDS ON HOW THE UPPER LEVEL FLOW
BREAKS DOWN ACROSS THE EASTERN U.S. THE SURFACE FEATURE DOES TEND
TO WEAKEN AS THE UPPER LEVEL SYSTEM PUSHES THROUGH. CURRENT TIMING
SUGGESTS BEST SHOT WILL OCCUR DURING MAX HEATING OF THE DAY...SO
HAVE CARRIED SCT SHOWERS. ONLY MARGINAL INSTABILITY AT BEST AS THE
FRONT CROSSES...THOUGH NOTING SOME ENHANCEMENT LATER IN THE DAY
INTO EARLY SUN NIGHT AS THE FRONT APPROACHES THE S COAST. HAVE NOT
MENTIONED THUNDER IN THE FORECAST...FOR NOW. HAVE ENDED PRECIP BY
AROUND MIDNIGHT...BUT AGAIN TIMING IN QUESTION.
MONDAY-TUESDAY...
QUITE A DIFFERENCE IN OP MODEL SOLUTIONS DURING THIS TIMEFRAME...
ALL IN THE WAY THEY HANDLE THE BREAKDOWN /OR LACK THEREOF/ OF THE
UPPER LEVEL PATTERN AND MOVEMENT OF A SHORT WAVE IN THE FLATTER H5
PATTERN AROUND THE LATE MONDAY/TUESDAY TIMEFRAME. LEANED CLOSER TO
THE EC MODEL...WHICH WAS IN FAIRLY GOOD AGREEMENT WITH THE GFS/EC
ENSEMBLES. KEPT MAINLY DRY FORECAST GOING...THOUGH DID KEEP IN
SLIGHT CHANCE POPS OVER CENTRAL AND NORTHERN AREAS DURING MONDAY
FOR NOW. TEMPS LOOK TO BE CLOSE TO SEASONAL NORMS DURING THIS
TIMEFRAME.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM...TODAY AND TONIGHT...
CIGS MAINLY BASED ON GFS AND ITS MAVMOS. WHILE VSBYS AN EVEN BLEND
OF NAM AND GFS.
THRU 12Z...HEAVY RAIN OVER COASTAL NJ-NYC AND LONG ISLAND AT 06Z
WILL TRACK NORTHEAST INTO CT/RI AND SOUTH OF THE MASS PIKE BY 12Z.
HOURLY RAINFALL RATES OF 1-2" WILL BE POSSIBLE IN THE HEAVIER
CONVECTION. SOUTHEAST WINDS WILL INCREASE TO 15-25 KT. CIGS AND
VSBYS TRENDING TOWARD IFR/MVFR TOWARD 12Z. LLWS ENTERING CT AS
STRONG SOUTHEAST LOW LEVEL JET APPROACHES FROM LONG ISLAND.
AFTER 12Z...HEAVY RAIN CONTINUES TO OVERSPREAD ALL OF CT/RI AND MA
BY LATE MORNING/EARLY AFTERNOON. LOW RISK OF STRONG TSTMS ACROSS
CT/RI AND SOUTHEAST MA 18Z-00Z FROM WEST TO EAST. GUSTY SE WINDS
OF 15-25 KT BEGIN TO RELAX AND SHIFT TO THE SW TOWARD 00Z.
WIDESPREAD IFR/MVFR IN NUMEROUS SHOWERS WITH EMBEDDED HEAVY
DOWNPOURS. LLWS AS STRONG LOW LEVEL SOUTHEAST JET MOVES ACROSS THE
AREA.
TONIGHT...IMPROVING TREND FROM IFR/MVFR TO VFR WITH TIME FROM WEST
TO EAST. RAIN EXITS EASTERN MA DURING THE EARLY EVENING WITH DRY
CONDITIONS ELSEWHERE. SOUTHEAST WINDS SHIFT TO SOUTHWEST.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. LOWER CONFIDENCE ON
HOW FAR NORTH POTENTIAL TSTMS WILL TRAVERSE THIS AFTERNOON AND
EARLY EVENING. TSTMS MOST LIKELY REMAIN SOUTH OF THE TERMINAL
AIRSPACE.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. LOW RISK OF A FEW
STRONG TSTMS EXITING THE NY HUDSON VALLEY INTO CT AFTER 18Z.
STRONG WINDS MAY CONCERN. OTHERWISE HEAVY RAIN MUCH OF TODAY WITH
SOME IMPROVEMENT LATER THIS AFTERNOON.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THURSDAY THROUGH SATURDAY...HIGH CONFIDENCE. VFR. LOW CHANCE FOR SEA
BREEZES ALONG THE COASTLINES MAINLY FRIDAY/SATURDAY. MAY SEE LOCAL
MVFR CONDITIONS IN SCT SHOWERS ACROSS S NH/N CENTRAL-W MA AFTER
MIDNIGHT SAT NIGHT.
SUNDAY...MODERATE CONFIDENCE. GENERALLY LOW END VFR CONDITIONS.
AREAS OF MVFR CIGS/VSBYS IN SCT SHOWERS DURING THE DAY...WHICH
SHOULD SLOWLY IMPROVE FROM W-E SUN NIGHT.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM...TONIGHT AND WEDNESDAY...
TONIGHT AND WEDNESDAY...MODERATE TO HIGH CONFIDENCE. AN ANOMALOUS
SHORTWAVE FOR AUGUST STANDARDS WILL MOVE EAST FROM THE GREAT LAKES.
THIS WILL INDUCE A STRONG SOUTH TO SOUTHEAST LOW LEVEL JET LATE
TONIGHT AND WEDNESDAY. THE RESULT WILL BE SOUTHEAST SCA WIND GUSTS
OF 25 TO 30 KNOTS AND BUILDING SEAS. SCA HEADLINES ARE POSTED FOR
SOME AREAS BEGINNING LATE TONIGHT AND ALL LOCATIONS BY WEDNESDAY.
IN ADDITION...HEAVY RAIN/ISOLATED THUNDERSTORMS AND AREAS OF FOG
WILL REDUCE VISIBILITIES FOR MARINERS. ALSO...THERE REMAINS A LOW
PROBABILITY FOR A WATERSPOUT GIVEN HIGH SHEAR ON A NORTHWARD MOVING
WARM FRONT.
OUTLOOK...WEDNESDAY NIGHT THROUGH SUNDAY...
WEDNESDAY NIGHT AND THURSDAY...SMALL CRAFTS IN PLACE THROUGH WED
NIGHT ON MOST WATERS BUT WINDS/SEAS WILL DIMINISH OVERNIGHT. MAY
NEED TO EXTEND INTO THU FOR THE OUTER WATERS AS SEAS MAY LINGER AT
AROUND 5-6 FT EARLY BEFORE SUBSIDING.
FRIDAY AND SATURDAY...EXPECT WINDS AND SEAS BELOW SMALL CRAFT
CRITERIA.
SUNDAY...COLD FRONT WILL APPROACH THE WATERS LATE SUN/SUN NIGHT BUT
EXPECT CONDITIONS TO REMAIN BELOW SMALL CRAFT LEVELS.
&&
.TIDES/COASTAL FLOODING...
A COASTAL FLOOD ADVISORY WAS ISSUED FOR THE EAST AND SOUTH COASTS
FOR THE WEDNESDAY HIGH TIDE CYCLE...THAT RUNS FROM LATE MORNING INTO
MID AFTERNOON. EAST TO SOUTHEAST FLOW AHEAD OF A WARM FRONT WILL
ALLOW FOR A 0.5 TO 1 FOOT STORM SURGE. THIS MAY BE ENOUGH TO
PRODUCE SOME POCKETS OF SPLASH OVER OR VERY MINOR COASTAL FLOODING
DURING THE WEDNESDAY NIGH TIDE. THE HEAVY RAIN MAY EXACERBATE THE
PROBLEM A BIT...SLOWING DOWN THE DRAINAGE AFTER THE HIGH TIDE.
OVERALL...THIS WILL BE A NUISANCE EVENT AT WORST BUT A FEW OF THE
MOST VULNERABLE SHORE ROADS COULD BE IMPACTED WITHIN AN HOUR OR TWO
OF HIGH TIDE.
&&
.EQUIPMENT...
THE KBOX RADAR IS CURRENTLY BACK IN SERVICE...BUT THE PART NEEDED TO
PERMANENTLY FIX THE RADAR WILL NOT BE IN UNTIL WEDNESDAY.
THEREFORE...ITS POSSIBLE THAT THE RADAR MAY GO DOWN AGAIN SO USE
WITH CAUTION.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...FLASH FLOOD WATCH FROM 6 AM EDT THIS MORNING THROUGH THIS
EVENING FOR CTZ002>004.
MA...FLASH FLOOD WATCH FROM 6 AM EDT THIS MORNING THROUGH THIS
EVENING FOR MAZ002>021-026.
COASTAL FLOOD ADVISORY FROM 9 AM THIS MORNING TO 4 PM EDT THIS
AFTERNOON FOR MAZ007-015-016-019>022-024.
NH...FLASH FLOOD WATCH FROM 6 AM EDT THIS MORNING THROUGH THIS
EVENING FOR NHZ011-012-015.
RI...FLASH FLOOD WATCH FROM 6 AM EDT THIS MORNING THROUGH THIS
EVENING FOR RIZ001>007.
COASTAL FLOOD ADVISORY FROM 9 AM THIS MORNING TO 4 PM EDT THIS
AFTERNOON FOR RIZ006-007.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ231>234.
SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 6 PM EDT THIS
EVENING FOR ANZ230.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ236.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ235-237.
SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 6 AM EDT
THURSDAY FOR ANZ250-251.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ254>256.
&&
$$
SYNOPSIS...FRANK/EVT
NEAR TERM...NOCERA/EVT
SHORT TERM...FRANK
LONG TERM...EVT
AVIATION...NOCERA/EVT
MARINE...FRANK/EVT
TIDES/COASTAL FLOODING...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1025 AM EDT WED AUG 13 2014
.DISCUSSION...
CURRENT-THIS AFTERNOON...THE MORNING SOUNDINGS FROM TAMPA AND CAPE
CANAVERAL INDICATED PRECIPITABLE WATER VALUES AT 1.87 INCHES AND
1.66 INCHES RESPECTIVELY. LOOK OUTSIDE SHOWED CUMULUS JUST STARTING
TO FORM IN THE MOIST SOUTHWEST FLOW. THE 915MHZ VERTICAL WIND
PROFILER(S) AT KENNEDY SPACE CENTER WERE DETECTING SOUTHWEST WINDS
10 TO 15 MPH FROM JUST OFF THE SURFACE/FIRST SAMPLING POINT TO
APPROX. 10000 FEET. RUC UPPER AIR/500MB CHART SHOWED TROUGHING
EXTENDING FROM THE GREAT LAKES TO THE NORTHEAST GULF OF MEXICO.
RECENT SURFACE ANALYSIS SHOWED THAT THE SURFACE RIDGE WAS STILL
BEING SUPPRESSED TO THE SOUTH OVER THE NORTH/CENTRAL BAHAMA
ISLANDS...SOUTHERN FLORIDA AND INTO THE SOUTHEAST GULF OF MEXICO.
THE DEEP SOUTHWEST FLOW WILL ADVECT THE MORE MOIST EASTERN GULF OF
MEXICO AIR INTO EAST CENTRAL FLORIDA THROUGHOUT THE DAY. ISOLATED
MORNING SHOWERS AND STORMS OVER THE EASTERN GULF WILL WORK THEIR WAY
INTO THE WESTERN COUNTIES...LAKE AND WESTERN PORTIONS OF
VOLUSIA...ORANGE...SEMINOLE...OKEECHOBEE COUNTIES LATE MORNING AND
EARLY AFTERNOON. DAYTIME HEATING DESTABILIZING THE MOIST AIR MASS
WILL LEAD TO INCREASING COVERAGE...SCATTERED 40 TO 50 PERCENT...OF
SHOWERS AND STORMS MID TO LATE AFTERNOON. MORNING SOUNDING 500MB
TEMPERATURES AT TAMPA AND CAPE CANAVERAL WERE AT -5C AND -6C
DEGREES. AFTERNOON STORMS LOOK TO BE HEAVY RAIN MAKERS BUT THE
FASTER 850-500MB STEERING WIND AT AROUND 15 MPH SUGGESTS THAT
ACCUMULATIONS MAY NOT BE AS MUCH AS IT COULD BE DUE TO FASTER STORM
MOTION. THE EAST COAST SEA BREEZE WILL STRUGGLE TO MAKE IT MUCH PAST
THE INDIAN RIVER LAGOON/U.S. 1 ALONG THE COAST FROM FORT PIERCE
NORTH. LIGHTER WIND AND MORE SOUTHERLY SOUTH OF FORT PIERCE COULD
ALLOW A SOUTH TO SOUTHEAST WIND TO DEVELOP AND PUSH TO THE
INTERSTATE 95 AND FLORIDA TURNPIKE AREA SOUTH OF FORT PIERCE.
PREVIOUS ZONES DISCUSSION
TODAY-TONIGHT...IN THE BATTLE BETWEEN THE EVER PERSISTENT AND
SUPPRESSED ATLANTIC RIDGE AXIS ACROSS SOUTH FLORIDA AND THE EAST
COAST TROUGH...IT APPEARS THAT THE RIDGE WILL BE THE WINNER FOR
TODAY.
THE UPPER LEVEL SHORTWAVE THE DROVE THE WEAK FRONTAL BOUNDARY INTO
THE SOUTHEAST WILL LIFT OUT TO THE NE LATER TODAY...TAKING WITH IT
THE SURFACE LOW AND FURTHER WEAKENING THE FRONTAL ZONE ACROSS FAR N
FLORIDA. MODELS ARE SHOWING MID LEVEL HEIGHT RISES OF A FEW
DECAMETER AND SURFACE PRESSURES UP A FEW MILLIBARS FROM YESTERDAY.
WHILE NOT VERY SIGNIFICANT IN TERMS OF ABSOLUTE NUMBERS...IT WILL
SHIFT THE FLOW A LITTLE MORE SOUTH-SOUTHWEST RATHER THAN THE MORE
RECENT WEST-SOUTHWEST. THIS WILL INITIALLY BETTER TAP INTO THE DRIER
AIR MID LEVEL AIR TO OUR SOUTH...THOUGH NOT QUITE TO THE EXTENT OF
THE 10-20% RHS PRESENT OVER THE NW BAHAMAS. HOWEVER BEHIND THIS
INITIAL DRY AIR PUSH...THERE LOOKS TO BE A POCKET OF HIGHER MOISTURE
ROUNDING THE RIDGE OUT OF THE SE GULF INTO THE PENINSULA INTO THE
AFTERNOON.
THIS ALL LOOKS TO TRANSLATE TO A MORE TYPICAL EARLY-MID AFTERNOON
START OF SHOWERS AND STORMS...MUCH LATER THAN THE PAST FEW
DAYS...AND COVERAGE IN THE 30-40 PERCENT RANGE ACROSS THE REGION.
MESOSCALE MODELS ARE SHOWING BETTER COVERAGE AROUND THE LAKE
OKEECHOBEE/TREASURE COAST REGION THIS AFTERNOON...LIKELY INITIATED
FROM THE CURRENT BAND MOVING INTO THE SW FLORIDA COAST. EAST COAST
SEA BREEZE LOOKS MORE LIKELY...ESPECIALLY SOUTH OF SEBASTIAN
INLET...WITH BETTER INLAND PENETRATION THAN THE PAST FEW DAYS.
HOWEVER STEERING FLOW WILL REMAIN OUT OF THE SOUTHWEST AND THE WEST
COAST SEA BREEZE WILL REMAIN THE DOMINANT CONVECTIVE INITIATOR
UNTIL VARIOUS OUTFLOW AND LAKE BREEZES GET GOING. SHOWERS AND STORMS
WILL LINGER THROUGH THE EVENING HOURS BEFORE PUSHING OFFSHORE.
DUE TO EXPECTED LATER START TO CONVECTION IN MOST LOCATIONS...HIGH
TEMPS WILL LIKELY BE CLOSER TO MOS GUIDANCE THAN PREVIOUS DAYS IN
THE LOW-MID 90S AREA-WIDE.
THU...THE DEEPER PRE-FRONTAL MOISTURE AHEAD OF THE FRONTAL BOUNDARY
ACROSS S GA AND FL PANHANDLE SHOULD BEGIN TO MOVE TOWARD E CENTRAL
FL FROM THE GULF BY THU AFTN. NAM AND GFS PROG PWATS OVER TWO INCHES
WITH FAIRLY DEEP SW FLOW AND A MID LVL IMPULSE PROGGED TO MOVE
ACROSS THE NRN PENINSULA IN THE AFTERNOON. WILL KEEP POPS RUNNING
ABOUT 10 PCT HIGHER THAN THE GFS AND CLOSER TO THE NAM GUIDANCE IN
THE 50-60 PCT RANGE. SHOWERS/STORMS SHOULD DEVELOP ON THE WEST SIDE
OF THE PENINSULA BY LATE MORNING INTO MID DAY AND TRACK EASTWARD
ACROSS E CENTRAL FL THROUGH THE AFTERNOON HOURS. THE EAST COAST SEA
BREEZE WILL BE PINNED NEAR THE COAST ACROSS VOLUSIA COUNTY AND WILL
MOVE ONLY SLOWLY INLAND SOUTH OF THE CAPE IN THE AFTERNOON. HIGHS
MAINLY IN THE LOWER 90S.
FRI...THE SFC RIDGE AXIS WILL REMAIN NEAR THE KEYS WITH LOW LVL FLOW
FROM THE WSW IN THE MORNING BECOMING SW IN THE AFTERNOON AND
SLIGHTLY WEAKER THAN THU. WITH DEEP MOISTURE AND THE EAST COAST SEA
BREEZE DEVELOPING ALONG THE COAST AND PUSHING INLAND SHOULD SEE
ANOTHER ROUND OF HEALTHY COVERAGE OF AFTERNOON SHOWERS AND LIGHTNING
STORMS ACROSS E CENTRAL FL DURING THE AFTERNOON HOURS. MID LEVEL
TEMPS COOL ABOUT A DEG AT H5 TO -7 TO -8 DEGS C WHICH SHOULD LEAD TO
THE POSSIBILITY OF A FEW STRONGER STORMS WITH BOUNDARY COLLISIONS.
WILL HAVE POPS IN THE LIKELY RANGE AROUND 60 PCT WITH HIGHS IN THE
LOWER 90S.
SAT-WED...ON SAT THE LOW LVL RIDGE WILL BEGIN TO LIFT NORTH TWD S FL
WITH ONE MORE DAY OF LOW LVL S/SW FLOW WITH CONTINUED HIGH MOISTURE
LEVELS MAINLY ACROSS NRN PORTIONS OF E CENTRAL FL. WILL CARRY POPS
IN THE 40-50 PCT RANGE WITH SCATTERED AFTERNOON STORMS EXPECTED. THE
SFC RIDGE WILL LIFT NORTHWARD TOWARD CENTRAL FL SUNDAY INTO MONDAY
WITH RAIN CHANCES DECREASING TO 30-40 PCT WITH HIGHEST COVERAGE
ACROSS NRN SECTIONS EACH AFTERNOON. 00Z GFS INDICATES AN EASTERLY
WAVE WILL ROUND THE LOW LVL RIDGE AXIS TUE AND WED AND BRING
ENHANCED MOISTURE LEVELS ONCE AGAIN TO THE AREA. THE 00Z ECMWF IS
SLOWER WITH THE EASTERLY WAVE AND DOES NOT REACH THE AREA BY THE
MIDDLE OF NEXT WEEK. WITH MODEL UNCERTAINTY WILL KEEP MID RANGE
SCATTERED POPS IN THE EXTENDED FOR NEXT TUE/WED. HIGHS AROUND 90/LWR
90S COAST AND LWR-MID 90S INTERIOR. LOWS IN THE 70S THROUGH THE
EXTENDED PERIOD.
&&
.AVIATION...
PREVAILING VFR THROUGH 16Z AS CU DEVELOPS. TEMPO MVFR CEILINGS
18Z-02Z IN/VC SCATTERED STORMS AND SHOWERS. VFR AFTER 14/04Z.
LOCAL MVFR/IFR VISIBILITIES IN/NEAR HEAVIER SHOWERS FROM KDED-KOBE
EAST.
PREVIOUS AVIATION DISCUSSION
PREVAILING VFR THROUGH 14Z WITH OCCASIONAL MVFR CIGS IN CU AFTER
DAYBREAK. ISOLD SHRA/TSRA DEVELOPING ACROSS REGION AFTER 14Z
BECOMING SCT AFTER 17Z AS WEST COAST SEA BREEZE MOVES THROUGH
REGION. GUSTS 35KTS POSSIBLE IN STRONGER STORMS. BEST COVERAGE
LIKELY TOWARDS KMLB-KSUA COAST WITH SEA/LAKE BREEZE COLLISION. EAST
COAST SEA BREEZE DEVELOPMENT EXPECTED KFPR/KSUA AFTER 18Z...MORE
UNCERTAIN AT KMLB AND KVRB WHICH ARE LIKELY TO SEE AT LEAST S WINDS.
&&
.MARINE...
CURRENT-THIS AFTERNOON...THE NOAA BUOYS AND CMAN BUOYS AT PORT
CANAVERAL AND SEBASTIAN INLET WERE RECORDING SOUTHWEST WINDS 7 TO 14
KNOTS AT 10AM. THE THREE NEARSHORE BUOYS WERE RECORDING 1 FOOT SEAS
OUT TO 20NM.
SEA BREEZE COMPONENT VERO BEACH FORT PIERCE INLET SOUTH MID TO LATE
AFTERNOON OTHERWISE SOUTHWEST WIND 10 TO 15 KNOTS BEYOND A FEW MILES
OF SHORE AND AROUND 10 KNOTS JUST OFF THE COAST.
PREVIOUS MARINE DISCUSSION
TODAY-TONIGHT...SLIGHT NORTHWARD SHIFT IN RIDGE AXIS ALONG WITH
WEAKENING OF FRONTAL BOUNDARY WILL KEEP THE GRADIENT LOOSER WITH
PREVAILING WINDS MORE SOUTH-SOUTHWEST AROUND 10KTS...OCCASIONALLY UP
TO 15 KNOTS OFFSHORE. EAST COAST SEA BREEZE EXPECTED SOUTH OF
SEBASTIAN INLET...BRINGING WINDS S-SE NEAR THE COAST IN THE
AFTERNOON. SEAS CONTINUE AROUND 1-2FT WITH UP TO 3 FT WELL OFFSHORE.
SEAS REMAIN CHOPPY WITH DOMINANT PERIODS REMAIN MIXED BETWEEN 8-9SEC
AND 3-4SEC. SHORTER PERIODS EXPECTED TO DOMINATE EARLY BECOMING
LONGER INTO THIS EVENING.
OFFSHORE MOVING STORMS THIS AFTERNOON AND EVENING WITH GUSTY WINDS
IN EXCESS OF 35 KNOTS WILL REMAIN THE PRIMARY BOATING THREAT.
S/SW WINDS TO 10-15 KNOTS INTO THE WEEKEND WITH OFFSHORE MOVING
STORMS EACH AFTERNOON THU-SAT. LOWER COVERAGE OF STORMS IS EXPECTED
SUNDAY AND MONDAY. SEAS 2 FT NEAR THE COAST AND UP TO 3-4 FT WELL
OFFSHORE TOWARD THE WEEKEND.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECASTS...WIMMER
IMPACT WX...CRISTALDI
PUBLIC SV...GLITTO
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
953 AM EDT WED AUG 13 2014
.UPDATE...STALLED FRONTAL BOUNDARY OVER SOUTHERN GEORGIA IN
CONCERT WITH MOIST AIRMASS AND MID LEVEL VORT FORECAST TO TRACK
FROM THE GULF OF MEXICO TO ADJACENT AND PARALLEL TO THE ST MARY`S
RIVER. THE HIGH RESOLUTION ARW AND HRRR SHOW BEST CONVERGENCE AND
NUMEROUS SHOWERS/TSTMS ALONG THE ST MARY`S RIVER THROUGH THE LATE
MORNING AND EARLY AFTERNOON WITH THE REMAINDER OF THE FORECAST
AREA FILLING IN THIS MID TO LATE AFTERNOON WITH SCATTERED SHOWERS.
CLAY...PUTMAN...FLAGER AND ST. JOHNS COUNTIES MAY HAVE MORE
SPOTTY TSTM COVERAGE THIS AFTERNOON WITH WITH SUPPRESSED ATLANTIC
RIDGE AXIS ACROSS SOUTH FLORIDA. BEST AREAL COVERAGE...THIS
AFTERNOON IS FORECAST TO SOUTH THE ST MARY`S RIVER BUT NORTH OF
LINE FROM CROSS CITY TO ALACHUA TO GREEN COVE SPRINGS TO PONTE
VEDRA.
&&
.AVIATION...
STALLED FRONTAL BOUNDARY CONTINUE TO RESIDE OVER SOUTHERN GA THIS
MORNING AS A RESULT A MOIST SOUTHWEST FLOW WILL CONTINUE THIS TAF
PERIOD. AN INCREASE OF SHOWERS AND THUNDERSTORMS IS ANTICIPATED
THIS AFTERNOON. MOIST ATMOSPHERE IS IN PLACE ACROSS THE REGION.
THE STEERING FLOW IS OUT OF THE SOUTHWEST AT ABOUT 20 KNOTS. WITH
SOME TRAINING POSSIBLE...SOME STORMS MAY PRODUCE A BRIEF PERIOD OF
HEAVY DOWNPOURS RESULTING IN REDUCED VISIBILITIES. SHOWERS AND
THUNDERSTORMS WILL BEGIN TO DECREASE IN AREAL COVERAGE AFTER 00Z
THEN WANING EVEN FURTHER AS THE EVENING PROGRESSES.
&&
.MARINE...
SW FLOW WILL PREVAIL THROUGH THE WEEKEND. WIND SPEEDS OUTSIDE OF
SCATTERED TO NUMEROUS STORMS WILL GENERALLY REMAIN 15 KNOTS OR
LESS...WITH NOCTURNAL WIND SURGES OFFSHORE APPROACHING CAUTION
LEVELS AT TIMES.
RIP CURRENTS: LOW RISK THROUGH THURSDAY WITH OFFSHORE FLOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 93 74 93 74 / 50 30 40 30
SSI 89 77 88 76 / 60 50 60 50
JAX 91 76 92 74 / 70 50 60 60
SGJ 90 75 91 75 / 60 50 60 60
GNV 89 74 90 73 / 70 40 60 60
OCF 91 74 90 73 / 50 40 60 60
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
CORDERO/CORDERO/WALSH
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
302 PM CDT WED AUG 13 2014
.DISCUSSION...
336 AM CDT
PRIMARY FORECAST CHALLENGES THIS MORNING INCLUDE THE BACK DOOR FRONT
COMING IN OFF THE LAKE LATER THIS AFTERNOON OR EARLY THIS EVENING
AND ASSOCIATED PRECIP CHANCES...FOLLOWED BY PRECIP CHANCES WITH
TRICKY SYSTEM THIS WEEKEND.
SURFACE ANALYSIS EARLY THIS MORNING SHOWS A TYPICAL WEAK SUMMER COLD
FRONT EXTENDING FROM FAR NORTHERN LOWER MICHIGAN WEST INTO NORTHERN
WISCONSIN WHERE IT BECOMES PRETTY ILL DEFINED. THE FRONT WILL SAG
SOUTHWARD TODAY...BUT SHOULD BE AIDED BY AND ACCELERATE SOUTHWARD
DOWN LAKE MICHIGAN THIS AFTERNOON AND EVENING. WHILE THE LAKE HAS
WARMED...AIR TEMPS IN THE MARINE LAYER OVER THE LAKE ARE IN THE LOW
TO MID 60S SO CONTRASTED WITH THE 80 DEGREE TEMPS OVER LAND SHOULD
PROVIDE A DECENT PUSH OF COLDER AIR AS THE COLD FRONT BECOMES
ENHANCED BY THE LAKE. HAVE LEANED SLIGHTLY TOWARD THE FASTER
SOLUTIONS OFFERED UP BY THE RAP AND 06Z NAM WHICH SUGGEST WE COULD
SEE FALLING TEMPS INTO FAR NE IL BY 21Z...SPREADING ACROSS THE METRO
AREA BY 00Z WITH THE MOST DRAMATIC COOLING (10F+ DROP) NEAR THE LAKE
WITH LESS OF A DROP EXPECTED INLAND. MANY MODELS DO BREAK OUT LIGHT
QPF...LIKELY PARTIALLY ASSOCIATED WITH THIS LAKE ENHANCED FRONT THIS
AFTERNOON...BUT FORECAST SOUNDINGS FROM THE MODELS THAT SHOW QPF ALL
SHOW THERMODYNAMIC PROFILES THAT ARE EXCEPTIONALLY UNFAVORABLE FOR
PRECIPITATION WITH INVERSION/ISOTHERMAL LAYER BETWEEN 700-600MB WITH
DRY AIR ABOVE THAT. GIVEN THE LACK OF LARGE SCALE FORCING AND
UNFAVORABLE THERMODYNAMICS HAVE ONLY INTRODUCED SLIGHT CHANCE POPS
FOR LIGHT SHOWERS THIS AFTERNOON OVER FAR NE IL WHERE MET GUIDANCE
HAS POPS OVER 40 PERCENT.
WEATHER LOOKS QUIET THURSDAY AND MUCH OF FRIDAY WITH HIGH PRESSURE
TRACKING ACROSS THE REGION...ALLOWING FOR LAKE BREEZE AND SLIGHTLY
BELOW AVERAGE TEMPS THURSDAY FOLLOWED BY LESS (IF ANY) LAKE COOLING
FRIDAY WITH MODERATING TEMPS ON DEVELOPING SOUTHERLY WINDS.
VIGOROUS SHORTWAVE OVER DESSERT SOUTHWEST WILL RIDE THE SUBTROPICAL
JET AROUND THE PERIPHERY OF THE UPPER RIDGE AND EMERGE OUT ONTO THE
HIGH PLAINS THURSDAY NIGHT INTO FRIDAY. GFS PHASES THIS WAVE WITH
DEPARTING NORTHERN STREAM SHORTWAVE AND IS MUCH MORE PROGRESSIVE
WITH THE MOVEMENT OF THIS FEATURE ACROSS THE REGION. THE NAM AND
ECMWF KEEP THIS SHORTWAVE SEPARATE FROM THE NORTHERN STREAM AND
RESULT IN A MUCH SLOWER MEANDERING OF THIS FEATURE INTO THE AREA
THIS WEEKEND WITH GRADUALLY INCREASING CHANCES FOR AT LEAST
SCATTERED SHOWERS/STORMS. THE PROGRESSIVE GFS WOULD SUGGEST A WET
SATURDAY AND DRY SUNDAY...WHILE ECMWF HAS A MORE PROLONGED PERIOD OF
AT LEAST POTENTIAL SHOWER/TSTM ACTIVITY THROUGH THE WEEKEND INTO
EARLY NEXT WEEK. SUSPECT ECMWF SOLUTION WILL BE CLOSER TO WHAT
EVENTUALLY BECOMES REALITY...BUT CONFIDENCE IS LOW AND NECESSITATES
SEVERAL DAYS WITH CHANCES OF SHOWERS AND TSTMS OVER THE WEEKEND INTO
EARLY NEXT WEEK. TEMPERATURES AND HUMIDITY SHOULD CREEP UP BACK TO
MORE SEASONABLE LEVELS THIS WEEKEND INTO EARLY NEXT WEEK AS UPPER
TROUGH OVER THE GREAT LAKES THIS MORNING LIFTS OUT AND PATTERN
DEAMPLIFIES.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* LAKE BREEZE WITH WINDS BECOMING NE AT 11 KT ARND 21Z...THEN
DIMINISHING TO 8 KT BY 22Z.
JEE
//DISCUSSION...UPDATED 18Z...
HIGH PRESSURE OVER THE PLAINS IS SLOWLY BUILDING EAST WHILE A WEAK
SURFACE TROUGH SWINGS THROUGH NE IL THIS AFTN. KEEPING THE TAFS
DRY DESPITE THE MODELS TRYING TO SQUEEZE OUT A LITTLE PRECIP. A
LAKE BREEZE IS EXPECTED AND STILL THINKING IT WILL TURN WINDS NE
ARND 11 KT AT ORD AND MDW AT 21Z. WINDS WILL BE NNE AT GYY. WINDS
WILL DIMINISH TO ARND 5 KT BY EARLY EVENING. EASTERLY WINDS WILL
SLOWLY PUSH WEST REACHING RFD THIS EVENING BUT THEY WILL BE ARND
5 KT. SKIES REMAIN VFR AND WINDS REMAIN LIGHT BTWN NORTH AND EAST
THROUGH THE REST OF THE PERIOD.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT THROUGH FRIDAY...VFR.
FRIDAY NIGHT THROUGH TUESDAY...PRIMARILY VFR BUT WITH PERIODIC
CHANCES FOR TSRA.
BMD
&&
.MARINE...
146 PM CDT
COLD FRONT WAS PUSHING SOUTH ACROSS SOUTHERN LAKE MICHIGAN THIS
AFTERNOON...AND SHOULD CLEAR THE SOUTH END THIS EVENING. MODEST
NORTH WINDS BEHIND THE FRONT WITH GUSTS 20-25 KT ON THE NORTHERN
QUARTER OR SO AT THIS TIME...IN TIGHTER GRADIENT IN THE WAKE OF LOW
PRESSURE MOVING AWAY OVER SOUTHWESTERN QUEBEC. WINDS ARE EXPECTED TO
DIMINISH TONIGHT HOWEVER...AS SURFACE HIGH PRESSURE RIDGE WEST OF
THE MISSISSIPPI MOVES EAST. QUIET MARINE WEATHER WILL BE THE RULE
THURSDAY INTO FRIDAY AS THE RIDGE MOVES ACROSS THE LAKE...AND LIGHT
SOUTH-SOUTHWEST RETURN FLOW SETS UP WEST OF THE RIDGE AXIS.
AREA OF LOW PRESSURE IS FORECAST TO DEVELOP ACROSS THE MID-MISSOURI
VALLEY FRIDAY INTO FRIDAY NIGHT...AND WILL LIFT NORTHEAST TOWARD THE
NORTHERN/WESTERN GREAT LAKES REGION THROUGH SATURDAY. SEVERAL DETAIL
DIFFERENCES EXIST IN VARIOUS MODEL SOLUTIONS OF THE TRACK OF THIS
LOW HOWEVER...RESULTING IN LOWER CONFIDENCE IN DETAILS OF THE WIND
FORECAST OVER THE WEEKEND. OVERALL HOWEVER...IT APPEARS THAT A
PERIOD OF SOUTH-SOUTHWEST WINDS WILL DEVELOP FRIDAY-FRIDAY NIGHT...
WITH WINDS EVENTUALLY BECOMING NORTHERLY SUNDAY ONWARD. SOME
POTENTIAL FOR WINDS AS HIGH AS 20-25 KT DURING THESE PERIODS...
THOUGH AGAIN LOWER CONFIDENCE IN THOSE SPEEDS GIVEN MODEL
DIFFERENCES WITH HANDLING OF THE LOW.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
148 PM CDT WED AUG 13 2014
.DISCUSSION...
336 AM CDT
PRIMARY FORECAST CHALLENGES THIS MORNING INCLUDE THE BACK DOOR FRONT
COMING IN OFF THE LAKE LATER THIS AFTERNOON OR EARLY THIS EVENING
AND ASSOCIATED PRECIP CHANCES...FOLLOWED BY PRECIP CHANCES WITH
TRICKY SYSTEM THIS WEEKEND.
SURFACE ANALYSIS EARLY THIS MORNING SHOWS A TYPICAL WEAK SUMMER COLD
FRONT EXTENDING FROM FAR NORTHERN LOWER MICHIGAN WEST INTO NORTHERN
WISCONSIN WHERE IT BECOMES PRETTY ILL DEFINED. THE FRONT WILL SAG
SOUTHWARD TODAY...BUT SHOULD BE AIDED BY AND ACCELERATE SOUTHWARD
DOWN LAKE MICHIGAN THIS AFTERNOON AND EVENING. WHILE THE LAKE HAS
WARMED...AIR TEMPS IN THE MARINE LAYER OVER THE LAKE ARE IN THE LOW
TO MID 60S SO CONTRASTED WITH THE 80 DEGREE TEMPS OVER LAND SHOULD
PROVIDE A DECENT PUSH OF COLDER AIR AS THE COLD FRONT BECOMES
ENHANCED BY THE LAKE. HAVE LEANED SLIGHTLY TOWARD THE FASTER
SOLUTIONS OFFERED UP BY THE RAP AND 06Z NAM WHICH SUGGEST WE COULD
SEE FALLING TEMPS INTO FAR NE IL BY 21Z...SPREADING ACROSS THE METRO
AREA BY 00Z WITH THE MOST DRAMATIC COOLING (10F+ DROP) NEAR THE LAKE
WITH LESS OF A DROP EXPECTED INLAND. MANY MODELS DO BREAK OUT LIGHT
QPF...LIKELY PARTIALLY ASSOCIATED WITH THIS LAKE ENHANCED FRONT THIS
AFTERNOON...BUT FORECAST SOUNDINGS FROM THE MODELS THAT SHOW QPF ALL
SHOW THERMODYNAMIC PROFILES THAT ARE EXCEPTIONALLY UNFAVORABLE FOR
PRECIPITATION WITH INVERSION/ISOTHERMAL LAYER BETWEEN 700-600MB WITH
DRY AIR ABOVE THAT. GIVEN THE LACK OF LARGE SCALE FORCING AND
UNFAVORABLE THERMODYNAMICS HAVE ONLY INTRODUCED SLIGHT CHANCE POPS
FOR LIGHT SHOWERS THIS AFTERNOON OVER FAR NE IL WHERE MET GUIDANCE
HAS POPS OVER 40 PERCENT.
WEATHER LOOKS QUIET THURSDAY AND MUCH OF FRIDAY WITH HIGH PRESSURE
TRACKING ACROSS THE REGION...ALLOWING FOR LAKE BREEZE AND SLIGHTLY
BELOW AVERAGE TEMPS THURSDAY FOLLOWED BY LESS (IF ANY) LAKE COOLING
FRIDAY WITH MODERATING TEMPS ON DEVELOPING SOUTHERLY WINDS.
VIGOROUS SHORTWAVE OVER DESSERT SOUTHWEST WILL RIDE THE SUBTROPICAL
JET AROUND THE PERIPHERY OF THE UPPER RIDGE AND EMERGE OUT ONTO THE
HIGH PLAINS THURSDAY NIGHT INTO FRIDAY. GFS PHASES THIS WAVE WITH
DEPARTING NORTHERN STREAM SHORTWAVE AND IS MUCH MORE PROGRESSIVE
WITH THE MOVEMENT OF THIS FEATURE ACROSS THE REGION. THE NAM AND
ECMWF KEEP THIS SHORTWAVE SEPARATE FROM THE NORTHERN STREAM AND
RESULT IN A MUCH SLOWER MEANDERING OF THIS FEATURE INTO THE AREA
THIS WEEKEND WITH GRADUALLY INCREASING CHANCES FOR AT LEAST
SCATTERED SHOWERS/STORMS. THE PROGRESSIVE GFS WOULD SUGGEST A WET
SATURDAY AND DRY SUNDAY...WHILE ECMWF HAS A MORE PROLONGED PERIOD OF
AT LEAST POTENTIAL SHOWER/TSTM ACTIVITY THROUGH THE WEEKEND INTO
EARLY NEXT WEEK. SUSPECT ECMWF SOLUTION WILL BE CLOSER TO WHAT
EVENTUALLY BECOMES REALITY...BUT CONFIDENCE IS LOW AND NECESSITATES
SEVERAL DAYS WITH CHANCES OF SHOWERS AND TSTMS OVER THE WEEKEND INTO
EARLY NEXT WEEK. TEMPERATURES AND HUMIDITY SHOULD CREEP UP BACK TO
MORE SEASONABLE LEVELS THIS WEEKEND INTO EARLY NEXT WEEK AS UPPER
TROUGH OVER THE GREAT LAKES THIS MORNING LIFTS OUT AND PATTERN
DEAMPLIFIES.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* LAKE BREEZE WITH WINDS BECOMING NE ARND 11 KT IN THE MID AFTN.
JEE
//DISCUSSION...UPDATED 18Z...
HIGH PRESSURE OVER THE PLAINS IS SLOWLY BUILDING EAST WHILE A WEAK
SURFACE TROUGH SWINGS THROUGH NE IL THIS AFTN. KEEPING THE TAFS
DRY DESPITE THE MODELS TRYING TO SQUEEZE OUT A LITTLE PRECIP. A
LAKE BREEZE IS EXPECTED AND STILL THINKING IT WILL TURN WINDS NE
ARND 11 KT AT ORD AND MDW AT 21Z. WINDS WILL BE NNE AT GYY. WINDS
WILL DIMINISH TO ARND 5 KT BY EARLY EVENING. EASTERLY WINDS WILL
SLOWLY PUSH WEST REACHING RFD THIS EVENING BUT THEY WILL BE ARND
5 KT. SKIES REMAIN VFR AND WINDS REMAIN LIGHT BTWN NORTH AND EAST
THROUGH THE REST OF THE PERIOD.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT THROUGH FRIDAY...VFR.
FRIDAY NIGHT THROUGH TUESDAY...PRIMARILY VFR BUT WITH PERIODIC
CHANCES FOR TSRA.
BMD
&&
.MARINE...
146 PM CDT
COLD FRONT WAS PUSHING SOUTH ACROSS SOUTHERN LAKE MICHIGAN THIS
AFTERNOON...AND SHOULD CLEAR THE SOUTH END THIS EVENING. MODEST
NORTH WINDS BEHIND THE FRONT WITH GUSTS 20-25 KT ON THE NORTHERN
QUARTER OR SO AT THIS TIME...IN TIGHTER GRADIENT IN THE WAKE OF LOW
PRESSURE MOVING AWAY OVER SOUTHWESTERN QUEBEC. WINDS ARE EXPECTED TO
DIMINISH TONIGHT HOWEVER...AS SURFACE HIGH PRESSURE RIDGE WEST OF
THE MISSISSIPPI MOVES EAST. QUIET MARINE WEATHER WILL BE THE RULE
THURSDAY INTO FRIDAY AS THE RIDGE MOVES ACROSS THE LAKE...AND LIGHT
SOUTH-SOUTHWEST RETURN FLOW SETS UP WEST OF THE RIDGE AXIS.
AREA OF LOW PRESSURE IS FORECAST TO DEVELOP ACROSS THE MID-MISSOURI
VALLEY FRIDAY INTO FRIDAY NIGHT...AND WILL LIFT NORTHEAST TOWARD THE
NORTHERN/WESTERN GREAT LAKES REGION THROUGH SATURDAY. SEVERAL DETAIL
DIFFERENCES EXIST IN VARIOUS MODEL SOLUTIONS OF THE TRACK OF THIS
LOW HOWEVER...RESULTING IN LOWER CONFIDENCE IN DETAILS OF THE WIND
FORECAST OVER THE WEEKEND. OVERALL HOWEVER...IT APPEARS THAT A
PERIOD OF SOUTH-SOUTHWEST WINDS WILL DEVELOP FRIDAY-FRIDAY NIGHT...
WITH WINDS EVENTUALLY BECOMING NORTHERLY SUNDAY ONWARD. SOME
POTENTIAL FOR WINDS AS HIGH AS 20-25 KT DURING THESE PERIODS...
THOUGH AGAIN LOWER CONFIDENCE IN THOSE SPEEDS GIVEN MODEL
DIFFERENCES WITH HANDLING OF THE LOW.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1228 PM CDT WED AUG 13 2014
.DISCUSSION...
336 AM CDT
PRIMARY FORECAST CHALLENGES THIS MORNING INCLUDE THE BACK DOOR FRONT
COMING IN OFF THE LAKE LATER THIS AFTERNOON OR EARLY THIS EVENING
AND ASSOCIATED PRECIP CHANCES...FOLLOWED BY PRECIP CHANCES WITH
TRICKY SYSTEM THIS WEEKEND.
SURFACE ANALYSIS EARLY THIS MORNING SHOWS A TYPICAL WEAK SUMMER COLD
FRONT EXTENDING FROM FAR NORTHERN LOWER MICHIGAN WEST INTO NORTHERN
WISCONSIN WHERE IT BECOMES PRETTY ILL DEFINED. THE FRONT WILL SAG
SOUTHWARD TODAY...BUT SHOULD BE AIDED BY AND ACCELERATE SOUTHWARD
DOWN LAKE MICHIGAN THIS AFTERNOON AND EVENING. WHILE THE LAKE HAS
WARMED...AIR TEMPS IN THE MARINE LAYER OVER THE LAKE ARE IN THE LOW
TO MID 60S SO CONTRASTED WITH THE 80 DEGREE TEMPS OVER LAND SHOULD
PROVIDE A DECENT PUSH OF COLDER AIR AS THE COLD FRONT BECOMES
ENHANCED BY THE LAKE. HAVE LEANED SLIGHTLY TOWARD THE FASTER
SOLUTIONS OFFERED UP BY THE RAP AND 06Z NAM WHICH SUGGEST WE COULD
SEE FALLING TEMPS INTO FAR NE IL BY 21Z...SPREADING ACROSS THE METRO
AREA BY 00Z WITH THE MOST DRAMATIC COOLING (10F+ DROP) NEAR THE LAKE
WITH LESS OF A DROP EXPECTED INLAND. MANY MODELS DO BREAK OUT LIGHT
QPF...LIKELY PARTIALLY ASSOCIATED WITH THIS LAKE ENHANCED FRONT THIS
AFTERNOON...BUT FORECAST SOUNDINGS FROM THE MODELS THAT SHOW QPF ALL
SHOW THERMODYNAMIC PROFILES THAT ARE EXCEPTIONALLY UNFAVORABLE FOR
PRECIPITATION WITH INVERSION/ISOTHERMAL LAYER BETWEEN 700-600MB WITH
DRY AIR ABOVE THAT. GIVEN THE LACK OF LARGE SCALE FORCING AND
UNFAVORABLE THERMODYNAMICS HAVE ONLY INTRODUCED SLIGHT CHANCE POPS
FOR LIGHT SHOWERS THIS AFTERNOON OVER FAR NE IL WHERE MET GUIDANCE
HAS POPS OVER 40 PERCENT.
WEATHER LOOKS QUIET THURSDAY AND MUCH OF FRIDAY WITH HIGH PRESSURE
TRACKING ACROSS THE REGION...ALLOWING FOR LAKE BREEZE AND SLIGHTLY
BELOW AVERAGE TEMPS THURSDAY FOLLOWED BY LESS (IF ANY) LAKE COOLING
FRIDAY WITH MODERATING TEMPS ON DEVELOPING SOUTHERLY WINDS.
VIGOROUS SHORTWAVE OVER DESSERT SOUTHWEST WILL RIDE THE SUBTROPICAL
JET AROUND THE PERIPHERY OF THE UPPER RIDGE AND EMERGE OUT ONTO THE
HIGH PLAINS THURSDAY NIGHT INTO FRIDAY. GFS PHASES THIS WAVE WITH
DEPARTING NORTHERN STREAM SHORTWAVE AND IS MUCH MORE PROGRESSIVE
WITH THE MOVEMENT OF THIS FEATURE ACROSS THE REGION. THE NAM AND
ECMWF KEEP THIS SHORTWAVE SEPARATE FROM THE NORTHERN STREAM AND
RESULT IN A MUCH SLOWER MEANDERING OF THIS FEATURE INTO THE AREA
THIS WEEKEND WITH GRADUALLY INCREASING CHANCES FOR AT LEAST
SCATTERED SHOWERS/STORMS. THE PROGRESSIVE GFS WOULD SUGGEST A WET
SATURDAY AND DRY SUNDAY...WHILE ECMWF HAS A MORE PROLONGED PERIOD OF
AT LEAST POTENTIAL SHOWER/TSTM ACTIVITY THROUGH THE WEEKEND INTO
EARLY NEXT WEEK. SUSPECT ECMWF SOLUTION WILL BE CLOSER TO WHAT
EVENTUALLY BECOMES REALITY...BUT CONFIDENCE IS LOW AND NECESSITATES
SEVERAL DAYS WITH CHANCES OF SHOWERS AND TSTMS OVER THE WEEKEND INTO
EARLY NEXT WEEK. TEMPERATURES AND HUMIDITY SHOULD CREEP UP BACK TO
MORE SEASONABLE LEVELS THIS WEEKEND INTO EARLY NEXT WEEK AS UPPER
TROUGH OVER THE GREAT LAKES THIS MORNING LIFTS OUT AND PATTERN
DEAMPLIFIES.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* LAKE BREEZE WITH WINDS BECOMING NE ARND 11 KT IN THE MID AFTN.
JEE
//DISCUSSION...UPDATED 18Z...
HIGH PRESSURE OVER THE PLAINS IS SLOWLY BUILDING EAST WHILE A WEAK
SURFACE TROUGH SWINGS THROUGH NE IL THIS AFTN. KEEPING THE TAFS
DRY DESPITE THE MODELS TRYING TO SQUEEZE OUT A LITTLE PRECIP. A
LAKE BREEZE IS EXPECTED AND STILL THINKING IT WILL TURN WINDS NE
ARND 11 KT AT ORD AND MDW AT 21Z. WINDS WILL BE NNE AT GYY. WINDS
WILL DIMINISH TO ARND 5 KT BY EARLY EVENING. EASTERLY WINDS WILL
SLOWLY PUSH WEST REACHING RFD THIS EVENING BUT THEY WILL BE ARND
5 KT. SKIES REMAIN VFR AND WINDS REMAIN LIGHT BTWN NORTH AND EAST
THROUGH THE REST OF THE PERIOD.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT THROUGH FRIDAY...VFR.
FRIDAY NIGHT THROUGH TUESDAY...PRIMARILY VFR BUT WITH PERIODIC
CHANCES FOR TSRA.
BMD
&&
.MARINE...
300 AM CDT
CONDITIONS CONTINUE TO SLOWLY IMPROVE ACROSS LAKE MICHIGAN AS WINDS
AND WAVES DIMINISH BEHIND THE DEPARTING LOW SYSTEM CURRENTLY MOVING
ACROSS THE EASTERN LAKES. A SECONDARY TROUGH WILL WORK ITS WAY SOUTH
ACROSS LAKE MICHIGAN TODAY WITH WINDS PICKING UP SLIGHTLY OUT OF THE
NORTH...ESPECIALLY ACROSS THE NORTH HALF OF THE LAKE WHERE WIND
SPEEDS WILL INCREASE BACK INTO THE 15 TO 25 KT RANGE. HIGH PRESSURE
WILL MOVE ACROSS THE LAKE LATE THURSDAY INTO FRIDAY WITH WINDS THEN
TURNING BACK TO THE SOUTHWEST/SOUTH FRIDAY AND SATURDAY.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1057 AM CDT WED AUG 13 2014
.DISCUSSION...
336 AM CDT
PRIMARY FORECAST CHALLENGES THIS MORNING INCLUDE THE BACK DOOR FRONT
COMING IN OFF THE LAKE LATER THIS AFTERNOON OR EARLY THIS EVENING
AND ASSOCIATED PRECIP CHANCES...FOLLOWED BY PRECIP CHANCES WITH
TRICKY SYSTEM THIS WEEKEND.
SURFACE ANALYSIS EARLY THIS MORNING SHOWS A TYPICAL WEAK SUMMER COLD
FRONT EXTENDING FROM FAR NORTHERN LOWER MICHIGAN WEST INTO NORTHERN
WISCONSIN WHERE IT BECOMES PRETTY ILL DEFINED. THE FRONT WILL SAG
SOUTHWARD TODAY...BUT SHOULD BE AIDED BY AND ACCELERATE SOUTHWARD
DOWN LAKE MICHIGAN THIS AFTERNOON AND EVENING. WHILE THE LAKE HAS
WARMED...AIR TEMPS IN THE MARINE LAYER OVER THE LAKE ARE IN THE LOW
TO MID 60S SO CONTRASTED WITH THE 80 DEGREE TEMPS OVER LAND SHOULD
PROVIDE A DECENT PUSH OF COLDER AIR AS THE COLD FRONT BECOMES
ENHANCED BY THE LAKE. HAVE LEANED SLIGHTLY TOWARD THE FASTER
SOLUTIONS OFFERED UP BY THE RAP AND 06Z NAM WHICH SUGGEST WE COULD
SEE FALLING TEMPS INTO FAR NE IL BY 21Z...SPREADING ACROSS THE METRO
AREA BY 00Z WITH THE MOST DRAMATIC COOLING (10F+ DROP) NEAR THE LAKE
WITH LESS OF A DROP EXPECTED INLAND. MANY MODELS DO BREAK OUT LIGHT
QPF...LIKELY PARTIALLY ASSOCIATED WITH THIS LAKE ENHANCED FRONT THIS
AFTERNOON...BUT FORECAST SOUNDINGS FROM THE MODELS THAT SHOW QPF ALL
SHOW THERMODYNAMIC PROFILES THAT ARE EXCEPTIONALLY UNFAVORABLE FOR
PRECIPITATION WITH INVERSION/ISOTHERMAL LAYER BETWEEN 700-600MB WITH
DRY AIR ABOVE THAT. GIVEN THE LACK OF LARGE SCALE FORCING AND
UNFAVORABLE THERMODYNAMICS HAVE ONLY INTRODUCED SLIGHT CHANCE POPS
FOR LIGHT SHOWERS THIS AFTERNOON OVER FAR NE IL WHERE MET GUIDANCE
HAS POPS OVER 40 PERCENT.
WEATHER LOOKS QUIET THURSDAY AND MUCH OF FRIDAY WITH HIGH PRESSURE
TRACKING ACROSS THE REGION...ALLOWING FOR LAKE BREEZE AND SLIGHTLY
BELOW AVERAGE TEMPS THURSDAY FOLLOWED BY LESS (IF ANY) LAKE COOLING
FRIDAY WITH MODERATING TEMPS ON DEVELOPING SOUTHERLY WINDS.
VIGOROUS SHORTWAVE OVER DESSERT SOUTHWEST WILL RIDE THE SUBTROPICAL
JET AROUND THE PERIPHERY OF THE UPPER RIDGE AND EMERGE OUT ONTO THE
HIGH PLAINS THURSDAY NIGHT INTO FRIDAY. GFS PHASES THIS WAVE WITH
DEPARTING NORTHERN STREAM SHORTWAVE AND IS MUCH MORE PROGRESSIVE
WITH THE MOVEMENT OF THIS FEATURE ACROSS THE REGION. THE NAM AND
ECMWF KEEP THIS SHORTWAVE SEPARATE FROM THE NORTHERN STREAM AND
RESULT IN A MUCH SLOWER MEANDERING OF THIS FEATURE INTO THE AREA
THIS WEEKEND WITH GRADUALLY INCREASING CHANCES FOR AT LEAST
SCATTERED SHOWERS/STORMS. THE PROGRESSIVE GFS WOULD SUGGEST A WET
SATURDAY AND DRY SUNDAY...WHILE ECMWF HAS A MORE PROLONGED PERIOD OF
AT LEAST POTENTIAL SHOWER/TSTM ACTIVITY THROUGH THE WEEKEND INTO
EARLY NEXT WEEK. SUSPECT ECMWF SOLUTION WILL BE CLOSER TO WHAT
EVENTUALLY BECOMES REALITY...BUT CONFIDENCE IS LOW AND NECESSITATES
SEVERAL DAYS WITH CHANCES OF SHOWERS AND TSTMS OVER THE WEEKEND INTO
EARLY NEXT WEEK. TEMPERATURES AND HUMIDITY SHOULD CREEP UP BACK TO
MORE SEASONABLE LEVELS THIS WEEKEND INTO EARLY NEXT WEEK AS UPPER
TROUGH OVER THE GREAT LAKES THIS MORNING LIFTS OUT AND PATTERN
DEAMPLIFIES.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* LAKE BREEZE WITH WINDS BECOMING NE ARND 11 KT IN THE MID AFTN.
JEE
//DISCUSSION...UPDATED 12Z...
HIGH PRESSURE IS CENTERED WEST OF THE TERMINALS TODAY WHICH WILL
RESULT IN MODEST WNW/NW FLOW THROUGH THE FIRST HALF OF THE DAY. A
WEAK SURFACE TROUGH IS LOCATED OVER WISCONSIN AND WILL DROP SOUTH
ACROSS THE TERMINALS TODAY WITH WINDS FRESHENING UP SLIGHTLY THIS
AFTERNOON. FORECAST SOUNDINGS SHOW WINDS AT THE TOP OF THE MIXED
LAYER NEAR 20 KT...BUT INCREASING CLOUD COVER TODAY SHOULD HELP KEEP
GUSTS IN CHECK...THOUGH DID BUMP SUSTAINED SPEEDS UP SLIGHTLY. AS
THE SURFACE TROUGH MOVES SOUTH ACROSS THE TERMINALS THIS
AFTERNOON/EVENING IT WILL LIKELY COME IN THE FORM OF AN ENHANCED
LAKE BREEZE WHICH WILL SHIFT WINDS TO THE NORTHEAST. THERE MAY BE A
SHORT WINDOW OF 11-13KT WINDS FOR AN HOUR OR TWO BEHIND THE BOUNDARY
BEFORE WINDS SETTLE BACK DOWN BELOW 10 KT THROUGH THE REMAINDER OF
THE FORECAST PERIOD. VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN A LAKE BREEZE...HIGH CONFIDENCE IN TIMING
AND WIND SPEEDS ARND 11 KT.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT THROUGH FRIDAY...VFR.
FRIDAY NIGHT THROUGH TUESDAY...PRIMARILY VFR BUT WITH PERIODIC
CHANCES FOR TSRA.
BMD
&&
.MARINE...
300 AM CDT
CONDITIONS CONTINUE TO SLOWLY IMPROVE ACROSS LAKE MICHIGAN AS WINDS
AND WAVES DIMINISH BEHIND THE DEPARTING LOW SYSTEM CURRENTLY MOVING
ACROSS THE EASTERN LAKES. A SECONDARY TROUGH WILL WORK ITS WAY SOUTH
ACROSS LAKE MICHIGAN TODAY WITH WINDS PICKING UP SLIGHTLY OUT OF THE
NORTH...ESPECIALLY ACROSS THE NORTH HALF OF THE LAKE WHERE WIND
SPEEDS WILL INCREASE BACK INTO THE 15 TO 25 KT RANGE. HIGH PRESSURE
WILL MOVE ACROSS THE LAKE LATE THURSDAY INTO FRIDAY WITH WINDS THEN
TURNING BACK TO THE SOUTHWEST/SOUTH FRIDAY AND SATURDAY.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
906 AM CDT WED AUG 13 2014
.DISCUSSION...
336 AM CDT
PRIMARY FORECAST CHALLENGES THIS MORNING INCLUDE THE BACK DOOR FRONT
COMING IN OFF THE LAKE LATER THIS AFTERNOON OR EARLY THIS EVENING
AND ASSOCIATED PRECIP CHANCES...FOLLOWED BY PRECIP CHANCES WITH
TRICKY SYSTEM THIS WEEKEND.
SURFACE ANALYSIS EARLY THIS MORNING SHOWS A TYPICAL WEAK SUMMER COLD
FRONT EXTENDING FROM FAR NORTHERN LOWER MICHIGAN WEST INTO NORTHERN
WISCONSIN WHERE IT BECOMES PRETTY ILL DEFINED. THE FRONT WILL SAG
SOUTHWARD TODAY...BUT SHOULD BE AIDED BY AND ACCELERATE SOUTHWARD
DOWN LAKE MICHIGAN THIS AFTERNOON AND EVENING. WHILE THE LAKE HAS
WARMED...AIR TEMPS IN THE MARINE LAYER OVER THE LAKE ARE IN THE LOW
TO MID 60S SO CONTRASTED WITH THE 80 DEGREE TEMPS OVER LAND SHOULD
PROVIDE A DECENT PUSH OF COLDER AIR AS THE COLD FRONT BECOMES
ENHANCED BY THE LAKE. HAVE LEANED SLIGHTLY TOWARD THE FASTER
SOLUTIONS OFFERED UP BY THE RAP AND 06Z NAM WHICH SUGGEST WE COULD
SEE FALLING TEMPS INTO FAR NE IL BY 21Z...SPREADING ACROSS THE METRO
AREA BY 00Z WITH THE MOST DRAMATIC COOLING (10F+ DROP) NEAR THE LAKE
WITH LESS OF A DROP EXPECTED INLAND. MANY MODELS DO BREAK OUT LIGHT
QPF...LIKELY PARTIALLY ASSOCIATED WITH THIS LAKE ENHANCED FRONT THIS
AFTERNOON...BUT FORECAST SOUNDINGS FROM THE MODELS THAT SHOW QPF ALL
SHOW THERMODYNAMIC PROFILES THAT ARE EXCEPTIONALLY UNFAVORABLE FOR
PRECIPITATION WITH INVERSION/ISOTHERMAL LAYER BETWEEN 700-600MB WITH
DRY AIR ABOVE THAT. GIVEN THE LACK OF LARGE SCALE FORCING AND
UNFAVORABLE THERMODYNAMICS HAVE ONLY INTRODUCED SLIGHT CHANCE POPS
FOR LIGHT SHOWERS THIS AFTERNOON OVER FAR NE IL WHERE MET GUIDANCE
HAS POPS OVER 40 PERCENT.
WEATHER LOOKS QUIET THURSDAY AND MUCH OF FRIDAY WITH HIGH PRESSURE
TRACKING ACROSS THE REGION...ALLOWING FOR LAKE BREEZE AND SLIGHTLY
BELOW AVERAGE TEMPS THURSDAY FOLLOWED BY LESS (IF ANY) LAKE COOLING
FRIDAY WITH MODERATING TEMPS ON DEVELOPING SOUTHERLY WINDS.
VIGOROUS SHORTWAVE OVER DESSERT SOUTHWEST WILL RIDE THE SUBTROPICAL
JET AROUND THE PERIPHERY OF THE UPPER RIDGE AND EMERGE OUT ONTO THE
HIGH PLAINS THURSDAY NIGHT INTO FRIDAY. GFS PHASES THIS WAVE WITH
DEPARTING NORTHERN STREAM SHORTWAVE AND IS MUCH MORE PROGRESSIVE
WITH THE MOVEMENT OF THIS FEATURE ACROSS THE REGION. THE NAM AND
ECMWF KEEP THIS SHORTWAVE SEPARATE FROM THE NORTHERN STREAM AND
RESULT IN A MUCH SLOWER MEANDERING OF THIS FEATURE INTO THE AREA
THIS WEEKEND WITH GRADUALLY INCREASING CHANCES FOR AT LEAST
SCATTERED SHOWERS/STORMS. THE PROGRESSIVE GFS WOULD SUGGEST A WET
SATURDAY AND DRY SUNDAY...WHILE ECMWF HAS A MORE PROLONGED PERIOD OF
AT LEAST POTENTIAL SHOWER/TSTM ACTIVITY THROUGH THE WEEKEND INTO
EARLY NEXT WEEK. SUSPECT ECMWF SOLUTION WILL BE CLOSER TO WHAT
EVENTUALLY BECOMES REALITY...BUT CONFIDENCE IS LOW AND NECESSITATES
SEVERAL DAYS WITH CHANCES OF SHOWERS AND TSTMS OVER THE WEEKEND INTO
EARLY NEXT WEEK. TEMPERATURES AND HUMIDITY SHOULD CREEP UP BACK TO
MORE SEASONABLE LEVELS THIS WEEKEND INTO EARLY NEXT WEEK AS UPPER
TROUGH OVER THE GREAT LAKES THIS MORNING LIFTS OUT AND PATTERN
DEAMPLIFIES.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* LAKE BREEZE WITH WINDS BECOMING NE ARND 11 KT IN THE MID AFTN.
JEE
//DISCUSSION...UPDATED 12Z...
HIGH PRESSURE IS CENTERED WEST OF THE TERMINALS TODAY WHICH WILL
RESULT IN MODEST WNW/NW FLOW THROUGH THE FIRST HALF OF THE DAY. A
WEAK SURFACE TROUGH IS LOCATED OVER WISCONSIN AND WILL DROP SOUTH
ACROSS THE TERMINALS TODAY WITH WINDS FRESHENING UP SLIGHTLY THIS
AFTERNOON. FORECAST SOUNDINGS SHOW WINDS AT THE TOP OF THE MIXED
LAYER NEAR 20 KT...BUT INCREASING CLOUD COVER TODAY SHOULD HELP KEEP
GUSTS IN CHECK...THOUGH DID BUMP SUSTAINED SPEEDS UP SLIGHTLY. AS
THE SURFACE TROUGH MOVES SOUTH ACROSS THE TERMINALS THIS
AFTERNOON/EVENING IT WILL LIKELY COME IN THE FORM OF AN ENHANCED
LAKE BREEZE WHICH WILL SHIFT WINDS TO THE NORTHEAST. THERE MAY BE A
SHORT WINDOW OF 11-13KT WINDS FOR AN HOUR OR TWO BEHIND THE BOUNDARY
BEFORE WINDS SETTLE BACK DOWN BELOW 10 KT THROUGH THE REMAINDER OF
THE FORECAST PERIOD. VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN LAKE BREEZE...MEDIUM-HIGH CONFIDENCE IN
TIMING...MAY BE AN HOUR EARLIER THAN CURRENTLY FORECAST.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT THROUGH FRIDAY...VFR.
FRIDAY NIGHT THROUGH TUESDAY...PRIMARILY VFR BUT WITH PERIODIC
CHANCES FOR TSRA.
BMD
&&
.MARINE...
300 AM CDT
CONDITIONS CONTINUE TO SLOWLY IMPROVE ACROSS LAKE MICHIGAN AS WINDS
AND WAVES DIMINISH BEHIND THE DEPARTING LOW SYSTEM CURRENTLY MOVING
ACROSS THE EASTERN LAKES. A SECONDARY TROUGH WILL WORK ITS WAY SOUTH
ACROSS LAKE MICHIGAN TODAY WITH WINDS PICKING UP SLIGHTLY OUT OF THE
NORTH...ESPECIALLY ACROSS THE NORTH HALF OF THE LAKE WHERE WIND
SPEEDS WILL INCREASE BACK INTO THE 15 TO 25 KT RANGE. HIGH PRESSURE
WILL MOVE ACROSS THE LAKE LATE THURSDAY INTO FRIDAY WITH WINDS THEN
TURNING BACK TO THE SOUTHWEST/SOUTH FRIDAY AND SATURDAY.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 10 AM WEDNESDAY.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 10 AM
WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
617 AM CDT WED AUG 13 2014
.DISCUSSION...
336 AM CDT
PRIMARY FORECAST CHALLENGES THIS MORNING INCLUDE THE BACK DOOR FRONT
COMING IN OFF THE LAKE LATER THIS AFTERNOON OR EARLY THIS EVENING
AND ASSOCIATED PRECIP CHANCES...FOLLOWED BY PRECIP CHANCES WITH
TRICKY SYSTEM THIS WEEKEND.
SURFACE ANALYSIS EARLY THIS MORNING SHOWS A TYPICAL WEAK SUMMER COLD
FRONT EXTENDING FROM FAR NORTHERN LOWER MICHIGAN WEST INTO NORTHERN
WISCONSIN WHERE IT BECOMES PRETTY ILL DEFINED. THE FRONT WILL SAG
SOUTHWARD TODAY...BUT SHOULD BE AIDED BY AND ACCELERATE SOUTHWARD
DOWN LAKE MICHIGAN THIS AFTERNOON AND EVENING. WHILE THE LAKE HAS
WARMED...AIR TEMPS IN THE MARINE LAYER OVER THE LAKE ARE IN THE LOW
TO MID 60S SO CONTRASTED WITH THE 80 DEGREE TEMPS OVER LAND SHOULD
PROVIDE A DECENT PUSH OF COLDER AIR AS THE COLD FRONT BECOMES
ENHANCED BY THE LAKE. HAVE LEANED SLIGHTLY TOWARD THE FASTER
SOLUTIONS OFFERED UP BY THE RAP AND 06Z NAM WHICH SUGGEST WE COULD
SEE FALLING TEMPS INTO FAR NE IL BY 21Z...SPREADING ACROSS THE METRO
AREA BY 00Z WITH THE MOST DRAMATIC COOLING (10F+ DROP) NEAR THE LAKE
WITH LESS OF A DROP EXPECTED INLAND. MANY MODELS DO BREAK OUT LIGHT
QPF...LIKELY PARTIALLY ASSOCIATED WITH THIS LAKE ENHANCED FRONT THIS
AFTERNOON...BUT FORECAST SOUNDINGS FROM THE MODELS THAT SHOW QPF ALL
SHOW THERMODYNAMIC PROFILES THAT ARE EXCEPTIONALLY UNFAVORABLE FOR
PRECIPITATION WITH INVERSION/ISOTHERMAL LAYER BETWEEN 700-600MB WITH
DRY AIR ABOVE THAT. GIVEN THE LACK OF LARGE SCALE FORCING AND
UNFAVORABLE THERMODYNAMICS HAVE ONLY INTRODUCED SLIGHT CHANCE POPS
FOR LIGHT SHOWERS THIS AFTERNOON OVER FAR NE IL WHERE MET GUIDANCE
HAS POPS OVER 40 PERCENT.
WEATHER LOOKS QUIET THURSDAY AND MUCH OF FRIDAY WITH HIGH PRESSURE
TRACKING ACROSS THE REGION...ALLOWING FOR LAKE BREEZE AND SLIGHTLY
BELOW AVERAGE TEMPS THURSDAY FOLLOWED BY LESS (IF ANY) LAKE COOLING
FRIDAY WITH MODERATING TEMPS ON DEVELOPING SOUTHERLY WINDS.
VIGOROUS SHORTWAVE OVER DESSERT SOUTHWEST WILL RIDE THE SUBTROPICAL
JET AROUND THE PERIPHERY OF THE UPPER RIDGE AND EMERGE OUT ONTO THE
HIGH PLAINS THURSDAY NIGHT INTO FRIDAY. GFS PHASES THIS WAVE WITH
DEPARTING NORTHERN STREAM SHORTWAVE AND IS MUCH MORE PROGRESSIVE
WITH THE MOVEMENT OF THIS FEATURE ACROSS THE REGION. THE NAM AND
ECMWF KEEP THIS SHORTWAVE SEPARATE FROM THE NORTHERN STREAM AND
RESULT IN A MUCH SLOWER MEANDERING OF THIS FEATURE INTO THE AREA
THIS WEEKEND WITH GRADUALLY INCREASING CHANCES FOR AT LEAST
SCATTERED SHOWERS/STORMS. THE PROGRESSIVE GFS WOULD SUGGEST A WET
SATURDAY AND DRY SUNDAY...WHILE ECMWF HAS A MORE PROLONGED PERIOD OF
AT LEAST POTENTIAL SHOWER/TSTM ACTIVITY THROUGH THE WEEKEND INTO
EARLY NEXT WEEK. SUSPECT ECMWF SOLUTION WILL BE CLOSER TO WHAT
EVENTUALLY BECOMES REALITY...BUT CONFIDENCE IS LOW AND NECESSITATES
SEVERAL DAYS WITH CHANCES OF SHOWERS AND TSTMS OVER THE WEEKEND INTO
EARLY NEXT WEEK. TEMPERATURES AND HUMIDITY SHOULD CREEP UP BACK TO
MORE SEASONABLE LEVELS THIS WEEKEND INTO EARLY NEXT WEEK AS UPPER
TROUGH OVER THE GREAT LAKES THIS MORNING LIFTS OUT AND PATTERN
DEAMPLIFIES.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* WIND SHIFT TO NORTHEAST THIS AFTERNOON/EVENING.
BMD
//DISCUSSION...UPDATED 12Z...
HIGH PRESSURE IS CENTERED WEST OF THE TERMINALS TODAY WHICH WILL
RESULT IN MODEST WNW/NW FLOW THROUGH THE FIRST HALF OF THE DAY. A
WEAK SURFACE TROUGH IS LOCATED OVER WISCONSIN AND WILL DROP SOUTH
ACROSS THE TERMINALS TODAY WITH WINDS FRESHENING UP SLIGHTLY THIS
AFTERNOON. FORECAST SOUNDINGS SHOW WINDS AT THE TOP OF THE MIXED
LAYER NEAR 20 KT...BUT INCREASING CLOUD COVER TODAY SHOULD HELP KEEP
GUSTS IN CHECK...THOUGH DID BUMP SUSTAINED SPEEDS UP SLIGHTLY. AS
THE SURFACE TROUGH MOVES SOUTH ACROSS THE TERMINALS THIS
AFTERNOON/EVENING IT WILL LIKELY COME IN THE FORM OF AN ENHANCED
LAKE BREEZE WHICH WILL SHIFT WINDS TO THE NORTHEAST. THERE MAY BE A
SHORT WINDOW OF 11-13KT WINDS FOR AN HOUR OR TWO BEHIND THE BOUNDARY
BEFORE WINDS SETTLE BACK DOWN BELOW 10 KT THROUGH THE REMAINDER OF
THE FORECAST PERIOD. VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM-HIGH IN LAKE BREEZE TIMING TO WITHIN AN HOUR OR TWO.
* MEDIUM IN WIND SPEED TODAY.
* HIGH CONFIDENCE IN VFR.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT THROUGH FRIDAY...VFR.
FRIDAY NIGHT THROUGH TUESDAY...PRIMARILY VFR BUT WITH PERIODIC
CHANCES FOR TSRA.
BMD
&&
.MARINE...
300 AM CDT
CONDITIONS CONTINUE TO SLOWLY IMPROVE ACROSS LAKE MICHIGAN AS WINDS
AND WAVES DIMINISH BEHIND THE DEPARTING LOW SYSTEM CURRENTLY MOVING
ACROSS THE EASTERN LAKES. A SECONDARY TROUGH WILL WORK ITS WAY SOUTH
ACROSS LAKE MICHIGAN TODAY WITH WINDS PICKING UP SLIGHTLY OUT OF THE
NORTH...ESPECIALLY ACROSS THE NORTH HALF OF THE LAKE WHERE WIND
SPEEDS WILL INCREASE BACK INTO THE 15 TO 25 KT RANGE. HIGH PRESSURE
WILL MOVE ACROSS THE LAKE LATE THURSDAY INTO FRIDAY WITH WINDS THEN
TURNING BACK TO THE SOUTHWEST/SOUTH FRIDAY AND SATURDAY.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 10 AM WEDNESDAY.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 10 AM
WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
403 AM CDT WED AUG 13 2014
.DISCUSSION...
336 AM CDT
PRIMARY FORECAST CHALLENGES THIS MORNING INCLUDE THE BACK DOOR FRONT
COMING IN OFF THE LAKE LATER THIS AFTERNOON OR EARLY THIS EVENING
AND ASSOCIATED PRECIP CHANCES...FOLLOWED BY PRECIP CHANCES WITH
TRICKY SYSTEM THIS WEEKEND.
SURFACE ANALYSIS EARLY THIS MORNING SHOWS A TYPICAL WEAK SUMMER COLD
FRONT EXTENDING FROM FAR NORTHERN LOWER MICHIGAN WEST INTO NORTHERN
WISCONSIN WHERE IT BECOMES PRETTY ILL DEFINED. THE FRONT WILL SAG
SOUTHWARD TODAY...BUT SHOULD BE AIDED BY AND ACCELERATE SOUTHWARD
DOWN LAKE MICHIGAN THIS AFTERNOON AND EVENING. WHILE THE LAKE HAS
WARMED...AIR TEMPS IN THE MARINE LAYER OVER THE LAKE ARE IN THE LOW
TO MID 60S SO CONTRASTED WITH THE 80 DEGREE TEMPS OVER LAND SHOULD
PROVIDE A DECENT PUSH OF COLDER AIR AS THE COLD FRONT BECOMES
ENHANCED BY THE LAKE. HAVE LEANED SLIGHTLY TOWARD THE FASTER
SOLUTIONS OFFERED UP BY THE RAP AND 06Z NAM WHICH SUGGEST WE COULD
SEE FALLING TEMPS INTO FAR NE IL BY 21Z...SPREADING ACROSS THE METRO
AREA BY 00Z WITH THE MOST DRAMATIC COOLING (10F+ DROP) NEAR THE LAKE
WITH LESS OF A DROP EXPECTED INLAND. MANY MODELS DO BREAK OUT LIGHT
QPF...LIKELY PARTIALLY ASSOCIATED WITH THIS LAKE ENHANCED FRONT THIS
AFTERNOON...BUT FORECAST SOUNDINGS FROM THE MODELS THAT SHOW QPF ALL
SHOW THERMODYNAMIC PROFILES THAT ARE EXCEPTIONALLY UNFAVORABLE FOR
PRECIPITATION WITH INVERSION/ISOTHERMAL LAYER BETWEEN 700-600MB WITH
DRY AIR ABOVE THAT. GIVEN THE LACK OF LARGE SCALE FORCING AND
UNFAVORABLE THERMODYNAMICS HAVE ONLY INTRODUCED SLIGHT CHANCE POPS
FOR LIGHT SHOWERS THIS AFTERNOON OVER FAR NE IL WHERE MET GUIDANCE
HAS POPS OVER 40 PERCENT.
WEATHER LOOKS QUIET THURSDAY AND MUCH OF FRIDAY WITH HIGH PRESSURE
TRACKING ACROSS THE REGION...ALLOWING FOR LAKE BREEZE AND SLIGHTLY
BELOW AVERAGE TEMPS THURSDAY FOLLOWED BY LESS (IF ANY) LAKE COOLING
FRIDAY WITH MODERATING TEMPS ON DEVELOPING SOUTHERLY WINDS.
VIGOROUS SHORTWAVE OVER DESSERT SOUTHWEST WILL RIDE THE SUBTROPICAL
JET AROUND THE PERIPHERY OF THE UPPER RIDGE AND EMERGE OUT ONTO THE
HIGH PLAINS THURSDAY NIGHT INTO FRIDAY. GFS PHASES THIS WAVE WITH
DEPARTING NORTHERN STREAM SHORTWAVE AND IS MUCH MORE PROGRESSIVE
WITH THE MOVEMENT OF THIS FEATURE ACROSS THE REGION. THE NAM AND
ECMWF KEEP THIS SHORTWAVE SEPARATE FROM THE NORTHERN STREAM AND
RESULT IN A MUCH SLOWER MEANDERING OF THIS FEATURE INTO THE AREA
THIS WEEKEND WITH GRADUALLY INCREASING CHANCES FOR AT LEAST
SCATTERED SHOWERS/STORMS. THE PROGRESSIVE GFS WOULD SUGGEST A WET
SATURDAY AND DRY SUNDAY...WHILE ECMWF HAS A MORE PROLONGED PERIOD OF
AT LEAST POTENTIAL SHOWER/TSTM ACTIVITY THROUGH THE WEEKEND INTO
EARLY NEXT WEEK. SUSPECT ECMWF SOLUTION WILL BE CLOSER TO WHAT
EVENTUALLY BECOMES REALITY...BUT CONFIDENCE IS LOW AND NECESSITATES
SEVERAL DAYS WITH CHANCES OF SHOWERS AND TSTMS OVER THE WEEKEND INTO
EARLY NEXT WEEK. TEMPERATURES AND HUMIDITY SHOULD CREEP UP BACK TO
MORE SEASONABLE LEVELS THIS WEEKEND INTO EARLY NEXT WEEK AS UPPER
TROUGH OVER THE GREAT LAKES THIS MORNING LIFTS OUT AND PATTERN
DEAMPLIFIES.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* WIND SHIFT TO NORTHEAST WEDNESDAY EVENING.
BMD
//DISCUSSION...UPDATED 06Z...
HIGH PRESSURE IS CENTERED ACROSS THE MID MISSOURI VALLEY THIS
EVENING WITH LIGHT FLOW AND VFR CONDITIONS EXPECTED THROUGH THE
OVERNIGHT HOURS. WINDS WILL GENERALLY BE OUT OF THE WEST TO
NORTHWEST THROUGH EARLY TO MID AFTERNOON TOMORROW...THEN A WEAK
TROUGH DROPPING ACROSS THE REGION WILL BACK THE WINDS MORE
PREDOMINATELY TO THE WEST...POSSIBLY SOUTHWEST FOR A PERIOD IN THE
AFTERNOON...BEFORE SHIFTING TO THE NORTHEAST WEDNESDAY EVENING
BEHIND THE TROUGH/LAKE BREEZE.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* MEDIUM IN WIND SHIFT TIMING.
* HIGH IN REMAINING FORECAST ELEMENTS.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...VFR. WX NIL.
FRIDAY...VFR. WX NIL. LAKE BREEZE DEVELOPMENT POSSIBLE.
FRIDAY NIGHT THROUGH MONDAY...PERIODIC CHANCES SHRA/TSRA. OCNL
PERIODS OF MVFR CIGS/VIS POSSIBLE.
KREIN
&&
.MARINE...
300 AM CDT
CONDITIONS CONTINUE TO SLOWLY IMPROVE ACROSS LAKE MICHIGAN AS WINDS
AND WAVES DIMINISH BEHIND THE DEPARTING LOW SYSTEM CURRENTLY MOVING
ACROSS THE EASTERN LAKES. A SECONDARY TROUGH WILL WORK ITS WAY SOUTH
ACROSS LAKE MICHIGAN TODAY WITH WINDS PICKING UP SLIGHTLY OUT OF THE
NORTH...ESPECIALLY ACROSS THE NORTH HALF OF THE LAKE WHERE WIND
SPEEDS WILL INCREASE BACK INTO THE 15 TO 25 KT RANGE. HIGH PRESSURE
WILL MOVE ACROSS THE LAKE LATE THURSDAY INTO FRIDAY WITH WINDS THEN
TURNING BACK TO THE SOUTHWEST/SOUTH FRIDAY AND SATURDAY.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 10 AM WEDNESDAY.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 10 AM
WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
336 AM CDT WED AUG 13 2014
.DISCUSSION...
336 AM CDT
PRIMARY FORECAST CHALLENGES THIS MORNING INCLUDE THE BACK DOOR FRONT
COMING IN OFF THE LAKE LATER THIS AFTERNOON OR EARLY THIS EVENING
AND ASSOCIATED PRECIP CHANCES...FOLLOWED BY PRECIP CHANCES WITH
TRICKY SYSTEM THIS WEEKEND.
SURFACE ANALYSIS EARLY THIS MORNING SHOWS A TYPICAL WEAK SUMMER COLD
FRONT EXTENDING FROM FAR NORTHERN LOWER MICHIGAN WEST INTO NORTHERN
WISCONSIN WHERE IT BECOMES PRETTY ILL DEFINED. THE FRONT WILL SAG
SOUTHWARD TODAY...BUT SHOULD BE AIDED BY AND ACCELERATE SOUTHWARD
DOWN LAKE MICHIGAN THIS AFTERNOON AND EVENING. WHILE THE LAKE HAS
WARMED...AIR TEMPS IN THE MARINE LAYER OVER THE LAKE ARE IN THE LOW
TO MID 60S SO CONTRASTED WITH THE 80 DEGREE TEMPS OVER LAND SHOULD
PROVIDE A DECENT PUSH OF COLDER AIR AS THE COLD FRONT BECOMES
ENHANCED BY THE LAKE. HAVE LEANED SLIGHTLY TOWARD THE FASTER
SOLUTIONS OFFERED UP BY THE RAP AND 06Z NAM WHICH SUGGEST WE COULD
SEE FALLING TEMPS INTO FAR NE IL BY 21Z...SPREADING ACROSS THE METRO
AREA BY 00Z WITH THE MOST DRAMATIC COOLING (10F+ DROP) NEAR THE LAKE
WITH LESS OF A DROP EXPECTED INLAND. MANY MODELS DO BREAK OUT LIGHT
QPF...LIKELY PARTIALLY ASSOCIATED WITH THIS LAKE ENHANCED FRONT THIS
AFTERNOON...BUT FORECAST SOUNDINGS FROM THE MODELS THAT SHOW QPF ALL
SHOW THERMODYNAMIC PROFILES THAT ARE EXCEPTIONALLY UNFAVORABLE FOR
PRECIPITATION WITH INVERSION/ISOTHERMAL LAYER BETWEEN 700-600MB WITH
DRY AIR ABOVE THAT. GIVEN THE LACK OF LARGE SCALE FORCING AND
UNFAVORABLE THERMODYNAMICS HAVE ONLY INTRODUCED SLIGHT CHANCE POPS
FOR LIGHT SHOWERS THIS AFTERNOON OVER FAR NE IL WHERE MET GUIDANCE
HAS POPS OVER 40 PERCENT.
WEATHER LOOKS QUIET THURSDAY AND MUCH OF FRIDAY WITH HIGH PRESSURE
TRACKING ACROSS THE REGION...ALLOWING FOR LAKE BREEZE AND SLIGHTLY
BELOW AVERAGE TEMPS THURSDAY FOLLOWED BY LESS (IF ANY) LAKE COOLING
FRIDAY WITH MODERATING TEMPS ON DEVELOPING SOUTHERLY WINDS.
VIGOROUS SHORTWAVE OVER DESSERT SOUTHWEST WILL RIDE THE SUBTROPICAL
JET AROUND THE PERIPHERY OF THE UPPER RIDGE AND EMERGE OUT ONTO THE
HIGH PLAINS THURSDAY NIGHT INTO FRIDAY. GFS PHASES THIS WAVE WITH
DEPARTING NORTHERN STREAM SHORTWAVE AND IS MUCH MORE PROGRESSIVE
WITH THE MOVEMENT OF THIS FEATURE ACROSS THE REGION. THE NAM AND
ECMWF KEEP THIS SHORTWAVE SEPARATE FROM THE NORTHERN STREAM AND
RESULT IN A MUCH SLOWER MEANDERING OF THIS FEATURE INTO THE AREA
THIS WEEKEND WITH GRADUALLY INCREASING CHANCES FOR AT LEAST
SCATTERED SHOWERS/STORMS. THE PROGRESSIVE GFS WOULD SUGGEST A WET
SATURDAY AND DRY SUNDAY...WHILE ECMWF HAS A MORE PROLONGED PERIOD OF
AT LEAST POTENTIAL SHOWER/TSTM ACTIVITY THROUGH THE WEEKEND INTO
EARLY NEXT WEEK. SUSPECT ECMWF SOLUTION WILL BE CLOSER TO WHAT
EVENTUALLY BECOMES REALITY...BUT CONFIDENCE IS LOW AND NECESSITATES
SEVERAL DAYS WITH CHANCES OF SHOWERS AND TSTMS OVER THE WEEKEND INTO
EARLY NEXT WEEK. TEMPERATURES AND HUMIDITY SHOULD CREEP UP BACK TO
MORE SEASONABLE LEVELS THIS WEEKEND INTO EARLY NEXT WEEK AS UPPER
TROUGH OVER THE GREAT LAKES THIS MORNING LIFTS OUT AND PATTERN
DEAMPLIFIES.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* WIND SHIFT TO NORTHEAST WEDNESDAY EVENING.
BMD
//DISCUSSION...UPDATED 06Z...
HIGH PRESSURE IS CENTERED ACROSS THE MID MISSOURI VALLEY THIS
EVENING WITH LIGHT FLOW AND VFR CONDITIONS EXPECTED THROUGH THE
OVERNIGHT HOURS. WINDS WILL GENERALLY BE OUT OF THE WEST TO
NORTHWEST THROUGH EARLY TO MID AFTERNOON TOMORROW...THEN A WEAK
TROUGH DROPPING ACROSS THE REGION WILL BACK THE WINDS MORE
PREDOMINATELY TO THE WEST...POSSIBLY SOUTHWEST FOR A PERIOD IN THE
AFTERNOON...BEFORE SHIFTING TO THE NORTHEAST WEDNESDAY EVENING
BEHIND THE TROUGH/LAKE BREEZE.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM IN WIND SHIFT TIMING.
* HIGH IN REMAINING FORECAST ELEMENTS.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...VFR. WX NIL.
FRIDAY...VFR. WX NIL. LAKE BREEZE DEVELOPMENT POSSIBLE.
FRIDAY NIGHT THROUGH MONDAY...PERIODIC CHANCES SHRA/TSRA. OCNL
PERIODS OF MVFR CIGS/VIS POSSIBLE.
KREIN
&&
.MARINE...
300 AM CDT
CONDITIONS CONTINUE TO SLOWLY IMPROVE ACROSS LAKE MICHIGAN AS WINDS
AND WAVES DIMINISH BEHIND THE DEPARTING LOW SYSTEM CURRENTLY MOVING
ACROSS THE EASTERN LAKES. A SECONDARY TROUGH WILL WORK ITS WAY SOUTH
ACROSS LAKE MICHIGAN TODAY WITH WINDS PICKING UP SLIGHTLY OUT OF THE
NORTH...ESPECIALLY ACROSS THE NORTH HALF OF THE LAKE WHERE WIND
SPEEDS WILL INCREASE BACK INTO THE 15 TO 25 KT RANGE. HIGH PRESSURE
WILL MOVE ACROSS THE LAKE LATE THURSDAY INTO FRIDAY WITH WINDS THEN
TURNING BACK TO THE SOUTHWEST/SOUTH FRIDAY AND SATURDAY.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014 UNTIL 4 AM WEDNESDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 10 AM WEDNESDAY.
LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 4 AM WEDNESDAY.
SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 10 AM
WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
300 AM CDT WED AUG 13 2014
.DISCUSSION...
815 PM CDT
SOME SMALL ADJUSTMENTS MADE TO THE FORECAST THE REMAINDER OF
TONIGHT. THE MOST NOTABLE ONE...ESPECIALLY FOR STARGAZERS HOPING TO
CATCH THE PERSEID METEOR SHOWER...WAS TO INCREASE SKY COVER
SLIGHTLY LATE TONIGHT. AREA OF CLOSE-CELLED CLOUDS ACROSS NORTHERN
MN INTO FAR NORTHWEST WI IS PROGRESSING SOUTH ON AN ANOMALOUSLY
STRONG AND MERIDIONAL UPPER/MID LEVEL JET FOR SUMMERTIME. THE 00Z
INL SOUNDING INDICATED A SATURATED LAYER ABOUT 7000 FT THICK WITH
THIS. LOOKING AT MODEL SOLUTIONS OF MOISTURE ON CORRELATING
THICKNESSES...THEY DO BRING HIGHER MOISTURE INTO NORTHERN IL LATE
TONIGHT. THE RAP IS THE MOST BULLISH AND BELIEVE TOO MUCH AS SOME
THINNING SHOULD OCCUR. HAVE LEANED MORE TOWARD FEW TO SCATTERED
CLOUDS DRIFTING OVER AREA LATER...NAMELY AFTER 2 AM.
DEW POINTS HAVE BEEN SLOW TO FALL WITH MID TO EVEN SOME UPPER 50S
LINGERING IN NORTH CENTRAL IL...WHICH IS A BIT CONCERNING FOR LOWS
FORECAST TO REACH THE UPPER 40S-LOWER 50S. BELIEVE THE AIR MASS
SHOULD ALLOW THE DEW POINTS TO FALL SOME WITH A CONTINUED LIGHT
NORTHERLY WIND...BUT MAYBE NOT ENOUGH FOR CURRENT FORECAST LOWS.
HAVE BUMPED UP A DEGREE OR TWO IN OUTLYING AREAS AT THIS POINT
AND WILL CONTINUE TO MONITOR.
MTF
//PREV DISCUSSION...
307 PM CDT
AFTERNOON GOES VAPOR IMAGERY DEPICTS STRONG MID-LEVEL SHORT WAVE
CONTINUES TO DIG SOUTHEAST ACROSS SOUTHERN LAKE MICHIGAN/NORTHEAST
ILLINOIS AND NORTHWEST INDIANA. RAIN SHOWERS HAVE DECREASED IN
COVERAGE WITH MAINLY SOME LIGHT SPRINKLES STILL ACROSS PARTS OF COOK
LAKE AND PORTER COUNTIES. PRECIP SHOULD COME TO AN END OVER THE NEXT
COUPLE OF HOURS AS THE MID-LEVEL TROUGH AND VORT AXES MOVE SOUTHEAST
OF THE AREA...WITH RISING HEIGHTS AND SUBSIDENCE WORKING TO ERODE
CLOUD COVER FROM THE WEST/NORTHWEST INTO THIS EVENING. DECREASING
CLOUD COVER OVER THE EASTERN HALF OF THE CWA SHOULD OCCUR IN TIME
FOR METEOR SHOWER VIEWING OVERNIGHT. COOLER/DRIER AIR FILTERING INTO
THE REGION FROM THE NORTH...COMBINED WITH DECREASING WINDS TONIGHT
AS SURFACE HIGH PRESSURE DRIFTS EAST ACROSS THE PLAINS AND ALLOWS
WEAKENING OF THE GRADIENT EAST OF THE MISSISSIPPI...WILL ALLOW FOR
TEMPS TO FALL INTO THE LOWER 50S AWAY FROM THE CITY AND EVEN INTO
THE UPPER 40S IN SOME OF THE TYPICALLY COLDER SPOTS.
ON WEDNESDAY...NORTHWEST FLOW CONTINUES ALOFT WITH DEEP TROUGH OVER
EASTERN NORTH AMERICA. GUIDANCE HAS BEEN PERSISTENT IN BRINGING A
SHORT WAVE SOUTHEAST THROUGH THE WESTERN PERIPHERY OF THE EASTERN
TROUGH WITH A WEAK SURFACE REFLECTION AND COLD FRONTAL TROUGH WHICH
PUSHES SOUTH FROM WI AND ACROSS NORTHERN IL/IN DURING THE LATE
AFTERNOON AND EVENING HOURS. MOST MODELS SQUEEZE OUT SOME VERY LIGHT
SPOTTY QPF ALONG/AHEAD OF THE FRONT IN THE AFTERNOON...THOUGH IT
APPEARS THAT MODEL BOUNDARY LAYER MOISTURE IS A BIT OVERDONE WHICH
IN TURN YIELDS WEAK CAPE/MOIST LAYER THAT IS ALSO SUSPECTED TO BE
OVER-FORECAST. THUS HAVE MAINTAINED DRY FORECAST THROUGH WEDNESDAY
WITH FRONTAL PASSAGE. FRONT/TROUGH MAY "BACK-DOOR" INTO FAR
NORTHEAST IL TOWARD EVENING BRINGING A QUICK COOLING INTO THE 60S
ALONG THE LAKE MICHIGAN SHORE ESPECIALLY IN LAKE COUNTY IL.
OTHERWISE...SHOULD BE A GOOD DEAL OF SUNSHINE WITH TEMPS REBOUNDING
TO AROUND 80/LOW 80S ACROSS WESTERN CWA WEDNESDAY...AND IN THE
MID-UPPER 70S FARTHER EAST. COOL 50S (AWAY FROM THE URBAN CORE OF
CHICAGO) EXPECTED BEHIND THE FRONT WEDNESDAY NIGHT...WITH ANOTHER
PLEASANT DAY THURSDAY WITH 70S EAST TO NEAR 80 WEST AS HIGH PRESSURE
BUILDS INTO THE REGION. HIGH PRESSURE REMAINS IN CONTROL INTO FRIDAY
THOUGH THE CENTER OF THE HIGH SLIDES EAST...ALLOWING DEVELOPMENT OF
SOUTHERLY RETURN FLOW AND ASSOCIATED WARM/MOIST ADVECTION ACROSS THE
PLAINS AND MISSISSIPPI VALLEY.
THE EXTENDED FORECAST PERIOD SATURDAY-TUESDAY LOOKS TO HAVE WARMER
TEMPS...BUT ALSO PERIODIC CHANCES OF THUNDERSTORMS AS SOUTHERLY LOW
LEVEL FLOW SETS UP AND SLOW MOVING MID-LEVEL DISTURBANCE MOVES
SLOWLY WEST TO EAST ACROSS THE REGION. TIMING DIFFERENCES DO EXIST
BETWEEN THE GLOBAL RUNS BEYOND THE FRIDAY NIGHT-SATURDAY PERIOD.
GOOD AGREEMENT IN DEVELOPMENT OF SURFACE LOW AND WARM FRONT FROM
NORTHERN MO/IA BORDER EAST INTO IN/OHIO VALLEY REGION WITH PRECIP
PRODUCTION AT VARIOUS TIMES EACH DAY. WITH DETAIL DIFFERENCES
INCREASING INTO THE MONDAY/TUESDAY TIMEFRAME HAVE MAINTAINED A
BLENDED GUIDANCE APPROACH WITH CHANCE POPS AND TEMPS WARMING INTO
THE LOW/MID 80S...THEN COOLING FROM THE NORTH A BIT TUESDAY WITH
HINT OF COLD FRONTAL TROUGH PASSAGE. PROBABLY NOT A TOTAL RAIN-OUT
IN REALITY FOR THE WEEKEND...AND FORECAST WILL BE REFINED AS THE
DETAILS BECOME CLEARER OVER THE NEXT SEVERAL DAYS.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* WIND SHIFT TO NORTHEAST WEDNESDAY EVENING.
BMD
//DISCUSSION...UPDATED 06Z...
HIGH PRESSURE IS CENTERED ACROSS THE MID MISSOURI VALLEY THIS
EVENING WITH LIGHT FLOW AND VFR CONDITIONS EXPECTED THROUGH THE
OVERNIGHT HOURS. WINDS WILL GENERALLY BE OUT OF THE WEST TO
NORTHWEST THROUGH EARLY TO MID AFTERNOON TOMORROW...THEN A WEAK
TROUGH DROPPING ACROSS THE REGION WILL BACK THE WINDS MORE
PREDOMINATELY TO THE WEST...POSSIBLY SOUTHWEST FOR A PERIOD IN THE
AFTERNOON...BEFORE SHIFTING TO THE NORTHEAST WEDNESDAY EVENING
BEHIND THE TROUGH/LAKE BREEZE.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM IN WIND SHIFT TIMING.
* HIGH IN REMAINING FORECAST ELEMENTS.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...VFR. WX NIL.
FRIDAY...VFR. WX NIL. LAKE BREEZE DEVELOPMENT POSSIBLE.
FRIDAY NIGHT THROUGH MONDAY...PERIODIC CHANCES SHRA/TSRA. OCNL
PERIODS OF MVFR CIGS/VIS POSSIBLE.
KREIN
&&
.MARINE...
300 AM CDT
CONDITIONS CONTINUE TO SLOWLY IMPROVE ACROSS LAKE MICHIGAN AS WINDS
AND WAVES DIMINISH BEHIND THE DEPARTING LOW SYSTEM CURRENTLY MOVING
ACROSS THE EASTERN LAKES. A SECONDARY TROUGH WILL WORK ITS WAY SOUTH
ACROSS LAKE MICHIGAN TODAY WITH WINDS PICKING UP SLIGHTLY OUT OF THE
NORTH...ESPECIALLY ACROSS THE NORTH HALF OF THE LAKE WHERE WIND
SPEEDS WILL INCREASE BACK INTO THE 15 TO 25 KT RANGE. HIGH PRESSURE
WILL MOVE ACROSS THE LAKE LATE THURSDAY INTO FRIDAY WITH WINDS THEN
TURNING BACK TO THE SOUTHWEST/SOUTH FRIDAY AND SATURDAY.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014 UNTIL 4 AM WEDNESDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 10 AM WEDNESDAY.
LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 4 AM WEDNESDAY.
SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 10 AM
WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1232 AM CDT WED AUG 13 2014
.DISCUSSION...
815 PM CDT
SOME SMALL ADJUSTMENTS MADE TO THE FORECAST THE REMAINDER OF
TONIGHT. THE MOST NOTABLE ONE...ESPECIALLY FOR STARGAZERS HOPING TO
CATCH THE PERSEID METEOR SHOWER...WAS TO INCREASE SKY COVER
SLIGHTLY LATE TONIGHT. AREA OF CLOSE-CELLED CLOUDS ACROSS NORTHERN
MN INTO FAR NORTHWEST WI IS PROGRESSING SOUTH ON AN ANOMALOUSLY
STRONG AND MERIDIONAL UPPER/MID LEVEL JET FOR SUMMERTIME. THE 00Z
INL SOUNDING INDICATED A SATURATED LAYER ABOUT 7000 FT THICK WITH
THIS. LOOKING AT MODEL SOLUTIONS OF MOISTURE ON CORRELATING
THICKNESSES...THEY DO BRING HIGHER MOISTURE INTO NORTHERN IL LATE
TONIGHT. THE RAP IS THE MOST BULLISH AND BELIEVE TOO MUCH AS SOME
THINNING SHOULD OCCUR. HAVE LEANED MORE TOWARD FEW TO SCATTERED
CLOUDS DRIFTING OVER AREA LATER...NAMELY AFTER 2 AM.
DEW POINTS HAVE BEEN SLOW TO FALL WITH MID TO EVEN SOME UPPER 50S
LINGERING IN NORTH CENTRAL IL...WHICH IS A BIT CONCERNING FOR LOWS
FORECAST TO REACH THE UPPER 40S-LOWER 50S. BELIEVE THE AIR MASS
SHOULD ALLOW THE DEW POINTS TO FALL SOME WITH A CONTINUED LIGHT
NORTHERLY WIND...BUT MAYBE NOT ENOUGH FOR CURRENT FORECAST LOWS.
HAVE BUMPED UP A DEGREE OR TWO IN OUTLYING AREAS AT THIS POINT
AND WILL CONTINUE TO MONITOR.
MTF
//PREV DISCUSSION...
307 PM CDT
AFTERNOON GOES VAPOR IMAGERY DEPICTS STRONG MID-LEVEL SHORT WAVE
CONTINUES TO DIG SOUTHEAST ACROSS SOUTHERN LAKE MICHIGAN/NORTHEAST
ILLINOIS AND NORTHWEST INDIANA. RAIN SHOWERS HAVE DECREASED IN
COVERAGE WITH MAINLY SOME LIGHT SPRINKLES STILL ACROSS PARTS OF COOK
LAKE AND PORTER COUNTIES. PRECIP SHOULD COME TO AN END OVER THE NEXT
COUPLE OF HOURS AS THE MID-LEVEL TROUGH AND VORT AXES MOVE SOUTHEAST
OF THE AREA...WITH RISING HEIGHTS AND SUBSIDENCE WORKING TO ERODE
CLOUD COVER FROM THE WEST/NORTHWEST INTO THIS EVENING. DECREASING
CLOUD COVER OVER THE EASTERN HALF OF THE CWA SHOULD OCCUR IN TIME
FOR METEOR SHOWER VIEWING OVERNIGHT. COOLER/DRIER AIR FILTERING INTO
THE REGION FROM THE NORTH...COMBINED WITH DECREASING WINDS TONIGHT
AS SURFACE HIGH PRESSURE DRIFTS EAST ACROSS THE PLAINS AND ALLOWS
WEAKENING OF THE GRADIENT EAST OF THE MISSISSIPPI...WILL ALLOW FOR
TEMPS TO FALL INTO THE LOWER 50S AWAY FROM THE CITY AND EVEN INTO
THE UPPER 40S IN SOME OF THE TYPICALLY COLDER SPOTS.
ON WEDNESDAY...NORTHWEST FLOW CONTINUES ALOFT WITH DEEP TROUGH OVER
EASTERN NORTH AMERICA. GUIDANCE HAS BEEN PERSISTENT IN BRINGING A
SHORT WAVE SOUTHEAST THROUGH THE WESTERN PERIPHERY OF THE EASTERN
TROUGH WITH A WEAK SURFACE REFLECTION AND COLD FRONTAL TROUGH WHICH
PUSHES SOUTH FROM WI AND ACROSS NORTHERN IL/IN DURING THE LATE
AFTERNOON AND EVENING HOURS. MOST MODELS SQUEEZE OUT SOME VERY LIGHT
SPOTTY QPF ALONG/AHEAD OF THE FRONT IN THE AFTERNOON...THOUGH IT
APPEARS THAT MODEL BOUNDARY LAYER MOISTURE IS A BIT OVERDONE WHICH
IN TURN YIELDS WEAK CAPE/MOIST LAYER THAT IS ALSO SUSPECTED TO BE
OVER-FORECAST. THUS HAVE MAINTAINED DRY FORECAST THROUGH WEDNESDAY
WITH FRONTAL PASSAGE. FRONT/TROUGH MAY "BACK-DOOR" INTO FAR
NORTHEAST IL TOWARD EVENING BRINGING A QUICK COOLING INTO THE 60S
ALONG THE LAKE MICHIGAN SHORE ESPECIALLY IN LAKE COUNTY IL.
OTHERWISE...SHOULD BE A GOOD DEAL OF SUNSHINE WITH TEMPS REBOUNDING
TO AROUND 80/LOW 80S ACROSS WESTERN CWA WEDNESDAY...AND IN THE
MID-UPPER 70S FARTHER EAST. COOL 50S (AWAY FROM THE URBAN CORE OF
CHICAGO) EXPECTED BEHIND THE FRONT WEDNESDAY NIGHT...WITH ANOTHER
PLEASANT DAY THURSDAY WITH 70S EAST TO NEAR 80 WEST AS HIGH PRESSURE
BUILDS INTO THE REGION. HIGH PRESSURE REMAINS IN CONTROL INTO FRIDAY
THOUGH THE CENTER OF THE HIGH SLIDES EAST...ALLOWING DEVELOPMENT OF
SOUTHERLY RETURN FLOW AND ASSOCIATED WARM/MOIST ADVECTION ACROSS THE
PLAINS AND MISSISSIPPI VALLEY.
THE EXTENDED FORECAST PERIOD SATURDAY-TUESDAY LOOKS TO HAVE WARMER
TEMPS...BUT ALSO PERIODIC CHANCES OF THUNDERSTORMS AS SOUTHERLY LOW
LEVEL FLOW SETS UP AND SLOW MOVING MID-LEVEL DISTURBANCE MOVES
SLOWLY WEST TO EAST ACROSS THE REGION. TIMING DIFFERENCES DO EXIST
BETWEEN THE GLOBAL RUNS BEYOND THE FRIDAY NIGHT-SATURDAY PERIOD.
GOOD AGREEMENT IN DEVELOPMENT OF SURFACE LOW AND WARM FRONT FROM
NORTHERN MO/IA BORDER EAST INTO IN/OHIO VALLEY REGION WITH PRECIP
PRODUCTION AT VARIOUS TIMES EACH DAY. WITH DETAIL DIFFERENCES
INCREASING INTO THE MONDAY/TUESDAY TIMEFRAME HAVE MAINTAINED A
BLENDED GUIDANCE APPROACH WITH CHANCE POPS AND TEMPS WARMING INTO
THE LOW/MID 80S...THEN COOLING FROM THE NORTH A BIT TUESDAY WITH
HINT OF COLD FRONTAL TROUGH PASSAGE. PROBABLY NOT A TOTAL RAIN-OUT
IN REALITY FOR THE WEEKEND...AND FORECAST WILL BE REFINED AS THE
DETAILS BECOME CLEARER OVER THE NEXT SEVERAL DAYS.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* WIND SHIFT TO NORTHEAST WEDNESDAY EVENING.
BMD
//DISCUSSION...UPDATED 06Z...
HIGH PRESSURE IS CENTERED ACROSS THE MID MISSOURI VALLEY THIS
EVENING WITH LIGHT FLOW AND VFR CONDITIONS EXPECTED THROUGH THE
OVERNIGHT HOURS. WINDS WILL GENERALLY BE OUT OF THE WEST TO
NORTHWEST THROUGH EARLY TO MID AFTERNOON TOMORROW...THEN A WEAK
TROUGH DROPPING ACROSS THE REGION WILL BACK THE WINDS MORE
PREDOMINATELY TO THE WEST...POSSIBLY SOUTHWEST FOR A PERIOD IN THE
AFTERNOON...BEFORE SHIFTING TO THE NORTHEAST WEDNESDAY EVENING
BEHIND THE TROUGH/LAKE BREEZE.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM IN WIND SHIFT TIMING.
* HIGH IN REMAINING FORECAST ELEMENTS.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...VFR. WX NIL.
FRIDAY...VFR. WX NIL. LAKE BREEZE DEVELOPMENT POSSIBLE.
FRIDAY NIGHT THROUGH MONDAY...PERIODIC CHANCES SHRA/TSRA. OCNL
PERIODS OF MVFR CIGS/VIS POSSIBLE.
KREIN
&&
.MARINE...
252 PM CDT
WITH LOW PRESSURE JUST NORTHEAST OF THE LAKE AND A FAIRLY TIGHT
PRESSURE GRADIENT OVER THE LAKE...WINDS AND WAVES DID
INCREASE/BUILD ACROSS THE ENTIRE LAKE. BOTH BUOY AND SHIP OBS HAVE
REPORTED AROUND GALES OR SLIGHTLY HIGHER OVER THE LAST COUPLE OF
HOURS...WITH TO 30 KT WINDS BEING REPORTED ELSEWHERE. GRADIENT
OVER THE LAKE WILL BEGIN WEAKENING THIS AFTERNOON WITH SPEEDS
DIMINISHING THROUGH THE EVENING TIME FRAME. WILL CANCEL/EXPIRE THE
GALE WARNING IN PLACE THROUGH 20Z AS THE STRONGEST WINDS SHOULD BE
OVER. WILL LIKELY MAKE MENTION OF A FEW GALE FORCE GUSTS FOR THE
REMAINDER OF THE AFTERNOON IN THE GLF NORTH HALF...AS STRONGER
WINDS JUST OFF THE SURFACE COULD STILL MIX DOWN OVER THE NEXT
COUPLE OF HOURS. SCA TIMING STILL APPEARS TO BE IN GOOD SHAPE WITH
THE WINDS DIMINISHING THIS AFTERNOON...BUT WITH HIGHER WAVES STILL
LINGERING THROUGH TONIGHT AND EARLY WEDNESDAY MORNING.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014 UNTIL 4 AM WEDNESDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 10 AM WEDNESDAY.
LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 4 AM WEDNESDAY.
SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 10 AM
WEDNESDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS GOODLAND KS
1126 AM MDT WED AUG 13 2014
.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 225 AM MDT WED AUG 13 2014
LATEST WV IMAGERY AND RAP ANALYSIS SHOW AMPLIFIED 594 DM RIDGE
CENTERED OVER THE SOUTHERN PLAINS EXTENDING NORTH ACROSS THE CENTRAL
PLAINS/CENTRAL ROCKIES INTO SOUTHERN CANADA. AT THE SURFACE THE LEE
TROUGH IS DEEPENING OVER EASTERN COLORADO WITH HIGH PRESSURE
BEGINNING TO SHIFT TOWARD EASTERN KANSAS.
TODAY-THURSDAY NIGHT...ANOTHER VERY WARM AND DRY DAY IS EXPECTED
TODAY AS H5 RIDGE CONTINUE TO DOMINATE PATTERN OVER THE CWA...AND
MAIN STORM TRACK REMAINS WELL OUTSIDE OUR AREA OF CONCERN. BY MIDDAY
THURSDAY THE NORTHERN EXTENT OF THE RIDGE WILL BEGIN TO FLATTEN IN
RESPONSE TO A SHORTWAVE TROUGH MOVING OUT OF THE FOUR CORNERS REGION
AND INTO THE NORTHERN PLAINS. WHILE INSTABILITY INCREASES...SOUNDING
SHOW HIGH TD DEPRESSIONS BELOW 500MB THROUGH AT LEAST EARLY THURSDAY
AFTERNOON...WHICH COULD LIMIT PRECIPITATION REACHING THE GROUND IN
ALL BUT THE STRONGEST UPDRAFTS UNTIL MID AFTERNOON. BETTER
LIFT/INSTABILITY SHOULD SUPPORT BETTER THUNDERSTORM COVERAGE BY LATE
THURSDAY AFTERNOON AND ESPECIALLY THURSDAY NIGHT...AND MODELS SHOW A
GOOD PRECIP SIGNAL DURING THESE PERIODS. I KEPT SLIGHT CHANCE POPS
IN PLACE MIDDAY THURSDAY...THOUGH CONFIDENCE WASNT HIGH FOR
INITIATION THAT EARLY AND TRENDED POPS UP BY THE EVENING OVERNIGHT
HOURS. BY THURSDAY NIGHT BETTER CAPE PROFILES AND INCREASING PWATS
WOULD SUPPORT THE POSSIBILITY OF LOCALIZED HEAVY RAIN...HOWEVER
THREAT IS UNCERTAIN AT THIS RANGE ESPECIALLY WITH BETTER STORM
MOTIONS. SHEER WILL BE DECENT...HOWEVER CAPE IS MARGINAL...SO
ELEVATED SEVERE THREAT IS UNCERTAIN.
FRIDAY-FRIDAY NIGHT...RIDGE REMAINS IN PLACE OVER THE SOUTHERN
PLAINS WITH NORTHWEST FLOW ALLOWING WEAK MID LEVEL VORTICITY TO
ROTATE THROUGH THE NORTHERN PLAINS. AS PRECIP COMES TO AN END WITH
DEPARTING SHORTWAVE ONLY WEAK FORCING WILL BE IN PLACE. MODERATE
INSTABILITY WILL BUILD BACK OVER THE CWA WITH DAYTIME HEATING...AND
THERE CONTINUES TO BE A WEAK PRECIP SIGNAL BETWEEN THE GFS AND
ECMWF...SO WHILE CONFIDENCE IS NOT HIGH WE WILL SEE MUCH
THUNDERSTORM ACTIVITY SLIGHT CHANCE POPS STILL SEEM REASONABLE FOR
NOW.
REGARDING TEMPS...GUIDANCE CONTINUES TO SHOW GOOD WAA ALONG EASTERN
SIDE OF LEE TROUGH THROUGH THURSDAY. LOW TO MID 90S FOR MOST
LOCATIONS TODAY AND THURSDAY SEEM REASONABLE...THOUGH INCREASING
CLOUD COVER COULD LIMIT WARMING SOME ON THURSDAY. FRIDAY TEMPS COULD
BE A BIT COOLER BEHIND TROUGH AND BUILDING NW FLOW...HOWEVER
GUIDANCE CONTINUES TO SHOW DECENT RECOVERY OF TEMPS ALOFT WITH LEE
TROUGH QUICKLY BUILDING BACK OVER EASTERN COLORADO. I USED CONSENSUS
FOR FRIDAY AS A BEST GUESS WHICH FAVORS SEASONAL TEMPS AROUND 90F.
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 225 AM MDT WED AUG 13 2014
AN UPPER LEVEL RIDGE WILL BE POSITIONED OVER THE SOUTHWEST PORTION
OF THE CONUS WITH WESTERLY/NORTHWESTERLY FLOW ALOFT ACROSS THE
CENTRAL HIGH PLAINS. MEDIUM RANGE GUIDANCE DISPLAYS SOME FAIRLY
SIGNIFICANT DIFFERENCES WITH TIMING AND AMPLITUDE OF THE A SHORTWAVE
TROUGH THAT WILL PASS THROUGH ON MONDAY. THE GFS IS THE MOST
AMPLIFIED AND HAS THE STRONGEST FORCING BUT SEVERAL GFS ENSEMBLE
MEMBERS DISPLAY LESS AMPLITUDE SIMILAR TO THE DETERMINISTIC ECMWF.
THIS LEADS TO UNCERTAINTY WITH REGARDS TO AMOUNT OF CONVECTION.
ASIDE FROM THIS SHORTWAVE THE PATTERN REMAINS FAIRLY BENIGN WITH
NEAR OR SLIGHTLY ABOVE NORMAL TEMPERATURES THROUGH THE ENTIRE
PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1123 AM MDT WED AUG 13 2014
VFR EXPECTED AT BOTH KGLD AND KMCK THROUGH THE TAF PERIOD. HIGH
PRESSURE ALOFT WILL SUPPRESS THUNDERSTORM CHANCES TODAY. LOW
PRESSURE AT THE SURFACE IN EASTERN COLORADO WILL RESULT IN BREEZY
SOUTHEASTERLY WINDS THROUGH SUNSET TONIGHT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BRB
AVIATION...024
AREA FORECAST DISCUSSION
NWS GOODLAND KS
510 AM MDT WED AUG 13 2014
.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 225 AM MDT WED AUG 13 2014
LATEST WV IMAGERY AND RAP ANALYSIS SHOW AMPLIFIED 594 DM RIDGE
CENTERED OVER THE SOUTHERN PLAINS EXTENDING NORTH ACROSS THE CENTRAL
PLAINS/CENTRAL ROCKIES INTO SOUTHERN CANADA. AT THE SURFACE THE LEE
TROUGH IS DEEPENING OVER EASTERN COLORADO WITH HIGH PRESSURE
BEGINNING TO SHIFT TOWARD EASTERN KANSAS.
TODAY-THURSDAY NIGHT...ANOTHER VERY WARM AND DRY DAY IS EXPECTED
TODAY AS H5 RIDGE CONTINUE TO DOMINATE PATTERN OVER THE CWA...AND
MAIN STORM TRACK REMAINS WELL OUTSIDE OUR AREA OF CONCERN. BY MIDDAY
THURSDAY THE NORTHERN EXTENT OF THE RIDGE WILL BEGIN TO FLATTEN IN
RESPONSE TO A SHORTWAVE TROUGH MOVING OUT OF THE FOUR CORNERS REGION
AND INTO THE NORTHERN PLAINS. WHILE INSTABILITY INCREASES...SOUNDING
SHOW HIGH TD DEPRESSIONS BELOW 500MB THROUGH AT LEAST EARLY THURSDAY
AFTERNOON...WHICH COULD LIMIT PRECIPITATION REACHING THE GROUND IN
ALL BUT THE STRONGEST UPDRAFTS UNTIL MID AFTERNOON. BETTER
LIFT/INSTABILITY SHOULD SUPPORT BETTER THUNDERSTORM COVERAGE BY LATE
THURSDAY AFTERNOON AND ESPECIALLY THURSDAY NIGHT...AND MODELS SHOW A
GOOD PRECIP SIGNAL DURING THESE PERIODS. I KEPT SLIGHT CHANCE POPS
IN PLACE MIDDAY THURSDAY...THOUGH CONFIDENCE WASNT HIGH FOR
INITIATION THAT EARLY AND TRENDED POPS UP BY THE EVENING OVERNIGHT
HOURS. BY THURSDAY NIGHT BETTER CAPE PROFILES AND INCREASING PWATS
WOULD SUPPORT THE POSSIBILITY OF LOCALIZED HEAVY RAIN...HOWEVER
THREAT IS UNCERTAIN AT THIS RANGE ESPECIALLY WITH BETTER STORM
MOTIONS. SHEER WILL BE DECENT...HOWEVER CAPE IS MARGINAL...SO
ELEVATED SEVERE THREAT IS UNCERTAIN.
FRIDAY-FRIDAY NIGHT...RIDGE REMAINS IN PLACE OVER THE SOUTHERN
PLAINS WITH NORTHWEST FLOW ALLOWING WEAK MID LEVEL VORTICITY TO
ROTATE THROUGH THE NORTHERN PLAINS. AS PRECIP COMES TO AN END WITH
DEPARTING SHORTWAVE ONLY WEAK FORCING WILL BE IN PLACE. MODERATE
INSTABILITY WILL BUILD BACK OVER THE CWA WITH DAYTIME HEATING...AND
THERE CONTINUES TO BE A WEAK PRECIP SIGNAL BETWEEN THE GFS AND
ECMWF...SO WHILE CONFIDENCE IS NOT HIGH WE WILL SEE MUCH
THUNDERSTORM ACTIVITY SLIGHT CHANCE POPS STILL SEEM REASONABLE FOR
NOW.
REGARDING TEMPS...GUIDANCE CONTINUES TO SHOW GOOD WAA ALONG EASTERN
SIDE OF LEE TROUGH THROUGH THURSDAY. LOW TO MID 90S FOR MOST
LOCATIONS TODAY AND THURSDAY SEEM REASONABLE...THOUGH INCREASING
CLOUD COVER COULD LIMIT WARMING SOME ON THURSDAY. FRIDAY TEMPS COULD
BE A BIT COOLER BEHIND TROUGH AND BUILDING NW FLOW...HOWEVER
GUIDANCE CONTINUES TO SHOW DECENT RECOVERY OF TEMPS ALOFT WITH LEE
TROUGH QUICKLY BUILDING BACK OVER EASTERN COLORADO. I USED CONSENSUS
FOR FRIDAY AS A BEST GUESS WHICH FAVORS SEASONAL TEMPS AROUND 90F.
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 225 AM MDT WED AUG 13 2014
AN UPPER LEVEL RIDGE WILL BE POSITIONED OVER THE SOUTHWEST PORTION
OF THE CONUS WITH WESTERLY/NORTHWESTERLY FLOW ALOFT ACROSS THE
CENTRAL HIGH PLAINS. MEDIUM RANGE GUIDANCE DISPLAYS SOME FAIRLY
SIGNIFICANT DIFFERENCES WITH TIMING AND AMPLITUDE OF THE A SHORTWAVE
TROUGH THAT WILL PASS THROUGH ON MONDAY. THE GFS IS THE MOST
AMPLIFIED AND HAS THE STRONGEST FORCING BUT SEVERAL GFS ENSEMBLE
MEMBERS DISPLAY LESS AMPLITUDE SIMILAR TO THE DETERMINISTIC ECMWF.
THIS LEADS TO UNCERTAINTY WITH REGARDS TO AMOUNT OF CONVECTION.
ASIDE FROM THIS SHORTWAVE THE PATTERN REMAINS FAIRLY BENIGN WITH
NEAR OR SLIGHTLY ABOVE NORMAL TEMPERATURES THROUGH THE ENTIRE
PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 510 AM MDT WED AUG 13 2014
VFR CONDITIONS WILL CONTINUE AT BOTH KGLD AND KMCK THROUGH THE
TAF PERIOD. SOUTHEASTERLY WINDS WILL INCREASE DURING THE DAY WITH
GUSTS 18-22KT. THESE GUSTS WILL DIMINISH AFTER SUNSET.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BRB
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
226 AM MDT WED AUG 13 2014
.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 225 AM MDT WED AUG 13 2014
LATEST WV IMAGERY AND RAP ANALYSIS SHOW AMPLIFIED 594 DM RIDGE
CENTERED OVER THE SOUTHERN PLAINS EXTENDING NORTH ACROSS THE CENTRAL
PLAINS/CENTRAL ROCKIES INTO SOUTHERN CANADA. AT THE SURFACE THE LEE
TROUGH IS DEEPENING OVER EASTERN COLORADO WITH HIGH PRESSURE
BEGINNING TO SHIFT TOWARD EASTERN KANSAS.
TODAY-THURSDAY NIGHT...ANOTHER VERY WARM AND DRY DAY IS EXPECTED
TODAY AS H5 RIDGE CONTINUE TO DOMINATE PATTERN OVER THE CWA...AND
MAIN STORM TRACK REMAINS WELL OUTSIDE OUR AREA OF CONCERN. BY MIDDAY
THURSDAY THE NORTHERN EXTENT OF THE RIDGE WILL BEGIN TO FLATTEN IN
RESPONSE TO A SHORTWAVE TROUGH MOVING OUT OF THE FOUR CORNERS REGION
AND INTO THE NORTHERN PLAINS. WHILE INSTABILITY INCREASES...SOUNDING
SHOW HIGH TD DEPRESSIONS BELOW 500MB THROUGH AT LEAST EARLY THURSDAY
AFTERNOON...WHICH COULD LIMIT PRECIPITATION REACHING THE GROUND IN
ALL BUT THE STRONGEST UPDRAFTS UNTIL MID AFTERNOON. BETTER
LIFT/INSTABILITY SHOULD SUPPORT BETTER THUNDERSTORM COVERAGE BY LATE
THURSDAY AFTERNOON AND ESPECIALLY THURSDAY NIGHT...AND MODELS SHOW A
GOOD PRECIP SIGNAL DURING THESE PERIODS. I KEPT SLIGHT CHANCE POPS
IN PLACE MIDDAY THURSDAY...THOUGH CONFIDENCE WASNT HIGH FOR
INITIATION THAT EARLY AND TRENDED POPS UP BY THE EVENING OVERNIGHT
HOURS. BY THURSDAY NIGHT BETTER CAPE PROFILES AND INCREASING PWATS
WOULD SUPPORT THE POSSIBILITY OF LOCALIZED HEAVY RAIN...HOWEVER
THREAT IS UNCERTAIN AT THIS RANGE ESPECIALLY WITH BETTER STORM
MOTIONS. SHEER WILL BE DECENT...HOWEVER CAPE IS MARGINAL...SO
ELEVATED SEVERE THREAT IS UNCERTAIN.
FRIDAY-FRIDAY NIGHT...RIDGE REMAINS IN PLACE OVER THE SOUTHERN
PLAINS WITH NORTHWEST FLOW ALLOWING WEAK MID LEVEL VORTICITY TO
ROTATE THROUGH THE NORTHERN PLAINS. AS PRECIP COMES TO AN END WITH
DEPARTING SHORTWAVE ONLY WEAK FORCING WILL BE IN PLACE. MODERATE
INSTABILITY WILL BUILD BACK OVER THE CWA WITH DAYTIME HEATING...AND
THERE CONTINUES TO BE A WEAK PRECIP SIGNAL BETWEEN THE GFS AND
ECMWF...SO WHILE CONFIDENCE IS NOT HIGH WE WILL SEE MUCH
THUNDERSTORM ACTIVITY SLIGHT CHANCE POPS STILL SEEM REASONABLE FOR
NOW.
REGARDING TEMPS...GUIDANCE CONTINUES TO SHOW GOOD WAA ALONG EASTERN
SIDE OF LEE TROUGH THROUGH THURSDAY. LOW TO MID 90S FOR MOST
LOCATIONS TODAY AND THURSDAY SEEM REASONABLE...THOUGH INCREASING
CLOUD COVER COULD LIMIT WARMING SOME ON THURSDAY. FRIDAY TEMPS COULD
BE A BIT COOLER BEHIND TROUGH AND BUILDING NW FLOW...HOWEVER
GUIDANCE CONTINUES TO SHOW DECENT RECOVERY OF TEMPS ALOFT WITH LEE
TROUGH QUICKLY BUILDING BACK OVER EASTERN COLORADO. I USED CONSENSUS
FOR FRIDAY AS A BEST GUESS WHICH FAVORS SEASONAL TEMPS AROUND 90F.
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 225 AM MDT WED AUG 13 2014
AN UPPER LEVEL RIDGE WILL BE POSITIONED OVER THE SOUTHWEST PORTION
OF THE CONUS WITH WESTERLY/NORTHWESTERLY FLOW ALOFT ACROSS THE
CENTRAL HIGH PLAINS. MEDIUM RANGE GUIDANCE DISPLAYS SOME FAIRLY
SIGNIFICANT DIFFERENCES WITH TIMING AND AMPLITUDE OF THE A SHORTWAVE
TROUGH THAT WILL PASS THROUGH ON MONDAY. THE GFS IS THE MOST
AMPLIFIED AND HAS THE STRONGEST FORCING BUT SEVERAL GFS ENSEMBLE
MEMBERS DISPLAY LESS AMPLITUDE SIMILAR TO THE DETERMINISTIC ECMWF.
THIS LEADS TO UNCERTAINTY WITH REGARDS TO AMOUNT OF CONVECTION.
ASIDE FROM THIS SHORTWAVE THE PATTERN REMAINS FAIRLY BENIGN WITH
NEAR OR SLIGHTLY ABOVE NORMAL TEMPERATURES THROUGH THE ENTIRE
PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1100 PM MDT TUE AUG 12 2014
VFR EXPECTED FOR BOTH KGLD AND KMCK. WINDS FROM TAF ISSUANCE
THROUGH 18Z FROM THE EAST/SOUTHEAST AROUND 10KTS. FROM 19Z THROUGH
THE REST OF THE TAF PERIOD GUSTS OF 15-20KTS EXPECTED. NO
PRECIPITATION EXPECTED.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BRB
AVIATION...99
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1100 PM MDT TUE AUG 12 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 152 PM MDT TUE AUG 12 2014
A RIDGE WILL BE OVER THE ROCKIES TONIGHT AND A SURFACE TROUGH OVER
EASTERN COLORADO. SOME SCATTERED CUMULUS HAVE DEVELOPED OVER
EASTERN COLORADO. CURRENT RADAR WITH NO RETURNS. THE HRRR AND NAM
BOTH DO NOT INDICATE STORMS FOR THIS EVENING AND THAT SEEMS
REASONABLE BASED ON VERY DRY FORECAST SOUNDINGS OVER THE AREA.
ALSO WATER VAPOR IMAGERY SHOWING STRONG SUBSIDENCE EAST OF THE
CENTRAL ROCKIES. POPS WILL BE NIL TONIGHT AND AGAIN ON WEDNESDAY
AS SUBSIDENCE CONTINUES. LOW TEMPERATURES TONIGHT WILL BE IN THE
LOWER 60S AND MAX TEMPERATURES WEDNESDAY AROUND 90.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 152 PM MDT TUE AUG 12 2014
A DRY FORECAST CONTINUES THROUGH WEDNESDAY NIGHT AND EARLY THURSDAY
AS THE RIDGE AND SUBSIDENCE CONTINUES OVER THE HIGH PLAINS. BY
THURSDAY AFTERNOON THE RIDGE BREAKS DOWN SOME AS A SHORTWAVES
MOVES INTO THE AREA. THIS SHORTWAVE WILL CONTINUE MOVING ACROSS
THE FA THURSDAY NIGHT INTO FRIDAY MORNING. STORMS SHOULD INITIATE
ON A SURFACE TROUGH IN EASTERN COLORADO THURSDAY AFTERNOON AND
THEN SPREAD EAST ACROSS THE REST OF THE FA THURSDAY NIGHT. CHANCE
POPS LOOK GOOD FOR THIS EVENT. STORMS WILL LIKELY LINGER IN THE
EASTERN FA EARLY FRIDAY MORNING WITH SUBSIDENCE MOVING INTO THE FA
FROM WEST TO EAST. CONFIDENCE IS NOT HIGH FOR STORMS FRIDAY
AFTERNOON BUT CANNOT RULE OUT AT LEAST AN ISOLATED STORM OR TWO SO
WILL LOWER POPS TO SLIGHT CHANCE.
IN THE EXTENDED...FROM FRIDAY NIGHT THROUGH TUESDAY...A BROAD
RIDGE WILL BE OVER THE WESTERN CONUS EXTENDING INTO THE HIGH
PLAINS. NUMEROUS WEAK DISTURBANCES WILL MOVE THROUGH THE RIDGE
INTO THE HIGH PLAINS. THIS WILL PROVIDE POTENTIAL FOR STORMS EACH
AFTERNOON AND EVENING ACROSS THE FA THROUGH TUESDAY. CONSEQUENTLY, PLAN
TO HAVE AT LEAST A SLIGHT CHANCE OF STORMS EACH DAY. MAX
TEMPERATURES WILL REACH THE LOWER 90S EACH DAY. MIN TEMPERATURES
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1100 PM MDT TUE AUG 12 2014
VFR EXPECTED FOR BOTH KGLD AND KMCK. WINDS FROM TAF ISSUANCE
THROUGH 18Z FROM THE EAST/SOUTHEAST AROUND 10KTS. FROM 19Z THROUGH
THE REST OF THE TAF PERIOD GUSTS OF 15-20KTS EXPECTED. NO
PRECIPITATION EXPECTED.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
AVIATION...99
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1251 AM EDT Wed Aug 13 2014
...Updated Aviation Discussion...
...Forecast Update...
Issued at 930 PM EDT Tue Aug 12 2014
Updating products to remove shower wording over the northeast. Had a
few small cells move just northeast of the region, but nothing is
going on in our area at this time. Some drier air is working into
the area, but with winds dying down, we should see some sites drop
into the upper 50s. This could be low enough for a few patches of
fog to develop toward daybreak, so have that still in for all but
the Bluegrass. Up there, we should see a swath of clouds come in
from the northwest, in association with an upper trough axis
swinging through the region. Latest RUC shows the clouds there may
break up briefly after midnight, but redevelop toward daybreak. Will
lean this way and keep sky grids in the partly cloudy range through
the night.
.SHORT TERM (Now through Sunday)...
Issued at 250 PM EDT Tue Aug 12 2014
A cold front has pushed through the region this afternoon. This
front along with cloud cover associated with an upper trough and the
front have kept our temps at bay in the upper 70s and lower 80s
today. Congested cu from the upper trough will continue to sweep
across our southern Indiana and extreme northern Kentucky counties
possibly causing an isld sprinkle or brief shower this evening.
However, the rest of the night looks dry with the upper trough
moving NE from the Great Lakes into southeast Canada. Drier air
will continue to advect in from the NW so don`t think fog will be a
big issue tonight. However, could see some patchy light fog in fog
prone areas of the east central KY towards morning where low levels
will remain a bit more saturated. Low temps will be in the upper
50s/lower 60s.
For Wednesday, expect a dry, cooler than normal day. Mostly sunny
skies will be the rule as sfc high pressure builds in from the
west. High temps should range from 77-82.
Wednesday night should be a decent rad cooling night under mostly
clear skies. A weak upper level impulse may approach from the north
late Wed night/Thurs morning which may create a more mixy
environment limiting fog potential. Still feel that at least patchy
fog is possible in our fog prone areas though with mostly clear
skies, good subsidence, and very light or calm winds for a good
portion of the night. Expect low temps in the mid 50s to lower 60s.
.LONG TERM (Sunday night through Friday)...
Issued at 247 PM EDT Tue Aug 12 2014
The long term period will start out with somewhat cooler and drier
weather before a return to higher temps and scattered rain chances.
Through Sunday the upper level trough over the eastern CONUS will
slowly shift off to the northeast. This will keep us in
northwesterly flow aloft. High pressure at the surface will be
building in Thursday and slowly shift off to the east through the
weekend.
There is just a bit of uncertainty in the Thursday forecast as a
vortmax will dive through the northwesterly flow and models try to
develop very light and isolated showers. However, with the high
pressure building in and a drier airmass, will keep the forecast dry
for now. Dry weather will continue through Saturday. Highs will be
in the lower to mid 80s Thursday and Friday with a warm up to the
mid to upper 80s on Saturday. Lows will range from the upper 50s to
mid 60s.
By the end of the weekend, the models develop a stronger shortwave
in the upper level flow. this will bring a better chance for precip
Sunday into Monday. The models show a difference in timing with this
wave, so for now will keep pops in the 20-30% range. Another system
will bring a second round of precipitation Monday into Tuesday.
Temperatures will be close to seasonal normals for this time of year
with highs in the mid to upper 80s and lows in the upper 60s to
lower 70s.
&&
.AVIATION (06Z TAF Update)...
Issued at 1249 AM EDT Wed Aug 13 2014
Cold pool strato-cu shield over Indiana made some minor inroads into
Kentucky earlier in the evening, but recently has been eroding as
the cyclonic curvature in the low-level winds has been lost. SDF and
BWG should stay clear through the night. LEX is closer to the edge,
but this looks more like Ohio`s stratus event, which actually opens
the door for potential fog formation. Current temp is just 2 degrees
away from crossing over the afternoon dewpoint, and should cool
another few degrees. However, good drying has occurred in the past
several hours, and low-level wind fields remain a bit mixy.
Therefore will lean on the GFS LAMP guidance and go with a few hrs
of MVFR visibilities around daybreak, but will not carry any low
ceilings.
VFR across the board by midday with NW winds just under 10 kt. Do
expect a cu field but it should remain scattered. With high pressure
better entrenched by sundown, expect to go clear and calm in the
evening.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........RJS
Short Term.....AMS
Long Term......EER
Aviation.......RAS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
941 PM EDT THU AUG 14 2014
.SYNOPSIS...
UPPER LEVEL LOW PRESSURE WILL REMAIN NORTHWEST OF MAINE THROUGH
THE WEEKEND. AS A RESULT...UNSETTLED CONDITIONS WILL PERSIST ACROSS THE
REGION RIGHT INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
920 PM UPDATE: SHWRS AND RN HAVE MOVED MSLY E OF THE FA OVR THE
LAST FEW HRS...BUT HRRR MODEL OUTPUT SHOWS THE BACK EDGE OF THE SHWRS
OVR NEW BRUNSWICK PROV MOVING BACK WWRD BRIEFLY INTO ERN AROOSTOOK
COUNTY LATE TNGT. SO WE USED THE TM SHFT FUNCTION TO INITIALLY MOVE
SHWRS EWRD FOR THE REMAINDER OF THE EVE...AND THEN TO HOLD SOME SHWRS
OVR NE PTNS OF THE REGION TIL ABOUT DAYBREAK. AFTWRDS...THIS BAND
OF SHWRS SHOULD RETREAT BACK INTO NEW BRUNSWICK PROV FOR GOOD.
OTHERWISE FCST HRLY TEMPS WERE MODIFIED FROM 9 PM OBSVD TEMPS AND
SLIGHTLY MODIFIED OVRNGT LOWS...WHICH WERE LOWERED A COUPLE OF DEG
OVR FAR NW ME BASED ON TRENDS SEEN IN 9 PM OBSVD TEMPS FROM THE
PRIOR FCST AT 9 PM.
ORGNL DISC: SHOWERS CONTINUE ACROSS ESPECIALLY NORTHERN AND
EASTERN MAINE THIS AFTERNOON AS AN OCCLUDED FRONT SLOWLY CROSSES
THE REGION. THERE`S STILL SOME ELEVATED INSTABILITY ASSOCIATED OUT
AHEAD OF THIS FEATURE, SO CAN`T TOTALLY RULE OUT AN ISOLATED
RUMBLE OF THUNDER ACROSS EASTERN AREAS UNTIL IT PASSES INTO NEW
BRUNSWICK. A LOW-LEVEL JET OF AROUND 40 KT ALSO LIES AHEAD OF THIS
FRONT, WHICH MEANS ANY CONVECTION THAT DOES DEVELOP HAS THE
CAPABILITY OF MIXING SOME OF THESE STRONGER WINDS DOWN. EXPECT THE
SHOWERS WILL COME TO AN END LATE THIS EVENING, WITH JUST ISOLATED
ACTIVITY AROUND BY MORNING. HOWEVER, WITH PLENTY OF LOW-LEVEL
MOISTURE AROUND, EXPECT FOG TO DEVELOP THIS EVENING, ESPECIALLY
DOWNEAST WHERE SOME CLEARING MAY BE POSSIBLE. SUBSEQUENT SHIFTS
WILL HAVE TO MONITOR CLOSELY AS THE FOG COULD BECOME QUITE DENSE
IN THESE AREAS.
FOR FRIDAY...AN UPPER LOW WILL SPIN ACROSS SOUTHERN QUEBEC THROUGH
THE DAY. THIS WILL COMBINE WITH THE MOISTURE LINGERING FROM TODAY`S
RAIN TO ALLOW SHOWERS TO DEVELOP, ESPECIALLY DURING THE AFTERNOON.
NORTHWESTERN MAINE WILL HAVE THE BEST CHANCES FOR SEEING RAIN AS
THEY WILL BE CLOSEST TO THE UPPER-LEVEL SUPPORT. HIGHS TOMORROW WILL
BE ON THE COOL SIDE NORTH /MID 60S TO AROUND 70), WHILE SOUTHERN
AREAS, WHICH WILL SEE SOME SUN ONCE THE FOG BURNS OFF, WILL BE A FEW
DEGREES WARMER AWAY FROM THE COAST.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
UPPER LEVEL LOW PRESSURE WILL REMAIN NORTHWEST OF THE REGION
FRIDAY NIGHT THROUGH SUNDAY...WHILE DISTURBANCES ROTATING AROUND
THE LOW CROSS THE REGION. UNSETTLED CONDITIONS WILL PERSIST FRIDAY
NIGHT THROUGH SUNDAY. THE BETTER CHANCES OF SHOWERS AND MOST
EXTENSIVE CLOUD COVER FRIDAY NIGHT THROUGH SATURDAY NIGHT WILL
OCCUR ACROSS NORTHERN AND CENTRAL PORTIONS OF THE FORECAST AREA.
ACROSS DOWNEAST AREAS...EXPECT A SLIGHT CHANCE OF SHOWERS ALONG
WITH PARTLY/MOSTLY CLOUDY SKIES FRIDAY NIGHT THROUGH SATURDAY
NIGHT. SHOWER CHANCES WILL INCREASE ACROSS THE ENTIRE FORECAST
AREA SUNDAY WITH A COLD FRONT STARTING TO MOVE EAST ACROSS THE
REGION. TEMPERATURES WILL BE AT BELOW NORMAL LEVELS SATURDAY/SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
UPPER LEVEL ENERGY MOVING OUT OF QUEBEC WILL KEEP REGION UNSETTLED
THROUGH MONDAY. MODELS ARE NOT IN GREAT AGREEMENT ON THE EVOLUTION
OF THE LOW AND UPPER LEVEL LOW THINKING THE BLEND APPROACH IS
REASONABLE AT KEEPING THE BEST CHANCES OF PRECIP ACROSS NORTHERN
MAINE WITH POPS LESSENING AS YOU GO SOUTHWEST FOR MONDAY. MONDAY
NIGHT INTO TUESDAY EXPECT CHANCES OF PRECIP TO DROP OFF AS UPPER
LEVEL RIDGE AND SURFACE HIGH BEGIN BUILDING EAST. HIGH PRESSURE
WILL FINALLY TAKE OVER TUESDAY INTO EARLY WEDNESDAY WITH MOSTLY TO
PARTLY SUNNY SKIES. THE MODELS DO HOWEVER INDICATE A LOW MOVING ACROSS
THE MID ATLANTIC TUESDAY NIGHT. THE ECMWF WANTS TO BRING THIS LOW
CLOSE TO THE REGION AS WE GO INTO LATER WEDNESDAY AND THE GFS/GFS
ENSEMBLE KEEP THIS LOW SOUTH OF THE FA. DUE TO THE UNCERTAINTY IN
THE MODELS WILL ONLY KEEP SLIGHT CHANCE PRECIP ACROSS THE REGION
FOR WEDNESDAY INTO THURSDAY UNDER PARTLY CLOUDY SKIES. HIGH
TEMPERATURES AT THE BEGINNING OF THE PERIOD WILL BE BELOW NORMAL
AND THROUGH THE WEEK WILL COME UP TO NEAR TO A LITTLE ABOVE
NORMAL. LOW TEMPERATURES ARE EXPECTED TO STAY CLOSE TO NORMAL
THROUGH THE PERIOD.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: WIDESPREAD IFR EXPECTED TONIGHT INTO EARLY FRIDAY
MORNING, WITH LIFR POSSIBLE, ESPECIALLY AT KHUL, KBGR, AND KBHB.
THIS WILL BE DUE TO FOG AND LOW CEILINGS. CONDITIONS WILL
GRADUALLY IMPROVE FRIDAY MORNING AS THE FOG BURNS OFF, ESPECIALLY
AT KBHB AND KBGR, BUT EXPECT MVFR CEILINGS TO HANG ON ACROSS THE
NORTH AS SHOWERS REDEVELOP BY AFTERNOON.
SHORT TERM: OCCASIONAL MVFR CONDITIONS ARE POSSIBLE ACROSS THE
REGION FRIDAY NIGHT THROUGH SATURDAY NIGHT...WITH THE BETTER
CHANCES ACROSS NORTHERN AND CENTRAL AREAS. MORE EXTENSIVE MVFR
CONDITIONS ARE EXPECTED ACROSS THE FORECAST AREA SUNDAY.
OCCASIONAL MVFR CONDITIONS ARE POSSIBLE WITH ANY SHOWERS MONDAY.
VFR CONDITIONS ARE EXPECTED MONDAY NIGHT AND TUESDAY.
&&
.MARINE...
NEAR TERM: 830 PM UPDATE...WV HTS DROPPED BLO 5 FT ACROSS THE
INNER HARBOR/BAY MZ052...SO WE CANX THE SCA FOR HAZ SEAS THERE. WE
XTNDED THE HAZ SEAS SCA OVR THE OUTER MZS TIL 08Z TO ALLOW MORE TM
FOR WV HTS TO SUBSIDE THERE. OTHERWISE...NO OTHER CHGS WERE MADE.
ORGNL DISC...A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS REMAINS IN
EFFECT FOR ALL OUR WATERS UNTIL 2 AM FRIDAY MORNING. ACROSS THE
OUTER WATERS, 6-8 FOOT WAVES WILL SLOWLY SUBSIDE THROUGH THE
EVENING. IN THE BAYS, WAVES ARE AT A MARGINAL 4-5 FEET, SO THE
ADVISORY MAY BE ABLE TO BE CANCELLED EARLY IN THESE LOCATIONS. THE
OTHER CONCERN IS THE POTENTIAL FOR DENSE FOG TONIGHT RESTRICTING
VISIBILITY TO BELOW 1 SM.
SHORT TERM: WINDS/SEAS ARE EXPECTED TO BE BELOW SMALL CRAFT
ADVISORY LEVELS FRIDAY NIGHT THROUGH THE WEEKEND. VISIBILITIES
COULD BE REDUCED IN SHOWERS SUNDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM EDT FRIDAY
FOR ANZ050-051.
&&
$$
NEAR TERM...VJN
SHORT TERM...NORCROSS
LONG TERM...JORDAN
AVIATION...VJN/NORCROSS
MARINE...VJN/NORCROSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
438 PM EDT WED AUG 13 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 331 PM EDT WED AUG 13 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NNW FLOW ALF OVER
THE UPR LKS BETWEEN SHARP UPR TROF CENTERED NEAR JAMES BAY AND AN
UPR RDG OVER THE WRN PLAINS. THERE IS A SHRTWV EMBEDDED IN THIS FLOW
THAT IS DIVING THRU ERN LK SUP...BUT THE MID LVLS ARE SUFFICIENTLY
DRY/STABLE OVER THE UPR LKS PER THE 12Z INL/YPL RAOBS THAT THERE
HAVE BEEN NO SHOWERS. BUT THESE RAOBS ALL SHOW A GOOD DEAL OF LLVL
MSTR. WITH THE ONSET OF DAYTIME HEATING...A GOOD DEAL OF LO CLD
DVLPD...ESPECIALLY OVER THE W AND NCENTRAL WHERE THE SFC-H925 NLY
FLOW UPSLOPES OFF LK SUP. THE STEADY/GUSTY N WIND IS CAUSING HIER
WAVES/DANGEROUS SWIMMING CONDITIONS IN THE LK SUP BEACHES E OF THE
KEWEENAW. CLOSER TO HI PRES OVER FAR NW ONTARIO WHERE THE LLVL
AIRMASS IS MUCH DRIER AS SHOWN ON THE 12Z CHURCHILL MANITOBA
RAOB...THERE ARE FEWER CLDS AND WINDS ARE LGT.
MAIN FCST CONCERNS IN THE SHORT TERM ARE CLD TRENDS THIS AFTN AND
THEN TEMPS TNGT AND THU AS THE DRY HI PRES IN ONTARIO WL DOMINATE.
LATE THIS AFTN/TNGT...UNDER CONFLUENT NW FLOW ALF/DEEP LYR QVECTOR
DVGC...SFC HI PRES OVER FAR NW ONTARIO IS PROGGED TO SINK OVER WRN
LK SUP BY 12Z THU. WITH LOSS OF DAYTIME HEATING AND LLVL DRY ADVCTN
IN THE LLVL NLY FLOW AHEAD OF THE SFC HI PRES...EXPECT ANY LINGERING
CLDS TO DISSIPATE THIS EVNG AND GIVE TO MOCLR SKIES OVERNGT. THE
ARRIVAL OF DRIER AIR FM THE N...WITH PWAT SINKING AS LO AS 0.33 INCH
OR 30-35 PCT OF NORMAL...FAVORS A LARGE DIURNAL DROP OF TEMP...
ESPECIALLY OVER THE W WHERE THE WINDS WL BE LIGHTER CLOSER TO THE
INCOMING SFC RDG AXIS. WL MAINTAIN FCST LO TEMPS IN THE 30S AT THE
COLDER INTERIOR LOCATIONS IN THIS AREA. STEADY N WIND OVER THE E
UNDER THE SHARPER PRES GRADIENT BTWN THE RDG AND LO PRES OVER QUEBEC
WL TEND TO RESTRICT THE DIURNAL TEMP DROP THERE.
THU...SFC HI PRES AXIS IS FCST TO SHIFT FM NCENTRAL UPR MI THRU LK
MI. WITH CORE OF DRY AIR OVHD...EXPECT NOTHING MORE THAN SOME
DIURNAL CU OVER THE INTERIOR. H85 TEMPS ARE FCST TO PEAK BTWN ABOUT
8C OVER THE E TO 12C OVER THE W. MIXING TO H8 ON FCST SDNGS
INDICATES MAX TEMPS WL PEAK NEAR 75 OVER THE INTERIOR W AND
SCENTRAL. WITH A STEADY NW WIND OFF LK SUP OVER THE E THAT WL
MAINTAIN HIER WAVES/SWIM RISK...TEMPS WL HAVE A HARD TIME RISING
OVER 70 EXCEPT CLOSER TO LK MI. AFTN MIXING WL CAUSE MIN RH TO
BOTTOM OUT AS LO AS 30-35 PCT OVER MUCH OF THE INTERIOR. DESPITE THE
SOMEWHAT COOLER TEMPS OVER THE E...STRONGER WINDS WL AGGRAVATE FIRE
WX CONDITIONS THERE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 436 PM EDT WED AUG 13 2014
THU NIGHT...WITH THE SFC RIDGE OVER THE AREA...EXPECT GOOD
RADIATIONAL COOLING CONDITIONS UNTIL LATE OVER THE WEST WHEN
MOISTURE BEGINS TO INCREASE. THE LOWER MINS...INTO THE LOWER 40S
INLAND...SHOULD PREVAIL ACROSS THE EAST WHERE PWAT VALUES REMAIN
BELOW 0.5 INCH.
FRI...WSW LOW LEVEL FLOW AND MOISTURE ADVECTION INCREASE AS THE HIGH
SHIFTS TOWARD THE OHIO VALLEY. EVEN THROUGH MLCAPE VALUES MAY CLIMB
INTO THE 400-800 J/KG RANGE AND PWAT RISES TO 1.5 INCHES OVER THE
WEST...THE MODELS SUGGEST THAT THE MAIN FORCING FOR ANY SHRA/TSRA WILL
REMAIN TO THE WEST AS A SHRTWV MOVES FROM SE FROM THE DAKOTAS.
SLIGHT OR LOWER END CHANCE POPS WERE STILL INCLUDED OVER THE WEST
GIVEN THE INSTABILITY AND POTENTIAL FOR EITHER A WEAK SHRTWV OR BAND
OF 300-310K ISENTROPIC LIFT TO SET OFF SOME SCT/ISOLD SHRA/TSRA.
FRI NIGHT INTO SAT...EXPECT A GREATER CHANCE FOR PCPN AS MODELS WERE
IN GOOD AGREEMENT IN BRINGING A SHORTWAVE TROUGH WITH MODERATE
700-300 MB QVECTOR CONV AND AN ASSOCIATED COLD FRONT THROUGH THE NRN
GREAT LAKES. BY SAT AFTERNOON IN THE WAKE OF THE FRONT...PCPN
CHANCES SHOULD DIMINISH ACROSS THE NORTH WITH COOLER MORE STABLE AIR
MOVING IN ON LOW LEVEL NRLY FLOW.
SUN-WED...MAINLY DRY WEATHER THROUGH MON IS EXPECTED WITH MID LEVEL
RIDGING AND A SFC RIDGE DOMINATING. THE GFS/GEM/ECMWF SUGGEST THAT A
SLOW MOVING SHRTWV AND SFC TROUGH WILL MOVE INTO THE WRN LAKES FROM
TUE INTO WED. ALTHOUGH CONFIDENCE IS LOW WITH THE POSITION/STRENGTH
OF THIS FEATURE...MDLS CONSENSUS OF INCREASING POPS AND TSRA
POTENTIAL SEEMS REASONABLE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 121 PM EDT WED AUG 13 2014
AS DRY HI PRES BUILDS INTO THE UPR LKS...ANY LINGERING LO CLDS/MVFR
CIGS WL DISSIPATE AND GIVE WAY TO VFR CONDITIONS BY 20Z AT ALL 3 TAF
SITES. GUSTY N WINDS THIS AFTN WL DIMINISH THIS EVNG WITH THE LOSS OF
DAYTIME HEATING AND AS THE PRES GRADIENT WEAKENS WITH THE CLOSER
APRCH OF THE SFC HI.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 331 PM EDT WED AUG 13 2014
UNDER A SHARP PRES GRADIENT BETWEEN HI PRES SINKING SOUTH THRU FAR
WESTERN ONTARIO AND SLOW MOVING LO PRES IN WESTERN QUEBEC...EXPECT N
TO NW WINDS AS HI AS 20-25 KTS OVER THE E HALF OF LAKE SUPERIOR THRU
THU. AS THE ONTARIO HI MOVES OVER THE UPPER LAKES LATER ON THU...
EXPECT WINDS TO DIMINISH UNDER 15 KTS BY FRI. THESE LIGHTER WINDS
WILL PERSIST INTO SAT...BUT THE SHARPENING PRES GRADIENT BEHIND A
COLD FRONTAL PASSAGE WILL CAUSE N-NE WINDS TO INCREASE UP TO 20 KTS
ON SAT NIGHT INTO SUN. AS THE HI PRES TRAILING THE FRONT SLIDES TO
THE SE EARLY NEXT WEEK...WINDS WILL SHIFT TO THE SSE UP TO 20 KTS ON
MON.
&&
.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...KC
LONG TERM...JLB
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
331 PM EDT WED AUG 13 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 331 PM EDT WED AUG 13 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NNW FLOW ALF OVER
THE UPR LKS BETWEEN SHARP UPR TROF CENTERED NEAR JAMES BAY AND AN
UPR RDG OVER THE WRN PLAINS. THERE IS A SHRTWV EMBEDDED IN THIS FLOW
THAT IS DIVING THRU ERN LK SUP...BUT THE MID LVLS ARE SUFFICIENTLY
DRY/STABLE OVER THE UPR LKS PER THE 12Z INL/YPL RAOBS THAT THERE
HAVE BEEN NO SHOWERS. BUT THESE RAOBS ALL SHOW A GOOD DEAL OF LLVL
MSTR. WITH THE ONSET OF DAYTIME HEATING...A GOOD DEAL OF LO CLD
DVLPD...ESPECIALLY OVER THE W AND NCENTRAL WHERE THE SFC-H925 NLY
FLOW UPSLOPES OFF LK SUP. THE STEADY/GUSTY N WIND IS CAUSING HIER
WAVES/DANGEROUS SWIMMING CONDITIONS IN THE LK SUP BEACHES E OF THE
KEWEENAW. CLOSER TO HI PRES OVER FAR NW ONTARIO WHERE THE LLVL
AIRMASS IS MUCH DRIER AS SHOWN ON THE 12Z CHURCHILL MANITOBA
RAOB...THERE ARE FEWER CLDS AND WINDS ARE LGT.
MAIN FCST CONCERNS IN THE SHORT TERM ARE CLD TRENDS THIS AFTN AND
THEN TEMPS TNGT AND THU AS THE DRY HI PRES IN ONTARIO WL DOMINATE.
LATE THIS AFTN/TNGT...UNDER CONFLUENT NW FLOW ALF/DEEP LYR QVECTOR
DVGC...SFC HI PRES OVER FAR NW ONTARIO IS PROGGED TO SINK OVER WRN
LK SUP BY 12Z THU. WITH LOSS OF DAYTIME HEATING AND LLVL DRY ADVCTN
IN THE LLVL NLY FLOW AHEAD OF THE SFC HI PRES...EXPECT ANY LINGERING
CLDS TO DISSIPATE THIS EVNG AND GIVE TO MOCLR SKIES OVERNGT. THE
ARRIVAL OF DRIER AIR FM THE N...WITH PWAT SINKING AS LO AS 0.33 INCH
OR 30-35 PCT OF NORMAL...FAVORS A LARGE DIURNAL DROP OF TEMP...
ESPECIALLY OVER THE W WHERE THE WINDS WL BE LIGHTER CLOSER TO THE
INCOMING SFC RDG AXIS. WL MAINTAIN FCST LO TEMPS IN THE 30S AT THE
COLDER INTERIOR LOCATIONS IN THIS AREA. STEADY N WIND OVER THE E
UNDER THE SHARPER PRES GRADIENT BTWN THE RDG AND LO PRES OVER QUEBEC
WL TEND TO RESTRICT THE DIURNAL TEMP DROP THERE.
THU...SFC HI PRES AXIS IS FCST TO SHIFT FM NCENTRAL UPR MI THRU LK
MI. WITH CORE OF DRY AIR OVHD...EXPECT NOTHING MORE THAN SOME
DIURNAL CU OVER THE INTERIOR. H85 TEMPS ARE FCST TO PEAK BTWN ABOUT
8C OVER THE E TO 12C OVER THE W. MIXING TO H8 ON FCST SDNGS
INDICATES MAX TEMPS WL PEAK NEAR 75 OVER THE INTERIOR W AND
SCENTRAL. WITH A STEADY NW WIND OFF LK SUP OVER THE E THAT WL
MAINTAIN HIER WAVES/SWIM RISK...TEMPS WL HAVE A HARD TIME RISING
OVER 70 EXCEPT CLOSER TO LK MI. AFTN MIXING WL CAUSE MIN RH TO
BOTTOM OUT AS LO AS 30-35 PCT OVER MUCH OF THE INTERIOR. DESPITE THE
SOMEWHAT COOLER TEMPS OVER THE E...STRONGER WINDS WL AGGRAVATE FIRE
WX CONDITIONS THERE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 335 AM EDT WED AUG 13 2014
THE UPPER LOW CURRENTLY JUST E OF THE CWA WILL DEEPEN WHILE MOVING
INTO SERN QUEBEC BY 12Z THU...AND WILL REMAIN NEARLY STATIONARY
THROUGH AT LEAST FRI /MODELS DISAGREE ON LOCATION AFTER FRIDAY/.
MEANWHILE...THE WELL DEFINED UPPER RIDGE CURRENTLY OVER THE ROCKIES
AND INTO WRN CANADA WILL SHIFT SLIGHTLY E BY THU MORNING...WITH A
PORTION OF THAT RIDGE EXTENDING FROM THE NRN PLAINS TO HUDSON BAY.
BETWEEN THESE TWO SYSTEMS...A SFC RIDGE WILL BE IN PLACE THU AND THU
NIGHT. NO PRECIP IS EXPECTED THU AND THU NIGHT. IT DOES LOOK LIKE WE
WILL MIX INTO A VERY DRY AIRMASS ON THU /1000-500MB RH AROUND 20
PERCENT/...WHICH WILL ALLOW MIN RH VALUES NEAR 30 PERCENT OVER ERN
UPPER MI AND IN THE LOW TO MID 30 PERCENT RANGE ELSEWHERE. WINDS
WILL BE GUSTY OVER THE ERN CWA...WITH GUSTS TO 20KTS OVER ERN UPPER
MI IN THE AFTERNOON. FIRE WX WILL BE MORE OF A CONCERN OVER ERN
UPPER MI.
PRECIP CHANCES INCREASE FRI INTO SAT AS A SHORTWAVE TROUGH MOVES
OVER THE AREA THROUGH THE WEAKENING UPPER RIDGE FRI AND A STRONG
SHORTWAVE TROUGH AND SFC COLD FRONT MOVE THROUGH LATE FRI NIGHT INTO
SAT. WITH MOISTURE INCREASING DURING THIS TIME AND BETTER FORCING
WITH THE SECOND FEATURE...HAVE GREATEST POPS THEN.
UNCERTAINTY INCREASES THROUGH THE REST OF THE FORECAST PERIOD...BUT
MODELS DO HINT THAT HIGH PRESSURE WILL BE IN CONTROL SUN INTO
MON...LEAVING THE AREA DRY. PRECIP MAY TRY TO MAKE A REAPPEARANCE
LATE MON INTO TUE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 121 PM EDT WED AUG 13 2014
AS DRY HI PRES BUILDS INTO THE UPR LKS...ANY LINGERING LO CLDS/MVFR
CIGS WL DISSIPATE AND GIVE WAY TO VFR CONDITIONS BY 20Z AT ALL 3 TAF
SITES. GUSTY N WINDS THIS AFTN WL DIMINISH THIS EVNG WITH THE LOSS OF
DAYTIME HEATING AND AS THE PRES GRADIENT WEAKENS WITH THE CLOSER
APRCH OF THE SFC HI.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 331 PM EDT WED AUG 13 2014
UNDER A SHARP PRES GRADIENT BETWEEN HI PRES SINKING SOUTH THRU FAR
WESTERN ONTARIO AND SLOW MOVING LO PRES IN WESTERN QUEBEC...EXPECT N
TO NW WINDS AS HI AS 20-25 KTS OVER THE E HALF OF LAKE SUPERIOR THRU
THU. AS THE ONTARIO HI MOVES OVER THE UPPER LAKES LATER ON THU...
EXPECT WINDS TO DIMINISH UNDER 15 KTS BY FRI. THESE LIGHTER WINDS
WILL PERSIST INTO SAT...BUT THE SHARPENING PRES GRADIENT BEHIND A
COLD FRONTAL PASSAGE WILL CAUSE N-NE WINDS TO INCREASE UP TO 20 KTS
ON SAT NIGHT INTO SUN. AS THE HI PRES TRAILING THE FRONT SLIDES TO
THE SE EARLY NEXT WEEK...WINDS WILL SHIFT TO THE SSE UP TO 20 KTS ON
MON.
&&
.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...KC
LONG TERM...TITUS
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
432 AM EDT WED AUG 13 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 402 PM EDT TUE AUG 12 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW JUST
EAST OF THE SAULT RESULTING IN NNW FLOW FROM NW ONTARIO THROUGH THE
WRN GREAT LAKES. THE BACK EDGE OF THE CLOUDS ASSOCIATED WITH THE LOW
HAD MOVED TO NEAR SAW-IMT LEAVING CLEAR SKIES OVER THE WEST AND
THICK CLOUDS WITH A FEW SPRINKLES OVER THE ERN CWA. AN UPSTREAM
CLIPPER SHORTWAVE TROUGH AND COLD FRONT THAT SUPPORTED A FEW LIGHT
SHOWERS OR SPRINKLES WAS MOVING THROUGH NW ONTARIO.
TONIGHT...EXPECT THAT SOME LIGHT SHOWERS OR SPRINKLES ASSOCIATED
WITH THE NW ONTARIO SHRTWV MAY MOVE INTO WRN LAKE SUPERIOR AND
POSSIBLY WRN UPPER MI. HOWEVER...SINCE FORCING WITH THE SHRTWV IS
WEAK AND LITTLE MOISTURE/INSTABILITY IS AVAILABLE DURING THE
OVERNIGHT...NO PCPN MENTION WAS ADDED TO THE FCST.
WED...BEHIND THE COLD FRONT...NNW WINDS WILL AGAIN INCREASE WHICH
COULD SUPPORT AN INCREASE IN UPSLOPE CLOUDS OVER N CNTRL UPPER MI.
TEMPS WILL REMAIN BELOW NORMAL WITH HIGHS FROM THE MID 60S NORTH TO
THE LOWER 70S SOUTH. SWIM RISK WILL AGAIN BE HIGH AS 3 TO 5 FOOT
WAVES ARE EXPECTED INTO MARQUETTE AND ALGER COUNTIES BY AFTERNOON.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 335 AM EDT WED AUG 13 2014
THE UPPER LOW CURRENTLY JUST E OF THE CWA WILL DEEPEN WHILE MOVING
INTO SERN QUEBEC BY 12Z THU...AND WILL REMAIN NEARLY STATIONARY
THROUGH AT LEAST FRI /MODELS DISAGREE ON LOCATION AFTER FRIDAY/.
MEANWHILE...THE WELL DEFINED UPPER RIDGE CURRENTLY OVER THE ROCKIES
AND INTO WRN CANADA WILL SHIFT SLIGHTLY E BY THU MORNING...WITH A
PORTION OF THAT RIDGE EXTENDING FROM THE NRN PLAINS TO HUDSON BAY.
BETWEEN THESE TWO SYSTEMS...A SFC RIDGE WILL BE IN PLACE THU AND THU
NIGHT. NO PRECIP IS EXPECTED THU AND THU NIGHT. IT DOES LOOK LIKE WE
WILL MIX INTO A VERY DRY AIRMASS ON THU /1000-500MB RH AROUND 20
PERCENT/...WHICH WILL ALLOW MIN RH VALUES NEAR 30 PERCENT OVER ERN
UPPER MI AND IN THE LOW TO MID 30 PERCENT RANGE ELSEWHERE. WINDS
WILL BE GUSTY OVER THE ERN CWA...WITH GUSTS TO 20KTS OVER ERN UPPER
MI IN THE AFTERNOON. FIRE WX WILL BE MORE OF A CONCERN OVER ERN
UPPER MI.
PRECIP CHANCES INCREASE FRI INTO SAT AS A SHORTWAVE TROUGH MOVES
OVER THE AREA THROUGH THE WEAKENING UPPER RIDGE FRI AND A STRONG
SHORTWAVE TROUGH AND SFC COLD FRONT MOVE THROUGH LATE FRI NIGHT INTO
SAT. WITH MOISTURE INCREASING DURING THIS TIME AND BETTER FORCING
WITH THE SECOND FEATURE...HAVE GREATEST POPS THEN.
UNCERTAINTY INCREASES THROUGH THE REST OF THE FORECAST PERIOD...BUT
MODELS DO HINT THAT HIGH PRESSURE WILL BE IN CONTROL SUN INTO
MON...LEAVING THE AREA DRY. PRECIP MAY TRY TO MAKE A REAPPEARANCE
LATE MON INTO TUE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1205 AM EDT WED AUG 13 2014
HIGH PRESSURE AND DRIER AIR MOVING INTO THE WESTERN U.P. WILL BRING
VFR CONDITIONS TO ALL SITES THROUGH THE FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 433 AM EDT WED AUG 13 2014
LAKE SUPERIOR WILL REMAIN STUCK BETWEEN EXITING LOW PRESSURE OVER S
QUEBEC AND A NEARING HIGH FROM W ONTARIO...WHICH WILL HELP KEEP
N-NNW WINDS NEAR 25KTS GOING OVER MAINLY THE E HALF OF LAKE
SUPERIOR. EXPECT THE HIGH TO SETTLE ACROSS THE UPPER GREAT LAKES
TONIGHT THROUGH FRIDAY. NW GUSTS NEAR 20KTS WILL STILL BE POSSIBLE
OVER FAR E LAKE SUPERIOR THURSDAY. AN ELONGATED TROUGH STRETCHING
FROM ND THROUGH ONTARIO AND CENTRAL QUEBEC FRIDAY AFTERNOON WILL
SINK ACROSS LAKE SUPERIOR FRIDAY NIGHT INTO SATURDAY. BEHING THE
TROUGH...HIGH PRESSURE OVER S CENTRAL CANADA SATURDAY WILL THEN
SLIDE ACROSS ONTARIO AND LAKE SUPERIOR FOR SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
BEACH HAZARDS STATEMENT FROM 8 AM EDT THIS MORNING THROUGH THIS
EVENING FOR MIZ005-006.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...07
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
335 AM EDT WED AUG 13 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 402 PM EDT TUE AUG 12 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW JUST
EAST OF THE SAULT RESULTING IN NNW FLOW FROM NW ONTARIO THROUGH THE
WRN GREAT LAKES. THE BACK EDGE OF THE CLOUDS ASSOCIATED WITH THE LOW
HAD MOVED TO NEAR SAW-IMT LEAVING CLEAR SKIES OVER THE WEST AND
THICK CLOUDS WITH A FEW SPRINKLES OVER THE ERN CWA. AN UPSTREAM
CLIPPER SHORTWAVE TROUGH AND COLD FRONT THAT SUPPORTED A FEW LIGHT
SHOWERS OR SPRINKLES WAS MOVING THROUGH NW ONTARIO.
TONIGHT...EXPECT THAT SOME LIGHT SHOWERS OR SPRINKLES ASSOCIATED
WITH THE NW ONTARIO SHRTWV MAY MOVE INTO WRN LAKE SUPERIOR AND
POSSIBLY WRN UPPER MI. HOWEVER...SINCE FORCING WITH THE SHRTWV IS
WEAK AND LITTLE MOISTURE/INSTABILITY IS AVAILABLE DURING THE
OVERNIGHT...NO PCPN MENTION WAS ADDED TO THE FCST.
WED...BEHIND THE COLD FRONT...NNW WINDS WILL AGAIN INCREASE WHICH
COULD SUPPORT AN INCREASE IN UPSLOPE CLOUDS OVER N CNTRL UPPER MI.
TEMPS WILL REMAIN BELOW NORMAL WITH HIGHS FROM THE MID 60S NORTH TO
THE LOWER 70S SOUTH. SWIM RISK WILL AGAIN BE HIGH AS 3 TO 5 FOOT
WAVES ARE EXPECTED INTO MARQUETTE AND ALGER COUNTIES BY AFTERNOON.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 335 AM EDT WED AUG 13 2014
THE UPPER LOW CURRENTLY JUST E OF THE CWA WILL DEEPEN WHILE MOVING
INTO SERN QUEBEC BY 12Z THU...AND WILL REMAIN NEARLY STATIONARY
THROUGH AT LEAST FRI /MODELS DISAGREE ON LOCATION AFTER FRIDAY/.
MEANWHILE...THE WELL DEFINED UPPER RIDGE CURRENTLY OVER THE ROCKIES
AND INTO WRN CANADA WILL SHIFT SLIGHTLY E BY THU MORNING...WITH A
PORTION OF THAT RIDGE EXTENDING FROM THE NRN PLAINS TO HUDSON BAY.
BETWEEN THESE TWO SYSTEMS...A SFC RIDGE WILL BE IN PLACE THU AND THU
NIGHT. NO PRECIP IS EXPECTED THU AND THU NIGHT. IT DOES LOOK LIKE WE
WILL MIX INTO A VERY DRY AIRMASS ON THU /1000-500MB RH AROUND 20
PERCENT/...WHICH WILL ALLOW MIN RH VALUES NEAR 30 PERCENT OVER ERN
UPPER MI AND IN THE LOW TO MID 30 PERCENT RANGE ELSEWHERE. WINDS
WILL BE GUSTY OVER THE ERN CWA...WITH GUSTS TO 20KTS OVER ERN UPPER
MI IN THE AFTERNOON. FIRE WX WILL BE MORE OF A CONCERN OVER ERN
UPPER MI.
PRECIP CHANCES INCREASE FRI INTO SAT AS A SHORTWAVE TROUGH MOVES
OVER THE AREA THROUGH THE WEAKENING UPPER RIDGE FRI AND A STRONG
SHORTWAVE TROUGH AND SFC COLD FRONT MOVE THROUGH LATE FRI NIGHT INTO
SAT. WITH MOISTURE INCREASING DURING THIS TIME AND BETTER FORCING
WITH THE SECOND FEATURE...HAVE GREATEST POPS THEN.
UNCERTAINTY INCREASES THROUGH THE REST OF THE FORECAST PERIOD...BUT
MODELS DO HINT THAT HIGH PRESSURE WILL BE IN CONTROL SUN INTO
MON...LEAVING THE AREA DRY. PRECIP MAY TRY TO MAKE A REAPPEARANCE
LATE MON INTO TUE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1205 AM EDT WED AUG 13 2014
HIGH PRESSURE AND DRIER AIR MOVING INTO THE WESTERN U.P. WILL BRING
VFR CONDITIONS TO ALL SITES THROUGH THE FCST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 402 PM EDT TUE AUG 12 2014
NORTH WINDS GUSTING TO MORE THAN 25 KTS ACROSS THE EASTERN PART OF
THE LAKE WILL DIMINISH THIS EVENING AS THE PRES GRADIENT WEAKENS. A
REINFORCING COLD FRONT WILL PUSH ACROSS THE LAKE ON WEDNESDAY
ALLOWING NORTHWESTERLY WIND GUSTS OF UP TO 25 KTS WEDNESDAY
AFTERNOON. WINDS SHOULD DIMINISH BY LATE WEDNESDAY AND THEN REMAIN
BELOW 15 KTS INTO THE UPCOMING WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
BEACH HAZARDS STATEMENT FROM 8 AM EDT THIS MORNING THROUGH THIS
EVENING FOR MIZ005-006.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS BILLINGS MT
237 PM MDT WED AUG 13 2014
.SHORT TERM...VALID FOR THU AND FRI...
FAIRLY ACTIVE WEATHER COMING IN THE SHORT TERM PERIOD.
MID LEVEL SHORTWAVE IS ROUNDING THE RIDGE AND MOVING INTO EASTERN
MT THIS AFTN. SHOWERS WITHOUT TSTMS HAVE BEEN DEVELOPING FROM
ROSEBUD INTO CUSTER AND POWDER RIVER COUNTIES FOR THE PAST COUPLE
HOURS. LATEST ANALYSIS SUGGESTS 1500-2500 J/KG OF SBCAPE NEAR THE
DAKOTAS BORDER...WITH DIMINISHING CIN...SO WOULD ANTICIPATE SOME
STRONGER CELLS TO POP UP OVER THE NEXT FEW HOURS AS ASCENT REACHES
OUR FAR EAST. BULK SHEAR REMAINS 25 KTS OR LESS SO DO NOT SEE A
SIGNIFICANT SEVERE THREAT...THOUGH WILL HAVE TO WATCH ANY STRONGER
CELLS FOR SMALL HAIL AND HEAVY RAIN THROUGH MAYBE 02Z OR SO. HRRR
HAS CONSISTENTLY SHOWN CELLS DEVELOPING IN FALLON/CARTER COUNTIES
BY 22-23Z.
NEXT FEATURE OF INTEREST IS MONSOONAL ENERGY LIFTING THROUGH THE
FOUR CORNERS AREA EMBEDDED IN A VERY MOIST SOUTHERLY FLOW ALOFT.
PACIFIC NW LOW IS MOVING VERY SLOWLY...SO TRAJECTORY OF MONSOON
WAVE TAKES IT INTO OUR CWA BY EARLY TOMORROW...RATHER THAN BEING
DEFLECTED TO THE EAST. HRRR RUNS HAVE ALSO BEEN CONSISTENT WITH
SHOWING A LARGE AREA OF SHOWERS APPROACHING OUR AREA FROM THE
SOUTH LATER TONIGHT. GIVEN THE FORCING AND MOISTURE ANTICIPATED
WITH THIS WEAK MONSOON ENERGY...HAVE RAISED POPS ACROSS OUR SOUTH
AND SOUTHEAST BEGINNING EARLY TOMORROW MORNING AND LASTING THROUGH
THE EVENING IN OUR SOUTHEAST...AS ALL MODELS SHOW A MID LEVEL
CIRCULATION MOVING SLOWLY THROUGH SOUTHEAST MT. MAIN IMPACT WITH
THIS SYSTEM WILL BE PCPN AND NOT SEVERE WX...AS SHOWERS ARE
EXPECTED TO BEGIN EARLY IN THE DAY AND SFC TEMPS WILL BE COOLER.
THERE WILL BE SOME LIGHTNING BUT DO NOT SEE A LARGE AMOUNT FOR THE
SAME REASONS. WILL KEEP LALS AT 3 FOR TOMORROW. IT COULD ACTUALLY
BE A BENEFICIAL DAY AS FAR AS FIRE WEATHER GOES.
FURTHER WEST...PACIFIC NW LOW WILL MOVE SLOWLY EAST BUT WILL STILL
BE OVER WA/OR TOMORROW AFTN. STRONGER UPPER DIFFLUENCE WILL BE
WEST OF US...AND TO OUR WEST WILL BE WHERE THE RISK OF STRONGER
STORMS WILL BE...BUT SHOULD BE ENOUGH MOISTURE AND INSTABILITY
FOR SCATTERED AFTN AND EVENING TSTMS EVEN AS MONSOON LOW BEGINS
TO SHIFT EAST.
LATEST MODEL TRENDS SUGGEST PACIFIC LOW WILL DRIFT SLIGHTLY NORTH
BY FRIDAY...SOMEWHERE NEAR EASTERN WA/NORTHERN ID BY LATE IN THE
DAY. AS A RESULT WE WILL BEGIN TO TAP INTO DRIER AIR FROM THE
NORTHERN GREAT BASIN...GFS SHOWS PWATS NEAR A HALF INCH IN PARK
COUNTY...AND STRONGER JET SUPPORT WILL EXIST IN NORTH CENTRAL MT.
WILL KEEP POPS AT SCATTERED BUT HAVE TAPERED THEM SLIGHTLY...IE
COVERAGE SHOULD BE LESS THAN ON THURSDAY. ALSO...MONSOONAL LOW
SHOULD BE IN THE DAKOTAS BY FRIDAY BUT MAY BE CLOSE ENOUGH TO
BRING WRAP AROUND SHOWERS/TSTMS TO OUR EAST. SOME MODEL
UNCERTAINTY IN THIS REGARD.
AS FOR TEMPERATURES...INCREASED CHANCES OF PCPN AND CLOUD COVER
WILL GIVE US A COOLER DAY TOMORROW...WITH HIGHS MAINLY IN THE 80S
TO LOWER 90S. IF SHOWERS PERSIST LONG ENOUGH SOME PARTS OF OUR
SOUTH OR SOUTHEAST MAY STRUGGLE TO GET OUT OF THE 70S. THESE AREAS
WILL REBOUND WITH THE DRIER AIR ON FRIDAY.
JKL
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
THE UPPER LOW IN THE PACIFIC NORTHWEST WILL BEGIN ITS MOVE TO THE
NORTHEAST ACROSS THE MONTANA/CANADA BORDER SATURDAY INTO SUNDAY.
ASSOCIATED SURFACE TROUGH WILL DEVELOP ACROSS EASTERN MT ON
SATURDAY WITH LOW LEVEL SOUTHEAST FLOW AHEAD OF IT. LOOKS LIKE
GOOD SHEAR AND INSTABILITY FOR THE BEST CHANCE FOR STORMS IN THIS
AREA OF SOUTHEAST MT FOR SATURDAY WITH ISOLATED POTENTIAL
ELSEWHERE. UPPER LEVEL CYCLONIC FLOW REMAINS FOR SUNDAY AS THE
SYSTEM MAKES ONLY SLOW PROGRESS EAST...SO CANT RULE OUT SOME
INSTABILTIY SHOWERS/STORMS PERSISTING. A DRIER NORTHWEST FLOW IS
EXPECTED TO DOMINATE FROM MONDAY INTO THE MIDDLE OF NEXT WEEK.
LOOKS LIKE MOST AREAS SHOULD REMAIN DRY...OUTSIDE OF SOME ISOLATED
ACTIVITY IN THE MOUNTAINS. TEMPERATURES EXPECTED TO BE NEAR
SEASONAL LEVELS FOR MUCH OF THE PERIOD. FRIEDERS
&&
.AVIATION...
ISOLATED THUNDERSTORMS ARE EXPECTED ACROSS THE REGION THIS
EVENING. LOCAL MVFR CONDITIONS...GUSTY WINDS AND SOME MOUNTAIN
OBSCURATIONS ARE POSSIBLE. CLOUD COVER WILL INCREASE OVERNIGHT
WITH THE POTENTIAL FOR MORE WIDESPREAD SHOWERS MOVING IN BEGINNING
THURSDAY MORNING AND CONTINUING THROUGH THE DAY. FRIEDERS
&&
.PRELIMINARY POINT TEMP/POPS...
THU FRI SAT SUN MON TUE WED
-----------------------------------------------------------
BIL 065/087 063/089 062/088 061/088 061/088 061/090 061/085
24/T 43/T 32/T 22/T 21/B 11/U 11/B
LVM 056/088 054/088 053/087 052/088 052/088 053/089 053/087
45/T 54/T 42/T 22/T 22/T 21/B 22/T
HDN 061/088 060/091 059/090 058/090 058/090 058/092 058/088
25/T 43/T 32/T 22/T 21/B 11/U 11/B
MLS 065/092 064/089 064/090 061/089 061/090 061/091 062/088
23/T 44/T 44/T 42/T 21/B 11/B 11/B
4BQ 064/086 064/088 063/089 060/089 059/090 059/090 060/089
26/T 64/T 43/T 32/T 21/B 11/B 11/B
BHK 060/091 061/086 060/087 056/086 056/087 055/087 057/085
34/T 44/T 45/T 43/T 21/B 11/B 22/T
SHR 059/084 057/089 056/089 054/088 054/088 054/089 055/087
26/T 43/T 32/T 22/T 21/B 11/U 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
841 AM MDT WED AUG 13 2014
.UPDATE...
ISOLATED SHOWERS CONTINUE TO DEVELOP ACROSS PARTS OF THE CWA THIS
MORNING IN RESPONSE TO SHORTWAVE LIFTING OUT OF NORTHWEST WY. HAVE
ADJUSTED MORNING POPS TO ACCOUNT FOR THIS ACTIVITY...WHICH EXTENDS
FROM NEAR BILLINGS AND HARLOWTON OVER TO MILES CITY. SHORTWAVE
WILL PUSH SLOWLY TO THE NORTHEAST AND SHOULD BE A FOCUS FOR
THUNDERSTORM DEVELOPMENT IN OUR EASTERN ZONES THIS AFTN. LATEST
SSEO/SREF HIGHLIGHT AREAS FROM MILES CITY TO BROADUS EASTWARD FOR
CONVECTION LATER TODAY. THOUGH SHEAR MAGNITUDE IS GENERALLY
WEAK...FAVORABLE DIRECTIONAL SHEAR AND CAPES OF 1000-1500 J/KG
COULD SUPPORT SOME STRONGER STORMS WITH SMALL HAIL AND HEAVY
RAIN. HAVE RAISED POPS TO SCATTERED IN THIS AREA. ELSEWHERE...WEAK
ENERGY FROM THE GREAT BASIN WILL PRODUCE ANOTHER ROUND OF
RELATIVELY HIGH-BASED CONVECTION IN OUR WEST THIS AFTN AND
EVENING...WITH GUSTY WINDS AGAIN BEING THE MAIN THREAT...BUT
OVERALL STRONGER FORCING ASSOCIATED WITH PACIFIC NW LOW WILL
REMAIN TO OUR WEST. OUR CENTRAL PARTS INCLUDING BILLINGS WILL BE
LEAST FAVORED FOR STORMS TODAY SO WILL KEEP POPS AT ISOLATED.
TEMPS WILL BE ABOVE NORMAL BUT SHOULD NOT BE QUITE AS WARM AS
TUESDAY...WHEN 100F WAS REACHED AT OUR OFFICE ON THE WEST END OF
BILLINGS.
JKL
&&
.SHORT TERM...VALID FOR TDY AND THU...
UPPER LEVEL RIDGE THAT HAS BEEN IN PLACE FOR THE LAST SEVERAL DAYS
WILL GIVE WAY TO A SHORTWAVE TROUGH...BRINGING WITH IT SOME
POTENTIAL FOR SENSIBLE WEATHER FOR SOUTHEASTERN MONTANA.
DURING THE OVERNIGHT HOURS...THE HRRR MODEL DID A FAIRLY GOOD JOB
OF DEPICTING CONVECTION IN WESTERN MONTANA. AFTER CLOSER LOOK AT
THE LAST FEW RUNS...DECIDED TO ADD A SLIGHT CHANCE OF AN ISOLATED
SHOWER IN THE CENTRAL ZONES...INCLUDING AREAS IN AND AROUND
BILLINGS AROUND 1800 UTC.
AMOUNT OF CLOUD COVER IS GOING TO BE AN ISSUE TODAY WITH RESPECT
TO HIGH TEMPS...AS THE TIMING OF THE ARRIVAL OF ADDITIONAL
MONSOONAL MOISTURE MAY KEEP THE SKIES CLOUDIER THAN INITIALLY
THOUGHT IN PREVIOUS FORECAST PERIODS...PRECLUDING THE FULL
POTENTIAL FOR MAXING OUT. AT 200 AM...IT WAS STILL 74 DEGREES AT
KBIL AND 72 AT KMLS. SO...KEPT WITH GOING FORECAST FOR THE MID 90S
FOR TODAY...ALTHOUGH COULD EASILY SEE KBIL OR KMLS APPROACH THE
CENTURY MARK IF THE CLOUDS CLEAR OUT.
IN PATTERNS LIKE THIS...ITS ALWAYS A GOOD IDEA TO KEEP A WATCH ON
THE POTENTIAL FOR FIRE STARTS DUE TO DRY THUNDERSTORMS. SPC
FIRE OUTLOOK PLACES CENTRAL MONTANA UNDER AN ISOLATED DRY
THUNDERSTORM RISK FOR WEDNESDAY...MAINLY DUE TO THE HOT AND DRY
NATURE OF THE PAST SEVERAL DAYS. WITH AN ISOLATED THREAT OF
THUNDERSTORMS...POTENTIAL LIGHTNING STRIKES COULD IGNITE SOME
STARTS...SIMILAR TO WHAT WAS SEEN ON TUESDAY. EITHER WAY IT BEARS
WATCHING.
THURSDAY SHOULD NOT BE QUITE AS WARM AS TUESDAY AND WEDNESDAY...AS
THE REGION CONTINUES TO BE UNDER GENERAL TROUGHINESS. BEST
DIVERGENCE PROGGED TO REMAIN TO THE NORTH AND WEST OF THE BYZ
CWA...BUT KEPT POP CHANCES FROM 40 TO 50 IN FAR WESTERN ZONES FOR
AN ISOLATED THUNDERSTORM TO FORM. NEITHER INSTABILITY OR SHEAR IS
THAT GREAT...SO ANY STORMS THAT FORM SHOULD NOT BE SEVERE IN
NATURE. SINGER
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
THE CHANCE OF SHOWERS AND THUNDERSTORMS CONTINUES TO LOOK ELEVATED
FRI AND SAT /ESPECIALLY IN SOUTHEASTERN MT/ AS THE UPPER-LEVEL LOW
CURRENTLY OVER THE PACIFIC NORTHWEST FILLS AND MIGRATES NORTHEAST.
THE 00 UTC GUIDANCE CONTINUES TO WAVER A BIT ON THE DETAILS OF THE
DEAMPLIFYING WAVE...BUT OFFERS ENOUGH AGREEMENT FOR US TO CONTINUE
ADVERTISING CHANCE-STYLE POPS EVERYWHERE FRI AND OVER SOUTHEASTERN
MT ON SAT. GIVEN THE TRENDS IN THE GFS AND ECMWF...IT APPEARS THAT
1/ A MONSOONAL MOISTURE PUSH THAT GETS PULLED NORTHWARD IN ADVANCE
OF THE UPPER-LEVEL LOW MAY ENHANCE PRECIPITATION OVER SOUTHEASTERN
MT ON FRI...AND 2/ SHEAR AND INSTABILITY COULD SUPPORT SOME SEVERE
THUNDERSTORM RISK IN SOUTHEASTERN MT ON SAT IF STORMS FIRE THERE.
BY LATER IN THE WEEKEND AND INTO NEXT WEEK...IT APPEARS THE LARGE-
SCALE FLOW FROM THE PACIFIC OCEAN INTO WESTERN NORTH AMERICA COULD
RESHUFFLE WITH A PERSISTENT 500-MB LOW ACROSS THE ALEUTIAN ISLANDS
PERHAPS GETTING REPLACED BY MEAN RIDGING. THE INTERIM EFFECT LOOKS
TO BE ZONAL FLOW ALOFT OVER THE LOCAL REGION WITH DIURNALLY-DRIVEN
LOW-END CONVECTIVE CHANCES AND SEASONABLY WARM TEMPERATURES DURING
THE SUN THROUGH TUE PERIOD...AT LEAST. HOWEVER...IF THE FULL-SCALE
RESHUFFLING TAKES PLACE AS THE 00 UTC GFS AND ECMWF SIMULATED...IT
IS VERY POSSIBLE THAT MEAN TROUGHING COULD BECOME ESTABLISHED OVER
THE NORTHERN ROCKIES OR NORTHERN PLAINS BY LATE NEXT WEEK AND THUS
LEAD TO COOLER AND POTENTIALLY WETTER CONDITIONS. THE JURY IS VERY
FAR FROM OUT ON THAT THOUGH AS PREDICTABILITY IS LOW REGARDING ANY
CHANGE LIKE THAT...MUCH LESS AT THIS TIME OF THE YEAR WHEN THERMAL
IMBALANCE AND DYNAMIC FORCING IN THE NORTHERN HEMISPHERE TYPICALLY
IS AT AN OVERALL MINIMUM. SCHULTZ
&&
.AVIATION...
ISOLATED TO WIDELY SCATTERED SHOWERS AND STORMS ARE EXPECTED
TODAY AND TONIGHT. LOCAL MVFR CONDITIONS...GUSTY WINDS AND SOME
MOUNTAIN OBSCURATIONS ARE POSSIBLE WITH THAT ACTIVITY...BUT THE
PROBABILITY OF IMPACT AT ANY ONE LOCATION IS NOT THAT HIGH. VFR
CONDITIONS ARE OTHERWISE EXPECTED OVER SOUTHERN MT AND NORTH
CENTRAL WY. SCHULTZ
&&
.PRELIMINARY POINT TEMP/POPS...
TDY THU FRI SAT SUN MON TUE
-------------------------------------------------------
BIL 095 065/092 063/090 062/088 061/088 061/088 061/090
2/T 23/T 43/T 32/T 22/T 22/T 22/T
LVM 092 057/090 054/088 053/087 052/088 052/088 053/089
3/T 45/T 54/T 42/T 22/T 22/T 22/T
HDN 097 063/095 063/091 060/090 058/090 058/090 058/092
2/T 23/T 43/T 32/T 22/T 22/T 22/T
MLS 097 066/096 066/089 064/090 061/089 061/090 061/091
3/T 22/T 44/T 44/T 42/T 22/T 22/T
4BQ 096 064/094 064/088 063/089 060/089 059/090 059/090
3/T 22/T 44/T 43/T 32/T 22/T 22/T
BHK 094 062/093 061/087 059/087 056/086 056/087 055/087
3/T 32/T 34/T 44/T 42/T 22/T 22/T
SHR 094 059/089 058/089 057/089 054/088 054/088 054/089
2/T 23/T 43/T 32/T 22/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
325 AM MDT WED AUG 13 2014
.SHORT TERM...VALID FOR TDY AND THU...
UPPER LEVEL RIDGE THAT HAS BEEN IN PLACE FOR THE LAST SEVERAL DAYS
WILL GIVE WAY TO A SHORTWAVE TROUGH...BRINGING WITH IT SOME
POTENTIAL FOR SENSIBLE WEATHER FOR SOUTHEASTERN MONTANA.
DURING THE OVERNIGHT HOURS...THE HRRR MODEL DID A FAIRLY GOOD JOB
OF DEPICTING CONVECTION IN WESTERN MONTANA. AFTER CLOSER LOOK AT
THE LAST FEW RUNS...DECIDED TO ADD A SLIGHT CHANCE OF AN ISOLATED
SHOWER IN THE CENTRAL ZONES...INCLUDING AREAS IN AND AROUND
BILLINGS AROUND 1800 UTC.
AMOUNT OF CLOUD COVER IS GOING TO BE AN ISSUE TODAY WITH RESPECT
TO HIGH TEMPS...AS THE TIMING OF THE ARRIVAL OF ADDITIONAL
MONSOONAL MOISTURE MAY KEEP THE SKIES CLOUDIER THAN INITIALLY
THOUGHT IN PREVIOUS FORECAST PERIODS...PRECLUDING THE FULL
POTENTIAL FOR MAXING OUT. AT 200 AM...IT WAS STILL 74 DEGREES AT
KBIL AND 72 AT KMLS. SO...KEPT WITH GOING FORECAST FOR THE MID 90S
FOR TODAY...ALTHOUGH COULD EASILY SEE KBIL OR KMLS APPROACH THE
CENTURY MARK IF THE CLOUDS CLEAR OUT.
IN PATTERNS LIKE THIS...ITS ALWAYS A GOOD IDEA TO KEEP A WATCH ON
THE POTENTIAL FOR FIRE STARTS DUE TO DRY THUNDERSTORMS. SPC
FIRE OUTLOOK PLACES CENTRAL MONTANA UNDER AN ISOLATED DRY
THUNDERSTORM RISK FOR WEDNESDAY...MAINLY DUE TO THE HOT AND DRY
NATURE OF THE PAST SEVERAL DAYS. WITH AN ISOLATED THREAT OF
THUNDERSTORMS...POTENTIAL LIGHTNING STRIKES COULD IGNITE SOME
STARTS...SIMILAR TO WHAT WAS SEEN ON TUESDAY. EITHER WAY IT BEARS
WATCHING.
THURSDAY SHOULD NOT BE QUITE AS WARM AS TUESDAY AND WEDNESDAY...AS
THE REGION CONTINUES TO BE UNDER GENERAL TROUGHINESS. BEST
DIVERGENCE PROGGED TO REMAIN TO THE NORTH AND WEST OF THE BYZ
CWA...BUT KEPT POP CHANCES FROM 40 TO 50 IN FAR WESTERN ZONES FOR
AN ISOLATED THUNDERSTORM TO FORM. NEITHER INSTABILITY OR SHEAR IS
THAT GREAT...SO ANY STORMS THAT FORM SHOULD NOT BE SEVERE IN
NATURE. SINGER
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
THE CHANCE OF SHOWERS AND THUNDERSTORMS CONTINUES TO LOOK ELEVATED
FRI AND SAT /ESPECIALLY IN SOUTHEASTERN MT/ AS THE UPPER-LEVEL LOW
CURRENTLY OVER THE PACIFIC NORTHWEST FILLS AND MIGRATES NORTHEAST.
THE 00 UTC GUIDANCE CONTINUES TO WAVER A BIT ON THE DETAILS OF THE
DEAMPLIFYING WAVE...BUT OFFERS ENOUGH AGREEMENT FOR US TO CONTINUE
ADVERTISING CHANCE-STYLE POPS EVERYWHERE FRI AND OVER SOUTHEASTERN
MT ON SAT. GIVEN THE TRENDS IN THE GFS AND ECMWF...IT APPEARS THAT
1/ A MONSOONAL MOISTURE PUSH THAT GETS PULLED NORTHWARD IN ADVANCE
OF THE UPPER-LEVEL LOW MAY ENHANCE PRECIPITATION OVER SOUTHEASTERN
MT ON FRI...AND 2/ SHEAR AND INSTABILITY COULD SUPPORT SOME SEVERE
THUNDERSTORM RISK IN SOUTHEASTERN MT ON SAT IF STORMS FIRE THERE.
BY LATER IN THE WEEKEND AND INTO NEXT WEEK...IT APPEARS THE LARGE-
SCALE FLOW FROM THE PACIFIC OCEAN INTO WESTERN NORTH AMERICA COULD
RESHUFFLE WITH A PERSISTENT 500-MB LOW ACROSS THE ALEUTIAN ISLANDS
PERHAPS GETTING REPLACED BY MEAN RIDGING. THE INTERIM EFFECT LOOKS
TO BE ZONAL FLOW ALOFT OVER THE LOCAL REGION WITH DIURNALLY-DRIVEN
LOW-END CONVECTIVE CHANCES AND SEASONABLY WARM TEMPERATURES DURING
THE SUN THROUGH TUE PERIOD...AT LEAST. HOWEVER...IF THE FULL-SCALE
RESHUFFLING TAKES PLACE AS THE 00 UTC GFS AND ECMWF SIMULATED...IT
IS VERY POSSIBLE THAT MEAN TROUGHING COULD BECOME ESTABLISHED OVER
THE NORTHERN ROCKIES OR NORTHERN PLAINS BY LATE NEXT WEEK AND THUS
LEAD TO COOLER AND POTENTIALLY WETTER CONDITIONS. THE JURY IS VERY
FAR FROM OUT ON THAT THOUGH AS PREDICTABILITY IS LOW REGARDING ANY
CHANGE LIKE THAT...MUCH LESS AT THIS TIME OF THE YEAR WHEN THERMAL
IMBALANCE AND DYNAMIC FORCING IN THE NORTHERN HEMISPHERE TYPICALLY
IS AT AN OVERALL MINIMUM. SCHULTZ
&&
.AVIATION...
ISOLATED TO WIDELY SCATTERED SHOWERS AND STORMS ARE EXPECTED TODAY
AND TONIGHT. LOCAL MVFR CONDITIONS...GUSTY WINDS AND SOME MOUNTAIN
OBSCURATIONS ARE POSSIBLE WITH THAT ACTIVITY...BUT THE PROBABILITY
OF IMPACT AT ANY ONE LOCATION IS NOT THAT HIGH. VFR CONDITIONS ARE
OTHERWISE EXPECTED OVER SOUTHERN MT AND NORTH CENTRAL WY. SCHULTZ
&&
.PRELIMINARY POINT TEMP/POPS...
TDY THU FRI SAT SUN MON TUE
-------------------------------------------------------
BIL 095 065/092 063/090 062/088 061/088 061/088 061/090
2/T 23/T 43/T 32/T 22/T 22/T 22/T
LVM 092 057/090 054/088 053/087 052/088 052/088 053/089
4/T 45/T 54/T 42/T 22/T 22/T 22/T
HDN 097 063/095 063/091 060/090 058/090 058/090 058/092
3/T 23/T 43/T 32/T 22/T 22/T 22/T
MLS 097 066/096 066/089 064/090 061/089 061/090 061/091
2/T 22/T 44/T 44/T 42/T 22/T 22/T
4BQ 097 064/094 064/088 063/089 060/089 059/090 059/090
3/T 22/T 44/T 43/T 32/T 22/T 22/T
BHK 094 062/093 061/087 059/087 056/086 056/087 055/087
2/T 22/T 34/T 44/T 42/T 22/T 22/T
SHR 094 059/089 058/089 057/089 054/088 054/088 054/089
3/T 33/T 43/T 32/T 22/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
305 PM PDT WED AUG 13 2014
.SYNOPSIS...DRIER AIR MOVING IN FROM THE WEST WILL LIMIT
THUNDERSTORM COVERAGE MAINLY TO MOHAVE COUNTY THURSDAY AND FRIDAY.
DRY WEATHER AND NEAR NORMAL TEMPERATURES WILL OCCUR THROUGH THE
WEEKEND AND INTO EARLY NEXT WEEK.
&&
.DISCUSSION...SATELLITE SHOWING SOME HIGHER TOPPED CONVECTION
ACROSS THE MOUNTAINS OF SOUTHERN CLARK COUNTY/NORTHEAST SAN
BERNARDINO COUNTY. THE STRONGEST STORMS ALONG WITH ANY LIGHTNING
HAVE BEEN OVER FAR NORTHERN LINCOLN COUNTY.
TRIMMED BACK ON POPS SIGNIFICANTLY THIS EVENING BASED ON SATELLITE
AND HRRR DATA LEAVING A SLIGHT CHANCE IN MAINLY FOR LINCOLN/MOHAVE
AND SOUTHERN CLARK COUNTIES.
DRYING WILL CONTINUE THROUGH THURSDAY AND FRIDAY. MOS GUIDANCE
SURFACE DEWPOINTS FOR LAS VEGAS ARE TO FALL FROM OUR CURRENT 60 INTO
THE 40S THURSDAY AND 30S FRIDAY. THIS DRYING WILL LIMIT ANY
THUNDERSTORM THREAT TO FAR EASTERN LINCOLN/MOHAVE COUNTIES TOMORROW.
ON FRIDAY THE ONLY AREA WILL BE FAR EASTERN MOHAVE COUNTY. THE
FORECAST LOOKS TO STAY DRY THROUGH THE WEEKEND INTO EARLY NEXT WEEK.
AS WE LOOSE THE MOISTURE, DAYTIME HIGHS WILL WARM BACK CLOSER TO
NORMAL FROM SATURDAY ONWARD.
&&
.AVIATION...FOR MCCARRAN...CUMULUS WHICH HAS DEVELOPED AROUND THE
SURROUNDING MTNS WILL DISSIPATE THIS EVENING LEAVING SKIES MOSTLY
CLEAR OVERNIGHT. ENOUGH MOISTURE WILL REMAIN IN PLACE FOR CUMULUS
DEVELOPMENT OVER THE MOUNTAINS THURSDAY AFTERNOON. WINDS SHOULD
CONTINUE TO FAVOR AN EAST-SOUTHEAST DIRECTION AT LESS THAN 10 KTS
INTO EARLY EVENING BEFORE SETTLING IN SOUTHERLY OVERNIGHT AND
THURSDAY
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SCATTERED CLOUDS THIS EVENING AND AGAIN THURSDAY WITH A
SLIGHT CHANCE OF THUNDERSTORMS OVER LINCOLN/MOHAVE COUNTIES.
WINDS WILL FAVOR TYPICAL DIURNAL WIND PATTERNS THROUGH THURSDAY
EXCEPT NEAR THUNDERSTORMS THIS AFTERNOON.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION SHOULD NOT BE
REQUIRED THURSDAY THROUGH THE WEEKEND.
&&
$$
PIERCE
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS RALEIGH NC
818 PM EDT THU AUG 14 2014 305
.SYNOPSIS...A DRY CYCLONIC FLOW ALOFT WILL PREVAIL OVER THE MID-
ATLANTIC AND CAROLINAS THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM THURSDAY...
OVERVIEW: CYCLONIC FLOW ALOFT WILL DOMINATE THE UPPER LEVEL PATTERN
ACROSS CENTRAL NC THROUGH TONIGHT...ON THE SOUTHERN PERIPHERY OF AN
UNSEASONABLY DEEP UPPER LEVEL LOW STALLED IN VICINITY OF THE LOWER
GREAT LAKES/SOUTHERN QUEBEC. 14Z WV IMAGERY AND RAP DATA INDICATED A
POTENT SHORTWAVE UPSTREAM OVER IL/IN THIS MORNING. THIS FEATURE IS
PROGGED TO TRACK SE THROUGH KY EARLY THIS AFTERNOON...THEN EASTWARD
THROUGH SOUTHERN WV INTO SOUTHERN VA BY 00Z. DPVA ASSOC/W THE WAVE
WILL RESULT IN WEAK HEIGHT/SLP FALLS OVER THE REGION...WITH LOW-
LEVEL FLOW GRADUALLY VEERING FROM N/NE THIS MORNING TO SW/WSW THIS
AFTERNOON. THE AIRMASS OVER CENTRAL NC THIS MORNING IS UNSEASONABLY
DRY (PWAT 0.71" PER 12Z GSO RAOB)...A RESULT OF MID-LEVEL SUBSIDENCE
AND LOW-LEVEL COLD ADVECTION IN THE WAKE OF THE COLD FRONTAL PASSAGE
EARLY YESTERDAY. SFC DEWPOINTS WERE IN THE UPPER 50S TO LOWER 60S AT
14Z...AND ARE EXPECTED TO FALL INTO THE UPPER 40S TO LOWER/MID 50S
VIA THIS AFTERNOON IN ASSOC/W DIURNAL HEATING/MIXING.
PRECIP/TEMPS: DIURNAL HEATING WILL BE INSUFFICIENT TO DESTABILIZE
THE ATMOSPHERE OVER CENTRAL NC THIS AFT/EVE GIVEN A VERY DRY
BOUNDARY LAYER AND LITTLE IF ANY MOISTURE ADVECTION/RECOVERY...EVEN
AS FLOW VEERS TO THE SW/WSW. AS A RESULT...THE POTENT SHORTWAVE
ENERGY TRACKING THROUGH SOUTHERN WV/VA LATE THIS AFT/EVE SHOULD
YIELD LITTLE MORE THAN SCATTERED UPPER LEVEL CLOUD COVER...THOUGH
ISOLD SHOWER ACTIVITY COULD BE POSSIBLE TO THE NORTH IN WV/VA.
EXPECT HIGHS BELOW NORMAL IN THE LOWER 80S NW TO MID/UPPER 80S SOUTH
AND SE OF THE TRIANGLE. LOWS TONIGHT SIMILAR TO LAST NIGHT ALBEIT A
LITTLE WARMER DUE TO AIRMASS MODIFICATION TODAY...IN THE LOWER 60S
EARLY FRI MORNING. -VINCENT
&&
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 255 PM THURSDAY...
OVERVIEW: CYCLONIC FLOW ALOFT WILL PERSIST OVER THE EAST COAST STATES
FRI INTO FRI NIGHT...ON THE SOUTHERN PERIPHERY OF AN UNSEASONABLY DEEP
UPPER LEVEL LOW STALLED OUT OVER SOUTHERN QUEBEC. AS THE UPPER LEVEL
TROUGH AXIS SHIFTS CLOSER TO THE COAST...WESTERLY FLOW ALOFT WILL GIVE
WAY TO NW FLOW ALOFT OVER THE CAROLINAS. A SECONDARY COLD FRONT WILL
APPROACH CENTRAL NC FROM THE NORTH TONIGHT BEFORE STALLING OUT WEST-
EAST IN VICINITY OF THE VA/NC BORDER ON FRIDAY. HEIGHT RISES ALOFT WILL
RESULT IN WEAK PRESSURE RISES OVER THE REGION FRI AS THE STALLED UPPER
LEVEL LOW IN QUEBEC WOBBLES NORTHWARD...THOUGH EPISODIC DPVA ASSOC/W
POTENT SHORTWAVE ENERGY DIGGING SOUTHEAST FROM CANADA THROUGH THE OH
VALLEY INTO THE CAROLINAS IN NW FLOW ALOFT WILL ALLOW FOR TROUGHING AT
TIMES.
CONVECTION: THE SECONDARY FRONT WILL STALL OUT ALONG OR NEAR THE VA
BORDER ON FRIDAY AS LOW-LEVEL FLOW (I.E. 925 MB) VEERS TO THE SSW/SW
AND ALLOWS MOISTURE RETURN...ESP IN CENTRAL/EASTERN NC. THE
COMBINATION OF DIURNAL HEATING AND INCREASED BOUNDARY LAYER MOISTURE
SHOULD ALLOW MARGINAL DESTABILIZATION FRI AFT/EVE...WITH MLCAPE VALUES
AS HIGH AS 1000-1500 J/KG SOUTH AND EAST OF THE TRIANGLE AND UP TO 500
J/KG IN THE NW PIEDMONT ACCORDING TO THE NAM...THOUGH THE GFS IS
NOTABLY MORE STABLE AND CAPPED. GIVEN EPISODIC DPVA IN THE PRESENCE OF
SOME DEGREE OF MOISTURE RETURN AND DESTABILIZATION...WILL INTRODUCE A
SLIGHT CHANCE OF CONVECTION DURING THE LATE AFTERNOON AND EVENING
HOURS. IF FOCUSED DPVA OCCURS AROUND OR SHORTLY AFTER PEAK HEATING IN
THE PRESENCE OF `NAM-LIKE` THERMO PROFILES WHEN 0-6 KM SHEAR IS PROGGED
AT 35-45 KT...A CONDITIONAL POTENTIAL FOR AN ISOLD SEVERE STORM WOULD
BE PRESENT. SUFFICIENT UNCERTAINTY IS PRESENT TO PRECLUDE ANY MENTION
OF HAZARDOUS WEATHER AT THIS TIME.
TEMPS: EXPECT HIGHS FRIDAY SLIGHTLY BELOW NORMAL IN THE MID/UPPER
80S...WITH LOWS FRI NIGHT IN THE 60S. -VINCENT
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS OF 310 PM THURSDAY...
THE UPPER AIR PATTERN DURING THE LONG RANGE EVOLVES FROM A NORTHEAST
CONUS TROUGH AND A DESERT SOUTHWEST RIDGE OVER THE WEEKEND TO A FLATTER
AND MORE ZONAL PATTERN BY THE MIDDLE OF NEXT WEEK. THIS WILL RESULT IN
A WARMING OF TEMPERATURES WITH SMALL CHANCES OF PRECIPITATION MAINLY
DURING THE EARLY TO MID PORTION OF NEXT WEEK.
MODEL GUIDANCE IS IN GOOD AGREEMENT THAT THE NORTHWEST FLOW PRESENT AT
THE START OF THE PERIOD SATURDAY AND THE ASSOCIATED LEE TROUGHING WILL
DAMPEN BY LATE SUNDAY. THE NAM/GFS/ECMWF INDICATE THAT SOME SCATTERED
CONVECTIVE PRECIPITATION IS POSSIBLE IN THE COASTAL PLAIN OR COASTAL
REGION DURING THE AFTN/EVENING. AROUND A THIRD OF THE SREF MEMBERS AT
FAY/RWI/RDU INDICATE SOME LIGHT PRECIPITATION WITH THE PRECIPITATION
GENERATED BY THE ARW MEMBERS FOR THE MOST PART ACROSS THESE LOCATIONS.
MOS GUIDANCE POPS ARE LOW AND GENERALLY RANGE LESS THAN 15%. GIVEN
THIS...HAVE OPTED TO INSERT A NARROW CORRIDOR OF SLIGHT CHANCE POPS FOR
SAT AFTERNOON IN THE COASTAL PLAIN BUT WILL HOLD OFF GOING ANY MORE
BULLISH. A SIMILAR SETUP OCCURS ON SUNDAY BUT GIVEN THE MORE WESTERLY
FLOW AND LOW CONFIDENCE WILL KEEP SUNDAY DRY FOR NOW. HIGHS WILL RANGE
IN THE UPPER 80S NORTH TO LOWER 90S SOUTH ON SAT AND A DEGREE OR TWO
WARMER ON SUN WITH MORNING LOWS IN THE UPPER 60S TO LOWER 70S.
STILL A FAIR AMOUNT OF UNCERTAINTY WITH THE PATTERN FOR NEXT WEEK AS A
COLD FRONT DROPS INTO THE MID ATLANTIC STATES AND BECOMES STATIONARY AS
A WEAK SURFACE LOW DEVELOPS OVER THE WESTERN OH VALLEY AND SLOWLY MOVES
EAST. GFS/ECMWF GUIDANCE DIFFERS QUITE A BIT ON THE EVOLUTION AND
EASTWARD PROGRESSION OF THIS SYSTEM. LATEST GUIDANCE FROM HPC LEANS
TOWARD THE ECMWF AND THE EC ENSEMBLE WHICH HAS BEEN MORE STABLE AND TO
WHICH THE GFS IS TRENDING. THE RESULT WILL BE AN INCREASE IN THE THREAT
OF MAINLY DIURNALLY FORCED CONVECTION DURING THE UPCOMING WORK WEEK
WITH PERHAPS THE BEST COVERAGE ON MONDAY AND TUESDAY. THICKNESS VALUES
INCREASE A BIT THROUGH THE PERIOD...WITH THE 1000-850 MB THICKNESS
REACHING THE 1430S BY THURSDAY. THIS WIL RESULT IN AN INCREASE IN MAX
TEMPS TO NEAR OR JUST ABOVE AVERAGE WITH HIGHS IN THE UPPER 80S TO
LOWER 90S. INCREASING MOISTURE WILL RESULT IN OVERNIGHT LOWS MODERATING
INTO THE LOWER 70S BY MID WEEK. -BLAES
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 817 PM THURSDAY...
24-HR TAF PERIOD: VFR CONDITIONS WILL CONTINUE TO PREVAIL OVER THE
NEXT 24 HOURS... AS HIGH PRESSURE BUILDS IN TO THE OHIO VALLEY.
WINDS WILL BECOME NEAR CALM TONIGHT... AND REMAIN LIGHT THROUGH THE
DAY TOMORROW.
LOOKING AHEAD: VFR CONDITIONS WILL PREVAIL THROUGH THE WEEKEND...THOUGH
WITH AN INCREASING POTENTIAL FOR AFTERNOON AND EVENING CONVECTION LATE
THIS WEEKEND THROUGH EARLY NEXT WEEK. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...VINCENT
LONG TERM...BLAES
AVIATION...SEC/VINCENT
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
733 AM EDT WED AUG 13 2014
.SYNOPSIS...
A COLD FRONT WILL SLOWLY PUSH OFFSHORE TODAY. HIGH PRESSURE WILL BUILD
INTO THE REGION THURSDAY. A WEAK FRONT WILL APPROACH THU NIGHT AND
LINGER ACROSS THE AREA FRIDAY. HIGH PRESSURE WILL SHIFT OFF THE
COAST SATURDAY AND REMAIN THERE WITH A TROUGH DEVELOPING INLAND
THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 733 AM WED...THE ATMOSPHERE REMAINS UNSTABLE WITH A WARM SW
FLOW PER RAP SOUNDINGS AND KMHX VWP...THOUGH LACK OF TRIGGERING
MECHANISM PROHIBITING CONVECTION THIS MORNING. CONDITIONS WARM AND
MUGGY WITH LOW/MID 70S INLAND TO UPR 70S ON THE COAST. PATCHY FOG
AND LOW STRATUS WILL BURN OFF SHORTLY.
POSITIVELY TILTED UPR TROUGH LOCATED ACROSS THE SPINE OF THE
SOUTHERN AND CENTRAL APPALACHIANS THIS MORNING PER H20 VAPOR
IMAGERY WILL SWING THROUGH EASTERN NC THIS AFTERNOON. THIS WILL
PROVIDE DECENT UPR FORCING AND DEEP LAYER SHEAR ACROSS THE EASTERN
FA...AND SHOULD THERE BE ENOUGH MOISTURE AVAILABILITY... COULD
SPUR THUNDERSTORM DEVELOPMENT MAINLY EAST OF HWY 17 THIS
AFTERNOON. THE KEY FACTOR WILL BE MOISTURE AVAILABILITY IN THE MID
LEVELS...WITH GFS/ECM KEEPING THE AREA DRY. NAM/SREF SOUNDINGS
HOWEVER ARE MORE AGGRESSIVE WITH INSTABILITY/MOISTURE...AND ON PAR
WITH NSSL WRF IN CONVECTIVE DEVELOPMENT NEAR THE COAST AFT 16Z.
ANY BACKING OF WINDS AHEAD OF SLOW MOVING COLD FRONT MOVING
THROUGH WOULD ENHANCE THE SFC BASED INSTABILITY AND WITH 30-35 KT
OF SHEAR IN PLACE...COULD GENERATE AN ISO STRONG/SEVERE
THUNDERSTORM. DUE TO THE UNCERTAINTY...WILL CAP POPS IN THE LOW
CHANCE/SCT RANGE FAR EASTERN AREAS...WITH NO POPS ACROSS THE
COASTAL PLAIN COUNTIES.
&&
.SHORT TERM /TONIGHT/...
AS OF 330 AM WED...ANY PRECIP WILL QUICKLY WANE AND SHIFT OFFSHORE
BY EVENING AS DRY AIR IS USHERED IN BEHIND FRONTAL PASSAGE. SFC
DEWPOINTS WILL DROP TO THE LOWER/MIDDLE 60S AND COMBINED WITH
LIGHT/CALM WINDS AND CLEARING SKIES...ALLOW TEMPS TO DROP
COMFORTABLY INTO THE 60S AREA WIDE...WITH LOW 70S IMMEDIATE COAST.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 315 AM WED...WEAK SFC HIGH PRES BUILDS INTO THE REGION THURS
WITH CYCLONIC FLOW CONTINUING ALOFT WITH AN UPPER LOW SLOWLY
PUSHING EAST ACROSS QUEBEC. A VERY DRY AIRMASS WILL BE IN PLACE FOR
AUGUST WITH PWATS BELOW 1"...AROUND 2 SD BELOW NORMAL...AND EXPECT
DRY CONDITIONS TO PREVAIL WITH COMFORTABLE TEMPS IN THE 80S WITH
DEWPOINTS IN THE LOWER 60S.
A SHORTWAVE MOVES THROUGH THE FLOW ALOFT LATE IN THE WEEK WITH A
WEAK TROF/BACKDOOR FRONT MOVING INTO THE REGION FRI. PWATS INCREASE
TO AROUND 1-1.25" WITH SHORTWAVE ENERGY AND FRONTAL CONVERGENCE
PROVIDING SUPPORT FOR ISOL TSTMS THROUGH PEAK HEATING. THE TROF
LINGERS ACROSS THE AREA THROUGH SATURDAY BEFORE DISSIPATING WITH
THE PIEDMONT TROF DEVELOPING INLAND AND HIGH PRESSURE CENTERED WELL
OFFSHORE PRODUCING DEEP SOUTHERLY FLOW ACROSS THE AREA. EXPECT
ISOLATED...MAINLY DIURNALLY DRIVEN CONVECTION ALONG THE SEABREEZE OR
INLAND TROUGH TO PERSIST SAT AND SUN.
MODELS DIVERGE IN THE TIMING AND STRENGTH OF A SHORTWAVE MOVING
THROUGH THE UPPER TROUGH ACROSS THE EAST COAST SUN NIGHT INTO MON.
THE GFS IS FASTER/STRONGER BRINGING INCREASING SUPPORT FOR SHOWERS
AND THUNDERSTORMS ACROSS THE REGION EARLY NEXT WEEK...HOWEVER TREND
IS TO FAVOR THE SLOWER AND WEAKER SOLUTION OF THE ECENS. FOLLOWED
CLOSELY TO WPC GUIDANCE EARLY NEXT WEEK CONTINUING THE TYPICAL
DIURNALLY DRIVEN CONVECTION.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 733 AM WED...MAINLY VFR CONDITIONS THROUGH THE PERIOD. WINDS
WILL BE GENERALLY W TO WNW TODAY BEHIND A COLD FRONTAL PASSAGE.
WINDS DROP TO CALM TONIGHT WITH CLEAR SKIES. ONLY A SMALL CHANCE
FOR LIGHT FOG TONIGHT AS DRY AIR FILTERS INTO THE REGION.
LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 315 AM WED...VFR CONDITIONS EXPECTED TO DOMINATE THROUGH MUCH
OF THE LONG TERM. HIGH PRES BUILDS ACROSS THE AREA THURS BRINGING
DRY CONDITIONS...THEN WILL SEE MOISTURE GRADUALLY INCREASE THROUGH
THE REST OF THE LONG TERM WITH ISOL...MAINLY DIURNALLY DRIVEN...
CONVECTION EACH AFTERNOON ALONG THE INLAND TROUGH OR SEABREEZE.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 330 AM WED...WINDS ARE SW TO W EARLY THIS MORNING IN THE
10-15 KT RANGE...THOUGH GUSTING AT TIMES TO 20 KT. SEAS RANGE FROM
2 TO 4 FT. THE W TO SW FLOW WILL CONTINUE IN THIS RANGE THROUGH
THIS AFTERNOON AHEAD OF AN APPROACHING COLD FRONT. COULD SEE SOME
SEAS TOPPING OUT AT 5 FT ACROSS SOUTHERN/CENTRAL WATERS TODAY. THE
WINDS TURN NW TO EVENTUALLY NORTH LATE TONIGHT BEHIND THE COLD
FRONT...THOUGH WILL GENERALLY REMAIN IN THE 10-15 KT RANGE.
LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 315 AM WED...LIGHT AND VARIABLE WINDS THURS WITH HIGH PRES
ACROSS THE AREA WHILE SEAS SUBSIDING THROUGH THE DAY. THE HIGH
SLIDES OFFSHORE DURING THE LATTER HALF OF THE WEEK WITH WINDS
VEERING TO SLY MAINLY 10 KT OR LESS AND SEAS GENERALLY 1 TO 3 FT.
WINDS MAY BECOME VARIABLE NORTHERN WATERS FRI WITH A BACKDOOR FRONT
POTENTIALLY MOVING INTO THE AREA FOR A BRIEF PERIOD...STILL SOME
DIFFERENCES AMONG THE MODELS JUST HOW FAR THE FRONT WILL PUSH INTO
THE REGION. WINDS RETURN TO SOUTHERLY BY FRIDAY NIGHT AND REMAIN
LIGHT...MAINLY BELOW 15 KT INTO SAT NIGHT. DISCOUNTING THE GFS AND
SUBSEQUENTLY WAVEWATCH III SAT NIGHT AND SUN AS IT IS ANOMALOUSLY
FAST AND STRONG BRINGING A ROBUST SHORTWAVE TROUGH AND ATTENDANT LOW
PRES SYSTEM ACROSS THE MID ATLANTIC...SUBSEQUENTLY BRINGING SW WINDS
TO 20-25 KT AND SEAS AS HIGH AS 5-8 FT ACROSS THE EASTERN NC WATERS
ON SUN. INSTEAD USED A BLEND OF THE ECMWF AND WPC GUIDANCE BRINGING
SW WINDS AROUND 10-15 KT AND KEEPING SEAS AROUND 2-4 FT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TL
NEAR TERM...TL
SHORT TERM...TL
LONG TERM...SK
AVIATION...SK/TL
MARINE...SK/TL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
330 AM EDT WED AUG 13 2014
.SYNOPSIS...
A COLD FRONT WILL SLOWLY PUSH OFFSHORE TODAY. HIGH PRESSURE WILL BUILD
INTO THE REGION THURSDAY. A WEAK FRONT WILL APPROACH THU NIGHT AND
LINGER ACROSS THE AREA FRIDAY. HIGH PRESSURE WILL SHIFT OFF THE
COAST SATURDAY AND REMAIN THERE WITH A TROUGH DEVELOPING INLAND
THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 330 AM WED...AN AREA OF CONVECTION EARLY THIS MORNING HAS
WEAKENED AS IT MOVED EAST TOWARDS THE EASTERN FA. TEMPORARY
SUBSIDENCE MAY BE LIMITING CONVECTION...ALONG WITH THE LACK OF A
TRIGGERING MECHANISM. NEVERTHELESS...THE ATMOSPHERE REMAINS
UNSTABLE WITH A WARM SW FLOW PER RAP SOUNDINGS AND KMHX VWP. HAVE
LEFT IN ISO MENTION OF THUNDER REST OF THE OVERNIGHT INTO WED AM.
POSITIVELY TILTED UPR TROUGH LOCATED ACROSS THE OHIO VALLEY THIS
MORNING PER H20 VAPOR IMAGERY WILL SWING THROUGH EASTERN NC THIS
AFTERNOON. THIS WILL PROVIDE DECENT UPR FORCING AND DEEP LAYER
SHEAR ACROSS THE EASTERN FA...AND SHOULD THERE BE ENOUGH MOISTURE
AVAILABILITY... COULD SPUR THUNDERSTORM DEVELOPMENT MAINLY EAST OF
HWY 17 THIS AFTERNOON. THE KEY FACTOR WILL BE MOISTURE
AVAILABILITY IN THE MID LEVELS...AS GFS/ECM KEEP THE AREA DRY.
NAM/SREF SOUNDINGS HOWEVER ARE MORE AGGRESSIVE WITH
INSTABILITY/MOISTURE...AND ON PAR WITH NSSL WRF IN CONVECTIVE
DEVELOPMENT NEAR THE COAST AFT 16Z. ANY BACKING OF WINDS AHEAD OF
SLOW MOVING COLD FRONT MOVING THROUGH WOULD ENHANCE THE SFC BASED
INSTABILITY AND WITH 30-35 KT OF SHEAR IN PLACE...COULD GENERATE
AN ISO STRONG/SEVERE THUNDERSTORM THREAT. DUE TO THE
UNCERTAINTY...WILL CAP POPS IN THE LOW CHANCE/SCT RANGE FAR EASTERN
AREAS...WITH NO POPS ACROSS THE COASTAL PLAIN COUNTIES.
&&
.SHORT TERM /TONIGHT/...
AS OF 330 AM WED...ANY PRECIP WILL QUICKLY WANE AND SHIFT OFFSHORE
BY EVENING AS DRY AIR IS USHERED IN BEHIND FRONTAL PASSAGE. SFC
DEWPOINTS WILL DROP TO THE LOWER/MIDDLE 60S AND COMBINED WITH
LIGHT/CALM WINDS AND CLEARING SKIES...ALLOW TEMPS TO DROP
COMFORTABLY INTO THE 60S AREA WIDE...WITH LOW 70S IMMEDIATE COAST.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 315 AM WED...WEAK SFC HIGH PRES BUILDS INTO THE REGION THURS
WITH CYCLONIC FLOW CONTINUING ALOFT WITH AN UPPER LOW SLOWLY
PUSHING EAST ACROSS QUEBEC. A VERY DRY AIRMASS WILL BE IN PLACE FOR
AUGUST WITH PWATS BELOW 1"...AROUND 2 SD BELOW NORMAL...AND EXPECT
DRY CONDITIONS TO PREVAIL WITH COMFORTABLE TEMPS IN THE 80S WITH
DEWPOINTS IN THE LOWER 60S.
A SHORTWAVE MOVES THROUGH THE FLOW ALOFT LATE IN THE WEEK WITH A
WEAK TROF/BACKDOOR FRONT MOVING INTO THE REGION FRI. PWATS INCREASE
TO AROUND 1-1.25" WITH SHORTWAVE ENERGY AND FRONTAL CONVERGENCE
PROVIDING SUPPORT FOR ISOL TSTMS THROUGH PEAK HEATING. THE TROF
LINGERS ACROSS THE AREA THROUGH SATURDAY BEFORE DISSIPATING WITH
THE PIEDMONT TROF DEVELOPING INLAND AND HIGH PRESSURE CENTERED WELL
OFFSHORE PRODUCING DEEP SOUTHERLY FLOW ACROSS THE AREA. EXPECT
ISOLATED...MAINLY DIURNALLY DRIVEN CONVECTION ALONG THE SEABREEZE OR
INLAND TROUGH TO PERSIST SAT AND SUN.
MODELS DIVERGE IN THE TIMING AND STRENGTH OF A SHORTWAVE MOVING
THROUGH THE UPPER TROUGH ACROSS THE EAST COAST SUN NIGHT INTO MON.
THE GFS IS FASTER/STRONGER BRINGING INCREASING SUPPORT FOR SHOWERS
AND THUNDERSTORMS ACROSS THE REGION EARLY NEXT WEEK...HOWEVER TREND
IS TO FAVOR THE SLOWER AND WEAKER SOLUTION OF THE ECENS. FOLLOWED
CLOSELY TO WPC GUIDANCE EARLY NEXT WEEK CONTINUING THE TYPICAL
DIURNALLY DRIVEN CONVECTION.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 330 AM WED...MAINLY VFR CONDITIONS THROUGH THE PERIOD. COULD
SEE SOME MVFR MAINLY DUE TO LOWERED VSBYS THROUGH SUNRISE THIS AM
AS WINDS REMAIN LIGHT AND LOW LEVEL MOISTURE IS ON THE HIGH SIDE.
ANY LIGHT FOG BURNS OFF AFTER SUNRISE WITH FEW OR SCT STRATO CU
THROUGH THE DAY. WINDS WILL BE GENERALLY W TO WNW TODAY BEHIND A
COLD FRONTAL PASSAGE. WINDS DROP TO CALM TONIGHT WITH CLEAR SKIES.
ONLY A SMALL CHANCE FOR LIGHT FOG TONIGHT AS DRY AIR FILTERS INTO
THE REGION.
LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 315 AM WED...VFR CONDITIONS EXPECTED TO DOMINATE THROUGH MUCH
OF THE LONG TERM. HIGH PRES BUILDS ACROSS THE AREA THURS BRINGING
DRY CONDITIONS...THEN WILL SEE MOISTURE GRADUALLY INCREASE THROUGH
THE REST OF THE LONG TERM WITH ISOL...MAINLY DIURNALLY DRIVEN...
CONVECTION EACH AFTERNOON ALONG THE INLAND TROUGH OR SEABREEZE.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 330 AM WED...WINDS ARE SW TO W EARLY THIS MORNING IN THE
10-15 KT RANGE...THOUGH GUSTING AT TIMES TO 20 KT. SEAS RANGE FROM
2 TO 4 FT. THE W TO SW FLOW WILL CONTINUE IN THIS RANGE THROUGH
THIS AFTERNOON AHEAD OF AN APPROACHING COLD FRONT. COULD SEE SOME
SEAS TOPPING OUT AT 5 FT ACROSS SOUTHERN/CENTRAL WATERS TODAY. THE
WINDS TURN NW TO EVENTUALLY NORTH LATE TONIGHT BEHIND THE COLD
FRONT...THOUGH WILL GENERALLY REMAIN IN THE 10-15 KT RANGE.
LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 315 AM WED...LIGHT AND VARIABLE WINDS THURS WITH HIGH PRES
ACROSS THE AREA WHILE SEAS SUBSIDING THROUGH THE DAY. THE HIGH
SLIDES OFFSHORE DURING THE LATTER HALF OF THE WEEK WITH WINDS
VEERING TO SLY MAINLY 10 KT OR LESS AND SEAS GENERALLY 1 TO 3 FT.
WINDS MAY BECOME VARIABLE NORTHERN WATERS FRI WITH A BACKDOOR FRONT
POTENTIALLY MOVING INTO THE AREA FOR A BRIEF PERIOD...STILL SOME
DIFFERENCES AMONG THE MODELS JUST HOW FAR THE FRONT WILL PUSH INTO
THE REGION. WINDS RETURN TO SOUTHERLY BY FRIDAY NIGHT AND REMAIN
LIGHT...MAINLY BELOW 15 KT INTO SAT NIGHT. DISCOUNTING THE GFS AND
SUBSEQUENTLY WAVEWATCH III SAT NIGHT AND SUN AS IT IS ANOMALOUSLY
FAST AND STRONG BRINGING A ROBUST SHORTWAVE TROUGH AND ATTENDANT LOW
PRES SYSTEM ACROSS THE MID ATLANTIC...SUBSEQUENTLY BRINGING SW WINDS
TO 20-25 KT AND SEAS AS HIGH AS 5-8 FT ACROSS THE EASTERN NC WATERS
ON SUN. INSTEAD USED A BLEND OF THE ECMWF AND WPC GUIDANCE BRINGING
SW WINDS AROUND 10-15 KT AND KEEPING SEAS AROUND 2-4 FT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TL
NEAR TERM...TL
SHORT TERM...TL
LONG TERM...SK
AVIATION...SK/TL
MARINE...SK/TL
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
434 AM EDT WED AUG 13 2014
.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO MOVE NORTHEAST AND WELL AWAY FROM THE
AREA TODAY. A TROUGH EXTENDING SOUTHWEST FROM THE LOW WILL MOVE
SOUTHEAST OF THE REGION TODAY AS YET ANOTHER TROUGH SWINGS THROUGH
THIS EVENING. MUCH COOLER TEMPERATURES WILL PREVAIL TODAY THROUGH
FRIDAY MORNING. HIGH PRESSURE WILL GRADUALLY BUILD SOUTHEAST ACROSS
THE OHIO VALLEY BY FRIDAY MORNING AND TO THE EAST COAST BY SATURDAY
MORNING. A WARM UP IS IN STORE FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LINE OF SHOWERS CONTINUES TO BREAK UP ALONG THE LAKE SHORE AS IT
MOVES INLAND FROM JUST SOUTH OF CUYAHOGA COUNTY NORTHEAST TO ERIE
AND CRAWFORD COUNTIES IN PENNSYLVANIA. THIS ACTIVITY IS IN
ASSOCIATION WITH THE FIRST OF TWO TROUGHS MOVING THROUGH THE REGION.
LATEST HRRR MODEL SHOWS PRECIPITATION GRADUALLY ENDING THROUGH THE
DAY AND THEN DRYING OUT LATER THIS EVENING OVER THE EASTERN PORTIONS
OF THE FORECAST AREA. WITH UPPER LEVEL LOW IN PLACE...CANT RULE OUT
CHANCE FOR A SHOWER OR TWO...ESPECIALLY THIS MORNING.
TEMPERATURES WILL BE COOLER TODAY ACROSS THE FORECAST AREA. WITH
CLOUDS AND POSSIBLE SHOWERS PRESENT IN THE EAST...HIGHS MAY NOT GET
OUT OF THE 60S. WE SHOULD START TO RETURN BACK TO SOME SUNSHINE
TODAY IN THE WEST AND THIS WILL ALLOW FOR SOME HEATING TO TAKE PLACE
AND RECOVER TEMPERATURES BACK TO THE 70S FOR HIGHS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
UPPER LEVEL PATTERN DESCRIPTION OF THE DAY...UGLY. HOW ELSE CAN ONE
DESCRIBE THE APPEARANCE OF A MEGA UPPER LEVEL LOW PRESSURE SYSTEM
THAT WILL DOMINATE THE EASTERN UNITED STATES OVER THE NEXT 24 TO 36
HOURS. DEEP UPPER LEVEL LOW WILL KEEP LOW PRESSURE AT THE SURFACE
PRESENT THROUGH TONIGHT. THIS WILL KEEP THE CYCLONIC FLOW AND A
RETURN OF A SECONDARY TROUGH INTO THE AREA TODAY. THE LOW WILL PULL
OUT TO THE NORTHEAST AND ALLOW SURFACE HIGH PRESSURE TO BUILD
SOUTHEAST INTO THE OHIO VALLEY REGION. THE COMBINATION OF THE
CYCLONIC FLOW FROM THE NORTHWEST AND THE HIGH TO THE WEST WILL KEEP
COLD AIR ADVECTION GOING THROUGH FRIDAY AT LEAST. SOME RECOVERY WILL
BEGIN TO TAKE PLACE ON SATURDAY AS THE SURFACE HIGH SHIFTS TO THE
EAST COAST ALLOWING FOR SOME RETURN SOUTHWESTERLY FLOW.
EVENTUALLY...ANOTHER SHOT OF MOISTURE COULD STREAM INTO THE AREA
SATURDAY INTO SATURDAY NIGHT AND BRING ANOTHER CHANCE FOR SOME
SHOWERS. THE MOISTURE IS IN RESPONSE TO A FAST MOVING UPPER LEVEL
TROUGH AND SURFACE LOW PRESSURE SYSTEM. FURTHER WARMING WILL TAKE
PLACE SATURDAY AND SATURDAY NIGHT IN THE WARM AIR ADVECTION.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
THE PERSISTENT TROUGH OVER THE GREAT LAKES IS PROGGED TO FLATTEN
OUT EARLY NEXT WEEK AS THE UPPER LOW OVER THE NORTHEAST SLOWLY LIFTS
OUT. MOST OF THE MODELS BRING ONE LAST SHORT WAVE ACROSS THE GREAT
LAKES EARLY SUNDAY AND WILL KEEP SHOWERS IN THE FORECAST FOR SUNDAY.
THE TIMING IS UNCERTAIN THOUGH AND THE SYSTEM COULD BE THROUGH EARLY
ON SUNDAY AND THE DAY MAY BE SALVAGEABLE.
MOST OF THE MODELS AND ENSEMBLES BUILD THE SURFACE HIGH ACROSS THE
LOWER GREAT LAKES BY MONDAY. THE OPERATIONAL ECWMF IS THE HOLD
OUT...KEEPING THE SURFACE FRONT NEARBY. WILL GO WITH THE CONSENSUS
AND TRY TO DRY THINGS OUT ON MONDAY. THE FRONT MAY TRY TO COME BACK
AS A WARM FRONT BY TUESDAY AND WILL BRING THE SHOWERS BACK INTO THE
FORECAST TUESDAY AND ESPECIALLY TUESDAY NIGHT.
LOWERED THE FORECAST TEMPERATURES BACK DOWN TO NORMAL OR A COUPLE OF
DEGREES BELOW NORMAL FOR SUNDAY AND MONDAY. STARTED TRENDING TEMPS
BACK UP A FEW DEGREES ON TUESDAY.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
THE TROUGH AND SHOWERS WILL MOVE SOUTHEAST OF THE AREA THIS
MORNING. AREAS OF IFR CEILINGS WILL CONTINUE THROUGH MID MORNING AS
THE BOUNDARY LAYER IS VERY MOIST. THE LOW CEILINGS WILL GRADUALLY
RISE TODAY WITH DAY TIME HEATING TO VFR CEILINGS 040-050 THIS
AFTERNOON. SKIES SHOULD CLEAR THIS EVENING EXCEPT FOR EXTREME
NORTHEAST OH AND NORTHWEST PA. THE WEST NORTHWEST WIND WILL BE A
BIT GUSTY THIS AFTERNOON.
OUTLOOK...NON VFR POSSIBLE IN SHOWERS/THUNDERSTORMS SATURDAY
EVENING INTO SUNDAY.
&&
.MARINE...
THE FORECAST IS TRICKY WITH REGARD TO THE SMALL CRAFT ADVISORY.
NORTHWEST WINDS HAVE PICKED UP ON THE LAKE AND THE SMALL CRAFT
ADVISORY WILL BE NEEDED INTO THE AFTERNOON. THERE WILL LIKELY BE A
DIMINISHING OF THE WINDS...ESPECIALLY ON THE WEST HALF OF THE LAKE
THIS AFTERNOON AND EVENING. IT WILL TAKE A WHILE FOR THE LAKE TO
SETTLE DOWN...THEN THE NEXT TROUGH IS DUE TONIGHT AND WINDS WILL
PICK BACK UP FROM THE NORTHWEST AND NORTH. WOULD RATHER NOT TAKE
DOWN THE SMALL CRAFT ADVISORY FOR A FEW HOURS LATE THIS AFTERNOON
AND EARLY THIS EVENING ON THE WEST HALF OF THE LAKE JUST TO REISSUE
IT AGAIN THIS EVENING SO WILL JUST KEEP IT GOING. WATERSPOUTS ARE
POSSIBLE ESPECIALLY TONIGHT (WED NIGHT) INTO THURSDAY MORNING AS THE
COLDEST AIR ALOFT PASSES OVER THE LAKE.
WINDS WILL VEER MORE FROM THE SOUTHWEST ON FRIDAY AHEAD OF THE NEXT
WEAK FRONT. NOT VERY CONFIDENT ON HOW STRONG THE SOUTHWEST WINDS MAY
GET BUT IT MAY REMAIN BRISK AND CHOPPY ON THE EAST HALF OF THE LAKE
GOING INTO THE WEEKEND.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THURSDAY FOR LEZ145>149.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT THURSDAY FOR LEZ142>144.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...KOSARIK
AVIATION...KOSARIK
MARINE...KOSARIK
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
337 AM EDT WED AUG 13 2014
.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO MOVE NORTHEAST AND WELL AWAY FROM THE
AREA TODAY. A TROUGH EXTENDING SOUTHWEST FROM THE LOW WILL MOVE
SOUTHEAST OF THE REGION TODAY AS YET ANOTHER TROUGH SWINGS THROUGH
THIS EVENING. MUCH COOLER TEMPERATURES WILL PREVAIL TODAY THROUGH
FRIDAY MORNING. HIGH PRESSURE WILL GRADUALLY BUILD SOUTHEAST ACROSS
THE OHIO VALLEY BY FRIDAY MORNING AND TO THE EAST COAST BY SATURDAY
MORNING. A WARM UP IS IN STORE FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LINE OF SHOWERS CONTINUES TO BREAK UP ALONG THE LAKE SHORE AS IT
MOVES INLAND FROM JUST SOUTH OF CUYAHOGA COUNTY NORTHEAST TO ERIE
AND CRAWFORD COUNTIES IN PENNSYLVANIA. THIS ACTIVITY IS IN
ASSOCIATION WITH THE FIRST OF TWO TROUGHS MOVING THROUGH THE REGION.
LATEST HRRR MODEL SHOWS PRECIPITATION GRADUALLY ENDING THROUGH THE
DAY AND THEN DRYING OUT LATER THIS EVENING OVER THE EASTERN PORTIONS
OF THE FORECAST AREA. WITH UPPER LEVEL LOW IN PLACE...CANT RULE OUT
CHANCE FOR A SHOWER OR TWO...ESPECIALLY THIS MORNING.
TEMPERATURES WILL BE COOLER TODAY ACROSS THE FORECAST AREA. WITH
CLOUDS AND POSSIBLE SHOWERS PRESENT IN THE EAST...HIGHS MAY NOT GET
OUT OF THE 60S. WE SHOULD START TO RETURN BACK TO SOME SUNSHINE
TODAY IN THE WEST AND THIS WILL ALLOW FOR SOME HEATING TO TAKE PLACE
AND RECOVER TEMPERATURES BACK TO THE 70S FOR HIGHS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
UPPER LEVEL PATTERN DESCRIPTION OF THE DAY...UGLY. HOW ELSE CAN ONE
DESCRIBE THE APPEARANCE OF A MEGA UPPER LEVEL LOW PRESSURE SYSTEM
THAT WILL DOMINATE THE EASTERN UNITED STATES OVER THE NEXT 24 TO 36
HOURS. DEEP UPPER LEVEL LOW WILL KEEP LOW PRESSURE AT THE SURFACE
PRESENT THROUGH TONIGHT. THIS WILL KEEP THE CYCLONIC FLOW AND A
RETURN OF A SECONDARY TROUGH INTO THE AREA TODAY. THE LOW WILL PULL
OUT TO THE NORTHEAST AND ALLOW SURFACE HIGH PRESSURE TO BUILD
SOUTHEAST INTO THE OHIO VALLEY REGION. THE COMBINATION OF THE
CYCLONIC FLOW FROM THE NORTHWEST AND THE HIGH TO THE WEST WILL KEEP
COLD AIR ADVECTION GOING THROUGH FRIDAY AT LEAST. SOME RECOVERY WILL
BEGIN TO TAKE PLACE ON SATURDAY AS THE SURFACE HIGH SHIFTS TO THE
EAST COAST ALLOWING FOR SOME RETURN SOUTHWESTERLY FLOW.
EVENTUALLY...ANOTHER SHOT OF MOISTURE COULD STREAM INTO THE AREA
SATURDAY INTO SATURDAY NIGHT AND BRING ANOTHER CHANCE FOR SOME
SHOWERS. THE MOISTURE IS IN RESPONSE TO A FAST MOVING UPPER LEVEL
TROUGH AND SURFACE LOW PRESSURE SYSTEM. FURTHER WARMING WILL TAKE
PLACE SATURDAY AND SATURDAY NIGHT IN THE WARM AIR ADVECTION.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
THE PERSISTENT TROUGH OVER THE GREAT LAKES IS PROGGED TO FLATTEN
OUT EARLY NEXT WEEK AS THE UPPER LOW OVER THE NORTHEAST SLOWLY LIFTS
OUT. MOST OF THE MODELS BRING ONE LAST SHORT WAVE ACROSS THE GREAT
LAKES EARLY SUNDAY AND WILL KEEP SHOWERS IN THE FORECAST FOR SUNDAY.
THE TIMING IS UNCERTAIN THOUGH AND THE SYSTEM COULD BE THROUGH EARLY
ON SUNDAY AND THE DAY MAY BE SALVAGEABLE.
MOST OF THE MODELS AND ENSEMBLES BUILD THE SURFACE HIGH ACROSS THE
LOWER GREAT LAKES BY MONDAY. THE OPERATIONAL ECWMF IS THE HOLD
OUT...KEEPING THE SURFACE FRONT NEARBY. WILL GO WITH THE CONSENSUS
AND TRY TO DRY THINGS OUT ON MONDAY. THE FRONT MAY TRY TO COME BACK
AS A WARM FRONT BY TUESDAY AND WILL BRING THE SHOWERS BACK INTO THE
FORECAST TUESDAY AND ESPECIALLY TUESDAY NIGHT.
LOWERED THE FORECAST TEMPERATURES BACK DOWN TO NORMAL OR A COUPLE OF
DEGREES BELOW NORMAL FOR SUNDAY AND MONDAY. STARTED TRENDING TEMPS
BACK UP A FEW DEGREES ON TUESDAY.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
THE TROUGH AND SHOWERS WILL MOVE SOUTHEAST OF THE AREA THIS
MORNING. AREAS OF IFR CEILINGS WILL CONTINUE THROUGH MID MORNING AS
THE BOUNDARY LAYER IS VERY MOIST. THE LOW CEILINGS WILL GRADUALLY
RISE TODAY WITH DAY TIME HEATING TO VFR CEILINGS 040-050 THIS
AFTERNOON. SKIES SHOULD CLEAR THIS EVENING EXCEPT FOR EXTREME
NORTHEAST OH AND NORTHWEST PA. THE WEST NORTHWEST WIND WILL BE A
BIT GUSTY THIS AFTERNOON.
OUTLOOK...NON VFR POSSIBLE IN SHOWERS/THUNDERSTORMS SATURDAY
EVENING INTO SUNDAY.
&&
.MARINE...
THE FORECAST IS TRICKY WITH REGARD TO THE SMALL CRAFT ADVISORY.
NORTHWEST WINDS HAVE PICKED UP ON THE LAKE AND THE SMALL CRAFT
ADVISORY WILL BE NEEDED INTO THE AFTERNOON. THERE WILL LIKELY BE A
DIMINISHING OF THE WINDS...ESPECIALLY ON THE WEST HALF OF THE LAKE
THIS AFTERNOON AND EVENING. IT WILL TAKE A WHILE FOR THE LAKE TO
SETTLE DOWN...THEN THE NEXT TROUGH IS DUE TONIGHT AND WINDS WILL
PICK BACK UP FROM THE NORTHWEST AND NORTH. WOULD RATHER NOT TAKE
DOWN THE SMALL CRAFT ADVISORY FOR A FEW HOURS LATE THIS AFTERNOON
AND EARLY THIS EVENING ON THE WEST HALF OF THE LAKE JUST TO REISSUE
IT AGAIN THIS EVENING SO WILL JUST KEEP IT GOING. WATERSPOUTS ARE
POSSIBLE ESPECIALLY TONIGHT (WED NIGHT) INTO THURSDAY MORNING AS THE
COLDEST AIR ALOFT PASSES OVER THE LAKE.
WINDS WILL VEER MORE FROM THE SOUTHWEST ON FRIDAY AHEAD OF THE NEXT
WEAK FRONT. NOT VERY CONFIDENT ON HOW STRONG THE SOUTHWEST WINDS MAY
GET BUT IT MAY REMAIN BRISK AND CHOPPY ON THE EAST HALF OF THE LAKE
GOING INTO THE WEEKEND.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
LEZ142>149.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...KOSARIK
AVIATION...KOSARIK
MARINE...KOSARIK
AREA FORECAST DISCUSSION
NWS MEDFORD OR
848 PM PDT THU AUG 14 2014
.SHORT TERM...A LOW IS CENTERED OVER NORTH CENTRAL OREGON AND
SOUTH CENTRAL WASHINGTON. THIS LOW HAS BROUGHT COOLER
TEMPERATURES, PARTLY TO MOSTLY CLOUDY SKIES AND A FEW LIGHT
SHOWERS TO THE AREA TODAY. THE LOW IS FORECAST TO GRADUALLY SHIFT
NORTHEASTWARD TONIGHT AND FRIDAY. THIS WILL ALLOW WEAK HIGH PRESSURE
TO BUILD INTO THE AREA WITH WARMING TEMPERATURES TOMORROW. MODELS
AND GUIDANCE CONTINUE TO SHOW TEMPERATURES WARMING ABOUT 7 TO 10
DEGREES TOMORROW WITH HIGHS IN THE LOWER TO MID 80S FOR VALLEYS
EAST OF THE CASCADES AND IN THE UPPER 80S TO LOW 90S FOR WEST SIDE
VALLEYS. OVERNIGHT LOW CLOUDS WILL PERSIST ALONG THE COAST AND
PUSH INTO THE UMPQUA BASIN. THESE LOW CLOUDS WILL CLEAR INLAND
DURING THE LATE MORNING AND RETREAT TO THE COAST BY AFTERNOON.
CONTINUED WARM AND DRY CONDITIONS ARE EXPECTED ACROSS INLAND AREAS
INTO THE WEEKEND. HOWEVER A WEAK LOW IS FORECAST TO DROP DOWN THE
OREGON COAST LATE SATURDAY AND SUNDAY. BY SUNDAY, THIS LOW IS
EXPECTED TO BRING A SLIGHT CHANCE OF THUNDERSTORMS INTO CENTRAL
PORTIONS OF THE AREA, MAINLY FROM WESTERN SISKIYOU COUNTY INTO THE
SOUTHERN OREGON CASCADES.
&&
.AVIATION...BASED ON THE 15/00Z TAF CYCLE...
MVFR CEILINGS ARE PRESENT ALONG THE COAST NORTH OF CAPE BLANCO THIS
AFTERNOON WHILE SKIES INLAND HAVE VFR CEILINGS WITH MAINLY BROKEN
COVERAGE OF LOW TOPPED ALTOCUMULUS. THE INLAND MID AND UPPER LEVEL
CLOUD COVER WILL DIMINISH OVERNIGHT WITH MOSTLY CLEAR SKIES THROUGH
FRIDAY EVENING...EXCEPT FOR AREAS OF SMOKE IN SISKIYOU COUNTY FROM
WILDFIRES.
MEANWHILE, A MIX OF IFR AND MVFR LOW CLOUDS AND FOG ARE EXPECTED TO
DEVELOP ALONG ALL OF THE SOUTHERN OREGON COAST AND ALSO SPREAD INTO
THE UMPQUA BASIN. THIS STRATUS AND FOG WILL BEGIN TO DISSIPATE
AROUND 15Z WITH IMPROVEMENT TO VFR EXPECTED IN THE UMPQUA BASIN
AROUND 16Z. THE CURRY COUNTY COAST AND COQUILLE VALLEY ARE LIKELY TO
IMPROVE BY THE END OF THE MORNING WHILE MVFR CONDITIONS MAY LINGER
INTO THE AFTERNOON AT THE COOS AND DOUGLAS COUNTY COAST. THE PATTERN
OF CONDITIONS WILL BE SIMILAR WITH LOW CLOUDS EXPECTED TO RETURN TO
THE COAST ONCE AGAIN ON FRIDAY EVENING. /DW
&&
.MARINE...UPDATED 230 PM PDT WED 14 AUG 2014...
THE WATERS WILL REMAIN BETWEEN HIGH PRESSURE CENTERED OFFSHORE AND
LOW PRESSURE INLAND WITH A GRADUAL TREND OF INCREASING NORTH WINDS
INTO THE WEEKEND. THIS IS LIKELY TO RESULT IN SMALL CRAFT
ADVISORY LEVEL WINDS AND SEAS IN THE OUTER WATERS SOUTH OF CAPE
BLANCO ON SATURDAY THEN ACROSS A LARGER PORTION OF THE WATERS ON
SUNDAY...WITH THE STRONGEST WINDS REMAINING IN THE OUTER WATERS
SOUTH OF CAPE BLANCO. THE INFLUENCE ON SEA HEIGHTS WILL REMAIN
RELATIVELY BALANCED BETWEEN WIND WAVE AND SWELL THROUGH SATURDAY
THEN THE STRONGER WINDS WILL TIP THE BALANCE ON SUNDAY. MODERATE
WINDS AND SEAS MAY CONTINUE THROUGH THE FIRST HALF OF NEXT WEEK WITH
A CONTINUATION OF HIGH PRESSURE OFFSHORE AND LOW PRESSURE INLAND.
/DW
&&
.PREV DISCUSSION... /ISSUED 250 PM PDT THU AUG 14 2014/
DISCUSSION...CURRENT WATER VAPOR IMAGE SHOWS THE UPPER LOW CENTERED
ALONG THE OREGON/WASHINGTON BORDER. THERE`S PLENTY OF CLOUD COVER
OVER THE REGION, BUT SO FAR HAVE NOT SEEN ANY REPORTS OF MEASURABLE
PRECIPITATION. THE NAM AND THE GFS SHOW QPF BREAKING OUT EAST OF THE
CASCADES AND THE NAM SHOWS SOME IN NORTHERN CAL FROM THE SHASTA
TRINITY NORTHEAST TOWARDS LAKEVIEW. THE HRRR RADAR REFLECTIVITY WAS
ALSO SHOWING SPOTTY PRECIPITATION IN THE ABOVE MENTIONED AREAS
EARLIER THIS AFTERNOON, BUT IT HAS NOT VERIFIED. SO I HAVE LOW
CONFIDENCE IN THAT SOLUTION. BOTTOM LINE IS I DOUBT MUCH IF ANYTHING
WILL HAPPEN THIS FAR SOUTH FOR A FEW REASONS. FIRST, THE MODELS ARE
SHOWING SLIGHT WARMING ALOFT. SECOND, THE STRONGEST TRIGGER AND
COOLER AIR ALOFT WILL BE OVER THE NORTHEAST PART OF THE REGION.
THIRD, THE POSITION OF THE LOW IS NOT ONE THAT IS FAVORABLE FOR AN
OUTBREAK OF PRECIPITATION AND FINALLY THE MODEL SOUNDINGS SHOW A SUB
DRY LAYER, SO IF ANYTHING DEVELOPS, MOST WILL NOT REACH THE GROUND.
WITH THAT SAID, I COULD NOT RULE OUT A FEW LIGHT SHOWERS, BUT
PROBABLY NOT ANYTHING MEASURABLE. FURTHER NORTH IN NORTHERN LAKE AND
KLAMATH COUNTIES, EXPECT A FEW ISOLATED STORMS TO DEVELOP LATE THIS
AFTERNOON AND EARLY EVENING, THEN ENDING SHORTLY AFTER DARK.
THE UPPER LOW WILL CONTINUE TO SLOWLY MOVE NORTHEAST TONIGHT AND
CLOUD COVER WILL GRADUALLY DECREASE OVER MOST INLAND LOCATIONS.
TEMPERATURES EAST OF THE CASCADES WILL COOL DOWN INTO THE UPPER 30S
IN THE COOLER SPOTS IN NORTHERN KLAMATH COUNTY.
DRY AND MILDER WEATHER RETURNS FRIDAY AS THE UPPER LOW CONTINUE TO
SLOWLY MOVE NORTHEAST AND WEAK RIDGING BUILDS IN. TEMPERATURES WILL
REBOUND TO NEAR NORMAL VALUES ACROSS THE BOARD.
THIS RIDGING WILL BE SHORT LIVED. THE MODELS ARE ALL IN FAIRLY GOOD
AGREEMENT SHOWING ANOTHER, WEAK POSITIVE TILTED UPPER TROUGH
DEVELOPING OFF THE OREGON COAST SATURDAY AND REMAINING THERE THROUGH
SUNDAY WITH WEAK SHORTWAVES MOVING FROM SOUTHWEST TO NORTHEAST OVER
THE AREA. RIGHT NOW IT DOES NOT LOOK UNSTABLE ENOUGH FOR STORMS TO
DEVELOP SATURDAY. THE GFS DOES SHOW MID LEVEL MOISTURE INCREASING IN
THE AFTERNOON, BUT NOT ENOUGH TO BE A CONCERN, ESPECIALLY WITH
LITTLE OR NO TRIGGER. SUNDAY IS A DIFFERENT STORY. THE NAM SHOWS MID
LEVEL MOISTURE INCREASING OVER THE CASCADES AND WESTERN SISKIYOU
COUNTY IN THE AFTERNOON WITH NEGATIVE LI`S, INCREASING CAPE AND
STRONGER TRIGGER. THE GFS SHOWS A SIMILAR SOLUTION, BUT IS WEAKER
WITH THE AFOREMENTIONED PARAMETERS. DESPITE THIS, FELT IS BEST TO
INTRODUCE A SLIGHT CHANCE OF THUNDERSTORMS FOR THOSE AREAS SUNDAY
AFTERNOON AND EVENING.
THE UPPER TROUGH WILL TRANSITION TO AN UPPER LOW MONDAY WITH
MULTIPLE SHORTWAVE MOVING THROUGH AND INSTABILITY INCREASING ENOUGH
TO KEEP A SLIGHT MENTION OF STORMS FOR THE CASCADES AND SISKIYOUS.
THE MODELS SHOW A NORTHERN BRANCH OF THE JET BECOMING A BIGGER PLAY
MAKER FROM TUESDAY INTO THE END OF THE NEXT WEEK. THIS WILL PUSH THE
UPPER LOW SOUTH TUESDAY, THUS KEEPING ANY THREAT OF STORMS SOUTH OF
THE FORECAST AREA. THE UPPER TROUGH WILL AMPLIFY WEDNESDAY INTO
THE END OF THE WEEK. THIS WILL KEEP US DRY WITH NEAR NORMAL
TEMPERATURES. -PETRUCELLI
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...NONE.
$$
CC
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
247 PM MDT WED AUG 13 2014
.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 247 PM MDT WED AUG 13 2014
UPPER RIDGING ACROSS THE CENTRAL CONUS CONTINUES WITH AN UPPER LOW
OVER THE PACIFIC NW. DEEP SWRLY FLOW HAS DEVELOPED ACROSS THE DESERT
SW INTO THE GREAT BASIN AND CNTRL ROCKIES...WITH INCREASING
MONSOONAL MOISTURE OVER MUCH OF THE WRN CONUS. A SERIES OF UPPER
WAVES ARE CROSS WY/ERN MT ATTM...WITH A MUCH STRONGER WAVE OVER
AZ/UT. STORMS HAVE ALREADY FIRED AHEAD OF THE FIRST WAVE NOW
CROSSING THE WRN/CNTRL CWA. RAP MODEL IS SHOWING 3000 J/KG
MLCAPE...BUT WITH A CAP IN PLACE...CONVECTION HAS BEEN LIMITED TO
HIGHER TERRAIN OF THE BLKHLS. HRRR SHOWS MORE STORMS DEVELOPING OVER
THE NEXT HOUR OR TWO ACROSS NE WY AND PUSHING EAST THROUGH THE EVNG
HOURS. MOST OF THE STORM ACTIVITY WOULD BE EAST OF THE CWA BY 06Z
WITH LINGERING SHOWERS POSSIBLE. WEAK SHEAR WILL KEEP STORMS FROM
REACHING SEVERE...THOUGH WITH STRONG INSTABILITY CANT RULE OUT A
STORM OR TWO PRODUCING SMALL HAIL AND GUSTY WINDS LIKE THE STORM
OVER THE NORTHERN BLACK HILLS LIKELY DID EARLIER THIS AFTERNOON.
STRONG WAVE OVER THE SWRN CONUS WILL SLIDE NE TONIGHT...THEN CROSS
THE CWA LATE THURSDAY. MONSOONAL FLOW WILL RESULT IN INCREASINGLY
MOIST PROFILES THROUGH THE DAY THURSDAY WITH PWATS FORECAST TO BE
180 PERCENT OF NORMAL OR MORE. WIND PROFILES SUGGEST STORMS WILL BE
SLOW MOVING WITH MEAN STORM MOTION UNDER 10KT. STORMS WILL CONTINUE
THROUGH THURSDAY NIGHT AS THE SYSTEM SLOWLY MOVES E/NE INTO ND/CNTRL
SD. WITH THE HEAVY RAINS THAT MANY AREAS HAVE RECEIVED IN THE LAST
WEEK...THINK THERE WILL BE A POTENTIAL FOR FLASH FLOODING THURSDAY
AFTERNOON AND THROUGH THURSDAY NIGHT. HAVE ISSUED A FLASH FLOOD
WATCH FOR THIS TIME PERIOD.
&&
.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 247 PM MDT WED AUG 13 2014
SEVERAL SHORTWAVES WILL AFFECT THE FORECAST AREA FROM FRIDAY INTO
EARLY NEXT WEEK...BRINGING AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS
TO PARTS OF THE FORECAST AREA NEARLY EVERY DAY. ON FRIDAY...A SLOW
MOVING SHORTWAVE HAS THE POTENTIAL TO CREATE LOCALLY HEAVY
RAINFALL GIVEN WEAK 850-300MB STEERING FLOW AND MODELED GREATER THAN
150 PERCENT PRECIPITABLE WATER AMOUNTS. TEMPERATURES THROUGH THE
PERIOD WILL BE WITHIN 5 DEGREES OF THE AVERAGE FOR THIS TIME OF YEAR.
&&
.AVIATION...FOR THE 18Z TAFS THROUGH 18Z THURSDAY
ISSUED AT 247 PM MDT WED AUG 13 2014
AN UPPER LEVEL DISTURBANCE WILL CREATE ISOLATED/SCATTERED TSRA THIS
AFTN OVER NORTHEASTERN WY AND THE BLKHLS... WITH THE THUNDERSTORMS
SLOWLY SPREADING EAST THROUGH TONIGHT. VFR CONDITIONS WILL PREVAIL
OUTSIDE OF ANY PRECIPITATION.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...FLASH FLOOD WATCH FROM THURSDAY AFTERNOON THROUGH LATE THURSDAY
NIGHT FOR SDZ001-002-012>014-024>032-041>044-072>074.
WY...FLASH FLOOD WATCH FROM THURSDAY AFTERNOON THROUGH LATE THURSDAY
NIGHT FOR WYZ054>058-071.
&&
$$
SHORT TERM...13
LONG TERM...10
AVIATION...10
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
610 PM CDT THU AUG 14 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 236 PM CDT THU AUG 14 2014
AT 3 PM...WHILE A 1020 MB HIGH PRESSURE IS PROVIDING PARTLY TO
MOSTLY SUNNY SKIES ACROSS THE LOCAL AREA...MODERATE TO STRONG 900
TO 500 MB FRONTOGENESIS IS PRODUCING A BAND OF SHOWERS AND
THUNDERSTORMS ACROSS EASTERN SOUTH DAKOTA AND NORTHWEST IOWA.
THE 14.12Z DETERMINISTIC AND MESO MODELS SHOW THAT THE 900 TO
500 MB FRONTOGENETIC FORCING AND MODERATE TO STRONG 310K
ISENTROPIC LIFT WILL SLOWLY EAST ACROSS SOUTHWEST MINNESOTA AND
WESTERN IOWA TONIGHT...AND INTO SOUTHEAST MINNESOTA AND NORTHEAST
IOWA ON FRIDAY. THIS IS SLIGHTLY SLOWER THAN PREVIOUS MODEL
SOLUTIONS...SO KEPT OUR AREA DRY TONIGHT AND THEN KEPT THE RAIN
CHANCES IN THE 20 TO 40 PERCENT RANGE MAINLY WEST OF THE
MISSISSIPPI RIVER ON FRIDAY. HOWEVER AM A BIT CONCERNED THAT WITH
THE WESTWARD TREND IN THE MODELS AND DRY LOW LEVELS THAT THESE
PRECIPITATION CHANCES MAY HAVE TO BE SHIFTED A BIT FURTHER WEST.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 236 PM CDT THU AUG 14 2014
ON FRIDAY NIGHT AND SATURDAY...THE MODELS CONTINUE TO SHOW THAT A
WEAKENING BACKDOOR DOOR COLD FRONT WILL MOVE SOUTH ACROSS
WISCONSIN...AND THE FRONTOGENETIC FORCING TO OUR SOUTH WILL
SLOWLY SHIFT SOUTH AND WEST AS A LOW PRESSURE SYSTEM MOVES
SOUTHEAST OUT OF SOUTH DAKOTA. DEPENDING ON HOW THIS EVOLVES...WE
MAY END UP WITH THE BEST CHANCES OF SHOWERS AND STORMS ALONG AND
NORTH OF INTERSTATE 94...AND ACROSS NORTHEAST IOWA AND SOUTHWEST
WISCONSIN. ELSEWHERE THERE IS A POSSIBILITY THAT THESE AREAS MAY
GET MISSED BY THE PRECIPITATION. THIS IS DUE TO THE SUBSIDENCE
BETWEEN THESE TWO SYSTEMS. THE 14.18Z NAM JUST CAME IN AND IT
SHOWS THAT THE 310K ISENTROPIC LIFT AND MOISTURE TRANSPORT IS MUCH
FURTHER SOUTHWEST...SO THERE ARE QUESTIONS ON WHETHER THE
PRECIPITATION CHANCES IN OUR SOUTH AND WEST MAY BE TOO HIGH.
ON SATURDAY NIGHT AND SUNDAY...THE MODELS CONTINUE TO SHOW THAT
A LOW PRESSURE SYSTEM WILL MOVE SOUTHEAST ACROSS IOWA. AS THIS LOW
MOVES INTO SOUTHEAST IOWA...DRIER AIR WILL ADVECT INTO THE AREA
FROM THE NORTHEAST. BOTH THE GFS AND ECMWF ARE SHOWING THIS WELL
IN THEIR SURFACE DEW POINTS. MEANWHILE THE NAM IS HOLDING ONTO THE
MID AND UPPER 60 DEW POINTS. SINCE THE NAM IS TYPICALLY TOO HIGH
WITH ITS DEW POINTS IN THESE SITUATIONS...PREFER THE DRIER GFS AND
ECMWF SOLUTIONS.
FROM MONDAY NIGHT INTO WEDNESDAY...THERE CONTINUES TO BE SOME GOOD
CONSISTENCY THAT A TROUGH OR CLOSED LOW WILL MOVE SLOWLY EAST
THROUGH THE AREA. THE MODEL CONSENSUS ALREADY HAS FAIRLY HIGH /40
TO 60 PERCENT/ PRECIPITATION CHANCES FOR THIS TIME PERIOD...SO
MADE NO CHANGES TO IT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 610 PM CDT THU AUG 14 2014
HIGH PRESSURE OVER WISCONSIN WILL SLIDE OFF TO THE SOUTHEAST
THROUGH THE PERIOD. A WEAK SHORT WAVE TROUGH OVER SOUTH DAKOTA
THIS AFTERNOON WILL MOVE ACROSS IOWA KEEPING ITS FORCING SOUTHWEST
OF THE FORECAST AREA. ANOTHER SHORT WAVE TROUGH IS EXPECTED TO
COME OUT OF THE SYSTEM CURRENTLY OVER MONTANA AND DROP ACROSS THE
AREA LATE TONIGHT THROUGH FRIDAY. AGAIN...NOT A LOT OF FORCING
EXPECTED FROM THIS WAVE BUT ENOUGH TO PRODUCE SOME VFR MID LEVEL
CEILINGS FROM LATE TONIGHT THROUGH FRIDAY. SOME CONCERN WHETHER
THIS WAVE WILL BE STRONG ENOUGH TO GENERATE SOME SHOWERS OUT OF
THE MID LEVEL CLOUDS. THE 14.12Z HI-RES ARW AND NMM ALONG WITH THE
14.21Z HRRR ALL START TO DEVELOP SOME SHOWERS AHEAD OF THIS WAVE
LATE THIS EVENING OVER WEST CENTRAL MINNESOTA. THESE SHOWERS
SHOULD STAY WEST OF THE AREA THROUGH 15.12Z BUT THE ARW AND NMM
THEN INDICATE THEY COULD IMPACT KRST AFTER 15.12Z. THE 14.18Z NAM
AND GFS ALSO STAY WEST OF THE AREA WITH THE SHOWERS FRIDAY
MORNING...SO FOR NOW...WILL STAY WITH A DRY FORECAST BUT WILL
MONITOR THE TRENDS THROUGH THE EVENING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
254 PM CDT WED AUG 13 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 254 PM CDT WED AUG 13 2014
LATEST WATER VAPOR SATELLITE IMAGERY SHOWING UPPER LEVEL TROUGH OVER
EASTERN UNITED STATES. WEAK SHORTWAVE ON THE BACKSIDE OF THE TROUGH
PUSHING SOUTH INTO THE GREAT LAKES PRODUCING CUMULUS CLOUDS ACROSS
THE UPPER GREAT LAKES REGION PER LATEST VISIBLE SATELLITE IMAGERY.
LATEST 19Z SURFACE ANALYSIS INDICATES WEAK COLD FRONT EXTENDING FROM
MICHIGAN INTO WESTERN WISCONSIN AND SURFACE RIDGE OVER ONTARIO AND
SASKATCHEWAN CANADA.
MAIN FORECAST CONCERNS TONIGHT IS FOG POTENTIAL IN RIVER VALLEYS
AND THE FAVORED AREAS IN CENTRAL WISCONSIN.
SURFACE RIDGE OVER SOUTHERN CANADA BUILDS INTO THE FORECAST AREA
TONIGHT. THIS WILL PROVIDE MOSTLY CLEAR SKIES AND CALM WINDS. THE
LATEST 13.12Z GFS/NAM AND 13.15Z RAP BUFKIT SOUNDINGS SHOW AN
INVERSION TO DEVELOP AFTER 06Z AND WINDS ABOVE THE SURFACE TO BE 10
TO 20 KNOTS. IN ADDITION...WITH A DRIER AIRMASS ADVECTING IN AND
NORTHERLY WIND COMPONENT OVERHEAD AND NEAR THE SURFACE. FOG
FORMATION WILL BE HARD TO DEVELOP IN RIVER VALLEYS AND FAVORED AREAS
IN CENTRAL WISCONSIN. HAVE REMOVED PATCHY FOG IN THESE AREAS FOR
TONIGHT.
SURFACE RIDGE WILL REMAIN IN CONTROL OF THE AREA THURSDAY AND
PRODUCE MOSTLY SUNNY SKIES AND DRY WEATHER CONDITIONS ACROSS THE
FORECAST AREA.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 254 PM CDT WED AUG 13 2014
UPPER LEVEL CLOSED LOW OVER THE PACIFIC NORTHWEST EJECTS OUT A PIECE
OF ENERGY INTO THE UPPER MIDWEST AND FLATTENS UPPER LEVEL RIDGE
FRIDAY INTO SATURDAY. THE DPROG/DT OF THE 13.12Z GFS/NAM INDICATES
THIS PIECE OF ENERGY MOVING INTO THE REGION SLIGHTLY FASTER. THE
13.12Z ECMWF IS SLOWER WITH THE PROGRESSION OF THE SHORTWAVE TROUGH
INTO THE UPPER MIDWEST. THE 13.12Z MODELS SHOW INCREASING
LIFT/FORCING AND MOISTURE INTO THE WESTERN HALF OF THE FORECAST AREA
AFTER 18Z FRIDAY. THE 13.12Z GFS/NAM BUFKIT SOUNDINGS SHOW DRY
AIRMASS ALOFT OVER THE FORECAST AREA DURING THE DAY FRIDAY. THIS
COULD INHIBIT PRECIPITATION MOVING INTO THE AREA. FOR NOW...KEPT
SMALL PRECIPITATION CHANCES ACROSS THE FORECAST AREA.
LIFT/FORCING AND MOISTURE INCREASES ACROSS MUCH OF THE FORECAST AREA
AFTER 00Z SATURDAY AND CONTINUES THROUGH MUCH OF THE DAY
SATURDAY...ESPECIALLY OVER THE SOUTHERN HALF OF THE FORECAST AREA.
HAVE INCREASED PRECIPITATION CHANCES ACROSS THIS PART OF THE
FORECAST AREA.
AT THIS TIME...SEVERE WEATHER THREATS LOOKS LOW...AS THE 13.12Z
GFS/NAM BUILD MINIMAL SURFACE BASED CAPE AND BUILD ELEVATED CAPE
OVER THE FORECAST AREA.
MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES SATURDAY NIGHT INTO
MIDDLE OF NEXT WEEK. THE 13.12Z GFS/ECMWF/GEM CONTINUE TO DEVELOP
WEST TO EAST ZONAL FLOW ACROSS THE CONTINENTAL UNITED STATES
SATURDAY NIGHT INTO MONDAY. THE 13.12Z GFS/ECMWF/GEM DIFFER
SIGNIFICANTLY ON TIMING AND PLACEMENT OF SHORTWAVE TROUGHS/SURFACE
FEATURES THROUGH MUCH OF THE TIME PERIOD...WHERE THE 13.12Z GFS IS
MORE PROGRESSIVE AND FARTHER SOUTH WITH SHORTWAVE TROUGH/SURFACE
FEATURES SUNDAY INTO MONDAY THAN THE 13.12Z GEM/ECMWF. BASED ON
THE DIFFERENCES IN TIMING AND PLACEMENT WITH SHORTWAVE ENERGY
THROUGH THIS TIME PERIOD...CONFIDENCE IN FORECAST REMAINS LOW AND
WILL KEEP PRECIPITATION CHANCES THROUGH EARLY OF NEXT WEEK. THE
UNSETTLED WEATHER PATTERN WILL CONTINUE INTO MIDDLE OF NEXT
WEEK...AS THE 13.12Z GFS/ECMWF ARE HINTING AT WEST TO
SOUTHWESTERLY FLOW ALOFT TO DEVELOP OVER THE ROCKY MOUNTAINS AND
CENTRAL UNITED STATES. THE 13.12Z GFS/ECMWF INDICATE AN IMPULSE TO
EJECT OUT INTO THE CENTRAL UNITED STATES WEDNESDAY. HOWEVER...WITH
TIMING AND PLACEMENT ISSUES IN ASSOCIATION WITH THE SHORTWAVE
TROUGH/SURFACE FEATURES...REGION COULD SEE A BREAK IN
PRECIPITATION CHANCES WEDNESDAY. TEMPERATURES THROUGH MUCH OF THE
PERIOD WILL BE NEAR NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1224 PM CDT WED AUG 13 2014
SURFACE ANALYSIS INDICATES A WEAK COLD FRONT WAS SLIDING SOUTH
ACROSS CENTRAL MINNESOTA AND WISCONSIN. A FEW CLOUDS WERE
DEVELOPING AHEAD OF THIS FRONT...BUT EXPECT THE FRONT TO MOVE
THROUGH BOTH TAF SITES BY OR NEAR 18Z AND ANY VFR CEILINGS THAT
DEVELOP SHOULD THEN BE TO THE SOUTH. HIGH PRESSURE WILL BUILD IN
BEHIND THE FRONT WITH CLEAR SKIES EXPECTED OVERNIGHT. THE WINDS
WILL BECOME LIGHT OVERNIGHT BUT THE 13.12Z NAM BUFKIT SOUNDINGS
SUGGESTS THERE IS LITTLE POTENTIAL FOR VALLEY FOG TO FORM.
TEMP/DEW POINT SPREADS ARE EXPECTED TO REMAIN AROUND 5F WITH THE
POTENTIAL FOR A DEEP LAYER OF 10 TO 20 KNOTS WINDS JUST ABOVE THE
SURFACE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...04
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1259 PM CDT WED AUG 13 2014
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND THURSDAY
ISSUED AT 156 AM CDT WED AUG 13 2014
RELATIVELY QUIET PERIOD. MAIN CONCERN IS WEAK BACK DOOR COLD FRONT
THAT WILL SLIDE ACROSS AREA DURING FIRST PART OF DAY. 13/00Z
NAM/GFS/ECMWF AND 13/03Z HRRR ALL INDICATE PRECIP WILL FORM SOUTH
OF FORECAST AREA THIS AFTERNOON ASSOC WITH BETTER INSTABILITY. AT
THAT POINT FRONT WILL BE ALONG OR SOUTH OF SOUTHERN BORDER OF FORECAST
AREA. NE WINDS MAY PICK UP FOR A BRIEF TIME BEHIND FRONT LATE
AFTERNOON INTO EARLY EVENING...THEN SFC HIGH PRESSURE MOVES SOUTH FROM
HUDSON BAY PROVIDING COOL NIGHT AND MILD THURSDAY. TEMPS TONIGHT
WILL PROBABLY TOUCH THE 30S IN FAR NORTHERN BOGS.
TEMP AND WIND FORECAST A BLEND OF PREVIOUS FORECAST WITH BEST
PERFORMING MODEL GUIDANCE.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY
ISSUED AT 156 AM CDT WED AUG 13 2014
NORTHWEST FLOW ALOFT DUE TO UPPER LOW ACROSS EASTERN CANADA WILL
BECOME MORE ZONAL BY THE WEEKEND. UPPER PATTERN SUCH THAT MODELS
ARE HAVING A HARD TIME WITH FEATURES AND WHEN AND WHERE BEST
CHANCES OF RAIN WOULD OCCUR. TEMPERATURES DURING THE PERIOD SHOULD
BE AT OR SLIGHTLY ABOVE NORMAL FOR MID AUGUST.
MODELS CONTINUE TO DIFFER IF PRECIPITATION WOULD BREAK OUT ON THE
BACKSIDE OF THE HIGH DUE TO 850MB WARM ADVECTION. LEANING TOWARD
SHOWERS AND STORMS BREAKING OUT WEST OF THE AREA THURSDAY NIGHT...
THUS LEFT THIS PERIOD DRY. WILL CONTINUE THE CHANCES FOR SHOWERS
AND STORMS FRIDAY AS BOUNDARY PUSHES NORTH. A CONTINUED CHANCE FOR
SHOWERS AND STORMS WILL CONTINUE FRIDAY NIGHT AND SATURDAY. UPPER
FLOW STILL NORTHWEST AT THIS POINT...THUS EXPECT BOUNDARY TO PUSH
SOUTH OF THE AREA SATURDAY NIGHT AND SUNDAY. HAVE REMOVED RAIN
CHANCES ACROSS THE NORTH SATURDAY NIGHT AND SUNDAY AS HIGH PRESSURE
BUILDS INTO THE AREA. ALMOST TEMPTED TO REMOVE RAIN CHANCES ACROSS
THE SOUTH...BUT CONFIDENCE WAS LOWER IN CASE BOUNDARY SHOULD LINGER
ACROSS THE AREA. BEYOND SUNDAY...LOW CONFIDENCE IN THE DETAILS OF
ANY WEATHER MAKER AND WHEN THE BEST CHANCES FOR SHOWERS AND STORMS
COULD OCCUR. DID NOT MAKE ANY SIGNIFICANT CHANGES BEYOND SUNDAY.
ONLY ADJUSTMENTS TO MAX/MIN TEMPERATURE GRIDS WAS TO ADD A DEGREE
OR TWO AT NIGHT AT THE TYPICALLY WARMER LOCATIONS...AND DROPPED A
DEGREE OR TWO IN THE TYPICAL COOLER SPOTS AT NIGHT.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1258 PM CDT WED AUG 13 2014
A SURFACE COLD FRONT WAS SOUTH OF THE FORECAST AREA BY 17Z AND
HIGH PRESSURE WAS STARTING TO BUILD IN BEHIND IT. THERE WAS QUITE
A BIT OF CUMULUS BEHIND THE FRONT BUT CIGS WERE MAINLY VFR...WITH
ISOLATED MVFR IN CENTRAL WISCONSIN. AS THE HIGH BUILDS IN WINDS
WILL SHIFT TO NORTH-NORTHEAST LATE THIS AFTERNOON IN THE KGRB AND
KATW AREAS SO HAVE SOME HIGHER SPEEDS AND GUSTS AT KGRB DUE TO
TRAJECTORY OVER THE WATERS OF GREEN BAY. CLOUDS SHOULD DISSIPATE
AROUND OR SHORTLY AFTER SUNSET AND WINDS IN EASTERN WISCONSIN
SHOULD BACK A BIT. WIND SPEEDS WILL BE LIGHT DURING THE OVERNIGHT
HOURS...AND WITH GENERALLY CLEAR SKIES...TEMPERATURES SHOULD DROP
RATHER QUICKLY. 12Z MOS GUIDANCE AGAIN SHOWED UNRESTRICTED VSBYS
TONIGHT BUT MAV DEW POINT DEPRESSIONS WERE ZERO TO 2F AT TIMES SO
HAVE A MENTION OF FOG...ESPECIALLY AT KAUW...KCWA...AND KRHI. WINDS
ON THURSDAY MORNING SHOULD BE LIGHT AND CLEAR SKIES ARE EXPECTED
ONCE ANY FOG DISSIPATES.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....JKL
LONG TERM......ECKBERG
AVIATION.......MG
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1034 AM CDT WED AUG 13 2014
.AVIATION/18Z TAFS/...CONTINUED VFR THIS PERIOD. SURFACE FRONT
WILL MOVE THROUGH SRN WI THIS AFTN AND EXIT TO THE SOUTH THIS
EVENING...SO WINDS WILL SHIFT NW-N-NE IN FAIRLY SHORT ORDER. SCT-
BKN MID CLOUDS SHIFTING SOUTH OF TAF SITES...THOUGH SOME CU
DEVELOPMENT POSSIBLE PER CU RULE. RAP SOUNDINGS SHOW PLENTY OF DRY
AIR WITHIN THE COLUMN WITH PARCEL TRAJ GETTING CAPPED OFF AROUND
10K FEET. HIGH PRESSURE SETTLES IN AND DOMINATES TONIGHT INTO
THURSDAY WITH VERY DRY AND STABLE AIRMASS.
PC
&&
.PREV DISCUSSION... /ISSUED 319 AM CDT WED AUG 13 2014/
TODAY...FORECAST CONFIDENCE IS HIGH.
A WEAK COLD FRONT WILL BE DROPPING SOUTH THROUGH THE STATE
TODAY...REACHING SOUTHERN WISCONSIN AT PEAK HEATING. THE
ATMOSPHERE IS PRETTY DRY...BUT THE FRONT DOES BRING WITH IT SOME
HIGHER SURFACE DEW POINTS. IN THE MID LEVELS...A SHORT WAVE TROF
WILL BE DROPPING SOUTH THROUGH THE BACK SIDE OF THE PARENT UPPER
LOW NORTHEAST OF THE GREAT LAKES. THIS BRINGS AN INCREASE IN THE
CYCLONIC FLOW ALOFT AT THE SAME TIME THE FRONT IS MOVING THROUGH.
THE COLD FRONT SHOULD GET SOME ENHANCEMENT BOTH IN TEMP CONTRAST
AND LOW LEVEL CONVERGENCE FROM INCREASING NORTHEAST WINDS ON THE
BACK SIDE OF THE COLD FRONT. THE NAM IS THE MOST AGGRESSIVE WITH
THE POTENTIAL INSTABILITY...WHILE THE GFS SHOWS A RATHER STRONG
ELEVATED WARM LAYER...CAPPING THINGS OFF. MANY OF THE MODELS ARE
KICKING OUT SOME VERY LIGHT AND SPLOTCHY QPF THIS AFTERNOON.
THEREFORE WILL INTRODUCE SOME SLIGHT CHANCES TO THE AREA AFTER
18Z. THIS SHOULD ALL BE SOUTH OF THE BORDER BY EVENING.
TONIGHT...FORECAST CONFIDENCE IS HIGH.
COOL...DRY AIR IN THE WAKE OF THE FRONT WILL BRING CLEAR SKIES TO
THE AREA TONIGHT. SOME RIVER FOG POSSIBLE.
SHORT TERM...THURSDAY THROUGH FRIDAY NIGHT...FORECAST CONFIDENCE
IS MEDIUM.
MODELS SHOWING 500 MB TROUGH SLOWLY MOVING WELL EAST OF THE
REGION DURING THIS PERIOD...WITH NORTHWEST FLOW LINGERING ACROSS
THE AREA. HIGH PRESSURE AT THE SURFACE SLIDES SOUTHEAST ACROSS
THE REGION THURSDAY...THEN SOUTHEAST OF THE AREA THURSDAY NIGHT
AND FRIDAY. THE HIGH WILL BRING QUIET WEATHER AND PLEASANT
TEMPERATURES FOR THURSDAY.
MODELS THEN SHOW WARM AIR ADVECTION IN THE LOW LEVELS OCCURRING
ACROSS THE REGION THURSDAY NIGHT INTO FRIDAY. THIS WILL BRING
WARMER AND MORE MOIST AIR INTO THE REGION. NAM/ECMWF MODELS ARE
ABOUT 12 HOURS SLOWER THAN GFS/CANADIAN MODELS WITH TIMING OF LOW
PRESSURE MOVING EAST FROM THE NORTH CENTRAL PLAINS STATES FRIDAY
INTO FRIDAY NIGHT. THEY ALL KEEP MAIN 500 MB SHORTWAVE TROUGH TO
THE SOUTHWEST OF THE AREA. MODELS ALSO DIFFER WITH PLACEMENT OF
850 MB LOW LEVEL JET AXIS AND NOSE FRIDAY NIGHT. FOR NOW...WILL
CONTINUE WITH CHANCE POPS FOR FRIDAY AFTERNOON INTO FRIDAY NIGHT.
LONG TERM...SATURDAY THROUGH TUESDAY...FORECAST CONFIDENCE IS
MEDIUM.
ECMWF/GFS CONTINUE TO DIFFER WITH TIMING AND PLACEMENT OF FEATURES
DURING THIS PERIOD. GFS IS ABOUT 24 HOURS QUICKER THAN ECMWF WITH
LOW PRESSURE AND 500 MB SHORTWAVE TROUGH MOVING TO THE SOUTH OF
THE AREA SATURDAY INTO SUNDAY. THEY ALSO DIFFER WITH THE FOLLOWING
SYSTEM FOR MONDAY INTO TUESDAY.
FOR NOW...WILL USE CONSENSUS BLEND OF MODELS FOR POPS AND
TEMPERATURES IN THIS PERIOD. MEAN LAYER AND ELEVATED CAPE IS
QUESTIONABLE IN THE SATURDAY NIGHT INTO SUNDAY NIGHT PERIOD...SO
WENT WITH JUST SLIGHT CHANCES FOR THUNDER IN THIS PERIOD. WARM
AND HUMID CONDITIONS SHOULD OCCUR DURING THIS TIME.
AVIATION/12Z TAFS/...
LOOK FOR VFR CONDITIONS THROUGH THE TAF PERIOD. THERE IS A WEAK
COLD FRONT DROPPING SOUTH THROUGH THE AREA THIS AFTERNOON AND IT
MAY TRIGGER SOME ISOLATED SHOWERS WITHIN A FAIRLY DRY ATMOSPHERE.
WINDS WILL SHIFT TO THE NORTH THEN NORTHEAST IN THE WAKE OF THE
FRONT. THOSE WINDS MAY GUST TO AROUND 20KTS BRIEFLY IN THE WAKE OF
THE FRONT IN THE MILWAUKEE AND KENOSHA AREAS AROUND 21Z TO 22Z
THIS AFTERNOON. THOSE WINDS WILL QUICKLY SETTLE DOWN WITH LIGHT
WINDS EXPECTED AFTER SUNSET.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...DAVIS
THURSDAY THROUGH TUESDAY...WOOD
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
554 AM CDT WED AUG 13 2014
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND THURSDAY
ISSUED AT 156 AM CDT WED AUG 13 2014
RELATIVELY QUIET PERIOD. MAIN CONCERN IS WEAK BACK DOOR COLD FRONT
THAT WILL SLIDE ACROSS AREA DURING FIRST PART OF DAY. 13/00Z
NAM/GFS/ECMWF AND 13/03Z HRRR ALL INDICATE PRECIP WILL FORM SOUTH
OF FORECAST AREA THIS AFTERNOON ASSOC WITH BETTER INSTABILITY. AT
THAT POINT FRONT WILL BE ALONG OR SOUTH OF SOUTHERN BORDER OF FORECAST
AREA. NE WINDS MAY PICK UP FOR A BRIEF TIME BEHIND FRONT LATE
AFTERNOON INTO EARLY EVENING...THEN SFC HIGH PRESSURE MOVES SOUTH FROM
HUDSON BAY PROVIDING COOL NIGHT AND MILD THURSDAY. TEMPS TONIGHT
WILL PROBABLY TOUCH THE 30S IN FAR NORTHERN BOGS.
TEMP AND WIND FORECAST A BLEND OF PREVIOUS FORECAST WITH BEST
PERFORMING MODEL GUIDANCE.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY
ISSUED AT 156 AM CDT WED AUG 13 2014
NORTHWEST FLOW ALOFT DUE TO UPPER LOW ACROSS EASTERN CANADA WILL
BECOME MORE ZONAL BY THE WEEKEND. UPPER PATTERN SUCH THAT MODELS
ARE HAVING A HARD TIME WITH FEATURES AND WHEN AND WHERE BEST
CHANCES OF RAIN WOULD OCCUR. TEMPERATURES DURING THE PERIOD SHOULD
BE AT OR SLIGHTLY ABOVE NORMAL FOR MID AUGUST.
MODELS CONTINUE TO DIFFER IF PRECIPITATION WOULD BREAK OUT ON THE
BACKSIDE OF THE HIGH DUE TO 850MB WARM ADVECTION. LEANING TOWARD
SHOWERS AND STORMS BREAKING OUT WEST OF THE AREA THURSDAY NIGHT...
THUS LEFT THIS PERIOD DRY. WILL CONTINUE THE CHANCES FOR SHOWERS
AND STORMS FRIDAY AS BOUNDARY PUSHES NORTH. A CONTINUED CHANCE FOR
SHOWERS AND STORMS WILL CONTINUE FRIDAY NIGHT AND SATURDAY. UPPER
FLOW STILL NORTHWEST AT THIS POINT...THUS EXPECT BOUNDARY TO PUSH
SOUTH OF THE AREA SATURDAY NIGHT AND SUNDAY. HAVE REMOVED RAIN
CHANCES ACROSS THE NORTH SATURDAY NIGHT AND SUNDAY AS HIGH PRESSURE
BUILDS INTO THE AREA. ALMOST TEMPTED TO REMOVE RAIN CHANCES ACROSS
THE SOUTH...BUT CONFIDENCE WAS LOWER IN CASE BOUNDARY SHOULD LINGER
ACROSS THE AREA. BEYOND SUNDAY...LOW CONFIDENCE IN THE DETAILS OF
ANY WEATHER MAKER AND WHEN THE BEST CHANCES FOR SHOWERS AND STORMS
COULD OCCUR. DID NOT MAKE ANY SIGNIFICANT CHANGES BEYOND SUNDAY.
ONLY ADJUSTMENTS TO MAX/MIN TEMPERATURE GRIDS WAS TO ADD A DEGREE
OR TWO AT NIGHT AT THE TYPICALLY WARMER LOCATIONS...AND DROPPED A
DEGREE OR TWO IN THE TYPICAL COOLER SPOTS AT NIGHT.
&&
.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 554 AM CDT WED AUG 13 2014
LOCAL IFR CIGS ACROSS NORTH-CENTRAL WI AIRPORTS ASSOCIATED WITH
AREA OF STRATUS. STRATUS WILL LIFT/DISSIPATE BY 9 AM. VFR CONDITIONS
ELSEWHERE. WINDS WILL SWITCH TO NORTHEAST LATER THIS AFTERNOON
BEHIND BACK DOOR COLD FRONT. GUSTS NEAR 20 KTS POSSIBLE ALONG LAKE
MICHIGAN/DOOR COUNTY FOR A TIME LATE THIS AFTERNOON AND EARLY
EVENING.
PATCHY GROUND FOG EXPECTED BETWEEN 08Z-12Z THURSDAY AM.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....JKL
LONG TERM......ECKBERG
AVIATION.......JKL
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND THURSDAY
ISSUED AT 156 AM CDT WED AUG 13 2014
RELATIVELY QUIET PERIOD. MAIN CONCERN IS WEAK BACK DOOR COLD FRONT
THAT WILL SLIDE ACROSS AREA DURING FIRST PART OF DAY. 13/00Z
NAM/GFS/ECMWF AND 13/03Z HRRR ALL INDICATE PRECIP WILL FORM SOUTH
OF FORECAST AREA THIS AFTERNOON ASSOC WITH BETTER INSTABILITY. AT
THAT POINT FRONT WILL BE ALONG OR SOUTH OF SOUTHERN BORDER OF FORECAST
AREA. NE WINDS MAY PICK UP FOR A BRIEF TIME BEHIND FRONT LATE
AFTERNOON INTO EARLY EVENING...THEN SFC HIGH PRESSURE MOVES SOUTH FROM
HUDSON BAY PROVIDING COOL NIGHT AND MILD THURSDAY. TEMPS TONIGHT
WILL PROBABLY TOUCH THE 30S IN FAR NORTHERN BOGS.
TEMP AND WIND FORECAST A BLEND OF PREVIOUS FORECAST WITH BEST
PERFORMING MODEL GUIDANCE.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY
ISSUED AT 156 AM CDT WED AUG 13 2014
NORTHWEST FLOW ALOFT DUE TO UPPER LOW ACROSS EASTERN CANADA WILL
BECOME MORE ZONAL BY THE WEEKEND. UPPER PATTERN SUCH THAT MODELS
ARE HAVING A HARD TIME WITH FEATURES AND WHEN AND WHERE BEST
CHANCES OF RAIN WOULD OCCUR. TEMPERATURES DURING THE PERIOD SHOULD
BE AT OR SLIGHTLY ABOVE NORMAL FOR MID AUGUST.
MODELS CONTINUE TO DIFFER IF PRECIPITATION WOULD BREAK OUT ON THE
BACKSIDE OF THE HIGH DUE TO 850MB WARM ADVECTION. LEANING TOWARD
SHOWERS AND STORMS BREAKING OUT WEST OF THE AREA THURSDAY NIGHT...
THUS LEFT THIS PERIOD DRY. WILL CONTINUE THE CHANCES FOR SHOWERS
AND STORMS FRIDAY AS BOUNDARY PUSHES NORTH. A CONTINUED CHANCE FOR
SHOWERS AND STORMS WILL CONTINUE FRIDAY NIGHT AND SATURDAY. UPPER
FLOW STILL NORTHWEST AT THIS POINT...THUS EXPECT BOUNDARY TO PUSH
SOUTH OF THE AREA SATURDAY NIGHT AND SUNDAY. HAVE REMOVED RAIN
CHANCES ACROSS THE NORTH SATURDAY NIGHT AND SUNDAY AS HIGH PRESSURE
BUILDS INTO THE AREA. ALMOST TEMPTED TO REMOVE RAIN CHANCES ACROSS
THE SOUTH...BUT CONFIDENCE WAS LOWER IN CASE BOUNDARY SHOULD LINGER
ACROSS THE AREA. BEYOND SUNDAY...LOW CONFIDENCE IN THE DETAILS OF
ANY WEATHER MAKER AND WHEN THE BEST CHANCES FOR SHOWERS AND STORMS
COULD OCCUR. DID NOT MAKE ANY SIGNIFICANT CHANGES BEYOND SUNDAY.
ONLY ADJUSTMENTS TO MAX/MIN TEMPERATURE GRIDS WAS TO ADD A DEGREE
OR TWO AT NIGHT AT THE TYPICALLY WARMER LOCATIONS...AND DROPPED A
DEGREE OR TWO IN THE TYPICAL COOLER SPOTS AT NIGHT.
&&
.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 156 AM CDT TUE AUG 12 2014
VFR CONDITIONS EXPECTED ACROSS FORECAST AREA THROUGH LATE EVENING.
WINDS WILL SWITCH TO NORTHEAST LATER THIS AFTERNOON BEHIND BACK
DOOR COLD FRONT. GUSTS NEAR 20 KTS POSSIBLE ALONG LAKE MICHIGAN
FOR A TIME LATE THIS AFTERNOON AND EARLY EVENING.
PATCHY GROUND FOG EXPECTED BETWEEN 08Z-12Z THURSDAY AM.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....JKL
LONG TERM......ECKBERG
AVIATION.......JKL
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1135 PM MDT THU AUG 14 2014
.UPDATE...
ISSUED AT 911 PM MDT THU AUG 14 2014
UPDATED FORECAST TO LOWER/REMOVE POPS OVER ALL BUT THE FAR
SOUTHEAST PLAINS.
UPDATE ISSUED AT 557 PM MDT THU AUG 14 2014
WITH HEAVY RAIN THREAT SHIFTING INTO NORTHEAST COLORADO THIS
EVENING...AND ONLY VERY ISOLATED STORMS ALONG THE CONTINENTAL
DIVIDE...WILL CANCEL FLASH FLOOD WATCH FOR ALL AREAS A LITTLE
EARLIER THAN SCHEDULED.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 310 PM MDT THU AUG 14 2014
SHORTWAVE CURRENTLY MOVING ACROSS NORTHERN CO HAS INITIATED
THUNDERSTORMS OVER THE PIKES PEAK REGION THIS AFTERNOON. HIGH
PRECIPITABLE WATERS RUNNING 150+% OF NORMAL IS ALLOWING FOR
EFFICIENT RAINFALL RATES AS EVIDENCED FROM RADAR KDP/S AND SPOTTER
REPORTS. THERE HAVE ALSO BEEN SOME PEA SIZE HAIL REPORTS WITH THE
STRONGER STORMS. AS THE SHORTWAVE CONTINUES TO DRAG ACROSS EASTERN
COLORADO...THUNDERSTORMS WILL CONTINUE TO SPREAD EASTWARD ACROSS
THE PLAINS. STORMS HAVE BEEN MOVING NORTHEAST AT 15 MPH...ENOUGH
TO ABATE SOME OF THE FLASH FLOOD RISK...BUT NOT ENTIRELY NEGATE IT
AS HEAVY RAINFALL RATES OF AROUND 2 INCHES PER HOUR CAN STILL
CAUSE PROBLEMS FOR THE BURN SCARS AND URBAN AREAS. THUS WILL KEEP
THE FLASH FLOOD WATCH GOING THROUGH 9 PM. BEEN A LITTLE HARDER TO
GET STRONGER CONVECTION GOING OUT WEST ALONG THE CONTINENTAL
DIVIDE AND SUSPECT THAT THREAT THERE IS RAPIDLY DIMINISHING AS
STABILITY HAS BEEN A FACTOR WITH THE CLOUD COVER AND EARLIER
RAINFALL. WILL KEEP THE WATCH GOING THROUGH THE PRIME HEATING
HOURS...BUT SUSPECT THAT WE MAY BE ABLE TO TAKE DOWN THE WATCH BY
6 PM FOR CHAFFEE/LAKE COUNTIES AND THE EASTERN SAN JUANS AND LA
GARITAS.
THUNDERSTORMS WILL SPREAD EASTWARD ACROSS THE PLAINS THROUGH THE
EVENING HOURS. LATEST HRRR SUGGESTS THAT THREAT FOR PIKES PEAK AREA
MAY BE ENDED BY 6-7 PM. HIGHEST POPS THROUGH THE EVENING HOURS WILL
BE ACROSS THE SOUTHEAST PLAINS AS THUNDERSTORMS DEVELOP ALONG
SOUTHWARD ADVANCING COLD FRONT. APPEARS BEST LIFT MAY BE ACROSS
NORTHWEST KANSAS AND EAST CENTRAL CO (KIOWA COUNTY) AS LOW LEVEL JET
IMPINGES ON THE FRONT...SO WILL KEEP HIGHEST POPS UP THAT WAY. MOST
OF THE ACTIVITY WILL BE DONE BY MIDNIGHT AS LINE OF THUNDERSTORMS
MOVES EAST INTO KANSAS.
A LITTLE LESS ACTIVE WEATHER IS EXPECTED TOMORROW. PRECIPITABLE
WATERS WILL DROP OFF BELOW 1 INCH FOR THE I-25 CORRIDOR AND
WESTWARD. STILL LOOKING AT SUFFICIENT MOISTURE FOR ISOLATED TO
SCATTERED THUNDERSTORMS...SO STILL CAN`T RULE OUT HEAVY RAIN ON BURN
SCARS AND POTENTIAL FOR FLASH FLOODING. BUT THREAT CERTAINLY LOOKS
LOWER DUE TO THE MORE ISOLATED NATURE OF THESE STRONGER CELLS.
GRIDS WILL CARRY MORE OF A DIURNAL POP TREND...WITH THUNDERSTORMS
FIRING OVER THE MOUNTAINS AROUND NOON...THEN DEVELOPING/SPREADING
EASTWARD ACROSS THE ADJACENT PLAINS DURING THE LATE AFTERNOON. -KT
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 310 PM MDT THU AUG 14 2014
FRIDAY NIGHT-THURSDAY...NOT MUCH CHANGE IN THE ONGOING FORECAST
THROUGH THE EXTENDED PERIOD WITH FLAT UPPER LEVEL RIDGING REMAINING
IN PLACE ACROSS THE GREAT BASIN THROUGH THE ROCKIES. THIS WILL KEEP
MONSOONAL MOISTURE PLUME SOUTH AND SOUTHWEST OF THE STATE WITH WEAK
WEST TO NORTHWEST FLOW ALOFT ACROSS THE STATE AND WEATHER SYSTEMS
MOVING ACROSS THE NORTHERN TIER OF STATES AND INTO THE UPPER
MIDWEST.
THERE LOOKS TO BE ENOUGH RESIDUAL MOISTURE IN PLACE TO WORK WITH
LATE SUMMER SOLAR HEATING TO KEEP ISOLATED TO SCATTERED AFTERNOON
AND EVENING STORMS IN THE FORECAST OVER AND NEAR THE HIGHER
TERRAIN...WITH A FEW STORMS POSSIBLY ROLLING ACROSS THE FAR SE
PLAINS THROUGH THE LATE EVENING AND OVERNIGHT HOURS. STORMS THAT DO
DEVELOP SHOULD BE GENERALLY HIGH BASED...THOUGH STILL CAN NOT RULE
OUT LOCALIZED HEAVY RAINFALL AND SMALL HAIL WITH STRONGER CELLS.
HARD TO PIN POINT BEST COVERAGE OF STORMS THOUGH COULD SEE INCREASED
COVERAGE SUNDAY THROUGH SUNDAY NIGHT AND AGAIN TUESDAY AND TUESDAY
NIGHT AS EMBEDDED DISTURBANCES MOVE ACROSS THE NORTHERN ROCKIES AND
INTO THE HIGH PLAINS. WITH RIDGING IN PLACE...TEMPERATURES ACROSS
THE AREA LOOK TO BE GENERALLY AT OR SLIGHTLY ABOVE LATE SUMMER
AVERAGES THROUGH THE PERIOD.
THERE COULD BE A CHANGE IN THE PATTERN INTO EARLY NEXT WEEKEND...AS
A BROAD UPPER TROUGH TRIES TO CARVE OUT ACROSS THE WEST COAST
OPENING THE DOOR TO INCREASING MOISTURE WITHIN DEVELOPING SOUTH TO
SOUTHWEST FLOW ALOFT ACROSS THE DESERT SOUTHWEST AND INTO THE
ROCKIES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1130 PM MDT THU AUG 14 2014
BACK EDGE OF TSRA JUST ABOUT INTO KANSAS AS OF 0530Z...AND EXPECT
VFR CONDITIONS MOST AREAS OVERNIGHT INTO MIDDAY FRIDAY. ISOLATED
TSRA WILL DEVELOP OVER THE MOUNTAINS 18Z-20Z FRI...AND A FEW
STORMS MAY SPREAD TOWARD LOWER ELEVATIONS 22Z-02Z. HAVE INCLUDED A
VCTS MENTION AT KCOS AFTER 22Z...BUT KEPT KPUB AND KALS CONVECTION
FREE AT THIS POINT AS ODDS FOR STORMS AT BOTH SITES LOOK FAIRLY
LOW. STORMS WILL DIMINISH QUICKLY IN THE EVENING WITH VFR
CONDITIONS OVERNIGHT ALL AREAS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...PETERSEN
SHORT TERM...KT
LONG TERM...MW
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
424 AM EDT FRI AUG 15 2014
.DISCUSSION...
TODAY...NOT MUCH CHANGE IN THE PATTERN FROM YESTERDAY WITH A STALLED
FRONT ACROSS SE GA INTO THE FL PANHANDLE. LOW-MID LVL WSW WINDS WILL
CONTINUE WITH DEEP MOISTURE OVER THE AREA AS PRECIPITABLE WATER
VALUES ARE FORECAST FROM FROM 2.0 TO 2.2 INCHES. SHORT RANGE MODELS
ALSO INDICATE MID LVL IMPULSES WILL TRAVERSE THE NRN/CENTRAL FL
PENINSULA TODAY LEADING TO SOME CONVECTIVE ORGANIZATION AS STORMS
MAKE THEIR WAY FROM THE WEST TO EAST ACROSS THE AREA. HRRR AND SPC
WRF RUN THIS MORNING INDICATE CONVECTION DEVELOPING TO OUR WEST BY
LATE MORNING AND MOVING TOWARD THE ORLANDO METRO BY EARLY AFTERNOON.
STORMS SHOULD THEN APPROACH CSTL VOLUSIA AND BREVARD COUNTY BY MID
AFTERNOON AND TOWARD THE TREASURE COAST INTO THE MID TO LATE
AFTERNOON HOURS. THE EAST COAST SEA BREEZE WILL LIKELY DEVELOP FROM
VERO BEACH SOUTH TO STUART AND INCH ONLY SLOWLY INLAND FROM THE
COAST. STORMS WILL MOVE EAST AROUND 15 MPH. THE PRIMARY THUNDERSTORM
HAZARDS WILL BE LOCALLY HEAVY RAIN...GUSTY WINDS AND FREQUENT
LIGHTNING. HIGHS WILL BE MAINLY AROUND 90 TO THE LOWER 90S.
TONIGHT...THERE WILL BE A CHANCE FOR EARLY EVENING STORMS POSSIBLY
MORE CONCENTRATED NEAR THE TREASURE COAST WHERE STORMS MAY LINGER
FROM LATE AFTN INTO THE EVENING. SW LOW LVL FLOW SHOULD PUSH MOST OF
THE ACTIVITY INTO THE ATLC BY LATE EVENING. LOWS WILL BE IN THE
LOWER TO MID 70S.
SAT...NOT MUCH CHANGE AS DEEP MOISTURE (PWATS AROUND 2 INCHES) IS
PROGGED TO CONTINUE ESPECIALLY ACROSS NORTHERN HALF OF FA. FAST
W/SW FLOW ALONG WITH A MID LEVEL IMPULSE SHOULD PRODUCE AN EARLY
START TO SHOWERS AND STORMS DURING THE MORNING ESP NORTH OF
ORLANDO. SHOULD SEE AN AFTERNOON SEA BREEZE DEVELOP WITH SOME
INLAND PENETRATION ACROSS MARTIN AND ST LUCIE COUNTIES BUT IT IS
NOT EXPECTED TO PUSH VERY FAR INLAND NORTH OF THE CAPE. HIGHEST
STORM CHANCES APPEAR TO BE LATE IN THE AFTN ASSOCD WITH A SEA
BREEZE COLLISION EXTENDING FROM COASTAL VOLUSIA SOUTHWARD TO LAKE
OKEECHOBEE. HAVE DRAWN 50 POPS NORTH AND 40 POPS SOUTH. HIGH
TEMPERATURES AROUND 90/LWR 90S NEAR THE COAST TO LWR-MID 90S OVER
THE INTERIOR. LOWS WILL BE IN THE 70S.
SUN...THE LOW LVL RIDGE AXIS WILL LIFT NORTHWARD T0 LAKE
OKEECHOBEE. THIS WILL REDUCE THE LOW LVL WESTERLY FLOW ACROSS
THE SOUTH WHICH WILL ALLOW AN EARLIER ONSET OF THE SEA BREEZE
SOUTH OF THE CAPE. RAIN CHANCES WILL BE LOWER DUE TO DECREASING
MOISTURE LEVELS AND LITTLE UPPER SUPPORT. FOCUS FOR STORMS WILL BE
OVER THE INTERIOR WITH PUSH BACK TO THE EAST COAST BUT COVERAGE
LOOKS LOWER THAN PREVIOUS DAYS AT 30 TO 40 PERCENT. INTERIOR
SECTIONS WILL BE A DEGREE OR TWO HOTTER GIVEN MORE SUN AND LESS
COVERAGE OF STORMS.
MON-THU...THE GFS AND ECMWF SHOW A DRYING TREND WITH DECREASING
MOISTURE IN THE H8-H5 LAYER. HAVE LOWERED RAIN CHANCES TO 20 PCT
TUE-WED AND 30 PERCENT THU. THIS MEANS HIGH TEMPERATURES WILL BE
HOT...SOLIDLY IN THE MID 90S INTERIOR AND POSSIBLY VOLUSIA
COAST...LOWER 90S SOUTH OF THE CAPE.
&&
.AVIATION...
SCT-NMRS TSRA WILL DVLP AND MOVE EASTWARD ACROSS E CENTRAL FL
THIS AFTN. EXPECT CONVECTION TO AFFECT NRN INTERIOR TERMINALS
INCLUDING KMCO FROM 18Z-20Z...WITH STORMS THEN PUSHING TWD THE
KDAB-KMLB BY 18Z-21Z. STORMS MAY MOVE IN FROM THE WEST AND DVLP
NEAR THE EAST COAST SEA BRZ BOUNDARY FROM 19Z-23Z FROM KVRB-KSUA.
MAINLY VFR WX AFT 01Z.
&&
.MARINE...
SW WINDS TO AROUND 10 KNOTS WILL BUILD SEAS TO 2-3 FT OFFSHORE BUT
STILL STAY NEAR 1-2 FT ALONG THE IMMEDIATE COAST WITH OFFSHORE FLOW.
EXPECT SHOWERS AND LIGHTNING STORMS TO AFFECT THE INTRACOASTAL AND
NEAR SHORE ATLANTIC WATERS FROM 2 PM TO 8 PM WITH STRONGER STORMS
CAPABLE OF PRODUCING WINDS ABOVE 35 KNOTS.
WEEKEND...SURFACE RIDGE AXIS IS FORECAST TO REMAIN SOUTH OF OUR
COASTAL WATERS SAT THEN SLOWLY LIFT NORTH TO LAKE OKEECHOBEE
SUNDAY. PERSISTENT WEST TO SOUTHWEST WINDS 10 TO 15 KNOTS SAT WILL
BRING SCATTERED LIGHTNING STORMS OFF THE COAST DURING THE AFTN/EVE
ALONG WITH GUSTY WINDS. OFFSHORE FLOW WEAKENS SUNDAY SOUTH OF
SEBASTIAN INLET WITH LESS STORM ACTIVITY ABLE TO REACH THE
TREASURE COAST. BUT STRONGER OFFSHORE STEERING FLOW WILL BRING
SCATTERED STORMS OFFSHORE VOLUSIA AND BREVARD COUNTIES AGAIN LATE
SUNDAY.
MON-TUE...SOUTH TO SOUTHWEST FLOW WILL TURN SE NEAR THE COAST IN A
SEA BREEZE. SOME DRIER AIR SHOULD LIMIT COVERAGE OF STORMS OVER
THE PENINSULA BY TUE BUT THERE WILL BE A THREAT FOR OFFSHORE
MOVING STORMS NORTH OF SEBASTIAN LATE MONDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 90 73 92 75 / 60 30 50 30
MCO 91 74 94 75 / 60 30 50 20
MLB 90 75 92 75 / 60 30 50 30
VRB 90 74 92 75 / 60 30 40 20
LEE 90 75 93 77 / 60 30 50 20
SFB 92 75 95 77 / 60 30 50 20
ORL 91 75 94 78 / 60 30 50 20
FPR 90 74 92 75 / 60 30 40 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...VOLKMER
LONG TERM....KELLY
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
402 AM CDT Fri Aug 15 2014
...Updated for short term discussion...
.SHORT TERM...(Today and tonight)
ISSUED AT 347 AM CDT FRI AUG 15 2014
A weak shortwave trough was approaching western Kansas this
morning. Ahead of this feature, elevated convection was ongoing near
the interstate 70 corridor. This upper level feature will pass
across southwest Kansas today. A narrow ribbon of low level
moisture from El Paso into eastern Mew Mexico is expected to
advect north-northeastward into southwest Kansas, leading to
destabilization. Surface based CAPE values will approach 1500
j/kg by afternoon. After some morning elevated convection, a weak
surface trough associated with the passage of the upper level
feature will lead to sufficient surface convergence for
thunderstorm development by early to mid afternoon. There is some
uncertainty as to how far west thunderstorm initiation will be.
The RAP pushes the surface trough through Dodge City late this
morning, suggesting that any afternoon storms would be confined to
south central Kansas. We opted keep the highest thunderstorm chances
southeast of Dodge City this afternoon. Highs today will be in the
lower to middle 90s given partial sunshine. Winds will be weaker
by tonight along with partly cloudy skies; and this should allow
temperatures to fall into the upper 60s.
.LONG TERM...(Saturday through Thursday)
ISSUED AT 255 AM CDT FRI AUG 15 2014
For Saturday, a stalled out warm front will be just north of Dodge
City. Some weak moisture convergence along this front may be enough
to set off some scattered late afternoon thunderstorms and into the
evening. Models show some moderate instability with CAPE over 2000
J/kg. Very weak upper level wind fields and lack of large scale
dynamics should be enough to preclude a severe thunderstorm threat.
Forecast soundings show an inverted V type sounding with some gusty
winds to 50 mph the main threat. Highs will be warm and in the mid
to upper 90s. Lows will be mild and in the upper 60s to around 70.
On Sunday, weak upper level ridging continues across the Central
Plains with a weak surface trough near Hays. With forecast moderate
instability and some weak moisture convergence will continue with a
slight chance of thunderstorms mainly near and north of Dodge City
by later in the afternoon and overnight. The severe threat again
looks minimal. Highs will continue in the mid to upper 90s with
overnight lows in the upper 60s.
For the period of Monday into Thursday of next week, a northern
branch upper level wave moves across the Plains on Monday afternoon
with a continued chance for thunderstorms. More weak upper level
waves move across the Plains into Thursday with small chances for
mainly late afternoon and evening thunderstorms. Highs continue in
the mid 90s with lows in the upper 60s to around 70.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 1253 AM CDT FRI AUG 15 2014
A few thunderstorms are possible at KHYS through 09z ahead of an
upper level disturbance. A weak frontal boundary will approach
western Kansas on Friday, resulting in chances for thunderstorms
after 20z at KHYS/KDDC. Outside of thunderstorms, VFR conditions
can be expected along with south winds at 10-15 kts, shifting to the
southwest after 15z and becoming light after 21z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 94 67 96 68 / 30 20 20 20
GCK 94 67 96 67 / 30 10 20 20
EHA 95 67 96 68 / 20 20 20 20
LBL 96 68 98 68 / 30 20 20 20
HYS 93 67 95 68 / 30 10 20 20
P28 95 69 98 70 / 30 30 10 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Finch
LONG TERM...Kruse
AVIATION...Finch
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
345 AM EDT FRI AUG 15 2014
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 345 AM EDT FRI AUG 15 2014
06Z SFC ANALYSIS SHOWS GENERALLY WEAK HIGH PRESSURE THROUGH THE OHIO
AND TENNESSEE VALLEYS. A STALLED FRONTAL BOUNDARY EXISTS OVER PARTS
OF CENTRAL AND EASTERN KENTUCKY. THIS IS RESPONSIBLE FOR THE EXTRA
MOISTURE IN THE FORM OF SHOWERS AND SPRINKLES THAT SANK THROUGH THE
CWA EARLIER IN THE EVENING. THE MOISTURE...FOLLOWED BY SOME CLEARING
IN THE WAKE OF THE FRONT...HAS LED TO AREAS OF DENSE FOG...GENERALLY
NORTH OF THE HAL ROGERS PARKWAY. AS THE NIGHT WEARS ON...EXPECT THE
FOG AND DENSE PARTS OF IT TO SETTLE FURTHER SOUTH. ACCORDINGLY...
HAVE ISSUED AN SPS AND A GRAPHICAST TO ADDRESS THE LOW VISIBILITIES.
THESE RUN THROUGH 5 AM AND WILL LIKELY BE REISSUED THROUGH 9 AM
SHOULD THE FOG NOT START TO DISSIPATE BY THEN. HOWEVER...OVER THE FAR
NORTHERN PARTS OF THE AREA SOME DRIER AIR IS WORKING INTO OUR CWA AND
SHOULD LIMIT THE FOG AND WITH TIME HELP TO CLEAR IT. SO WILL LIKELY
TAKE THIS INTO CONSIDERATION WITH RESPECT TO THE FOG THREAT THROUGH
THE REST OF THE NIGHT AND SPS OUTLINE. THE PROXIMITY OF THE FRONT HAS
ALSO BROUGHT HIGHER DEWPOINTS TO THE AREA RESULTING IN A MILDER AND
MORE UNIFORM TEMPERATURE NIGHT THAN INITIALLY ANTICIPATED. AS
SUCH...TEMPS AND DEWPOINTS THROUGH THE AREA ARE GENERALLY IN THE
LOWER 60S WITH A FEW POCKETS OF UPPER 50S ON THE FRINGES...AWAY FROM
THE STALLED BOUNDARIES.
THE MODELS ARE IN DECENT AGREEMENT ALOFT WITH THE MAIN FEATURES THAT
WILL AFFECT THE AREA THROUGH THE SHORT TERM. A BROAD AND DEEP UPPER
LOW WILL CONTINUE TO MOVE NORTHEAST AND AWAY FROM THE REGION. IN ITS
WAKE NORTHWEST FLOW WILL BRING A COUPLE WEAK MID LEVEL ENERGY PACKETS
OVER KENTUCKY TONIGHT AND DURING THE DAY SATURDAY. FOR THIS...A
GENERAL MODEL COMPROMISE IS PREFERRED WHILE THE HRRR AND NAM12 WAS
GIVEN THE MOST WEIGHT FOR THE NEAR TERM PORTION OF THE FORECAST.
SENSIBLE WEATHER WILL FEATURE AREAS OF DENSE FOG AROUND THIS MORNING
AND THE RESIDUAL FRONT OVER THE SOUTHERN PORTION OF THE AREA. THIS
FRONT WAS MORE PROLIFIC THAN EXPECTED DURING THE DAY AND EVENING ON
THURSDAY. WITH THIS IN MIND WILL KEEP A SMALL CHANCE OF SPRINKLES AND
SHOWERS IN THE FORECAST ACROSS THE SOUTH TODAY. HIGH CLOUDS WILL BE
ON THE INCREASE FROM THE WEST TONIGHT INTO SATURDAY AS THE FRONT
STARTS TO MOVE BACK NORTHEAST. CANNOT RULE OUT A SHOWER WITH THIS
LATER TONIGHT OR ON SATURDAY...BUT FOR NOW WILL KEEP IT DRY IN THE
FORECAST GRIDS. TEMPERATURES WILL BE JUST ON THE COOL SIDE OF NORMAL
THROUGH SATURDAY THANKS IN PART TO THE EXTRA CLOUDS AROUND. AGAIN
TONIGHT...PATCHY VALLEY FOG CAN BE EXPECTED TO DEVELOP AFTER
MIDNIGHT...BUT LIKELY BE MITIGATED BY THE ADDITIONAL CLOUDS.
STARTED WITH THE CONSSHORT FOR THE T/TD/WIND GRIDS THROUGH THE FIRST
24 HOURS AND USED THE SUPERBLEND FOR THE REST OF THE SHORT TERM. DID
MAKE SOME ADJUSTMENTS TONIGHT FOR MINOR RIDGE AND VALLEY TEMPERATURE
DIFFERENCES. WITH THE POPS...ENDED UP A NOTCH HIGHER THAN MOS TODAY
ACROSS OUR SOUTHERN ZONES...OWING TO THE LINGERING FRONT. FOR THE
REST OF THE FORECAST...WAS IN LINE WITH GUIDANCE.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 340 AM EDT FRI AUG 15 2014
THE EXTENDED FORECAST BEGINS ON SATURDAY NIGHT WITH THE UPPER LEVEL
PATTERN BEGINNING TO BREAK DOWN AND UPPER LEVEL FEATURES MOVING ALONG
A BIT FASTER. THROUGH THE PERIOD...NUMEROUS UPPER LEVEL SHORTWAVES
WILL MOVE THROUGH THE OH RIVER VALLEY AS THE UPPER LEVEL PATTERN
BECOMES MORE ZONAL AND MAINTAINS THIS PATTERN THROUGH THE ENTIRE
EXTENDED. IN THE LOWER LEVELS...THE MORE POTENT FEATURE WILL BE THE
SURFACE LOW MOVING THROUGH ON MONDAY WITH PLENTY OF SURFACE BASED
INSTABILITY AND UPPER LEVEL SUPPORT. THIS DAY WILL BE A SCENARIO TO
MONITOR AS SEVERE WEATHER IS POSSIBLE BUT WITH A LACK OF
CONFIDENCE...CERTAINLY NOT SOMETHING TO HIGHLIGHT AT THIS POINT.
ALSO...THE FORECAST PROBLEM HERE WILL BE TIMING...ESPECIALLY WITH A
TRANSITIONS TO A MORE ZONAL PATTERN.
FOR THE REST OF THE EXTENDED...SOUTHERLY FLOW WITH A SURFACE
STATIONARY BOUNDARY SETTING UP ALONG THE LOWER OH VALLEY WILL ALLOW
FOR MAINLY AFTERNOON AND EVENING CONVECTION THROUGH THE TUESDAY TO
THURSDAY PERIOD. THIS APPEARS TO BE THE SET UP BUT THE GFS AND EURO
STILL SHOW SOME DIFFERENCES IN THEIR SOLUTIONS. ALSO KEEPING IN
MIND...THAT MODELS DO HAVE TROUBLE WITH TRANSITION PERIODS IN THE
UPPER LEVEL FLOW. THIS IN MIND...DID STAY WITH THE MODEL ALL BLEND
SOLUTION...EVEN LOWERED POPS SLIGHTLY BELOW THAT VALUE IN THE
EXTENDED BASED UPON LACK OF CONFIDENCE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 200 AM EDT FRI AUG 15 2014
A STALLED OUT BOUNDARY WILL LINGER OVER EASTERN KENTUCKY OVER THE
NEXT 24 TO 36 HOURS. THIS BOUNDARY WILL RESULT IN SLIGHTLY HIGHER
DEWPOINTS...LEADING TO PRETTY GOOD FOG POTENTIAL THROUGH THE REST OF
THE NIGHT. QUESTION REMAIN REGARDING HOW MUCH CLOUD COVER WILL LINGER
OVER THE CWA INTO DAWN. FROM THIS...THERE MAY BE A NARROW CORRIDOR
ACROSS EASTERN KENTUCKY WITH A BIT MORE CLOUD COVER HELPING TO KEEP
THE WORST OF THE FOG AT BAY. HOWEVER...ANY AREAS THAT CLEAR WILL BE
PRONE TO DENSE FOG...SO HAVE CONTINUED TO BE PESSIMISTIC WITH THE
TAFS AND TOOK ALL VISIBILITIES BELOW AIRPORT MINIMUMS THROUGH THE
REMAINDER OF THE NIGHT. THE FOG WILL BURN OFF TOMORROW MORNING WITH
THE THREAT OF MORE SHOWERS ACROSS THE SOUTH IN THE AFTERNOON AS THE
BOUNDARY CONTINUES TO SLOWLY SAG SOUTHWARD. WINDS THROUGH THE PERIOD
WILL BE LIGHT AND VARIABLE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...KAS/GREIF
AREA FORECAST DISCUSSION
NWS CARIBOU ME
341 AM EDT FRI AUG 15 2014
.SYNOPSIS...
UPPER LEVEL LOW PRESSURE WILL REMAIN NORTHWEST OF MAINE THROUGH
THE WEEKEND. AS A RESULT...UNSETTLED CONDITIONS WILL PERSIST ACROSS THE
REGION RIGHT INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
UNSETTLED CONDITIONS THIS TERM W/ANOTHER ROUND OF SHOWERS
EXPECTED. FOG WILL ALSO BE A CONCERN.
THE 06Z SURFACE ANALYSIS SHOWED WEAK LOW PRES LIFTING ACROSS NEW
BRUNSWICK W/THE OCCLUDED FRONT ACROSS NORTHERN MAINE. AREA OF
SHOWERS ACROSS NEW BRUNSWICK MOVING NNW PER THE LATEST RADAR W/THE
WESTERN EDGE JUST E OF THE MAINE BORDER. THE LATEST RAP AND HRRR
3KM DOING WELL W/THIS AREA AND THE PLACEMENT OF THE LOW AND FRONT.
A BLEND OF THE THESE 2 MODELS SHOW THE WESTERN EDGE JUST SKIRTING
THE MAINE-NEW BRUNSWICK BORDER THROUGH THIS MORNING AS THE BEST
FORCING REMAINS WELL E AND SW OF THE REGION. OOZ UA AND SATELLITE
WV IMAGERY SHOW CLOSED UPPER LOW SPINNING OVER QUEBEC W/SPOKES OF
ENERGY ROTATING AROUND THE LOW. THE IMPULSE THAT IS FORECAST TO
AFFECT OUR CWA WAS MOVING ACROSS NYS AND VT AND IS EXPECTED TO
MOVE ACROSS THE REGION BY THIS AFTERNOON INTO THIS EVENING. SOME
LLVL CONVERGENCE COMBINED W/SOME MID LEVEL SUPPORT WILL ALLOW FOR
SHOWERS TO BREAK OUT MAINLY ACROSS THE NORTHERN AND CENTRAL AREAS.
DECIDED TO GO W/CHANCE POPS(30-40%) FOR THIS AFTERNOON INTO
TONIGHT BUT TRIMMED BACK THE QPF A BIT W/TOTALS THROUGH TONIGHT
RUNNING LESS THAN 0.10". SOUNDINGS INDICATE SB/MUCAPES LESS THAN
150 JOULES TODAY INTO THE EVENING AND THEREFORE LEFT TSTMS OUT OF
THE FORECAST. CLOUDS AND SHOWERS WILL HOLD DOWN TEMPERATURES
W/READINGS WILL RUN INTO THE UPPER 60S ACROSS THE NORTH AND WEST
WHILE CENTRAL AND DOWNEAST SHOULD SEE LOWER 70S. COOL FOR MID
AUGUST.
FOG HAS DEVELOPED THIS MORNING THANKS TO LIGHT WINDS/PARTIAL
CLEARING AND A WET GROUND. THE FOG WAS THE MOST DENSE ACROSS THE
COAST BUT PATCHY DENSE WILL BE NUISANCE THROUGH SUNRISE JUST ABOUT
EVERYWHERE. DECIDED TO LEAVE FOG OUT NORTH OF THE DOWNEAST AND
COASTAL AREAS TONIGHT DUE TO CLOUDS AND SHOWERS. ATTM, IT LOOKS AS
THOUGH THE FOG ACROSS THE DOWNEAST AND THE COAST WILL BE PATCHY.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
A UPPER LOW OVER NORTHERN QUEBEC AT THE START OF NEAR TERM PERIOD
IS FORECAST TO DRIFT SLOWLY SOUTHEAST ACROSS NEW BRUNSWICK TO
EASTERN NOVA SCOTIA BY THE END OF THE PERIOD. A NEW FRONTAL SYSTEM
WILL MOVE FROM SRN MAINE TOWARDS THE EASTERN NOVA SCOTIA BY END OF
THE PERIOD. UNSETTLE WEATHER WILL PERSIST ACROSS MAINE THROUGH THE
PERIOD.
LOADED USED HPC GRIDS FOR QPF...NAWAVE 4 FOR SEAS IN THE COASTAL
WATERS...AND A BLEND OF NAM/GFS/GEM/ECMWF THROUGH THE PERIOD FOR
ALL OTHER ELEMENTS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AT THE START OF THE PERIOD AN UPPER LEVEL LOW WILL BE MOVING INTO
THE WESTERN CANADIAN MARITIMES...HIGHER PRESSURE WILL BEGIN
BUILDING INTO MAINE. THE RIDGE WILL SET ACROSS THE REGION AND
REMAIN THROUGH THE END OF THE PERIOD. POSSIBLE SHOWERS ACROSS NRN
MAINE TOWARDS THE END OF THE PERIOD AS LOWER PRESSURE BEGINS TO
ERODE THE NORTHERN PORTIONS OF THE RIDGE.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: MVFR/IFR THIS MORNING W/CONDITIONS IMPROVING TO VFR FOR
KBGR AND KBHB. THE NORTHERN TERMINALS FROM KHUL TO KFVE WILL SEE
MVFR HANG LONGER INTO THIS AFTERNOON. MVFR W/PERIODS OF IFR
COULD BE SEEN LATER TONIGHT MAINLY ACROSS THE NORTHERN TAFS SITES
W/SHOWERS AND LOW CIGS.
SHORT TERM: MAINLY MVFR CONDITIONS ACROSS NRN AND CNTRL ME THROUGH THE
PERIOD. OCNL PERIODS WERE CIGS WILL FALL IFR IN SHWRS. IFR
CONDITIONS FOR BGR AND BHB THROUGH MUCH OF THE NEAR TERM PERIOD.
IMPROVING CONDITIONS AFTER MID DAY MONDAY AS HIGHER PRESSURE
BUILDS INTO THE AREA.
&&
.MARINE...
NEAR TERM: DROPPED THE SCA FOR HAZARDOUS SEAS AS WAVE HEIGHTS HAVE
DROPPED BELOW 6 FT AND WILL CONTINUE TO SUBSIDE TODAY INTO
TONIGHT. WINDS ARE AT 10 KTS ATTM AND THINKING HERE IS THAT THE
WINDS WILL STAY LIGHT RIGHT INTO TONIGHT AT SPEEDS OF 10 KTS OR LESS.
SHORT TERM: WINDS AND SEAS BELOW SCA THROUGH THE PERIOD.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...NORTON
LONG TERM...NORTON
AVIATION...HEWITT/NORTON
MARINE...HEWITT/NORTON
AREA FORECAST DISCUSSION
NWS CARIBOU ME
129 AM EDT FRI AUG 15 2014
.SYNOPSIS...
UPPER LEVEL LOW PRESSURE WILL REMAIN NORTHWEST OF MAINE THROUGH
THE WEEKEND. AS A RESULT...UNSETTLED CONDITIONS WILL PERSIST ACROSS THE
REGION RIGHT INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
130 AM UPDATE: LARGE AREA OF SHOWERS HANGING ACROSS NEW BRUNSWICK
W/SOME SCATTERED ACTIVITY ACROSS PORTIONS OF THE CENTRAL
HIGHLANDS. LLVL CONVERGENCE RESIDES ACROSS NEW BRUNSWICK AND IN
THE WESTERN AREAS AS EVIDENT OF THE LATEST SURFACE ANALYSIS. THE
LATEST RUN OF THE HRRR 3KM WAS HANDLING THE PLACEMENTS OF RAINFALL WELL
PER THE LATEST RADAR LOOP AS WELL AS THE RAP. LATEST UA COINCIDES
W/THE SATELLITE WV LOOPS OF SHEARED VORTICITY RIDING N OVERNIGHT
W/WEAK LIFT. THEREFORE, THINKING HERE IS THAT THE BULK OF THAT
RAIN IN NEW BRUNSWICK WILL STAY E OF THE BORDER W/THE WESTERN EDGE
GRACING AROOSTOOK COUNTY THROUGH EARLY MORNING.
SOME PARTIAL CLEARING TAKING PLACE PER THE LATEST IR SATELLITE
IMAGERY AND METARS. THIS HAS LED TO SOME FOG ESPECIALLY ACROSS
DOWNEAST AND THE COAST. PREVIOUS SHIFTS HAVE FOG IN PLACE AND WILL
KEEP IT AS IS THROUGH EARLY MORNING.
FOR FRIDAY...AN UPPER LOW WILL SPIN ACROSS SOUTHERN QUEBEC THROUGH
THE DAY. THIS WILL COMBINE WITH THE MOISTURE LINGERING FROM TODAY`S
RAIN TO ALLOW SHOWERS TO DEVELOP, ESPECIALLY DURING THE AFTERNOON.
NORTHWESTERN MAINE WILL HAVE THE BEST CHANCES FOR SEEING RAIN AS
THEY WILL BE CLOSEST TO THE UPPER-LEVEL SUPPORT. HIGHS TOMORROW WILL
BE ON THE COOL SIDE NORTH /MID 60S TO AROUND 70), WHILE SOUTHERN
AREAS, WHICH WILL SEE SOME SUN ONCE THE FOG BURNS OFF, WILL BE A FEW
DEGREES WARMER AWAY FROM THE COAST.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
UPPER LEVEL LOW PRESSURE WILL REMAIN NORTHWEST OF THE REGION
FRIDAY NIGHT THROUGH SUNDAY...WHILE DISTURBANCES ROTATING AROUND
THE LOW CROSS THE REGION. UNSETTLED CONDITIONS WILL PERSIST FRIDAY
NIGHT THROUGH SUNDAY. THE BETTER CHANCES OF SHOWERS AND MOST
EXTENSIVE CLOUD COVER FRIDAY NIGHT THROUGH SATURDAY NIGHT WILL
OCCUR ACROSS NORTHERN AND CENTRAL PORTIONS OF THE FORECAST AREA.
ACROSS DOWNEAST AREAS...EXPECT A SLIGHT CHANCE OF SHOWERS ALONG
WITH PARTLY/MOSTLY CLOUDY SKIES FRIDAY NIGHT THROUGH SATURDAY
NIGHT. SHOWER CHANCES WILL INCREASE ACROSS THE ENTIRE FORECAST
AREA SUNDAY WITH A COLD FRONT STARTING TO MOVE EAST ACROSS THE
REGION. TEMPERATURES WILL BE AT BELOW NORMAL LEVELS SATURDAY/SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
UPPER LEVEL ENERGY MOVING OUT OF QUEBEC WILL KEEP REGION UNSETTLED
THROUGH MONDAY. MODELS ARE NOT IN GREAT AGREEMENT ON THE EVOLUTION
OF THE LOW AND UPPER LEVEL LOW THINKING THE BLEND APPROACH IS
REASONABLE AT KEEPING THE BEST CHANCES OF PRECIP ACROSS NORTHERN
MAINE WITH POPS LESSENING AS YOU GO SOUTHWEST FOR MONDAY. MONDAY
NIGHT INTO TUESDAY EXPECT CHANCES OF PRECIP TO DROP OFF AS UPPER
LEVEL RIDGE AND SURFACE HIGH BEGIN BUILDING EAST. HIGH PRESSURE
WILL FINALLY TAKE OVER TUESDAY INTO EARLY WEDNESDAY WITH MOSTLY TO
PARTLY SUNNY SKIES. THE MODELS DO HOWEVER INDICATE A LOW MOVING ACROSS
THE MID ATLANTIC TUESDAY NIGHT. THE ECMWF WANTS TO BRING THIS LOW
CLOSE TO THE REGION AS WE GO INTO LATER WEDNESDAY AND THE GFS/GFS
ENSEMBLE KEEP THIS LOW SOUTH OF THE FA. DUE TO THE UNCERTAINTY IN
THE MODELS WILL ONLY KEEP SLIGHT CHANCE PRECIP ACROSS THE REGION
FOR WEDNESDAY INTO THURSDAY UNDER PARTLY CLOUDY SKIES. HIGH
TEMPERATURES AT THE BEGINNING OF THE PERIOD WILL BE BELOW NORMAL
AND THROUGH THE WEEK WILL COME UP TO NEAR TO A LITTLE ABOVE
NORMAL. LOW TEMPERATURES ARE EXPECTED TO STAY CLOSE TO NORMAL
THROUGH THE PERIOD.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: WIDESPREAD IFR EXPECTED TONIGHT INTO EARLY FRIDAY
MORNING, WITH LIFR POSSIBLE, ESPECIALLY AT KHUL, KBGR, AND KBHB.
THIS WILL BE DUE TO FOG AND LOW CEILINGS. CONDITIONS WILL
GRADUALLY IMPROVE FRIDAY MORNING AS THE FOG BURNS OFF, ESPECIALLY
AT KBHB AND KBGR, BUT EXPECT MVFR CEILINGS TO HANG ON ACROSS THE
NORTH AS SHOWERS REDEVELOP BY AFTERNOON.
SHORT TERM: OCCASIONAL MVFR CONDITIONS ARE POSSIBLE ACROSS THE
REGION FRIDAY NIGHT THROUGH SATURDAY NIGHT...WITH THE BETTER
CHANCES ACROSS NORTHERN AND CENTRAL AREAS. MORE EXTENSIVE MVFR
CONDITIONS ARE EXPECTED ACROSS THE FORECAST AREA SUNDAY.
OCCASIONAL MVFR CONDITIONS ARE POSSIBLE WITH ANY SHOWERS MONDAY.
VFR CONDITIONS ARE EXPECTED MONDAY NIGHT AND TUESDAY.
&&
.MARINE...
NEAR TERM: 830 PM UPDATE...WV HTS DROPPED BLO 5 FT ACROSS THE
INNER HARBOR/BAY MZ052...SO WE CANX THE SCA FOR HAZ SEAS THERE. WE
XTNDED THE HAZ SEAS SCA OVR THE OUTER MZS TIL 08Z TO ALLOW MORE TM
FOR WV HTS TO SUBSIDE THERE. OTHERWISE...NO OTHER CHGS WERE MADE.
ORGNL DISC...A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS REMAINS IN
EFFECT FOR ALL OUR WATERS UNTIL 2 AM FRIDAY MORNING. ACROSS THE
OUTER WATERS, 6-8 FOOT WAVES WILL SLOWLY SUBSIDE THROUGH THE
EVENING. IN THE BAYS, WAVES ARE AT A MARGINAL 4-5 FEET, SO THE
ADVISORY MAY BE ABLE TO BE CANCELLED EARLY IN THESE LOCATIONS. THE
OTHER CONCERN IS THE POTENTIAL FOR DENSE FOG TONIGHT RESTRICTING
VISIBILITY TO BELOW 1 SM.
SHORT TERM: WINDS/SEAS ARE EXPECTED TO BE BELOW SMALL CRAFT
ADVISORY LEVELS FRIDAY NIGHT THROUGH THE WEEKEND. VISIBILITIES
COULD BE REDUCED IN SHOWERS SUNDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM EDT EARLY
THIS MORNING FOR ANZ050-051.
&&
$$
NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
310 AM EDT FRI AUG 15 2014
.SHORT TERM (TODAY AND TONIGHT)...
SOME CLOUDS ARE MOVING ACROSS NORTHERN PORTIONS OF THE AREA THIS
MORNING IN ASSOCIATION WITH THE NOSE OF AN UPPER JET STREAK AND WEAK
500 MB VORT MAX. THE NAM CONTINUES TO SHOW SOME PRECIP IN NORTHERN
AREAS THROUGH THE DAY...BUT THIS APPEARS OVERDONE WITH NO
SIGNIFICANT UPSTREAM VORT MAXES OF NOTE IN WV IMAGERY AND A FORECAST
SOUNDING THAT APPEARS TO BE WELL CAPPED. THE GFS AND RAP ARE
DRIER...AND WILL GO IN THAT DIRECTION FOR TODAY. A WARMING TREND
WILL CONTINUE AS THE 850 MB RIDGE BUILDS IN FROM THE WEST...WITH
HIGHS IN THE MID TO UPPER 80S IN MOST VALLEY LOCATIONS. SOME THIN
HIGH CLOUDS MAY MOVE IN TONIGHT IN THE NW FLOW ALOFT.
.LONG TERM (SATURDAY THROUGH THURSDAY)...
A SERIES OF SHORT-WAVE TROUGHS WILL MOVE FROM THE NORTHERN PLAINS
INTO THE GREAT LAKES/OHIO VALLEY SATURDAY THROUGH TUESDAY. THESE
WAVES WILL HELP PULL MOISTURE/INSTABILITY BACK INTO THE TENNESSEE
VALLEY KEEPING THE WEATHER UNSETTLED AS WELL AS PULLING OUTFLOW
BOUNDARIES INTO THE AREA. WILL CALL FOR CHANCE POPS BEGINNING
SUNDAY AFTERNOON. BEST CHANCES OF SHOWERS AND THUNDERSTORMS WILL BE
ACROSS THE SOUTHWEST VIRGINIA/NORTHEAST TENNESSEE AND NORTHERN
PLATEAU DUE TO PROXIMITY TO UPPER DYNAMICS.
EVEN THOUGH SHORT-WAVES HAVE EXITED BY WEDNESDAY AND THURSDAY...
PLENTY OF MOISTURE/INSTABILITY REMAINS WITH MAINLY DIURNAL TERRAIN
FORCED CONVECTION EXPECTED EACH DAY.
DUE TO PERFORMANCE...WENT A COUPLE OF DEGREES COOLER THAN GFX MOS
HIGHS...ESPECIALLY AT CHA. GENERALLY FOLLOWED MOS MINS THROUGH THE
PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 88 64 90 67 / 0 0 0 10
KNOXVILLE MCGHEE TYSON AIRPORT, TN 86 63 87 66 / 10 10 0 10
OAK RIDGE, TN 86 62 88 66 / 10 10 0 10
TRI CITIES AIRPORT, TN 84 57 86 61 / 10 10 0 10
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS/DH
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1235 AM CDT FRI AUG 15 2014
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...CLOUD COVER HAS CLEARED THIS EVENING AS THUNDERSTORM
ACTIVITY QUICKLY DISSIPATED WITH LOSS OF HEATING. SKIES WILL
GENERALLY REMAIN CLEAR THROUGH THE REST OF THE NIGHT...WITH SOME
MINIMAL GROUND FOG POSSIBLE AT KHRL DUE TO MOIST GROUND FROM RAIN
YESTERDAY. BREEZY CONDITIONS EXPECTED TOMORROW AS LOW PRESSURE
DEEPENS IN WEST TEXAS. HIGHER BREEZES WILL DISRUPT THE SEABREEZE
DURING THE AFTERNOON...WITH MUCH MORE ISOLATED COVERAGE...IF ANY.
&&
.PREV DISCUSSION... /ISSUED 250 PM CDT THU AUG 14 2014/
SHORT TERM /NOW THROUGH FRIDAY NIGHT...AFTERNOON WATER VAPOR
SHOWS DRY AIR MOVING THROUGH SOUTH TEXAS INTO THE NORTHERN
PORTIONS OF THE CWA. CRP SOUNDING SHOWED PWATS OF 1.51 INCHES.
DOWN IN THE VALLEY...MORE MOISTURE IS PRESENT WITH BRO SOUNDING OF
2.04. SEA BREEZE IS MOVING INLAND WITH A FEW SHOWERS ACROSS THE
COASTAL COUNTIES. HRRR SHOWS ISOLATED SHOWERS CONTINUING ALONG THE
SEA BREEZE WITH MOST ACTIVITY DONE AND OVER WITH BY EARLY EVENING.
HAVE SLIGHT CHANCE POPS FOLLOWING THE SEA BREEZE THROUGH THE REST
OF THE DAY. HIGHS STILL EXPECTED INTO THE MID-UPPER 90S WITH LOWER
100S ACROSS THE UPPER VALLEY.
NAM 500-300MB RH SHOWS DRY AIR ENGULFING THE AREA BY MID EVENING
WHICH WILL SHUT DOWN ANY PRECIP REMAINING. THEREFORE...SKIES WILL
CLEAR OUT AND WINDS WILL SUBSIDE ALLOWING TEMPERATURES TO FALL INTO
THE MID-UPPER 70S TO AROUND 80 DEGREES.
FRIDAY A SHORTWAVE TROUGH WILL MOVE DOWN THE EASTERN SIDE OF THE
RIDGE PARKED OVER THE SOUTHWEST WHICH WILL HELP STRENGTHEN SURFACE
TROUGHING TO OUR WEST AND STRENGTHEN WINDS ACROSS THE AREA FRIDAY
AFTERNOON THROUGH THE SHORT TERM. BREEZIER CONDITIONS EXPECTED
FRIDAY AFTERNOON IN THE VALLEY AND PROGRESSES INTO THE COASTAL
WATERS FRIDAY NIGHT. NOT MUCH IN THE WAY OF PRECIP FRIDAY WITH
LOWERED 1000-500MB RH AND PWATS FALLING TO 1.7 INCHES. DID PUT 10
POPS FOR EAST OF HWY 281 BUT NOTHING MENTIONABLE IN THE ZONES.
FAVORED THE ECMWF MOS FOR TEMPERATURES SINCE MAV/MET SEEM A LITTLE
LOW FOR THIS REGIME.
LONG TERM /SATURDAY THROUGH WEDNESDAY/...A PERSISTENT H5 RIDGE
WILL STRETCH FROM THE DESERT SOUTHWEST TO THE FLORIDA PENINSULA
AND WILL DOMINATE THE UPPER PATTERN THROUGH THE MAJORITY OF THE
PERIOD. THE RIDGE WILL NATURALLY EXHIBIT WEAKNESS OVER THE WEST
GULF HOWEVER... SIMPLY A REFLECTION OF THE TWO STRONGER ENDS OF
THE BARBELL TO THE EAST AND WEST. SFC HIGH PRESSURE WILL BE
SUPPORTED OVER THE NORTH AND EAST GULF...PROVIDING A MODERATE
ANTICYCLONIC FLOW OVER THE WEST GULF AND THE CWA. DRIER AIR WILL
HOLD SWAY OVER LAND AREAS WITH JUST A SILENT SLIGHT CHANCE OF RAIN
FOR THE GULF THROUGH MUCH OF THE LONG TERM. AN EXCEPTION WILL BE
NEXT WEDNESDAY WHEN A SLUG OF MOISTURE MOVES UP FROM THE SOUTH AND
APPEARS TO HAVE ENOUGH JUICE TO JUSTIFY A NONSILENT 20 PERCENT
CHANCE OF SHOWERS AND TSTMS. THIS UPTICK IN POPS REPRESENTS THE
EFFECTS OF A TROPICAL WAVE MOVING INTO THE SOUTHWEST GULF AT THAT
TIME. OTHERWISE...WITH SUCH CONSISTENCY IN THE FORECAST. THERE WAS
NOT MUCH REASON TO CHANGE THE INHERITED FORECAST SIGNIFICANTLY.
TEMPS WILL RUN SLIGHTLY ABOVE NORMAL WITH LIGHT TO MODERATE
ONSHORE WINDS AND A MIX OF CLOUDS AND SUN. AFTN HEAT LOWS INLAND
WILL TIGHTEN THE GRADIENT SOMEWHAT WITH BREEZY AND GUSTY WINDS
SHOWING UP OVER STARR AND ZAPATA COUNTIES. NO MAJOR DIFFERENCES
NOTED BETWEEN THE GFS AND ECMWF AT THIS WRITING.
MARINE...
NOW THROUGH FRIDAY NIGHT...WINDS WILL REMAIN LIGHT TO MODERATE
WITH LOW SEAS THROUGH FRIDAY MORNING. WINDS AND SEAS WILL BEGIN TO
INCREASE FRIDAY AFTERNOON AND EVENING AS LOW PRESSURE STRENGTHENS
TO OUR WEST AND INTERACTS WITH HIGH PRESSURE OVER THE GULF. SMALL
CRAFT EXERCISE CAUTION MAY BE NEEDED FOR THE LAGUNA FRIDAY AND THE
OFFSHORE WATERS FRIDAY NIGHT
SATURDAY THROUGH MONDAY...BROAD H5 RIDGING FROM THE SOUTHWEST
UNITED STATES EAST ACROSS THE GULF THROUGH THE NORTH ATLANTIC
WILL SUPPORT HIGH PRESSURE ACROSS THE NORTH GULF AT THE SURFACE.
SLIGHTLY LOWER PRESSURE WILL PERSIST OVER THE BAY OF CAMPECHE. A
SLIGHT WEAKNESS OVER THE WEST GULF SPLITTING THE MAIN RIDGE WILL
KEEP THE DOOR OPEN FOR SLIGHTLY ENHANCED MARINE SHOWER AND TSTM
ACTIVITY. MODERATE TO BREEZY SOUTH SOUTHEAST WINDS WILL PREVAIL
WITH MODERATE SEAS OF 3 TO 4 FEET WHICH MAY INCREASE A FOOT OR SO
LATE IN THE WEEKEND. SMALL CRAFT EXERCISE CAUTION CONDITIONS MAY
BE POSSIBLE FROM TIME TO TIME DUE TO STRONGER WINDS.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WWW.WEATHER.GOV/BROWNSVILLE
64/51
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
306 AM CDT FRI AUG 15 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 306 AM CDT FRI AUG 15 2014
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED AN UPPER LOW OVER THE PACIFIC NORTHWEST...RIDGING FROM THE
SOUTHWESTERN U.S. INTO ALBERTA...AND TROUGHING OVER EASTERN CANADA
INTO THE NORTHEASTERN U.S.. ALSO OF NOTE WAS A SHORTWAVE OVER
SOUTHEAST MONTANA...WHICH WITH A STREAM OF MOISTURE TRANSPORT
BRINGING PRECIPITABLE WATER UP TO 1.5-2 INCHES ACROSS MUCH OF THE
PLAINS...HAS SUPPORTED SHOWERS AND EMBEDDED THUNDERSTORMS FROM THE
DAKOTAS INTO KS. ANOTHER AREA OF SCATTERED SHOWERS AND STORMS WERE
PRESENT FROM EASTERN SOUTH DAKOTA INTO SOUTHWEST MN AND WESTERN
IA...IN AN AREA OF MID-LEVEL FRONTOGENESIS AND NOSE OF 850MB
MOISTURE TRANSPORT. FURTHER TO THE EAST OVER THE FORECAST AREA...
HIGH PRESSURE AND DRY AIR DOMINATE. PRECIPITABLE WATER VALUES FROM
00Z SOUNDINGS RANGED FROM 1.25 INCHES AT MPX TO 0.44 INCHES AT GRB.
SOME HIGHER CLOUDS WERE FLOWING INTO LOCATIONS ALONG/WEST OF THE
MISSISSIPPI RIVER...HELPING TO KEEP TEMPERATURES UP THERE.
HOWEVER...IN CENTRAL WISCONSIN WHERE THE AIR IS DRIEST AND SKIES ARE
MAINLY CLEAR...READINGS HAVE DIPPED INTO THE LOW 40S WITH SOME
PATCHY FOG AROUND.
THE NORTHWEST FLOW REGIME THE FORECAST AREA SITS IN IS PROGGED TO
REMAIN IN PLACE THROUGH TONIGHT. MUCH OF THE FOCUS IS HOW CLOSE THE
SHORTWAVE IN SOUTHEAST MONTANA CAN PUSH EAST TOWARDS THE AREA...
BEFORE IT GETS CAUGHT UP IN THE NORTHWEST FLOW. MODELS ARE IN GOOD
AGREEMENT TRACKING THE SHORTWAVE INTO EASTERN SOUTH DAKOTA BY 12Z
SATURDAY. THIS TRACK DOES HELP TO SPREAD HIGHER PRECIPITABLE WATER
TOWARDS THE AREA...WITH VALUES INCREASING TO 1.5-1.75 INCHES ALONG
AND WEST OF THE MS RIVER FOR TONIGHT. HOWEVER...THE SLOW PROGRESSION
OF THE SHORTWAVE...COMBINED WITH THE NOSE OF 850MB MOISTURE
TRANSPORT PROGGED TO REMAIN MOSTLY WEST OF I-35 SUGGESTS A VERY LOW
PROBABILITY OF ANY PRECIPITATION FOR THE FORECAST AREA. THE 15.00Z
NAM...GFS...HIRES-ARW/NMM...NSSL WRF AND ECMWF DEPICT LITTLE IF ANY
PRECIPITATION...LEADING TO HIGHER CONFIDENCE OF A DRY FORECAST.
REALLY ONLY SMALL PRECIPITATION POTENTIAL WOULD BE...
1. THIS MORNING IN A SECTION OF NORTHEAST IOWA FROM THE
PRECIPITATION OFF TO OUR WEST TRYING TO PUSH IN.
2. ALONG THE MS RIVER WHERE THE HRRR/HIRES-ARW/NMM/NSSL WRF ALL
DEPICT A WEAK BAND OF SHOWERS OR SPRINKLES. APPEARS TO BE
CORRELATED WITH A VERY WEAK SHORTWAVE DROPPING DOWN OUT OF THE DLH
AREA.
3. LATE TONIGHT...WEAK ISENTROPIC LIFT MAY BE ABLE TO INITIATE
SOME SHOWERS OVER FAR NORTHEAST IA AND SOUTHWEST
WISCONSIN...SIMILAR TO THE 15.00Z ECMWF/NSSL WRF-ARW.
925MB TEMPS ARE PROGGED TO BE ABOUT 2C WARMER BY 00Z TODAY COMPARED
TO 00Z YESTERDAY...SO WE SHOULD BE ABLE TO TACK ON A FEW DEGREES TO
YESTERDAYS HIGHS. HOWEVER...CLOUD COVER MAY HOLD TEMPERATURES BACK
SOME...PARTICULARLY ACROSS NORTHEAST IOWA. WITH HIGHER PRECIPITABLE
WATER VALUES IN PLACE TONIGHT ALONG WITH SOME CLOUD COVER...MOST
LOCATIONS WILL SEE A WARMER NIGHT. EVEN SO...CENTRAL WISCONSIN LOOKS
TO CONTINUE TO BE THE COOL SPOT WITH THE DRIEST AIR PRESENT THERE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 306 AM CDT FRI AUG 15 2014
THE WEEKEND FORECAST LOOKS TO BE DOMINATED BY TWO FEATURES. FIRST...
THE SHORTWAVE TROUGH OVER EASTERN SOUTH DAKOTA AT 12Z SATURDAY...
WHICH LOOKS TO UNDER CUT THE FORECAST AREA BY HEADING ROUGHLY
THROUGH IOWA ON SUNDAY. SIMILAR TO THE SHORT TERM PERIOD...GIVEN THE
SLOW PROGRESSION OF THE SHORTWAVE KEEPING THE DYNAMICS TO THE
WEST...AND THE 850MB MOISTURE TRANSPORT NOSE AHEAD OF IT STAYING
NEAR OR SOUTH OF I-80...BELIEVE MUCH OF ITS PRECIPITATION SHOULD
STAY TO THE SOUTH OF THE FORECAST AREA. WITH THE SHORTWAVE GETTING
CLOSER ON SUNDAY...ESPECIALLY IN THE 15.00Z GFS...WILL HAVE TO
MAINTAIN SOME LOW CHANCES OF SHOWERS/STORMS WEST OF THE MS RIVER AND
SOUTH OF I-90 IN WISCONSIN. THE SECOND FEATURE...A SHORTWAVE TROUGH
DROPPING THROUGH ONTARIO ALLOWS A COLD FRONT TO DROP SOUTH THROUGH
THE FORECAST AREA LATE SATURDAY THROUGH SATURDAY NIGHT. THIS COLD
FRONT...COMBINED WITH DAYTIME HEATING AND SOME MOISTURE PUSHED EAST
INTO THE FORECAST AREA...SHOULD BE ENOUGH TO TRIGGER ISOLATED TO
MAYBE SCATTERED SHOWERS AND THUNDERSTORMS NORTH OF I-94 SATURDAY
AFTERNOON. GIVEN THE NORTHWEST UPPER FLOW AND SOUTHWARD PROGRESSION
OF THE FRONT...THESE MAY TRY TO DROP SOUTH THROUGH THE AREA SATURDAY
NIGHT...PROVIDED THEY DONT FALL APART WITH LOSS OF DAYTIME
INSTABILITY. SATURDAYS HIGHS SHOULD BE CLOSE TO TODAY GIVEN NEARLY
IDENTICAL 925MB TEMPS. WITH THE PASSAGE OF THE COLD FRONT SATURDAY
NIGHT...925MB TEMPS COOLING ABOUT 3C...POTENTIAL FOR A STRATUS DECK
AND A SWITCH TO EASTERLY FLOW...EXPECT COOLER CONDITIONS FOR SUNDAY.
ATTENTION EARLY NEXT WEEK THEN TURNS TO THE UPPER LOW OVER THE
PACIFIC NORTHWEST. THERE IS SURPRISINGLY GOOD MODEL AGREEMENT FOR
THE LOW TO DROP INTO THE FORECAST AREA ON TUESDAY. RETURNING
MOISTURE TRANSPORT AHEAD OF THIS UPPER LOW COMBINED WITH DPVA SHOULD
YIELD SOME SHOWERS AND THUNDERSTORMS...TRACKING INTO AREAS
ALONG/WEST OF THE MISSISSIPPI ON MONDAY AND GRADUALLY ACROSS THE
REST OF THE AREA MONDAY NIGHT AND TUESDAY. HAVE CONTINUED TO MENTION
50-60 PERCENT CHANCES. QUICK SOUNDING CHECK WOULD SUGGEST NO SEVERE
WEATHER DUE TO WEAK SHEAR.
FOR THE MIDDLE OF THE WEEK...THE UPPER LOW GRADUALLY FILLS AND LIFTS
NORTHEAST OUT OF THE REGION...IN RESPONSE TO RIDGING BUILDING UP
OVER THE PLAINS. STILL NEED TO MAINTAIN SOME LOW CHANCES OF
PRECIPITATION ON WEDNESDAY WITH THE UPPER LOW IN THE AREA...AND
ALTHOUGH 500MB HEIGHTS RISE GOING INTO THURSDAY...ITS ALSO
ACCOMPANIED BY WARM/MOIST AIR ADVECTION. THEREFORE...CHANCES OF
SHOWERS AND STORMS CONTINUE INTO THURSDAY. THE WARM ADVECTION WILL
BE ENOUGH TOO TO SEND TEMPERATURES ABOVE NORMAL FOR THURSDAY AFTER
GENERALLY HOLDING NEAR OR BELOW NORMAL UNTIL THEN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1143 PM CDT THU AUG 14 2014
THE LARGE AREA OF HIGH PRESSURE REMAINS NEAR THE SOUTHERN TIP OF
LAKE MICHIGAN THIS EVENING. THE HIGH WILL CONTINUE TO SLOWLY
SLIDE OFF TO THE SOUTHEAST THROUGH THE PERIOD AS WEAK SHORT WAVE
TROUGHS MOVE OVER THE REGION. ONE OF THESE SHORT WAVE TROUGHS WAS
OVER SOUTH DAKOTA WHERE SCATTERED SHOWERS AND STORMS WERE
OCCURRING. THE 15.00Z NAM CONTINUES TO SHOW THIS WAVE MOVING BY
WEST OF THE AREA LATE TONIGHT INTO FRIDAY MORNING WITH THE SHOWERS
ALSO STAYING WEST OF THE AREA. EARLIER RUNS OF THE HRRR SUGGESTED
SOME OF THESE SHOWERS COULD POSSIBLY GET INTO THE AREA BUT
SUBSEQUENT RUNS THIS EVENING...WITH THE 15.03Z BEING THE
LATEST...ALL SHOW THIS STAYING WEST OF THE AREA SIMILAR TO THE
NAM. ADDITIONAL ACTIVITY SHOULD DEVELOP FRIDAY WITH THIS SHORT
WAVE TROUGH...BUT BY THEN IT SHOULD BE FAR ENOUGH SOUTH THAT IT
WILL NOT IMPACT EITHER TAF. THEREFORE...EXPECTING VFR CONDITIONS
THROUGH THE PERIOD WITH A MID LEVEL CEILING MOVING IN LATE TONIGHT
OR FRIDAY MORNING WITH THE PASSAGE OF THE SHORT WAVE TROUGH.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1143 PM CDT THU AUG 14 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 236 PM CDT THU AUG 14 2014
AT 3 PM...WHILE A 1020 MB HIGH PRESSURE IS PROVIDING PARTLY TO
MOSTLY SUNNY SKIES ACROSS THE LOCAL AREA...MODERATE TO STRONG 900
TO 500 MB FRONTOGENESIS IS PRODUCING A BAND OF SHOWERS AND
THUNDERSTORMS ACROSS EASTERN SOUTH DAKOTA AND NORTHWEST IOWA.
THE 14.12Z DETERMINISTIC AND MESO MODELS SHOW THAT THE 900 TO
500 MB FRONTOGENETIC FORCING AND MODERATE TO STRONG 310K
ISENTROPIC LIFT WILL SLOWLY EAST ACROSS SOUTHWEST MINNESOTA AND
WESTERN IOWA TONIGHT...AND INTO SOUTHEAST MINNESOTA AND NORTHEAST
IOWA ON FRIDAY. THIS IS SLIGHTLY SLOWER THAN PREVIOUS MODEL
SOLUTIONS...SO KEPT OUR AREA DRY TONIGHT AND THEN KEPT THE RAIN
CHANCES IN THE 20 TO 40 PERCENT RANGE MAINLY WEST OF THE
MISSISSIPPI RIVER ON FRIDAY. HOWEVER AM A BIT CONCERNED THAT WITH
THE WESTWARD TREND IN THE MODELS AND DRY LOW LEVELS THAT THESE
PRECIPITATION CHANCES MAY HAVE TO BE SHIFTED A BIT FURTHER WEST.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 236 PM CDT THU AUG 14 2014
ON FRIDAY NIGHT AND SATURDAY...THE MODELS CONTINUE TO SHOW THAT A
WEAKENING BACKDOOR DOOR COLD FRONT WILL MOVE SOUTH ACROSS
WISCONSIN...AND THE FRONTOGENETIC FORCING TO OUR SOUTH WILL
SLOWLY SHIFT SOUTH AND WEST AS A LOW PRESSURE SYSTEM MOVES
SOUTHEAST OUT OF SOUTH DAKOTA. DEPENDING ON HOW THIS EVOLVES...WE
MAY END UP WITH THE BEST CHANCES OF SHOWERS AND STORMS ALONG AND
NORTH OF INTERSTATE 94...AND ACROSS NORTHEAST IOWA AND SOUTHWEST
WISCONSIN. ELSEWHERE THERE IS A POSSIBILITY THAT THESE AREAS MAY
GET MISSED BY THE PRECIPITATION. THIS IS DUE TO THE SUBSIDENCE
BETWEEN THESE TWO SYSTEMS. THE 14.18Z NAM JUST CAME IN AND IT
SHOWS THAT THE 310K ISENTROPIC LIFT AND MOISTURE TRANSPORT IS MUCH
FURTHER SOUTHWEST...SO THERE ARE QUESTIONS ON WHETHER THE
PRECIPITATION CHANCES IN OUR SOUTH AND WEST MAY BE TOO HIGH.
ON SATURDAY NIGHT AND SUNDAY...THE MODELS CONTINUE TO SHOW THAT
A LOW PRESSURE SYSTEM WILL MOVE SOUTHEAST ACROSS IOWA. AS THIS LOW
MOVES INTO SOUTHEAST IOWA...DRIER AIR WILL ADVECT INTO THE AREA
FROM THE NORTHEAST. BOTH THE GFS AND ECMWF ARE SHOWING THIS WELL
IN THEIR SURFACE DEW POINTS. MEANWHILE THE NAM IS HOLDING ONTO THE
MID AND UPPER 60 DEW POINTS. SINCE THE NAM IS TYPICALLY TOO HIGH
WITH ITS DEW POINTS IN THESE SITUATIONS...PREFER THE DRIER GFS AND
ECMWF SOLUTIONS.
FROM MONDAY NIGHT INTO WEDNESDAY...THERE CONTINUES TO BE SOME GOOD
CONSISTENCY THAT A TROUGH OR CLOSED LOW WILL MOVE SLOWLY EAST
THROUGH THE AREA. THE MODEL CONSENSUS ALREADY HAS FAIRLY HIGH /40
TO 60 PERCENT/ PRECIPITATION CHANCES FOR THIS TIME PERIOD...SO
MADE NO CHANGES TO IT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1143 PM CDT THU AUG 14 2014
THE LARGE AREA OF HIGH PRESSURE REMAINS NEAR THE SOUTHERN TIP OF
LAKE MICHIGAN THIS EVENING. THE HIGH WILL CONTINUE TO SLOWLY
SLIDE OFF TO THE SOUTHEAST THROUGH THE PERIOD AS WEAK SHORT WAVE
TROUGHS MOVE OVER THE REGION. ONE OF THESE SHORT WAVE TROUGHS WAS
OVER SOUTH DAKOTA WHERE SCATTERED SHOWERS AND STORMS WERE
OCCURRING. THE 15.00Z NAM CONTINUES TO SHOW THIS WAVE MOVING BY
WEST OF THE AREA LATE TONIGHT INTO FRIDAY MORNING WITH THE SHOWERS
ALSO STAYING WEST OF THE AREA. EARLIER RUNS OF THE HRRR SUGGESTED
SOME OF THESE SHOWERS COULD POSSIBLY GET INTO THE AREA BUT
SUBSEQUENT RUNS THIS EVENING...WITH THE 15.03Z BEING THE
LATEST...ALL SHOW THIS STAYING WEST OF THE AREA SIMILAR TO THE
NAM. ADDITIONAL ACTIVITY SHOULD DEVELOP FRIDAY WITH THIS SHORT
WAVE TROUGH...BUT BY THEN IT SHOULD BE FAR ENOUGH SOUTH THAT IT
WILL NOT IMPACT EITHER TAF. THEREFORE...EXPECTING VFR CONDITIONS
THROUGH THE PERIOD WITH A MID LEVEL CEILING MOVING IN LATE TONIGHT
OR FRIDAY MORNING WITH THE PASSAGE OF THE SHORT WAVE TROUGH.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
AREA FORECAST DISCUSSION
NWS TUCSON AZ
903 AM MST FRI AUG 15 2014
.SYNOPSIS...THUNDERSTORM CHANCES REMAIN IN THE FORECAST INTO EARLY
NEXT WEEK. SOME STORMS WILL PRODUCE HEAVY RAIN THAT MAY LEAD TO
FLOODING.
&&
.DISCUSSION...THUNDERSTORMS ONGOING THIS MORNING TRIGGERED BY
SHORT WAVE TROUGH DISTINCTLY SHOWING UP ON WATER VAPOR IMAGERY
TRACKING EASTWARD. HAVE RAISED POPS FROM TUCSON EASTWARD THIS
MORNING AS A RESULT. HRRR AND 12Z NAM PICKING UP ON THIS. THEY ARE
ALSO INDICATING THAT MID LEVEL FLOW WILL BECOME NORTHEASTERLY BEHIND
THIS SYSTEM AND SHOW STORMS MOVING OFF THE RIM TOWARD THE SW DURING
THE LATE AFTERNOON HOURS TODAY. THUS HAVE RAISED POPS A BIT TO THE
EAST THIS AFTERNOON AS WELL. HAVE LOWERED TEMPERATURES A FEW
DEGREES...ESPECIALLY IN EASTERN AREAS WHERE CLOUDS AND STORMS WILL
RESIDE FOR A LONGER TIME TODAY...KD
&&
.AVIATION...VALID THRU 16/18Z.
ISOLATED TO SCATTERED TSRA ARE EXPECTED THROUGH THIS
EVENING...ESPECIALLY EAST OF A LINE FROM KOLS-KTUS-KSOW. SOME TSRA
WILL PRODUCE LOCAL IFR CONDITIONS IN +RA ALONG WITH GUSTS TO 45 KTS.
OTHERWISE...SURFACE WIND WILL GENERALLY BE LESS THAN 10 KTS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...DAILY ROUNDS OF THUNDERSTORMS WILL CONTINUE INTO
NEXT WEEK ACROSS AT LEAST PARTS OF SOUTHEAST ARIZONA. HEAVY
RAINS...LIGHTNING AND OUTFLOW WINDS WILL BE THE MAIN THUNDERSTORM
IMPACTS.
&&
.PREV DISCUSSION...ENOUGH MOISTURE WILL RESIDE ACROSS SOUTHEAST
ARIZONA THROUGH THE WEEKEND FOR SCATTERED AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS. REALLY CAN`T PICK OUT WHICH DAY WILL BE
THE MOST ACTIVE. HOWEVER MODELS ARE SUGGESTING THAT THE
INTERNATIONAL BORDER AREAS WILL HAVE THE BEST CHANCES FOR
THUNDERSTORMS...SOME WITH HEAVY RAIN. HIGHS WILL GENERALLY BE
SEVERAL DEGREES ABOVE NORMAL.
MOISTURE INCREASING NEXT WEEK UNDER SOUTHERLY FLOW ALOFT WITH LOW
PRESSURE TO OUR WEST AND HIGH PRESSURE TO THE EAST.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PUEBLO CO
746 AM MDT FRI AUG 15 2014
.UPDATE...
ISSUED AT 745 AM MDT FRI AUG 15 2014
BLENDED LATEST OBSERVATIONS INTO FRONT END OF FORECAST GRIDS. ALSO
TWEAKED SKY COVER TO FIT LATEST SATELLITE TRENDS. NO OTHER CHANGES
AT THIS TIME.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM MDT FRI AUG 15 2014
...MONSOONAL AIR MASS REMAINS BUT LESS OF A TRIGGER THAN YESTERDAY...
THE AIR MASS OVER THE REGION REMAINS PLENTY MOIST...BUT THERE IS NOT
SO MUCH OF TRIGGER TO GET THINGS GOING TODAY AS YESTERDAY.
YESTERDAY...A FAIRLY STRONG SHORTWAVE MOVED THROUGH NORTHERN
COLORADO...TRIGGERING SOME RATHER INTENSE RAINFALL OVER THE PIKES
PEAK REGION...WITH GENERALLY WEAKER ACTIVITY ELSEWHERE. TODAY...THE
OVERALL AIR MASS IS SIMILAR BUT THERE DOESN`T SEEM TO BE AS MUCH OF A
DISTURBANCE AVAILABLE TO GET THINGS GOING.
WATER VAPOR PICTURES THIS MORNING DO SHOW A SWIRL IN THE IMAGERY
OVER NORTHWEST ARIZONA AND THE RUC DOES IDENTIFY A WEAK DEPRESSION
ASSOCIATED WITH THIS SWIRL. HOWEVER...SHORT TERM MODELS DON`T DO
MUCH WITH THE DEPRESSION THROUGH THE DAY. THE NAM12 DOES HINT AT A
VERY WEAK PIECE OF ENERGY ROUNDING THE TOP OF THE RIDGE THIS
AFTERNOON AND THEN DROPPING SOUTHEAST THROUGH THE PLAINS THIS
EVENING. THIS MIGHT BE A PIECE OF THE ENERGY NEAR THE 4 CORNERS
REGION...OR IT MIGHT JUST BE MODEL FEEDBACK TO CONVECTION DEVELOPING
OVER THE MOUNTAINS. IN ANY EVENT...IT DOESN`T LOOK NEARLY AS STRONG
AS YESTERDAY`S SHORTWAVE. SO...EXPECTING TODAY`S CONVECTION TO BE
MORE TERRAIN DRIVEN...DEVELOPING OVER THE MOUNTAINS BY EARLY
AFTERNOON...BEFORE DRIFTING SOUTHEASTWARD ACROSS THE PLAINS LATER IN
THE AFTERNOON INTO THE EVENING.
WITH THE MONSOON PLUME REMAINING OVER THE REGION...AND SURFACE
DEWPOINTS REMAINING HIGH...THE POTENTIAL FOR ANY GIVEN THUNDERSTORM
TO PRODUCE LOCALIZED FLASH FLOODING WILL CONTINUE...NOT ONLY FOR THE
BURN SCARS...BUT FOR ANYWHERE AN INTENSE...SLOW MOVING STORM HAPPENS
TO TRACK. THIS WILL BE THE PRIMARY WEATHER CONCERN TODAY...ALONG
WITH LIGHTNING AND THE POSSIBILITY OF LOCAL THUNDERSTORM WIND BURSTS
TO 40 OR 50 MPH. LW
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 400 AM MDT FRI AUG 15 2014
MODELS STRUGGLING WITH THE EXTENDED PERIOD WITH RUN TO RUN
INCONSISTENCIES...AND HAVE NOT MADE MANY CHANGES TO THE GOING
FORECAST.
HIGH PRESSURE WILL CONTINUE ACROSS THE DESERT SOUTHWEST THROUGH
EARLY NEXT WEEK WITH SEVERAL WEAK DISTURBANCES PASSING ACROSS
COLORADO. THIS WILL KEEP THE MONSOON LIKE PATTERN GOING ACROSS
THE STATE WITH MOISTURE BEING THE LIMITING FACTOR. EXPECT DAILY
AFTERNOON AND EVENING CONVECTION ACROSS THE MOUNTAINS WHERE
DIURNAL HEATING AND INSTABILITY WILL FAVOR THUNDERSTORM
DEVELOPMENT. WHILE MOISTURE MAY BE MORE LIMITED...THUNDERSTORMS
WILL STILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL...AND
FLASH FLOODING WILL CONTINUE TO BE AN ISSUE ON AREA BURN SCARS
ALONG WITH AREAS THAT HAVE SEEN RECENT HEAVY RAIN. LESS CERTAINTY
EXISTS ON THE EASTERN PLAINS. THE GFS CONTINUES TO PRODUCE DAILY
ROUNDS OF THUNDERSTORMS THAT MOVE OFF THE MOUNTAINS AND INTO THE
PLAINS EACH NIGHT. THE NAM AND ECMWF ARE LESS EXCITED ABOUT SHOWER
AND THUNDERSTORM ACTIVITY ACROSS THE PLAINS. FOR NOW HAVE LOW POPS
THROUGH THE EVENING HOURS FOR THE PLAINS GIVEN THE UNCERTAINTY.
CURRENT MODEL PROJECTIONS HAVE DECENT WAVES MOVING ACROSS THE
REGION SUNDAY AND TUESDAY...WHICH MAY BE THE DAYS THAT SEE THE
GREATEST THUNDERSTORM POTENTIAL FOR THE PLAINS.
LACK OF MODEL CONSISTENCY BY LATE TUESDAY THROUGH THURSDAY LEADS
TO LOW FORECAST CONFIDENCE. THE 00Z GFS DROPPED A LOW PRESSURE
CENTER DOWN THE CALIFORNIA COAST...WITH A STRONG TROUGH DIGGING
ACROSS THE PACIFIC NORTHWEST. A QUICK GLANCE OF THE 06Z RUN DOES
NOT HAVE THIS LOW AT ALL...WITH A MORE BROAD PACIFIC NORTHWEST
TROUGH. GIVEN THESE INCONSISTENCIES...HAVE CONTINUED THE LOW POPS
ACROSS THE REGION ON WEDNESDAY AND THURSDAY...BUT THESE WILL NEED
TO BE ADJUSTED BASED ON FUTURE MODEL GUIDANCE.
TEMPERATURES WILL REMAIN WARM THROUGH THE EXTENDED PERIOD WITH
UPPER 80S TO MID 90S ACROSS THE LOWER ELEVATIONS. MOZLEY
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 400 AM MDT FRI AUG 15 2014
MONSOON MOISTURE PLUME REMAINS OVER FLIGHT AREA TODAY. UNLIKE
YESTERDAY...THERE IS NOT MUCH OF A DISTURBANCE MOVING THROUGH TO
HELP TRIGGER CONVECTION TODAY. HOWEVER...THE MOUNTAINS WILL BE A
SUFFICIENT TRIGGER FOR AREAS IN A NEAR THE HIGHER TERRAIN...WITH
SOME ACTIVITY DRIFTING SOUTHEAST ACROSS THE PLAINS DURING THE LATE
AFTERNOON AND EVENING HOURS.
PRIMARY STORM HAZARDS TODAY WILL INCLUDE LOCALIZED FLASH FLOODING...
LIGHTNING AND WIND GUSTS UP TO 50 MPH. WITH COVERAGE TIED MOSTLY TO
THE MOUNTAINS...KCOS IS THE MOST LIKELY TARGET FOR A THUNDERSTORM
TODAY...WHILE KALS AND KPUB MAY BE FAR ENOUGH REMOVED FROM THE
TERRAIN TO AVOID CONVECTION. SO...FOR NOW...WILL CONTINUE WITH
CURRENT TERMINAL FORECAST OF POSSIBLE VCTS AT KCOS AFTER 21 OR
22Z...AND KEEP THUNDERSTORMS OUT OF THE FORECAST AT KALS AND KPUB.
LOCAL MVFR/IFR/LIFR CONDITIONS POSSIBLE WITH ANY THUNDERSTORMS
ACROSS THE AREA...PRIMARILY 18Z-06Z. LW
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...LW
SHORT TERM...LW
LONG TERM...MOZLEY
AVIATION...LW
AREA FORECAST DISCUSSION
NWS PUEBLO CO
431 AM MDT FRI AUG 15 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM MDT FRI AUG 15 2014
...MONSOONAL AIR MASS REMAINS BUT LESS OF A TRIGGER THAN YESTERDAY...
THE AIR MASS OVER THE REGION REMAINS PLENTY MOIST...BUT THERE IS NOT
SO MUCH OF TRIGGER TO GET THINGS GOING TODAY AS YESTERDAY.
YESTERDAY...A FAIRLY STRONG SHORTWAVE MOVED THROUGH NORTHERN
COLORADO...TRIGGERING SOME RATHER INTENSE RAINFALL OVER THE PIKES
PEAK REGION...WITH GENERALLY WEAKER ACTIVITY ELSEWHERE. TODAY...THE
OVERALL AIR MASS IS SIMILAR BUT THERE DOESN`T SEEM TO BE AS MUCH OF A
DISTURBANCE AVAILABLE TO GET THINGS GOING.
WATER VAPOR PICTURES THIS MORNING DO SHOW A SWIRL IN THE IMAGERY
OVER NORTHWEST ARIZONA AND THE RUC DOES IDENTIFY A WEAK DEPRESSION
ASSOCIATED WITH THIS SWIRL. HOWEVER...SHORT TERM MODELS DON`T DO
MUCH WITH THE DEPRESSION THROUGH THE DAY. THE NAM12 DOES HINT AT A
VERY WEAK PIECE OF ENERGY ROUNDING THE TOP OF THE RIDGE THIS
AFTERNOON AND THEN DROPPING SOUTHEAST THROUGH THE PLAINS THIS
EVENING. THIS MIGHT BE A PIECE OF THE ENERGY NEAR THE 4 CORNERS
REGION...OR IT MIGHT JUST BE MODEL FEEDBACK TO CONVECTION DEVELOPING
OVER THE MOUNTAINS. IN ANY EVENT...IT DOESN`T LOOK NEARLY AS STRONG
AS YESTERDAY`S SHORTWAVE. SO...EXPECTING TODAY`S CONVECTION TO BE
MORE TERRAIN DRIVEN...DEVELOPING OVER THE MOUNTAINS BY EARLY
AFTERNOON...BEFORE DRIFTING SOUTHEASTWARD ACROSS THE PLAINS LATER IN
THE AFTERNOON INTO THE EVENING.
WITH THE MONSOON PLUME REMAINING OVER THE REGION...AND SURFACE
DEWPOINTS REMAINING HIGH...THE POTENTIAL FOR ANY GIVEN THUNDERSTORM
TO PRODUCE LOCALIZED FLASH FLOODING WILL CONTINUE...NOT ONLY FOR THE
BURN SCARS...BUT FOR ANYWHERE AN INTENSE...SLOW MOVING STORM HAPPENS
TO TRACK. THIS WILL BE THE PRIMARY WEATHER CONCERN TODAY...ALONG
WITH LIGHTNING AND THE POSSIBILITY OF LOCAL THUNDERSTORM WIND BURSTS
TO 40 OR 50 MPH. LW
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 400 AM MDT FRI AUG 15 2014
MODELS STRUGGLING WITH THE EXTENDED PERIOD WITH RUN TO RUN
INCONSISTENCIES...AND HAVE NOT MADE MANY CHANGES TO THE GOING
FORECAST.
HIGH PRESSURE WILL CONTINUE ACROSS THE DESERT SOUTHWEST THROUGH
EARLY NEXT WEEK WITH SEVERAL WEAK DISTURBANCES PASSING ACROSS
COLORADO. THIS WILL KEEP THE MONSOON LIKE PATTERN GOING ACROSS
THE STATE WITH MOISTURE BEING THE LIMITING FACTOR. EXPECT DAILY
AFTERNOON AND EVENING CONVECTION ACROSS THE MOUNTAINS WHERE
DIURNAL HEATING AND INSTABILITY WILL FAVOR THUNDERSTORM
DEVELOPMENT. WHILE MOISTURE MAY BE MORE LIMITED...THUNDERSTORMS
WILL STILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL...AND
FLASH FLOODING WILL CONTINUE TO BE AN ISSUE ON AREA BURN SCARS
ALONG WITH AREAS THAT HAVE SEEN RECENT HEAVY RAIN. LESS CERTAINTY
EXISTS ON THE EASTERN PLAINS. THE GFS CONTINUES TO PRODUCE DAILY
ROUNDS OF THUNDERSTORMS THAT MOVE OFF THE MOUNTAINS AND INTO THE
PLAINS EACH NIGHT. THE NAM AND ECMWF ARE LESS EXCITED ABOUT SHOWER
AND THUNDERSTORM ACTIVITY ACROSS THE PLAINS. FOR NOW HAVE LOW POPS
THROUGH THE EVENING HOURS FOR THE PLAINS GIVEN THE UNCERTAINTY.
CURRENT MODEL PROJECTIONS HAVE DECENT WAVES MOVING ACROSS THE
REGION SUNDAY AND TUESDAY...WHICH MAY BE THE DAYS THAT SEE THE
GREATEST THUNDERSTORM POTENTIAL FOR THE PLAINS.
LACK OF MODEL CONSISTENCY BY LATE TUESDAY THROUGH THURSDAY LEADS
TO LOW FORECAST CONFIDENCE. THE 00Z GFS DROPPED A LOW PRESSURE
CENTER DOWN THE CALIFORNIA COAST...WITH A STRONG TROUGH DIGGING
ACROSS THE PACIFIC NORTHWEST. A QUICK GLANCE OF THE 06Z RUN DOES
NOT HAVE THIS LOW AT ALL...WITH A MORE BROAD PACIFIC NORTHWEST
TROUGH. GIVEN THESE INCONSISTENCIES...HAVE CONTINUED THE LOW POPS
ACROSS THE REGION ON WEDNESDAY AND THURSDAY...BUT THESE WILL NEED
TO BE ADJUSTED BASED ON FUTURE MODEL GUIDANCE.
TEMPERATURES WILL REMAIN WARM THROUGH THE EXTENDED PERIOD WITH
UPPER 80S TO MID 90S ACROSS THE LOWER ELEVATIONS. MOZLEY
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 400 AM MDT FRI AUG 15 2014
MONSOON MOISTURE PLUME REMAINS OVER FLIGHT AREA TODAY. UNLIKE
YESTERDAY...THERE IS NOT MUCH OF A DISTURBANCE MOVING THROUGH TO
HELP TRIGGER CONVECTION TODAY. HOWEVER...THE MOUNTAINS WILL BE A
SUFFICIENT TRIGGER FOR AREAS IN A NEAR THE HIGHER TERRAIN...WITH
SOME ACTIVITY DRIFTING SOUTHEAST ACROSS THE PLAINS DURING THE LATE
AFTERNOON AND EVENING HOURS.
PRIMARY STORM HAZARDS TODAY WILL INCLUDE LOCALIZED FLASH FLOODING...
LIGHTNING AND WIND GUSTS UP TO 50 MPH. WITH COVERAGE TIED MOSTLY TO
THE MOUNTAINS...KCOS IS THE MOST LIKELY TARGET FOR A THUNDERSTORM
TODAY...WHILE KALS AND KPUB MAY BE FAR ENOUGH REMOVED FROM THE
TERRAIN TO AVOID CONVECTION. SO...FOR NOW...WILL CONTINUE WITH
CURRENT TERMINAL FORECAST OF POSSIBLE VCTS AT KCOS AFTER 21 OR
22Z...AND KEEP THUNDERSTORMS OUT OF THE FORECAST AT KALS AND KPUB.
LOCAL MVFR/IFR/LIFR CONDITIONS POSSIBLE WITH ANY THUNDERSTORMS
ACROSS THE AREA...PRIMARILY 18Z-06Z. LW
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...LW
LONG TERM...MOZLEY
AVIATION...LW
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
910 AM EDT FRI AUG 15 2014
.DISCUSSION...
CURRENT-THIS AFTERNOON...THE 8AM/12Z SOUNDINGS INDICATED THAT THE
PRECIPITABLE WATER VALUES FOR CENTRAL FLORIDA CONTINUE TO ABOVE 2
INCHES MEANING A VERY MOIST ATMOSPHERE. NOTED THAT THE 15/06Z GFS
POSITIONED THE 1000-500MB RELATIVE HUMIDITY A LITTLE FURTHER SOUTH
THAN PREVIOUS DAYS. BOTH THE MORNING SOUNDINGS FOR CENTRAL AND SOUTH
FLORIDA AND THE VERTICAL WIND PROFILER(S) AT THE SPACE CENTER SHOW
DEEP LAYER ...SURFACE TO 500MB...WESTERLY FLOW. THE TROUGHING
ASSOCIATED WITH AN UPPER LEVEL LOW OVER CANADA EXTENDS OVER THE
EASTERN THIRD OF THE U.S. AND INTO THE NORTHEAST GULF MEXICO
CONTINUES TO KEEP THE LOW AND MID LEVEL RIDGE SUPPRESSED TO THE
SOUTH OVER THE CENTRAL BAHAMA ISLAND SOUTH FLORIDA AND THE FLORIDA
STRAIT FOR ANOTHER DAY. THE CIRRUS AND MID LEVEL CLOUDINESS FROM
LATE NIGHT AND EARLY MORNING STORMS STREAMING OVERHEAD MAY DELAY
DAYTIME HEATING FOR THE MORNING AND DELAY ONSET OF HIGHER COVERAGE
OF STORMS FOR THE AFTERNOON.
TIMING OF THE WEATHER FOR THE REST OF THE DAY LOOKS REASONABLE BASED
ON TRENDS OBSERVED FOR THE PAST 2 TO 3 DAYS.
ZONE UPDATE WILL ADDRESS CHANGES TO THE VARIOUS WIND GRIDS AND MAX
TEMPERATURES FOR THIS AFTERNOON IF THE CIRRUS AND MID LEVEL
CLOUDINESS LOOKS LIKE IT WILL PLAY A SIGNIFICANT ROLE IN HINDERING
DAYTIME HEATING.
PREVIOUS ZONES DISCUSSION
TODAY...NOT MUCH CHANGE IN THE PATTERN FROM YESTERDAY WITH A STALLED
FRONT ACROSS SE GA INTO THE FL PANHANDLE. LOW-MID LVL WSW WINDS WILL
CONTINUE WITH DEEP MOISTURE OVER THE AREA AS PRECIPITABLE WATER
VALUES ARE FORECAST FROM FROM 2.0 TO 2.2 INCHES. SHORT RANGE MODELS
ALSO INDICATE MID LVL IMPULSES WILL TRAVERSE THE NRN/CENTRAL FL
PENINSULA TODAY LEADING TO SOME CONVECTIVE ORGANIZATION AS STORMS
MAKE THEIR WAY FROM THE WEST TO EAST ACROSS THE AREA. HRRR AND SPC
WRF RUN THIS MORNING INDICATE CONVECTION DEVELOPING TO OUR WEST BY
LATE MORNING AND MOVING TOWARD THE ORLANDO METRO BY EARLY AFTERNOON.
STORMS SHOULD THEN APPROACH CSTL VOLUSIA AND BREVARD COUNTY BY MID
AFTERNOON AND TOWARD THE TREASURE COAST INTO THE MID TO LATE
AFTERNOON HOURS. THE EAST COAST SEA BREEZE WILL LIKELY DEVELOP FROM
VERO BEACH SOUTH TO STUART AND INCH ONLY SLOWLY INLAND FROM THE
COAST. STORMS WILL MOVE EAST AROUND 15 MPH. THE PRIMARY THUNDERSTORM
HAZARDS WILL BE LOCALLY HEAVY RAIN...GUSTY WINDS AND FREQUENT
LIGHTNING. HIGHS WILL BE MAINLY AROUND 90 TO THE LOWER 90S.
TONIGHT...THERE WILL BE A CHANCE FOR EARLY EVENING STORMS POSSIBLY
MORE CONCENTRATED NEAR THE TREASURE COAST WHERE STORMS MAY LINGER
FROM LATE AFTN INTO THE EVENING. SW LOW LVL FLOW SHOULD PUSH MOST OF
THE ACTIVITY INTO THE ATLC BY LATE EVENING. LOWS WILL BE IN THE
LOWER TO MID 70S.
SAT...NOT MUCH CHANGE AS DEEP MOISTURE (PWATS AROUND 2 INCHES) IS
PROGGED TO CONTINUE ESPECIALLY ACROSS NORTHERN HALF OF FA. FAST
W/SW FLOW ALONG WITH A MID LEVEL IMPULSE SHOULD PRODUCE AN EARLY
START TO SHOWERS AND STORMS DURING THE MORNING ESP NORTH OF
ORLANDO. SHOULD SEE AN AFTERNOON SEA BREEZE DEVELOP WITH SOME
INLAND PENETRATION ACROSS MARTIN AND ST LUCIE COUNTIES BUT IT IS
NOT EXPECTED TO PUSH VERY FAR INLAND NORTH OF THE CAPE. HIGHEST
STORM CHANCES APPEAR TO BE LATE IN THE AFTN ASSOCD WITH A SEA
BREEZE COLLISION EXTENDING FROM COASTAL VOLUSIA SOUTHWARD TO LAKE
OKEECHOBEE. HAVE DRAWN 50 POPS NORTH AND 40 POPS SOUTH. HIGH
TEMPERATURES AROUND 90/LWR 90S NEAR THE COAST TO LWR-MID 90S OVER
THE INTERIOR. LOWS WILL BE IN THE 70S.
SUN...THE LOW LVL RIDGE AXIS WILL LIFT NORTHWARD T0 LAKE
OKEECHOBEE. THIS WILL REDUCE THE LOW LVL WESTERLY FLOW ACROSS
THE SOUTH WHICH WILL ALLOW AN EARLIER ONSET OF THE SEA BREEZE
SOUTH OF THE CAPE. RAIN CHANCES WILL BE LOWER DUE TO DECREASING
MOISTURE LEVELS AND LITTLE UPPER SUPPORT. FOCUS FOR STORMS WILL BE
OVER THE INTERIOR WITH PUSH BACK TO THE EAST COAST BUT COVERAGE
LOOKS LOWER THAN PREVIOUS DAYS AT 30 TO 40 PERCENT. INTERIOR
SECTIONS WILL BE A DEGREE OR TWO HOTTER GIVEN MORE SUN AND LESS
COVERAGE OF STORMS.
MON-THU...THE GFS AND ECMWF SHOW A DRYING TREND WITH DECREASING
MOISTURE IN THE H8-H5 LAYER. HAVE LOWERED RAIN CHANCES TO 20 PCT
TUE-WED AND 30 PERCENT THU. THIS MEANS HIGH TEMPERATURES WILL BE
HOT...SOLIDLY IN THE MID 90S INTERIOR AND POSSIBLY VOLUSIA
COAST...LOWER 90S SOUTH OF THE CAPE.
&&
.AVIATION...
CURRENT...FIRST ROUND OF STORMS PUSHED THROUGH THE WESTERN TAF SITES
BY 12. NEXT ROUND OF SCATTERED STORMS MOVING ACROSS THE EASTERN GULF
AND WEST COAST OF FLORIDA FROM CEDAR KEY TO PUNTA GORDA PER RADAR.
TEMPO MVFR CEILINGS AND VISIBILITIES ALL DAY AS STORMS MOVE WEST TO
EAST AT 15 KNOTS. STRONGER STORMS POSSIBLE AT THE COAST MELBOURNE
SOUTH AS EXISTING STORMS INTERACT WITH ANY SEA BREEZES TRYING FORM
AT THE COAST.
PREVIOUS AVIATION DISCUSSION
SCT-NMRS TSRA WILL DVLP AND MOVE EASTWARD ACROSS E CENTRAL FL
THIS AFTN. EXPECT CONVECTION TO AFFECT NRN INTERIOR TERMINALS
INCLUDING KMCO FROM 18Z-20Z...WITH STORMS THEN PUSHING TWD THE
KDAB-KMLB BY 18Z-21Z. STORMS MAY MOVE IN FROM THE WEST AND DVLP
NEAR THE EAST COAST SEA BRZ BOUNDARY FROM 19Z-23Z FROM KVRB-KSUA.
MAINLY VFR WX AFT 01Z.
&&
.MARINE...
CURRENT-THIS AFTERNOON...NOAA BUOYS 009 AND 010 RECORDING SOUTHWEST
WINDS THAT WERE AVERAGING 10 TO 15 KNOTS AND 2 TO 3 FOOT SEAS. CMAN
AND SCRIPPS BUOYS WERE RECORDING SOUTHWEST WINDS TO 10 KNOTS AND 1
FOOT SEAS.
SURFACE RIDGE AXIS REMAINS SOUTH OF THE AREA THUS SOUTHWEST FLOW
CONTINUES. ANY SEA BREEZE SHOULD FORM AT THE COAST SEBASTIAN INLET
SOUTH. INCREASING COVERAGE OF AFTERNOON STORMS MOVING WEST TO EAST
OVER THE MAINLAND LAKES...RIVERS AND CROSSING THE HALIFAX RIVER AND
THE MOSQUITO INDIAN RIVER LAGOONS INTO THE NEARSHORE WATERS LATER
TODAY.
MORNING UPDATE TO THE MARINE FORECAST WILL BE TO THE WIND GRIDS.
PREVIOUS MARINE DISCUSSION
SW WINDS TO AROUND 10 KNOTS WILL BUILD SEAS TO 2-3 FT OFFSHORE BUT
STILL STAY NEAR 1-2 FT ALONG THE IMMEDIATE COAST WITH OFFSHORE FLOW.
EXPECT SHOWERS AND LIGHTNING STORMS TO AFFECT THE INTRACOASTAL AND
NEAR SHORE ATLANTIC WATERS FROM 2 PM TO 8 PM WITH STRONGER STORMS
CAPABLE OF PRODUCING WINDS ABOVE 35 KNOTS.
WEEKEND...SURFACE RIDGE AXIS IS FORECAST TO REMAIN SOUTH OF OUR
COASTAL WATERS SAT THEN SLOWLY LIFT NORTH TO LAKE OKEECHOBEE
SUNDAY. PERSISTENT WEST TO SOUTHWEST WINDS 10 TO 15 KNOTS SAT WILL
BRING SCATTERED LIGHTNING STORMS OFF THE COAST DURING THE AFTN/EVE
ALONG WITH GUSTY WINDS. OFFSHORE FLOW WEAKENS SUNDAY SOUTH OF
SEBASTIAN INLET WITH LESS STORM ACTIVITY ABLE TO REACH THE
TREASURE COAST. BUT STRONGER OFFSHORE STEERING FLOW WILL BRING
SCATTERED STORMS OFFSHORE VOLUSIA AND BREVARD COUNTIES AGAIN LATE
SUNDAY.
MON-TUE...SOUTH TO SOUTHWEST FLOW WILL TURN SE NEAR THE COAST IN A
SEA BREEZE. SOME DRIER AIR SHOULD LIMIT COVERAGE OF STORMS OVER
THE PENINSULA BY TUE BUT THERE WILL BE A THREAT FOR OFFSHORE
MOVING STORMS NORTH OF SEBASTIAN LATE MONDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 90 73 92 75 / 60 30 50 30
MCO 91 74 94 75 / 60 30 50 20
MLB 90 75 92 75 / 60 30 50 30
VRB 90 74 92 75 / 60 30 40 20
LEE 90 75 93 77 / 60 30 50 20
SFB 92 75 95 77 / 60 30 50 20
ORL 91 75 94 78 / 60 30 50 20
FPR 90 74 92 75 / 60 30 40 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
IMPACT WX...LASCODY
PUBLIC SV...GLITTO
FORECASTS...WIMMER
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1102 AM CDT FRI AUG 15 2014
.DISCUSSION...
331 AM CDT
SHORT TERM...THROUGH FRIDAY NIGHT...
FOR THE REMAINDER OF THE NIGHT...WITH THE CENTER OF HIGH PRESSURE
MOVING OVERHEAD...WINDS HAVE BECOME LIGHT AND VARIABLE UNDER MOSTLY
CLEAR SKIES. AN UNSEASONABLY...DRY AIRMASS IS IN PLACE WITH MANY
LOCATIONS EXPECTED TO SEE MIN TEMPS DROP INTO THE MIDDLE TO UPPER
40S. WHILE THIS WILL LIKELY NOT REACH RECORD BREAKING LOW
TEMPERATURES OVERNIGHT...THE LOWS WILL BE AROUND 15 DEGREES BELOW
NORMAL. FRIDAY SHOULD REMAIN QUIET AS THE CENTER OF HIGH PRESSURE
SETTLES INTO THE OHIO VALLEY AND A TROUGH OF LOW PRESSURE DEVELOPS
OVER THE CENTRAL PLAINS. A SOUTHWESTERLY GRADIENT WILL SET UP WITH
WINDS INCREASING FROM LIGHT AND VARIABLE TO ARND 10 KT THIS
AFTERNOON. THE MAIN CONCERN FOR THIS AFTERNOON WILL BE WHETHER A
LAKE BREEZE WILL FORM AND HOW FAR INLAND IT MIGHT PUSH...WHICH IN
TURN WOULD AFFECT TEMPS ALONG THE LAKEFRONT. WITH MOSTLY CLEAR
SKIES...TEMPERATURES SHOULD REACH ARND 80F THIS AFTERNOON. A WEAK
GRADIENT AND ADEQUATE DIFFERENTIAL HEATING BETWEEN THE LAKE AND LAND
SHOULD ALLOW FORMATION OF A LAKE BREEZE THIS AFTERNOON.
HOWEVER...THE LATEST SHORT RANGE MODEL GUIDANCE SUGGESTS THAT WINDS
THROUGH THE BOUNDARY LAYER SHOULD BE SWLY TO ARND 10KT. SO...WHILE
THE DEVELOPMENT OF A LAKE BREEZE IS LIKELY...THE QUESTION BECOMES
WHETHER IT WILL PENETRATE INLAND ENOUGH TO IMPACT TEMPERATURES
ACROSS THE INLAND PORTIONS OF THE CHICAGO METRO AREA. AT THIS
POINT...FEEL THAT THE LAKE BREEZE WILL REMAIN CLOSE TO
SHORE...KEEPING LAKEFRONT MAX TEMPS IN THE MIDDLE 70S.
THE NEXT FEATURE OF CONCERN WILL BE A NORTHERN STREAM SHORTWAVE
CURRENTLY OVERTOPPING THE UPPER RIDGE OVER THE NRN PLAINS AND A
MIDDLE STREAM SHORTWAVE OVER THE CENTRAL PLAINS. WITH WEAK UPPER
LEVEL WINDS ON THE ERN SIDE OF THE UPPER RIDGE...THESE SYSTEMS WILL
TRACK RATHER SLOWLY ACROSS THE PLAINS. THE LATEST GUIDANCE SUGGESTS
THAT THE MORE SOUTHERN OF THE 2 SHORTWAVES WILL MOVE OUT AHEAD OF
THE NRN STREAM SHORTWAVE...BRINGING INCREASING CLOUDINESS FRIDAY
EVENING AND THEN STRENGTHENING AS IT MOVES OVER NRN MO/SRN IA BY
SATURDAY MORNING. AN ASSOCIATED SFC LOW IS EXPECTED TO MOVE INTO
SERN IA BY SATURDAY MORNING WITH A DEVELOPING WARM FRONT EXTENDING
SEWD ALONG THE MISSISSIPPI RIVER. THE TRACK AND TIMING OF THE LEAD
SHORTWAVE IS STILL A BIT UNCERTAIN WITH SOME TIMING AND INTENSITY
DIFFERENCES AMONG THE SHORT RANGE GUIDANCE...THE GENERAL TREND
SHOULD BE FOR INCREASING POPS OVER THE WRN PORTIONS OF THE
CWA...WITH LOCATIONS ALONG AND POSSIBLE JUST EAST OF THE I-39
CORRIDOR SEE SOME RAIN AFTER MIDNIGHT FRIDAY NIGHT AND INTO THE EARLY
MORNING HOURS.
KREIN
SATURDAY THROUGH SUNDAY...
BIGGEST CONCERN WILL BE ON QPF TOTALS SAT INTO SUN WITH A SLOW
MOVING WAVE. THIS COUPLED WITH INCREASED PWAT VALUES NEARING 2"
PRIMARILY SAT...RAISES CONCERNS ABOUT SLOW MOVING STORMS THAT COULD
BE EFFICIENT AT PRODUCING VERY HEAVY RAINFALL IN A SHORT PERIOD OF
TIME. THESE ANOMALOUSLY HIGH PWAT VALUES ARE PROGGED TO LINGER THRU
SUN.
500MB TROUGH AXIS WILL CONTINUE TO PIVOT EAST AWAY FROM THE GREAT
LAKES REGION...AS THE LONGWAVE PATTERN BEGINS TO TRANSITION INTO A
QUASI-ZONAL SETUP. THIS WILL ALLOW SYSTEMS TO EASILY TRAVERSE THE
CONUS FROM WEST TO EAST. HOWEVER THE WRINKLE WITH THIS SETUP WILL BE
THAT OPER GUIDANCE IS INDICATING THE ACTIVE ZONE WILL SETUP ACROSS
THE CWFA SAT AFTN THRU SUN EVE. GUIDANCE HAS BEEN CONSISTENT WITH
DEVELOPING A SFC RIDGE OVER CENTRAL ONTARIO AND HELPING TO KEEP A
STALLED FRONTAL BOUNDARY ACROSS THE MID-MISSOURI VALLEY STRETCHING
EAST INTO THE OHIO VALLEY SAT NGT/SUN. AS PREVIOUSLY NOTED ABOUT A
SLOW MOVING SYSTEM...GUIDANCE HAS A WAVE LIFTING NORTHEAST INTO THE
SOUTHWEST PORTIONS OF THE CWFA SAT AFTN AND SLOWLY LIFTING NORTHEAST
SUN. WITHIN THIS PERIOD IT IS BECOMING AN INCREASED CONCERN THAT IF
CONVECTION DEVELOPS...WHICH APPEARS FAVORABLE...THAT SOME OF THESE
STORMS COULD EASILY PUT DOWN HEAVY RAINFALL IN A SHORT PERIOD OF
TIME. TEMPS SAT WILL LIKELY BE HELD DOWN SOMEWHAT GIVEN THE
INCREASED SOLAR SHIELDING...HOWEVER WITH LLVL MOISTURE INCREASING
DEW PTS WILL BE PUSHING INTO THE UPR 60S AND RESULT IN HUMID CONDS.
WINDS WILL BE LIGHT AS WELL...GENERALLY FROM THE SOUTH.
YET ANOTHER WEAK MID-LVL VORT WILL SLIDE EAST INTO THIS ZONE SUN AND
WITH THE HIGH LLVL MOISTURE AND WEAK FLOW...THE CONCERN FOR LOCALLY
HEAVY RAINFALL WILL PERSIST INTO SUN EVE. FORTUNATELY GUIDANCE HAS
BEEN INDICATING THAT THE QUASI-STATIONARY FRONTAL BOUNDARY MAY SLIP
FURTHER SOUTH AND COULD DISPLACE THE LOCATION OF HEAVIER RAINFALL TO
THE SOUTHERN CWFA SUN AFTN/EVE. THIS WOULD ALLOW A SLIGHTLY DRIER
NORTHERLY WIND TO PROVIDE SOME RELIEF TO AREAS NORTH OF I-80 WITH
HIGHS IN THE UPR 70S SUN.
MONDAY THROUGH THURSDAY...
ENSEMBLES ARE DEMONSTRATING SOME SPREAD IN THE MEDIUM TERM THRU
TUE...WITH REGARDS TO THE TIMING OF THE FLOW TRANSITIONING OUT OF
THE QUASI-ZONAL SETUP. BEYOND MID-WEEK GUIDANCE IS RATHER CONSISTENT
IN REDEVELOPING A NORTH ATLANTIC RIDGE...ALONG WITH SOME RIDGING
TRYING TO DEVELOP ACROSS THE PAC-NW. WHILE CONFIDENCE IS LOW...THIS
COULD SUGGEST THAT SOME DEGREE OF TROUGHING COULD RETURN TO THE
CENTRAL CONUS AND PERHAPS BRING SOME QUIETER WEATHER BACK TO THE
CWFA.
HOWEVER...CONFIDENCE IS LOW AS THERE IS STILL SOME SPREAD AMONGST
MEMBERS. OPER GUIDANCE IS ALSO SHOWING CONSIDERABLE SPREAD IN THE
EXTENDED PERIODS. THE OVERALL THEME APPEARS TO BE TEMPS RETURNING TO
SEASONAL CONDS IN THE LOW TO PSBLY MID 80S WITH OVERNIGHT LOWS IN
THE 60S.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* LAKE BREEZE SHOULD REMAIN EAST OF THE TERMINALS...SO EXPECTING
SW WINDS LESS THAN 10 KT.
JEE
//DISCUSSION...UPDATED 12Z...
HIGH PRESSURE WILL SETTLE INTO THE OHIO VALLEY TODAY AS A TROUGH
OF LOW PRESSURE DEVELOPS OVER THE CENTRAL PLAINS. A MORE SWLY
GRADIENT WILL DEVELOP THROUGH THE DAY. THE WEAK GRADIENT AND
DIFFERENTIAL HEATING UNDER SCT SKY COVER SHOULD ALLOW FOR LAKE
BREEZE DEVELOPMENT AGAIN TODAY...BUT WINDS JUST OFF THE DECK
SHOULD APPROACH 10KT AND...AT THIS TIME...DO NOT ANTICIPATE THAT
THE LAKE BREEZE WILL PENETRATE INLAND FAR ENOUGH TO IMPACT
ORD/MDW...THOUGH IT COULD BE CLOSE FOR MDW AND THAT SITE COULD
TURN ELY. THE LAKE BREEZE SHOULD PUSH INLAND OF GYY...WHICH SHOULD
TURN ENELY IN THE AFTERNOON. RFD/DPA SHOULD REMAIN WELL WITHING
THE SYNOPTIC FLOW OF SWLY...VEERING WNWLY IN THE AFTERNOON.
A MID LEVEL IMPULSE APPROACHING THE MIDDLE MISSISSIPPI VALLEY LATE
TONIGHT WILL BRING INCREASING CLOUD COVER AND THE NEXT ROUND OF
PCPN TO THE REGION. ANTICIPATE THAT PCPN SHOULD REACH RFD SHORTLY
BY DAYBREAK AND REACH THE CHICAGO AREA TERMINALS BY LATE MORNING.
THERE SHOULD BE SOME TS WITH THIS SYSTEM...BUT THE CHANCES WILL BE
GREATER AFTER 18Z THAN BEFORE.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM-HIGH CONFIDENCE IN WIND TRENDS AND LAKE BREEZE NOT
REACHING ORD/MDW.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT THROUGH THURSDAY...PERIODIC CHANCES FOR SHRA/TSRA.
KREIN
&&
.MARINE...
350 AM CDT
SURFACE HIGH PRESSURE IS NOW CENTERED JUST SOUTH OF THE SOUTHERN
TIP OF LAKE MICHIGAN WILL CONTINUE TO BUILD SOUTHEAST INTO THE
OHIO VALLEY FRIDAY. WITH SFC TROUGHING OVER THE CNTRL PLAINS WINDS
WILL MORE SOUTHWESTERLY FOR FRIDAY AND INTO SATURDAY. A COLD FRONT
IS EXPECTED TO DROP SOUTH DOWN THE LENGTH OF LAKE
MICHIGAN...THROUGH THE NORTHERN HALF OF THE LAKE SATURDAY
AFTERNOON AND AND REACHING THE SOUTHERN END OF THE LAKE LATE
SATURDAY NIGHT. WINDS SHOULD SHIFT TO NORTHERLY FOLLOWING THE
FROPA WITH A SHORT PERIOD WITH WINDS UP 20 KT. AS HIGH PRESSURE
BUILDS ACROSS ONTARIO SATURDAY NIGHT WHILE LOW PRESSURE MOVES
THROUGH IL/IN...WINDS SHOULD BECOME ELY ACROSS THE LAKE. THE
PROGRESSION OF THE PATTERN SHOULD BE RELATIVELY SLOW...WITH
GENERALLY ELY WINDS OVER THE LAKE INTO EARLY NEXT WEEK.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1020 AM CDT Fri Aug 15 2014
.UPDATE...
ISSUED AT 1009 AM CDT FRI AUG 15 2014
Area of showers and thunderstorms advancing east across Iowa and
northern Missouri this morning, ahead of a shortwave across the
Plains. Latest high-resolution models show this progressing toward
the Mississippi River the remainder of the morning, before
decaying in west central Illinois, but the HRRR suggests some
light showers may make it as far east as Springfield by 4 pm.
Existing 20% PoP`s across the western CWA still sufficient.
Temperatures off to a chilly start in the northeast CWA underneath
an area of high pressure, with 44 degrees observed at the Danville
airport for a low. A decent recovery so far as sunshine as boosted
temperatures into the lower 60s. Remainder of the CWA is largely
in the upper 60s/lower 70s at 10 am with clouds increasing.
Question will be how much the clouds impact the temperatures this
afternoon, especially across the west. Have only made minor
changes for now, generally around a degree or so, to blend in with
the current trends. Latest HRRR and RAP seem a bit too high with
mid 80s this afternoon despite the cloud cover, so have leaned
more toward the LAMP guidance.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 328 AM CDT FRI AUG 15 2014
Boundary that pushed across parts of central thru southeast Illinois
yesterday has finally shifted just south of Interstate 70 early this
morning. Rather tight temp/dew point gradient across the forecast
area with upper 40 dew points across the northeast, while over our
far southwest counties, readings were in the low to mid 60s.
Quite a bit of mid and high level cloudiness was streaming southeast
into Iowa and extreme west central Illinois ahead of our next
shortwave over western Nebraska, and that cloud cover will have an
affect on afternoon highs, especially across the north and west.
High pressure just to our north and east will drift slowly away from
our area today with a return southerly flow developing by this
afternoon and evening. Forecast soundings continue to indicate quite
a bit of dry air in the low levels of the atmosphere thru this
evening so will keep our area dry but will have to keep an eye out
for our western counties as some of the shower activity forecast
over Iowa today may approach our far west by late afternoon or early
this evening. For now, will keep any mention of rain out in the west
until early this evening.
Models continue to indicate the more favorable 850 mb theta-e
advection/moisture convergence and low level jet position for
overnight convection would be to our west with whatever develops
over Iowa late tonight pushing into our far western areas after
midnight. PoPs will be on the increase, especially across the west
this evening with rain probably holding off over areas east of I-57
until Saturday morning.
&&
.LONG TERM...(Saturday through Friday)
ISSUED AT 328 AM CDT FRI AUG 15 2014
An unsettled weather pattern taking shape over central and southeast
IL with daily chances of showers and thunderstorms from this weekend
through the middle of next week, as humid conditions return along
with building heat by the middle of next week. 00Z forecast models
continue to show short waves/upper level low/trof moving into IL
later this weekend though still some timing differences and qpf
amounts vary between models and from run to run. Still looks like
increase chances of showers and thunderstorms from west to east
during the weekend with highest chances SW counties Sat and shifting
into eastern IL by Sunday night. SPC has 5% risk of severe storms
along and west of a Springfield to Peoria line Saturday while slight
risk of severe storms (15%) is WSW of IL over central and northern
MO. SPC then has 5% risk of severe storms Sunday SE of a Champaign
to Shelbyville line mainly in the afternoon and early evening hours.
Heavy rain threat also this weekend especially Sunday with
precipitable water values peaking from 2-2.50 inches. Highs 80-85F
over central IL this weekend with mid 80s over southeast IL. Humid
this weekend with dew points in the upper 60s and lower 70s.
Short wave trof/low exits east of IL early next work week but more
energy arriving thereafter to keep chances of showers and
thunderstorms going into middle of next week as humid dew points in
the upper 60s to mid 70s prevail. Temperatures to also heat up into
the mid to upper 80s by middle and later part of next week as upper
level heights rise over IL. SW parts of CWA approaching 90F from
Wed-Fri and afternoon heat indices in the mid to upper 90s.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
ISSUED AT 615 AM CDT FRI AUG 15 2014
VFR conditions are expected thru this evening with the threat for
cigs and vsbys to lower to MVFR towards 12z, especially in PIA and
SPI as rain chances increase. A band of lower VFR cigs has developed
over the past several hours from near PIA southeast towards DEC with
cigs ranging from SCT-BKN at 3500-4500 feet. Forecast soundings
indicate these should become more scattered later this morning, with
mainly a mid and high level deck expected into the afternoon hours.
As a weather system over the central Plains this morning moves in
our direction later today and tonight, rain chances will start to
increase, especially across the west tonight with the potential for
cigs to lower to MVFR at PIA and SPI with scattered TSRA possible
after 05z. Surface winds will not be much of a factor thru tonight
with winds out of the east and southeast at 4 to 9 kts.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEELHART
SHORT TERM...SMITH
LONG TERM...07
AVIATION...SMITH
AREA FORECAST DISCUSSION...UPDATED
NWS DODGE CITY KS
555 AM CDT Fri Aug 15 2014
...Updated for Aviation...
.SHORT TERM...(Today and tonight)
ISSUED AT 347 AM CDT FRI AUG 15 2014
A weak shortwave trough was approaching western Kansas this
morning. Ahead of this feature, elevated convection was ongoing near
the interstate 70 corridor. This upper level feature will pass
across southwest Kansas today. A narrow ribbon of low level
moisture from El Paso into eastern Mew Mexico is expected to
advect north-northeastward into southwest Kansas, leading to
destabilization. Surface based CAPE values will approach 1500
j/kg by afternoon. After some morning elevated convection, a weak
surface trough associated with the passage of the upper level
feature will lead to sufficient surface convergence for
thunderstorm development by early to mid afternoon. There is some
uncertainty as to how far west thunderstorm initiation will be.
The RAP pushes the surface trough through Dodge City late this
morning, suggesting that any afternoon storms would be confined to
south central Kansas. We opted keep the highest thunderstorm chances
southeast of Dodge City this afternoon. Highs today will be in the
lower to middle 90s given partial sunshine. Winds will be weaker
by tonight along with partly cloudy skies; and this should allow
temperatures to fall into the upper 60s.
.LONG TERM...(Saturday through Thursday)
ISSUED AT 255 AM CDT FRI AUG 15 2014
For Saturday, a stalled out warm front will be just north of Dodge
City. Some weak moisture convergence along this front may be enough
to set off some scattered late afternoon thunderstorms and into the
evening. Models show some moderate instability with CAPE over 2000
J/kg. Very weak upper level wind fields and lack of large scale
dynamics should be enough to preclude a severe thunderstorm threat.
Forecast soundings show an inverted V type sounding with some gusty
winds to 50 mph the main threat. Highs will be warm and in the mid
to upper 90s. Lows will be mild and in the upper 60s to around 70.
On Sunday, weak upper level ridging continues across the Central
Plains with a weak surface trough near Hays. With forecast moderate
instability and some weak moisture convergence will continue with a
slight chance of thunderstorms mainly near and north of Dodge City
by later in the afternoon and overnight. The severe threat again
looks minimal. Highs will continue in the mid to upper 90s with
overnight lows in the upper 60s.
For the period of Monday into Thursday of next week, a northern
branch upper level wave moves across the Plains on Monday afternoon
with a continued chance for thunderstorms. More weak upper level
waves move across the Plains into Thursday with small chances for
mainly late afternoon and evening thunderstorms. Highs continue in
the mid 90s with lows in the upper 60s to around 70.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
ISSUED AT 551 AM CDT FRI AUG 15 2014
The upper level shortwave trough will be moving east this morning
and taking any lingering showers and thunderstorms with it. At the
surface a weak trough will move east across western Kansas today
with light south to southwest winds shifting to light and variable
after 19-21Z. VFR conditions will continue into tonight.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 94 67 96 68 / 30 20 20 20
GCK 94 67 96 67 / 30 10 20 20
EHA 95 67 96 68 / 10 10 20 20
LBL 96 68 98 68 / 30 20 20 20
HYS 93 67 95 68 / 50 20 20 20
P28 95 69 98 70 / 30 30 10 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Finch
LONG TERM...Kruse
AVIATION...Kruse
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
800 AM EDT FRI AUG 15 2014
.UPDATE...
ISSUED AT 755 AM EDT FRI AUG 15 2014
THE AREAS OF DENSE FOG REMAIN THE PRIMARY WEATHER ISSUE EARLY THIS
MORNING WITH THE LOWEST VIS FOUND GENERALLY BETWEEN THE HAL ROGERS
PARKWAY AND INTERSTATE 64. EXPECT THE FOG TO BREAK UP OVER THE NEXT
HOUR OR SO WITH A PARTLY TO MOSTLY SUNNY DAY TO FOLLOW FOR MOST OF
THE AREA. SO THIS UPDATE PRIMARILY JUST CONSISTS OF MATCHING THE OBS
AND TRENDS FOR THE T AND TD GRIDS. THESE HAVE BEEN SENT TO THE NDFD
AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 345 AM EDT FRI AUG 15 2014
06Z SFC ANALYSIS SHOWS GENERALLY WEAK HIGH PRESSURE THROUGH THE OHIO
AND TENNESSEE VALLEYS. A STALLED FRONTAL BOUNDARY EXISTS OVER PARTS
OF CENTRAL AND EASTERN KENTUCKY. THIS IS RESPONSIBLE FOR THE EXTRA
MOISTURE IN THE FORM OF SHOWERS AND SPRINKLES THAT SANK THROUGH THE
CWA EARLIER IN THE EVENING. THE MOISTURE...FOLLOWED BY SOME CLEARING
IN THE WAKE OF THE FRONT...HAS LED TO AREAS OF DENSE FOG...GENERALLY
NORTH OF THE HAL ROGERS PARKWAY. AS THE NIGHT WEARS ON...EXPECT THE
FOG AND DENSE PARTS OF IT TO SETTLE FURTHER SOUTH. ACCORDINGLY...
HAVE ISSUED AN SPS AND A GRAPHICAST TO ADDRESS THE LOW VISIBILITIES.
THESE RUN THROUGH 5 AM AND WILL LIKELY BE REISSUED THROUGH 9 AM
SHOULD THE FOG NOT START TO DISSIPATE BY THEN. HOWEVER...OVER THE FAR
NORTHERN PARTS OF THE AREA SOME DRIER AIR IS WORKING INTO OUR CWA AND
SHOULD LIMIT THE FOG AND WITH TIME HELP TO CLEAR IT. SO WILL LIKELY
TAKE THIS INTO CONSIDERATION WITH RESPECT TO THE FOG THREAT THROUGH
THE REST OF THE NIGHT AND SPS OUTLINE. THE PROXIMITY OF THE FRONT HAS
ALSO BROUGHT HIGHER DEWPOINTS TO THE AREA RESULTING IN A MILDER AND
MORE UNIFORM TEMPERATURE NIGHT THAN INITIALLY ANTICIPATED. AS
SUCH...TEMPS AND DEWPOINTS THROUGH THE AREA ARE GENERALLY IN THE
LOWER 60S WITH A FEW POCKETS OF UPPER 50S ON THE FRINGES...AWAY FROM
THE STALLED BOUNDARIES.
THE MODELS ARE IN DECENT AGREEMENT ALOFT WITH THE MAIN FEATURES THAT
WILL AFFECT THE AREA THROUGH THE SHORT TERM. A BROAD AND DEEP UPPER
LOW WILL CONTINUE TO MOVE NORTHEAST AND AWAY FROM THE REGION. IN ITS
WAKE NORTHWEST FLOW WILL BRING A COUPLE WEAK MID LEVEL ENERGY PACKETS
OVER KENTUCKY TONIGHT AND DURING THE DAY SATURDAY. FOR THIS...A
GENERAL MODEL COMPROMISE IS PREFERRED WHILE THE HRRR AND NAM12 WAS
GIVEN THE MOST WEIGHT FOR THE NEAR TERM PORTION OF THE FORECAST.
SENSIBLE WEATHER WILL FEATURE AREAS OF DENSE FOG AROUND THIS MORNING
AND THE RESIDUAL FRONT OVER THE SOUTHERN PORTION OF THE AREA. THIS
FRONT WAS MORE PROLIFIC THAN EXPECTED DURING THE DAY AND EVENING ON
THURSDAY. WITH THIS IN MIND WILL KEEP A SMALL CHANCE OF SPRINKLES AND
SHOWERS IN THE FORECAST ACROSS THE SOUTH TODAY. HIGH CLOUDS WILL BE
ON THE INCREASE FROM THE WEST TONIGHT INTO SATURDAY AS THE FRONT
STARTS TO MOVE BACK NORTHEAST. CANNOT RULE OUT A SHOWER WITH THIS
LATER TONIGHT OR ON SATURDAY...BUT FOR NOW WILL KEEP IT DRY IN THE
FORECAST GRIDS. TEMPERATURES WILL BE JUST ON THE COOL SIDE OF NORMAL
THROUGH SATURDAY THANKS IN PART TO THE EXTRA CLOUDS AROUND. AGAIN
TONIGHT...PATCHY VALLEY FOG CAN BE EXPECTED TO DEVELOP AFTER
MIDNIGHT...BUT LIKELY BE MITIGATED BY THE ADDITIONAL CLOUDS.
STARTED WITH THE CONSSHORT FOR THE T/TD/WIND GRIDS THROUGH THE FIRST
24 HOURS AND USED THE SUPERBLEND FOR THE REST OF THE SHORT TERM. DID
MAKE SOME ADJUSTMENTS TONIGHT FOR MINOR RIDGE AND VALLEY TEMPERATURE
DIFFERENCES. WITH THE POPS...ENDED UP A NOTCH HIGHER THAN MOS TODAY
ACROSS OUR SOUTHERN ZONES...OWING TO THE LINGERING FRONT. FOR THE
REST OF THE FORECAST...WAS IN LINE WITH GUIDANCE.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 340 AM EDT FRI AUG 15 2014
THE EXTENDED FORECAST BEGINS ON SATURDAY NIGHT WITH THE UPPER LEVEL
PATTERN BEGINNING TO BREAK DOWN AND UPPER LEVEL FEATURES MOVING ALONG
A BIT FASTER. THROUGH THE PERIOD...NUMEROUS UPPER LEVEL SHORTWAVES
WILL MOVE THROUGH THE OH RIVER VALLEY AS THE UPPER LEVEL PATTERN
BECOMES MORE ZONAL AND MAINTAINS THIS PATTERN THROUGH THE ENTIRE
EXTENDED. IN THE LOWER LEVELS...THE MORE POTENT FEATURE WILL BE THE
SURFACE LOW MOVING THROUGH ON MONDAY WITH PLENTY OF SURFACE BASED
INSTABILITY AND UPPER LEVEL SUPPORT. THIS DAY WILL BE A SCENARIO TO
MONITOR AS SEVERE WEATHER IS POSSIBLE BUT WITH A LACK OF
CONFIDENCE...CERTAINLY NOT SOMETHING TO HIGHLIGHT AT THIS POINT.
ALSO...THE FORECAST PROBLEM HERE WILL BE TIMING...ESPECIALLY WITH A
TRANSITIONS TO A MORE ZONAL PATTERN.
FOR THE REST OF THE EXTENDED...SOUTHERLY FLOW WITH A SURFACE
STATIONARY BOUNDARY SETTING UP ALONG THE LOWER OH VALLEY WILL ALLOW
FOR MAINLY AFTERNOON AND EVENING CONVECTION THROUGH THE TUESDAY TO
THURSDAY PERIOD. THIS APPEARS TO BE THE SET UP BUT THE GFS AND EURO
STILL SHOW SOME DIFFERENCES IN THEIR SOLUTIONS. ALSO KEEPING IN
MIND...THAT MODELS DO HAVE TROUBLE WITH TRANSITION PERIODS IN THE
UPPER LEVEL FLOW. THIS IN MIND...DID STAY WITH THE MODEL ALL BLEND
SOLUTION...EVEN LOWERED POPS SLIGHTLY BELOW THAT VALUE IN THE
EXTENDED BASED UPON LACK OF CONFIDENCE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 800 AM EDT FRI AUG 15 2014
A STALLED OUT BOUNDARY LINGERS OVER EASTERN KENTUCKY FOR THE NEXT 24
TO 36 HOURS. THIS BOUNDARY HAS LED TO PRETTY GOOD FOG FORMATION FOR
MUCH OF THE AREA EARLY THIS MORNING. THE FOG WILL BURN OFF BETWEEN 12
AND 14Z AT THE TAF SITES. THE THREAT OF MORE SHOWERS WILL REMAIN ACROSS
THE SOUTH THIS AFTERNOON AS THE BOUNDARY CONTINUES TO SLOWLY SAG
SOUTHWARD. PATCHY FOG...LOCALLY DENSE...CAN BE ANTICIPATED AGAIN LATE
TONIGHT FOR THE TAF SITES. WINDS THROUGH THE PERIOD WILL CONTINUE TO BE
LIGHT AND VARIABLE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS CARIBOU ME
644 AM EDT FRI AUG 15 2014
.SYNOPSIS...
UPPER LEVEL LOW PRESSURE WILL REMAIN NORTHWEST OF MAINE THROUGH
THE WEEKEND. AS A RESULT...UNSETTLED CONDITIONS WILL PERSIST ACROSS THE
REGION RIGHT INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
630 AM UPDATE...DECIDED INCREASE THE FOG FOR THE ENTIRE CWA
THROUGH THIS MORNING PER THE LATEST OBS. THE FOG WILL LIFT AND
BURN OFF AFTER 8 AM THANKS TO THE SUN AND WARMING TEMPERATURES.
PULLED BACK ON THE ARRIVAL OF CLOUDS AND SHOWER USING THE HRRR AND
RAP WHICH APPEAR TO BE DOING QUITE WELL W/THE LATEST SET UP. WV
SATELLITE SHOWED ONE DISTURBANCE MOVING INTO SOUTHERN QUEBEC ATTM
WHICH WILL LIFT NORTH TODAY INCREASING THE CHANCE FOR SHOWERS.
PREVIOUS DISCUSSION...
UNSETTLED CONDITIONS THIS TERM W/ANOTHER ROUND OF SHOWERS
EXPECTED. FOG WILL ALSO BE A CONCERN.
THE 06Z SURFACE ANALYSIS SHOWED WEAK LOW PRES LIFTING ACROSS NEW
BRUNSWICK W/THE OCCLUDED FRONT ACROSS NORTHERN MAINE. AREA OF
SHOWERS ACROSS NEW BRUNSWICK MOVING NNW PER THE LATEST RADAR W/THE
WESTERN EDGE JUST E OF THE MAINE BORDER. THE LATEST RAP AND HRRR
3KM DOING WELL W/THIS AREA AND THE PLACEMENT OF THE LOW AND FRONT.
A BLEND OF THE THESE 2 MODELS SHOW THE WESTERN EDGE JUST SKIRTING
THE MAINE-NEW BRUNSWICK BORDER THROUGH THIS MORNING AS THE BEST
FORCING REMAINS WELL E AND SW OF THE REGION. OOZ UA AND SATELLITE
WV IMAGERY SHOW CLOSED UPPER LOW SPINNING OVER QUEBEC W/SPOKES OF
ENERGY ROTATING AROUND THE LOW. THE IMPULSE THAT IS FORECAST TO
AFFECT OUR CWA WAS MOVING ACROSS NYS AND VT AND IS EXPECTED TO
MOVE ACROSS THE REGION BY THIS AFTERNOON INTO THIS EVENING. SOME
LLVL CONVERGENCE COMBINED W/SOME MID LEVEL SUPPORT WILL ALLOW FOR
SHOWERS TO BREAK OUT MAINLY ACROSS THE NORTHERN AND CENTRAL AREAS.
DECIDED TO GO W/CHANCE POPS(30-40%) FOR THIS AFTERNOON INTO
TONIGHT BUT TRIMMED BACK THE QPF A BIT W/TOTALS THROUGH TONIGHT
RUNNING LESS THAN 0.10". SOUNDINGS INDICATE SB/MUCAPES LESS THAN
150 JOULES TODAY INTO THE EVENING AND THEREFORE LEFT TSTMS OUT OF
THE FORECAST. CLOUDS AND SHOWERS WILL HOLD DOWN TEMPERATURES
W/READINGS WILL RUN INTO THE UPPER 60S ACROSS THE NORTH AND WEST
WHILE CENTRAL AND DOWNEAST SHOULD SEE LOWER 70S. COOL FOR MID
AUGUST.
FOG HAS DEVELOPED THIS MORNING THANKS TO LIGHT WINDS/PARTIAL
CLEARING AND A WET GROUND. THE FOG WAS THE MOST DENSE ACROSS THE
COAST BUT PATCHY DENSE WILL BE NUISANCE THROUGH SUNRISE JUST ABOUT
EVERYWHERE. DECIDED TO LEAVE FOG OUT NORTH OF THE DOWNEAST AND
COASTAL AREAS TONIGHT DUE TO CLOUDS AND SHOWERS. ATTM, IT LOOKS AS
THOUGH THE FOG ACROSS THE DOWNEAST AND THE COAST WILL BE PATCHY.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
A UPPER LOW OVER NORTHERN QUEBEC AT THE START OF NEAR TERM PERIOD
IS FORECAST TO DRIFT SLOWLY SOUTHEAST ACROSS NEW BRUNSWICK TO
EASTERN NOVA SCOTIA BY THE END OF THE PERIOD. A NEW FRONTAL SYSTEM
WILL MOVE FROM SRN MAINE TOWARDS THE EASTERN NOVA SCOTIA BY END OF
THE PERIOD. UNSETTLE WEATHER WILL PERSIST ACROSS MAINE THROUGH THE
PERIOD.
LOADED USED HPC GRIDS FOR QPF...NAWAVE 4 FOR SEAS IN THE COASTAL
WATERS...AND A BLEND OF NAM/GFS/GEM/ECMWF THROUGH THE PERIOD FOR
ALL OTHER ELEMENTS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AT THE START OF THE PERIOD AN UPPER LEVEL LOW WILL BE MOVING INTO
THE WESTERN CANADIAN MARITIMES...HIGHER PRESSURE WILL BEGIN
BUILDING INTO MAINE. THE RIDGE WILL SET ACROSS THE REGION AND
REMAIN THROUGH THE END OF THE PERIOD. POSSIBLE SHOWERS ACROSS NRN
MAINE TOWARDS THE END OF THE PERIOD AS LOWER PRESSURE BEGINS TO
ERODE THE NORTHERN PORTIONS OF THE RIDGE.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: MVFR/IFR THIS MORNING W/CONDITIONS IMPROVING TO VFR FOR
KBGR AND KBHB. THE NORTHERN TERMINALS FROM KHUL TO KFVE WILL SEE
MVFR HANG LONGER INTO THIS AFTERNOON. MVFR W/PERIODS OF IFR
COULD BE SEEN LATER TONIGHT MAINLY ACROSS THE NORTHERN TAFS SITES
W/SHOWERS AND LOW CIGS.
SHORT TERM: MAINLY MVFR CONDITIONS ACROSS NRN AND CNTRL ME THROUGH THE
PERIOD. OCNL PERIODS WERE CIGS WILL FALL IFR IN SHWRS. IFR
CONDITIONS FOR BGR AND BHB THROUGH MUCH OF THE NEAR TERM PERIOD.
IMPROVING CONDITIONS AFTER MID DAY MONDAY AS HIGHER PRESSURE
BUILDS INTO THE AREA.
&&
.MARINE...
NEAR TERM: DROPPED THE SCA FOR HAZARDOUS SEAS AS WAVE HEIGHTS HAVE
DROPPED BELOW 6 FT AND WILL CONTINUE TO SUBSIDE TODAY INTO
TONIGHT. WINDS ARE AT 10 KTS ATTM AND THINKING HERE IS THAT THE
WINDS WILL STAY LIGHT RIGHT INTO TONIGHT AT SPEEDS OF 10 KTS OR LESS.
SHORT TERM: WINDS AND SEAS BELOW SCA THROUGH THE PERIOD.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...NORTON
LONG TERM...NORTON
AVIATION...HEWITT/NORTON
MARINE...HEWITT/NORTON
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
539 AM CDT FRI AUG 15 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 306 AM CDT FRI AUG 15 2014
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED AN UPPER LOW OVER THE PACIFIC NORTHWEST...RIDGING FROM THE
SOUTHWESTERN U.S. INTO ALBERTA...AND TROUGHING OVER EASTERN CANADA
INTO THE NORTHEASTERN U.S.. ALSO OF NOTE WAS A SHORTWAVE OVER
SOUTHEAST MONTANA...WHICH WITH A STREAM OF MOISTURE TRANSPORT
BRINGING PRECIPITABLE WATER UP TO 1.5-2 INCHES ACROSS MUCH OF THE
PLAINS...HAS SUPPORTED SHOWERS AND EMBEDDED THUNDERSTORMS FROM THE
DAKOTAS INTO KS. ANOTHER AREA OF SCATTERED SHOWERS AND STORMS WERE
PRESENT FROM EASTERN SOUTH DAKOTA INTO SOUTHWEST MN AND WESTERN
IA...IN AN AREA OF MID-LEVEL FRONTOGENESIS AND NOSE OF 850MB
MOISTURE TRANSPORT. FURTHER TO THE EAST OVER THE FORECAST AREA...
HIGH PRESSURE AND DRY AIR DOMINATE. PRECIPITABLE WATER VALUES FROM
00Z SOUNDINGS RANGED FROM 1.25 INCHES AT MPX TO 0.44 INCHES AT GRB.
SOME HIGHER CLOUDS WERE FLOWING INTO LOCATIONS ALONG/WEST OF THE
MISSISSIPPI RIVER...HELPING TO KEEP TEMPERATURES UP THERE.
HOWEVER...IN CENTRAL WISCONSIN WHERE THE AIR IS DRIEST AND SKIES ARE
MAINLY CLEAR...READINGS HAVE DIPPED INTO THE LOW 40S WITH SOME
PATCHY FOG AROUND.
THE NORTHWEST FLOW REGIME THE FORECAST AREA SITS IN IS PROGGED TO
REMAIN IN PLACE THROUGH TONIGHT. MUCH OF THE FOCUS IS HOW CLOSE THE
SHORTWAVE IN SOUTHEAST MONTANA CAN PUSH EAST TOWARDS THE AREA...
BEFORE IT GETS CAUGHT UP IN THE NORTHWEST FLOW. MODELS ARE IN GOOD
AGREEMENT TRACKING THE SHORTWAVE INTO EASTERN SOUTH DAKOTA BY 12Z
SATURDAY. THIS TRACK DOES HELP TO SPREAD HIGHER PRECIPITABLE WATER
TOWARDS THE AREA...WITH VALUES INCREASING TO 1.5-1.75 INCHES ALONG
AND WEST OF THE MS RIVER FOR TONIGHT. HOWEVER...THE SLOW PROGRESSION
OF THE SHORTWAVE...COMBINED WITH THE NOSE OF 850MB MOISTURE
TRANSPORT PROGGED TO REMAIN MOSTLY WEST OF I-35 SUGGESTS A VERY LOW
PROBABILITY OF ANY PRECIPITATION FOR THE FORECAST AREA. THE 15.00Z
NAM...GFS...HIRES-ARW/NMM...NSSL WRF AND ECMWF DEPICT LITTLE IF ANY
PRECIPITATION...LEADING TO HIGHER CONFIDENCE OF A DRY FORECAST.
REALLY ONLY SMALL PRECIPITATION POTENTIAL WOULD BE...
1. THIS MORNING IN A SECTION OF NORTHEAST IOWA FROM THE
PRECIPITATION OFF TO OUR WEST TRYING TO PUSH IN.
2. ALONG THE MS RIVER WHERE THE HRRR/HIRES-ARW/NMM/NSSL WRF ALL
DEPICT A WEAK BAND OF SHOWERS OR SPRINKLES. APPEARS TO BE
CORRELATED WITH A VERY WEAK SHORTWAVE DROPPING DOWN OUT OF THE DLH
AREA.
3. LATE TONIGHT...WEAK ISENTROPIC LIFT MAY BE ABLE TO INITIATE
SOME SHOWERS OVER FAR NORTHEAST IA AND SOUTHWEST
WISCONSIN...SIMILAR TO THE 15.00Z ECMWF/NSSL WRF-ARW.
925MB TEMPS ARE PROGGED TO BE ABOUT 2C WARMER BY 00Z TODAY COMPARED
TO 00Z YESTERDAY...SO WE SHOULD BE ABLE TO TACK ON A FEW DEGREES TO
YESTERDAYS HIGHS. HOWEVER...CLOUD COVER MAY HOLD TEMPERATURES BACK
SOME...PARTICULARLY ACROSS NORTHEAST IOWA. WITH HIGHER PRECIPITABLE
WATER VALUES IN PLACE TONIGHT ALONG WITH SOME CLOUD COVER...MOST
LOCATIONS WILL SEE A WARMER NIGHT. EVEN SO...CENTRAL WISCONSIN LOOKS
TO CONTINUE TO BE THE COOL SPOT WITH THE DRIEST AIR PRESENT THERE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 306 AM CDT FRI AUG 15 2014
THE WEEKEND FORECAST LOOKS TO BE DOMINATED BY TWO FEATURES. FIRST...
THE SHORTWAVE TROUGH OVER EASTERN SOUTH DAKOTA AT 12Z SATURDAY...
WHICH LOOKS TO UNDER CUT THE FORECAST AREA BY HEADING ROUGHLY
THROUGH IOWA ON SUNDAY. SIMILAR TO THE SHORT TERM PERIOD...GIVEN THE
SLOW PROGRESSION OF THE SHORTWAVE KEEPING THE DYNAMICS TO THE
WEST...AND THE 850MB MOISTURE TRANSPORT NOSE AHEAD OF IT STAYING
NEAR OR SOUTH OF I-80...BELIEVE MUCH OF ITS PRECIPITATION SHOULD
STAY TO THE SOUTH OF THE FORECAST AREA. WITH THE SHORTWAVE GETTING
CLOSER ON SUNDAY...ESPECIALLY IN THE 15.00Z GFS...WILL HAVE TO
MAINTAIN SOME LOW CHANCES OF SHOWERS/STORMS WEST OF THE MS RIVER AND
SOUTH OF I-90 IN WISCONSIN. THE SECOND FEATURE...A SHORTWAVE TROUGH
DROPPING THROUGH ONTARIO ALLOWS A COLD FRONT TO DROP SOUTH THROUGH
THE FORECAST AREA LATE SATURDAY THROUGH SATURDAY NIGHT. THIS COLD
FRONT...COMBINED WITH DAYTIME HEATING AND SOME MOISTURE PUSHED EAST
INTO THE FORECAST AREA...SHOULD BE ENOUGH TO TRIGGER ISOLATED TO
MAYBE SCATTERED SHOWERS AND THUNDERSTORMS NORTH OF I-94 SATURDAY
AFTERNOON. GIVEN THE NORTHWEST UPPER FLOW AND SOUTHWARD PROGRESSION
OF THE FRONT...THESE MAY TRY TO DROP SOUTH THROUGH THE AREA SATURDAY
NIGHT...PROVIDED THEY DONT FALL APART WITH LOSS OF DAYTIME
INSTABILITY. SATURDAYS HIGHS SHOULD BE CLOSE TO TODAY GIVEN NEARLY
IDENTICAL 925MB TEMPS. WITH THE PASSAGE OF THE COLD FRONT SATURDAY
NIGHT...925MB TEMPS COOLING ABOUT 3C...POTENTIAL FOR A STRATUS DECK
AND A SWITCH TO EASTERLY FLOW...EXPECT COOLER CONDITIONS FOR SUNDAY.
ATTENTION EARLY NEXT WEEK THEN TURNS TO THE UPPER LOW OVER THE
PACIFIC NORTHWEST. THERE IS SURPRISINGLY GOOD MODEL AGREEMENT FOR
THE LOW TO DROP INTO THE FORECAST AREA ON TUESDAY. RETURNING
MOISTURE TRANSPORT AHEAD OF THIS UPPER LOW COMBINED WITH DPVA SHOULD
YIELD SOME SHOWERS AND THUNDERSTORMS...TRACKING INTO AREAS
ALONG/WEST OF THE MISSISSIPPI ON MONDAY AND GRADUALLY ACROSS THE
REST OF THE AREA MONDAY NIGHT AND TUESDAY. HAVE CONTINUED TO MENTION
50-60 PERCENT CHANCES. QUICK SOUNDING CHECK WOULD SUGGEST NO SEVERE
WEATHER DUE TO WEAK SHEAR.
FOR THE MIDDLE OF THE WEEK...THE UPPER LOW GRADUALLY FILLS AND LIFTS
NORTHEAST OUT OF THE REGION...IN RESPONSE TO RIDGING BUILDING UP
OVER THE PLAINS. STILL NEED TO MAINTAIN SOME LOW CHANCES OF
PRECIPITATION ON WEDNESDAY WITH THE UPPER LOW IN THE AREA...AND
ALTHOUGH 500MB HEIGHTS RISE GOING INTO THURSDAY...ITS ALSO
ACCOMPANIED BY WARM/MOIST AIR ADVECTION. THEREFORE...CHANCES OF
SHOWERS AND STORMS CONTINUE INTO THURSDAY. THE WARM ADVECTION WILL
BE ENOUGH TOO TO SEND TEMPERATURES ABOVE NORMAL FOR THURSDAY AFTER
GENERALLY HOLDING NEAR OR BELOW NORMAL UNTIL THEN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 538 AM CDT FRI AUG 15 2014
A WEAK DISTURBANCE WILL SLIDE ACROSS THE REGION TODAY BRINGING
SHOWERS AND THUNDERSTORMS TO PORTIONS OF SOUTHERN MINNESOTA INTO
CENTRAL/WESTERN IOWA. THIS ACTIVITY SHOULD STAY WEST OF THE TAF
SITES WITH VFR CONDITIONS EXPECTED. PLAN ON SOUTH WINDS OF 6 TO 10
KTS TODAY WITH CLOUD BASES RANGING FROM 8 TO 12 KFT. A MOIST
AIRMASS SLIDES INTO THE REGION TONIGHT AND WILL CREATE SOME
VISIBILITY RESTRICTIONS. PLAN ON 4-5 SM BR AT THE TAF SITES LATE
THIS EVENING THROUGH EARLY SATURDAY MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS PUEBLO CO
246 PM MDT FRI AUG 15 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 244 PM MDT FRI AUG 15 2014
CONVECTION THIS AFTERNOON HAS BEEN MORE SPARSE TODAY VS
YESTERDAY...AT LEAST AS OF 20Z. HOWEVER...THE MTNS HAVE HAD MORE
SUN TODAY...AND THUNDERSTORMS ARE FIRING OVER THE MOUNTAINS ALONG
THE LEADING EDGE OF A WEAK SHORTWAVE MOVING INTO WESTERN CO.
VARIOUS HIGH RES MODELS INCREASE THUNDERSTORM COVERAGE ACROSS THE
MOUNTAINS...THEN SPREAD THEM EASTWARD INTO THE ADJACENT PLAINS
DURING THE AFTERNOON AND EVENING HOURS. SFC DEW POINTS HAVE BEEN
LOWER TODAY...DROPPING OFF INTO THE LOWER 40S AND EVEN SOME UPPER
30S ACROSS THE MOUNTAINS...WITH UPPER 40S TO MID 50S ACROSS THE
PLAINS...AND THIS HAS LIMITED CAPE TO AROUND 500 J/KG ACCORDING TO
SPC MESO ANALYSIS. PRECIP WATERS ARE RUNNING LOWER AS
WELL...AROUND 80% OF NORMAL IN THE NORTH TO 130% OF NORMAL IN THE
SOUTH BASED ON THE BLENDED TPW SATELLITE PRODUCT.
THUS...THUNDERSTORMS SHOULD NOT BE AS EFFICIENT HEAVY RAINFALL
PRODUCERS AS THEY WERE YESTERDAY. THAT SAID...THERE IS STILL
SUFFICIENT MOISTURE FOR LOCALLY HEAVY RAIN WITH THE STRONGER
STORMS. IF ONE OF THESE HITS BURN SCARS OR AREAS OF STEEP
TERRAIN...THEN LOCALIZED FLASH FLOODING WILL STILL BE A CONCERN.
FORTUNATELY...STORMS APPEAR TO BE MOVING PRETTY GOOD (SOUTHEAST AT
15 MPH)...WHICH MAY LIMIT THREAT SOME. HRRR SUGGESTS GREATEST
THREAT WINDOW FOR THE WALD0 WILL BE FROM 21Z-00Z. THE PAPOOSE AND
WEST FORK BURN SCARS AS WELL AS THE CONTINENTAL DIVIDE WILL SEE
THE GREATEST THREAT BETWEEN 20Z AND 00Z. THUNDERSTORMS MAY MOVE
OFF INTO THE ADJACENT PLAINS THROUGH THE LATE AFTERNOON AND
EVENING...BUT THEY DON`T LOOK TOO ORGANIZED AND THERE ISN`T MUCH
OF A LOW LEVEL JET TO HELP SUSTAIN CONVECTION AFTER DARK...SO WILL
END MOST POPS BY MIDNIGHT.
SATURDAY LOOKS EVEN DRIER THAN TODAY AS PRECIPITABLE WATERS FALL OFF
TO LESS THAN AN .75 INCHES ALONG/WEST OF I-25. STILL ENOUGH
MOISTURE FOR ISOLATED DIURNAL THUNDERSTORMS...BUT COVERAGE SHOULD BE
EVEN LOWER. STILL ENOUGH MOISTURE FOR LOCALLY HEAVY RAIN WITH THE
STRONGER CELLS...BUT THREAT SHOULD BE LOWER DUE TO THE LIMITED
COVERAGE. TEMPERATURES TOMORROW SHOULD BE A FEW DEGREES WARMER THAN
TODAY. -KT
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 244 PM MDT FRI AUG 15 2014
EXTENDED FORECAST FOR SE CO LOOKS PRETTY TYPICAL FOR THE MIDDLE
OF AUGUST. DAILY STORM CHANCES AND TEMPS AROUND 90 DEGREES FOR THE
PLAINS. MAIN QUESTION WILL BE THE PROGRESSION OF A W COAST CUTOFF
LOW AND PACNW TROUGH...ESPECIALLY LATE IN THE PERIOD.
SAT NIGHT...CONVECTION SHOULD BE WRAPPING UP PRETTY EARLY AFTER
SUNSET. WILL LEAVE HIGHEST POPS SAT EVE OVER THE RATON MESA AND
FAR SERN PLAINS...WHERE THE MODELS ARE FOCUSING THE HEAVIEST QPF.
SUNDAY...A SHORT WAVE DISTURBANCE WILL PUSH THROUGH IN THE NW FLOW
LATE IN THE DAY. LOOKS LIKE THE MAIN IMPACT FROM THIS DISTURBANCE
WILL COME AFTER 00Z...AND BE FOCUSED ON THE PIKES PEAK REGION AND
PALMER DVD. EXPECT STORMS TO DEVELOP OVER THE MTS SOMEWHAT LATER
THAN USUAL...MOSTLY AFTER 20Z...AND IT WILL BE ISOLD-SCT IN COVERAGE.
THE SHORTWAVE SHOULD RESULT IN MORE WIDESPREAD COVERAGE OF STORMS
BUT THERE IS STILL SOME UNCERTAINTY ON HOW FAR WEST THE BULK OF THE
DEVELOPING CLUSTER OF STORMS WILL BE. HAVE THE HIGHEST POPS FROM THE
PIKES PEAK AREA SEW TO KLAA...FROM 00-03Z. SUNDAY SHOULD BE THE
WARMEST DAY OF THE PERIOD AS H7 TEMPS CLIMB TO NR 17 DEG C IN THE
AFTERNOON. COULD SEE A FEW SPOTS CLIMB INTO THE UPPER 90S OVER THE
LOWER ARKANSAS VALLEY.
MONDAY...THE MAIN FOCUS FOR ANY CONVECTION WILL BE OVER THE ERN
MTS AS LIGHT UPSLOPE FLOW PERSISTS ON THE BACKSIDE OF THE TROUGH
MOVING THROUGH THE UPPER MISS VALLEY. WILL KEEP ISOLD-SCT POPS THERE
WITH MORE ISOLD ACTIVITY POSSIBLE OVER THE BALANCE OF THE ERN PLAINS
AND SAN LUIS VALLEY. IF TRENDS CONTINUE...MAY BE ABLE TO DROP
MENTIONABLE POPS FROM ALL BUT THE MTS ON MONDAY.
TUESDAY...WILL SEE THE START OF A SWITCH BACK TO INCREASING MONSOONAL
MOISTURE. THE CUTOFF OFF THE CA COAST MAY BEGIN TO RETROGRADE DURING
THIS PERIOD...WHILE A TROUGH IN THE PACNW BEGINS MOVING INTO ID AND
MT. THE ECMWF CONTINUES OT BE A LITTLE MORE AGGRESSIVE IN BRINGING A
RETURN OF MONSOONAL MOISTURE TO THE AREA...WHILE THE GFS HOLDS BACK
A BIT. LOW POPS LOOK APPROPRIATE FOR THE REGION...ISOLD FOR THE
LOWER ELEVS AND SCT IN THE MTS.
BY WED-FRI...THE PACNW TROUGH SHOULD START TO ADVANCE INTO THE NRN
ROCKIES...AS THE UPPER HIGH TO OUR SW SHIFTS INTO ERN TX. THIS SHOULD
BRING A RETURN TO A STRONGER MONSOONAL PATTERN...WITH MORE MOISTURE
BEING DRAWN NWD FROM THE SUBTROPICS INTO WRN CO. WILL LEAVE LOW
ENSEMBLE POPS INTACT FOR NOW...BUT IF TRENDS CONTINUE MAY HAVE TO
SLOWLY RAMP UP POPS FOR THE END OF THE WEEK. ROSE
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 244 PM MDT FRI AUG 15 2014
VFR CONDITIONS EXPECTED OVER THE NEXT 24 HOURS. THUNDERSTORMS
WILL MOVE OFF THE MOUNTAINS INTO THE ADJACENT LOWER ELEVATIONS
DURING THE LATE AFTERNOON AND EVENING HOURS. KCOS AND KALS WILL
HAVE THE BEST CHANCE OF SEEING A THUNDERSTORM IN THE VICINITY OF
THE TERMINALS. ERRATIC GUSTY WINDS UP TO 40 KTS AND BRIEF MVFR
CIGS/VIS WITH TSRA WILL BE THE MAIN STORM THREATS. THREAT
DIMINISHES BY 02Z AND KCOS AND KPUB TERMINALS MAY SEE A BRIEF
NORTH WIND SHIFT FROM THUNDERSTORM OUTFLOWS DURING THE LATE
AFTERNOON AND EVENING. SKIES CLEAR OUT OVERNIGHT WITH ANOTHER
ROUND OF MORE ISOLATED THUNDERSTORMS POSSIBLE OVER THE MOUNTAINS
ON SATURDAY. THESE MAY HAVE A HARDER TIME MOVING OFF INTO THE
ADJACENT LOWER ELEVATIONS SO TERMINALS ARE MORE LIKELY TO BE
SPARED ON SATURDAY. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KT
LONG TERM...ROSE
AVIATION...KT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1120 AM MDT FRI AUG 15 2014
.UPDATE...
ISSUED AT 745 AM MDT FRI AUG 15 2014
BLENDED LATEST OBSERVATIONS INTO FRONT END OF FORECAST GRIDS. ALSO
TWEAKED SKY COVER TO FIT LATEST SATELLITE TRENDS. NO OTHER CHANGES
AT THIS TIME.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM MDT FRI AUG 15 2014
...MONSOONAL AIR MASS REMAINS BUT LESS OF A TRIGGER THAN YESTERDAY...
THE AIR MASS OVER THE REGION REMAINS PLENTY MOIST...BUT THERE IS NOT
SO MUCH OF TRIGGER TO GET THINGS GOING TODAY AS YESTERDAY.
YESTERDAY...A FAIRLY STRONG SHORTWAVE MOVED THROUGH NORTHERN
COLORADO...TRIGGERING SOME RATHER INTENSE RAINFALL OVER THE PIKES
PEAK REGION...WITH GENERALLY WEAKER ACTIVITY ELSEWHERE. TODAY...THE
OVERALL AIR MASS IS SIMILAR BUT THERE DOESN`T SEEM TO BE AS MUCH OF A
DISTURBANCE AVAILABLE TO GET THINGS GOING.
WATER VAPOR PICTURES THIS MORNING DO SHOW A SWIRL IN THE IMAGERY
OVER NORTHWEST ARIZONA AND THE RUC DOES IDENTIFY A WEAK DEPRESSION
ASSOCIATED WITH THIS SWIRL. HOWEVER...SHORT TERM MODELS DON`T DO
MUCH WITH THE DEPRESSION THROUGH THE DAY. THE NAM12 DOES HINT AT A
VERY WEAK PIECE OF ENERGY ROUNDING THE TOP OF THE RIDGE THIS
AFTERNOON AND THEN DROPPING SOUTHEAST THROUGH THE PLAINS THIS
EVENING. THIS MIGHT BE A PIECE OF THE ENERGY NEAR THE 4 CORNERS
REGION...OR IT MIGHT JUST BE MODEL FEEDBACK TO CONVECTION DEVELOPING
OVER THE MOUNTAINS. IN ANY EVENT...IT DOESN`T LOOK NEARLY AS STRONG
AS YESTERDAY`S SHORTWAVE. SO...EXPECTING TODAY`S CONVECTION TO BE
MORE TERRAIN DRIVEN...DEVELOPING OVER THE MOUNTAINS BY EARLY
AFTERNOON...BEFORE DRIFTING SOUTHEASTWARD ACROSS THE PLAINS LATER IN
THE AFTERNOON INTO THE EVENING.
WITH THE MONSOON PLUME REMAINING OVER THE REGION...AND SURFACE
DEWPOINTS REMAINING HIGH...THE POTENTIAL FOR ANY GIVEN THUNDERSTORM
TO PRODUCE LOCALIZED FLASH FLOODING WILL CONTINUE...NOT ONLY FOR THE
BURN SCARS...BUT FOR ANYWHERE AN INTENSE...SLOW MOVING STORM HAPPENS
TO TRACK. THIS WILL BE THE PRIMARY WEATHER CONCERN TODAY...ALONG
WITH LIGHTNING AND THE POSSIBILITY OF LOCAL THUNDERSTORM WIND BURSTS
TO 40 OR 50 MPH. LW
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 400 AM MDT FRI AUG 15 2014
MODELS STRUGGLING WITH THE EXTENDED PERIOD WITH RUN TO RUN
INCONSISTENCIES...AND HAVE NOT MADE MANY CHANGES TO THE GOING
FORECAST.
HIGH PRESSURE WILL CONTINUE ACROSS THE DESERT SOUTHWEST THROUGH
EARLY NEXT WEEK WITH SEVERAL WEAK DISTURBANCES PASSING ACROSS
COLORADO. THIS WILL KEEP THE MONSOON LIKE PATTERN GOING ACROSS
THE STATE WITH MOISTURE BEING THE LIMITING FACTOR. EXPECT DAILY
AFTERNOON AND EVENING CONVECTION ACROSS THE MOUNTAINS WHERE
DIURNAL HEATING AND INSTABILITY WILL FAVOR THUNDERSTORM
DEVELOPMENT. WHILE MOISTURE MAY BE MORE LIMITED...THUNDERSTORMS
WILL STILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL...AND
FLASH FLOODING WILL CONTINUE TO BE AN ISSUE ON AREA BURN SCARS
ALONG WITH AREAS THAT HAVE SEEN RECENT HEAVY RAIN. LESS CERTAINTY
EXISTS ON THE EASTERN PLAINS. THE GFS CONTINUES TO PRODUCE DAILY
ROUNDS OF THUNDERSTORMS THAT MOVE OFF THE MOUNTAINS AND INTO THE
PLAINS EACH NIGHT. THE NAM AND ECMWF ARE LESS EXCITED ABOUT SHOWER
AND THUNDERSTORM ACTIVITY ACROSS THE PLAINS. FOR NOW HAVE LOW POPS
THROUGH THE EVENING HOURS FOR THE PLAINS GIVEN THE UNCERTAINTY.
CURRENT MODEL PROJECTIONS HAVE DECENT WAVES MOVING ACROSS THE
REGION SUNDAY AND TUESDAY...WHICH MAY BE THE DAYS THAT SEE THE
GREATEST THUNDERSTORM POTENTIAL FOR THE PLAINS.
LACK OF MODEL CONSISTENCY BY LATE TUESDAY THROUGH THURSDAY LEADS
TO LOW FORECAST CONFIDENCE. THE 00Z GFS DROPPED A LOW PRESSURE
CENTER DOWN THE CALIFORNIA COAST...WITH A STRONG TROUGH DIGGING
ACROSS THE PACIFIC NORTHWEST. A QUICK GLANCE OF THE 06Z RUN DOES
NOT HAVE THIS LOW AT ALL...WITH A MORE BROAD PACIFIC NORTHWEST
TROUGH. GIVEN THESE INCONSISTENCIES...HAVE CONTINUED THE LOW POPS
ACROSS THE REGION ON WEDNESDAY AND THURSDAY...BUT THESE WILL NEED
TO BE ADJUSTED BASED ON FUTURE MODEL GUIDANCE.
TEMPERATURES WILL REMAIN WARM THROUGH THE EXTENDED PERIOD WITH
UPPER 80S TO MID 90S ACROSS THE LOWER ELEVATIONS. MOZLEY
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1041 AM MDT FRI AUG 15 2014
THUNDERSTORMS SHOULD BE LESS WIDESPREAD TODAY THAN YESTERDAY AND
THE ATMOSPHERIC MOISTURE HAS DECREASED SOME...BUT SEVERAL HIGH
RES MODELS DEVELOP THUNDERSTORMS OVER THE MOUNTAINS AROUND NOON
AND SPREAD THEM OFF INTO THE ADJACENT PLAINS AROUND 3 PM. ENOUGH
ATMOSPHERIC MOISTURE REMAINS IN PLACE FOR A FEW EMBEDDED STRONG
THUNDERSTORMS CAPABLE OF LOCALLY HEAVY RAINFALL...BRIEF MVFR
CONDITIONS...AND ERRATIC WIND GUSTS UP TO 40 KTS. KCOS HAS THE
BEST CHANCE OF THE 3 TERMINALS TO BE AFFECTED...THOUGH ITS STILL
UNCLEAR IF IT WILL TAKE A DIRECT HIT. WILL MAINTAIN VCTS IN THE
KCOS TAF...THOUGH WILL INCLUDE A TEMPO 15G30KT GROUP TO ACCOUNT
FOR HIGHER LIKELIHOOD OF SEEING ERRATIC WIND GUSTS FROM NEARBY
THUNDERSTORMS. KALS COULD ALSO SEE A VCTS...THOUGH PROBABILITY
LOOKS A LITTLE LOWER THAN AT KCOS. KPUB HAS THE LEAST PROBABILITY
OF BEING AFFECTED BY -TSRA...SO WILL LEAVE VCTS OUT FOR NOW...BUT
THIS WILL NEED TO BE MONITORED AS HIGH RES MODELS ARE TRENDING
TOWARDS BRINGING A BROKEN LINE OF THUNDERSTORMS THROUGH THE AREA
BETWEEN 23Z-00Z. BOTH KCOS AND KPUB WILL SEE A BRIEF NORTH TO
NORTHWEST WIND SHIFT DURING THE LATE AFTERNOON/EVENING DUE TO
OUTFLOW FROM THUNDERSTORMS. SKIES CLEAR OUT OVERNIGHT AND SATURDAY
APPEARS TO HAVE A LATER START AND EVEN A LESSER COVERAGE OF
THUNDERSTORMS. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...LW
SHORT TERM...LW
LONG TERM...MOZLEY
AVIATION...KT
AREA FORECAST DISCUSSION
NWS MIAMI FL
313 PM EDT FRI AUG 15 2014
.DISCUSSION...
AS OF 1830Z...VERY ACTIVE CONVECTION ACROSS THE ATLANTIC COAST
AND THE ADJACENT ATLANTIC WATERS. VERY ACTIVE THUNDERSTORMS EXTEND
FROM NORTHEAST MIAMI DADE NORTHWARD THROUGH EASTERN BROWARD AND
PALM BEACH COUNTIES. THE LATEST HRRR MESO-SCALE MODEL GUIDANCE
WHICH INITIALIZED GENERALLY WELL ON THIS CONVECTION INDICATES
THIS ACTIVITY STARTING TO DISSIPATE AROUND 22Z. BUT AS ALWAYS WITH
EXISTING OUTFLOW BOUNDARIES ADDITIONAL CONVECTION COULD LINGER
INTO THE EARLY EVENING HOURS WITH THE CURRENT FORECAST INDICATING
ACTIVE CONVECTION WITH NUMEROUS SHOWERS/THUNDERSTORMS ACROSS THE
EASTERN HALF OF THE PENINSULA THROUGH 00Z THIS EVENING.
THE LATEST MODEL GUIDANCE INDICATES SOME RELATIVELY DRIER AIR
FORECAST TO MOVE NORTHWARD INTO THE FLORIDA STRAITS TONIGHT INTO
SATURDAY. HOWEVER...THE GUIDANCE INDICATES THAT IT MAY NOT MAKE IT
FAR ENOUGH NORTHWARD ON SATURDAY SUCH THAT LINGERING DEEP
MOISTURE OVER MOST OF THE PENINSULA AND ADJACENT WATERS COULD LEAD
TO ADDITIONAL AFTERNOON SHOWERS/THUNDERSTORMS ACROSS THE REGION
WITH THE SATURDAY FORECAST INDICATING THE GREATEST COVERAGE ACROSS
THE INTERIOR ALTHOUGH SCATTERED ACTIVITY IS FORECAST FOR THE GULF
AND ATLANTIC COAST METRO AREAS. BY SUNDAY THE GUIDANCE INDICATES
THAT THE DRIER AIR IS FORECAST TO CONTINUE MOVING NORTH WITH A
CONSIDERABLE REDUCTION ACROSS THE REGION IN SHOWERS/THUNDERSTORMS
WITH MAINLY THE INTERIOR REGIONS FORECAST TO HAVE SCATTERED
ACTIVITY.
THERE IS GUIDANCE SUGGESTING THAT SOME DUST ASSOCIATED WITH THE SAHARAN
AIR LAYER COULD ENTER THE REGION LATE SATURDAY INTO SUNDAY THEN
MOVE ACROSS THE REGION LATE SUNDAY AND PERSIST INTO EARLY NEXT
WEEK. SO THERE MAY BE NOTICEABLY HAZY SKIES SUNDAY INTO EARLY
NEXT WEEK.
&&
.MARINE...
LIGHT SOUTH TO SOUTHWEST WINDS ARE FORECAST ACROSS THE REGIONAL
WATERS TONIGHT THROUGH SATURDAY. BY SUNDAY WINDS ARE FORECAST TO
BECOME EAST TO SOUTHEAST WHILE REMAINING AROUND OR BELOW 10 KNOTS
AND PERSISTING INTO EARLY NEXT WEEK. REGIONAL SEAS ARE FORECAST TO
BE 2 FEET OR LESS THROUGH THE WEEKEND INTO AT LEAST EARLY NEXT
WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 90 77 90 78 / 60 30 50 20
FORT LAUDERDALE 91 79 91 81 / 60 20 50 20
MIAMI 91 78 90 80 / 60 20 40 10
NAPLES 90 78 90 78 / 50 20 30 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...21/KM
LONG TERM....60/BD
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
500 PM CDT FRI AUG 15 2014
.DISCUSSION...
254 PM CDT
THE MAIN FORECAST CONCERNS WILL CONTINUE TO FOCUS ON THE CHANCES OF
THUNDERSTORMS AND THE POSSIBILITY OF HEAVY RAIN ACROSS PORTIONS OF MY
AREA THROUGH THE WEEKEND.
COOL SURFACE HIGH PRESSURE CONTINUES TO SHIFT EAST-SOUTHEASTWARD
OVER THE OHIO VALLEY EARLY THIS AFTERNOON. THIS IS PRODUCING ANOTHER
FABULOUS WEATHER DAY ACROSS THE REGION THIS AFTERNOON WITH
TEMPERATURES PRIMARILY IN THE MID TO UPPER 70S. HOWEVER...ATTENTION
IS BEGINNING TO FOCUS ON THE SYSTEM TO OUR WEST...WHICH IS ALREADY
PUSHING SOME HIGHER LEVEL CLOUDINESS INTO MY SOUTHWESTERN AREAS.
WATER VAPOR IMAGERY EARLY THIS AFTERNOON INDICATES THE PRESENCE OF A
COUPLE OF MID/UPPER LEVEL DISTURBANCES ACROSS THE PLAINS. THE FIRST
IS LOCATED OVER THE WESTERN DAKOTAS...WITH THE SECOND OVER THE
NEBRASKA-KANSAS BOARDER. HOWEVER...IT IS THE SOUTHERNMOST
DISTURBANCE THAT IS THE MAIN FOCUS FOR THE WEATHER EXPECTED MUCH OF
THIS WEEKEND ACROSS NORTHERN ILLINOIS/NORTHWESTERN INDIANA. MODEL
GUIDANCE IS IN GOOD AGREEMENT WITH TRACKING THIS DISTURBANCE SLOWLY
EASTWARD ACROSS SOUTHERN IOWA TONIGHT...THEN EAST-SOUTHEASTWARD
ACROSS CENTRAL ILLINOIS BY SUNDAY MORNING. THE GFS AND ECMWF ARE
FAVORED WITH THE HANDLING OF THE SYSTEM THROUGH THE WEEKEND.
CONVECTIVE ACTIVITY WILL LIKELY FIRE UP DOWNSTREAM OF THE SOUTHERN
NEBRASKA DISTURBANCE TONIGHT...NAMELY ACROSS PORTIONS OF SOUTHERN
IOWA...MISSOURI AND PERHAPS ACROSS FAR WESTERN ILLINOIS ALONG THE
NOSE OF A DEVELOPING SOUTH-SOUTHWESTERLY LOW LEVEL JET. THE REMNANTS
OF SOME OF THIS ACTIVITY WILL TRY TO MOVE EASTWARD ACROSS THE AREA
SATURDAY MORNING. HOWEVER...IT APPEARS THIS ACTIVITY WILL LIKELY
WEAKEN CONSIDERABLY WITH EASTWARD EXTENT DURING THE MORNING AS IT
MOVES AWAY FROM THE BETTER FORCING AND INSTABILITY. AS SUCH...IT
APPEARS THE THREAT FOR THUNDERSTORMS WILL BE LOW ACROSS MUCH OF
NORTHEASTERN ILLINOIS AND INTO INDIANA...WITH POSSIBLY ONLY SOME
SHOWERS VOID OF THUNDER POSSIBLE.
ADDITIONAL SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE SATURDAY
AFTERNOON AND NIGHT AS THE MAIN UPPER SYSTEM MOVES FROM SOUTHEASTERN
IOWA OVER CENTRAL ILLINOIS. HOWEVER...AGAIN IT APPEARS THE MAIN
THREAT OF THUNDER WILL REMAIN ALONG AND SOUTH OF INTERSTATE 80 TO
THE EAST OF THE TRACK OF THE MID LEVEL WAVE. THERE IS A THREAT FOR
SOME VERY HEAVY RAINFALL WITH THESE STORMS ON SATURDAY/SATURDAY
NIGHT ACROSS CENTRAL ILLINOIS GIVEN PWATS COULD BE IN EXCESS OF 2
INCHES AND WARM CLOUD DEPTHS IN EXCESS OF 13,000 FEET. THIS THREAT
WILL NEED TO BE WATCHED...BUT AT THIS TIME IT APPEARS THE PRIMARILY
THREAT FOR THIS HEAVY RAINFALL COULD REMAIN JUST OUTSIDE MY AREA.
A COLD FRONT IS ALSO EXPECTED TO DROP DOWN LAKE MICHIGAN LATE
SATURDAY. THIS COLD FRONT SHOULD SHIFT SOUTHWARD ACROSS NORTHERN
ILLINOIS BY LATE SATURDAY NIGHT/EARLY SUNDAY MORNING. ONCE THIS
FRONT PUSHES THROUGH...ONSHORE FLOW WILL PREVAIL ACROSS NORTHEASTERN
ILLINOIS AND PORTIONS OF NORTHWESTERN INDIANA. THIS SHOULD KEEP MUCH
OF NORTHERN ILLINOIS DRY BUT CLOUDY ON SUNDAY. AS A RESULT...I
HAVE DROPPED POPS ACROSS MUCH OF NORTHERN ILLINOIS ON SUNDAY.
HOWEVER...THE EFFECTS OF THE MID LEVEL SYSTEM WILL STILL POSSIBLY
LEAD TO ADDITIONAL THUNDERSTORMS SUNDAY...PRIMARILY ACROSS MY EAST
CENTRAL ILLINOIS AND NORTHWESTERN INDIANA COUNTIES. HEAVY RAINFALL
WILL AGAIN BE A THREAT WITH THESE STORMS.
THINGS FINALLY QUITE DOWN AREA-WIDE FOR A SHORT PERIOD LATE MONDAY.
HOWEVER...THE WEATHER PATTERN FROM MID TO LATE THIS COMING WEEK
LOOKS TO BE A WARMER AND ACTIVE AT TIMES. THE UPPER LOW/TROUGH
CURRENT IN PLACE ACROSS THE PACIFIC NORTHWEST IS PROGGED TO SHIFT
EASTWARD ACROSS THE UPPER MIDWEST BY TUESDAY. THIS WILL BRING OUR
NEXT CHANCE OF SHOWERS AND STORMS TO AREA...ALONG WITH WARMER
TEMPERATURES. ADDITIONAL WAVES OF STORMS ARE POSSIBLE LATER IN THE
WEEK AS WELL WITH THE LIKELIHOOD OF THE MID/UPPER LEVEL PATTERN
REMAINING DISTURBED ACROSS THE NORTHERN HALF OF THE COUNTRY.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* CHANCE FOR BRIEF SOUTHEAST WINDS EARLY THIS EVE BUT SPEEDS
SHOULD BE UNDER 10 KT.
* SCATTERED SHOWERS WITH A SLIGHT CHANCE OF A THUNDERSTORM
TOMORROW AFTERNOON.
JEE/MTF
//DISCUSSION...UPDATED 18Z...
HIGH PRESSURE IS OVER THE REGION AND SLOWLY SHIFTING EAST. THE
NEXT LOW PRESSURE SYSTEM IS OVER THE PLAINS AND GUIDANCE IS
FINALLY ALIGNING WITH THE LOW PASSING THROUGH SOUTH CENTRAL IL
LATE SATURDAY NIGHT THROUGH SUNDAY.
FOR TODAY...THE WEAK FLOW WILL LEAD TO LIGHT WINDS VARYING FROM
SOUTH TO SOUTHWEST WITH INCREASING CLOUDS THROUGH THIS EVENING. A
LAKE BREEZE IS EXPECTED TO FORM...BUT FLOW IS STRONG ENOUGH ALOFT
TO KEEP IT EAST OF THE TERMINALS. IN FACT CAN STILL CLEARLY SEE
SMOKE FROM GARY MOVING NORTHEAST OVER THE LAKE SO NO LAKE BREEZE
HAS FORMED YET. WINDS WEAKEN TONIGHT WITH SOUTH TO SOUTH-
SOUTHWEST WINDS.
WITH GUIDANCE AGREEING ON THE NEXT LOW...THINKING THE MAJORITY OF
SHOWERS AND STORMS WILL REMAIN SOUTH OF THE TERMINALS. SCATTERED
SHOWERS MAY MOVE OVER THE TERMINALS IN THE VERY LATE MORNING TO
EARLY AFTERNOON. CONDITIONS DO NOT LOOK EXTREMELY FAVORABLE FOR
THUNDERSTORMS AT THIS TIME...BUT WILL STILL MENTION A SLIGHT
CHANCE OF THUNDER WITH HEAVY DOWNPOURS POSSIBLE. GUIDANCE HINTS AT
MVFR CIGS AT GYY WITH A MUCH SMALLER CHANCE OVER THE EASTERN
TERMINALS. WILL CONTINUE TO CARRY SCT025 AT RFD...BUT HAVE LOW
CONFIDENCE IN MVFR CIGS. SSW TO SW WINDS MAINLY UNDER 10 KT ARE
EXPECTED TOMORROW.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM THAT LAKE BREEZE WILL REMAIN EAST OF THE AREA LATE THIS
AFTERNOON/EARLY THIS EVE.
* MEDIUM IN COVERAGE AND TIMING OF SHOWERS TOMORROW...LOW
CONFIDENCE IN THUNDERSTORMS.
* HIGH IN ALL OTHER FORECAST ELEMENTS.
JEE/MTF
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT THROUGH THURSDAY...PERIODIC CHANCES FOR SHRA/TSRA.
KREIN
&&
.MARINE...
215 PM CDT
LARGE AREA OF HIGH PRESSURE CENTERED JUST SOUTH OF LAKE MICHIGAN
WILL SHIFT SOUTHEAST TONIGHT. A WEAK LOW PRESSURE SYSTEM IN SOUTH
CENTRAL CANADA WILL DEEPEN SOME TONIGHT AS IT PASSES JUST NORTH OF
THE UPPER GREAT LAKES REGION. THE PRESSURE GRADIENT INCREASES
OVERNIGHT INTO EARLY SATURDAY MORNING...ESPECIALLY ALONG THE
NORTHERN HALF OF THE LAKE. THIS WILL MAINTAIN SW FLOW
TONIGHT...WITH WINDS APPROACHING 25-30 KT FOR A BRIEF TIME IN THE
NORTH LATE TONIGHT. BEHIND THE LOW...HIGH PRESSURE BUILDS INTO
SOUTHERN ONTARIO AND SENDS A COLD FRONT SOUTH DOWN THE LAKE
SATURDAY AFTERNOON AND EVENING. ADDITIONALLY...AN AREA OF LOW
PRESSURE IN THE CENTRAL PLAINS WILL SLOWLY DRIFT EAST TO THE OHIO
VALLEY BY LATE SUNDAY THEN CONTINUE TO THE ATLANTIC SEABOARD
MONDAY. THIS WILL HELP MAINTAIN OR A PERIOD OF NORTH TO
NORTHEASTERLY WINDS. ADDITIONAL WEAKER LOW PRESSURE AREAS WILL
PUSH TOWARD THE GREAT LAKES NEXT WEEK...MAINTAINING A SOUTH
COMPONENT TO THE WIND WITH OCCASIONAL THUNDERSTORMS THROUGH MID
WEEK.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
308 PM CDT Fri Aug 15 2014
.SHORT TERM...(This evening through Saturday)
ISSUED AT 307 PM CDT FRI AUG 15 2014
Decaying MCS moving toward the CWA early this afternoon, with some
light showers being reported near Galesburg. Most precipitation
still west of the Mississippi River, with the HRRR showing it
reaching about as far east as Springfield late this afternoon before
diminishing. Latest LAPS soundings from Springfield and Jacksonville
showing a fair amount of dry air below 700 mb, so am not expecting a
lot of accumulation out of this.
Shortwave currently moving southeast out of South Dakota/Nebraska
starting to produce additional storms in Kansas, and this area of
storms should expand as the wave moves eastward and the low level
jet increases. HRRR and NAM show this next MCS approaching far
western Illinois by late evening, but the other high-res models such
as the ARW and NMM are a bit slower with arrival across the western
CWA after about 2-3 am. All models show the MCS diminishing during
the morning, but redevelopment taking place toward late afternoon in
the west near a surface low in southeast Iowa. Extensive cloud cover
should mitigate much of the severe weather potential, but
precipitable water values increasing to over 2 inches will result in
some locally heavy rains.
&&
.LONG TERM...(Saturday night through Friday)
ISSUED AT 307 PM CDT FRI AUG 15 2014
Occluded low pressure will reach western IL around 00z/7pm Saturday,
bringing abundant moisture with the potential for some heavy rains.
The latest model runs have shown a diminishing threat for strong
storms in western IL, and SPC has reduced the 5% threat area to just
west of a line from Rushville to Springfield. The threat for thunder
in general will remain low due to limited ice formation and only
weak instability. Limited afternoon sunshine after morning rain
showers will also help to keep instability in check for Saturday
evening. Rain will be likely during the evening southwest of
Lincoln, then expand to the Indiana border after midnight Sat night.
Likely rain will continue on Sunday east of I-55 as the slow moving
low pressure system moves to near LWV by 00z/7pm Sunday. Bufkit
sounding analysis shows better instability ahead of the low in our
southeast areas Sunday afternoon, with MUCAPE up to 1500 J/kg, but
confidence is low that storms will become very strong due to limited
sunshine once again.
Precipitable water values will remain very high through Sunday with
2" to 2.3" across most of central and southeast IL. Locally heavy
rainfall from Saturday through Sunday evening could push 2 day totals
between 2" and 3".
As the low pulls east of IL on Sunday night, we expect diminishing
precip chances from west to east, with a break in the rain expected
at least on Monday. The Canadian GEM still indicated lingering
rain in most of our area, so we left some slight chance PoPs for
Monday.
The next weather system will arrive quickly late Monday night and
Tuesday, with increasing precip chances NW of the IL Monday night.
Relatively good agreement of a warm front moving east across IL on
Tuesday prompted chance PoPs across the board. The upper trough will
deepen into IL on Tuesday night and Wed, with a trailing cold front
lingering across IL through Thursday, keeping rain chances
entrenched in the forecast through Thursday night. Warm and very
muggy air will dominate the mid week period with the rain chances,
as dewpoints remain in the low 70s and highs climb into the mid to
upper 80s.
Friday should bring a break in the rain as upper level ridging
develops bringing even warmer air into central IL the following
weekend.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 1235 PM CDT FRI AUG 15 2014
Area of decaying showers/storms dropping southeast from Iowa may
brush KSPI/KPIA later this afternoon. A period of dry weather is
then expected at these sites until after 06Z, when another
convective complex moves east from Iowa/Missouri. At the TAF sites
further east, have limited shower mention to about the 08-15Z time
frame as VCSH, as several of the models weaken the overnight rain
enough that the eastward extent is still in question.
Have seen some cloud heights as low as around 3500 feet this
afternoon with initial cumulus development, but most ceilings
should be above 10KFT. Ceilings lower again late evening and
overnight ahead of the convection, but have kept at VFR levels.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GEELHART
LONG TERM...SHIMON
AVIATION...GEELHART
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
218 PM CDT FRI AUG 15 2014
.DISCUSSION...
331 AM CDT
SHORT TERM...THROUGH FRIDAY NIGHT...
FOR THE REMAINDER OF THE NIGHT...WITH THE CENTER OF HIGH PRESSURE
MOVING OVERHEAD...WINDS HAVE BECOME LIGHT AND VARIABLE UNDER MOSTLY
CLEAR SKIES. AN UNSEASONABLY...DRY AIRMASS IS IN PLACE WITH MANY
LOCATIONS EXPECTED TO SEE MIN TEMPS DROP INTO THE MIDDLE TO UPPER
40S. WHILE THIS WILL LIKELY NOT REACH RECORD BREAKING LOW
TEMPERATURES OVERNIGHT...THE LOWS WILL BE AROUND 15 DEGREES BELOW
NORMAL. FRIDAY SHOULD REMAIN QUIET AS THE CENTER OF HIGH PRESSURE
SETTLES INTO THE OHIO VALLEY AND A TROUGH OF LOW PRESSURE DEVELOPS
OVER THE CENTRAL PLAINS. A SOUTHWESTERLY GRADIENT WILL SET UP WITH
WINDS INCREASING FROM LIGHT AND VARIABLE TO ARND 10 KT THIS
AFTERNOON. THE MAIN CONCERN FOR THIS AFTERNOON WILL BE WHETHER A
LAKE BREEZE WILL FORM AND HOW FAR INLAND IT MIGHT PUSH...WHICH IN
TURN WOULD AFFECT TEMPS ALONG THE LAKEFRONT. WITH MOSTLY CLEAR
SKIES...TEMPERATURES SHOULD REACH ARND 80F THIS AFTERNOON. A WEAK
GRADIENT AND ADEQUATE DIFFERENTIAL HEATING BETWEEN THE LAKE AND LAND
SHOULD ALLOW FORMATION OF A LAKE BREEZE THIS AFTERNOON.
HOWEVER...THE LATEST SHORT RANGE MODEL GUIDANCE SUGGESTS THAT WINDS
THROUGH THE BOUNDARY LAYER SHOULD BE SWLY TO ARND 10KT. SO...WHILE
THE DEVELOPMENT OF A LAKE BREEZE IS LIKELY...THE QUESTION BECOMES
WHETHER IT WILL PENETRATE INLAND ENOUGH TO IMPACT TEMPERATURES
ACROSS THE INLAND PORTIONS OF THE CHICAGO METRO AREA. AT THIS
POINT...FEEL THAT THE LAKE BREEZE WILL REMAIN CLOSE TO
SHORE...KEEPING LAKEFRONT MAX TEMPS IN THE MIDDLE 70S.
THE NEXT FEATURE OF CONCERN WILL BE A NORTHERN STREAM SHORTWAVE
CURRENTLY OVERTOPPING THE UPPER RIDGE OVER THE NRN PLAINS AND A
MIDDLE STREAM SHORTWAVE OVER THE CENTRAL PLAINS. WITH WEAK UPPER
LEVEL WINDS ON THE ERN SIDE OF THE UPPER RIDGE...THESE SYSTEMS WILL
TRACK RATHER SLOWLY ACROSS THE PLAINS. THE LATEST GUIDANCE SUGGESTS
THAT THE MORE SOUTHERN OF THE 2 SHORTWAVES WILL MOVE OUT AHEAD OF
THE NRN STREAM SHORTWAVE...BRINGING INCREASING CLOUDINESS FRIDAY
EVENING AND THEN STRENGTHENING AS IT MOVES OVER NRN MO/SRN IA BY
SATURDAY MORNING. AN ASSOCIATED SFC LOW IS EXPECTED TO MOVE INTO
SERN IA BY SATURDAY MORNING WITH A DEVELOPING WARM FRONT EXTENDING
SEWD ALONG THE MISSISSIPPI RIVER. THE TRACK AND TIMING OF THE LEAD
SHORTWAVE IS STILL A BIT UNCERTAIN WITH SOME TIMING AND INTENSITY
DIFFERENCES AMONG THE SHORT RANGE GUIDANCE...THE GENERAL TREND
SHOULD BE FOR INCREASING POPS OVER THE WRN PORTIONS OF THE
CWA...WITH LOCATIONS ALONG AND POSSIBLE JUST EAST OF THE I-39
CORRIDOR SEE SOME RAIN AFTER MIDNIGHT FRIDAY NIGHT AND INTO THE EARLY
MORNING HOURS.
KREIN
SATURDAY THROUGH SUNDAY...
BIGGEST CONCERN WILL BE ON QPF TOTALS SAT INTO SUN WITH A SLOW
MOVING WAVE. THIS COUPLED WITH INCREASED PWAT VALUES NEARING 2"
PRIMARILY SAT...RAISES CONCERNS ABOUT SLOW MOVING STORMS THAT COULD
BE EFFICIENT AT PRODUCING VERY HEAVY RAINFALL IN A SHORT PERIOD OF
TIME. THESE ANOMALOUSLY HIGH PWAT VALUES ARE PROGGED TO LINGER THRU
SUN.
500MB TROUGH AXIS WILL CONTINUE TO PIVOT EAST AWAY FROM THE GREAT
LAKES REGION...AS THE LONGWAVE PATTERN BEGINS TO TRANSITION INTO A
QUASI-ZONAL SETUP. THIS WILL ALLOW SYSTEMS TO EASILY TRAVERSE THE
CONUS FROM WEST TO EAST. HOWEVER THE WRINKLE WITH THIS SETUP WILL BE
THAT OPER GUIDANCE IS INDICATING THE ACTIVE ZONE WILL SETUP ACROSS
THE CWFA SAT AFTN THRU SUN EVE. GUIDANCE HAS BEEN CONSISTENT WITH
DEVELOPING A SFC RIDGE OVER CENTRAL ONTARIO AND HELPING TO KEEP A
STALLED FRONTAL BOUNDARY ACROSS THE MID-MISSOURI VALLEY STRETCHING
EAST INTO THE OHIO VALLEY SAT NGT/SUN. AS PREVIOUSLY NOTED ABOUT A
SLOW MOVING SYSTEM...GUIDANCE HAS A WAVE LIFTING NORTHEAST INTO THE
SOUTHWEST PORTIONS OF THE CWFA SAT AFTN AND SLOWLY LIFTING NORTHEAST
SUN. WITHIN THIS PERIOD IT IS BECOMING AN INCREASED CONCERN THAT IF
CONVECTION DEVELOPS...WHICH APPEARS FAVORABLE...THAT SOME OF THESE
STORMS COULD EASILY PUT DOWN HEAVY RAINFALL IN A SHORT PERIOD OF
TIME. TEMPS SAT WILL LIKELY BE HELD DOWN SOMEWHAT GIVEN THE
INCREASED SOLAR SHIELDING...HOWEVER WITH LLVL MOISTURE INCREASING
DEW PTS WILL BE PUSHING INTO THE UPR 60S AND RESULT IN HUMID CONDS.
WINDS WILL BE LIGHT AS WELL...GENERALLY FROM THE SOUTH.
YET ANOTHER WEAK MID-LVL VORT WILL SLIDE EAST INTO THIS ZONE SUN AND
WITH THE HIGH LLVL MOISTURE AND WEAK FLOW...THE CONCERN FOR LOCALLY
HEAVY RAINFALL WILL PERSIST INTO SUN EVE. FORTUNATELY GUIDANCE HAS
BEEN INDICATING THAT THE QUASI-STATIONARY FRONTAL BOUNDARY MAY SLIP
FURTHER SOUTH AND COULD DISPLACE THE LOCATION OF HEAVIER RAINFALL TO
THE SOUTHERN CWFA SUN AFTN/EVE. THIS WOULD ALLOW A SLIGHTLY DRIER
NORTHERLY WIND TO PROVIDE SOME RELIEF TO AREAS NORTH OF I-80 WITH
HIGHS IN THE UPR 70S SUN.
MONDAY THROUGH THURSDAY...
ENSEMBLES ARE DEMONSTRATING SOME SPREAD IN THE MEDIUM TERM THRU
TUE...WITH REGARDS TO THE TIMING OF THE FLOW TRANSITIONING OUT OF
THE QUASI-ZONAL SETUP. BEYOND MID-WEEK GUIDANCE IS RATHER CONSISTENT
IN REDEVELOPING A NORTH ATLANTIC RIDGE...ALONG WITH SOME RIDGING
TRYING TO DEVELOP ACROSS THE PAC-NW. WHILE CONFIDENCE IS LOW...THIS
COULD SUGGEST THAT SOME DEGREE OF TROUGHING COULD RETURN TO THE
CENTRAL CONUS AND PERHAPS BRING SOME QUIETER WEATHER BACK TO THE
CWFA.
HOWEVER...CONFIDENCE IS LOW AS THERE IS STILL SOME SPREAD AMONGST
MEMBERS. OPER GUIDANCE IS ALSO SHOWING CONSIDERABLE SPREAD IN THE
EXTENDED PERIODS. THE OVERALL THEME APPEARS TO BE TEMPS RETURNING TO
SEASONAL CONDS IN THE LOW TO PSBLY MID 80S WITH OVERNIGHT LOWS IN
THE 60S.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SCATTERED SHOWERS WITH A SLIGHT CHANCE OF A THUNDERSTORM
TOMORROW AFTERNOON.
JEE
//DISCUSSION...UPDATED 18Z...
HIGH PRESSURE IS OVER THE REGION AND SLOWLY SHIFTING EAST. THE
NEXT LOW PRESSURE SYSTEM IS OVER THE PLAINS AND GUIDANCE IS
FINALLY ALIGNING WITH THE LOW PASSING THROUGH SOUTH CENTRAL IL
LATE SATURDAY NIGHT THROUGH SUNDAY.
FOR TODAY...THE WEAK FLOW WILL LEAD TO LIGHT WINDS VARYING FROM
SOUTH TO SOUTHWEST WITH INCREASING CLOUDS THROUGH THIS EVENING. A
LAKE BREEZE IS EXPECTED TO FORM...BUT FLOW IS STRONG ENOUGH ALOFT
TO KEEP IT EAST OF THE TERMINALS. IN FACT CAN STILL CLEARLY SEE
SMOKE FROM GARY MOVING NORTHEAST OVER THE LAKE SO NO LAKE BREEZE
HAS FORMED YET. WINDS WEAKEN TONIGHT WITH SOUTH TO SOUTH-
SOUTHWEST WINDS.
WITH GUIDANCE AGREEING ON THE NEXT LOW...THINKING THE MAJORITY OF
SHOWERS AND STORMS WILL REMAIN SOUTH OF THE TERMINALS. SCATTERED
SHOWERS MAY MOVE OVER THE TERMINALS IN THE VERY LATE MORNING TO
EARLY AFTERNOON. CONDITIONS DO NOT LOOK EXTREMELY FAVORABLE FOR
THUNDERSTORMS AT THIS TIME...BUT WILL STILL MENTION A SLIGHT
CHANCE OF THUNDER WITH HEAVY DOWNPOURS POSSIBLE. GUIDANCE HINTS AT
MVFR CIGS AT GYY WITH A MUCH SMALLER CHANCE OVER THE EASTERN
TERMINALS. WILL CONTINUE TO CARRY SCT025 AT RFD...BUT HAVE LOW
CONFIDENCE IN MVFR CIGS. SSW TO SW WINDS MAINLY UNDER 10 KT ARE
EXPECTED TOMORROW.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE THE LAKE BREEZE REMAINING EAST OF THE TERMINALS.
* MEDIUM CONFIDENCE IN COVERAGE AND TIMING OF SHOWERS
TOMORROW...LOW CONFIDENCE IN THUNDERSTORMS.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT THROUGH THURSDAY...PERIODIC CHANCES FOR SHRA/TSRA.
KREIN
&&
.MARINE...
215 PM CDT
LARGE AREA OF HIGH PRESSURE CENTERED JUST SOUTH OF LAKE MICHIGAN
WILL SHIFT SOUTHEAST TONIGHT. A WEAK LOW PRESSURE SYSTEM IN SOUTH
CENTRAL CANADA WILL DEEPEN SOME TONIGHT AS IT PASSES JUST NORTH OF
THE UPPER GREAT LAKES REGION. THE PRESSURE GRADIENT INCREASES
OVERNIGHT INTO EARLY SATURDAY MORNING...ESPECIALLY ALONG THE
NORTHERN HALF OF THE LAKE. THIS WILL MAINTAIN SW FLOW
TONIGHT...WITH WINDS APPROACHING 25-30 KT FOR A BRIEF TIME IN THE
NORTH LATE TONIGHT. BEHIND THE LOW...HIGH PRESSURE BUILDS INTO
SOUTHERN ONTARIO AND SENDS A COLD FRONT SOUTH DOWN THE LAKE
SATURDAY AFTERNOON AND EVENING. ADDITIONALLY...AN AREA OF LOW
PRESSURE IN THE CENTRAL PLAINS WILL SLOWLY DRIFT EAST TO THE OHIO
VALLEY BY LATE SUNDAY THEN CONTINUE TO THE ATLANTIC SEABOARD
MONDAY. THIS WILL HELP MAINTAIN OR A PERIOD OF NORTH TO
NORTHEASTERLY WINDS. ADDITIONAL WEAKER LOW PRESSURE AREAS WILL
PUSH TOWARD THE GREAT LAKES NEXT WEEK...MAINTAINING A SOUTH
COMPONENT TO THE WIND WITH OCCASIONAL THUNDERSTORMS THROUGH MID
WEEK.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
132 PM CDT Fri Aug 15 2014
.UPDATE...
ISSUED AT 129 PM CDT FRI AUG 15 2014
Have sent out an update to lower high temperatures across
primarily the northwest half of the CWA today. Extensive cloud
cover from decaying MCS has limited the temperature rise into the
lower 70s as of early afternoon. With more clouds and some showers
moving in later this afternoon, temperatures likely to rise only a
couple more degrees.
UPDATE ISSUED AT 1009 AM CDT FRI AUG 15 2014
Area of showers and thunderstorms advancing east across Iowa and
northern Missouri this morning, ahead of a shortwave across the
Plains. Latest high-resolution models show this progressing toward
the Mississippi River the remainder of the morning, before
decaying in west central Illinois, but the HRRR suggests some
light showers may make it as far east as Springfield by 4 pm.
Existing 20% PoP`s across the western CWA still sufficient.
Temperatures off to a chilly start in the northeast CWA underneath
an area of high pressure, with 44 degrees observed at the Danville
airport for a low. A decent recovery so far as sunshine as boosted
temperatures into the lower 60s. Remainder of the CWA is largely
in the upper 60s/lower 70s at 10 am with clouds increasing.
Question will be how much the clouds impact the temperatures this
afternoon, especially across the west. Have only made minor
changes for now, generally around a degree or so, to blend in with
the current trends. Latest HRRR and RAP seem a bit too high with
mid 80s this afternoon despite the cloud cover, so have leaned
more toward the LAMP guidance.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 328 AM CDT FRI AUG 15 2014
Boundary that pushed across parts of central thru southeast Illinois
yesterday has finally shifted just south of Interstate 70 early this
morning. Rather tight temp/dew point gradient across the forecast
area with upper 40 dew points across the northeast, while over our
far southwest counties, readings were in the low to mid 60s.
Quite a bit of mid and high level cloudiness was streaming southeast
into Iowa and extreme west central Illinois ahead of our next
shortwave over western Nebraska, and that cloud cover will have an
affect on afternoon highs, especially across the north and west.
High pressure just to our north and east will drift slowly away from
our area today with a return southerly flow developing by this
afternoon and evening. Forecast soundings continue to indicate quite
a bit of dry air in the low levels of the atmosphere thru this
evening so will keep our area dry but will have to keep an eye out
for our western counties as some of the shower activity forecast
over Iowa today may approach our far west by late afternoon or early
this evening. For now, will keep any mention of rain out in the west
until early this evening.
Models continue to indicate the more favorable 850 mb theta-e
advection/moisture convergence and low level jet position for
overnight convection would be to our west with whatever develops
over Iowa late tonight pushing into our far western areas after
midnight. PoPs will be on the increase, especially across the west
this evening with rain probably holding off over areas east of I-57
until Saturday morning.
&&
.LONG TERM...(Saturday through Friday)
ISSUED AT 328 AM CDT FRI AUG 15 2014
An unsettled weather pattern taking shape over central and southeast
IL with daily chances of showers and thunderstorms from this weekend
through the middle of next week, as humid conditions return along
with building heat by the middle of next week. 00Z forecast models
continue to show short waves/upper level low/trof moving into IL
later this weekend though still some timing differences and qpf
amounts vary between models and from run to run. Still looks like
increase chances of showers and thunderstorms from west to east
during the weekend with highest chances SW counties Sat and shifting
into eastern IL by Sunday night. SPC has 5% risk of severe storms
along and west of a Springfield to Peoria line Saturday while slight
risk of severe storms (15%) is WSW of IL over central and northern
MO. SPC then has 5% risk of severe storms Sunday SE of a Champaign
to Shelbyville line mainly in the afternoon and early evening hours.
Heavy rain threat also this weekend especially Sunday with
precipitable water values peaking from 2-2.50 inches. Highs 80-85F
over central IL this weekend with mid 80s over southeast IL. Humid
this weekend with dew points in the upper 60s and lower 70s.
Short wave trof/low exits east of IL early next work week but more
energy arriving thereafter to keep chances of showers and
thunderstorms going into middle of next week as humid dew points in
the upper 60s to mid 70s prevail. Temperatures to also heat up into
the mid to upper 80s by middle and later part of next week as upper
level heights rise over IL. SW parts of CWA approaching 90F from
Wed-Fri and afternoon heat indices in the mid to upper 90s.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 1235 PM CDT FRI AUG 15 2014
Area of decaying showers/storms dropping southeast from Iowa may
brush KSPI/KPIA later this afternoon. A period of dry weather is
then expected at these sites until after 06Z, when another
convective complex moves east from Iowa/Missouri. At the TAF sites
further east, have limited shower mention to about the 08-15Z time
frame as VCSH, as several of the models weaken the overnight rain
enough that the eastward extent is still in question.
Have seen some cloud heights as low as around 3500 feet this
afternoon with initial cumulus development, but most ceilings
should be above 10KFT. Ceilings lower again late evening and
overnight ahead of the convection, but have kept at VFR levels.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEELHART
SHORT TERM...SMITH
LONG TERM...07
AVIATION...GEELHART
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1122 AM CDT FRI AUG 15 2014
.UPDATE...
ISSUED AT 1120 AM CDT FRI AUG 15 2014
LOW LEVEL JET WAS BEGINNING TO WEAKEN AND SO WAS THE MCS IN CENTRAL
IA. THE ACTIVITY WAS MOVING SOUTHEAST IN THE NORTHWEST FLOW ALOFT.
THE HRRR MESO MODEL PUSHES SCATTERED SHOWERS INTO OUR WESTERN AND
SOUTHERN CWA THROUGH EARLY THIS AFTERNOON THEN WEAKENING. THERE
MAY ALSO BE ISOLATED THUNDERSTORMS. IN OUR NORTHEAST CWA DRIER AIR
IN PLACE AND MORE SUNSHINE EXPECTED THERE. OTHERWISE THICKER CLOUD
COVER IN OUR SOUTHWEST WILL KEEP TEMPERATURES IN THE MID 70S. HAVE
UPDATED THE GRIDS TO LOWER TEMPERATURES AND INCREASE SKY COVER.
WILL MONITOR TRENDS AND MAY HAVE TO LOWER READINGS EVEN MORE.
&&
.SYNOPSIS...
ISSUED AT 233 AM CDT FRI AUG 15 2014
NORTHWEST FLOW ALOFT ACROSS THE MIDWEST IS PUSHING CONVECTIVE
ACTIVITY OVER SD-MN AREA INTO IOWA...WHILE THE KEY SYSTEM OF THE
DAY...AN UPPER LEVEL SHORTWAVE TROUGH AND AREA OF PRECIP...IS
STILL EVOLVING OVER NE AND KS. SURFACE HIGH PRESSURE IS TO THE
EAST WHILE A WARMER AND MORE MOIST AIR MASS RESIDES TO OUR WEST AS
ILLUSTRATED BY A 20 DEGREE DEW POINT GRADIENT FROM CHICAGO TO DES
MOINES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 233 AM CDT FRI AUG 15 2014
CURRENT ONGOING SHOWER AND THUNDERSTORM ACTIVITY IS MAINLY
NUISANCE STUFF BEFORE THE MORE SIGNIFICANT ACTIVITY LATER TONIGHT.
AIR MASS OVER MOST OF THE CWA IS CURRENTLY RATHER COOL AND
DRY...AND THIS WILL CHALLENGE THE PERSISTENCE OF THE CONVECTIVE
ACTIVITY AS IT MOVES SOUTHEASTWARD THROUGH THE MORNING. SHORT RANGE
MODEL TRENDS SUGGEST THESE STORMS WILL WEAKEN AS THEY MOVE INTO OUR
AREA...THUS HAVE ONLY LOW POPS.
AS THE DAY PROGRESSES THE AIR MASS OVER THE AREA WILL BECOME MORE
HUMID WITH PWS CURRENTLY AROUND .75 INCH INCREASING UP TO AROUND
1.25 INCH BY 00Z. THIS IS AHEAD OF THE TROUGH WHICH IS FORECAST TO
MOVE SLOWLY EAST TODAY AND TONIGHT AND FOCUS THUNDERSTORM ACTIVITY
DURING THE OVERNIGHT HOURS...PRIMARILY IN THE SOUTHWEST PART OF
THE CWA. STORMS OVERNIGHT WILL ALSO BE SUPPORTED BY THE LLJ AND
850 MB BOUNDARY...THOUGH MODELS VARY ON THE DETAILS. FOLLOWED A
SOLUTION SUGGESTED BY THE 00Z ECMWF AND GEM PLUS A SPEEDIER NAM. WITH
THE MOISTENING AIR MASS...LOCALLY HEAVY RAIN IS POSSIBLE BUT THE
THREAT OF ANYTHING MORE THAN ISOLATED SEVERE WEATHER IS LOW DUE TO
LIMITED INSTABILITY.
WARM ADVECTION TODAY WILL BE COUNTERED BY MORE EXTENSIVE CLOUDINESS
THAN WE EXPERIENCED YESTERDAY...THUS EXPECT LITTLE NET CHANGE IN
MAX TEMPS AS THOSE FACTORS BALANCE OUT. WARMER AIR AND CLOUDS TONIGHT
HOWEVER WILL KEEP MIN TEMPS SEVERAL DEGREES WARMER THAN THIS
MORNINGS LOWS. WOLF
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 233 AM CDT FRI AUG 15 2014
DAILY CHANCES OF SHOWERS AND THUNDERSTORMS WILL TYPICAL MID AUGUST
TEMPERATURES.
OVERVIEW...INITIALIZATION AND VERIFICATION GOOD WITH MINOR BL MOISTURE
AND PRECIPITATION BIASES WITH AMERICAN SOLUTIONS A BIT TOO MOIST AND
TOO COVERAGE OF QPF AMOUNTS. RUN TO RUN VARIANCE SUPPORTS A 75/25 MIX
OF THE HI-RES ECMWF TO A MIX OF GEM-NH/GFS. LARGE SCALE FORCING TOOLS
SUGGEST LITTLE OR NO SEVERE RISK WITH SEVERAL EPISODES OF SHOWERS AND
STORMS OF MOSTLY THE PULSE VARIETY WITH SOME AREAS OF PRECIPITATION...MAINLY
SATURDAY.
LONG TERM FORECAST CONFIDENCE...AVERAGE (GOOD)...TIMING OF SHOWERS AND
STORMS AND LOCATION COVERAGE POOR TO FAIR...EXCEPT HIGHER CONFIDENCE
IN SATURDAY/S EVENT. INITIALIZATION AND VERIFICATION COUPLED WITH
SERIES OF UPPER DISTURBANCE MAKE FOR MARGINAL CONFIDENCE OF POPS
WITH AGAIN THE BEST CONFIDENCE SATURDAY/S EVENT IN SOUTHERN PORTIONS.
TEMPERATURES SHOULD GENERALLY BE WITHIN 3 DEGREES OF FORECAST.
SATURDAY...A MCS EVENT SUGGESTED TO AFFECT THE REGION WITH LIKELY POPS
SOUTH AND MODERATE TO HIGH CHANCE POPS NORTH. PW VALUES AOA 1.5" SUGGESTING
MODERATE TO LOCALLY SOME LOWER END RAIN AMOUNTS TO 1 INCH...OR MORE.
BEST FORCING SUGGESTED TO BE ALONG AND SOUTH OF HIGHWAY 34 WITH EVAPORATIVE
COOLING THAT SHOULD KEEP SOME AREAS HIGHS IN THE UPPER 70S....OTHERWISE...LOWER
80S. SATURDAY NIGHT...LINGERING SHOWERS AND EMBEDDED THUNDER ALONG WEAK
BOUNDARY IN NW FLOW WITH CHANCE POPS SUPPORTED...MINS WITH CLOUDS IN
THE MID TO UPPER 60S.
SUNDAY THROUGH THURSDAY...NW FLOW CONTINUES WITH A SERIES OF WEAK DISTURBANCES
SUGGESTING ISOLATED TO CHANCE POPS EVERY FORECAST PERIOD ATTM. MINOR
CHANGES IN TEMPERATURES WITH SLIGHTLY WARMER TEMPERATURES LATE NEXT
WEEK. HIGHS MOSTLY IN THE LOWER 80S...RISING INTO THE MID/UPPER
80S BY THURSDAY. LOWS IN THE MID/UPPER 60S. LIMITED INSTABILITY...SHEAR
AND FORCING SUGGEST LITTLE OR NO ORGANIZED SEVERE RISK ATTM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1120 AM CDT FRI AUG 15 2014
VFR CONDITIONS WILL GENERALLY PREVAIL THROUGH THE PERIOD.
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS AFTERNOON WILL BE WEAK
AND LIKELY HAVE LITTLE IF ANY IMPACT ON AREA TAF SITES. AS WARMER
AND MORE HUMID AIR PUSHES INTO THE AREA TONIGHT AS A SHORT WAVE
TROUGH PROGRESSES INTO THE MIDWEST...A GREATER CHANCE OF THUNDERSTORMS
IS EXPECTED OVERNIGHT TOWARD MORNING...ESPECIALLY IN THE BRL AREA.
THESE STORMS WILL LIKELY PRODUCE MVFR OR IFR CONDITIONS... THOUGH
CHANCES ARE LOWER THAT THEY WILL OCCUR AT CID...MLI AND DBQ COMPARED
TO BRL.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...HAASE
SYNOPSIS...WOLF
SHORT TERM...WOLF
LONG TERM...NICHOLS
AVIATION...HAASE
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
142 PM CDT Fri Aug 15 2014
...UPDATED AVIATION...
.SHORT TERM...(Today and tonight)
ISSUED AT 347 AM CDT FRI AUG 15 2014
A weak shortwave trough was approaching western Kansas this
morning. Ahead of this feature, elevated convection was ongoing near
the interstate 70 corridor. This upper level feature will pass
across southwest Kansas today. A narrow ribbon of low level
moisture from El Paso into eastern Mew Mexico is expected to
advect north-northeastward into southwest Kansas, leading to
destabilization. Surface based CAPE values will approach 1500
j/kg by afternoon. After some morning elevated convection, a weak
surface trough associated with the passage of the upper level
feature will lead to sufficient surface convergence for
thunderstorm development by early to mid afternoon. There is some
uncertainty as to how far west thunderstorm initiation will be.
The RAP pushes the surface trough through Dodge City late this
morning, suggesting that any afternoon storms would be confined to
south central Kansas. We opted keep the highest thunderstorm chances
southeast of Dodge City this afternoon. Highs today will be in the
lower to middle 90s given partial sunshine. Winds will be weaker
by tonight along with partly cloudy skies; and this should allow
temperatures to fall into the upper 60s.
.LONG TERM...(Saturday through Thursday)
ISSUED AT 255 AM CDT FRI AUG 15 2014
For Saturday, a stalled out warm front will be just north of Dodge
City. Some weak moisture convergence along this front may be enough
to set off some scattered late afternoon thunderstorms and into the
evening. Models show some moderate instability with CAPE over 2000
J/kg. Very weak upper level wind fields and lack of large scale
dynamics should be enough to preclude a severe thunderstorm threat.
Forecast soundings show an inverted V type sounding with some gusty
winds to 50 mph the main threat. Highs will be warm and in the mid
to upper 90s. Lows will be mild and in the upper 60s to around 70.
On Sunday, weak upper level ridging continues across the Central
Plains with a weak surface trough near Hays. With forecast moderate
instability and some weak moisture convergence will continue with a
slight chance of thunderstorms mainly near and north of Dodge City
by later in the afternoon and overnight. The severe threat again
looks minimal. Highs will continue in the mid to upper 90s with
overnight lows in the upper 60s.
For the period of Monday into Thursday of next week, a northern
branch upper level wave moves across the Plains on Monday afternoon
with a continued chance for thunderstorms. More weak upper level
waves move across the Plains into Thursday with small chances for
mainly late afternoon and evening thunderstorms. Highs continue in
the mid 90s with lows in the upper 60s to around 70.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 141 PM CDT FRI AUG 15 2014
Light westerly surface wind with VFR flight conditions will persist
as a mid level wave continues east through the region. Enhanced mid
level frontogenesis will likely kick off a line of elevated
thunderstorms later this afternoon, however these will likely be
mainly east and south of DDC and HYS and will not be considered as a
prevailing condition, but monitored for potential updates for VCTS
is needed.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 68 96 68 96 / 10 20 20 20
GCK 67 96 67 96 / 10 20 20 20
EHA 68 96 68 96 / 10 20 20 20
LBL 68 98 68 97 / 10 20 20 20
HYS 68 95 68 95 / 20 20 20 20
P28 71 98 70 97 / 10 10 20 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Finch
LONG TERM...Kruse
AVIATION...Russell
AREA FORECAST DISCUSSION
NWS JACKSON KY
330 PM EDT FRI AUG 15 2014
.UPDATE...
ISSUED AT 1215 PM EDT FRI AUG 15 2014
THE SLOW MOVING COLD FRONT THAT WORKED THROUGH THE REGION ON THU
AFTERNOON AND THU NIGHT APPEARS TO HAVE MOVED SOUTH OF THE AREA PER
THE WIND FIELDS. HOWEVER...A SECONDARY SFC TROUGH IS APPARENT IN VIS
IMAGERY AND SFC WIND FIELDS FROM THE WV MOUNTAINS WEST TO JUST NORTH
OF THE MTN PARKWAY AND WEST INTO CENTRAL KY. LOW CLOUDS HAVE PERSISTED
IN THE BIG SANDY VALLEY...ESPECIALLY TUG FORK REGION THE LONGEST AND
NEAR THIS SFC CONVERGENCE ZONE. TEMPS WHERE THE FOG AND LOW STRATUS
HAS BEEN SLOWEST TO LIFT INTO STRATOCU AND CU HAVE REMAINED IN THE
60S SO FAR WHILE ELSEWHERE OUTSIDE OF THE HIGHEST TERRAIN TEMPS HAVE
CLIMBED INTO THE 70S. HOURLY TEMPERATURE AND SKY GRIDS HAVE BEEN AND
WILL CONTINUE TO BE ADJUSTED FOR THIS.
OTHERWISE...A STRAY SHOWER ACROSS THE SOUTHERNMOST TIER OF COUNTIES
CANNOT BE RULED OUT...FROM WAYNE COUNTY OVER TO HARLAN COUNTY.
HOWEVER...GUIDANCE SEEMS TO HAVE TRENDED DOWN WITH THIS. THE HRRR
WHICH DID A REASONABLY GOOD JOB WITH AFTERNOON AND EVENING CONVECTION
ON THU HAS CONSISTENTLY KEPT ANY ACTIVITY FROM NEAR THE INTERSTATE 81
CORRIDOR OF VA/TN SOUTH AND EAST. AT THIS TIME...WE WILL CONTINUE
WITH PERSISTENCE FROM THE PREVIOUS FORECAST FOR POPS.
UPDATE ISSUED AT 755 AM EDT FRI AUG 15 2014
THE AREAS OF DENSE FOG REMAIN THE PRIMARY WEATHER ISSUE EARLY THIS
MORNING WITH THE LOWEST VIS FOUND GENERALLY BETWEEN THE HAL ROGERS
PARKWAY AND INTERSTATE 64. EXPECT THE FOG TO BREAK UP OVER THE NEXT
HOUR OR SO WITH A PARTLY TO MOSTLY SUNNY DAY TO FOLLOW FOR MOST OF
THE AREA. SO THIS UPDATE PRIMARILY JUST CONSISTS OF MATCHING THE OBS
AND TRENDS FOR THE T AND TD GRIDS. THESE HAVE BEEN SENT TO THE NDFD
AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 345 AM EDT FRI AUG 15 2014
06Z SFC ANALYSIS SHOWS GENERALLY WEAK HIGH PRESSURE THROUGH THE OHIO
AND TENNESSEE VALLEYS. A STALLED FRONTAL BOUNDARY EXISTS OVER PARTS
OF CENTRAL AND EASTERN KENTUCKY. THIS IS RESPONSIBLE FOR THE EXTRA
MOISTURE IN THE FORM OF SHOWERS AND SPRINKLES THAT SANK THROUGH THE
CWA EARLIER IN THE EVENING. THE MOISTURE...FOLLOWED BY SOME CLEARING
IN THE WAKE OF THE FRONT...HAS LED TO AREAS OF DENSE FOG...GENERALLY
NORTH OF THE HAL ROGERS PARKWAY. AS THE NIGHT WEARS ON...EXPECT THE
FOG AND DENSE PARTS OF IT TO SETTLE FURTHER SOUTH. ACCORDINGLY...
HAVE ISSUED AN SPS AND A GRAPHICAST TO ADDRESS THE LOW VISIBILITIES.
THESE RUN THROUGH 5 AM AND WILL LIKELY BE REISSUED THROUGH 9 AM
SHOULD THE FOG NOT START TO DISSIPATE BY THEN. HOWEVER...OVER THE FAR
NORTHERN PARTS OF THE AREA SOME DRIER AIR IS WORKING INTO OUR CWA AND
SHOULD LIMIT THE FOG AND WITH TIME HELP TO CLEAR IT. SO WILL LIKELY
TAKE THIS INTO CONSIDERATION WITH RESPECT TO THE FOG THREAT THROUGH
THE REST OF THE NIGHT AND SPS OUTLINE. THE PROXIMITY OF THE FRONT HAS
ALSO BROUGHT HIGHER DEWPOINTS TO THE AREA RESULTING IN A MILDER AND
MORE UNIFORM TEMPERATURE NIGHT THAN INITIALLY ANTICIPATED. AS
SUCH...TEMPS AND DEWPOINTS THROUGH THE AREA ARE GENERALLY IN THE
LOWER 60S WITH A FEW POCKETS OF UPPER 50S ON THE FRINGES...AWAY FROM
THE STALLED BOUNDARIES.
THE MODELS ARE IN DECENT AGREEMENT ALOFT WITH THE MAIN FEATURES THAT
WILL AFFECT THE AREA THROUGH THE SHORT TERM. A BROAD AND DEEP UPPER
LOW WILL CONTINUE TO MOVE NORTHEAST AND AWAY FROM THE REGION. IN ITS
WAKE NORTHWEST FLOW WILL BRING A COUPLE WEAK MID LEVEL ENERGY PACKETS
OVER KENTUCKY TONIGHT AND DURING THE DAY SATURDAY. FOR THIS...A
GENERAL MODEL COMPROMISE IS PREFERRED WHILE THE HRRR AND NAM12 WAS
GIVEN THE MOST WEIGHT FOR THE NEAR TERM PORTION OF THE FORECAST.
SENSIBLE WEATHER WILL FEATURE AREAS OF DENSE FOG AROUND THIS MORNING
AND THE RESIDUAL FRONT OVER THE SOUTHERN PORTION OF THE AREA. THIS
FRONT WAS MORE PROLIFIC THAN EXPECTED DURING THE DAY AND EVENING ON
THURSDAY. WITH THIS IN MIND WILL KEEP A SMALL CHANCE OF SPRINKLES AND
SHOWERS IN THE FORECAST ACROSS THE SOUTH TODAY. HIGH CLOUDS WILL BE
ON THE INCREASE FROM THE WEST TONIGHT INTO SATURDAY AS THE FRONT
STARTS TO MOVE BACK NORTHEAST. CANNOT RULE OUT A SHOWER WITH THIS
LATER TONIGHT OR ON SATURDAY...BUT FOR NOW WILL KEEP IT DRY IN THE
FORECAST GRIDS. TEMPERATURES WILL BE JUST ON THE COOL SIDE OF NORMAL
THROUGH SATURDAY THANKS IN PART TO THE EXTRA CLOUDS AROUND. AGAIN
TONIGHT...PATCHY VALLEY FOG CAN BE EXPECTED TO DEVELOP AFTER
MIDNIGHT...BUT LIKELY BE MITIGATED BY THE ADDITIONAL CLOUDS.
STARTED WITH THE CONSSHORT FOR THE T/TD/WIND GRIDS THROUGH THE FIRST
24 HOURS AND USED THE SUPERBLEND FOR THE REST OF THE SHORT TERM. DID
MAKE SOME ADJUSTMENTS TONIGHT FOR MINOR RIDGE AND VALLEY TEMPERATURE
DIFFERENCES. WITH THE POPS...ENDED UP A NOTCH HIGHER THAN MOS TODAY
ACROSS OUR SOUTHERN ZONES...OWING TO THE LINGERING FRONT. FOR THE
REST OF THE FORECAST...WAS IN LINE WITH GUIDANCE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 328 PM EDT FRI AUG 15 2014
KY WILL BE TRANSITIONING FROM AN UPPER LEVEL TROUGHING PATTERN TO
MORE ZONAL FLOW BY THE BEGINNING OF THE FORECAST PERIOD. SEVERAL
SHORTWAVES ARE POISED TO MOVE THROUGH THIS LONGWAVE PATTERN DURING
THE EXTENDED FORECAST PERIOD...IMPACTING MUCH OF KY. THE FIRST OF
THESE SHORTWAVES WILL MOVE INTO THE REGION DURING THE DAY
SUNDAY...WITH A COLD FRONT AND PRECIP CHANCES EXPECTED TO FOLLOW
SUIT. THE GFS AND THE NAM ARE NOW THE MOST PROGRESSIVE...SHOWING
PRECIP ENCOMPASSING ALL OF EASTERN KY BY 0Z MONDAY. THE ECMWF IS
ABOUT 6 HOURS BEHIND...WHILE THE GEM IS MUCH MORE SCATTERED IN NATURE
AND APPEARS TO BE THE OUTLIER OF THE MODELS. WILL KEEP CLOSER TO THE
NAM AND GFS SOLUTIONS AT THIS TIME. A GOOD AREA OF CONVERGENCE WILL
ACCOMPANY THE ONSET OF PRECIP THROUGH THE DAY SUNDAY...AS WILL DECENT
LOW LEVEL SHEAR AND CAPE VALUES. EXPECT A GOOD CHANCE FOR
THUNDERSTORMS THIS DAY...THOUGH SEVERE HAIL AND WIND THREAT SEEM
FAIRLY LOW GIVEN THE SATURATION IN THE MID AND UPPER LEVELS AND THE
LACK OF STRONG WINDS ALOFT.
THE FIRST SHORT WAVE WILL SLOWLY PASS THROUGH SUNDAY INTO MONDAY
NIGHT...WITH INCREASED CHANCES FOR CONVECTION ACROSS MUCH OF EASTERN
KY DURING THE AFTERNOON HOURS WITH PEAK HEATING. WHILE BRIEF DRYING
IS EXPECTED OVER THE WESTERN PORTION OF THE CWA MONDAY NIGHT...THIS
WILL UNFORTUNATELY BE SHORT LIVED. ALTHOUGH THE SURFACE LOW AND
SHORTWAVE WILL BE MOVING EASTWARD...THE SURFACE COLD FRONT WILL
ELONGATE EASTWARD...BECOMING NEARLY STATIONARY WITH NO UPPER LEVEL
FORCING TO PUSH IT OUT OF THE OHIO RIVER VALLEY REGION. LATEST ECMWF
IS STILL POSITIONING THE STATIONARY FRONT JUST TO THE NORTH OF THE
OHIO RIVER VALLEY FROM TUESDAY THROUGH THURSDAY...BEFORE FINALLY
PULLING NORTHWARD DURING THE DAY FRIDAY. AS A RESULT...KY WILL FIND
ITSELF IN THE WARM SECTOR...WITH GOOD WAA AND SEASONABLE OR WARMER
HIGH TEMPS FOR WEDNESDAY THROUGH FRIDAY /GENERALLY IN THE MID AND
UPPER 80S/. MOIST WARM FLOW OFF THE ATLANTIC...AND A GOOD BAROCLINIC
ZONE/FRONTOGENESIS...WILL BE ENOUGH TO SPARK SHOWERS AND
THUNDERSTORMS EACH DAY FOR THE REMAINDER OF THE FORECAST...MAINLY
DURING THE AFTERNOON AND EARLY EVENING HOURS...BEFORE FINALLY
TAPERING OFF ACROSS SOUTHERN KY DURING THE DAY FRIDAY. ALLBLEND GAVE
HIGHER END CHANCES FOR DURING THE DAY FRIDAY THAT WHAT WAS WARRANTED
GIVEN THE LIFTING FRONT...SO DROPPED THEM BACK TO SLIGHT CHANCES AND
LOW END CHANCES...TAPERING OFF LATE IN THE AFTERNOON FRIDAY.
THE GULF FLOW AND A NEARBY BOUNDARY WILL BE ENOUGH TO KEEP CLOUD
COVER ACROSS THE CWA DURING MUCH OF THE FORECAST PERIOD.
THIS...ALONG WITH ZONAL FLOW AND ONGOING PRECIP...WILL HELP TO
HAMPER TEMPS FROM REACHING THEIR MAX AND MIX POTENTIAL DURING THE
EXTENDED. HIGHS...AS MENTIONED ABOVE...WILL REMAIN IN THE 80S WITH
HIGH HUMIDITY POSSIBLE. MEANWHILE OVERNIGHT LOWS...WITH LACK OF MAX
RADIATIONAL COOLING...WILL REMAIN IN THE UPPER 60S TO AROUND 70.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 155 PM EDT FRI AUG 15 2014
A SLOW MOVING BOUNDARY HAS MOVED/MIXED SOUTH ACROSS THE NORTHERN TWO
THIRDS OF THE CWA. THE THREAT FOR A STRAY SHOWER WILL REMAIN ACROSS
THE HIGHEST TERRAIN THROUGH 21Z...BUT THIS WILL NOT AFFECT THE TAF
SITES... AS THE BOUNDARY AND SECONDARY TROUGH CONTINUE TO SLOWLY SAG
INTO THE TN VALLEYS. AREAS OF FOG...POSSIBLY DENSE AT SEVERAL OF THE
TAF SITES... CAN BE ANTICIPATED GENERALLY 4Z TO 14Z. THIS WILL AFFECT
THE TAF SITES TO VARYING DEGREES. MOS GUIDANCE AND LAMP GUIDANCE HITS
THIS RATHER HARD AT JKL...LOZ AND SME AND PERSISTENCE WAS BLENDED
INTO THIS THINKING FOR A FORECAST OF TIMING WITH SJS LIKELY TO BE
AFFECTED AS WELL. LOCATIONS NORTH OF THE MTN PARKWAY SHOULD BE LEAST
AFFECTED DUE TO A DRIER AIRMASS THERE. WINDS THROUGH THE PERIOD WILL
CONTINUE TO BE LIGHT AND VARIABLE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
206 PM EDT FRI AUG 15 2014
.UPDATE...
ISSUED AT 1215 PM EDT FRI AUG 15 2014
THE SLOW MOVING COLD FRONT THAT WORKED THROUGH THE REGION ON THU
AFTERNOON AND THU NIGHT APPEARS TO HAVE MOVED SOUTH OF THE AREA PER
THE WIND FIELDS. HOWEVER...A SECONDARY SFC TROUGH IS APPARENT IN VIS
IMAGERY AND SFC WIND FIELDS FROM THE WV MOUNTAINS WEST TO JUST NORTH
OF THE MTN PARKWAY AND WEST INTO CENTRAL KY. LOW CLOUDS HAVE PERSISTED
IN THE BIG SANDY VALLEY...ESPECIALLY TUG FORK REGION THE LONGEST AND
NEAR THIS SFC CONVERGENCE ZONE. TEMPS WHERE THE FOG AND LOW STRATUS
HAS BEEN SLOWEST TO LIFT INTO STRATOCU AND CU HAVE REMAINED IN THE
60S SO FAR WHILE ELSEWHERE OUTSIDE OF THE HIGHEST TERRAIN TEMPS HAVE
CLIMBED INTO THE 70S. HOURLY TEMPERATURE AND SKY GRIDS HAVE BEEN AND
WILL CONTINUE TO BE ADJUSTED FOR THIS.
OTHERWISE...A STRAY SHOWER ACROSS THE SOUTHERNMOST TIER OF COUNTIES
CANNOT BE RULED OUT...FROM WAYNE COUNTY OVER TO HARLAN COUNTY.
HOWEVER...GUIDANCE SEEMS TO HAVE TRENDED DOWN WITH THIS. THE HRRR
WHICH DID A REASONABLY GOOD JOB WITH AFTERNOON AND EVENING CONVECTION
ON THU HAS CONSISTENTLY KEPT ANY ACTIVITY FROM NEAR THE INTERSTATE 81
CORRIDOR OF VA/TN SOUTH AND EAST. AT THIS TIME...WE WILL CONTINUE
WITH PERSISTENCE FROM THE PREVIOUS FORECAST FOR POPS.
UPDATE ISSUED AT 755 AM EDT FRI AUG 15 2014
THE AREAS OF DENSE FOG REMAIN THE PRIMARY WEATHER ISSUE EARLY THIS
MORNING WITH THE LOWEST VIS FOUND GENERALLY BETWEEN THE HAL ROGERS
PARKWAY AND INTERSTATE 64. EXPECT THE FOG TO BREAK UP OVER THE NEXT
HOUR OR SO WITH A PARTLY TO MOSTLY SUNNY DAY TO FOLLOW FOR MOST OF
THE AREA. SO THIS UPDATE PRIMARILY JUST CONSISTS OF MATCHING THE OBS
AND TRENDS FOR THE T AND TD GRIDS. THESE HAVE BEEN SENT TO THE NDFD
AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 345 AM EDT FRI AUG 15 2014
06Z SFC ANALYSIS SHOWS GENERALLY WEAK HIGH PRESSURE THROUGH THE OHIO
AND TENNESSEE VALLEYS. A STALLED FRONTAL BOUNDARY EXISTS OVER PARTS
OF CENTRAL AND EASTERN KENTUCKY. THIS IS RESPONSIBLE FOR THE EXTRA
MOISTURE IN THE FORM OF SHOWERS AND SPRINKLES THAT SANK THROUGH THE
CWA EARLIER IN THE EVENING. THE MOISTURE...FOLLOWED BY SOME CLEARING
IN THE WAKE OF THE FRONT...HAS LED TO AREAS OF DENSE FOG...GENERALLY
NORTH OF THE HAL ROGERS PARKWAY. AS THE NIGHT WEARS ON...EXPECT THE
FOG AND DENSE PARTS OF IT TO SETTLE FURTHER SOUTH. ACCORDINGLY...
HAVE ISSUED AN SPS AND A GRAPHICAST TO ADDRESS THE LOW VISIBILITIES.
THESE RUN THROUGH 5 AM AND WILL LIKELY BE REISSUED THROUGH 9 AM
SHOULD THE FOG NOT START TO DISSIPATE BY THEN. HOWEVER...OVER THE FAR
NORTHERN PARTS OF THE AREA SOME DRIER AIR IS WORKING INTO OUR CWA AND
SHOULD LIMIT THE FOG AND WITH TIME HELP TO CLEAR IT. SO WILL LIKELY
TAKE THIS INTO CONSIDERATION WITH RESPECT TO THE FOG THREAT THROUGH
THE REST OF THE NIGHT AND SPS OUTLINE. THE PROXIMITY OF THE FRONT HAS
ALSO BROUGHT HIGHER DEWPOINTS TO THE AREA RESULTING IN A MILDER AND
MORE UNIFORM TEMPERATURE NIGHT THAN INITIALLY ANTICIPATED. AS
SUCH...TEMPS AND DEWPOINTS THROUGH THE AREA ARE GENERALLY IN THE
LOWER 60S WITH A FEW POCKETS OF UPPER 50S ON THE FRINGES...AWAY FROM
THE STALLED BOUNDARIES.
THE MODELS ARE IN DECENT AGREEMENT ALOFT WITH THE MAIN FEATURES THAT
WILL AFFECT THE AREA THROUGH THE SHORT TERM. A BROAD AND DEEP UPPER
LOW WILL CONTINUE TO MOVE NORTHEAST AND AWAY FROM THE REGION. IN ITS
WAKE NORTHWEST FLOW WILL BRING A COUPLE WEAK MID LEVEL ENERGY PACKETS
OVER KENTUCKY TONIGHT AND DURING THE DAY SATURDAY. FOR THIS...A
GENERAL MODEL COMPROMISE IS PREFERRED WHILE THE HRRR AND NAM12 WAS
GIVEN THE MOST WEIGHT FOR THE NEAR TERM PORTION OF THE FORECAST.
SENSIBLE WEATHER WILL FEATURE AREAS OF DENSE FOG AROUND THIS MORNING
AND THE RESIDUAL FRONT OVER THE SOUTHERN PORTION OF THE AREA. THIS
FRONT WAS MORE PROLIFIC THAN EXPECTED DURING THE DAY AND EVENING ON
THURSDAY. WITH THIS IN MIND WILL KEEP A SMALL CHANCE OF SPRINKLES AND
SHOWERS IN THE FORECAST ACROSS THE SOUTH TODAY. HIGH CLOUDS WILL BE
ON THE INCREASE FROM THE WEST TONIGHT INTO SATURDAY AS THE FRONT
STARTS TO MOVE BACK NORTHEAST. CANNOT RULE OUT A SHOWER WITH THIS
LATER TONIGHT OR ON SATURDAY...BUT FOR NOW WILL KEEP IT DRY IN THE
FORECAST GRIDS. TEMPERATURES WILL BE JUST ON THE COOL SIDE OF NORMAL
THROUGH SATURDAY THANKS IN PART TO THE EXTRA CLOUDS AROUND. AGAIN
TONIGHT...PATCHY VALLEY FOG CAN BE EXPECTED TO DEVELOP AFTER
MIDNIGHT...BUT LIKELY BE MITIGATED BY THE ADDITIONAL CLOUDS.
STARTED WITH THE CONSSHORT FOR THE T/TD/WIND GRIDS THROUGH THE FIRST
24 HOURS AND USED THE SUPERBLEND FOR THE REST OF THE SHORT TERM. DID
MAKE SOME ADJUSTMENTS TONIGHT FOR MINOR RIDGE AND VALLEY TEMPERATURE
DIFFERENCES. WITH THE POPS...ENDED UP A NOTCH HIGHER THAN MOS TODAY
ACROSS OUR SOUTHERN ZONES...OWING TO THE LINGERING FRONT. FOR THE
REST OF THE FORECAST...WAS IN LINE WITH GUIDANCE.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 340 AM EDT FRI AUG 15 2014
THE EXTENDED FORECAST BEGINS ON SATURDAY NIGHT WITH THE UPPER LEVEL
PATTERN BEGINNING TO BREAK DOWN AND UPPER LEVEL FEATURES MOVING ALONG
A BIT FASTER. THROUGH THE PERIOD...NUMEROUS UPPER LEVEL SHORTWAVES
WILL MOVE THROUGH THE OH RIVER VALLEY AS THE UPPER LEVEL PATTERN
BECOMES MORE ZONAL AND MAINTAINS THIS PATTERN THROUGH THE ENTIRE
EXTENDED. IN THE LOWER LEVELS...THE MORE POTENT FEATURE WILL BE THE
SURFACE LOW MOVING THROUGH ON MONDAY WITH PLENTY OF SURFACE BASED
INSTABILITY AND UPPER LEVEL SUPPORT. THIS DAY WILL BE A SCENARIO TO
MONITOR AS SEVERE WEATHER IS POSSIBLE BUT WITH A LACK OF
CONFIDENCE...CERTAINLY NOT SOMETHING TO HIGHLIGHT AT THIS POINT.
ALSO...THE FORECAST PROBLEM HERE WILL BE TIMING...ESPECIALLY WITH A
TRANSITIONS TO A MORE ZONAL PATTERN.
FOR THE REST OF THE EXTENDED...SOUTHERLY FLOW WITH A SURFACE
STATIONARY BOUNDARY SETTING UP ALONG THE LOWER OH VALLEY WILL ALLOW
FOR MAINLY AFTERNOON AND EVENING CONVECTION THROUGH THE TUESDAY TO
THURSDAY PERIOD. THIS APPEARS TO BE THE SET UP BUT THE GFS AND EURO
STILL SHOW SOME DIFFERENCES IN THEIR SOLUTIONS. ALSO KEEPING IN
MIND...THAT MODELS DO HAVE TROUBLE WITH TRANSITION PERIODS IN THE
UPPER LEVEL FLOW. THIS IN MIND...DID STAY WITH THE MODEL ALL BLEND
SOLUTION...EVEN LOWERED POPS SLIGHTLY BELOW THAT VALUE IN THE
EXTENDED BASED UPON LACK OF CONFIDENCE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 155 PM EDT FRI AUG 15 2014
A SLOW MOVING BOUNDARY HAS MOVED/MIXED SOUTH ACROSS THE NORTHERN TWO
THIRDS OF THE CWA. THE THREAT FOR A STRAY SHOWER WILL REMAIN ACROSS
THE HIGHEST TERRAIN THROUGH 21Z...BUT THIS WILL NOT AFFECT THE TAF
SITES... AS THE BOUNDARY AND SECONDARY TROUGH CONTINUE TO SLOWLY SAG
INTO THE TN VALLEYS. AREAS OF FOG...POSSIBLY DENSE AT SEVERAL OF THE
TAF SITES... CAN BE ANTICIPATED GENERALLY 4Z TO 14Z. THIS WILL AFFECT
THE TAF SITES TO VARYING DEGREES. MOS GUIDANCE AND LAMP GUIDANCE HITS
THIS RATHER HARD AT JKL...LOZ AND SME AND PERSISTENCE WAS BLENDED
INTO THIS THINKING FOR A FORECAST OF TIMING WITH SJS LIKELY TO BE
AFFECTED AS WELL. LOCATIONS NORTH OF THE MTN PARKWAY SHOULD BE LEAST
AFFECTED DUE TO A DRIER AIRMASS THERE. WINDS THROUGH THE PERIOD WILL
CONTINUE TO BE LIGHT AND VARIABLE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1241 PM EDT FRI AUG 15 2014
.UPDATE...
ISSUED AT 1215 PM EDT FRI AUG 15 2014
THE SLOW MOVING COLD FRONT THAT WORKED THROUGH THE REGION ON THU
AFTERNOON AND THU NIGHT APPEARS TO HAVE MOVED SOUTH OF THE AREA PER
THE WIND FIELDS. HOWEVER...A SECONDARY SFC TROUGH IS APPARENT IN VIS
IMAGERY AND SFC WIND FIELDS FROM THE WV MOUNTAINS WEST TO JUST NORTH
OF THE MTN PARKWAY AND WEST INTO CENTRAL KY. LOW CLOUDS HAVE PERSISTED
IN THE BIG SANDY VALLEY...ESPECIALLY TUG FORK REGION THE LONGEST AND
NEAR THIS SFC CONVERGENCE ZONE. TEMPS WHERE THE FOG AND LOW STRATUS
HAS BEEN SLOWEST TO LIFT INTO STRATOCU AND CU HAVE REMAINED IN THE
60S SO FAR WHILE ELSEWHERE OUTSIDE OF THE HIGHEST TERRAIN TEMPS HAVE
CLIMBED INTO THE 70S. HOURLY TEMPERATURE AND SKY GRIDS HAVE BEEN AND
WILL CONTINUE TO BE ADJUSTED FOR THIS.
OTHERWISE...A STRAY SHOWER ACROSS THE SOUTHERNMOST TIER OF COUNTIES
CANNOT BE RULED OUT...FROM WAYNE COUNTY OVER TO HARLAN COUNTY.
HOWEVER...GUIDANCE SEEMS TO HAVE TRENDED DOWN WITH THIS. THE HRRR
WHICH DID A REASONABLY GOOD JOB WITH AFTERNOON AND EVENING CONVECTION
ON THU HAS CONSISTENTLY KEPT ANY ACTIVITY FROM NEAR THE INTERSTATE 81
CORRIDOR OF VA/TN SOUTH AND EAST. AT THIS TIME...WE WILL CONTINUE
WITH PERSISTENCE FROM THE PREVIOUS FORECAST FOR POPS.
UPDATE ISSUED AT 755 AM EDT FRI AUG 15 2014
THE AREAS OF DENSE FOG REMAIN THE PRIMARY WEATHER ISSUE EARLY THIS
MORNING WITH THE LOWEST VIS FOUND GENERALLY BETWEEN THE HAL ROGERS
PARKWAY AND INTERSTATE 64. EXPECT THE FOG TO BREAK UP OVER THE NEXT
HOUR OR SO WITH A PARTLY TO MOSTLY SUNNY DAY TO FOLLOW FOR MOST OF
THE AREA. SO THIS UPDATE PRIMARILY JUST CONSISTS OF MATCHING THE OBS
AND TRENDS FOR THE T AND TD GRIDS. THESE HAVE BEEN SENT TO THE NDFD
AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 345 AM EDT FRI AUG 15 2014
06Z SFC ANALYSIS SHOWS GENERALLY WEAK HIGH PRESSURE THROUGH THE OHIO
AND TENNESSEE VALLEYS. A STALLED FRONTAL BOUNDARY EXISTS OVER PARTS
OF CENTRAL AND EASTERN KENTUCKY. THIS IS RESPONSIBLE FOR THE EXTRA
MOISTURE IN THE FORM OF SHOWERS AND SPRINKLES THAT SANK THROUGH THE
CWA EARLIER IN THE EVENING. THE MOISTURE...FOLLOWED BY SOME CLEARING
IN THE WAKE OF THE FRONT...HAS LED TO AREAS OF DENSE FOG...GENERALLY
NORTH OF THE HAL ROGERS PARKWAY. AS THE NIGHT WEARS ON...EXPECT THE
FOG AND DENSE PARTS OF IT TO SETTLE FURTHER SOUTH. ACCORDINGLY...
HAVE ISSUED AN SPS AND A GRAPHICAST TO ADDRESS THE LOW VISIBILITIES.
THESE RUN THROUGH 5 AM AND WILL LIKELY BE REISSUED THROUGH 9 AM
SHOULD THE FOG NOT START TO DISSIPATE BY THEN. HOWEVER...OVER THE FAR
NORTHERN PARTS OF THE AREA SOME DRIER AIR IS WORKING INTO OUR CWA AND
SHOULD LIMIT THE FOG AND WITH TIME HELP TO CLEAR IT. SO WILL LIKELY
TAKE THIS INTO CONSIDERATION WITH RESPECT TO THE FOG THREAT THROUGH
THE REST OF THE NIGHT AND SPS OUTLINE. THE PROXIMITY OF THE FRONT HAS
ALSO BROUGHT HIGHER DEWPOINTS TO THE AREA RESULTING IN A MILDER AND
MORE UNIFORM TEMPERATURE NIGHT THAN INITIALLY ANTICIPATED. AS
SUCH...TEMPS AND DEWPOINTS THROUGH THE AREA ARE GENERALLY IN THE
LOWER 60S WITH A FEW POCKETS OF UPPER 50S ON THE FRINGES...AWAY FROM
THE STALLED BOUNDARIES.
THE MODELS ARE IN DECENT AGREEMENT ALOFT WITH THE MAIN FEATURES THAT
WILL AFFECT THE AREA THROUGH THE SHORT TERM. A BROAD AND DEEP UPPER
LOW WILL CONTINUE TO MOVE NORTHEAST AND AWAY FROM THE REGION. IN ITS
WAKE NORTHWEST FLOW WILL BRING A COUPLE WEAK MID LEVEL ENERGY PACKETS
OVER KENTUCKY TONIGHT AND DURING THE DAY SATURDAY. FOR THIS...A
GENERAL MODEL COMPROMISE IS PREFERRED WHILE THE HRRR AND NAM12 WAS
GIVEN THE MOST WEIGHT FOR THE NEAR TERM PORTION OF THE FORECAST.
SENSIBLE WEATHER WILL FEATURE AREAS OF DENSE FOG AROUND THIS MORNING
AND THE RESIDUAL FRONT OVER THE SOUTHERN PORTION OF THE AREA. THIS
FRONT WAS MORE PROLIFIC THAN EXPECTED DURING THE DAY AND EVENING ON
THURSDAY. WITH THIS IN MIND WILL KEEP A SMALL CHANCE OF SPRINKLES AND
SHOWERS IN THE FORECAST ACROSS THE SOUTH TODAY. HIGH CLOUDS WILL BE
ON THE INCREASE FROM THE WEST TONIGHT INTO SATURDAY AS THE FRONT
STARTS TO MOVE BACK NORTHEAST. CANNOT RULE OUT A SHOWER WITH THIS
LATER TONIGHT OR ON SATURDAY...BUT FOR NOW WILL KEEP IT DRY IN THE
FORECAST GRIDS. TEMPERATURES WILL BE JUST ON THE COOL SIDE OF NORMAL
THROUGH SATURDAY THANKS IN PART TO THE EXTRA CLOUDS AROUND. AGAIN
TONIGHT...PATCHY VALLEY FOG CAN BE EXPECTED TO DEVELOP AFTER
MIDNIGHT...BUT LIKELY BE MITIGATED BY THE ADDITIONAL CLOUDS.
STARTED WITH THE CONSSHORT FOR THE T/TD/WIND GRIDS THROUGH THE FIRST
24 HOURS AND USED THE SUPERBLEND FOR THE REST OF THE SHORT TERM. DID
MAKE SOME ADJUSTMENTS TONIGHT FOR MINOR RIDGE AND VALLEY TEMPERATURE
DIFFERENCES. WITH THE POPS...ENDED UP A NOTCH HIGHER THAN MOS TODAY
ACROSS OUR SOUTHERN ZONES...OWING TO THE LINGERING FRONT. FOR THE
REST OF THE FORECAST...WAS IN LINE WITH GUIDANCE.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 340 AM EDT FRI AUG 15 2014
THE EXTENDED FORECAST BEGINS ON SATURDAY NIGHT WITH THE UPPER LEVEL
PATTERN BEGINNING TO BREAK DOWN AND UPPER LEVEL FEATURES MOVING ALONG
A BIT FASTER. THROUGH THE PERIOD...NUMEROUS UPPER LEVEL SHORTWAVES
WILL MOVE THROUGH THE OH RIVER VALLEY AS THE UPPER LEVEL PATTERN
BECOMES MORE ZONAL AND MAINTAINS THIS PATTERN THROUGH THE ENTIRE
EXTENDED. IN THE LOWER LEVELS...THE MORE POTENT FEATURE WILL BE THE
SURFACE LOW MOVING THROUGH ON MONDAY WITH PLENTY OF SURFACE BASED
INSTABILITY AND UPPER LEVEL SUPPORT. THIS DAY WILL BE A SCENARIO TO
MONITOR AS SEVERE WEATHER IS POSSIBLE BUT WITH A LACK OF
CONFIDENCE...CERTAINLY NOT SOMETHING TO HIGHLIGHT AT THIS POINT.
ALSO...THE FORECAST PROBLEM HERE WILL BE TIMING...ESPECIALLY WITH A
TRANSITIONS TO A MORE ZONAL PATTERN.
FOR THE REST OF THE EXTENDED...SOUTHERLY FLOW WITH A SURFACE
STATIONARY BOUNDARY SETTING UP ALONG THE LOWER OH VALLEY WILL ALLOW
FOR MAINLY AFTERNOON AND EVENING CONVECTION THROUGH THE TUESDAY TO
THURSDAY PERIOD. THIS APPEARS TO BE THE SET UP BUT THE GFS AND EURO
STILL SHOW SOME DIFFERENCES IN THEIR SOLUTIONS. ALSO KEEPING IN
MIND...THAT MODELS DO HAVE TROUBLE WITH TRANSITION PERIODS IN THE
UPPER LEVEL FLOW. THIS IN MIND...DID STAY WITH THE MODEL ALL BLEND
SOLUTION...EVEN LOWERED POPS SLIGHTLY BELOW THAT VALUE IN THE
EXTENDED BASED UPON LACK OF CONFIDENCE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 800 AM EDT FRI AUG 15 2014
A STALLED OUT BOUNDARY LINGERS OVER EASTERN KENTUCKY FOR THE NEXT 24
TO 36 HOURS. THIS BOUNDARY HAS LED TO PRETTY GOOD FOG FORMATION FOR
MUCH OF THE AREA EARLY THIS MORNING. THE FOG WILL BURN OFF BETWEEN 12
AND 14Z AT THE TAF SITES. THE THREAT OF MORE SHOWERS WILL REMAIN ACROSS
THE SOUTH THIS AFTERNOON AS THE BOUNDARY CONTINUES TO SLOWLY SAG
SOUTHWARD. PATCHY FOG...LOCALLY DENSE...CAN BE ANTICIPATED AGAIN LATE
TONIGHT FOR THE TAF SITES. WINDS THROUGH THE PERIOD WILL CONTINUE TO BE
LIGHT AND VARIABLE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
359 PM EDT FRI AUG 15 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 351 PM EDT FRI AUG 15 2014
WV IMAGERY AND RUC ANALYSIS INDICATED NW MID/UPPER LEVEL FLOW
THROUGH THE WRN GREAT LAKES BETWEEN A RIDGE FROM THE NRN PLAINS INTO
CNTRL ALBERTA AND A TROUGH OVER QUEBEC. AN UPSTREAM SHORTWAVE TROUGH
AND ASSOCIATED COLD FRONT WAS DIVING SE THROUGH NW ONTARIO. AT THE
SFC...LIGHT SW WINDS PREVAILED ACROSS UPPER MI AS HIGH PRES SINKS
INTO THE SRN LAKES.
TONIGHT INTO SAT...EXPECT SHRA/TSRA TO DEVELOP MAINLY AFT 06Z OVER
NORTHERN LAKE SUPERIOR THAT WILL SPREAD QUICKLY SE AS MODELS WERE IN
GOOD AGREEMENT IN BRINGING THE SHORTWAVE TROUGH WITH MODERATE 700-300
MB QVECTOR CONV...STRONG UPPER LEVEL DIV WITH THE LEFT EXIT OF A 90
KNOT 250-300 MB JET...AND AN ASSOCIATED COLD FRONT THROUGH THE NRN
GREAT LAKES. MODELS SHRTWV FORCING SUGGEST THAT THE ERN CWA WILL SEE
THE GREATEST PCPN COVERAGE/QPF WITH LIKELY TO CATEGORICAL POPS. GIVEN
POTENTIAL OF MUCAPE TO NEAR 800 J/KG... MODERATE TO STRONG DYNAMICS
AND EFFECTIVE SHEAR TO 40 KNOTS SOME EVEN MAINLY ELEVATED STORMS
ABOVE THE SHALLOW BNDRY LAYER MAY BE STRONG CAPABLE OF PRODUCING SOME
GUSTY WINDS AND SMALL HAIL. BY SAT AFTERNOON IN THE WAKE OF THE
FRONT...PCPN CHANCES SHOULD DIMINISH ACROSS THE NORTH WITH COOLER
MORE STABLE AIR MOVING IN ON LOW LEVEL NRLY FLOW. SOME DRIZZLE MAY
LINGER IN THE HIGHER TERRAIN N CNTRL IN THE MORNING IN THE WAKE OF
ANY SHOWERS EARLIER IN THE MORNING.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 348 PM EDT FRI AUG 15 2014
MAIN FCST CONCERNS IN THE LONG RANGE WL FOCUS ON TEMPS/PSBL LO CLDS
EARLY NEXT WEEK WITH NNE FLOW ON THE SRN FLANK OF DRY CNDN HI PRES
FCST TO DOMINATE. HOW QUICKLY A CHC OF SHOWERS WL RETURN TO THE FCST
IS THE CHALLENGE FOR THE MIDDLE OF NEXT WEEK.
SAT NGT...UNDER CONFLUENT NW FLOW ALF BTWN UPR RDG IN THE PLAINS AND
DEEP TROF IN QUEBEC...SFC HI PRES OVER FAR NW ONTARIO IS PROGGED TO
DRIFT SLOWLY SEWD TOWARD NRN LK SUP BY 12Z SUN. ANY LINGERING CLDS
EARLY OVER THE SCENTRAL ASSOCIATED WITH DEPARTING COLD FNT WL SHIFT
TO THE S AS THE HI PRES BUILDS TOWARD THE CWA UNDER LARGER SCALE
DNVA/DEEP LYR QVECTOR DVGC AND THE AIRMASS DRIES. IN FACT...
GUIDANCE INDICATES PWAT WL SINK TO ARND 0.5 INCH BY 12Z SUN...ABOUT
50 PCT OF NORMAL. THE MAJOR CONCERN IS THE POTENTIAL FOR SOME LO
CLDS TO DVLP...MAINLY IN THOSE AREAS OVER THE NCNTRL IMPACTED BY
UPSLOPE NNE WIND COMPONENT ON THE SRN FLANK OF THE APRCHG HI PRES.
IN FACT...THE 12Z NAM/REGIONAL CNDN/LOCAL WRF ARW FCST SDNGS SHOW A
SHALLOW...MOIST INFUSION OF COOLER AIR BLO SHARP SUBSIDENCE INVRN
BASED NEAR H9 ASSOCIATED WITH THE LARGER SCALE SUBSIDENCE/DRYING.
THESE FCSTS ARE BACKED UP BY SOME FAIRLY EXTENSIVE LO CLD COVER NOW
PRESENT OVER FAR NW ONTARIO ASSOCIATED WITH SHALLOW MOIST LYR
DEPICTED ON THE 12Z CHURCHILL MANITOBA RAOB. WL THUS INTRODUCE MORE
CLDS INTO THE FCST...MAINLY OVER THE NCENTRAL. THESE CLDS AND
EXPECTED STEADY NNE WIND WL LIMIT THE DIURNAL TEMP FALL A BIT
ESPECIALLY NEAR LK SUP OVER THE E HALF WHERE THE PRES GRADIENT IS
FCST TO BE A BIT TIGHTER. EXPECT THE LOWEST MIN TEMPS IN THE 40S
OVER THE INTERIOR W...CLOSER TO THE RDG AXIS EXTENDING FM THE HI
CENTER S TOWARD THE UPR MIDWEST AND WHERE WINDS WL BE LIGHTER AND
DOWNSLOPE WIND COMPONENT SHOULD LIMIT THE POTENTIAL FOR MORE
EXTENSIVE LO CLD.
SUN THRU MON...AS UPR RDG AXIS BUILDS INTO THE GREAT LKS FM THE W
FOLLOWING A SLOWLY EXITING QUEBEC TROF...SFC HI PRES IS FCST TO
DRIFT SLOWLY E AND INTO WRN QUEBEC BY MON AFTN. AM LO CLDS MAINLY
OVER THE NCENTRAL ON SUN MRNG SHOULD MIX OUT DURING THE AFTN WITH
DAYTIME HEATING AND THE ARRIVAL OF DRIER AIR. OTRW...THE WX OVER UPR
MI SHOULD REMAIN UNEVENTFUL WITH RDG AXIS EXTENDING WWD FM THE HI
CENTER INTO THE UPR LKS AND RELATIVELY DRY AIRMASS LINGERING. BOTH
SUN AND MON SHOULD FEATURE PLEASANT MAX TEMPS IN THE 70S AWAY FM LK
MODERATION AS H85 TEMPS ARE FCST TO TOP OUT BTWN 10-12C AND SUN AND
11-13C ON MON. MIN TEMPS ON SUN NGT WL DIP INTO THE 40S OVER THE
INTERIOR UNDER MOCLR SKIES/LIGHT WINDS DESPITE A SLOW INCRS IN PWAT
AOA 0.75 INCH.
EXTENDED...REMNANT OF CUTOFF UPR LO NOW MOVING EWD THRU THE PAC NW
IS FCST TO DRIFT SLOWLY E AND INTO THE UPR LKS ON TUE-THU NEXT WEEK
AT THE SAME TIME LARGER SCALE UPR RDG WL BE BUILDING OVER THE UPR
LKS DOWNSTREAM OF DEEPENING TROF OVER WRN CANADA/THE NW CONUS. FCST
WL INCLUDE SOME POPS AS THE SHRTWV/DEEPER MSTR INFLUENCE THE AREA...
BUT SLOWLY RISING H5 UNDER THE EXPANDING MEAN RDG SHOULD TEND TO
LIMIT THE SHOWER COVERAGE AND POPS TO THE CHC RANGE. WITH FCST H85
TEMPS NOT FAR FM 13-15C AND SOME CLDS...TEMPS SHOULD BE NOT FAR FM
THE MID/LATE AUG NORM. AS THE SHRTWV/DEEPER MSTR SLOWLY LIFT TO THE
NE AND H85 TEMPS WARM INTO THE 17-20C RANGE BY NEXT FRI UNDER THE
SLOWLY BLDG UPR RDG...EXPECT A RETURN OF ABV NORMAL TEMPS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 143 PM EDT FRI AUG 15 2014
VFR CONDITIONS WILL PREVAIL THROUGH THIS EVENING...AS DRY HIGH
PRESSURE AREA BUILDS TO THE SOUTH...AND INCREASED MOISTURE BEGINS TO
MOVE IN. A DISTURBANCE AND COLD FRONT MOVING SE THROUGH THE NRN
LAKES WILL BRING SCT SHOWERS AND POSSIBLY A THUNDERSTORMS TO CMX/SAW
LATE TONIGHT INTO EARLY SAT. BEHIND THE COLD FRONT...NRLY FLOW WITH
COMBINED WITH ABUNDANT LOW LEVEL MOISTURE IS LIKELY TO BRING IFR
CIGS TO CMX/SAW SAT MORNING AND MVFR CIGS TO IWD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 348 PM EDT FRI AUG 15 2014
EXPECT WINDS UNDER 20 KTS THRU NEXT WED AS A RELATIVELY WEAK PRES
GRADIENT DOMINATES THE UPPER GREAT LAKES ABOVE THE CHILLY WATERS OF
LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...JLB
MARINE...KC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
357 PM CDT FRI AUG 15 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 357 PM CDT FRI AUG 15 2014
RAIN HAS PUSHED WELL TO THE SOUTH INTO IOWA THIS AFTERNOON FROM
SOUTHWESTERN MN THIS MORNING. CONSIDERABLE CLOUDINESS CONTINUES...
PARTICULARLY OVER WRN MN WHERE LOWER CLOUDS ARE BEING OBSERVED IN
RICHER LOW LEVEL MOISTURE...WITH MORE FAIR WX CU ACROSS ERN MN
AND WRN WI. DEW POINTS HAVE RISEN A GOOD 5 TO 15 DEGREES ACROSS
THE CWA SINCE YESTERDAY AFTERNOON WITH WAA EXPECTED TO CONTINUE
THROUGH SATURDAY. MODELS ARE A BIT AT ODDS WITH RESPECT TO FOG AND
LOW STRATUS TONIGHT WITH THE HI-RES MODELS INCLUDING THE
HRRR...HOPWRF...AND RAP NOT SHOWING TOO MUCH...WHILE FORECAST
SOUNDINGS OF THE NAM AND GFS AND THEIR MOS PRODUCTS INDICATING MUCH
MORE IN THE WAY OF RICH BOUNDARY LAYER MOISTURE. GIVEN THE RECENT
DRY SPELL...I AM HESITANT TO BUY INTO WIDESPREAD DENSE FOG AND AM
THINKING MORE LOW CLOUD FORMATION...ESPECIALLY IF 15-20 KT WINDS
AROUND 1KFT VERIFIES. DID ADD AREAS OF FOG INTO THE GRIDS...BUT AT
THIS POINT IT SHOULD NOT BE ANYTHING TOO SIGNIFICANT OUTSIDE OF
AVIATION INTERESTS.
TONIGHT AND MOST OF SATURDAY IS LOOKING DRY. LITTLE IN THE WAY OF
FORCING WILL PRECLUDE DEVELOPMENT UNTIL SATURDAY AFTERNOON IN
CENTRAL MN AND NWRN WI WHEN A WEAK COOL FRONT ADVANCES SOUTH FROM
NORTHERN MINNESOTA AND LAKE SUPERIOR. THERE WILL BE A SECONDARY
AREA OF FORCING ACROSS SOUTHWESTERN MN WHERE A WEAK VORTICITY MAX
PUSHES IN DURING THE LATE AFTERNOON. HOWEVER...MID LEVEL RIDGING
WILL ALSO BE IN PLACE WHICH SHOULD LIMIT THE OVERALL COVERAGE TO
SLIGHT CHC TO LOW CHC RANGE INTO EVENING.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 357 PM CDT FRI AUG 15 2014
FOR THE LONG TERM...BEST CHANCE FOR PRECIP STILL LOOKS TO COME
MONDAY INTO TUESDAY...WHERE ONE WILL CONTINUE TO FIND LIKELY POPS.
AFTER THAT...MODEL DISAGREEMENT STARTS TO INCREASE
APPRECIABLY...THOUGH WE ARE STILL SEEING THE IDEA OF A TROUGH
SETTING UP ACROSS THE NORTHERN ROCKIES...THERE ARE JUST SIGNIFICANT
TIMING DIFFERENCES AS TO WHEN ENERGY FROM SAID TROUGH WORKS ACROSS
THE NORTHERN PLAINS.
WE WILL BE STARTING OFF THIS PERIOD WITH HIGH PRESSURE AGAIN
BUILDING SOUTH ACROSS THE GREAT LAKES FROM WESTERN ONTARIO. THIS
WILL PUSH A WEAK COLD INTO SW MN SATURDAY NIGHT...HELPING CONFINE
THE INSTABILITY THROUGH SUNDAY INTO SW MN AS WELL...AS DRIER AIR
WORKS IN FROM THE NORTHEAST. HAVE MAINTAINED SOME 20 POPS OUT IN SW
MN FOR AREAS THAT ARE EXPECTED TO BE NEAR THE BOUNDARY. HAVE GONE NO
HIGHER THAN THAT WITH POPS AS OUTSIDE OF THAT WEAK SFC
BOUNDARY...THE FORCING IS NIL AS AN H5 ANTICYCLONE WILL BE DRIFTING
OVER MN...WITH NO LLJ SUPPORT TO SPEAK OF EITHER WITH H85 RIDGING
MOVING THROUGH AS WELL.
FOR MONDAY...PRECIP CHANCES WILL BE ON THE INCREASE AS THE UPPER LOW
CURRENTLY SPINNING ACROSS WASHINGTON WORKS THROUGH THE RIDGE AND
COMES DIVING ACROSS MN MONDAY AND ACROSS WI TUESDAY. THIS HAS BEEN A
FAIRLY STABLE SIGNAL IN THE MODELS THE PAST FEW DAYS...SO CONTINUED
TO RUN WITH LIKELY POPS...THOUGH SLOWED THEIR EWRD PROGRESSION
ACROSS THE AREA SUNDAY NIGHT INTO MONDAY...AS ONCE AGAIN WE WILL
HAVE VERY DRY HIGH PRESSURE OVER THE GREAT LAKES HELPING TO SLOW THE
EWRD PROGRESSION OF MOISTURE/PRECIP WITH THIS SYSTEM. STILL LOOKS
GOOD FOR A WIDESPREAD QUARTER TO ONE INCH WITH THIS SYSTEM...BUT
DOES NOT LOOK LIKE HEAVY PRECIP WILL BE MUCH OF A THREAT...AS
MOISTURE TRANSPORT DOES NOT LOOK TO GET CARRIED AWAY...WITH THE LLJ
ONLY TOPPING OUT AROUND 20 KTS...AND THE PW PLUME ASSOCIATED WITH
THIS PRECIP WILL ONLY BE AROUND 1.5 INCHES. WE JUST LOOK TO HAVE
GOOD UPPER DIFFLUENCE AND FORCING WITH THE H5 WAVE DROPPING ACROSS
THE AREA. SEVERE THREAT LOOKS MINIMAL AS WELL AS BOTH THERMODYNAMIC
AND KINEMATIC FIELDS LOOK WEAK...JUST LOOKS LIKE SOME MUCH NEEDED
LIGHT-MODERATE RAIN AT THIS POINT.
FROM TUESDAY AND BEYOND...MODEL DISCREPANCIES INCREASE QUITE A BIT
WITH THE WAVE AS IT MOVES FROM MN TOWARD THE GREAT LAKES. THE
GEM/GFS MAINTAIN A DEEPER/STRONGER UPPER WAVE ACROSS MN/WI...WHILE
THE ECMWF ALLOWS IT TO GET ABSORBED INTO THE MAIN BELT OF
WESTERLIES. THIS DIFFERENCE IN TURN INFLUENCES HOW THE MODELS BEGIN
TO BRING THE DEVELOPING TROUGH IN THE NRN ROCKIES OUT INTO THE
PLAINS. THE GEM/GFS SOLUTION KEEPS THE UPPER LOW OVER THE GREAT
LAKES LONGER...WHICH IN TURN KEEPS ENERGY WITH THE WRN TROUGH HELD
UP OUT WEST UNTIL THE WEEKEND. THE ECMWF ALLOWS FOR A MUCH MORE
PROGRESSIVE PATTERN WITH RESPECT TO THE TROUGH...BRINGING PIECES OF
THE TROUGH ACROSS THE UPPER MS VALLEY ON THURSDAY AND AGAIN OVER THE
WEEKEND. THE GFS/GEM SOLUTION WOULD KEEP ANY ENERGY FROM THE WRN
TROUGH GETTING HERE UNTIL THE WEEKEND...WITH WEDNESDAY THROUGH
FRIDAY OF NEXT WEEK BEING MAINLY DRY AS WE STAY UNDER MORE OF THE
INFLUENCE OF AN UPPER RIDGE...AS THE INFLUENCE OF THE UPPER THROUGH
REMAINS TO THE NORTHWEST. GIVEN THE SPREAD IN MODELS...KEPT CLOSE TO
GFS/ECMWF BLEND FOR POPS...WHICH MEANS POPS TUESDAY ARE MAINLY TO
THE EAST /CLOSER TO THE UPPER LOW/...WEDNESDAY IS MAINLY DRY...WHILE
THU/FRI SEES THE RETURN OF 20-30 POPS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 117 PM CDT FRI AUG 15 2014
SOME MVFR CIGS ARE PRESENT AT TAF ISSUANCE TIME ACROSS WRN
MN...CLOSEST TO WHERE RAIN FELL EARLIER THIS MORNING. THESE CIGS
HAVE BEEN RISING AS THEY PUSH OVER WARMER LOCATIONS AS EXPECTED
SO NOT ANTICIPATING TOO MANY ISSUES AT RWF AND AXN TODAY. LOW
LEVEL MOISTURE WILL INCREASE TONIGHT WHICH WILL LEAD TO AREAS OF
FOG AND IFR/LIFR STRATUS POTENTIAL. WINDS WILL BE LIGHT...BUT THE
GROUND HAS BEEN QUITE DRY AS OF LATE SO LEANING MORE TOWARD THE
STRATUS SIDE OF THINGS. STILL CANNOT RULE OUT BRIEF INSTANCES OF
DENSE FOG AT ANY OF THE TAF SITES EXCEPT MSP LATE TONIGHT AND
SATURDAY MORNING.
KMSP...VFR TODAY WITH DETERIORATING CONDITIONS LIKELY LATE TONIGHT
AND SATURDAY MORNING. AS FOG DEVELOPS IN THE OUTLYING AREAS
TONIGHT...IT WILL LIFT INTO STRATUS SATURDAY MORNING SO FAIRLY
CONFIDENT IN IFR CIGS FOR A TIME. VFR CONDITIONS RETURN FOR THE
LATE MORNING AND AFTERNOON.
/OUTLOOK FOR KMSP/
SUN...VFR. WIND E 5-10 KTS.
MON...VFR/MVFR WITH TSRA LIKELY...MAINLY LATE. WINDS S 5-10 KTS.
TUE...VFR WITH TSRA POSSIBLE EARLY. WIND NW 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...BORGHOFF
LONG TERM...MPG
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
356 PM CDT Fri Aug 15 2014
.SHORT TERM: (Through Sunday Afternoon)
Issued at 355 PM CDT Fri Aug 15 2014
An initial round of showers was located over UIN-COU and has been
steadily heading east with no models handling this well at all.
This rain was initially fueled by a low level jet and WAA along and
just north of an effectively stationary frontal boundary stretching
from northwest MO thru the STL metro area and into far southern IL.
But with little downstream to slow it down, it has not diminished
much as it has pushed east.
We expect this to move into STL metro eventually toward sunset as
scattered SHRA before finally dwindling.
A more organized system lurks further to the northwest over eastern
Nebraska, and with the prevailing northwest flow over our region,
will move east-southeast towards northeast MO by Saturday morning
and thru southwest IL later on Saturday night and Sunday morning,
pulling away Sunday afternoon. There have been some discrepancies
between the models on exactly how fast and where to move this system
with an early merger with another upper level disturbance in the
works this evening, but the latest runs seem to confirm the slow
nature of it and with a track that makes logical sense. This system
will also carry with it very moist air thru the column, with PWs in
excess of two inches, which is higher than two standard deviations
above the mean for mid-August.
Have been generous with PoPs given the available moisture and slow
moving nature of the system, with likelys every period thru Sunday,
but in the end, probably not high enough and categorical range will
be needed at some point, just a matter of where. Localized heavy
rainfall will be the main threat thru the weekend, especially if
nocturnal rainfall can get going, but not to the point of where feel
a Flash Flood Watch is needed.
Severe threats will be marginal each day, peaking with the max
heating in the afternoon, and likely on the southeast flank of the
best lo level focus where the better instability will be. On
Saturday, probably south of UIN, thru COU with STL metro on the
southeast edge. On Sunday, southeast of STL metro, perhaps outside
of the CWA.
TES
.LONG TERM: (Monday through Next Friday)
Issued at 355 PM CDT Fri Aug 15 2014
The rather moist atmosphere will remain in place on Monday, with
another weak upper level system possible. Models are resolving this
poorly but will not take much to get something going either, so have
maintained a low PoP. More of the same with weak disturbances
possible in the NW flow thru the middle of next week and so have no
real reason to drop the chance mention of rain. Max temps each day
will be seasonably warm but held in check somewhat by rain threat.
By late next week, there is a trend to go more zonal with the flow
and build the upper ridge--a more typical summertime pattern we have
seen very little of this year. Trended towards dry and above
average on temps, which places daytime maxes in the 90s. If the
humidity holds, could see potentially dangerous heat and humidity
for next weekend.
TES
&&
.AVIATION: (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1109 AM CDT Fri Aug 15 2014
Bit of a tricky forecast this period, and as usual models
not in total agreement in a northwest flow situation. Main issue
is what will happen with the two short waves. Most models
basically want to combine them while the GFS makes a case to keep
them separate. Models were slow with the existing warm air
advection rain over northern MO. The HRRR is the best right now
with the existing rain, and it develops another mass of rain over
NW MO this evening and moves it east overnight. Given lack of
confidence in other model solution will trend the forecast toward
the HRRR.
Specifics for KSTL: Appears existing TSRA/SHRA will stay north of
terminal so expect to stay dry with mid cloud overcast today into
this evening. Per the HRRR, rain could move into the area at 06z
or shortly after. Will move up the existing forecast VCTS 1 hour
to 08z. A prevailing looks possible by 12z, but will leave it out
for now. Hopefully the next model runs trend toward a more
universal decision. Cold front does not drag across the terminal
until Sunday morning, with the GFS a bit faster than the NAM.
Would expect covection to fire up again Sat afternoon into the
evening so another VCTS will be needed after 18z Sat.
JPK
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
350 PM CDT Fri Aug 15 2014
.SHORT TERM: (Through Late Tonight)
Issued at 350 PM CDT Fri Aug 15 2014
An initial round of showers was located over UIN-COU and has been
steadily heading east with no models handling this well at all.
This rain was initially fueled by a low level jet and WAA along and
just north of an effectively stationary frontal boundary stretching
from northwest MO thru the STL metro area and into far southern IL.
But with little downstream to slow it down, it has not diminished
much as it has pushed east.
We expect this to move into STL metro eventually toward sunset as
scattered SHRA before finally dwindling.
A more organized system lurks further to the northwest over eastern
Nebraska, and with the prevailing northwest flow over our region,
will move east-southeast towards northeast MO by Saturday morning
and thru southwest IL later on Saturday night and Sunday morning,
pulling away Sunday afternoon. There have been some discrepancies
between the models on exactly how fast and where to move this system
with an early merger with another upper level disturbance in the
works this evening, but the latest runs seem to confirm the slow
nature of it and with a track that makes logical sense. This system
will also carry with it very moist air thru the column, with PWs in
excess of two inches, which is higher than two standard deviations
above the mean for mid-August.
Have been generous with PoPs given the available moisture and slow
moving nature of the system, with likelys every period thru Sunday,
but in the end, probably not high enough and categorical range will
be needed at some point, just a matter of where. Localized heavy
rainfall will be the main threat thru the weekend, especially if
nocturnal rainfall can get going, but not to the point of where feel
a Flash Flood Watch is needed.
Severe threats will be marginal each day, peaking with the max
heating in the afternoon, and likely on the southeast flank of the
best lo level focus where the better instability will be. On
Saturday, probably south of UIN, thru COU with STL metro on the
southeast edge. On Sunday, southeast of STL metro, perhaps outside
of the CWA.
TES
.LONG TERM: (Saturday through Next Friday)
Issued at 350 PM CDT Fri Aug 15 2014
The rather moist atmosphere will remain in place on Monday, with
another weak upper level system possible. Models are resolving this
poorly but will not take much to get something going either, so have
maintained a low PoP. More of the same with weak disturbances
possible in the NW flow thru the middle of next week and so have no
real reason to drop the chance mention of rain. Max temps each day
will be seasonably warm but held in check somewhat by rain threat.
By late next week, there is a trend to go more zonal with the flow
and build the upper ridge--a more typical summertime pattern we have
seen very little of this year. Trended towards dry and above
average on temps, which places daytime maxes in the 90s. If the
humidity holds, could see potentially dangerous heat and humidity
for next weekend.
TES
&&
.AVIATION: (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1109 AM CDT Fri Aug 15 2014
Bit of a tricky forecast this period, and as usual models
not in total agreement in a northwest flow situation. Main issue
is what will happen with the two short waves. Most models
basically want to combine them while the GFS makes a case to keep
them separate. Models were slow with the existing warm air
advection rain over northern MO. The HRRR is the best right now
with the existing rain, and it develops another mass of rain over
NW MO this evening and moves it east overnight. Given lack of
confidence in other model solution will trend the forecast toward
the HRRR.
Specifics for KSTL: Appears existing TSRA/SHRA will stay north of
terminal so expect to stay dry with mid cloud overcast today into
this evening. Per the HRRR, rain could move into the area at 06z
or shortly after. Will move up the existing forecast VCTS 1 hour
to 08z. A prevailing looks possible by 12z, but will leave it out
for now. Hopefully the next model runs trend toward a more
universal decision. Cold front does not drag across the terminal
until Sunday morning, with the GFS a bit faster than the NAM.
Would expect covection to fire up again Sat afternoon into the
evening so another VCTS will be needed after 18z Sat.
JPK
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1142 AM CDT Fri Aug 15 2014
.SHORT TERM: (Through Tonight)
Issued at 245 AM CDT Fri Aug 15 2014
Focus thru this period will be precip chances.
TSRA have developed on the nose of the LLJ over wrn IA and nwrn
MO. These storms may move sewd thru the morning, but believe they
will struggle to reach the CWA. Believe isod to sct storms will be
possible this afternoon as an approaching s/w reaches the region.
Chances increase tonight as the LLJ ahead of the low approaches
the region.
As for temps, have trended twd the warmer guidance thru the
period. While ample clouds shud linger thru today, the approaching
thermal ridge shud allow temps to climb despite the cloud cover.
Cloud cover tonight shud also help keep temps warm.
Tilly
.LONG TERM: (Saturday through Thursday)
Issued at 334 AM CDT Fri Aug 15 2014
Storms shud be ongoing across nrn portions of the CWA Sat morning.
These storms shud dissipate during the morning allowing for
heating and redevelopment during the afternoon, persisting into
the evening. Differences among mdls reduce confidence somewhat.
However, with fropa expected on Sat, storms shud be possible
across much of the region again mainly during the afternoon into
overnight. Mdls suggest a sfc boundary may linger across portions
of the area on Sun. Have kept chance PoPs across much of the area
due to timing differences for precip moving out of the area on Sat
night as well as the boundary which may provide a focus for
additional storms.
For Mon and beyond, mdls suggest upper level ridge building over
the region with height rises persisting thru the end of the
period. While the GFS suggests much more precip compared to the
ECMWF, have kept low chance PoPs going due to the uncertainty. Have
trended twd a warming trend thru the end of the period with the
height rises.
Tilly
&&
.AVIATION: (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1109 AM CDT Fri Aug 15 2014
Bit of a tricky forecast this period, and as usual models
not in total agreement in a northwest flow situation. Main issue
is what will happen with the two short waves. Most models
basically want to combine them while the GFS makes a case to keep
them separate. Models were slow with the existing warm air
advection rain over northern MO. The HRRR is the best right now
with the existing rain, and it develops another mass of rain over
NW MO this evening and moves it east overnight. Given lack of
confidence in other model solution will trend the forecast toward
the HRRR.
Specifics for KSTL: Appears existing TSRA/SHRA will stay north of
terminal so expect to stay dry with mid cloud overcast today into
this evening. Per the HRRR, rain could move into the area at 06z
or shortly after. Will move up the existing forecast VCTS 1 hour
to 08z. A prevailing looks possible by 12z, but will leave it out
for now. Hopefully the next model runs trend toward a more
universal decision. Cold front does not drag across the terminal
until Sunday morning, with the GFS a bit faster than the NAM.
Would expect covection to fire up again Sat afternoon into the
evening so another VCTS will be needed after 18z Sat.
JPK
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 89 72 89 74 / 20 30 50 60
Quincy 84 68 85 68 / 30 60 60 70
Columbia 89 69 90 70 / 20 50 50 60
Jefferson City 90 70 90 71 / 20 40 40 50
Salem 83 66 85 69 / 10 10 40 60
Farmington 86 68 86 69 / 20 20 30 40
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BISMARCK ND
556 PM CDT FRI AUG 15 2014
.UPDATE...
ISSUED AT 556 PM CDT FRI AUG 15 2014
THE LATEST MODEL GUIDANCE CONTINUES TO PROG THE HEAVY RAIN
POTENTIAL CONTINUING OVER SOUTHWESTERN NORTH DAKOTA TONIGHT. MOST
MODELS ARE A LITTLE TOO FAR SOUTH WITH THE ONGOING ACTIVITY...WITH
THE 12Z GEM ACTUALLY DOING A PRETTY GOOD JOB PAINTING THE HIGHEST
QPF WHERE THE CURRENT CONVECTION IS LOCATED.
FOR THE UPDATE...ADJUSTED POPS UPWARDS BASED ON CURRENT RADAR OBS
AND EXTRAPOLATED THE HIGHER POPS SOUTHEASTWARD THROUGH THE
OVERNIGHT HOURS...BASED ON THE 12Z GEM SOLUTION. WILL KEEP THE
CURRENT FLASH FLOOD WATCH AS IS FOR THIS UPDATE.
ALSO EXTENDED THE FLOOD ADVISORY FOR BILLINGS...SOUTHWESTERN
MCKENZIE...AND GOLDEN VALLEY COUNTIES UNTIL 530 AM CDT. THE LATEST
RAINFALL REPORT FROM BEACH IS 4.6 INCHES...AND IT IS STILL
RAINING. OVERLAND FLOODING CONTINUES TO BE AN ISSUE WITH SOME
COUNTY ROADS UNDER WATER.
THE UPDATED GRIDDED AND TEXT PRODUCTS WILL BE OUT SHORTLY.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 549 PM CDT FRI AUG 15 2014
HEAVY RAINFALL AND ASSOCIATED FLASH FLOODING WILL HIGHLIGHT THE
SHORT TERM FORECAST.
EXTENDED THE FLASH FLOOD WATCH THROUGH 12 UTC SATURDAY ACROSS THE
SOUTHWEST. THE 12 UTC WRF-ARW/NMM...INCOMING 18 UTC NAM AND 16-17
UTC HRRR ITERATIONS CONTINUE TO FOCUS RAIN SHOWERS AND
THUNDERSTORMS WITH PROLONGED MODERATE TO HEAVY RAINFALL ACROSS THE
SOUTHWEST AND FAR SOUTH CENTRAL LATE THIS AFTERNOON AND INTO THE
EARLY EVENING IN ASSOCIATION WITH THE UPPER LEVEL LOW EVIDENT ON
WATER VAPOR ACROSS THE SOUTHWEST. THESE SOLUTIONS WANE CONVECTION
A BIT AFTER SUNSET...THEN REDEVELOP THUNDERSTORMS ACROSS THE WEST
REINVIGORATED BY INCREASING UPPER LEVEL DIFFLUENCE AND IMPULSES
EJECTING OUT OF THE PACIFIC NORTHWEST CLOSED LOW. THIS IS IN
AGREEMENT WITH NESDIS SATELLITE PRECIPITATION ESTIMATES AND
HIGHLIGHTS FOR HEAVY RAINFALL TONIGHT. GIVEN THIS REGENERATION OF
SLOW MOVING STORMS LATE TONIGHT OVER ALREADY SATURATED AREAS WITH
PWATS NEAR 1.75 INCHES...THE EXTENSION OF THE WATCH IS WARRANTIED.
THE 12 UTC WRF-ARW/NMM DO HIGHLIGHT SIOUX AND EMMONS COUNTIES LATE
TONIGHT AS WELL FOR HEAVY RAIN...AND THIS WILL HAVE TO BE
MONITORED. ADDITIONAL SCATTERED THUNDERSTORMS WITH HEAVY RAIN WILL
CONTINUE ACROSS MUCH OF THE AREA SATURDAY AS THE PACIFIC NORTHWEST
UPPER LEVEL LOW BEGINS TO PROPAGATE INTO THE NORTHERN PLAINS. WILL
ALLOW FURTHER SHIFTS TO EVALUATE IF A FLASH FLOOD WATCH IS NEEDED.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 549 PM CDT FRI AUG 15 2014
THE MAIN FORECAST ISSUE IN THE EXTENDED PERIOD WILL CONTINUE TO BE
THE THREAT OF HEAVY RAINFALL THROUGH THE WEEKEND AND INTO EARLY NEXT
WEEK. DETERMINISTIC MODELS ARE IN REASONABLE AGREEMENT IN BRINGING
AN UPPER LEVEL LOW CURRENTLY OVER EASTERN WASHINGTON...EAST ALONG
THE INTERNATIONAL BORDER...TO THE EASTERN DAKOTAS BY MONDAY
AFTERNOON. ALTHOUGH THE THREAT OF SEVERE WEATHER WILL BE LOW. WE
WILL STILL NEED TO MONITOR THE THREAT OF HEAVY RAINFALL...
PARTICULARLY IN THE SUNDAY NIGHT INTO EARLY MONDAY PERIOD.
PERHAPS A BRIEF DRY PERIOD TUESDAY INTO EARLY WEDNESDAY. BUT MODELS
THEN START SHIFTING INTO MORE OF A SOUTHWEST FLOW BY MID TO LATE
WEEK BRINGING INCREASED PRECIPITATION CHANCES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 556 PM CDT FRI AUG 15 2014
THUNDERSTORM POTENTIAL WILL HIGHLIGHT THE 00 UTC TAF CYCLE.
KDIK/KBIS/KISN HAVE THE BEST POTENTIAL TO BE IMPACTED BY STORMS
WITH POSSIBLE IFR CONDITIONS. SEE TAFS FOR EXPECTED TIMING AND
IMPACTS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR NDZ017-018-
031>033-040-041-043-044.
&&
$$
UPDATE...TM
SHORT TERM...AYD
LONG TERM...TWH
AVIATION...TM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
549 PM CDT FRI AUG 15 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 549 PM CDT FRI AUG 15 2014
HEAVY RAINFALL AND ASSOCIATED FLASH FLOODING WILL HIGHLIGHT THE
SHORT TERM FORECAST.
EXTENDED THE FLASH FLOOD WATCH THROUGH 12 UTC SATURDAY ACROSS THE
SOUTHWEST. THE 12 UTC WRF-ARW/NMM...INCOMING 18 UTC NAM AND 16-17
UTC HRRR ITERATIONS CONTINUE TO FOCUS RAIN SHOWERS AND
THUNDERSTORMS WITH PROLONGED MODERATE TO HEAVY RAINFALL ACROSS THE
SOUTHWEST AND FAR SOUTH CENTRAL LATE THIS AFTERNOON AND INTO THE
EARLY EVENING IN ASSOCIATION WITH THE UPPER LEVEL LOW EVIDENT ON
WATER VAPOR ACROSS THE SOUTHWEST. THESE SOLUTIONS WANE CONVECTION
A BIT AFTER SUNSET...THEN REDEVELOP THUNDERSTORMS ACROSS THE WEST
REINVIGORATED BY INCREASING UPPER LEVEL DIFFLUENCE AND IMPULSES
EJECTING OUT OF THE PACIFIC NORTHWEST CLOSED LOW. THIS IS IN
AGREEMENT WITH NESDIS SATELLITE PRECIPITATION ESTIMATES AND
HIGHLIGHTS FOR HEAVY RAINFALL TONIGHT. GIVEN THIS REGENERATION OF
SLOW MOVING STORMS LATE TONIGHT OVER ALREADY SATURATED AREAS WITH
PWATS NEAR 1.75 INCHES...THE EXTENSION OF THE WATCH IS WARRANTIED.
THE 12 UTC WRF-ARW/NMM DO HIGHLIGHT SIOUX AND EMMONS COUNTIES LATE
TONIGHT AS WELL FOR HEAVY RAIN...AND THIS WILL HAVE TO BE
MONITORED. ADDITIONAL SCATTERED THUNDERSTORMS WITH HEAVY RAIN WILL
CONTINUE ACROSS MUCH OF THE AREA SATURDAY AS THE PACIFIC NORTHWEST
UPPER LEVEL LOW BEGINS TO PROPAGATE INTO THE NORTHERN PLAINS. WILL
ALLOW FURTHER SHIFTS TO EVALUATE IF A FLASH FLOOD WATCH IS NEEDED.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 549 PM CDT FRI AUG 15 2014
THE MAIN FORECAST ISSUE IN THE EXTENDED PERIOD WILL CONTINUE TO BE
THE THREAT OF HEAVY RAINFALL THROUGH THE WEEKEND AND INTO EARLY NEXT
WEEK. DETERMINISTIC MODELS ARE IN REASONABLE AGREEMENT IN BRINGING
AN UPPER LEVEL LOW CURRENTLY OVER EASTERN WASHINGTON...EAST ALONG
THE INTERNATIONAL BORDER...TO THE EASTERN DAKOTAS BY MONDAY
AFTERNOON. ALTHOUGH THE THREAT OF SEVERE WEATHER WILL BE LOW. WE
WILL STILL NEED TO MONITOR THE THREAT OF HEAVY RAINFALL...
PARTICULARLY IN THE SUNDAY NIGHT INTO EARLY MONDAY PERIOD.
PERHAPS A BRIEF DRY PERIOD TUESDAY INTO EARLY WEDNESDAY. BUT MODELS
THEN START SHIFTING INTO MORE OF A SOUTHWEST FLOW BY MID TO LATE
WEEK BRINGING INCREASED PRECIPITATION CHANCES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 549 PM CDT FRI AUG 15 2014
THUNDERSTORM POTENTIAL WILL HIGHLIGHT THE 18 UTC TAF CYCLE.
KDIK/KBIS/KISN HAVE THE BEST POTENTIAL TO BE IMPACTED BY STORMS
WITH POSSIBLE IFR CONDITIONS. SEE TAFS FOR EXPECTED TIMING AND
IMPACTS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR NDZ017-018-
031>033-040-041-043-044.
&&
$$
SHORT TERM...AYD
LONG TERM...TWH
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS NORMAN OK
244 PM CDT FRI AUG 15 2014
.DISCUSSION...
LATE TODAY THROUGH TONIGHT...A 500 MB SHORT WAVE
ACROSS THE CENTRAL PLAINS WILL TRANSLATE TO THE EAST INTO THE
MIDWEST. THIS WILL RESULT IN THE 500 MB RIDGE TO RETROGRADE
SLIGHTLY TO THE WEST. A DIFFUSE FRONTAL BOUNDARY WILL APPROACH
NORTHWEST OKLAHOMA LATER TODAY. BOTH THE NAM AND HRRR SUGGEST
ISOLATED SHOWERS AND STORMS MAY DEVELOP ALONG OR AHEAD OF THE
BOUNDARY LATE TODAY INTO THIS EVENING...BUT COVERAGE APPEARS TO BE
LIMITED. BEST CHANCES WILL BE ACROSS THE NORTHWEST. LARGE DEW
POINT DEPRESSIONS SUGGEST GUSTY WINDS WILL BE THE MAIN THREAT FROM
ANY STORMS THAT DO DEVELOP. HRRR ALSO SUGGESTS A COMPLEX MAY MOVE
THROUGH THE TEXAS PANHANDLE. THIS MAY CLIP EXTREME WESTERN AND
SOUTHWESTERN PARTS OF THE CWA.
ON SATURDAY...THE BOUNDARY WILL LIKELY BE VERY DIFFUSE. ISOLATED
STORMS WILL BE POSSIBLE ACROSS THE AREA. THE BIGGER STORY WILL BE
TEMPERATURES. 850MB TEMPERATURES ARE PROGGED TO BE BETWEEN 25 TO 28C
ACROSS THE CWA. AS A RESULT...SATURDAY MIGHT BE THE HOTTEST DAY IN
FORECAST THE PERIOD. MANY AREAS WILL SEE AT LEAST 100 DEGREE HEAT.
BEYOND SATURDAY...THE CWA APPEARS TO BE WITHIN A WEAKNESS IN THE
RIDGE. ISOLATED THUNDERSTORMS CAN NOT BE RULED OUT ALMOST ANY DAY
THROUGH AT LEAST MID-WEEK. TEMPERATURES LOOK TO BE SEASONABLY
HOT...THOUGH NOT AS HOT AS SATURDAY. THE RIDGE MAY TRY TO BUILD INTO
THE REGION BY LATE NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 74 99 74 98 / 10 20 20 20
HOBART OK 73 100 73 98 / 10 20 20 20
WICHITA FALLS TX 76 99 77 98 / 10 20 20 20
GAGE OK 68 101 69 98 / 20 20 20 20
PONCA CITY OK 74 98 72 98 / 20 20 20 20
DURANT OK 73 97 76 96 / 10 20 20 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
30/10/84
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
334 PM CDT FRI AUG 15 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 333 PM CDT FRI AUG 15 2014
AT THE SURFACE...WEAK LOW LEVEL CONVERGENCE AXIS ALONG THE FAR
WESTERN BORDER OF CWA THIS EVENING...WITH UPPER LEVELS FEATURING
DEFORMATION AXIS ALONG WITH SEVERAL WEAK WAVES WERE PRESENT OVER THE
NORTHERN PLAINS. ATMOSPHERE REMAINS VERY MOIST WITH PRECIPITABLE
WATER FROM 1.5 TO 1.8 INCHES...BUT OVERALL INSTABILITY IS FAIRLY
MEAGER /500-1000 J/KG AT MOST/ AND CLOUDS AND PRECIP HAVE KEPT A
LITTLE CAPPING IN PLACE TOWARD SURFACE BASED CONVECTION.
WITH THERMAL ADVECTION FAIRLY UNFOCUSED OVER THE NEXT 12-24
HOURS...PRETTY MUCH FOLLOWED THE LOCATION OF THE MID LEVEL VORTICITY
AXIS TO MAP PRECIPITATION CHANCES THROUGH THE IMMEDIATE TERM.
HOWEVER...FOR THIS EVENING...THE SUBTROPICAL PORTION OF WAVE WILL
BEGIN TO SINK SOUTHEAST ACROSS NEBRASKA EARLY THIS EVENING...AND
LEAVE MUCH OF THE AREA IN WEAK TO NON EXISTENT FORCING BETWEEN THE
FIRST IMPULSE LOCATED ALONG THE VORTEX AXIS IN IOWA...AND THE SECOND
WANDERING IN WESTERN NORTH DAKOTA. LOCATION OF SUCH FICKLE FEATURES
WILL PRETTY MUCH DRIVE THE MORE CONCENTRATED CHANCES FOR
PRECIPITATION OVER THE NEXT DAY. ERRONEOUS INSTABILITY APPEARS TO
BE THE CULPRIT FOR VARIOUS SHORT TERM HIGH RESOLUTION MODELS IN
PRECIPITATION DEVELOPMENT...AND HAVE SHOWN SOME PREFERENCE TO
OVERALL DRIER SUGGESTED BY HRRR WHICH PRETTY HAS TRENDED TO HAVING
MUCH OF ANY THREAT FOR PRECIP BY EARLY EVENING. WEAK MEAN WIND
SPEEDS WILL ALSO MEAN THAT PRECIPITATION WILL NOT SO MUCH MOVE INTO
ANY AREA AND WILL HAVE TO DEVELOP IN PLACE.
STRATUS EXPECTED TO DEVELOP LATER IN THE NIGHT WITH WEAK FLOW AND
ABUNDANT LOW LEVEL MOISTURE...WHICH WILL IMPACT POTENTIAL FOR TEMPS
ON SATURDAY. WHILE TEMPS LARGELY DEPENDENT ON CLOUDS/PRECIP...HAVE
SIDED SOMEWHAT COOLER THAN MEAN GUIDANCE...ESPECIALLY IN MORE
PRECIPITATION FAVORED WEST/JAMES VALLEY.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 333 PM CDT FRI AUG 15 2014
ON SATURDAY NIGHT...FOLLOWED A 500MB VORT FILAMENT AS IT MOVES
EASTWARD ACROSS OUR FORECAST AREA AS GUIDANCE FOR TIMING AND
PLACEMENT OF CONVECTIVE CHANCES. THE 500MB FLOW IS STRONGLY
DIFFLUENT...WITH NOT A LOT OF WIND UPSTAIRS TO PUSH THE INDIVIDUAL
CELLS EASTWARD. COUPLED WITH THE DAYTIME HEATING...THOUGHTS ARE THAT
LOW END LIKELY POPS ARE WARRANTED FROM THE JAMES RIVER VALLEY TO I
29 IN SOUTH DAKOTA...PLACED SQUARELY ON THE VORT FILAMENT IN THE
EARLY EVENING. POPS THEN RAPIDLY DECREASE HEADING EAST OF I 29 AS
THE FORCING MECHANISM COMES TO A HALT. AFTER EARLY EVENING...THE
CHANCE FOR RAIN WILL LIKELY WIND DOWN AS WE LOSE HEATING...COUPLED
WITH THE FACT THAT THE VORT FILAMENT ALSO WEAKENS AS IT MOVES
EASTWARD ACROSS OUR FORECAST AREA.
SUNDAYS PRECIP CHANCES ARE DIFFICULT TO FIGURE OUT. BUT IN GENERAL
IT APPEARS THAT CHANCE POPS ARE WARRANTED MAINLY EAST OF I 29 ALONG
THE DIFFLUENT FLOW ALOFT...AND KEPT THINGS DRY IN OUR FAR WESTERN
ZONES. HIGHS AND LOWS SUNDAY AND SATURDAY NIGHT LOOK NON EVENTFUL
FOR THIS TIME OF YEAR...WITH 60S PRESENT SATURDAY NIGHT...AND UPPER
70S TO MID 80S ON SUNDAY.
THE NEXT WAVE WE CAN FOLLOW IS A SYNOPTIC SCALE FEATURE WHICH THE
VARIOUS MODELS MOVE ACROSS OUR AREA LATE SUNDAY NIGHT AND MONDAY
MORNING. LIKELY POPS ARE WARRANTED FOR MOST LOCATIONS. SEVERE
CHANCES ARE NOT REAL GREAT BECAUSE MUCH OF THE CONVECTION SHOULD
REMAIN WEST OF OUR FORECAST AREA SUNDAY EVENING...AND THE MID LEVEL
WIND SHEAR IS NOT REAL STRONG.
IN THE EXTENDED PORTION OF THE FORECAST BEGINNING MONDAY NIGHT...
THE DETERMINISTIC MODELS ARE IN PRETTY GOOD AGREEMENT IN DROPPING
THE UPPER LOW/TROUGH THROUGH THE EASTERN PLAINS...PRIMARILY IN THE
FAR EASTERN DAKOTAS...MINNESOTA AND IOWA. A CORRESPONDING SURFACE
WIND SHIFT TO A NORTHWESTERLY DIRECTION FOLLOWS SUIT LATE MONDAY
NIGHT AND TUESDAY. THEN THE UPPER TROUGH EVER SO SLOWLY MOVES
EASTWARD INTO THE GREAT LAKES REGION BY WEDNESDAY. THIS IS WHERE
MODEL DISCREPANCY BEGINS...AT LEAST BETWEEN THE DETERMINISTIC GFS
AND ECMWF IN HOW QUICKLY THEY ADVANCE THE NEXT UPPER TROUGH EASTWARD
ACROSS THE PACIFIC NORTHWEST. THE ECMWF ACTUALLY SHOWS TWO WAVES...
WITH ONE PASSING QUICKLY EASTWARD IN OUR AREA WEDNESDAY NIGHT...AND
A SECOND ONE FOLLOWING THEREAFTER. THE GFS MORPHS EVERYTHING INTO
ONE LARGER WAVE WEST OF OUR FORECAST AREA. THE GEM GLOBAL IS OFF ON
ITS OWN. ALL IN ALL...IT APPEARS CHANCES FOR CONVECTION ARE NOT REAL
GREAT MONDAY NIGHT THROUGH FRIDAY. WITH THIS MUCH DISCREPANCY...
ENSEMBLE BLENDING IS THE WAY TO GO BUT DID PUT SOME CREDENCE IN THE
ECMWF WAVE PASSAGE WEDNESDAY NIGHT...WHICH GIVE DECENT CHANCE POPS
FOR MUCH OF OUR AREA.
OTHERWISE FOR TEMPERATURES...LOOKS LIKE A LOT OF 60S FOR LOWS AND
80S FOR HIGHS...WITH 850MB TEMPERATURES NOT REAL NOTEWORTHY ONE WAY
OR ANOTHER. IT DOES LOOK HUMID THROUGH THE EXTENDED PERIOD...EVEN ON
TUESDAY WHEN THE LIGHT NORTHWEST SURFACE FLOW OCCURS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1152 AM CDT FRI AUG 15 2014
CONVECTION SHOULD CONTINUE TO BE THE LARGEST ISSUE WITH AVIATION
FORECASTS THROUGH THE NEXT 24 HOURS. MODELS STRUGGLING WITH THE
OVERALL WEAKLY FORCED AND WEAKLY UNSTABLE ATMOSPHERE. LIKELY TO
GET AN AFTERNOON ENHANCEMENT ALONG AND WEST OF A KHON TO KFSD TO
KSLB LINE...WITH LIKELY BRIEF MVFR CEILINGS AND VISIBILITIES.
INDICATIONS ARE THAT ACTIVITY WILL WANE BY AROUND 06Z IN THIS
AXIS...BUT UNTIL THEN...SLOW MOVEMENT WILL MEAN IMPACTED AREAS MAY
BE THAT WAY FOR SEVERAL HOURS. LATER IN THE OVERNIGHT AND SATURDAY
MORNING SUGGEST BLOSSOMING OF MVFR TO IFR STRATUS AS PRECIPITATION
THREAT WINDS DOWN.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHAPMAN
LONG TERM...MJ
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1125 AM MDT FRI AUG 15 2014
.UPDATE...
ISSUED AT 1015 AM MDT FRI AUG 15 2014
UPDATED FORECAST TO REMOVE FLASH FLOOD WATCH AND TO LOWER HIGHS
ACROSS PORTIONS OF THE AREA FOR TODAY. SCATTERED SHOWERS ARE
MOVING EAST OF THE AREA WITH A FEW LIGHT SHOWERS REMAINING OVER
NORTHWESTERN SOUTH DAKOTA. HRRR AND LOCAL WRF MODELS HAVE
DECREASED THE INTENSITY OF THE RAINFALL THROUGH THE AFTERNOON WITH
THE LATEST NAM INDICATING LOWERING OF PW VALUES. THUS CANCELLED
FLASH FLOOD WATCH WITH THIS UPDATE. CLOUD COVER AND SHOWERS WILL
KEEP HIGH TEMPERATURES LOWER THAN ORIGINALLY FORECAST...THUS
LOWERED HIGHS FOR TODAY AS WELL.
&&
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 337 AM MDT FRI AUG 15 2014
UPPER LEVEL ANALYSIS HAS WEAK RIDGING ACROSS THE SOUTHERN CONUS
WITH STRONG SHORTWAVE MOVING THROUGH THE RIDGE ACROSS THE NORTHERN
PLAINS...AND STRONGER UPPER LOW SPINNING ACROSS THE PACIFIC
NORTHWEST. SKIES ARE MOSTLY CLEAR TO THE WEST OF THE BLACK HILLS
AND MOSTLY CLOUDY TO THE EAST. MAIN BATCH OF SHOWERS AND
THUNDERSTORMS HAVE LIFTED INTO NORTHWEST SOUTH DAKOTA...WITH SOME
WEAK RETURNS SHOWING UP ACROSS SOUTH CENTRAL SOUTH DAKOTA AND
NORTHERN NEBRASKA. AT THE SURFACE...BROAD AREA OF LOW PRESSURE
STRETCHES FROM WESTERN NORTH DAKOTA TO WESTERN KANSAS.
TEMPERATURES AT 3 AM ARE IN THE 60S TO LOWER 70S.
TODAY...STRONG SHORTWAVE THAT BROUGHT SHOWERS AND THUNDERSTORMS TO
THE AREA YESTERDAY...WILL SLIDE SLOWLY EAST ALONG THE SD/ND BORDER
TODAY. SURFACE BOUNDARY ACROSS CENTRAL SD WILL NOT MOVE MUCH...SO
EAST TO SOUTHEAST BOUNDARY LAYER FLOW WILL CONTINUE TO BRING
MOISTURE INTO NORTHERN AND EASTERN PORTIONS OF THE FORECAST AREA
TODAY. PW`S REMAIN HIGH ACROSS THIS AREA...SO HEAVY RAINS WILL
STILL BE A CONCERN TODAY...FROM NORTHWEST THROUGH SOUTH CENTRAL
SOUTH DAKOTA. A FLASH FLOOD WATCH WILL REMAIN IN EFFECT FOR THESE
AREAS THROUGH LATE THIS AFTERNOON. HIGH TEMPERATURES WILL CLIMB
INTO THE MID 70S TO MID 80S.
TONIGHT...UPPER SHORTWAVE WILL SLOWLY PUSH INTO EASTERN SOUTH
DAKOTA AS WEAK SURFACE HIGH MOVES INTO EASTERN MONTANA. SCATTERED
SHOWERS AND THUNDERSTORMS WILL STILL BE POSSIBLE ACROSS NORTHWEST
INTO SOUTH CENTRAL SOUTH DAKOTA...WITH HEAVY RAIN THREAT
DIMINISHING THROUGH THE EVENING. LOW TEMPERATURES WILL FALL INTO
THE MID 50S TO MID 60S.
SATURDAY...SHORTWAVE UPPER RIDGE TRIES TO BUILD INTO WESTERN AREAS
AS SHORTWAVE TROF SHIFTS EAST. ANTECEDENT MOISTURE...SURFACE
HEATING...AND WEAK ENERGY MOVING ACROSS THE NORTHERN PLAINS MAY
PRODUCE AN ISOLATED STORM OR TWO...BUT MAINLY DRY CONDITIONS
SHOULD PREVAIL. HIGH TEMPERATURES WILL BE IN THE UPPER 70S TO
UPPER 80S. ISOLATED SHOWERS MAY PERSIST INTO THE EVENING ACROSS
THE BLACK HILLS INTO NORTHWEST SOUTH DAKOTA. LOW TEMPERATURES WILL
FALL INTO THE MID 50S TO MID 60S.
&&
.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 337 AM MDT FRI AUG 15 2014
SUNDAY/MONDAY WILL FEATURE WESTERLY FLOW ALOFT AS A COUPLE OF
SHORTWAVE TROUGHS MOVES ACROSS THE NORTHERN PLAINS. BEST POPS APPEAR
TO BE DURING PEAK HEATING SUNDAY AFTERNOON/EVENING WITH SUFFICIENT
CAPE/SHEAR ON THE SD PLAINS FOR ISOLATED SEVERE STORMS.
UPPER LEVEL PATTERN THEN TRANSITIONS FOR NEXT WEEK WITH DEVELOPING
LARGE SCALE UPPER TROUGH OVER WESTERN NORTH AMERICA. RESULT FOR CWA
WILL BE A SHIFT TO SOUTHWEST FLOW ALOFT...WITH THE STRENGTH OF
RIDGING OVER THE CENTRAL US DEPENDENT ON WHETHER YOU BUY THE 00Z GFS
OR ECMWF. ECMWF WEAKEST WITH UPPER RIDGE. SPLIT THE DIFFERENCE WHICH
MEANS SEASONAL TEMPERATURES AND LOWISH POPS GIVEN DRIER AIR MIXING
OUT ACROSS PORTIONS OF THE CWA FROM THE HIGHER TERRAIN TO OUR WEST.
&&
.AVIATION...FOR THE 18Z TAFS THROUGH 18Z SATURDAY
ISSUED AT 1115 AM MDT FRI AUG 15 2014
SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE OVER THE REGION
THIS AFTERNOON AND EVENING. THE BEST CHANCE OF PRECIPITATION WILL
BE OVER NORTHWESTERN SOUTH DAKOTA. THE PRECIPITATION WILL END
FROM WEST TO EAST THIS EVENING. AREAS OF MVFR CIGS WILL BE FOUND
OVER PARTS OF FAR NORTHWESTERN SOUTH DAKOTA THROUGH MUCH OF THE
AFTERNOON. AFTER MIDNIGHT...MORE WIDEPSREAD MVFR CIGS WILL
DEVELOP OVER PARTS OF WESTERN SOUTH DAKOTA. CONDITIONS WILL
IMPROVE TO VFR AGAIN BY MID MORNING ON SATURDAY.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...MLS
SHORT TERM...15
LONG TERM...HELGESON
AVIATION...10
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1021 AM MDT FRI AUG 15 2014
.UPDATE...
ISSUED AT 1015 AM MDT FRI AUG 15 2014
UPDATED FORECAST TO REMOVE FLASH FLOOD WATCH AND TO LOWER HIGHS
ACROSS PORTIONS OF THE AREA FOR TODAY. SCATTERED SHOWERS ARE
MOVING EAST OF THE AREA WITH A FEW LIGHT SHOWERS REMAINING OVER
NORTHWESTERN SOUTH DAKOTA. HRRR AND LOCAL WRF MODELS HAVE
DECREASED THE INTENSITY OF THE RAINFALL THROUGH THE AFTERNOON WITH
THE LATEST NAM INDICATING LOWERING OF PW VALUES. THUS CANCELLED
FLASH FLOOD WATCH WITH THIS UPDATE. CLOUD COVER AND SHOWERS WILL
KEEP HIGH TEMPERATURES LOWER THAN ORIGINALLY FORECAST...THUS
LOWERED HIGHS FOR TODAY AS WELL.
&&
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 337 AM MDT FRI AUG 15 2014
UPPER LEVEL ANALYSIS HAS WEAK RIDGING ACROSS THE SOUTHERN CONUS
WITH STRONG SHORTWAVE MOVING THROUGH THE RIDGE ACROSS THE NORTHERN
PLAINS...AND STRONGER UPPER LOW SPINNING ACROSS THE PACIFIC
NORTHWEST. SKIES ARE MOSTLY CLEAR TO THE WEST OF THE BLACK HILLS
AND MOSTLY CLOUDY TO THE EAST. MAIN BATCH OF SHOWERS AND
THUNDERSTORMS HAVE LIFTED INTO NORTHWEST SOUTH DAKOTA...WITH SOME
WEAK RETURNS SHOWING UP ACROSS SOUTH CENTRAL SOUTH DAKOTA AND
NORTHERN NEBRASKA. AT THE SURFACE...BROAD AREA OF LOW PRESSURE
STRETCHES FROM WESTERN NORTH DAKOTA TO WESTERN KANSAS.
TEMPERATURES AT 3 AM ARE IN THE 60S TO LOWER 70S.
TODAY...STRONG SHORTWAVE THAT BROUGHT SHOWERS AND THUNDERSTORMS TO
THE AREA YESTERDAY...WILL SLIDE SLOWLY EAST ALONG THE SD/ND BORDER
TODAY. SURFACE BOUNDARY ACROSS CENTRAL SD WILL NOT MOVE MUCH...SO
EAST TO SOUTHEAST BOUNDARY LAYER FLOW WILL CONTINUE TO BRING
MOISTURE INTO NORTHERN AND EASTERN PORTIONS OF THE FORECAST AREA
TODAY. PW`S REMAIN HIGH ACROSS THIS AREA...SO HEAVY RAINS WILL
STILL BE A CONCERN TODAY...FROM NORTHWEST THROUGH SOUTH CENTRAL
SOUTH DAKOTA. A FLASH FLOOD WATCH WILL REMAIN IN EFFECT FOR THESE
AREAS THROUGH LATE THIS AFTERNOON. HIGH TEMPERATURES WILL CLIMB
INTO THE MID 70S TO MID 80S.
TONIGHT...UPPER SHORTWAVE WILL SLOWLY PUSH INTO EASTERN SOUTH
DAKOTA AS WEAK SURFACE HIGH MOVES INTO EASTERN MONTANA. SCATTERED
SHOWERS AND THUNDERSTORMS WILL STILL BE POSSIBLE ACROSS NORTHWEST
INTO SOUTH CENTRAL SOUTH DAKOTA...WITH HEAVY RAIN THREAT
DIMINISHING THROUGH THE EVENING. LOW TEMPERATURES WILL FALL INTO
THE MID 50S TO MID 60S.
SATURDAY...SHORTWAVE UPPER RIDGE TRIES TO BUILD INTO WESTERN AREAS
AS SHORTWAVE TROF SHIFTS EAST. ANTECEDENT MOISTURE...SURFACE
HEATING...AND WEAK ENERGY MOVING ACROSS THE NORTHERN PLAINS MAY
PRODUCE AN ISOLATED STORM OR TWO...BUT MAINLY DRY CONDITIONS
SHOULD PREVAIL. HIGH TEMPERATURES WILL BE IN THE UPPER 70S TO
UPPER 80S. ISOLATED SHOWERS MAY PERSIST INTO THE EVENING ACROSS
THE BLACK HILLS INTO NORTHWEST SOUTH DAKOTA. LOW TEMPERATURES WILL
FALL INTO THE MID 50S TO MID 60S.
&&
.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 337 AM MDT FRI AUG 15 2014
SUNDAY/MONDAY WILL FEATURE WESTERLY FLOW ALOFT AS A COUPLE OF
SHORTWAVE TROUGHS MOVES ACROSS THE NORTHERN PLAINS. BEST POPS APPEAR
TO BE DURING PEAK HEATING SUNDAY AFTERNOON/EVENING WITH SUFFICIENT
CAPE/SHEAR ON THE SD PLAINS FOR ISOLATED SEVERE STORMS.
UPPER LEVEL PATTERN THEN TRANSITIONS FOR NEXT WEEK WITH DEVELOPING
LARGE SCALE UPPER TROUGH OVER WESTERN NORTH AMERICA. RESULT FOR CWA
WILL BE A SHIFT TO SOUTHWEST FLOW ALOFT...WITH THE STRENGTH OF
RIDGING OVER THE CENTRAL US DEPENDENT ON WHETHER YOU BUY THE 00Z GFS
OR ECMWF. ECMWF WEAKEST WITH UPPER RIDGE. SPLIT THE DIFFERENCE WHICH
MEANS SEASONAL TEMPERATURES AND LOWISH POPS GIVEN DRIER AIR MIXING
OUT ACROSS PORTIONS OF THE CWA FROM THE HIGHER TERRAIN TO OUR WEST.
&&
.AVIATION...FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING
ISSUED AT 337 AM MDT FRI AUG 15 2014
SCATTERED/NUMEROUS TSRA WILL PERSIST OVER NORTHWEST INTO CENTRAL SD
TODAY WITH LOCAL IFR CIGS/VSBYS. AREAS MVFR ST OVER NORTHWEST SD
THIS MORNING. ADDITIONAL ISOLATED/SCATTERED TSRA WILL DEVELOP TODAY
OVER REST OF FORECAST AREA WITH LOCAL MVFR VSBYS. OUTSIDE OF
STORMS/ST...VFR CONDITIONS WILL PREVAIL THROUGH THIS AFTERNOON.
CONDITIONS WILL IMPROVE FROM WEST TO EAST TONIGHT AS
ST/PRECIPITATION SLOWLY MOVES EAST.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...MLS
SHORT TERM...15
LONG TERM...HELGESON
AVIATION...HELGESON
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
332 PM EDT FRI AUG 15 2014
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCES WILL TRACK SOUTHEAST ACROSS OUR
REGION TONIGHT. MEANWHILE...A FRONTAL ZONE STALLED OVER THE AREA
WILL GRADUALLY LIFT NORTH OF THE REGION AS A WARM FRONT SATURDAY
INTO SUNDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 332 PM EDT FRIDAY...
UPPER LEVEL TROUGH WILL REMAIN ALONG THE EAST COAST TONIGHT INTO
SATURDAY. A SHORTWAVE WILL DROP SOUTHEAST IN THE NORTHWEST FLOW
TONIGHT ACROSS THE AREA. THIS WILL COMBINE WITH A STALL FRONTAL
BOUNDARY TO CREATE SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS
IN THE UNSTABLE AIR THIS AFTERNOON INTO THIS EVENING. MSAS PLACED
THE MOST UNSTABLE AIR ACROSS SOUTHWEST PORTIONS WITH LI MINUS ONE
TO MINUS THREE. SPC MESOSCALE ANALYSIS HIGHLIGHTED MUCAPE ABOUT
1000 J/KG IN THE SOUTHWEST. SHAPED POPS TOWARDS HRRR FOR THIS
EVENING INTO TONIGHT.
SHOWERS OR STORMS SHOULD FADE TONIGHT WITH LOSS OF HEATING AND NO
REAL SUPPORT ALOFT WITH TIMING CLOSE TO YESTERDAY...BECAUSE HIGHER
THETA-E AIR RESIDES ACROSS THE SOUTHERN CWA INTO TONIGHT. CLEAR TO
PARTLY CLOUDY CONDITIONS EXPECTED OVERNIGHT. PATCHY VALLEY FOG
EXPECTED LATE TONIGHT IN THE USUAL PLACES AS WELL AS SOUTHSIDE VA/NW
NC PER ANY SHOWER ACTIVITY THIS AFTERNOON/EVENING. PLAYED LOW
TEMPERATURES OVERNIGHT CLOSE TO THE ADJMAVBC WITH READINGS FROM THE
MID TO UPPER 40S IN THE DEEPER MOUNTAIN VALLEYS TO THE LOWER 60S IN
THE SOUTHEAST...WITH HIGH PRESSURE MOVING OVERHEAD ACROSS THE
CENTRAL APPALACHIANS.
UPPER LEVEL TROUGHING OVER THE NORTHEAST STATES WITH GRADUALLY SHIFT
EAST ON SATURDAY...RESULTING A WEAK ZONAL UPPER LEVEL PATTERN.
FRONTAL BOUNDARY LIFTS NORTH ACROSS A WARM FRONT...AS A WAVE OF LOW
PRESSURE MOVES ACROSS EASTERN NORTH CAROLINA AND VIRGINIA SATURDAY.
MORNING LOW CLOUDS AND FOG WILL LIFT OR BURN OFF QUICKLY SATURDAY.
MAY SEE AN ISOLATED SHOWER OR STORM IN THE SOUTHEAST DURING THE
AFTERNOON NEAR THE FRONT...HOWEVER CHANCES APPEAR TOO LOW AT THIS
POINT TO ADD MENTION IN THE FORECAST WITH LIMITED LIFT. THE DAY
TWO CONVECTIVE OUTLOOK HAS PLACED THE CHANCE OF GENERAL
THUNDERSTORM WAY TO OUR EAST SATURDAY ACROSS EASTERN NORTH
CAROLINA. WENT WITH HIGH TEMPERATURES ON SATURDAY FROM AROUND 80
DEGREES IN THE MOUNTAINS TO THE UPPER 80S IN THE PIEDMONT.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 301 PM EDT FRIDAY...
THE FORECAST PERIOD BEGINS WITH A WEAK SURFACE HIGH OVER THE
SOUTHERN APPALACHIANS AND A LEE TROUGH ACROSS THE MID ATLANTIC
COASTAL PIEDMONT. BY SUNDAY AFTERNOON...THE SURFACE HIGH WITHERS
AWAY WITH DIURNAL SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS THE
MOUNTAINS. THESE STORMS ARE EXPECTED TO FADE THROUGH THE EVENING.
MODELS ARE ALSO SHOWING A SHORT WAVES TRACKING EAST BUT NORTH OF THE
AREA SUNDAY MORNING. THIS WAVE AND ASSOCIATED CONVECTION MAY LAY AN
OUTFLOW BOUNDARY ACROSS THE MOUNTAINS TO FURTHER ENHANCE THE
DEVELOPMENT OF AFTERNOON CONVECTION.
SUNDAY NIGHT INTO MONDAY...MODELS ARE MOVING A MESOSCALE COMPLEX
FROM THE OHIO VALLEY TO THE MID ATLANTIC REGION. THE 12Z GFS KEEPS
THIS COMPLEX MOVING EAST ACROSS PENNSYLVANIA MONDAY NIGHT. THE 12Z
NAM/ECM HAS A MORE SOUTHERN TRACK WITH THE COMPLEX TRACKING ACROSS
WEST VIRGINIA MONDAY AND OVER CENTRAL-NORTHERN VIRGINIA MONDAY
AFTERNOON/NIGHT. THIS SOUTHERN TRACK WOULD CLIP THE FORECAST AREA
ALONG AND NORTH OF I64. OUTFLOW BOUNDARIES MAY GENERATE STORMS
ACROSS THE REST OF THE FORECAST AREA LATE MONDAY AFTERNOON/NIGHT.
SUNDAY WILL SEE TEMPERATURES WARMER THAN NORMAL WITH A SOUTHERLY
FLOW AND ABUNDANT SUNSHINE. DESPITE THE COOL START TO THE
MONTH...SUMMER IS NOT OVER FROM A WEATHER STAND POINT. MONDAY WILL
ALSO BE A WARMER THAN NORMAL DAY...ESPECIALLY IF THE MESOSCALE
COMPLEX STAYS WELL TO THE NORTH. SINCE MODELS ARE DELAYING
CONVECTION ACROSS THE SOUTHERN TWO/THIRDS OF THE FORECAST
AREA...WILL CONTINUE TO RUN WITH THE WARMER GUIDANCE.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 100 PM EDT FRIDAY...
UNSETTLED PATTERN DURING THIS PERIOD. SEVERAL SHORTWAVES PIVOT
THROUGH THE REGION TUESDAY AND WEDNESDAY AND THEN MID LEVEL RIDGING
SETS UP FOR THE REST OF THE PERIOD...WITH ADDITIONAL DISTURBANCES
RIDING ALONG THE RIDGE FROM THE NORTHWEST INTO OUR REGION. PLENTY OF
MOISTURE AND INSTABILITY WILL BE PRESENT FOR SCATTERED SHOWERS AND
THUNDERSTORMS EACH DAY. PLACED SLIGHT CHANCE TO CHANCE POPS IN EACH
DAY WITH THE MAX POPS DURING THE AFTERNOON/EVENING HOURS...AND
SLIGHTLY LOWER POPS DURING THE OVERNIGHT HOURS.
TEMPERATURES WILL BE CLOSER TO NORMAL AS 850MB TEMPS RISE FROM +16C
AT THE BEGINNING OF THE PERIOD TO NEAR +20C BY THE WEEKEND. THIS
WILL COORDINATE TO SURFACE HIGH TEMPS NEAR 90 EAST OF THE BLUE RIDGE
AND LOW TO MID 80S FROM THE BLUE RIDGE AND POINTS TO THE WEST.
DEWPOINTS WILL HOLD IN THE MID TO UPPER 60S THROUGH THE PERIOD WHICH
WILL KEEP NIGHT TIME TEMPS ON THE MILD SIDE.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
AS OF 130 PM EDT FRIDAY...
SCT TO BKN MVFR CLOUDS ARE POSSIBLE ESPECIALLY IN THE WEST THIS
AFTERNOON INTO TONIGHT. ISOLD MVFR CONVECTION IS POSSIBLE THIS
AFTERNOON INTO THIS EVENING AS SHORTWAVE ROTATES ACROSS OUR AREA.
BEST CHANCE WILL BE ACROSS SOUTHERN PORTIONS OF FORECAST AREA
THIS AFTERNOON INTO TONIGHT. STORMS WILL BE TOO ISOLATED TO
MENTION AT MOST TAF SITES.
WINDS W TO SW WINDS MAINLY UNDER 8 KNOTS THIS AFTERNOON WILL
BECOME LIGHT AND VARIABLE TONIGHT INTO SATURDAY.
VFR CONDITIONS TONIGHT AS HIGH PRESSURE SINKS IN BEHIND THE UPPER
SHORTWAVE. FOG WILL AGAIN FORM IN THE RIVER VALLEYS ESPECIALLY
AROUND LWB/BCB.
EXPECT MAINLY VFR INTO THE WEEKEND..WITH HIGH PRESSURE IN PLACE.
HIGH CONFIDENCE IN CEILINGS...VISIBILITIES...AND WINDS DURING THE
PERIOD.
WEATHER PATTERN BECOMES MORE TYPICAL FOR AUGUST BY EARLY NEXT
WEEK. LOW PROBABILITY FOR AFTERNOON AND EVENING
THUNDERSTORMS...THEN FOG IN FAVORED VALLEY LOCATIONS OVERNIGHT.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...KK
NEAR TERM...KK
SHORT TERM...RCS
LONG TERM...CF
AVIATION...KK/WP
YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1155 AM CDT FRI AUG 15 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 306 AM CDT FRI AUG 15 2014
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED AN UPPER LOW OVER THE PACIFIC NORTHWEST...RIDGING FROM THE
SOUTHWESTERN U.S. INTO ALBERTA...AND TROUGHING OVER EASTERN CANADA
INTO THE NORTHEASTERN U.S.. ALSO OF NOTE WAS A SHORTWAVE OVER
SOUTHEAST MONTANA...WHICH WITH A STREAM OF MOISTURE TRANSPORT
BRINGING PRECIPITABLE WATER UP TO 1.5-2 INCHES ACROSS MUCH OF THE
PLAINS...HAS SUPPORTED SHOWERS AND EMBEDDED THUNDERSTORMS FROM THE
DAKOTAS INTO KS. ANOTHER AREA OF SCATTERED SHOWERS AND STORMS WERE
PRESENT FROM EASTERN SOUTH DAKOTA INTO SOUTHWEST MN AND WESTERN
IA...IN AN AREA OF MID-LEVEL FRONTOGENESIS AND NOSE OF 850MB
MOISTURE TRANSPORT. FURTHER TO THE EAST OVER THE FORECAST AREA...
HIGH PRESSURE AND DRY AIR DOMINATE. PRECIPITABLE WATER VALUES FROM
00Z SOUNDINGS RANGED FROM 1.25 INCHES AT MPX TO 0.44 INCHES AT GRB.
SOME HIGHER CLOUDS WERE FLOWING INTO LOCATIONS ALONG/WEST OF THE
MISSISSIPPI RIVER...HELPING TO KEEP TEMPERATURES UP THERE.
HOWEVER...IN CENTRAL WISCONSIN WHERE THE AIR IS DRIEST AND SKIES ARE
MAINLY CLEAR...READINGS HAVE DIPPED INTO THE LOW 40S WITH SOME
PATCHY FOG AROUND.
THE NORTHWEST FLOW REGIME THE FORECAST AREA SITS IN IS PROGGED TO
REMAIN IN PLACE THROUGH TONIGHT. MUCH OF THE FOCUS IS HOW CLOSE THE
SHORTWAVE IN SOUTHEAST MONTANA CAN PUSH EAST TOWARDS THE AREA...
BEFORE IT GETS CAUGHT UP IN THE NORTHWEST FLOW. MODELS ARE IN GOOD
AGREEMENT TRACKING THE SHORTWAVE INTO EASTERN SOUTH DAKOTA BY 12Z
SATURDAY. THIS TRACK DOES HELP TO SPREAD HIGHER PRECIPITABLE WATER
TOWARDS THE AREA...WITH VALUES INCREASING TO 1.5-1.75 INCHES ALONG
AND WEST OF THE MS RIVER FOR TONIGHT. HOWEVER...THE SLOW PROGRESSION
OF THE SHORTWAVE...COMBINED WITH THE NOSE OF 850MB MOISTURE
TRANSPORT PROGGED TO REMAIN MOSTLY WEST OF I-35 SUGGESTS A VERY LOW
PROBABILITY OF ANY PRECIPITATION FOR THE FORECAST AREA. THE 15.00Z
NAM...GFS...HIRES-ARW/NMM...NSSL WRF AND ECMWF DEPICT LITTLE IF ANY
PRECIPITATION...LEADING TO HIGHER CONFIDENCE OF A DRY FORECAST.
REALLY ONLY SMALL PRECIPITATION POTENTIAL WOULD BE...
1. THIS MORNING IN A SECTION OF NORTHEAST IOWA FROM THE
PRECIPITATION OFF TO OUR WEST TRYING TO PUSH IN.
2. ALONG THE MS RIVER WHERE THE HRRR/HIRES-ARW/NMM/NSSL WRF ALL
DEPICT A WEAK BAND OF SHOWERS OR SPRINKLES. APPEARS TO BE
CORRELATED WITH A VERY WEAK SHORTWAVE DROPPING DOWN OUT OF THE DLH
AREA.
3. LATE TONIGHT...WEAK ISENTROPIC LIFT MAY BE ABLE TO INITIATE
SOME SHOWERS OVER FAR NORTHEAST IA AND SOUTHWEST
WISCONSIN...SIMILAR TO THE 15.00Z ECMWF/NSSL WRF-ARW.
925MB TEMPS ARE PROGGED TO BE ABOUT 2C WARMER BY 00Z TODAY COMPARED
TO 00Z YESTERDAY...SO WE SHOULD BE ABLE TO TACK ON A FEW DEGREES TO
YESTERDAYS HIGHS. HOWEVER...CLOUD COVER MAY HOLD TEMPERATURES BACK
SOME...PARTICULARLY ACROSS NORTHEAST IOWA. WITH HIGHER PRECIPITABLE
WATER VALUES IN PLACE TONIGHT ALONG WITH SOME CLOUD COVER...MOST
LOCATIONS WILL SEE A WARMER NIGHT. EVEN SO...CENTRAL WISCONSIN LOOKS
TO CONTINUE TO BE THE COOL SPOT WITH THE DRIEST AIR PRESENT THERE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 306 AM CDT FRI AUG 15 2014
THE WEEKEND FORECAST LOOKS TO BE DOMINATED BY TWO FEATURES. FIRST...
THE SHORTWAVE TROUGH OVER EASTERN SOUTH DAKOTA AT 12Z SATURDAY...
WHICH LOOKS TO UNDER CUT THE FORECAST AREA BY HEADING ROUGHLY
THROUGH IOWA ON SUNDAY. SIMILAR TO THE SHORT TERM PERIOD...GIVEN THE
SLOW PROGRESSION OF THE SHORTWAVE KEEPING THE DYNAMICS TO THE
WEST...AND THE 850MB MOISTURE TRANSPORT NOSE AHEAD OF IT STAYING
NEAR OR SOUTH OF I-80...BELIEVE MUCH OF ITS PRECIPITATION SHOULD
STAY TO THE SOUTH OF THE FORECAST AREA. WITH THE SHORTWAVE GETTING
CLOSER ON SUNDAY...ESPECIALLY IN THE 15.00Z GFS...WILL HAVE TO
MAINTAIN SOME LOW CHANCES OF SHOWERS/STORMS WEST OF THE MS RIVER AND
SOUTH OF I-90 IN WISCONSIN. THE SECOND FEATURE...A SHORTWAVE TROUGH
DROPPING THROUGH ONTARIO ALLOWS A COLD FRONT TO DROP SOUTH THROUGH
THE FORECAST AREA LATE SATURDAY THROUGH SATURDAY NIGHT. THIS COLD
FRONT...COMBINED WITH DAYTIME HEATING AND SOME MOISTURE PUSHED EAST
INTO THE FORECAST AREA...SHOULD BE ENOUGH TO TRIGGER ISOLATED TO
MAYBE SCATTERED SHOWERS AND THUNDERSTORMS NORTH OF I-94 SATURDAY
AFTERNOON. GIVEN THE NORTHWEST UPPER FLOW AND SOUTHWARD PROGRESSION
OF THE FRONT...THESE MAY TRY TO DROP SOUTH THROUGH THE AREA SATURDAY
NIGHT...PROVIDED THEY DONT FALL APART WITH LOSS OF DAYTIME
INSTABILITY. SATURDAYS HIGHS SHOULD BE CLOSE TO TODAY GIVEN NEARLY
IDENTICAL 925MB TEMPS. WITH THE PASSAGE OF THE COLD FRONT SATURDAY
NIGHT...925MB TEMPS COOLING ABOUT 3C...POTENTIAL FOR A STRATUS DECK
AND A SWITCH TO EASTERLY FLOW...EXPECT COOLER CONDITIONS FOR SUNDAY.
ATTENTION EARLY NEXT WEEK THEN TURNS TO THE UPPER LOW OVER THE
PACIFIC NORTHWEST. THERE IS SURPRISINGLY GOOD MODEL AGREEMENT FOR
THE LOW TO DROP INTO THE FORECAST AREA ON TUESDAY. RETURNING
MOISTURE TRANSPORT AHEAD OF THIS UPPER LOW COMBINED WITH DPVA SHOULD
YIELD SOME SHOWERS AND THUNDERSTORMS...TRACKING INTO AREAS
ALONG/WEST OF THE MISSISSIPPI ON MONDAY AND GRADUALLY ACROSS THE
REST OF THE AREA MONDAY NIGHT AND TUESDAY. HAVE CONTINUED TO MENTION
50-60 PERCENT CHANCES. QUICK SOUNDING CHECK WOULD SUGGEST NO SEVERE
WEATHER DUE TO WEAK SHEAR.
FOR THE MIDDLE OF THE WEEK...THE UPPER LOW GRADUALLY FILLS AND LIFTS
NORTHEAST OUT OF THE REGION...IN RESPONSE TO RIDGING BUILDING UP
OVER THE PLAINS. STILL NEED TO MAINTAIN SOME LOW CHANCES OF
PRECIPITATION ON WEDNESDAY WITH THE UPPER LOW IN THE AREA...AND
ALTHOUGH 500MB HEIGHTS RISE GOING INTO THURSDAY...ITS ALSO
ACCOMPANIED BY WARM/MOIST AIR ADVECTION. THEREFORE...CHANCES OF
SHOWERS AND STORMS CONTINUE INTO THURSDAY. THE WARM ADVECTION WILL
BE ENOUGH TOO TO SEND TEMPERATURES ABOVE NORMAL FOR THURSDAY AFTER
GENERALLY HOLDING NEAR OR BELOW NORMAL UNTIL THEN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1155 AM CDT FRI AUG 15 2014
INCREASING LOW LEVEL MOISTURE OVER THE NEXT COUPLE DAYS AS HIGH
PRESSURE MEANDERS AWAY TO THE SOUTHEAST. LIGHT SFC WIND
FIELD...COUPLED WITH RISING TDS...BRINGS THE THREAT FOR SOME FOG
INTO THE QUESTION FOR THE OVERNIGHT HOURS. LOOKING SPECIFICALLY AT
RIVER VALLEY FOG FOR KLSE...THE DEPTH OF THE LIGHT WIND LAYER IS
SHALLOW PER RAP/NAM/GFS BUFKIT SOUNDINGS...GENERALLY LESS THAN 500
FT THROUGH THE NIGHT. PLUS...THE SOUNDINGS ALSO POINT TO SOME WEAK
LIFT IN THE LOWER LAYERS ALONG WITH THE POTENTIAL FOR MID/UPPER
LEVEL CLOUDINESS ASSOCIATED WITH A TROUGH PASSING TO THE SOUTH. THE
INCREASING TDS CERTAINLY FAVOR SOME FUZZ OVERNIGHT...MVFR BR VSBYS.
AS FOR THICKER-MORE SIGNIFICANT REDUCTIONS...CAN/T RULE IT OUT...BUT
CONFIDENCE SHAKY. IF SKIES ARE MORE CLEAR THAN NOT...AND IF THE
DEPTH OF THE LIGHT WIND LAYER INCREASES...LOWER VSBYS WOULD BECOME
MORE LIKELY. WORST CASE SCENARIO WOULD BE SUB 1SM BR WITH STRATUS
UNDER 1KFT. WILL LIKELY HOLD WITH A MORE OPTIMISTIC OUTCOME FOR
NOW...LETTING LATER MODEL RUNS AND TRENDS MOVE THE FORECAST AS
NECESSARY. CERTAINLY SOMETHING TO WATCH FOR THROUGH THE NIGHTTIME
HOURS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RIECK