Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/15/12
AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
454 PM PDT SAT JUL 14 2012
.UPDATE...
WENT AHEAD AND PULLED THE THUNDERSTORM CHANCES FOR THE REMAINDER
OF THIS AFTERNOON AND EVENING. CUMULUS BUILDUPS IN MONO- MINERAL
JUST DON`T HAVE ENOUGH MOISTURE/INSTABILITY TO REALLY GET GOING
TODAY. DRY AIRMASS HAS PUSHED THE BULK OF THE MOISTURE INTO
EASTERN NEVADA. ALL PUBLIC AND FIRE PRODUCTS HAVE BEEN UPDATED AND
SENT. WEB PRODUCTS WILL UPDATE SHORTLY.
AS FOR TOMORROW`S FORECAST, WITH THE DRYING THAT WE SAW TODAY,
TOMORROW IS LOOKING MUCH LESS PROBABLE FOR THUNDERSTORMS. POPS
WILL LIKELY BE TRIMMED BACK FOR SUNDAY, BUT WILL WAIT UNTIL THE
00Z MODEL RUNS TO COME IN BEFORE MAKING ANY BIG CHANGES TO SUNDAY.
HOON
&&
.PREVIOUS DISCUSSION... /ISSUED 201 PM PDT SAT JUL 14 2012/
SHORT TERM...
CURRENT WATER VAPOR IMAGERY DEPICTS A VERY DRY AIRMASS ALOFT THAT
HAS MOVED ACROSS WESTERN NEVADA OVERNIGHT AND THIS MORNING.
COMPARED TO YESTERDAY MORNING, THE 12Z OBSERVED PRECIPITABLE
WATER AT KRNO DROPPED 0.20 INCHES (TO 0.37 IN). WITH THE DEEPER
MOISTURE DISPLACED TO THE EAST, CONVECTION HAS BEEN A LOT SLOWER
TO DEVELOP THIS AFTERNOON. BASED ON THE LATEST HRRR FORECAST,
VISIBLE SATELLITE AND RADAR TRENDS, DECIDED TO TRIM BACK COVERAGE
OF THUNDERSTORMS FOR THIS AFTERNOON AND EVENING. THE BEST CHANCE
WILL BE ACROSS MINERAL, EASTERN MONO AND SOUTHEASTERN CHURCHILL
COUNTIES WHERE THE LATEST SPC MESOANALYSIS SHOWS MUCAPES OF AROUND
500 J/KG. WITH LITTLE IN THE WAY OF SHEAR, ANY STORMS THAT FORM
WILL BE PULSE STORMS THAT WILL SLOWLY DRIFT TO THE EAST-NORTHEAST.
ON SUNDAY, THE 12Z GFS/NAM/ECMWF ARE IN GOOD AGREEMENT THAT THE
AREA OF LOW PRESSURE OVER CENTRAL OREGON WILL LIFT TO THE
NORTHEAST WHILE A WEAK AREA OF LOW PRESSURE DEVELOPS NEAR THE
CENTRAL CALIFORNIA COAST. THIS WILL SET UP AN AREA OF DEFORMATION
ACROSS THE RENO CWA FROM TAHOE NORTHEAST TO WINNEMUCCA. SOUTH OF THIS
BOUNDARY, THE FLOW WILL TURN MORE SOUTHERLY, ALLOWING MONSOON
MOISTURE TO BUILD BACK ACROSS SOUTHEASTERN HALF OF THE CWA WITH
MODEL PWATS INCREASING TO NEAR 0.75 INCHES. THE EXISTING FORECAST
LOOKS GOOD WITH ISOLATED COVERAGE SOUTH OF I-80 AND SCATTERED
STORMS SOUTH OF US-50. THE STORMS ACROSS MINERAL AND MONO COUNTIES
WILL BE ON THE WET SIDE, WITH WET/DRY HYBRID STORMS CLOSER TO THE
MOISTURE BOUNDARY BETWEEN I-80 AND US-50 (SEE THE FIRE WEATHER
DISCUSSION BELOW FOR MORE DETAILS).
THE WEAKNESS NEAR THE CALIFORNIA COAST WILL WEAKEN ON MONDAY AS A
STRONGER AREA OF LOW PRESSURE BUILDS SOUTH ACROSS WESTERN
WASHINGTON AND OREGON. THIS WILL TURN THE UPPER LEVEL FLOW BACK TO
THE SOUTHWEST, USHERING IN DRIER AIR ACROSS THE RENO CWA. THE BEST
CHANCE FOR ANY CONVECTION WILL BE ACROSS MINERAL AND MONO
COUNTIES, CLOSER TO THE DEEPER MOISTURE.
THE AREA OF LOW PRESSURE WILL CONTINUE TO SLIDE SLOWLY SOUTH
ACROSS WESTERN OREGON ON TUESDAY. THIS WILL KEEP DRY SOUTHWEST
FLOW IN PLACE. DEPENDING ON THE PLACEMENT OF THE LOW, THERE IS A
VERY SMALL CHANCE THAT EXTREME NORTHERN LASSEN COUNTY AND THE
SURPRISE VALLEY COULD SEE A PASSING SHOWER ON TUESDAY AFTERNOON
SO A SLGT CHANCE WAS INTRODUCED WITH THIS PACKAGE FOR THOSE AREAS.
MYRICK
LONG TERM...WEDNESDAY THROUGH SATURDAY...
A TROUGH LOCATED OVER THE PACIFIC NORTHWEST WILL CREATE A DRY AND
STABLE SOUTHWEST FLOW ALOFT WEDNESDAY AND THURSDAY. NUMERICAL
GUIDANCE DIFFERS FOR FRIDAY AND SATURDAY...SOME SOLUTIONS BRING
THE TROUGH EASTWARD WHILE OTHER SOLUTIONS MOVE IT WESTWARD AND
BUILD THE RIDGE OVER THE EASTERN SIERRA AND WESTERN NEVADA. THE
OVERALL CONSENSUS IS FOR A DRY FORECAST WITH A WARMING TREND
THROUGH SATURDAY...WHICH IS ALREADY COVERED WELL BY THE ONGOING
FORECAST.
ONE WILD CARD IS THE SLIGHT CHANCE THAT MOISTURE FROM THE REMNANTS
OF HURRICANE FABIO COULD BE DRAWN NORTHWARD FRIDAY. TWO RECENT RUNS
OF THE GFS ARE THE ONLY ONES SHOWING THIS SOLUTION. WITH FABIO
CURRENTLY LOCATED 550 MILES SSW OF THE SOUTHERN TIP OF
BAJA-CALIFORNIA CONFIDENCE IS VERY LOW IN THIS SCENARIO. FOR NOW A
SLIGHT CHANCE OF THUNDERSTORMS WAS INTRODUCED FRIDAY FOR MONO
COUNTY. JCM
AVIATION...
VFR CONDITIONS WILL PREVAIL OVERALL THROUGH THE WEEKEND AND INTO
NEXT WEEK. THUNDERSTORMS ARE POSSIBLE SUNDAY AFTERNOON FROM I-80
SOUTHWARD. IN THE VICINITY OF THESE STORMS THE CIG/VSBYS SHOULD BE
AOA 5000/5 WITH GUSTY SFC WINDS.
FOR THE TERMINALS ISOLATED STORMS ARE POSSIBLE SUNDAY AFTERNOON AND
EARLY EVENING IN THE VICINITIES OF KTRK..KTVL AND KRNO...WITH
SOMEWHAT BETTER POTENTIAL FOR THUNDERSTORMS IN THE VICINITY OF KMMH.
JCM
FIRE WEATHER...
HAVE TRIMMED BACK THUNDERSTORM COVERAGE THIS AFTERNOON BASED ON
LATEST RADAR AND SATELLITE TRENDS TO ENCOMPASS EASTERN MONO COUNTY
INTO MINERAL AND EASTERN CHURCHILL COUNTIES. WITH PLENTY OF MID AND
UPPER LEVEL DRY AIR WORKING INTO THE REGION IT HAS SUPPRESSED
THUNDERSTORM DEVELOPMENT.
TYPICAL AFTERNOON ZEPHYR WINDS CAN BE EXPECTED WITH GUSTS OF 25 TO
30 MPH LATE THIS AFTERNOON AND INTO THE EARLY EVENING. THESE GUSTS
WILL CORRESPOND WITH HUMIDITY VALUES AROUND 10-15% WITH LOCALLY
CRITICAL CONDITIONS POSSIBLE. HOWEVER, THESE WILL NOT BE WIDESPREAD
ENOUGH TO WARRANT ANY RED FLAG WARNINGS TODAY. AFTERNOON WESTERLY
WINDS CAN BE EXPECTED AGAIN SUNDAY, BUT WILL BE ABOUT 5 MPH LESS IN
SPEED.
A PIECE OF ENERGY AND WEAK DEFORMATION BAND WILL HELP TO FOCUS
THUNDERSTORM DEVELOPMENT SUNDAY AFTERNOON WITH ISOLATED COVERAGE
POSSIBLE BETWEEN INTERSTATE 80 AND HIGHWAY 50 AND SCATTERED COVERAGE
SOUTH OF HIGHWAY 50. THE DEEPEST MOISTURE WILL BE SOUTH OF HIGHWAY
50 AND EAST OF HIGHWAY 95, SO STORMS THROUGH THIS AREA WILL BE WET.
NORTH AND WEST OF THERE, A HYBRID OF STORMS ARE POSSIBLE WITH THE
POTENTIAL FOR A DRY LIGHTNING STRIKE OUTSIDE OF THE WET THUNDERSTORM
CORE. THIS COULD START NEW FIRES, BUT WITH THE SMALL AREA OF HYBRID
STORMS, AM NOT PLANNING ANY RED FLAG WARNINGS AT THIS TIME. IN
ADDITION, WATCHING HOW THE DRY AIR WORKING INTO CALIFORNIA AND
WESTERN NEVADA HAS SQUELCHED THUNDERSTORM DEVELOPMENT TODAY, AM A
BIT CONCERNED THAT MODELS MAY BE OVERDOING THE CONVECTIVE POTENTIAL
SUNDAY AND COVERAGE MAY NEED TO BE TRIMMED A BIT. DF
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
1239 PM PDT FRI JUL 13 2012
.SYNOPSIS...
INCREASING MONSOON MOISTURE WILL BRING SCATTERED SHOWERS AND
THUNDERSTORMS TO THE MOUNTAINS AND DESERT THIS AFTERNOON AND
EVENING. THUNDERSTORMS WILL PRODUCE HEAVY RAIN...AND THERE IS THE
POTENTIAL FOR FLASH FLOODS. A WEAK SOUTH TO SOUTHWEST FLOW ALOFT
OVER THE WEEKEND WILL BRING DECREASING THUNDERSTORM ACTIVITY.
&&
.DISCUSSION...
QUICK TEMPERATURE UPDATE FOR THIS AFTERNOON. VALUES IN THE SOUTH
END OF THE SJV ARE COMING IN WELL AHEAD OF EXPECTED VALUES AND
ACHIEVING BETTER THAN PRACTICALLY ALL DATA WOULD SUGGEST. ON THE
OTHER SIDE OF THE MOUNTAINS OUR DESERT AREAS ARE VERY SLOW TO WARM
THIS AFTERNOON GIVEN THE HIGH MOISTURE CONTENT OF THE AIR AND GOOD
CLOUD COVER. SEEING SOME BREAKS NOW BUT THINK THOSE WILL BE
FILLING BACK IN AS THE AFTERNOON PROGRESSES.
FLASH FLOOD WATCH STILL LOOKS GOOD. INCREASED HEAT IN THE VALLEY
COULD SUPPORT MORE INSTABILITY IN THE NEARBY MOUNTAINS FOR THE
REMAINDER OF THE DAYS. LATEST RUNS OF THE HRRR CONTINUE TO POINT
TO THE MOUNTAINS OF TULARE AND KERN COUNTIES AS THE FAVORED AREA
FOR DEVELOPMENT.
&&
.PREV DISCUSSION... /ISSUED 1005 AM PDT FRI JUL 13 2012/
DISCUSSION...
DEEP MOISTURE COVERS THE SE HALF OF OUR CWA ATTM. REGIONAL 13.12Z
RAOBS AND LATEST OBJECTIVE ANALYSIS DEPICT PRECIPITABLE WATER
VALUES NEAR 2.0 INCHES JUST TO THE SOUTHEAST OF OUR CWA WHICH IS
NEAR THE 99TH PERCENTILE FOR THE RAOB SITES. THE PLUME OF
ANOMALOUSLY HIGH MOISTURE /PLUS-4 ST DEVS/ WILL BE ORIENTED FROM
NORTH TO SOUTH ALONG THE COLORADO RIVER AND UP INTO NV/UT...THE
HNX FORECAST AREA WILL BE JUST ON THE WESTERN PERIPHERY OF IT.
FEATURES OF NOTE ON SATELLITE IMAGERY INCLUDE THE UPPER LEVEL
LOW/POTENTIAL VORTICITY ANOMALY NEAR SAN DIEGO AND THE LARGER
LOW MOVING INTO WASHINGTON /WITH AN ASSOCIATED TROUGH DIPPING
TOWARD THE CENTRAL CALIFORNIA COAST/. THE 13.12Z NAM APPEARS TO
HAVE INITIALIZED EXCEPTIONAL WELL THIS MORNING...WILL BE UTILIZING
IT AND HRRR RUNS THROUGH THE DAY.
LATEST OBSERVATIONAL AND MODEL DATA SUPPORT OUR AREA OF CONCERN
TODAY WILL BE EASTERN FRESNO...TULARE...AND MUCH OF KERN COUNTIES.
THIS REGION WILL BE IN THE FAVORED MOISTURE CONVERGENCE AREA OF
THE SOUTHERN CALIFORNIA LOW AND WILL ALSO GET SOME MINOR UPPER
LEVEL SUPPORT FROM THE INCOMING UPSTREAM TROUGH. INSTABILITY MAY
STRUGGLE TO DEVELOP THROUGH THE DAY DUE TO THE INCREASED MOISTURE
BUT BY THIS AFTERNOON WE SHOULD SEE MLCAPE VALUES IN THE 500-1000
J/KG RANGE OVER THE SIERRA SOUTH OF KINGS CANYON AND THE
TEHACHAPIS. STORM MOTION /CORFIDI VECTORS/ SUPPORT A SLOW
SOUTHWARD MOVEMENT OF 5-10 KTS. WITH THIS SCENARIO...THE FLASH
FLOOD WATCH CURRENTLY IN EFFECT LOOKS GOOD. EXPECT SOME
PRECIPITATION TO CONTINUE INTO THE LATE EVENING/OVERNIGHT HOURS
THOUGH THE UPPER LEVEL FORCING AND DEEPEST MOISTURE WILL BE MOVING
EAST WITH TIME.
TEMPERATURES WILL BE DIFFICULT TODAY AS WELL. MID-LEVEL CLOUDS ARE
QUICKLY ERODING WHICH...AFTER A WARM MORNING...WILL ALLOW FOR A
WARM AND MUGGY AFTERNOON TO UNFOLD. SHOULD STILL SEE A SEVERAL
DEGREE DROP FROM YESTERDAY.
&&
.AVIATION...
SCATTERED THUNDERSTORMS ARE LIKELY OVER THE MOUNTAINS AND DESERT
THROUGH 18Z SATURDAY WITH ISOLATED THUNDERSTORMS POSSIBLE ALONG
THE EAST SIDE AND SOUTH END OF THE SAN JOAQUIN VALLEY AND ADJACENT
FOOTHILLS BETWEEN 20Z TODAY AND 06Z SATURDAY. OTHERWISE...VFR
CONDITIONS WILL PREVAIL ACROSS THE CENTRAL CALIFORNIA INTERIOR
THROUGH 18Z SATURDAY.
&&
.AIR QUALITY ISSUES...
ON FRIDAY JULY 13 2012... UNHEALTHY IN FRESNO COUNTY. UNHEALTHY
FOR SENSITIVE GROUPS IN KERN... KINGS... MADERA... MERCED AND
TULARE COUNTIES AND SEQUOIA NATIONAL PARK AND FOREST.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.CERTAINTY...
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS MEDIUM.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.
THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED
BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP FOR ADDITIONAL INFORMATION
AND/OR TO PROVIDE FEEDBACK.
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 11 PM PDT THIS EVENING CAZ095-097>099.
&&
$$
PUBLIC...INIGUEZ
AVN/FW...BEAN
SYNOPSIS...BSO
WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
1005 AM PDT FRI JUL 13 2012
.SYNOPSIS...
INCREASING MONSOON MOISTURE WILL BRING SCATTERED SHOWERS AND
THUNDERSTORMS TO THE MOUNTAINS AND DESERT THIS AFTERNOON AND
EVENING. THUNDERSTORMS WILL PRODUCE HEAVY RAIN...AND THERE IS THE
POTENTIAL FOR FLASH FLOODS. A WEAK SOUTH TO SOUTHWEST FLOW ALOFT
OVER THE WEEKEND WILL BRING DECREASING THUNDERSTORM ACTIVITY.
&&
.DISCUSSION...
DEEP MOISTURE COVERS THE SE HALF OF OUR CWA ATTM. REGIONAL 13.12Z
RAOBS AND LATEST OBJECTIVE ANALYSIS DEPICT PRECIPITABLE WATER
VALUES NEAR 2.0 INCHES JUST TO THE SOUTHEAST OF OUR CWA WHICH IS
NEAR THE 99TH PERCENTILE FOR THE RAOB SITES. THE PLUME OF
ANOMALOUSLY HIGH MOISTURE /PLUS-4 ST DEVS/ WILL BE ORIENTED FROM
NORTH TO SOUTH ALONG THE COLORADO RIVER AND UP INTO NV/UT...THE
HNX FORECAST AREA WILL BE JUST ON THE WESTERN PERIPHERY OF IT.
FEATURES OF NOTE ON SATELLITE IMAGERY INCLUDE THE UPPER LEVEL
LOW/POTENTIAL VORTICITY ANOMALY NEAR SAN DIEGO AND THE LARGER
LOW MOVING INTO WASHINGTON /WITH AN ASSOCIATED TROUGH DIPPING
TOWARD THE CENTRAL CALIFORNIA COAST/. THE 13.12Z NAM APPEARS TO
HAVE INITIALIZED EXCEPTIONAL WELL THIS MORNING...WILL BE UTILIZING
IT AND HRRR RUNS THROUGH THE DAY.
LATEST OBSERVATIONAL AND MODEL DATA SUPPORT OUR AREA OF CONCERN
TODAY WILL BE EASTERN FRESNO...TULARE...AND MUCH OF KERN COUNTIES.
THIS REGION WILL BE IN THE FAVORED MOISTURE CONVERGENCE AREA OF
THE SOUTHERN CALIFORNIA LOW AND WILL ALSO GET SOME MINOR UPPER
LEVEL SUPPORT FROM THE INCOMING UPSTREAM TROUGH. INSTABILITY MAY
STRUGGLE TO DEVELOP THROUGH THE DAY DUE TO THE INCREASED MOISTURE
BUT BY THIS AFTERNOON WE SHOULD SEE MLCAPE VALUES IN THE 500-1000
J/KG RANGE OVER THE SIERRA SOUTH OF KINGS CANYON AND THE
TEHACHAPIS. STORM MOTION /CORFIDI VECTORS/ SUPPORT A SLOW
SOUTHWARD MOVEMENT OF 5-10 KTS. WITH THIS SCENARIO...THE FLASH
FLOOD WATCH CURRENTLY IN EFFECT LOOKS GOOD. EXPECT SOME
PRECIPITATION TO CONTINUE INTO THE LATE EVENING/OVERNIGHT HOURS
THOUGH THE UPPER LEVEL FORCING AND DEEPEST MOISTURE WILL BE MOVING
EAST WITH TIME.
TEMPERATURES WILL BE DIFFICULT TODAY AS WELL. MID-LEVEL CLOUDS ARE
QUICKLY ERODING WHICH...AFTER A WARM MORNING...WILL ALLOW FOR A
WARM AND MUGGY AFTERNOON TO UNFOLD. SHOULD STILL SEE A SEVERAL
DEGREE DROP FROM YESTERDAY.
&&
.PREV DISCUSSION... /ISSUED 402 AM PDT FRI JUL 13 2012/
DISCUSSION...
ANOTHER UPPER TROF WAS LOCATED OVER WESTERN WA...WITH TROF AXIS
SAGGING SOUTH ALONG THE WEST COAST. THIS TROF WILL COMPETE WITH
THE MONSOON TRAJECTORY THE NEXT 24-48 HRS...BUT EVENTUALLY WILL
WIN OUT WITH A DRYING W-SW FLOW GRADUALLY SPREADING OVER CA. THIS
WILL MEAN DECREASING TSTM ACTIVITY SAT...AND EVEN LESS SUN.
HOWEVER...NOT COMPLETELY CONVINCED ALL TSTM ACTIVITY WILL END
AFTER THIS WEEKEND.
CLOUDS AND SCT PRECIP WILL BE THE CONTROLLING FACTOR IN TEMPS THE
NEXT FEW DAYS. THE OVERALL TREND THRU SUN WILL BE A GRADUAL
DOWNTURN IN THE HOT TEMPS...BUT IF ONE DAY IS MORE/OR LESS/ CLOUDY
THAN ANOTHER...TEMPS MAY NOT REFLECT THE OVERALL TREND. NIGHTS
WILL CONT TO BE WARM WHERE CLOUDS PERSIST...BUT WILL EVENTUALLY
COOL OFF AS WEAK ONSHORE FLOW ALOFT KICKS IN...AND THE SJV COMING
UNDER INCREASING MARINE INFLUENCE.
MODELS IN THE MEDIUM RANGE NOT CONSISTENT IN HANDLING WEST COAST
TROF THRU NEXT WEEK...OR PLACEMENT OF LOWEST HEIGHTS. FOR NOW
FOLLOWED PERSISTENCE WITH TEMPS AT OR SLIGHTLY LESS THAN NORMAL
AND DRY EVERYWHERE. A VERY LOW CONFIDENCE FACTOR IN THE MEDIUM
RANGE.
&&
.AVIATION...
SCATTERED THUNDERSTORMS ARE LIKELY OVER THE MOUNTAINS AND DESERT
THROUGH 18Z SATURDAY WITH ISOLATED THUNDERSTORMS POSSIBLE ALONG
THE EAST SIDE AND SOUTH END OF THE SAN JOAQUIN VALLEY AND ADJACENT
FOOTHILLS BETWEEN 20Z TODAY AND 06Z SATURDAY. OTHERWISE...VFR
CONDITIONS WILL PREVAIL ACROSS THE CENTRAL CALIFORNIA INTERIOR
THROUGH 18Z SATURDAY.
&&
.AIR QUALITY ISSUES...
ON FRIDAY JULY 13 2012... UNHEALTHY IN FRESNO COUNTY. UNHEALTHY
FOR SENSITIVE GROUPS IN KERN... KINGS... MADERA... MERCED AND
TULARE COUNTIES AND SEQUOIA NATIONAL PARK AND FOREST.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.CERTAINTY...
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS MEDIUM.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.
THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED
BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP FOR ADDITIONAL INFORMATION
AND/OR TO PROVIDE FEEDBACK.
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS EVENING CAZ095-097>099.
&&
$$
PUBLIC...INIGUEZ/BINGHAM
AVN/FW...BEAN
SYNOPSIS...BSO
WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS DENVER CO
817 PM MDT SAT JUL 14 2012
.UPDATE...
&&
.SHORT TERM...WEAK CONVECTION IN THE MOUNTAINS CONTINUES TO
DIMINISH THIS EVENING WITH ONLY SOME LIGHT ISOLATED RAIN SHOWERS
REMAINING WEST OF THE DIVIDE. DRY ON THE PLAINS AS 00Z SOUNDING
SHOWED STRONG MID LEVEL STABILITY AT 450MB.
.AVIATION...OUTFLOW BOUNDARY HAS SHIFTED SURFACE WINDS TO THE
SOUTHWEST AT ALL TERMINALS THIS EVENING. WINDS WILL WEAKEN A BIT
AND TURN MORE SOUTHERLY OVERNIGHT. THE BROKEN MID AND HIGH LEVEL
DECK OF CLOUDS WILL GRADUALLY THIN OUT LATER TONIGHT. ONLY MINOR
TINKERING TO THE WINDS THROUGH TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 343 PM MDT SAT JUL 14 2012/
SHORT TERM...THE UPPER LEVEL RIDGE OVER EASTERN CO TONIGHT WILL
CONTINUE TO SLOWLY SHIFT TO THE EAST FOR SUNDAY. AS A RESULT...THE
SUBTROPICAL MOISTURE OVER WESTERN CO WILL CONTINUE TO SPREAD EAST
INTO THE NORTHEASTERN PLAINS AS WELL. THE LATEST HRRR CONFINES THE
DEEP CONVECTION TO THE HIGH COUNTRY TONIGHT. WITH THE RIDGE
OVERHEAD IT WILL BE TOO STABLE OVER THE NORTHEAST PLAINS FOR
THUNDERSTORMS. WL KEEP ISOLD POPS IN ZONE 38 BUT DROP IT FOR THE
REMAINDER THE URBAN CORRIDOR. ON SUNDAY...PRECIPITABLE WATER VALUES
CONTINUE TO CLIMB WITH VALUES CLOSE TO ONE INCH IN THE AFTERNOON.
FCST CAPES IN THE MOUNTAINS 300-400 J/KG WITH VALUES 800-1100 J/KG
OVER THE URBAN CORRIDOR AND NORTHEAST PLAINS. ALTHOUGH IT WILL BE
HOT AGAIN SUNDAY AFTN...CLOUD COVER AND THUNDERSTORMS SHOULD
INHIBIT HEATING SLIGHTLY IN THE AFTERNOON.
LONG TERM...591 RIDGE OVER THE WESTERN GREAT PLAINS CONTINUES ITS
SLOW EASTWARD PROGRESSION OVER THE GREAT PLAINS THROUGH MID-WEEK.
THE SHIFT ALLOWS SOUTHWESTERLY FLOW ON THE WEST SIDE OF THIS RIDGE
TO TRANSPORT INCREASING AMOUNTS OF MOIST SUBTROPICAL AIR UP OVER
COLORADO DURING THE FIRST HALF OF THE WEEK. THIS LATEST PLUME OF
MONSOONAL MOISTURE LOOKS NEITHER AS MOIST OR AS DEEP AS THE PLUME
WE DEALT WITH A WEEK OR SO AGO WHEN STORMS BROUGHT HEAVY RAIN AND
RESULTING FLASH FLOODING TO THE FORECAST AREA. THE AXIS OF THE
500-700MB MOISTURE STREAM STARTS OUT OVER THE WESTERN VALLEYS OF
COLORADO MONDAY MORNING AND THROUGH THE DAY MODELS SHOW IT
SHIFTING EAST OVER THE MTNS AND AND FRONT RANGE FOOTHILLS WITH
PRECIPITABLE WATER VALUES UP AROUND 1.25 INCHES OVER THE FRONT
RANGE BY LATE IN THE DAY. MODELS ALSO SHOW A WEAK MID-LEVEL SHORTWAVE
TROUGH/THERMAL TROUGH EMBEDDED IN THE SOUTHWEST FLOW ALOFT
PASSING OVER THE NORTH CENTRAL MTNS IN THE AFTERNOON AND OVER THE
NORTHEAST PLAINS MONDAY EVENING WHICH SHOULD FURTHER ENHANCE
T-STORM DEVELOPMENT IN THE AREA. HIGH SCATTERED POPS LOOK GOOD FOR
NOW FOR THE MTNS AND NEARBY PLAINS...WITH CHANCES FOR PCPN
DECREASING FARTHER OUT ACROSS THE PLAINS WHERE THE AIRMAS STILL
APPEARS WEAKLY CAPPED. COULD SEE LOCALLY HEAVY RAINFALL FROM
STORMS IN AND NEAR THE FRONT RANGE. SHEAR NOT ALL THAT GREAT...SO
THE CHANCE FOR SEVERE APPEARS LOW.
FOR THE REMAINDER OF THE WEEK...TUESDAY LOOKS TO BE NEARLY AS
WET/STORMY AS ON MONDAY WITH THE MONSOON MOISTURE PLUME
CONTINUING TO CREEP EASTWARD OVER THE STATE. ONCE AGAIN COULD SEE
A FEW LATE STORMS PRODUCING LOCALLY HEAVY RAINFALL...MAINLY OVER
AND NEAR THE MTNS. SHOULD ALSO SEE RAIN CHANCES INCREASE ON THE
PLAINS WITH INFLUX OF LOW-LEVEL MOISTURE WITH A GUSTY SOUTHEAST
FLOW. CAN`T RULE OUT AN ISOLATED SEVERE T-STORM ON THE PLAINS
WITH BETTER SHEAR AND INSTABILITY IN PLACE. BY WEDNESDAY...THE
MONSOON MOISTURE FLOW APPEARS TO WEAKEN WITH THE UPPER RIDGE OUT
EAST WEAKENING SOME. THEREFORE T-STORM CHANCES SHOULD GO DOWN AND
WITH MORE SUNSHINE TEMPERATURES WILL BEGIN TO NUDGE UPWARD.
THURSDAY AND BEYOND...MEDIUM RANGE MODELS SHOW THE GREAT PLAINS
RIDGE STRENGTHENING AGAIN AS IT BEGINS TO BUILD WESTERN TOWARDS
THE ROCKY MTN REGION. INCREASE SOUTHERLY FLOW AHEAD OF THIS RIDGE
APPEARS TO BRING ANOTHER SURGE OF MOIST SUBTROPICAL AIR UP INTO
THE FOUR CORNERS AREA BY WEEK`S END...AND POSSIBLY OVER THE
REMAINDER OF COLORADO BY THE WEEK. SO POSSIBLY ANOTHER SHOT FOR
DECENT RAINFALL BY END OF THE EXTENDED PERIOD.
AVIATION...GUSTY SELY WINDS WILL CONTINUE INTO EARLY EVENING
THEN SHIFT TO MORE OF A SOUTHERLY DIRECTION AND DECREASE AFTER
06Z. DO NOT ANTICIPATE TSTMS IN ANY OF THE DENVER TAFS THIS
AFTERNOON AND EVENING...WITH BETTER POTENTIAL FOR STORMS SUNDAY
AFTN. VFR CONDITIONS WITH NO RESTRICTIONS OVER THE NEXT 18Z HOURS
WITH JUST A SLIGHT CHANCE OF STORMS AFTER 20Z SUNDAY.
HYDROLOGY...THERE WILL BE A SLIGHT CHANCE OF TSTMS IN THE BURN
AREAS UNTIL AROUND 04Z...ALTHOUGH THE THREAT IS LOW...THE STORMS
COULD PRODUCE 0.10-0.20 INCHES OF RAINFALL IN 30 MINUTES.
INCREASING CHANCE OF TSTMS SUNDAY AFTERNOON WITH A GREATER
POTENTIAL FOR BRIEF HEAVY RAINFALL AFTER 20Z SUNDAY.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ENTREKIN/COOPER
LONG TERM....BAKER
AVIATION...ENTREKIN/COOPER
AREA FORECAST DISCUSSION
NWS MIAMI FL
144 PM EDT FRI JUL 13 2012
.AVIATION...MOSTLY VFR CONDITIONS EXPECTED AT THE S FL TERMINALS
THROUGH THE PERIOD. MODERATE EAST FLOW HAS PUSHED CONVECTION
INLAND AWAY FROM THE E CST EXCEPT FOR A FEW SHRA. SCT TSRA WILL
CONTINUE TO DEVELOP THROUGH THE AFTERNOON AND MOVE W AND COULD
AFFECT THE KAPF TERMINAL UNTIL AROUND 22Z. SPARSE COVERAGE WILL
LIMIT THE CHANCES FOR A DIRECT HIT AND HAVE CONTINUED THE VCTS FOR
NOW AND WILL AMEND IF NECESSARY.
KOB
&&
.PREV DISCUSSION... /ISSUED 903 AM EDT FRI JUL 13 2012/
UPDATE...
WATER VAPOR AND VISIBLE SATELLITE FROM THIS MORNING SHOWED A WEAK
TROPICAL WAVE ACROSS THE EASTERN GULF WITH SHOWER ACTIVITY OVER
THE LOCAL GULF WATERS. ISOLATED TO SCATTERED STREAMER SHOWERS
CONTINUED TO MOVE ACROSS THE LOCAL ATLANTIC WATERS AND TOWARD THE
EAST COAST. THE 12Z SOUNDING SHOWED PWATS STILL AROUND 2.1
INCHES...WITH DEEP EASTERLY FLOW ACROSS SOUTH FLORIDA.
HOWEVER...WATER VAPOR SHOWED DRIER AIR BEGINNING TO MOVE TOWARDS
THE EAST COAST OF FLORIDA THIS MORNING...AND FORECAST SOUNDINGS
SHOW THIS DRIER AIR MOVING INTO THE REGION THROUGHOUT THE DAY.
THIS SHOULD KEEP THE HIGHEST CHANCES OF RAIN FOR THE EAST COAST
AREAS IN THE MORNING TO EARLY AFTERNOON HOURS. THE EAST COAST SEA
BREEZE WILL MOVE INLAND AND DRIER AIR SHOULD LIMIT ACTIVITY TO
JUST A FEW STREAMER SHOWERS BY THE MID AFTERNOON. FOR THE WEST
COAST...THE GULF COAST SEA BREEZE IS EXPECTED TO MOVE INLAND THIS
AFTERNOON. LOW LEVEL CONVERGENCE AND SEA BREEZE INTERACTIONS WILL
LEAD TO NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE INTERIOR
AND GULF COAST. LIGHTNING PROBABILITIES ARE ALSO VERY HIGH FOR THE
GULF COAST AND THE HRRR AND LOCAL WRF SUPPORT THE IDEA OF HIGH
RAIN CHANCES FOR THE GULF COAST...ESPECIALLY AFTER 18Z. THE
CURRENT FORECAST SUPPORTS THIS THINKING AS WELL...AND THE ONLY
CHANGE WAS TO BUMP UP POPS THIS MORNING FOR THE GULF WATERS DOING
TO THE ONGOING CONVECTION.
PREV DISCUSSION... /ISSUED 740 AM EDT FRI JUL 13 2012/
AVIATION...S FLA WILL BE ON THE EAST SIDE OF A TROPICAL WAVE THAT
HAS MOVED INTO THE EASTERN GULF OF MEX. A DEEP MOIST E TO ESE WIND
FLOW HAS DEVELOPED. SCATTERED SHRA WITH ISOLD TSRA WILL MOVE W-WNW
ACROSS THE ATLC AND ONSHORE. VCSH IN E COAST TERMINALS AND EXPECT
BRIEF MVFR CIG/VSBY AS SHRA PASS WILL AMEND AS NECESSARY ESPECIALLY
IF A TSRA NEARS ANY ONE TERMINAL. EXPECT TSRA TO DEVELOP OVER THE
MAINLAND AFT 14Z AND VCTS 14Z TO 18Z AND EXPECT ACTIVITY TO MOVE
INLAND AWAY FROM THE E COAST TERMINALS. AT KAPF...DEVELOPING TSRA
INLAND FROM TERMINAL AFTER 18Z WILL MOVE W TOWARD THE GULF AND VCTS
AFT 18Z. SURFACE WINDS E COAST CALM TO E-SE < 10 KTS BECOMING 10 TO
15 KTS AFT 14Z. AT KAPF...SURFACE WINDS E < 10 KTS BECOMING SSW-SW
AFT 17Z AS WEST COAST SEA BREEZE DEVELOPS.
PREV DISCUSSION... /ISSUED 416 AM EDT FRI JUL 13 2012/
DISCUSSION...WATER VAPOR IMAGERY SHOWS RIDGING ALOFT BUILDING
INTO SOUTH FL FROM THE NORTHEAST. A MID/UPPER LEVEL LOW SPINNING
EAST OF THE BAHAMAS WILL MOVE NORTHWEST TOWARDS THE CAROLINA COAST
BY SUNDAY...BUT WITH A TROUGH EXTENDING SW OF THIS FEATURE AND
MOVING NW ACROSS SOUTH FL SAT NIGHT-SUN. PWATS WILL SLOWLY
DECREASE FROM EAST TO WEST TODAY (BUT STILL AROUND 1.75 EAST
COAST THIS AFTERNOON) BEFORE INCREASING BACK TO AROUND 2 INCHES
ALONG THIS TROUGH AXIS SAT NIGHT-SUN. IT NEVER DOES BECOME DRY
ENOUGH TO PRECLUDE ANYTHING LESS THAN CHANCE POPS. HIGHEST
MOISTURE/CONVERGENCE THIS AFTERNOON WILL BE ALONG THE GULF
COAST...SO HAVE INCREASED POPS TO LIKELY THERE FOR THIS AFTERNOON.
THE WEATHER THROUGH THE WEEKEND WILL FEATURE BEST CHANCES FOR
SHOWERS/STORMS ALONG THE ATLANTIC COAST AT NIGHT THEN OVER THE
INTERIOR/GULF IN THE AFTERNOON. THE TROUGH SAT NIGHT-SUN COULD ACT
TO PRODUCE GOOD CONVERGENCE ALONG A PORTION OF THE ATLANTIC
COAST...SO WILL NEED TO WATCH THIS IN LATER MODEL RUNS TO SEE IF
POPS MAY NEED TO BE INCREASED.
THE WEATHER PATTERN FOR NEXT WEEK WILL FEATURE RIDGING BUILDING
INTO SOUTH FLORIDA FROM THE ATLANTIC...AND THIS RIDGE WILL BE
STRONGER THAN NORMAL WHICH WILL LEAD TO INCREASING TEMPS ALONG
WITH HUMIDITY ESPECIALLY BY THE MIDDLE TO LATER PART OF NEXT WEEK.
IMPRESSIVE 500 MB HEIGHTS ARE OVER AFRICA AND INTO THE EASTERN
ATLANTIC WITH BOTH GFS/ECMWF SHOWING 500 MB HEIGHTS OF NEAR 600
DECAMETERS EARLY NEXT WEEK. THE STRONG RIDGE WILL GRADUALLY BUILD
WESTWARD WITH TIME NEXT WEEK WITH AN INCREASINGLY HOT AIRMASS
LOCALLY. GFS/ECMWF SHOW 850 MB TEMPS UP TO 20C BY MID WEEK...SOME
+2.5C ABOVE AVG. FOLLOWED CLOSER TO THE MEX/MCX GUIDANCE BEYOND
THE SHORT TERM AS OPPOSED TO BIAS CORRECTED GUIDANCE AS THE HOTTER
GFS NUMBERS LOOK MORE APPROPRIATE...AND IT COULD END UP HOTTER.
HEAT INDICES LIKELY WILL BE IN THE 100-105 RANGE ACROSS SOUTH FL.
ALSO...A FORMIDABLE SAHARAN AIR LAYER (SAL) COULD MOVE IN SOMETIME
DURING THE MIDDLE TO LATTER PART OF NEXT WEEK. THIS WOULD BRING
HAZY SKIES TO THE AREA AND A LESSER COVERAGE OF TSTORMS, THOUGH
THEY COULD BE STRONGER GIVEN INCREASED INSTABILITY. WE HAVE DAYS
TO SEE HOW STRONG THIS RIDGE WILL BE AND IF A SAL MOVES IN...BUT
RIGHT NOW IT LOOKS AS SUCH.
MARINE...WINDS WILL REMAIN LIGHT TO MODERATE WITH SEAS OF LESS
THAN 4 FEET EXPECTED THROUGH THE PERIOD...SO NO CONCERNS.
FIRE WEATHER...NO CONCERNS.
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MIAMI FL
903 AM EDT FRI JUL 13 2012
.UPDATE...
WATER VAPOR AND VISIBLE SATELLITE FROM THIS MORNING SHOWED A WEAK
TROPICAL WAVE ACROSS THE EASTERN GULF WITH SHOWER ACTIVITY OVER
THE LOCAL GULF WATERS. ISOLATED TO SCATTERED STREAMER SHOWERS
CONTINUED TO MOVE ACROSS THE LOCAL ATLANTIC WATERS AND TOWARD THE
EAST COAST. THE 12Z SOUNDING SHOWED PWATS STILL AROUND 2.1
INCHES...WITH DEEP EASTERLY FLOW ACROSS SOUTH FLORIDA.
HOWEVER...WATER VAPOR SHOWED DRIER AIR BEGINNING TO MOVE TOWARDS
THE EAST COAST OF FLORIDA THIS MORNING...AND FORECAST SOUNDINGS
SHOW THIS DRIER AIR MOVING INTO THE REGION THROUGHOUT THE DAY.
THIS SHOULD KEEP THE HIGHEST CHANCES OF RAIN FOR THE EAST COAST
AREAS IN THE MORNING TO EARLY AFTERNOON HOURS. THE EAST COAST SEA
BREEZE WILL MOVE INLAND AND DRIER AIR SHOULD LIMIT ACTIVITY TO
JUST A FEW STREAMER SHOWERS BY THE MID AFTERNOON. FOR THE WEST
COAST...THE GULF COAST SEA BREEZE IS EXPECTED TO MOVE INLAND THIS
AFTERNOON. LOW LEVEL CONVERGENCE AND SEA BREEZE INTERACTIONS WILL
LEAD TO NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE INTERIOR
AND GULF COAST. LIGHTNING PROBABILITIES ARE ALSO VERY HIGH FOR THE
GULF COAST AND THE HRRR AND LOCAL WRF SUPPORT THE IDEA OF HIGH
RAIN CHANCES FOR THE GULF COAST...ESPECIALLY AFTER 18Z. THE
CURRENT FORECAST SUPPORTS THIS THINKING AS WELL...AND THE ONLY
CHANGE WAS TO BUMP UP POPS THIS MORNING FOR THE GULF WATERS DOING
TO THE ONGOING CONVECTION.
&&
.PREV DISCUSSION... /ISSUED 740 AM EDT FRI JUL 13 2012/
AVIATION...S FLA WILL BE ON THE EAST SIDE OF A TROPICAL WAVE THAT
HAS MOVED INTO THE EASTERN GULF OF MEX. A DEEP MOIST E TO ESE WIND
FLOW HAS DEVELOPED. SCATTERED SHRA WITH ISOLD TSRA WILL MOVE W-WNW
ACROSS THE ATLC AND ONSHORE. VCSH IN E COAST TERMINALS AND EXPECT
BRIEF MVFR CIG/VSBY AS SHRA PASS WILL AMEND AS NECESSARY ESPECIALLY
IF A TSRA NEARS ANY ONE TERMINAL. EXPECT TSRA TO DEVELOP OVER THE
MAINLAND AFT 14Z AND VCTS 14Z TO 18Z AND EXPECT ACTIVITY TO MOVE
INLAND AWAY FROM THE E COAST TERMINALS. AT KAPF...DEVELOPING TSRA
INLAND FROM TERMINAL AFTER 18Z WILL MOVE W TOWARD THE GULF AND VCTS
AFT 18Z. SURFACE WINDS E COAST CALM TO E-SE < 10 KTS BECOMING 10 TO
15 KTS AFT 14Z. AT KAPF...SURFACE WINDS E < 10 KTS BECOMING SSW-SW
AFT 17Z AS WEST COAST SEA BREEZE DEVELOPS.
PREV DISCUSSION... /ISSUED 416 AM EDT FRI JUL 13 2012/
DISCUSSION...WATER VAPOR IMAGERY SHOWS RIDGING ALOFT BUILDING
INTO SOUTH FL FROM THE NORTHEAST. A MID/UPPER LEVEL LOW SPINNING
EAST OF THE BAHAMAS WILL MOVE NORTHWEST TOWARDS THE CAROLINA COAST
BY SUNDAY...BUT WITH A TROUGH EXTENDING SW OF THIS FEATURE AND
MOVING NW ACROSS SOUTH FL SAT NIGHT-SUN. PWATS WILL SLOWLY
DECREASE FROM EAST TO WEST TODAY (BUT STILL AROUND 1.75 EAST
COAST THIS AFTERNOON) BEFORE INCREASING BACK TO AROUND 2 INCHES
ALONG THIS TROUGH AXIS SAT NIGHT-SUN. IT NEVER DOES BECOME DRY
ENOUGH TO PRECLUDE ANYTHING LESS THAN CHANCE POPS. HIGHEST
MOISTURE/CONVERGENCE THIS AFTERNOON WILL BE ALONG THE GULF
COAST...SO HAVE INCREASED POPS TO LIKELY THERE FOR THIS AFTERNOON.
THE WEATHER THROUGH THE WEEKEND WILL FEATURE BEST CHANCES FOR
SHOWERS/STORMS ALONG THE ATLANTIC COAST AT NIGHT THEN OVER THE
INTERIOR/GULF IN THE AFTERNOON. THE TROUGH SAT NIGHT-SUN COULD ACT
TO PRODUCE GOOD CONVERGENCE ALONG A PORTION OF THE ATLANTIC
COAST...SO WILL NEED TO WATCH THIS IN LATER MODEL RUNS TO SEE IF
POPS MAY NEED TO BE INCREASED.
THE WEATHER PATTERN FOR NEXT WEEK WILL FEATURE RIDGING BUILDING
INTO SOUTH FLORIDA FROM THE ATLANTIC...AND THIS RIDGE WILL BE
STRONGER THAN NORMAL WHICH WILL LEAD TO INCREASING TEMPS ALONG
WITH HUMIDITY ESPECIALLY BY THE MIDDLE TO LATER PART OF NEXT WEEK.
IMPRESSIVE 500 MB HEIGHTS ARE OVER AFRICA AND INTO THE EASTERN
ATLANTIC WITH BOTH GFS/ECMWF SHOWING 500 MB HEIGHTS OF NEAR 600
DECAMETERS EARLY NEXT WEEK. THE STRONG RIDGE WILL GRADUALLY BUILD
WESTWARD WITH TIME NEXT WEEK WITH AN INCREASINGLY HOT AIRMASS
LOCALLY. GFS/ECMWF SHOW 850 MB TEMPS UP TO 20C BY MID WEEK...SOME
+2.5C ABOVE AVG. FOLLOWED CLOSER TO THE MEX/MCX GUIDANCE BEYOND
THE SHORT TERM AS OPPOSED TO BIAS CORRECTED GUIDANCE AS THE HOTTER
GFS NUMBERS LOOK MORE APPROPRIATE...AND IT COULD END UP HOTTER.
HEAT INDICES LIKELY WILL BE IN THE 100-105 RANGE ACROSS SOUTH FL.
ALSO...A FORMIDABLE SAHARAN AIR LAYER (SAL) COULD MOVE IN SOMETIME
DURING THE MIDDLE TO LATTER PART OF NEXT WEEK. THIS WOULD BRING
HAZY SKIES TO THE AREA AND A LESSER COVERAGE OF TSTORMS, THOUGH
THEY COULD BE STRONGER GIVEN INCREASED INSTABILITY. WE HAVE DAYS
TO SEE HOW STRONG THIS RIDGE WILL BE AND IF A SAL MOVES IN...BUT
RIGHT NOW IT LOOKS AS SUCH.
MARINE...WINDS WILL REMAIN LIGHT TO MODERATE WITH SEAS OF LESS
THAN 4 FEET EXPECTED THROUGH THE PERIOD...SO NO CONCERNS.
FIRE WEATHER...NO CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 77 88 77 / 40 30 30 30
FORT LAUDERDALE 88 79 89 78 / 40 30 30 40
MIAMI 88 77 89 78 / 40 30 30 40
NAPLES 91 74 93 75 / 60 40 50 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...84/AK
AVIATION/RADAR...30/KOB
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
ISSUED BY NATIONAL WEATHER SERVICE WILMINGTON NC
304 PM EDT FRI JUL 13 2012
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL EXPAND ACROSS THE SOUTHEAST STATES
THROUGH THE WEEKEND. HIGH PRESSURE WILL BEGIN TO SINK SOUTHWARD
BY EARLY NEXT WEEK AS A TROUGH OF LOW PRESSURE DEVELOPS INLAND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM FRIDAY...CONVECTION ONGOING JUST WEST OF THE SEA BREEZE
AS ANTICIPATED...WITH WEAKER SHOWERS STILL ADVECTING ONSHORE DUE TO
THE DEEP SE FLOW.
LATEST RUC FORECAST PROFILES CONTINUE TO INDICATE 1500 TO 2500 J/KG
OF SURFACE BASED CAPE WHICH IS HELPING TO FUEL THE SCATTERED TSTMS
TODAY. MOST OF THE ACTIVITY IS NOW WEST OF THE SLOWLY PENETRATING
SEA BREEZE...BUT KCLX RADAR STILL INDICATES WEAK SHOWERS ADVECTING
INLAND FROM THE OCEAN. EXPECT THIS TO PERSIST AT LEAST UNTIL
NIGHTFALL...ALTHOUGH OVERALL COVERAGE AND INTENSITY WILL DECREASE
SIGNIFICANTLY WITH LOSS OF HEATING. THE BIGGEST THREAT THROUGH THE
REST OF THE EVE WILL BE VERY HEAVY RAINFALL WITH ISOLATED/LOCALIZED
FLOODING...MOSTLY WEST OF I-95. TEMPS WILL SLOWLY COOL NEAR THE
COAST WITH THE SEA BREEZE...AND LEVEL OUT NEAR 90 WELL INLAND.
AFTER NIGHTFALL THERE IS LIKELY TO BE A BREAK IN SHRA/TSRA...BUT
RENEWED ACTIVITY WILL DEVELOP ACROSS THE WATERS WHERE COOLING AIR
TEMPS WILL HELP FORCE STEEPER LOW LEVEL LAPSE RATES AND INCREASE
INSTABILITY. SIMILAR TO LAST NIGHT...SHOWERS WILL WORK TOWARDS THE
COAST AND HAVE CONTINUED SCHC TRW- ALONG THE COAST THROUGH THE
OVERNIGHT. DO NOTE A BUILDING MID LEVEL CAP DUE TO WESTWARD
RETROGRESSION OF MID LEVEL HIGH PRESSURE ACROSS THE ATLANTIC
HOWEVER...AND THIS WILL LIMIT INTENSITY AND COVERAGE OF SHOWERS.
MINS TONIGHT WILL BE TEMPERED BY CONTINUING SE FLOW AND SOME
ENHANCED LOW LEVEL CLOUD COVER. BUFR PROFILES INDICATE THAT
1500-2000 FT STRATUS WILL CREATE A CEILING DURING THE
OVERNIGHT...BUT WITH INCREASING DRY AIR ABOVE 850MB EVIDENT...EXPECT
THIS WILL BE TRANSIENT IN NATURE...MOSTLY DURING ANY SHOWERS THAT
MAY ADVECT ONSHORE. STILL...THIS WILL BE ENOUGH TO LIMIT OVERALL
COOLING...AND EXPECT MINS AROUND 73 WELL INLAND TO NEAR 80 AT THE
COAST.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...DEEP ONSHORE BUT RELATIVELY LIGHT WIND FLOW
TO PREVAIL OVER THE WEEKEND...BUT BECAUSE BERMUDA HIGH PRESSURE
EXPANDS WESTWARD...DRIER MID-LEVEL SUSIDENT AIR INFILTRATES THE
COLUMN VIA EASTERLY TRAJECTORIES. DESPITE NOTEWORTHY LOW-LEVEL
MOISTURE SATURDAY AND SUNDAY...THIS SOMEWHAT PARCHED AIR ALOFT
WILL SERVE TO LIMIT CONVECTIVE COVERAGE OVER THE WEEKEND AND WE
HAVE KEPT POP VALUES IN THE ISOLATED TO LOW-END SCATTERED RANGE.
THE LOWER PWAT VALUES WILL ALSO LESSEN THE FLOODING POTENTIAL.
HAVE TAYLORED POPS TO CORRELATE WITH DIURNAL HEATING AND WE SEE
LITTLE UPPER SUPPORT.
ONE ITEM OF NOTE. APPEARS A PEICE OR PORTION OF A TROPICAL WAVE
APPROACHING FLORIDA MAY INCREASE COASTAL SHOWERS OFF GA/SC. HAVE
HELP POPS IN THE ISOLATED-SCT CATEGORY HOWEVER UNTIL WE GET SOME
ADDITIONAL RESOLUTION ON THIS APPROACHING FEATURE BY 00Z MONDAY.
THE AFTERNOON SEA BREEZE CIRCULATION WILL LIKELY GENERATE SE-ESE
15-20 MPH WINDS GUSTS NEAR SHORE AND ALONG THE COAST AFTERNOONS.
THE PATTERN SUPPORTS TEMPERATURES VERY CLOSE TO CLIMATOLOGICAL
STANDARDS UPPER 80S COAST AND LOW/MID 90S INLAND...AND MAX TEMPS
NEAR THE COAST MAY BE REALIZED IN THE EARLY TO MIDDLE AFTERNOON
DUE TO THE SEA BREEZE CIRCUALTION.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
THIS PERIOD TO BE DOMINATED BY DEEP-LAYER HIGH PRESSURE..THOUGH
LOW PRESSURE WILL TRY TO EXERT MORE INFLUENCE BY THE MIDDLE OF
NEXT WEEK. OVERALL NO MAJOR CHANGES TO THE PREVIOUS FORECAST WITH
MAINLY SCATTERED AFTERNOON/EVENING SHOWERS AND TSTMS. POTENTIALLY
THE GREATEST COVERAGE LATE NEXT WEEK AS AN INLAND SURFACE TROUGH
DEVELOPS.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
AS OF 19Z...EXPECT MOST OF THE CONVECTION THIS AFTERNOON TO BE
INLAND FROM THE TERMINALS...BUT CLOSE ENOUGH FOR THE FIRST COUPLE
OF HOURS TO WARRENT A VCSH. A RUMBLE OF THUNDER IS POSSIBLE...BUT
MOST OF THE ACTIVITY WILL BE LOW TOPPED...TROPICAL IN NATURE.
TONIGHT...SOUTHEAST FLOW WILL PREVAIL THROUGH MOST OF THE
TROPOSPHERE WITH EXCELLENT VISIBILITIES EARLY. THERE MAY BE SOME
MVFR STRATUS DEVELOPMENT OVERNIGHT IN THE MOIST ENVIRONMENT...AND
SOUNDINGS SUGGEST BKN 1500 FT CIGS AT BOTH TERMINALS. HAVE
MENTIONED TEMPO MVFR FOR POTENTIAL...MOST LIKELY IN ANY SHOWERS
THAT MAY ADVECT ONSHORE DURING THE NIGHT.
SATURDAY...CONTINUE SOUTHEAST FLOW. THE ATMOSPHERE WILL BE A BIT
DRIER THAN TODAY...NEVERTHELESS AN ISOLATED SHOWER IS POSSIBLE
TOWARD THE END OF THE FORECAST PERIOD.
EXTENDED AVIATION OUTLOOK...LOW PROBABILITIES OF SUB-VFR CONDS IN
MOSTLY AFTERNOON/EVENING SH/TSTMS THROUGH THE MIDDLE OF NEXT WEEK.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM FRIDAY...AN ONGOING 3FT/8SEC SE SWELL WILL CONTINUE
AND BE THE DOMINANT WAVE WITHIN THE SPECTRUM TODAY. LIGHT SE
WINDS OF 10-15 KTS WILL CONTRIBUTE LITTLE...SO OVERALL WAVE
HEIGHTS WILL BE 2-4 FT...HIGHEST IN THE OUTER PORTIONS OF
AMZ374. ADDITIONALLY...WINDS WILL GUST ABOVE 15 KTS NEAR THE
COAST DURING THE SEA BREEZE THROUGH THIS EVE WHICH MAY FORCE
SLIGHTLY STEEPER WAVE FACES...BUT THE MAJORITY OF THE WATERS
WILL SEE A SWELL- DOMINATED SPECTRUM. IN THIS TROPICAL AIRMASS
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE
THROUGH THE PERIOD. BRIEFLY HIGHER WINDS/WAVES WITH HEAVY RAIN
WILL OCCUR WITHIN ANY OF THESE STORMS...BUT THEY WILL BE QUITE
ISOLATED BEFORE INCREASING IN COVERAGE LATE TONIGHT.
SATURDAY THROUGH WEDNESDAY...MODERATE SE-ESE WINDS EXPECTED OVER
THE WATERS THIS WEEKEND....WITH GUSTS NEAR 20 KT POSSIBLE EACH
AFTERNOON ASSOCIATED WITH THE SEA BREEZE CIRCUALTION. SEAS 3 FT
OVER THE WEEKEND BUT A FEW 4 FOOTERS MAY PREVAIL SINCE THE SE
FLOW IS PERSISTENT AND A DECENT WAVE BUILDER. EXPECT SE WAVES
SAT/SUN 3-4 FEET IN 6-8 SECOND INTERVALS. ISOLATED TSTMS ON THE
WATERS WLL BE FAVORED OVERNIGHT AND EARLY MORNING WHEN BUOYANCY
OVER THE OCEAN IS MAXIMIZED. MARINERS ARE ENCOURGAED TO CONSULT
RADAR TRENDS BEFORE HEADING OUT.
FOR MONDAY THROUGH WEDNESDAY...NEAR TYPICAL BERMUDA HIGH PRESSURE
IN PLACE AND MODERATE S-SW WINDS ARE EXPCETED. WE COULD SEE AN
INCREASE IN SW WINDS LATE TUE AS A SURFACE TROUGH AMPLIFIES OVER
THE CAROLINA INTERIOR...AGAINST BERMUDA HIGH PRESSURE OFFSHORE.
THIS COULD BRING SUSTAINED WINDS NEAR 20 KNOTS TUE AFTERNOON INTO
WEDNESDAY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...JDW
SHORT TERM...MJC
LONG TERM...SHK
AVIATION...HDL/JDW
AREA FORECAST DISCUSSION
NWS POCATELLO ID
101 PM MDT FRI JUL 13 2012
.SHORT TERM...UPPER FLOW FROM THE SOUTH TODAY IS BRINGING A LARGE
PLUME OF MONSOON MOISTURE THRU THE GREAT BASIN INTO ID. WIDESPREAD
SHOWERS AND A FEW TSTMS ARE MOVING THRU THE MAGIC VALLEY INTO THE
CENTRAL MTNS...WITH ISOLD SHOWERS ELSEWHERE. MODELS HAVING SOME
DIFFICULTY AGREEING ON A SOLUTION TONIGHT AND SATURDAY. BOTH THE
GFS AND NAM HAVE BEEN UP AND DOWN ON PRECIP CHANCES. THE NAM IS
NOT INITIALIZING AT ALL WELL WITH THE LOCATION PRECIP SO FAR...
AND THE GFS IS NOT MUCH BETTER. THE HRRR IS DOING QUITE WELL SO
FAR...BUT ONLY GOES OUT TO EARLY THIS EVENING. IT DOES SHOW A
RATHER LARGE AREA OF PRECIP MOVING NORTH FROM UT BY EARLY EVE.
THIS IS CONSISTENT WITH THE CURRENT FCST THINKING...SO WILL STAY
THE COURSE AND GO WITH INCREASING CHANCES FOR PRECIP TONIGHT AND
STAYING ON THE HIGH SIDE FOR SATURDAY. A LOOK AT MODEL SOUNDINGS
SHOW THE AIRMASS MOISTENING UP AT ALL LEVELS...SO MEASURABLE
RAINFALL AMOUNTS APPEAR LIKELY. THE PRECIP AND CLOUD COVER WILL
KEEP TEMPS ON THE COOL SIDE...SO ONLY EXPECTING ISOLD TO WIDELY
SCATTERED TSTMS EMBEDDED WITH THE SHOWERS THRU SATURDAY. BY SUNDAY
...A SMALL UPPER LOW DROPS INTO NW WA. A SMALL NORTHERN STREAM
TROF ROTATES THRU FOR MORE SHOWERS AND TSTMS ON SUNDAY.
.LONG TERM...THE UPPER LOW MIGRATES FROM NW WA TO SW OR BY MON
NIGHT... AND STAYS PUT THRU WED. THIS WILL PUSH DRIER AIR INTO THE
REGION AND RESULT IN ISOLD TO WIDELY SCATTERED TSTMS MAINLY IN THE
MTNS THRU THE END OF THE WEEK. TEMPS WILL CLIMB BACK TO NORMAL
READINGS NEXT WEEK. HEDGES
&&
.AVIATION...A STEADY STREAM OF MOISTURE WILL CONTINUE TO FLOW INTO
THE AREA THROUGH THE NEXT 24 TO 36 HOURS. SHOWERS...AND PERHAPS AN
ISOLATED THUNDERSTORM...ARE EXPECTED AT THE TERMINALS STARTING THIS
EVENING. MOS GUIDANCE MAY BE OVERDONE ON THE TS PROBABILITIES AS
MORE CLOUD COVER SHOULD CURTAIL MUCH OF THE CONVECTIVE ACTIVITY.
HINSBERGER
&&
.FIRE WEATHER...MONSOONAL MOISTURE WILL CONTINUE STREAMING INTO
IDAHO THROUGH THE WEEKEND LEADING TO INCREASED CHANCES OF A WETTING
RAINFALL. THUNDERSTORM POTENTIAL IS THE GREATEST AT THE LEADING EDGE
OF THE TROPICAL MOISTURE AND WILL THUS KEEP RED FLAG WARNING FOR THE
CENTRAL MOUNTAINS AND EASTERN HIGHLANDS BELOW 6500 FT. NO RED FLAG
HEADLINES ARE BEING CONSIDERED AT THE MOMENT FOR THE WEEKEND AS
LIGHTNING ACTIVITY SHOULD WANE DUE TO THE LACK OF SURFACE
HEATING...BUT SOME ISOLATED THUNDERSTORMS MAY OCCUR IF LIFT FROM THE
UPPER TROUGH IN OR/WA IS STRONG ENOUGH. HUMIDITY BEGINS TO DECREASE
GRADUALLY STARTING EARLY NEXT WEEK AND TEMPERATURES SHOULD ALSO
GRADUALLY RISE. HINSBERGER
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 11 PM MDT THIS EVENING BELOW 6500 FEET
FOR THE IDZ411-476-477.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1005 PM CDT SAT JUL 14 2012
.DISCUSSION...
837 PM CDT
CONVECTIVE ACTIVITY HAS SETTLED THIS EVENING AND SHOULD BE DRY
THROUGH THE REMAINDER OF THE EVENING. HAVE TWEAKED POPS TO REFLECT
DIMINISHED CHANCES. LATE TONIGHT ANOTHER MID LEVEL DISTURBANCE IS
EXPECTED TO DROP SOUTH ACROSS THE AREA. ISOLATED THUNDERSTORMS
ASSOCIATED WITH THIS WAVE HAVE ALREADY DEVELOPED OVER PORTIONS OF
WISCONSIN...BUT OVERALL FORCING/MOISTURE CONVERGENCE APPEARS TO BE
VERY WEAK AND DO NOT EXPECT MORE THAN ISOLATED COVERAGE IF ANY AS IT
MOVES INTO NORTHERN ILLINOIS. OTHERWISE...ONLY MADE MINOR TWEAKS TO
HOURLY TRENDS FOR T/TD...OVERALL FORECAST APPEARS ON TRACK. BMD
//PREV DISCUSSION...
210 PM CDT
CONCERNS WITH THE FORECAST ARE CENTERED ON CONVECTION THROUGH THIS
EVENING...AND THEN HOT TEMPERATURES THE NEXT SEVERAL DAYS.
SHORT TERM...REST OF THIS AFTERNOON THROUGH SUNDAY...
TOWERING CUMULUS ALONG WITH SOME SCATTERED STORMS HAVE DEVELOPED
EARLY THIS AFTERNOON ACROSS MAINLY THE EASTERN HALF OF THE
FORECAST AREA ALONG AND AHEAD OF A SHEARED OUT UPPER IMPULSE AND
AN ELEVATED /850-700MB/ WIND AND MOISTURE CONVERGENCE ZONE. GIVEN
A FAIRLY UNSTABLE AIR MASS PER MODIFIED AMDAR SOUNDINGS AND RAP
ANALYSIS...WITH MLCAPE VALUES OF 1000 TO 1500 J/KG...THESE STORMS
SHOULD CONTINUE TO REGENERATE WITH THE FURTHER FOCI OF BOUNDARY
INTERACTIONS. HAVE ALREADY SEEN THE DIVERGENT VELOCITY SIGNATURES
ON RADAR UNDERNEATH THESE STORMS WITHIN JUST TWO RADAR
VCPS...SHOWING THE DOWNDRAFT POTENTIAL ONCE AGAIN. ENVIRONMENTAL
DCAPE VALUES ANALYZED BY THE RAP OF 700 TO 1000 J/KG ARE SLIGHTLY
LESS THAN YESTERDAY...BUT SUFFICIENT ENOUGH FOR A POSSIBLE
ISOLATED SEVERE GUST...INCLUDING IN NEARSHORE AREAS OF THE LAKE IN
ANY STORMS THAT DRIFT NORTHEAST OVER THAT AREA.
AN UPPER LEVEL SHORT WAVE...AS PART OF THE LARGER BROAD
TROUGH...IS MOVING SOUTHEAST ACROSS WESTERN WI EARLY THIS
AFTERNOON. THE INITIAL SURFACE BOUNDARY UNDERNEATH THIS IS HELPING
TO FOCUS SOME SCATTERED STORMS...WITH SIMILAR ML INSTABILITY OF
1000 TO 1500 J/KG. MORE DEVELOPMENT IS ANTICIPATED THROUGH EARLY
EVENING IN ADVANCE OF THIS AS CONVERGENCE IMPROVES...AND SOME OF
THIS MAY POTENTIALLY BE ALONG OUTFLOW THAT IS ALREADY INTO
NORTHWEST IL. EXPLICIT CONVECTIVE MODELS DO KEY IN ON SCATTERED
STORM DEVELOPMENT TOWARD THE I-39 CORRIDOR BY LATE AFTERNOON. WITH
THE SHORT WAVE AND FRONTAL APPROACH...ALONG WITH DEEP LAYER SHEAR
VALUES OF SEMI-DECENT 30 KT PROJECTED...THESE SHOWERS AND
STORMS HAVE POTENTIAL TO HANG ON LATER INTO THE EVENING.
THE COOL FRONT WILL MOVE THROUGH THE AREA LATE TONIGHT AND SUNDAY
MORNING...BUT WASHING OUT AS IT DOES. TEMPERATURES ON SUNDAY ARE
ACTUALLY EXPECTED TO BE SLIGHTLY HIGHER THAN TODAY...AND DEW
POINTS SHOULD BE CLOSE. THIS WILL AGAIN PROVIDE MODEST
INSTABILITY...BUT HEIGHT RISES ALOFT SHOULD TEMPER STORM
DEVELOPMENT. A ROGUE LATE AFTERNOON CELL OR TWO CANNOT BE RULED
OUT ALONG WEAK SURFACE CONVERGENCE...BUT HAVE NOT MENTIONED IN THE
FORECAST AT THIS TIME. HIGHS ON SUNDAY LOOK TO TOP OUT IN THE
LOWER TO MID 90S...WITH A LAKE BREEZE PROVIDING SOME COOLING FOR
DOWNTOWN CHICAGO AND NEARBY AREAS DURING THE AFTERNOON. THESE LAKE
SHORE AREAS STILL MAY REACH 90 OR NEAR IT BEFORE THE LAKE BREEZE
PUSHES THROUGH.
MTF
LONG TERM...SUNDAY NIGHT THROUGH SATURDAY...
THE UPPER LEVEL RIDGE REESTABLISHES ITSELF ACROSS THE CENTRAL US AS
THE TROUGH MOVES OFF TOWARD THE NEW ENGLAND AREA. A WEAKENING AREA
OF LOW PRESSURE MOVES NORTH OF THE GREAT LAKES MONDAY NIGHT...WHILE
ITS COLD FRONT SINKS SOUTH DOWN THE LAKE ON TUESDAY.
PRECIP CHANCES DIMINISH AS THE TROUGH DRIFTS EASTWARD SUNDAY NIGHT.
THE BEST CHANCE OF PRECIP IN THE EXTENDED IS ALONG THE COLD FRONT
LATE TUESDAY THROUGH WEDNESDAY. GUIDANCE DIFFERS ON THE SPEED OF
THE FRONT...WITH THE GFS BRINGING THE FRONT THROUGH MUCH FASTER THAN
THE ECMWF. GIVEN ISSUES WITH THE GFS LATELY...AND THE ECMWF HAVING
VERY CONSISTENT TIMING OVER THE PAST FEW DAYS...GOING WITH THE
SLOWER SOLUTION. BOTH MODELS INDICATE MOISTURE WILL POOL ALONG THE
FRONT...BUT THEN DISSIPATE AS THE FRONT ENTERS NORTHERN IL.
THEREFORE...KEPT BEST PRECIP CHANCES NORTH OF I-80. LIMITED ACTUAL
PRECIP CHANCES TO LESS THAN 50 PERCENT GIVEN THE MODEL TRENDS AND
DRY CONDITIONS.
HIGH PRESSURE BUILDS IN BEHIND THE FRONT...AND GUIDANCE SUGGESTS
RANDOM PERIODS OF PRECIP DURING THE LATTER HALF OF NEXT WEEK.
HOWEVER...WITH NO CLEAR SOURCE OF FORCING...QUESTIONABLE MOISTURE
SOURCES...AND DROUGHT CONDITIONS...DECIDED TO KEEP THE REMAINDER OF
THE EXTENDED DRY. AT THIS POINT THE BIGGER CRIME IS GETTING FOLKS
HOPES UP FOR RAIN ONLY TO DISAPPOINT.
HEAT BUILDS ACROSS THE REGION THROUGH TUESDAY. GUIDANCE SUGGESTS
THERE WILL ONLY BE A SMALL PUSH OF SLIGHTLY COOLER AIR BEHIND THE
FRONT...WITH WEDNESDAY LOOKING TO BE A BIT COOLER. HOWEVER 850 HPA
TEMPS BEGIN TO WARM ALMOST IMMEDIATELY WITH THE UPPER LEVEL RIDGE SW
OF THE CWA. THEREFORE...THE LATTER HALF OF NEXT WEEK LOOKS ABOVE
AVERAGE.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* LIGHT SOUTH WIND BECOMING SOUTHWEST OVERNIGHT.
* VERY LOW PROBABILITY SHRA/TSRA POTENTIAL LATER TONIGHT INTO
SUNDAY MORNING.
* WIND SHIFT FROM LIGHT WEST-SOUTHWEST TO EAST-NORTHEAST WITH WEAK
TROUGH PASSAGE MID-LATE SUNDAY MORNING AND LAKE BREEZE PUSH FROM
THE EAST SUNDAY AFTERNOON.
RATZER
//DISCUSSION...UPDATED 00Z...
A WEAK AREA OF LOW PRESSURE WAS OVER LAKE SUPERIOR EARLY THIS
EVENING...WITH A TROUGH EXTENDING SOUTH-SOUTHWEST ACROSS WISCONSIN
INTO WEST CENTRAL IOWA. ISOLATED THUNDERSTORMS WHICH HAD FORMED
ACROSS THE CHICAGO AREA EARLIER HAVE DISSIPATED...WHILE A FEW
ISOLATED STORMS REMAIN SOUTH OF THE TERMINALS ALONG AN
APPROXIMATELY IKK-BMI-SPI LINE WHERE AN OUTFLOW BOUNDARY FROM
OVERNIGHT CONVECTION HAD TAKEN RESIDENCE. ALL OF THIS ACTIVITY
SHOULD CONTINUE TO FADE THIS EVENING WITH THE LOSS OF DIURNAL
HEATING AND INSTABILITY. WINDS...WHICH HAD BECOME SOMEWHAT CHAOTIC
WITH EARLIER LAKE BREEZE AND CONVECTIVE OUTFLOWS ACROSS METRO
TERMINALS WERE RETURNING TO A SOUTH-SOUTHEAST DIRECTION AS OF 23Z
AND SHOULD CONTINUE TO VEER SOUTHWEST THROUGH LATE EVENING. SPEEDS
WILL REMAIN LESS THAN 10 KTS IN THE WEAK PRESSURE GRADIENT IN
PLACE ACROSS THE REGION.
FORECAST CONCERNS THEN SHIFT TO LOW PROBABILITY POTENTIAL FOR
DEVELOPMENT OF ISOLATED TSRA AGAIN LATER TONIGHT INTO SUNDAY
MORNING AS MID-LEVEL SHORT WAVE DIGS ACROSS THE UPPER MIDWEST AND
WEAK SURFACE TROUGH OVER WI/IA GRADUALLY SAGS ACROSS THE AREA
THROUGH SUNDAY. WEAK BUT PERSISTENT LIFT AND MOIST/WARM ADVECTION
AHEAD OF THE MID LEVEL WAVE IS EXPECTED TO CONTINUE...WITH
FORECAST SOUNDINGS INDICATING SOME MOISTENING AROUND THE 800
MB/6000 FT LEVEL DURING THE AFTER MIDNIGHT HOURS. WHILE MID/UPPER
LEVEL TEMPS REMAIN RELATIVELY WARM...THIS DOES INDICATE THE
POTENTIAL FOR DEVELOPMENT OF ISOLATED SHRA/TSRA DURING THE PRE-DAWN
HOURS SIMILAR TO LAST NIGHT. MOST OF THE HIGH-RES EXPLICIT
CONVECTION MODEL GUIDANCE DOES NOT DEVELOP SUCH CONVECTION...
THOUGH THERE IS SOME SUPPORT IN THE SHORT-RANGE ENSEMBLE GUIDANCE.
OVERALL HOWEVER...PROBABILITY AND CONFIDENCE IS TOO LOW TO INCLUDE
IN POINT TAF PRODUCTS SO HAVE LIMITED FORECAST MENTION TO
DEVELOPMENT OF A BROKEN VFR DECK AROUND 6000 FT. BETTER WARM/MOIST
ADVECTION THEN SHIFTS NORTHEAST/EAST OF THE TERMINALS SUNDAY
MORNING. SOME POTENTIAL EXISTS FOR ISOLATED TSRA/SHRA DEVELOPMENT
THROUGH THE MORNING AS WEAK SURFACE TROUGH SAGS ACROSS
AREA...THOUGH LIGHT WINDS AND RELATIVELY WARM MID-LEVEL TEMPS
CONTINUE TO ARGUE AGAINST A SIGNIFICANT THREAT.
WITH SURFACE BOUNDARY SAGGING ACROSS THE TERMINALS DURING THE MID-
LATE MORNING HOURS...LIGHT SOUTHWEST-WEST WINDS ARE EXPECTED TO
SHIFT NORTH. HOWEVER...GRADIENT IS VERY WEAK AND WINDS WILL LIKELY
BECOME MORE VARIABLE. THIS WILL ALLOW EASTERLY LAKE BREEZE TO
DEVELOP ACROSS CHICAGO SITES DURING THE EARLY-MID AFTERNOON HOURS.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* HIGH CONFIDENCE IN OVERALL WIND TRENDS.
* MEDIUM-HIGH CONFIDENCE IN NO ADDITIONAL TSRA AT TERMINALS.
* HIGH CONFIDENCE IN LAKE BREEZE OCCURRENCE SUNDAY.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...VFR.
TUESDAY...VFR. CHANCE TSRA TUES NGT.
WEDNESDAY...SLGT CHANCE TSRA. OTHERWISE VFR.
THURSDAY AND FRIDAY...VFR.
RATZER
&&
.MARINE...
145 PM CDT
LOW PRESSURE ACROSS LAKE SUPERIOR WILL CONTINUE TO MOVE EAST
THROUGH SUNDAY. THIS WILL STEER A COOL FRONT ACROSS THE LAKE LATE
TONIGHT. AHEAD OF THIS WILL BE SOME SCATTERED STORMS...SOME OF
WHICH ARE LIKELY TO BE GUSTY BASED ON THE ENVIRONMENT. THESE WILL
BE MOST FAVORED ACROSS THE SOUTHERN THIRD OF THE LAKE INCLUDING
NEAR SHORE AREAS OF IL...IN...AND SOUTHWEST MI. WINDS BEHIND THE
FRONT ON SUNDAY WILL BECOME LIGHT AND BEGIN TURNING BACK TO
SOUTHERLY ALREADY BY AFTERNOON. SOUTHWEST WINDS WILL INCREASE ON
MON...WITH OPEN WATER LOCATIONS ACROSS THE NORTH LIKELY REACHING
30 KT DURING MON NIGHT. A COOL FRONT WILL SLOWLY WORK SOUTH
ACROSS THE LAKE ON TUESDAY AND TUESDAY NIGHT. THIS WILL SHIFT
WINDS TO THE NORTH AND PROVIDE A FOCUS FOR SCATTERED THUNDERSTORMS
ONCE AGAIN.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
838 PM CDT SAT JUL 14 2012
.DISCUSSION...
837 PM CDT
CONVECTIVE ACTIVITY HAS SETTLED THIS EVENING AND SHOULD BE DRY
THROUGH THE REMAINDER OF THE EVENING. HAVE TWEAKED POPS TO REFLECT
DIMINISHED CHANCES. LATE TONIGHT ANOTHER MID LEVEL DISTURBANCE IS
EXPECTED TO DROP SOUTH ACROSS THE AREA. ISOLATED THUNDERSTORMS
ASSOCIATED WITH THIS WAVE HAVE ALREADY DEVELOPED OVER PORTIONS OF
WISCONSIN...BUT OVERALL FORCING/MOISTURE CONVERGENCE APPEARS TO BE
VERY WEAK AND DO NOT EXPECT MORE THAN ISOLATED COVERAGE IF ANY AS IT
MOVES INTO NORTHERN ILLINOIS. OTHERWISE...ONLY MADE MINOR TWEAKS TO
HOURLY TRENDS FOR T/TD...OVERALL FORECAST APPEARS ON TRACK. BMD
&&
.PREV DISCUSSION...
210 PM CDT
CONCERNS WITH THE FORECAST ARE CENTERED ON CONVECTION THROUGH THIS
EVENING...AND THEN HOT TEMPERATURES THE NEXT SEVERAL DAYS.
SHORT TERM...REST OF THIS AFTERNOON THROUGH SUNDAY...
TOWERING CUMULUS ALONG WITH SOME SCATTERED STORMS HAVE DEVELOPED
EARLY THIS AFTERNOON ACROSS MAINLY THE EASTERN HALF OF THE
FORECAST AREA ALONG AND AHEAD OF A SHEARED OUT UPPER IMPULSE AND
AN ELEVATED /850-700MB/ WIND AND MOISTURE CONVERGENCE ZONE. GIVEN
A FAIRLY UNSTABLE AIR MASS PER MODIFIED AMDAR SOUNDINGS AND RAP
ANALYSIS...WITH MLCAPE VALUES OF 1000 TO 1500 J/KG...THESE STORMS
SHOULD CONTINUE TO REGENERATE WITH THE FURTHER FOCI OF BOUNDARY
INTERACTIONS. HAVE ALREADY SEEN THE DIVERGENT VELOCITY SIGNATURES
ON RADAR UNDERNEATH THESE STORMS WITHIN JUST TWO RADAR
VCPS...SHOWING THE DOWNDRAFT POTENTIAL ONCE AGAIN. ENVIRONMENTAL
DCAPE VALUES ANALYZED BY THE RAP OF 700 TO 1000 J/KG ARE SLIGHTLY
LESS THAN YESTERDAY...BUT SUFFICIENT ENOUGH FOR A POSSIBLE
ISOLATED SEVERE GUST...INCLUDING IN NEARSHORE AREAS OF THE LAKE IN
ANY STORMS THAT DRIFT NORTHEAST OVER THAT AREA.
AN UPPER LEVEL SHORT WAVE...AS PART OF THE LARGER BROAD
TROUGH...IS MOVING SOUTHEAST ACROSS WESTERN WI EARLY THIS
AFTERNOON. THE INITIAL SURFACE BOUNDARY UNDERNEATH THIS IS HELPING
TO FOCUS SOME SCATTERED STORMS...WITH SIMILAR ML INSTABILITY OF
1000 TO 1500 J/KG. MORE DEVELOPMENT IS ANTICIPATED THROUGH EARLY
EVENING IN ADVANCE OF THIS AS CONVERGENCE IMPROVES...AND SOME OF
THIS MAY POTENTIALLY BE ALONG OUTFLOW THAT IS ALREADY INTO
NORTHWEST IL. EXPLICIT CONVECTIVE MODELS DO KEY IN ON SCATTERED
STORM DEVELOPMENT TOWARD THE I-39 CORRIDOR BY LATE AFTERNOON. WITH
THE SHORT WAVE AND FRONTAL APPROACH...ALONG WITH DEEP LAYER SHEAR
VALUES OF SEMI-DECENT 30 KT PROJECTED...THESE SHOWERS AND
STORMS HAVE POTENTIAL TO HANG ON LATER INTO THE EVENING.
THE COOL FRONT WILL MOVE THROUGH THE AREA LATE TONIGHT AND SUNDAY
MORNING...BUT WASHING OUT AS IT DOES. TEMPERATURES ON SUNDAY ARE
ACTUALLY EXPECTED TO BE SLIGHTLY HIGHER THAN TODAY...AND DEW
POINTS SHOULD BE CLOSE. THIS WILL AGAIN PROVIDE MODEST
INSTABILITY...BUT HEIGHT RISES ALOFT SHOULD TEMPER STORM
DEVELOPMENT. A ROGUE LATE AFTERNOON CELL OR TWO CANNOT BE RULED
OUT ALONG WEAK SURFACE CONVERGENCE...BUT HAVE NOT MENTIONED IN THE
FORECAST AT THIS TIME. HIGHS ON SUNDAY LOOK TO TOP OUT IN THE
LOWER TO MID 90S...WITH A LAKE BREEZE PROVIDING SOME COOLING FOR
DOWNTOWN CHICAGO AND NEARBY AREAS DURING THE AFTERNOON. THESE LAKE
SHORE AREAS STILL MAY REACH 90 OR NEAR IT BEFORE THE LAKE BREEZE
PUSHES THROUGH.
MTF
LONG TERM...SUNDAY NIGHT THROUGH SATURDAY...
THE UPPER LEVEL RIDGE REESTABLISHES ITSELF ACROSS THE CENTRAL US AS
THE TROUGH MOVES OFF TOWARD THE NEW ENGLAND AREA. A WEAKENING AREA
OF LOW PRESSURE MOVES NORTH OF THE GREAT LAKES MONDAY NIGHT...WHILE
ITS COLD FRONT SINKS SOUTH DOWN THE LAKE ON TUESDAY.
PRECIP CHANCES DIMINISH AS THE TROUGH DRIFTS EASTWARD SUNDAY NIGHT.
THE BEST CHANCE OF PRECIP IN THE EXTENDED IS ALONG THE COLD FRONT
LATE TUESDAY THROUGH WEDNESDAY. GUIDANCE DIFFERS ON THE SPEED OF
THE FRONT...WITH THE GFS BRINGING THE FRONT THROUGH MUCH FASTER THAN
THE ECMWF. GIVEN ISSUES WITH THE GFS LATELY...AND THE ECMWF HAVING
VERY CONSISTENT TIMING OVER THE PAST FEW DAYS...GOING WITH THE
SLOWER SOLUTION. BOTH MODELS INDICATE MOISTURE WILL POOL ALONG THE
FRONT...BUT THEN DISSIPATE AS THE FRONT ENTERS NORTHERN IL.
THEREFORE...KEPT BEST PRECIP CHANCES NORTH OF I-80. LIMITED ACTUAL
PRECIP CHANCES TO LESS THAN 50 PERCENT GIVEN THE MODEL TRENDS AND
DRY CONDITIONS.
HIGH PRESSURE BUILDS IN BEHIND THE FRONT...AND GUIDANCE SUGGESTS
RANDOM PERIODS OF PRECIP DURING THE LATTER HALF OF NEXT WEEK.
HOWEVER...WITH NO CLEAR SOURCE OF FORCING...QUESTIONABLE MOISTURE
SOURCES...AND DROUGHT CONDITIONS...DECIDED TO KEEP THE REMAINDER OF
THE EXTENDED DRY. AT THIS POINT THE BIGGER CRIME IS GETTING FOLKS
HOPES UP FOR RAIN ONLY TO DISAPPOINT.
HEAT BUILDS ACROSS THE REGION THROUGH TUESDAY. GUIDANCE SUGGESTS
THERE WILL ONLY BE A SMALL PUSH OF SLIGHTLY COOLER AIR BEHIND THE
FRONT...WITH WEDNESDAY LOOKING TO BE A BIT COOLER. HOWEVER 850 HPA
TEMPS BEGIN TO WARM ALMOST IMMEDIATELY WITH THE UPPER LEVEL RIDGE SW
OF THE CWA. THEREFORE...THE LATTER HALF OF NEXT WEEK LOOKS ABOVE
AVERAGE.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* LIGHT SOUTH-SOUTHEAST WIND BECOMING SOUTHWEST THIS EVENING.
* VERY LOW PROBABILITY SHRA/TSRA POTENTIAL LATER TONIGHT INTO
SUNDAY MORNING.
* WIND SHIFT FROM LIGHT WEST-SOUTHWEST TO EAST-NORTHEAST WITH WEAK
TROUGH PASSAGE MID-LATE SUNDAY MORNING AND LAKE BREEZE PUSH FROM
THE EAST SUNDAY AFTERNOON.
RATZER
//DISCUSSION...UPDATED 00Z...
A WEAK AREA OF LOW PRESSURE WAS OVER LAKE SUPERIOR EARLY THIS
EVENING...WITH A TROUGH EXTENDING SOUTH-SOUTHWEST ACROSS WISCONSIN
INTO WEST CENTRAL IOWA. ISOLATED THUNDERSTORMS WHICH HAD FORMED
ACROSS THE CHICAGO AREA EARLIER HAVE DISSIPATED...WHILE A FEW
ISOLATED STORMS REMAIN SOUTH OF THE TERMINALS ALONG AN
APPROXIMATELY IKK-BMI-SPI LINE WHERE AN OUTFLOW BOUNDARY FROM
OVERNIGHT CONVECTION HAD TAKEN RESIDENCE. ALL OF THIS ACTIVITY
SHOULD CONTINUE TO FADE THIS EVENING WITH THE LOSS OF DIURNAL
HEATING AND INSTABILITY. WINDS...WHICH HAD BECOME SOMEWHAT CHAOTIC
WITH EARLIER LAKE BREEZE AND CONVECTIVE OUTFLOWS ACROSS METRO
TERMINALS WERE RETURNING TO A SOUTH-SOUTHEAST DIRECTION AS OF 23Z
AND SHOULD CONTINUE TO VEER SOUTHWEST THROUGH LATE EVENING. SPEEDS
WILL REMAIN LESS THAN 10 KTS IN THE WEAK PRESSURE GRADIENT IN
PLACE ACROSS THE REGION.
FORECAST CONCERNS THEN SHIFT TO LOW PROBABILITY POTENTIAL FOR
DEVELOPMENT OF ISOLATED TSRA AGAIN LATER TONIGHT INTO SUNDAY
MORNING AS MID-LEVEL SHORT WAVE DIGS ACROSS THE UPPER MIDWEST AND
WEAK SURFACE TROUGH OVER WI/IA GRADUALLY SAGS ACROSS THE AREA
THROUGH SUNDAY. WEAK BUT PERSISTENT LIFT AND MOIST/WARM ADVECTION
AHEAD OF THE MID LEVEL WAVE IS EXPECTED TO CONTINUE...WITH
FORECAST SOUNDINGS INDICATING SOME MOISTENING AROUND THE 800
MB/6000 FT LEVEL DURING THE AFTER MIDNIGHT HOURS. WHILE MID/UPPER
LEVEL TEMPS REMAIN RELATIVELY WARM...THIS DOES INDICATE THE
POTENTIAL FOR DEVELOPMENT OF ISOLATED SHRA/TSRA DURING THE PRE-DAWN
HOURS SIMILAR TO LAST NIGHT. MOST OF THE HIGH-RES EXPLICIT
CONVECTION MODEL GUIDANCE DOES NOT DEVELOP SUCH CONVECTION...
THOUGH THERE IS SOME SUPPORT IN THE SHORT-RANGE ENSEMBLE GUIDANCE.
OVERALL HOWEVER...PROBABILITY AND CONFIDENCE IS TOO LOW TO INCLUDE
IN POINT TAF PRODUCTS SO HAVE LIMITED FORECAST MENTION TO
DEVELOPMENT OF A BROKEN VFR DECK AROUND 6000 FT. BETTER WARM/MOIST
ADVECTION THEN SHIFTS NORTHEAST/EAST OF THE TERMINALS SUNDAY
MORNING. SOME POTENTIAL EXISTS FOR ISOLATED TSRA/SHRA DEVELOPMENT
THROUGH THE MORNING AS WEAK SURFACE TROUGH SAGS ACROSS
AREA...THOUGH LIGHT WINDS AND RELATIVELY WARM MID-LEVEL TEMPS
CONTINUE TO ARGUE AGAINST A SIGNIFICANT THREAT.
WITH SURFACE BOUNDARY SAGGING ACROSS THE TERMINALS DURING THE MID-
LATE MORNING HOURS...LIGHT SOUTHWEST-WEST WINDS ARE EXPECTED TO
SHIFT NORTH. HOWEVER...GRADIENT IS VERY WEAK AND WINDS WILL LIKELY
BECOME MORE VARIABLE. THIS WILL ALLOW EASTERLY LAKE BREEZE TO
DEVELOP ACROSS CHICAGO SITES DURING THE EARLY-MID AFTERNOON HOURS.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH CONFIDENCE IN OVERALL WIND TRENDS.
* MEDIUM-HIGH CONFIDENCE IN NO ADDITIONAL TSRA AT TERMINALS.
* HIGH CONFIDENCE IN LAKE BREEZE OCCURRENCE SUNDAY.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...VFR.
TUESDAY...VFR. CHANCE TSRA TUES NGT.
WEDNESDAY...SLGT CHANCE TSRA. OTHERWISE VFR.
THURSDAY AND FRIDAY...VFR.
RATZER
&&
.MARINE...
145 PM CDT
LOW PRESSURE ACROSS LAKE SUPERIOR WILL CONTINUE TO MOVE EAST
THROUGH SUNDAY. THIS WILL STEER A COOL FRONT ACROSS THE LAKE LATE
TONIGHT. AHEAD OF THIS WILL BE SOME SCATTERED STORMS...SOME OF
WHICH ARE LIKELY TO BE GUSTY BASED ON THE ENVIRONMENT. THESE WILL
BE MOST FAVORED ACROSS THE SOUTHERN THIRD OF THE LAKE INCLUDING
NEAR SHORE AREAS OF IL...IN...AND SOUTHWEST MI. WINDS BEHIND THE
FRONT ON SUNDAY WILL BECOME LIGHT AND BEGIN TURNING BACK TO
SOUTHERLY ALREADY BY AFTERNOON. SOUTHWEST WINDS WILL INCREASE ON
MON...WITH OPEN WATER LOCATIONS ACROSS THE NORTH LIKELY REACHING
30 KT DURING MON NIGHT. A COOL FRONT WILL SLOWLY WORK SOUTH
ACROSS THE LAKE ON TUESDAY AND TUESDAY NIGHT. THIS WILL SHIFT
WINDS TO THE NORTH AND PROVIDE A FOCUS FOR SCATTERED THUNDERSTORMS
ONCE AGAIN.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
832 PM CDT SAT JUL 14 2012
.DISCUSSION...
ISSUED 825 PM CDT SAT JUL 14 2012
CONVECTION CONTINUES TO DISSIPATE EARLY THIS EVENING WITH SEVERAL
LOCATIONS RECEIVING SOME DECENT RAINFALL FOR A CHANGE. PEORIA...
BLOOMINGTON AND THE NWS AT LINCOLN RECEIVED OVER 1 INCH OF RAIN.
SOME GUSTY WINDS AND SMALL HAIL WERE ASSOCIATED WITH THE STRONGEST
UPDRAFTS...BUT THOSE WERE FEW AND FAR BETWEEN. LATEST SATELLITE
DATA INDICATES THE 500 MB TROF AXIS RIGHT OVER THE FORECAST
AREA EARLY THIS EVENING. THERE WAS ANOTHER WEAK SHORTWAVE SEEN
OVER NW IL AND THAT WAS DRIFTING ESE AND MAY KEEP AT LEAST ISOLATED
SHOWERS GOING INTO THE OVERNIGHT HOURS. AREAS THAT DID RECEIVE THE
RAINFALL TODAY WILL SEE SOME FOG DEVELOP LATER TONIGHT. CURRENT
ZONE FORECAST HAS A GOOD HANDLE ON THE TRENDS THIS EVENING SO
OTHER THAN THE USUAL TWEAKS WITH THE HOURLY TEMPS...NO OTHER CHANGES
WERE MADE. AS A RESULT...NO ZONE UPDATE WILL BE NEEDED EARLY THIS
EVENING.
SMITH
&&
.AVIATION...
ISSUED 620 PM CDT SAT JUL 14 2012
COVERAGE OF THUNDERSTORMS EARLY THIS EVENING AND THEN FOG POTENTIAL
OVERNIGHT ARE THE MAIN FORECAST CONCERNS. WIDELY SCATTERED TSRA
CONTINUES ALONG SEVERAL OUTFLOW BOUNDARIES LATE THIS AFTERNOON. THE
MOST PERSISTENT AREA IS NEAR AND TO THE EAST OF KBMI. MOST OF THESE
STORMS WERE MOVING SLOWLY EAST AT 10 MPH OR LESS PRODUCING LOCALLY
BRIEF IFR CIGS/VSYBS WITH WIND GUSTS TO 40 MPH ALONG WITH TORRENTIAL
RAINFALL. MOST OF THIS ACTIVITY IS EXPECTED TO DIMINISH AT OR JUST
AFTER SUNSET. WE STILL MAY SEE ISOLATED SHOWERS AROUND FROM TIME
TO TIME OVERNIGHT BUT COVERAGE TOO LIMITED TO INCLUDE IN THE 00Z
TAFS. WITH MORE AREAS RECEIVING RAINFALL TODAY...FOG IS A DISTINCT
POSSIBILITY...ESP AT PIA...BMI AND CMI WHERE WE WILL SEE SOME BRIEF
MVFR VSBYS AT OR JUST AFTER 09Z. ONCE ANY FOG BURNS OFF...VFR
CONDITIONS WILL PREVAIL DURING THE DAY SUNDAY. SFC WINDS WILL BE
ALL OVER THE PLACE THIS EVENING THANKS TO THE NUMEROUS OUTFLOW
BOUNDARIES SO WILL START OUT WITH A VARIABLE DIRECTION AND THEN
MOST AREAS SHOULD SEE A LIGHT SOUTH WIND OVERNIGHT WITH SOUTH
WINDS ON SUNDAY AT AROUND 10 KTS.
SMITH
&&
.PREV DISCUSSION...
ISSUED 236 PM CDT SAT JUL 14 2012
SCATTERED SHOWERS ACROSS CENTRAL ILLINOIS CONTINUE...WITH VERY
LITTLE MOVEMENT UNDER A WEAK UPPER LEVEL TROF. CONVECTIVE ACTIVITY
TO THE NW THIS MORNING SHOWING UP AS A LITTLE WEAK VORTEX ON VIS
SAT IMAGERY THIS AFTERNOON. BECAUSE OF THAT...HAVE MADE A COUPLE
OF CHANGES TO THE POPS FOR THE OVERNIGHT. OTHER THAN
THAT...FORECAST IS MOSTLY DRY BEYOND TONIGHT. NEXT CHANCE FOR
PRECIP COMES MID WEEK NEXT WEEK. ECMWF NOW HAVING SIMILAR ISSUE TO
THE LAST FEW RUNS OF THE GFS...SO KEEP SCALING BACK THE EXTENDED
POPS
SHORT TERM...TONIGHT AND TOMORROW...
FIRST CONCERN IS THE SMALL VORTEX TO THE NW MOVING NEAR THE REGION
IN THE OVERNIGHT. NEITHER HRRR NOR THE 4KM WRF ARE PICKING UP ON
THE SYSTEM...BUT THE AVAILABLE MOISTURE HAS NOW BEEN A BIT
ALTERED... PARTICULARLY IN THE EASTERN HALF OF THE CWA. FEEL LESS
LIKE THE SHOWERS AFTER 00Z WILL BE LIMITED TO REMNANTS FROM
TODAY...AND HAVE EXPANDED THE CHANCE POPS TO COVER THE ENTIRE
OVERNIGHT. IN ANY SPOTS THAT CLEAR OUT IN THE
OVERNIGHT...PARTICULARLY IN THE EAST WHERE THE BOUNDARY LAYER
MOISTURE HAS BEEN SIGNIF INCREASED BY THE SHOWERS AND
THUNDERSTORMS THIS AFTERNOON...PATCHY FOG WILL BE POSSIBLE IN THE
EARLY MORNING...AND HAVE PLACED THE MENTION IN THE GRIDS FOR A
COUPLE HOURS... MAINLY EAST OF I-55. TOMORROW...IN THE WAKE OF
EXITING SHOWERS...SOME SMALL POPS MOSTLY SOUTH OF INTERSTATE 70.
THESE POPS ARE MOSTLY A PRODUCT OF PREVIOUS MODEL SOLUTIONS WITH
THE ACTIVITY IN THE OHIO RIVER VALLEY. WILL KEEP THEM IN FOR ANY
LINGERING OVERNIGHT PRECIP...BUT MOSTLY REFLECTIVE OF EARLY IN THE
DAY.
LONG TERM...MONDAY THROUGH FRIDAY...
SCATTERED PRECIP THIS AFTERNOON WILL DO LITTLE TO ALLEVIATE THE
DROUGHT OVER THE REGION... PARTICULARLY WITH THE RIDGE BUILDING IN
THE WESTERN CONUS YET AGAIN...AND PUSHING 850MB TEMPS UP AND SFC
TEMPS BACK INTO THE MID-UPPER 90S. DRY WEATHER CONTINUES...HAVE
RAISED MAX TEMPS A DEGREE OR TWO OVER GUIDANCE SINCE MODELS KEEP
PRECIP AND CLOUD COVER IN ABSENCE OF REAL MOISTURE. BEST CHANCES FOR
PRECIP IN EXTENDED COME WITH WED NIGHT AND A PASSING TROF/SFC
BOUNDARY AS AN UPPER WAVE RIPPLES THROUGH THE 500MB FLOW ALONG THE
US/CAN BORDER. THIS FAR SOUTH...AVAILABLE MOISTURE WILL BE
QUESTIONABLE...AS WILL THE AMOUNT OF SFC CONVERGENCE. HAVE PULLED
BACK THE BLENDED POPS WHEREVER POSSIBLE. SCT SHOWER ACTIVITY IS
ALL THAT IS LIKELY IN THIS FORECAST...A VERY SMALL PERCENTAGE OF
AREA WILL SEE THE PRECIP.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
724 PM CDT SAT JUL 14 2012
.DISCUSSION...
210 PM CDT
CONCERNS WITH THE FORECAST ARE CENTERED ON CONVECTION THROUGH THIS
EVENING...AND THEN HOT TEMPERATURES THE NEXT SEVERAL DAYS.
SHORT TERM...REST OF THIS AFTERNOON THROUGH SUNDAY...
TOWERING CUMULUS ALONG WITH SOME SCATTERED STORMS HAVE DEVELOPED
EARLY THIS AFTERNOON ACROSS MAINLY THE EASTERN HALF OF THE
FORECAST AREA ALONG AND AHEAD OF A SHEARED OUT UPPER IMPULSE AND
AN ELEVATED /850-700MB/ WIND AND MOISTURE CONVERGENCE ZONE. GIVEN
A FAIRLY UNSTABLE AIR MASS PER MODIFIED AMDAR SOUNDINGS AND RAP
ANALYSIS...WITH MLCAPE VALUES OF 1000 TO 1500 J/KG...THESE STORMS
SHOULD CONTINUE TO REGENERATE WITH THE FURTHER FOCI OF BOUNDARY
INTERACTIONS. HAVE ALREADY SEEN THE DIVERGENT VELOCITY SIGNATURES
ON RADAR UNDERNEATH THESE STORMS WITHIN JUST TWO RADAR
VCPS...SHOWING THE DOWNDRAFT POTENTIAL ONCE AGAIN. ENVIRONMENTAL
DCAPE VALUES ANALYZED BY THE RAP OF 700 TO 1000 J/KG ARE SLIGHTLY
LESS THAN YESTERDAY...BUT SUFFICIENT ENOUGH FOR A POSSIBLE
ISOLATED SEVERE GUST...INCLUDING IN NEARSHORE AREAS OF THE LAKE IN
ANY STORMS THAT DRIFT NORTHEAST OVER THAT AREA.
AN UPPER LEVEL SHORT WAVE...AS PART OF THE LARGER BROAD
TROUGH...IS MOVING SOUTHEAST ACROSS WESTERN WI EARLY THIS
AFTERNOON. THE INITIAL SURFACE BOUNDARY UNDERNEATH THIS IS HELPING
TO FOCUS SOME SCATTERED STORMS...WITH SIMILAR ML INSTABILITY OF
1000 TO 1500 J/KG. MORE DEVELOPMENT IS ANTICIPATED THROUGH EARLY
EVENING IN ADVANCE OF THIS AS CONVERGENCE IMPROVES...AND SOME OF
THIS MAY POTENTIALLY BE ALONG OUTFLOW THAT IS ALREADY INTO
NORTHWEST IL. EXPLICIT CONVECTIVE MODELS DO KEY IN ON SCATTERED
STORM DEVELOPMENT TOWARD THE I-39 CORRIDOR BY LATE AFTERNOON. WITH
THE SHORT WAVE AND FRONTAL APPROACH...ALONG WITH DEEP LAYER SHEAR
VALUES OF SEMI-DECENT 30 KT PROJECTED...THESE SHOWERS AND
STORMS HAVE POTENTIAL TO HANG ON LATER INTO THE EVENING.
THE COOL FRONT WILL MOVE THROUGH THE AREA LATE TONIGHT AND SUNDAY
MORNING...BUT WASHING OUT AS IT DOES. TEMPERATURES ON SUNDAY ARE
ACTUALLY EXPECTED TO BE SLIGHTLY HIGHER THAN TODAY...AND DEW
POINTS SHOULD BE CLOSE. THIS WILL AGAIN PROVIDE MODEST
INSTABILITY...BUT HEIGHT RISES ALOFT SHOULD TEMPER STORM
DEVELOPMENT. A ROGUE LATE AFTERNOON CELL OR TWO CANNOT BE RULED
OUT ALONG WEAK SURFACE CONVERGENCE...BUT HAVE NOT MENTIONED IN THE
FORECAST AT THIS TIME. HIGHS ON SUNDAY LOOK TO TOP OUT IN THE
LOWER TO MID 90S...WITH A LAKE BREEZE PROVIDING SOME COOLING FOR
DOWNTOWN CHICAGO AND NEARBY AREAS DURING THE AFTERNOON. THESE LAKE
SHORE AREAS STILL MAY REACH 90 OR NEAR IT BEFORE THE LAKE BREEZE
PUSHES THROUGH.
MTF
LONG TERM...SUNDAY NIGHT THROUGH SATURDAY...
THE UPPER LEVEL RIDGE REESTABLISHES ITSELF ACROSS THE CENTRAL US AS
THE TROUGH MOVES OFF TOWARD THE NEW ENGLAND AREA. A WEAKENING AREA
OF LOW PRESSURE MOVES NORTH OF THE GREAT LAKES MONDAY NIGHT...WHILE
ITS COLD FRONT SINKS SOUTH DOWN THE LAKE ON TUESDAY.
PRECIP CHANCES DIMINISH AS THE TROUGH DRIFTS EASTWARD SUNDAY NIGHT.
THE BEST CHANCE OF PRECIP IN THE EXTENDED IS ALONG THE COLD FRONT
LATE TUESDAY THROUGH WEDNESDAY. GUIDANCE DIFFERS ON THE SPEED OF
THE FRONT...WITH THE GFS BRINGING THE FRONT THROUGH MUCH FASTER THAN
THE ECMWF. GIVEN ISSUES WITH THE GFS LATELY...AND THE ECMWF HAVING
VERY CONSISTENT TIMING OVER THE PAST FEW DAYS...GOING WITH THE
SLOWER SOLUTION. BOTH MODELS INDICATE MOISTURE WILL POOL ALONG THE
FRONT...BUT THEN DISSIPATE AS THE FRONT ENTERS NORTHERN IL.
THEREFORE...KEPT BEST PRECIP CHANCES NORTH OF I-80. LIMITED ACTUAL
PRECIP CHANCES TO LESS THAN 50 PERCENT GIVEN THE MODEL TRENDS AND
DRY CONDITIONS.
HIGH PRESSURE BUILDS IN BEHIND THE FRONT...AND GUIDANCE SUGGESTS
RANDOM PERIODS OF PRECIP DURING THE LATTER HALF OF NEXT WEEK.
HOWEVER...WITH NO CLEAR SOURCE OF FORCING...QUESTIONABLE MOISTURE
SOURCES...AND DROUGHT CONDITIONS...DECIDED TO KEEP THE REMAINDER OF
THE EXTENDED DRY. AT THIS POINT THE BIGGER CRIME IS GETTING FOLKS
HOPES UP FOR RAIN ONLY TO DISAPPOINT.
HEAT BUILDS ACROSS THE REGION THROUGH TUESDAY. GUIDANCE SUGGESTS
THERE WILL ONLY BE A SMALL PUSH OF SLIGHTLY COOLER AIR BEHIND THE
FRONT...WITH WEDNESDAY LOOKING TO BE A BIT COOLER. HOWEVER 850 HPA
TEMPS BEGIN TO WARM ALMOST IMMEDIATELY WITH THE UPPER LEVEL RIDGE SW
OF THE CWA. THEREFORE...THE LATTER HALF OF NEXT WEEK LOOKS ABOVE
AVERAGE.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* LIGHT SOUTH-SOUTHEAST WIND BECOMING SOUTHWEST THIS EVENING.
* VERY LOW PROBABILITY SHRA/TSRA POTENTIAL LATER TONIGHT INTO
SUNDAY MORNING.
* WIND SHIFT FROM LIGHT WEST-SOUTHWEST TO EAST-NORTHEAST WITH WEAK
TROUGH PASSAGE MID-LATE SUNDAY MORNING AND LAKE BREEZE PUSH FROM
THE EAST SUNDAY AFTERNOON.
RATZER
//DISCUSSION...UPDATED 00Z...
A WEAK AREA OF LOW PRESSURE WAS OVER LAKE SUPERIOR EARLY THIS
EVENING...WITH A TROUGH EXTENDING SOUTH-SOUTHWEST ACROSS WISCONSIN
INTO WEST CENTRAL IOWA. ISOLATED THUNDERSTORMS WHICH HAD FORMED
ACROSS THE CHICAGO AREA EARLIER HAVE DISSIPATED...WHILE A FEW
ISOLATED STORMS REMAIN SOUTH OF THE TERMINALS ALONG AN
APPROXIMATELY IKK-BMI-SPI LINE WHERE AN OUTFLOW BOUNDARY FROM
OVERNIGHT CONVECTION HAD TAKEN RESIDENCE. ALL OF THIS ACTIVITY
SHOULD CONTINUE TO FADE THIS EVENING WITH THE LOSS OF DIURNAL
HEATING AND INSTABILITY. WINDS...WHICH HAD BECOME SOMEWHAT CHAOTIC
WITH EARLIER LAKE BREEZE AND CONVECTIVE OUTFLOWS ACROSS METRO
TERMINALS WERE RETURNING TO A SOUTH-SOUTHEAST DIRECTION AS OF 23Z
AND SHOULD CONTINUE TO VEER SOUTHWEST THROUGH LATE EVENING. SPEEDS
WILL REMAIN LESS THAN 10 KTS IN THE WEAK PRESSURE GRADIENT IN
PLACE ACROSS THE REGION.
FORECAST CONCERNS THEN SHIFT TO LOW PROBABILITY POTENTIAL FOR
DEVELOPMENT OF ISOLATED TSRA AGAIN LATER TONIGHT INTO SUNDAY
MORNING AS MID-LEVEL SHORT WAVE DIGS ACROSS THE UPPER MIDWEST AND
WEAK SURFACE TROUGH OVER WI/IA GRADUALLY SAGS ACROSS THE AREA
THROUGH SUNDAY. WEAK BUT PERSISTENT LIFT AND MOIST/WARM ADVECTION
AHEAD OF THE MID LEVEL WAVE IS EXPECTED TO CONTINUE...WITH
FORECAST SOUNDINGS INDICATING SOME MOISTENING AROUND THE 800
MB/6000 FT LEVEL DURING THE AFTER MIDNIGHT HOURS. WHILE MID/UPPER
LEVEL TEMPS REMAIN RELATIVELY WARM...THIS DOES INDICATE THE
POTENTIAL FOR DEVELOPMENT OF ISOLATED SHRA/TSRA DURING THE PRE-DAWN
HOURS SIMILAR TO LAST NIGHT. MOST OF THE HIGH-RES EXPLICIT
CONVECTION MODEL GUIDANCE DOES NOT DEVELOP SUCH CONVECTION...
THOUGH THERE IS SOME SUPPORT IN THE SHORT-RANGE ENSEMBLE GUIDANCE.
OVERALL HOWEVER...PROBABILITY AND CONFIDENCE IS TOO LOW TO INCLUDE
IN POINT TAF PRODUCTS SO HAVE LIMITED FORECAST MENTION TO
DEVELOPMENT OF A BROKEN VFR DECK AROUND 6000 FT. BETTER WARM/MOIST
ADVECTION THEN SHIFTS NORTHEAST/EAST OF THE TERMINALS SUNDAY
MORNING. SOME POTENTIAL EXISTS FOR ISOLATED TSRA/SHRA DEVELOPMENT
THROUGH THE MORNING AS WEAK SURFACE TROUGH SAGS ACROSS
AREA...THOUGH LIGHT WINDS AND RELATIVELY WARM MID-LEVEL TEMPS
CONTINUE TO ARGUE AGAINST A SIGNIFICANT THREAT.
WITH SURFACE BOUNDARY SAGGING ACROSS THE TERMINALS DURING THE MID-
LATE MORNING HOURS...LIGHT SOUTHWEST-WEST WINDS ARE EXPECTED TO
SHIFT NORTH. HOWEVER...GRADIENT IS VERY WEAK AND WINDS WILL LIKELY
BECOME MORE VARIABLE. THIS WILL ALLOW EASTERLY LAKE BREEZE TO
DEVELOP ACROSS CHICAGO SITES DURING THE EARLY-MID AFTERNOON HOURS.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH CONFIDENCE IN OVERALL WIND TRENDS.
* MEDIUM-HIGH CONFIDENCE IN NO ADDITIONAL TSRA AT TERMINALS.
* HIGH CONFIDENCE IN LAKE BREEZE OCCURRENCE SUNDAY.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...VFR.
TUESDAY...VFR. CHANCE TSRA TUES NGT.
WEDNESDAY...SLGT CHANCE TSRA. OTHERWISE VFR.
THURSDAY AND FRIDAY...VFR.
RATZER
&&
.MARINE...
145 PM CDT
LOW PRESSURE ACROSS LAKE SUPERIOR WILL CONTINUE TO MOVE EAST
THROUGH SUNDAY. THIS WILL STEER A COOL FRONT ACROSS THE LAKE LATE
TONIGHT. AHEAD OF THIS WILL BE SOME SCATTERED STORMS...SOME OF
WHICH ARE LIKELY TO BE GUSTY BASED ON THE ENVIRONMENT. THESE WILL
BE MOST FAVORED ACROSS THE SOUTHERN THIRD OF THE LAKE INCLUDING
NEAR SHORE AREAS OF IL...IN...AND SOUTHWEST MI. WINDS BEHIND THE
FRONT ON SUNDAY WILL BECOME LIGHT AND BEGIN TURNING BACK TO
SOUTHERLY ALREADY BY AFTERNOON. SOUTHWEST WINDS WILL INCREASE ON
MON...WITH OPEN WATER LOCATIONS ACROSS THE NORTH LIKELY REACHING
30 KT DURING MON NIGHT. A COOL FRONT WILL SLOWLY WORK SOUTH
ACROSS THE LAKE ON TUESDAY AND TUESDAY NIGHT. THIS WILL SHIFT
WINDS TO THE NORTH AND PROVIDE A FOCUS FOR SCATTERED THUNDERSTORMS
ONCE AGAIN.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
625 PM CDT SAT JUL 14 2012
.DISCUSSION...
ISSUED 236 PM CDT SAT JUL 14 2012
SCATTERED SHOWERS ACROSS CENTRAL ILLINOIS CONTINUE...WITH VERY
LITTLE MOVEMENT UNDER A WEAK UPPER LEVEL TROF. CONVECTIVE ACTIVITY
TO THE NW THIS MORNING SHOWING UP AS A LITTLE WEAK VORTEX ON VIS
SAT IMAGERY THIS AFTERNOON. BECAUSE OF THAT...HAVE MADE A COUPLE
OF CHANGES TO THE POPS FOR THE OVERNIGHT. OTHER THAN
THAT...FORECAST IS MOSTLY DRY BEYOND TONIGHT. NEXT CHANCE FOR
PRECIP COMES MID WEEK NEXT WEEK. ECMWF NOW HAVING SIMILAR ISSUE TO
THE LAST FEW RUNS OF THE GFS...SO KEEP SCALING BACK THE EXTENDED
POPS
SHORT TERM...TONIGHT AND TOMORROW...
FIRST CONCERN IS THE SMALL VORTEX TO THE NW MOVING NEAR THE REGION
IN THE OVERNIGHT. NEITHER HRRR NOR THE 4KM WRF ARE PICKING UP ON
THE SYSTEM...BUT THE AVAILABLE MOISTURE HAS NOW BEEN A BIT
ALTERED... PARTICULARLY IN THE EASTERN HALF OF THE CWA. FEEL LESS
LIKE THE SHOWERS AFTER 00Z WILL BE LIMITED TO REMNANTS FROM
TODAY...AND HAVE EXPANDED THE CHANCE POPS TO COVER THE ENTIRE
OVERNIGHT. IN ANY SPOTS THAT CLEAR OUT IN THE
OVERNIGHT...PARTICULARLY IN THE EAST WHERE THE BOUNDARY LAYER
MOISTURE HAS BEEN SIGNIF INCREASED BY THE SHOWERS AND
THUNDERSTORMS THIS AFTERNOON...PATCHY FOG WILL BE POSSIBLE IN THE
EARLY MORNING...AND HAVE PLACED THE MENTION IN THE GRIDS FOR A
COUPLE HOURS... MAINLY EAST OF I-55. TOMORROW...IN THE WAKE OF
EXITING SHOWERS...SOME SMALL POPS MOSTLY SOUTH OF INTERSTATE 70.
THESE POPS ARE MOSTLY A PRODUCT OF PREVIOUS MODEL SOLUTIONS WITH
THE ACTIVITY IN THE OHIO RIVER VALLEY. WILL KEEP THEM IN FOR ANY
LINGERING OVERNIGHT PRECIP...BUT MOSTLY REFLECTIVE OF EARLY IN THE
DAY.
LONG TERM...MONDAY THROUGH FRIDAY...
SCATTERED PRECIP THIS AFTERNOON WILL DO LITTLE TO ALLEVIATE THE
DROUGHT OVER THE REGION... PARTICULARLY WITH THE RIDGE BUILDING IN
THE WESTERN CONUS YET AGAIN...AND PUSHING 850MB TEMPS UP AND SFC
TEMPS BACK INTO THE MID-UPPER 90S. DRY WEATHER CONTINUES...HAVE
RAISED MAX TEMPS A DEGREE OR TWO OVER GUIDANCE SINCE MODELS KEEP
PRECIP AND CLOUD COVER IN ABSENCE OF REAL MOISTURE. BEST CHANCES FOR
PRECIP IN EXTENDED COME WITH WED NIGHT AND A PASSING TROF/SFC
BOUNDARY AS AN UPPER WAVE RIPPLES THROUGH THE 500MB FLOW ALONG THE
US/CAN BORDER. THIS FAR SOUTH...AVAILABLE MOISTURE WILL BE
QUESTIONABLE...AS WILL THE AMOUNT OF SFC CONVERGENCE. HAVE PULLED
BACK THE BLENDED POPS WHEREVER POSSIBLE. SCT SHOWER ACTIVITY IS
ALL THAT IS LIKELY IN THIS FORECAST...A VERY SMALL PERCENTAGE OF
AREA WILL SEE THE PRECIP.
&&
.AVIATION...
ISSUED 620 PM CDT SAT JUL 14 2012
COVERAGE OF THUNDERSTORMS EARLY THIS EVENING AND THEN FOG POTENTIAL
OVERNIGHT ARE THE MAIN FORECAST CONCERNS. WIDELY SCATTERED TSRA
CONTINUES ALONG SEVERAL OUTFLOW BOUNDARIES LATE THIS AFTERNOON. THE
MOST PERSISTENT AREA IS NEAR AND TO THE EAST OF KBMI. MOST OF THESE
STORMS WERE MOVING SLOWLY EAST AT 10 MPH OR LESS PRODUCING LOCALLY
BRIEF IFR CIGS/VSYBS WITH WIND GUSTS TO 40 MPH ALONG WITH TORRENTIAL
RAINFALL. MOST OF THIS ACTIVITY IS EXPECTED TO DIMINISH AT OR JUST
AFTER SUNSET. WE STILL MAY SEE ISOLATED SHOWERS AROUND FROM TIME
TO TIME OVERNIGHT BUT COVERAGE TOO LIMITED TO INCLUDE IN THE 00Z
TAFS. WITH MORE AREAS RECEIVING RAINFALL TODAY...FOG IS A DISTINCT
POSSIBILITY...ESP AT PIA...BMI AND CMI WHERE WE WILL SEE SOME BRIEF
MVFR VSBYS AT OR JUST AFTER 09Z. ONCE ANY FOG BURNS OFF...VFR
CONDITIONS WILL PREVAIL DURING THE DAY SUNDAY. SFC WINDS WILL BE
ALL OVER THE PLACE THIS EVENING THANKS TO THE NUMEROUS OUTFLOW
BOUNDARIES SO WILL START OUT WITH A VARIABLE DIRECTION AND THEN
MOST AREAS SHOULD SEE A LIGHT SOUTH WIND OVERNIGHT WITH SOUTH
WINDS ON SUNDAY AT AROUND 10 KTS.
SMITH
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
653 AM CDT FRI JUL 13 2012
.UPDATE...
RAP TRENDS AND THE LIFT TOOL CONTINUE TO GENERALLY SUPPORT EARLIER
THINKING. CONVECTION SHOULD CONTINUE THROUGH MID MORNING BEFORE
SLOWLY DISSIPATING EITHER LATE THIS MORNING OR BY EARLY AFTERNOON.
BASED ON RADAR TRENDS...WILL ADJUST POPS FOR THE MORNING HOURS
WITH HIGHER COVERAGE IN THE NORTHWEST/NORTH PARTS OF THE CWFA. IF
THE CURRENT RAP TRENDS ARE CORRECT DIURNAL CONVECTION SHOULD
DEVELOP BY MID AFTERNOON AS THE VORT MAX/SHORTWAVE BEHIND THE
CURRENT ONE BEGINS MOVING INTO EASTERN IOWA. WEAK WIND FLOW/SHEAR
ALOFT SHOULD RESULT IN NON-SEVERE STORMS. OVERALL COVERAGE THIS
AFTERNOON WILL AGAIN BE ISOLATED TO SCATTERED. ..08..
&&
.AVIATION...
NOCTURNAL ELEVATED CONVECTION CONTINUES TO BE HELPED BY A
DISTURBANCE ALOFT. POTENTIAL MVFR CONDITIONS WITH TSRA MAY BE SEEN
AT KCID/KDBQ/KMLI 12Z-18Z/13. DIURNAL TSRA CONVECTION IS EXPECTED
TO DVLP AFT 18Z/13 AND DISSIPATE AFTER SUNSET. OTHERWISE...VFR
CONDITIONS ARE EXPECTED OUTSIDE OF TSRA THROUGH 03Z/14. THERE IS A
POSSIBILITY OF NOCTURNAL TSRA AFT 06Z/14. ..08..
&&
.PREV DISCUSSION... /ISSUED 356 AM CDT FRI JUL 13 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS HIGH PRESSURE OVER THE EASTERN GREAT LAKES WITH
TWO TROFS ACROSS THE PLAINS. DEW POINTS WERE IN THE 50S ACROSS THE
IMMEDIATE GREAT LAKES WITH 60S OVER MOST OF THE MIDWEST.
SHORT TERM...TODAY AND TONIGHT...
SATELLITE TRENDS THE PAST SEVERAL HOURS HAS HAD CONSIDERABLE
DEVELOPMENT OF MID LEVEL CLOUDS. RADAR IN TURN HAS ALSO DEVELOPED
ELEVATED ISOLATED TO SCATTERED CONVECTION ACROSS IOWA.
RAP TRENDS AND THE LIFT TOOL HAVE BEEN QUITE USEFUL IN DEPICTING THE
CURRENT CONVECTION. THE LIFT TOOL SHOWS WEAK THETA E GRADIENTS
WORKING IN CONCERT WITH CONVERGENCE TO PRODUCE THE CONVECTION. RAP
TRENDS PERSIST THIS ACROSS ROUGHLY THE NORTHWEST TWO THIRDS OF THE
CWFA DURING THE MORNING HOURS IN ASSOCIATION WITH THE VORT MAX
MOVING THROUGH IN THE FLOW ALOFT. INTERESTINGLY...THE VORT MAX
SUDDENLY STRENGTHENS BY LATE MORNING WHICH MAY OR MAY NOT BE A
CONVECTIVE FEEDBACK ISSUE WITH THE RAP MODEL.
THE QUESTION THEN TURNS TO WHETHER OR NOT CONVECTION WILL DEVELOP
DURING THE AFTERNOON HOURS. THE LIFT TOOL HAS NEGATIVE THETA E LAPSE
RATES ACROSS THE AREA WITH SOME WEAK CONVERGENCE ALOFT. THE MAIN
VARIABLE WILL BE HOW MUCH THE CLOUDS HOLD DOWN TEMPERATURES.
CONVECTIVE TEMPERATURES ARE ESSENTIALLY IN THE UPPER 80S TO LOWER
90S WHICH IS THE FCST MAX TEMPERATURES. THUS WILL CONTINUE WITH
ISOLATED TO SCATTERED CONVECTION DURING THE AFTERNOON.
ANY DIURNAL CONVECTION THAT DEVELOPS THIS AFTERNOON WILL CONTINUE
INTO THE EARLY EVENING AND SHOULD DISSIPATE SHORTLY AFTER SUNSET.
HOWEVER...ANOTHER VORT MAX IN THE FLOW IS JUST UPSTREAM SO
CONVECTION COULD PERSIST LATER INTO THE EVENING...OR...RE-DEVELOP
AROUND MIDNIGHT AND THEN PERSIST THROUGH THE NIGHT. GIVEN THE WEAK
CHARACTERISTICS OF THE FLOW ALOFT...THE SECOND SCENARIO WOULD SEEM
MORE PLAUSIBLE. INDEED THE LIFT TOOL DOES SUGGEST ANOTHER THETA E
GRADIENT MOVING INTO THE CWFA AROUND MIDNIGHT. THUS...WILL GO WITH
THE CONCEPT OF ISOLATED TO SCATTERED NOCTURNAL CONVECTION DEVELOPING
AND THEN PERSISTING THROUGH SUNRISE. ..08..
LONG TERM...SATURDAY THROUGH THURSDAY...
THE LATEST MODEL RUNS CONTINUE TO DROP A WEAK BOUNDARY INTO THE
REGION SATURDAY. THIS SHOULD GIVE AT LEAST THE NORTHERN HALF OF
THE AREA A REASONABLE CHANCE OF SCATTERED THUNDERSTORMS
ESPECIALLY WITH THE BOUNDARY SETTLING INTO THE NORTH DURING PRIME
HEATING. WILL GO WITH 30/40 POPS FOR THE NORTHERN HALF OF THE CWFA
AND KEEP LOW CHANCE POPS GOING IN THE FAR SOUTH WHERE THUNDERSTORM
DEVELOPMENT WILL BE DEPENDENT ON OUTFLOWS TO PROVIDE SOME FOCUS
FOR TSRA INITIATION. ANY STORMS THAT DEVELOP SATURDAY SHOULD BE
OF THE PULSE VARIETY WITH THE WEAK DEEP LAYER SHEAR IN PLACE. THE
NAM WAS SHOWING CAPES EXCEEDING 3000 J/KG DURING THE AFTERNOON. IF
THESE CAPES ARE REALIZED THEN SOME OF THE STRONGER STORMS WILL BE
CAPABLE OF PRODUCING SOME STRONG WINDS GUSTS. KEPT SOME LOW POPS
GOING FOR SATURDAY NIGHT WITH THE BOUNDARY STILL IN THE AREA AND
CONTINUED SOME LOW POPS SOUTHEAST SUNDAY TO ACCOUNT FOR THE ECMWF
SOLUTION WHICH HOLDS A WEAK BOUNDARY IN OUR SOUTHEAST DURING THE
DAY.
SUNDAY NIGHT AND MONDAY WARMER AIR POURS BACK TO INTO THE REGION AS
UPPER RIDGING BUILDS EAST OUT OF THE ROCKIES. IT LOOKS LIKE
WIDESPREAD 90S WILL RETURN TO THE REGION MONDAY AND TUESDAY WITH
HEAT INDICES APPROACHING 100. WITH THE RIDGE BUILDING IN...A DRY
FORECAST IS IN ORDER MONDAY AND MONDAY NIGHT.
FOR TUESDAY THROUGH THURSDAY THE GFS/ECMWF CONTINUE TO SHOW A S/W
MOVING THROUGH THE NORTHERN TIER OF STATES AND SUPPRESSING THE
MIDWEST RIDGE. THE S/W WILL ALSO DROP ANOTHER BOUNDARY SOUTH INTO
THE REGION. WITH THE GFS/ECMWF HOLDING THE BOUNDARY JUST SOUTH OF
THE AREA INTO THURSDAY WILL KEEP SOME LOW POPS GOING TUESDAY
THROUGH THURSDAY...BUT HOLD THEM IN THE SLIGHT CHANCE/LOW CHANCE
RANGE SINCE MODELS KEEP MID LEVEL TEMPS ON THE WARM SIDE NEAR THE
BOUNDARY. IF THE GFS/ECMWF PROGS VERIFY THEN A SURFACE HIGH
SETTING UP OVER THE WESTERN GREAT LAKES SHOULD KEEP EAST/NORTHEAST
LOW LEVEL FLOW OVER THE AREA FOR MID/LATE WEEK. TEMPERATURES
TUESDAY SHOULD STILL BE IN THE 90S AS THE FRONT MOVES THROUGH THEN
INCREASING EAST OR NORTHEAST FLOW WEDNESDAY INTO THURSDAY SHOULD
TAKE THE EDGE OFF THE HEAT.
DLF
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION...CORRECTED
NWS QUAD CITIES IA IL
356 AM CDT FRI JUL 13 2012
.SYNOPSIS...
06Z SFC ANALYSIS HAS HIGH PRESSURE OVER THE EASTERN GREAT LAKES WITH
TWO TROFS ACROSS THE PLAINS. DEW POINTS WERE IN THE 50S ACROSS THE
IMMEDIATE GREAT LAKES WITH 60S OVER MOST OF THE MIDWEST.
&&
.SHORT TERM...TODAY AND TONIGHT...
SATELLITE TRENDS THE PAST SEVERAL HOURS HAS HAD CONSIDERABLE
DEVELOPMENT OF MID LEVEL CLOUDS. RADAR IN TURN HAS ALSO DEVELOPED
ELEVATED ISOLATED TO SCATTERED CONVECTION ACROSS IOWA.
RAP TRENDS AND THE LIFT TOOL HAVE BEEN QUITE USEFUL IN DEPICTING THE
CURRENT CONVECTION. THE LIFT TOOL SHOWS WEAK THETA E GRADIENTS
WORKING IN CONCERT WITH CONVERGENCE TO PRODUCE THE CONVECTION. RUC
TRENDS PERSIST THIS ACROSS ROUGHLY THE NORTHWEST TWO THIRDS OF THE
CWFA DURING THE MORNING HOURS IN ASSOCIATION WITH THE VORT MAX
MOVING THROUGH IN THE FLOW ALOFT. INTERESTINGLY...THE VORT MAX
SUDDENLY STRENGTHENS BY LATE MORNING WHICH MAY OR MAY NOT BE A
CONVECTIVE FEEDBACK ISSUE WITH THE RAP MODEL.
THE QUESTION THEN TURNS TO WHETHER OR NOT CONVECTION WILL DEVELOP
DURING THE AFTERNOON HOURS. THE LIFT TOOL HAS NEGATIVE THETA E LAPSE
RATES ACROSS THE AREA WITH SOME WEAK CONVERGENCE ALOFT. THE MAIN
VARIABLE WILL BE HOW MUCH THE CLOUDS HOLD DOWN TEMPERATURES.
CONVECTIVE TEMPERATURES ARE ESSENTIALLY IN THE UPPER 80S TO LOWER
90S WHICH IS THE FCST MAX TEMPERATURES. THUS WILL CONTINUE WITH
ISOLATED TO SCATTERED CONVECTION DURING THE AFTERNOON.
ANY DIURNAL CONVECTION THAT DEVELOPS THIS AFTERNOON WILL CONTINUE
INTO THE EARLY EVENING AND SHOULD DISSIPATE SHORTLY AFTER SUNSET.
HOWEVER...ANOTHER VORT MAX IN THE FLOW IS JUST UPSTREAM SO
CONVECTION COULD PERSIST LATER INTO THE EVENING...OR...RE-DEVELOP
AROUND MIDNIGHT AND THEN PERSIST THROUGH THE NIGHT. GIVEN THE WEAK
CHARACTERISTICS OF THE FLOW ALOFT...THE SECOND SCENARIO WOULD SEEM
MORE PLAUSIBLE. INDEED THE LIFT TOOL DOES SUGGEST ANOTHER THETA E
GRADIENT MOVING INTO THE CWFA AROUND MIDNIGHT. THUS...WILL GO WITH
THE CONCEPT OF ISOLATED TO SCATTERED NOCTURNAL CONVECTION DEVELOPING
AND THEN PERSISTING THROUGH SUNRISE.
08
.LONG TERM...SATURDAY THROUGH THURSDAY...
THE LATEST MODEL RUNS CONTINUE TO DROP A WEAK BOUNDARY INTO THE
REGION SATURDAY. THIS SHOULD GIVE AT LEAST THE NORTHERN HALF OF
THE AREA A REASONABLE CHANCE OF SCATTERED THUNDERSTORMS
ESPECIALLY WITH THE BOUNDARY SETTLING INTO THE NORTH DURING PRIME
HEATING. WILL GO WITH 30/40 POPS FOR THE NORTHERN HALF OF THE CWFA
AND KEEP LOW CHANCE POPS GOING IN THE FAR SOUTH WHERE THUNDERSTORM
DEVELOPMENT WILL BE DEPENDENT ON OUTFLOWS TO PROVIDE SOME FOCUS
FOR TSRA INITIATION. ANY STORMS THAT DEVELOP SATURDAY SHOULD BE
OF THE PULSE VARIETY WITH THE WEAK DEEP LAYER SHEAR IN PLACE. THE
NAM WAS SHOWING CAPES EXCEEDING 3000 J/KG DURING THE AFTERNOON. IF
THESE CAPES ARE REALIZED THEN SOME OF THE STRONGER STORMS WILL BE
CAPABLE OF PRODUCING SOME STRONG WINDS GUSTS. KEPT SOME LOW POPS
GOING FOR SATURDAY NIGHT WITH THE BOUNDARY STILL IN THE AREA AND
CONTINUED SOME LOW POPS SOUTHEAST SUNDAY TO ACCOUNT FOR THE ECMWF
SOLUTION WHICH HOLDS A WEAK BOUNDARY IN OUR SOUTHEAST DURING THE
DAY.
SUNDAY NIGHT AND MONDAY WARMER AIR POURS BACK TO INTO THE REGION AS
UPPER RIDGING BUILDS EAST OUT OF THE ROCKIES. IT LOOKS LIKE
WIDESPREAD 90S WILL RETURN TO THE REGION MONDAY AND TUESDAY WITH
HEAT INDICES APPROACHING 100. WITH THE RIDGE BUILDING IN...A DRY
FORECAST IS IN ORDER MONDAY AND MONDAY NIGHT.
FOR TUESDAY THROUGH THURSDAY THE GFS/ECMWF CONTINUE TO SHOW A S/W
MOVING THROUGH THE NORTHERN TIER OF STATES AND SUPPRESSING THE
MIDWEST RIDGE. THE S/W WILL ALSO DROP ANOTHER BOUNDARY SOUTH INTO
THE REGION. WITH THE GFS/ECMWF HOLDING THE BOUNDARY JUST SOUTH OF
THE AREA INTO THURSDAY WILL KEEP SOME LOW POPS GOING TUESDAY
THROUGH THURSDAY...BUT HOLD THEM IN THE SLIGHT CHANCE/LOW CHANCE
RANGE SINCE MODELS KEEP MID LEVEL TEMPS ON THE WARM SIDE NEAR THE
BOUNDARY. IF THE GFS/ECMWF PROGS VERIFY THEN A SURFACE HIGH
SETTING UP OVER THE WESTERN GREAT LAKES SHOULD KEEP EAST/NORTHEAST
LOW LEVEL FLOW OVER THE AREA FOR MID/LATE WEEK. TEMPERATURES
TUESDAY SHOULD STILL BE IN THE 90S AS THE FRONT MOVES THROUGH THEN
INCREASING EAST OR NORTHEAST FLOW WEDNESDAY INTO THURSDAY SHOULD
TAKE THE EDGE OFF THE HEAT.
DLF
&&
.AVIATION...
ELEVATED CONVECTION HAS DEVELOPED IN RESPONSE TO AN UPPER LEVEL
DISTURBANCE. KCID IS BEING AFFECTED WITH KDBQ/KMLI POSSIBLY BEING
AFFECTED AS WELL. MVFR CONDITIONS THAT MAY BRIEFLY DROP TO IFR ARE
EXPECTED. ISOLATED TO SCATTERED CONVECTION IS EXPECTED TO PERSIST
THROUGH 00Z/14 AND POSSIBLY BEYOND. WHEN TSRA OR VCTS IS NOT
AFFECTING A TAF SITE...VFR CONDITIONS ARE EXPECTED.
08
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION...CORRECTED
NWS QUAD CITIES IA IL
342 AM CDT FRI JUL 13 2012
.SYNOPSIS...
06Z SFC ANALYSIS HAS HIGH PRESSURE OVER THE EASTERN GREAT LAKES WITH
TWO TROFS ACROSS THE PLAINS. DEW POINTS WERE IN THE 50S ACROSS THE
IMMEDIATE GREAT LAKES WITH 60S OVER MOST OF THE MIDWEST.
&&
.SHORT TERM...ODAY AND TONIGHT...
SATELLITE TRENDS THE PAST SEVERAL HOURS HAS HAD CONSIDERABLE
DEVELOPMENT OF MID LEVEL CLOUDS. RADAR IN TURN HAS ALSO DEVELOPED
ELEVATED ISOLATED TO SCATTERED CONVECTION ACROSS IOWA.
RAP TRENDS AND THE LIFT TOOL HAVE BEEN QUITE USEFUL IN DEPICTING THE
CURRENT CONVECTION. THE LIFT TOOL SHOWS WEAK THETA E GRADIENTS
WORKING IN CONCERT WITH CONVERGENCE TO PRODUCE THE CONVECTION. RUC
TRENDS PERSIST THIS ACROSS ROUGHLY THE NORTHWEST TWO THIRDS OF THE
CWFA DURING THE MORNING HOURS IN ASSOCIATION WITH THE VORT MAX
MOVING THROUGH IN THE FLOW ALOFT. INTERESTINGLY...THE VORT MAX
SUDDENLY STRENGTHENS BY LATE MORNING WHICH MAY OR MAY NOT BE A
CONVECTIVE FEEDBACK ISSUE WITH THE RAP MODEL.
THE QUESTION THEN TURNS TO WHETHER OR NOT CONVECTION WILL DEVELOP
DURING THE AFTERNOON HOURS. THE LIFT TOOL HAS NEGATIVE THETA E LAPSE
RATES ACROSS THE AREA WITH SOME WEAK CONVERGENCE ALOFT. THE MAIN
VARIABLE WILL BE HOW MUCH THE CLOUDS HOLD DOWN TEMPERATURES.
CONVECTIVE TEMPERATURES ARE ESSENTIALLY IN THE UPPER 80S TO LOWER
90S WHICH IS THE FCST MAX TEMPERATURES. THUS WILL CONTINUE WITH
ISOLATED TO SCATTERED CONVECTION DURING THE AFTERNOON.
ANY DIURNAL CONVECTION THAT DEVELOPS THIS AFTERNOON WILL CONTINUE
INTO THE EARLY EVENING AND SHOULD DISSIPATE SHORTLY AFTER SUNSET.
HOWEVER...ANOTHER VORT MAX IN THE FLOW IS JUST UPSTREAM SO
CONVECTION COULD PERSIST LATER INTO THE EVENING...OR...RE-DEVELOP
AROUND MIDNIGHT AND THEN PERSIST THROUGH THE NIGHT. GIVEN THE WEAK
CHARACTERISTICS OF THE FLOW ALOFT...THE SECOND SCENARIO WOULD SEEM
MORE PLAUSIBLE. INDEED THE LIFT TOOL DOES SUGGEST ANOTHER THETA E
GRADIENT MOVING INTO THE CWFA AROUND MIDNIGHT. THUS...WILL GO WITH
THE CONCEPT OF ISOLATED TO SCATTERED NOCTURNAL CONVECTION DEVELOPING
AND THEN PERSISTING THROUGH SUNRISE.
08
.LONG TERM...SATURDAY THROUGH THURSDAY...
THE LATEST MODEL RUNS CONTINUE TO DROP A WEAK BOUNDARY INTO THE
REGION SATURDAY. THIS SHOULD GIVE AT LEAST THE NORTHERN HALF OF
THE AREA A REASONABLE CHANCE OF SCATTERED THUNDERSTORMS
ESPECIALLY WITH THE BOUNDARY SETTLING INTO THE NORTH DURING PRIME
HEATING. WILL GO WITH 30/40 POPS FOR THE NORTHERN HALF OF THE CWFA
AND KEEP LOW CHANCE POPS GOING IN THE FAR SOUTH WHERE THUNDERSTORM
DEVELOPMENT WILL BE DEPENDENT ON OUTFLOWS TO PROVIDE SOME FOCUS
FOR TSRA INITIATION. ANY STORMS THAT DEVELOP SATURDAY SHOULD BE
OF THE PULSE VARIETY WITH THE WEAK DEEP LAYER SHEAR IN PLACE. THE
NAM WAS SHOWING CAPES EXCEEDING 3000 J/KG DURING THE AFTERNOON. IF
THESE CAPES ARE REALIZED THEN SOME OF THE STRONGER STORMS WILL BE
CAPABLE OF PRODUCING SOME STRONG WINDS GUSTS. KEPT SOME LOW POPS
GOING FOR SATURDAY NIGHT WITH THE BOUNDARY STILL IN THE AREA AND
CONTINUED SOME LOW POPS SOUTHEAST SUNDAY TO ACCOUNT FOR THE ECMWF
SOLUTION WHICH HOLDS A WEAK BOUNDARY IN OUR SOUTHEAST DURING THE
DAY.
SUNDAY NIGHT AND MONDAY WARMER AIR POURS BACK TO INTO THE REGION AS
UPPER RIDGING BUILDS EAST OUT OF THE ROCKIES. IT LOOKS LIKE
WIDESPREAD 90S WILL RETURN TO THE REGION MONDAY AND TUESDAY WITH
HEAT INDICES APPROACHING 100. WITH THE RIDGE BUILDING IN...A DRY
FORECAST IS IN ORDER MONDAY AND MONDAY NIGHT.
FOR TUESDAY THROUGH THURSDAY THE GFS/ECMWF CONTINUE TO SHOW A S/W
MOVING THROUGH THE NORTHERN TIER OF STATES AND SUPPRESSING THE
MIDWEST RIDGE. THE S/W WILL ALSO DROP ANOTHER BOUNDARY SOUTH INTO
THE REGION. WITH THE GFS/ECMWF HOLDING THE BOUNDARY JUST SOUTH OF
THE AREA INTO THURSDAY WILL KEEP SOME LOW POPS GOING TUESDAY
THROUGH THURSDAY...BUT HOLD THEM IN THE SLIGHT CHANCE/LOW CHANCE
RANGE SINCE MODELS KEEP MID LEVEL TEMPS ON THE WARM SIDE NEAR THE
BOUNDARY. IF THE GFS/ECMWF PROGS VERIFY THEN A SURFACE HIGH
SETTING UP OVER THE WESTERN GREAT LAKES SHOULD KEEP EAST/NORTHEAST
LOW LEVEL FLOW OVER THE AREA FOR MID/LATE WEEK. TEMPERATURES
TUESDAY SHOULD STILL BE IN THE 90S AS THE FRONT MOVES THROUGH THEN
INCREASING EAST OR NORTHEAST FLOW WEDNESDAY INTO THURSDAY SHOULD
TAKE THE EDGE OFF THE HEAT.
DLF
&&
.AVIATION...
ELEVATED CONVECTION HAS DEVELOPED IN RESPONSE TO AN UPPER LEVEL
DISTURBANCE. KCID IS BEING AFFECTED WITH KDBQ/KMLI POSSIBLY BEING
AFFECTED AS WELL. MVFR CONDITIONS THAT MAY BRIEFLY DROP TO IFR ARE
EXPECTED. ISOLATED TO SCATTERED CONVECTION IS EXPECTED TO PERSIST
THROUGH 00Z/14 AND POSSIBLY BEYOND. WHEN TSRA OR VCTS IS NOT
AFFECTING A TAF SITE...VFR CONDITIONS ARE EXPECTED.
08
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
333 AM CDT FRI JUL 13 2012
.SYNOPSIS...
06Z SFC ANALYSIS HAS HIGH PRESSURE OVER THE EASTERN GREAT LAKES WITH
TWO TROFS ACROSS THE PLAINS. DEW POINTS WERE IN THE 50S ACROSS THE
IMMEDIATE GREAT LAKES WITH 60S OVER MOST OF THE MIDWEST.
&&
.SHORT TERM...ODAY AND TONIGHT...
SATELLITE TRENDS THE PAST SEVERAL HOURS HAS HAD CONSIDERABLE
DEVELOPMENT OF MID LEVEL CLOUDS. RADAR IN TURN HAS ALSO DEVELOPED
ELEVATED ISOLATED TO SCATTERED CONVECTION ACROSS IOWA.
RAP TRENDS AND THE LIFT TOOL HAVE BEEN QUITE USEFUL IN DEPICTING THE
CURRENT CONVECTION. THE LIFT TOOL SHOWS WEAK THETA E GRADIENTS
WORKING IN CONCERT WITH CONVERGENCE TO PRODUCE THE CONVECTION. RUC
TRENDS PERSIST THIS ACROSS ROUGHLY THE NORTHWEST TWO THIRDS OF THE
CWFA DURING THE MORNING HOURS IN ASSOCIATION WITH THE VORT MAX
MOVING THROUGH IN THE FLOW ALOFT. INTERESTINGLY...THE VORT MAX
SUDDENLY STRENGTHENS BY LATE MORNING WHICH MAY OR MAY NOT BE A
CONVECTIVE FEEDBACK ISSUE WITH THE RAP MODEL.
THE QUESTION THEN TURNS TO WHETHER OR NOT CONVECTION WILL DEVELOP
DURING THE AFTERNOON HOURS. THE LIFT TOOL HAS NEGATIVE THETA E LAPSE
RATES ACROSS THE AREA WITH SOME WEAK CONVERGENCE ALOFT. THE MAIN
VARIABLE WILL BE HOW MUCH THE CLOUDS HOLD DOWN TEMPERATURES.
CONVECTIVE TEMPERATURES ARE ESSENTIALLY IN THE UPPER 80S TO LOWER
90S WHICH IS THE FCST MAX TEMPERATURES. THUS WILL CONTINUE WITH
ISOLATED TO SCATTERED CONVECTION DURING THE AFTERNOON.
ANY DIURNAL CONVECTION THAT DEVELOPS THIS AFTERNOON WILL CONTINUE
INTO THE EARLY EVENING AND SHOULD DISSIPATE SHORTLY AFTER SUNSET.
HOWEVER...ANOTHER VORT MAX IN THE FLOW IS JUST UPSTREAM SO
CONVECTION COULD PERSIST LATER INTO THE EVENING...OR...RE-DEVELOP
AROUND MIDNIGHT AND THEN PERSIST THROUGH THE NIGHT. GIVEN THE WEAK
CHARACTERISTICS OF THE FLOW ALOFT...THE SECOND SCENARIO WOULD SEEM
MORE PLAUSIBLE. INDEED THE LIFT TOOL DOES SUGGEST ANOTHER THETA E
GRADIENT MOVING INTO THE CWFA AROUND MIDNIGHT. THUS...WILL GO WITH
THE CONCEPT OF ISOLATED TO SCATTERED NOCTURNAL CONVECTION DEVELOPING
AND THEN PERSISTING THROUGH SUNRISE.
08
.LONG TERM...SATURDAY THROUGH THURSDAY...
THE LATEST MODEL RUNS CONTINUE TO DROP A WEAK BOUNDARY INTO THE
REGION SATURDAY. THIS SHOULD GIVE AT LEAST THE NORTHERN HALF OF
THE AREA A REASONABLE CHANCE OF SCATTERED THUNDERSTORMS
ESPECIALLY WITH THE BOUNDARY SETTLING INTO THE NORTH DURING PRIME
HEATING. WILL GO WITH 30/40 POPS FOR THE NORTHERN HALF OF THE CWFA
AND KEEP LOW CHANCE POPS GOING IN THE FAR SOUTH WHERE THUNDERSTORM
DEVELOPMENT WILL BE DEPENDENT ON OUTFLOWS TO PROVIDE SOME FOCUS
FOR TSRA INITIATION. ANY STORMS THAT DEVELOP SATURDAY SHOULD BE
OF THE PULSE VARIETY WITH THE WEAK DEEP LAYER SHEAR IN PLACE. THE
NAM WAS SHOWING CAPES EXCEEDING 3000 J/KG DURING THE AFTERNOON. IF
THESE CAPES ARE REALIZED THEN SOME OF THE STRONGER STORMS WILL BE
CAPABLE OF PRODUCING SOME STRONG WINDS GUSTS. KEPT SOME LOW POPS
GOING FOR SATURDAY NIGHT WITH THE BOUNDARY STILL IN THE AREA AND
CONTINUED SOME LOW POPS SOUTHEAST SUNDAY TO ACCOUNT FOR THE ECMWF
SOLUTION WHICH HOLDS A WEAK BOUNDARY IN OUR SOUTHEAST DURING THE
DAY.
SUNDAY NIGHT THROUGH TUESDAY WARMER AIR POURS BACK TO INTO THE
REGION AS UPPER RIDGING BUILDS EAST OUT OF THE ROCKIES. IT LOOKS
LIKE WIDESPREAD 90S WILL RETURN TO THE REGION MONDAY AND TUESDAY
WITH HEAT INDICES APPROACHING 100. WITH THE RIDGE BUILDING IN...A
DRY FORECAST IS IN ORDER.
FOR WEDNESDAY AND THURSDAY THE GFS/ECMWF CONTINUE TO SHOW A S/W
MOVING THROUGH THE NORTHERN TIER OF STATES AND SUPPRESSING THE
MIDWEST RIDGE. THE S/W WILL ALSO DROP ANOTHER BOUNDARY SOUTH INTO
THE REGION. WILL KEEP SOME LOW POPS GOING WEDNESDAY THROUGH THURSDAY...
BUT HOLD THEM IN THE SLIGHT CHANCE/LOW CHANCE RANGE SINCE MODELS KEEP
MID LEVEL TEMPS ON THE WARM SIDE NEAR THE BOUNDARY. IF THE
GFS/ECMWF PROGS VERIFY THEN A SURFACE HIGH SETTING UP OVER THE
WESTERN GREAT LAKES SHOULD KEEP EAST/NORTHEAST LOW LEVEL FLOW OVER
THE AREA...TAKING THE EDGE OFF THE HEAT FOR THE END OF THE WEEK.
DLF
&&
.AVIATION...
ELEVATED CONVECTION HAS DEVELOPED IN RESPONSE TO AN UPPER LEVEL
DISTURBANCE. KCID IS BEING AFFECTED WITH KDBQ/KMLI POSSIBLY BEING
AFFECTED AS WELL. MVFR CONDITIONS THAT MAY BRIEFLY DROP TO IFR ARE
EXPECTED. ISOLATED TO SCATTERED CONVECTION IS EXPECTED TO PERSIST
THROUGH 00Z/14 AND POSSIBLY BEYOND. WHEN TSRA OR VCTS IS NOT
AFFECTING A TAF SITE...VFR CONDITIONS ARE EXPECTED.
08
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
606 PM CDT SAT JUL 14 2012
...UPDATE TO AVIATION...
.SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 304 PM
CDT SAT JUL 14 2012
A RIDGE OF UPPER LEVEL HIGH PRESSURE WILL DOMINATE THE HIGH PLAINS
FROM NEW MEXICO INTO WESTERN KANSAS AND NEBRASKA INTO SUNDAY. A LEE
TROUGH OF LOW PRESSURE WILL ALSO REMAIN IN EASTERN COLORADO WITH
LIGHT SOUTH TO SOUTHEAST WINDS TONIGHT. THE PRESSURE GRADIENT THEN
TIGHTENS ON SUNDAY WITH SOUTH TO SOUTHWEST WINDS OF 15 TO 25 MPH AND
GUSTY. A MID LEVEL CAPPING INVERSION WILL ALSO CONTINUE INTO SUNDAY
AFTERNOON, AND WITH TEMPERATURES APPROACHING 100, THE CAP MAY WEAKEN
ENOUGH TO SUPPORT SOME HIGH BASED THUNDERSTORMS LATE THIS AFTERNOON
INTO EARLY EVENING AND AGAIN ON SUNDAY. WILL ADD A SLIGHT CHANCE OF
THUNDER MAINLY EAST OF A LINE FROM WAKEENEY TO MEADE. WITH DEWPOINTS
ALSO MIXING OUT, IF ANY THUNDERSTORMS FORM, THEY COULD PUT OUT SOME
LOCALLY STRONG GUSTS FROM 40 TO 50 MPH. THE HRRR MESOSCALE MODEL
ALSO SUPPORTS A FEW THUNDERSTORMS LATE THIS AFTERNOON AND EARLY
EVENING.
OVERNIGHT LOWS WILL BE MILD AND IN THE MID TO UPPER 60S UNDER MOSTLY
CLEAR SKIES. FOR SUNDAY EXPECT HIGHS NEAR THE CENTURY MARK WITH
MOSTLY CLEAR TO PARTLY CLOUDY SKIES.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 435 PM CDT SAT JUL 14 2012
THERE WERE LITTLE OVERALL CHANGES IN EXPECTATIONS NOTED FOR THE
EXTENDED FORECAST PERIOD. THE GENERAL PATTERN CONTINUES TO INDICATE
A WEAKLY POSITIVE TILTED UPPER RIDGE BUILDING INTO THE GREAT PLAINS.
THE RIDGE BECOMES SLOWLY FLATTENED WITH TIME AS SHORTWAVES RIDE THE
NORTHERN PERIPHERY OF THIS RIDGE THROUGH THE WEEK. THIS WARM AIRMASS
WILL BE MARKED BY WARM TEMPERATURES IN THE MID TO UPPER 90S, AND
TEMPERATURES AROUND 100 DEGREES BY MID TO LATE WEEK. CAPPING IS
WEAK, ESPECIALLY ACROSS CENTRAL KANSAS WHERE 700 MB TEMPERATURES ARE
UNDER 10 DEGREES C. AN ISOLATED BRIEF AIRMASS THUNDERSTORM CANNOT
BE COMPLETELY RULED OUT ANY DAY, BUT CHANCES ARE QUITE LOW GIVEN THE
LACK OF NOTED SURFACE CONVERGENCE. THE BEST CHANCES MIGHT BE FARTHER
WEST AND SOUTH ON THE HIGHER TERRAIN OF THE PANHANDLES AND EASTERN
COLORADO. SOUTHWEST KANSAS SHOULD REMAIN IN A WARM SECTOR THROUGH HE
ENTIRE PERIOD, WHILE A STATIONARY FRONT RUNNING FROM IOWA THROUGH
NEBRASKA AND SOUTH DAKOTA SHOULD BE A FOCUS FOR MESOSCALE CONVECTIVE
SYSTEMS EACH NIGHT THROUGH THE MID TO LATE WEEK, AND REMAIN FOCUSED
WELL AWAY FROM CENTRAL KANSAS. CONVECTIVE STORMS THAT DEVELOP FARTHER
WEST WILL HAVE POOR STEERING FLOW WITH SUCH LIGHT MEAN WINDS DUE TO
THE UPPER HIGH. THE ATMOSPHERE WILL PROBABLY BE MORE CONDUCIVE TO
HEAT BURSTS AND GUSTY WINDS THAN TO SEVERE THUNDERSTORMS, ESPECIALLY
WEST OF HIGHWAY 283 TO THE COLORADO LINE.
TEMPERATURES BY LATE IN THE WEEK WERE RAISED A FEW DEGREES. SOME OF
THE BIAS CORRECTED MODEL OUTPUT STATISTICS GUIDANCE IS SUPPORTIVE OF
WARMER HIGHS UNDER THE UPPER RIDGE BY FRIDAY AND SATURDAY.
WIDESPREAD TEMPERATURES IN EXCESS OF 100 DEGREES AND POSSIBLY TO
AROUND 105 ARE INDICATED BY THIS GUIDANCE, AND SEEMS QUITE
REASONABLE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 600 PM CDT SAT JUL 14 2012
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES THROUGH EARLY SUNDAY
AFTERNOON. AS FOR WINDS, A LEE SIDE TROUGH OF LOW PRESSURE WILL REMAIN
ENTRENCHED ACROSS EASTERN COLORADO THROUGH SUNDAY AFTERNOON. AS A
RESULT, LIGHT SOUTHERLY WINDS EARLY THIS EVENING WILL CONTINUE
OVERNIGHT THEN INCREASE SOMEWHAT TO AROUND 15 TO 25KT BY LATE
SUNDAY MORNING AS DAYTIME HEATING INCREASES.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 69 100 72 97 / 10 10 0 10
GCK 68 100 70 98 / 10 10 0 0
EHA 68 98 68 99 / 10 10 10 10
LBL 70 100 70 99 / 10 10 0 10
HYS 68 101 71 98 / 10 10 0 10
P28 72 99 72 96 / 20 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KRUSE
LONG TERM...RUSSELL
AVIATION...JJOHNSON
AREA FORECAST DISCUSSION
NWS TOPEKA KS
102 PM CDT FRI JUL 13 2012
...UPDATE TO AVIATION...
.DISCUSSION...
0Z UPPER AIR DATA HAD A FEW WESTERLY 60-65KT REPORTS AT 250MB IN
IDAHO AND WYOMING ROUNDING THE TOP OF THE WESTERN CONUS UPPER
RIDGE. NEARBY MID LEVELS REMAIN ON THE COOL AND DAMP SIDE
CONSIDERING LOWER LEVEL CONDITIONS OF HIGHS REACHING THE MIDDLE AND
UPPER 90S AND DEWPOINTS PRIMARILY IN THE LOWER AND MIDDLE 60S.
ISOLATED CONVECTION CONTINUES TO IMPACT EAST CENTRAL KANSAS AT 07Z
WHERE MID CLOUD HAS AGAIN PREVAILED THROUGH THE NIGHT. UPSTREAM
PRECIPITATION IN NEBRASKA HAS SLOWLY DIMINISHED THOUGH SOME RECENT
REDEVELOPMENT IS NOTED IN NORTHEASTERN SECTIONS OF THAT STATE.
MODELS CONTINUE TO BE CONSISTENT WITH RESPECTABLE MID-SUMMER UPPER
DYNAMICS WORKING THEIR WAY SOUTHEAST INTO EASTERN KANSAS TODAY.
ROCKIES UPPER JET TO DIVE SOUTHEAST INTO CENTRAL KANSAS WHILE
POTENTIAL VORTICITY ANOMALY REACHES NORTHERN KANSAS BY MIDDAY WITH
SOME UPPER LEVEL Q-VECTOR CONVERGENCE RESULTING. THESE FEATURES
REACH THE 2-4C 700MB DEWPOINTS AND THE BULK OF THE
GUIDANCE...INCLUDING THE LAST SEVERAL RUNS OF THE HRRR AND THE 06Z
NAM...EXPANDS PRECIP COVERAGE BY 18Z AS A RESULT. STRENGTH OF
PRECIPITATION IS SOMEWHAT IN QUESTION AS THE EARLY TIMING OF THE
FORCING MAY KEEP STRONG INSOLATION IN CHECK AND MIXED-LAYER CAPE
LIMITED. LARGER SCALE FORCING NOT REACHING EAST CENTRAL KANSAS UNTIL
LATER IN THE DAY WOULD SUGGEST THIS AREA COULD HAVE THE GREATER
POTENTIAL FOR STRONGER STORMS...BUT THIS WILL DEPEND ON HOW LONG THE
ONGOING PRECIP LASTS. HAVE INCREASED POPS WELL ABOVE CLIMO LEVELS
BUT HELD OFF ON ANYTHING ABOVE CHANCE GIVEN COVERAGE UNCERTAINTY.
TEMPERATURES ARE ALSO A CHALLENGE...AND FIRST PERIOD SREF SPREADS
ARE RATHER HIGH. WILL KEEP EASTERN AREAS A FEW DEGREES BELOW
THURSDAYS LEVELS WITH AT LEAST MORE CLOUD EXPECTED IN LIGHT SYNOPTIC
WINDS. PRECIP CONVERGE SHOULD TAPER FROM NORTHWEST TO SOUTHEAST IN
THE LATE AFTERNOON AND EVENING AS THE FORCING MOVES OFF...BUT NOT
EXPECTING A LOT OF CHANGE TO PROFILES...SUGGESTING SOME CHANCE FOR
ELEVATED CONVECTION COULD LINGER AT LEST INTO THE EVENING.
BEYOND TONIGHT...PRECIP CHANCES ARE ON THE LOW SIDE AS THE WESTERN
RIDGE BUILDS INTO THE PLAINS. HARD TO COMPLETELY RULE OUT MORE
EVENTS OF ISOLATED ACTIVITY...BUT HARD TO JUSTIFY A MENTION AT THIS
POINT. CONVERGENCE NEAR A STALLING FRONT IN NEBRASKA APPEARS WEAK AT
BEST FOR SATURDAY AND GETTING ANYTHING TO SURVIVE INTO KANSAS IS
UNLIKELY. THE GFS ATTEMPTS TO BRING A FRONT SOUTH TO NEAR THE KANSAS
BORDER EARLY NEXT WEEK...BUT THE ECMWF KEEPS IT NORTH. MUCH TOO
LITTLE CONFIDENCE FOR A MENTION WITH THIS POSSIBILITY AT THIS POINT.
AS FOR TEMPERATURES...850MB TEMPS WARM A BIT FURTHER SATURDAY WITH
UPPER 90S TO AROUND 100 COMMONPLACE. INCREASED LOW LEVEL SOUTHEAST
FLOW MAY TONE DOWN TEMPS SUNDAY...BUT A MORE WESTERLY COMPONENT
SHOULD PUSH HIGHS BACK UP TO AROUND 100 FOR MUCH OF NEXT WEEK.
HUMIDITIES STILL DONT LOOK TOO BAD...BUT THE APPEARS TO BE SOME
POTENTIAL FOR HEAT HEADLINES DUE TO HEATS PERSISTENCE.
65
&&
.AVIATION...
SHOWERS NEAR KTOP AND KFOE WILL DEPART THE AREA SHORTLY...WITH
SKIES GRADUALLY CLEARING UP. MODEL GUIDANCE SUGGESTS FOG FORMATION
AT THE TERMINALS OVERNIGHT...HOWEVER GIVEN THE DRY ATMOSPHERE IN
THE LOWEST 10KFT WILL OPT TO NOT INCLUDE FOG MENTION FOR TONIGHT.
HOWEVER...WITH THE RAINFALL FROM TODAY THERE IS A POSSIBILITY THAT
SOME SHALLOW GROUND FOG MAY OCCUR...BUT WITH CERTAINTY RATHER LOW
WILL HANDLE THE FOG THREAT WITH FUTURE FORECASTS AND AMENDMENTS.
JL
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
652 AM CDT FRI JUL 13 2012
...UPDATE TO AVIATION...
.DISCUSSION...
0Z UPPER AIR DATA HAD A FEW WESTERLY 60-65KT REPORTS AT 250MB IN
IDAHO AND WYOMING ROUNDING THE TOP OF THE WESTERN CONUS UPPER
RIDGE. NEARBY MID LEVELS REMAIN ON THE COOL AND DAMP SIDE
CONSIDERING LOWER LEVEL CONDITIONS OF HIGHS REACHING THE MIDDLE AND
UPPER 90S AND DEWPOINTS PRIMARILY IN THE LOWER AND MIDDLE 60S.
ISOLATED CONVECTION CONTINUES TO IMPACT EAST CENTRAL KANSAS AT 07Z
WHERE MID CLOUD HAS AGAIN PREVAILED THROUGH THE NIGHT. UPSTREAM
PRECIPITATION IN NEBRASKA HAS SLOWLY DIMINISHED THOUGH SOME RECENT
REDEVELOPMENT IS NOTED IN NORTHEASTERN SECTIONS OF THAT STATE.
MODELS CONTINUE TO BE CONSISTENT WITH RESPECTABLE MID-SUMMER UPPER
DYNAMICS WORKING THEIR WAY SOUTHEAST INTO EASTERN KANSAS TODAY.
ROCKIES UPPER JET TO DIVE SOUTHEAST INTO CENTRAL KANSAS WHILE
POTENTIAL VORTICITY ANOMALY REACHES NORTHERN KANSAS BY MIDDAY WITH
SOME UPPER LEVEL Q-VECTOR CONVERGENCE RESULTING. THESE FEATURES
REACH THE 2-4C 700MB DEWPOINTS AND THE BULK OF THE
GUIDANCE...INCLUDING THE LAST SEVERAL RUNS OF THE HRRR AND THE 06Z
NAM...EXPANDS PRECIP COVERAGE BY 18Z AS A RESULT. STRENGTH OF
PRECIPITATION IS SOMEWHAT IN QUESTION AS THE EARLY TIMING OF THE
FORCING MAY KEEP STRONG INSOLATION IN CHECK AND MIXED-LAYER CAPE
LIMITED. LARGER SCALE FORCING NOT REACHING EAST CENTRAL KANSAS UNTIL
LATER IN THE DAY WOULD SUGGEST THIS AREA COULD HAVE THE GREATER
POTENTIAL FOR STRONGER STORMS...BUT THIS WILL DEPEND ON HOW LONG THE
ONGOING PRECIP LASTS. HAVE INCREASED POPS WELL ABOVE CLIMO LEVELS
BUT HELD OFF ON ANYTHING ABOVE CHANCE GIVEN COVERAGE UNCERTAINTY.
TEMPERATURES ARE ALSO A CHALLENGE...AND FIRST PERIOD SREF SPREADS
ARE RATHER HIGH. WILL KEEP EASTERN AREAS A FEW DEGREES BELOW
THURSDAYS LEVELS WITH AT LEAST MORE CLOUD EXPECTED IN LIGHT SYNOPTIC
WINDS. PRECIP CONVERGE SHOULD TAPER FROM NORTHWEST TO SOUTHEAST IN
THE LATE AFTERNOON AND EVENING AS THE FORCING MOVES OFF...BUT NOT
EXPECTING A LOT OF CHANGE TO PROFILES...SUGGESTING SOME CHANCE FOR
ELEVATED CONVECTION COULD LINGER AT LEST INTO THE EVENING.
BEYOND TONIGHT...PRECIP CHANCES ARE ON THE LOW SIDE AS THE WESTERN
RIDGE BUILDS INTO THE PLAINS. HARD TO COMPLETELY RULE OUT MORE
EVENTS OF ISOLATED ACTIVITY...BUT HARD TO JUSTIFY A MENTION AT THIS
POINT. CONVERGENCE NEAR A STALLING FRONT IN NEBRASKA APPEARS WEAK AT
BEST FOR SATURDAY AND GETTING ANYTHING TO SURVIVE INTO KANSAS IS
UNLIKELY. THE GFS ATTEMPTS TO BRING A FRONT SOUTH TO NEAR THE KANSAS
BORDER EARLY NEXT WEEK...BUT THE ECMWF KEEPS IT NORTH. MUCH TOO
LITTLE CONFIDENCE FOR A MENTION WITH THIS POSSIBILITY AT THIS POINT.
AS FOR TEMPERATURES...850MB TEMPS WARM A BIT FURTHER SATURDAY WITH
UPPER 90S TO AROUND 100 COMMONPLACE. INCREASED LOW LEVEL SOUTHEAST
FLOW MAY TONE DOWN TEMPS SUNDAY...BUT A MORE WESTERLY COMPONENT
SHOULD PUSH HIGHS BACK UP TO AROUND 100 FOR MUCH OF NEXT WEEK.
HUMIDITIES STILL DONT LOOK TOO BAD...BUT THE APPEARS TO BE SOME
POTENTIAL FOR HEAT HEADLINES DUE TO HEATS PERSISTENCE.
65
&&
.AVIATION...
SCATTERED THUNDERSTORMS WILL PREVAIL FOR MUCH OF THE DAY AS A
SHORT WAVE MOVES SOUTHEAST ACROSS NORTHEAST KANSAS THROUGH THE
DAY. AFTER 22Z CONVECTION SHOULD COME TO AN END AS THE FORCING
WITH THE WAVE SHIFTS TO THE EAST. MAINLY STAYED WITH VCTS...BUT
DID GO WITH A TEMPO FOR TOP BETWEEN 13Z-15Z WITH MVFR VSBYS AND
ALSO CIGS WITH HEAVIER RAIN ARE POSSIBLE. VFR EXPECTED OUTSIDE OF
THE CONVECTION.
53
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
321 AM CDT FRI JUL 13 2012
.DISCUSSION...
0Z UPPER AIR DATA HAD A FEW WESTERLY 60-65KT REPORTS AT 250MB IN
IDAHO AND WYOMING ROUNDING THE TOP OF THE WESTERN CONUS UPPER
RIDGE. NEARBY MID LEVELS REMAIN ON THE COOL AND DAMP SIDE
CONSIDERING LOWER LEVEL CONDITIONS OF HIGHS REACHING THE MIDDLE AND
UPPER 90S AND DEWPOINTS PRIMARILY IN THE LOWER AND MIDDLE 60S.
ISOLATED CONVECTION CONTINUES TO IMPACT EAST CENTRAL KANSAS AT 07Z
WHERE MID CLOUD HAS AGAIN PREVAILED THROUGH THE NIGHT. UPSTREAM
PRECIPITATION IN NEBRASKA HAS SLOWLY DIMINISHED THOUGH SOME RECENT
REDEVELOPMENT IS NOTED IN NORTHEASTERN SECTIONS OF THAT STATE.
MODELS CONTINUE TO BE CONSISTENT WITH RESPECTABLE MID-SUMMER UPPER
DYNAMICS WORKING THEIR WAY SOUTHEAST INTO EASTERN KANSAS TODAY.
ROCKIES UPPER JET TO DIVE SOUTHEAST INTO CENTRAL KANSAS WHILE
POTENTIAL VORTICITY ANOMALY REACHES NORTHERN KANSAS BY MIDDAY WITH
SOME UPPER LEVEL Q-VECTOR CONVERGENCE RESULTING. THESE FEATURES
REACH THE 2-4C 700MB DEWPOINTS AND THE BULK OF THE
GUIDANCE...INCLUDING THE LAST SEVERAL RUNS OF THE HRRR AND THE 06Z
NAM...EXPANDS PRECIP COVERAGE BY 18Z AS A RESULT. STRENGTH OF
PRECIPITATION IS SOMEWHAT IN QUESTION AS THE EARLY TIMING OF THE
FORCING MAY KEEP STRONG INSOLATION IN CHECK AND MIXED-LAYER CAPE
LIMITED. LARGER SCALE FORCING NOT REACHING EAST CENTRAL KANSAS UNTIL
LATER IN THE DAY WOULD SUGGEST THIS AREA COULD HAVE THE GREATER
POTENTIAL FOR STRONGER STORMS...BUT THIS WILL DEPEND ON HOW LONG THE
ONGOING PRECIP LASTS. HAVE INCREASED POPS WELL ABOVE CLIMO LEVELS
BUT HELD OFF ON ANYTHING ABOVE CHANCE GIVEN COVERAGE UNCERTAINTY.
TEMPERATURES ARE ALSO A CHALLENGE...AND FIRST PERIOD SREF SPREADS
ARE RATHER HIGH. WILL KEEP EASTERN AREAS A FEW DEGREES BELOW
THURSDAYS LEVELS WITH AT LEAST MORE CLOUD EXPECTED IN LIGHT SYNOPTIC
WINDS. PRECIP CONVERGE SHOULD TAPER FROM NORTHWEST TO SOUTHEAST IN
THE LATE AFTERNOON AND EVENING AS THE FORCING MOVES OFF...BUT NOT
EXPECTING A LOT OF CHANGE TO PROFILES...SUGGESTING SOME CHANCE FOR
ELEVATED CONVECTION COULD LINGER AT LEST INTO THE EVENING.
BEYOND TONIGHT...PRECIP CHANCES ARE ON THE LOW SIDE AS THE WESTERN
RIDGE BUILDS INTO THE PLAINS. HARD TO COMPLETELY RULE OUT MORE
EVENTS OF ISOLATED ACTIVITY...BUT HARD TO JUSTIFY A MENTION AT THIS
POINT. CONVERGENCE NEAR A STALLING FRONT IN NEBRASKA APPEARS WEAK AT
BEST FOR SATURDAY AND GETTING ANYTHING TO SURVIVE INTO KANSAS IS
UNLIKELY. THE GFS ATTEMPTS TO BRING A FRONT SOUTH TO NEAR THE KANSAS
BORDER EARLY NEXT WEEK...BUT THE ECMWF KEEPS IT NORTH. MUCH TOO
LITTLE CONFIDENCE FOR A MENTION WITH THIS POSSIBILITY AT THIS POINT.
AS FOR TEMPERATURES...850MB TEMPS WARM A BIT FURTHER SATURDAY WITH
UPPER 90S TO AROUND 100 COMMONPLACE. INCREASED LOW LEVEL SOUTHEAST
FLOW MAY TONE DOWN TEMPS SUNDAY...BUT A MORE WESTERLY COMPONENT
SHOULD PUSH HIGHS BACK UP TO AROUND 100 FOR MUCH OF NEXT WEEK.
HUMIDITIES STILL DONT LOOK TOO BAD...BUT THE APPEARS TO BE SOME
POTENTIAL FOR HEAT HEADLINES DUE TO HEATS PERSISTENCE.
65
&&
.AVIATION...
THE NAM AND GFS ARE A LITTLE MORE AGGRESSIVE IN SHOWING SOME MID
LEVEL ISENTROPIC LIFT THROUGH THE NIGHT AND ISOLATED PRECIP
SPREADING INTO NORTHEAST KS AS A WEAK DISTURBANCE MOVES THROUGH
SOUTHERN NEB. CONFIDENCE IN LOCATION AND COVERAGE IS LOW. HOWEVER
LATEST RUNS OF THE HRRR SUGGEST SCT TS MAY BE POSSIBLE ACROSS
NORTHEAST KS BEFORE 12Z. IN ANY CASE ODDS ARE THAT VFR CONDITIONS
WILL PREVAIL. IF STORMS DEVELOP THERE COULD BE A BRIEF 15 TO 30
MINUTE WINDOW OF REDUCED VSBY. WITH LOW CONFIDENCE AND LOW SKILL IN
FORECASTING CONVECTIVE DETAILS...WILL OPT TO KEEP A VFR FORECAST AND
MONITOR TRENDS FOR POSSIBLE ADDITION OF A TEMPO FOR MVFR VSBY AND
TS.
WOLTERS
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1045 PM MDT THU JUL 12 2012
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 146 PM MDT THU JUL 12 2012
SURFACE TROUGH IS STARTING TO PUSH INTO THE WESTERN PORTION OF
THE AREA WITH A SHORTWAVE MOVING OVER THE TOP OF IT BEGINNING THIS
AFTERNOON. DECENT SURFACE CONVERGENCE ALONG IT WITH LITTLE TO NO
INHIBITION. SO DO EXPECT THUNDERSTORMS TO DEVELOP BUT HOW FAR EAST
TO TAKE THEM IS A QUESTION. STORM MOVEMENTS NEAR 15 KNOTS SO THEY
SHOULD MAKE SOME PROGRESS. EARLIER MODEL OUTPUT WAS NOT TOTALLY
EXCITED ABOUT GENERATING PRECIPITATION ACROSS CWA THROUGH TONIGHT.
HOWEVER...THE LATEST HRRR IS GENERATING SOME LIGHT QPF.
WITH THE AMOUNT OF INSTABILITY AND LIFT BELIEVE THERE IS ENOUGH
THERE TO HAVE A SLIGHT CHANCE THROUGH THE ENTIRE NIGHT. SO GRIDS
WERE ADJUSTED ACCORDINGLY THROUGH TONIGHT. WINDS LOOK TO BECOME
LIGHT AND CLOUDS DECREASE AFTER WHATEVER CONVECTION THERE IS IS
DONE. DEPENDING ON HOW LOW THE DEWPOINTS ARE...TEMPERATURES COULD
DROP A LITTLE...ESPECIALLY IN THE WEST. LOOK TO HAVE PLENTY OF SUN
TOMORROW WITH MODELS SHOWING A RATHER CHAOTIC WIND FIELD...MOSTLY
FROM AN EASTERLY DIRECTION. NAM 2M/NWP HAS BEEN DOING WELL IN THIS
HOT PATTERN AND THINK IT IS ON THE RIGHT TRACK. GFS STILL LOOKS TOO
MOIST AND COOL IN THE LOWER LEVELS. SO BASED ON THE NAM 2M/NWP AND
850 MB TEMPERATURE CONCENSUS...RAISED MAXES FOR FRIDAY TO NEAR 100
FOR MANY LOCATIONS. MUCH WARMER AND DRIER AT MID LEVELS LOOKS TO
KEEP IT DRY TOMORROW AS WELL.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 240 PM MDT THU JUL 12 2012
AT THE START OF THE EXTENDED PERIOD...THE UPPER HIGH NOW OVER UTAH
WILL HAVE MIGRATED TO THE CO-NM AREA AS THE LARGE SCALE UPPER TROUGH
BECOMES ESTABLISHED IN THE WEST. THE UPPER HIGH WILL BE THE
DOMINANT PLAYER IN OUR WEATHER AS IT STALLS OVER THE CENTRAL PLAINS
EARLY NEXT WEEK. WITH WEAK FLOW ALOFT AND LACK OF SURFACE FEATURES
TO FOCUS CONVECTION...THUNDERSTORM POTENTIAL DURING THIS PERIOD WILL
BE ISOLATED AT BEST. BOTH THE GFS AND ECMWF SUGGEST THE POTENTIAL
FOR INCREASING THUNDERSTORM COVERAGE IN DAYS 6 AND 7 AS A CANADIAN
SURFACE HIGH BUILDS SOUTH AND STALLS CLOSE TO OUR FORECAST AREA. IF
THIS SCENARIO DOES UNFOLD THEN POPS IN THE FAR EXTENDED PERIODS WILL
NEED TO BE ADJUSTED UPWARD.
DAY-TO-DAY TEMPERATURE CHANGES ARE EXPECTED TO BE INSIGNIFICANT.
MODELS FORECAST 850 TEMPS AROUND 30-32C THROUGH THE PERIOD WHICH
WILL TRANSLATE TO HIGHS IN THE MID 90S TO NEAR 100 DEGREES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1038 PM MDT THU JUL 12 2012
THE CURRENT RADAR TREND INDICATES THAT STORMS SHOULD MOVE PAST
KMCK PRIOR TO 06Z AND THE REST OF THE NIGHT SHOULD BE QUIET.
THE NAM HAS A GOOD HANDLE ON CURRENT ACTIVITY AND DOES NOT BRING
ANY STORMS INTO KGLD OVERNIGHT. THEREFORE EXPECT VFR CONDITIONS
AND LIGHT SOUTHEAST WIND FOR THE NEXT 24 HOURS AS HIGH PRESSURE
ALOFT CONTINUES OVER THE ROCKIES.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...DLF
AVIATION...FS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1138 PM CDT THU JUL 12 2012
.DISCUSSION...
SEE PREV DISCUSSION.
&&
.AVIATION...
THE NAM AND GFS ARE A LITTLE MORE AGGRESSIVE IN SHOWING SOME MID
LEVEL ISENTROPIC LIFT THROUGH THE NIGHT AND ISOLATED PRECIP
SPREADING INTO NORTHEAST KS AS A WEAK DISTURBANCE MOVES THROUGH
SOUTHERN NEB. CONFIDENCE IN LOCATION AND COVERAGE IS LOW. HOWEVER
LATEST RUNS OF THE HRRR SUGGEST SCT TS MAY BE POSSIBLE ACROSS
NORTHEAST KS BEFORE 12Z. IN ANY CASE ODDS ARE THAT VFR CONDITIONS
WILL PREVAIL. IF STORMS DEVELOP THERE COULD BE A BRIEF 15 TO 30
MINUTE WINDOW OF REDUCED VSBY. WITH LOW CONFIDENCE AND LOW SKILL IN
FORECASTING CONVECTIVE DETAILS...WILL OPT TO KEEP A VFR FORECAST AND
MONITOR TRENDS FOR POSSIBLE ADDITION OF A TEMPO FOR MVFR VSBY AND
TS.
WOLTERS
&&
.PREV DISCUSSION.../ISSUED 341 PM CDT THU JUL 12 2012/
SHORT TERM - THROUGH FRIDAY...ISOLATED THUNDERSTORMS HAVE
DEVELOPED IN THE EASTERN HALF OF THE FORECAST AREA THIS AFTERNOON
IN A ZONE OF WEAK LOW LEVEL CONVERGENT FLOW WITH A HINT OF ASCENT
ALOFT COURTESY OF A VERY WEAK SHORT WAVE TROUGH. INSTABILITY WAS
ON THE ORDER OF 1000 TO 2000 J/KG...AND DEEP LAYER SHEAR IS ON THE
ORDER OF 10 KTS SO THE END RESULT IS A VERY PULSE-LIKE STORM MODE
WITH CELLS QUICK TO GO UP AND QUICK TO COLLAPSE. THERE IS A RATHER
DEEP LAYER OF DRY ADIABATIC LAPSE RATES IN THE LOW LEVELS SO THE
STRONGER STORMS HAVE PUT OUT SOME WIND GUSTS IN THE 40 TO 50 MPH
RANGE. THIS ISOLATED ACTIVITY SHOULD CONTINUE THROUGH MID TO LATE
AFTERNOON WITH A GRADUAL DECREASING TREND LIKELY AS OUTFLOW
STABILIZES THE BOUNDARY LAYER BIT BY BIT.
THERE IS SOME POTENTIAL FOR REDEVELOPMENT BETWEEN 22Z AND 02Z IN FAR
NORTHERN KANSAS AS A SLIGHTLY STRONGER PIECE OF SHORT WAVE ENERGY
MOVES INTO THE AREA FROM CENTRAL NEBRASKA. CONVECTIVE DEVELOPMENT
DEPENDS LARGELY ON WHETHER THE MID/UPPER FORCING WILL ARRIVE BEFORE
THE CAP STRENGTHENS. AT THE CURRENT TIME...IT APPEARS THAT A FEW
STORMS WILL BE POSSIBLE THROUGH MID EVENING WITH ISOLATED STRONG
WIND GUSTS ASSOCIATED WITH ANY STRONG STORMS.
YET ANOTHER SHORT WAVE TROUGH WILL MOVE FROM THE DAKOTAS SOUTH INTO
NORTHEAST KANSAS ON FRIDAY WITH ISOLATED TO SCATTERED STORMS
EXPECTED JUST ABOUT ANY TIME DURING THE DAY. THE BEST CHANCES APPEAR
TO BE IN NORTHEAST AND EAST CENTRAL KANSAS. THIS WILL BE A
CONVECTIVE SET UP SIMILAR TO THURSDAY WITH SLIGHTLY MORE DEEP LAYER
SHEAR AND A SLIGHTLY SHALLOWER DRY ADIABATIC LAYER. COULD SEE A FEW
STRONG STORMS WITH ISOLATED HAIL OR STRONG WIND GUSTS. HIGH TEMPS
WILL BE DEPENDENT UPON DAYTIME CLOUD COVER BUT WOULD EXPECT THE
ENTIRE AREA TO HIT THE MIDDLE 90S WITH SOME HIGHER READINGS POSSIBLE
IN AREAS WITH LESS CLOUDS.
BARJENBRUCH
SATURDAY THROUGH THURSDAY...EXPECT SHOWERS AND THUNDERSTORMS TO
WIND DOWN ON FRIDAY NIGHT INTO SATURDAY MORNING...WITH THE BEST
CHANCES FOR SHOWERS ENDING GRADUALLY FROM WEST TO EAST. THE
WARMING TREND WILL CONTINUE THROUGH THE WEEKEND AND NEXT WORK WEEK
AS 500 MB PRESSURE HEIGHTS WILL RISE...INDICATING THE PRESENCE OF
THE UPPER LEVEL RIDGE. WITH SOUTHERLY FLOW AND AMPLE SUNSHINE
EXPECT HIGHS TO REACH THE UPPER 90S TO LOWER 100S BY EARLY NEXT
WEEK...WITH HOT TEMPERATURES LASTING THROUGH THE ENTIRE WEEK. WILL
MAINTAIN A DRY FORECAST FOR THE REST OF THE WEEK GIVEN LACK OF ANY
LOW LEVEL TRIGGERING MECHANISM AND UPPER LEVEL SUPPORT. LONG RANGE
MODELS HINT AT THE POSSIBILITY OF A VERY WEAK BOUNDARY MOVING INTO
NORTHEAST KANSAS BY THE WED/THU TIME PERIOD AND THIS BOUNDARY MAY
BE ABLE TO KICK OFF SOME SHOWERS...BUT GIVEN HOW WEAK THE BOUNDARY
LOOKS TO BE IT MAY STALL OUT NORTH OF THE FORECAST AREA. SHOULD
THE BOUNDARY BE ABLE TO SLIDE SOUTH OF THE KS/NE BORDER SOME
SLIGHT RELIEF FROM THE HEAT WOULD BE EXPERIENCED NORTH OF THE
BOUNDARY.
JL
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1100 PM EDT SAT JUL 14 2012
.UPDATE...
ISSUED AT 1100 PM EDT SAT JUL 14 2012
CONVECTION HAS DISSIPATED WITH THE LOSS OF DAYTIME HEATING. OVERNIGHT...
A LULL IN THE ACTIVITY IS EXPECTED...BUT 21Z SREF AND 0Z NAM SHOW
CONVECTIVE DEVELOPMENT GENERALLY OVER WESTERN SECTIONS TOWARD DAWN IN
ADVANCE OF AN APPROACHING SHORTWAVE. THE 18Z GFS IS RELATIVELY CONSISTENT
WITH THIS IDEA AS WELL. THEREFORE WE HAVE CONTINUED WITH A LULL IN
POPS OVER THE NEXT COUPLE OF HOURS AND THEN HAVE THEM INCREASING INTO
THE ISOLATED TO SCATTERED RANGE LATE. SOME SLIGHT ADJUSTMENTS TO
HOURLY TEMPS AND DEWPOINTS WERE ALSO MADE. UPDATED GRIDS AND ZFP ARE
ALREADY OUT.
UPDATE ISSUED AT 815 PM EDT SAT JUL 14 2012
CONVECTION CONTINUES TO WEAKEN AS WE APPROACH SUNSET...AND OVERALL
INTENSITIES HAVE DIMINISHED OVER THE PAST HOUR OR SO. MEASURABLE RAIN
CHANCES WILL BE HIGHEST INITIALLY FROM NEAR JKL TOWARD THE BIG SANDY
REGION AS THE REMAINING CONVECTION WORKS EAST NORTHEAST AND GRADUALLY
IS EXPECTED TO CONTINUE TO WEAKEN OVER THE NEXT TWO HOURS. POPS AND
SKY WERE UPDATED ACCORDINGLY BASED ON THESE TRENDS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 335 PM EDT SAT JUL 14 2012
19Z SFC ANALYSIS SHOWS A WEAK PRESSURE PATTERN THROUGHOUT EAST
KENTUCKY WITH NO CLEAR SYNOPTIC SCALE FEATURES TO KEY IN ON.
HOWEVER...GIVEN THE HIGH PW AIR IN PLACE...NO CAP...AND SOME UPPER
LEVEL ENERGY...NOT MUCH WAS NEEDED TO INITIATE THE STORMS LATE THIS
MORNING THAT CONTINUE TO PERCOLATE OVER THE CWA AT THIS HOUR. THE
CLOUDS FILLED IN FROM THE SOUTH BY MID MORNING AND CONVECTION
FOLLOWED SHORTLY THEREAFTER. A FEW OF THE CELLS HAVE GOTTEN STRONG
AND OTHERS HAVE MERGED/TRAINED OVER THE SAME SPOTS CREATING A CONCERN
FOR MINOR URBAN OR SMALL STREAM FLOODING. REGARDLESS...THE RAINS IN
MANY LOCATIONS ARE NOW PUTTING A SERIOUS DENT IN THEIR ANNUAL
RAINFALL DEFICIT THANKS TO THESE PAST FEW DAYS. TEMPERATURES THIS
AFTERNOON HAVE BEEN HIGHLY DEPENDENT ON THE CONVECTIVE PATTERN AND
BREAKS FOR SUNSHINE WITH READINGS CURRENTLY RANGING FROM THE LOW 70S
IN THE RAIN COOLED SOUTHERN I-75 CORRIDOR TO MID 80S JUST SOUTH OF
STORMS NEAR I-64 AND IN THE...THUS FAR RAIN FREE...FAR SOUTHEAST.
DEWPOINTS...MEANWHILE...REMAIN PEGGED IN THE LOW TO MID 70S SUPPLYING
ALL THE JUICE THE CONVECTION COULD NEED.
THE MODELS REMAIN IN AGREEMENT THAT EAST KENTUCKY WILL BE ON THE
FRINGE OF THE WESTERN EXTENT OF A WEAK BERMUDA RIDGE AND AHEAD OF
TROUGHING COMING FROM THE NORTHERN PLAINS AND CROSSING THE GREAT
LAKES ON SUNDAY. THE ENERGY FROM THIS TROUGH WILL PASS BY TO THE
NORTH LATER SUNDAY AND THIS WILL SERVE TO FURTHER LIMIT THE EFFECT OF
THE EASTERN RIDGE ON OUR WEATHER INTO THE START OF THE NEW WORK WEEK.
IN THIS ENVIRONMENT THE MESOSCALE...OR SMALLER...WILL DOMINATE SO
HAVE LEANED MOST HEAVILY ON THE DETAILS OF THE NAM12 WITH A HEALTHY
DOSE OF THE HRRR EARLY ON TONIGHT.
SENSIBLE WEATHER WILL FEATURE SHOWERS AND THUNDERSTORMS WINDING
DOWN...FOR THE MOST PART...AFTER SUNSET...BUT NOT BEFORE LEAVING
BEHIND A FAIR AMOUNT OF RAINFALL IN SEVERAL LOCATIONS. EXPECT A LULL
THROUGH THE MIDDLE OF THE NIGHT WITH PATCHY FOG A GOOD BET. THE
APPROACH OF A SHORTWAVE INTO THE OHIO VALLEY LATE TONIGHT GIVES SOME
CREDENCE TO THE NAM12/S IDEA OF A CONVECTIVE CLUSTER FORMING OVER
CENTRAL TENNESSEE AND DRIFTING INTO THE CUMBERLAND VALLEY BY DAWN.
SOME SUPPORT FROM THE GFS BOLSTERS THIS IDEA...AS WELL. ACCORDINGLY...
HAVE DEVIATED FROM A STRICTLY DIURNALLY DRIVEN POP AND WX PATTERN TO
ALLOW FOR THIS IDEA IN THE GRIDS...THOUGH NOT WHOLE HOG JUST YET.
OTHERWISE...EXPECT A NEAR REPEAT OF TODAY FOR SUNDAY WITH CONVECTION
DRIVEN MAINLY BY DIURNAL HEATING AND MINOR OUTFLOWS/DIFFERENTIAL
HEATING BOUNDARIES. FOR BOTH TONIGHT AND SUNDAY NIGHT HAVE BEEN
GENEROUS WITH THE PATCHY FOG IN THE GRIDS AFTER MIDNIGHT...BUT HELD
OFF ON ANY DENSE UNTIL IT BECOMES MORE APPARENT WHERE THE BEST
NOCTURNAL CLEARING WILL OCCUR.
FOR TEMPERATURES...FOLLOWED A BLEND OF THE INHERITED GRIDS...
PERSISTENCE...AND SOME OF THE LATEST MET VALUES...AGAIN NOT MUCH IN
THE WAY OF TERRAIN EFFECTS FOR LOWS GIVEN THE HIGH DEWPOINTS. AS FOR
POPS...HAVE ENDED UP SIMILAR TO A BLEND OF THE MET AND MAV MOS
THROUGHOUT THE PERIOD.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 340 PM EDT SAT JUL 14 2012
THE MODELS REMAIN IN VERY GOOD AGREEMENT WITH THE GENERAL LONG WAVE
PATTERN THROUGH THE EXTENDED. A SHORT WAVE TROUGH WILL BE EXITING
THE APPALACHIANS ON MONDAY...HELPING TO TEMPORARILY BUCKLE
RIDGING ACROSS THE PLAINS AND INTO THE MISSISSIPPI VALLEY THROUGH
TUESDAY. THE RIDGE WILL THEN BUILD BACK IN STRONGER ACROSS THE
PLAINS...WITH A MORE VIGOROUS SHORT WAVE TROUGH TO MOVE THROUGH THE
GREAT LAKES AND NEW ENGLAND FOR WEDNESDAY AND THURSDAY...SENDING A
COLD FRONT SOUTH ACROSS THE OHIO VALLEY. THE MODELS HAVE COME ON
BOARD A BIT MORE...WITH A MORE PROGRESSIVE SOLUTION FOR THESE
FEATURES. FOR EASTERN KENTUCKY...THIS WILL KEEP THE THREAT OF
SCATTERED...MAINLY DIURNALLY DRIVEN CONVECTION ACROSS MOST OF THE AREA
THROUGH FRIDAY...BEFORE DEEPER MOISTURE SINKS FAR ENOUGH SOUTH ON
SATURDAY...TO ONLY JUSTIFY A FEW POPS UP ALONG THE TN/VA BORDER.
TEMPERATURES CONTINUE TO LOOK SLIGHTLY ABOVE NORMAL...WITH
PERSISTENT HUMIDITY UNTIL NEXT WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 815 PM EDT SAT JUL 14 2012
ANOTHER TRICKY AVN FORECAST WITH DIURNALLY DRIVEN CONVECTION
DECREASING...BUT SOME DEBRIS CLOUDS AND STRATUS LINGER OUTSIDE OF
CONVECTION. THERE IS ALSO SOME CHANCE IF A RENEWAL IN ACTIVITY TOWARDS
DAWN AS A SHORTWAVE MOVES IN. AN INCREASE IS EXPECTED AGAIN ON SUN
FROM AROUND 16Z ON WITH ANOTHER ROUND OF SCATTERED TO NUMEROUS
STORMS. SC AND STRATUS NEAR SME AND LOZ BEHIND PRECIP OR IN VICINITY
SHOULD AT LEAST TEMPORARILY DIMINISH WITH MORE IN THE WAY OF SOME
MVFR OR IFR FOG DEVELOPING BY AROUND 3Z...AND VSBY DROPPING TOWARD
LIFR OR EVEN VLIFR AT THE TAF SITES TOWARD DAWN. OUTSIDE OF
CONVECTION...CONDITIONS SHOULD IMPROVE TO VFR BY AROUND 13Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM....GEOGERIAN
AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
816 PM EDT SAT JUL 14 2012
.UPDATE...
ISSUED AT 815 PM EDT SAT JUL 14 2012
CONVECTION CONTINUES TO WEAKEN AS WE APPROACH SUNSET...AND OVERALL
INTENSITIES HAVE DIMINISHED OVER THE PAST HOUR OR SO. MEASURABLE RAIN
CHANCES WILL BE HIGHEST INITIALLY FROM NEAR JKL TOWARD THE BIG SANDY
REGION AS THE REMAINING CONVECTION WORKS EAST NORTHEAST AND GRADUALLY
IS EXPECTED TO CONTINUE TO WEAKEN OVER THE NEXT TWO HOURS. POPS AND
SKY WERE UPDATED ACCORDINGLY BASED ON THESE TRENDS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 335 PM EDT SAT JUL 14 2012
19Z SFC ANALYSIS SHOWS A WEAK PRESSURE PATTERN THROUGHOUT EAST
KENTUCKY WITH NO CLEAR SYNOPTIC SCALE FEATURES TO KEY IN ON.
HOWEVER...GIVEN THE HIGH PW AIR IN PLACE...NO CAP...AND SOME UPPER
LEVEL ENERGY...NOT MUCH WAS NEEDED TO INITIATE THE STORMS LATE THIS
MORNING THAT CONTINUE TO PERCOLATE OVER THE CWA AT THIS HOUR. THE
CLOUDS FILLED IN FROM THE SOUTH BY MID MORNING AND CONVECTION
FOLLOWED SHORTLY THEREAFTER. A FEW OF THE CELLS HAVE GOTTEN STRONG
AND OTHERS HAVE MERGED/TRAINED OVER THE SAME SPOTS CREATING A CONCERN
FOR MINOR URBAN OR SMALL STREAM FLOODING. REGARDLESS...THE RAINS IN
MANY LOCATIONS ARE NOW PUTTING A SERIOUS DENT IN THEIR ANNUAL
RAINFALL DEFICIT THANKS TO THESE PAST FEW DAYS. TEMPERATURES THIS
AFTERNOON HAVE BEEN HIGHLY DEPENDENT ON THE CONVECTIVE PATTERN AND
BREAKS FOR SUNSHINE WITH READINGS CURRENTLY RANGING FROM THE LOW 70S
IN THE RAIN COOLED SOUTHERN I-75 CORRIDOR TO MID 80S JUST SOUTH OF
STORMS NEAR I-64 AND IN THE...THUS FAR RAIN FREE...FAR SOUTHEAST.
DEWPOINTS...MEANWHILE...REMAIN PEGGED IN THE LOW TO MID 70S SUPPLYING
ALL THE JUICE THE CONVECTION COULD NEED.
THE MODELS REMAIN IN AGREEMENT THAT EAST KENTUCKY WILL BE ON THE
FRINGE OF THE WESTERN EXTENT OF A WEAK BERMUDA RIDGE AND AHEAD OF
TROUGHING COMING FROM THE NORTHERN PLAINS AND CROSSING THE GREAT
LAKES ON SUNDAY. THE ENERGY FROM THIS TROUGH WILL PASS BY TO THE
NORTH LATER SUNDAY AND THIS WILL SERVE TO FURTHER LIMIT THE EFFECT OF
THE EASTERN RIDGE ON OUR WEATHER INTO THE START OF THE NEW WORK WEEK.
IN THIS ENVIRONMENT THE MESOSCALE...OR SMALLER...WILL DOMINATE SO
HAVE LEANED MOST HEAVILY ON THE DETAILS OF THE NAM12 WITH A HEALTHY
DOSE OF THE HRRR EARLY ON TONIGHT.
SENSIBLE WEATHER WILL FEATURE SHOWERS AND THUNDERSTORMS WINDING
DOWN...FOR THE MOST PART...AFTER SUNSET...BUT NOT BEFORE LEAVING
BEHIND A FAIR AMOUNT OF RAINFALL IN SEVERAL LOCATIONS. EXPECT A LULL
THROUGH THE MIDDLE OF THE NIGHT WITH PATCHY FOG A GOOD BET. THE
APPROACH OF A SHORTWAVE INTO THE OHIO VALLEY LATE TONIGHT GIVES SOME
CREDENCE TO THE NAM12/S IDEA OF A CONVECTIVE CLUSTER FORMING OVER
CENTRAL TENNESSEE AND DRIFTING INTO THE CUMBERLAND VALLEY BY DAWN.
SOME SUPPORT FROM THE GFS BOLSTERS THIS IDEA...AS WELL. ACCORDINGLY...
HAVE DEVIATED FROM A STRICTLY DIURNALLY DRIVEN POP AND WX PATTERN TO
ALLOW FOR THIS IDEA IN THE GRIDS...THOUGH NOT WHOLE HOG JUST YET.
OTHERWISE...EXPECT A NEAR REPEAT OF TODAY FOR SUNDAY WITH CONVECTION
DRIVEN MAINLY BY DIURNAL HEATING AND MINOR OUTFLOWS/DIFFERENTIAL
HEATING BOUNDARIES. FOR BOTH TONIGHT AND SUNDAY NIGHT HAVE BEEN
GENEROUS WITH THE PATCHY FOG IN THE GRIDS AFTER MIDNIGHT...BUT HELD
OFF ON ANY DENSE UNTIL IT BECOMES MORE APPARENT WHERE THE BEST
NOCTURNAL CLEARING WILL OCCUR.
FOR TEMPERATURES...FOLLOWED A BLEND OF THE INHERITED GRIDS...
PERSISTENCE...AND SOME OF THE LATEST MET VALUES...AGAIN NOT MUCH IN
THE WAY OF TERRAIN EFFECTS FOR LOWS GIVEN THE HIGH DEWPOINTS. AS FOR
POPS...HAVE ENDED UP SIMILAR TO A BLEND OF THE MET AND MAV MOS
THROUGHOUT THE PERIOD.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 340 PM EDT SAT JUL 14 2012
THE MODELS REMAIN IN VERY GOOD AGREEMENT WITH THE GENERAL LONG WAVE
PATTERN THROUGH THE EXTENDED. A SHORT WAVE TROUGH WILL BE EXITING
THE APPALACHIANS ON MONDAY...HELPING TO TEMPORARILY BUCKLE
RIDGING ACROSS THE PLAINS AND INTO THE MISSISSIPPI VALLEY THROUGH
TUESDAY. THE RIDGE WILL THEN BUILD BACK IN STRONGER ACROSS THE
PLAINS...WITH A MORE VIGOROUS SHORT WAVE TROUGH TO MOVE THROUGH THE
GREAT LAKES AND NEW ENGLAND FOR WEDNESDAY AND THURSDAY...SENDING A
COLD FRONT SOUTH ACROSS THE OHIO VALLEY. THE MODELS HAVE COME ON
BOARD A BIT MORE...WITH A MORE PROGRESSIVE SOLUTION FOR THESE
FEATURES. FOR EASTERN KENTUCKY...THIS WILL KEEP THE THREAT OF
SCATTERED...MAINLY DIURNALLY DRIVEN CONVECTION ACROSS MOST OF THE AREA
THROUGH FRIDAY...BEFORE DEEPER MOISTURE SINKS FAR ENOUGH SOUTH ON
SATURDAY...TO ONLY JUSTIFY A FEW POPS UP ALONG THE TN/VA BORDER.
TEMPERATURES CONTINUE TO LOOK SLIGHTLY ABOVE NORMAL...WITH
PERSISTENT HUMIDITY UNTIL NEXT WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 815 PM EDT SAT JUL 14 2012
ANOTHER TRICKY AVN FORECAST WITH DIURNALLY DRIVEN CONVECTION
DECREASING...BUT SOME DEBRIS CLOUDS AND STRATUS LINGER OUTSIDE OF
CONVECTION. THERE IS ALSO SOME CHANCE IF A RENEWAL IN ACTIVITY TOWARDS
DAWN AS A SHORTWAVE MOVES IN. AN INCREASE IS EXPECTED AGAIN ON SUN
FROM AROUND 16Z ON WITH ANOTHER ROUND OF SCATTERED TO NUMEROUS
STORMS. SC AND STRATUS NEAR SME AND LOZ BEHIND PRECIP OR IN VICINITY
SHOULD AT LEAST TEMPORARILY DIMINISH WITH MORE IN THE WAY OF SOME
MVFR OR IFR FOG DEVELOPING BY AROUND 3Z...AND VSBY DROPPING TOWARD
LIFR OR EVEN VLIFR AT THE TAF SITES TOWARD DAWN. OUTSIDE OF
CONVECTION...CONDITIONS SHOULD IMPROVE TO VFR BY AROUND 13Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM....GEOGERIAN
AVIATION...JP
AREA FORECAST DISCUSSION
NWS JACKSON KY
126 AM EDT FRI JUL 13 2012
.UPDATE...
ISSUED AT 122 AM EDT FRI JUL 13 2012
STEADY BUT MOSTLY LIGHT RAIN...IDEAL TO BREAK THE RECENT DROUGHT
CONTINUES WITH RADAR STILL SHOWING MORE RAIN ADVANCING THROUGH MIDDLE
TENN. UPDATED GRIDS TO REFLECT CURRENT VALUES BUT NO CHANGE NEEDED
FOR ZONES.
UPDATE ISSUED AT 1050 PM EDT THU JUL 12 2012
ISSUED AN UPDATE TO FRESHEN UP THE GRIDS. THE FORECAST IS IN GREAT
SHAPE AND A NEW ZFP WILL NOT BE NEEDED. SENT THE GRIDS TO NDFD.
UPDATE ISSUED AT 854 PM EDT THU JUL 12 2012
WITH THE BOUNDARY DOWN SOUTH SLOW TO GENERATE AND PUSH NORTH TO
PROVIDE SOME INSTABILITY...HAVE ISSUED AN UPDATE. PULLED THUNDER OUT
OF THE EARLY PART OF THE NIGHT TILL DAWN AS LIGHTNING STRIKES HAVE
BEEN NONEXISTENT. LATER TONIGHT AS THE LOW CONTINUES TO DEVELOP...THE
BOUNDARY WILL EVENTUALLY SLIDE NORTH BINGING SOME INSTABILITY INTO
THE AREA. A NEW ZFP WAS ISSUED AND THE FORECAST IS GOOD TO GO.
UPDATE ISSUED AT 557 PM EDT THU JUL 12 2012
ACROSS EASTERN KENTUCKY...A SHIELD OF SOAKING RAINFALL CONTINUES TO EDGE
NORTH INTO THE FORECAST AREA WITH AN EMBEDDED RUMBLE OF THUNDER OR TWO.
THE CONVECTION NORTH OF THE EDGE OF THE RAINFALL HAS SINCE DIED OFF
AND SO WILL EXPECT FEW INSTANCES OF THUNDER THROUGH THE OVERNIGHT
PERIOD. HAVE ADJUSTED THE TEMPERATURE TRENDS AND DEWS ACCORDING TO
THE APPROACH OF THE RAINFALL. DECIDED NOT TO ISSUE A NEW ZFP AND SENT
GRIDS TO NDFD...HOWEVER...IF STRIKES ACROSS THE AREA CONTINUE TO BE
NIL INTO THE EVENING...MAY PULL THUNDER FOR THE NIGHT WITH THE NEXT
ZFP ISSUANCE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 340 PM EDT THU JUL 12 2012
18Z SFC ANALYSIS SHOWS HIGH PRESSURE TO THE NORTHEAST OF THE AREA
WITH AN INVERTED TROUGH TAKING SHAPE THROUGH WESTERN TENNESSEE AND UP
INTO CENTRAL KENTUCKY. AT THE NOSE OF THIS...A LARGE PCPN SHIELD IS
STEADILY OVERTAKING MORE OF THE JKL CWA FROM SOUTHEAST TO NORTHWEST.
THE THICK CLOUDS AND EARLY PCPN REALLY KEPT TEMPERATURES FROM
CLIMBING TOO HIGH IN THE CUMBERLAND VALLEY AND AS SUCH THE STABILITY
HAS TAKEN THE FORM OF MAINLY SHOWERS THERE. FURTHER TO THE NORTH AND
WEST...THOUGH...MORE HEATING AND INSTABILITY HAS LED TO HEALTHIER
CONVECTIVE CELLS AND EVEN THE ODD THUNDERSTORM. EXPECT THAT TO BE THE
CASE THROUGH THE EVENING...THOUGH THE BULK OF THE PCPN WILL FALL AS
SHOWERS. SPECIFICALLY...TEMPERATURE READINGS AT 2 PM EDT VARIED FROM
THE LOWER 80S IN THE NORTHWEST WITH THE THINNER CLOUDS...TO LOWER 70S
IN THE FAR SOUTHEAST IN THE SHOWERS. WINDS HAVE BEEN LIGHT THROUGH
THE DAY AND GENERALLY FROM THE SOUTHEAST...WHICH HAS ALSO LIKELY
HELPED TO GENERATE LOW LEVEL DOWNSLOPING WORKING AGAINST THE PCPN
THROUGH THIS AFTERNOON. EVEN SO...WHERE THE CONVECTION HAS BEEN
STRONGER IT ALSO HAS MOVED SLOWLY AND IS LEAVING BEHIND DECENT
RAINFALL TOTALS OVER A SHORT AMOUNT OF TIME...GIVEN THE HIGH PW
ENVIRONMENT.
THE MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE UPPER LEVEL PATTERN
AND FEATURES TO AFFECT THE REGION THROUGH THE SHORT TERM. KENTUCKY
AND THE MID MISSISSIPPI VALLEY WILL BE IN BETWEEN TWO RIDGES TO THE
WEST AND EAST. THIS LOWER HEIGHT REGION IS POOLING WEAK PACKETS OF
SHORTWAVE ENERGY WHILE THE NEAREST TROUGH STAYS OFF TO THE NORTH
CLOSER TO GREAT LAKES AND NOT ABLE TO PUSH OUT THE LOST ENERGY...
THROUGH SATURDAY MORNING. THE WEAKNESS ALOFT COMBINED WITH SOME
ENERGY AND HIGH PWS OVER THE AREA WILL KEEP THE THREAT OF WIDESPREAD
AND OCCASIONALLY HEAVY RAINS IN THE FORECAST FOR THE BULK OF THE
PERIOD. WITH THE MODEL SIMILARITIES HAVE FOLLOWED A BLENDED APPROACH
FAVORING THE NAM12 FOR MESOSCALE DETAILS.
SENSIBLE WEATHER WILL FEATURE A MUCH NEEDED SOAKING RAIN EVENT
THROUGH FRIDAY AS THE UPPER LEVEL FACTORS COMBINE WITH THE HIGH PWS
AIR IN PLACE TO SUPPORT CONVECTION. SPECIFICALLY...EXPECT THE BEST
CHANCE FOR HEAVY RAINS TO OCCUR LATER TONIGHT AND INTO THE FIRST
PART OF FRIDAY PER THE EVOLUTION DEPICTED IN THE LATEST HRRR AND
NAM12. THIS WILL GIVE A FAIRLY UNIFORM PATTERN OF HIGHER RAIN
AMOUNTS...BUT THERE WILL STILL LIKELY BE CONSIDERABLE VARIABILITY
WITH LOCALIZED HIGHER AMOUNTS GIVEN THE CONVECTIVE NATURE. WILL
CONTINUE TO MENTION THE EXCESSIVE POTENTIAL IN THE HWO...BUT STILL
LEAVE IT OUT FROM THE GRIDS AND ZONES. THE PCPN WILL START TO WANE
LATER ON FRIDAY AS THE CORE OF IT SHIFTS NORTHWEST AND OUT OF THE
BULK OF THE CWA. THERE WILL STILL BE A GOOD THREAT OF SHOWERS AND
EVEN A THUNDERSTORM INTO SATURDAY MORNING BUT THE BEST RAINS WILL
HAVE MOVED ON BY THEN. THIS RAIN IS QUITE BENEFICIAL AND WILL
HOPEFULLY PUT A DECENT DENT IN OUR RAINFALL DEFICIT. AS FOR TEMPS...
KEPT THEM FAIRLY UNIFORM SPATIALLY AND ELEVATIONALLY...WITH THE
DIFFERENCES DRIVEN MORE BY THE RAIN PATTERN AND HIGH MOISTURE CONTENT
OF THE AIR RATHER THAN ANY TERRAIN DIFFERENCES.
FOLLOWED THE MET TEMPERATURES AND DEWPOINTS MOST CLOSELY FOR THE
SHORT TERM AS THEY LOOKED REASONABLE FOR THE PCPN PATTERN AND MATCHED
WELL WITH THE INHERITED GRIDS. AS FOR POPS...GENERALLY ENDED UP ON
THE HIGH SIDE OF GUIDANCE...WHICH WAS ALSO FAIRLY SIMILAR THROUGH THE
PERIOD.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 320 PM EDT THU JUL 12 2012
THE MODELS CONTINUE TO SHOW AN UNSETTLED PATTERN TO REMAIN ACROSS
THE OHIO AND TENNESSEE VALLEYS THROUGH THE EXTENDED AS AN UPPER
LEVEL RIDGE REMAINS NEARLY ANCHORED ACROSS BERMUDA...KEEPING A
PERSISTENT FEED OF MOISTURE ACROSS EASTERN KENTUCKY...WHILE AT THE
SAME TIME EXPOSING THE REGION TO PASSING WEAK DISTURBANCES IN THE
FLOW AROUND THE RIDGE. GIVEN THE CONTINUED LOW CONFIDENCE IN TIMING
ANYTHING THIS FAR OUT...WILL KEEP THE HIGHEST POPS CENTERED AROUND
THE DIURNALLY FAVORED PERIODS. TOWARDS THE END OF THE WORK WEEK...A
NORTHERN STREAM TROUGH WILL ATTEMPT TO BRING A COLD FRONT THROUGH
THE AREA. WILL STICK WITH A SLOWER TIMING WITH THIS FEATURE.
FOR TEMPERATURES...SLIGHTLY ABOVE NORMAL READINGS WILL REIGN...WITH
HIGHS IN THE MID TO UPPER 80S...AND LOWS AROUND 70.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 130 AM EDT FRI JUL 13 2012
WITH DEVELOPING PRECIP SHIELD MOVING NORTH AND CONTINUING TO PROVIDE
AMPLE COVERAGE OF SHOWER ACTIVITY...MVFR TO IFR CONDITIONS WILL
PERSIST ACROSS THE AREA...INCLUDING THE TAF SITES...FOR MOST OF THE
NEXT 24 HOUR TAF PERIOD. WITH SOME HEATING TOMORROW...MVFR TO IFR
WILL PERSIST...BUT AS WARMER AIR TRACKS NORTH AND DAYTIME
HEATING...ADDED VCTS TO THE TAF SITES. OTHERWISE...IFR UNTIL THIS
AFTERNOON WHEN HEATING MAY BRING CONDITIONS TO VFR EVEN WITH
OCCASIONAL TSRA UNTIL AFTER SUNSET AND THEN THE FOG...BR...RETURNS
VSBY TO MVFR.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DUSTY
SHORT TERM...GREIF
LONG TERM....GEOGERIAN
AVIATION...DUSTY
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
1147 PM CDT THU JUL 12 2012
.AVIATION...
VFR CONDITIONS TO PREVAIL OUTSIDE CONVECTION...WHICH SHOULD ONLY
DIP BRIEFLY TO MVFR CIGS/VSBY. CONVECTION MAY HAVE EARLIER
INITIATION AS CONVERGENT BAND OFF THE COAST BECOMES MORE ACTIVE
AND SPREADS INLAND IN THE MORNING ON OUTFLOW BOUNDARIES AND SEA
BREEZE. GUST POTENTIAL CAN BE NEAR 40 KT WITH EARLY CONVECTION BUT
SETTLE TO 25 KT IN LATE MORNING/AFTERNOON AS COVERAGE INCREASES. 24/RR
&&
.PREV DISCUSSION... /ISSUED 827 PM CDT THU JUL 12 2012/
UPDATE...
..SOUNDING DISCUSSION...
NO PROBLEMS WITH THE FLIGHT THIS EVENING. THE SOUNDING SHOWS A BIT
OF A SURFACE INVERSION IN PLACE ON THE NORTHSHORE WHICH HAS HELPED
TO QUIET THE SHOWER AND THUNDERSTORM ACTIVITY. ON THE SOUTHSHORE...
A FEW STORMS ARE CONTINUING TO FIRE IN THE METRO NEW ORLEANS AREA.
A STEADY STREAM OF MOISTURE IS WORKING INTO LOWER LEVELS FROM THE
SOUTHWEST TO THE NORTHEAST ACROSS THE AREA SO ADDITIONAL
DEVELOPMENT IS POSSIBLE AS HINTED TO BY THE HRRR MODELING. THAT
SAID...CONVECTION IS ALREADY WANING OVERALL AND THERE COULD BE
ANOTHER LULL ACROSS THE ENTIRE AREA FOR SEVERAL HOURS BEFORE
THINGS BEGIN TO DEVELOP AGAIN TOMORROW. WINDS ARE OF OUT THE
SOUTHWEST AT THE SURFACE AND INTO MID LEVELS AND ARE LIGHT AND
VARIABLE ALOFT.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 69 90 71 91 / 30 60 30 60
BTR 72 91 72 91 / 30 60 30 60
ASD 72 90 72 90 / 30 50 30 50
MSY 74 90 75 90 / 30 50 30 50
GPT 73 90 73 89 / 30 50 30 50
PQL 71 92 71 90 / 30 50 30 50
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1028 AM EDT FRI JUL 13 2012
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES ALONG WITH INCREASING HUMIDITY
WILL BRING SHOWERS AND THUNDERSTORMS TO THE AREA THROUGH THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WITH 1030AM UPDATE...STILL TRYING TO GET A HANDLE ON JUST HOW FAR
NORTH PRECIPITATION WILL MAKE IT DURING THE DAY. SURFACE DEWPOINT
DEPRESSION AT MORGANTOWN IS 6 DEGREES...WHILE IT IS 17 DEGREES AT
PITTSBURGH. 12Z PIT SOUNDING STILL SHOWS A GOOD BIT OF DRY AIR IN
THE SURFACE-850MB LAYER...AND EXPECT THAT IT COULD BE SEVERAL
HOURS BEFORE AIR IN EASTERN OHIO...NORTHERN WV PANHANDLE...AND
SOUTHWESTERN PENNSYLVANIA MOISTENS UP ENOUGH AT LOW LEVELS FOR
PRECIPITATION TO START FALLING. HAVE ALSO LOWERED HIGH
TEMPERATURES BY A FEW DEGREES IN LOCATIONS THAT HAVE CHANCE FOR
PRECIPITATION TODAY. PREVIOUS DISCUSSION FOLLOWS.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A TROUGH AXIS
CENTERED ACROSS THE MISSOURI VALLEY WITH THE UPPER OHIO VALLEY IN
A SOUTHWESTERLY FLOW AHEAD OF THIS FEATURE. A DEVELOPING SHORT
WAVE IS RIDING NORTHEASTWARD ALONG THE OHIO RIVER ON THE EASTERN
PERIPHERY OF THE LONG WAVE TROUGH. THIS FEATURE IS PROVIDING
FORCING FOR SHOWERS ACROSS MUCH OF WEST VIRGINIA. A TIGHT 500MB
MOISTURE GRADIENT IS LOCATED ALONG THE MASON-DIXON LINE AND IS
SLOWLY SLIDING NORTHWARD INTO SOUTHWESTERN PA. 1000-850MB LAYER
REMAINS QUITE DRY WITH 10-15 DEGREE DEW POINT DEPRESSIONS ACROSS
MUCH OF THE AREA.
THE SHORT WAVE WILL SLIDE SLOWLY NORTHEASTWARD INTO NORTH-CENTRAL
WV, EASTERN OHIO, AND SOUTHWESTERN PA TODAY. FORCING FROM THE WAVE
WILL ALLOW FOR SHOWERS TO DEVELOP AND MOVE INTO AREAS SOUTH OF THE
I-70 CORRIDOR LATE THIS MORNING INTO THE EARLY AFTERNOON. THERE
IS SOME UNCERTAINTY WITH THIS FORECAST IN REGARDS TO HOW LONG IT
WILL TAKE FOR 1000-850MB LAYER TO SATURATE. DEEPER MOISTURE SHOULD
ADVECT INTO THE AREA BY EVENING. MID-LEVEL MOISTURE WILL
CONTINUE TO FILTER ACROSS THE AREA THROUGHOUT THE DAY, KEEPING SKIES
MOSTLY CLOUDY ACROSS THE AREA.
TEMP FORECAST IS CHALLENGING TODAY AS NORTHWARD ENCROACHMENT OF
LOW-LEVEL MOISTURE AND SHOWERS WILL BE LIMITING FACTORS SOUTH OF
PITTSBURGH. MAV/ECS GUIDANCE IS IN THE MID 70S FOR AREAS SOUTH OF
PITTSBURGH AND MET GUIDANCE IS IN THE MID 80S FOR HIGHS IN THE
SAME AREAS. FORECAST TAKES COOLER POCKET OF 850MB TEMPS (AROUND
13-14C) INDICATED BY GFS/ECMWF INTO CONSIDERATION FOR AREAS SOUTH
OF PITTSBURGH. HIGHS ARE FORECAST TO RANGE FROM THE MID 70S ACROSS
NORTH-CENTRAL WV TO THE MID 80S ALONG THE I-80 CORRIDOR.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
THERE IS ECMWF/GFS AGREEMENT THAT THE SHORT WAVE WILL SHIFT NORTHEAST
OF THE AREA OVERNIGHT. 305K ISENTROPIC ANALYSIS INDICATES THAT
UPLIFT WILL CONTINUE BEHIND THIS FEATURE IN A MOIST SOUTHWESTERLY
FLOW. THUS, CHANCE POPS CONTINUE ACROSS MOST OF THE AREA
OVERNIGHT. CLOUD COVERAGE ALONG WITH WARM TD ADVECTION WILL LIMIT
LOWS TONIGHT, RANGING FROM THE UPPER 60S ACROSS NORTH-CENTRAL WV
TO THE LOWER 60S ACROSS THE I-80 CORRIDOR AND EASTERN RIDGES.
OVER THE WEEKEND, AN UPPER LEVEL RIDGE AXIS WILL REMAIN IN PLACE
ACROSS THE CAROLINAS WITH THE LONG WAVE TROUGH DE-AMPLIFYING AND
SLIDING EASTWARD ACROSS THE GREAT LAKES. WITH THE UPPER OHIO
VALLEY BETWEEN THESE TWO FEATURES, IT WILL REMAIN IN A MOIST,
SOUTHWESTERLY MID-LEVEL FLOW SATURDAY AND SUNDAY. THUS, CHANCE POPS
CONTINUE THROUGH THE WEEKEND, INCREASING TO LIKELY WITH MODERATE
INSTABILITY RETURNING THUNDERSTORMS TO THE FORECAST BY THE
AFTERNOON ON SATURDAY.
THUNDERSTORMS REMAIN IN THE FORECAST THROUGH SUNDAY AS DEW POINTS
WARM INTO THE LOWER 70S AND PWATS INCREASE TO AROUND 2 INCHES
ACROSS THE MAJORITY OF THE AREA. IT IS POSSIBLE THAT A FEW OF THE
STORMS MAYS BECOME STRONG WITH GUSTY WINDS AND HEAVY DOWNPOURS
OVER THE WEEKEND. AT THIS TIME, WIND PROFILE (0-6KM BULK SHEAR
25KTS) APPEARS TO BE MARGINALLY TOO WEAK TO MENTION A SEVERE
THREAT IN THE HWO AND THUS CONCUR WITH THE STORM PREDICTION
CENTER`S GENERAL THUNDERSTORM OUTLOOK.
HIGH TEMPERATURES WILL BE NEAR NORMAL SEASONAL VALUES OVER THE
WEEKEND WITH LOWS AROUND 5 DEGREES ABOVE NORMAL.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
MAINTAINED A CHANCE OF SHOWERS AND THUNDERSTORMS THIS PERIOD WITH
CONTINUED HIGHER HUMIDITY AND WARMER THAN NORMAL TEMPERATURES.
BLEND OF RECENT NAEFS AND ECMWF MODEL OUTPUT CONTINUE TO SHOW
WEAK SOUTH TO SOUTHWESTERLY WINDS AT LOW LEVELS ACROSS THE UPPER
OHIO VALLEY.
AT UPPER LEVELS, THE INITIAL WEAK SHORT-WAVE TROUGH NEAR THE GREAT
LAKES MAY BE SHEARED AS SHORT-WAVE TROUGH MOVES TOWARD THE GREAT
LAKES FROM CENTRAL CANADA. THIS SCENARIO COULD RESULT IN A
SOUTHEASTWARD MOVING COLD FRONT THROUGH THE GREAT LAKES AND
PERHAPS UPPER OHIO VALLEY, BUT LIKELY NOT BEFORE THURSDAY.
SO EXPECT CONTINUED HUMID CONDITIONS ACROSS THE UPPER OHIO VALLEY
THIS PERIOD, WHICH WILL PROMOTE A CONTINUING CHANCE OF SHOWERS AND
THUNDERSTORMS.
FORECASTED TEMPERATURES UP TO 7 DEGREES WARMER THAN NORMAL BASED
ON HPC GUIDANCE WHICH IN GENERAL WAS A COUPLE DEGREES WARMER THAN
GFS AND ECMWF MOS BUT CLOSE TO NAEFS MEDIAN VALUES.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
EAST COAST HIGH PRESSURE WILL PROVIDE GENERAL VFR CONDITIONS FOR
TODAY INTO TONIGHT, ALTHOUGH SHOWERS AND ISOLATED THUNDERSTORMS CAN
POTENTIALLY PROVIDE BRIEF RESTRICTIONS...ESPECIALLY IN THE SOUTHERN
PORTS LATE THIS MORNING AND THIS AFTERNOON.
OUTLOOK...FRIDAY NIGHT THROUGH TUESDAY...
CONTINUED HUMID CONDITIONS WILL PROMOTE POSSIBLE RESTRICTIONS DUE
TO PATCHY FOG AND HAZE EACH MORNING, AND SCATTERED THUNDERSTORMS
AT ANY TIME.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
817 AM EDT FRI JUL 13 2012
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES ALONG WITH INCREASING HUMIDITY
WILL BRING SHOWERS AND THUNDERSTORMS TO THE AREA THROUGH THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MINOR CHANGES WERE MADE TO TEMPERATURES AND POPS BASED ON SURFACE
OBSERVATIONS AND RECENT RADAR TREND.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A TROUGH AXIS
CENTERED ACROSS THE MISSOURI VALLEY WITH THE UPPER OHIO VALLEY IN
A SOUTHWESTERLY FLOW AHEAD OF THIS FEATURE. A DEVELOPING SHORT
WAVE IS RIDING NORTHEASTWARD ALONG THE OHIO RIVER ON THE EASTERN
PERIPHERY OF THE LONG WAVE TROUGH. THIS FEATURE IS PROVIDING
FORCING FOR SHOWERS ACROSS MUCH OF WEST VIRGINIA. A TIGHT 500MB
MOISTURE GRADIENT IS LOCATED ALONG THE MASON-DIXON LINE AND IS
SLOWLY SLIDING NORTHWARD INTO SOUTHWESTERN PA. 1000-850MB LAYER
REMAINS QUITE DRY WITH 10-15 DEGREE DEW POINT DEPRESSIONS ACROSS
MUCH OF THE AREA.
THE SHORT WAVE WILL SLIDE SLOWLY NORTHEASTWARD INTO NORTH-CENTRAL
WV, EASTERN OHIO, AND SOUTHWESTERN PA TODAY. FORCING FROM THE WAVE
WILL ALLOW FOR SHOWERS TO DEVELOP AND MOVE INTO AREAS SOUTH OF THE
I-70 CORRIDOR LATE THIS MORNING INTO THE EARLY AFTERNOON. THERE
IS SOME UNCERTAINTY WITH THIS FORECAST IN REGARDS TO HOW LONG IT
WILL TAKE FOR 1000-850MB LAYER TO SATURATE. DEEPER MOISTURE SHOULD
ADVECT INTO THE AREA BY EVENING. MID-LEVEL MOISTURE WILL
CONTINUE TO FILTER ACROSS THE AREA THROUGHOUT THE DAY, KEEPING SKIES
MOSTLY CLOUDY ACROSS THE AREA.
TEMP FORECAST IS CHALLENGING TODAY AS NORTHWARD ENCROACHMENT OF
LOW-LEVEL MOISTURE AND SHOWERS WILL BE LIMITING FACTORS SOUTH OF
PITTSBURGH. MAV/ECS GUIDANCE IS IN THE MID 70S FOR AREAS SOUTH OF
PITTSBURGH AND MET GUIDANCE IS IN THE MID 80S FOR HIGHS IN THE
SAME AREAS. FORECAST TAKES COOLER POCKET OF 850MB TEMPS (AROUND
13-14C) INDICATED BY GFS/ECMWF INTO CONSIDERATION FOR AREAS SOUTH
OF PITTSBURGH. HIGHS ARE FORECAST TO RANGE FROM THE MID 70S ACROSS
NORTH-CENTRAL WV TO THE MID 80S ALONG THE I-80 CORRIDOR.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
THERE IS ECMWF/GFS AGREEMENT THAT THE SHORT WAVE WILL SHIFT NORTHEAST
OF THE AREA OVERNIGHT. 305K ISENTROPIC ANALYSIS INDICATES THAT
UPLIFT WILL CONTINUE BEHIND THIS FEATURE IN A MOIST SOUTHWESTERLY
FLOW. THUS, CHANCE POPS CONTINUE ACROSS MOST OF THE AREA
OVERNIGHT. CLOUD COVERAGE ALONG WITH WARM TD ADVECTION WILL LIMIT
LOWS TONIGHT, RANGING FROM THE UPPER 60S ACROSS NORTH-CENTRAL WV
TO THE LOWER 60S ACROSS THE I-80 CORRIDOR AND EASTERN RIDGES.
OVER THE WEEKEND, AN UPPER LEVEL RIDGE AXIS WILL REMAIN IN PLACE
ACROSS THE CAROLINAS WITH THE LONG WAVE TROUGH DE-AMPLIFYING AND
SLIDING EASTWARD ACROSS THE GREAT LAKES. WITH THE UPPER OHIO
VALLEY BETWEEN THESE TWO FEATURES, IT WILL REMAIN IN A MOIST,
SOUTHWESTERLY MID-LEVEL FLOW SATURDAY AND SUNDAY. THUS, CHANCE POPS
CONTINUE THROUGH THE WEEKEND, INCREASING TO LIKELY WITH MODERATE
INSTABILITY RETURNING THUNDERSTORMS TO THE FORECAST BY THE
AFTERNOON ON SATURDAY.
THUNDERSTORMS REMAIN IN THE FORECAST THROUGH SUNDAY AS DEW POINTS
WARM INTO THE LOWER 70S AND PWATS INCREASE TO AROUND 2 INCHES
ACROSS THE MAJORITY OF THE AREA. IT IS POSSIBLE THAT A FEW OF THE
STORMS MAYS BECOME STRONG WITH GUSTY WINDS AND HEAVY DOWNPOURS
OVER THE WEEKEND. AT THIS TIME, WIND PROFILE (0-6KM BULK SHEAR
25KTS) APPEARS TO BE MARGINALLY TOO WEAK TO MENTION A SEVERE
THREAT IN THE HWO AND THUS CONCUR WITH THE STORM PREDICTION
CENTER`S GENERAL THUNDERSTORM OUTLOOK.
HIGH TEMPERATURES WILL BE NEAR NORMAL SEASONAL VALUES OVER THE
WEEKEND WITH LOWS AROUND 5 DEGREES ABOVE NORMAL.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
MAINTAINED A CHANCE OF SHOWERS AND THUNDERSTORMS THIS PERIOD WITH
CONTINUED HIGHER HUMIDITY AND WARMER THAN NORMAL TEMPERATURES.
BLEND OF RECENT NAEFS AND ECMWF MODEL OUTPUT CONTINUE TO SHOW
WEAK SOUTH TO SOUTHWESTERLY WINDS AT LOW LEVELS ACROSS THE UPPER
OHIO VALLEY.
AT UPPER LEVELS, THE INITIAL WEAK SHORT-WAVE TROUGH NEAR THE GREAT
LAKES MAY BE SHEARED AS SHORT-WAVE TROUGH MOVES TOWARD THE GREAT
LAKES FROM CENTRAL CANADA. THIS SCENARIO COULD RESULT IN A
SOUTHEASTWARD MOVING COLD FRONT THROUGH THE GREAT LAKES AND
PERHAPS UPPER OHIO VALLEY, BUT LIKELY NOT BEFORE THURSDAY.
SO EXPECT CONTINUED HUMID CONDITIONS ACROSS THE UPPER OHIO VALLEY
THIS PERIOD, WHICH WILL PROMOTE A CONTINUING CHANCE OF SHOWERS AND
THUNDERSTORMS.
FORECASTED TEMPERATURES UP TO 7 DEGREES WARMER THAN NORMAL BASED
ON HPC GUIDANCE WHICH IN GENERAL WAS A COUPLE DEGREES WARMER THAN
GFS AND ECMWF MOS BUT CLOSE TO NAEFS MEDIAN VALUES.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
EAST COAST HIGH PRESSURE WILL PROVIDE GENERAL VFR CONDITIONS FOR
TODAY INTO TONIGHT, ALTHOUGH SHOWERS AND ISOLATED THUNDERSTORMS CAN
POTENTIALLY PROVIDE BRIEF RESTRICTIONS...ESPECIALLY IN THE SOUTHERN
PORTS LATE THIS MORNING AND THIS AFTERNOON.
OUTLOOK...FRIDAY NIGHT THROUGH TUESDAY...
CONTINUED HUMID CONDITIONS WILL PROMOTE POSSIBLE RESTRICTIONS DUE
TO PATCHY FOG AND HAZE EACH MORNING, AND SCATTERED THUNDERSTORMS
AT ANY TIME.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
422 AM EDT FRI JUL 13 2012
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES ALONG WITH INCREASING HUMIDITY
WILL BRING SHOWERS AND THUNDERSTORMS TO THE AREA THROUGH THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A TROUGH AXIS
CENTERED ACROSS THE MISSOURI VALLEY WITH THE UPPER OHIO VALLEY IN
A SOUTHWESTERLY FLOW AHEAD OF THIS FEATURE. A DEVELOPING SHORT
WAVE IS RIDING NORTHEASTWARD ALONG THE OHIO RIVER ON THE EASTERN
PERIPHERY OF THE LONG WAVE TROUGH. THIS FEATURE IS PROVIDING
FORCING FOR SHOWERS ACROSS MUCH OF WEST VIRGINIA. A TIGHT 500MB
MOISTURE GRADIENT IS LOCATED ALONG THE MASON-DIXON LINE AND IS
SLOWLY SLIDING NORTHWARD INTO SOUTHWESTERN PA. 1000-850MB LAYER
REMAINS QUITE DRY WITH 10-15 DEGREE DEW POINT DEPRESSIONS ACROSS
MUCH OF THE AREA.
THE SHORT WAVE WILL SLIDE SLOWLY NORTHEASTWARD INTO NORTH-CENTRAL
WV, EASTERN OHIO, AND SOUTHWESTERN PA TODAY. FORCING FROM THE WAVE
WILL ALLOW FOR SHOWERS TO DEVELOP AND MOVE INTO AREAS SOUTH OF THE
I-70 CORRIDOR LATE THIS MORNING INTO THE EARLY AFTERNOON. THERE
IS SOME UNCERTAINTY WITH THIS FORECAST IN REGARDS TO HOW LONG IT
WILL TAKE FOR 1000-850MB LAYER TO SATURATE. DEEPER MOISTURE SHOULD
ADVECT INTO THE AREA BY EVENING. MID-LEVEL MOISTURE WILL
CONTINUE TO FILTER ACROSS THE AREA THROUGHOUT THE DAY, KEEPING SKIES
MOSTLY CLOUDY ACROSS THE AREA. THIS WILL LIMIT HEATING AND
INSTABILITY, THUS ONLY HAVE A SCHC THUNDER LIMITED TO THE I-80
CORRIDOR WITH JUST SHOWERS ELSEWHERE.
TEMP FORECAST IS CHALLENGING TODAY AS NORTHWARD ENCROACHMENT OF
LOW-LEVEL MOISTURE AND SHOWERS WILL BE LIMITING FACTORS SOUTH OF
PITTSBURGH. MAV/ECS GUIDANCE IS IN THE MID 70S FOR AREAS SOUTH OF
PITTSBURGH AND MET GUIDANCE IS IN THE MID 80S FOR HIGHS IN THE
SAME AREAS. FORECAST TAKES COOLER POCKET OF 850MB TEMPS (AROUND
13-14C) INDICATED BY GFS/ECMWF INTO CONSIDERATION FOR AREAS SOUTH
OF PITTSBURGH. HIGHS ARE FORECAST TO RANGE FROM THE MID 70S ACROSS
NORTH-CENTRAL WV TO THE MID 80S ALONG THE I-80 CORRIDOR.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
THERE IS ECMWF/GFS AGREEMENT THAT THE SHORT WAVE WILL SHIFT NORTHEAST
OF THE AREA OVERNIGHT. 305K ISENTROPIC ANALYSIS INDICATES THAT
UPLIFT WILL CONTINUE BEHIND THIS FEATURE IN A MOIST SOUTHWESTERLY
FLOW. THUS, CHANCE POPS CONTINUE ACROSS MOST OF THE AREA
OVERNIGHT. CLOUD COVERAGE ALONG WITH WARM TD ADVECTION WILL LIMIT
LOWS TONIGHT, RANGING FROM THE UPPER 60S ACROSS NORTH-CENTRAL WV
TO THE LOWER 60S ACROSS THE I-80 CORRIDOR AND EASTERN RIDGES.
OVER THE WEEKEND, AN UPPER LEVEL RIDGE AXIS WILL REMAIN IN PLACE
ACROSS THE CAROLINAS WITH THE LONG WAVE TROUGH DE-AMPLIFYING AND
SLIDING EASTWARD ACROSS THE GREAT LAKES. WITH THE UPPER OHIO
VALLEY BETWEEN THESE TWO FEATURES, IT WILL REMAIN IN A MOIST,
SOUTHWESTERLY MID-LEVEL FLOW SATURDAY AND SUNDAY. THUS, CHANCE POPS
CONTINUE THROUGH THE WEEKEND, INCREASING TO LIKELY WITH MODERATE
INSTABILITY RETURNING THUNDERSTORMS TO THE FORECAST BY THE
AFTERNOON ON SATURDAY.
THUNDERSTORMS REMAIN IN THE FORECAST THROUGH SUNDAY AS DEW POINTS
WARM INTO THE LOWER 70S AND PWATS INCREASE TO AROUND 2 INCHES
ACROSS THE MAJORITY OF THE AREA. IT IS POSSIBLE THAT A FEW OF THE
STORMS MAYS BECOME STRONG WITH GUSTY WINDS AND HEAVY DOWNPOURS
OVER THE WEEKEND. AT THIS TIME, WIND PROFILE (0-6KM BULK SHEAR
25KTS) APPEARS TO BE MARGINALLY TOO WEAK TO MENTION A SEVERE
THREAT IN THE HWO AND THUS CONCUR WITH THE STORM PREDICTION
CENTER`S GENERAL THUNDERSTORM OUTLOOK.
HIGH TEMPERATURES WILL BE NEAR NORMAL SEASONAL VALUES OVER THE
WEEKEND WITH LOWS AROUND 5 DEGREES ABOVE NORMAL.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
MAINTAINED A CHANCE OF SHOWERS AND THUNDERSTORMS THIS PERIOD WITH
CONTINUED HIGHER HUMIDITY AND WARMER THAN NORMAL TEMPERATURES.
BLEND OF RECENT NAEFS AND ECMWF MODEL OUTPUT CONTINUE TO SHOW
WEAK SOUTH TO SOUTHWESTERLY WINDS AT LOW LEVELS ACROSS THE UPPER
OHIO VALLEY.
AT UPPER LEVELS, THE INITIAL WEAK SHORT-WAVE TROUGH NEAR THE GREAT
LAKES MAY BE SHEARED AS SHORT-WAVE TROUGH MOVES TOWARD THE GREAT
LAKES FROM CENTRAL CANADA. THIS SCENARIO COULD RESULT IN A
SOUTHEASTWARD MOVING COLD FRONT THROUGH THE GREAT LAKES AND
PERHAPS UPPER OHIO VALLEY, BUT LIKELY NOT BEFORE THURSDAY.
SO EXPECT CONTINUED HUMID CONDITIONS ACROSS THE UPPER OHIO VALLEY
THIS PERIOD, WHICH WILL PROMOTE A CONTINUING CHANCE OF SHOWERS AND
THUNDERSTORMS.
FORECASTED TEMPERATURES UP TO 7 DEGREES WARMER THAN NORMAL BASED
ON HPC GUIDANCE WHICH IN GENERAL WAS A COUPLE DEGREES WARMER THAN
GFS AND ECMWF MOS BUT CLOSE TO NAEFS MEDIAN VALUES.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
EAST COAST HIGH PRESSURE WILL PROVIDE GENERAL VFR CONDITIONS FOR
TODAY INTO TONIGHT, ALTHOUGH SHOWERS AND ISOLATED THUNDERSTORMS CAN
POTENTIALLY PROVIDE BRIEF RESTRICTIONS...ESPECIALLY IN THE SOUTHERN
PORTS LATE THIS MORNING AND THIS AFTERNOON.
OUTLOOK...FRIDAY NIGHT THROUGH TUESDAY...
CONTINUED HUMID CONDITIONS WILL PROMOTE POSSIBLE RESTRICTIONS DUE
TO PATCHY FOG AND HAZE EACH MORNING, AND SCATTERED THUNDERSTORMS
AT ANY TIME.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
218 AM EDT FRI JUL 13 2012
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES ALONG WITH INCREASING HUMIDITY
WILL BRING SHOWERS AND THUNDERSTORMS TO THE AREA THROUGH THE
WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
06Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO
INCREASE POPS SOUTH OF PITTSBURGH THIS AFTERNOON AND TO ACCOUNT
FOR THE LATEST TRENDS IN TEMP.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A TROUGH AXIS
CENTERED ACROSS THE MISSOURI VALLEY WITH THE UPPER OHIO VALLEY IN
A SOUTHWESTERLY FLOW AHEAD OF THIS FEATURE. A DEVELOPING SHORT
WAVE IS RIDING NORTHEASTWARD ALONG THE OHIO RIVER ON THE EASTERN
PERIPHERY OF THE LONG WAVE TROUGH. THIS FEATURE IS PROVIDING
FORCING FOR SHOWERS ACROSS MUCH OF SOUTHERN WEST VIRGINIA. A TIGHT
500MB MOISTURE GRADIENT IS LOCATED ACROSS NORTH-CENTRAL WV AND IS
SLOWLY SLIDING NORTHWARD INTO THE AREA. 1000-850MB LAYER REMAINS
QUITE DRY WITH 10-15 DEGREE DEW POINT DEPRESSIONS ACROSS MUCH OF
THE AREA.
THE SHORT WAVE WILL SLIDE SLOWLY NORTHEASTWARD INTO NORTH-CENTRAL
WV, EASTERN OHIO, AND SOUTHWESTERN PA TODAY. FORCING FROM THE WAVE
WILL ALLOW FOR SHOWERS TO DEVELOP AND MOVE INTO AREAS SOUTH OF THE
I-70 CORRIDOR LATE THIS MORNING INTO THE EARLY AFTERNOON. THERE
IS SOME UNCERTAINTY WITH THIS FORECAST IN REGARDS TO HOW LONG IT
WILL TAKE FOR 1000-850MB LAYER TO SATURATE. DEEPER MOISTURE SHOULD
ADVECT INTO THE AREA BY EVENING. MID-LEVEL MOISTURE WILL
CONTINUE TO FILTER ACROSS THE AREA THROUGHOUT THE DAY, KEEPING SKIES
MOSTLY CLOUDY ACROSS THE AREA. THIS WILL LIMIT HEATING AND
INSTABILITY, THUS ONLY HAVE A SCHC THUNDER MENTION FOR MOST OF THE
AREA AND JUST SHOWERS ACROSS THE SOUTHEASTERN RIDGES.
TEMP FORECAST IS CHALLENGING TODAY AS NORTHWARD ENCROACHMENT OF
LOW-LEVEL MOISTURE AND SHOWERS COULD KEEP TEMPS DOWN SOUTH OF
PITTSBURGH. MAV GUIDANCE IS IN THE MID 70S FOR AREAS SOUTH OF
PITTSBURGH AND MET GUIDANCE IS IN THE MID 80S FOR HIGHS IN THE
SAME AREAS. FORECAST TAKES COOLER POCKET OF 850MB TEMPS (AROUND
13-14C) INTO CONSIDERATION AND IS CLOSER TO THE COOLER MAV
GUIDANCE FOR AREAS SOUTH OF PITTSBURGH. HIGHS ARE FORECAST TO
RANGE FROM THE MID 70S ACROSS NORTH-CENTRAL WV TO THE MID 80S
ALONG THE I-80 CORRIDOR.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
BLEND OF RECENT SREF MODEL OUTPUT, COUPLED WITH DETAILS FROM
RECENT NAM MODEL OUTPUT, SHOW THUNDERSTORM CHANCES ACROSS THE
UPPER OHIO VALLEY INCREASING THIS PERIOD.
THIS IS DUE TO A COUPLE FACTORS. THE FIRST FACTOR IS INCREASING
SURFACE LAYER HUMIDITY THAT WILL PROMOTE INCREASED VERTICAL
INSTABILITY. THE SECOND FACTOR IS A TREND TOWARD BETTER ORGANIZED
LIFTING MECHANISMS. AT SOME POINT THERE WILL BE INCREASED
MOISTURE CONVERGENCE ALONG THE LEADING EDGE OF THE HIGHER SURFACE
DEW POINTS, A MESOSCALE FEATURE THAT COULD BE TERMED A DEW POINT
WARM FRONT. THE SLOW EASTWARD PROGRESSION OF AN UPPER LEVEL SHORT-
WAVE TROUGH NEAR THE GREAT LAKES, CAN PROVIDE ANOTHER SOURCE OF
LIFT AND INSTABILITY WITH ITS PRECEDING DIFFLUENT FLOW AND
SLIGHTLY COLDER TEMPERATURES ALOFT.
DESPITE THE INCREASED THUNDERSTORM POTENTIAL, CONCUR WITH SPC
REGARDING RESTRICTED SEVERE POTENTIAL DUE TO LACK OF VERTICAL
WIND SHEAR. THERE CAN BE MORE OF A POTENTIAL FOR HEAVIER
THUNDERSTORM RAINS DUE TO LARGER THAN NORMAL PRECIPITABLE WATER
VALUES AND POTENTIAL FOR SLOW THUNDERSTORM MOVEMENT OR TRAINING.
SOIL CONDITIONS ARE SUCH THAT MORE THAN 2 INCHES OF RAIN WOULD BE
NEEDED IN 2 HOURS OR LESS TO CAUSE FLOODING ISSUES.
FORECASTED WARMER THAN NORMAL TEMPERATURES THIS PERIOD, BUT WITH A
SLIGHTLY SMALL DIURNAL TEMPERATURE RANGE DUE TO AN INCREASED CLOUD
COVER, MORE HUMID SURFACE LAYER, AND THUNDERSTORM POTENTIAL. THIS
IS SUPPORTED BY RECENT GFS AND NAM MOS, WHICH SHOWED MOST PERIODS
WITH TEMPERATURES 2 TO 5 DEGREES WARMER THAN NORMAL.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
MAINTAINED A CHANCE OF SHOWERS AND THUNDERSTORMS THIS PERIOD WITH
CONTINUED HIGHER HUMIDITY AND WARMER THAN NORMAL TEMPERATURES.
BLEND OF RECENT NAEFS AND ECMWF MODEL OUTPUT CONTINUE TO SHOW
WEAK SOUTH TO SOUTHWESTERLY WINDS AT LOW LEVELS ACROSS THE UPPER
OHIO VALLEY.
AT UPPER LEVELS, THE INITIAL WEAK SHORT-WAVE TROUGH NEAR THE GREAT
LAKES MAY BE SHEARED AS SHORT-WAVE TROUGH MOVES TOWARD THE GREAT
LAKES FROM CENTRAL CANADA. THIS SCENARIO COULD RESULT IN A
SOUTHEASTWARD MOVING COLD FRONT THROUGH THE GREAT LAKES AND
PERHAPS UPPER OHIO VALLEY, BUT LIKELY NOT BEFORE THURSDAY.
SO EXPECT CONTINUED HUMID CONDITIONS ACROSS THE UPPER OHIO VALLEY
THIS PERIOD, WHICH WILL PROMOTE A CONTINUING CHANCE OF SHOWERS AND
THUNDERSTORMS.
FORECASTED TEMPERATURES UP TO 7 DEGREES WARMER THAN NORMAL BASED
ON HPC GUIDANCE WHICH IN GENERAL WAS A COUPLE DEGREES WARMER THAN
GFS AND ECMWF MOS BUT CLOSE TO NAEFS MEDIAN VALUES.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
EAST COAST HIGH PRESSURE WILL PROVIDE GENERAL VFR CONDITIONS FOR
TODAY INTO TONIGHT, ALTHOUGH SHOWERS AND ISOLATED THUNDERSTORMS CAN
POTENTIALLY PROVIDE BRIEF RESTRICTIONS...ESPECIALLY IN THE SOUTHERN
PORTS LATE THIS MORNING AND THIS AFTERNOON.
OUTLOOK...FRIDAY NIGHT THROUGH TUESDAY...
CONTINUED HUMID CONDITIONS WILL PROMOTE POSSIBLE RESTRICTIONS DUE
TO PATCHY FOG AND HAZE EACH MORNING, AND SCATTERED THUNDERSTORMS
AT ANY TIME.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
149 PM EDT FRI JUL 13 2012
.UPDATE...
ISSUED AT 1206 PM EDT FRI JUL 13 2012
SKIES REMAIN FAIRLY CLEAR OVR MUCH OF THE AREA. MID CLOUDS TRIED TO
MAKE PUSH INTO WESTERN CWA A FEW HOURS AGO BUT FELL APART RAPIDLY.
WV LOOP AND RUC ANALYSIS INDICATES THAT THERE IS A DECENT AMOUNT OF
DRY AIR OVR MUCH OF NORTHEAST AND NORTHERN WISCONSIN AND INTO WESTERN
UPR MICHIGAN. 12Z GRB SOUNDING TURNED UP A K INDEX NEAR 30C BUT THE
WV LOOP INDICATES THIS IS ONLY A VERY SMALL AREA OF HIGHER MOISTURE
LIFTING TOWARD BAY OF GREEN BAY. DELAYED INCREASING CLOUD TREND IN
THE WEST. EVENTUALLY COULD SEE AT LEAST ISOLD SHRA/TSRA FORM IN THE
WEST AS WE PUSH PAST CONVECTIVE TEMPS IN THE MID 80S AND SOME WEAK
FORCING AND MOISTURE ADVECTION EDGES ACROSS THAT AREA OUT AHEAD OF
STRONGER DYNAMICS FM LARGER SCALE TROUGH FM NORTHWEST ONTARIO INTO
NORTHERN MINNESOTA.
SINCE H85 TEMPS HAVE ROSE ANOTHER 1-2C COMPARED TO YDY AND SKY COVER
SHOULD BE MINIMAL FOR MUCH OF THE AREA...HAVE BUMPED UP FCST HIGHS
THIS AFTN TO VALUES A COUPLE DEGREES HIGHER THAN THOSE OBSERVED YDY.
MAIN RESULT WILL BE MANY AREAS PUSHING TOWARD OR JUST PAST THE 90
DEGREE MARK. EVEN SO...SINCE DWPNTS WILL CONTNIUE TO MIX OUT WITH
THE DRIER AIR OVERHEAD WILL NOT BE AS HUMID AS IT COULD BE GIVEN THE
WARMTH. THE DRIER AIR AND A BIT OF A SOUTH WIND WILL OVERALL MAKE FOR A
COMFORTABLE 90 DEGREE DAY.
FINALLY...LOOKING AHEAD FOR TONIGHT AND SATURDAY...CURRENT POPS/WX
ARE GENERALLY ON TRACK. UPPER TROUGH AXIS IS FCST TO BE SQUARELY
OVERHEAD UPR MICHIGAN BY SATURDAY AFTN...SO EXPECT HIGHER COVERAGE
TO SHRA/TSRA BY THAT TIME AS HAS OCCURRED BENEATH THE UPR TROUGH
AXIS THE LAST COUPLE DAYS. H85-H3 WINDS ARE WEAK BENEATH THE TROUGH
AXIS AND GIVEN INCREASING PWATS TOWARD 150 PCT OF NORMAL...SEEMS LIKE
MAIN ISSUE ON SATURDAY WILL BE HEAVY DOWNPOURS. ALREADY SEEING THIS
AS KBDE IN FAR NORTHERN MN THIS MORNING /BENEATH THE TROUGH AXIS/
RECEIVED JUST UNDER 2 INCHES OF RAIN IN LESS THAN 2 HOURS WITH A SLOW
MOVING THUNDERSTORM.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 456 AM EDT FRI JUL 13 2012
SHORT TERM PATTERN WILL BE DOMINATED BY A 500MB TROUGH CURRENTLY
OVER SRN MANITOBA/ND/NW MN...THAT WILL LATER PHASE WITH AN UPPER LOW
/AND ASSOCIATED TROUGH/ CURRENTLY OVER NRN ALBERTA. AT THE
SFC...CURRENTLY THERE IS A TROUGH JUST E OF THE UPPER TROUGH AXIS
INTO FAR WRN MN...AND HIGH PRESSURE OVER THE ERN SEABOARD. THIS PUTS
IN THE CWA UNDER SW LOW LEVEL FLOW INITIALLY. SHOWERS FROM JUST W OF
LAKE SUPERIOR STRETCHING ALONG THE WI/MN BORDER HAVE BEEN INCREASING
IN COVERAGE EARLY TONIGHT...ALONG A RIBBON OF HIGHER MOISTURE IN THE
WAA REGIME AHEAD OF THE SFC TROUGH.
FOR TODAY...THE SRN UPPER TROUGH WILL PHASE WITH THE NRN UPPER LOW
BY 00Z SAT...DEEPENING THE SRN EXTENT OF THE TROUGH THE AXIS MOVES
TO JUST W OF LAKE SUPERIOR AND ALONG THE WI/MN BORDER...WITH THE SFC
TROUGH ALMOST DIRECTLY BENEATH THE UPPER TROUGH. TRICKY TO SAY WHEN
SHOWERS WILL GET INTO UPPER MI...AS THE RIBBON OF MOISTURE SLOWLY
MOVES E. THE NAM IS ONE OF THE FASTER AND MORE AGRESSIVE MODELS WITH
BRINGING THE MOISTURE INTO WRN UPPER MI THIS AFTERNOON...BUT OUTPUTS
LITTLE QPF AS VER LOW LEVEL WILL BE DRY. PRIOR TO AROUND 21Z
TODAY...IF ANY PRECIP MAKES IT TO THE GROUND IT SHOULD BE FAIRLY
LIGHT. THINK BEST CHANCES FOR WRN UPPER MI TO SEE PRECIP TODAY WILL
BE THIS EVENING WHILE WE STILL HAVE DECENT SFC HEATING AND A
SHORTWAVE INDICATED BY MODELS MOVES IN FROM THE S. 850MB TEMPS OF UP
TO 19C BY LATE IN THE DAY WILL SUPPORT HIGH TEMPS IN THE 80S TO
AROUND 90...WARMEST CENTRAL AND E AWAY FROM LAKE MI.
TONIGHT...THE SFC AND UPPER TROUGHS WILL MOVE INTO FAR WRN UPPER MI
BY 12Z SAT. PRECIP WILL AGAIN BE TRICKY AS MODELS HAVE A HARD TIME
TO DEALING WITH CONVECTIVE LEFTOVERS. ONE THING AGREED ON BY MODELS
IS THAT ERN UPPER MI WILL BE DRIER THAN WRN UPPER MI...SINCE DRY LOW
LEVEL AIR WILL LINGER OVER THE E THROUGH THE NIGHT. SEEMS THE BEST
CHANCES FOR PRECIP WILL BE OVER WRN UPPER MI AND ALONG THE WI
BORDER...WHERE I KEPT CHANCE AND SLIGHT CHANCE POPS...AND THE E
SHOULD BE DRY. OVERALL CONFIDENCE IN OVERNIGHT PRECIP IS LOW.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 456 AM EDT FRI JUL 13 2012
MEDIUM RANGE GUIDANCE IS IN OVERALL DECENT AGREEMENT ON THE BIG
PICTURE FOR NEXT WEEK AS IT PERTAINS TO UPPER MI. SLOW MOVING TROF
PASSING ACROSS THE WRN GREAT LAKES THIS WEEKEND WILL BE FOLLOWED BY
WEAK RIDGING EARLY NEXT WEEK AS WRN CONUS RIDGE EXPANDS EASTWARD.
SHORTWAVE CRUISING ACROSS THE NRN CONUS/SRN CANADA WILL THEN
TRANSLATE TO TROF AMPLIFICATION OVER SE CANADA/NE CONUS MIDWEEK.
THEREAFTER...RIDGE WILL BUILD/EXPAND ACROSS THE CONUS WITH CENTER OF
HOT RIDGE AGAIN SETTING UP OVER THE CNTRL STATES. END RESULT WILL BE
ABOVE NORMAL TEMPS THRU EARLY NEXT WEEK...2 MAYBE 3 DAYS OF MORE
PLEASANT SUMMER WEATHER MIDWEEK AS TROF AMPLIFIES TO THE E...AND
THEN A RETURN TO POTENTIALLY WELL ABOVE NORMAL TEMPS LATE WEEK/NEXT
WEEKEND AS HOT RIDGE EXPANDS OVER THE CNTRL CONUS. PATTERN DOES NOT
LOOK TO FAVOR WELL ORGANIZED PCPN EVENTS. BEST SHOTS FOR PCPN WILL BE
THIS WEEKEND WITH SLOW MOVING TROF AND POSSIBLY SOMETIME LATER
MON/TUE AS COLD FRONT PASSES. DRY DAYS ARE A GOOD BET MIDWEEK AS SFC
HIGH PRES SETTLES ACROSS THE UPPER LAKES...AND THEN RESURGENCE OF
HEAT TOWARD THE UPPER LAKES LATE NEXT WEEK WILL PROBABLY SUPPORT SOME
THREAT OF CONVECTION AT THAT TIME.
AS ALLUDED TO ABOVE...TROF CURRENTLY OVER THE ERN DAKOTAS/WRN MN
WILL SLOWLY MOVE ACROSS THE GREAT LAKES THIS WEEKEND. WITH TROF AXIS
REACHING UPPER MI SAT AND COINCIDING WITH DAYTIME HEATING...
SHRA/TSRA COVERAGE SHOULD BECOME NMRS. CNTRL UPPER MI MAY BE FAVORED
FOR BEST COVERAGE GIVEN MORE IDEAL TIMING OF TROF WITH RESPECT TO
DIURNAL CYCLE AND DUE TO SOME ASSISTANCE FROM LAKE BREEZES. DEEP
LAYER SHEAR IS GENERALLY UNDER 20KT...SO ORGANIZED SVR STORMS ARE
NOT EXPECTED. HOWEVER...IF THERE IS ENOUGH DAYTIME HEATING TO
SIGNIFICANTLY BOOST INSTABILITY...THERE MAY BE ISOLD PULSE TYPE SVR
STORMS SAT AFTN. RELATIVELY SLOW STORM MOVEMENT COULD LEAD TO SOME
LOCALLY HVY RAINFALL.
PCPN SHOULD GRADUALLY END FROM W TO E SAT NIGHT. SINCE MID LEVEL
TROF AXIS WILL BE E OF THE FCST AREA BY SUN MORNING...IT APPEARS SUN
WILL PROBABLY TURN OUT TO BE A DRY DAY. HOWEVER....RETAINED SLIGHT
CHC POPS ACROSS THE SCNTRL/SE AS LAKE BREEZE INTERACTION MIGHT STILL
YIELD ISOLD SHRA/TSRA. MIXING TO AROUND 800MB SUPPORTS MAX TEMPS
UPWARDS OF AROUND 90F AWAY FROM MODEST LAKE BREEZE COOLING.
SHORTWAVE WILL EJECT FROM TROF ALONG THE W COAST SUN NIGHT. IN
RESPONSE TO THE WAVE TRACKING TOWARD SCNTRL CANADA...LOW-LEVEL JET
WILL INCREASE ACROSS THE PLAINS. THIS SHOULD SUPPORT A CLUSTER OF
SHRA/TSRA ON NOSE OF LOW-LEVEL JET AND ALONG EDGE OF CAP ACROSS
ND/SRN SASKACHEWAN INTO NRN MN/SRN MANITOBA. AT THIS TIME... IT
APPEARS LOW-LEVEL JET WILL STILL BE W OF THE AREA BY 12Z MON...SO DO
NOT ANTICIPATE ANY CONVECTION LATE SUN NIGHT...EXCEPT POSSIBLY OVER
WRN LAKE SUPERIOR.
LOW-LEVEL JET SLIDES ACROSS THE AREA MON. THERE IS SOME UNCERTAINTY
ON WHERE THE EDGE OF THE CAP WILL RESIDE...BUT GENERAL CONSENSUS IS
THAT AT LEAST THE NRN/ERN PORTIONS OF THE FCST AREA WILL BE CLOSE
ENOUGH TO WARRANT A MENTION OF SHRA/TSRA. WITH AREA ON THE CAPE
GRADIENT AND UNDER 35-45KT OF DEEP LAYER SHEAR...ORGANIZED SVR
STORMS WILL BE POSSIBLE IF THERE IS CONVECTION. IF THERE IS NO PCPN
AND NOT MUCH CLOUD COVER...TEMPS UNDER WAA SHOULD EASILY RISE INTO
THE LWR 90S IN MOST AREAS AWAY FROM LOCAL COOLING NEAR THE GREAT
LAKES...MAINLY LAKE MI UNDER S TO SW BOUNDARY LAYER FLOW.
COLD FRONT SLIDES ACROSS THE AREA MON NIGHT/TUE MORNING...PROVIDING
A CHC OF SHRA/TSRA. WILL HANG ONTO CHC POPS THRU TUE AFTN GIVEN SOME
UNCERTAINTY IN FRONTAL TIMING. OTHERWISE...COOLER/DRIER MORE
COMFORTABLE AIR MASS WILL BEGIN SPREADING INTO THE AREA TUE. A MORE
PLEASANT SUMMER DAY SHAPING UP FOR WED AS SFC HIGH PRES SETTLES OVER
THE UPPER LAKES. HIGHS SHOULD BE IN THE LWR 70S ALONG LAKE SUPERIOR
TO UPPER 70S/AROUND 80 INLAND WITH DWPTS FALLING THRU THE 50S. IT
SHOULD REMAIN COMFORTABLE THU (DWPTS IN THE 50S)...THOUGH IT WILL
BEGIN TO WARM UP JUST A LITTLE AS RETURN FLOW DEVELOPS ON BACKSIDE
OF DEPARTING HIGH PRES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 147 PM EDT FRI JUL 13 2012
A COLD FRONT/UPPER LOW WILL APPROACH UPPER MICHIGAN LATE THIS
AFTERNOON INTO THIS EVENING WHICH MAY TRIGGER WIDELY SCATTERED SHRA
AND TSRA ACROSS FAR WESTERN UPPER MI INCLUDING IWD AND PERHAPS CMX.
WITH LOSS OF DAYTIME HEATING/INSTABILITY...EXPECT GENERALLY QUIET
CONDITIONS MOST OF TONIGHT. INCREASING SHRA/TSRA CHANCES ARE
EXPECTED LATE TONIGHT THROUGH SATURDAY AS THE UPPER LOW MOVES
OVERHEAD. BASED ON WHAT IS OCCURRING UPSTREAM IN MINNESOTA...BEST
CHANCE OF TSRA WILL BE FM MID MORNING THROUGH THE AFTN HOURS ON
SATURDAY. ALL TAF SITES COULD EXPERIENCE SCT SHRA/TSRA. APPEARS
GREATEST CHANCE FOR TSRA WOULD BE LATE SATURDAY MORNING AT CMX AND
INTO SATURDAY AFTN AT SAW. STORMS COULD DROP HEAVY RAIN WHICH COULD
BRIEFLY RESULT IN IFR OR MVFR CONDITIONS IF A STORM DIRECTLY IMPACTS
ONE OF THE TAF SITES.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 456 AM EDT FRI JUL 13 2012
A RIDGE OF HIGH PRESSURE CURRENTLY OVER THE REGION WILL SLOWLY GIVE
WAY TO A WEAK TROUGH THAT WILL MOVE THROUGH OVER THE WEEKEND. OUT
AHEAD OF THE TROUGH...S TO SE WINDS MAY REACH 20 KTS IN GUSTS OVR
PORTIONS OF CNTRL AND EAST LAKE SUPERIOR TODAY INTO EARLY TONIGHT.
OTHERWISE...WINDS WILL BE LESS THAN 20 KTS THROUGH THE WEEKEND AND
INTO EARLY NEXT WEEK IN WAKE OF THE TROUGH.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...TITUS
LONG TERM...ROLFSON
AVIATION...JLA
MARINE...TITUS
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1209 PM EDT FRI JUL 13 2012
.UPDATE...
ISSUED AT 1206 PM EDT FRI JUL 13 2012
SKIES REMAIN FAIRLY CLEAR OVR MUCH OF THE AREA. MID CLOUDS TRIED TO
MAKE PUSH INTO WESTERN CWA A FEW HOURS AGO BUT FELL APART RAPIDLY.
WV LOOP AND RUC ANALYSIS INDICATES THAT THERE IS A DECENT AMOUNT OF
DRY AIR OVR MUCH OF NORTHEAST AND NORTHERN WISCONSIN AND INTO WESTERN
UPR MICHIGAN. 12Z GRB SOUNDING TURNED UP A K INDEX NEAR 30C BUT THE
WV LOOP INDICATES THIS IS ONLY A VERY SMALL AREA OF HIGHER MOISTURE
LIFTING TOWARD BAY OF GREEN BAY. DELAYED INCREASING CLOUD TREND IN
THE WEST. EVENTUALLY COULD SEE AT LEAST ISOLD SHRA/TSRA FORM IN THE
WEST AS WE PUSH PAST CONVECTIVE TEMPS IN THE MID 80S AND SOME WEAK
FORCING AND MOISTURE ADVECTION EDGES ACROSS THAT AREA OUT AHEAD OF
STRONGER DYNAMICS FM LARGER SCALE TROUGH FM NORTHWEST ONTARIO INTO
NORTHERN MINNESOTA.
SINCE H85 TEMPS HAVE ROSE ANOTHER 1-2C COMPARED TO YDY AND SKY COVER
SHOULD BE MINIMAL FOR MUCH OF THE AREA...HAVE BUMPED UP FCST HIGHS
THIS AFTN TO VALUES A COUPLE DEGREES HIGHER THAN THOSE OBSERVED YDY.
MAIN RESULT WILL BE MANY AREAS PUSHING TOWARD OR JUST PAST THE 90
DEGREE MARK. EVEN SO...SINCE DWPNTS WILL CONTNIUE TO MIX OUT WITH
THE DRIER AIR OVERHEAD WILL NOT BE AS HUMID AS IT COULD BE GIVEN THE
WARMTH. THE DRIER AIR AND A BIT OF A SOUTH WIND WILL OVERALL MAKE FOR A
COMFORTABLE 90 DEGREE DAY.
FINALLY...LOOKING AHEAD FOR TONIGHT AND SATURDAY...CURRENT POPS/WX
ARE GENERALLY ON TRACK. UPPER TROUGH AXIS IS FCST TO BE SQUARELY
OVERHEAD UPR MICHIGAN BY SATURDAY AFTN...SO EXPECT HIGHER COVERAGE
TO SHRA/TSRA BY THAT TIME AS HAS OCCURRED BENEATH THE UPR TROUGH
AXIS THE LAST COUPLE DAYS. H85-H3 WINDS ARE WEAK BENEATH THE TROUGH
AXIS AND GIVEN INCREASING PWATS TOWARD 150 PCT OF NORMAL...SEEMS LIKE
MAIN ISSUE ON SATURDAY WILL BE HEAVY DOWNPOURS. ALREADY SEEING THIS
AS KBDE IN FAR NORTHERN MN THIS MORNING /BENEATH THE TROUGH AXIS/
RECEIVED JUST UNDER 2 INCHES OF RAIN IN LESS THAN 2 HOURS WITH A SLOW
MOVING THUNDERSTORM. &&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 456 AM EDT FRI JUL 13 2012
SHORT TERM PATTERN WILL BE DOMINATED BY A 500MB TROUGH CURRENTLY
OVER SRN MANITOBA/ND/NW MN...THAT WILL LATER PHASE WITH AN UPPER LOW
/AND ASSOCIATED TROUGH/ CURRENTLY OVER NRN ALBERTA. AT THE
SFC...CURRENTLY THERE IS A TROUGH JUST E OF THE UPPER TROUGH AXIS
INTO FAR WRN MN...AND HIGH PRESSURE OVER THE ERN SEABOARD. THIS PUTS
IN THE CWA UNDER SW LOW LEVEL FLOW INITIALLY. SHOWERS FROM JUST W OF
LAKE SUPERIOR STRETCHING ALONG THE WI/MN BORDER HAVE BEEN INCREASING
IN COVERAGE EARLY TONIGHT...ALONG A RIBBON OF HIGHER MOISTURE IN THE
WAA REGIME AHEAD OF THE SFC TROUGH.
FOR TODAY...THE SRN UPPER TROUGH WILL PHASE WITH THE NRN UPPER LOW
BY 00Z SAT...DEEPENING THE SRN EXTENT OF THE TROUGH THE AXIS MOVES
TO JUST W OF LAKE SUPERIOR AND ALONG THE WI/MN BORDER...WITH THE SFC
TROUGH ALMOST DIRECTLY BENEATH THE UPPER TROUGH. TRICKY TO SAY WHEN
SHOWERS WILL GET INTO UPPER MI...AS THE RIBBON OF MOISTURE SLOWLY
MOVES E. THE NAM IS ONE OF THE FASTER AND MORE AGRESSIVE MODELS WITH
BRINGING THE MOISTURE INTO WRN UPPER MI THIS AFTERNOON...BUT OUTPUTS
LITTLE QPF AS VER LOW LEVEL WILL BE DRY. PRIOR TO AROUND 21Z
TODAY...IF ANY PRECIP MAKES IT TO THE GROUND IT SHOULD BE FAIRLY
LIGHT. THINK BEST CHANCES FOR WRN UPPER MI TO SEE PRECIP TODAY WILL
BE THIS EVENING WHILE WE STILL HAVE DECENT SFC HEATING AND A
SHORTWAVE INDICATED BY MODELS MOVES IN FROM THE S. 850MB TEMPS OF UP
TO 19C BY LATE IN THE DAY WILL SUPPORT HIGH TEMPS IN THE 80S TO
AROUND 90...WARMEST CENTRAL AND E AWAY FROM LAKE MI.
TONIGHT...THE SFC AND UPPER TROUGHS WILL MOVE INTO FAR WRN UPPER MI
BY 12Z SAT. PRECIP WILL AGAIN BE TRICKY AS MODELS HAVE A HARD TIME
TO DEALING WITH CONVECTIVE LEFTOVERS. ONE THING AGREED ON BY MODELS
IS THAT ERN UPPER MI WILL BE DRIER THAN WRN UPPER MI...SINCE DRY LOW
LEVEL AIR WILL LINGER OVER THE E THROUGH THE NIGHT. SEEMS THE BEST
CHANCES FOR PRECIP WILL BE OVER WRN UPPER MI AND ALONG THE WI
BORDER...WHERE I KEPT CHANCE AND SLIGHT CHANCE POPS...AND THE E
SHOULD BE DRY. OVERALL CONFIDENCE IN OVERNIGHT PRECIP IS LOW.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 456 AM EDT FRI JUL 13 2012
MEDIUM RANGE GUIDANCE IS IN OVERALL DECENT AGREEMENT ON THE BIG
PICTURE FOR NEXT WEEK AS IT PERTAINS TO UPPER MI. SLOW MOVING TROF
PASSING ACROSS THE WRN GREAT LAKES THIS WEEKEND WILL BE FOLLOWED BY
WEAK RIDGING EARLY NEXT WEEK AS WRN CONUS RIDGE EXPANDS EASTWARD.
SHORTWAVE CRUISING ACROSS THE NRN CONUS/SRN CANADA WILL THEN
TRANSLATE TO TROF AMPLIFICATION OVER SE CANADA/NE CONUS MIDWEEK.
THEREAFTER...RIDGE WILL BUILD/EXPAND ACROSS THE CONUS WITH CENTER OF
HOT RIDGE AGAIN SETTING UP OVER THE CNTRL STATES. END RESULT WILL BE
ABOVE NORMAL TEMPS THRU EARLY NEXT WEEK...2 MAYBE 3 DAYS OF MORE
PLEASANT SUMMER WEATHER MIDWEEK AS TROF AMPLIFIES TO THE E...AND
THEN A RETURN TO POTENTIALLY WELL ABOVE NORMAL TEMPS LATE WEEK/NEXT
WEEKEND AS HOT RIDGE EXPANDS OVER THE CNTRL CONUS. PATTERN DOES NOT
LOOK TO FAVOR WELL ORGANIZED PCPN EVENTS. BEST SHOTS FOR PCPN WILL BE
THIS WEEKEND WITH SLOW MOVING TROF AND POSSIBLY SOMETIME LATER
MON/TUE AS COLD FRONT PASSES. DRY DAYS ARE A GOOD BET MIDWEEK AS SFC
HIGH PRES SETTLES ACROSS THE UPPER LAKES...AND THEN RESURGENCE OF
HEAT TOWARD THE UPPER LAKES LATE NEXT WEEK WILL PROBABLY SUPPORT SOME
THREAT OF CONVECTION AT THAT TIME.
AS ALLUDED TO ABOVE...TROF CURRENTLY OVER THE ERN DAKOTAS/WRN MN
WILL SLOWLY MOVE ACROSS THE GREAT LAKES THIS WEEKEND. WITH TROF AXIS
REACHING UPPER MI SAT AND COINCIDING WITH DAYTIME HEATING...
SHRA/TSRA COVERAGE SHOULD BECOME NMRS. CNTRL UPPER MI MAY BE FAVORED
FOR BEST COVERAGE GIVEN MORE IDEAL TIMING OF TROF WITH RESPECT TO
DIURNAL CYCLE AND DUE TO SOME ASSISTANCE FROM LAKE BREEZES. DEEP
LAYER SHEAR IS GENERALLY UNDER 20KT...SO ORGANIZED SVR STORMS ARE
NOT EXPECTED. HOWEVER...IF THERE IS ENOUGH DAYTIME HEATING TO
SIGNIFICANTLY BOOST INSTABILITY...THERE MAY BE ISOLD PULSE TYPE SVR
STORMS SAT AFTN. RELATIVELY SLOW STORM MOVEMENT COULD LEAD TO SOME
LOCALLY HVY RAINFALL.
PCPN SHOULD GRADUALLY END FROM W TO E SAT NIGHT. SINCE MID LEVEL
TROF AXIS WILL BE E OF THE FCST AREA BY SUN MORNING...IT APPEARS SUN
WILL PROBABLY TURN OUT TO BE A DRY DAY. HOWEVER....RETAINED SLIGHT
CHC POPS ACROSS THE SCNTRL/SE AS LAKE BREEZE INTERACTION MIGHT STILL
YIELD ISOLD SHRA/TSRA. MIXING TO AROUND 800MB SUPPORTS MAX TEMPS
UPWARDS OF AROUND 90F AWAY FROM MODEST LAKE BREEZE COOLING.
SHORTWAVE WILL EJECT FROM TROF ALONG THE W COAST SUN NIGHT. IN
RESPONSE TO THE WAVE TRACKING TOWARD SCNTRL CANADA...LOW-LEVEL JET
WILL INCREASE ACROSS THE PLAINS. THIS SHOULD SUPPORT A CLUSTER OF
SHRA/TSRA ON NOSE OF LOW-LEVEL JET AND ALONG EDGE OF CAP ACROSS
ND/SRN SASKACHEWAN INTO NRN MN/SRN MANITOBA. AT THIS TIME... IT
APPEARS LOW-LEVEL JET WILL STILL BE W OF THE AREA BY 12Z MON...SO DO
NOT ANTICIPATE ANY CONVECTION LATE SUN NIGHT...EXCEPT POSSIBLY OVER
WRN LAKE SUPERIOR.
LOW-LEVEL JET SLIDES ACROSS THE AREA MON. THERE IS SOME UNCERTAINTY
ON WHERE THE EDGE OF THE CAP WILL RESIDE...BUT GENERAL CONSENSUS IS
THAT AT LEAST THE NRN/ERN PORTIONS OF THE FCST AREA WILL BE CLOSE
ENOUGH TO WARRANT A MENTION OF SHRA/TSRA. WITH AREA ON THE CAPE
GRADIENT AND UNDER 35-45KT OF DEEP LAYER SHEAR...ORGANIZED SVR
STORMS WILL BE POSSIBLE IF THERE IS CONVECTION. IF THERE IS NO PCPN
AND NOT MUCH CLOUD COVER...TEMPS UNDER WAA SHOULD EASILY RISE INTO
THE LWR 90S IN MOST AREAS AWAY FROM LOCAL COOLING NEAR THE GREAT
LAKES...MAINLY LAKE MI UNDER S TO SW BOUNDARY LAYER FLOW.
COLD FRONT SLIDES ACROSS THE AREA MON NIGHT/TUE MORNING...PROVIDING
A CHC OF SHRA/TSRA. WILL HANG ONTO CHC POPS THRU TUE AFTN GIVEN SOME
UNCERTAINTY IN FRONTAL TIMING. OTHERWISE...COOLER/DRIER MORE
COMFORTABLE AIR MASS WILL BEGIN SPREADING INTO THE AREA TUE. A MORE
PLEASANT SUMMER DAY SHAPING UP FOR WED AS SFC HIGH PRES SETTLES OVER
THE UPPER LAKES. HIGHS SHOULD BE IN THE LWR 70S ALONG LAKE SUPERIOR
TO UPPER 70S/AROUND 80 INLAND WITH DWPTS FALLING THRU THE 50S. IT
SHOULD REMAIN COMFORTABLE THU (DWPTS IN THE 50S)...THOUGH IT WILL
BEGIN TO WARM UP JUST A LITTLE AS RETURN FLOW DEVELOPS ON BACKSIDE
OF DEPARTING HIGH PRES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 729 AM EDT FRI JUL 13 2012
VFR CONDITIONS ARE GENERALLY EXPECTED ACROSS ALL SITES FOR THE NEXT
24 HOURS. A COLD FRONT/UPPER DISTURBANCE WILL APPROACH UPPER
MICHIGAN LATE THIS AFTERNOON INTO THIS EVENING WHICH MAY TRIGGER
WIDELY SCATTERED SHOWERS AND THUNDERSTORMS THIS AFTERNOON ACROSS FAR
WESTERN UPPER MI INCLUDING IWD. THIS COULD ALLOW FOR BRIEF IFR
CONDITIONS AT IWD AFT 22Z TODAY...BUT THERE IS NOT ENOUGH CONFIDENCE
TO INCLUDE IN THE TERMINAL AT THIS TIME. CONFIDENCE ON PRECIP IS
LOW...ESPECIALLY AT SAW AND CMX WHICH WILL BE MORE ON THE FRINGES OF
WHERE THE BEST PRECIP CHANCES ARE. FOR CMX AND SAW...JUST PUT VCSH
IN THE FORECAST AT THIS TIME GIVEN THE UNCERTAINTY. OTHERWISE...S-SW
WINDS WILL GUST TO AROUND 20 KT AHEAD OF THE COLD FRONT ON FRIDAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 456 AM EDT FRI JUL 13 2012
A RIDGE OF HIGH PRESSURE CURRENTLY OVER THE REGION WILL SLOWLY GIVE
WAY TO A WEAK TROUGH THAT WILL MOVE THROUGH OVER THE WEEKEND. OUT
AHEAD OF THE TROUGH...S TO SE WINDS MAY REACH 20 KTS IN GUSTS OVR
PORTIONS OF CNTRL AND EAST LAKE SUPERIOR TODAY INTO EARLY TONIGHT.
OTHERWISE...WINDS WILL BE LESS THAN 20 KTS THROUGH THE WEEKEND AND
INTO EARLY NEXT WEEK IN WAKE OF THE TROUGH.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...TITUS
LONG TERM...ROLFSON
AVIATION...TITUS
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1200 PM EDT FRI JUL 13 2012
.SYNOPSIS...
ISSUED AT 337 AM EDT FRI JUL 13 2012
IT WILL REMAIN SUMMERY TODAY AND THROUGH THE WEEKEND WITH DAYTIME
TEMPERATURES REACHING AROUND 90 EACH DAY. WE WILL HAVE SCATTERED
CHANCES FOR SHOWERS AND THUNDERSTORMS AS A WEAK FRONT AND UPPER
LEVEL DISTURBANCE MOVES INTO THE REGION. ALTHOUGH THE PRECIPITATION
IS EXPECTED TO REMAIN SCATTERED...THE BEST CHANCE FOR RAIN WILL COME
SATURDAY INTO EARLY SATURDAY NIGHT. WE WILL SEE LITTLE CHANGE IN
TEMPERATURES INTO NEXT WEEK...WITH ANOTHER CHANCE OF SCATTERED
STORMS TUESDAY NIGHT.
&&
.UPDATE...
ISSUED AT 1159 AM EDT FRI JUL 13 2012
HAVE UPDATED TO EXPAND A SMALL CHANCE (20 POP/ISOLATED WORDING)
ACROSS THE ENTIRE FORECAST AREA. COVERAGE IS OBVIOUSLY EXPECTED TO
BE LOW...BUT THE 4KM NSSL WRF...4KM SPC WRF AND THE LATEST HRRR
ARE ALL INDICATING ISOLATED DEVELOPMENT CWA WIDE THIS AFTERNOON.
A WEAK LAKE BREEZE MAY END UP BEING A FOCUS. IN ADDITION...WATER
VAPOR IMAGERY SEEMS TO INDICATE A WEAK SHORTWAVE MOVING THROUGH
THE CWA AT THIS TIME NOTED BY A LITTLE BETTER MOISTURE IN AN
OVERALL MINIMUM ACROSS THE SOUTHERN GREAT LAKES.
MODIFYING AREA MORNING SOUNDINGS INDICATE THAT WE SHOULD BE ABLE
TO REALIZE CAPE VALUES AROUND 1000 J/KG AND LI/S AROUND -3 TO -4C.
THESE VALUES ARE WITH TEMPS AROUND 90 AND DEW POINTS IN THE UPPER
50S. THE THINKING IS WE WILL LIKELY MIX DOWN SLIGHTLY DRIER AIR.
IF WE HANG ON TO THE LOW TO MID 60S DEW POINTS...THE INSTABILITY
WILL OBVIOUSLY BE HIGHER. NOT EXPECTING ANYTHING SEVERE AS VERY
LITTLE SHEAR EXISTS. THE NAM FOR INSTANCE HAS WINDS LESS THAN 15
KNOTS ALL THE WAY THROUGH ABOUT 18000FT. SO...PULSE STORMS ARE
EXPECTED FIRING OFF LAKE BREEZE CONVERGENCE AND OUTFLOW
BOUNDARIES. GIVEN THE WEAK SHEAR THE LIFE CYCLE OF STORMS TODAY WILL
BE FAIRLY SHORT. LOCALLY HEAVY RAIN AND LIGHTNING WOULD BE THE MAIN
THREATS.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 337 AM EDT FRI JUL 13 2012
OVERALL THINKING HAS NOT CHANGED MUCH THROUGH THE SHORT TERM...
ALTHOUGH SOME TWEAKS WERE MADE FOR SATURDAY NIGHT AND SUNDAY AS
THE TIMING OF THE UPPER WAVE HAS CHANGED SOMEWHAT.
MAIN NORTHERN STREAM SHORT WAVE WAS OVER THE DAKOTAS MOVING INTO
WESTERN MN THIS MORNING. HOWEVER TROUGHING EXTENDED AS FAR EAST AS
CHICAGO WHICH RESEMBLES A WARM FRONT ALOFT. THIS FEATURE MOVES NE
FROM CHI TOWARD CENTRAL LOWER THROUGH THE DAY. THERE WAS AN
EXPANDING AREA OF CLOUDS WITH THIS FEATURE AND ALSO A FEW SPOTTY
RADAR RETURNS. SOUNDINGS ARE QUITE DRY IN THE LOW LEVELS...SO
ANYTHING THAT TRIES TO GENERATE WILL BE HIGH BASED AND SHOULD ONLY
PRODUCE THE CHANCE OF A BRIEF SHOWER. CAN NOT RULE OUT A LIGHTNING
STRIKE TOO. SEEMS LIKE THIS WILL HEAD ACROSS THE NORTHERN CWA
WHERE 20 POPS WILL BE CARRIED TODAY.
SLIGHTLY BETTER CHANCES FOR RAIN SHOULD MOVE INTO THE AREA LATE
TONIGHT...PEAKING SATURDAY INTO SATURDAY EVENING AS THE MAIN SHORT
WAVE MAKES IT EAST INTO THE GREAT LAKES. STILL NOT OVERLY
IMPRESSED BY THE LACK OF JET DYNAMICS AND THE SYSTEM IS NOT
LOADED WITH MOISTURE EITHER. FEEL OUR 40 POPS COVER IT WELL FOR
SATURDAY. HOWEVER WILL INCREASE THE FORECAST TO 40 POPS INTO
SATURDAY EVENING AS THE SHORT WAVE SHOULD CROSS THE CWA IN THIS
TIME FRAME. SEVERE POTENTIAL LOOKS VERY LOW GIVEN THE WEAK WIND
FIELDS.
MUCH OF THE ACTION APPEARS TO BE EAST OF THE AREA INTO
SUNDAY...ALTHOUGH THE SE CWA MAY STILL SEE LINGERING
SHOWERS/STORMS. THEREFORE...REMOVED POPS OVER THE NW AND LOWERED
POPS OVER THE CENTRAL CWA AS THE UPPER SUPPORT MOVES SOUTH AND
EAST. ALSO BUMPED UP MAX TEMPS SEVERAL DEGREES WITH MORE SUNSHINE
EXPECTED.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 337 AM EDT FRI JUL 13 2012
GIVEN THE PREVAILING AND TO SOME EXTENT EXPANDING DROUGHT OVER
SOUTHWEST LOWER MICHIGAN... THE MAIN ISSUE IS CAN WE GET A
SIGNIFICANT RAINFALL EVENT DURING THIS TIME? THE OTHER ISSUE IS THE
TEMPERATURE...JUST HOW HOT DOES IT GET THIS COMING WEEK?
THROUGH THURSDAY MORNING THE MODELS ARE LARGELY IN AGREEMENT AT THE
JET STREAM LEVEL AS TO WHAT WILL HAPPEN. A SYSTEM NOW IN THE GULF OF
ALASKA RACES ACROSS SOUTHERN CANADA AND PHASES WITH THE CLOSED UPPER
LOW CURRENTLY OVER NW CANADA BUT BY THEN EAST OF HUDSON BAY. THIS
CREATES AN UPPER LEVEL JET ASSIST FOR THE GULF OF ALASKA SYSTEM AS
IT PHASES WITH THE CLOSED UPPER LOW. THAT IN TURN HELPS PUSH THE
COLD FRONT SOUTH INTO THE SOUTHERN GREAT LAKES TUESDAY NIGHT INTO
WEDNESDAY. IT IS AT THIS TIME WE STAND OUR BEST CHANCE OF SEEING
SHOWERS AND THUNDERSTORMS ACROSS THE CWA. BEYOND THAT SOME ISSUES
DEVELOP WITH THE NEXT PACIFIC SYSTEM LATE IN THE WEEK WHERE THE
ECMWF IS STRONGER WITH THE SYSTEM THAT COMES ON SHORE IN THE PACIFIC
NORTHWEST WHICH LEADS TO A LARGER UP-STREAM SUBTROPICAL HIGH.
AS FOR OUR CONVECTION WITH THE COLD FRONT TUESDAY NIGHT... THAT BY
ITSELF IS AN ISSUE. THE FRONT IS COMING THROUGH EARLY WEDNESDAY
MORNING. NOT THE BEST TIME FOR CONVECTION IN THE FIRST PLACE. ON THE
UP SIDE THE PRECIPITABLE WATER WILL BE OVER 2 INCHES (NEARLY DOUBLE
NORMAL). ALSO THERE IS A TAIL OF UPPER LEVEL JET CORE CROSSING
CENTRAL LOWER MICHIGAN TUESDAY NIGHT INTO WEDNESDAY MORNING THAT
PUTS SOUTHWEST MICHIGAN IN THE RIGHT ENTRANCE REGION OF THE JET CORE
(THAT WILL HELP WITH THE LIFT FOR CONVECTION). THERE IS CONVERGENCE
ON THE SURFACE FRONT... ANOTHER GOOD THING. THE MOST UNSTABLE CAP IS
BETWEEN 2000 AND 3000 J/KG EVEN AT NIGHT SO THAT IS A POSITIVE TOO.
THE DEEP LAYER SHEAR IS NEAR 30 KNOTS DUE TO JET CORE MOVING
THROUGH. SO IT WOULD SEEM WE DO HAVE A SHOT AT SOME CONVECTION WITH
THE FRONT SO I HAVE BETWEEN 30 AND 40 PCT FOR NOW AND CALLED THAT
GOOD.
THE OVER RIDING STORY FOR THIS WEEK THROUGH IS THE POLAR JET STREAM
STAYS WELL NORTH OF 55 NORTH THROUGH THIS COMING WEEK (BASED ON THE
PV15 WIND MAX). THAT MEANS WHATEVER COLD PUSH WE GET WILL BE FEEBLE
AT BEST AND SHORT LIVED. OVERALL OUR HOT WEATHER WILL LIKELY
CONTINUE THROUGH THE WEEK WITH ONLY A MINOR COOL OFF (NOT EVEN TO
NORMAL) WED/THU. GIVEN THE GFS MAX TEMP FOR THE 84 HOUR THROUGH 240
HOUR (8TH THROUGH THE 11TH) AS A MEAN AVERAGE ERROR OF OVER 8
DEGREES ON THE HIGH TEMPERATURE AND BIAS IS ABOUT THE SAME... WHILE
THE ECMWF FOR THE TIME HAS A MEAN AVERAGE ERROR OF ONLY 4 DEGREES...
I PUSHED THE HIGHS UP TO BE CLOSER TO THE ECMWF VALUES THROUGH THE
WEEK. NOTE: CURIOUSLY THE ERROR FOR THE LOW TEMPS FAVORS THE GFS SO
I DID NOT DO MUCH WITH THE LOWS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 650 AM EDT FRI JUL 13 2012
VFR CIGS/VSBY ARE EXPECTED THROUGH SATURDAY MORNING. THERE COULD
BE A FEW THUNDERSTORMS AROUND MID AFTERNOON INTO THE EARLY EVENING
SO I CONTINUED THE VCTS IN ALL THE INLAND TAF SITES TODAY. ANY
STORM WILL BE SHORT LIVED BUT THERE COULD BE A BRIEF LOWERING OF
THE VISIBILITY IN THE HEAVER SHOWERS. CLOUD BASES SHOULD STILL BE
IN THE 6000 TO 7000 FT RANGE THIS MORNING AND MORE LIKE 8000 TO
9000 FT AGL THIS AFTERNOON (BASED ON 06Z NAM12 AND 09Z RAP SOUNDINGS).
&&
.MARINE...
ISSUED AT 337 AM EDT FRI JUL 13 2012
A LIGHT SOUTHERLY FLOW WILL CONTINUE THROUGH SATURDAY...THEN
VEER TO THE WEST LATE SATURDAY NIGHT WITH THE FRONT COMING
THROUGH. WAVE ACTION SHOULD REMAIN LOW.
&&
.HYDROLOGY...
ISSUED AT 337 AM EDT FRI JUL 13 2012
PCPN LATE TONIGHT INTO EARLY SUNDAY STILL LOOKS RATHER LIGHT...NOT
THE DROUGHT BUSTER THAT WE NEED. CAN NOT RULE OUT LOCALIZED HEAVY
RAINS...BUT MOST RIVER BASIN AVERAGES WILL BE UNDER A QUARTER
INCH...HAVING VERY LITTLE HYDRO IMPACT.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...DUKE
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...JK
MARINE...JK
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
651 AM EDT FRI JUL 13 2012
.SYNOPSIS...
ISSUED AT 337 AM EDT FRI JUL 13 2012
IT WILL REMAIN SUMMERY TODAY AND THROUGH THE WEEKEND WITH DAYTIME
TEMPERATURES REACHING AROUND 90 EACH DAY. WE WILL HAVE SCATTERED
CHANCES FOR SHOWERS AND THUNDERSTORMS AS A WEAK FRONT AND UPPER
LEVEL DISTURBANCE MOVES INTO THE REGION. ALTHOUGH THE PRECIPITATION
IS EXPECTED TO REMAIN SCATTERED...THE BEST CHANCE FOR RAIN WILL COME
SATURDAY INTO EARLY SATURDAY NIGHT. WE WILL SEE LITTLE CHANGE IN
TEMPERATURES INTO NEXT WEEK...WITH ANOTHER CHANCE OF SCATTERED
STORMS TUESDAY NIGHT.
&&
.UPDATE...
ISSUED AT 650 AM EDT FRI JUL 13 2012
BASED ON THE NSSL WAF (13TH 00Z) AND LOOKING AT SOUNDING FROM THE
09Z RAP AND 06Z NAM12 THE DEPTH OF THE MOISTURE IN THE SOUNDINGS
INCREASE FROM 800 TO 600 MB AT 15Z TO 75O MB TO 550 MB BY 21Z.
THIS SHOULD ALLOW SOME PARCELS TO GET A LITTLE MORE DEPTH BEFORE
THE RUN IN THE VERY DRY AIR ABOVE 550 MB. WITH THE AID UPSTREAM
SHORTWAVE SEEN NICELY ON OUR WATER VAPOR LOOPS...IN COMBINATION
WITH THE LAKE BREEZE CONVERGENCE THERE SHOULD BE ENOUGH LOCALIZED
LIFT TO ALLOW A FEW SHOWERS AND ISOLATED THUNDERSTORMS TO GET
GOING. I EXPANDED THE AREA OF POTENTIAL SHOWERS TO COVER MORE OF
THE CWA. EVEN SO THE CHANCE OF ANY ONE LOCATION GETTING THE
SHOWERS WILL BE LIMITED AT BEST.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 337 AM EDT FRI JUL 13 2012
OVERALL THINKING HAS NOT CHANGED MUCH THROUGH THE SHORT TERM...
ALTHOUGH SOME TWEAKS WERE MADE FOR SATURDAY NIGHT AND SUNDAY AS
THE TIMING OF THE UPPER WAVE HAS CHANGED SOMEWHAT.
MAIN NORTHERN STREAM SHORT WAVE WAS OVER THE DAKOTAS MOVING INTO
WESTERN MN THIS MORNING. HOWEVER TROUGHING EXTENDED AS FAR EAST AS
CHICAGO WHICH RESEMBLES A WARM FRONT ALOFT. THIS FEATURE MOVES NE
FROM CHI TOWARD CENTRAL LOWER THROUGH THE DAY. THERE WAS AN
EXPANDING AREA OF CLOUDS WITH THIS FEATURE AND ALSO A FEW SPOTTY
RADAR RETURNS. SOUNDINGS ARE QUITE DRY IN THE LOW LEVELS...SO
ANYTHING THAT TRIES TO GENERATE WILL BE HIGH BASED AND SHOULD ONLY
PRODUCE THE CHANCE OF A BRIEF SHOWER. CAN NOT RULE OUT A LIGHTNING
STRIKE TOO. SEEMS LIKE THIS WILL HEAD ACROSS THE NORTHERN CWA
WHERE 20 POPS WILL BE CARRIED TODAY.
SLIGHTLY BETTER CHANCES FOR RAIN SHOULD MOVE INTO THE AREA LATE
TONIGHT...PEAKING SATURDAY INTO SATURDAY EVENING AS THE MAIN SHORT
WAVE MAKES IT EAST INTO THE GREAT LAKES. STILL NOT OVERLY
IMPRESSED BY THE LACK OF JET DYNAMICS AND THE SYSTEM IS NOT
LOADED WITH MOISTURE EITHER. FEEL OUR 40 POPS COVER IT WELL FOR
SATURDAY. HOWEVER WILL INCREASE THE FORECAST TO 40 POPS INTO
SATURDAY EVENING AS THE SHORT WAVE SHOULD CROSS THE CWA IN THIS
TIME FRAME. SEVERE POTENTIAL LOOKS VERY LOW GIVEN THE WEAK WIND
FIELDS.
MUCH OF THE ACTION APPEARS TO BE EAST OF THE AREA INTO
SUNDAY...ALTHOUGH THE SE CWA MAY STILL SEE LINGERING
SHOWERS/STORMS. THEREFORE...REMOVED POPS OVER THE NW AND LOWERED
POPS OVER THE CENTRAL CWA AS THE UPPER SUPPORT MOVES SOUTH AND
EAST. ALSO BUMPED UP MAX TEMPS SEVERAL DEGREES WITH MORE SUNSHINE
EXPECTED.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 337 AM EDT FRI JUL 13 2012
GIVEN THE PREVAILING AND TO SOME EXTENT EXPANDING DROUGHT OVER
SOUTHWEST LOWER MICHIGAN... THE MAIN ISSUE IS CAN WE GET A
SIGNIFICANT RAINFALL EVENT DURING THIS TIME? THE OTHER ISSUE IS THE
TEMPERATURE...JUST HOW HOT DOES IT GET THIS COMING WEEK?
THROUGH THURSDAY MORNING THE MODELS ARE LARGELY IN AGREEMENT AT THE
JET STREAM LEVEL AS TO WHAT WILL HAPPEN. A SYSTEM NOW IN THE GULF OF
ALASKA RACES ACROSS SOUTHERN CANADA AND PHASES WITH THE CLOSED UPPER
LOW CURRENTLY OVER NW CANADA BUT BY THEN EAST OF HUDSON BAY. THIS
CREATES AN UPPER LEVEL JET ASSIST FOR THE GULF OF ALASKA SYSTEM AS
IT PHASES WITH THE CLOSED UPPER LOW. THAT IN TURN HELPS PUSH THE
COLD FRONT SOUTH INTO THE SOUTHERN GREAT LAKES TUESDAY NIGHT INTO
WEDNESDAY. IT IS AT THIS TIME WE STAND OUR BEST CHANCE OF SEEING
SHOWERS AND THUNDERSTORMS ACROSS THE CWA. BEYOND THAT SOME ISSUES
DEVELOP WITH THE NEXT PACIFIC SYSTEM LATE IN THE WEEK WHERE THE
ECMWF IS STRONGER WITH THE SYSTEM THAT COMES ON SHORE IN THE PACIFIC
NORTHWEST WHICH LEADS TO A LARGER UP-STREAM SUBTROPICAL HIGH.
AS FOR OUR CONVECTION WITH THE COLD FRONT TUESDAY NIGHT... THAT BY
ITSELF IS AN ISSUE. THE FRONT IS COMING THROUGH EARLY WEDNESDAY
MORNING. NOT THE BEST TIME FOR CONVECTION IN THE FIRST PLACE. ON THE
UP SIDE THE PRECIPITABLE WATER WILL BE OVER 2 INCHES (NEARLY DOUBLE
NORMAL). ALSO THERE IS A TAIL OF UPPER LEVEL JET CORE CROSSING
CENTRAL LOWER MICHIGAN TUESDAY NIGHT INTO WEDNESDAY MORNING THAT
PUTS SOUTHWEST MICHIGAN IN THE RIGHT ENTRANCE REGION OF THE JET CORE
(THAT WILL HELP WITH THE LIFT FOR CONVECTION). THERE IS CONVERGENCE
ON THE SURFACE FRONT... ANOTHER GOOD THING. THE MOST UNSTABLE CAP IS
BETWEEN 2000 AND 3000 J/KG EVEN AT NIGHT SO THAT IS A POSITIVE TOO.
THE DEEP LAYER SHEAR IS NEAR 30 KNOTS DUE TO JET CORE MOVING
THROUGH. SO IT WOULD SEEM WE DO HAVE A SHOT AT SOME CONVECTION WITH
THE FRONT SO I HAVE BETWEEN 30 AND 40 PCT FOR NOW AND CALLED THAT
GOOD.
THE OVER RIDING STORY FOR THIS WEEK THROUGH IS THE POLAR JET STREAM
STAYS WELL NORTH OF 55 NORTH THROUGH THIS COMING WEEK (BASED ON THE
PV15 WIND MAX). THAT MEANS WHATEVER COLD PUSH WE GET WILL BE FEEBLE
AT BEST AND SHORT LIVED. OVERALL OUR HOT WEATHER WILL LIKELY
CONTINUE THROUGH THE WEEK WITH ONLY A MINOR COOL OFF (NOT EVEN TO
NORMAL) WED/THU. GIVEN THE GFS MAX TEMP FOR THE 84 HOUR THROUGH 240
HOUR (8TH THROUGH THE 11TH) AS A MEAN AVERAGE ERROR OF OVER 8
DEGREES ON THE HIGH TEMPERATURE AND BIAS IS ABOUT THE SAME... WHILE
THE ECMWF FOR THE TIME HAS A MEAN AVERAGE ERROR OF ONLY 4 DEGREES...
I PUSHED THE HIGHS UP TO BE CLOSER TO THE ECMWF VALUES THROUGH THE
WEEK. NOTE: CURIOUSLY THE ERROR FOR THE LOW TEMPS FAVORS THE GFS SO
I DID NOT DO MUCH WITH THE LOWS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 650 AM EDT FRI JUL 13 2012
VFR CIGS/VSBY ARE EXPECTED THROUGH SATURDAY MORNING. THERE COULD
BE A FEW THUNDERSTORMS AROUND MID AFTERNOON INTO THE EARLY EVENING
SO I CONTINUED THE VCTS IN ALL THE INLAND TAF SITES TODAY. ANY
STORM WILL BE SHORT LIVED BUT THERE COULD BE A BRIEF LOWERING OF
THE VISIBILITY IN THE HEAVER SHOWERS. CLOUD BASES SHOULD STILL BE
IN THE 6000 TO 7000 FT RANGE THIS MORNING AND MORE LIKE 8000 TO
9000 FT AGL THIS AFTERNOON (BASED ON 06Z NAM12 AND 09Z RAP SOUNDINGS).
&&
.MARINE...
ISSUED AT 337 AM EDT FRI JUL 13 2012
A LIGHT SOUTHERLY FLOW WILL CONTINUE THROUGH SATURDAY...THEN
VEER TO THE WEST LATE SATURDAY NIGHT WITH THE FRONT COMING
THROUGH. WAVE ACTION SHOULD REMAIN LOW.
&&
.HYDROLOGY...
ISSUED AT 337 AM EDT FRI JUL 13 2012
PCPN LATE TONIGHT INTO EARLY SUNDAY STILL LOOKS RATHER LIGHT...NOT
THE DROUGHT BUSTER THAT WE NEED. CAN NOT RULE OUT LOCALIZED HEAVY
RAINS...BUT MOST RIVER BASIN AVERAGES WILL BE UNDER A QUARTER
INCH...HAVING VERY LITTLE HYDRO IMPACT.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...JK
MARINE...JK
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1236 PM CDT FRI JUL 13 2012
.AVIATION... /18Z TAF ISSUANCE/
TWO CONCERNS THIS TAF CYCLE. THE FIRST IS SHRA/TSRA CHANCES THIS
AFTERNOON AND EVENING WHILE THE OTHER IS MVFR OR LOWER
CEILINGS/VISIBILITIES IN FOG LATE TONIGHT. EARLY THIS AFTERNOON
SHOWERS WERE BEGINNING TO INCREASE IN COVERAGE BETWEEN KAXN AND
KSTC. THIS IS ALONG THE SURFACE FRONT AND UPPER LOW/TROF ALOFT.
SHORT TERM GUIDANCE IS IN PRETTY GOOD AGREEMENT THAT ACTIVITY
SHOULD CONTINUE TO INCREASE IN COVERAGE THIS AFTERNOON AND SPREAD
SOUTHEAST. KMSP...KRNH AND KEAU SEEM TO HAVE THE BEST CHANCE FOR
SHRA/TSRA BUT CONFIDENCE IS LOW ON COVERAGE AT ANY ONE SITE.
THEREFORE...CONTINUED VCSH/VCTS. THE WESTERN TERMINALS MAY SEE A
BRIEF SHOWER AS WELL WITH VCSH INDICATED AT KAXN AND KRWF. SCT-
BKN040-050 WILL BE COMMON THIS AFTERNOON WITH A MID LEVEL CEILING
ABOVE. WINDS THIS AFTERNOON WILL BE SOUTH AT NEAR 10 KNOTS FROM
KMSP ON EAST WITH SOUTHWEST TO WEST WINDS LESS THAN 10 KNOTS TO
THE WEST.
THE FRONTAL BOUNDARY ACROSS WESTERN MN WILL WASH OUT TONIGHT
ACROSS WESTERN WI AND SOUTHERN MN. LOW LEVEL MOISTURE COMBINED
WITH LIGHT WINDS AND THE POTENTIAL FOR ADDED GROUND MOISTURE FROM
AFTERNOON/EVENING SHOWERS SHOULD LEAD TO MVFR OR LOWER CONDITIONS
AT KRNH AND KEAU DURING THE LATE NIGHT HOURS. CONFIDENCE IS PRETTY
HIGH AND INDICATED MVFR OR LESS AFTER 08Z. IT/S QUITE CONCEIVABLE
THAT THE FOG COULD DEVELOP AS EARLY AS 04Z-06Z...DEPENDING ON HOW
MUCH RAIN OCCURS IN THE EVENING ALONG WITH THE CLEARING TREND.
KMSP...SHOWERS POSSIBLE AFTER 20Z WITH THUNDER CHANCES INCREASING
AFTER 22Z AND LASTING INTO THE EARLY EVENING. SMALL THREAT FOR
5-6SM IN FOG/HAZE TOWARD DAYBREAK SATURDAY WITH LIGHT WINDS.
/OUTLOOK/
SATURDAY AFTERNOON/NIGHT...VFR. WINDS NORTHERLY AT 5 TO 10 KTS.
SUNDAY...VFR. WINDS SE AT 5-15 KTS.
MONDAY...VFR. WINDS S-SW 10-20 KTS.
&&
.DISCUSSION... /ISSUED 325 AM CDT FRI JUL 13 2012/
THE UPCOMING SEVEN DAYS LOOKS TO BE RELATIVELY QUIET FROM A PCPN
PERSPECTIVE... WITH THE BEST CHANCES BEING OVER THE NEXT 24
HOURS... BUT IT STARTING TO LOOK MORE INTERESTING WITH RESPECT TO
A FEW CHANCES FOR EXCESSIVE HEAT. IN THE BIG PICTURE... THE LATEST
WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSIS SHOW A FAIRLY
HEALTHY SHORTWAVE MOVING THROUGH THE REGION AT THE CURRENT TIME...
WITH TWO MAIN PV ANOMALIES AND AREAS OF ENHANCED FORCING. ONE CAN
BE SEEN DROPPING SOUTHEAST THROUGH SOUTHEAST SOUTH DAKOTA AT THE
CURRENT TIME... AND IS HELPING TO ENHANCE THE PCPN OUT AHEAD OF IT
OVER THE SOUTHERN PART OF MINNESOTA. THE SECOND ANOMALY IS OVER
NORTHEAST NORTH DAKOTA... AND IS SLOWLY SLIDING EAST WITH TIME...
AND HELPING TO KEEP SOME PCPN GOING IN THAT AREA. ZOOMING OUT...
AN AMPLIFIED RIDGE REMAINS OVER THE WESTERN CONUS... WITH AN UPPER
TROUGH OVER THE PACIFIC NORTHWEST. THE GENERAL THEME OVER THE NEXT
24 TO 36 HOURS WILL BE FOR THE SHORTWAVE CURRENTLY TO OUR WEST TO
DROP SLOWLY SOUTHEAST AND HELP PUSH THE SURFACE TROUGH/FRONT
THROUGH THE AREA TODAY THROUGH SATURDAY... BRINGING CHANCES FOR
SHRA/TSRA TO THE AREA. AFTER THAT WE WILL SEE THE RIDGE OVER THE
ROCKIES BUILD INTO THE AREA... AND BRING INCREASINGLY WARM
TEMPERATURES INTO THE AREA THROUGH MONDAY. WE SHOULD THEN SEE SOME
BRIEF DEPRESSION IN THE UPPER HEIGHTS OVER THE AREA... BUT BY THE
MIDDLE OF THE WEEK THE UPPER RIDGE LOOKS TO RE-AMPLIFY OVER THE
CENTER OF THE COUNTRY. BY THE END OF THE WEEK THERE IS A FAIR
AMOUNT OF DISAGREEMENT BETWEEN THE GFS AND ECMWF... WITH THE GFS
DROPPING AND UPPER TROUGH INTO EASTERN CANADA AND DEVELOPING
NORTHWEST FLOW OVER US... WHILE THE ECMWF CONTINUES TO BUILD THE
UPPER RIDGE AND WOULD REALLY HAVE US COOKING BY THE END OF THE
WEEK. THE ECMWF HAS BEEN FAIRLY CONSISTENT WITH THE IDEA THE PAST
FEW RUNS... SO IT WILL CERTAINLY BE SOMETHING TO MONITOR. AT THIS
POINT... A VERY WARM MONDAY LOOKS TO BE A GOOD BET... WITH ANOTHER
PERHAPS WARMER SPAN OF WEATHER DEVELOPING BY THE END OF THE WEEK
THROUGH THE FOLLOWING WEEKEND.
FOR TODAY... WE SHOULD CONTINUE TO SEE SOME SCATTERED SHRA/TSRA
MIGRATE SLOWLY EAST THROUGH THE DAY AS THE SURFACE TROUGH PUSHES
EAST AHEAD OF UPPER WAVE. THE LOW LEVEL CONVERGENCE/UPPER LEVEL
DIVERGENCE COUPLET LOOKS TO PUSH EAST OF THE I-35 CORRIDOR BY THIS
AFTERNOON... SO THE BEST CHANCE FOR MORE WIDESPREAD PCPN WILL BE
OVER THE EASTERN PART OF THE CWFA... ALONG WITH THE MAIN POTENTIAL
FOR ANY SEVERE STORMS. HOWEVER... WITH THE UPPER TROUGH MOVING SO
SLOWLY TODAY AND TONIGHT... WE COULD CERTAINLY SEE SOME LINGERING
SHRA BEHIND THE SURFACE BOUNDARY BENEATH THE UPPER PV ANOMALY AND
ASSOCIATED MID-LEVEL COLD POOL. IN TERMS OF SEVERE WEATHER
POTENTIAL... THINGS STILL LOOK LIKE THE HAVE THE PAST SEVERAL
DAYS... WITH DECENT MLCAPE VALUES AOA 1500 J/KG TODAY INTO THIS
EVENING... BUT MEAGER DEEP LAYER AND LOW LEVEL SHEAR. SO... STILL
LOOKS LIKE WE/LL MAINLY BE DEALING WITH MULTI-CELL PULSE STORMS...
WITH THE PRIMARY THREAT BEING MARGINALLY SEVERE HAIL AND PERHAPS
SOME DOWNBURST WIND GUSTS GIVEN EXPECTED SURFACE DELTA THETA-E
VALUES AOA 25K. SOME PCPN COULD LINGER OVER THE EASTERN PART OF
THE AREA FOR A GOOD PART OF SATURDAY GIVEN THE SLOW EASTWARD
MIGRATION OF THE UPPER WAVE. HOWEVER... BY SATURDAY NIGHT WE
SHOULD SEE UPPER RIDGING WORK BACK ACROSS THE AREA... WITH A
SURFACE RIDGE NOSING DOWN FROM CENTRAL CANADA AS WELL. FAIRLY
ROBUST RETURN FLOW LOOKS TO SETUP SUNDAY AFTERNOON... PUSHING THE
WARM FRONT WELL NORTH THROUGH THE AREA BY EVENING. WE WILL THEN
SEE LOW PRESSURE ORGANIZE OVER THE HIGH PLAINS SUNDAY NIGHT INTO
MONDAY... WITH THE WARM SECTOR BECOME WELL ESTABLISHED OVER OUR
AREA. CHANCES FOR PCPN ON MONDAY AS THIS LOW PUSHES EAST LOOK LIKE
THEY WILL BE CONFINED TO THE NORTH OF OUR AREA CLOSER TO THE WARM
FRONTAL BOUNDARY AS 700MB TEMPERATURES AOA 12C ENCOMPASS ALL OF
CENTRAL AND SOUTHERN MINNESOTA. THE COLD FRONT WILL EVENTUALLY
DROP SOUTH THROUGH THE AREA MONDAY NIGHT AND TUESDAY AS THE
SURFACE LOW MOVES OFF INTO THE GREAT LAKES... AND WE COULD SEE
SOME SHRA/TSRA DROP THROUGH THE AREA AT THAT TIME AS WE FINALLY
PUSH THE CAP SOUTH OF THE REGION.
A BRIEF SHOT OF COOLER AND DRIER AIR LOOKS TO WORK INTO THE AREA
TUESDAY NIGHT THROUGH WEDNESDAY AS 500MB HEIGHTS FALL AND A DECENT
SURFACE HIGH SETTLES SOUTH INTO THE AREA FROM CANADA. HOWEVER...
AS WE/VE SEEN MOST OF THE SUMMER... WE WON/T HAVE NEAR OR SLIGHTLY
BELOW NORMAL TEMPERATURES REMAINING OVER THE AREA FOR TOO LONG...
AND RETURN FLOW WILL SET BACK UP BY THURSDAY. AS SOUTHWESTERLY
FLOW DEVELOPS AND STARTS TO BRING WARMER TEMPERATURES AND MOISTURE
BACK INTO THE AREA... WE COULD SEE SOME PCPN DEVELOP OVER THE
AREA... SO INCLUDED SOME POPS ON THURSDAY TO ACCOUNT FOR THAT
SCENARIO. AFTER THURSDAY... AND BEYOND THE CURRENT FORECAST
PERIOD... IS THE POINT AT WHICH THE GFS AND ECMWF START TO
DIVERGE QUITE A BIT... AND THERE IS A FAIR AMOUNT OF SPREAD IN THE
GEFS AT THIS POINT AS WELL... WITH SOME MEMBERS SUGGESTING
SOLUTIONS CLOSER TO THAT OF THE ECMWF. IN A NUTSHELL... THE ECMWF
REALLY BUILDS THE UPPER RIDGE OVER THE CENTRAL CONUS AND INTO
SOUTHERN CANADA... WHILE THE GFS HOLDS A DEEP UPPER TROUGH OVER
EASTERN CANADA... AND MANAGES TO KEEP THE UPPER RIDGE AT BAY TO
OUR WEST. SHOULD THINGS PAN OUT AS THE ECMWF SUGGESTS... WE COULD
BE LOOKING AT A PROLONGED SPELL OF WELL ABOVE NORMAL TEMPERATURES
FROM THE END OF THE WEEK INTO THE FIRST PART OF THE FOLLOWING
WEEK.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
RAH/TRH
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
704 AM CDT FRI JUL 13 2012
.UPDATED FOR 12Z AVIATION DISCUSSION...
&&
.DISCUSSION...
THE UPCOMING SEVEN DAYS LOOKS TO BE RELATIVELY QUIET FROM A PCPN
PERSPECTIVE... WITH THE BEST CHANCES BEING OVER THE NEXT 24
HOURS... BUT IT STARTING TO LOOK MORE INTERESTING WITH RESPECT TO
A FEW CHANCES FOR EXCESSIVE HEAT. IN THE BIG PICTURE... THE LATEST
WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSES SHOW A FAIRLY
HEALTHY SHORTWAVE MOVING THROUGH THE REGION AT THE CURRENT TIME...
WITH TWO MAIN PV ANOMALIES AND AREAS OF ENHANCED FORCING. ONE CAN
BE SEEN DROPPING SOUTHEAST THROUGH SOUTHEAST SOUTH DAKOTA AT THE
CURRENT TIME... AND IS HELPING TO ENHANCE THE PCPN OUT AHEAD OF IT OVER
THE SOUTHERN PART OF MINNESOTA. THE SECOND ANOMALY IS OVER
NORTHEAST NORTH DAKOTA... AND IS SLOWLY SLIDING EAST WITH TIME...
AND HELPING TO KEEP SOME PCPN GOING IN THAT AREA. ZOOMING OUT...
AN AMPLIFIED RIDGE REMAINS OVER THE WESTERN CONUS... WITH AN UPPER
TROUGH OVER THE PACIFIC NORTHWEST. THE GENERAL THEME OVER THE NEXT
24 TO 36 HOURS WILL BE FOR THE SHORTWAVE CURRENTLY TO OUR WEST TO
DROP SLOWLY SOUTHEAST AND HELP PUSH THE SURFACE TROUGH/FRONT
THROUGH THE AREA TODAY THROUGH SATURDAY... BRINGING CHANCES FOR
SHRA/TSRA TO THE AREA. AFTER THAT WE WILL SEE THE RIDGE OVER THE
ROCKIES BUILD INTO THE AREA... AND BRING INCREASINGLY WARM
TEMPERATURES INTO THE AREA THROUGH MONDAY. WE SHOULD THEN SEE SOME
BRIEF DEPRESSION IN THE UPPER HEIGHTS OVER THE AREA... BUT BY THE
MIDDLE OF THE WEEK THE UPPER RIDGE LOOKS TO RE-AMPLIFY OVER THE
CENTER OF THE COUNTRY. BY THE END OF THE WEEK THERE IS A FAIR
AMOUNT OF DISAGREEMENT BETWEEN THE GFS AND ECMWF... WITH THE GFS
DROPPING AND UPPER TROUGH INTO EASTERN CANADA AND DEVELOPING
NORTHWEST FLOW OVER US... WHILE THE ECMWF CONTINUES TO BUILD THE
UPPER RIDGE AND WOULD REALLY HAVE US COOKING BY THE END OF THE
WEEK. THE ECMWF HAS BEEN FAIRLY CONSISTENT WITH THE IDEA THE PAST
FEW RUNS... SO IT WILL CERTAINLY BE SOMETHING TO MONITOR. AT THIS
POINT... A VERY WARM MONDAY LOOKS TO BE A GOOD BET... WITH ANOTHER
PERHAPS WARMER SPAN OF WEATHER DEVELOPING BY THE END OF THE WEEK
THROUGH THE FOLLOWING WEEKEND.
FOR TODAY... WE SHOULD CONTINUE TO SEE SOME SCATTERED SHRA/TSRA
MIGRATE SLOWLY EAST THROUGH THE DAY AS THE SURFACE TROUGH PUSHES
EAST AHEAD OF UPPER WAVE. THE LOW LEVEL CONVERGENCE/UPPER LEVEL
DIVERGENCE COUPLET LOOKS TO PUSH EAST OF THE I-35 CORRIDOR BY THIS
AFTERNOON... SO THE BEST CHANCE FOR MORE WIDESPREAD PCPN WILL BE
OVER THE EASTERN PART OF THE CWFA... ALONG WITH THE MAIN POTENTIAL
FOR ANY SEVERE STORMS. HOWEVER... WITH THE UPPER TROUGH MOVING SO
SLOWLY TODAY AND TONIGHT... WE COULD CERTAINLY SEE SOME LINGERING
SHRA BEHIND THE SURFACE BOUNDARY BENEATH THE UPPER PV ANOMALY AND
ASSOCIATED MID-LEVEL COLD POOL. IN TERMS OF SEVERE WEATHER
POTENTIAL... THINGS STILL LOOK LIKE THE HAVE THE PAST SEVERAL
DAYS... WITH DECENT MLCAPE VALUES AOA 1500 J/KG TODAY INTO THIS
EVENING... BUT MEAGER DEEP LAYER AND LOW LEVEL SHEAR. SO... STILL
LOOKS LIKE WE/LL MAINLY BE DEALING WITH MULTI-CELL PULSE STORMS...
WITH THE PRIMARY THREAT BEING MARGINALLY SEVERE HAIL AND PERHAPS
SOME DOWNBURST WIND GUSTS GIVEN EXPECTED SURFACE DELTA THETA-E
VALUES AOA 25K. SOME PCPN COULD LINGER OVER THE EASTERN PART OF
THE AREA FOR A GOOD PART OF SATURDAY GIVEN THE SLOW EASTWARD
MIGRATION OF THE UPPER WAVE. HOWEVER... BY SATURDAY NIGHT WE
SHOULD SEE UPPER RIDGING WORK BACK ACROSS THE AREA... WITH A
SURFACE RIDGE NOSING DOWN FROM CENTRAL CANADA AS WELL. FAIRLY
ROBUST RETURN FLOW LOOKS TO SETUP SUNDAY AFTERNOON... PUSHING THE
WARM FRONT WELL NORTH THROUGH THE AREA BY EVENING. WE WILL THEN
SEE LOW PRESSURE ORGANIZE OVER THE HIGH PLAINS SUNDAY NIGHT INTO
MONDAY... WITH THE WARM SECTOR BECOME WELL ESTABLISHED OVER OUR
AREA. CHANCES FOR PCPN ON MONDAY AS THIS LOW PUSHES EAST LOOK LIKE
THEY WILL BE CONFINED TO THE NORTH OF OUR AREA CLOSER TO THE WARM
FRONTAL BOUNDARY AS 700MB TEMPERATURES AOA 12C ENCOMPASS ALL OF
CENTRAL AND SOUTHERN MINNESOTA. THE COLD FRONT WILL EVENTUALLY
DROP SOUTH THROUGH THE AREA MONDAY NIGHT AND TUESDAY AS THE
SURFACE LOW MOVES OFF INTO THE GREAT LAKES... AND WE COULD SEE
SOME SHRA/TSRA DROP THROUGH THE AREA AT THAT TIME AS WE FINALLY
PUSH THE CAP SOUTH OF THE REGION.
A BRIEF SHOT OF COOLER AND DRIER AIR LOOKS TO WORK INTO THE AREA
TUESDAY NIGHT THROUGH WEDNESDAY AS 500MB HEIGHTS FALL AND A DECENT
SURFACE HIGH SETTLES SOUTH INTO THE AREA FROM CANADA. HOWEVER...
AS WE/VE SEEN MOST OF THE SUMMER... WE WON/T HAVE NEAR OR SLIGHTLY
BELOW NORMAL TEMPERATURES REMAINING OVER THE AREA FOR TOO LONG...
AND RETURN FLOW WILL SET BACK UP BY THURSDAY. AS SOUTHWESTERLY
FLOW DEVELOPS AND STARTS TO BRING WARMER TEMPERATURES AND MOISTURE
BACK INTO THE AREA... WE COULD SEE SOME PCPN DEVELOP OVER THE
AREA... SO INCLUDED SOME POPS ON THURSDAY TO ACCOUNT FOR THAT
SCENARIO. AFTER THURSDAY... AND BEYOND THE CURRENT FORECAST
PERIOD... IS THE POINT AT WHICH THE GFS AND ECMWF START TO
DIVERGE QUITE A BIT... AND THERE IS A FAIR AMOUNT OF SPREAD IN THE
GEFS AT THIS POINT AS WELL... WITH SOME MEMBERS SUGGESTING
SOLUTIONS CLOSER TO THAT OF THE ECMWF. IN A NUTSHELL... THE ECMWF
REALLY BUILDS THE UPPER RIDGE OVER THE CENTRAL CONUS AND INTO
SOUTHERN CANADA... WHILE THE GFS HOLDS A DEEP UPPER TROUGH OVER
EASTERN CANADA... AND MANAGES TO KEEP THE UPPER RIDGE AT BAY TO
OUR WEST. SHOULD THINGS PAN OUT AS THE ECMWF SUGGESTS... WE COULD
BE LOOKING AT A PROLONGED SPELL OF WELL ABOVE NORMAL TEMPERATURES
FROM THE END OF THE WEEK INTO THE FIRST PART OF THE FOLLOWING
WEEK.
&&
.AVIATION.../12Z TAF ISSUANCE/
AN UPPER LEVEL DISTURBANCE WILL SLIDE ACROSS THE REGION OVER THE
NEXT 24 HOURS AND CAUSE SOME SHOWERS AND THUNDERSTORMS TO DEVELOP.
THESE ARE ALREADY ONGOING NEAR THE MN/WI BORDER. EXPECT THESE
PULSE STORMS TO PERCOLATE THROUGHOUT THE DAY...WITH BETTER CHANCES
DURING THE LATE AFTERNOON AND EARLY EVENING AT THE EASTERN SITES.
KMSP...SHOWERS AND THUNDERSTORMS SEEM TO BE REDEVELOPING ON THE
EASTERN SIDE OF THE METRO THIS MORNING. ANTICIPATING A BREAK THIS
MORNING THROUGH THE EARLY AFTERNOON BEFORE MORE WIDESPREAD SHOWERS
DEVELOP ONCE AGAIN. THIS CONVECTION WILL BE VERY PULSE-LIKE IN
NATURE...SO CURRENTLY JUST HAVE A VC-GROUP. THIS WILL LIKELY NEED
TO BE FINE TUNED LATER TODAY...BUT DIDNT FEEL CONFIDENT WITH
SEVERAL HOURS OF THUNDER.
/OUTLOOK/
SATURDAY...VFR WITH TSRA ENDING. WINDS N AT 5 KT.
SUNDAY...VFR. WINDS W AT 10G15KT.
MONDAY...VFR. WINDS SSW AT 10G15KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
TRH/JRB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
325 AM CDT FRI JUL 13 2012
.DISCUSSION...
THE UPCOMING SEVEN DAYS LOOKS TO BE RELATIVELY QUIET FROM A PCPN
PERSPECTIVE... WITH THE BEST CHANCES BEING OVER THE NEXT 24
HOURS... BUT IT STARTING TO LOOK MORE INTERESTING WITH RESPECT TO
A FEW CHANCES FOR EXCESSIVE HEAT. IN THE BIG PICTURE... THE LATEST
WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSES SHOW A FAIRLY
HEALTHY SHORTWAVE MOVING THROUGH THE REGION AT THE CURRENT TIME...
WITH TWO MAIN PV ANOMALIES AND AREAS OF ENHANCED FORCING. ONE CAN
BE SEEN DROPPING SOUTHEAST THROUGH SOUTHEAST SOUTH DAKOTA AT THE
CURRENT TIME... AND IS HELPING TO ENHANCE THE PCPN OUT AHEAD OF IT OVER
THE SOUTHERN PART OF MINNESOTA. THE SECOND ANOMALY IS OVER
NORTHEAST NORTH DAKOTA... AND IS SLOWLY SLIDING EAST WITH TIME...
AND HELPING TO KEEP SOME PCPN GOING IN THAT AREA. ZOOMING OUT...
AN AMPLIFIED RIDGE REMAINS OVER THE WESTERN CONUS... WITH AN UPPER
TROUGH OVER THE PACIFIC NORTHWEST. THE GENERAL THEME OVER THE NEXT
24 TO 36 HOURS WILL BE FOR THE SHORTWAVE CURRENTLY TO OUR WEST TO
DROP SLOWLY SOUTHEAST AND HELP PUSH THE SURFACE TROUGH/FRONT
THROUGH THE AREA TODAY THROUGH SATURDAY... BRINGING CHANCES FOR
SHRA/TSRA TO THE AREA. AFTER THAT WE WILL SEE THE RIDGE OVER THE
ROCKIES BUILD INTO THE AREA... AND BRING INCREASINGLY WARM
TEMPERATURES INTO THE AREA THROUGH MONDAY. WE SHOULD THEN SEE SOME
BRIEF DEPRESSION IN THE UPPER HEIGHTS OVER THE AREA... BUT BY THE
MIDDLE OF THE WEEK THE UPPER RIDGE LOOKS TO RE-AMPLIFY OVER THE
CENTER OF THE COUNTRY. BY THE END OF THE WEEK THERE IS A FAIR
AMOUNT OF DISAGREEMENT BETWEEN THE GFS AND ECMWF... WITH THE GFS
DROPPING AND UPPER TROUGH INTO EASTERN CANADA AND DEVELOPING
NORTHWEST FLOW OVER US... WHILE THE ECMWF CONTINUES TO BUILD THE
UPPER RIDGE AND WOULD REALLY HAVE US COOKING BY THE END OF THE
WEEK. THE ECMWF HAS BEEN FAIRLY CONSISTENT WITH THE IDEA THE PAST
FEW RUNS... SO IT WILL CERTAINLY BE SOMETHING TO MONITOR. AT THIS
POINT... A VERY WARM MONDAY LOOKS TO BE A GOOD BET... WITH ANOTHER
PERHAPS WARMER SPAN OF WEATHER DEVELOPING BY THE END OF THE WEEK
THROUGH THE FOLLOWING WEEKEND.
FOR TODAY... WE SHOULD CONTINUE TO SEE SOME SCATTERED SHRA/TSRA
MIGRATE SLOWLY EAST THROUGH THE DAY AS THE SURFACE TROUGH PUSHES
EAST AHEAD OF UPPER WAVE. THE LOW LEVEL CONVERGENCE/UPPER LEVEL
DIVERGENCE COUPLET LOOKS TO PUSH EAST OF THE I-35 CORRIDOR BY THIS
AFTERNOON... SO THE BEST CHANCE FOR MORE WIDESPREAD PCPN WILL BE
OVER THE EASTERN PART OF THE CWFA... ALONG WITH THE MAIN POTENTIAL
FOR ANY SEVERE STORMS. HOWEVER... WITH THE UPPER TROUGH MOVING SO
SLOWLY TODAY AND TONIGHT... WE COULD CERTAINLY SEE SOME LINGERING
SHRA BEHIND THE SURFACE BOUNDARY BENEATH THE UPPER PV ANOMALY AND
ASSOCIATED MID-LEVEL COLD POOL. IN TERMS OF SEVERE WEATHER
POTENTIAL... THINGS STILL LOOK LIKE THE HAVE THE PAST SEVERAL
DAYS... WITH DECENT MLCAPE VALUES AOA 1500 J/KG TODAY INTO THIS
EVENING... BUT MEAGER DEEP LAYER AND LOW LEVEL SHEAR. SO... STILL
LOOKS LIKE WE/LL MAINLY BE DEALING WITH MULTI-CELL PULSE STORMS...
WITH THE PRIMARY THREAT BEING MARGINALLY SEVERE HAIL AND PERHAPS
SOME DOWNBURST WIND GUSTS GIVEN EXPECTED SURFACE DELTA THETA-E
VALUES AOA 25K. SOME PCPN COULD LINGER OVER THE EASTERN PART OF
THE AREA FOR A GOOD PART OF SATURDAY GIVEN THE SLOW EASTWARD
MIGRATION OF THE UPPER WAVE. HOWEVER... BY SATURDAY NIGHT WE
SHOULD SEE UPPER RIDGING WORK BACK ACROSS THE AREA... WITH A
SURFACE RIDGE NOSING DOWN FROM CENTRAL CANADA AS WELL. FAIRLY
ROBUST RETURN FLOW LOOKS TO SETUP SUNDAY AFTERNOON... PUSHING THE
WARM FRONT WELL NORTH THROUGH THE AREA BY EVENING. WE WILL THEN
SEE LOW PRESSURE ORGANIZE OVER THE HIGH PLAINS SUNDAY NIGHT INTO
MONDAY... WITH THE WARM SECTOR BECOME WELL ESTABLISHED OVER OUR
AREA. CHANCES FOR PCPN ON MONDAY AS THIS LOW PUSHES EAST LOOK LIKE
THEY WILL BE CONFINED TO THE NORTH OF OUR AREA CLOSER TO THE WARM
FRONTAL BOUNDARY AS 700MB TEMPERATURES AOA 12C ENCOMPASS ALL OF
CENTRAL AND SOUTHERN MINNESOTA. THE COLD FRONT WILL EVENTUALLY
DROP SOUTH THROUGH THE AREA MONDAY NIGHT AND TUESDAY AS THE
SURFACE LOW MOVES OFF INTO THE GREAT LAKES... AND WE COULD SEE
SOME SHRA/TSRA DROP THROUGH THE AREA AT THAT TIME AS WE FINALLY
PUSH THE CAP SOUTH OF THE REGION.
A BRIEF SHOT OF COOLER AND DRIER AIR LOOKS TO WORK INTO THE AREA
TUESDAY NIGHT THROUGH WEDNESDAY AS 500MB HEIGHTS FALL AND A DECENT
SURFACE HIGH SETTLES SOUTH INTO THE AREA FROM CANADA. HOWEVER...
AS WE/VE SEEN MOST OF THE SUMMER... WE WON/T HAVE NEAR OR SLIGHTLY
BELOW NORMAL TEMPERATURES REMAINING OVER THE AREA FOR TOO LONG...
AND RETURN FLOW WILL SET BACK UP BY THURSDAY. AS SOUTHWESTERLY
FLOW DEVELOPS AND STARTS TO BRING WARMER TEMPERATURES AND MOISTURE
BACK INTO THE AREA... WE COULD SEE SOME PCPN DEVELOP OVER THE
AREA... SO INCLUDED SOME POPS ON THURSDAY TO ACCOUNT FOR THAT
SCENARIO. AFTER THURSDAY... AND BEYOND THE CURRENT FORECAST
PERIOD... IS THE POINT AT WHICH THE GFS AND ECMWF START TO
DIVERGE QUITE A BIT... AND THERE IS A FAIR AMOUNT OF SPREAD IN THE
GEFS AT THIS POINT AS WELL... WITH SOME MEMBERS SUGGESTING
SOLUTIONS CLOSER TO THAT OF THE ECMWF. IN A NUTSHELL... THE ECMWF
REALLY BUILDS THE UPPER RIDGE OVER THE CENTRAL CONUS AND INTO
SOUTHERN CANADA... WHILE THE GFS HOLDS A DEEP UPPER TROUGH OVER
EASTERN CANADA... AND MANAGES TO KEEP THE UPPER RIDGE AT BAY TO
OUR WEST. SHOULD THINGS PAN OUT AS THE ECMWF SUGGESTS... WE COULD
BE LOOKING AT A PROLONGED SPELL OF WELL ABOVE NORMAL TEMPERATURES
FROM THE END OF THE WEEK INTO THE FIRST PART OF THE FOLLOWING
WEEK.
&&
.AVIATION.../06Z TAF ISSUANCE/
/ISSUED 1025 PM CDT THU JUL 12 2012/
LINE OF SCT SHWRS AND TSTMS EXTENDING FROM NW MN INTO SE SODAK
CONTINUES TO MAKE PROGRESS EASTWARD AHEAD OF UPPER TROF IN THE DKTS.
WEAK VORT IN NE SODAK NEAR KHON APPEARS TO BE LENDING SOME SUPPORT
TO STORMS IN WC MN TOWARD KBKX AND KHON. MID LEVEL WARM ADVECTION
SHUD HELP TO MAINTAIN SOME OF THIS ACTIVITY AS IT PUSHES EAST. PCPN
WILL BE EAST OF AXN BY TAF ISSUE TIME...AND COVERAGE PROBBLY LOW
ENUF TO CONFINE PCPN MENTION TO A VCNTY GROUP. WEAK SURFACE TROF
WILL CONTINUE TO PROGRESS EAST INTO E MN FRI AFTN AND EXPECTED TO
GENERATE ANOTHER ROUND OF SCT SHWRS AND TSTMS.
KMSP...UPSTREAM CONVECTION MAY REACH THE MSP AREA ARND 08-09Z...BUT
EXPECT COVERAGE TO REMAIN LOW ENUF TO CONFINE PCPN MENTION TO VCSH.
WEAK SURFACE TROF NEAR THE DKTS BORDER AROUND 20-21Z AND SHUD BE
SUFFICIENT INSTABILITY FOR ANOTHER ROUND OF SHWRS AND TSTMS...BUT
EXPECT BETTER COVERAGE TO BE EAST OF MSP.
/OUTLOOK/
SATURDAY...VFR WITH SHRA ENDING IN THE MORNING. WINDS NW AT 5 TO 10KTS.
SUNDAY...VFR. WINDS SE AT 5-10 KTS.
MONDAY...VFR. WINDS S-SW 10-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
533 PM CDT FRI JUL 13 2012
.UPDATE...
ISSUED AT 421 PM CDT FRI JUL 13 2012
OUTFLOW DOMINATED CONVECTION CONTINUES TO STEADILY REDEVELOP
SOUTHEAST TOWARD BEST SURFACE CONVERGENCE. BELIEVE THIS TREND WILL
CONTINUE THIS EVENING WITH SCATTERED STORMS PROPOGATING/DEVELOPING
AS FAR SOUTHEAST AS THE ST. LOUIS METROPOLITAN AREA BY DUSK.
LOSS OF DIURNAL INSTABILITY WILL CAUSE COVERAGE OF CONVECTION TO
RAPIDLY DECREASE AFTER SUNSET...BUT LIKE THE PAST FEW
NIGHTS...ISOLATED SHOWERS AND STORMS COULD PERCOLATE INTO THE
OVERNIGHT HOURS.
CVKING
&&
.SHORT TERM...
ISSUED AT 248 PM CDT FRI JUL 13 2012
(TONIGHT)
SCATTERED CONVECTION HAS DEVELOPED ACROSS THE NWRN HALF OF THE CWA
AHEAD OF A PV ANOMALY THAT WAS LOCATED OVER IA PER WATER VAPOR
IMAGERY AND RAP 1.5 PVU FIELDS. MAINLY PULSE-TYPE THUNDERSTORMS ARE
EXPECTED DUE TO WEAK SHEAR COMBINED WITH LITTLE CINH AND A FEW
THOUSAND J/KG OF CAPE. DRY SUBCLOUD LAYER AND A WELL-MIXED
BOUNDARY LAYER WILL ONCE AGAIN SUPPORT OCCASIONAL DOWNBURSTS WHEN
THE CORES OF THE STRONGEST STORMS COLLAPSE HOWEVER WIDESPREAD
SEVERE WEATHER IS NOT EXPECTED AT THIS TIME. PCPN COVERAGE SHOULD
DIMINISH LATER THIS EVENING WITH THE LOSS OF DAYTIME HEATING
HOWEVER A FEW AREAS OF ELEVATED CONVECTION MIGHT CONTINUE TO
PERCOLATE OVERNIGHT AS THE SHORTWAVE MOVES INTO NRN MO.
KANOFSKY/CARNEY
&&
.LONG TERM...
ISSUED AT 248 PM CDT FRI JUL 13 2012
(TOMORROW THROUGH NEXT THURSDAY)
VORT MAX MOVING ACROSS THE UPPER MIDWEST AND ITS ASSOCIATED SFC
TROF WILL PROVIDE BOTH A SOURCE OF LARGE SCALE LIFT AND A LOW
LEVEL FOCUSING MECHANISM FOR SCT TSRA/SHRA TOMORROW. GENERALLY
PULSE-TYPE THUNDERSTORMS ARE EXPECTED DUE TO WEAK SHEAR. ISOLATED
DIURNAL PCPN MAY REDEVELOP AND LINGER ACROSS THE SERN HALF OF THE
CWA ON SUN AND MON AS THE TROF SETTLES SEWD AND THE ELONGATED
VORTICITY AXIS SHEARS OUT.
A GRADUAL WARMING TREND IS EXPECTED OVER THE NEXT SEVERAL DAYS AS AN
UPPER LEVEL RIDGE BUILDS EWD. H85 TEMPERATURES OF 20-24 DEG C WOULD
SUPPORT AFTN HIGHS RANGING FROM THE MID 90S TO NEAR THE CENTURY
MARK. THE CENTRAL REGION ALLBLEND INITIALIZATION REMAINS
CONTAMINATED BY INCORRECT GFS OUTPUT /NCEP STAFF CONTINUE TO
TROUBLESHOOT BUT HAVE NOT YET IDENTIFIED THE SOURCE OF THE
PROBLEM/ THEREFORE I DEVIATED SIGNIFICANTLY FROM THE RECOMMENDED
INITIALIZATION TO REDUCE POPS AND RAISE TEMPS ON DAYS 4-7. A WEAK
SFC FRONT WILL APPROACH THE CWA ON WED/THU AND MOISTURE POOLING
AHEAD OF THE FRONT COULD DRIVE HEAT INDEX READINGS OVER 105 DEG F
IN SOME AREAS. ISOLATED TO SCATTERED THUNDERSTORMS WILL BE
POSSIBLE THROUGH THE EXTENDED PD HOWEVER THERE ARE NO STRONG
SIGNALS TO SUPPORT HIGHER THAN SCHC POPS ACROSS MO/IL WHICH
REMAINS IN A MODERATE TO SEVERE DROUGHT.
KANOFSKY
&&
.AVIATION...
ISSUED AT 527 PM CDT FRI JUL 13 2012
LINE OF SCATTERED THUNDERSTORMS FROM CENTRAL MISSOURI TO WEST
CENTRAL ILLINOIS HAS PRODUCED QUITE AN OUTFLOW THAT IS MOVING
SOUTHEAST TOWARD THE ST. LOUIS METRO TAF SITES. THIS WILL SWING
WINDS AROUND TO THE NORTHWEST WITH GUSTS TO 25KT AROUND 00Z.
COULD SEE THUNDERSTORMS REDEVELOP ALONG THIS BOUNDARY AND HAVE
INCLUDED A TEMPO FOR AN HOUR TO ACCOUNT FOR THIS. OF COURSE THIS
WILL BE NOWCASTED WITH LATEST RADAR TRENDS.
CONVECTION SHOULD WEAKEN WITH LOSS OF DAYTIME HEATING AFTER
SUNSET...ALTHOUGH A FEW SHOWERS COULD LINGER GIVEN VICINITY OF
WEAK MID/UPPER LEVEL TROF. WIND WILL BE LIGHT AND VARIABLE OVERNIGHT.
HAVE A RENEWED CHANCE OF SCATTERED CONVECTION TOMORROW AFTERNOON
FOR ST. LOUIS METRO TAF SITES AS 500MB SHEAR AXIS IS FORECAST TO
BE OVERHEAD. HAVE HANDLED THIS THREAT WITH A PROB30 GROUP.
SPECIFICS FOR KSTL...
EXPECT OUTFLOW BOUNDARY TO IMPACT TERMINAL AROUND 00Z WITH A WIND
SHIFT TO THE NORTHWEST AND GUSTS TO 25KT. ALSO WILL BE WATCHING TO
SEE IF THUNDERSTORMS CAN REDEVELOP ALONG THIS BOUNDARY.
OTHERWISE...VFR CONDITIONS EXPECTED OVERNIGHT WITH WINDS BECOMING
LIGHT AND VARIABLE. A RENEWED THREAT OF THUNDERSTORMS TOMORROW
AFTERNOON...BUT COVERAGE WILL REMAIN SCT...SO HAVE ONLY INCLUDED
A PROB30 GROUP AT THIS TIME.
CVKING
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
427 PM CDT FRI JUL 13 2012
.UPDATE...
ISSUED AT 421 PM CDT FRI JUL 13 2012
OUTFLOW DOMINATED CONVECTION CONTINUES TO STEADILY REDEVELOP
SOUTHEAST TOWARD BEST SURFACE CONVERGENCE. BELIEVE THIS TREND WILL
CONTINUE THIS EVENING WITH SCATTERED STORMS PROPOGATING/DEVELOPING
AS FAR SOUTHEAST AS THE ST. LOUIS METROPOLITAN AREA BY DUSK.
LOSS OF DIURNAL INSTABILITY WILL CAUSE COVERAGE OF CONVECTION TO
RAPIDLY DECREASE AFTER SUNSET...BUT LIKE THE PAST FEW
NIGHTS...ISOLATED SHOWERS AND STORMS COULD PERCOLATE INTO THE
OVERNIGHT HOURS.
CVKING
&&
.SHORT TERM...
ISSUED AT 248 PM CDT FRI JUL 13 2012
(TONIGHT)
SCATTERED CONVECTION HAS DEVELOPED ACROSS THE NWRN HALF OF THE CWA
AHEAD OF A PV ANOMALY THAT WAS LOCATED OVER IA PER WATER VAPOR
IMAGERY AND RAP 1.5 PVU FIELDS. MAINLY PULSE-TYPE THUNDERSTORMS ARE
EXPECTED DUE TO WEAK SHEAR COMBINED WITH LITTLE CINH AND A FEW
THOUSAND J/KG OF CAPE. DRY SUBCLOUD LAYER AND A WELL-MIXED
BOUNDARY LAYER WILL ONCE AGAIN SUPPORT OCCASIONAL DOWNBURSTS WHEN
THE CORES OF THE STRONGEST STORMS COLLAPSE HOWEVER WIDESPREAD
SEVERE WEATHER IS NOT EXPECTED AT THIS TIME. PCPN COVERAGE SHOULD
DIMINISH LATER THIS EVENING WITH THE LOSS OF DAYTIME HEATING
HOWEVER A FEW AREAS OF ELEVATED CONVECTION MIGHT CONTINUE TO
PERCOLATE OVERNIGHT AS THE SHORTWAVE MOVES INTO NRN MO.
KANOFSKY/CARNEY
&&
.LONG TERM...
ISSUED AT 248 PM CDT FRI JUL 13 2012
(TOMORROW THROUGH NEXT THURSDAY)
VORT MAX MOVING ACROSS THE UPPER MIDWEST AND ITS ASSOCIATED SFC
TROF WILL PROVIDE BOTH A SOURCE OF LARGE SCALE LIFT AND A LOW
LEVEL FOCUSING MECHANISM FOR SCT TSRA/SHRA TOMORROW. GENERALLY
PULSE-TYPE THUNDERSTORMS ARE EXPECTED DUE TO WEAK SHEAR. ISOLATED
DIURNAL PCPN MAY REDEVELOP AND LINGER ACROSS THE SERN HALF OF THE
CWA ON SUN AND MON AS THE TROF SETTLES SEWD AND THE ELONGATED
VORTICITY AXIS SHEARS OUT.
A GRADUAL WARMING TREND IS EXPECTED OVER THE NEXT SEVERAL DAYS AS AN
UPPER LEVEL RIDGE BUILDS EWD. H85 TEMPERATURES OF 20-24 DEG C WOULD
SUPPORT AFTN HIGHS RANGING FROM THE MID 90S TO NEAR THE CENTURY
MARK. THE CENTRAL REGION ALLBLEND INITIALIZATION REMAINS
CONTAMINATED BY INCORRECT GFS OUTPUT /NCEP STAFF CONTINUE TO
TROUBLESHOOT BUT HAVE NOT YET IDENTIFIED THE SOURCE OF THE
PROBLEM/ THEREFORE I DEVIATED SIGNIFICANTLY FROM THE RECOMMENDED
INITIALIZATION TO REDUCE POPS AND RAISE TEMPS ON DAYS 4-7. A WEAK
SFC FRONT WILL APPROACH THE CWA ON WED/THU AND MOISTURE POOLING
AHEAD OF THE FRONT COULD DRIVE HEAT INDEX READINGS OVER 105 DEG F
IN SOME AREAS. ISOLATED TO SCATTERED THUNDERSTORMS WILL BE
POSSIBLE THROUGH THE EXTENDED PD HOWEVER THERE ARE NO STRONG
SIGNALS TO SUPPORT HIGHER THAN SCHC POPS ACROSS MO/IL WHICH
REMAINS IN A MODERATE TO SEVERE DROUGHT.
KANOFSKY
&&
.AVIATION...
ISSUED AT 1235 PM CDT FRI JUL 13 2012
UPPER LEVEL SYSTEM IS GENERATING SCATTERED STORMS ACROSS NORTHEAST
MISSOURI/WEST CENTRAL ILLINOIS. SOME ISOLATED SHOWERS ARE POPPING
UP ON RADAR AS FAR SOUTH AS CENTRAL MISSOURI AT THIS TIME AS WELL.
THINK STORMS WILL INCREASE IN COVERAGE THIS AFTERNOON ACROSS
CENTRAL AND NORTHEAST MISSOURI AS WELL AS WEST CENTRAL ILLINOIS...PRODUCING
OCCASIONAL DOWN BURSTS WITH GUSTS TO 30-40KTS AND ISOLATED POCKETS
OF IFR IN HEAVY RAIN. ELSEWHERE...ISOLATED SHOWERS OR
THUNDERSTORMS WILL BE POSSIBLE. VFR FLIGHT CONDITIONS WILL PREVAIL OTHERWISE.
SPECIFICS FOR KSTL...
UPPER LEVEL SYSTEM IS PRODDING THUNDERSTORMS NORTHWEST OF THE
TERMINAL THIS AFTERNOON. CAN`T TOTALLY RULE OUT A THUNDERSTORM AT
LAMBERT...ESPECIALLY LATER IN THE AFTERNOON/EARLY EVENING.
HOWEVER...CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE IN THE TAF AT
THIS TIME. OTHERWISE...VFR FLIGHT CONDITIONS ARE EXPECTED TO
PREVAIL. THERE WILL BE ANOTHER CHANCE FOR STORMS SATURDAY AFTERNOON.
CARNEY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
253 PM CDT FRI JUL 13 2012
.SHORT TERM...
ISSUED AT 248 PM CDT FRI JUL 13 2012
(TONIGHT)
SCATTERED CONVECTION HAS DEVELOPED ACROSS THE NWRN HALF OF THE CWA
AHEAD OF A PV ANOMALY THAT WAS LOCATED OVER IA PER WATER VAPOR
IMAGERY AND RAP 1.5 PVU FIELDS. MAINLY PULSE-TYPE THUNDERSTORMS ARE
EXPECTED DUE TO WEAK SHEAR COMBINED WITH LITTLE CINH AND A FEW
THOUSAND J/KG OF CAPE. DRY SUBCLOUD LAYER AND A WELL-MIXED
BOUNDARY LAYER WILL ONCE AGAIN SUPPORT OCCASIONAL DOWNBURSTS WHEN
THE CORES OF THE STRONGEST STORMS COLLAPSE HOWEVER WIDESPREAD
SEVERE WEATHER IS NOT EXPECTED AT THIS TIME. PCPN COVERAGE SHOULD
DIMINISH LATER THIS EVENING WITH THE LOSS OF DAYTIME HEATING
HOWEVER A FEW AREAS OF ELEVATED CONVECTION MIGHT CONTINUE TO
PERCOLATE OVERNIGHT AS THE SHORTWAVE MOVES INTO NRN MO.
KANOFSKY/CARNEY
&&
.LONG TERM...
ISSUED AT 248 PM CDT FRI JUL 13 2012
(TOMORROW THROUGH NEXT THURSDAY)
VORT MAX MOVING ACROSS THE UPPER MIDWEST AND ITS ASSOCIATED SFC
TROF WILL PROVIDE BOTH A SOURCE OF LARGE SCALE LIFT AND A LOW
LEVEL FOCUSING MECHANISM FOR SCT TSRA/SHRA TOMORROW. GENERALLY
PULSE-TYPE THUNDERSTORMS ARE EXPECTED DUE TO WEAK SHEAR. ISOLATED
DIURNAL PCPN MAY REDEVELOP AND LINGER ACROSS THE SERN HALF OF THE
CWA ON SUN AND MON AS THE TROF SETTLES SEWD AND THE ELONGATED
VORTICITY AXIS SHEARS OUT.
A GRADUAL WARMING TREND IS EXPECTED OVER THE NEXT SEVERAL DAYS AS AN
UPPER LEVEL RIDGE BUILDS EWD. H85 TEMPERATURES OF 20-24 DEG C WOULD
SUPPORT AFTN HIGHS RANGING FROM THE MID 90S TO NEAR THE CENTURY
MARK. THE CENTRAL REGION ALLBLEND INITIALIZATION REMAINS
CONTAMINATED BY INCORRECT GFS OUTPUT /NCEP STAFF CONTINUE TO
TROUBLESHOOT BUT HAVE NOT YET IDENTIFIED THE SOURCE OF THE
PROBLEM/ THEREFORE I DEVIATED SIGNIFICANTLY FROM THE RECOMMENDED
INITIALIZATION TO REDUCE POPS AND RAISE TEMPS ON DAYS 4-7. A WEAK
SFC FRONT WILL APPROACH THE CWA ON WED/THU AND MOISTURE POOLING
AHEAD OF THE FRONT COULD DRIVE HEAT INDEX READINGS OVER 105 DEG F
IN SOME AREAS. ISOLATED TO SCATTERED THUNDERSTORMS WILL BE
POSSIBLE THROUGH THE EXTENDED PD HOWEVER THERE ARE NO STRONG
SIGNALS TO SUPPORT HIGHER THAN SCHC POPS ACROSS MO/IL WHICH
REMAINS IN A MODERATE TO SEVERE DROUGHT.
KANOFSKY
&&
.AVIATION...
ISSUED AT 1235 PM CDT FRI JUL 13 2012
UPPER LEVEL SYSTEM IS GENERATING SCATTERED STORMS ACROSS NORTHEAST
MISSOURI/WEST CENTRAL ILLINOIS. SOME ISOLATED SHOWERS ARE POPPING
UP ON RADAR AS FAR SOUTH AS CENTRAL MISSOURI AT THIS TIME AS WELL.
THINK STORMS WILL INCREASE IN COVERAGE THIS AFTERNOON ACROSS
CENTRAL AND NORTHEAST MISSOURI AS WELL AS WEST CENTRAL ILLINOIS...PRODUCING
OCCASIONAL DOWN BURSTS WITH GUSTS TO 30-40KTS AND ISOLATED POCKETS
OF IFR IN HEAVY RAIN. ELSEWHERE...ISOLATED SHOWERS OR
THUNDERSTORMS WILL BE POSSIBLE. VFR FLIGHT CONDITIONS WILL PREVAIL OTHERWISE.
SPECIFICS FOR KSTL...
UPPER LEVEL SYSTEM IS PRODDING THUNDERSTORMS NORTHWEST OF THE
TERMINAL THIS AFTERNOON. CAN`T TOTALLY RULE OUT A THUNDERSTORM AT
LAMBERT...ESPECIALLY LATER IN THE AFTERNOON/EARLY EVENING.
HOWEVER...CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE IN THE TAF AT
THIS TIME. OTHERWISE...VFR FLIGHT CONDITIONS ARE EXPECTED TO
PREVAIL. THERE WILL BE ANOTHER CHANCE FOR STORMS SATURDAY AFTERNOON.
CARNEY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1107 AM EDT FRI JUL 13 2012
.SYNOPSIS...
INCREASING MOISTURE WILL LEAD TO ISOLATED TO SCATTERED SHOWERS AND
PERHAPS A THUNDERSTORM THIS AFTERNOON INTO EVENING...SOUTH OF THE
NEW YORK THRUWAY. MORE SIGNIFICANT MOISTURE WILL BEGIN TO RETURN
OVER THE WEEKEND WITH AN INCREASING CHANCE OF RAIN AND
THUNDERSTORMS...ESPECIALLY SATURDAY NIGHT INTO SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1045 AM UPDATE...
SOME MID TO HIGH LEVEL CLOUDS STREAMING INTO THE SOUTHERN PORTION
OF THE CWA AT THIS TIME. WATER VAPOR IMAGERY SHOWS HIGHER MOISTURE
VALUES ACROSS THE SOUTHERN AND CENTRAL CWA WITH DRY AIR HOLDING ON
ALONG AND NORTH OF THE THRUWAY. FORECAST PW AT VALUES ARE MUCH
HIGHER ACROSS NE PA AND THE SOUTHERN TIER OF NY WITH VALUES
APPROACHING 1.5 INCHES COMPARED TO AROUND .75 OF AN INCH ACROSS ONEIDA
COUNTY. ADDED CHANCE POPS FOR SHOWERS AND T`STORMS FOR THE CENTRAL
ZONES THIS AFTERNOON AND EVENING. EXPECTING AREAS ALONG AND NORTH
OF THE THRUWAY TO REMAIN DRY TODAY. WE ARE NOT EXPECTING ANY
SEVERE THUNDERSTORMS TODAY DUE TO NARROW CAPES AND VERY LITTLE
FLOW THROUGHOUT THE COLUMN...HOWEVER ANY STORMS THAT DO FORM WILL
BE SLOW MOVERS AND THEREFORE ADDED THE MENTION OF LOCALIZED HEAVY
RAINFALL IN THE HWO.
AS FOR TEMPERATURES, WE HAVE RAISED OUR EXPECTED MAXES A DEGREE OR
TWO INTO THE LOW TO MID 90S FOR LOWER ELEVATIONS OF THE NORTHERN
AND CENTRAL CWA WHERE A LITTLE BIT MORE SUN WILL FILTER THROUGH
THE HIGH CLOUDS. HIGHS SHOULD BE MAINLY IN THE MID TO UPPER 80S
ACROSS NE PA WITH MORE CLOUDS.
PREVIOUS DISCUSSION...
THE WEATHER SHOULD REMAIN QUIET FOR THE REMAINDER OF
THE MORNING. MODELS ARE INDICATING A MODERATE AREA OF 500MB VORT
ADV MOVING THROUGH NEPA AND THE SOUTHERN TIER THIS AFTERNOON.
THERE WILL BE MID AND UPPER LEVEL MOISTURE AVAILABLE THIS
AFTERNOON AS WELL. HOWEVER, THIS IS MOVING AROUND A FAIRLY STRONG
UPPER LEVEL RIDGE, WHICH SHOULD INHIBIT SOME OF THE DEVELOPMENT.
ALSO, MODELS ARE DIFFERING WITH COVERAGE AND TIMING OF ANY
CONVECTION THIS AFTERNOON. HAVE INCREASED COVERAGE OF POP, BUT
KEPT THE ACTUAL POP VALUE IN THE ISOLD RANGE. THERE IS PLENTY OF
CAPE AROUND TODAY, WITH THE NAM COMING IN AT AROUND 1600 JOULES
OVER THE SOUTHERN TIER TODAY. THE GFS IS NOT SO GENEROUS WITH THE
CAPE, BRINGING LESS THAN 100 JOULES TO THE SOUTHERN TIER, BUT IS
SHOWING ABOUT 600 JOULES IN THE SYRACUSE AREA. BUT, BEST DYNAMICS
LOOK TO BE SOUTH OF THE GFS CAPE FORECAST LOCATION. WENT MORE IN
LINE WITH THE NAM FOR ANY CONVECTIVE DEVELOPMENT TODAY, ALTHOUGH
STILL KEPT THE AREA FAIRLY BROAD. THE HRRR IS ALSO SHOWING SOME
WEAK DEVELOPMENT ACROSS THE CENTRAL AND SOUTHERN PORTIONS OF THE
CWA THIS AFTERNOON. AS THE DAY PROGRESSES, MBE VALUES ARE FAIRLY
LOW, SO SHOWERS MAY NOT MOVE VERY FAST, AS WAS THE CASE YESTERDAY.
ALSO, PWATS LOOK TO RISE ABOVE AN INCH LATER TODAY, WHICH BOTH
SUPPORT THE NOTION OF POSSIBLE HEAVY RAIN THAT DOES NOT MOVE VERY
MUCH, IF ANY DO DEVELOP.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
MODELS ARE IN AGREEMENT WITH THE RETURN OF ABUNDANT MOISTURE THIS
WEEKEND. THIS WILL BE COMING UP FROM THE SOUTH, AROUND THE BERMUDA
HIGH. THEY ALSO INDICATE SEVERAL WEAK SHORT WAVES WILL MOVE
THROUGH THE UPPER LEVEL FLOW. THESE WILL COMBINE WITH THE MOISTURE
AND DAYTIME HEATING TO ALLOW THE DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS THIS WEEKEND. CHANCES OF PRECIPITATION RISE THROUGH
THE WEEKEND.
BY SUNDAY, THE UPPER LEVEL RIDGE BEGINS TO BREAK DOWN AND A SFC
TROUGH MOVES ACROSS THE AREA. THIS WILL ALLOW SCT SHOWERS AND
STORMS THROUGHOUT THE DAY SUNDAY. CURRENTLY WENT WITH 50 POPS
ACROSS THE BOARD SUNDAY, BUT WOULD NOT BE SURPRISED IF HIGHER POPS
ARE NEEDED. THEN, AN UPPER LEVEL TROUGH FOLLOWS THE SFC TROUGH,
WHICH WILL PROLONG THE SHOWERS OVER THE CWA INTO SUNDAY NIGHT.
THERE IS SOME SMALL TIMING DIFFERENCES, BUT NOT ENOUGH TO MAKE A
SIGNIFICANT DIFFERENCE IN THE FORECAST. THERE IS THE POTENTIAL,
HOWEVER, FOR SOME HEAVY RAIN WITH ANY STORMS THAT DO DEVELOP.
CURRENT QPF TOTALS ARE AROUND A HALF INCH FROM EARLY SUNDAY
MORNING THROUGH SUNDAY AFTERNOON. SOME MODELS ARE INDICATING THAT
AROUND AND INCH TO AN INCH AND A QUARTER ARE POSSIBLE THOUGH. OF
COURSE, THIS COULD VERY WELL CHANGE, EITHER MORE OR LESS RAIN,
OVER THE NEXT COUPLE OF MODELS RUNS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
THE EXTENDED PERIOD WILL REMAIN WARM AND HUMID THROUGH WEDNESDAY WITH
A SOUTHWEST FLOW ACROSS THE REGION DUE TO RETURN FLOW FROM HIGH
PRESSURE OFF THE MID ATLANTIC COAST. SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE JUST ABOUT ANYTIME IN THIS TYPE OF PATTERN WITH THE MAIN
CHALLENGE BEING WHETHER ANY PERIODS OF ENHANCED ACTIVITY CAN BE
TIMED. COVERAGE OF STORMS IN THE ABSENCE OF SIGNIFICANT DYNAMICAL
FORCING WILL PROBABLY BE JUST 20 OR 30 PERCENT. LATEST GFS/ECMWF
GUIDANCE INDICATES THAT THE BEST CHANCE FOR STORMS WILL BE ON
WEDNESDAY AS A COLD FRONT DROPS THROUGH THE REGION. A COOLER/DRIER
AIR MASS WILL FOLLOW THE FRONT ON THURSDAY. TEMPERATURES WILL
CONTINUE TO AVERAGE ABOVE NORMAL...WITH HIGHS MAINLY IN THE MID
80S TO LOWER 90S AND LOWS IN THE 60S. HIGHS ON THURSDAY WILL BE
COOLER GENERALLY IN THE LOWER TO MIDDLE 80S.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS ARE EXPECTED THROUGH THIS TAF PERIOD AS SFC HIGH
PRESSURE REMAINS OVER THE AREA. MID LEVEL MOISTURE AND A WEAK
UPPER LEVEL DISTURBANCE WILL MAKE FOR SCT/BKN CLOUDS AROUND 6-7K FT
TODAY. ISOLATED CONVECTION WILL OCCUR THIS AFTERNOON ACROSS NE PA
AND THE SOUTHERN TIER BUT NOT INCLUDED IN TAFS DUE TO VERY LIMITED
AREAL COVERAGE. OVERNIGHT, AS THIS WAVE PASSES SKIES SHOULD
SCATTER OUT WITH THE POSSIBILITY OF MVFR VSBYS AT KELM TOWARD
DAYBREAK DUE TO BR.
LIGHT AND VARIABLE WINDS BECOMING W/SW BY LATE MORNING AROUND 5
KNOTS THEN LIGHT AGAIN TONIGHT.
OUTLOOK...
SAT/SUN/MON...GENERALLY VFR. CHC FOR SCT MVFR IN
SHWRS/TSTMS...MAINLY IN THE AFTN/EVNG.
TUE...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SLI/MDP
NEAR TERM...MDP/SLI/MM
SHORT TERM...SLI
LONG TERM...MSE/RRM
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1003 AM EDT FRI JUL 13 2012
.SYNOPSIS...
HIGH PRESSURE WILL LINGER ACROSS THE MID ATLANTIC STATES AND NEW
ENGLAND TODAY...THEN WILL SLIDE OFF THE EAST COAST DURING THE
UPCOMING WEEKEND. THIS FEATURE WILL CONTINUE TO CIRCULATE VERY WARM
AND INCREASINGLY MOIST AIR ACROSS THE REGION...RESULTING IN A
CONTINUATION OF ABOVE NORMAL TEMPERATURES...ALONG WITH SLOWLY
INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH THE
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
DEWPOINTS FROM KBUF TO KROC HAVE INCREASED 5-10F OVER THE PAST 24
HOURS WHILE DEWPOINTS WELL INLAND HAVE NOT CHANGED MUCH. THE 12Z
KBUF SOUNDING ALSO SHOWS A BIT MORE AVAILABLE LOW LEVEL MOISTURE
WITH PRECIPITABLE WATER CREEPING UP PAST THE ONE INCH MARK. WITH
MORE AVAILABLE LOW LEVEL MOISTURE...FORECAST CAPES WITH
TEMPERATURES NEAR 90 YIELD VALUES NEAR 1000J/KG. NUMEROUS RUNS OF
THE HRRR AND SOME OF THE HIGHER RES MODELS FROM SPC SHOW
CONVECTION THIS AFTERNOON ALONG LAKE BREEZES. CURRENT FORECAST
PORTRAYS THIS WELL WITH A 20-30 PERCENT CHANCE OF TSTORM
DEVELOPMENT LATER THIS AFTERNOON GENERALLY INLAND...WITH THE
HIGHEST THREAT ALONG THE LAKE ERIE BREEZE AND INTO THE HIGHER
TERRAIN IN THE SOUTHERN TIER. WILL LEAVE FORECAST ALONE ALTHOUGH
WILL ADD THE WORD INLAND TO THE WORDED ZFP. GRIDS LOOK GREAT.
AS WAS THE CASE YESTERDAY...THE VERY WEAK FLOW THROUGHOUT THE
DEPTH OF THE TROPOSPHERE WILL RESULT IN A VERY SLOW MOVEMENT TO
ANY SHOWERS AND STORMS THAT DO DEVELOP...RESULTING IN A POTENTIAL
FOR HIGHLY LOCALIZED AREAS OF HEAVY RAINFALL.
EXPECT ANY CONVECTION THAT FORMS THIS AFTERNOON TO ONCE AGAIN LINGER
INTO EARLY THIS EVENING...THEN SLOWLY DIE OUT AFTER SUNSET WITH THE
LOSS OF HEATING. THIS SHOULD RESULT IN A RETURN OF MAINLY DRY
WEATHER FOR THE SECOND HALF OF THE UPCOMING NIGHT.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
CONDITIONS STILL LOOK FAVORABLE FOR SOME BADLY NEEDED RAINFALL
DURING THIS PERIOD...ESPECIALLY ON SUNDAY WHEN AN APPROACHING UPPER
LEVEL TROUGH WILL INTERACT WITH ABUNDANT LOW LEVEL MOISTURE THAT WILL
BE IN PLACE.
ON SATURDAY...THE MODELS ARE STILL SHOWING A VARIETY OF SOLUTIONS
REGARDING THE THE TIMING AND LOCATION OF A SERIES OF SHORTWAVES THAT
WILL BE MOVING NORTH FROM THE OHIO VALLEY. THEREFORE...WILL MAINTAIN
CONTINUITY AND INDICATE A GRADUAL SOUTH TO NORTH INCREASE IN CHANCE
POPS AS THE DEEP LAYERED SOUTHERLY FLOW TRANSPORTS INCREASING
MOISTURE NORTH TOWARD THE LOWER LAKES.
AS THE UPPER LEVEL TROUGH AND EMBEDDED SHORT WAVE HEAD EAST TOWARD
THE LOWER LAKES SATURDAY NIGHT AND SUNDAY...IT WILL INTERCEPT
MOISTURE THAT WILL BE STREAMING NORTH FROM THE OHIO VALLEY. WHILE
THIS PERIOD LOOKS TO BE OUR BEST CHANCE TO RECEIVE SOME MEASURABLE
PCPN...IT MUST BE EMPHASIZED THAT THE PRECIP MODE WILL BE
CONVECTIVE...MEANING SOME AREAS HAVE THE POTENTIAL TO RECEIVE A
CONSIDERABLE AMOUNT OF RAIN IN A SHORT AMOUNT OF TIME WHILE OTHER
AREAS RECEIVE NOTHING. THIS IS NOT THE KIND STEADY RAIN OVER AN
EXTENDED PERIOD OR AREA THAT WE TYPICALLY WANT TO MITIGATE DROUGHT
CONDITIONS. HOWEVER...THE LATEST CORFIDI VECTOR ANALYSIS DOES
HINT AT THE POSSIBILITY OF BACK BUILDING CELLS SATURDAY NIGHT INTO
SUNDAY MORNING AS A MODEST LOW LEVEL JET TRACKS EAST ACROSS WESTERN
AND CENTRAL NEW YORK. IF THIS COMES TO FRUITION...MORE BENEFICIAL
RAINFALL MAY BE POSSIBLE.
THERE IS HIGH CONFIDENCE THAT THIS WILL BE A RATHER WARM AND HUMID
PERIOD. WITH DEWPOINTS EXPECTED TO BE IN THE MID AND UPPER
60S...THERE WILL BE LITTLE RELIEF FROM THE UNCOMFORTABLE CONDITIONS
SATURDAY NIGHT. OVERNIGHT LOWS WILL RANGE FROM THE MID AND UPPER 60S
ACROSS THE SOUTHERN TIER TO THE LOWER 70S ALONG THE LAKE PLAINS.
HIGH TEMPERATURES ON SATURDAY AND SUNDAY WILL RANGE THROUGH THE
80S...ALTHOUGH SUNDAY WILL BE SLIGHTLY COOLER DUE TO THE ANTICIPATED
INCREASE IN CLOUD COVER AND BETTER CHANCE FOR RAIN.
AS THE UPPER LEVEL TROUGH PUSHES EAST INTO NEW ENGLAND SUNDAY
NIGHT...EXPECT ANY ONGOING CONVECTION TO TAPER OFF GRADUALLY FROM
WEST TO EAST.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
EXPECT WARM AND HUMID WEATHER TO CONTINUE THROUGH THE FIRST PORTION
OF NEXT WEEK AS THE AREA REMAINS ON THE NORTHERN FRINGE OF RETURN
FLOW AROUND THE BERMUDA HIGH ANCHORED OFF OF THE SOUTHEAST U.S.
COAST. WITH 850MB TEMPS HOLDING AROUND +18C...AND POSSIBLY
WARMER...EXPECT AFTERNOON HIGHS TO RUN IN THE UPPER 80S AND POSSIBLY
THE LOWER 90S. WITH PLENTY OF MOISTURE STILL IN PLACE...AFTERNOON
CONVECTION...MAINLY ALONG LAKE BREEZE BOUNDARIES...CANNOT BE RULED
OUT. GIVEN THE WARM AND MOIST BOUNDARY LAYER...WIDESPREAD CONVECTION
WILL LIKELY BE LIMITED BY WEAK MID-LEVEL LAPSE RATES. THERE IS ALSO
A POSSIBILITY THAT CONVECTION MAY BE TRIGGERED OR ENHANCED BY WEAK
SHORTWAVES MOVING THROUGH THE PROGRESSIVE FLOW ALOFT.
MODEL AGREEMENT IS CURRENTLY SURPRISINGLY GOOD IN SUGGESTING A
SIGNIFICANT CHANGE BY THE MIDDLE OF NEXT WEEK. NORTHERN STEAM
SHORTWAVE ENERGY IS CURRENTLY PROGGED TO PHASE WITH AN UPPER LOW
TRACKING ACROSS NORTHERN CANADA...SWINGING A STRONG SHORTWAVE TROUGH
ACROSS THE GREAT LAKES WEDNESDAY. AN ACCOMPANYING COLD FRONT IS
CURRENTLY PREDICTED TO SWING ACROSS THE LOWER GREAT LAKES SOMETIME
LATE WEDNESDAY...RESULTING IN SIGNIFICANTLY COOLER AND DRIER WEATHER
FOR THE LATTER HALF OF NEXT WEEK.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
TODAY...EXPECT VFR CONDITIONS...WITH DIURNAL CU ALSO EXPECTED TO
REDEVELOP WITH DIURNAL HEATING.
WITH INCREASING DAYTIME INSTABILITY...ISOLATED TO SCATTERED
SHOWERS AND STORMS WILL ONCE AGAIN REDEVELOP ALONG FAVORED LAKE
BREEZE CONVERGENCE ZONES...TERRAIN FEATURES...AND LEFTOVER OUTFLOW
BOUNDARIES FROM CONVECTION YESTERDAY. THE BEST AREAL COVERAGE OF
THIS IS MOST LIKELY TO BE FROM THE WESTERN SOUTHERN TIER
NORTHEASTWARD ACROSS THE FINGER LAKES...WITH MORE SPARSE COVERAGE
MORE LIKELY FURTHER TO THE NORTH AND WEST FROM KBUF EASTWARD TO
KROC/KFZY. HAVE THEREFORE CONTINUED WITH A MENTION OF VCSH IN THE
KJHW TAF FOR NOW...WITH NO MENTION ELSEWHERE GIVEN THE EXPECTED
SPARSER COVERAGE.
TONIGHT...ANY CONVECTION SHOULD AGAIN TEND TO SLOWLY WIND DOWN
WITH THE LOSS OF HEATING THIS EVENING...LEAVING BEHIND VFR
CONDITIONS UNDER JUST SOME SCATTERED MID CLOUDS...ALONG WITH
SOME CIRRUS.
OUTLOOK...
SATURDAY AND SUNDAY...AREAS OF MVFR IN SCATTERED -SHRA/-TSRA.
MONDAY AND TUESDAY...MAINLY VFR WITH THE CHANCE OF A SHOWER OR
THUNDERSTORM.
&&
.MARINE...
HIGH PRESSURE WILL REMAIN ACROSS THE LOWER GREAT LAKES REGION
TODAY...BEFORE DRIFTING OFF THE EAST COAST THIS WEEKEND. THIS
FEATURE WILL MAINTAIN GENERALLY LIGHT WINDS AND MINIMAL WAVES
THROUGH THE WEEKEND. FAIR WEATHER WILL ALSO GENERALLY CONTINUE
THROUGH TODAY...WITH CHANCES FOR SHOWERS AND THUNDERSTORMS THEN
INCREASING DURING THE COURSE OF THE WEEKEND.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JJR
NEAR TERM...JJR/ZAFF
SHORT TERM...TJP
LONG TERM...TJP/WOOD
AVIATION...JJR
MARINE...JJR
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
558 AM EDT FRI JUL 13 2012
.SYNOPSIS...
MOSTLY QUIET WEATHER TODAY...WITH POSSIBLY AN ISOLATED SHOWER OR
EVEN A THUNDERSTORM LATE THIS AFTERNOON AS AN UPPER LEVEL RIDGE
HOLDS ON FOR ON MORE DAY. MOISTURE WILL BEGIN TO RETURN ON
SATURDAY WITH AN INCREASING CHANCE OF RAIN AND THUNDERSTORMS
THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE WEATHER SHOULD REMAIN QUIET FOR THE REMAINDER OF THE
MORNING. MODELS ARE INDICATING A MODERATE AREA OF 500MB VORT ADV
MOVING THROUGH NEPA AND THE SOUTHERN TIER THIS AFTERNOON. THERE
WILL BE MID AND UPPER LEVEL MOISTURE AVAILABLE THIS AFTERNOON AS
WELL. HOWEVER, THIS IS MOVING AROUND A FAIRLY STRONG UPPER LEVEL
RIDGE, WHICH SHOULD INHIBIT SOME OF THE DEVELOPMENT. ALSO, MODELS
ARE DIFFERING WITH COVERAGE AND TIMING OF ANY CONVECTION THIS
AFTERNOON. HAVE INCREASED COVERAGE OF POP, BUT KEPT THE ACTUAL POP
VALUE IN THE ISOLD RANGE. THERE IS PLENTY OF CAPE AROUND TODAY,
WITH THE NAM COMING IN AT AROUND 1600 JOULES OVER THE SOUTHERN
TIER TODAY. THE GFS IS NOT SO GENEROUS WITH THE CAPE, BRINGING
LESS THAN 100 JOULES TO THE SOUTHERN TIER, BUT IS SHOWING ABOUT
600 JOULES IN THE SYRACUSE AREA. BUT, BEST DYNAMICS LOOK TO BE
SOUTH OF THE GFS CAPE FORECASTED LOCATION. WENT MORE IN LINE WITH
THE NAM FOR ANY CONVECTIVE DEVELOPMENT TODAY, ALTHOUGH STILL KEPT
THE AREA FAIRLY BROAD. THE HRRR IS ALSO SHOWING SOME WEAK
DEVELOPMENT ACROSS THE CENTRAL AND SOUTHERN PORTIONS OF THE CWA
THIS AFTERNOON. AS THE DAY PROGRESSES, MBE VALUES ARE FAIRLY LOW,
SO SHOWERS MAY NOT MOVE VERY FAST, AS WAS THE CASE YESTERDAY.
ALSO, PWATS LOOK TO RISE ABOVE AN INCH LATER TODAY, WHICH BOTH
SUPPORT THE NOTION OF POSSIBLE HEAVY RAIN THAT DOES NOT MOVE VERY
MUCH, IF ANY DO DEVELOP.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
MODELS ARE IN AGREEMENT WITH THE RETURN OF ABUNDANT MOISTURE THIS
WEEKEND. THIS WILL BE COMING UP FROM THE SOUTH, AROUND THE BERMUDA
HIGH. THEY ALSO INDICATE SEVERAL WEAK SHORT WAVES WILL MOVE
THROUGH THE UPPER LEVEL FLOW. THESE WILL COMBINE WITH THE MOISTURE
AND DAYTIME HEATING TO ALLOW THE DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS THIS WEEKEND. CHANCES OF PRECIPITATION RISE THROUGH
THE WEEKEND.
BY SUNDAY, THE UPPER LEVEL RIDGE BEGINS TO BREAK DOWN AND A SFC
TROUGH MOVES ACROSS THE AREA. THIS WILL ALLOW SCT SHOWERS AND
STORMS THROUGHOUT THE DAY SUNDAY. CURRENTLY WENT WITH 50 POPS
ACROSS THE BOARD SUNDAY, BUT WOULD NOT BE SURPRISED IF HIGHER POPS
ARE NEEDED. THEN, AN UPPER LEVEL TROUGH FOLLOWS THE SFC TROUGH,
WHICH WILL PROLONG THE SHOWERS OVER THE CWA INTO SUNDAY NIGHT.
THERE IS SOME SMALL TIMING DIFFERENCES, BUT NOT ENOUGH TO MAKE A
SIGNIFICANT DIFFERENCE IN THE FORECAST. THERE IS THE POTENTIAL,
HOWEVER, FOR SOME HEAVY RAIN WITH ANY STORMS THAT DO DEVELOP.
CURRENT QPF TOTALS ARE AROUND A HALF INCH FROM EARLY SUNDAY
MORNING THROUGH SUNDAY AFTERNOON. SOME MODELS ARE INDICATING THAT
AROUND AND INCH TO AN INCH AND A QUARTER ARE POSSIBLE THOUGH. OF
COURSE, THIS COULD VERY WELL CHANGE, EITHER MORE OR LESS RAIN,
OVER THE NEXT COUPLE OF MODELS RUNS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
THE EXTENDED PERIOD WILL REMAIN WARM AND HUMID THROUGH WEDNESDAY WITH
A SOUTHWEST FLOW ACROSS THE REGION DUE TO RETURN FLOW FROM HIGH
PRESSURE OFF THE MID ATLANTIC COAST. SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE JUST ABOUT ANYTIME IN THIS TYPE OF PATTERN WITH THE MAIN
CHALLENGE BEING WHETHER ANY PERIODS OF ENHANCED ACTIVITY CAN BE
TIMED. COVERAGE OF STORMS IN THE ABSENCE OF SIGNIFICANT DYNAMICAL
FORCING WILL PROBABLY BE JUST 20 OR 30 PERCENT. LATEST GFS/ECMWF
GUIDANCE INDICATES THAT THE BEST CHANCE FOR STORMS WILL BE ON
WEDNESDAY AS A COLD FRONT DROPS THROUGH THE REGION. A COOLER/DRIER
AIR MASS WILL FOLLOW THE FRONT ON THURSDAY. TEMPERATURES WILL
CONTINUE TO AVERAGE ABOVE NORMAL...WITH HIGHS MAINLY IN THE MID
80S TO LOWER 90S AND LOWS IN THE 60S. HIGHS ON THURSDAY WILL BE
COOLER GENERALLY IN THE LOWER TO MIDDLE 80S.
&&
.AVIATION /10Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS ARE EXPECTED THROUGH THIS TAF PERIOD AS SFC HIGH
PRESSURE REMAINS OVER THE AREA. MID LEVEL MOISTURE AND A WEAK
UPPER LEVEL DISTURBANCE WILL MAKE FOR SCT/BKN CLOUDS AROUND 6-7K FT
TODAY. ISOLATED CONVECTION WILL OCCUR THIS AFTERNOON ACROSS NE PA
AND THE SOUTHERN TIER BUT NOT INCLUDED IN TAFS DUE TO VERY LIMITED
AREAL COVERAGE. OVERNIGHT, AS THIS WAVE PASSES SKIES SHOULD
SCATTER OUT WITH THE POSSIBILITY OF MVFR VSBYS AT KELM TOWARD
DAYBREAK DUE TO BR.
LIGHT AND VARIABLE WINDS BECOMING W/SW BY LATE MORNING AROUND 5
KNOTS THEN LIGHT AGAIN TONIGHT.
OUTLOOK...
SAT/SUN/MON...GENERALLY VFR. CHC FOR SCT MVFR IN
SHWRS/TSTMS...MAINLY IN THE AFTN/EVNG.
TUE...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SLI
NEAR TERM...SLI
SHORT TERM...SLI
LONG TERM...MSE/RRM
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
440 AM EDT FRI JUL 13 2012
.SYNOPSIS...
MOSTLY QUIET WEATHER TODAY...WITH POSSIBLY AN ISOLATED SHOWER OR
EVEN A THUNDERSTORM LATE THIS AFTERNOON AS AN UPPER LEVEL RIDGE
HOLDS ON FOR ON MORE DAY. MOISTURE WILL BEGIN TO RETURN ON
SATURDAY WITH AN INCREASING CHANCE OF RAIN AND THUNDERSTORMS
THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE WEATHER SHOULD REMAIN QUIET FOR THE REMAINDER OF THE
MORNING. MODELS ARE INDICATING A MODERATE AREA OF 500MB VORT ADV
MOVING THROUGH NEPA AND THE SOUTHERN TIER THIS AFTERNOON. THERE
WILL BE MID AND UPPER LEVEL MOISTURE AVAILABLE THIS AFTERNOON AS
WELL. HOWEVER, THIS IS MOVING AROUND A FAIRLY STRONG UPPER LEVEL
RIDGE, WHICH SHOULD INHIBIT SOME OF THE DEVELOPMENT. ALSO, MODELS
ARE DIFFERING WITH COVERAGE AND TIMING OF ANY CONVECTION THIS
AFTERNOON. HAVE INCREASED COVERAGE OF POP, BUT KEPT THE ACTUAL POP
VALUE IN THE ISOLD RANGE. THERE IS PLENTY OF CAPE AROUND TODAY,
WITH THE NAM COMING IN AT AROUND 1600 JOULES OVER THE SOUTHERN
TIER TODAY. THE GFS IS NOT SO GENEROUS WITH THE CAPE, BRINGING
LESS THAN 100 JOULES TO THE SOUTHERN TIER, BUT IS SHOWING ABOUT
600 JOULES IN THE SYRACUSE AREA. BUT, BEST DYNAMICS LOOK TO BE
SOUTH OF THE GFS CAPE FORECASTED LOCATION. WENT MORE IN LINE WITH
THE NAM FOR ANY CONVECTIVE DEVELOPMENT TODAY, ALTHOUGH STILL KEPT
THE AREA FAIRLY BROAD. THE HRRR IS ALSO SHOWING SOME WEAK
DEVELOPMENT ACROSS THE CENTRAL AND SOUTHERN PORTIONS OF THE CWA
THIS AFTERNOON. AS THE DAY PROGRESSES, MBE VALUES ARE FAIRLY LOW,
SO SHOWERS MAY NOT MOVE VERY FAST, AS WAS THE CASE YESTERDAY.
ALSO, PWATS LOOK TO RISE ABOVE AN INCH LATER TODAY, WHICH BOTH
SUPPORT THE NOTION OF POSSIBLE HEAVY RAIN THAT DOES NOT MOVE VERY
MUCH, IF ANY DO DEVELOP.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
MODELS ARE IN AGREEMENT WITH THE RETURN OF ABUNDANT MOISTURE THIS
WEEKEND. THIS WILL BE COMING UP FROM THE SOUTH, AROUND THE BERMUDA
HIGH. THEY ALSO INDICATE SEVERAL WEAK SHORT WAVES WILL MOVE
THROUGH THE UPPER LEVEL FLOW. THESE WILL COMBINE WITH THE MOISTURE
AND DAYTIME HEATING TO ALLOW THE DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS THIS WEEKEND. CHANCES OF PRECIPITATION RISE THROUGH
THE WEEKEND.
BY SUNDAY, THE UPPER LEVEL RIDGE BEGINS TO BREAK DOWN AND A SFC
TROUGH MOVES ACROSS THE AREA. THIS WILL ALLOW SCT SHOWERS AND
STORMS THROUGHOUT THE DAY SUNDAY. CURRENTLY WENT WITH 50 POPS
ACROSS THE BOARD SUNDAY, BUT WOULD NOT BE SURPRISED IF HIGHER POPS
ARE NEEDED. THEN, AN UPPER LEVEL TROUGH FOLLOWS THE SFC TROUGH,
WHICH WILL PROLONG THE SHOWERS OVER THE CWA INTO SUNDAY NIGHT.
THERE IS SOME SMALL TIMING DIFFERENCES, BUT NOT ENOUGH TO MAKE A
SIGNIFICANT DIFFERENCE IN THE FORECAST. THERE IS THE POTENTIAL,
HOWEVER, FOR SOME HEAVY RAIN WITH ANY STORMS THAT DO DEVELOP.
CURRENT QPF TOTALS ARE AROUND A HALF INCH FROM EARLY SUNDAY
MORNING THROUGH SUNDAY AFTERNOON. SOME MODELS ARE INDICATING THAT
AROUND AND INCH TO AN INCH AND A QUARTER ARE POSSIBLE THOUGH. OF
COURSE, THIS COULD VERY WELL CHANGE, EITHER MORE OR LESS RAIN,
OVER THE NEXT COUPLE OF MODELS RUNS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
THE EXTENDED PERIOD WILL REMAIN WARM AND HUMID THROUGH WEDNESDAY WITH
A SOUTHWEST FLOW ACROSS THE REGION DUE TO RETURN FLOW FROM HIGH
PRESSURE OFF THE MID ATLANTIC COAST. SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE JUST ABOUT ANYTIME IN THIS TYPE OF PATTERN WITH THE MAIN
CHALLENGE BEING WHETHER ANY PERIODS OF ENHANCED ACTIVITY CAN BE
TIMED. COVERAGE OF STORMS IN THE ABSENCE OF SIGNIFICANT DYNAMICAL
FORCING WILL PROBABLY BE JUST 20 OR 30 PERCENT. LATEST GFS/ECMWF
GUIDANCE INDICATES THAT THE BEST CHANCE FOR STORMS WILL BE ON
WEDNESDAY AS A COLD FRONT DROPS THROUGH THE REGION. A COOLER/DRIER
AIR MASS WILL FOLLOW THE FRONT ON THURSDAY. TEMPERATURES WILL
CONTINUE TO AVERAGE ABOVE NORMAL...WITH HIGHS MAINLY IN THE MID
80S TO LOWER 90S AND LOWS IN THE 60S. HIGHS ON THURSDAY WILL BE
COOLER GENERALLY IN THE LOWER TO MIDDLE 80S.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS ARE EXPECTED THROUGH THIS TAF PERIOD AS SFC HIGH
PRESSURE REMAINS OVER THE AREA. INCREASING MID LEVEL MOISTURE AND
AND A WEAK MID LEVEL DISTURBANCE WILL MAKE FOR SCT/BKN CLOUDS
AROUND 6-7K FT THROUGH THE PERIOD. FOG IS NOT EXPECTED AT KELM
THIS MORNING DUE TO MID LEVEL CLOUDS AND A LARGE TEMP/DEW POINT
SPREAD AT 05Z. ISOLATED CONVECTION WILL OCCUR THIS AFTERNOON
ACROSS NE PA AND THE SOUTHERN TIER BUT NOT INCLUDED IN TAFS DUE TO
VERY LIMITED AREAL COVERAGE.
LIGHT AND VARIABLE WINDS BECOMING W/SW BY MID MORNING AROUND 5
KNOTS THEN LIGHT AGAIN TONIGHT.
OUTLOOK...
SAT/SUN/MON...GENERALLY VFR. CHC FOR SCT MVFR IN
SHWRS/TSTMS...MAINLY IN THE AFTN/EVNG.
TUE...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SLI
NEAR TERM...SLI
SHORT TERM...SLI
LONG TERM...MSE/RRM
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1025 PM EDT SAT JUL 14 2012
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL EXTEND ACROSS THE AREA THROUGH THE
MIDDLE OF NEXT WEEK. A COLD FRONT WILL APPROACH FROM THE NORTH LATE
NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM SATURDAY...ASIDE FROM A FEW TWEAKS TO SKY COVER AND
DEWPOINT...ALL OTHER FORECAST ELEMENTS ARE ON TRACK WITH PRIOR
FORECASTS. SCATTERED SHOWERS DEVELOPING ACROSS THE GULF STREAM MAY
MAKE IT TO THE BEACHES AFTER 3-4 AM ACCORDING TO LINEAR
EXTRAPOLATION AND THE LATEST HRRR MODEL RUN. PREVIOUS DISCUSSION
FROM 730 PM FOLLOWS...
BERMUDA HIGH PRESSURE CONTINUES TO PUMP A HUMID TROPICAL AIRMASS
ONSHORE IN THE LOWEST LEVELS. THERE IS A RATHER STEEP DECREASE IN
MOISTURE ALOFT WITH PRECIPITABLE WATER VALUES ABOUT A HALF INCH
LOWER THAN THIS TIME LAST NIGHT...MAINLY DUE TO DECREASES IN
MOISTURE BETWEEN 950-400 MB. WITH LIGHT SURFACE WINDS TONIGHT AND
MAINLY CLEAR SKIES LOWS SHOULD FALL INTO THE LOWER 70S AWAY FROM THE
BEACHES...NEAR OR EVEN A DEGREE BELOW NORMAL FOR MOST AREAS. A FEW
OF THE MARINE SHOWERS OBSERVED ON SATELLITE AND RADAR MAY WORK THEIR
WAY ONSHORE FOR THE COASTAL COUNTIES LATE THIS EVENING AND
OVERNIGHT...BUT ANY MEASURABLE RAIN SHOULD REMAIN ISOLATED IN NATURE.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 2 PM SATURDAY...BERMUDA RIDGE WILL EXTEND ACROSS THE EASTERN
CAROLINAS AT THE BEGINNING OF THE PERIOD...WITH A SLIGHT TRANSLATION
TO THE SE...AWAY FROM THE AREA DURING THE LATER PORTION OF THE
PERIOD. THE SEABREEZE BOUNDARY WILL BE PRESENT...BUT PINNED CLOSER
TO THE COAST MON VS SUN GIVEN 800-900 MB FLOW WILL BE MORE WESTERLY.
DEVELOPING PIEDMONT TROUGH WILL BECOME RATHER PRONOUNCED MON
AFTERNOON AND EVE.
HIGH PRESSURE ALOFT WILL PERSIST INTO SUN...AND THEN BREAK DOWN AS
WE GO INTO MON. LOW PRESSURE ALOFT...CURRENTLY SEEN ON WATER VAPOR
IMAGERY NEAR 29.4 N AND 72.3 W...WILL CONTINUE TO MOVE W TOWARD THE
LOWER SOUTHEAST COAST AND SOME OF THE MODELS HAVE THIS FEATURE
REACHING THE COAST ON MON.
AIRMASS WILL BE DRIER ON SUN AND SUBSIDENCE WILL BE STRONGER...
HOWEVER...DEEP EASTERLY FLOW SHOULD ALLOW SHOWERS ACROSS THE WATERS
TO REACH THE IMMEDIATE COAST WHILE OTHER SHOWERS DEVELOP ALONG THE
SEABREEZE BOUNDARY AND MOVE WELL INLAND GIVEN THE EASTERLY FLOW.
RAINFALL RATES SHOULD BE MUCH LOWER THAN EARLIER IN THE WEEK GIVEN
THE PRESENCE OF DRIER AIR. CONVECTION SHOULD ALSO BE RATHER SHALLOW
WITH A CAP DEVELOPING AROUND 10 KFT. AT THIS TIME...EXPECT
CONVECTION WILL BE ISOLATED TO PERHAPS WIDELY SCATTERED WITH MOST
LOCATIONS BEING RAIN FREE THROUGH THE DAY. ANY CONVECTION SHOULD END
QUICKLY DURING THE EVE AND WITH DEVELOPING LAND BREEZE...EXPECT ANY
SHOWERS OFFSHORE WILL NOT BE ABLE TO PUSH ON SHORE OVERNIGHT AS FLOW
BECOMES WESTERLY.
ON MON...AS RIDGING BREAKS DOWN...SOME CONVECTION SHOULD BE ABLE TO
FORM ALONG THE STRENGTHENING PIEDMONT TROUGH AND PERHAPS THE
SEABREEZE...NEAR THE COAST. PRECIPITABLE WATER VALUES BEGIN TO
INCREASE AND SHOULD BE BETWEEN 1.75 AND 2 INCHES MON AFTERNOON AND
EVE. STILL SOME CAPPING EVIDENT AROUND 12 KFT...SO NOT WILLING TO GO
MUCH HIGHER THAN SLIGHT CHANCE/SMALL CHANCE AT THIS TIME. SHOULD
UPPER LOW/TROUGH TO OUR S BE STRONGER OR FURTHER N...THAN CURRENTLY
EXPECTED...THAN CONVECTIVE COVERAGE MAY NEED TO BE INCREASED WITH
LATER FORECASTS.
EASTERLY FLOW ON SUN WILL ALLOW MARINE INFLUENCES TO PENETRATE WELL
INLAND...ACTING TO MODIFY THE MAXIMUM TEMP FORECAST...AND WILL KEEP
HIGHS WITHIN A DEG OR TWO OF THE 90 DEG MARK...LOWEST ALONG THE
IMMEDIATE COAST. A MORE WESTERLY FLOW ON MON...SHOULD BE ENOUGH TO
ADD A COUPLE OF DEG TO THOSE HIGHS. OVERNIGHTS LOWS WILL BE IN THE
LOWER TO MID 70S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 2 PM SATURDAY...MAIN FOCUS OF THE EXTENDED FORECAST IS ON
THE LATTER PERIODS WHEN AN EAST COAST TROUGH DEVELOPS AS RIDGING
SHIFTS TO THE WEST. THIS SITUATION LOOKS SOMEWHAT SIMILAR TO THE
SYNOPTIC PATTERN ACROSS OUR AREA THE PAST FEW DAYS.
EARLY ON...A DIFFUSE MID LEVEL PATTERN WILL PREVAIL WITH A GENERAL
WEAKNESS OF HEIGHTS ACROSS THE SOUTHEAST AS WEAK RIDGING PREVAILS
ACROSS THE MISSISSIPPI VALLEY. AT THE SURFACE...THE PIEDMONT TROUGH
AND SEA BREEZE WILL BE THE FOCUS OF DIURNAL SHOWERS AND
THUNDERSTORMS WITH MINIMAL CHANCES BOTH TUESDAY AND WEDNESDAY.
MEDIUM RANGE GUIDANCE IS IN GOOD AGREEMENT WITH HEIGHT FALLS FOR
THURSDAY THROUGH SATURDAY WITH A SURFACE FRONT MOVING FROM THE MID
ATLANTIC TO TAKING RESIDENCE ACROSS CAPE FEAR BY
SATURDAY...AGAIN...NOT UNLIKE THE SITUATION WE EXPERIENCED THIS LAST
WEEK SO THE PROSPECTS FOR ANOTHER SEVERAL DAYS OF BENEFICIAL RAINS
LOOK GOOD AT THIS POINT. INCREASED POPS TO GOOD CHANCE NORTHERN
AREAS THURSDAY AND ALL AREAS FRIDAY AND SATURDAY.
REGARDING TEMPERATURES...NO REAL SURPRISES FOR THE MIDDLE OF JULY
WITH WARM READINGS EARLY ON...PERHAPS A COUPLE OF DEGREES ABOVE
CLIMATOLOGY TRENDING SLIGHTLY COOLER LATER IN THE PERIOD COURTESY OF
THE BETTER COVERAGE OF SHOWERS AND THUNDERSTORMS.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AS OF 00Z...SEA BREEZE CONVECTION HAS ABOUT ENDED FOR THE NIGHT. IT
IS NOT IMPOSSIBLE THOUGH THAT COASTAL TERMINALS COULD SEE A PASSING
SHOWER AFTER SUNSET AS LAND BREEZE BEGINS TO SET UP AND SE FLOW
ENCROACHES UPON IT. CONFIDENCE OF ANY ONE TERMINAL BEING IMPACTED
IS LOW. OVERNIGHT...EXPECTATIONS ARE SIMILAR TO LAST NIGHT WITH
MVFR FOG POSSIBLE AT ALL TERMINALS FOR BRIEF PERIODS EXCEPT AT LBT
WHERE IFR CONDITIONS ARE POSSIBLE. MORE SEA BREEZE CONVECTION IS
EXPECTED AFTER ABOUT 17Z SUNDAY BUT COVERAGE SHOULD BE LIMITED AND
TSRA WILL NOT BE INCLUDED AT TAFS AT THIS TIME. SE FLOW WILL
CONTINUE DURING DAYLIGHT HOURS THROUGH THE PERIOD.
EXTENDED OUTLOOK...CHANCE OF AFTERNOON SHOWERS AND MORNING FOG EACH
DAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM SATURDAY...NO CHANGES ARE NEEDED WITH THIS LATE
EVENING NEAR TERM UPDATE. PREVIOUS DISCUSSION FROM 730 PM
FOLLOWS...
BERMUDA HIGH PRESSURE WELL OFFSHORE EXTENDS A RIDGE AXIS WEST AND
TOWARD THE NC COASTLINE. SOUTHEASTERLY FLOW SOUTH OF THE RIDGE WILL
CONTINUE THROUGH THE NIGHT AVERAGING 10 KNOTS. CONTAINED WITHIN THIS
TROPICAL AIRMASS ARE ISOLATED BRIEF SHOWERS VISIBLE ON SATELLITE AND
RADAR DATA ACROSS TENS OF THOUSANDS OF SQUARE MILES OF THE WESTERN
ATLANTIC. A FEW OF THESE WILL PROBABLY WORK THEIR WAY INTO THE
COASTAL WATERS LATE THIS EVENING AND OVERNIGHT. SEAS AVERAGE 2-3 FT
THIS EVENING...HIGHEST NORTH OF CAPE FEAR...WITH DOMINANT PERIODS
5-6 SECONDS (WIND WAVE) AND 8-9 SECONDS (SOUTHEAST SWELL.)
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 2 PM SATURDAY...BERMUDA RIDGE WILL MAINTAIN A SE TO SSE WIND
ACROSS THE WATERS SUN. THE SEABREEZE BOUNDARY WILL ENHANCE THE WINDS
ACROSS THE NEAR SHORE WATERS SLIGHTLY...BUT STILL SUSTAINED WINDS
WILL BE HELD TO AROUND 10 KT. THE WIND DIRECTION WILL VEER TO SW SUN
NIGHT AND SPEEDS SHOULD INCREASE SLIGHTLY AS THE PIEDMONT TROUGH
DEVELOPS AND STRENGTHENS MON AFTERNOON AND INTO MON NIGHT WITH
MODEST NOCTURNAL JETTING NOTED. WILL CAP SUSTAINED SW WINDS AT 15 KT
LATER MON AFTERNOON AND NIGHT. SEAS WILL BE IN THE 2 TO 4 FT RANGE
THROUGH THE PERIOD. A WEAK 8 TO 9 SECOND EASTERLY SWELL WILL BE
PRESENT THROUGH THE PERIOD.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 2 PM SATURDAY...SUMMERTIME PATTERN CONTINUES FOR THE MARINE
COMMUNITY WITH A SOUTHWESTERLY FLOW OF 10-15 KNOTS THROUGH THE
PERIOD. WINDS MAY INCREASE SLIGHTLY LATE IN THE PERIOD AS A FRONT
MOVING IN FROM THE MID ATLANTIC ENHANCES THE PIEDMONT TROUGH.
WINDS AT THAT POINT COULD INCREASE TO A RANGE OF 15-20 KNOTS. SEAS
ARE 2-4 FEET THROUGHOUT BUT COULD INCREASE LATE WEDNESDAY INTO
THURSDAY VIA THE ENHANCEMENT OF THE PIEDMONT TROUGH WITH THE
POSSIBILITY OF SOME FIVE FOOTERS.
&&
.EQUIPMENT...
AS OF 1030 PM SATURDAY...PLEASE BE CAREFUL USING PRECIPITATION DATA
FROM THE FLORENCE SC ASOS (KFLO) UNTIL TECHNICIANS ARE ABLE TO
ACCESS WHAT IS WRONG WITH THE RAIN GAUGE. SEVERAL TIMES EARLIER THIS
YEAR THE GAUGE BECAME CLOGGED WITH BIRD DROPPINGS...AND THIS MAY
HAVE HAPPENED AGAIN TODAY WHERE VERY LARGE DIFFERENCES BETWEEN
RADAR-ESTIMATED RAINFALL AND ASOS-REPORTED RAINFALL EXIST.
ALSO...OBSERVATIONS FROM THE SOUTHPORT NC (KSUT) AWOS OF REDUCED
VISIBILITY AND A LOW CLOUD CEILING THIS EVENING ARE PROBABLY FALSE.
SIMILAR DUBIOUS OBSERVATIONS OCCURRED AT THIS STATION LAST NIGHT.
THIS AWOS IS MAINTAINED BY THE NC DEPARTMENT OF TRANSPORTATION AND
NOT THE NWS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...RJD
LONG TERM...SHK
AVIATION...RAN
EQUIPMENT...TRA
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
630 AM EDT FRI JUL 13 2012
.SYNOPSIS...
A WEAK FRONT STALLED OVER THE CAROLINAS PLUS A HUMID TROPICAL
AIRMASS WILL BRING A CONTINUING RISK OF SHOWERS AND THUNDERSTORMS
THROUGH SATURDAY. A GRADUAL DRYING TREND WILL BEGIN SATURDAY AS
BERMUDA HIGH PRESSURE STRENGTHENS OVER THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 333 AM FRIDAY...MODELS INDICATE DEEPER ONSHORE TROPICAL
FLOW...E TO SE WINDS...WILL BECOME MORE DOMINATE THRU THE ATM COLUMN
DURING THIS NEAR TERM PERIOD. NAMBUFR HOURLY SOUNDINGS THRU SATURDAY
MORNING HIGHLIGHT THIS NICELY. VIA LATEST KLTX 88D...ALONG WITH THE
LATEST HRRR MODEL RUNS...THE ADJACENT ATLANTIC NOCTURNAL SHRA ENGINE
HAS RAMPED UP EARLY THIS MORNING. TRAJECTORIES MOVE THIS
ISOLATED/SCATTERED PCPN OCCASIONALLY ONSHORE THROUGH SUNRISE...WITH
MUCH OF IT DISSIPATING AS IT MOVES FURTHER INLAND. THIS ENGINE WILL
SLOWLY DWINDLE DOWN AFTER SUNRISE. PWS TO REMAIN IN THAT 2 INCH
REALM THRUOUT THE NEAR TERM AND WILL NOT TAKE TOO MUCH FORCING TO
IGNITE CONVECTION DURING THE DAY. DRIER AIR TO EVENTUALLY START
FILTERING INTO THE FA BY SATURDAY. NEVERTHELESS...THE DAYS
INSOLATION TO PROVIDE SOME DESTABILIZATION SEVERAL HRS AFTER SUNRISE
ALLOWING FOR CONVECTION TO DEVELOP MAINLY ALONG THE IMMEDIATE COAST.
THE ACTIVITY WILL EXPAND INLAND THRUOUT THE DAY. MODEL SOUNDINGS
INDICATE CONTINUED SLOW STORM MOTIONS IE. NW AT 5 MPH...AND WITH
PCPN MORE TROPICAL IN NATURE...EXPECT POSSIBLE HEAVY DOWNPOURS FROM
ANY CONVECTIVE ACTIVITY...EVEN WITHOUT THE PRESENCE OF THUNDER.
ONCE THE DAYS INSOLATION ENDS...OR THE AVAILABLE CAPE IS USED
UP...CONVECTION WILL QUICKLY DISSIPATE THIS EVENING...LEAVING
CONVECTIVE DEBRIS CLOUDS FOR THE REMAINDER OF TONIGHT. MODELS AGAIN
RAMP UP THE NOCTURNAL ATLANTIC SHRA ENGINE AFTER MIDNIGHT
TONIGHT...WITH SPORADIC ONSHORE MOVEMENT OF THE PCPN. AS FOR MAX/MIN
TEMPS...MAINLY COMPROMISED BETWEEN THE NAM AND GFS MOS GUIDANCE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY..UPPER RIDGE BUILDS INTO THE REGION FROM POINTS
EAST ON SATURDAY. MEANWHILE SURFACE HIGH ACROSS THE WEST ATLANTIC
REMAINS QUITE WEAK. A VERY DEEP BUT WEAK EAST TO SOUTHEASTERLY FLOW
WILL SET UP AND THE MID LEVELS WILL DRY SLIGHTLY BUT NOT SO MUCH HAD
THE HEIGHT RISES BUILT IN FROM THE WEST. SOME VERY BRIEF MORNING
TROPICAL SHOWERS APPEAR POSSIBLE ALONG THE COAST MAINLY IN THE
MORNING. AFTERNOON CONVECTION SHOULD BE ISOLATED AT BEST DUE TO THE
MID LEVEL DRYING...AND MAY STAY WEST OF THE FORECAST AREA
ALTOGETHER. AN UPPER LOW WILL BE APPROACHING IN THE EASTERLY FLOW
AND MODEL SPREAD IS CONSIDERABLE WITH NOT ONLY THE TRACK OF THIS
SYSTEM BUT ALSO WHETHER OR NOT IT HAS ANY SURFACE REFLECTION. MODELS
HAVE SLOWED WITH ITS PROGRESSION AND IT NOW LOOKS LIKE IT WILL STAY
EAST OF THE REGION DURING THE SHORT TERM...IF IT AFFECTS US AT ALL.
SUNDAY WILL THUS END UP VERY SIMILAR TO SATURDAY AS FAR AS RAIN
DISTRIBUTION AND CHANCES. GUIDANCE SHOWING SUNDAY AFTERNOON TURNING
OUT A LITTLE WARMER THAN SAT BUT NOT SO MUCH AS PREV FCST SO A SMALL
TWEAK WAS MADE THERE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...BARRING ANY SIGNIFICANT WEATHER RESULTING FROM
THE UPPER LOW COMING FROM THE EAST THE LONG TERM LOOKS VERY QUIET.
AFOREMENTIONED LOW MAY RECURVE FROM THE COAST OR CONTINUE WESTWARD
OVER LAND...MODELS AREN`T TOO SURE. OTHERWISE MID LEVEL FLOW WILL BE
LIGHT AND VARIABLE AND THE WEST ATLANTIC HIGH WILL SHOW LITTLE
MOVEMENT. MOISTURE RETURN LOOKS WEAK BUT SOME ISOLATED DIURNAL
CONVECTION STILL SEEMS LIKELY EACH DAY. TEMPERATURES WILL BE RIGHT
WHERE THEY SHOULD BE FOR THE TIME OF YEAR.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 12Z...LIFR CONDITIONS INLAND SHOULD MIX OUT FAIRLY QUICKLY
WITH THE JULY SUN...13-14Z. A MVFR CUMULUS CEILING MAY FORM AROUND
14Z...WITH HIGH PWATS AND LOW LFC. ONSHORE FLOW WILL CREATE SHOWERS
A BIT EARLIER THAN USUAL ALONG THE SEA BREEZE BOUNDARY...MOVING WEST
OF THE COASTAL TERMINALS BY 18-19Z. A RUMBLE OF THUNDER IS
POSSIBLE...BUT MOST OF THE ACTIVITY WILL BE LOW TOPPED...TROPICAL IN
NATURE. TONIGHT...SOUTHEAST FLOW WILL PREVAIL THROUGH MOST OF THE
TROPOSPHERE WITH EXCELLENT VISIBILITIES EARLY. POSSIBLE MVFR FOG
TOWARD MORNING...DEPENDING ON CLOUD COVER AND RADIATIONAL COOLING
CONDITIONS.
EXTENDED OUTLOOK...A CHANCE OF THUNDERSTORMS EACH DAY...MAINLY IN
THE AFTERNOON AND EVENING. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 345 AM FRIDAY...THE SFC RIDGE AXIS EXTENDING WEST AND INLAND
FROM THE WESTERN ATLANTIC HIGH AKA BERMUDA HIGH...WILL REMAIN JUST
NORTH OF THE COASTAL WATERS. THIS SFC PRESSURE PATTERN WILL YIELD A
E-SE WIND FLOW AROUND 10 KT. IN FACT BY SATURDAY MORNING...MODEL
SOUNDINGS OVER THE WATERS INDICATE A DEEP TROPICAL SE FLOW TO HAVE
EVOLVED...IE. SFC THRU 50K FT. THE SFC PG WILL REMAIN RATHER RELAXED
THRU THE PERIOD...RESULTING WITH CONTINUED 10 KT WIND SPEEDS.
SCATTERED ATLANTIC SHRA ACTIVITY WILL BE HIGHER DURING THE NOCTURNAL
PORTIONS OF THE 24 HR DAY...WANING TO JUST ISOLATED DURING THE DAY.
SIG SEAS WILL BECOME DOMINATED BY THE ESE GROUND SWELL AT 1 TO 2
FT...BUILDING TO 2 TO 3 FT...AND LIKELY HIGHER BEYOND THE NEAR TERM
PERIOD. WAVEWATCH3 ILLUSTRATES THE INITIAL SWELL INCREASE
TODAY...AND THEN FURTHER BUILDING IT TO POSSIBLY UP TO 4 FT
SATURDAY. RIP CURRENT RISK WILL BE ON THE INCREASE THIS WEEKEND.
THE IN-HOUSE WATERSPOUT RISK ASSESSMENT PLACES A MODERATE CHANCE
ACROSS THE LOCAL WATERS TODAY. WILL HIGHLIGHT ITS POSSIBILITY IN THE
COASTAL SECTION OF THE HAZARDOUS WEATHER OUTLOOK.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY..WEAK HIGH PRESSURE ACROSS THE WESTERN ATLANTIC ON
SATURDAY WITH A SIMILARLY SUBTLE TROUGH WELL OFF THE COAST BY
SUNDAY. THE LATTER WILL TILT FLOW FROM THE SOUTHEAST TO EAST OR EVEN
NORTHEASTER WHILE SPEEDS REMAIN CAPPED AT JUST 10 KT. THE UPPER
FEATURE DEVELOPING THIS TROUGH IS RATHER STRONG BY JULY STANDARDS
AND COULD LEAD TO A SURFACE FEATURE STRONGER THAN CURRENTLY DEPICTED
IN GUIDANCE. IF THIS TURNS OUT TO BE THE CASE THEN WINDS WILL BE A
BIT HIGHER THAN FORECAST WITH A SIMILAR ADJUSTMENT MAYBE NEEDED FOR
SEAS. OTHERWISE WAVES WILL STAY AT OR BELOW 3 FT.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM FRIDAY...SOUTHWEST WINDS GENERALLY IN THE 10 TO 15 KT
RANGE AND SEAS AVERAGING 2 TO 4 FT THROUGH THE PERIOD...THE MOST
COMMON SET OF CONDITIONS LOCALLY FOR THE SUMMER. HIGH PRESSURE
ACROSS THE WEST ATLANTIC WILL BE FAIRLY WEAK. SWELL ENERGY PROGGED
TO BE AROUND 10 SEC AND THE WIND CHOP 4-5 SECONDS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...DCH
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
405 AM EDT FRI JUL 13 2012
.SYNOPSIS...
A WEAK FRONT STALLED OVER THE CAROLINAS PLUS A HUMID TROPICAL
AIRMASS WILL BRING A CONTINUING RISK OF SHOWERS AND THUNDERSTORMS
THROUGH SATURDAY. A GRADUAL DRYING TREND WILL BEGIN SATURDAY AS
BERMUDA HIGH PRESSURE STRENGTHENS OVER THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 333 AM FRIDAY...MODELS INDICATE DEEPER ONSHORE TROPICAL
FLOW...E TO SE WINDS...WILL BECOME MORE DOMINATE THRU THE ATM COLUMN
DURING THIS NEAR TERM PERIOD. NAMBUFR HOURLY SOUNDINGS THRU SATURDAY
MORNING HIGHLIGHT THIS NICELY. VIA LATEST KLTX 88D...ALONG WITH THE
LATEST HRRR MODEL RUNS...THE ADJACENT ATLANTIC NOCTURNAL SHRA ENGINE
HAS RAMPED UP EARLY THIS MORNING. TRAJECTORIES MOVE THIS
ISOLATED/SCATTERED PCPN OCCASIONALLY ONSHORE THROUGH SUNRISE...WITH
MUCH OF IT DISSIPATING AS IT MOVES FURTHER INLAND. THIS ENGINE WILL
SLOWLY DWINDLE DOWN AFTER SUNRISE. PWS TO REMAIN IN THAT 2 INCH
REALM THRUOUT THE NEAR TERM AND WILL NOT TAKE TOO MUCH FORCING TO
IGNITE CONVECTION DURING THE DAY. DRIER AIR TO EVENTUALLY START
FILTERING INTO THE FA BY SATURDAY. NEVERTHELESS...THE DAYS
INSOLATION TO PROVIDE SOME DESTABILIZATION SEVERAL HRS AFTER SUNRISE
ALLOWING FOR CONVECTION TO DEVELOP MAINLY ALONG THE IMMEDIATE COAST.
THE ACTIVITY WILL EXPAND INLAND THRUOUT THE DAY. MODEL SOUNDINGS
INDICATE CONTINUED SLOW STORM MOTIONS IE. NW AT 5 MPH...AND WITH
PCPN MORE TROPICAL IN NATURE...EXPECT POSSIBLE HEAVY DOWNPOURS FROM
ANY CONVECTIVE ACTIVITY...EVEN WITHOUT THE PRESENCE OF THUNDER.
ONCE THE DAYS INSOLATION ENDS...OR THE AVAILABLE CAPE IS USED
UP...CONVECTION WILL QUICKLY DISSIPATE THIS EVENING...LEAVING
CONVECTIVE DEBRIS CLOUDS FOR THE REMAINDER OF TONIGHT. MODELS AGAIN
RAMP UP THE NOCTURNAL ATLANTIC SHRA ENGINE AFTER MIDNIGHT
TONIGHT...WITH SPORADIC ONSHORE MOVEMENT OF THE PCPN. AS FOR MAX/MIN
TEMPS...MAINLY COMPROMISED BETWEEN THE NAM AND GFS MOS GUIDANCE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY..UPPER RIDGE BUILDS INTO THE REGION FROM POINTS
EAST ON SATURDAY. MEANWHILE SURFACE HIGH ACROSS THE WEST ATLANTIC
REMAINS QUITE WEAK. A VERY DEEP BUT WEAK EAST TO SOUTHEASTERLY FLOW
WILL SET UP AND THE MID LEVELS WILL DRY SLIGHTLY BUT NOT SO MUCH HAD
THE HEIGHT RISES BUILT IN FROM THE WEST. SOME VERY BRIEF MORNING
TROPICAL SHOWERS APPEAR POSSIBLE ALONG THE COAST MAINLY IN THE
MORNING. AFTERNOON CONVECTION SHOULD BE ISOLATED AT BEST DUE TO THE
MID LEVEL DRYING...AND MAY STAY WEST OF THE FORECAST AREA
ALTOGETHER. AN UPPER LOW WILL BE APPROACHING IN THE EASTERLY FLOW
AND MODEL SPREAD IS CONSIDERABLE WITH NOT ONLY THE TRACK OF THIS
SYSTEM BUT ALSO WHETHER OR NOT IT HAS ANY SURFACE REFLECTION. MODELS
HAVE SLOWED WITH ITS PROGRESSION AND IT NOW LOOKS LIKE IT WILL STAY
EAST OF THE REGION DURING THE SHORT TERM...IF IT AFFECTS US AT ALL.
SUNDAY WILL THUS END UP VERY SIMILAR TO SATURDAY AS FAR AS RAIN
DISTRIBUTION AND CHANCES. GUIDANCE SHOWING SUNDAY AFTERNOON TURNING
OUT A LITTLE WARMER THAN SAT BUT NOT SO MUCH AS PREV FCST SO A SMALL
TWEAK WAS MADE THERE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...BARRING ANY SIGNIFICANT WEATHER RESULTING FROM
THE UPPER LOW COMING FROM THE EAST THE LONG TERM LOOKS VERY QUIET.
AFOREMENTIONED LOW MAY RECURVE FROM THE COAST OR CONTINUE WESTWARD
OVER LAND...MODELS AREN`T TOO SURE. OTHERWISE MID LEVEL FLOW WILL BE
LIGHT AND VARIABLE AND THE WEST ATLANTIC HIGH WILL SHOW LITTLE
MOVEMENT. MOISTURE RETURN LOOKS WEAK BUT SOME ISOLATED DIURNAL
CONVECTION STILL SEEMS LIKELY EACH DAY. TEMPERATURES WILL BE RIGHT
WHERE THEY SHOULD BE FOR THE TIME OF YEAR.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 06Z...PERIODS OF MVFR/IFR OVERNIGHT DUE FOG/STRATUS THROUGH
THE EARLY FRIDAY MORNING HRS. MORNING MVFR CONVECTION AT THE COASTAL
TERMS...WILL EXPAND TO THE INLAND TERMS THIS AFTERNOON.
FCST GUIDANCE/LATEST KLTX88D SUGGEST ADDITIONAL SHRA/TSRA TO
DEVELOP OVER THE ADJACENT ATLANTIC WATERS EARLY THIS MORNING
...SPORADICALLY MOVING ONSHORE PRIOR TO SUNRISE. FOR NOW HAVE
INTRODUCED VCSH. GIVEN ABUNDANT RAINFALL IN SOME LOCATIONS AND LIGHT
AND VARIABLE WINDS...ANTICIPATE MVFR FOG...WITH MVFR/IFR LOW CIGS
DUE TO STRATUS EARLY THIS MORNING. EXPECT ANY LINGERING FOG TO CLEAR
OUT BY SEVERAL HRS AFTER SUNRISE. GUIDANCE DEPICTS CIGS BETWEEN
2000-3000FT AND ISOLATED/SCATTERED TSRA AT THE COAST AFTER
SUNRISE...EXPANDING INLAND BY THE EARLY AFTERNOON. SYNOPTIC NE-E
WINDS 5 KT OR LESS THIS MORNING WILL VEER TO THE SE 5 TO 10 KT...
WITH GUSTS UP TO 15 KT AT THE COASTAL TERMS...BY MIDDAY. ANTICIPATE
STORMS TO GRADUALLY TAPER OFF INTO THE LATE EVENING HOURS.
EXTENDED OUTLOOK...A CHANCE OF THUNDERSTORMS EACH DAY...MAINLY IN
THE AFTERNOON AND EVENING. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 345 AM FRIDAY...THE SFC RIDGE AXIS EXTENDING WEST AND INLAND
FROM THE WESTERN ATLANTIC HIGH AKA BERMUDA HIGH...WILL REMAIN JUST
NORTH OF THE COASTAL WATERS. THIS SFC PRESSURE PATTERN WILL YIELD A
E-SE WIND FLOW AROUND 10 KT. IN FACT BY SATURDAY MORNING...MODEL
SOUNDINGS OVER THE WATERS INDICATE A DEEP TROPICAL SE FLOW TO HAVE
EVOLVED...IE. SFC THRU 50K FT. THE SFC PG WILL REMAIN RATHER RELAXED
THRU THE PERIOD...RESULTING WITH CONTINUED 10 KT WIND SPEEDS.
SCATTERED ATLANTIC SHRA ACTIVITY WILL BE HIGHER DURING THE NOCTURNAL
PORTIONS OF THE 24 HR DAY...WANING TO JUST ISOLATED DURING THE DAY.
SIG SEAS WILL BECOME DOMINATED BY THE ESE GROUND SWELL AT 1 TO 2
FT...BUILDING TO 2 TO 3 FT...AND LIKELY HIGHER BEYOND THE NEAR TERM
PERIOD. WAVEWATCH3 ILLUSTRATES THE INITIAL SWELL INCREASE
TODAY...AND THEN FURTHER BUILDING IT TO POSSIBLY UP TO 4 FT
SATURDAY. RIP CURRENT RISK WILL BE ON THE INCREASE THIS WEEKEND.
THE IN-HOUSE WATERSPOUT RISK ASSESSMENT PLACES A MODERATE CHANCE
ACROSS THE LOCAL WATERS TODAY. WILL HIGHLIGHT ITS POSSIBILITY IN THE
COASTAL SECTION OF THE HAZARDOUS WEATHER OUTLOOK.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY..WEAK HIGH PRESSURE ACROSS THE WESTERN ATLANTIC ON
SATURDAY WITH A SIMILARLY SUBTLE TROUGH WELL OFF THE COAST BY
SUNDAY. THE LATTER WILL TILT FLOW FROM THE SOUTHEAST TO EAST OR EVEN
NORTHEASTER WHILE SPEEDS REMAIN CAPPED AT JUST 10 KT. THE UPPER
FEATURE DEVELOPING THIS TROUGH IS RATHER STRONG BY JULY STANDARDS
AND COULD LEAD TO A SURFACE FEATURE STRONGER THAN CURRENTLY DEPICTED
IN GUIDANCE. IF THIS TURNS OUT TO BE THE CASE THEN WINDS WILL BE A
BIT HIGHER THAN FORECAST WITH A SIMILAR ADJUSTMENT MAYBE NEEDED FOR
SEAS. OTHERWISE WAVES WILL STAY AT OR BELOW 3 FT.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM FRIDAY...SOUTHWEST WINDS GENERALLY IN THE 10 TO 15 KT
RANGE AND SEAS AVERAGING 2 TO 4 FT THROUGH THE PERIOD...THE MOST
COMMON SET OF CONDITIONS LOCALLY FOR THE SUMMER. HIGH PRESSURE
ACROSS THE WEST ATLANTIC WILL BE FAIRLY WEAK. SWELL ENERGY PROGGED
TO BE AROUND 10 SEC AND THE WIND CHOP 4-5 SECONDS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...DCH
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...DCH/SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
355 AM EDT FRI JUL 13 2012
.SYNOPSIS...
A WEAK FRONT STALLED OVER THE CAROLINAS PLUS A HUMID TROPICAL
AIRMASS WILL BRING A CONTINUING RISK OF SHOWERS AND THUNDERSTORMS
THROUGH SATURDAY. A GRADUAL DRYING TREND WILL BEGIN SATURDAY AS
BERMUDA HIGH PRESSURE STRENGTHENS OVER THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 333 AM FRIDAY...MODELS INDICATE DEEPER ONSHORE TROPICAL
FLOW...E TO SE WINDS...WILL BECOME MORE DOMINATE THRU THE ATM COLUMN
DURING THIS NEAR TERM PERIOD. NAMBUFR HOURLY SOUNDINGS THRU SATURDAY
MORNING HIGHLIGHT THIS NICELY. VIA LATEST KLTX 88D...ALONG WITH THE
LATEST HRRR MODEL RUNS...THE ADJACENT ATLANTIC NOCTURNAL SHRA ENGINE
HAS RAMPED UP EARLY THIS MORNING. TRAJECTORIES MOVE THIS
ISOLATED/SCATTERED PCPN OCCASIONALLY ONSHORE THROUGH SUNRISE...WITH
MUCH OF IT DISSIPATING AS IT MOVES FURTHER INLAND. THIS ENGINE WILL
SLOWLY DWINDLE DOWN AFTER SUNRISE. PWS TO REMAIN IN THAT 2 INCH
REALM THRUOUT THE NEAR TERM AND WILL NOT TAKE TOO MUCH FORCING TO
IGNITE CONVECTION DURING THE DAY. DRIER AIR TO EVENTUALLY START
FILTERING INTO THE FA BY SATURDAY. NEVERTHELESS...THE DAYS
INSOLATION TO PROVIDE SOME DESTABILIZATION SEVERAL HRS AFTER SUNRISE
ALLOWING FOR CONVECTION TO DEVELOP MAINLY ALONG THE IMMEDIATE COAST.
THE ACTIVITY WILL EXPAND INLAND THRUOUT THE DAY. MODEL SOUNDINGS
INDICATE CONTINUED SLOW STORM MOTIONS IE. NW AT 5 MPH...AND WITH
PCPN MORE TROPICAL IN NATURE...EXPECT POSSIBLE HEAVY DOWNPOURS FROM
ANY CONVECTIVE ACTIVITY...EVEN WITHOUT THE PRESENCE OF THUNDER.
ONCE THE DAYS INSOLATION ENDS...OR THE AVAILABLE CAPE IS USED
UP...CONVECTION WILL QUICKLY DISSIPATE THIS EVENING...LEAVING
CONVECTIVE DEBRIS CLOUDS FOR THE REMAINDER OF TONIGHT. MODELS AGAIN
RAMP UP THE NOCTURNAL ATLANTIC SHRA ENGINE AFTER MIDNIGHT
TONIGHT...WITH SPORADIC ONSHORE MOVEMENT OF THE PCPN. AS FOR MAX/MIN
TEMPS...MAINLY COMPROMISED BETWEEN THE NAM AND GFS MOS GUIDANCE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY..UPPER RIDGE BUILDS INTO THE REGION FROM POINTS
EAST ON SATURDAY. MEANWHILE SURFACE HIGH ACROSS THE WEST ATLANTIC
REMAINS QUITE WEAK. A VERY DEEP BUT WEAK EAST TO SOUTHEASTERLY FLOW
WILL SET UP AND THE MID LEVELS WILL DRY SLIGHTLY BUT NOT SO MUCH HAD
THE HEIGHT RISES BUILT IN FROM THE WEST. SOME VERY BRIEF MORNING
TROPICAL SHOWERS APPEAR POSSIBLE ALONG THE COAST MAINLY IN THE
MORNING. AFTERNOON CONVECTION SHOULD BE ISOLATED AT BEST DUE TO THE
MID LEVEL DRYING...AND MAY STAY WEST OF THE FORECAST AREA
ALTOGETHER. AN UPPER LOW WILL BE APPROACHING IN THE EASTERLY FLOW
AND MODEL SPREAD IS CONSIDERABLE WITH NOT ONLY THE TRACK OF THIS
SYSTEM BUT ALSO WHETHER OR NOT IT HAS ANY SURFACE REFLECTION. MODELS
HAVE SLOWED WITH ITS PROGRESSION AND IT NOW LOOKS LIKE IT WILL STAY
EAST OF THE REGION DURING THE SHORT TERM...IF IT AFFECTS US AT ALL.
SUNDAY WILL THUS END UP VERY SIMILAR TO SATURDAY AS FAR AS RAIN
DISTRIBUTION AND CHANCES. GUIDANCE SHOWING SUNDAY AFTERNOON TURNING
OUT A LITTLE WARMER THAN SAT BUT NOT SO MUCH AS PREV FCST SO A SMALL
TWEAK WAS MADE THERE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...BARRING ANY SIGNIFICANT WEATHER RESULTING FROM
THE UPPER LOW COMING FROM THE EAST THE LONG TERM LOOKS VERY QUIET.
AFOREMENTIONED LOW MAY RECURVE FROM THE COAST OR CONTINUE WESTWARD
OVER LAND...MODELS AREN`T TOO SURE. OTHERWISE MID LEVEL FLOW WILL BE
LIGHT AND VARIABLE AND THE WEST ATLANTIC HIGH WILL SHOW LITTLE
MOVEMENT. MOISTURE RETURN LOOKS WEAK BUT SOME ISOLATED DIURNAL
CONVECTION STILL SEEMS LIKELY EACH DAY. TEMPERATURES WILL BE RIGHT
WHERE THEY SHOULD BE FOR THE TIME OF YEAR.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 06Z...PERIODS OF MVFR/IFR OVERNIGHT DUE FOG/STRATUS THROUGH
THE EARLY FRIDAY MORNING HRS. MORNING MVFR CONVECTION AT THE COASTAL
TERMS...WILL EXPAND TO THE INLAND TERMS THIS AFTERNOON.
FCST GUIDANCE/LATEST KLTX88D SUGGEST ADDITIONAL SHRA/TSRA TO
DEVELOP OVER THE ADJACENT ATLANTIC WATERS EARLY THIS MORNING
...SPORADICALLY MOVING ONSHORE PRIOR TO SUNRISE. FOR NOW HAVE
INTRODUCED VCSH. GIVEN ABUNDANT RAINFALL IN SOME LOCATIONS AND LIGHT
AND VARIABLE WINDS...ANTICIPATE MVFR FOG...WITH MVFR/IFR LOW CIGS
DUE TO STRATUS EARLY THIS MORNING. EXPECT ANY LINGERING FOG TO CLEAR
OUT BY SEVERAL HRS AFTER SUNRISE. GUIDANCE DEPICTS CIGS BETWEEN
2000-3000FT AND ISOLATED/SCATTERED TSRA AT THE COAST AFTER
SUNRISE...EXPANDING INLAND BY THE EARLY AFTERNOON. SYNOPTIC NE-E
WINDS 5 KT OR LESS THIS MORNING WILL VEER TO THE SE 5 TO 10 KT...
WITH GUSTS UP TO 15 KT AT THE COASTAL TERMS...BY MIDDAY. ANTICIPATE
STORMS TO GRADUALLY TAPER OFF INTO THE LATE EVENING HOURS.
EXTENDED OUTLOOK...A CHANCE OF THUNDERSTORMS EACH DAY...MAINLY IN
THE AFTERNOON AND EVENING. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM THURSDAY...THE FRONT INLAND HAS ACTUALLY SLID SOUTH AS
A COLD FRONT TO NEAR CAPE FEAR LATE THIS EVENING. NORTHEAST WINDS
ARE NOW BEING OBSERVED AT WRIGHTSVILLE BEACH AND AT THE WILMINGTON
AIRPORT. WITH NO INCREASE IN SOUTHEASTERLY WINDS OFFSHORE EXPECTED
THERE IS LITTLE REASON TO BELIEVE THE BOUNDARY WILL SUDDENLY SHIFT
BACK TO THE NORTH OVERNIGHT...SO WE`VE ADJUSTED OUR WIND FORECAST TO
SHOW EAST TO NORTHEAST FLOW NEAR AND NORTH OF CAPE FEAR OVERNIGHT.
FORTUNATELY NO INCREASE IN WIND SPEEDS ARE EXPECTED. ANY OTHER
CHANGES TO THE FORECAST ARE MINOR THIS EVENING. PREVIOUS DISCUSSION
FROM 730 PM FOLLOWS...
A WEAK FRONT STALLED ACROSS THE INLAND CAROLINAS HELPED FOCUS SHOWER
AND THUNDERSTORM ACTIVITY THERE THIS AFTERNOON. ACROSS THE COASTAL
WATERS A SOUTHEAST WIND AROUND 10 KT WILL CONTINUE THROUGH THE
NIGHT. AS IS TYPICAL IN THESE TROPICAL AIRMASSES SCATTERED SHOWERS
AND EVEN A FEW THUNDERSTORMS MAY DEVELOP ACROSS THE COASTAL WATERS
OVERNIGHT IN THIS WARM AND HUMID REGIME. ACTIVITY SHOULD GENERALLY
DRIFT TOWARD THE NORTH-NORTHWEST AND MAY BEGIN TO REACH THE BEACHES
AFTER 3 AM ACCORDING TO THE LATEST RAPID-UPDATE HRRR COMPUTER MODEL.
ALTHOUGH SEVERE WEATHER IS NOT EXPECTED BRIEFLY HEAVY RAINFALL AND
THE POTENTIAL OF WATERSPOUTS WILL EXIST.
AREA BUOYS SHOW 2-FOOT SEAS THIS EVENING WITH ALMOST ALL OF THE WAVE
ENERGY EMBODIED IN A 9-SECOND SOUTHEAST SWELL. NO SIGNIFICANT CHANGE
IS EXPECTED OVERNIGHT.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY..WEAK HIGH PRESSURE ACROSS THE WESTERN ATLANTIC ON
SATURDAY WITH A SIMILARLY SUBTLE TROUGH WELL OFF THE COAST BY
SUNDAY. THE LATTER WILL TILT FLOW FROM THE SOUTHEAST TO EAST OR EVEN
NORTHEASTER WHILE SPEEDS REMAIN CAPPED AT JUST 10 KT. THE UPPER
FEATURE DEVELOPING THIS TROUGH IS RATHER STRONG BY JULY STANDARDS
AND COULD LEAD TO A SURFACE FEATURE STRONGER THAN CURRENTLY DEPICTED
IN GUIDANCE. IF THIS TURNS OUT TO BE THE CASE THEN WINDS WILL BE A
BIT HIGHER THAN FORECAST WITH A SIMILAR ADJUSTMENT MAYBE NEEDED FOR
SEAS. OTHERWISE WAVES WILL STAY AT OR BELOW 3 FT.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM FRIDAY...SOUTHWEST WINDS GENERALLY IN THE 10 TO 15 KT
RANGE AND SEAS AVERAGING 2 TO 4 FT THROUGH THE PERIOD...THE MOST
COMMON SET OF CONDITIONS LOCALLY FOR THE SUMMER. HIGH PRESSURE
ACROSS THE WEST ATLANTIC WILL BE FAIRLY WEAK. SWELL ENERGY PROGGED
TO BE AROUND 10 SEC AND THE WIND CHOP 4-5 SECONDS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...DCH/SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
309 AM EDT FRI JUL 13 2012
.SYNOPSIS...
A WEAK FRONT STALLED OVER THE CAROLINAS PLUS A HUMID TROPICAL
AIRMASS WILL BRING A CONTINUING RISK OF SHOWERS AND THUNDERSTORMS
THROUGH SATURDAY. A GRADUAL DRYING TREND WILL BEGIN SATURDAY AS
BERMUDA HIGH PRESSURE STRENGTHENS OVER THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM THURSDAY...THE FRONT HAS ACTUALLY PUSHED SOUTH THROUGH
WILMINGTON...WHITEVILLE...CONWAY...MARION AND FLORENCE THIS EVENING
WHERE WEAK NORTHEAST WINDS ARE NOW BEING OBSERVED. ABOVE AND AHEAD
OF THE BOUNDARY NO INCREASE IN SOUTHEAST WINDS ARE EXPECTED SO THERE
IS LITTLE REASON TO BELIEVE THE BOUNDARY WILL SUDDENLY SHIFT BACK TO
THE THE NORTH. THERE IS LITTLE REAL AIRMASS DIFFERENCE ON EITHER
SIDE OF THE FRONT SO IMPACTS ON SENSIBLE WEATHER (OTHER THAN WIND
DIRECTION) ARE LIKELY TO BE MINOR. PREVIOUS DISCUSSION FROM 730 PM
FOLLOWS...
A STATIONARY FRONT ACROSS THE CAROLINAS IS OUTLINED ALONG A WEAK
PRESSURE TROUGH AND BY A SHIFT FROM SOUTHEAST TO NORTHEAST WINDS.
THE FRONT RUNS APPROXIMATELY FROM JACKSONVILLE NC ACROSS SOUTHERN
DUPLIN AND SAMPSON COUNTIES TO NEAR FAYETTEVILLE...THEN
SOUTHWESTWARD THROUGH BENNETTSVILLE AND DARLINGTON TO JUST NORTH OF
COLUMBIA. THUNDERSTORMS IGNITED TODAY ALONG THIS FRONT AND ALSO
ALONG THE SEABREEZE BOUNDARY...PUSHED SLOWLY NORTHWESTWARD BY THE
0-6 KM MEAN WIND. SURFACE-BASED INSTABILITY HAS BEEN NEARLY
EXHAUSTED NOW WITH RADAR PRECIPITATION ESTIMATES SHOWING AT LEAST 80
PERCENT OF OUR FORECAST AREA RECEIVED SOME RAINFALL TODAY.
INLAND CONVECTION SHOULD COMPLETELY DISSIPATE OVER THE NEXT 2 HOURS
BUT PLENTY OF CONVECTIVE DEBRIS CLOUDINESS WILL REMAIN THROUGH THE
NIGHT. ATTENTION THEN WILL SHIFT BACK TO THE COASTAL WATERS WHERE
THE HRRR AND EVEN THE SYNOPTIC MODELS (GFS AND NAM) SHOW A RENEWED
FOCUS FOR CONVECTION AFTER MIDNIGHT. THE STEERING FLOW WILL REMAIN
ORIENTED ONSHORE MEANING WE WILL CONTINUE TO SHOW INCREASING
PROBABILITIES FOR SHOWERS AND THUNDERSTORMS FOR THE COASTAL COUNTIES
LATE TONIGHT. LOWS TONIGHT SHOULD REACH 70-75...WARMEST AT THE
BEACHES.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY..UPPER RIDGE BUILDS INTO THE REGION FROM POINTS
EAST ON SATURDAY. MEANWHILE SURFACE HIGH ACROSS THE WEST ATLANTIC
REMAINS QUITE WEAK. A VERY DEEP BUT WEAK EAST TO SOUTHEASTERLY FLOW
WILL SET UP AND THE MID LEVELS WILL DRY SLIGHTLY BUT NOT SO MUCH HAD
THE HEIGHT RISES BUILT IN FROM THE WEST. SOME VERY BRIEF MORNING
TROPICAL SHOWERS APPEAR POSSIBLE ALONG THE COAST MAINLY IN THE
MORNING. AFTERNOON CONVECTION SHOULD BE ISOLATED AT BEST DUE TO THE
MID LEVEL DRYING...AND MAY STAY WEST OF THE FORECAST AREA
ALTOGETHER. AN UPPER LOW WILL BE APPROACHING IN THE EASTERLY FLOW
AND MODEL SPREAD IS CONSIDERABLE WITH NOT ONLY THE TRACK OF THIS
SYSTEM BUT ALSO WHETHER OR NOT IT HAS ANY SURFACE REFLECTION. MODELS
HAVE SLOWED WITH ITS PROGRESSION AND IT NOW LOOKS LIKE IT WILL STAY
EAST OF THE REGION DURING THE SHORT TERM...IF IT AFFECTS US AT ALL.
SUNDAY WILL THUS END UP VERY SIMILAR TO SATURDAY AS FAR AS RAIN
DISTRIBUTION AND CHANCES. GUIDANCE SHOWING SUNDAY AFTERNOON TURNING
OUT A LITTLE WARMER THAN SAT BUT NOT SO MUCH AS PREV FCST SO A SMALL
TWEAK WAS MADE THERE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...BARRING ANY SIGNIFICANT WEATHER RESULTING FROM
THE UPPER LOW COMING FROM THE EAST THE LONG TERM LOOKS VERY QUIET.
AFOREMENTIONED LOW MAY RECURVE FROM THE COAST OR CONTINUE WESTWARD
OVER LAND...MODELS AREN`T TOO SURE. OTHERWISE MID LEVEL FLOW WILL BE
LIGHT AND VARIABLE AND THE WEST ATLANTIC HIGH WILL SHOW LITTLE
MOVEMENT. MOISTURE RETURN LOOKS WEAK BUT SOME ISOLATED DIURNAL
CONVECTION STILL SEEMS LIKELY EACH DAY. TEMPERATURES WILL BE RIGHT
WHERE THEY SHOULD BE FOR THE TIME OF YEAR.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 06Z...PERIODS OF MVFR/IFR OVERNIGHT DUE FOG/STRATUS THROUGH
THE EARLY FRIDAY MORNING HRS. MORNING MVFR CONVECTION AT THE COASTAL
TERMS...WILL EXPAND TO THE INLAND TERMS THIS AFTERNOON.
FCST GUIDANCE/LATEST KLTX88D SUGGEST ADDITIONAL SHRA/TSRA TO
DEVELOP OVER THE ADJACENT ATLANTIC WATERS EARLY THIS MORNING
...SPORADICALLY MOVING ONSHORE PRIOR TO SUNRISE. FOR NOW HAVE
INTRODUCED VCSH. GIVEN ABUNDANT RAINFALL IN SOME LOCATIONS AND LIGHT
AND VARIABLE WINDS...ANTICIPATE MVFR FOG...WITH MVFR/IFR LOW CIGS
DUE TO STRATUS EARLY THIS MORNING. EXPECT ANY LINGERING FOG TO CLEAR
OUT BY SEVERAL HRS AFTER SUNRISE. GUIDANCE DEPICTS CIGS BETWEEN
2000-3000FT AND ISOLATED/SCATTERED TSRA AT THE COAST AFTER
SUNRISE...EXPANDING INLAND BY THE EARLY AFTERNOON. SYNOPTIC NE-E
WINDS 5 KT OR LESS THIS MORNING WILL VEER TO THE SE 5 TO 10 KT...
WITH GUSTS UP TO 15 KT AT THE COASTAL TERMS...BY MIDDAY. ANTICIPATE
STORMS TO GRADUALLY TAPER OFF INTO THE LATE EVENING HOURS.
EXTENDED OUTLOOK...A CHANCE OF THUNDERSTORMS EACH DAY...MAINLY IN
THE AFTERNOON AND EVENING. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM THURSDAY...THE FRONT INLAND HAS ACTUALLY SLID SOUTH AS
A COLD FRONT TO NEAR CAPE FEAR LATE THIS EVENING. NORTHEAST WINDS
ARE NOW BEING OBSERVED AT WRIGHTSVILLE BEACH AND AT THE WILMINGTON
AIRPORT. WITH NO INCREASE IN SOUTHEASTERLY WINDS OFFSHORE EXPECTED
THERE IS LITTLE REASON TO BELIEVE THE BOUNDARY WILL SUDDENLY SHIFT
BACK TO THE NORTH OVERNIGHT...SO WE`VE ADJUSTED OUR WIND FORECAST TO
SHOW EAST TO NORTHEAST FLOW NEAR AND NORTH OF CAPE FEAR OVERNIGHT.
FORTUNATELY NO INCREASE IN WIND SPEEDS ARE EXPECTED. ANY OTHER
CHANGES TO THE FORECAST ARE MINOR THIS EVENING. PREVIOUS DISCUSSION
FROM 730 PM FOLLOWS...
A WEAK FRONT STALLED ACROSS THE INLAND CAROLINAS HELPED FOCUS SHOWER
AND THUNDERSTORM ACTIVITY THERE THIS AFTERNOON. ACROSS THE COASTAL
WATERS A SOUTHEAST WIND AROUND 10 KT WILL CONTINUE THROUGH THE
NIGHT. AS IS TYPICAL IN THESE TROPICAL AIRMASSES SCATTERED SHOWERS
AND EVEN A FEW THUNDERSTORMS MAY DEVELOP ACROSS THE COASTAL WATERS
OVERNIGHT IN THIS WARM AND HUMID REGIME. ACTIVITY SHOULD GENERALLY
DRIFT TOWARD THE NORTH-NORTHWEST AND MAY BEGIN TO REACH THE BEACHES
AFTER 3 AM ACCORDING TO THE LATEST RAPID-UPDATE HRRR COMPUTER MODEL.
ALTHOUGH SEVERE WEATHER IS NOT EXPECTED BRIEFLY HEAVY RAINFALL AND
THE POTENTIAL OF WATERSPOUTS WILL EXIST.
AREA BUOYS SHOW 2-FOOT SEAS THIS EVENING WITH ALMOST ALL OF THE WAVE
ENERGY EMBODIED IN A 9-SECOND SOUTHEAST SWELL. NO SIGNIFICANT CHANGE
IS EXPECTED OVERNIGHT.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY..WEAK HIGH PRESSURE ACROSS THE WESTERN ATLANTIC ON
SATURDAY WITH A SIMILARLY SUBTLE TROUGH WELL OFF THE COAST BY
SUNDAY. THE LATTER WILL TILT FLOW FROM THE SOUTHEAST TO EAST OR EVEN
NORTHEASTER WHILE SPEEDS REMAIN CAPPED AT JUST 10 KT. THE UPPER
FEATURE DEVELOPING THIS TROUGH IS RATHER STRONG BY JULY STANDARDS
AND COULD LEAD TO A SURFACE FEATURE STRONGER THAN CURRENTLY DEPICTED
IN GUIDANCE. IF THIS TURNS OUT TO BE THE CASE THEN WINDS WILL BE A
BIT HIGHER THAN FORECAST WITH A SIMILAR ADJUSTMENT MAYBE NEEDED FOR
SEAS. OTHERWISE WAVES WILL STAY AT OR BELOW 3 FT.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM FRIDAY...SOUTHWEST WINDS GENERALLY IN THE 10 TO 15 KT
RANGE AND SEAS AVERAGING 2 TO 4 FT THROUGH THE PERIOD...THE MOST
COMMON SET OF CONDITIONS LOCALLY FOR THE SUMMER. HIGH PRESSURE
ACROSS THE WEST ATLANTIC WILL BE FAIRLY WEAK. SWELL ENERGY PROGGED
TO BE AROUND 10 SEC AND THE WIND CHOP 4-5 SECONDS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...DCH/SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
155 AM EDT FRI JUL 13 2012
.SYNOPSIS...
A WEAK FRONT STALLED OVER THE CAROLINAS PLUS A HUMID TROPICAL
AIRMASS WILL BRING A CONTINUING RISK OF SHOWERS AND THUNDERSTORMS
THROUGH SATURDAY. A GRADUAL DRYING TREND WILL BEGIN SATURDAY AS
BERMUDA HIGH PRESSURE STRENGTHENS OVER THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM THURSDAY...THE FRONT HAS ACTUALLY PUSHED SOUTH THROUGH
WILMINGTON...WHITEVILLE...CONWAY...MARION AND FLORENCE THIS EVENING
WHERE WEAK NORTHEAST WINDS ARE NOW BEING OBSERVED. ABOVE AND AHEAD
OF THE BOUNDARY NO INCREASE IN SOUTHEAST WINDS ARE EXPECTED SO THERE
IS LITTLE REASON TO BELIEVE THE BOUNDARY WILL SUDDENLY SHIFT BACK TO
THE THE NORTH. THERE IS LITTLE REAL AIRMASS DIFFERENCE ON EITHER
SIDE OF THE FRONT SO IMPACTS ON SENSIBLE WEATHER (OTHER THAN WIND
DIRECTION) ARE LIKELY TO BE MINOR. PREVIOUS DISCUSSION FROM 730 PM
FOLLOWS...
A STATIONARY FRONT ACROSS THE CAROLINAS IS OUTLINED ALONG A WEAK
PRESSURE TROUGH AND BY A SHIFT FROM SOUTHEAST TO NORTHEAST WINDS.
THE FRONT RUNS APPROXIMATELY FROM JACKSONVILLE NC ACROSS SOUTHERN
DUPLIN AND SAMPSON COUNTIES TO NEAR FAYETTEVILLE...THEN
SOUTHWESTWARD THROUGH BENNETTSVILLE AND DARLINGTON TO JUST NORTH OF
COLUMBIA. THUNDERSTORMS IGNITED TODAY ALONG THIS FRONT AND ALSO
ALONG THE SEABREEZE BOUNDARY...PUSHED SLOWLY NORTHWESTWARD BY THE
0-6 KM MEAN WIND. SURFACE-BASED INSTABILITY HAS BEEN NEARLY
EXHAUSTED NOW WITH RADAR PRECIPITATION ESTIMATES SHOWING AT LEAST 80
PERCENT OF OUR FORECAST AREA RECEIVED SOME RAINFALL TODAY.
INLAND CONVECTION SHOULD COMPLETELY DISSIPATE OVER THE NEXT 2 HOURS
BUT PLENTY OF CONVECTIVE DEBRIS CLOUDINESS WILL REMAIN THROUGH THE
NIGHT. ATTENTION THEN WILL SHIFT BACK TO THE COASTAL WATERS WHERE
THE HRRR AND EVEN THE SYNOPTIC MODELS (GFS AND NAM) SHOW A RENEWED
FOCUS FOR CONVECTION AFTER MIDNIGHT. THE STEERING FLOW WILL REMAIN
ORIENTED ONSHORE MEANING WE WILL CONTINUE TO SHOW INCREASING
PROBABILITIES FOR SHOWERS AND THUNDERSTORMS FOR THE COASTAL COUNTIES
LATE TONIGHT. LOWS TONIGHT SHOULD REACH 70-75...WARMEST AT THE
BEACHES.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 230 PM THURSDAY..IT WILL TURN DECIDEDLY DRIER AS WE MOVE FROM
FRI TO SAT WITH PRECIPITABLE WATER VALUES DROPPING FROM AROUND 2
INCHES FRI TO ONE AND A QUARTER INCHES DURING SAT.
BERMUDA RIDGE WILL EXPAND FROM THE WESTERN ATLANTIC AND ACROSS THE
EASTERN CAROLINAS THIS PERIOD...WITH A DEEP EASTERLY FLOW ENVELOPING
THE AREA. FRI WILL BEGIN WITH AN INVERTED TROUGH NEAR OR AT THE
COAST AND MOVING WESTWARD. THERE IS ALSO A SUBTLE FEATURE ALOFT
BEING DEPICTED BY THE MODELS...MOVING WESTWARD DURING FRI. THIS
COUPLED WITH THE SEABREEZE SHOULD BRING ANOTHER GOOD CHANCE OF
SHOWERS AND THUNDERSTORMS TO COASTAL LOCATIONS DURING THE MORNING
WITH POPS INCREASING INLAND AS THESE FEATURES MOVE INLAND DURING THE
AFTERNOON WHILE LOWERING AT THE COAST. AT THIS TIME...WILL HOLD
COVERAGE AT SCATTERED ALTHOUGH LOCALLY...COVERAGE MAY BECOME
NUMEROUS. STORM MOTIONS AROUND 5 KT AND HIGH ATMOSPHERIC WATER
CONTENT SHOULD YIELD SLOW MOVING THUNDERSTORMS WITH HEAVY DOWNPOURS.
THIS MAY RESULT IN PONDING OF WATER IN LOW LYING AND POOR DRAINAGE
AREAS. EXAMINATION OF OTHER PARAMETERS INDICATE THE RISK FOR SEVERE
WEATHER IS OTHERWISE LOW AT THIS TIME.
SAT...DRIER AIR AND DEVELOPING CAP AROUND 8-10 KFT...WILL NOT BE AN
ENVIRONMENT CONDUCIVE FOR CONVECTION...EVEN ALONG THE SEABREEZE.
WILL CONFINE POPS TO SMALL CHANCE AT THIS TIME.
IT SHOULD BE NOTED THAT WITH THE DEVELOPING AND DEEPENING EASTERLY
FLOW...NOCTURNAL SHOWERS DEVELOPING ACROSS THE CLIMATOLOGICALLY
FAVORED WATERS MAY MOVE ONSHORE OVERNIGHT/EARLY MORNING HOURS AND
THIS SEEMS MOST PLAUSIBLE LATE FRI NIGHT AND SAT MORNING.
TEMPS WILL NOT DEVIATE MUCH FROM NORMAL VALUES FOR MID JULY...WITH
HIGHS AND LOWS GENERALLY STAYING WITHIN A DEG OR TWO OF NORMAL.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 250 PM THURSDAY...RETURN FLOW WILL CONTINUE AROUND BERMUDA
HIGH THROUGH THE PERIOD. LOCAL AREA WILL REMAIN ON THE WESTERN
PERIPHERY OF THE RIDGE WITH DEEPER S-SW RETURN FLOW THROUGH THE
LOW LEVELS OF THE ATMOSPHERE. A MINOR PERTURBATION IN THE FLOW MAY
RIDE THROUGH FROM THE EAST SUN INTO MON WITH INCREASED CHC OF
PCP...BUT BASICALLY EXPECT DRIER MORE SUBSIDENT CONDITIONS THROUGH
THE MID TO UPPER LEVELS THROUGH MOST OF THE PERIOD. OVERALL EXPECT
MORE TYPICAL SUMMERTIME WEATHER WITH CU BUILDING EACH AFTERNOON
AND CONVECTION POSSIBLE MAINLY ALONG SEA BREEZE AND FURTHER INLAND
ALONG PIEDMONT TROUGH.
AS RIDGE GETS SUPPRESSED A BIT FURTHER SOUTH HEADING LATE
MON THROUGH MID WEEK...A BETTER WESTERLY COMPONENT TO THE FLOW WILL
DEVELOP THROUGH THE LOW LEVELS. THIS SHOULD HELP TO PRODUCE A SLIGHT
WARMING TREND. MAX TEMPS WILL REACH BETWEEN 90 AND 95 MOST DAYS AND
REMAIN IN THE 70S OVERNIGHT.
AT THE VERY END OF PERIOD MAY SEE NORTHERN STREAM SHORTWAVE DIG DOWN
INTO THE CAROLINAS AND PUSH A FRONT THROUGH LATE THURS INTO FRI.
THIS WOULD PRODUCE MORE WIDESPREAD CONVECTION BUT TOO FAR OUT TO
FEEL CONFIDENT.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 06Z...PERIODS OF MVFR/IFR OVERNIGHT DUE FOG/STRATUS THROUGH
THE EARLY FRIDAY MORNING HRS. MORNING MVFR CONVECTION AT THE COASTAL
TERMS...WILL EXPAND TO THE INLAND TERMS THIS AFTERNOON.
FCST GUIDANCE/LATEST KLTX88D SUGGEST ADDITIONAL SHRA/TSRA TO
DEVELOP OVER THE ADJACENT ATLANTIC WATERS EARLY THIS MORNING
...SPORADICALLY MOVING ONSHORE PRIOR TO SUNRISE. FOR NOW HAVE
INTRODUCED VCSH. GIVEN ABUNDANT RAINFALL IN SOME LOCATIONS AND LIGHT
AND VARIABLE WINDS...ANTICIPATE MVFR FOG...WITH MVFR/IFR LOW CIGS
DUE TO STRATUS EARLY THIS MORNING. EXPECT ANY LINGERING FOG TO CLEAR
OUT BY SEVERAL HRS AFTER SUNRISE. GUIDANCE DEPICTS CIGS BETWEEN
2000-3000FT AND ISOLATED/SCATTERED TSRA AT THE COAST AFTER
SUNRISE...EXPANDING INLAND BY THE EARLY AFTERNOON. SYNOPTIC NE-E
WINDS 5 KT OR LESS THIS MORNING WILL VEER TO THE SE 5 TO 10 KT...
WITH GUSTS UP TO 15 KT AT THE COASTAL TERMS...BY MIDDAY. ANTICIPATE
STORMS TO GRADUALLY TAPER OFF INTO THE LATE EVENING HOURS.
EXTENDED OUTLOOK...A CHANCE OF THUNDERSTORMS EACH DAY...MAINLY IN
THE AFTERNOON AND EVENING. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM THURSDAY...THE FRONT INLAND HAS ACTUALLY SLID SOUTH AS
A COLD FRONT TO NEAR CAPE FEAR LATE THIS EVENING. NORTHEAST WINDS
ARE NOW BEING OBSERVED AT WRIGHTSVILLE BEACH AND AT THE WILMINGTON
AIRPORT. WITH NO INCREASE IN SOUTHEASTERLY WINDS OFFSHORE EXPECTED
THERE IS LITTLE REASON TO BELIEVE THE BOUNDARY WILL SUDDENLY SHIFT
BACK TO THE NORTH OVERNIGHT...SO WE`VE ADJUSTED OUR WIND FORECAST TO
SHOW EAST TO NORTHEAST FLOW NEAR AND NORTH OF CAPE FEAR OVERNIGHT.
FORTUNATELY NO INCREASE IN WIND SPEEDS ARE EXPECTED. ANY OTHER
CHANGES TO THE FORECAST ARE MINOR THIS EVENING. PREVIOUS DISCUSSION
FROM 730 PM FOLLOWS...
A WEAK FRONT STALLED ACROSS THE INLAND CAROLINAS HELPED FOCUS SHOWER
AND THUNDERSTORM ACTIVITY THERE THIS AFTERNOON. ACROSS THE COASTAL
WATERS A SOUTHEAST WIND AROUND 10 KT WILL CONTINUE THROUGH THE
NIGHT. AS IS TYPICAL IN THESE TROPICAL AIRMASSES SCATTERED SHOWERS
AND EVEN A FEW THUNDERSTORMS MAY DEVELOP ACROSS THE COASTAL WATERS
OVERNIGHT IN THIS WARM AND HUMID REGIME. ACTIVITY SHOULD GENERALLY
DRIFT TOWARD THE NORTH-NORTHWEST AND MAY BEGIN TO REACH THE BEACHES
AFTER 3 AM ACCORDING TO THE LATEST RAPID-UPDATE HRRR COMPUTER MODEL.
ALTHOUGH SEVERE WEATHER IS NOT EXPECTED BRIEFLY HEAVY RAINFALL AND
THE POTENTIAL OF WATERSPOUTS WILL EXIST.
AREA BUOYS SHOW 2-FOOT SEAS THIS EVENING WITH ALMOST ALL OF THE WAVE
ENERGY EMBODIED IN A 9-SECOND SOUTHEAST SWELL. NO SIGNIFICANT CHANGE
IS EXPECTED OVERNIGHT.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 230 PM THURSDAY...HIGH PRESSURE WILL DOMINATE THE MARINE
ENVIRONMENT. A WEAK INVERTED TROUGH IS EXPECTED TO DEVELOP AND
PERSIST THROUGH AT LEAST THE FIRST PART OF FRI...BUT THIS FEATURE
WILL BE LOCATED MAINLY W OF THE WATERS. SE TO ESE WINDS ON FRI WILL
BACK TO A MORE EASTERLY DIRECTION ON SAT. WIND SPEEDS ARE NOT
EXPECTED TO EXCEED 15 KT. AN ESE SWELL IS EXPECTED TO INCREASE
THROUGH THE PERIOD. THE SWELL WILL LENGTHEN FROM 7 SECONDS TO 9
SECONDS. THIS SWELL WILL ALLOW OVERALL SEAS TO BUILD FROM 2 TO 3 FT
FRI TO 3 TO 4 FT SAT.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 250 PM THURSDAY...EXPECT SOUTHERLY RETURN FLOW AROUND
BERMUDA HIGH THROUGH THE PERIOD. AS HIGH BECOMES SUPPRESSED A BIT
FURTHER SOUTH MON INTO TUES EXPECT S-SE WINDS TO VEER AROUND
BECOMING MORE S TO SW. OVERALL SPEEDS SHOULD BE AROUND 10 KTS
INCREASING SLIGHTLY AND BECOMING A BIT GUSTY EACH AFTERNOONS IN
SEA BREEZE. THIS PERSISTENT SOUTHERLY PUSH WILL KEEP SEAS AROUND 2
TO 4 FT THROUGH THE PERIOD. WNA SHOWS LONGER PERIOD 9 TO 10 SECOND
E-SE SWELL MIXING WITH LOCALLY DRIVEN WIND WAVES THROUGH THE
PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...RJD
LONG TERM...RGZ
AVIATION...DCH/SGL
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
908 PM CDT SAT JUL 14 2012
.DISCUSSION...
MAIN CHANGES FOR THE EVENING UPDATE WERE TO TWEAK POPS A BIT. SOME
LIGHT RADAR RETURNS HAVE ENTERED THE FAR NORTHWESTERN CWA. NOT
MUCH CAME DOWN FROM THIS AS IT WAS CROSSING THE CENTRAL AND
WESTERN PORTIONS OF THE STATE...BUT A FEW LOCATIONS REPORTED BRIEF
-RA UNDER THE HEAVIER RETURNS. THINK THAT THE ACTIVITY IS MOSTLY
MID LEVEL AND JUST INCLUDED AN ISOLATED SPRINKLE MENTION IN THAT
AREA FOR NOW. MORE SIGNIFICANT PRECIP IS OUT WEST STRETCHING FROM
NEAR GARRISON TO WILLIS TON AND MOVING NORTHEASTWARD WITH A WEAK
SHORTWAVE COMING THROUGH. THINK THAT MOST OF THE ACTIVITY WILL
MOVE OFF INTO CANADA TO OUR WEST...BUT THERE IS THE POSSIBILITY OF
A FEW OF THE NORTHWESTERN COUNTIES GETTING CLIPPED AFTER MIDNIGHT.
THREW IN SOME 30 POPS FOR THE WESTERN PORTIONS OF DEVILS LAKE
BASIN. HRRR RUNS HAVE BEEN REALLY OVERDOING CONVECTION BUT NAM
SEEMS TO BE UNDERDONE...SO WENT A BIT IN BETWEEN. LEFT LOWS IN THE
60S TO LOW 70S.
&&
.AVIATION...
VFR CONDITIONS WILL CONTINUE THROUGHOUT THE PERIOD WITH SLOWLY
LOWERING HIGH AND MID CLOUDS. NOT ENOUGH CERTAINTY WITH CONVECTION
TO INCLUDE IT WITH THE TAF SITES AT THIS POINT...BUT IF ANYTHING
OCCURS IT WILL BE OUT AROUND KDVL. LIGHT AND VARIABLE WINDS
TONIGHT WILL BEGIN TO PICK UP OUT OF THE EAST AND SOUTHEAST BY
TOMORROW...WITH SOME GUSTS UP AROUND 20 KTS POSSIBLE IN THE AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 328 PM CDT SAT JUL 14 2012/
SHORT TERM...TONIGHT THROUGH TUESDAY
PRIMARY FORECAST CHALLENGE WILL BE TEMPERATURES AND PRECIPITATION
CHANCES ON SUNDAY. GFS/NAM/ECMWF/GEM MASS FIELDS ARE IN REASONABLE
AGREEMENT...BUT THERE EXIST SIGNIFICANT DIFFERENCES IN THE LOW-
LEVEL THERMAL AND MOISTURE PROFILES. THE GFS IS TOO MOIST AND A
BIT COOL...THE NAM IS TOO DRY AND DOWNRIGHT HOT...AND THE ECMWF IS
SOMEWHERE IN-BETWEEN. WILL LEAN ON THE ECMWF SOLUTION FOR
TEMPERATURES AND PRECIPITATION PLACEMENT.
LATE THIS AFTERNOON AND EVENING...THERMAL CU ACROSS NORTHWEST AND
WEST CENTRAL MN WILL DISSIPATE QUICKLY AFTER SUNSET WHILE MID-HIGH
LEVEL CLOUDS INCREASE FROM THE WEST. ROGUE THUNDERSTORM THAT
INITIATED OFF THE SOUTHERN SHORE OF LOWER RED LAKE EARLIER THIS
AFTERNOON QUICKLY DISSIPATED AND DO NOT EXPECT FURTHER CONVECTIVE
DEVELOPMENT. OVERNIGHT LOWS WILL BE IN THE 60S TO NEAR 70 DEGREES
GIVEN CLOUD COVER AND LIGHT SOUTHEAST WIND. REGIONAL RADARS
SHOWING SOME ECHOES ACROSS NORTHWEST ND THIS AFTERNOON...BUT
NEARBY SURFACE OBSERVATIONS NOT REPORTING ANY RAIN AND CLOUD BASES
ARE 10 KFT OR HIGHER. WILL HOLD OFF ON PRECIPITATION UNTIL SUNDAY
MORNING.
FOR SUNDAY...SURFACE LOW/TROUGH ACROSS EASTERN MT WILL DRIFT ACROSS
ND THROUGH THE DAY AND REACH THE RED RIVER VALLY BY 12 UTC MONDAY
MORNING. 700 HPA TEMPERATURES INCREASE FROM +10 TO +12 C...
EFFECTIVELY CAPPING THE LOWER ATMOSPHERE. SCATTERED SHOWERS AND
STORMS ARE POSSIBLE MAINLY ACROSS THE DEVILS LAKE BASIN AND
NORTHERN VALLEY IN ASSOCIATION WITH MID-LEVEL WARM AIR ADVECTION
AHEAD OF THE CAP...BUT MOST OF THE DAY SHOULD BE DRY. BEING IN THE
SYSTEM/S WARM SECTOR WITH 925 HPA TEMPERATURES IN THE +20 TO +25 C
RANGE...AFTERNOON HIGHS WILL SOAR INTO THE LOWER TO MID 90S ACROSS
MUCH OF EASTERN ND. WITH DEW POINTS IN THE MID TO UPPER 60S...HEAT
INDEX VALUES APPROACH 100 DEGREES IN ISOLATED SPOTS ACROSS
SOUTHEAST ND. WILL HOLD OFF ON A HEAT ADVISORY FOR NOW...BUT LATER
SHIFTS MAY NEED TO RECONSIDER IF SURFACE MOISTURE INCREASES MORE
THAN CURRENTLY FORECAST. SUNDAY WILL BE LOCALLY BREEZY WITH SOUTH-
SOUTHEAST WIND FROM 15 TO 20 MPH.
CONVECTIVE CHANCES INCREASE LATE SUNDAY AFTERNOON AND EVENING AS
SURFACE TROUGH APPROACHES FROM THE WEST AND 850 HPA LOW-LEVEL JET
INCREASES TO 40 KTS BY 06 UTC MONDAY. IF MOISTURE CAN POOL ALONG
THE BOUNDARY AND THE MID-LEVEL CAP IS BROKEN...THERE IS 1000 TO
3000 J/KG OF MLCAPE AND 30 TO 50 KTS OF BULK SHEAR FOR CONVECTIVE
INITIATION. SPC DAY TWO CONVECTIVE OUTLOOK PAINTS A SLIGHT RISK
FOR SEVERE STORMS ACROSS THE DEVILS LAKE BASIN IF CONVECTIVE
PARAMETERS ALIGN. TOO MANY IFS AT THIS POINT TO ADD SEVERE MENTION
TO THE GRIDS...BUT SOMETHING TO WATCH.
BEST CHANCE FOR CONVECTION WILL BE ALONG AND NORTH OF THE
INTERNATIONAL BORDER SUNDAY NIGHT AS ALL MODELS SUGGEST SOME KIND
OF CONVECTIVE COMPLEX DEVELOPING ALONG THE MID-LEVEL WARM FRONT.
GFS IS TOO FAR SOUTH WITH THIS COMPLEX...WHICH MAY BE DUE TO ITS
ANOMALOUSLY HIGH LOW-LEVEL MOISTURE. THE ECMWF PAINTS THE HIGHEST
QPF JUST NORTH OF THE BORDER. WILL TRIM 60 POPS BACK A BIT...BUT
LEAVE A SLIVER ACROSS THE NORTHERN TIER COUNTIES. CHANCE POPS WILL
EXTEND SOUTH TO THE HIGHWAY 200 CORRIDOR WITH NO PRECIPITATION
EXPECTED ACROSS SOUTHEAST ND INTO WEST CENTRAL MN.
SOME LINGERING SHOWERS AND THUNDERSTORMS ARE POSSIBLE ON MONDAY
BEFORE DRYING OUT ON TUESDAY. COOLER AIRMASS DROPS BEHIND
DEPARTING SYSTEM ON MONDAY WITH SLIGHTLY LOWER TEMPERATURES...
NEARING SEASONAL AVERAGES FOR THE FIRST TIME IN DAYS BY TUESDAY.
LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
THE GFS CONTINUES TO BE OVERDONE WITH QPF...AND PREFER THE
DRIER/WARMER ECMWF. THE BEST CHANCE FOR SOME CONVECTION SHOULD BE
WED NIGHT AND THU AS A WAVE TRIES TO BREAK DOWN THE RIDGE ALOFT AND
WILL MENTION SOME LOWER POPS. WOULD NOT BE SURPRISED TO SEE MINIMAL
PRECIP EVEN ON THU WITH THE DRY/WARM PATTERN CONTINUING.
OTHERWISE...EXPECT A DRY EXTENDED WITH TEMPS STARTING THE PERIOD
NEAR NORMAL AND WARMING ABOVE NORMAL BY THE END OF THE WEEK.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
JR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1142 PM EDT SAT JUL 14 2012
.SYNOPSIS...
A MOISTURE BOUNDARY WILL TRIGGER SHOWERS AND THUNDERSTORMS SUNDAY
AND BRING DRIER AIR OVER THE REGION SUNDAY NIGHT INTO MONDAY. A
SURGE OF WARM AIR AHEAD OF A COLD FRONT WILL BRING VERY WARM AIR
INTO PENNSYLVANIA TUESDAY INTO WEDNESDAY. AS THE UPPER RIDGE
RETROGRADES TUESDAY THROUGH FRIDAY A TROUGH WILL DEVELOP OVER THE
NORTHEAST. THIS SHOULD PUSH COOLER AND DRIER AIR INTO OUR REGION
LATE WEDNESDAY INTO THURSDAY. IT SHOULD BE COOLER AND DRIER
THURSDAY THROUGH SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
MOST OF THE REGION HAS REMAINED RAIN FREE TONIGHT. RADAR AND ONE
SPOTTER REPORT SUGGEST OVER 2 INCHES OF RAIN HAS FALLEN IN
SOUTHERN SOMERSET COUNTY. RADAR AND SATELLITE SHOW SHOWERS AND
STORMS OVER WEST VIRGINIA TRYING TO MOVE INTO SOUTHWESTERN
PENNSYLVANIA.
THE HRRR AND NAM4KM SUGGEST ANY SHOWERS SHOULD ARC MORE
ANTICYCLONICALLY AS THEY MOVE INTO PA. THIS COULD LIMIT THE
NORTHERN EXTENT OF THE RAIN TONIGHT. THOUGH BOTH SHOW A NEW AREA
DEVELOP OVER NORTHERN PA AROUND 0600 UTC.
DESPITE THIS THERE IS ONE STRAY STORM WALKING ACROSS ARMSTRONG AND
INDIANA COUNTIES WHICH COULD BRING RAIN TO CLEARFIELD COUNTY. THE
STORMS IN SOMERSET COUNTY ARE VERY SLOW MOVING TOO.
BIASED POPS EARLY WITH RADAR AND LATER HALF OF OVERNIGHT WITH SREF
WHICH HAD LOWER POPS. HARD TO CHASE HOURLY HRRR RUNS. BUT BUMPED
UP POPS ALONG NY BORDER.
TEMPS CLOSE TO GUIDANCE. LOW 60S NORTH NEAR 70 IN URBAN AREAS IN
SOUTHEAST.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
VERY WARM HUMID DAY AS A BOUNDARY APPROACHES FROM THE NW. NOT MUCH
OF A FRONT AS IT HAS BEEN WARM TO OUR NORTH BENEATH THE
ANOMALOUSLY HIGH HEIGHTS TO OUR NORTH. THE PW VALUE PEAK OVER PA
TOMORROW AHEAD OF THIS BOUNDARY...THIS COULD TRIGGER MORE
ORGANIZED SHOWERS AND T-STORMS. THERE IS SOME ENHANCED WINDS AT
850 AND 700 HPA SO THERE COULD BE SOME STRONG GUSTS IN ANY STORMS
WHICH DEVELOP.
THE LOWER PW VALUE BEHIND THE BOUNDARY SHOULD MOVE NORTHWEST TO
SOUTHEAST ACROSS THE STATE LATE SUNDAY. THE HUMIDITY DROP SUNDAY
EVENING INTO MONDAY SHOULD BE SIGNIFICANT. BUT IT WILL BE HOT AND
HUMID AHEAD OF THIS FEATURE ON SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
BUMPED UP TEMPERATURES MONDAY AND LOWERED POPS OVERNIGHT SUNDAY
INTO MONDAY.
PREVIOUS DISCUSSION: A WEAK TROF IN THE GENERALLY WESTERLY FLOW
WILL BE EXITING TO THE EAST AT THE START OF THE PERIOD. A RISE IN
HEIGHTS BEHIND THE TROF WILL BE SHORT LIVED AS A NORTHERN STREAM
UPPER TROF/LOW CENTER IS FORECAST TO COME TO A HALT OVER NORTHERN
QUEBEC BY MID WEEK. THIS WILL LEAD TO STEADILY FALLING HEIGHTS
OVER THE NEW ENGLAND AND THE MID ATLANTIC STATES....AND THE
PASSAGE OF A COLD FRONT AROUND MID WEEK. AHEAD OF THE FRONT
ANOTHER HOT SPELL LOOKS IN THE OFFING WITH A DISTINCT COOLING
OFF/DRYING OUT PERIOD LATE IN THE WEEK BEHIND THE FRONT.
MINS AT DAYBREAK MONDAY WILL BE ABOVE NORMAL...VARYING FROM THE
LOWER TO MID 60S ACROSS THE MTNS...TO UPPER 60S TO AROUND 70
DEGREES ELSEWHERE.
FOR MONDAY...A SFC RIDGE OF HIGH PRESSURE EXTENDING NE ALONG THE
APPALACHIANS...AND FLAT RIDGING SLIDING SOUTHEAST ALOFT WILL SUPPLY
US WITH A PARTLY TO MOSTLY SUNNY...HOT AND HUMID MONDAY. LATER
SHIFTS WILL NEED TO KEEP AN EYE ON POTENTIAL HEAT INDICES CLIMBING
TO AROUND 100-102 IN THE LOWER SUSQ VALLEY SHOULD TEMPS AND SFC
DEWPOINTS TURN OUT TO BE ANOTHER FEW DEGREES HIGHER. CURRENTLY...
HEAT INDICES IN THAT AREA ARE FORECAST TO BE IN THE LOW-MID 90S.
ISOLATED TO SCTD AFTERNOON AN EVENING TSRA ARE POSSIBLE ALONG THE
LEE TROUGH THAT SHOULD RESIDE ACROSS OUR FAR SERN ZONES MONDAY.
MINIMAL CHANCES FOR RAIN CONTINUE FOR MOST OF THE CENTRAL AND
EASTERN PORTIONS OF THE CWA ON TUESDAY...AS A MID LEVEL THERMAL
RIDGE CRESTING THE AREA HELPS TO CAP OFF THE MAJORITY OF CONVECTION.
THE PEAK IN THE UPCOMING...SHORT-LIVED HEAT WAVE WILL BE TUESDAY
WHEN 850 TEMPS VIA THE 00Z GEFS CLIMB TO AROUND PLUS 2 ST DEVIATIONS
OR 20-22C. THIS WILL TRANSLATE INTO MAX TEMPS IN THE U80S ACROSS THE
HIGHER TERRAIN OF THE NORTH AND WEST...AND LOWER TO MID 90S
THROUGHOUT THE CENTRAL AND SE VALLEYS.
DEEP LAYER...WEST TO NWRLY SHEAR INCREASES WEDNESDAY AS A POTENT
UPPER TROUGH AND SFC COLD FRONT PUSHES SE FROM THE GLAKES REGION.
A ROUND OR TWO OF GUSTY TSRA IS POSSIBLE WITH THIS FRONTAL
PASSAGE.
TO CLOSE OUT THE WEEK...A REFRESHINGLY DRIER AND RELATIVELY COOLER
AIRMASS WILL OVERSPREAD THE STATE AS A DEEP UPPER LOW SLIDES ACROSS
EASTERN CANADA WITH STRONG NW FLOW ALOFT OVER THE GREAT LAKES AND
NERN U.S.. DRY DEWPOINTS IN THE U40S TO 50S WILL SUPPORT COOL
COMFORTABLE NIGHTS WEDNESDAY NIGHT THROUGH FRIDAY NIGHT.
&&
.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
MORE IN THE WAY OF SHOWERS AND STORMS MOVING INTO SW PA...
ADJUSTED 03Z TAFS.
EXPECT CONDITIONS TO IMPROVE BY LATE SUNDAY MORNING...AS WINDS
SHIFT MORE TO THE WEST. WINDS MAY BE GUSTY AS INTENSE JULY SUN
WARMS THINGS UP. BEST CHC FOR A GUSTY THUNDERSTORM WILL BE ALONG
THE LEE SIDE TROUGH.
OUTLOOK...
MON...MAINLY VFR BUT WITH ISOLATED SHOWERS/STORMS PSBL.
TUE...VFR/NO SIG WX.
WED...SCT TSTM IMPACTS PSBL.
THU...ISOLATED SHWR PSBL ACROSS S PA EARLY...
OTHERWISE VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GRUMM
NEAR TERM...GRUMM/LA CORTE/MARTIN
SHORT TERM...GRUMM/LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1026 PM EDT SAT JUL 14 2012
.SYNOPSIS...
A MOISTURE BOUNDARY WILL TRIGGER SHOWERS AND THUNDERSTORMS SUNDAY
AND BRING DRIER AIR OVER THE REGION SUNDAY NIGHT INTO MONDAY. A
SURGE OF WARM AIR AHEAD OF A COLD FRONT WILL BRING VERY WARM AIR
INTO PENNSYLVANIA TUESDAY INTO WEDNESDAY. AS THE UPPER RIDGE
RETROGRADES TUESDAY THROUGH FRIDAY A TROUGH WILL DEVELOP OVER THE
NORTHEAST. THIS SHOULD PUSH COOLER AND DRIER AIR INTO OUR REGION
LATE WEDNESDAY INTO THURSDAY. IT SHOULD BE COOLER AND DRIER
THURSDAY THROUGH SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
MOST OF THE REGION HAS REMAINED RAIN FREE TONIGHT. RADAR AND ONE
SPOTTER REPORT SUGGEST OVER 2 INCHES OF RAIN HAS FALLEN IN
SOUTHERN SOMERSET COUNTY. RADAR AND SATELLITE SHOW SHOWERS AND
STORMS OVER WEST VIRGINIA TRYING TO MOVE INTO SOUTHWESTERN
PENNSYLVANIA.
THE HRRR AND NAM4KM SUGGEST ANY SHOWERS SHOULD ARC MORE
ANTICYCLONICALLY AS THEY MOVE INTO PA. THIS COULD LIMIT THE
NORTHERN EXTENT OF THE RAIN TONIGHT. THOUGH BOTH SHOW A NEW AREA
DEVELOP OVER NORTHERN PA AROUND 0600 UTC.
DESPITE THIS THERE IS ONE STRAY STORM WALKING ACROSS ARMSTRONG AND
INDIANA COUNTIES WHICH COULD BRING RAIN TO CLEARFIELD COUNTY. THE
STORMS IN SOMERSET COUNTY ARE VERY SLOW MOVING TOO.
BIASED POPS EARLY WITH RADAR AND LATER HALF OF OVERNIGHT WITH SREF
WHICH HAD LOWER POPS. HARD TO CHASE HOURLY HRRR RUNS. BUT BUMPED
UP POPS ALONG NY BORDER.
TEMPS CLOSE TO GUIDANCE. LOW 60S NORTH NEAR 70 IN URBAN AREAS IN SOUTHEAST.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
VERY WARM HUMID DAY AS A BOUNDARY APPROACHES FROM THE NW. NOT MUCH
OF A FRONT AS IT HAS BEEN WARM TO OUR NORTH BENEATH THE
ANOMALOUSLY HIGH HEIGHTS TO OUR NORTH. THE PW VALUE PEAK OVER PA
TOMORROW AHEAD OF THIS BOUNDARY...THIS COULD TRIGGER MORE
ORGANIZED SHOWERS AND T-STORMS. THERE IS SOME ENHANCED WINDS AT
850 AND 700 HPA SO THERE COULD BE SOME STRONG GUSTS IN ANY STORMS
WHICH DEVELOP.
THE LOWER PW VALUE BEHIND THE BOUNDARY SHOULD MOVE NORTHWEST TO
SOUTHEAST ACROSS THE STATE LATE SUNDAY. THE HUMIDITY DROP SUNDAY
EVENING INTO MONDAY SHOULD BE SIGNIFICANT. BUT IT WILL BE HOT AND
HUMID AHEAD OF THIS FEATURE ON SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
BUMPED UP TEMPERATURES MONDAY AND LOWERED POPS OVERNIGHT SUNDAY
INTO MONDAY.
PREVIOUS DISCUSSION: A WEAK TROF IN THE GENERALLY WESTERLY FLOW
WILL BE EXITING TO THE EAST AT THE START OF THE PERIOD. A RISE IN
HEIGHTS BEHIND THE TROF WILL BE SHORT LIVED AS A NORTHERN STREAM
UPPER TROF/LOW CENTER IS FORECAST TO COME TO A HALT OVER NORTHERN
QUEBEC BY MID WEEK. THIS WILL LEAD TO STEADILY FALLING HEIGHTS
OVER THE NEW ENGLAND AND THE MID ATLANTIC STATES....AND THE
PASSAGE OF A COLD FRONT AROUND MID WEEK. AHEAD OF THE FRONT
ANOTHER HOT SPELL LOOKS IN THE OFFING WITH A DISTINCT COOLING
OFF/DRYING OUT PERIOD LATE IN THE WEEK BEHIND THE FRONT.
MINS AT DAYBREAK MONDAY WILL BE ABOVE NORMAL...VARYING FROM THE
LOWER TO MID 60S ACROSS THE MTNS...TO UPPER 60S TO AROUND 70
DEGREES ELSEWHERE.
FOR MONDAY...A SFC RIDGE OF HIGH PRESSURE EXTENDING NE ALONG THE
APPALACHIANS...AND FLAT RIDGING SLIDING SOUTHEAST ALOFT WILL SUPPLY
US WITH A PARTLY TO MOSTLY SUNNY...HOT AND HUMID MONDAY. LATER
SHIFTS WILL NEED TO KEEP AN EYE ON POTENTIAL HEAT INDICES CLIMBING
TO AROUND 100-102 IN THE LOWER SUSQ VALLEY SHOULD TEMPS AND SFC
DEWPOINTS TURN OUT TO BE ANOTHER FEW DEGREES HIGHER. CURRENTLY...
HEAT INDICES IN THAT AREA ARE FORECAST TO BE IN THE LOW-MID 90S.
ISOLATED TO SCTD AFTERNOON AN EVENING TSRA ARE POSSIBLE ALONG THE
LEE TROUGH THAT SHOULD RESIDE ACROSS OUR FAR SERN ZONES MONDAY.
MINIMAL CHANCES FOR RAIN CONTINUE FOR MOST OF THE CENTRAL AND
EASTERN PORTIONS OF THE CWA ON TUESDAY...AS A MID LEVEL THERMAL
RIDGE CRESTING THE AREA HELPS TO CAP OFF THE MAJORITY OF CONVECTION.
THE PEAK IN THE UPCOMING...SHORT-LIVED HEAT WAVE WILL BE TUESDAY
WHEN 850 TEMPS VIA THE 00Z GEFS CLIMB TO AROUND PLUS 2 ST DEVIATIONS
OR 20-22C. THIS WILL TRANSLATE INTO MAX TEMPS IN THE U80S ACROSS THE
HIGHER TERRAIN OF THE NORTH AND WEST...AND LOWER TO MID 90S
THROUGHOUT THE CENTRAL AND SE VALLEYS.
DEEP LAYER...WEST TO NWRLY SHEAR INCREASES WEDNESDAY AS A POTENT
UPPER TROUGH AND SFC COLD FRONT PUSHES SE FROM THE GLAKES REGION.
A ROUND OR TWO OF GUSTY TSRA IS POSSIBLE WITH THIS FRONTAL
PASSAGE.
TO CLOSE OUT THE WEEK...A REFRESHINGLY DRIER AND RELATIVELY COOLER
AIRMASS WILL OVERSPREAD THE STATE AS A DEEP UPPER LOW SLIDES ACROSS
EASTERN CANADA WITH STRONG NW FLOW ALOFT OVER THE GREAT LAKES AND
NERN U.S.. DRY DEWPOINTS IN THE U40S TO 50S WILL SUPPORT COOL
COMFORTABLE NIGHTS WEDNESDAY NIGHT THROUGH FRIDAY NIGHT.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
EXPECT MORE IN THE WAY OF SHOWERS LATER TONIGHT...ALONG WITH
MORE IN THE WAY OF LOW CIGS AND FOG. HOWEVER...STILL NOT SEEING
OR EXPECTING A LARGE AMT OF ADVERSE WEATHER.
EXPECT CONDITIONS TO IMPROVE BY LATE SUNDAY MORNING...AS WINDS
SHIFT MORE TO THE WEST. WINDS MAY BE GUSTY AS INTENSE JULY SUN
WARMS THINGS UP. BEST CHC FOR A GUSTY THUNDERSTORM WILL BE ALONG
THE LEE SIDE TROUGH.
OUTLOOK...
MON...MAINLY VFR BUT WITH ISOLATED SHOWERS/STORMS PSBL.
TUE...VFR/NO SIG WX.
WED...SCT TSTM IMPACTS PSBL.
THU...ISOLATED SHWR PSBL ACROSS S PA EARLY...
OTHERWISE VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GRUMM
NEAR TERM...GRUMM/LA CORTE/MARTIN
SHORT TERM...GRUMM/LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...LA CORTE/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
742 PM EDT SAT JUL 14 2012
.SYNOPSIS...
AN APPROACHING WARM FRONT WILL BRING INCREASINGLY MOIST AND
UNSETTLED CONDITIONS TO THE REGION FOR THE REMAINDER OF THE
WEEKEND. WARM AND HUMID WEATHER WILL CONTINUE THROUGH MIDWEEK
BEFORE A COLD FRONT BRINGS DRIER AND A MORE COMFORTABLE AIRMASS
FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
ISOLATED SHOWERS AND STORMS SOUTH OF INTERSTATE 80. MORE IN THE
WAY OF WIDESPREAD ACTIVITY ACROSS NW OH AND SW OF PIT. ACTIVITY
MAY INCREASE LATER TONIGHT...BUT NOT SEEING LOT OF POTENTIAL FOR
WIDESPREAD ACTIVITY.
MINOR CHANGES MADE TO THE PACKAGE.
EARLIER DISCUSSION BELOW.
CLOUDS APPEAR TO BE DIMINISHING A BIT OVER THE
REGION...BUT THERE IS A GOOD MIX OF LOW...MID...AND HIGH CLOUDS SO
CENTRAL AREAS WILL JUST SEE PEEKS OF SUN. MOSTLY SUNNY IN THE
NORTHEASTERN AREAS AND A BIT OF A CLEAR SLOT MOVING INTO THE WEST.
RADAR SHOWS SHOWER ACTIVITY ON THE WANE. ONLY TWO SHOWERS OF NOTE
WELL TO OUR WEST. SO...LOWERED THE POPS THIS EVENING AND EARLY
TONIGHT. ADDITIONALLY THE HRRR AND 4KM NAM SHOW SOME MAINLY RANDOM
SHOWERS. THE 15Z SREF POPS ARE LOWER THAN THE 0900 UTC RUN.
LOWERED THE POPS...BEST CHANCE IN WEST OVERNIGHT BASED ON SREF
POPS AND ALL THE LIGHTNING ON THE SATELLITE IMAGERY OVER NORTHERN
KY AND SOUTHERN OH. SOME OF THAT COULD BRING MORE CLOUDS AND RAIN
TO SOUTHWESTERN AREAS OVERNIGHT. ANY STORMS THAT DEVELOP COULD
EASILY PRODUCE 1-2 INCHES OF QPF. SREF SHOWS AREAS OF 30 PERCENT
CHANCE OF 1 OR MORE INCHES. PW IS 45 T0 50 MM SO 1-2 INCHES SEEMS
REASONABLE. HIGHEST PROBABILITY WOULD BE IN WESTERN THIRD OF PA
OVERNIGHT. WOULD NOT KNOW IS WHERE UNTIL THE STORM/SHOWERS
APPEARED ON RADAR.
A BIT WARMER OVERNIGHT TONIGHT THAN LAST NIGHT TOO.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
THE 15Z SREF WAS CAUSE TO LOWER POPS A BIT ON SUNDAY BUT STILL ALL
SIGNALS POINT TO BEST CHANCE SHOWERS AND THUNDERSTORMS WOULD BE
SUNDAY. THE HIGHER PW AIR IS PUSHING EAST SUNDAY SO THE WETTER
SUSPECTS WOULD BE IN THE EAST. THE GOOD NEWS IS MOST AREAS ARE IN
THE 50 TO 70 POPS RANGE IN MOST GUIDANCE AND DRIER AIR IS MOVING
IN. THE WEATHER IN THE WEST COULD IMPROVE LATE IN THE AFTERNOON
AND EVENING SUNDAY. DRY AIR IS GOING TO END OUR (BY SUNDAY
AFTERNOON) 3 DAY MOSTLY CLOUDY HUMID PERIOD.
PREVIOUS DISCUSSION HITS MOST OF THE POINTS :
BASICALLY ALL THE GUIDANCE POINTS TO A NEAR CERTAINTY OF SEEING
MEASURABLE RAIN OVER MOST OF THE REGION TOMORROW...ESPECIALLY IN
THE AFTERNOON. MUCH NEEDED RAINFALL SHOULD AMOUNT TO BASIN AVERAGE
AMOUNTS IN THE 0.25-0.50 RANGE ACROSS MUCH OF CENTRAL PENN. THE
LIKELIHOOD OF LOCALIZED 1-2 INCH AMOUNTS EXISTS IN AREAS IMPACTED
BY REPEAT SHOWERS/STORMS SUNDAY AFTERNOON AND EVENING.
MAX TEMPS SUNDAY WILL BE HIGHLY DEPENDENT ON THE AMOUNT OF
INSOLATION WE CAN GET THROUGH THE RATHER EXPANSIVE LAYERED MID
CLOUD DECK. FCST HIGHS CURRENTLY RANGE FROM AROUND 80F ACROSS THE
MTNS...TO A STEAMY 90 DEGREES ACROSS THE LOWER SUSQ VALLEY REGION.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
A WEAK TROF IN THE GENERALLY WESTERLY FLOW WILL BE EXITING TO THE
EAST AT THE START OF THE PERIOD. A RISE IN HEIGHTS BEHIND THE TROF
WILL BE SHORT LIVED AS A NORTHERN STREAM UPPER TROF/LOW CENTER IS
FORECAST TO COME TO A HALT OVER NORTHERN QUEBEC BY MID WEEK. THIS
WILL LEAD TO STEADILY FALLING HEIGHTS OVER THE NEW ENGLAND AND THE
MID ATLANTIC STATES....AND THE PASSAGE OF A COLD FRONT AROUND MID
WEEK. AHEAD OF THE FRONT ANOTHER HOT SPELL LOOKS IN THE OFFING
WITH A DISTINCT COOLING OFF/DRYING OUT PERIOD LATE IN THE WEEK
BEHIND THE FRONT.
MINS AT DAYBREAK MONDAY WILL BE ABOVE NORMAL...VARYING FROM THE
LOWER TO MID 60S ACROSS THE MTNS...TO UPPER 60S TO AROUND 70
DEGREES ELSEWHERE.
FOR MONDAY...A SFC RIDGE OF HIGH PRESSURE EXTENDING NE ALONG THE
APPALACHIANS...AND FLAT RIDGING SLIDING SOUTHEAST ALOFT WILL SUPPLY
US WITH A PARTLY TO MOSTLY SUNNY...HOT AND HUMID MONDAY. LATER
SHIFTS WILL NEED TO KEEP AN EYE ON POTENTIAL HEAT INDICES CLIMBING
TO AROUND 100-102 IN THE LOWER SUSQ VALLEY SHOULD TEMPS AND SFC
DEWPOINTS TURN OUT TO BE ANOTHER FEW DEGREES HIGHER. CURRENTLY...
HEAT INDICES IN THAT AREA ARE FORECAST TO BE IN THE LOW-MID 90S.
ISOLATED TO SCTD AFTERNOON AN EVENING TSRA ARE POSSIBLE ALONG THE
LEE TROUGH THAT SHOULD RESIDE ACROSS OUR FAR SERN ZONES MONDAY.
MINIMAL CHANCES FOR RAIN CONTINUE FOR MOST OF THE CENTRAL AND
EASTERN PORTIONS OF THE CWA ON TUESDAY...AS A MID LEVEL THERMAL
RIDGE CRESTING THE AREA HELPS TO CAP OFF THE MAJORITY OF CONVECTION.
THE PEAK IN THE UPCOMING...SHORT-LIVED HEAT WAVE WILL BE TUESDAY
WHEN 850 TEMPS VIA THE 00Z GEFS CLIMB TO AROUND PLUS 2 ST DEVIATIONS
OR 20-22C. THIS WILL TRANSLATE INTO MAX TEMPS IN THE U80S ACROSS THE
HIGHER TERRAIN OF THE NORTH AND WEST...AND LOWER TO MID 90S
THROUGHOUT THE CENTRAL AND SE VALLEYS.
DEEP LAYER...WEST TO NWRLY SHEAR INCREASES WEDNESDAY AS A POTENT
UPPER TROUGH AND SFC COLD FRONT PUSHES SE FROM THE GLAKES REGION.
A ROUND OR TWO OF GUSTY TSRA IS POSSIBLE WITH THIS FRONTAL
PASSAGE.
TO CLOSE OUT THE WEEK...A REFRESHINGLY DRIER AND RELATIVELY COOLER
AIRMASS WILL OVERSPREAD THE STATE AS A DEEP UPPER LOW SLIDES ACROSS
EASTERN CANADA WITH STRONG NW FLOW ALOFT OVER THE GREAT LAKES AND
NERN U.S.. DRY DEWPOINTS IN THE U40S TO 50S WILL SUPPORT COOL
COMFORTABLE NIGHTS WEDNESDAY NIGHT THROUGH FRIDAY NIGHT.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
EXPECT MORE IN THE WAY OF SHOWERS LATER TONIGHT...ALONG WITH
MORE IN THE WAY OF LOW CIGS AND FOG. HOWEVER...STILL NOT SEEING
OR EXPECTING A LARGE AMT OF ADVERSE WEATHER.
EXPECT CONDITIONS TO IMPROVE BY LATE SUNDAY MORNING...AS WINDS
SHIFT MORE TO THE WEST. WINDS MAY BE GUSTY AS INTENSE JULY SUN
WARMS THINGS UP. BEST CHC FOR A GUSTY THUNDERSTORM WILL BE ALONG
THE LEE SIDE TROUGH.
OUTLOOK...
MON...MAINLY VFR BUT WITH ISOLATED SHOWERS/STORMS PSBL.
TUE...VFR/NO SIG WX.
WED...SCT TSTM IMPACTS PSBL.
THU...ISOLATED SHWR PSBL ACROSS S PA EARLY...
OTHERWISE VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...GRUMM/LA CORTE/MARTIN
SHORT TERM...GRUMM/LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...LA CORTE/MARTIN
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
916 PM CDT SAT JUL 14 2012
.UPDATE...
MINOR SHORT TERM UPDATES BASED MOSTLY ON OBSERVED CONDITIONS. SEE
BELOW FOR RATIONALE.
&&
.DISCUSSION...
SHOWERS AND THUNDERSTORMS HAVE DIMINISHED QUICKLY YET AGAIN THIS
EVENING. UPDATED GRIDS FOR OBSERVED CONDITIONS IN THE VERY SHORT
RANGE. LOW LEVEL CIRCULATION APPARENT IN RAP13...PROFILER
WINDS...VWP WINDS AND SATELLITE LOOPS NEAR LONGVIEW (KGGG). AT
700MB PROFILER AND VWP WINDS SUGGEST TROUGH IS NEAR OR JUST OFF
THE SE TEXAS COAST AND CURVE BACK TO THE LOW. PWAT VALUES DO
APPEAR SLIGHTLY REDUCED FROM PREVIOUS EVENINGS WITH 00Z RAOB
VALUES RANGING FROM 1.8 TO NEAR 2 INCHES. BLENDED TPW IMAGERY FOR
THE CWA ARE AROUND 1.88 INCH SO STILL PLENTY MOISTURE RICH BUT A
TAD LOWER. SFC MESO BOUNDARIES GALORE THIS EVENING FROM CONVECTIVE
OUTFLOWS AND A LATE DEVELOPING SEA BREEZE. ONE BOUNDARY FROM NORTH
OF COLLEGE STATION TO CALDWELL ON SOUTHWESTWARD. ANOTHER OVER
COLORADO COUNTY..SEVERAL FROM CONVECTION OCCURRING NORTH OF CWA
AND OLD SEA BREEZE BOUNDARY FROM LIBERTY TO KHOU TO KBYY. HRRR AND
TX TECH WRF REFLECTIVITY FORECASTS ARE FOR GENERALLY QUIET NIGHT
WITH SOME DEVELOPMENT TOWARDS SUNRISE BUT FEEL WITH MULTITUDE OF
BOUNDARIES AND SLOWLY RETREATING TROUGH/LOW SOME ISOLATED TO
SCATTERED CONVECTION POSSIBLE A COUPLE OF HOURS PRIOR TO SUNRISE
MAINLY NEAR COAST AND NORTH OF A LINE FROM NORMANGEE TO LIVINGSTON
NEARER TO 850-700MB LOW. THIS IS HANDLED WELL IN OUR CURRENT
FORECAST LATER TONIGHT AND TOMORROW MORNING SO NO CHANGE
NECESSARY. STILL A POSSIBILITY FOR SOME ISOLATED HEAVY RAINS ON
SUNDAY SO MENTION OF LOCALLY HEAVY RAINS IN ZFP/GRIDS REMAINS A
GOOD IDEA. 04
&&
.PREV DISCUSSION... /ISSUED 636 PM CDT SAT JUL 14 2012/
AVIATION...
SCT LATE AFTN OUTFLOW DOMINATED SHRA/TSTMS SHOULD DIMINISH IN
AREAL COVERAGE WITH THE LOSS OF HEATING. DO EXPECT SOME REDEVELOPMENT
LATER TONIGHT AND TOWARD MORNING. THOUGH IT COULD BE ANYWHERE...MOST
FAVORABLE LOCATIONS WOULD BE CLOSER TO THE COAST AND UP TOWARD THE
LAKE LIVINGSTON AREA CLOSER TO THE UPPER CIRCULATION AND WHERE THE
MORE FAVORABLE JET STRUCTURE WILL BE. BEST COURSE OF ACTION WILL
PROBABLY BE TO USE VCSH/VCTS`S AND AMEND WHEN NECESSARY VERSUS
CLUTTER TAFS WITH TEMPOS ETC. PRECIP SHOULD EXPAND IN COVERAGE
WITH MID/LATE MORNING HEATING AGAIN SUNDAY. 47
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 73 88 73 92 74 / 20 50 20 30 20
HOUSTON (IAH) 74 89 74 91 75 / 20 50 30 40 20
GALVESTON (GLS) 80 88 82 90 81 / 30 50 40 40 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...04
AREA FORECAST DISCUSSION
NWS SPOKANE WA
305 PM PDT Fri Jul 13 2012
.SYNOPSIS...
Warm and increasingly humid conditions are expected over the
Inland Northwest through the weekend as a slow-moving upper level
low tracks through the region. this air mass will contribute to a
chance of thunderstorms on both Saturday and Sunday. Some of the
storms could produce locally heavy rains and possibly some large
hail. the low will track out of the region late Sunday night or
Monday followed by Seasonably with slight chances for thunderstorms.
&&
.DISCUSSION...
Tonight: Upper level low pressure system is spinning along coastal
WA this afternoon. This is bring up monsoonal moisture from the
Desert Southwest. This moisture is expected to push into our
southeastern zones tonight. However, the more immediate threat
will be surface based convection that is expected to develop
during the late afternoon hours. First we need to break through
the cap to release what is potentially a considerable amount of
convective potential energy (CAPE). The strongest CAPE values of
up to 2000 J/KG is located across the northern mountains with
around 20-40 J/KG of convective inhibition (CIN) that has capped
the atmosphere. South of a line from southern Kootenai County to
Moses Lake will be significantly more CIN that will likely not get
broken through the evening hours. The HRRR model shows Some
convection begin to develop during the afternoon or early evening
hours along and north of a line from Coeur d`Alene, Wilbur and to
Moses Lake. This convection will move northward with potential
risks including hail (potentially some sever in size), gusty
outflow winds and cloud to ground lightning strikes.
During the overnight hours, the monsoonal moisture moving
northward will being to spread across our southeastern zones.
Upper level laps rates will become increasingly more unstable
through the night into tomorrow morning north and westward.
Water vapor satellite imagery shows an upper level wave at the
base of the low pressure system, currently across southwestern WA
into western OR. This short wave will continue to rotate around
the low in a counter-clockwise fashion where it is expected to
swing around into southeast WA by the early morning hours tomorrow
morning. This short wave will provide the lift that will kick off
more widespread thunderstorm activity. /SVH
Saturday...the closed upper low currently over NW WA will remain fixed
over the region at least through Saturday afternoon. Models are in
very good agreement that the low will dip slowly SE during the
next 24 hrs...centering itself near The Dalles. As the low moves
toward this area...it will begin to pool of monsoonal moisture
currently over southern Idaho northward into much of our forecast
area. This will result in increasing chances of precipitation
through the day especially for locations north and east of the
center of the low. Model guidance has been fairly wishy-washy on
where to place the heaviest rain...but it should be co-located
where we expected the greatest upper level difluence...NE WA/N ID
and near the core of the low near the Cascades. Model stability
parameters would place the greatest risk of thunderstorms along a
theta-e ridge axis wrapping around the top of the low...or from
the central ID Panhandle through the northern tier of WA and into
the Cascades. We cannot entirely rule out severe thunderstorms
based on CAPE values ranging from 1000-2000 j/kg with much weaker
CIN or convective caps than what we are seeing today...however
shear values away from the low are very weak.
By Sunday...the low is only expected to move into the Blue Mts before
opening up into a trough during the afternoon. This will result in
likely showers and thunderstorms across the eastern third of WA
and all of N Idaho through early afternoon. Then yet another
strong upper level low tracks into the nw WA by late in the day.
This low will likely destabilize the Cascades and result in
another round of thunderstorms for much of the area. Heavy rains
will again be possible.
By Monday the second low is expected to meander slowly
s-sw...through SW WA/NW OR which should lessen the chance for
widespread convection for locations north of i90 and keep the risk
of thunder going elsewhere.
Temperatures forecasts over the next several days will prove a
difficult task as much will depend on how widespread the convection
becomes and what areas are impacted. Locations which see full
sunshine will continue to see daytime readings in the 90s...while
locations which see little if any sun could conceivably see highs
in the mid 70s to lower 80s. fx
Monday Night through Friday: No significant changes were made to
the extended range part of the fcst, which keeps the upper low
nearly stationary over the Pacific Nw through Wed. The recent
trend in model guidance has the ECMWF becoming increasingly more
aligned with the GFS the last couple runs. However...the ECMWF was
the quickest with ejecting this stalled upper low NE across the
region than the GFS by mid weak. Now it`s the GFS that has the
faster ejection of the low, pushing its core NE through Oregon and
Wa Wed and Wed Nt. A nearly non-existent upper trough on the ECMWF
will dig south down the BC coast Wed Nt. These two models are
nearly 180 degrees out of phase with this digging 500 mb low at
this point...with the GFS much stronger, and certainly a more
effective kicker/ejector of the stalled low. That said, we
continued with a very conservative approach to making any big
changes in the fcst based on the high level of uncertainty caused
by the above mentioned differences. So, we did not go with a wet
fcst for Wed Nt per the GFS. Leaning heavily toward a pattern
recognition approach, we kept at least isolated rain showers and
thunderstorms in nearly every period of the fcst. bz
&&
.AVIATION...
18Z TAFS: Upper level low pressure system spinning over southwestern
WA will continue to bring the risk for thunderstorms through
Saturday afternoon. A wave rotating around the low into the Cascades
will continue to generate a line of elevated thunderstorms into the
early afternoon hours. There is a lot of uncertainty as far as where
and how much surface based convection we will see later this
afternoon. Models continue to show strong uncapped instability
across the Cascades over into the Okanogan Highlands, as well as
over into the Northern Panhandle. This is where we expect the best
chances for afternoon thunderstorms to develop with the potential
for a few strong storms. KEAT and more so KMWH will be on the
southern fringe of this convection and may see a thunderstorm or two
this afternoon before this activity lifts northward this evening. By
tonight, we will shift to an elevated threat of thunderstorms around
03Z around the KLWS and KPUW taf sites then continuing to shift
northward and westward into KGEG, KSFF, KCOE and possibly KMWH by
the lat nighttime hours. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 68 87 65 81 60 84 / 30 40 50 70 50 20
Coeur d`Alene 66 86 62 76 58 84 / 50 50 60 70 50 20
Pullman 64 86 61 82 58 83 / 50 40 50 70 30 20
Lewiston 71 94 70 91 66 92 / 50 30 50 70 20 10
Colville 64 89 62 79 60 87 / 50 60 50 70 60 30
Sandpoint 63 82 58 76 55 82 / 60 70 50 70 50 30
Kellogg 64 83 60 76 56 84 / 90 70 60 80 50 30
Moses Lake 67 93 66 92 62 89 / 20 40 30 30 20 20
Wenatchee 69 93 70 89 65 88 / 30 30 30 30 20 20
Omak 67 95 66 87 63 89 / 50 60 30 50 50 40
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Red Flag Warning until 5 PM PDT Sunday for East Washington
Central Cascade Valleys (Zone 677)-East Washington Northern
Columbia Basin (Zone 673)-East Washington Okanogan/Methow
Valleys (Zone 684)-East Washington South Central Cascade
Valleys (Zone 676).
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1257 PM PDT Fri Jul 13 2012
.SYNOPSIS...
Warm and increasingly humid conditions are expected over the
Inland Northwest today and tomorrow. Showers and thunderstorms
will bring the potential for locally heavy rain. Some spots could
receive torrential rains on Saturday afternoon and Saturday
evening under slow moving thunderstorms. The slow moving storm
system responsible for the humid and stormy conditions will move
out of the region by Sunday night. Seasonably warm conditions are
expected next week with slight chances for thunderstorms.
&&
.DISCUSSION...
A quick update to the forecast for this afternoon. A tightly wound
short wave rotating around the upper level low pressure system has
shifted the elevated thunderstorm threat into the east slopes of
the northern Cascades. Our attention is now focusing on the
potential for surface based convection. Models continue to show
uncapped energy to be tapped into from the northern portion of the
Moses Lake Area, rotating clockwise around the northern portions
of the Spokane Area and into the Central Panhandle Mountains.
Visible satellite imagery does not show any cumulus development
through 1245 PM, which indicates at least a weak cap that still
needs to be overcome. The HRRR model suggests that we will see
this cap get broken around 400 PM with thunderstorms developing
across the Moses Lake Area, Waterville Plateau and Spokane Area.
Oddly enough, this model does not develop any convection over the
mountains initially. This is contrary to what is expected, thus I
do not have a lot of confidence in the placement of the initial
convection. We are going with convection to develop over the
higher terrain later this afternoon with some isolated cells
possible over the northern portion of the basin. LAPS data shows
CAPE values of up to 2000 J/KG with a convective inhibition of
around 20-50 J/KG across the northern mountains. Once this cap
gets broken, I expect isolated to scattered thunderstorms to
develop. Shear between 0-6 km is not strong, but will be enough to
support supercells with the large amount of energy that is
available to be tapped into. Any thunderstorms that develop will
be capable of producing at least penny size hail stones with some
isolated severe hail possible as well. /SVH
&&
.AVIATION...
18Z TAFS: Upper level low pressure system spinning over southwestern
WA will continue to bring the risk for thunderstorms through
Saturday afternoon. A wave rotating around the low into the Cascades
will continue to generate a line of elevated thunderstorms into the
early afternoon hours. There is a lot of uncertainty as far as where
and how much surface based convection we will see later this
afternoon. Models continue to show strong uncapped instability
across the Cascades over into the Okanogan Highlands, as well as
over into the Northern Panhandle. This is where we expect the best
chances for afternoon thunderstorms to develop with the potential
for a few strong storms. KEAT and more so KMWH will be on the
southern fringe of this convection and may see a thunderstorm or two
this afternoon before this activity lifts northward this evening. By
tonight, we will shift to an elevated threat of thunderstorms around
03Z around the KLWS and KPUW taf sites then continuing to shift
northward and westward into KGEG, KSFF, KCOE and possibly KMWH by
the lat nighttime hours. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 92 68 84 65 81 60 / 20 90 60 50 50 20
Coeur d`Alene 91 66 84 62 78 58 / 30 90 70 50 60 30
Pullman 87 64 84 61 83 58 / 10 80 50 60 50 20
Lewiston 95 71 89 70 89 66 / 10 50 50 60 50 20
Colville 96 64 85 62 79 60 / 50 90 70 50 60 50
Sandpoint 91 63 81 58 76 55 / 50 80 70 60 70 50
Kellogg 93 63 82 60 76 56 / 40 90 70 70 70 40
Moses Lake 95 68 91 66 92 62 / 20 40 30 30 20 20
Wenatchee 93 69 87 70 89 65 / 30 30 40 30 10 20
Omak 96 67 89 66 88 63 / 50 90 60 30 40 40
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
637 PM CDT SAT JUL 14 2012
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND SUNDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW WEAK SHORTWAVE
TROUGHING EXTENDING FROM LAKE SUPERIOR TO THE SOUTHERN MISSISSIPPI
VALLEY EARLY THIS AFTERNOON. SCATTERED TO NUMEROUS SHOWER ACTIVITY
DEVELOPED MIDDAY OVER NORTH-CENTRAL AND FAR NORTHEAST WISCONSIN
THOUGH ACTIVITY HAS BEEN MUCH SLOWER TO DEVELOP OVER THE FOX VALLEY
AND CENTRAL WISCONSIN. THE MOST PROMINENT BAND OF BROKEN SHOWERS APPEARS TO
BE ALONG A SURFACE TROUGH WHICH EXTENDS FROM ABOUT HOUGHTON TO EAU
CLAIRE. AS THE TROUGH EXITS THE AREA LATE THIS EVENING...PRECIP
CHANCES ARE THE MAIN FORECAST CONCERN TONIGHT FOLLOWED BY TEMPS
TOMORROW.
TONIGHT...THE SHORTWAVE TROUGH WILL MOVE ACROSS EASTERN WISCONSIN
DURING THE EVENING HOURS. FEEL THAT MUCH OF THE SHOWER AND
THUNDERSTORM ACTIVITY WILL DIMINISH FAIRLY QUICKLY WITH LOSS OF
DAYTIME HEATING...BUT CONVERGENCE UP TO 700 MB DOES LINGER OVER THE
FAR EAST UNTIL 06Z SO WILL KEEP AN ISOLATED SHOWER MENTION THROUGH
THAT TIME. PLENTY OF MOSTLY CLEAR SKIES UPSTREAM OVER MINNESOTA AND
THINK THIS CLEARING WILL ARRIVE TONIGHT BEHIND THE TROUGH. THE
BOUNDARY LAYER WILL REMAIN MOIST...ESPECIALLY IF GOOD RAINS DEVELOP
THIS AFTERNOON...SO THINK THE COMBO OF LIGHT WINDS AND CLEAR SKIES
WILL PROMOTE FOG FORMATION. WILL INCREASE WORDING TO AREAS OF FOG
OVER THE HIGHER TERRAIN. LOWS MAINLY IN THE 60S WITH SOME 50S IN
THE COLD SPOTS.
SUNDAY...THE TROUGH WILL HAVE MOVED WELL TO EAST AT THE START OF
SUNDAY...AND MID-LEVEL HEIGHTS WILL BE REBOUNDING THROUGH THE DAY.
LIKE THE PREVIOUS FORECAST MENTIONED...WILL HAVE INSTABILITY DEVELOP
THROUGH THE DAY WITH STEEP LOW LEVEL LAPSE RATES. BUT PLENTY OF DRY
AIR WILL EXIST ABOVE THE MIXED LEVEL AND PROGGED SOUNDINGS INDICATE
CAPPING WILL STRENGTHEN AS HEIGHTS REBOUND. DESPITE WEAK
CONVERGENCE DEVELOPING OVER NE WISCONSIN ALONG THE LAKE
BREEZE...THINK THE MIXING OF THE DRIER AIR ALOFT AND STRENGTHENING
CAPPING WILL THWART SHOWER DEVELOPMENT. WILL STICK WITH A DRY
FORECAST. 850MB TEMPS AROUND 20C ARGUES FOR LOW 90S FOR HIGHS...AND
WILL GO WITH UPPER 80S NORTH TO MID 90S SOUTH.
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY.
OVERALL CURRENT TROF AND RIDGE PATTERN OVER THE U.S TO FLUCTUATE A
BIT OVER AREA THROUGH THE PERIOD WITH MAIN WESTERLIES REMAINING
OVER CENTRAL CANADA. MUCH OF THIS PERIOD WILL BE DEALING WITH
RIDGE...ITS STRENGTH AND LOCATION AND ITS EFFECT ON TEMPERATURES.
EXPECT CONTINUATION OF VERY WARM TO HOT CONDITIONS FOR MONDAY AND
OVER THE SOUTH HALF ON TUESDAY BEFORE CANADIAN HIGH PRESSURE
BRINGS SOME RELIEF TO ENTIRE AREA WEDNESDAY ONWARD. OVERALL MAX
TEMPERATURES TO RUN AT OR ABOVE NORMS.
ON MONDAY...INCREASING SOUTH TO SOUTHWEST FLOW AHEAD OF LOW
PRESSURE OVER THE PLAINS TO CONTINUE HOT AND HUMID CONDITIONS WITH
OVERNIGHT CONDITIONS SUN AND MON LEANING TOWARDS MUGGY SIDE. HEAT
INDICES OVER FAR SOUTHERN CWA TO REACH 100 DURING THE AFTERNOON.
LOW PRESSURE PASS TO OUR NORTH WILL PULL FRONT INTO LAKE SUPERIOR
REGION. HAVE SLOWED PCPN MOVING INTO AREA KEEPING IT CLOSER TO OR
BEHIND FRONT...MORE COLLATED WITH 850 BAROCLINIC ZONE. BEST POPS
NORTH MON NIGHT CLOSER TO SUPPORTING JET DYNAMICS.
ON TUESDAY...FRONT TO DROP SOUTH INTO SOUTHERN WI BY LATE
AFTERNOON. FRONT WEAKENS AND HAVE LOSS OF JET SUPPORT...SO WILL
STAY WITH LOWER POPS AS IT MOVES SOUTH. QUESTION THIS DAY IS MORE
ON TEMPS WITH CLOUDS AND PCPN CAUSING ISSUES. FOR BOTH MONDAY AND
TUESDAY...WESTERLY COMPONENT TO LLVL WINDS TO KEEP LAKE BREEZE RIGHT
ALONG LAKE. SHEER IS LIMITED THROUGH THE PERIOD...SO DO NOT EXPECT
ANY SIG SEVERE ATTM.
HIGH PRESSURE DROPPING OUT OF CANADA WILL BRING A BIT LESS HEAT
BUT ALSO DRIER AIRMASS INTO STATE...WITH DEW POINTS RETURNING INTO
THE LOWER HALF OF THE 50S. DROPPED OVERNIGHT LOWS SLIGHTLY.
&&
.AVIATION...AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE AREA
THIS EVENING. IT WILL BE ACCOMPANIED BY SCATTERED SHOWERS AND
THUNDERSTORMS THAT WILL COME TO AN END FROM NORTHWEST TO
SOUTHEAST. SKIES WILL CLEAR OVERNIGHT WITH GROUND FOG
POSSIBLE...ESPECIALLY AT PLACES LIKE LNL/ARV/EGV/RHI/TKV. SUNDAY
WILL BE SUNNY AND HOT WITH LIGHT WINDS.
RDM
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
304 PM CDT FRI JUL 13 2012
.SHORT TERM...TONIGHT AND SATURDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW VARIOUS
SHORTWAVE TROUGHS EXTENDING FROM THE BOUNDARY WATERS OF MINNESOTA TO
THE SOUTHERN MISSOURI VALLEY EARLY THIS AFTERNOON. AHEAD OF THESE
TROUGHS...SHOWERS AND THUNDERSTORMS ARE MOST CLUSTERED OVER NORTHERN
MINNESOTA AND ALSO OVER EASTERN IOWA AND NORTHERN MISSOURI. LOCAL
MESOANALYSIS SHOWS CIN HAS ERODED OVER MUCH OF THE AREA WITH DAYTIME
HEATING...AND WIDELY SCATTERED SHOWERS AND STORMS ARE NOW POPPING
ACROSS MUCH OF THE FORECAST AREA. AS THE UPPER TROUGHS UPSTREAM
SLOWLY MOVE EAST OVER THE NEXT 24 HOURS...PRECIP CHANCES ARE THE
MAIN FORECAST CONCERN.
TONIGHT...SHORTWAVE TROUGH OVER MINNESOTA AND OTHER WEAK IMPULSES
ROTATING AROUND IT WILL SLOWLY MOVE SOUTHEAST ACROSS EASTERN
MINNESOTA AND WESTERN WISCONSIN. LARGE-SCALE ASCENT IS PRETTY WEAK
AND MID-LEVEL LAPSE RATES ARE ONLY AROUND 6 C/KM BUT THERE IS AMPLE
MOISTURE AVAILABLE WITH PWATS AROUND AND SLIGHTLY HIGHER THAN 1.50
INCHES. AS A RESULT...THINK SPOTTY SHOWER ACTIVITY THAT POPPED UP
THIS AFTERNOON WILL DIMINISH THIS EVENING. THEN AS THE SHORTWAVE
ENERGY MOVES CLOSER...WILL SEE SCATTERED SHOWERS AND ISOLATED
THUNDER PUSH BACK INTO THE WESTERN AND SOUTHERN PARTS OF THE
FORECAST AREA. NOT ENTIRELY CONFIDENT IN COVERAGE SINCE SHOWERS AND
STORMS WERE FAIRLY WIDESPREAD OVER WESTERN WISCONSIN WHEN I WALKED
IN THE DOOR THIS MORNING. WILL PLAY THE ODDS OF THE DIURNAL CYCLE
AND ERROR ON THE LOW SIDE. A MUGGY NIGHT WITH LOWS IN THE 60S.
SATURDAY...THE SHORTWAVE TROUGH WILL MAKE SLOW PROGRESS EASTBOUND
ACROSS THE STATE THROUGH THE DAY. THE 09Z SREF INDICATES THAT WILL
SEE SHOWERS AND STORMS DEVELOP FAIRLY QUICKLY BETWEEN 15-18Z
TOMORROW WHEN LOW LEVEL LAPSE RATES HAVE A CHANCE TO STEEPEN AND
INSTABILITY TO DEVELOP. CAPES ARE NOT THAT IMPRESSIVE (600-700
J/KG) AND THEY ARE RATHER SKINNY...BUT THERE IS PLENTY OF MOISTURE
AROUND (STILL 1.5 INCHES). WIND FIELDS ARE RATHER LIGHT SO STORMS
SHOULD BE SLOW MOVING...BUT COVERAGE UPSTREAM ONLY SUGGESTS AN
ISOLATED DAMAGING WIND AND HEAVY RAIN THREAT. THOUGH TEMPS WILL BE
A FEW DEGREES COOLER...HIGHER HUMIDITY WILL MAKE IT FEEL MORE
MUGGY. HIGHS RANGING THROUGH THE 80S.
.LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY.
AN UPPER LEVEL SHORT WAVE AND A SURFACE BOUNDARY WILL PASS EAST
OF WISCONSIN DURING THE FIRST PERIOD OF THE FORECAST. ONLY HAVE
CHANCE POPS GOING IN THE EAST AND THEN NOTHING AFTER 06Z
SUNDAY...EXCEPT FOR SOME PATCHY FOG. A WARM FRONT PUSHING NORTH
INTO WISCONSIN WILL BRING MUCH ABOVE NORMAL TEMPERATURES TO THE
AREA...MAINLY ON MONDAY. THERE WILL BE A SLIGHT CHANCE OF SHOWERS
AND STORMS IN THE NORTH ON MONDAY IN THE VICINITY OF THE FRONT.
THERE IS A CHANCE OF THUNDERSTORMS MONDAY NIGHT AND TUESDAY ACROSS
CENTRAL WISCONSIN AS A COLD FRONT MOVES THROUGH THE STATE.
TEMPERATURES SHOULD REMAIN VERY WARM/HOT ON TUESDAY BUT THEY
SHOULD BE A BIT COOLER THAN MONDAY WITH CLOUDS AND POSSIBLE
CONVECTION. PRECIPITATION CHANCES MAINLY CONFINED TO CENTRAL AND
EAST CENTRAL WISCONSIN ON TUESDAY NIGHT...THEN IT LOOKS LIKE A
PERIOD OF DRY WEATHER WITH TEMPERATURES A LITTLE CLOSER TO NORMAL
FOR THIS TIME OF YEAR. A SHORT WAVE MOVING SOUTHEAST ACROSS THE
WESTERN GREAT LAKES REGION WILL BRING A CHANCE OF SHOWERS AND
STORMS TO NORTHERN WISCONSIN ON FRIDAY.
&&
.AVIATION...FOR 12Z TAF ISSUANCE. EXPECT CLD BASES TO RESULT IN
MAINLY VFR CIGS. BUT SOME LOWER CIGS COULD DEVELOP IN RGNS OF MORE
CONCENTRATED SHOWER ACTIVITY. IF ENOUGH RAIN FALLS TDA...SOME FG
COULD DEVELOP TNGT...THOUGH BETTER CHC OF THAT WL BE SAT NGT.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MPC/MG
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
242 PM CDT FRI JUL 13 2012
.SHORT TERM...TONIGHT THROUGH MONDAY NIGHT
242 PM CDT FRI JUL 13 2012
A RARE FORECAST CHALLENGE INVOLVING RAIN FOR THIS PACKAGE BUT DONT
WORRY - HEAT STILL AN UPCOMING CONCERN AS WELL.
WHILE UPPER RIDGE REMAINS OVER ROCKIES...AND IS PREDICTED TO BUILD
BACK IN BY END OF WEEKEND...SHORT WAVE TROUGH APROACHING AREA FROM
THE NORTHWEST. THIS HAD GENERATED SOME RAIN OVERNIGHT WITH LINGERING
SHOWERS STILL TRANSVERSING THE AREA. MEANWHILE...KEEPING A CLOSE EYE
ON NEW CONVECTIVE DEVELOPMENT IN REGION WITH DECENT DESTABILIZATION
OVER MUCH OF CENTRAL AND SOUTHERN MINNESOTA THIS AFTERNOON WHERE
EARLIER CLEARING HAD TAKEN PLACE.
A BIT UNCLEAR ON HOW EXPANSIVE CONVECTION WILL BECOME HEADING INTO
THE EVENING BUT WIND SHEAR IN ALL LAYERS REMAINS WEAK. MESOSCALE
MODELS CONTINUE TO HINT AT MORE SCATTERED COVERAGE BUT HIGHLY
VARIABLE IN THEIR OUTPUT. AIRMASS IS A BIT MORE STABLE OVER
SOUTHEAST MINNESOTA COMPARED TO AREAS WHERE STRONGER STORMS ARE
FORMING SO NOT SURE HOW INTENSE THEY COULD BE AS THEY ADVECT CLOSER.
EITHER WAY NOT EXPECTING MUCH FOR ORGANIZATION WITH STORMS BUT
LOCALIZED CORES COULD PRODUCE SMALL BOUTS OF HAIL AND GUSTY WINDS.
RAINFALL WILL GENERALLY BE SPOTTY BUT HOPING MOST AREAS AT LEAST SEE
SOME. MUCAPE VALUES WILL DROP OFF QUICKLY THIS EVENING SO CONVECTION
TOO SHOULD WANE. TRENDED RAINFALL RISK IN THAT DIRECTION OVERNIGHT.
13.12Z MODEL SUITES IN GOOD AGREEMENT WITH SHORT WAVE TROUGH PASSAGE
A BIT EARLIER THAN PREVIOUS FORECASTS...INTO GREAT LAKES BY SATURDAY
AFTERNOON /15.00Z/. TRIED TO PUSH MAIN RAIN RISK ON SATURDAY MORE
EAST OF THE RIVER THAN WEST WITH DIMINISHING CHANCES THROUGH THE
DAY. AGAIN...RAINFALL LIKELY TO BE SPOTTY.
HIGH PRESSURE BUILDS BACK IN FOR QUIET WEATHER SATURDAY NIGHT INTO
SUNDAY. LOW LEVEL WARM AIR ADVECTION RETURNS IN EARNEST BY SUNDAY
AFTERNOON THOUGH...ESPECIALLY NORTHWEST OF THE AREA. WILL SEE
TEMPERATURES REBOUND AS UPPER RIDGE BEGINS TO BUILD BACK IN WITH
HIGHS LIKELY IN THE 90S AND SOME HEAT INDEX VALUES APPROACHING 100.
GUIDANCE 850 TEMPERATURES OF 22-25C SUGGESTED WITH ANOMOLIES OF +2
COULD SUPPORT AT LEAST NEAR RECORD HIGHS INTO MONDAY WITH SOME
RETURNING MOISTURE AS WELL. DEPENDING ON HOW HEAT INDEX FORECAST
DETAILS WORK OUT OVER THE WEEKEND...COULD SEE AT LEAST SHORT BOUT OF
HEAT ADVISORIES FOR EARLY NEXT WEEK.
.LONG TERM...TUESDAY THROUGH FRIDAY
242 PM CDT FRI JUL 13 2012
WHILE MEAN UPPER RIDGE ACROSS NATIONS MID SECTION CONTINUES TO BUILD
IN OUTER FORECAST PERIODS...SUBTLE FEATURES IN LOWER LEVELS WILL
BARE WATCHING.
APPEARS THERE COULD BE ENOUGH NORTHWEST FLOW ALOFT TO PUSH FRONTAL
BOUNDARY SOUTH ON TUESDAY. HIGHS TUESDAY WILL BE DEPENDENT ON THIS
WITH ANOTHER HOT DAY AHEAD OF FRONT...ACROSS MAINLY SOUTH. GENERALLY
GOING WITH IDEA THAT LARGE HUDSON BAY HIGH PRESSURE AREA WILL PUSH
THIS BOUNDARY FAR ENOUGH SOUTH FOR DRY FORECAST AROUND MID WEEK
UNTIL MORE WARMER AIR HEADS IN BY FRIDAY.
&&
.AVIATION...THROUGH 18Z SATURDAY
1209 PM CDT FRI JUL 13 2012
SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE TO BUBBLE ACROSS THE
AREA THIS MORNING AHEAD OF THE SHORT WAVE TROUGH AND COLD FRONT
CROSSING THE UPPER MIDWEST. JUST ENOUGH LIFT FROM THE SHORT WAVE
TROUGH ALONG WITH BEING ON THE CONVERGENT EASTERN EDGE OF THE WEAK
MOISTURE TRANSPORT IS PROVIDING JUST ENOUGH TO KEEP THE ACTIVITY
GOING. THE 13.12Z RAP AND NAM SUGGEST LITTLE CHANGE IN THIS SET UP
THROUGH THE AFTERNOON AS THE SHORT WAVE TROUGH AND COLD FRONT MOVE
SLOWLY TO THE EAST SO EXPECTING THE SCATTERED ACTIVITY TO KEEP
GOING/REDEVELOPING. CONFIDENCE ON WHEN THESE WILL BE NEAR THE TAF
SITES REMAINS LOW SO WILL CONTINUE WITH VCTS AND UPDATED WHEN OR
IF ANY ACTIVITY GETS CLOSE TO THE AIRPORTS. SHOULD SEE THE
CONVECTION DIE OUT PRETTY QUICK THIS EVENING AS THE CAPE
DIMINISHES. THE FRONT SHOULD MOVE THROUGH BOTH SITES SATURDAY
MORNING WITH THE WINDS COMING AROUND TO THE WEST AND THEN
NORTHWEST DURING THE AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
242 PM CDT FRI JUL 13 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...SHEA
LONG TERM....SHEA
AVIATION.....04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1209 PM CDT FRI JUL 13 2012
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
245 AM CDT FRI JUL 13 2012
FORECAST CONCERNS FOCUS ON THE POTENTIAL FOR SHOWERS/STORMS OVER THE
NEXT COUPLE DAYS.
CURRENT CONVECTION ACROSS THE REGION FORMING AROUND A WEAK SFC
BOUNDARY...SOME ELEVATED FRONTOGENESIS AND INSTABILITY...ALONG WITH
A LOW LEVEL MOISTURE BOUNDARY. MESO MODELS NOT DOING A GREAT JOB
WITH CAPTURING THE SHOWERS/STORMS. TRENDS THOUGH WOULD SUGGEST THAT
THE ACTIVITY WILL GRADUALLY DIMINISH LATER THIS MORNING AS IT MOVES
AWAY FROM THE MORE FAVORABLE ATMOSPHERE IN THE WEST. CONFIDENCE NOT
OVERLY HIGH...BUT WILL TREND THE FORECAST WITH THIS IN MIND.
CONDITIONS WILL BE MONITORED AND UPDATES TO THE FORECAST MADE...AS
NEEDED.
UPPER LEVEL SHORTWAVE TROUGH SET TO DRIVE SLOWLY EAST/SOUTHEAST FROM
THE NORTHERN PLAINS EARLY THIS MORNING...TO ACROSS WI BY 18Z SAT. A
SFC FRONT WILL ACCOMPANY THE SYSTEM...WITH SOME FRONTOGENETIC
RESPONSE PORTRAYED BY THE NAM/GFS...ALTHOUGH NOT WELL DEFINED.
MOISTURE TRANSPORT IS SOMEWHAT MEAGER AHEAD OF THE FRONT WITH
SHALLOW WARM CLOUD DEPTHS...STILL ABOUT 1.5 PWS. NAM12 DOES BUILD
ABOUT 2-3K J/KG OF MUCAPE AHEAD OF THE FRONT TODAY...AND ABOUT THE
SAME FOR SAT. ITS A FAIRLY SKINNY CAPE PROFILE PER BUFKIT
SOUNDINGS...USUALLY NOT SUPPORTIVE FOR EXPLOSIVE CONVECTION/STRONG
UPDRAFTS. WIND SHEAR IS LOCATED WELL BEHIND THE SYSTEM THOUGH...AND
DOES NOT LOOK TO BE MUCH OF FACTOR IN STORM
DEVELOPMENT/ORGANIZATION. ALL IN ALL...THERE WILL BE ENOUGH ELEMENTS
FOR MORE SHOWER/STORM DEVELOPMENT THIS AFTERNOON INTO SATURDAY.
CAN/T RULE OUT A SEVERE RISK DESPITE THE POOR SETUP...MOSTLY WEST OF
THE MISSISSIPPI RIVER. WHILE THIS SYSTEM SHOULD BRING SOME MUCH
NEEDED RAIN TO PORTIONS OF THE FORECAST AREA...ITS NOT THE SOAKER
THAT MOST NEED.
.LONG TERM...MONDAY THROUGH THURSDAY
245 AM CDT FRI JUL 13 2012
DECENT AGREEMENT BETWEEN THE GFS AND ECMWF WITH TRACKING AN UPPER
LEVEL SHORTWAVE TROUGH ACROSS SOUTHERN CANADA MON
NIGHT-TUE...SLIDING AN ASSOCIATED SFC FRONT ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY. THERE LOOKS TO BE A FEED OF LOW LEVEL
MOISTURE AHEAD OF THE BOUNDARY...WITH PWS OVER 1.5 INCHES AND SOME
INSTABILITY ADDED TO THE MIX. SHOULD BE ENOUGH FOR SOME
SHOWER/STORMS...BUT HOW WIDESPREAD THE ACTIVITY WOULD BE IS IN
QUESTION. LATEST POSITIONING AND TIMING WOULD FAVOR THE BETTER
CHANCES ACROSS THE SOUTH. A SFC HIGH THEN BUILDS BACK ACROSS THE
REGION...WITH SOME SUGGESTION OF ANOTHER AMPLIFYING RIDGE FOR NEXT
WEEKEND.
AS FOR TEMPS...850 MB ANOMALIES CONTINUE TO PEG AROUND +2 FOR MON
INTO TUE. MONDAY IS STILL SHAPING UP TO BE THE HOT DAY...WITH SOME
LOCATIONS FLIRTING WITH 100 STILL POSSIBLE. THE FRONT WILL HAVE SOME
SAY IN HIGHS FOR TUE...SO TIMING/POSITIONING WILL BE IMPORTANT.
TEMPS SHOULD COOL BACK TO MORE SEASONABLE NORMALS...BUT HEAT COULD
QUICKLY RETURN FOR NEXT WEEKEND IF THE AFOREMENTIONED RIDGE BUILDING
OCCURS.
&&
.AVIATION...THROUGH 18Z SATURDAY
1209 PM CDT FRI JUL 13 2012
SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE TO BUBBLE ACROSS THE
AREA THIS MORNING AHEAD OF THE SHORT WAVE TROUGH AND COLD FRONT
CROSSING THE UPPER MIDWEST. JUST ENOUGH LIFT FROM THE SHORT WAVE
TROUGH ALONG WITH BEING ON THE CONVERGENT EASTERN EDGE OF THE WEAK
MOISTURE TRANSPORT IS PROVIDING JUST ENOUGH TO KEEP THE ACTIVITY
GOING. THE 13.12Z RAP AND NAM SUGGEST LITTLE CHANGE IN THIS SET UP
THROUGH THE AFTERNOON AS THE SHORT WAVE TROUGH AND COLD FRONT MOVE
SLOWLY TO THE EAST SO EXPECTING THE SCATTERED ACTIVITY TO KEEP
GOING/REDEVELOPING. CONFIDENCE ON WHEN THESE WILL BE NEAR THE TAF
SITES REMAINS LOW SO WILL CONTINUE WITH VCTS AND UPDATED WHEN OR
IF ANY ACTIVITY GETS CLOSE TO THE AIRPORTS. SHOULD SEE THE
CONVECTION DIE OUT PRETTY QUICK THIS EVENING AS THE CAPE
DIMINISHES. THE FRONT SHOULD MOVE THROUGH BOTH SITES SATURDAY
MORNING WITH THE WINDS COMING AROUND TO THE WEST AND THEN
NORTHWEST DURING THE AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
245 AM CDT FRI JUL 13 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...04
AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
905 PM PDT SAT JUL 14 2012
.UPDATE...
CONVECTION FINALLY GOT ENOUGH INSTABILITY TO BREAK THROUGH THE CAP
IN MINERAL COUNTY. WENT AHEAD AND PUT ISOLATED SHOWERS AND
THUNDERSTORMS BACK INTO THE FORECAST FOR MINERAL COUNTY, AS WE
COULD SEE A FEW STORMS MAINLY SOUTH AND EAST OF HAWTHORNE BEFORE
MIDNIGHT. HOON
&&
.PREVIOUS DISCUSSION... /ISSUED 454 PM PDT SAT JUL 14 2012/
UPDATE...
WENT AHEAD AND PULLED THE THUNDERSTORM CHANCES FOR THE REMAINDER
OF THIS AFTERNOON AND EVENING. CUMULUS BUILDUPS IN MONO- MINERAL
JUST DON`T HAVE ENOUGH MOISTURE/INSTABILITY TO REALLY GET GOING
TODAY. DRY AIRMASS HAS PUSHED THE BULK OF THE MOISTURE INTO
EASTERN NEVADA. ALL PUBLIC AND FIRE PRODUCTS HAVE BEEN UPDATED AND
SENT. WEB PRODUCTS WILL UPDATE SHORTLY.
AS FOR TOMORROW`S FORECAST, WITH THE DRYING THAT WE SAW TODAY,
TOMORROW IS LOOKING MUCH LESS PROBABLE FOR THUNDERSTORMS. POPS
WILL LIKELY BE TRIMMED BACK FOR SUNDAY, BUT WILL WAIT UNTIL THE
00Z MODEL RUNS TO COME IN BEFORE MAKING ANY BIG CHANGES TO SUNDAY.
HOON
PREVIOUS DISCUSSION... /ISSUED 201 PM PDT SAT JUL 14 2012/
SHORT TERM...
CURRENT WATER VAPOR IMAGERY DEPICTS A VERY DRY AIRMASS ALOFT THAT
HAS MOVED ACROSS WESTERN NEVADA OVERNIGHT AND THIS MORNING.
COMPARED TO YESTERDAY MORNING, THE 12Z OBSERVED PRECIPITABLE
WATER AT KRNO DROPPED 0.20 INCHES (TO 0.37 IN). WITH THE DEEPER
MOISTURE DISPLACED TO THE EAST, CONVECTION HAS BEEN A LOT SLOWER
TO DEVELOP THIS AFTERNOON. BASED ON THE LATEST HRRR FORECAST,
VISIBLE SATELLITE AND RADAR TRENDS, DECIDED TO TRIM BACK COVERAGE
OF THUNDERSTORMS FOR THIS AFTERNOON AND EVENING. THE BEST CHANCE
WILL BE ACROSS MINERAL, EASTERN MONO AND SOUTHEASTERN CHURCHILL
COUNTIES WHERE THE LATEST SPC MESOANALYSIS SHOWS MUCAPES OF AROUND
500 J/KG. WITH LITTLE IN THE WAY OF SHEAR, ANY STORMS THAT FORM
WILL BE PULSE STORMS THAT WILL SLOWLY DRIFT TO THE EAST-NORTHEAST.
ON SUNDAY, THE 12Z GFS/NAM/ECMWF ARE IN GOOD AGREEMENT THAT THE
AREA OF LOW PRESSURE OVER CENTRAL OREGON WILL LIFT TO THE
NORTHEAST WHILE A WEAK AREA OF LOW PRESSURE DEVELOPS NEAR THE
CENTRAL CALIFORNIA COAST. THIS WILL SET UP AN AREA OF DEFORMATION
ACROSS THE RENO CWA FROM TAHOE NORTHEAST TO WINNEMUCCA. SOUTH OF THIS
BOUNDARY, THE FLOW WILL TURN MORE SOUTHERLY, ALLOWING MONSOON
MOISTURE TO BUILD BACK ACROSS SOUTHEASTERN HALF OF THE CWA WITH
MODEL PWATS INCREASING TO NEAR 0.75 INCHES. THE EXISTING FORECAST
LOOKS GOOD WITH ISOLATED COVERAGE SOUTH OF I-80 AND SCATTERED
STORMS SOUTH OF US-50. THE STORMS ACROSS MINERAL AND MONO COUNTIES
WILL BE ON THE WET SIDE, WITH WET/DRY HYBRID STORMS CLOSER TO THE
MOISTURE BOUNDARY BETWEEN I-80 AND US-50 (SEE THE FIRE WEATHER
DISCUSSION BELOW FOR MORE DETAILS).
THE WEAKNESS NEAR THE CALIFORNIA COAST WILL WEAKEN ON MONDAY AS A
STRONGER AREA OF LOW PRESSURE BUILDS SOUTH ACROSS WESTERN
WASHINGTON AND OREGON. THIS WILL TURN THE UPPER LEVEL FLOW BACK TO
THE SOUTHWEST, USHERING IN DRIER AIR ACROSS THE RENO CWA. THE BEST
CHANCE FOR ANY CONVECTION WILL BE ACROSS MINERAL AND MONO
COUNTIES, CLOSER TO THE DEEPER MOISTURE.
THE AREA OF LOW PRESSURE WILL CONTINUE TO SLIDE SLOWLY SOUTH
ACROSS WESTERN OREGON ON TUESDAY. THIS WILL KEEP DRY SOUTHWEST
FLOW IN PLACE. DEPENDING ON THE PLACEMENT OF THE LOW, THERE IS A
VERY SMALL CHANCE THAT EXTREME NORTHERN LASSEN COUNTY AND THE
SURPRISE VALLEY COULD SEE A PASSING SHOWER ON TUESDAY AFTERNOON
SO A SLGT CHANCE WAS INTRODUCED WITH THIS PACKAGE FOR THOSE AREAS.
MYRICK
LONG TERM...WEDNESDAY THROUGH SATURDAY...
A TROUGH LOCATED OVER THE PACIFIC NORTHWEST WILL CREATE A DRY AND
STABLE SOUTHWEST FLOW ALOFT WEDNESDAY AND THURSDAY. NUMERICAL
GUIDANCE DIFFERS FOR FRIDAY AND SATURDAY...SOME SOLUTIONS BRING
THE TROUGH EASTWARD WHILE OTHER SOLUTIONS MOVE IT WESTWARD AND
BUILD THE RIDGE OVER THE EASTERN SIERRA AND WESTERN NEVADA. THE
OVERALL CONSENSUS IS FOR A DRY FORECAST WITH A WARMING TREND
THROUGH SATURDAY...WHICH IS ALREADY COVERED WELL BY THE ONGOING
FORECAST.
ONE WILD CARD IS THE SLIGHT CHANCE THAT MOISTURE FROM THE REMNANTS
OF HURRICANE FABIO COULD BE DRAWN NORTHWARD FRIDAY. TWO RECENT RUNS
OF THE GFS ARE THE ONLY ONES SHOWING THIS SOLUTION. WITH FABIO
CURRENTLY LOCATED 550 MILES SSW OF THE SOUTHERN TIP OF
BAJA-CALIFORNIA CONFIDENCE IS VERY LOW IN THIS SCENARIO. FOR NOW A
SLIGHT CHANCE OF THUNDERSTORMS WAS INTRODUCED FRIDAY FOR MONO
COUNTY. JCM
AVIATION...
VFR CONDITIONS WILL PREVAIL OVERALL THROUGH THE WEEKEND AND INTO
NEXT WEEK. THUNDERSTORMS ARE POSSIBLE SUNDAY AFTERNOON FROM I-80
SOUTHWARD. IN THE VICINITY OF THESE STORMS THE CIG/VSBYS SHOULD BE
AOA 5000/5 WITH GUSTY SFC WINDS.
FOR THE TERMINALS ISOLATED STORMS ARE POSSIBLE SUNDAY AFTERNOON AND
EARLY EVENING IN THE VICINITIES OF KTRK..KTVL AND KRNO...WITH
SOMEWHAT BETTER POTENTIAL FOR THUNDERSTORMS IN THE VICINITY OF KMMH.
JCM
FIRE WEATHER...
HAVE TRIMMED BACK THUNDERSTORM COVERAGE THIS AFTERNOON BASED ON
LATEST RADAR AND SATELLITE TRENDS TO ENCOMPASS EASTERN MONO COUNTY
INTO MINERAL AND EASTERN CHURCHILL COUNTIES. WITH PLENTY OF MID AND
UPPER LEVEL DRY AIR WORKING INTO THE REGION IT HAS SUPPRESSED
THUNDERSTORM DEVELOPMENT.
TYPICAL AFTERNOON ZEPHYR WINDS CAN BE EXPECTED WITH GUSTS OF 25 TO
30 MPH LATE THIS AFTERNOON AND INTO THE EARLY EVENING. THESE GUSTS
WILL CORRESPOND WITH HUMIDITY VALUES AROUND 10-15% WITH LOCALLY
CRITICAL CONDITIONS POSSIBLE. HOWEVER, THESE WILL NOT BE WIDESPREAD
ENOUGH TO WARRANT ANY RED FLAG WARNINGS TODAY. AFTERNOON WESTERLY
WINDS CAN BE EXPECTED AGAIN SUNDAY, BUT WILL BE ABOUT 5 MPH LESS IN
SPEED.
A PIECE OF ENERGY AND WEAK DEFORMATION BAND WILL HELP TO FOCUS
THUNDERSTORM DEVELOPMENT SUNDAY AFTERNOON WITH ISOLATED COVERAGE
POSSIBLE BETWEEN INTERSTATE 80 AND HIGHWAY 50 AND SCATTERED COVERAGE
SOUTH OF HIGHWAY 50. THE DEEPEST MOISTURE WILL BE SOUTH OF HIGHWAY
50 AND EAST OF HIGHWAY 95, SO STORMS THROUGH THIS AREA WILL BE WET.
NORTH AND WEST OF THERE, A HYBRID OF STORMS ARE POSSIBLE WITH THE
POTENTIAL FOR A DRY LIGHTNING STRIKE OUTSIDE OF THE WET THUNDERSTORM
CORE. THIS COULD START NEW FIRES, BUT WITH THE SMALL AREA OF HYBRID
STORMS, AM NOT PLANNING ANY RED FLAG WARNINGS AT THIS TIME. IN
ADDITION, WATCHING HOW THE DRY AIR WORKING INTO CALIFORNIA AND
WESTERN NEVADA HAS SQUELCHED THUNDERSTORM DEVELOPMENT TODAY, AM A
BIT CONCERNED THAT MODELS MAY BE OVERDOING THE CONVECTIVE POTENTIAL
SUNDAY AND COVERAGE MAY NEED TO BE TRIMMED A BIT. DF
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION...CORRECTED
NWS NEW YORK NY
519 AM EDT SUN JUL 15 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL APPROACH THE AREA TODAY AND MOVE ACROSS
TONIGHT. HOT AND HUMID CONDITIONS WILL THEN PERSIST THROUGH THE
MIDDLE OF THE WEEK WITH A BERMUDA HIGH PRESSURE SYSTEM DOMINATING
OUR WEATHER. A STRONGER COLD FRONT WILL MOVE ACROSS THE REGION ON
WEDNESDAY...FOLLOWED BY HIGH PRESSURE AND MORE SEASONABLE
CONDITIONS FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLOUDS WILL INCREASE FROM W TO E THIS MORNING AS UPPER RIDGE AXIS
SLIDES E. TRICKY FORECAST TODAY IN REGARDS TO POPS BUT THINKING
THERE WILL BE TWO ROUNDS OF ACTIVITY. THE FIRST IS THIS MORNING
WITH A WEAK SHORTWAVE. HAVE YET TO SEE SHOWERS BEGIN
EXPANDING...BUT 00Z SPC WRF AND LATEST HRRR HIGH RES MODELS ARE IN
GOOD AGREEMENT THAT SHOWERS SHOULD START BECOMING MORE NUMEROUS
BETWEEN 09Z AND 12Z IN NJ AND PA AND TRACK INTO NE NJ. EASTERN
SECTIONS PROBABLY WON`T SEE MUCH OF ANYTHING THIS MORNING AND MUCH
OF THE DAY MAY EVEN BE DRY. MAY HAVE GONE OVERBOARD WITH POPS THIS
MORNING AND MAY NEED TO DECREASE THEM. SOUNDINGS ARE INDICATING
ELEVATED INSTABILITY IS PRESENT SO HAVE KEPT THE MENTION OF
THUNDER.
THERE IS UNCERTAINTY WITH HOW THE AFTERNOON PLAYS OUT. BOTH NAM
AND GFS ARE INDICATING NVA OVER THE AREA WITH THE SECOND SHORTWAVE
MOVING ACROSS TONIGHT. HOWEVER WEAK SFC TROUGH ACROSS WESTERN
ZONES SHOULD BE ENOUGH TO TRIGGER SCT SHOWERS/TSTMS ACROSS WESTERN
PORTIONS OF THE AREA. PWATS INCREASE TO 2+ INCHES THIS AFTERNOON
WITH INCREASING THETA E AND TALL SKINNY CAPE PROFILES WHICH ARE
FAVORABLE FOR HEAVY RAIN. NAM IS NOW KEEPING STRONGER SHEAR TO
THE WEST...WHILE GFS INCREASES IT TO 25-30 KT THIS AFTN AND EVE.
THEREFORE THERE IS A CHANCE THAT THE MID LEVEL FLOW COULD BE
STRONG ENOUGH TO PRODUCE A FEW STRONG STORMS. HOWEVER...EXPECT
THE MAIN THREAT TO BE URBAN AND SMALL STREAM FLOODING. SEE HYDRO
SECTION BELOW FOR MORE DETAILS.
HIGHS ARE EXPECTED TO RANGE BETWEEN MID AND UPPER 80S...BUT WILL
ALSO DEPEND ON THICKNESS OF CLOUD COVER AND ANY PRECIP THIS
MORNING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
WEAK COLD FRONT AND UPPER SHORTWAVE MOVE ACROSS TONIGHT WITH
DECREASING ATMOSPHERIC MOISTURE LEVELS AND THEREFORE DECREASING
THE HEAVY RAIN THREAT. HIGHEST POPS ARE CONFINED TO THIS TIME
PERIOD WHEN THERE WILL BE BETTER SYNOPTIC FORCING PRESENT. FRONT
SHOULD BE S OF THE AREA BY 12Z. MUCH MORE SUN EXPECTED ON MON
WITH RISING HEIGHTS AND H85 TEMPS AROUND 17-18C. THIS TRANSLATES
TO HIGHS IN THE LOWER TO MID 90S...SLIGHTLY COOLER AT THE
IMMEDIATE COAST. SW FLOW COURTESY OF BERMUDA HIGH OVER THE
ATLANTIC WILL ALSO KEEP IT MUGGY WITH DEWPOINTS GENERALLY AROUND
THE 70 DEGREE MARK. THIS WILL RESULT IN HEAT INDICES IN THE MID TO
UPPER 90S FOR MUCH OF THE AREA. NYC WILL LIKELY NEED A HEAT ADVSY
FOR MON...BUT ITS STILL A THIRD PERIOD EVENT SO WILL HOLD OFF.
DESPITE A THERMAL TROUGH ACROSS THE AREA ON MONDAY...WARM MID
LEVELS WILL KEEP A LID ON ANY SHOWER/TSTM ACTIVITY.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
A WARM RIDGE ALOFT WILL ENCAPSULATE MUCH OF THE COUNTRY EAST OF THE
ROCKIES THROUGH THE MIDDLE OF NEXT WEEK...WHILE A POLAR VORTEX OVER
HUDSON BAY IN CANADA DESCENDS SE AND CARVES OUT A STRONG UPPER TROF
ACROSS EASTERN CANADA AND THE NORTHEAST MID TO LATE WEEK. THE LATTER
OF WHICH WILL ALSO SEND A STRONG COLD FRONT THROUGH THE REGION ON
WED AFT/EVE. PRIOR TO THAT TIME...HOT...MUGGY WEATHER WILL BE ON
TAP FOR MON-WED.
GLOBAL MODELS ARE IN GOOD AGREEMENT WITH THE MASS FIELDS AND KEEP
THE AREA DRY MON AND TUE AHEAD OF THE MID WEEK COLD FRONT. MODEL
UPPER AIR SOUNDINGS SHOW STRONG MID LEVEL CAPPING WITH A DRY MIXED
LAYER.
IT WILL BE HOT AND HUMID TUE-WED WITH HIGHS GENERALLY IN THE MID
TO UPPER 90S FOR TUE. EXPECT COOLER CONDITIONS ALONG THE IMMEDIATE
COAST. OVERNIGHT LOWS WILL MAINLY BE IN THE 70S. THE TRICKY PART
OF THE FORECAST COMES WITH HEAT INDEX VALUES....WITH MID 90S TO
AROUND 100 FOR TUE AND WED. MODELS...IN PARTICULAR...THE GFS AND
NAM...DIFFER IN HOW MUCH MIXING THERE IS IN THE BOUNDARY LAYER.
THIS TYPICALLY RESULTS IN DEW POINTS SEVERAL DEGREES COOLER IN THE
NAM...WITH THE GFS NOTORIOUSLY HIGHER AND POOR AT MIXING DRIER AIR
TO THE SURFACE. A COMPROMISE OF THE GUIDANCE WAS USED HERE. HEAT
ADVISORIES WILL LIKELY BE REQUIRED FOR PORTIONS OF THE AREA...IN
PARTICULAR NYC METRO.
A STRONG COLD FRONT IMPACTS THE AREA WED AFT/EVE WITH ANOTHER GOOD
CHANCE FOR CONVECTION. MODERATE TO HIGH INSTABILITY AND WEAK SHEAR
WILL LIKELY PRODUCE ISOLATED STRONG TO SEVERE CONVECTION.
DRIER...MORE SEASONABLE CONDITIONS RETURN FOR THU-SAT AS STRONG
CANADIAN HIGH PRESSURE BUILDS SE FROM THE GREAT LAKES.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
WEAK HIGH PRESSURE AND A WEAK TROUGH OF LOW PRESSURE REMAIN IN
THE VICINITY TODAY. A WEAK COLD FRONT PASSES THROUGH TONIGHT.
SHOULD BE VFR MOST OF THE DAY...BUT CIGS 2000-3000 FT POSSIBLE
WITH MORNING SHOWERS. THESE SHOWERS HAVE NOT YET FORMED...BUT
SCATTERED COVERAGE IS ANTICIPATED TO DEVELOP AND BE IN THE
VICINITY BY AROUND 12Z. NOT ENOUGH CONFIDENCE TO GO WITH TSTMS IN
THE MORNING. ANOTHER ROUND OF SHOWERS WITH A BETTER CHANCE OF
EMBEDDED TSTMS IS ANTICIPATED LATE THIS AFTERNOON INTO THE
EVENING AHEAD OF AN APPROACHING WEAK COLD FRONT. LOCAL MVFR TO IFR
CONDITIONS POSSIBLE DURING THIS TIME. SHOWERS/TSTMS STILL POSSIBLE
AT ANY POINT THIS AFTERNOON...HOWEVER...NOT ENOUGH CONFIDENCE IN
GOING WITH A PREVAILING MENTION OF EITHER BEFORE THE TIMING OF THE
PROB30 GROUPS.
OUTLOOK FOR 06Z MON THROUGH THU...
.SUN NIGHT...CONTINUED CHANCE OF MVFR/IFR CONDITIONS IN
ANY SHOWERS/TSTMS.
.MON-TUE...VFR.
.WED...SCT AFTERNOON SHOWERS/TSTMS.
.THU...VFR.
&&
.MARINE...
MAINLY SW TO WSW FLOW 10-15 KT ACROSS THE OPEN OCEAN WATERS...AND
5-10 KT ELSEWHERE THROUGH WEDNESDAY. OCCASIONAL GUSTS JUST
BELOW 25 KT ARE POSSIBLE IN THE NY BIGHT REGION AND NEAR SHORE THIS
AFTERNOON INTO THIS EVENING. WAVEWATCH SEAS APPEAR A LITTLE OVERDONE
LATE THIS AFTERNOON INTO TONIGHT. AS A RESULT HAVE CAPPED OCEAN SEAS
AT 4 FT THROUGH TONIGHT. SEAS THEREAFTER PRIMARILY 2 TO 4 FT.
THUNDERSTORMS WILL BE POSSIBLE MAINLY LATE THIS AFTERNOON AND
TONIGHT...AND ONCE AGAIN WEDNESDAY AFTERNOON AND NIGHT AS A COLD
FRONT APPROACHES AND PASSES THROUGH. WINDS SHIFT NORTHERLY BEHIND
THE FRONT ON THURSDAY WITH PERHAPS A WEAK ONSHORE FLOW DEVELOPING
LOCALLY DURING THE AFTERNOON.
&&
.HYDROLOGY...
WHILE BASIN AVG QPF THROUGH TONIGHT RUNS
FROM AROUND 1/3 TO 3/4 INCH...HIGHEST NW OF NYC AND LOWEST OVER
ERN CT/LONG ISLAND...LOCALLY HEAVY RAINFALL OF 1-2 INCHES OR MORE
IS POSSIBLE UNDER ANY STRONGER CONVECTION GIVEN THE FORECAST NEAR-
TROPICAL NATURE OF THE ATMOSPHERE...AS CONVECTION WILL BE VERY
EFFICIENT IN CONVERTING AVAILABLE MOISTURE TO RAINFALL.
THERE IS FAIRLY HIGH POTENTIAL FOR MINOR URBAN/POOR DRAINAGE/SMALL
STREAM FLOODING. LOCALIZED FLASH FLOODING CANNOT BE RULED
OUT...ESPECIALLY IN AREAS THAT EXPERIENCE MULTIPLE ROUNDS OF HEAVY
RAIN...BUT THE FLASH FLOOD THREAT PROBABILITY/COVERAGE BOTH APPEAR
TOO SMALL TO WARRANT A FLASH FLOOD WATCH.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW YORK NY
443 AM EDT SUN JUL 15 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL APPROACH THE AREA TODAY AND MOVE ACROSS
TONIGHT. HOT AND HUMID CONDITIONS WILL THEN PERSIST THROUGH THE
MIDDLE OF THE WEEK WITH A BERMUDA HIGH PRESSURE SYSTEM DOMINATING
OUR WEATHER. A STRONGER COLD FRONT WILL MOVE ACROSS THE REGION ON
WEDNESDAY...FOLLOWED BY HIGH PRESSURE AND MORE SEASONABLE
CONDITIONS FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
TRICKY FORECAST TODAY IN REGARDS TO POPS BUT THINKING THERE WILL
BE TWO ROUNDS OF ACTIVITY. THE FIRST IS THIS MORNING WITH A WEAK
SHORTWAVE. HAVE YET TO SEE SHOWERS BEGIN EXPANDING...BUT 00Z SPC
WRF AND LATEST HRRR HIGH RES MODELS ARE IN GOOD AGREEMENT THAT
SHOWERS SHOULD START BECOMING MORE NUMEROUS BETWEEN 09Z AND 12Z
IN NJ AND PA AND TRACK INTO NE NJ. EASTERN SECTIONS PROBABLY WON`T
SEE MUCH OF ANYTHING THIS MORNING AND MUCH OF THE DAY MAY EVEN BE
DRY. MAY HAVE GONE OVERBOARD WITH POPS THIS MORNING AND MAY NEED
TO DECREASE THEM. SOUNDINGS ARE INDICATING ELEVATED INSTABILITY IS
PRESENT SO HAVE KEPT THE MENTION OF THUNDER.
THERE IS UNCERTAINTY WITH HOW THE AFTERNOON PLAYS OUT. BOTH NAM
AND GFS ARE INDICATING NVA OVER THE AREA WITH THE SECOND SHORTWAVE
MOVING ACROSS TONIGHT. HOWEVER WEAK SFC TROUGH ACROSS WESTERN
ZONES SHOULD BE ENOUGH TO TRIGGER SCT SHOWERS/TSTMS ACROSS WESTERN
PORTIONS OF THE AREA. PWATS INCREASE TO 2+ INCHES THIS AFTERNOON
WITH INCREASING THETA E AND TALL SKINNY CAPE PROFILES WHICH ARE
FAVORABLE FOR HEAVY RAIN. THEREFORE...EXPECT THE MAIN THREAT TO BE
URBAN AND SMALL STREAM FLOODING. SEE HYDRO SECTION BELOW FOR MORE
DETAILS. NAM IS NOW KEEPING STRONGER SHEAR TO THE WEST...WHILE GFS
INCREASES IT TO 25-30 KT THIS AFTN AND EVE. THEREFORE IS A CHANCE
THAT THE MID LEVEL FLOW COULD BE STRONG ENOUGH TO PRODUCE A FEW
STRONG STORMS.
CLOUDS WILL INCREASE FROM W TO E THIS MORNING AS UPPER RIDGE AXIS
SLIDES E. HIGHS ARE EXPECTED TO RANGE BETWEEN MID AND UPPER
80S...BUT WILL ALSO DEPEND ON THICKNESS OF CLOUD COVER AND ANY
PRECIP THIS MORNING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
WEAK COLD FRONT AND UPPER SHORTWAVE MOVE ACROSS TONIGHT WITH
DECREASING ATMOSPHERIC MOISTURE LEVELS AND THEREFORE DECREASING
THE HEAVY RAIN THREAT. HIGHEST POPS ARE CONFINED TO THIS TIME
PERIOD WHEN THERE WILL BE BETTER SYNOTIC FORCING PRESENT. FRONT
SHOULD BE S OF THE AREA BY 12Z. MUCH MORE SUN EXPECTED ON MON
WITH RISING HEIGHTS AND H85 TEMPS AROUND 17-18C. THIS TRANSLATES
TO HIGHS IN THE LOWER TO MID 90S...SLIGHTLY COOLER AT THE
IMMEDIATE COAST. SW FLOW COURTESY OF BERMUDA HIGH OVER THE
ATLANTIC WILL ALSO KEEP IT MUGGY WITH DEWPOINTS GENERALLY AROUND
THE 70 DEGREE MARK. THIS WILL RESULT IN HEAT INDICES IN THE MID TO
UPPER 90S FOR MUCH OF THE AREA. NYC WILL LIKELY NEED A HEAT ADVSY
FOR MON...BUT ITS STILL A THIRD PERIOD EVENT SO WILL HOLD OFF.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
A WARM RIDGE ALOFT WILL ENCAPSULATE MUCH OF THE COUNTRY EAST OF THE
ROCKIES THROUGH THE MIDDLE OF NEXT WEEK...WHILE A POLAR VORTEX OVER
HUDSON BAY IN CANADA DESCENDS SE AND CARVES OUT A STRONG UPPER TROF
ACROSS EASTERN CANADA AND THE NORTHEAST MID TO LATE WEEK. THE LATTER
OF WHICH WILL ALSO SEND A STRONG COLD FRONT THROUGH THE REGION ON
WED AFT/EVE. PRIOR TO THAT TIME...HOT...MUGGY WEATHER WILL BE ON
TAP FOR MON-WED.
GLOBAL MODELS ARE IN GOOD AGREEMENT WITH THE MASS FIELDS AND KEEP
THE AREA DRY MON AND TUE AHEAD OF THE MID WEEK COLD FRONT. MODEL
UPPER AIR SOUNDINGS SHOW STRONG MID LEVEL CAPPING WITH A DRY MIXED
LAYER.
IT WILL BE HOT AND HUMID TUE-WED WITH HIGHS GENERALLY IN THE MID
TO UPPER 90S FOR TUE. EXPECT COOLER CONDITIONS ALONG THE IMMEDIATE
COAST. OVERNIGHT LOWS WILL MAINLY BE IN THE 70S. THE TRICKY PART
OF THE FORECAST COMES WITH HEAT INDEX VALUES....WITH MID 90S TO
AROUND 100 FOR TUE AND WED. MODELS...IN PARTICULAR...THE GFS AND
NAM...DIFFER IN HOW MUCH MIXING THERE IS IN THE BOUNDARY LAYER.
THIS TYPICALLY RESULTS IN DEW POINTS SEVERAL DEGREES COOLER IN THE
NAM...WITH THE GFS NOTORIOUSLY HIGHER AND POOR AT MIXING DRIER AIR
TO THE SURFACE. A COMPROMISE OF THE GUIDANCE WAS USED HERE. HEAT
ADVISORIES WILL LIKELY BE REQUIRED FOR PORTIONS OF THE AREA...IN
PARTICULAR NYC METRO.
A STRONG COLD FRONT IMPACTS THE AREA WED AFT/EVE WITH ANOTHER GOOD
CHANCE FOR CONVECTION. MODERATE TO HIGH INSTABILITY AND WEAK SHEAR
WILL LIKELY PRODUCE ISOLATED STRONG TO SEVERE CONVECTION.
DRIER...MORE SEASONABLE CONDITIONS RETURN FOR THU-SAT AS STRONG
CANADIAN HIGH PRESSURE BUILDS SE FROM THE GREAT LAKES.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
WEAK HIGH PRESSURE AND A WEAK TROUGH OF LOW PRESSURE REMAIN IN
THE VICINITY TODAY. A WEAK COLD FRONT PASSES THROUGH TONIGHT.
SHOULD BE VFR MOST OF THE DAY...BUT CIGS 2000-3000 FT POSSIBLE
WITH MORNING SHOWERS. THESE SHOWERS HAVE NOT YET FORMED...BUT
SCATTERED COVERAGE IS ANTICIPATED TO DEVELOP AND BE IN THE
VICINITY BY AROUND 12Z. NOT ENOUGH CONFIDENCE TO GO WITH TSTMS IN
THE MORNING. ANOTHER ROUND OF SHOWERS WITH A BETTER CHANCE OF
EMBEDDED TSTMS IS ANTICIPATED LATE THIS AFTERNOON INTO THE
EVENING AHEAD OF AN APPROACHING WEAK COLD FRONT. LOCAL MVFR TO IFR
CONDITIONS POSSIBLE DURING THIS TIME. SHOWERS/TSTMS STILL POSSIBLE
AT ANY POINT THIS AFTERNOON...HOWEVER...NOT ENOUGH CONFIDENCE IN
GOING WITH A PREVAILING MENTION OF EITHER BEFORE THE TIMING OF THE
PROB30 GROUPS.
OUTLOOK FOR 06Z MON THROUGH THU...
.SUN NIGHT...CONTINUED CHANCE OF MVFR/IFR CONDITIONS IN
ANY SHOWERS/TSTMS.
.MON-TUE...VFR.
.WED...SCT AFTERNOON SHOWERS/TSTMS.
.THU...VFR.
&&
.MARINE...
MAINLY SW TO WSW FLOW 10-15 KT ACROSS THE OPEN OCEAN WATERS...AND
5-10 KT ELSEWHERE THROUGH WEDNESDAY. OCCASIONAL GUSTS JUST
BELOW 25 KT ARE POSSIBLE IN THE NY BIGHT REGION AND NEAR SHORE THIS
AFTERNOON INTO THIS EVENING. WAVEWATCH SEAS APPEAR A LITTLE OVERDONE
LATE THIS AFTERNOON INTO TONIGHT. AS A RESULT HAVE CAPPED OCEAN SEAS
AT 4 FT THROUGH TONIGHT. SEAS THEREAFTER PRIMARILY 2 TO 4 FT.
THUNDERSTORMS WILL BE POSSIBLE MAINLY LATE THIS AFTERNOON AND
TONIGHT...AND ONCE AGAIN WEDNESDAY AFTERNOON AND NIGHT AS A COLD
FRONT APPROACHES AND PASSES THROUGH. WINDS SHIFT NORTHERLY BEHIND
THE FRONT ON THURSDAY WITH PERHAPS A WEAK ONSHORE FLOW DEVELOPING
LOCALLY DURING THE AFTERNOON.
&&
.HYDROLOGY...
WHILE BASIN AVG QPF FROM LATE TONIGHT THROUGH SUNDAY NIGHT RUNS
FROM AROUND 1/3 TO 3/4 INCH...HIGHEST NW OF NYC AND LOWEST OVER
ERN CT/LONG ISLAND...LOCALLY HEAVY RAINFALL OF 1-2 INCHES OR MORE
IS POSSIBLE UNDER ANY STRONGER CONVECTION GIVEN THE FORECAST NEAR-
TROPICAL NATURE OF THE ATMOSPHERE...AS CONVECTION WILL BE VERY
EFFICIENT IN CONVERTING AVAILABLE MOISTURE TO RAINFALL.
THERE IS FAIRLY HIGH POTENTIAL FOR MINOR URBAN/POOR DRAINAGE/SMALL
STREAM FLOODING. LOCALIZED FLASH FLOODING CANNOT BE RULED
OUT...ESPECIALLY IN AREAS THAT EXPERIENCE MULTIPLE ROUNDS OF HEAVY
RAIN...BUT THE FLASH FLOOD THREAT PROBABILITY/COVERAGE BOTH APPEAR
TOO SMALL TO WARRANT A FLASH FLOOD WATCH.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBANY NY
215 AM EDT SUN JUL 15 2012
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE IN THE OHIO VALLEY AND GREAT LAKES WILL
BRING A CHANCE OF BENEFICIAL SHOWERS AND POSSIBLY THUNDERSTORMS
TODAY. HIGH PRESSURE WILL BUILD FROM THE OHIO VALLEY MONDAY AND
TUESDAY WITH MAINLY SUNNY HOT CONDITIONS.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 130 AM...REGIONAL RADARS INDICATED CONVECTION IN PA WILL
LIKELY REMAIN OUT OF OUR REGION THROUGH ABOUT 12Z. THEREFORE WENT
AHEAD AND REMOVED POPS UNTIL THEN. IT SHOULD BE NOTED THAT THE
LATEST HRRR EXPERIMENTAL MODEL DID BRING A CLUSTER OF SHOWERS INTO
THE SCHOHARIE VALLEY AT 10Z...BUT THEN DISSIPATED THEM RIGHT AFTER
THAT. NOT BUYING INTO THIS SOLUTION.
SOME HIGH CLOUDINESS OVER THE REGION AND WAS GENERALLY THICKENING.
MANY SPOTS STILL REPORTING A BREEZE AROUND 5 MPH OR SO. DECIDED TO
RAISE TEMPS 1-3 DEGS IN A FEW SPOTS OVERNIGHT.
UPSTREAM CLOUDS WERE THICKENING EVEN MORE ACROSS THE GREAT LAKES
WHERE A PRETTY POTENT SHORT WAVE WAS. THIS WILL BE THE SYSTEM TO
AFFECT OUR REGION LATER TODAY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
RELATIVELY WELL DEFINED UPPER IMPULSE PREDICTED BY GUIDANCE AND
ENSEMBLES TO TRACK THROUGH THE REGION SUNDAY. WHILE CONVECTION HAS
DIMINISHED FROM EARLIER...A LOT OF MID LEVEL CLOUDS INDICATED LOTS
OF DEEP LAYER MOISTURE. THERE SHOULD BE MORE CLOUDS THAN SUN SUNDAY
WITH LIKELY SHOWERS AND THUNDERSTORMS BY MIDDAY. DID TEMPER THE POPS
BACK A LITTLE DURING THE MORNING.
LOW LEVEL JET ENERGY IS RELATIVELY WEAK...AND THERE SHOULD BE VERY
LITTLE THERMAL FORCING...SO CONVECTION SHOULD BE MOSTLY HEAVY
RAINERS...ALTHOUGH WITH THE INSTABILITY IN PLACE...AND SOME BREAKS
IN THE CLOUDS...ALONG WITH HIGHS IN THE 80S IN MOST AREAS...SOME
VERY ISOLATED STRONG WINDS AND HAIL ARE POSSIBLE. ANY AREAS THAT
COULD SEE A PROLONGED PERIOD OF SUN COULD SEE HIGHS AROUND 90...BUT
THAT LOOKS INCREASINGLY UNLIKELY THAT TEMPS WOULD GET THAT HIGH.
GUIDANCE SUGGESTS THE UPPER SYSTEM IS PREDICTED TO EXIT THE REGION
SUNDAY NIGHT INTO MONDAY...BUT STAY TUNED AS GUIDANCE OFTEN DOES
NOT TIME THE MOVEMENT OF CONVECTIVELY BASED SYSTEMS WELL. THE
WARM AND HUMID AIRMASS SHOULD STILL BE OVER THE REGION...BUT NO
ORGANIZED LOW LEVEL FOCUS OTHER THAN OLD OUFLOW BOUNDARIES.
SO...GRADUAL CLEARING...AND MAYBE SOME FOG SUNDAY NIGHT...THEN
CONTINUED DECREASING CLOUDS MONDAY... WITH JUST VERY ISOLATED
THUNDERSTORMS POSSIBLE...NOT ENOUGH TO ACKNOWLEDGE IN FORECAST
YET. HIGHS IN THE 80S TO MID 90S. ANOTHER WARM AND HUMID NIGHT
MONDAY NIGHT WITH LOWS IN THE 60S TO NEAR 70.
SOME SLIGHT WARMING OF THE BOUNDARY LAYER WELL AHEAD OF THE NEXT
APPROACHING SYSTEM. LOW LEVEL JET ENERGY GRADUALLY INCREASES...
ESPECIALLY IN NORTHERN AREAS BY LATER TUESDAY AFTERNOON. SOME
ISOLATED THUNDERSTORMS ARE POSSIBLE...ESPECIALLY IN AREAS OF
TERRAIN. HIGHS AGAIN WELL INTO THE 80S TO LOWER 90S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HAVE GENERALLY POPULATED THIS PORTION OF GRIDDED DATABASE WITH A
50/50 BLEND OF 18Z HPC MOS...AND 12Z/GMOS.
TUE NT-WED NT...BROAD UPPER LEVEL TROUGH IS EXPECTED TO DEVELOP
ACROSS EAST CENTRAL CANADA EXTENDING INTO THE EASTERN GREAT
LAKES...WITH AN ATTENDANT SFC COLD FRONT APPROACHING FROM THE GREAT
LAKES DURING THIS PERIOD. THERE ARE SOME TIMING DIFFERENCES IN SFC
FROPA ACROSS THE REGION...WITH THE 12Z/GFS SLIGHTLY
FASTER...OCCURRING MIDDAY TUESDAY FROM ALBANY N AND W...AND THE
AFTERNOON TO THE S/E...AND THE 12Z/ECMWF A BIT SLOWER...GEN RALLY
DURING THE AFTERNOON/EVENING HOURS. WILL INDICATE CHC POPS FOR MUCH
OF THE DAY...ALTHOUGH WILL TAPER ACROSS NW AREAS LATER IN THE DAY
WITH EXPECTATION FOR MAIN FROPA TO OCCUR EARLIER. FOR WED NT...WILL
KEEP SOME POPS THROUGH THE EVENING HOURS FOR AREAS S/E OF
ALBANY...TO ACCOUNT FOR POSSIBILITY OF SLIGHTLY SLOWER FROPA.
OTHERWISE...EXPECT A VERY WARM/HUMID NIGHT TUE NT/EARLY WED
AM...WITH MINS ONLY FALLING INTO THE UPPER 60S TO LOWER 70S ACROSS
MUCH OF THE HUDSON RIVER VALLEY AND MOHAWK RIVER VALLEY...WITH
LOWER/MID 60S ELSEWHERE. ON WED...GENERALLY EXPECT MAXES TO REACH
85-90 IN THE HUDSON RIVER VALLEY FROM ALBANY SOUTH...AND 80-85
NORTH...WITH GENERALLY UPPER 70S TO MID 80S ELSEWHERE. SOME AREAS
COULD BE WARMER FROM ALBANY S AND E SHOULD MORE SUNSHINE OCCUR WED
AM THAN CURRENTLY EXPECTED. BY WED NT/THU AM...EXPECT SOMEWHAT
COOLER/LESS HUMID CONDITIONS TO FILTER INTO THE REGION...WITH MINS
FALLING TO 60-65 WITHIN THE HUDSON RIVER VALLEY/MOHAWK RIVER
VALLEYS...AND 55-60 ELSEWHERE...ALTHOUGH SOME LOWER 50S WILL BE
POSSIBLE WITHIN PORTIONS OF THE SOUTHERN ADIRONDACKS.
THU-SAT...EXPECT DRY CONDITIONS...AS A SFC HIGH SLOWLY BUILDS INTO
THE REGION FROM THE GREAT LAKES. TEMPS MAY EVEN BE A BIT BELOW
SEASONAL LEVELS THU-FRI...GIVEN POTENTIAL 850 TEMPS FALLING INTO THE
+8 TO +10C RANGE...BEFORE WARMING TO NEAR OR ABOVE NORMAL BY
FRI-SAT. THIS TRANSLATES INTO MAX TEMPS IN THE UPPER 70S/LOWER 80S
IN VALLEYS THU...AND LOWER/MID 80S FRI-SAT...WITH OVERNIGHT MINS
FALLING INTO THE 50S IN MOST AREAS...WITH SOME 40S POSSIBLE ACROSS
PORTIONS OF THE SOUTHERN ADIRONDACKS/NORTH COUNTRY FRI AM.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
MAINLY VFR CONDITIONS ARE EXPECTED AT THE KALB/KGFL/KPOU/KPSF TAF
SITES UNTIL AN UPPER LEVEL DISTURBANCE BEGIN TO IMPACT THE REGION
BEGINING AROUND NOON SUNDAY AND CONTINUING INTO SUNDAY EVENING.
THERE COULD BE SOME MVFR FOG AT DURING THE REST OF TONIGHT AT KGFL
AND KPSF AND TEMPO GROUPS HAVE BEEN INCLUDED AT THESE LOCATIONS TO
ACCOUNT FOR THAT POSSIBLITY.
AS THE UPPER LEVEL TROF APPROACHES...SCATTERED TO NUMEROUS SHOWERS
AND THUNDERSTORMS WILL SPREAD ACROSS THE REGION OCCASIONAL
REDUCTIONS INTO THE MVFR RANGE IS LIKELY AT ALL THE TAF SITES...AND
IFR CONDITIONS ARE NOT OUT OF THE QUESTION...BUT FOR NOW HAVE NOT
BEEN INCLUDED IN THE FORECAST.
HAVE INCLUDED VCTS FOR ALL TAF SITES SUNDAY AFTERNOON...GENERALLY
BETWEEN 19Z SUNDAY AND 01Z MONDAY DUE TO THE SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS THAT ARE EXPECTED.
CALM OR LIGHT SOUTH WINDS FOR THE REST OF TONIGHT...THEN BECOMING
SOUTH TO SOUTHWEST AT 5-10 KT LATE SUNDAY MORNING INTO THE
AFTERNOON. WINDS WILL BE STRONGER...AND VARIABLE IN DIRECTION IN AND
NEAR ANY THUNDERSTORMS.
OUTLOOK...
SUN NT...MVFR...CHC IFR...SHWRS AND TSTRMS.
MON-WED...VFR/MVFR. ISOLD-SCT SHOWERS/TSTMS.
&&
.FIRE WEATHER...
AN UPPER LEVEL DISTURBANCE IN THE OHIO VALLEY AND GREAT LAKES
WILL BRING A CHANCE OF SIGNIFICANT SHOWERS AND POSSIBLY
THUNDERSTORMS ON SUNDAY. MORE ISOLATED TO SCATTERED THUNDERSTORMS
ARE POSSIBLE THROUGH WEDNESDAY AS A WARM AND HUMID AIRMASS STAYS
OVER OUR REGION.
THE DISTURBANCE ON SUNDAY SHOULD BRING SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS AND HUMID CONDITIONS. THIS SYSTEM HAS
THE POTENTIAL TO BRING 0.25 INCHES OR MORE...MAINLY SOUTH OF
ALBANY.
HIGH PRESSURE WILL BUILD EAST FROM THE OHIO VALLEY INTO OUR REGION
ON MONDAY...BRINGING MORE HOT WEATHER.
RELATIVE HUMIDITY VALUES WILL RECOVER TO 80 TO 100 PERCENT
TONIGHT...AND REMAIN ELEVATED 60 TO 80 PERCENT MOST OF SUNDAY.
HUMIDITY VALUES WILL REMAIN ELEVATED THROUGH MONDAY...DESPITE NO
MORE RAIN EXPECTED.
ONLY ISOLATED THUNDERSTORMS ARE EXPECTED MONDAY AND TUESDAY WITH
POSSIBLY MORE SIGNIFICANT ACTIVITY ON WEDNESDAY.
THE SURFACE WIND WILL BE LIGHT AND VARIABLE AND GENERALLY 10 MPH OR
LESS. LOCALLY HIGHER GUSTS ARE POSSIBLE WITH ANY THUNDERSTORM.
&&
.HYDROLOGY...
NO SIGNIFICANT HYDRO PROBLEMS ARE EXPECTED FOR THE NEXT FIVE DAYS.
SCATTERED SHOWERS AND THUNDERSTORMS...MAINLY IN AREAS OF TERRAIN
THIS AFTERNOON...COULD PRODUCE VERY LOCALIZED AMOUNTS OVER HALF
AN INCH. HOWEVER...RAINFALL BASIN AVERAGE WILL REMAIN WELL BELOW
0.25 INCHES WITH NO EFFECT ON THE SLUGGISH WATERSHEDS.
THERE IS POTENTIAL FOR A AVERAGE RIVER BASIN QUARTER INCH OR MORE OF
RAINFALL...MAINLY SOUTH OF ALBANY ON SUNDAY. SOME LOCALITIES COULD
RECEIVE OVER AN INCH OF RAINFALL FROM DOWNPOURS. FURTHER
NORTH...FROM ALBANY NORTHWARD...IT LOOKS AS LESS THAN A QUARTER OF
AN INCH OF RAIN WILL FALL ACROSS THE RIVER BASIN.
EITHER WAY...EVEN THESE RAIN WILL BE ONLY MINOR RELIEF FROM OUR
INCREASE DRY SPELL...WITH NO RISES ON ANY RIVERS EXPECTED.
AFTER SUNDAY...OUR NEXT CHANCE OF ANY REAL SHOWERS AND STORMS WILL
BE LATE TUESDAY OR EARLY WEDNESDAY WITH THE PASSAGE OF A PRETTY
STRONG COLD FRONT FOR THE TIME OF YEAR.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV/KL
SHORT TERM...HWJIV/NAS
LONG TERM...KL
AVIATION...GJM
FIRE WEATHER...NAS
HYDROLOGY...NAS
AREA FORECAST DISCUSSION
NWS ALBANY NY
150 AM EDT SUN JUL 15 2012
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE IN THE OHIO VALLEY AND GREAT LAKES WILL
BRING A CHANCE OF BENEFICIAL SHOWERS AND POSSIBLY THUNDERSTORMS
TODAY. HIGH PRESSURE WILL BUILD FROM THE OHIO VALLEY MONDAY AND
TUESDAY WITH MAINLY SUNNY HOT CONDITIONS.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 130 AM...REGIONAL RADARS INDICATED CONVECTION IN PA WILL
LIKELY REMAIN OUT OF OUR REGION THROUGH ABOUT 12Z. THEREFORE WENT
AHEAD AND REMOVED POPS UNTIL THEN. IT SHOULD BE NOTED THAT THE
LATEST HRRR EXPERIMENTAL MODEL DID BRING A CLUSTER OF SHOWERS INTO
THE SCHOHARIE VALLEY AT 10Z...BUT THEN DISSIPATED THEM RIGHT AFTER
THAT. NOT BUYING INTO THIS SOLUTION.
SOME HIGH CLOUDINESS OVER THE REGION AND WAS GENERALLY THICKENING.
MANY SPOTS STILL REPORTING A BREEZE AROUND 5 MPH OR SO. DECIDED TO
RAISE TEMPS 1-3 DEGS IN A FEW SPOTS OVERNIGHT.
UPSTREAM CLOUDS WERE THICKENING EVEN MORE ACROSS THE GREAT LAKES
WHERE A PRETTY POTENT SHORT WAVE WAS. THIS WILL BE THE SYSTEM TO
AFFECT OUR REGION LATER TODAY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
RELATIVELY WELL DEFINED UPPER IMPULSE PREDICTED BY GUIDANCE AND
ENSEMBLES TO TRACK THROUGH THE REGION SUNDAY. WHILE CONVECTION HAS
DIMINISHED FROM EARLIER...A LOT OF MID LEVEL CLOUDS INDICATED LOTS
OF DEEP LAYER MOISTURE. THERE SHOULD BE MORE CLOUDS THAN SUN SUNDAY
WITH LIKELY SHOWERS AND THUNDERSTORMS BY MIDDAY. DID TEMPER THE POPS
BACK A LITTLE DURING THE MORNING.
LOW LEVEL JET ENERGY IS RELATIVELY WEAK...AND THERE SHOULD BE VERY
LITTLE THERMAL FORCING...SO CONVECTION SHOULD BE MOSTLY HEAVY
RAINERS...ALTHOUGH WITH THE INSTABILITY IN PLACE...AND SOME BREAKS
IN THE CLOUDS...ALONG WITH HIGHS IN THE 80S IN MOST AREAS...SOME
VERY ISOLATED STRONG WINDS AND HAIL ARE POSSIBLE. ANY AREAS THAT
COULD SEE A PROLONGED PERIOD OF SUN COULD SEE HIGHS AROUND 90...BUT
THAT LOOKS INCREASINGLY UNLIKELY THAT TEMPS WOULD GET THAT HIGH.
GUIDANCE SUGGESTS THE UPPER SYSTEM IS PREDICTED TO EXIT THE REGION
SUNDAY NIGHT INTO MONDAY...BUT STAY TUNED AS GUIDANCE OFTEN DOES
NOT TIME THE MOVEMENT OF CONVECTIVELY BASED SYSTEMS WELL. THE
WARM AND HUMID AIRMASS SHOULD STILL BE OVER THE REGION...BUT NO
ORGANIZED LOW LEVEL FOCUS OTHER THAN OLD OUFLOW BOUNDARIES.
SO...GRADUAL CLEARING...AND MAYBE SOME FOG SUNDAY NIGHT...THEN
CONTINUED DECREASING CLOUDS MONDAY... WITH JUST VERY ISOLATED
THUNDERSTORMS POSSIBLE...NOT ENOUGH TO ACKNOWLEDGE IN FORECAST
YET. HIGHS IN THE 80S TO MID 90S. ANOTHER WARM AND HUMID NIGHT
MONDAY NIGHT WITH LOWS IN THE 60S TO NEAR 70.
SOME SLIGHT WARMING OF THE BOUNDARY LAYER WELL AHEAD OF THE NEXT
APPROACHING SYSTEM. LOW LEVEL JET ENERGY GRADUALLY INCREASES...
ESPECIALLY IN NORTHERN AREAS BY LATER TUESDAY AFTERNOON. SOME
ISOLATED THUNDERSTORMS ARE POSSIBLE...ESPECIALLY IN AREAS OF
TERRAIN. HIGHS AGAIN WELL INTO THE 80S TO LOWER 90S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HAVE GENERALLY POPULATED THIS PORTION OF GRIDDED DATABASE WITH A
50/50 BLEND OF 18Z HPC MOS...AND 12Z/GMOS.
TUE NT-WED NT...BROAD UPPER LEVEL TROUGH IS EXPECTED TO DEVELOP
ACROSS EAST CENTRAL CANADA EXTENDING INTO THE EASTERN GREAT
LAKES...WITH AN ATTENDANT SFC COLD FRONT APPROACHING FROM THE GREAT
LAKES DURING THIS PERIOD. THERE ARE SOME TIMING DIFFERENCES IN SFC
FROPA ACROSS THE REGION...WITH THE 12Z/GFS SLIGHTLY
FASTER...OCCURRING MIDDAY TUESDAY FROM ALBANY N AND W...AND THE
AFTERNOON TO THE S/E...AND THE 12Z/ECMWF A BIT SLOWER...GEN RALLY
DURING THE AFTERNOON/EVENING HOURS. WILL INDICATE CHC POPS FOR MUCH
OF THE DAY...ALTHOUGH WILL TAPER ACROSS NW AREAS LATER IN THE DAY
WITH EXPECTATION FOR MAIN FROPA TO OCCUR EARLIER. FOR WED NT...WILL
KEEP SOME POPS THROUGH THE EVENING HOURS FOR AREAS S/E OF
ALBANY...TO ACCOUNT FOR POSSIBILITY OF SLIGHTLY SLOWER FROPA.
OTHERWISE...EXPECT A VERY WARM/HUMID NIGHT TUE NT/EARLY WED
AM...WITH MINS ONLY FALLING INTO THE UPPER 60S TO LOWER 70S ACROSS
MUCH OF THE HUDSON RIVER VALLEY AND MOHAWK RIVER VALLEY...WITH
LOWER/MID 60S ELSEWHERE. ON WED...GENERALLY EXPECT MAXES TO REACH
85-90 IN THE HUDSON RIVER VALLEY FROM ALBANY SOUTH...AND 80-85
NORTH...WITH GENERALLY UPPER 70S TO MID 80S ELSEWHERE. SOME AREAS
COULD BE WARMER FROM ALBANY S AND E SHOULD MORE SUNSHINE OCCUR WED
AM THAN CURRENTLY EXPECTED. BY WED NT/THU AM...EXPECT SOMEWHAT
COOLER/LESS HUMID CONDITIONS TO FILTER INTO THE REGION...WITH MINS
FALLING TO 60-65 WITHIN THE HUDSON RIVER VALLEY/MOHAWK RIVER
VALLEYS...AND 55-60 ELSEWHERE...ALTHOUGH SOME LOWER 50S WILL BE
POSSIBLE WITHIN PORTIONS OF THE SOUTHERN ADIRONDACKS.
THU-SAT...EXPECT DRY CONDITIONS...AS A SFC HIGH SLOWLY BUILDS INTO
THE REGION FROM THE GREAT LAKES. TEMPS MAY EVEN BE A BIT BELOW
SEASONAL LEVELS THU-FRI...GIVEN POTENTIAL 850 TEMPS FALLING INTO THE
+8 TO +10C RANGE...BEFORE WARMING TO NEAR OR ABOVE NORMAL BY
FRI-SAT. THIS TRANSLATES INTO MAX TEMPS IN THE UPPER 70S/LOWER 80S
IN VALLEYS THU...AND LOWER/MID 80S FRI-SAT...WITH OVERNIGHT MINS
FALLING INTO THE 50S IN MOST AREAS...WITH SOME 40S POSSIBLE ACROSS
PORTIONS OF THE SOUTHERN ADIRONDACKS/NORTH COUNTRY FRI AM.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS ARE EXPECTED EARLY THIS EVENING. THEN...EXPECT
AREAS OF MVFR VSBYS TO DEVELOP DUE TO BR. THERE IS A SLIGHT CHANCE
THAT PATCHY GROUND FOG AND IFR VSBYS COULD DEVELOP AFTER
07Z...ESP AT KGFL AND KPSF...BUT OVERALL PROBABILITY TOO LOW TO
MENTION IN CURRENT TAFS.
ANY AREAS OF MVFR/IFR VSBYS SHOULD GIVE WAY TO VFR CONDITIONS
SUNDAY MORNING. HOWEVER...AS SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS DEVELOP IN THE AFTERNOON...SOME REDUCTIONS INTO THE
MVFR/IFR RANGE ARE POSSIBLE.
HAVE INCLUDED MENTION OF VCTS FOR ALL TAF SITES SUNDAY
AFTERNOON...AS SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE
EXPECTED.
LIGHT SOUTH WINDS WILL BECOME NEARLY CALM OVERNIGHT. WINDS WILL
BECOME SOUTH TO SOUTHWEST AT 5-10 KT LATE SUNDAY MORNING INTO THE
AFTERNOON. WINDS WILL BE STRONGER...AND VARIABLE IN DIRECTION IN
AND NEAR ANY THUNDERSTORMS.
OUTLOOK...
SUN NT...MVFR...CHC IFR...SHWRS AND TSTRMS.
MON-WED...VFR/MVFR. ISOLD-SCT SHOWERS/TSTMS.
&&
.FIRE WEATHER...
AN UPPER LEVEL DISTURBANCE IN THE OHIO VALLEY AND GREAT LAKES
WILL BRING A CHANCE OF SIGNIFICANT SHOWERS AND POSSIBLY
THUNDERSTORMS ON SUNDAY. MORE ISOLATED TO SCATTERED THUNDERSTORMS
ARE POSSIBLE THROUGH WEDNESDAY AS A WARM AND HUMID AIRMASS STAYS
OVER OUR REGION.
THE DISTURBANCE ON SUNDAY SHOULD BRING SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS AND HUMID CONDITIONS. THIS SYSTEM HAS
THE POTENTIAL TO BRING 0.25 INCHES OR MORE...MAINLY SOUTH OF
ALBANY.
HIGH PRESSURE WILL BUILD EAST FROM THE OHIO VALLEY INTO OUR REGION
ON MONDAY...BRINGING MORE HOT WEATHER.
RELATIVE HUMIDITY VALUES WILL RECOVER TO 80 TO 100 PERCENT
TONIGHT...AND REMAIN ELEVATED 60 TO 80 PERCENT MOST OF SUNDAY.
HUMIDITY VALUES WILL REMAIN ELEVATED THROUGH MONDAY...DESPITE NO
MORE RAIN EXPECTED.
ONLY ISOLATED THUNDERSTORMS ARE EXPECTED MONDAY AND TUESDAY WITH
POSSIBLY MORE SIGNIFICANT ACTIVITY ON WEDNESDAY.
THE SURFACE WIND WILL BE LIGHT AND VARIABLE AND GENERALLY 10 MPH OR
LESS. LOCALLY HIGHER GUSTS ARE POSSIBLE WITH ANY THUNDERSTORM.
&&
.HYDROLOGY...
NO SIGNIFICANT HYDRO PROBLEMS ARE EXPECTED FOR THE NEXT FIVE DAYS.
SCATTERED SHOWERS AND THUNDERSTORMS...MAINLY IN AREAS OF TERRAIN
THIS AFTERNOON...COULD PRODUCE VERY LOCALIZED AMOUNTS OVER HALF
AN INCH. HOWEVER...RAINFALL BASIN AVERAGE WILL REMAIN WELL BELOW
0.25 INCHES WITH NO EFFECT ON THE SLUGGISH WATERSHEDS.
THERE IS POTENTIAL FOR A AVERAGE RIVER BASIN QUARTER INCH OR MORE OF
RAINFALL...MAINLY SOUTH OF ALBANY ON SUNDAY. SOME LOCALITIES COULD
RECEIVE OVER AN INCH OF RAINFALL FROM DOWNPOURS. FURTHER
NORTH...FROM ALBANY NORTHWARD...IT LOOKS AS LESS THAN A QUARTER OF
AN INCH OF RAIN WILL FALL ACROSS THE RIVER BASIN.
EITHER WAY...EVEN THESE RAIN WILL BE ONLY MINOR RELIEF FROM OUR
INCREASE DRY SPELL...WITH NO RISES ON ANY RIVERS EXPECTED.
AFTER SUNDAY...OUR NEXT CHANCE OF ANY REAL SHOWERS AND STORMS WILL
BE LATE TUESDAY OR EARLY WEDNESDAY WITH THE PASSAGE OF A PRETTY
STRONG COLD FRONT FOR THE TIME OF YEAR.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV/KL
SHORT TERM...HWJIV/NAS
LONG TERM...KL
AVIATION...KL/BGM
FIRE WEATHER...NAS
HYDROLOGY...NAS
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
454 AM EDT Sun Jul 15 2012
.NEAR TERM [Through Today]...
A rather amplified and complex upper level pattern is depicted
this morning by the 05z RAP analysis. Two shortwave troughs across
the Pacific Northwest and the Upper Midwest are complimented by
two ridges across the Plains states and the Southeast states.
Pinched off from the easternmost trough is a weak closed low
centered over the Southern Plains. Finally, a TUTT draped across
the western Caribbean, northeast into the western Atlantic,
continues its slow westward progression.
For this afternoon, subsidence provided by the southeastern U.S.
ridge will provide our local area with slightly drier conditions.
That being said, precipitable water levels are expected to remain
at or slightly above climatological normals for this time of year.
With no large scale support for ascent expected, the local
seabreeze fronts will dominate this afternoon`s weather pattern.
With slightly more easterly flow regime expected today, a slightly
modified regime 2 is expected. This regime would favor the
Panhandle Seabreeze Front and the East Coast Seabreeze Front. Thus
PoPs are highest across the Florida Panhandle, and later across
our eastern counties in Georgia and Florida.
With respect to the threat for severe weather, no severe weather
is expected across our Florida counties this afternoon. Lower than
normal instability coupled with several other poor to marginal
thermodynamic variables will be the limiting factors here. There
does exist a slight chance for severe storms across our Georgia
and Alabama counties today, with a few caveats. Drier mid-level
air will increase the theta-e differences between the middle and
lower troposphere. This coupled with steep low level lapse rates
will increase the threat for severe downbursts. However, the dry
air may also be the limiting factor in storm development. The best
case scenario for severe storm development across Georgia would
be late in the afternoon/early evening when the East Coast
Seabreeze enters the primed atmosphere. The same story holds true
for southeast Alabama, with a different forcing mechanism. Any
storms that for across Alabama will likely be due to boundary
interactions from the Panhandle Seabreeze. A late afternoon/early
evening threat timeline is expected across Alabama as well.
Waterspouts will be possible again today, primarily along eastward
facing Big Bend beaches due to the more easterly wind component.
The threat should diminish by the afternoon with the diminishing
wind enhancement behind yesterday`s East Coast Seabreeze Front.
&&
.SHORT TERM [Tonight Through Tuesday]...
Seabreeze circulations will continue to influence the
precipitation pattern through the remainder of the short term.
However, beginning Monday, the aforementioned TUTT will move
southwest into our eastern forecast area. This will especially
enhance PoPs across north Florida, east of the Apalachicola
River. On Tuesday, the trough will overspread our entire forecast
area enhancing PoPs area wide.
Temperatures will hold near climatological averages in the lower
90s each afternoon, and the lower 70s each night.
&&
.LONG TERM [Tuesday Night through Sunday]...
Very little change to the extended fcst this cycle as the latest
00 UTC GFS and ECMWF have remained in fairly good agreement with a
Synoptic pattern dominated by a TUTT Low which will gradually open
up into an Upper Level Trof. This should further increase fcst
confidence in above Climo Pops and near Climo Max Temps through
much of the period. Despite the fairly disturbed pattern, the MEX
High Temps appeared too high (Mid 90s in many areas away from the
coast) for the expected levels of cloud cover and rain chances, so
used a 2-1 Blend of the lower and more realistic looking HPC and
MOS Guidance grids. The Euro (and GFS to some extent) do both show
some potential for a brief break in this pattern on Friday, with
possible Upper Level Ridging moving in from the east, before the
mean Trof builds back southward over the weekend, bringing a
return to higher rain chances.
&&
.AVIATION...
A bit more of a challenging Taf package for the overnight and
early morning hours than last night, as the numerical guidance
(which is fairly pessimistic at many of the Terminals) is split
with the Hi-Res models which are generally keeping VFR conditions
through the night. Although conditions could worsen a bit more
than expected with no Cirrus Canopy tonight, decided on only tempo
MVFR conditions at DHN and ABY for this package. On Sunday, expect
the convective coverage to be lower than Saturday with the more of
an easterly flow developing, so only went with Prob30s at ECP and
VLD, with VCTS at TLH, and just VFR the rest of the day at ABY and
DHN.
&&
.MARINE...
Winds and seas will remain below headline criteria for the next
several days as the subtropical ridge keeps a firm hold on the
region. Enhancements nearing SCEC criteria are possible this
morning and tomorrow morning along the East Coast Seabreeze Front.
Flow will shift more southerly by Tuesday, effectively ending the
East Coast Seabreeze enhancements.
&&
.FIRE WEATHER...
Still no fire weather concerns in sight over the foreseeable
future across the Tri-State area, as ample low-level moisture will
keep afternoon relative humidities fairly high through the period.
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
MARINE...None.
&&
$$
NEAR TERM...Harrigan
SHORT TERM...Harrigan
LONG TERM...Gould
AVIATION...Gould
MARINE...Harrigan
FIRE WEATHER...Gould
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
323 AM EDT Sun Jul 15 2012
.NEAR TERM [Through Today]...
A rather amplified and complex upper level pattern is depicted
this morning by the 05z RAP analysis. Two shortwave troughs across
the Pacific Northwest and the Upper Midwest are complimented by
two ridges across the Plains states and the Southeast states.
Pinched off from the easternmost trough is a weak closed low
centered over the Southern Plains. Finally, a TUTT draped across
the western Caribbean, northeast into the western Atlantic,
continues its slow westward progression.
For this afternoon, subsidence provided by the southeastern U.S.
ridge will provide our local area with slightly drier conditions.
That being said, precipitable water levels are expected to remain
at or slightly above climatological normals for this time of year.
With no large scale support for ascent expected, the local
seabreeze fronts will dominate this afternoon`s weather pattern.
With slightly more easterly flow regime expected today, a slightly
modified regime 2 is expected. This regime would favor the
Panhandle Seabreeze Front and the East Coast Seabreeze Front. Thus
PoPs are highest across the Florida Panhandle, and later across
our eastern counties in Georgia and Florida.
With respect to the threat for severe weather, no severe weather
is expected across our Florida counties this afternoon. Lower than
normal instability coupled with several other poor to marginal
thermodynamic variables will be the limiting factors here. There
does exist a slight chance for severe storms across our Georgia
and Alabama counties today, with a few caveats. Drier mid-level
air will increase the theta-e differences between the middle and
lower troposphere. This coupled with steep low level lapse rates
will increase the threat for severe downbursts. However, the dry
air may also be the limiting factor in storm development. The best
case scenario for severe storm development across Georgia would
be late in the afternoon/early evening when the East Coast
Seabreeze enters the primed atmosphere. The same story holds true
for southeast Alabama, with a different forcing mechanism. Any
storms that for across Alabama will likely be due to boundary
interactions from the Panhandle Seabreeze. A late afternoon/early
evening threat timeline is expected across Alabama as well.
Waterspouts will be possible again today, primarily along eastward
facing Big Bend beaches due to the more easterly wind component.
The threat should diminish by the afternoon with the passage of
yesterday`s East Coast Seabreeze Front.
&&
.SHORT TERM [Tonight Through Tuesday]...
Seabreeze circulations will continue to influence the
precipitation pattern through the remainder of the short term.
However, beginning Monday, the aforementioned TUTT will move
southwest into our eastern forecast area. This will especially
enhance PoPs across north Florida, east of the Apalachicola
River. On Tuesday, the trough will overspread our entire forecast
area enhancing PoPs area wide.
Temperatures will hold near climatological averages in the lower
90s each afternoon, and the lower 70s each night.
&&
.LONG TERM [Tuesday Night through Sunday]...
Updating shortly...
&&
.AVIATION...
A bit more of a challenging Taf package for the overnight and
early morning hours than last night, as the numerical guidance
(which is fairly pessimistic at many of the Terminals) is split
with the Hi-Res models which are generally keeping VFR conditions
through the night. Although conditions could worsen a bit more
than expected with no Cirrus Canopy tonight, decided on only tempo
MVFR conditions at DHN and ABY for this package. On Sunday, expect
the convective coverage to be lower than Saturday with the more of
an easterly flow developing, so only went with Prob30s at ECP and
VLD, with VCTS at TLH, and just VFR the rest of the day at ABY and
DHN.
&&
.MARINE...
Winds and seas will remain below headline criteria for the next
several days as the subtropical ridge keeps a firm hold on the
region. Enhancements nearing SCEC criteria are possible this
morning and tomorrow morning along the East Coast Seabreeze Front.
Flow will shift more southerly by Tuesday, effectively ending the
East Coast Seabreeze enhancements.
&&
.FIRE WEATHER...
Updating shortly...
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
MARINE...None.
&&
$$
NEAR TERM...Harrigan
SHORT TERM...Harrigan
LONG TERM...Gould
AVIATION...Gould
MARINE...Harrigan
FIRE WEATHER...Gould
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
409 AM CDT SUN JUL 15 2012
.DISCUSSION...
837 PM CDT
CONVECTIVE ACTIVITY HAS SETTLED THIS EVENING AND SHOULD BE DRY
THROUGH THE REMAINDER OF THE EVENING. HAVE TWEAKED POPS TO REFLECT
DIMINISHED CHANCES. LATE TONIGHT ANOTHER MID LEVEL DISTURBANCE IS
EXPECTED TO DROP SOUTH ACROSS THE AREA. ISOLATED THUNDERSTORMS
ASSOCIATED WITH THIS WAVE HAVE ALREADY DEVELOPED OVER PORTIONS OF
WISCONSIN...BUT OVERALL FORCING/MOISTURE CONVERGENCE APPEARS TO BE
VERY WEAK AND DO NOT EXPECT MORE THAN ISOLATED COVERAGE IF ANY AS IT
MOVES INTO NORTHERN ILLINOIS. OTHERWISE...ONLY MADE MINOR TWEAKS TO
HOURLY TRENDS FOR T/TD...OVERALL FORECAST APPEARS ON TRACK. BMD
//PREV DISCUSSION...
210 PM CDT
CONCERNS WITH THE FORECAST ARE CENTERED ON CONVECTION THROUGH THIS
EVENING...AND THEN HOT TEMPERATURES THE NEXT SEVERAL DAYS.
SHORT TERM...REST OF THIS AFTERNOON THROUGH SUNDAY...
TOWERING CUMULUS ALONG WITH SOME SCATTERED STORMS HAVE DEVELOPED
EARLY THIS AFTERNOON ACROSS MAINLY THE EASTERN HALF OF THE
FORECAST AREA ALONG AND AHEAD OF A SHEARED OUT UPPER IMPULSE AND
AN ELEVATED /850-700MB/ WIND AND MOISTURE CONVERGENCE ZONE. GIVEN
A FAIRLY UNSTABLE AIR MASS PER MODIFIED AMDAR SOUNDINGS AND RAP
ANALYSIS...WITH MLCAPE VALUES OF 1000 TO 1500 J/KG...THESE STORMS
SHOULD CONTINUE TO REGENERATE WITH THE FURTHER FOCI OF BOUNDARY
INTERACTIONS. HAVE ALREADY SEEN THE DIVERGENT VELOCITY SIGNATURES
ON RADAR UNDERNEATH THESE STORMS WITHIN JUST TWO RADAR
VCPS...SHOWING THE DOWNDRAFT POTENTIAL ONCE AGAIN. ENVIRONMENTAL
DCAPE VALUES ANALYZED BY THE RAP OF 700 TO 1000 J/KG ARE SLIGHTLY
LESS THAN YESTERDAY...BUT SUFFICIENT ENOUGH FOR A POSSIBLE
ISOLATED SEVERE GUST...INCLUDING IN NEARSHORE AREAS OF THE LAKE IN
ANY STORMS THAT DRIFT NORTHEAST OVER THAT AREA.
AN UPPER LEVEL SHORT WAVE...AS PART OF THE LARGER BROAD
TROUGH...IS MOVING SOUTHEAST ACROSS WESTERN WI EARLY THIS
AFTERNOON. THE INITIAL SURFACE BOUNDARY UNDERNEATH THIS IS HELPING
TO FOCUS SOME SCATTERED STORMS...WITH SIMILAR ML INSTABILITY OF
1000 TO 1500 J/KG. MORE DEVELOPMENT IS ANTICIPATED THROUGH EARLY
EVENING IN ADVANCE OF THIS AS CONVERGENCE IMPROVES...AND SOME OF
THIS MAY POTENTIALLY BE ALONG OUTFLOW THAT IS ALREADY INTO
NORTHWEST IL. EXPLICIT CONVECTIVE MODELS DO KEY IN ON SCATTERED
STORM DEVELOPMENT TOWARD THE I-39 CORRIDOR BY LATE AFTERNOON. WITH
THE SHORT WAVE AND FRONTAL APPROACH...ALONG WITH DEEP LAYER SHEAR
VALUES OF SEMI-DECENT 30 KT PROJECTED...THESE SHOWERS AND
STORMS HAVE POTENTIAL TO HANG ON LATER INTO THE EVENING.
THE COOL FRONT WILL MOVE THROUGH THE AREA LATE TONIGHT AND SUNDAY
MORNING...BUT WASHING OUT AS IT DOES. TEMPERATURES ON SUNDAY ARE
ACTUALLY EXPECTED TO BE SLIGHTLY HIGHER THAN TODAY...AND DEW
POINTS SHOULD BE CLOSE. THIS WILL AGAIN PROVIDE MODEST
INSTABILITY...BUT HEIGHT RISES ALOFT SHOULD TEMPER STORM
DEVELOPMENT. A ROGUE LATE AFTERNOON CELL OR TWO CANNOT BE RULED
OUT ALONG WEAK SURFACE CONVERGENCE...BUT HAVE NOT MENTIONED IN THE
FORECAST AT THIS TIME. HIGHS ON SUNDAY LOOK TO TOP OUT IN THE
LOWER TO MID 90S...WITH A LAKE BREEZE PROVIDING SOME COOLING FOR
DOWNTOWN CHICAGO AND NEARBY AREAS DURING THE AFTERNOON. THESE LAKE
SHORE AREAS STILL MAY REACH 90 OR NEAR IT BEFORE THE LAKE BREEZE
PUSHES THROUGH.
MTF
LONG TERM...SUNDAY NIGHT THROUGH SATURDAY...
THE UPPER LEVEL RIDGE REESTABLISHES ITSELF ACROSS THE CENTRAL US AS
THE TROUGH MOVES OFF TOWARD THE NEW ENGLAND AREA. A WEAKENING AREA
OF LOW PRESSURE MOVES NORTH OF THE GREAT LAKES MONDAY NIGHT...WHILE
ITS COLD FRONT SINKS SOUTH DOWN THE LAKE ON TUESDAY.
PRECIP CHANCES DIMINISH AS THE TROUGH DRIFTS EASTWARD SUNDAY NIGHT.
THE BEST CHANCE OF PRECIP IN THE EXTENDED IS ALONG THE COLD FRONT
LATE TUESDAY THROUGH WEDNESDAY. GUIDANCE DIFFERS ON THE SPEED OF
THE FRONT...WITH THE GFS BRINGING THE FRONT THROUGH MUCH FASTER THAN
THE ECMWF. GIVEN ISSUES WITH THE GFS LATELY...AND THE ECMWF HAVING
VERY CONSISTENT TIMING OVER THE PAST FEW DAYS...GOING WITH THE
SLOWER SOLUTION. BOTH MODELS INDICATE MOISTURE WILL POOL ALONG THE
FRONT...BUT THEN DISSIPATE AS THE FRONT ENTERS NORTHERN IL.
THEREFORE...KEPT BEST PRECIP CHANCES NORTH OF I-80. LIMITED ACTUAL
PRECIP CHANCES TO LESS THAN 50 PERCENT GIVEN THE MODEL TRENDS AND
DRY CONDITIONS.
HIGH PRESSURE BUILDS IN BEHIND THE FRONT...AND GUIDANCE SUGGESTS
RANDOM PERIODS OF PRECIP DURING THE LATTER HALF OF NEXT WEEK.
HOWEVER...WITH NO CLEAR SOURCE OF FORCING...QUESTIONABLE MOISTURE
SOURCES...AND DROUGHT CONDITIONS...DECIDED TO KEEP THE REMAINDER OF
THE EXTENDED DRY. AT THIS POINT THE BIGGER CRIME IS GETTING FOLKS
HOPES UP FOR RAIN ONLY TO DISAPPOINT.
HEAT BUILDS ACROSS THE REGION THROUGH TUESDAY. GUIDANCE SUGGESTS
THERE WILL ONLY BE A SMALL PUSH OF SLIGHTLY COOLER AIR BEHIND THE
FRONT...WITH WEDNESDAY LOOKING TO BE A BIT COOLER. HOWEVER 850 HPA
TEMPS BEGIN TO WARM ALMOST IMMEDIATELY WITH THE UPPER LEVEL RIDGE SW
OF THE CWA. THEREFORE...THE LATTER HALF OF NEXT WEEK LOOKS ABOVE
AVERAGE.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* LIGHT SOUTH WIND BECOMING SOUTHWEST OVERNIGHT.
* VERY LOW PROBABILITY SHRA/TSRA POTENTIAL THROUGH MID MORNING.
* WIND SHIFT FROM LIGHT WEST-SOUTHWEST TO EAST-NORTHEAST WITH WEAK
TROUGH PASSAGE MID-LATE MORNING AND LAKE BREEZE PUSH FROM THE
EAST THIS AFTERNOON.
MDB
//DISCUSSION...UPDATED 09Z...
WEAK UPPER TROUGH/WEAK SURFACE FRONT CONTINUE TO APPROACH THE AREA
FROM THE NORTHWEST. EARLIER SPOTTY CONVECTION ASSOCIATED WITH IT
ACROSS CENTRAL/SOUTHERN WISCONSIN HAS DISSIPATED WITH LITTLE IN
THE WAY OF CLOUD COVER BEING GENERATED BY THE WAVE AT THIS TIME.
STILL EXPECT THAT THE TERMINALS WILL REMAIN DRY AS THESE FEATURES
PASS BUT A NON-ZERO CHANCE FOR SOME ISOLATED DEVELOPMENT DOES
EXIST BUT IS TOO LOW TO INCLUDE MENTION IN THE TAFS.
MDB
FROM 06Z...
THE MAIN FORECAST CONCERNS ARE SLIM CHANCES FOR ISOLD SHRA/TSRA
THROUGH DAYBREAK...AN OFF CHANCE THIS AFTERNOON...AND A LAKE
BREEZE PUSHING INLAND DURING THE AFTERNOON. SATELLITE IMAGERY
CONTINUES TO SHOW AN UPPER LEVEL TROUGH MOVING SOUTHEASTWARD
ACROSS CENTRAL/SOUTHERN WISCONSIN EARLY TONIGHT. RADAR CONTINUES
TO SHOW SOME SHRA/TSRA ACTIVITY AHEAD OF THIS WAVE ACROSS SOUTHERN
WI BUT LATEST IMAGERY SHOWS A WEAKENING TREND TO THIS ACTIVITY.
ENERGY ASSOCIATED WITH THE SHORTWAVE WILL REACH THE AREA IN THE
NEXT 2-3 HOURS OR SO AND BRING A VERY LOW CHANCE FOR KICKING OFF
SHRA/TSRA AS IT DOES SO. WILL CONTINUE TO LEAVE ANY PRECIP MENTION
OUT OF THE TAFS WITH THE CHANCE FOR OCCURRENCE TOO LOW. SHOULD
ANYTHING MAKE IT INTO NORTHERN ILLINOIS/NW INDIANA IT WOULD BE
VERY ISOLATED. IN ADDITION...A WEAK SURFACE TROUGH WILL BE
SETTLING ACROSS THE AREA LATER THIS MORNING. THIS MAY ALSO SERVE
AS A FOCUS FOR SHRA/TSRA DEVELOPMENT DURING THE MID/LATE MORNING
HOURS BUT THIS CHANCE IS ALSO VERY LOW.
LIGHT WINDS FAVORING A SOUTHWESTERLY DIRECTION WILL TURN NORTHERLY
AS THE SURFACE TROUGH PASSES MID/LATE MORNING. THE FLOW WILL
REMAIN WEAK WHICH WILL SUPPORT THE DEVELOPMENT OF A LAKE BREEZE
WHICH SHOULD MOVE FAIRLY FAR INLAND THIS AFTERNOON. WINDS WILL
TURN EAST TO NORTHEAST AS THE LAKE BREEZE BOUNDARY PASSES. IT IS
POSSIBLE THAT THE LAKE BREEZE COULD AID SOME SPOTTY TSRA
DEVELOPMENT THIS AFTERNOON BUT WARMING OF THE MID LEVELS SHOULD
PRECLUDE MUCH OF NOT ALL DEVELOPMENT THIS AFTERNOON.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* HIGH CONFIDENCE IN OVERALL WIND TRENDS.
* MEDIUM-HIGH CONFIDENCE IN NO ADDITIONAL TSRA AT TERMINALS.
* HIGH CONFIDENCE IN LAKE BREEZE OCCURRENCE THIS AFTERNOON.
MDB
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...VFR.
TUESDAY...VFR. CHANCE TSRA TUES NGT.
WEDNESDAY...SLGT CHANCE TSRA. OTHERWISE VFR.
THURSDAY AND FRIDAY...VFR.
RATZER
&&
.MARINE...
246 AM CDT
A SERIES OF SYSTEMS WILL PASS NORTH OF LAKE MICHIGAN BETWEEN NOW AND
WEDNESDAY...EACH BRINGING A COOL FRONTAL BOUNDARY DOWN THE LAKE. THE
FIRST AREA OF LOW PRESSURE IS MOVING ACROSS EASTERN ONTARIO AND
EXTENDS TOWARD NORTHERN LAKE MICHIGAN. A WEAK FRONT CONTINUES TO
DROP SOUTHWARD DOWN THE LAKE AND WILL BE TO THE SOUTH BY LATE
MORNING. HIGH PRESSURE THEN QUICKLY RETURNS BEHIND THE FRONT THIS
AFTERNOON. WINDS WILL LIKELY BECOME LIGHT AND VARIABLE OR ONSHORE
ACROSS MUCH OF THE CENTRAL AND SOUTHERN PART OF THE LAKE THIS
AFTERNOON THEN BECOME SOUTHERLY ACROSS THE LAKE THIS EVENING.
ANOTHER LOW PRESSURE SYSTEM TAKES SHAPE ACROSS THE DAKOTAS AND
TURNS EASTWARD AND CROSSES LAKE SUPERIOR MONDAY EVENING. THIS LOW
IS EXPECTED TO BE FAIRLY WELL ORGANIZED AND TIGHTENS THE PRESSURE
GRADIENT ACROSS THE NORTHERN END OF THE LAKE LEADING TO A PERIOD
OF 25-30 KT WINDS LATE MONDAY AFTERNOON AND MONDAY EVENING. AS THE
LOW EXITS INTO SOUTHERN QUEBEC TUESDAY A COLD FRONT WILL MARCH
DOWN THE LAKE BRINGING A SHIFT FROM BREEZY SOUTHERLY WINDS TO
BREEZY NORTHWESTERLY WINDS. AT THIS POINT...SPEEDS ON THE BACK
SIDE OF THE FRONT LOOK TO BE MODESTLY LOWER THAN THE WINDS AHEAD
OF THE FRONT. WILL NEED TO WATCH FOR SMALL CRAFT ADVISORY
CONDITIONS FROM WEDNESDAY AFTERNOON BUT AT THIS POINT IT SEEMS
THAT CRITERIA WILL NOT BE MET...HOWEVER...THE LONG FETCH IN PLACE
BEHIND THIS FRONT MAY ALLOW WAVES TO BUILD ENOUGH TO WARRANT
ISSUANCE. HIGH PRESSURE THEN BUILDS IN WEDNESDAY NIGHT AND DRIFTS
EASTWARD ACROSS MICHIGAN INTO FRIDAY NIGHT. ONCE THE STRONGER
NORTH TO NORTHEAST WINDS DIMINISH WEDNESDAY NIGHT LIGHTER WINDS
WILL RETURN AND FAVOR AN EAST TO SOUTHEAST DIRECTION INTO EARLY
SATURDAY WITH A PERIOD OF MORE ONSHORE WINDS FRIDAY WITH A LIGHTER
SYNOPTIC SCALE FLOW SUPPORTING LAKE BREEZE DEVELOPMENT.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
254 AM CDT SUN JUL 15 2012
.DISCUSSION...
837 PM CDT
CONVECTIVE ACTIVITY HAS SETTLED THIS EVENING AND SHOULD BE DRY
THROUGH THE REMAINDER OF THE EVENING. HAVE TWEAKED POPS TO REFLECT
DIMINISHED CHANCES. LATE TONIGHT ANOTHER MID LEVEL DISTURBANCE IS
EXPECTED TO DROP SOUTH ACROSS THE AREA. ISOLATED THUNDERSTORMS
ASSOCIATED WITH THIS WAVE HAVE ALREADY DEVELOPED OVER PORTIONS OF
WISCONSIN...BUT OVERALL FORCING/MOISTURE CONVERGENCE APPEARS TO BE
VERY WEAK AND DO NOT EXPECT MORE THAN ISOLATED COVERAGE IF ANY AS IT
MOVES INTO NORTHERN ILLINOIS. OTHERWISE...ONLY MADE MINOR TWEAKS TO
HOURLY TRENDS FOR T/TD...OVERALL FORECAST APPEARS ON TRACK. BMD
//PREV DISCUSSION...
210 PM CDT
CONCERNS WITH THE FORECAST ARE CENTERED ON CONVECTION THROUGH THIS
EVENING...AND THEN HOT TEMPERATURES THE NEXT SEVERAL DAYS.
SHORT TERM...REST OF THIS AFTERNOON THROUGH SUNDAY...
TOWERING CUMULUS ALONG WITH SOME SCATTERED STORMS HAVE DEVELOPED
EARLY THIS AFTERNOON ACROSS MAINLY THE EASTERN HALF OF THE
FORECAST AREA ALONG AND AHEAD OF A SHEARED OUT UPPER IMPULSE AND
AN ELEVATED /850-700MB/ WIND AND MOISTURE CONVERGENCE ZONE. GIVEN
A FAIRLY UNSTABLE AIR MASS PER MODIFIED AMDAR SOUNDINGS AND RAP
ANALYSIS...WITH MLCAPE VALUES OF 1000 TO 1500 J/KG...THESE STORMS
SHOULD CONTINUE TO REGENERATE WITH THE FURTHER FOCI OF BOUNDARY
INTERACTIONS. HAVE ALREADY SEEN THE DIVERGENT VELOCITY SIGNATURES
ON RADAR UNDERNEATH THESE STORMS WITHIN JUST TWO RADAR
VCPS...SHOWING THE DOWNDRAFT POTENTIAL ONCE AGAIN. ENVIRONMENTAL
DCAPE VALUES ANALYZED BY THE RAP OF 700 TO 1000 J/KG ARE SLIGHTLY
LESS THAN YESTERDAY...BUT SUFFICIENT ENOUGH FOR A POSSIBLE
ISOLATED SEVERE GUST...INCLUDING IN NEARSHORE AREAS OF THE LAKE IN
ANY STORMS THAT DRIFT NORTHEAST OVER THAT AREA.
AN UPPER LEVEL SHORT WAVE...AS PART OF THE LARGER BROAD
TROUGH...IS MOVING SOUTHEAST ACROSS WESTERN WI EARLY THIS
AFTERNOON. THE INITIAL SURFACE BOUNDARY UNDERNEATH THIS IS HELPING
TO FOCUS SOME SCATTERED STORMS...WITH SIMILAR ML INSTABILITY OF
1000 TO 1500 J/KG. MORE DEVELOPMENT IS ANTICIPATED THROUGH EARLY
EVENING IN ADVANCE OF THIS AS CONVERGENCE IMPROVES...AND SOME OF
THIS MAY POTENTIALLY BE ALONG OUTFLOW THAT IS ALREADY INTO
NORTHWEST IL. EXPLICIT CONVECTIVE MODELS DO KEY IN ON SCATTERED
STORM DEVELOPMENT TOWARD THE I-39 CORRIDOR BY LATE AFTERNOON. WITH
THE SHORT WAVE AND FRONTAL APPROACH...ALONG WITH DEEP LAYER SHEAR
VALUES OF SEMI-DECENT 30 KT PROJECTED...THESE SHOWERS AND
STORMS HAVE POTENTIAL TO HANG ON LATER INTO THE EVENING.
THE COOL FRONT WILL MOVE THROUGH THE AREA LATE TONIGHT AND SUNDAY
MORNING...BUT WASHING OUT AS IT DOES. TEMPERATURES ON SUNDAY ARE
ACTUALLY EXPECTED TO BE SLIGHTLY HIGHER THAN TODAY...AND DEW
POINTS SHOULD BE CLOSE. THIS WILL AGAIN PROVIDE MODEST
INSTABILITY...BUT HEIGHT RISES ALOFT SHOULD TEMPER STORM
DEVELOPMENT. A ROGUE LATE AFTERNOON CELL OR TWO CANNOT BE RULED
OUT ALONG WEAK SURFACE CONVERGENCE...BUT HAVE NOT MENTIONED IN THE
FORECAST AT THIS TIME. HIGHS ON SUNDAY LOOK TO TOP OUT IN THE
LOWER TO MID 90S...WITH A LAKE BREEZE PROVIDING SOME COOLING FOR
DOWNTOWN CHICAGO AND NEARBY AREAS DURING THE AFTERNOON. THESE LAKE
SHORE AREAS STILL MAY REACH 90 OR NEAR IT BEFORE THE LAKE BREEZE
PUSHES THROUGH.
MTF
LONG TERM...SUNDAY NIGHT THROUGH SATURDAY...
THE UPPER LEVEL RIDGE REESTABLISHES ITSELF ACROSS THE CENTRAL US AS
THE TROUGH MOVES OFF TOWARD THE NEW ENGLAND AREA. A WEAKENING AREA
OF LOW PRESSURE MOVES NORTH OF THE GREAT LAKES MONDAY NIGHT...WHILE
ITS COLD FRONT SINKS SOUTH DOWN THE LAKE ON TUESDAY.
PRECIP CHANCES DIMINISH AS THE TROUGH DRIFTS EASTWARD SUNDAY NIGHT.
THE BEST CHANCE OF PRECIP IN THE EXTENDED IS ALONG THE COLD FRONT
LATE TUESDAY THROUGH WEDNESDAY. GUIDANCE DIFFERS ON THE SPEED OF
THE FRONT...WITH THE GFS BRINGING THE FRONT THROUGH MUCH FASTER THAN
THE ECMWF. GIVEN ISSUES WITH THE GFS LATELY...AND THE ECMWF HAVING
VERY CONSISTENT TIMING OVER THE PAST FEW DAYS...GOING WITH THE
SLOWER SOLUTION. BOTH MODELS INDICATE MOISTURE WILL POOL ALONG THE
FRONT...BUT THEN DISSIPATE AS THE FRONT ENTERS NORTHERN IL.
THEREFORE...KEPT BEST PRECIP CHANCES NORTH OF I-80. LIMITED ACTUAL
PRECIP CHANCES TO LESS THAN 50 PERCENT GIVEN THE MODEL TRENDS AND
DRY CONDITIONS.
HIGH PRESSURE BUILDS IN BEHIND THE FRONT...AND GUIDANCE SUGGESTS
RANDOM PERIODS OF PRECIP DURING THE LATTER HALF OF NEXT WEEK.
HOWEVER...WITH NO CLEAR SOURCE OF FORCING...QUESTIONABLE MOISTURE
SOURCES...AND DROUGHT CONDITIONS...DECIDED TO KEEP THE REMAINDER OF
THE EXTENDED DRY. AT THIS POINT THE BIGGER CRIME IS GETTING FOLKS
HOPES UP FOR RAIN ONLY TO DISAPPOINT.
HEAT BUILDS ACROSS THE REGION THROUGH TUESDAY. GUIDANCE SUGGESTS
THERE WILL ONLY BE A SMALL PUSH OF SLIGHTLY COOLER AIR BEHIND THE
FRONT...WITH WEDNESDAY LOOKING TO BE A BIT COOLER. HOWEVER 850 HPA
TEMPS BEGIN TO WARM ALMOST IMMEDIATELY WITH THE UPPER LEVEL RIDGE SW
OF THE CWA. THEREFORE...THE LATTER HALF OF NEXT WEEK LOOKS ABOVE
AVERAGE.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* LIGHT SOUTH WIND BECOMING SOUTHWEST OVERNIGHT.
* VERY LOW PROBABILITY SHRA/TSRA POTENTIAL LATER TONIGHT INTO
EARLY MORNING.
* WIND SHIFT FROM LIGHT WEST-SOUTHWEST TO EAST-NORTHEAST WITH WEAK
TROUGH PASSAGE MID-LATE MORNING AND LAKE BREEZE PUSH FROM THE
EAST THIS AFTERNOON.
MDB
//DISCUSSION...UPDATED 06Z...
THE MAIN FORECAST CONCERNS ARE SLIM CHANCES FOR ISOLD SHRA/TSRA
THROUGH DAYBREAK...AN OFF CHANCE THIS AFTERNOON...AND A LAKE
BREEZE PUSHING INLAND DURING THE AFTERNOON. SATELLITE IMAGERY
CONTINUES TO SHOW AN UPPER LEVEL TROUGH MOVING SOUTHEASTWARD
ACROSS CENTRAL/SOUTHERN WISCONSIN EARLY TONIGHT. RADAR CONTINUES
TO SHOW SOME SHRA/TSRA ACTIVITY AHEAD OF THIS WAVE ACROSS SOUTHERN
WI BUT LATEST IMAGERY SHOWS A WEAKENING TREND TO THIS ACTIVITY.
ENERGY ASSOCIATED WITH THE SHORTWAVE WILL REACH THE AREA IN THE
NEXT 2-3 HOURS OR SO AND BRING A VERY LOW CHANCE FOR KICKING OFF
SHRA/TSRA AS IT DOES SO. WILL CONTINUE TO LEAVE ANY PRECIP MENTION
OUT OF THE TAFS WITH THE CHANCE FOR OCCURRENCE TOO LOW. SHOULD
ANYTHING MAKE IT INTO NORTHERN ILLINOIS/NW INDIANA IT WOULD BE
VERY ISOLATED. IN ADDITION...A WEAK SURFACE TROUGH WILL BE
SETTLING ACROSS THE AREA LATER THIS MORNING. THIS MAY ALSO SERVE
AS A FOCUS FOR SHRA/TSRA DEVELOPMENT DURING THE MID/LATE MORNING
HOURS BUT THIS CHANCE IS ALSO VERY LOW.
LIGHT WINDS FAVORING A SOUTHWESTERLY DIRECTION WILL TURN NORTHERLY
AS THE SURFACE TROUGH PASSES MID/LATE MORNING. THE FLOW WILL
REMAIN WEAK WHICH WILL SUPPORT THE DEVELOPMENT OF A LAKE BREEZE
WHICH SHOULD MOVE FAIRLY FAR INLAND THIS AFTERNOON. WINDS WILL
TURN EAST TO NORTHEAST AS THE LAKE BREEZE BOUNDARY PASSES. IT IS
POSSIBLE THAT THE LAKE BREEZE COULD AID SOME SPOTTY TSRA
DEVELOPMENT THIS AFTERNOON BUT WARMING OF THE MID LEVELS SHOULD
PRECLUDE MUCH OF NOT ALL DEVELOPMENT THIS AFTERNOON.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN OVERALL WIND TRENDS.
* MEDIUM-HIGH CONFIDENCE IN NO ADDITIONAL TSRA AT TERMINALS.
* HIGH CONFIDENCE IN LAKE BREEZE OCCURRENCE THIS AFTERNOON.
MDB
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...VFR.
TUESDAY...VFR. CHANCE TSRA TUES NGT.
WEDNESDAY...SLGT CHANCE TSRA. OTHERWISE VFR.
THURSDAY AND FRIDAY...VFR.
RATZER
&&
.MARINE...
246 AM CDT
A SERIES OF SYSTEMS WILL PASS NORTH OF LAKE MICHIGAN BETWEEN NOW AND
WEDNESDAY...EACH BRINGING A COOL FRONTAL BOUNDARY DOWN THE LAKE. THE
FIRST AREA OF LOW PRESSURE IS MOVING ACROSS EASTERN ONTARIO AND
EXTENDS TOWARD NORTHERN LAKE MICHIGAN. A WEAK FRONT CONTINUES TO
DROP SOUTHWARD DOWN THE LAKE AND WILL BE TO THE SOUTH BY LATE
MORNING. HIGH PRESSURE THEN QUICKLY RETURNS BEHIND THE FRONT THIS
AFTERNOON. WINDS WILL LIKELY BECOME LIGHT AND VARIABLE OR ONSHORE
ACROSS MUCH OF THE CENTRAL AND SOUTHERN PART OF THE LAKE THIS
AFTERNOON THEN BECOME SOUTHERLY ACROSS THE LAKE THIS EVENING.
ANOTHER LOW PRESSURE SYSTEM TAKES SHAPE ACROSS THE DAKOTAS AND
TURNS EASTWARD AND CROSSES LAKE SUPERIOR MONDAY EVENING. THIS LOW
IS EXPECTED TO BE FAIRLY WELL ORGANIZED AND TIGHTENS THE PRESSURE
GRADIENT ACROSS THE NORTHERN END OF THE LAKE LEADING TO A PERIOD
OF 25-30 KT WINDS LATE MONDAY AFTERNOON AND MONDAY EVENING. AS THE
LOW EXITS INTO SOUTHERN QUEBEC TUESDAY A COLD FRONT WILL MARCH
DOWN THE LAKE BRINGING A SHIFT FROM BREEZY SOUTHERLY WINDS TO
BREEZY NORTHWESTERLY WINDS. AT THIS POINT...SPEEDS ON THE BACK
SIDE OF THE FRONT LOOK TO BE MODESTLY LOWER THAN THE WINDS AHEAD
OF THE FRONT. WILL NEED TO WATCH FOR SMALL CRAFT ADVISORY
CONDITIONS FROM WEDNESDAY AFTERNOON BUT AT THIS POINT IT SEEMS
THAT CRITERIA WILL NOT BE MET...HOWEVER...THE LONG FETCH IN PLACE
BEHIND THIS FRONT MAY ALLOW WAVES TO BUILD ENOUGH TO WARRANT
ISSUANCE. HIGH PRESSURE THEN BUILDS IN WEDNESDAY NIGHT AND DRIFTS
EASTWARD ACROSS MICHIGAN INTO FRIDAY NIGHT. ONCE THE STRONGER
NORTH TO NORTHEAST WINDS DIMINISH WEDNESDAY NIGHT LIGHTER WINDS
WILL RETURN AND FAVOR AN EAST TO SOUTHEAST DIRECTION INTO EARLY
SATURDAY WITH A PERIOD OF MORE ONSHORE WINDS FRIDAY WITH A LIGHTER
SYNOPTIC SCALE FLOW SUPPORTING LAKE BREEZE DEVELOPMENT.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1241 AM CDT SUN JUL 15 2012
.DISCUSSION...
837 PM CDT
CONVECTIVE ACTIVITY HAS SETTLED THIS EVENING AND SHOULD BE DRY
THROUGH THE REMAINDER OF THE EVENING. HAVE TWEAKED POPS TO REFLECT
DIMINISHED CHANCES. LATE TONIGHT ANOTHER MID LEVEL DISTURBANCE IS
EXPECTED TO DROP SOUTH ACROSS THE AREA. ISOLATED THUNDERSTORMS
ASSOCIATED WITH THIS WAVE HAVE ALREADY DEVELOPED OVER PORTIONS OF
WISCONSIN...BUT OVERALL FORCING/MOISTURE CONVERGENCE APPEARS TO BE
VERY WEAK AND DO NOT EXPECT MORE THAN ISOLATED COVERAGE IF ANY AS IT
MOVES INTO NORTHERN ILLINOIS. OTHERWISE...ONLY MADE MINOR TWEAKS TO
HOURLY TRENDS FOR T/TD...OVERALL FORECAST APPEARS ON TRACK. BMD
//PREV DISCUSSION...
210 PM CDT
CONCERNS WITH THE FORECAST ARE CENTERED ON CONVECTION THROUGH THIS
EVENING...AND THEN HOT TEMPERATURES THE NEXT SEVERAL DAYS.
SHORT TERM...REST OF THIS AFTERNOON THROUGH SUNDAY...
TOWERING CUMULUS ALONG WITH SOME SCATTERED STORMS HAVE DEVELOPED
EARLY THIS AFTERNOON ACROSS MAINLY THE EASTERN HALF OF THE
FORECAST AREA ALONG AND AHEAD OF A SHEARED OUT UPPER IMPULSE AND
AN ELEVATED /850-700MB/ WIND AND MOISTURE CONVERGENCE ZONE. GIVEN
A FAIRLY UNSTABLE AIR MASS PER MODIFIED AMDAR SOUNDINGS AND RAP
ANALYSIS...WITH MLCAPE VALUES OF 1000 TO 1500 J/KG...THESE STORMS
SHOULD CONTINUE TO REGENERATE WITH THE FURTHER FOCI OF BOUNDARY
INTERACTIONS. HAVE ALREADY SEEN THE DIVERGENT VELOCITY SIGNATURES
ON RADAR UNDERNEATH THESE STORMS WITHIN JUST TWO RADAR
VCPS...SHOWING THE DOWNDRAFT POTENTIAL ONCE AGAIN. ENVIRONMENTAL
DCAPE VALUES ANALYZED BY THE RAP OF 700 TO 1000 J/KG ARE SLIGHTLY
LESS THAN YESTERDAY...BUT SUFFICIENT ENOUGH FOR A POSSIBLE
ISOLATED SEVERE GUST...INCLUDING IN NEARSHORE AREAS OF THE LAKE IN
ANY STORMS THAT DRIFT NORTHEAST OVER THAT AREA.
AN UPPER LEVEL SHORT WAVE...AS PART OF THE LARGER BROAD
TROUGH...IS MOVING SOUTHEAST ACROSS WESTERN WI EARLY THIS
AFTERNOON. THE INITIAL SURFACE BOUNDARY UNDERNEATH THIS IS HELPING
TO FOCUS SOME SCATTERED STORMS...WITH SIMILAR ML INSTABILITY OF
1000 TO 1500 J/KG. MORE DEVELOPMENT IS ANTICIPATED THROUGH EARLY
EVENING IN ADVANCE OF THIS AS CONVERGENCE IMPROVES...AND SOME OF
THIS MAY POTENTIALLY BE ALONG OUTFLOW THAT IS ALREADY INTO
NORTHWEST IL. EXPLICIT CONVECTIVE MODELS DO KEY IN ON SCATTERED
STORM DEVELOPMENT TOWARD THE I-39 CORRIDOR BY LATE AFTERNOON. WITH
THE SHORT WAVE AND FRONTAL APPROACH...ALONG WITH DEEP LAYER SHEAR
VALUES OF SEMI-DECENT 30 KT PROJECTED...THESE SHOWERS AND
STORMS HAVE POTENTIAL TO HANG ON LATER INTO THE EVENING.
THE COOL FRONT WILL MOVE THROUGH THE AREA LATE TONIGHT AND SUNDAY
MORNING...BUT WASHING OUT AS IT DOES. TEMPERATURES ON SUNDAY ARE
ACTUALLY EXPECTED TO BE SLIGHTLY HIGHER THAN TODAY...AND DEW
POINTS SHOULD BE CLOSE. THIS WILL AGAIN PROVIDE MODEST
INSTABILITY...BUT HEIGHT RISES ALOFT SHOULD TEMPER STORM
DEVELOPMENT. A ROGUE LATE AFTERNOON CELL OR TWO CANNOT BE RULED
OUT ALONG WEAK SURFACE CONVERGENCE...BUT HAVE NOT MENTIONED IN THE
FORECAST AT THIS TIME. HIGHS ON SUNDAY LOOK TO TOP OUT IN THE
LOWER TO MID 90S...WITH A LAKE BREEZE PROVIDING SOME COOLING FOR
DOWNTOWN CHICAGO AND NEARBY AREAS DURING THE AFTERNOON. THESE LAKE
SHORE AREAS STILL MAY REACH 90 OR NEAR IT BEFORE THE LAKE BREEZE
PUSHES THROUGH.
MTF
LONG TERM...SUNDAY NIGHT THROUGH SATURDAY...
THE UPPER LEVEL RIDGE REESTABLISHES ITSELF ACROSS THE CENTRAL US AS
THE TROUGH MOVES OFF TOWARD THE NEW ENGLAND AREA. A WEAKENING AREA
OF LOW PRESSURE MOVES NORTH OF THE GREAT LAKES MONDAY NIGHT...WHILE
ITS COLD FRONT SINKS SOUTH DOWN THE LAKE ON TUESDAY.
PRECIP CHANCES DIMINISH AS THE TROUGH DRIFTS EASTWARD SUNDAY NIGHT.
THE BEST CHANCE OF PRECIP IN THE EXTENDED IS ALONG THE COLD FRONT
LATE TUESDAY THROUGH WEDNESDAY. GUIDANCE DIFFERS ON THE SPEED OF
THE FRONT...WITH THE GFS BRINGING THE FRONT THROUGH MUCH FASTER THAN
THE ECMWF. GIVEN ISSUES WITH THE GFS LATELY...AND THE ECMWF HAVING
VERY CONSISTENT TIMING OVER THE PAST FEW DAYS...GOING WITH THE
SLOWER SOLUTION. BOTH MODELS INDICATE MOISTURE WILL POOL ALONG THE
FRONT...BUT THEN DISSIPATE AS THE FRONT ENTERS NORTHERN IL.
THEREFORE...KEPT BEST PRECIP CHANCES NORTH OF I-80. LIMITED ACTUAL
PRECIP CHANCES TO LESS THAN 50 PERCENT GIVEN THE MODEL TRENDS AND
DRY CONDITIONS.
HIGH PRESSURE BUILDS IN BEHIND THE FRONT...AND GUIDANCE SUGGESTS
RANDOM PERIODS OF PRECIP DURING THE LATTER HALF OF NEXT WEEK.
HOWEVER...WITH NO CLEAR SOURCE OF FORCING...QUESTIONABLE MOISTURE
SOURCES...AND DROUGHT CONDITIONS...DECIDED TO KEEP THE REMAINDER OF
THE EXTENDED DRY. AT THIS POINT THE BIGGER CRIME IS GETTING FOLKS
HOPES UP FOR RAIN ONLY TO DISAPPOINT.
HEAT BUILDS ACROSS THE REGION THROUGH TUESDAY. GUIDANCE SUGGESTS
THERE WILL ONLY BE A SMALL PUSH OF SLIGHTLY COOLER AIR BEHIND THE
FRONT...WITH WEDNESDAY LOOKING TO BE A BIT COOLER. HOWEVER 850 HPA
TEMPS BEGIN TO WARM ALMOST IMMEDIATELY WITH THE UPPER LEVEL RIDGE SW
OF THE CWA. THEREFORE...THE LATTER HALF OF NEXT WEEK LOOKS ABOVE
AVERAGE.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* LIGHT SOUTH WIND BECOMING SOUTHWEST OVERNIGHT.
* VERY LOW PROBABILITY SHRA/TSRA POTENTIAL LATER TONIGHT INTO
EARLY MORNING.
* WIND SHIFT FROM LIGHT WEST-SOUTHWEST TO EAST-NORTHEAST WITH WEAK
TROUGH PASSAGE MID-LATE MORNING AND LAKE BREEZE PUSH FROM THE
EAST THIS AFTERNOON.
MDB
//DISCUSSION...UPDATED 06Z...
THE MAIN FORECAST CONCERNS ARE SLIM CHANCES FOR ISOLD SHRA/TSRA
THROUGH DAYBREAK...AN OFF CHANCE THIS AFTERNOON...AND A LAKE
BREEZE PUSHING INLAND DURING THE AFTERNOON. SATELLITE IMAGERY
CONTINUES TO SHOW AN UPPER LEVEL TROUGH MOVING SOUTHEASTWARD
ACROSS CENTRAL/SOUTHERN WISCONSIN EARLY TONIGHT. RADAR CONTINUES
TO SHOW SOME SHRA/TSRA ACTIVITY AHEAD OF THIS WAVE ACROSS SOUTHERN
WI BUT LATEST IMAGERY SHOWS A WEAKENING TREND TO THIS ACTIVITY.
ENERGY ASSOCIATED WITH THE SHORTWAVE WILL REACH THE AREA IN THE
NEXT 2-3 HOURS OR SO AND BRING A VERY LOW CHANCE FOR KICKING OFF
SHRA/TSRA AS IT DOES SO. WILL CONTINUE TO LEAVE ANY PRECIP MENTION
OUT OF THE TAFS WITH THE CHANCE FOR OCCURRENCE TOO LOW. SHOULD
ANYTHING MAKE IT INTO NORTHERN ILLINOIS/NW INDIANA IT WOULD BE
VERY ISOLATED. IN ADDITION...A WEAK SURFACE TROUGH WILL BE
SETTLING ACROSS THE AREA LATER THIS MORNING. THIS MAY ALSO SERVE
AS A FOCUS FOR SHRA/TSRA DEVELOPMENT DURING THE MID/LATE MORNING
HOURS BUT THIS CHANCE IS ALSO VERY LOW.
LIGHT WINDS FAVORING A SOUTHWESTERLY DIRECTION WILL TURN NORTHERLY
AS THE SURFACE TROUGH PASSES MID/LATE MORNING. THE FLOW WILL
REMAIN WEAK WHICH WILL SUPPORT THE DEVELOPMENT OF A LAKE BREEZE
WHICH SHOULD MOVE FAIRLY FAR INLAND THIS AFTERNOON. WINDS WILL
TURN EAST TO NORTHEAST AS THE LAKE BREEZE BOUNDARY PASSES. IT IS
POSSIBLE THAT THE LAKE BREEZE COULD AID SOME SPOTTY TSRA
DEVELOPMENT THIS AFTERNOON BUT WARMING OF THE MID LEVELS SHOULD
PRECLUDE MUCH OF NOT ALL DEVELOPMENT THIS AFTERNOON.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN OVERALL WIND TRENDS.
* MEDIUM-HIGH CONFIDENCE IN NO ADDITIONAL TSRA AT TERMINALS.
* HIGH CONFIDENCE IN LAKE BREEZE OCCURRENCE THIS AFTERNOON.
MDB
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...VFR.
TUESDAY...VFR. CHANCE TSRA TUES NGT.
WEDNESDAY...SLGT CHANCE TSRA. OTHERWISE VFR.
THURSDAY AND FRIDAY...VFR.
RATZER
&&
.MARINE...
145 PM CDT
LOW PRESSURE ACROSS LAKE SUPERIOR WILL CONTINUE TO MOVE EAST
THROUGH SUNDAY. THIS WILL STEER A COOL FRONT ACROSS THE LAKE LATE
TONIGHT. AHEAD OF THIS WILL BE SOME SCATTERED STORMS...SOME OF
WHICH ARE LIKELY TO BE GUSTY BASED ON THE ENVIRONMENT. THESE WILL
BE MOST FAVORED ACROSS THE SOUTHERN THIRD OF THE LAKE INCLUDING
NEAR SHORE AREAS OF IL...IN...AND SOUTHWEST MI. WINDS BEHIND THE
FRONT ON SUNDAY WILL BECOME LIGHT AND BEGIN TURNING BACK TO
SOUTHERLY ALREADY BY AFTERNOON. SOUTHWEST WINDS WILL INCREASE ON
MON...WITH OPEN WATER LOCATIONS ACROSS THE NORTH LIKELY REACHING
30 KT DURING MON NIGHT. A COOL FRONT WILL SLOWLY WORK SOUTH
ACROSS THE LAKE ON TUESDAY AND TUESDAY NIGHT. THIS WILL SHIFT
WINDS TO THE NORTH AND PROVIDE A FOCUS FOR SCATTERED THUNDERSTORMS
ONCE AGAIN.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1120 PM CDT SAT JUL 14 2012
.DISCUSSION...
ISSUED 825 PM CDT SAT JUL 14 2012
CONVECTION CONTINUES TO DISSIPATE EARLY THIS EVENING WITH SEVERAL
LOCATIONS RECEIVING SOME DECENT RAINFALL FOR A CHANGE. PEORIA...
BLOOMINGTON AND THE NWS AT LINCOLN RECEIVED OVER 1 INCH OF RAIN.
SOME GUSTY WINDS AND SMALL HAIL WERE ASSOCIATED WITH THE STRONGEST
UPDRAFTS...BUT THOSE WERE FEW AND FAR BETWEEN. LATEST SATELLITE
DATA INDICATES THE 500 MB TROF AXIS RIGHT OVER THE FORECAST
AREA EARLY THIS EVENING. THERE WAS ANOTHER WEAK SHORTWAVE SEEN
OVER NW IL AND THAT WAS DRIFTING ESE AND MAY KEEP AT LEAST ISOLATED
SHOWERS GOING INTO THE OVERNIGHT HOURS. AREAS THAT DID RECEIVE THE
RAINFALL TODAY WILL SEE SOME FOG DEVELOP LATER TONIGHT. CURRENT
ZONE FORECAST HAS A GOOD HANDLE ON THE TRENDS THIS EVENING SO
OTHER THAN THE USUAL TWEAKS WITH THE HOURLY TEMPS...NO OTHER CHANGES
WERE MADE. AS A RESULT...NO ZONE UPDATE WILL BE NEEDED EARLY THIS
EVENING.
&&
.AVIATION...
ISSUED 1115 PM CDT SAT JUL 14 2012
FOG DEVELOPMENT AND COVERAGE DURING THE EARLY MORNING HOURS THE
MAIN FORECAST CONCERN.
ALL THE STORMS HAVE DISSIPATED LEAVING MAINLY CLEAR SKIES AND
LIGHT WINDS WHICH SHOULD LEAD TO FOG DEVELOPMENT...ESPECIALLY IN
THE AREAS THAT RECEIVED THE RAIN OVER THE PAST 24 HOURS. THAT
WOULD INCLUDE PIA...BMI AND CMI. DECATUR DID RECEIVE SOME VERY
LIGHT AMOUNTS SO WILL INCLUDE SOME BRIEF MVFR VSBYS STARTING AT
09Z. FURTHER NORTH...MVFR AND POSSIBLY SOME BRIEF IFR VSBYS
STARTING AT 09Z. WHAT FOG WE DO SEE OVERNIGHT SHOULD QUICKLY
DISSPATE SUNDAY MORNING BY 13 OR 14Z FOLLOWED BY A RAPID INCREASE
IN CUMULUS AFTR 16Z. FORECAST SOUNDINGS SUGGEST THERE SHOULD BE
ENOUGH DRY AIR MIX DOWN TO KEEP CLOUDS SCATTERED BUT THAT WILL
HAVE TO BE WATCHED...ESPECIALLY AT BMI AND CMI. CLOUD BASES WILL
RANGE FROM 4000-5000 FEET BY LATE MORNING WITH THE CUMULUS FIELD
DISSIPATING QUICKLY BY 00Z. SFC WINDS WILL BE LIGHT SOUTHERLY
TONIGHT AND SSW AT 10 KTS OR LESS ON SUNDAY/SUNDAY EVENING.
SMITH
&&
.PREV DISCUSSION...
ISSUED 236 PM CDT SAT JUL 14 2012
SCATTERED SHOWERS ACROSS CENTRAL ILLINOIS CONTINUE...WITH VERY
LITTLE MOVEMENT UNDER A WEAK UPPER LEVEL TROF. CONVECTIVE ACTIVITY
TO THE NW THIS MORNING SHOWING UP AS A LITTLE WEAK VORTEX ON VIS
SAT IMAGERY THIS AFTERNOON. BECAUSE OF THAT...HAVE MADE A COUPLE
OF CHANGES TO THE POPS FOR THE OVERNIGHT. OTHER THAN
THAT...FORECAST IS MOSTLY DRY BEYOND TONIGHT. NEXT CHANCE FOR
PRECIP COMES MID WEEK NEXT WEEK. ECMWF NOW HAVING SIMILAR ISSUE TO
THE LAST FEW RUNS OF THE GFS...SO KEEP SCALING BACK THE EXTENDED
POPS
SHORT TERM...TONIGHT AND TOMORROW...
FIRST CONCERN IS THE SMALL VORTEX TO THE NW MOVING NEAR THE REGION
IN THE OVERNIGHT. NEITHER HRRR NOR THE 4KM WRF ARE PICKING UP ON
THE SYSTEM...BUT THE AVAILABLE MOISTURE HAS NOW BEEN A BIT
ALTERED... PARTICULARLY IN THE EASTERN HALF OF THE CWA. FEEL LESS
LIKE THE SHOWERS AFTER 00Z WILL BE LIMITED TO REMNANTS FROM
TODAY...AND HAVE EXPANDED THE CHANCE POPS TO COVER THE ENTIRE
OVERNIGHT. IN ANY SPOTS THAT CLEAR OUT IN THE
OVERNIGHT...PARTICULARLY IN THE EAST WHERE THE BOUNDARY LAYER
MOISTURE HAS BEEN SIGNIF INCREASED BY THE SHOWERS AND
THUNDERSTORMS THIS AFTERNOON...PATCHY FOG WILL BE POSSIBLE IN THE
EARLY MORNING...AND HAVE PLACED THE MENTION IN THE GRIDS FOR A
COUPLE HOURS... MAINLY EAST OF I-55. TOMORROW...IN THE WAKE OF
EXITING SHOWERS...SOME SMALL POPS MOSTLY SOUTH OF INTERSTATE 70.
THESE POPS ARE MOSTLY A PRODUCT OF PREVIOUS MODEL SOLUTIONS WITH
THE ACTIVITY IN THE OHIO RIVER VALLEY. WILL KEEP THEM IN FOR ANY
LINGERING OVERNIGHT PRECIP...BUT MOSTLY REFLECTIVE OF EARLY IN THE
DAY.
LONG TERM...MONDAY THROUGH FRIDAY...
SCATTERED PRECIP THIS AFTERNOON WILL DO LITTLE TO ALLEVIATE THE
DROUGHT OVER THE REGION... PARTICULARLY WITH THE RIDGE BUILDING IN
THE WESTERN CONUS YET AGAIN...AND PUSHING 850MB TEMPS UP AND SFC
TEMPS BACK INTO THE MID-UPPER 90S. DRY WEATHER CONTINUES...HAVE
RAISED MAX TEMPS A DEGREE OR TWO OVER GUIDANCE SINCE MODELS KEEP
PRECIP AND CLOUD COVER IN ABSENCE OF REAL MOISTURE. BEST CHANCES FOR
PRECIP IN EXTENDED COME WITH WED NIGHT AND A PASSING TROF/SFC
BOUNDARY AS AN UPPER WAVE RIPPLES THROUGH THE 500MB FLOW ALONG THE
US/CAN BORDER. THIS FAR SOUTH...AVAILABLE MOISTURE WILL BE
QUESTIONABLE...AS WILL THE AMOUNT OF SFC CONVERGENCE. HAVE PULLED
BACK THE BLENDED POPS WHEREVER POSSIBLE. SCT SHOWER ACTIVITY IS
ALL THAT IS LIKELY IN THIS FORECAST...A VERY SMALL PERCENTAGE OF
AREA WILL SEE THE PRECIP.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
147 AM EDT SUN JUL 15 2012
.AVIATION.../06Z TAFS/
LIGHT SW FLOW OVER THE AREA THIS MORNING WITH MOIST AIRMASS IN
PLACE. THIS MAY ALLOW SOME MVFR VSBYS IN BR TO DVLP OVERNIGHT.
REMAINDER OF THE FCST SHOULD SEE VFR CONDITIONS. CONSIDERABLE
DIURNAL CU EXPECTED TODAY... ESPECIALLY AT FWA. MODERATE
INSTABILITY SHOULD DEVELOP ONCE AGAIN BUT WK FORCING ASSOCIATED
WITH SHRTWV MOVG ACROSS THE GRTLKS SUGGESTS LITTLE CHC OF TSTMS
AT THE TERMINALS. SKIES EXPECTED TO CLEAR THIS EVENING AND WINDS
DIMINISH AS A RIDGE OF HIGH PRESSURE MOVES INTO THE AREA.
&&
.PREV DISCUSSION... /ISSUED 311 PM EDT SAT JUL 14 2012/
SHORT TERM...
OTHER THAN BAND OF ISOLD CONVN FORMING ALG NRN EDGE OF SUB-TROPICAL
MSTR PLUME THIS AFTN...ATTN FOCUSED ON SLW EWD PROGRESSION OF MCV
OVR NE IL EMBEDDED WITHIN LARGER SCALE TROUGHING ANCHORED BY POTENT
SW SEEN IN VAPOR OVR NE MN. TAIL END OF IL MCV ACTIVELY CONVG
THROUGH E/NE IL ATTM WITHIN AXIS OF STG SFC BASED
HEATING/DESTABILIZATION. SHRT TERM RUC SOLUTIONS CARRY ORGANIZING
CLUSTER FM KMDW - S OF KIKK E/NEWD THROUGH NWRN CWA LT THIS
AFTN/EVE AND HAVE GENERALLY BOUGHT INTO ITS SOLUTION...DROPPING
POP/WX MENTION AFT 03Z.
OTHERWISE NRN STREAM SW TROUGH AND ASSOCD SFC TROUGH WILL BUCK EWD
THIS PD W/UNFVRBL TIMING SUN AFTN AND PER GENERAL WKNG OF UPR TROUGH
AND POORLY ALIGNED LL FLW SWD THROUGH THE OH VALLEY...MEASURABLE
PCPN CHCS APPEAR SLIM AND FIT IN CONTEXT OF HIGHRES INDICATIONS OF
AT BEST ISOLD AFTN DVLPMNT OVR FAR ERN/SERN AREAS. THUS PER THE
PREPONDERANCE OF MODEL BASED GUIDANCE WILL CHOP CONSIDERABLY AND
CONFINED TO SUN AFTN PD ALONE. TEMPS CONTD WELL ABV NORMAL THROUGH
THE PD.
LONG TERM...MONDAY THROUGH SATURDAY
MID LEVEL HEIGHTS TO BUILD ACROSS THE SOUTHERN GREAT LAKES REGION ON
MONDAY AS VORT FILAMENT CONTINUES TO GET ELONGATED AND WEAKEN FROM
NEW ENGLAND INTO THE MID MS RIVER VALLEY. MEANWHILE...UPPER LOW
WHICH HAS BEEN DIVORCED FROM MAIN WESTERLIES ACROSS THE PACIFIC
NORTHWEST WILL EVENTUALLY GET ABSORBED BY A STRONGER PV ANOMALY
DROPPING SOUTHWARD ACROSS BC CANADA. SEVERAL WEAK DISTURBANCES WILL
EJECT EASTWARD FROM THIS PV ANOMALY ACROSS FAR SOUTHERN CANADA/GREAT
LAKES REGION INTO TUESDAY...THROUGH THE BASE OF HUDSON BAY UPPER
LEVEL TROUGH. THIS WILL EVENTUALLY ALLOW A COOL FRONT TO DROP
SOUTHWARD ACROSS THE SOUTHERN GREAT LAKES TUESDAY NIGHT INTO
WEDNESDAY. IN THE MEANTIME...STRONGER WEST/SOUTHWEST LOW LEVEL FLOW
BETWEEN LOW LEVEL TROUGHING TO THE NORTHWEST AND SOUTHEAST CONUS
ANTICYCLONE. THIS WILL ALLOW A WEST TO EAST ORIENTED LOW LEVEL
THERMAL RIDGE TO ADVECT EASTWARD IN ADVANCE OF THE COOL FRONT
MONDAY/TUESDAY. MORE FAVORABLE LOW LEVEL THERMAL RIDGE POSITIONING
ON TUESDAY SHOULD MAKE THIS THE HOTTEST DAY OF THE PERIOD...ALTHOUGH
WILDCARD WILL BE POTENTIAL OF SOME CIRRUS BLOWOFF FROM UPSTREAM
CONVECTION. COMPLICATING THE TEMPERATURE FORECAST THIS PERIOD ARE
LARGE DIFFERENCES IN GUIDANCE THERMODYNAMIC PROFILES. 12Z NAM
SUGGESTS MIXING UP TO ABOUT 725 HPA TUESDAY AFTERNOON WHILE GFS IS
MOISTER AND MUCH MORE SHALLOW WITH MIXING. HAVE GENERALLY DISCOUNTED
GFS IDEA WITH MOIST LOW LEVEL BIAS AS OF LATE...WITH MORE WEIGHT TO
THE DEEPER MIXED NAM...ALTHOUGH THIS SOLUTION MAY BE TOO WELL MIXED.
THIS LARGELY SUPPORTS GOING HIGHS IN THE MID TO UPPER 90S AND HAVE
SLIGHTLY ADJUSTED PREVIOUS FORECAST UPWARD...ALTHOUGH POTENTIAL
AFOREMENTIONED HIGH CLOUD ISSUES WILL NEED TO BE CONSIDERED. MAY
NEED TO CONSIDER HEAT HEADLINES EVENTUALLY FOR TUESDAY WITH HEAT
INDICES AROUND 100 EXPECTED.
NO SIGNIFICANT CHANGES MADE TO LOW CHANCE TSRA POPS LATE TUESDAY
NIGHT ACROSS THE NORTH...EXPANDING ACROSS REMAINDER OF FORECAST AREA
WEDNESDAY WITH THE FRONT. LIMITING FACTORS FOR ORGANIZED CONVECTION
ARE MORE SUBSTANTIAL SHEAR PROFILES WELL BEHIND THE FRONT...LIMITED
MID LEVEL LAPSE RATES...AND STRONGER UPPER FORCING TRACKING ACROSS
THE NORTHERN GREAT LAKES. COOLER CONDITIONS FOR THURSDAY AND FRIDAY
BEHIND THE FRONT...ALTHOUGH IT APPEARS HEAT WILL RETURN AS UPPER
RIDGING BUILDS BACK INTO THE AREA JUST BEYOND THIS FORECAST PERIOD.
LOCAL AREA COULD BE PRONE TO CONVECTIVE CHANCES IN ADVANCE OF THIS
BUILDING RIDGE TOWARD THE END OF THE PERIOD...BUT CONFIDENCE MUCH TO
LOW TO INCLUDE IN ONGOING VERY DRY PATTERN.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...T
LONG TERM...MARSILI
AVIATION...JT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1217 AM CDT SUN JUL 15 2012
...UPDATED SYNOPSIS AND AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1209 AM CDT SUN JUL 15 2012
AT 00Z SUNDAY A 500MB HIGH WAS CENTERED OVER SOUTHEAST COLORADO
AND NORTHEAST NEW MEXICO AND AN UPPER LEVEL RIDGE AXIS EXTENDED
NORTH NORTHEAST INTO NORTH DAKOTA. AN UPPER LEVEL TROUGH WAS
POSITIONED ACROSS THE NORTHWESTERN UNITED STATES AND A WEAK
ANTICYCLONIC FLOW APPEARS TO BE LOCATED ACROSS EASTERN NEW
MEXICO. A 70KT UPPER LEVEL JET WAS LOCATED WEST OF A 500MB HIGH
AND EXTENDED FROM SOUTHWEST WYOMING INTO SOUTHEAST CALIFORNIA.
ANOTHER JET STREAK WAS LOCATED BETWEEN THE DEVELOPING EAST TEXAS
UPPER LOW AND THE SOUTHEAST COLORADO UPPER HIGH. THE NOSE OF THIS
UPPER JET WAS LOCATED NEAR SOUTH CENTRAL KANSAS AND NORTHWEST
OKLAHOMA. A 700MB HIGH EXTENDED FROM THE PANHANDLE OF OKLAHOMA
ACROSS WESTERN KANSAS WITH TEMPERATURES RANGING FROM +12C AT DODGE
CITY, AMARILLO, AND NORTH PLATTE TO +17C AT DENVER. AN AREA OF
HIGHER DEWPOINTS WERE ALSO PRESENT ALONG AND EAST OF THE 12C
ISOTHERM. 850MB TEMPERATURES ACROSS WESTERN KANSAS AT 00Z SUNDAY
WERE 1-2C WARMER WHEN COMPARED TO 00Z SATURDAY TEMPERATURES BUT
SOME COOLING (1-2C) WAS OBSERVED AT OKLAHOMA CITY AND SPRINGFIELD.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 304 PM
CDT SAT JUL 14 2012
A RIDGE OF UPPER LEVEL HIGH PRESSURE WILL DOMINATE THE HIGH PLAINS
FROM NEW MEXICO INTO WESTERN KANSAS AND NEBRASKA INTO SUNDAY. A LEE
TROUGH OF LOW PRESSURE WILL ALSO REMAIN IN EASTERN COLORADO WITH
LIGHT SOUTH TO SOUTHEAST WINDS TONIGHT. THE PRESSURE GRADIENT THEN
TIGHTENS ON SUNDAY WITH SOUTH TO SOUTHWEST WINDS OF 15 TO 25 MPH AND
GUSTY. A MID LEVEL CAPPING INVERSION WILL ALSO CONTINUE INTO SUNDAY
AFTERNOON, AND WITH TEMPERATURES APPROACHING 100, THE CAP MAY WEAKEN
ENOUGH TO SUPPORT SOME HIGH BASED THUNDERSTORMS LATE THIS AFTERNOON
INTO EARLY EVENING AND AGAIN ON SUNDAY. WILL ADD A SLIGHT CHANCE OF
THUNDER MAINLY EAST OF A LINE FROM WAKEENEY TO MEADE. WITH DEWPOINTS
ALSO MIXING OUT, IF ANY THUNDERSTORMS FORM, THEY COULD PUT OUT SOME
LOCALLY STRONG GUSTS FROM 40 TO 50 MPH. THE HRRR MESOSCALE MODEL
ALSO SUPPORTS A FEW THUNDERSTORMS LATE THIS AFTERNOON AND EARLY
EVENING.
OVERNIGHT LOWS WILL BE MILD AND IN THE MID TO UPPER 60S UNDER MOSTLY
CLEAR SKIES. FOR SUNDAY EXPECT HIGHS NEAR THE CENTURY MARK WITH
MOSTLY CLEAR TO PARTLY CLOUDY SKIES.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 435 PM CDT SAT JUL 14 2012
THERE WERE LITTLE OVERALL CHANGES IN EXPECTATIONS NOTED FOR THE
EXTENDED FORECAST PERIOD. THE GENERAL PATTERN CONTINUES TO INDICATE
A WEAKLY POSITIVE TILTED UPPER RIDGE BUILDING INTO THE GREAT PLAINS.
THE RIDGE BECOMES SLOWLY FLATTENED WITH TIME AS SHORTWAVES RIDE THE
NORTHERN PERIPHERY OF THIS RIDGE THROUGH THE WEEK. THIS WARM AIRMASS
WILL BE MARKED BY WARM TEMPERATURES IN THE MID TO UPPER 90S, AND
TEMPERATURES AROUND 100 DEGREES BY MID TO LATE WEEK. CAPPING IS
WEAK, ESPECIALLY ACROSS CENTRAL KANSAS WHERE 700 MB TEMPERATURES ARE
UNDER 10 DEGREES C. AN ISOLATED BRIEF AIRMASS THUNDERSTORM CANNOT
BE COMPLETELY RULED OUT ANY DAY, BUT CHANCES ARE QUITE LOW GIVEN THE
LACK OF NOTED SURFACE CONVERGENCE. THE BEST CHANCES MIGHT BE FARTHER
WEST AND SOUTH ON THE HIGHER TERRAIN OF THE PANHANDLES AND EASTERN
COLORADO. SOUTHWEST KANSAS SHOULD REMAIN IN A WARM SECTOR THROUGH HE
ENTIRE PERIOD, WHILE A STATIONARY FRONT RUNNING FROM IOWA THROUGH
NEBRASKA AND SOUTH DAKOTA SHOULD BE A FOCUS FOR MESOSCALE CONVECTIVE
SYSTEMS EACH NIGHT THROUGH THE MID TO LATE WEEK, AND REMAIN FOCUSED
WELL AWAY FROM CENTRAL KANSAS. CONVECTIVE STORMS THAT DEVELOP FARTHER
WEST WILL HAVE POOR STEERING FLOW WITH SUCH LIGHT MEAN WINDS DUE TO
THE UPPER HIGH. THE ATMOSPHERE WILL PROBABLY BE MORE CONDUCIVE TO
HEAT BURSTS AND GUSTY WINDS THAN TO SEVERE THUNDERSTORMS, ESPECIALLY
WEST OF HIGHWAY 283 TO THE COLORADO LINE.
TEMPERATURES BY LATE IN THE WEEK WERE RAISED A FEW DEGREES. SOME OF
THE BIAS CORRECTED MODEL OUTPUT STATISTICS GUIDANCE IS SUPPORTIVE OF
WARMER HIGHS UNDER THE UPPER RIDGE BY FRIDAY AND SATURDAY.
WIDESPREAD TEMPERATURES IN EXCESS OF 100 DEGREES AND POSSIBLY TO
AROUND 105 ARE INDICATED BY THIS GUIDANCE, AND SEEMS QUITE
REASONABLE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1209 AM CDT SUN JUL 15 2012
SURFACE PRESSURE GRADIENT ACROSS WESTERN KANSAS WILL STRENGTHEN
TODAY AS SURFACE PRESSURES FALL ALONG WITH LEE OF THE ROCKIES.
SURFACE LEE TROUGH WILL STAY WEST OF WESTERN KANSAS TODAY SO
SOUTH/SOUTHEAST WINDS WILL PERSIST AS WIND SPEEDS INCREASE INTO
THE 15 TO 20KT RANGE BY THE EARLY AFTERNOON. BUFR SOUNDINGS KEEP A
LAYER OF MOISTURE IN THE 700-600MB LEVEL ALONG WITH SOME WEAK MID
LEVEL INSTABILITY SO SOME HIGH BASED (VFR) CLOUDS ARE EXPECTED
LATER THIS MORNING/AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 72 97 72 98 / 0 10 10 10
GCK 70 98 72 97 / 0 0 10 10
EHA 68 99 70 95 / 10 10 10 10
LBL 70 99 72 97 / 0 10 10 10
HYS 71 98 74 99 / 0 10 10 10
P28 72 96 75 99 / 0 0 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...KRUSE
LONG TERM...RUSSELL
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS JACKSON KY
123 AM EDT SUN JUL 15 2012
.UPDATE...
ISSUED AT 1100 PM EDT SAT JUL 14 2012
CONVECTION HAS DISSIPATED WITH THE LOSS OF DAYTIME HEATING. OVERNIGHT...
A LULL IN THE ACTIVITY IS EXPECTED...BUT 21Z SREF AND 0Z NAM SHOW
CONVECTIVE DEVELOPMENT GENERALLY OVER WESTERN SECTIONS TOWARD DAWN IN
ADVANCE OF AN APPROACHING SHORTWAVE. THE 18Z GFS IS RELATIVELY CONSISTENT
WITH THIS IDEA AS WELL. THEREFORE WE HAVE CONTINUED WITH A LULL IN
POPS OVER THE NEXT COUPLE OF HOURS AND THEN HAVE THEM INCREASING INTO
THE ISOLATED TO SCATTERED RANGE LATE. SOME SLIGHT ADJUSTMENTS TO
HOURLY TEMPS AND DEWPOINTS WERE ALSO MADE. UPDATED GRIDS AND ZFP ARE
ALREADY OUT.
UPDATE ISSUED AT 815 PM EDT SAT JUL 14 2012
CONVECTION CONTINUES TO WEAKEN AS WE APPROACH SUNSET...AND OVERALL
INTENSITIES HAVE DIMINISHED OVER THE PAST HOUR OR SO. MEASURABLE RAIN
CHANCES WILL BE HIGHEST INITIALLY FROM NEAR JKL TOWARD THE BIG SANDY
REGION AS THE REMAINING CONVECTION WORKS EAST NORTHEAST AND GRADUALLY
IS EXPECTED TO CONTINUE TO WEAKEN OVER THE NEXT TWO HOURS. POPS AND
SKY WERE UPDATED ACCORDINGLY BASED ON THESE TRENDS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 335 PM EDT SAT JUL 14 2012
19Z SFC ANALYSIS SHOWS A WEAK PRESSURE PATTERN THROUGHOUT EAST
KENTUCKY WITH NO CLEAR SYNOPTIC SCALE FEATURES TO KEY IN ON.
HOWEVER...GIVEN THE HIGH PW AIR IN PLACE...NO CAP...AND SOME UPPER
LEVEL ENERGY...NOT MUCH WAS NEEDED TO INITIATE THE STORMS LATE THIS
MORNING THAT CONTINUE TO PERCOLATE OVER THE CWA AT THIS HOUR. THE
CLOUDS FILLED IN FROM THE SOUTH BY MID MORNING AND CONVECTION
FOLLOWED SHORTLY THEREAFTER. A FEW OF THE CELLS HAVE GOTTEN STRONG
AND OTHERS HAVE MERGED/TRAINED OVER THE SAME SPOTS CREATING A CONCERN
FOR MINOR URBAN OR SMALL STREAM FLOODING. REGARDLESS...THE RAINS IN
MANY LOCATIONS ARE NOW PUTTING A SERIOUS DENT IN THEIR ANNUAL
RAINFALL DEFICIT THANKS TO THESE PAST FEW DAYS. TEMPERATURES THIS
AFTERNOON HAVE BEEN HIGHLY DEPENDENT ON THE CONVECTIVE PATTERN AND
BREAKS FOR SUNSHINE WITH READINGS CURRENTLY RANGING FROM THE LOW 70S
IN THE RAIN COOLED SOUTHERN I-75 CORRIDOR TO MID 80S JUST SOUTH OF
STORMS NEAR I-64 AND IN THE...THUS FAR RAIN FREE...FAR SOUTHEAST.
DEWPOINTS...MEANWHILE...REMAIN PEGGED IN THE LOW TO MID 70S SUPPLYING
ALL THE JUICE THE CONVECTION COULD NEED.
THE MODELS REMAIN IN AGREEMENT THAT EAST KENTUCKY WILL BE ON THE
FRINGE OF THE WESTERN EXTENT OF A WEAK BERMUDA RIDGE AND AHEAD OF
TROUGHING COMING FROM THE NORTHERN PLAINS AND CROSSING THE GREAT
LAKES ON SUNDAY. THE ENERGY FROM THIS TROUGH WILL PASS BY TO THE
NORTH LATER SUNDAY AND THIS WILL SERVE TO FURTHER LIMIT THE EFFECT OF
THE EASTERN RIDGE ON OUR WEATHER INTO THE START OF THE NEW WORK WEEK.
IN THIS ENVIRONMENT THE MESOSCALE...OR SMALLER...WILL DOMINATE SO
HAVE LEANED MOST HEAVILY ON THE DETAILS OF THE NAM12 WITH A HEALTHY
DOSE OF THE HRRR EARLY ON TONIGHT.
SENSIBLE WEATHER WILL FEATURE SHOWERS AND THUNDERSTORMS WINDING
DOWN...FOR THE MOST PART...AFTER SUNSET...BUT NOT BEFORE LEAVING
BEHIND A FAIR AMOUNT OF RAINFALL IN SEVERAL LOCATIONS. EXPECT A LULL
THROUGH THE MIDDLE OF THE NIGHT WITH PATCHY FOG A GOOD BET. THE
APPROACH OF A SHORTWAVE INTO THE OHIO VALLEY LATE TONIGHT GIVES SOME
CREDENCE TO THE NAM12/S IDEA OF A CONVECTIVE CLUSTER FORMING OVER
CENTRAL TENNESSEE AND DRIFTING INTO THE CUMBERLAND VALLEY BY DAWN.
SOME SUPPORT FROM THE GFS BOLSTERS THIS IDEA...AS WELL. ACCORDINGLY...
HAVE DEVIATED FROM A STRICTLY DIURNALLY DRIVEN POP AND WX PATTERN TO
ALLOW FOR THIS IDEA IN THE GRIDS...THOUGH NOT WHOLE HOG JUST YET.
OTHERWISE...EXPECT A NEAR REPEAT OF TODAY FOR SUNDAY WITH CONVECTION
DRIVEN MAINLY BY DIURNAL HEATING AND MINOR OUTFLOWS/DIFFERENTIAL
HEATING BOUNDARIES. FOR BOTH TONIGHT AND SUNDAY NIGHT HAVE BEEN
GENEROUS WITH THE PATCHY FOG IN THE GRIDS AFTER MIDNIGHT...BUT HELD
OFF ON ANY DENSE UNTIL IT BECOMES MORE APPARENT WHERE THE BEST
NOCTURNAL CLEARING WILL OCCUR.
FOR TEMPERATURES...FOLLOWED A BLEND OF THE INHERITED GRIDS...
PERSISTENCE...AND SOME OF THE LATEST MET VALUES...AGAIN NOT MUCH IN
THE WAY OF TERRAIN EFFECTS FOR LOWS GIVEN THE HIGH DEWPOINTS. AS FOR
POPS...HAVE ENDED UP SIMILAR TO A BLEND OF THE MET AND MAV MOS
THROUGHOUT THE PERIOD.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 340 PM EDT SAT JUL 14 2012
THE MODELS REMAIN IN VERY GOOD AGREEMENT WITH THE GENERAL LONG WAVE
PATTERN THROUGH THE EXTENDED. A SHORT WAVE TROUGH WILL BE EXITING
THE APPALACHIANS ON MONDAY...HELPING TO TEMPORARILY BUCKLE
RIDGING ACROSS THE PLAINS AND INTO THE MISSISSIPPI VALLEY THROUGH
TUESDAY. THE RIDGE WILL THEN BUILD BACK IN STRONGER ACROSS THE
PLAINS...WITH A MORE VIGOROUS SHORT WAVE TROUGH TO MOVE THROUGH THE
GREAT LAKES AND NEW ENGLAND FOR WEDNESDAY AND THURSDAY...SENDING A
COLD FRONT SOUTH ACROSS THE OHIO VALLEY. THE MODELS HAVE COME ON
BOARD A BIT MORE...WITH A MORE PROGRESSIVE SOLUTION FOR THESE
FEATURES. FOR EASTERN KENTUCKY...THIS WILL KEEP THE THREAT OF
SCATTERED...MAINLY DIURNALLY DRIVEN CONVECTION ACROSS MOST OF THE AREA
THROUGH FRIDAY...BEFORE DEEPER MOISTURE SINKS FAR ENOUGH SOUTH ON
SATURDAY...TO ONLY JUSTIFY A FEW POPS UP ALONG THE TN/VA BORDER.
TEMPERATURES CONTINUE TO LOOK SLIGHTLY ABOVE NORMAL...WITH
PERSISTENT HUMIDITY UNTIL NEXT WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 123 AM EDT SUN JUL 15 2012
FOG AGAIN WILL BE THE FORECAST CHALLENGE THROUGH THE FIRST 6 HRS OF
THE PERIOD. VFR CONDITIONS ARE PRESENT AT ALL TAF SITES AT ISSUANCE
BUT CIGS ARE GRADUALLY THINNING AND THIS SHOULD ALLOW FOR ANOTHER
ROUND OF LOW STRATUS BUILDING DOWN INTO THE VALLEYS TOWARDS
DAYBREAK...WITH IFR OR WORSE DEVELOPING ON THE RIDGES WITHIN THE FIRST
COUPLE OF HOURS OF THE PERIOD BEFORE AFFECTING THE LOWER ELEVATIONS
BETWEEN 10Z AND 12Z. NEAR TERM MODELS SHOW PRECIP DEVELOPING OVER TN
BEFORE MOVING INTO CENTRAL KY AROUND 12Z AND HAVE INCLUDED VC GROUPS
TO ADDRESS THIS. SCATTERED TO NUMEROUS TSTMS ARE EXPECTED TO DEVELOP
THIS AFTERNOON AND WILL ONCE AGAIN BRING TEMPORARY...LOCALIZED IFR OR
WORSE TO ANY TERMINAL THAT SEES CONVECTION TODAY. HOWEVER...WITH LOW
CONFIDENCE IN TIMING AND EXACT PLACEMENT OF CONVECTION...WILL
CONTINUE WITH VC GROUPS FOR NOW AND LET THE 12Z ISSUANCE TAKE A
BETTER LOOK AT THIS. LOW LEVEL WINDS ARE EXPECTED TO REDEVELOP AFTER
12Z OUT OF THE SW TO AROUND 5 TO 10 KTS AND CONTINUE THROUGH THE
EVENING BEFORE DIMINISHING WITH CONVECTION AFTER SUNSET.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM....GEOGERIAN
AVIATION...MB
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
430 AM EDT SUN JUL 15 2012
.SYNOPSIS...
THE COMBINATION OF A MID-LEVEL DISTURBANCE CROSSING THE GREAT
LAKES AND A MOIST AIR MASS IN PLACE ACROSS THE UPPER OHIO VALLEY
WILL MAKE SHOWERS AND THUNDERSTORMS LIKELY BY THIS AFTERNOON. A
DRY START TO THE WEEK IS THEN EXPECTED AS HIGH PRESSURE ALOFT
APPROACHES FROM THE SOUTHWEST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO VALLEY
IN A SOUTHWESTERLY FLOW BETWEEN A RIDGE ACROSS THE CAROLINAS AND A
TROUGH ACROSS THE WESTERN GREAT LAKES. AT THE SURFACE, DISCERNIBLE
FRONTAL/PRESSURE FEATURES ARE LACKING WITH A BROAD AREA OF TDS IN
THE UPPER 60S TO LOWER 70S ACROSS THE REGION. A SATURATED
ATMOSPHERIC COLUMN REMAINS IN PLACE WITH PRECIPITABLE WATER VALUES
IN THE 1.8-2.0 INCH RANGE EARLY THIS MORNING. DESPITE ONLY WEAK
CAPE REMAINING, ABUNDANT MOISTURE IN PLACE IS ENOUGH TO SUPPORT
WIDELY SCATTERED SHOWERS MOVING ACROSS THE AREA.
THE SOUTHWESTERLY MID-LEVEL FLOW WILL BECOME MORE ZONAL TODAY AS
THE TROUGH CROSSES THE GREAT LAKES. 500MB HEIGHTS WILL FALL
SLIGHTLY AS THIS FEATURE PASSES NORTH OF THE AREA, PROVIDING
ENOUGH FORCING IN A MOIST AND UNSTABLE ENVIRONMENT TO CONTRIBUTE
TO THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS. COVERAGE OF
CONVECTION IS EXPECTED TO INCREASE THIS MORNING AS ELEVATED
INSTABILITY INCREASES FROM THE SOUTHWEST. EXPECT MOSTLY CLOUDY
SKIES AGAIN TODAY WITH ABUNDANT MOISTURE. FOR TEMPS, HIGHS ARE
CLOSEST TO MAV GUIDANCE, RANGING FROM THE UPPER 70S ALONG THE I-80
CORRIDOR AND EASTERN RIDGES TO THE MID 80S IN EASTERN OHIO.
PWAT VALUES NEAR 2 INCHES WITH DEEP MOISTURE IN PLACE ALONG WITH
MODERATE INSTABILITY WILL SUPPORT LOCALLY HEAVY DOWNPOURS TODAY.
STORM MOTION OF AROUND 30KTS ALONG WITH THE GROUND BEING
RELATIVELY DRY ACROSS MUCH OF THE AREA WILL BE LIMITING FACTORS
FOR A FLASH FLOODING THREAT TODAY. HOWEVER, IF MULTIPLE STORMS
TRAIN OVER AREAS, FLOODING COULD BECOME A THREAT. WITH 0-6KM BULK
SHEAR AROUND 30KTS, ITS NOT OF THE QUESTION THAT A FEW ISOLATED
STRONG TO SEVERE THUNDERSTORMS WILL DEVELOP THIS AFTERNOON INTO
THE EVENING WITH THE PRIMARY THREAT BEING OF GUSTY WINDS AIDED
BY MOISTURE LOADING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THERE IS OPERATIONAL MODEL AGREEMENT THAT THE MID-LEVEL TROUGH
WILL SHIFT EAST OF THE AREA WITH THE FLOW BECOMING NORTHWESTERLY.
WITH DEEP LAYER MOISTURE ADVECTING EAST OF THE AREA, CONVECTION
WITH LOCALLY HEAVY DOWNPOURS WILL DIMINISH BY 06Z WITH POPS
DECREASING TO SCHC QUICKLY AND DRY BY MONDAY MORNING. A DRY LAYER
ABOVE 850MB ALONG WITH 500MB RIDGING BUILDING INTO THE OHIO VALLEY
WILL ALLOW FOR A MOSTLY DRY FORECAST THROUGH THE DAY MONDAY AND
INTO MONDAY NIGHT. MODERATE INSTABILITY MAY BE ENOUGH TO INITIATE
AN ISOLATED SHOWER OR THUNDERSTORM SOUTHEAST OF PITTSBURGH INTO
THE AFTERNOON.
HIGHS MONDAY ARE A MAV/MET BLEND, RANGING FROM THE MID TO UPPER
80S ACROSS THE AREA. WITH TDS IN THE MID TO UPPER 60S TONIGHT AND
MONDAY NIGHT, LOWS WILL RANGE FROM THE MID 60S ACROSS THE I-80
CORRIDOR TO NEAR 70 FOR THE PITTSBURGH METRO AND LOCATIONS
SOUTHWESTWARD.
ECMWF/GFS ARE IN AGREEMENT THAT THE 500MB RIDGE CENTERED ACROSS
THE TENNESSEE VALLEY WILL EDGE TOWARD THE UPPER OHIO VALLEY ON
TUESDAY. IN ADDITION, THE REGION WILL BE IN WARM AIR ADVECTION
AHEAD OF A COLD FRONT APPROACHING FROM THE NORTHWEST. WITH 850MB
TEMPS FORECAST TO WARM TO NEAR 20C BY TUESDAY AFTERNOON, THIS
SUPPORTS HIGHS IN THE LOWER 90S ACROSS LOWLAND AREAS. WITH WARMEST
TDS IN EASTERN OHIO, HEAT INDICES WILL APPROACH 100 AND A HEAT
ADVISORY MAY BE NEEDED FOR LOCATIONS ALONG AND WEST OF I-77.
TUESDAY WILL BE A WARM AND MUGGY NIGHT WITH TEMPS ONLY COOLING
INTO THE LOWER 70S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
A COLD FRONT IS PROGGED TO MOVE SLOWLY SOUTHWARD ACROSS THE GREAT
LAKES AND THROUGH THE UPPER OHIO VALLEY ON WEDNESDAY. SCATTERED
SHOWERS AND THUNDERSTORMS WILL ACCOMPANY THIS BOUNDARY THROUGH
WEDNESDAY EVENING. DRY CONDITIONS CAN BE EXPECTED THURSDAY THROUGH
SATURDAY AS SURFACE HIGH PRESSURE BUILDS IN ACROSS THE GREAT LAKES
AND INTO NEW ENGLAND.
STAYED CLOSE TO HPC NUMBERS WITH TEMPERATURES REMAINING BETWEEN 5
AND 10 DEGREES ABOVE NORMAL THROUGH WEDNESDAY NIGHT...THEN CLOSER TO
NORMAL FOR THE LATTER PART OF THE WEEK.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
THUNDERSTORMS HAVE CLEARED ALL SITES TO THE NORTHEAST FOR THE
EVENING AS OF 0530Z. SOME SHOWER ACTIVITY CONTINUES TO DEVELOP OVER
EASTERN OHIO AND MOVE NORTHEASTWARD...BUT IT IS RATHER SCATTERED.
THIS WILL NOT BE CARRIED AT ANY PARTICULAR TERMINAL...HOWEVER
CONTINUED INPUT OF MOISTURE INTO THE LOWER LEVELS FROM ANY
ADDITIONAL SHOWERS WILL ONLY INCREASE THE LIKELIHOOD OF VISIBILITIES
STARTING TO SLIDE OFF WITHIN THE NEXT 1-3 HOURS. ALL SITES SHOULD GO
MVFR PER BOTH STATISTICAL GUIDANCE AND PER SUGGESTIONS FROM BUFKIT
DATA. SHOWERS WILL REDEVELOP BY LATE MORNING SUNDAY AGAIN AS THINGS
BEGIN TO DESTABILIZE...WHICH SHOULD ALLOW FOR FOG TO BREAKUP BY THAT
TIME. FRIES
OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...
WEAK RIDGING SHOULD PROVIDE GENERALLY VFR CONDITIONS MONDAY INTO
TUESDAY. A COLD FRONT WILL SAG SOUTHWARD ACROSS THE GREAT LAKES AND
THROUGH THE OHIO VALLEY TUESDAY NIGHT AND WEDNESDAY. RESTRICTIONS
CAN BE EXPECTED IN SCATTERED PREFRONTAL THUNDERSTORMS. PREVAILING
VFR WEATHER SHOULD RETURN BY THURSDAY AS A SURFACE HIGH BUILDS IN.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
228 AM EDT SUN JUL 15 2012
.SYNOPSIS...
A LOW PRESSURE TROUGH ACROSS THE MISSISSIPPI VALLEY WILL CONTINUE
TO CHANNEL HUMID CONDITIONS NORTHWARD ACROSS THE UPPER OHIO VALLEY
TODAY, MAKING SHOWERS AND THUNDERSTORMS LIKELY. A DRY START TO THE
WEEK IS EXPECTED AS HIGH PRESSURE ALOFT APPROACHES FROM THE SOUTHWEST.
&&
.NEAR TERM /THROUGH TODAY/...
06Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED THIS
MORNING TO REMOVE THUNDER FROM THE FORECAST THROUGH 14Z.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO VALLEY
IN A SOUTHWESTERLY FLOW BETWEEN A RIDGE ACROSS THE CAROLINAS AND A
TROUGH ACROSS THE WESTERN GREAT LAKES. AT THE SURFACE, DISCERNIBLE
FRONTAL/PRESSURE FEATURES ARE LACKING WITH A BROAD AREA OF TDS IN
THE UPPER 60S TO LOWER 70S ACROSS THE REGION. A SATURATED
ATMOSPHERIC COLUMN REMAINS IN PLACE WITH PRECIPITABLE WATER VALUES
IN THE 1.8-2.0 INCH RANGE EARLY THIS MORNING. DESPITE ONLY WEAK
CAPE REMAINING, ABUNDANT MOISTURE IN PLACE IS ENOUGH TO SUPPORT
SCATTERED SHOWERS MOVING ACROSS THE AREA.
THE SOUTHWESTERLY MID-LEVEL FLOW WILL BECOME MORE ZONAL TODAY AS
THE TROUGH CROSSES THE GREAT LAKES. 500MB HEIGHTS WILL LOWER
SLIGHTLY AS THIS FEATURE PASSES NORTH OF THE AREA, PROVIDING
ENOUGH FORCING IN A MOIST AND UNSTABLE ENVIRONMENT TO CONTRIBUTE
TO THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS. COVERAGE OF
CONVECTION IS EXPECTED TO INCREASE THIS MORNING AS ELEVATED
INSTABILITY INCREASES FROM THE SOUTHWEST. PWAT VALUES NEAR 2
INCHES WITH DEEP MOISTURE IN PLACE ALONG WITH MODERATE INSTABILITY
WILL SUPPORT LOCALLY HEAVY DOWNPOURS. STORM MOTION OF AROUND 30KTS
ALONG WITH THE GROUND BEING RELATIVELY DRY ACROSS MUCH OF THE AREA
WILL CONTRIBUTE TO LIMIT THE FLASH FLOODING THREAT TODAY, SO NO
MENTION IN THE HWO AT TIME. HOWEVER, IF MULTIPLE STORMS TRAIN OVER
AREAS WHICH BECOME SATURATED, FLOODING COULD BECOME A THREAT. FOR
TEMPS, HIGHS ARE CLOSEST TO MAV GUIDANCE, RANGING FROM THE LOWER
TO MID 80S ACROSS THE UPPER OHIO VALLEY.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM MONDAY/...
THERE IS OPERATIONAL MODEL AGREEMENT THAT THE MID-LEVEL TROUGH
WILL SHIFT EAST OF THE AREA, WITH THE FLOW BECOMING NORTHWESTERLY.
WITH DEEP LAYER MOISTURE ADVECTING EAST OF THE AREA, THIS WILL
DECREASE POPS TO SCHC QUICKLY OVERNIGHT AND DRY BY MONDAY MORNING.
A DRY LAYER ABOVE 850MB ALONG WITH 500MB RIDGING BUILDING INTO THE
OHIO VALLEY WILL ALLOW FOR A DRY FORECAST THROUGH THE DAY MONDAY.
HIGHS ARE A MAV/MET BLEND, RANGING FROM THE MID TO UPPER 80S
ACROSS THE AREA.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
A COLD FRONT IS PROGGED TO MOVE SLOWLY SOUTHWARD ACROSS THE GREAT
LAKES AND THROUGH THE UPPER OHIO VALLEY TUESDAY NIGHT AND
WEDNESDAY. SCATTERED SHOWERS AND THUNDERSTORMS WILL ACCOMPANY THIS
BOUNDARY THROUGH WEDNESDAY EVENING. DRY CONDITIONS CAN BE EXPECTED
THURSDAY THROUGH SATURDAY AS SURFACE HIGH PRESSURE BUILDS IN ACROSS
THE GREAT LAKES AND INTO NEW ENGLAND.
STAYED CLOSE TO HPC NUMBERS WITH TEMPERATURES REMAINING BETWEEN 5
AND 10 DEGREES ABOVE NORMAL THROUGH WEDNESDAY NIGHT...THEN CLOSER TO
NORMAL FOR THE LATTER PART OF THE WEEK.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
THUNDERSTORMS HAVE CLEARED ALL SITES TO THE NORTHEAST FOR THE
EVENING AS OF 0530Z. SOME SHOWER ACTIVITY CONTINUES TO DEVELOP OVER
EASTERN OHIO AND MOVE NORTHEASTWARD...BUT IT IS RATHER SCATTERED.
THIS WILL NOT BE CARRIED AT ANY PARTICULAR TERMINAL...HOWEVER
CONTINUED INPUT OF MOISTURE INTO THE LOWER LEVELS FROM ANY
ADDITIONAL SHOWERS WILL ONLY INCREASE THE LIKELIHOOD OF VISIBILITIES
STARTING TO SLIDE OFF WITHIN THE NEXT 1-3 HOURS. ALL SITES SHOULD GO
MVFR PER BOTH STATISTICAL GUIDANCE AND PER SUGGESTIONS FROM BUFKIT
DATA. SHOWERS WILL REDEVELOP BY LATE MORNING SUNDAY AGAIN AS THINGS
BEGIN TO DESTABILIZE...WHICH SHOULD ALLOW FOR FOG TO BREAKUP BY THAT
TIME. FRIES
OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...
WEAK RIDGING SHOULD PROVIDE GENERALLY VFR CONDITIONS MONDAY INTO
TUESDAY. A COLD FRONT WILL SAG SOUTHWARD ACROSS THE GREAT LAKES AND
THROUGH THE OHIO VALLEY TUESDAY NIGHT AND WEDNESDAY. RESTRICTIONS
CAN BE EXPECTED IN SCATTERED PREFRONTAL THUNDERSTORMS. PREVAILING
VFR WEATHER SHOULD RETURN BY THURSDAY AS A SURFACE HIGH BUILDS IN.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
522 AM EDT SUN JUL 15 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 520 AM EDT SUN JUL 15 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW TROF JUST E OF THE FCST
AREA. SHRA/TSRA THAT ACCOMPANIED THE TROF ACROSS THE AREA YESTERDAY
HAVE RECENTLY EXITED THE SE PORTION OF THE FCST AREA. IN ITS WAKE...
CALM WIND/CLEARING SKIES AND MOISTURE FROM YESTERDAY`S RAINFALL HAS
LED TO SOME FOG DEVELOPMENT. FOG WILL QUICKLY BURN OFF WITHIN A
COUPLE HRS AFTER SUNRISE. UPSTREAM...A MID LEVEL RIDGE IS NOSING
INTO THE DAKOTAS/WRN MN. AS THE RIDGE SHIFTS E TODAY...UPPER MI WILL
FALL UNDER HEIGHT RISES/DEEP LAYER QVECTOR DIVERGENCE. MUCH DRIER
AIR...MAINLY IN THE MID LEVELS PER UPSTREAM 00Z KINL/CWPL
SOUNDINGS...WILL WORK AGAINST ANY AFTN CONVECTIVE DEVELOPMENT
DESPITE LAKE BREEZES PROVIDING LOW-LEVEL FORCING. THE K-INDEX ON THE
00Z CWPL/KINL SOUNDINGS WAS -11/-14C RESPECTIVELY DUE TO VERY DRY
AIR AROUND 700MB (DWPT DEPRESSIONS WERE IN EXCESS OF 40C). SO...
GOING DRY FCST APPEARS ON TRACK DESPITE SOME HIGH RES GUIDANCE
CONTINUING TO SHOW ISOLD CONVECTION OVER THE SCNTRL THIS AFTN.
MIXING TO AROUND 800MB ON FCST SOUNDINGS SUPPORTS MAX TEMPS UPWARDS
OF AROUND 90F. LIGHT GRADIENT WIND WILL ALLOW LAKE BREEZES OFF
LAKE SUPERIOR AND LAKE MICHIGAN TO PROVIDE SOME COOLING LAKESIDE.
SHORTWAVE ENERGY EJECTING FROM THE TROF CURRENTLY OVER THE WRN
STATES WILL HEAD INTO SCNTRL CANADA TONIGHT. IN RESPONSE...LOW-LEVEL
JET WILL INCREASE TO 45-50KT INTO THE NRN PLAINS. THIS WILL LIKELY
SUPPORT A CLUSTER OF SHRA/TSRA ON THE NOSE OF THE LOW-LEVEL JET AND
ALONG EDGE OF CAP ACROSS ND INTO SRN MANITOBA/NRN MN AND NRN
ONTARIO. AT THIS TIME...IT STILL APPEARS LOW-LEVEL JET WILL BE W OF
THE AREA AT 12Z MON...SO DO NOT ANTICIPATE ANY CONVECTION LATE
TONIGHT...EXCEPT POSSIBLY OVER NW LAKE SUPERIOR/ISLE ROYALE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 520 AM EDT SUN JUL 15 2012
BY 12Z MONDAY THE FRONTAL BOUNDARY WOULD BE ACROSS LAKE SUPERIOR
/AS A WARM FRONT/...STRETCHING FROM THE SFC LOW SET UP FROM NW MN TO
CENTRAL SD. DEPENDING ON THE AMOUNT OF MIXING /UP TO AROUND 800MB AT
SAW/ A FEW GUSTS OF 30 TO 35KTS COULD BE POSSIBLE FROM LATE MORNING
THROUGH THE REMAINDER OF THE DAYTIME HOURS. IF CLOUD COVER DOES NOT
INHIBIT MIXING...THESE STRONGER GUSTS COULD BE POSSIBLE ACROSS THE
DOWNSLOPE LOCATIONS NEAR LAKE SUPERIOR GIVEN THE STRENGTHENING SW
FLOW. AS FOR THE OFFICIAL FCST...HAVE INCREASED WINDS QUITE A BIT
FROM THE PREVIOUS FORECAST...WITH GUSTS OF 20-25KTS ACROSS MUCH OF
THE CWA BY MID AFTERNOON.
THE RECORD HIGH TEMP FOR MONDAY AT WFO MQT IS 95 DEGREES...WHICH MAY
BE BROKEN BY THE END OF THE DAY. CURRENTLY GOING ONLY A COUPLE OF
DEGREES COOLER THAN THIS RECORD...WITH 850MB TEMPS OF 22-24C
ALLOWING SEVERAL SITES ACROSS THE INTERIOR W HALF OF UPPER MI
REACHING 95 OR ABOVE.
THE SFC LOW SHOULD PUSH ACROSS THE AREA MONDAY AFTERNOON
THROUGH TUESDAY NIGHT. THE TRACK IS STILL UNCERTAIN...WITH THE
14/18Z GFS AND 15/00Z NAM PUSHING THE SFC LOW ACROSS THE KEWEENAW
PENINSULA AND ACROSS LAKE SUPERIOR BY EARLY MONDAY EVENING. THE
FARTHER SOUTH 14/12Z ECMWF INDICATES A BROADER LOW...STRETCHING
ACROSS CENTRAL AND SOUTHERN UPPER MI MONDAY NIGHT. THE 14/12Z
CANADIAN IS BEYOND CONSENSUS FROM MONDAY AFTERNOON ON...TRACKING THE
SFC LOW ACROSS ONTARIO AND N LAKE SUPERIOR...AND WILL NOT BE USED IN
THIS FORECAST UNTIL IT MOVES BACK IN LINE WITH THE REMAINDER OF
AVAILABLE GUIDANCE WEDNESDAY MORNING.
HIGH PRESSURE OVER CENTRAL CANADA TUESDAY MORNING WILL SLOWLY SHIFT
SE ACROSS LAKE SUPERIOR AND UPPER MI TUESDAY THROUGH THURSDAY. THE
COOLEST AFTERNOON TEMPS LOOK TO BE WEDNESDAY...TOPPING OUT IN THE
70S...COOLEST NEAR LAKE SUPERIOR AS DRY COOL AIR REMAINS. 850MB
TEMPS WEDNESDAY WILL BE A COOL 10-12C. THE FCST FOR THE CWA WILL
REMAIN DRY TUESDAY NIGHT THROUGH FRIDAY NIGHT. EXPECT THE SFC HIGH
TO DRIFT E TO THE LOWER GREAT LAKES AND W QUEBEC BY DAYBREAK FRIDAY
AND THE NEW ENGLAND COAST FRIDAY NIGHT...WITH A RIDGE REMAINING
ACROSS THE UPPER GREAT LAKES REGION.
A RELATIVELY WEAK SFC LOW STRETCHING FROM CENTRAL CANADA THROUGH THE
CENTRAL PLAINS LOOKS TO BECOME BETTER ORGANIZED TO OUR W SATURDAY
NIGHT...AS A SERIES OF DISTURBANCES NEAR FROM W AND CENTRAL CANADA
AS 500MB RIDGE BECOMES SUPPRESSED ACROSS THE CENTRAL AND SOUTHERN
PLAINS. KEPT CHANCE POPS FOR SATURDAY...ALTHOUGH CONFIDENCE IS
MODERATE TO LOW FOR SPECIFICS THAT FAR OUT IN THIS FCST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 132 AM EDT SUN JUL 15 2012
GIVEN CLEARING SKIES AND ADDITIONAL LOW-LEVEL MOISTURE FM RECENT
RAINFALL...EXPECT STRATUS/FOG TO DEVELOP OVER MUCH OF UPPER MI.
CONFIDENCE IS FAIRLY HIGH THAT FOG WILL BRING KSAW VSBY AND CIGS
DOWN TO LIFR AND POSSIBLE VLIFR CONDITIONS OVERNIGHT AS RAINFALL WAS
MORE ABUNDANT IN THAT AREA ON SATURDAY. AT IWD AND CMX...LESSER
RAINFALL ON SATURDAY CASTS SOME UNCERTAINTY AS TO FOG POTENTIAL
OVERNIGHT. HAVE ALREADY SEEN LOWER STRATUS DECK FORM AT CMX...AND
THOUGH THAT MAY BE INTERMITTENT INITIALLY FOR THE OVERNIGHT HOURS
DUE TO BLOWOFF CLOUDS OVR WESTERN LK SUPERIOR...WILL GO WITH IDEA
THAT STRATUS AND IFR FOG STAY IN THERE OVERNIGHT. MAY EVEN SEE LOWER
VSBY LATER TONIGHT BRIEFLY IF THE BLOWOFF DISIPPATES COMPLETELY. AT
IWD WILL KEEP WITH AN MVFR VSBY FOR JUST PATCHY FOG. ALL CIG/VSBY
REDUCTION WILL BE DONE SHORTLY AFT SUNRISE. EXPECT VFR CONDITIONS
FROM MID MORNING THRU THE END OF THE FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 520 AM EDT SUN JUL 15 2012
BIGGEST CONCERN IN THE SHORT TERM WILL BE FOG. 11-3.9MICRON
SATELLITE IMAGERY INDICATES FOG (PROBABLY NOT STRATUS) EXPANDING S
AND E FROM NCNTRL LAKE SUPERIOR. MORE FOG MAY BE DEVELOPING FROM
KEWEENAW BAY TOWARD MARQUETTE/MUNISING. WITH DEVELOPING MESO HIGH
PRES OVER THE LAKE TODAY...IT`S QUITE POSSIBLE FOG MAY END UP
SPREADING TO THE SHORELINES AROUND THE ENTIRE LAKE TODAY. ALWAYS
DIFFICULT TO FCST MARINE FOG...SO TRENDS WILL NEED TO MONITORED
CLOSELY TODAY FOR MOVEMENT/DEVELOPMENT/DISSIPATION OF FOG. ONCE
DAYLIGHT ARRIVES...VIS SATELLITE IMAGERY WILL PROVIDE A BETTER LOOK
AT HOW THE FOG IS EVOLVING. QUITE POSSIBLE DENSE FOG ADVY MAY NEED
TO BE ISSUED. FOR NOW...CARRIED FOG MENTION THRU EARLY AFTN OVER
MAINLY CNTRL AND ERN LAKE SUPERIOR.
OTHERWISE...WITH HIGH PRES DEVELOPING OVER LAKE SUPERIOR TODAY...
WINDS WILL BE UNDER 15KT. ALTHOUGH WINDS WILL BECOME S-SE TONIGHT IN
ADVANCE OF APPROACHING LOW PRES...SPEEDS SHOULD REMAIN 15KT OR LESS.
THERE IS SOME UNCERTAINTY IN WHERE WARM FRONT ASSOCIATED WITH THE
LOW WILL BE POSITIONED MON. AT THIS TIME...IT APPEARS THAT AT LEAST
SRN PORTIONS OF THE LAKE WILL SEE INCREASING S-SW WINDS MON UPWARDS
OF 20KT AS WARM FRONT DRIFTS N. AS LOW PASSES ACROSS THE AREA MON
NIGHT...A COLD FRONT WILL PUSH S...BRINGING A SHIFT TO NORTHERLY
WINDS UPWARDS OF 20KT INTO TUE MORNING. HIGH PRES WILL THEN BUILD
INTO THE UPPER GREAT LAKES DURING THE MIDWEEK PERIOD...RESULTING IN
WINDS UNDER 20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...JLA
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS BUFFALO NY
552 AM EDT SUN JUL 15 2012
.SYNOPSIS...
A SOUTHWESTERLY FLOW WILL BRING INCREASINGLY HUMID AIR INTO THE REGION
TODAY ALONG WITH SOME SHOWERS AND THUNDERSTORMS. A FEW STORMS WILL
CONTAIN LOCALLY HEAVY RAINFALL...BUT ANY HEAVIER RAIN AMOUNTS WILL
BE SPOTTY. A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE LOWER GREAT
LAKES MONDAY WITH MAINLY DRY CONDITIONS.
&&
.NEAR TERM /THROUGH TONIGHT/...
TODAY WILL BRING AN OPPORTUNITY FOR DROUGHT RELIEF...HOWEVER SHOWERS
AND THUNDERSTORMS WILL BE PATCHY IN NATURE...SO MANY COULD MISS OUT.
THERE APPEARS TO BE TWO FEATURES WHICH WILL KEY THIS ACTIVITY. THE
FIRST IS A MODEST 25 KT LOW LEVEL JET FOUND AT 925 MB...WHICH IS
KEYING THE ADVANCE OF LOW LEVEL MOISTURE. THE SECOND IS AN UPPER
LEVEL TROF AXIS...WHICH WILL CROSS THE REGION LATE AFTERNOON INTO
THIS EVENING.
AS IS OFTEN THE CASE...MODEL GUIDANCE IS STRUGGLING A BIT WITH
CONVECTION...WITH A FAIR SPREAD OF QPF SOLUTIONS BETWEEN THE
NAM/RGEM/GFS/EUROPEAN/SREF. THE HRRR HAS ALSO BEEN INCONSISTENT RUN TO
RUN AND HAS BEEN LATE IN CATCHING ON TO CONVECTION WHICH HAS
DEVELOPED. GIVEN THIS SCENARIO WILL TEND TO WEIGHT RADAR TRENDS
IN THE NEAR TERM...AND A SREF WEIGHTED ENSEMBLE OF AVAILABLE
GUIDANCE FROM LATE MORNING ON. THIS SUGGESTS FAIRLY MODEST SHOWER
ACTIVITY WILL MOVE ACROSS THE REGION THROUGH MID TO LATE
MORNING...WITH THE BEST CHANCE FOR THIS SOUTH OF LAKE ONTARIO.
EXPECT SHOWERS TO BE HIT AND MISS.
THERE SEEMS TO BE A FAIR CONSENSUS THAT THE MOST SIGNIFICANT RAINS
WILL COME LATE MORNING AND EARLY AFTERNOON. THIS MAKES SENSE GIVEN
THE APPROACH OF A SLOW MOVING UPPER LEVEL TROF AND THE
CONTRIBUTION OF DAYTIME HEATING. THIS WILL LIKELY BRING SHOWERS
AND THUNDERSTORMS TO THE SOUTHERN TIER AND INTO THE FINGER LAKES
REGION...AND PERHAPS ELSEWHERE THOUGH COVERAGE SHOULD BE A BIT
MORE SPARSE. CONVECTION WILL FORM ALONG ANY BOUNDARY IT CAN
FIND...BUT HAVE SOME CONCERN MUCH OF THE BUFFALO METRO AREA (AND
WATERTOWN FOR THAT MATTER) WILL MISS OUT IN A SOUTHWEST FLOW WHICH
CAN TEND TO SHADOW THE REGION FROM AFTERNOON CONVECTION.
AS HAS BEEN THE CASE THE PAST TWO DAYS...THE FLOW ALOFT WILL BE
FAIRLY LIGHT. HOWEVER...TODAY THE PRECIPITABLE WATER VALUES WILL BE
SIGNIFICANTLY GREATER...BETWEEN 1.75 INCHES AND 2.00 INCHES. IF IT
WERE NOT FOR THE VERY DRY CONDITIONS IN PLACE...THIS WOULD POSE A
GREATER FLOODING THREAT...BUT EVEN STILL THERE IS A REAL POTENTIAL
FOR FLOODING ALBEIT LOCALIZED. HAVE THE MOST CONCERN FOR THE
SOUTHERN TIER...WHERE TERRAIN CAN FUNNEL RUNOFF. DUE TO THE HIT OR
MISS NATURE OF CONVECTION...MEAN QPFS COULD BE A BIT MISLEADING.
WHILE BASIN-WIDE QPF FORECASTS RANGE FROM NEAR A HALF INCH EXPECTED
IN THE SOUTHERN TIER DOWN TO A TENTH OF AN INCH NORTH AND WEST OF
I-90...RAINFALL BY LOCATION SHOULD VARY SIGNIFICANTLY.
THE UPPER TROF WILL SLOWLY MOVE ACROSS THE REGION BY THIS
EVENING...BUT BY THIS TIME...DRIER AIR SHOULD BE IN PLACE IN THE
BOUNDARY LAYER...SO SHOWER AND THUNDERSTORMS SHOULD TAPER OFF
AND/OR EXIT EAST. THE WEAK FRONTAL BOUNDARY ASSOCIATED WITH THE
TROF WILL NOT ACTUALLY CROSS THE REGION TONIGHT. THIS WILL KEEP
MOIST AIR IN PLACE...AND DEPENDING ON RAINFALL TODAY COULD RESULT
IN AREAS OF FOG TONIGHT.
TEMPERATURES WILL BE A BIT COOLER TODAY THAN THEY WERE
YESTERDAY...HOWEVER INCREASED MOISTURE WILL MAKE IT FEEL MORE MUGGY.
HIGHS SHOULD BE IN THE LOWER 80S NORTH OF THE THRU-WAY...BUT MAY
STAY IN THE UPPER 70S IN THE SOUTHERN TIER WHERE CLOUDS AND SHOWERS
SHOULD LIMIT TEMPERATURES A BIT. FOR TONIGHT...LOWS WILL RANGE FROM
THE LOWER 60S IN THE SOUTHERN TIER...TO AROUND 70 IN THE
BUFFALO/ROCHESTER METRO AREAS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
DURING THE COURSE OF MONDAY...THE AXIS OF A WEAK UPPER LEVEL TROUGH
DRAPED FROM THE NEW ENGLAND COAST TO THE MID ATLANTIC STATES WILL
SLIDE OUT TO SEA...ALLOWING THE LEADING EDGE OF BROAD/FLAT UPPER
RIDGING TO EDGE NORTHEAST INTO THE LOWER LAKES. MEANWHILE AT THE
SURFACE...LINGERING WEAK TROUGHINESS ACROSS THE LOWER LAKES AT THE
START OF THE DAY WILL ALSO SLIDE EASTWARD...GIVING WAY TO MODEST LOW
LEVEL RIDGING DURING THE AFTERNOON.
GIVEN THESE DEVELOPMENTS...EXPECT THAT MONDAY SHOULD LARGELY BE
ANOTHER DRY AND HOT/HUMID DAY...WITH 850 MB TEMPS OF +16C/+17C AGAIN
SUPPORTING WIDESPREAD HIGHS IN THE UPPER 80S/LOWER 90S GIVEN WHAT
SHOULD BE A DECENT AMOUNT OF SUNSHINE. WHILE BOTH THE GFS AND ECMWF
BOTH SPIT OUT SOME LIGHT QPF ACROSS THE AREA PRIOR TO THE DEPARTURE
OF THE LOW LEVEL TROUGH...BELIEVE THAT THIS IS OVERDONE GIVEN ONLY
WEAK LINGERING FORCING AND FAIRLY WARM MID LEVEL TEMPS...WHICH
SHOULD HELP TO KEEP ANY PRECIP ISOLATED IN COVERAGE AT BEST. HAVE
THEREFORE KEPT POPS AT THE VERY LOW END OF THE SLIGHT CHANCE RANGE
OR BELOW ON MONDAY.
MONDAY NIGHT...BROAD/FLAT UPPER RIDGING WILL REMAIN INTACT ACROSS
MUCH OF THE AREA...WHILE A SLOW MOVING COLD FRONTAL BOUNDARY OVER
CENTRAL ONTARIO PROVINCE SAGS SOUTHWARD INTO THE UPPER LAKES AND
SOUTHERN ONTARIO. WHILE I CANNOT TOTALLY RULE OUT SOME ASSOCIATED
ISOLATED CONVECTION SNEAKING INTO THE SAINT LAWRENCE VALLEY TOWARD
DAYBREAK ON TUESDAY...IT DOES APPEAR THAT THE FRONT WILL REMAIN FAR
ENOUGH TO OUR NORTH AND THAT WE WILL REMAIN CAPPED ENOUGH FOR MAINLY
DRY WEATHER TO CONTINUE AREAWIDE. WITH NO AIRMASS CHANGE AND AN
INCREASING SOUTHWESTERLY LOW LEVEL FLOW EXPECTED WITH TIME IN
RESPONSE TO THE APPROACHING FRONT...EXPECT DOWNRIGHT SULTRY
TEMPERATURES WITH OVERNIGHT LOWS RANGING FROM THE MID AND UPPER 60S
ACROSS INTERIOR SECTIONS...TO THE LOWER 70S ACROSS THE LAKE PLAINS.
ON TUESDAY...THE AFOREMENTIONED FRONT WILL CONTINUE TO SLOWLY SAG
SOUTH TOWARD OUR REGION...WITH NOTABLE TIMING DIFFERENCES SEEN
AMONGST THE VARIOUS GUIDANCE PACKAGES. THE 00Z NAM IS AN EXTREMELY
FAST OUTLIER THAT BRINGS THE FRONT COMPLETELY THROUGH THE AREA BY
THE END OF THE DAY...WHICH SEEMS HIGHLY UNLIKELY GIVEN ITS
NEAR-PARALLEL ORIENTATION TO THE UPPER LEVEL FLOW...NOT TO MENTION
THE PROPENSITY FOR SUCH BOUNDARIES TO GET HUNG UP ACROSS THE LOWER
LAKES AT THIS TIME OF YEAR. FOR THIS REASON...HAVE COMPLETELY
DISREGARDED THIS SOLUTION. OF THE REMAINING GUIDANCE...THE GFS
REMAINS A BIT ON THE FASTER SIDE THOUGH NOT AS FAST AS ITS PREVIOUS
RUNS...BRINGING THE BOUNDARY INTO NORTHERN NEW YORK/LAKE ONTARIO BY
THE END OF THE DAY...WHICH IS CLOSE ENOUGH TO GENERATE SOME
CONVECTION ACROSS BOTH THE NORTH COUNTRY AND NIAGARA/ORLEANS
COUNTIES. MEANWHILE...THE VERY CONSISTENT ECMWF REMAINS A TOUCH
SLOWER THAN THE GFS AND ONLY BRINGS A RISK OF CONVECTION INTO THE
NORTH COUNTRY...WITH THE 00Z GEM GLOBAL A BIT SLOWER STILL. AT THIS
JUNCTURE...FEEL A COMPROMISE BETWEEN THE GFS/ECMWF REPRESENTS THE
MOST PLAUSIBLE SCENARIO...WHICH WOULD BRING AT LEAST A LOW TO MODEST
CHANCE OF CONVECTION TO LAKE ONTARIO AND THE NORTH COUNTRY BY LATE
IN THE DAY.
FURTHER TO THE SOUTH...CONDITIONS SHOULD REMAIN DRY THROUGH THE DAY
ON TUESDAY...THANKS TO BOTH GREATER DISTANCE FROM THE FRONT AND
STRONG MID LEVEL CAPPING...AS EVEN HOTTER AIR RIDES EAST ALONG THE
PERIPHERY OF THE MAIN UPPER LEVEL RIDGE. A CONSENSUS OF THE
GFS/GEM/ECMWF SUPPORTS 850 MB TEMPS RISING TO THE +20/+21C RANGE
AREAWIDE DURING THE COURSE OF TUESDAY...AND THIS COUPLED WITH GOOD
MIXING AND A DECENT AMOUNT OF SUN WILL LIKELY RESULT IN A REAL
SCORCHER OF A DAY SOUTH OF LAKE ONTARIO. AT THIS POINT...WIDESPREAD
HIGHS IN THE LOWER TO MID 90S APPEAR TO BE A SOLID BET...WITH UPPER
90S NOT AT ALL OUT OF THE QUESTION FOR THE NORMAL HOT SPOTS IN
INTERIOR PORTIONS OF OUR CWA. COUPLED WITH DEWPOINTS IN THE MID TO
UPPER 60S...SOME LOCATIONS SOUTH OF LAKE ONTARIO COULD SEE APPARENT
TEMPERATURES REACHING THE 100 DEGREE MARK TUESDAY AFTERNOON...WHICH
WOULD NECESSITATE THE ISSUANCE OF A HEAT ADVISORY. AS IT REMAINS FAR
TOO EARLY FOR THAT...FOR NOW WILL JUST MENTION THIS POTENTIAL IN THE
HWO. EAST OF LAKE ONTARIO...SOMEWHAT GREATER AMOUNTS OF CLOUD COVER
WILL LIKELY HELP KEEP TEMPS A LITTLE COOLER...THOUGH IT SHOULD STILL
BE UNCOMFORTABLY HOT EVEN THERE WITH HIGHS IN THE UPPER 80S TO LOWER
90S.
TUESDAY NIGHT AND WEDNESDAY...THE COLD FRONT WILL SLOWLY SAG SOUTH
ACROSS THE REGION...BRINGING A RISK OF CONVECTION TO THE ENTIRE
CWA...ALONG WITH THE POTENTIAL FOR LOCALLY HEAVY RAINFALL GIVEN
PRECIPITABLE WATER VALUES IN THE VICINITY OF AROUND 2 INCHES. AT
THIS JUNCTURE...THE TIMING OF THIS BOUNDARY REMAINS AN ISSUE WITH
THE GFS REMAINING THE FASTEST...THE CANADIAN THE SLOWEST...AND THE
ECMWF IN THE MIDDLE...WITH FROPA TIMES RANGING BETWEEN EARLY TO MID
WEDNESDAY MORNING AND WEDNESDAY AFTERNOON. GIVEN THAT THIS FRONT
APPEARS TO BE ANAFRONTAL WITH MOST OF ITS PRECIP FALLING BEHIND THE
ACTUAL SURFACE BOUNDARY...THIS MEANS THAT ANY ASSOCIATED CONVECTION
COULD END AS EARLY AS SOMETIME WEDNESDAY MORNING...OR AS LATE AS THE
END OF THE DAY WEDNESDAY.
GIVEN THE CONTINUED UNCERTAINTIES IN TIMING AND THE AFOREMENTIONED
NEAR-PARALLEL ORIENTATION OF THE FRONT TO THE UPPER FLOW...FEEL IT
IS BEST TO SLOW DOWN THE TIMING OF THIS FRONT AND ITS ASSOCIATED
CONVECTION A BIT FROM THE PREVIOUS FORECAST...FAVORING A COMPROMISE
SOLUTION ALONG THE LINES OF THE ECMWF. AS A RESULT...CHANCES FOR
CONVECTION WILL BE IN PLACE FROM TUESDAY NIGHT THROUGH WEDNESDAY
MORNING ACROSS THE ENTIRE AREA...BEFORE DIMINISHING FROM NORTH TO
SOUTH DURING THE COURSE OF WEDNESDAY AFTERNOON. TEMPERATURE-WISE...
EXPECT ANOTHER SULTRY NIGHT IN ADVANCE OF THE FRONT TUESDAY NIGHT
WITH LOWS AGAIN RANGING FROM THE UPPER 60S TO LOWER 70S...FOLLOWED
BY SOMEWHAT COOLER HIGHS IN THE UPPER 70S TO MID 80S ON WEDNESDAY
GIVEN THE PASSAGE OF THE FRONT AND ITS ASSOCIATED CLOUD COVER/PRECIP.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
SIMPLY PUT...SPRAWLING CANADIAN HIGH PRESSURE WILL BUILD SOUTHEAST
ACROSS THE GREAT LAKES AND NORTHEAST DURING THIS PERIOD...BRINGING A
RETURN TO DRY WEATHER ALONG WITH A COOLER AND NOTICEABLY LESS HUMID
AIRMASS.
IN TERMS OF ACTUAL TEMPERATURES...EXPECT DAILY HIGHS TO FALL BACK
INTO THE MID 70S TO LOWER 80S FOR BOTH THURSDAY AND FRIDAY...BEFORE
WARMING BACK INTO THE LOWER TO MID 80S ON SATURDAY AS WARMING
COMMENCES ALOFT. MEANWHILE...NIGHTTIME LOWS WILL RANGE IN THE MID
50S TO LOWER 60S ALL THREE NIGHTS. HUMIDITY LEVELS WILL ALSO BE MUCH
MORE COMFORTABLE...WITH DEWPOINTS REMAINING IN THE MID TO UPPER 50S
DURING THE BULK OF THE PERIOD.
&&
.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
THE THREAT FOR SHOWERS AND THUNDERSTORMS WILL INCREASE FROM SW TO NE
BETWEEN 09Z AND 15Z AS A WEAK LOW LEVEL JET KEYS THE ADVANCE OF
MOIST AIR. RADAR SUGGESTS THESE STORMS WILL BE SCATTERED IN
NATURE...NOT IMPACTING ALL TAF SITES. MOISTURE IN THE LOW LAYERS
MAY LOWER JHW TO IFR OR LOWER EARLY THIS MORNING...BUT AN
APPROACHING THUNDERSTORM MAY MIX THIS OUT AROUND DAYBREAK.
BEHIND THIS INITIAL AREA OF SHOWERS AND THUNDERSTORMS WILL BE
ANOTHER OPPORTUNITY FOR CONVECTION WITH AN APPROACHING SHORTWAVE
THIS AFTERNOON. LAKE SHADOWING WILL DIMINISH THE POTENTIAL AT
BUF/IAG/ART...THOUGH THE LAKES ARE WARM ENOUGH THAT THUNDERSTORMS
CANNOT COMPLETELY BE RULED OUT AT ANY TAF LOCATION. THIS SAID...THE
BEST CHANCE FOR THUNDERSTORMS WILL BE OUT AHEAD OF THIS SHORTWAVE AT
JHW/ROC EARLY THIS AFTERNOON.
EXPECT A GENERAL CLEARING TREND FROM WEST TO EAST LATE THIS
AFTERNOON AND EVENING. THIS SHOULD RESULT IN MAINLY VFR
CONDITIONS...BUT THERE WILL BE AN INCREASING CHANCE FOR FOG
OVERNIGHT. THE COMBINATION OF LIGHT WINDS AND LINGERING BOUNDARY
LAYER MOISTURE MAY RESULT IN FAIRLY WIDESPREAD IFR OR LOWER
CONDITIONS LATE TONIGHT...ESPECIALLY IF SKIES CLEAR OUT.
OUTLOOK...
MONDAY AND TUESDAY...MAINLY VFR.
TUESDAY NIGHT...AREAS OF MVFR IN SCATTERED -SHRA/-TSRA.
WEDNESDAY...BECOMING VFR.
THURSDAY...VFR.
&&
.MARINE...
HIGH PRESSURE WILL REMAIN ANCHORED ALONG THE MID ATLANTIC COAST
THROUGH EARLY NEXT WEEK. MEANWHILE A WEAK TROUGH WILL APPROACH THE
LOWER LAKES TODAY AND ALLOW SOUTHWEST WINDS TO INCREASE
SOMEWHAT TO THE 10-15 KNOT RANGE...WITH THE STRONGEST WINDS ON LAKE
ERIE. EXPECT CONDITIONS TO REMAIN BELOW SMALL CRAFT CRITERIA...BUT
WAVES MAY GET A LITTLE CHOPPY ON LAKE ERIE.
A RIDGE OF HIGH PRESSURE WILL NOSE INTO THE LOWER LAKES MONDAY WITH
RELATIVELY LIGHT WINDS. SOUTHWEST WINDS WILL PICK UP AGAIN TUESDAY
AHEAD OF A STRONGER COLD FRONT...ESPECIALLY ON LAKE ERIE WHERE
CONDITIONS MAY APPROACH SMALL CRAFT ADVISORY CRITERIA.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL
MARINE...APFFEL/JJR
AREA FORECAST DISCUSSION
NWS BUFFALO NY
331 AM EDT SUN JUL 15 2012
.SYNOPSIS...
A SOUTHWESTERLY FLOW WILL BRING INCREASINGLY HUMID AIR INTO THE REGION
TODAY ALONG WITH SOME SHOWERS AND THUNDERSTORMS. A FEW STORMS WILL
CONTAIN LOCALLY HEAVY RAINFALL...BUT ANY HEAVIER RAIN AMOUNTS WILL
BE SPOTTY. A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE LOWER GREAT
LAKES MONDAY WITH MAINLY DRY CONDITIONS.
&&
.NEAR TERM /THROUGH TONIGHT/...
TODAY WILL BRING AN OPPORTUNITY FOR DROUGHT RELIEF...HOWEVER SHOWERS
AND THUNDERSTORMS WILL BE PATCHY IN NATURE...SO MANY COULD MISS OUT.
THERE APPEARS TO BE TWO FEATURES WHICH WILL KEY THIS ACTIVITY. THE
FIRST IS A MODEST 25 KT LOW LEVEL JET FOUND AT 925 MB...WHICH IS
KEYING THE ADVANCE OF LOW LEVEL MOISTURE. DEW POINTS HAVE RISEN TO
AROUND 70 ACROSS OHIO EARLY THIS MORNING...WITH MODEST SHOWER
ACTIVITY EXTENDING FROM SOUTHERN ONTARIO TO FAR SOUTHWESTERN NEW
YORK. THIS IS LIFTING TO THE NE...AND SHOULD SPREAD FURTHER INTO THE
CWA THROUGH MID-MORNING.
AS IS OFTEN THE CASE...MODEL GUIDANCE IS STRUGGLING A BIT WITH
CONVECTION...WITH A FAIR SPREAD OF QPF SOLUTIONS BETWEEN THE
NAM/RGEM/GFS/EUROPEAN/SREF. THE HRRR HAS ALSO BEEN INCONSISTENT RUN TO
RUN...AND GIVEN THIS SCENARIO WILL TEND TO WEIGHT RADAR TRENDS IN THE
NEAR TERM...AND A SREF WEIGHTED ENSEMBLE OF AVAILABLE GUIDANCE FROM
LATE MORNING ON. THIS SUGGESTS FAIRLY MODEST SHOWER ACTIVITY WILL
MOVE ACROSS THE REGION THROUGH MID TO LATE MORNING...WITH THE BEST
CHANCE FOR THIS SOUTH OF LAKE ONTARIO. EXPECT SHOWERS TO BE HIT AND
MISS.
THERE SEEMS TO BE A FAIR CONSENSUS THAT THE MOST SIGNIFICANT RAINS
WILL COME EARLY AFTERNOON. THIS MAKES SENSE GIVEN THE APPROACH OF A
SLOW MOVING UPPER LEVEL TROF AND THE CONTRIBUTION OF DAYTIME
HEATING. THIS WILL LIKELY BRING SHOWERS AND THUNDERSTORMS TO THE
SOUTHERN TIER AND INTO THE FINGER LAKES REGION...AND PERHAPS
ELSEWHERE THOUGH COVERAGE SHOULD BE A BIT MORE SPARSE. CONVECTION
WILL FORM ALONG ANY BOUNDARY IT CAN FIND...BUT HAVE SOME CONCERN
MUCH OF THE BUFFALO METRO AREA (AND WATERTOWN FOR THAT MATTER) WILL
MISS OUT IN A SOUTHWEST FLOW WHICH CAN TEND TO SHADOW THE REGION
FROM AFTERNOON CONVECTION.
AS HAS BEEN THE CASE THE PAST TWO DAYS...THE FLOW ALOFT WILL BE
FAIRLY LIGHT. HOWEVER...TODAY THE PRECIPITABLE WATER VALUES WILL BE
SIGNIFICANTLY GREATER...BETWEEN 1.75 INCHES AND 2.00 INCHES. IF IT
WERE NOT FOR THE VERY DRY CONDITIONS IN PLACE...THIS WOULD POSE A
GREATER FLOODING THREAT...BUT EVEN STILL THERE IS A REAL POTENTIAL
FOR FLOODING ALBEIT LOCALIZED. HAVE THE MOST CONCERN FOR THE
SOUTHERN TIER...WHERE TERRAIN CAN FUNNEL RUNOFF. DUE TO THE HIT OR
MISS NATURE OF CONVECTION...MEAN QPFS COULD BE A BIT MISLEADING.
WHILE BASIN-WIDE QPF FORECASTS RANGE FROM NEAR A HALF INCH EXPECTED
IN THE SOUTHERN TIER DOWN TO A TENTH OF AN INCH NORTH AND WEST OF
I-90...RAINFALL BY LOCATION SHOULD VARY SIGNIFICANTLY.
THE UPPER TROF WILL SLOWLY MOVE ACROSS THE REGION THIS EVENING...BUT
BY THIS TIME...DRIER AIR SHOULD BE IN PLACE IN THE BOUNDARY
LAYER...SO SHOWER AND THUNDERSTORMS SHOULD TAPER OFF AND/OR EXIT
EAST. THE WEAK FRONTAL BOUNDARY ASSOCIATED WITH THE TROF WILL NOT
ACTUALLY CROSS THE REGION TONIGHT. THIS WILL KEEP MOIST AIR IN
PLACE...AND DEPENDING ON RAINFALL TODAY COULD RESULT IN FOG TONIGHT.
TEMPERATURES WILL BE A BIT COOLER TODAY THAN THEY WERE
YESTERDAY...HOWEVER INCREASED MOISTURE WILL MAKE IT FEEL MORE MUGGY.
HIGHS SHOULD BE IN THE LOWER 80S NORTH OF THE THRU-WAY...BUT MAY
STAY IN THE UPPER 70S IN THE SOUTHERN TIER WHERE CLOUDS AND SHOWERS
SHOULD LIMIT TEMPERATURES A BIT. FOR TONIGHT...LOWS WILL RANGE FROM
THE LOWER 60S IN THE SOUTHERN TIER...TO AROUND 70 IN THE
BUFFALO/ROCHESTER METRO AREAS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
DURING THE COURSE OF MONDAY...THE AXIS OF A WEAK UPPER LEVEL TROUGH
DRAPED FROM THE NEW ENGLAND COAST TO THE MID ATLANTIC STATES WILL
SLIDE OUT TO SEA...ALLOWING THE LEADING EDGE OF BROAD/FLAT UPPER
RIDGING TO EDGE NORTHEAST INTO THE LOWER LAKES. MEANWHILE AT THE
SURFACE...LINGERING WEAK TROUGHINESS ACROSS THE LOWER LAKES AT THE
START OF THE DAY WILL ALSO SLIDE EASTWARD...GIVING WAY TO MODEST LOW
LEVEL RIDGING DURING THE AFTERNOON.
GIVEN THESE DEVELOPMENTS...EXPECT THAT MONDAY SHOULD LARGELY BE
ANOTHER DRY AND HOT/HUMID DAY...WITH 850 MB TEMPS OF +16C/+17C AGAIN
SUPPORTING WIDESPREAD HIGHS IN THE UPPER 80S/LOWER 90S GIVEN WHAT
SHOULD BE A DECENT AMOUNT OF SUNSHINE. WHILE BOTH THE GFS AND ECMWF
BOTH SPIT OUT SOME LIGHT QPF ACROSS THE AREA PRIOR TO THE DEPARTURE
OF THE LOW LEVEL TROUGH...BELIEVE THAT THIS IS OVERDONE GIVEN ONLY
WEAK LINGERING FORCING AND FAIRLY WARM MID LEVEL TEMPS...WHICH
SHOULD HELP TO KEEP ANY PRECIP ISOLATED IN COVERAGE AT BEST. HAVE
THEREFORE KEPT POPS AT THE VERY LOW END OF THE SLIGHT CHANCE RANGE
OR BELOW ON MONDAY.
MONDAY NIGHT...BROAD/FLAT UPPER RIDGING WILL REMAIN INTACT ACROSS
MUCH OF THE AREA...WHILE A SLOW MOVING COLD FRONTAL BOUNDARY OVER
CENTRAL ONTARIO PROVINCE SAGS SOUTHWARD INTO THE UPPER LAKES AND
SOUTHERN ONTARIO. WHILE I CANNOT TOTALLY RULE OUT SOME ASSOCIATED
ISOLATED CONVECTION SNEAKING INTO THE SAINT LAWRENCE VALLEY TOWARD
DAYBREAK ON TUESDAY...IT DOES APPEAR THAT THE FRONT WILL REMAIN FAR
ENOUGH TO OUR NORTH AND THAT WE WILL REMAIN CAPPED ENOUGH FOR MAINLY
DRY WEATHER TO CONTINUE AREAWIDE. WITH NO AIRMASS CHANGE AND AN
INCREASING SOUTHWESTERLY LOW LEVEL FLOW EXPECTED WITH TIME IN
RESPONSE TO THE APPROACHING FRONT...EXPECT DOWNRIGHT SULTRY
TEMPERATURES WITH OVERNIGHT LOWS RANGING FROM THE MID AND UPPER 60S
ACROSS INTERIOR SECTIONS...TO THE LOWER 70S ACROSS THE LAKE PLAINS.
ON TUESDAY...THE AFOREMENTIONED FRONT WILL CONTINUE TO SLOWLY SAG
SOUTH TOWARD OUR REGION...WITH NOTABLE TIMING DIFFERENCES SEEN
AMONGST THE VARIOUS GUIDANCE PACKAGES. THE 00Z NAM IS AN EXTREMELY
FAST OUTLIER THAT BRINGS THE FRONT COMPLETELY THROUGH THE AREA BY
THE END OF THE DAY...WHICH SEEMS HIGHLY UNLIKELY GIVEN ITS
NEAR-PARALLEL ORIENTATION TO THE UPPER LEVEL FLOW...NOT TO MENTION
THE PROPENSITY FOR SUCH BOUNDARIES TO GET HUNG UP ACROSS THE LOWER
LAKES AT THIS TIME OF YEAR. FOR THIS REASON...HAVE COMPLETELY
DISREGARDED THIS SOLUTION. OF THE REMAINING GUIDANCE...THE GFS
REMAINS A BIT ON THE FASTER SIDE THOUGH NOT AS FAST AS ITS PREVIOUS
RUNS...BRINGING THE BOUNDARY INTO NORTHERN NEW YORK/LAKE ONTARIO BY
THE END OF THE DAY...WHICH IS CLOSE ENOUGH TO GENERATE SOME
CONVECTION ACROSS BOTH THE NORTH COUNTRY AND NIAGARA/ORLEANS
COUNTIES. MEANWHILE...THE VERY CONSISTENT ECMWF REMAINS A TOUCH
SLOWER THAN THE GFS AND ONLY BRINGS A RISK OF CONVECTION INTO THE
NORTH COUNTRY...WITH THE 00Z GEM GLOBAL A BIT SLOWER STILL. AT THIS
JUNCTURE...FEEL A COMPROMISE BETWEEN THE GFS/ECMWF REPRESENTS THE
MOST PLAUSIBLE SCENARIO...WHICH WOULD BRING AT LEAST A LOW TO MODEST
CHANCE OF CONVECTION TO LAKE ONTARIO AND THE NORTH COUNTRY BY LATE
IN THE DAY.
FURTHER TO THE SOUTH...CONDITIONS SHOULD REMAIN DRY THROUGH THE DAY
ON TUESDAY...THANKS TO BOTH GREATER DISTANCE FROM THE FRONT AND
STRONG MID LEVEL CAPPING...AS EVEN HOTTER AIR RIDES EAST ALONG THE
PERIPHERY OF THE MAIN UPPER LEVEL RIDGE. A CONSENSUS OF THE
GFS/GEM/ECMWF SUPPORTS 850 MB TEMPS RISING TO THE +20/+21C RANGE
AREAWIDE DURING THE COURSE OF TUESDAY...AND THIS COUPLED WITH GOOD
MIXING AND A DECENT AMOUNT OF SUN WILL LIKELY RESULT IN A REAL
SCORCHER OF A DAY SOUTH OF LAKE ONTARIO. AT THIS POINT...WIDESPREAD
HIGHS IN THE LOWER TO MID 90S APPEAR TO BE A SOLID BET...WITH UPPER
90S NOT AT ALL OUT OF THE QUESTION FOR THE NORMAL HOT SPOTS IN
INTERIOR PORTIONS OF OUR CWA. COUPLED WITH DEWPOINTS IN THE MID TO
UPPER 60S...SOME LOCATIONS SOUTH OF LAKE ONTARIO COULD SEE APPARENT
TEMPERATURES REACHING THE 100 DEGREE MARK TUESDAY AFTERNOON...WHICH
WOULD NECESSITATE THE ISSUANCE OF A HEAT ADVISORY. AS IT REMAINS FAR
TOO EARLY FOR THAT...FOR NOW WILL JUST MENTION THIS POTENTIAL IN THE
HWO. EAST OF LAKE ONTARIO...SOMEWHAT GREATER AMOUNTS OF CLOUD COVER
WILL LIKELY HELP KEEP TEMPS A LITTLE COOLER...THOUGH IT SHOULD STILL
BE UNCOMFORTABLY HOT EVEN THERE WITH HIGHS IN THE UPPER 80S TO LOWER
90S.
TUESDAY NIGHT AND WEDNESDAY...THE COLD FRONT WILL SLOWLY SAG SOUTH
ACROSS THE REGION...BRINGING A RISK OF CONVECTION TO THE ENTIRE
CWA...ALONG WITH THE POTENTIAL FOR LOCALLY HEAVY RAINFALL GIVEN
PRECIPITABLE WATER VALUES IN THE VICINITY OF AROUND 2 INCHES. AT
THIS JUNCTURE...THE TIMING OF THIS BOUNDARY REMAINS AN ISSUE WITH
THE GFS REMAINING THE FASTEST...THE CANADIAN THE SLOWEST...AND THE
ECMWF IN THE MIDDLE...WITH FROPA TIMES RANGING BETWEEN EARLY TO MID
WEDNESDAY MORNING AND WEDNESDAY AFTERNOON. GIVEN THAT THIS FRONT
APPEARS TO BE ANAFRONTAL WITH MOST OF ITS PRECIP FALLING BEHIND THE
ACTUAL SURFACE BOUNDARY...THIS MEANS THAT ANY ASSOCIATED CONVECTION
COULD END AS EARLY AS SOMETIME WEDNESDAY MORNING...OR AS LATE AS THE
END OF THE DAY WEDNESDAY.
GIVEN THE CONTINUED UNCERTAINTIES IN TIMING AND THE AFOREMENTIONED
NEAR-PARALLEL ORIENTATION OF THE FRONT TO THE UPPER FLOW...FEEL IT
IS BEST TO SLOW DOWN THE TIMING OF THIS FRONT AND ITS ASSOCIATED
CONVECTION A BIT FROM THE PREVIOUS FORECAST...FAVORING A COMPROMISE
SOLUTION ALONG THE LINES OF THE ECMWF. AS A RESULT...CHANCES FOR
CONVECTION WILL BE IN PLACE FROM TUESDAY NIGHT THROUGH WEDNESDAY
MORNING ACROSS THE ENTIRE AREA...BEFORE DIMINISHING FROM NORTH TO
SOUTH DURING THE COURSE OF WEDNESDAY AFTERNOON. TEMPERATURE-WISE...
EXPECT ANOTHER SULTRY NIGHT IN ADVANCE OF THE FRONT TUESDAY NIGHT
WITH LOWS AGAIN RANGING FROM THE UPPER 60S TO LOWER 70S...FOLLOWED
BY SOMEWHAT COOLER HIGHS IN THE UPPER 70S TO MID 80S ON WEDNESDAY
GIVEN THE PASSAGE OF THE FRONT AND ITS ASSOCIATED CLOUD COVER/PRECIP.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
SIMPLY PUT...SPRAWLING CANADIAN HIGH PRESSURE WILL BUILD SOUTHEAST
ACROSS THE GREAT LAKES AND NORTHEAST DURING THIS PERIOD...BRINGING A
RETURN TO DRY WEATHER ALONG WITH A COOLER AND NOTICEABLY LESS HUMID
AIRMASS.
IN TERMS OF ACTUAL TEMPERATURES...EXPECT DAILY HIGHS TO FALL BACK
INTO THE MID 70S TO LOWER 80S FOR BOTH THURSDAY AND FRIDAY...BEFORE
WARMING BACK INTO THE LOWER TO MID 80S ON SATURDAY AS WARMING
COMMENCES ALOFT. MEANWHILE...NIGHTTIME LOWS WILL RANGE IN THE MID
50S TO LOWER 60S ALL THREE NIGHTS. HUMIDITY LEVELS WILL ALSO BE MUCH
MORE COMFORTABLE...WITH DEWPOINTS REMAINING IN THE MID TO UPPER 50S
DURING THE BULK OF THE PERIOD.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
THE THREAT FOR SHOWERS AND THUNDERSTORMS WILL INCREASE FROM SW TO NE
BETWEEN 06Z AND 15Z AS A WEAK LOW LEVEL JET KEYS THE ADVANCE OF
MOIST AIR. RADAR SUGGESTS THESE STORMS WILL BE SCATTERED IN
NATURE...NOT IMPACTING ALL TAF SITES. THERE IS A MINIMAL CHANCE FOR
FOG AT BUF/IAG/ROC/ART...BUT AT JHW THERE APPEARS A GOOD CHANCE FOR
A SHOWER SHORTLY AFTER 06Z...WHICH MAY LEAD TO FOG AND LOW CLOUDS
IFR OR LOWER.
BEHIND THIS INITIAL AREA OF SHOWERS AND THUNDERSTORMS WILL BE
ANOTHER OPPORTUNITY FOR CONVECTION WITH AN APPROACHING SHORTWAVE
THIS AFTERNOON. LAKE SHADOWING WILL DIMINISH THE POTENTIAL AT
BUF/IAG/ART...THOUGH THE LAKES ARE WARM ENOUGH THAT THUNDERSTORMS
CANNOT COMPLETELY BE RULED OUT AT ANY TAF LOCATION. THIS SAID...THE
BEST CHANCE FOR THUNDERSTORMS WILL BE OUT AHEAD OF THIS SHORTWAVE AT
JHW/ROC EARLY THIS AFTERNOON.
EXPECT A GENERAL CLEARING TREND FROM WEST TO EAST LATE THIS
AFTERNOON AND EVENING. THIS SHOULD RESULT IN MAINLY VFR
CONDITIONS...BUT THERE WILL BE AN INCREASING CHANCE FOR FOG
OVERNIGHT. THE COMBINATION OF LIGHT WINDS AND LINGERING BOUNDARY
LAYER MOISTURE MAY RESULT IN FAIRLY WIDESPREAD IFR OR LOWER
CONDITIONS LATE TONIGHT...ESPECIALLY IF SKIES CLEAR OUT.
OUTLOOK...
MONDAY AND TUESDAY...MAINLY VFR.
TUESDAY NIGHT...AREAS OF MVFR IN SCATTERED -SHRA/-TSRA.
WEDNESDAY...BECOMING VFR.
THURSDAY...VFR.
&&
.MARINE...
HIGH PRESSURE WILL REMAIN ANCHORED ALONG THE MID ATLANTIC COAST
THROUGH EARLY NEXT WEEK. MEANWHILE A WEAK TROUGH WILL APPROACH THE
LOWER LAKES TODAY AND ALLOW SOUTHWEST WINDS TO INCREASE
SOMEWHAT TO THE 10-15 KNOT RANGE...WITH THE STRONGEST WINDS ON LAKE
ERIE. EXPECT CONDITIONS TO REMAIN BELOW SMALL CRAFT CRITERIA...BUT
WAVES MAY GET A LITTLE CHOPPY ON LAKE ERIE.
A RIDGE OF HIGH PRESSURE WILL NOSE INTO THE LOWER LAKES MONDAY WITH
RELATIVELY LIGHT WINDS. SOUTHWEST WINDS WILL PICK UP AGAIN TUESDAY
AHEAD OF A STRONGER COLD FRONT...ESPECIALLY ON LAKE ERIE WHERE
CONDITIONS MAY APPROACH SMALL CRAFT ADVISORY CRITERIA.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL
MARINE...APFFEL/JJR
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1126 PM CDT SAT JUL 14 2012
.AVIATION...
NOT MUCH CHANGE FROM EARLIER THINKING. DO EXPECT SOME SCT
SHRA/TSTM REDEVELOPMENT LATER TONIGHT AND TOWARD MORNING. THOUGH
IT COULD BE ANYWHERE...MOST FAVORABLE LOCATIONS WOULD BE CLOSER TO
THE COAST AND UP TOWARD THE LAKE LIVINGSTON AREA CLOSER TO THE
UPPER CIRCULATION AND WHERE THE MORE FAVORABLE JET STRUCTURE WILL
BE. BEST COURSE OF ACTION WILL PROBABLY BE TO USE VCSH/VCTS`S AND
AMEND WHEN NECESSARY VERSUS CLUTTER TAFS WITH TEMPOS ETC. PRECIP
SHOULD EXPAND IN COVERAGE WITH MID/LATE MORNING HEATING AGAIN
SUNDAY. PRECIP SHOULD TAKER OFF FROM SOUTH TO NORTH DURING THE
LATE AFTN AND EARLY EVNG HOURS. 47
&&
.PREV DISCUSSION... /ISSUED 916 PM CDT SAT JUL 14 2012/
SHOWERS AND THUNDERSTORMS HAVE DIMINISHED QUICKLY YET AGAIN THIS
EVENING. UPDATED GRIDS FOR OBSERVED CONDITIONS IN THE VERY SHORT
RANGE. LOW LEVEL CIRCULATION APPARENT IN RAP13...PROFILER
WINDS...VWP WINDS AND SATELLITE LOOPS NEAR LONGVIEW (KGGG). AT
700MB PROFILER AND VWP WINDS SUGGEST TROUGH IS NEAR OR JUST OFF
THE SE TEXAS COAST AND CURVE BACK TO THE LOW. PWAT VALUES DO
APPEAR SLIGHTLY REDUCED FROM PREVIOUS EVENINGS WITH 00Z RAOB
VALUES RANGING FROM 1.8 TO NEAR 2 INCHES. BLENDED TPW IMAGERY FOR
THE CWA ARE AROUND 1.88 INCH SO STILL PLENTY MOISTURE RICH BUT A
TAD LOWER. SFC MESO BOUNDARIES GALORE THIS EVENING FROM CONVECTIVE
OUTFLOWS AND A LATE DEVELOPING SEA BREEZE. ONE BOUNDARY FROM NORTH
OF COLLEGE STATION TO CALDWELL ON SOUTHWESTWARD. ANOTHER OVER
COLORADO COUNTY..SEVERAL FROM CONVECTION OCCURRING NORTH OF CWA
AND OLD SEA BREEZE BOUNDARY FROM LIBERTY TO KHOU TO KBYY. HRRR AND
TX TECH WRF REFLECTIVITY FORECASTS ARE FOR GENERALLY QUIET NIGHT
WITH SOME DEVELOPMENT TOWARDS SUNRISE BUT FEEL WITH MULTITUDE OF
BOUNDARIES AND SLOWLY RETREATING TROUGH/LOW SOME ISOLATED TO
SCATTERED CONVECTION POSSIBLE A COUPLE OF HOURS PRIOR TO SUNRISE
MAINLY NEAR COAST AND NORTH OF A LINE FROM NORMANGEE TO LIVINGSTON
NEARER TO 850-700MB LOW. THIS IS HANDLED WELL IN OUR CURRENT
FORECAST LATER TONIGHT AND TOMORROW MORNING SO NO CHANGE
NECESSARY. STILL A POSSIBILITY FOR SOME ISOLATED HEAVY RAINS ON
SUNDAY SO MENTION OF LOCALLY HEAVY RAINS IN ZFP/GRIDS REMAINS A
GOOD IDEA. 04
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 73 88 73 92 74 / 20 50 20 30 20
HOUSTON (IAH) 74 89 74 91 75 / 20 50 30 40 20
GALVESTON (GLS) 80 88 82 90 81 / 30 50 40 40 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
853 AM PDT SUN JUL 15 2012
.SYNOPSIS...
AN UPPER-LEVEL TROUGH STRENGTHENING ALONG THE WEST COAST...WILL
BRING STRONGER ONSHORE FLOW...GRADUAL INLAND DRYING...AND A DEEPER
MARINE LAYER THROUGH TUESDAY. IT WILL BE COOLER...WITH MARINE CLOUDS
EXTENDING FARTHER INTO THE VALLEYS EACH MORNING. LATER NEXT WEEK...
HIGH PRESSURE OVER THE MIDDLE OF THE COUNTRY WILL REBUILD
WESTWARD...BRINGING WARMER DAYS AND SOME INCREASE IN MONSOONAL
MOISTURE. THE ADDED MOISTURE WILL LIKELY RESULT IN SOME AFTERNOON
CLOUDS OVER THE MOUNTAINS...AND PERHAPS SOME RENEWED CHANCE OF
THUNDERSTORMS OVER THE WEEKEND OR EARLY NEXT WEEK.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
&&
VISIBLE SATELLITE IMAGERY EARLY THIS MORNING SHOWED EXTENSIVE MARINE
STRATUS OFFSHORE AND EXTENDING WELL INTO THE VALLEYS. BASED ON THE
12Z MIRAMAR SOUNDING...THE LAYER HAD DEEPENED TO AROUND 2000 FT AT
12Z AND WAS CAPPED BY A STRONG 10 DEGREE C INVERSION. SFC PRESSURE
GRADIENTS REMAINED WEAK...BUT WERE ONSHORE GENERALLY 2-4 MBS TO THE
DESERTS.
WATER VAPOR IMAGERY THROUGH 15Z SHOWS THE UPPER-LEVEL TROUGH ALONG
THE WEST COAST WAS IN FULL DEEPENING MODE WHICH WILL DEFINE OUR
WEATHER FOR THE NEXT SEVERAL DAYS. LOWER SFC PRESSURES OVER THE
INTERIOR...STRONGER ONSHORE FLOW...AND A DEEPENING MARINE LAYER WILL
BRING COOLER DAYS AND SOME NOCTURNAL CLOUDS/FOG WELL INTO THE
VALLEYS THROUGH TUE. INLAND...BETTER ONSHORE FLOW WILL BRING DRYING
WITH LOWER DEWPOINTS INTO THE DESERTS.
FOR TODAY...SOME RESIDUAL BOUNDARY LAYER MOISTURE WILL LIKELY RESULT
IN SOME CU BUILD-UPS OVER THE MOUNTAINS. AN ISOLATED SHOWER IS NOT
OUT OF THE QUESTION EITHER BASED ON AVBL SFC DEWPOINTS IN THE MTNS/
DESERTS AND THE HIGHER RESOLUTION HRRR MODEL. FOR NOW...THE POP
LOOKS TOO LOW FOR MENTION IN THE ZONES. ALONG THE COAST...THE STRONG
INVERSION MAY CONTRIBUTE TO A LATE BREAK-UP OF THE STRATUS...BUT THE
THICKNESS OF THE CLOUD DECK BASED ON SFC OBSERVATIONS SHOW IT SHOULD
BREAK...EVEN AT MOST BEACHES...WITH AT LEAST A FEW HOURS OF SUN
TODAY. ELSEWHERE... SUNNY...WITH TEMPS A FEW DEGREES LOWER THAN
YESTERDAY W OF THE MTNS...BUT A FEW DEGREES HIGHER IN THE LOWER
DESERTS DUE TO LOWER HUMIDITY.
WEDNESDAY SHOULD BE THE TRANSITION DAY WITH THE MARINE LAYER
BEGINNING TO DECREASE IN DEPTH AND SLOW INLAND WARMING AS THE TROUGH
OF LOW PRESSURE NEAR THE WEST COAST BEGINS TO WEAKEN AND HIGH
PRESSURE TO THE EAST BEGINS TO STRENGTHEN. FOR WED NIGHT/THU...SOME
MID/HIGH LEVEL MOISTURE FROM THE REMNANTS OF HURRICANE FABIO WILL BE
DRAWN NORTHWARD ACROSS CALIFORNIA...MAINLY NORTH OF ORANGE COUNTY.
FOR SOUTHWEST CALIFORNIA...THE MAIN IMPACT WOULD APPEAR TO BE SOME
INCREASE IN MID/HIGH LEVEL CLOUDS. CHANCES FOR SPRINKLES/SHWRS THIS
FAR SOUTH LOOK MINIMAL. THE HIGH CLOUDS MAY CONTRIBUTE TO A COLORFUL
SUNSET THOUGH...FOR THOSE AREAS UNOBSCURED BY LOWER MARINE CLOUDS.
WARMER INLAND FOR THE LATTER HALF OF THE WEEK AS HIGH PRESSURE
BROADENS ACROSS THE WESTERN HALF OF THE COUNTRY. THIS WILL TURN
UPPER-LEVEL WINDS AGAIN MORE SOUTHEASTERLY...SOME MONSOONAL MOISTURE
MAY INCREASE OVER SW CA...BRINGING PERIODS OF MID/HIGH CLOUDS AND
AFTERNOON CU OVER THE MOUNTAINS. POPS HAVE BEEN BUMPED UP OVER
CLIMATOLOGY TO REFLECT AN INCREASED CHANCE OF CONVECTIVE SHOWERS BUT
CONFIDENCE NOT HIGH ENOUGH TO INCLUDE IN THE CURRENT FORECAST. TEMPS
SHOULD BE NEAR MID-SUMMER AVERAGES.
&&
.AVIATION...
151545Z...COAST/VALLEYS...STRATUS WILL CLEAR MOST VALLEYS THROUGH
17Z AND COASTAL AREAS BETWEEN 16Z AND 18Z EXCEPT ALONG THE BEACHES
WHERE PATCHY BKN CLOUDS WILL LINGER THROUGH THE AFTERNOON. STRATUS
WILL RETURN TO COASTAL AIRPORTS BETWEEN 00Z AND 04Z AND THE VALLEYS
BETWEEN 05Z AND 09Z WITH LITTLE CHANGE TO BASES...1000-1500 FT MSL
AND TOPS TO 2000 FT MSL. LOCAL VIS BELOW 3 MI WILL OCCUR IN THE
VALLEYS LATE TONIGHT.
MTNS/DESERTS...SCATTERED CUMULUS WITH BASES 8000-9000 FT MSL ARE
EXPECTED OVER THE MTNS AND SOME DESERT AREAS THROUGH 02Z.
OTHERWISE...MOSTLY CLEAR WITH UNRESTRICTED VIS THROUGH MONDAY.
.MARINE...
HURRICANE FABIO...CURRENTLY IN OUR SWELL WINDOW NEAR 17N/117W WILL
BRING INCREASING SOUTH SWELL BY MONDAY NIGHT OR TUESDAY...GENERALLY
4 FEET IN THE COASTAL WATERS. THIS WILL BE A BIT HIGHER THAN WITH
THE LAST 2 HURRICANES DUE TO THE SLOWER MOVEMENT OF FABIO AND HENCE
A LONGER DURATION OF THE SWELL GENERATION...DESPITE FABIO BEING LESS
STRONG. THIS WILL BRING ANOTHER ROUND OF ABOVE NORMAL SURF AND RIP
CURRENTS ON MAINLY S/SW FACING BEACHES LATE MONDAY NIGHT THROUGH
WED...THEN GRADUALLY DIMINISHING THROUGH THU.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC...JAD
AVIATION/MARINE...MAXWELL
AREA FORECAST DISCUSSION...Updated
NWS TALLAHASSEE FL
700 AM EDT Sun Jul 15 2012
Updated Aviation Discussion.
.NEAR TERM [Through Today]...
A rather amplified and complex upper level pattern is depicted
this morning by the 05z RAP analysis. Two shortwave troughs across
the Pacific Northwest and the Upper Midwest are complimented by
two ridges across the Plains states and the Southeast states.
Pinched off from the easternmost trough is a weak closed low
centered over the Southern Plains. Finally, a TUTT draped across
the western Caribbean, northeast into the western Atlantic,
continues its slow westward progression.
For this afternoon, subsidence provided by the southeastern U.S.
ridge will provide our local area with slightly drier conditions.
That being said, precipitable water levels are expected to remain
at or slightly above climatological normals for this time of year.
With no large scale support for ascent expected, the local
seabreeze fronts will dominate this afternoon`s weather pattern.
With slightly more easterly flow regime expected today, a slightly
modified regime 2 is expected. This regime would favor the
Panhandle Seabreeze Front and the East Coast Seabreeze Front. Thus
PoPs are highest across the Florida Panhandle, and later across
our eastern counties in Georgia and Florida.
With respect to the threat for severe weather, no severe weather
is expected across our Florida counties this afternoon. Lower than
normal instability coupled with several other poor to marginal
thermodynamic variables will be the limiting factors here. There
does exist a slight chance for severe storms across our Georgia
and Alabama counties today, with a few caveats. Drier mid-level
air will increase the theta-e differences between the middle and
lower troposphere. This coupled with steep low level lapse rates
will increase the threat for severe downbursts. However, the dry
air may also be the limiting factor in storm development. The best
case scenario for severe storm development across Georgia would
be late in the afternoon/early evening when the East Coast
Seabreeze enters the primed atmosphere. The same story holds true
for southeast Alabama, with a different forcing mechanism. Any
storms that for across Alabama will likely be due to boundary
interactions from the Panhandle Seabreeze. A late afternoon/early
evening threat timeline is expected across Alabama as well.
Waterspouts will be possible again today, primarily along eastward
facing Big Bend beaches due to the more easterly wind component.
The threat should diminish by the afternoon with the diminishing
wind enhancement behind yesterday`s East Coast Seabreeze Front.
&&
.SHORT TERM [Tonight Through Tuesday]...
Seabreeze circulations will continue to influence the
precipitation pattern through the remainder of the short term.
However, beginning Monday, the aforementioned TUTT will move
southwest into our eastern forecast area. This will especially
enhance PoPs across north Florida, east of the Apalachicola
River. On Tuesday, the trough will overspread our entire forecast
area enhancing PoPs area wide.
Temperatures will hold near climatological averages in the lower
90s each afternoon, and the lower 70s each night.
&&
.LONG TERM [Tuesday Night through Sunday]...
Very little change to the extended fcst this cycle as the latest
00 UTC GFS and ECMWF have remained in fairly good agreement with a
Synoptic pattern dominated by a TUTT Low which will gradually open
up into an Upper Level Trof. This should further increase fcst
confidence in above Climo Pops and near Climo Max Temps through
much of the period. Despite the fairly disturbed pattern, the MEX
High Temps appeared too high (Mid 90s in many areas away from the
coast) for the expected levels of cloud cover and rain chances, so
used a 2-1 Blend of the lower and more realistic looking HPC and
MOS Guidance grids. The Euro (and GFS to some extent) do both show
some potential for a brief break in this pattern on Friday, with
possible Upper Level Ridging moving in from the east, before the
mean Trof builds back southward over the weekend, bringing a
return to higher rain chances.
&&
.AVIATION...
The Hi-Res models turned out to be correct, as VFR conditions
prevailed through the night and early morning at all of the
terminals. For the remainder of today, VFR conditions should prevail
with slightly lower PoPs than yesterday...especially further to the
north. Did upgrade ECP and VLD to convective tempos, with VCTS at
TLH, and just VFR the rest of the day at ABY and DHN.
&&
.MARINE...
Winds and seas will remain below headline criteria for the next
several days as the subtropical ridge keeps a firm hold on the
region. Enhancements nearing SCEC criteria are possible this
morning and tomorrow morning along the East Coast Seabreeze Front.
Flow will shift more southerly by Tuesday, effectively ending the
East Coast Seabreeze enhancements.
&&
.FIRE WEATHER...
Still no fire weather concerns in sight over the foreseeable
future across the Tri-State area, as ample low-level moisture will
keep afternoon relative humidities fairly high through the period.
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
MARINE...None.
&&
$$
NEAR TERM...Harrigan
SHORT TERM...Harrigan
LONG TERM...Gould
AVIATION...Gould
MARINE...Harrigan
FIRE WEATHER...Gould
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1015 AM EDT SUN JUL 15 2012
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL EXTEND ACROSS THE REGION AS
A WEAK TROUGH OF LOW PRESSURE DEVELOPS INLAND. A COLD FRONT WILL
APPROACH FROM THE NORTH LATE IN THE WEEK AND LIKELY STALL OUT
THROUGH THE WEEKEND LEADING TO UNSETTLED CONDITIONS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATE MORNING WATER VAPOR IMAGERY SHOWS A WELL DEFINED TUTT LOW
SPINNING IN THE VICINITY OF 31.3N/-76.9W. DRY AIR ALONG ITS
WESTERN PERIPHERY HAS INFILTRATED SOUTHEAST SOUTH CAROLINA AND
SOUTHEAST GEORGIA WITH PWATS MEASURED ON THE 15/12Z CHS RAOB WELL
BELOW 2 INCHES. THE ATMOSPHERE REMAINS TROPICAL DESPITE THE
PRESENCE OF MID-LEVEL DRY AIR WITH A DEEP/MOIST FLOW FROM OF THE
ATLANTIC HELPING TO ADVECT RICH LOW-LEVEL THETA AIR INTO THE
REGION. CONVECTIVE TEMPERATURES ARE JUST ABOUT TO BE SURPASSED PER
REGIONAL RAP BUFR SOUNDINGS AND IN FACT SHOWER ACTIVITY IS
ALREADY BEGINNING TO BLOSSOM AS EXPECTED ALONG THE COAST.
CONVECTION WILL CONTINUE TO EXPAND OVER THE NEXT SEVERAL HOURS
WITH SCATTERED SHOWERS/TSTMS EXPECTED TO CONCENTRATE INLAND AHEAD
OF AN ILL-DEFINED PURE SEA BREEZE CIRCULATION OVER THE NEXT
SEVERAL HOURS. OPTED TO MODIFY THE CURRENT POP REGIME SLIGHTLY TO
HIGHLIGHT A LARGER AREA OF CHANCE POPS OF 30-40 PERCENT. CONVECTION
SHOULD GRADUALLY END FROM EAST-WEST LATER THIS AFTERNOON IN THE
WAKE OF THE SEA BREEZE. NUDGED HIGHS DOWN JUST A DEGREE OR TWO FOR
MOST AREAS. HIGHS WILL RANGE FROM THE LOWER 90S INLAND TO THE MID
80S AT THE BEACHES.
THE RISK FOR A FEW STRONG TO SEVERE TSTMS WILL BE A BIT HIGHER
COMPARED TO THE PAST SEVERAL DAYS WITH SLIGHTLY DRIER MID-LEVEL
AIR NOW IN PLACE. THERMODYNAMIC PARAMETERS ON THE MODIFIED 15/12Z
CHS RAOB DEPICTED DCAPES NEAR 1400 J/KG WITH A WINDEX NEAR 60
KT...WHICH IS SUPPORTIVE OF AN ENHANCED WET MICROBURST
ENVIRONMENT. ATTM THINK THE RISK IS LIKELY TOO LOW TO JUSTIFY A
MENTION IN THE HAZARDOUS WEATHER OUTLOOK...BUT ONE OR TWO SEVERE
TSTM WARNINGS CAN NOT BE COMPLETELY RULED OUT THROUGH MID-LATE
AFTERNOON...MAINLY INLAND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
THE CONVECTION WILL DIMINISH OVER LAND WITH THE SUNSET...SO MOST
PLACES WILL BE DRY DURING SUNDAY EVENING. ONCE AGAIN...SCATTERED
SHOWERS SHOULD AGAIN REDEVELOP OVER THE COASTAL WATERS AND MOVE
TOWARD THE COAST DURING THE LATE NIGHT HOURS...BUT MOST ACTIVITY
SHOULD REMAIN OFFSHORE.
A MID/UPPER-LEVEL LOW PRESSURE SYSTEM WILL MOVE ONSHORE MONDAY AND
THEN SHIFT SOUTHWEST OF THE AREA TUESDAY AND WEDNESDAY. MAINLY
AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS EACH DAY WITH PROBABLY
THE BETTER COVERAGE COMING TUESDAY AND WEDNESDAY AS A SURFACE TROUGH
OF LOW PRESSURE DEVELOPS INLAND. TEMPERATURES GENERALLY NEAR NORMAL
MONDAY...THEN SLIGHTLY ABOVE NORMAL TUESDAY AND WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
MID/UPPER-LEVEL HIGH PRESSURE OVER THE ATLANTIC TO EDGE WESTWARD AND
EXERT MORE INFLUENCE ON THE AREA THURSDAY INTO FRIDAY BEFORE
WEAKENING TOWARD THE END OF THE WEEK AS A TROUGH SHIFTS OFFSHORE TO
THE NORTH. THIS FEATURE WILL PUSH A COLD FRONT TOWARD THE AREA
ALTHOUGH CLIMATOLOGY WOULD SUGGEST IT WILL REMAIN TO THE NORTH.
FAVORABLE SYNOPTIC LIFT AND DEEPER MOISTURE ALONG WITH THE SURFACE
FRONT AND AREAS OF LOW PRESSURE ALONG IT WILL CREATE MORE FAVORABLE
CONDITIONS FOR SHOWERS AND THUNDERSTORMS FRIDAY THROUGH THE WEEKEND.
PRECIPITABLE WATER VALUES OF AT LEAST 2 INCHES WILL SUPPORT THE
THREAT FOR LOCALIZED HEAVY RAINFALL. TEMPERATURES TO START OUT ABOVE
NORMAL BEFORE FALLING BACK CLOSER TO NORMAL LATER IN THE WEEK AND
OVER THE WEEKEND WITH INCREASED CLOUDS/RAIN.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
VFR FOR THE NEXT 24 HOURS. ISOLATED SHOWERS AND POSSIBLY A TSTM
COULD IMPACT KCHS/KSAV AT JUST ABOUT ANY TIME THROUGH MID-
AFTERNOON...BUT ANY IMPACT DURATIONS SHOULD REMAIN LESS THAN 5-10
MINUTES AT BEST. WILL NOT HIGHLIGHT ANY MENTION OF SHRA OR TSRA AT
EITHER TERMINAL JUST YET BECAUSE OF THIS. LOW CHANCE FOR SHALLOW
GROUND FOG IMPACTING THE TERMINALS EARLY MONDAY.
EXTENDED AVIATION OUTLOOK...THERE ARE NO CONCERNS OF GREATER THAN 30
PERCENT CONFIDENCE.
&&
.MARINE...
WINDS WILL CONTINUE TO BE LIGHT TODAY AND TONIGHT IN THE VICINITY
OF THE SURFACE RIDGE. SUSTAINED WINDS WILL BE LESS THAN 15 KNOTS.
THERE MAY BE A SMALL SWELL OF 2 FEET OR SO IN THE WATERS DUE TO
THE LONG FETCH OF SOUTHEASTERLIES EXTENDING WELL OUT INTO THE
ATLANTIC...BUT THE SURFACE WINDS WILL BE TOO LIGHT TOO ADD MUCH
WIND WAVE INTO THE EQUATION...SO 2 TO 3 FEET NEARSHORE AND 3 TO 4
FEET OFFSHORE LOOK GOOD TODAY.
MONDAY THROUGH FRIDAY...ATLANTIC HIGH PRESSURE TO REMAIN IN CONTROL
THIS PERIOD WITH A WEAK TROPICAL WAVE OF LOW PRESSURE LIKELY
AFFECTING THE AREA MONDAY. THEREAFTER...A SOUTH/SOUTHWESTERLY FLOW
WILL DOMINATE AS A TROUGH OF LOW PRESSURE SETS UP INLAND AND
ATLANTIC HIGH PRESSURE STRENGTHENS OFFSHORE. CONDITIONS SHOULD
REMAIN BELOW ADVISORY LEVELS THROUGH THE PERIOD ALTHOUGH WINDS/SEAS
WILL BE ON THE INCREASE STARTING MID WEEK AS THE PRESSURE GRADIENT
STRENGTHENS BETWEEN THESE TWO SYSTEMS.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...ALSHEIMER/RJB
LONG TERM...RJB
AVIATION...
MARINE...
AREA FORECAST DISCUSSION
NWS JACKSON KY
1054 AM EDT SUN JUL 15 2012
.UPDATE...
ISSUED AT 1054 AM EDT SUN JUL 15 2012
SHOWERS CONTINUE TO FOCUS ALONG THE NORTHWEST PORTION OF THE CWA
THIS MORNING...AS A LOW LEVEL JET ALONG WITH SOME UPPER LEVEL
DIVERGENCE REMAIN IN PLACE NEAR THE OHIO RIVER. SOME OF THE HEAVIER
SHOWERS AND ISOLATED THUNDERSTORMS HAVE BEEN DROPPING A LOT OF RAIN
IN A SHORT PERIOD OF TIME...UP TO AN INCH IN LESS THAN 30 MINUTES.
FORTUNATELY...STORM MOTIONS ARE AROUND 15 KTS...HOWEVER WILL HAVE TO
MONITOR AT LEAST A FEW LOCATIONS FOR REPEATED ROUNDS...WHICH COULD
LEAD TO MINOR FLOODING IN LOW LYING AREAS AT A MINIMUM. HAVE
INCREASED POPS UP TO CATEGORICAL GIVEN THE RADAR TRENDS.
THE LATEST NAM SHOWS ACTIVITY PEAKING IN THE 15-18Z TIME FRAME AND
THEN SCATTERING OUT MORE FOR THE REST OF THE AFTERNOON AS SOME MID-
LEVEL CAPPING DEVELOPS. THIS IS SIMILAR TO THE 06Z RUN...SO IT MAY BE
ON TO SOMETHING. THE LAST RUN OF THE SREF CONTINUES THE HIGHER POPS
THROUGH 21Z AND THIS MAY ALSO BE A CONTENDER WITH ANY OUTFLOW
BOUNDARY INTERACTION. FOR NOW...WILL LEAN TOWARDS THE NAM IDEA.
FRESHENED UP THE REST OF THE GRIDS...MAINLY TO ALLOW FOR A FASTER
DIURNAL RISE WHERE CLOUDS ARE STARTING OUT THINNER. HIGHS RANGING
FROM THE LOWER 80S IN THE NORTH TO A FEW UPPER 80S IN THE SOUTHEAST
LOOK ON TARGET.
UPDATE ISSUED AT 700 AM EDT SUN JUL 15 2012
SHOWERS HAVE INCREASED OVER ERN KY THIS MORNING WITH A FEW RUMBLES
AS WELL...LENDING SOME CREDIBILITY TO THE HRRR AND NAM12...AND HAVE
BENT THE GRIDS IN THIS DIRECTION THROUGH THE REMAINDER OF THE
MORNING. ALSO UPDATED SKY...ALONG WITH TEMPS AND DEW PTS TO ESTABLISH
TRENDS HEADING INTO THE DAY. OTHERWISE...THE FCST IS ESSENTIALLY ON
TRACK. UPDATED ZONES WILL BE ISSUED SHORTLY.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 232 AM EDT SUN JUL 15 2012
ESSENTIALLY LOOKING AT A PERSISTENCE FORECAST FOR TODAY AND TONIGHT
WITH LITTLE CHANGE ANTICIPATED IN THE OVERALL. THE QUESTION REMAINS
WHERE AND WHEN CONVECTION WILL INITIATE...BUT THE NEAR TERM MODELS
ARE STILL PLUGGING SOME EARLY MORNING DEVELOPMENT OVER CNTRL TN AND
KY SPREADING EAST THROUGH THE MORNING AND CONTINUING THROUGH THE
AFTERNOON BEFORE DIMINISHING THIS EVENING FOLLOWING THE LOSS OF
DAYTIME HEATING.
MODELS ARE IN GENERAL AGREEMENT IN DEVELOPING SOME HEALTHY INSTABILITY
THIS MORNING...UPWARDS OF 3K J/KG MU CAPE AGAIN WITH CONVECTIVE TEMPS
IN THE LOWER 80S AND CURRENT FCST HIGHS IN THE MID 80S. FCST PWATS
CONTINUE TO RUN ABOUT 2 INCHES THROUGHOUT THE DAY...AND WITH A RIGHT
ENTRANCE REGION OF A MODEST 50-60KT UPPER LEVEL JET TRAVERSING UP THE
OHIO VALLEY THIS AFTERNOON...COUPLED WITH A MID LEVEL SHORT WAVE
MOVING UP FROM THE TN VALLEY...CAN SEE LITTLE REASON THIS MORNING
WHY WE WOULD NOT SEE SOME EFFICIENT TSTMS AGAIN LATER THIS MORNING
CONTINUING THROUGH THE AFTERNOON...WITH LOCALLY HEAVY RAINFALL AGAIN
THE PRIMARY CONCERN.
MONDAY IS LOOKING A LITTLE MORE INTERESTING THIS MORNING WITH FCST
SOUNDINGS DEPICTING A STRONGER CAP DEVELOPING BY LATE MORNING
CONTINUING THROUGH THE PEAK HEATING HOURS AS THE STRONG BERMUDA HIGH
IS PROGGED TO SHIFT WEST TOWARDS THE CENTRAL APPALACHIANS...WEAKENING
SLIGHTLY IN THE PROCESS. DRIER...BUT WARMER MID LEVEL ADVECTION WILL
EITHER SQUASH PRECIP CHANCES OR...IF THE CAP BREAKS...COULD RESULT
IN SOME STRONG STORMS AGAIN DEVELOPING DURING THE AFTERNOON WITH
DAMAGING WINDS POSSIBLE IN ADDITION TO THE THREAT FOR LOCALLY HEAVY
RAINFALL.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 232 PM EDT SAT JUL 14 2012
THE MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE GENERAL LONG WAVE
PATTERN...HOWEVER THERE ARE SOME DIFFERENCES IN THE TIMING SOME OF
THE SHORT WAVES LATER ON DURING THE PERIOD. ON MONDAY
NIGHT...KENTUCKY WILL BE DOMINATED BY THE UPPER RIDGE WITH A MAJOR
TROUGH JUST OFF THE WEST COAST. ALL THE FRONTAL ACTIVITY WILL BE
WELL NORTH OF THE AREA AND THE COAL FIELDS WILL BE DOMINATED BY THE
WARM...MOIST AND UNSTABLE AIR MASS. WITH TIME...AN UPPER TROUGH BEGINS
TO DROP SOUTH FROM AN UPPER LOW CENTER OVER THE CANADIAN MARITIMES.
THIS WILL ALLOW A COLD FRONT TO START MOVING TO THE SOUTH. BY
THURSDAY MORNING...THE FRONT WILL BE OVER NORTHERN KENTUCKY AND WILL
SLOWLY MOVE SOUTH DURING THE DAY. BY FRIDAY MORNING THE FRONT WILL
HAVE MOVED INTO CENTRAL TENNESSEE. THE 00GMT GFS IS WANTING TO SLOW
THE FRONT DOWN AND SORT OF STALL IT OVER THE AREA ON FRIDAY...WHILE
THE 12 GMT ECMWF WANTS TO MOVES IT SOUTH OF THE AREA MORE QUICKLY.
IN GENERAL...I HAVE MORE CONFIDENCE IN THE ECMWF AND WILL BE NUDGING
THE FORECAST TOWARD THE FASTER FRONTAL PASSAGE. IN EITHER CASE...AS
THE FRONT MOVES TO THE SOUTH...DRIER AIR WILL BE MOVING INTO THE
AREA AND MAKE THINGS MORE COMFORTABLE. EVEN THOUGH THE HIGHS WILL
STILL BE A LITTLE ABOVE NORMAL. THE OVERNIGHT LOWS WILL DROP DUE TO
THE DRIER AIR. IN THE MEAN TIME...KENTUCKY WILL BE UNDER A DIRTY
RIDGE WITH WARM MOIST UNSTABLE AIR OVER THE AREA WHICH WILL BE ABLE
TO PRODUCE MAINLY AFTERNOON AND EVENING CONVECTIVE THUNDERSTORMS AND
SHOWERS AND WILL KEEP TEMPERATURES WARM AND MISERABLE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 700 AM EDT SUN JUL 15 2012
SCT SHRA WITH A FEW TSTMS MOVING NE ACROSS CNTRL AND NERN KY THIS
MORNING BUT ARE NOT AFFECTING THE TAF SITES JUST YET. MORE TSTMS ARE
EXPECTED TO DEVELOP THROUGH THE MORNING AND CONTINUE THROUGH THE
AFTERNOON...AND WILL ONCE AGAIN BRING TEMPORARY...LOCALIZED IFR OR
WORSE TO ANY TERMINAL THAT SEES CONVECTION TODAY. HOWEVER...WITH LOW
CONFIDENCE IN TIMING AND EXACT PLACEMENT...WILL CONTINUE WITH VC
GROUPS. LOW LEVEL WINDS ARE EXPECTED TO REDEVELOP AFTER 12Z OUT OF
THE SW TO AROUND 5 TO 10 KTS AND CONTINUE THROUGH THE EVENING BEFORE
DIMINISHING WITH CONVECTION AFTER SUNSET.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...MB
LONG TERM....JJ
AVIATION...MB
AREA FORECAST DISCUSSION
NWS JACKSON KY
701 AM EDT SUN JUL 15 2012
.UPDATE...
ISSUED AT 700 AM EDT SUN JUL 15 2012
SHOWERS HAVE INCREASED OVER ERN KY THIS MORNING WITH A FEW RUMBLES
AS WELL...LENDING SOME CREDIBILITY TO THE HRRR AND NAM12...AND HAVE
BENT THE GRIDS IN THIS DIRECTION THROUGH THE REMAINDER OF THE
MORNING. ALSO UPDATED SKY...ALONG WITH TEMPS AND DEW PTS TO ESTABLISH
TRENDS HEADING INTO THE DAY. OTHERWISE...THE FCST IS ESSENTIALLY ON
TRACK. UPDATED ZONES WILL BE ISSUED SHORTLY.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 232 AM EDT SUN JUL 15 2012
ESSENTIALLY LOOKING AT A PERSISTENCE FORECAST FOR TODAY AND TONIGHT
WITH LITTLE CHANGE ANTICIPATED IN THE OVERALL. THE QUESTION REMAINS
WHERE AND WHEN CONVECTION WILL INITIATE...BUT THE NEAR TERM MODELS
ARE STILL PLUGGING SOME EARLY MORNING DEVELOPMENT OVER CNTRL TN AND
KY SPREADING EAST THROUGH THE MORNING AND CONTINUING THROUGH THE
AFTERNOON BEFORE DIMINISHING THIS EVENING FOLLOWING THE LOSS OF
DAYTIME HEATING.
MODELS ARE IN GENERAL AGREEMENT IN DEVELOPING SOME HEALTHY INSTABILITY
THIS MORNING...UPWARDS OF 3K J/KG MU CAPE AGAIN WITH CONVECTIVE TEMPS
IN THE LOWER 80S AND CURRENT FCST HIGHS IN THE MID 80S. FCST PWATS
CONTINUE TO RUN ABOUT 2 INCHES THROUGHOUT THE DAY...AND WITH A RIGHT
ENTRANCE REGION OF A MODEST 50-60KT UPPER LEVEL JET TRAVERSING UP THE
OHIO VALLEY THIS AFTERNOON...COUPLED WITH A MID LEVEL SHORT WAVE
MOVING UP FROM THE TN VALLEY...CAN SEE LITTLE REASON THIS MORNING
WHY WE WOULD NOT SEE SOME EFFICIENT TSTMS AGAIN LATER THIS MORNING
CONTINUING THROUGH THE AFTERNOON...WITH LOCALLY HEAVY RAINFALL AGAIN
THE PRIMARY CONCERN.
MONDAY IS LOOKING A LITTLE MORE INTERESTING THIS MORNING WITH FCST
SOUNDINGS DEPICTING A STRONGER CAP DEVELOPING BY LATE MORNING
CONTINUING THROUGH THE PEAK HEATING HOURS AS THE STRONG BERMUDA HIGH
IS PROGGED TO SHIFT WEST TOWARDS THE CENTRAL APPALACHIANS...WEAKENING
SLIGHTLY IN THE PROCESS. DRIER...BUT WARMER MID LEVEL ADVECTION WILL
EITHER SQUASH PRECIP CHANCES OR...IF THE CAP BREAKS...COULD RESULT
IN SOME STRONG STORMS AGAIN DEVELOPING DURING THE AFTERNOON WITH
DAMAGING WINDS POSSIBLE IN ADDITION TO THE THREAT FOR LOCALLY HEAVY
RAINFALL.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 232 PM EDT SAT JUL 14 2012
THE MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE GENERAL LONG WAVE
PATTERN...HOWEVER THERE ARE SOME DIFFERENCES IN THE TIMING SOME OF
THE SHORT WAVES LATER ON DURING THE PERIOD. ON MONDAY
NIGHT...KENTUCKY WILL BE DOMINATED BY THE UPPER RIDGE WITH A MAJOR
TROUGH JUST OFF THE WEST COAST. ALL THE FRONTAL ACTIVITY WILL BE
WELL NORTH OF THE AREA AND THE COAL FIELDS WILL BE DOMINATED BY THE
WARM...MOIST AND UNSTABLE AIR MASS. WITH TIME...AN UPPER TROUGH BEGINS
TO DROP SOUTH FROM AN UPPER LOW CENTER OVER THE CANADIAN MARITIMES.
THIS WILL ALLOW A COLD FRONT TO START MOVING TO THE SOUTH. BY
THURSDAY MORNING...THE FRONT WILL BE OVER NORTHERN KENTUCKY AND WILL
SLOWLY MOVE SOUTH DURING THE DAY. BY FRIDAY MORNING THE FRONT WILL
HAVE MOVED INTO CENTRAL TENNESSEE. THE 00GMT GFS IS WANTING TO SLOW
THE FRONT DOWN AND SORT OF STALL IT OVER THE AREA ON FRIDAY...WHILE
THE 12 GMT ECMWF WANTS TO MOVES IT SOUTH OF THE AREA MORE QUICKLY.
IN GENERAL...I HAVE MORE CONFIDENCE IN THE ECMWF AND WILL BE NUDGING
THE FORECAST TOWARD THE FASTER FRONTAL PASSAGE. IN EITHER CASE...AS
THE FRONT MOVES TO THE SOUTH...DRIER AIR WILL BE MOVING INTO THE
AREA AND MAKE THINGS MORE COMFORTABLE. EVEN THOUGH THE HIGHS WILL
STILL BE A LITTLE ABOVE NORMAL. THE OVERNIGHT LOWS WILL DROP DUE TO
THE DRIER AIR. IN THE MEAN TIME...KENTUCKY WILL BE UNDER A DIRTY
RIDGE WITH WARM MOIST UNSTABLE AIR OVER THE AREA WHICH WILL BE ABLE
TO PRODUCE MAINLY AFTERNOON AND EVENING CONVECTIVE THUNDERSTORMS AND
SHOWERS AND WILL KEEP TEMPERATURES WARM AND MISERABLE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 700 AM EDT SUN JUL 15 2012
SCT SHRA WITH A FEW TSTMS MOVING NE ACROSS CNTRL AND NERN KY THIS
MORNING BUT ARE NOT AFFECTING THE TAF SITES JUST YET. MORE TSTMS ARE
EXPECTED TO DEVELOP THROUGH THE MORNING AND CONTINUE THROUGH THE
AFTERNOON...AND WILL ONCE AGAIN BRING TEMPORARY...LOCALIZED IFR OR
WORSE TO ANY TERMINAL THAT SEES CONVECTION TODAY. HOWEVER...WITH LOW
CONFIDENCE IN TIMING AND EXACT PLACEMENT...WILL CONTINUE WITH VC
GROUPS. LOW LEVEL WINDS ARE EXPECTED TO REDEVELOP AFTER 12Z OUT OF
THE SW TO AROUND 5 TO 10 KTS AND CONTINUE THROUGH THE EVENING BEFORE
DIMINISHING WITH CONVECTION AFTER SUNSET.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MB
SHORT TERM...MB
LONG TERM....JJ
AVIATION...MB
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
942 AM EDT SUN JUL 15 2012
.SYNOPSIS...
THE COMBINATION OF A MID-LEVEL DISTURBANCE CROSSING THE GREAT
LAKES AND A MOIST AIR MASS IN PLACE ACROSS THE UPPER OHIO VALLEY
WILL MAKE SHOWERS AND THUNDERSTORMS LIKELY BY THIS AFTERNOON. A
DRY START TO THE WEEK IS THEN EXPECTED AS HIGH PRESSURE ALOFT
APPROACHES FROM THE SOUTHWEST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE TO REMOVE MENTION OF MORNING FOG.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO VALLEY
IN A SOUTHWESTERLY FLOW BETWEEN A RIDGE ACROSS THE CAROLINAS AND A
TROUGH ACROSS THE WESTERN GREAT LAKES. AT THE SURFACE, DISCERNIBLE
FRONTAL/PRESSURE FEATURES ARE LACKING WITH A BROAD AREA OF TDS IN
THE UPPER 60S TO LOWER 70S ACROSS THE REGION. A SATURATED
ATMOSPHERIC COLUMN REMAINS IN PLACE WITH PRECIPITABLE WATER VALUES
IN THE 1.8-2.0 INCH RANGE EARLY THIS MORNING. DESPITE ONLY WEAK
CAPE REMAINING, ABUNDANT MOISTURE IN PLACE IS ENOUGH TO SUPPORT
WIDELY SCATTERED SHOWERS MOVING ACROSS THE AREA.
THE SOUTHWESTERLY MID-LEVEL FLOW WILL BECOME MORE ZONAL TODAY AS
THE TROUGH CROSSES THE GREAT LAKES. 500MB HEIGHTS WILL FALL
SLIGHTLY AS THIS FEATURE PASSES NORTH OF THE AREA, PROVIDING
ENOUGH FORCING IN A MOIST AND UNSTABLE ENVIRONMENT TO CONTRIBUTE
TO THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS. COVERAGE OF
CONVECTION IS EXPECTED TO INCREASE THIS MORNING AS ELEVATED
INSTABILITY INCREASES FROM THE SOUTHWEST. EXPECT MOSTLY CLOUDY
SKIES AGAIN TODAY WITH ABUNDANT MOISTURE. FOR TEMPS, HIGHS ARE
CLOSEST TO MAV GUIDANCE, RANGING FROM THE UPPER 70S ALONG THE I-80
CORRIDOR AND EASTERN RIDGES TO THE MID 80S IN EASTERN OHIO.
PWAT VALUES NEAR 2 INCHES WITH DEEP MOISTURE IN PLACE ALONG WITH
MODERATE INSTABILITY WILL SUPPORT LOCALLY HEAVY DOWNPOURS TODAY.
STORM MOTION OF AROUND 30KTS ALONG WITH THE GROUND BEING
RELATIVELY DRY ACROSS MUCH OF THE AREA WILL BE LIMITING FACTORS
FOR A FLASH FLOODING THREAT TODAY. HOWEVER, IF MULTIPLE STORMS
TRAIN OVER AREAS, FLOODING COULD BECOME A THREAT. WITH 0-6KM BULK
SHEAR AROUND 30KTS, ITS NOT OF THE QUESTION THAT A FEW ISOLATED
STRONG TO SEVERE THUNDERSTORMS WILL DEVELOP THIS AFTERNOON INTO
THE EVENING WITH THE PRIMARY THREAT BEING OF GUSTY WINDS AIDED
BY MOISTURE LOADING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THERE IS OPERATIONAL MODEL AGREEMENT THAT THE MID-LEVEL TROUGH
WILL SHIFT EAST OF THE AREA WITH THE FLOW BECOMING NORTHWESTERLY.
WITH DEEP LAYER MOISTURE ADVECTING EAST OF THE AREA, CONVECTION
WITH LOCALLY HEAVY DOWNPOURS WILL DIMINISH BY 06Z WITH POPS
DECREASING TO SCHC QUICKLY AND DRY BY MONDAY MORNING. A DRY LAYER
ABOVE 850MB ALONG WITH 500MB RIDGING BUILDING INTO THE OHIO VALLEY
WILL ALLOW FOR A MOSTLY DRY FORECAST THROUGH THE DAY MONDAY AND
INTO MONDAY NIGHT. MODERATE INSTABILITY MAY BE ENOUGH TO INITIATE
AN ISOLATED SHOWER OR THUNDERSTORM SOUTHEAST OF PITTSBURGH INTO
THE AFTERNOON.
HIGHS MONDAY ARE A MAV/MET BLEND, RANGING FROM THE MID TO UPPER
80S ACROSS THE AREA. WITH TDS IN THE MID TO UPPER 60S TONIGHT AND
MONDAY NIGHT, LOWS WILL RANGE FROM THE MID 60S ACROSS THE I-80
CORRIDOR TO NEAR 70 FOR THE PITTSBURGH METRO AND LOCATIONS
SOUTHWESTWARD.
ECMWF/GFS ARE IN AGREEMENT THAT THE 500MB RIDGE CENTERED ACROSS
THE TENNESSEE VALLEY WILL EDGE TOWARD THE UPPER OHIO VALLEY ON
TUESDAY. IN ADDITION, THE REGION WILL BE IN WARM AIR ADVECTION
AHEAD OF A COLD FRONT APPROACHING FROM THE NORTHWEST. WITH 850MB
TEMPS FORECAST TO WARM TO NEAR 20C BY TUESDAY AFTERNOON, THIS
SUPPORTS HIGHS IN THE LOWER 90S ACROSS LOWLAND AREAS. WITH WARMEST
TDS IN EASTERN OHIO, HEAT INDICES WILL APPROACH 100 AND A HEAT
ADVISORY MAY BE NEEDED FOR LOCATIONS ALONG AND WEST OF I-77.
TUESDAY WILL BE A WARM AND MUGGY NIGHT WITH TEMPS ONLY COOLING
INTO THE LOWER 70S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
GLOBAL MODEL AGREEMENT AND RUN-TO-RUN CONSISTENCY IS VERY GOOD ON
THE SOUTHWARD PROGRESSION OF A COLD FRONT ACROSS THE AREA ON
WEDNESDAY. THE GFS AND ECMWF BOTH DEPICT IT CLEARING VIRTUALLY ALL
OF THE FORECAST AREA SAVE FOR MAYBE THE FARTHEST SOUTHEASTERN
COUNTIES BY THURSDAY MORNING. BECAUSE OF THIS AND DUE TO A MUCH
DRIER COLUMN FORECAST TO INFILTRATE THE AREA AFTER THIS TIME
FRAME...THE FORECAST WAS DRIED OUT BEYOND WEDNESDAY NIGHT. THE
RESULTANT DEEP NORTHWESTERLY FLOW WILL BRING MUCH LESS HUMID
CONDITIONS INTO THE REGION...HOWEVER WITH 850 MB TEMPERATURES FROM
THE MODEL CONSENSUS STILL RUNNING IN THE MID TEENS...TEMPERATURES
ARE LIKELY TO REMAIN AT LEAST UP TOWARD NORMAL HIGHS FOR JULY.
FRIES
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
THUNDERSTORMS HAVE CLEARED ALL SITES TO THE NORTHEAST FOR THE
EVENING AS OF 0530Z. SOME SHOWER ACTIVITY CONTINUES TO DEVELOP OVER
EASTERN OHIO AND MOVE NORTHEASTWARD...BUT IT IS RATHER SCATTERED.
THIS WILL NOT BE CARRIED AT ANY PARTICULAR TERMINAL...HOWEVER
CONTINUED INPUT OF MOISTURE INTO THE LOWER LEVELS FROM ANY
ADDITIONAL SHOWERS WILL ONLY INCREASE THE LIKELIHOOD OF VISIBILITIES
STARTING TO SLIDE OFF WITHIN THE NEXT 1-3 HOURS. ALL SITES SHOULD GO
MVFR PER BOTH STATISTICAL GUIDANCE AND PER SUGGESTIONS FROM BUFKIT
DATA. SHOWERS WILL REDEVELOP BY LATE MORNING SUNDAY AGAIN AS THINGS
BEGIN TO DESTABILIZE...WHICH SHOULD ALLOW FOR FOG TO BREAKUP BY THAT
TIME. FRIES
OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...
WEAK RIDGING SHOULD PROVIDE GENERALLY VFR CONDITIONS MONDAY INTO
TUESDAY. A COLD FRONT WILL SAG SOUTHWARD ACROSS THE GREAT LAKES AND
THROUGH THE OHIO VALLEY TUESDAY NIGHT AND WEDNESDAY. RESTRICTIONS
CAN BE EXPECTED IN SCATTERED PREFRONTAL THUNDERSTORMS. PREVAILING
VFR WEATHER SHOULD RETURN BY THURSDAY AS A SURFACE HIGH BUILDS IN.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
636 AM EDT SUN JUL 15 2012
.SYNOPSIS...
THE COMBINATION OF A MID-LEVEL DISTURBANCE CROSSING THE GREAT
LAKES AND A MOIST AIR MASS IN PLACE ACROSS THE UPPER OHIO VALLEY
WILL MAKE SHOWERS AND THUNDERSTORMS LIKELY BY THIS AFTERNOON. A
DRY START TO THE WEEK IS THEN EXPECTED AS HIGH PRESSURE ALOFT
APPROACHES FROM THE SOUTHWEST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO VALLEY
IN A SOUTHWESTERLY FLOW BETWEEN A RIDGE ACROSS THE CAROLINAS AND A
TROUGH ACROSS THE WESTERN GREAT LAKES. AT THE SURFACE, DISCERNIBLE
FRONTAL/PRESSURE FEATURES ARE LACKING WITH A BROAD AREA OF TDS IN
THE UPPER 60S TO LOWER 70S ACROSS THE REGION. A SATURATED
ATMOSPHERIC COLUMN REMAINS IN PLACE WITH PRECIPITABLE WATER VALUES
IN THE 1.8-2.0 INCH RANGE EARLY THIS MORNING. DESPITE ONLY WEAK
CAPE REMAINING, ABUNDANT MOISTURE IN PLACE IS ENOUGH TO SUPPORT
WIDELY SCATTERED SHOWERS MOVING ACROSS THE AREA.
THE SOUTHWESTERLY MID-LEVEL FLOW WILL BECOME MORE ZONAL TODAY AS
THE TROUGH CROSSES THE GREAT LAKES. 500MB HEIGHTS WILL FALL
SLIGHTLY AS THIS FEATURE PASSES NORTH OF THE AREA, PROVIDING
ENOUGH FORCING IN A MOIST AND UNSTABLE ENVIRONMENT TO CONTRIBUTE
TO THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS. COVERAGE OF
CONVECTION IS EXPECTED TO INCREASE THIS MORNING AS ELEVATED
INSTABILITY INCREASES FROM THE SOUTHWEST. EXPECT MOSTLY CLOUDY
SKIES AGAIN TODAY WITH ABUNDANT MOISTURE. FOR TEMPS, HIGHS ARE
CLOSEST TO MAV GUIDANCE, RANGING FROM THE UPPER 70S ALONG THE I-80
CORRIDOR AND EASTERN RIDGES TO THE MID 80S IN EASTERN OHIO.
PWAT VALUES NEAR 2 INCHES WITH DEEP MOISTURE IN PLACE ALONG WITH
MODERATE INSTABILITY WILL SUPPORT LOCALLY HEAVY DOWNPOURS TODAY.
STORM MOTION OF AROUND 30KTS ALONG WITH THE GROUND BEING
RELATIVELY DRY ACROSS MUCH OF THE AREA WILL BE LIMITING FACTORS
FOR A FLASH FLOODING THREAT TODAY. HOWEVER, IF MULTIPLE STORMS
TRAIN OVER AREAS, FLOODING COULD BECOME A THREAT. WITH 0-6KM BULK
SHEAR AROUND 30KTS, ITS NOT OF THE QUESTION THAT A FEW ISOLATED
STRONG TO SEVERE THUNDERSTORMS WILL DEVELOP THIS AFTERNOON INTO
THE EVENING WITH THE PRIMARY THREAT BEING OF GUSTY WINDS AIDED
BY MOISTURE LOADING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THERE IS OPERATIONAL MODEL AGREEMENT THAT THE MID-LEVEL TROUGH
WILL SHIFT EAST OF THE AREA WITH THE FLOW BECOMING NORTHWESTERLY.
WITH DEEP LAYER MOISTURE ADVECTING EAST OF THE AREA, CONVECTION
WITH LOCALLY HEAVY DOWNPOURS WILL DIMINISH BY 06Z WITH POPS
DECREASING TO SCHC QUICKLY AND DRY BY MONDAY MORNING. A DRY LAYER
ABOVE 850MB ALONG WITH 500MB RIDGING BUILDING INTO THE OHIO VALLEY
WILL ALLOW FOR A MOSTLY DRY FORECAST THROUGH THE DAY MONDAY AND
INTO MONDAY NIGHT. MODERATE INSTABILITY MAY BE ENOUGH TO INITIATE
AN ISOLATED SHOWER OR THUNDERSTORM SOUTHEAST OF PITTSBURGH INTO
THE AFTERNOON.
HIGHS MONDAY ARE A MAV/MET BLEND, RANGING FROM THE MID TO UPPER
80S ACROSS THE AREA. WITH TDS IN THE MID TO UPPER 60S TONIGHT AND
MONDAY NIGHT, LOWS WILL RANGE FROM THE MID 60S ACROSS THE I-80
CORRIDOR TO NEAR 70 FOR THE PITTSBURGH METRO AND LOCATIONS
SOUTHWESTWARD.
ECMWF/GFS ARE IN AGREEMENT THAT THE 500MB RIDGE CENTERED ACROSS
THE TENNESSEE VALLEY WILL EDGE TOWARD THE UPPER OHIO VALLEY ON
TUESDAY. IN ADDITION, THE REGION WILL BE IN WARM AIR ADVECTION
AHEAD OF A COLD FRONT APPROACHING FROM THE NORTHWEST. WITH 850MB
TEMPS FORECAST TO WARM TO NEAR 20C BY TUESDAY AFTERNOON, THIS
SUPPORTS HIGHS IN THE LOWER 90S ACROSS LOWLAND AREAS. WITH WARMEST
TDS IN EASTERN OHIO, HEAT INDICES WILL APPROACH 100 AND A HEAT
ADVISORY MAY BE NEEDED FOR LOCATIONS ALONG AND WEST OF I-77.
TUESDAY WILL BE A WARM AND MUGGY NIGHT WITH TEMPS ONLY COOLING
INTO THE LOWER 70S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
GLOBAL MODEL AGREEMENT AND RUN-TO-RUN CONSISTENCY IS VERY GOOD ON
THE SOUTHWARD PROGRESSION OF A COLD FRONT ACROSS THE AREA ON
WEDNESDAY. THE GFS AND ECMWF BOTH DEPICT IT CLEARING VIRTUALLY ALL
OF THE FORECAST AREA SAVE FOR MAYBE THE FARTHEST SOUTHEASTERN
COUNTIES BY THURSDAY MORNING. BECAUSE OF THIS AND DUE TO A MUCH
DRIER COLUMN FORECAST TO INFILTRATE THE AREA AFTER THIS TIME
FRAME...THE FORECAST WAS DRIED OUT BEYOND WEDNESDAY NIGHT. THE
RESULTANT DEEP NORTHWESTERLY FLOW WILL BRING MUCH LESS HUMID
CONDITIONS INTO THE REGION...HOWEVER WITH 850 MB TEMPERATURES FROM
THE MODEL CONSENSUS STILL RUNNING IN THE MID TEENS...TEMPERATURES
ARE LIKELY TO REMAIN AT LEAST UP TOWARD NORMAL HIGHS FOR JULY.
FRIES
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
THUNDERSTORMS HAVE CLEARED ALL SITES TO THE NORTHEAST FOR THE
EVENING AS OF 0530Z. SOME SHOWER ACTIVITY CONTINUES TO DEVELOP OVER
EASTERN OHIO AND MOVE NORTHEASTWARD...BUT IT IS RATHER SCATTERED.
THIS WILL NOT BE CARRIED AT ANY PARTICULAR TERMINAL...HOWEVER
CONTINUED INPUT OF MOISTURE INTO THE LOWER LEVELS FROM ANY
ADDITIONAL SHOWERS WILL ONLY INCREASE THE LIKELIHOOD OF VISIBILITIES
STARTING TO SLIDE OFF WITHIN THE NEXT 1-3 HOURS. ALL SITES SHOULD GO
MVFR PER BOTH STATISTICAL GUIDANCE AND PER SUGGESTIONS FROM BUFKIT
DATA. SHOWERS WILL REDEVELOP BY LATE MORNING SUNDAY AGAIN AS THINGS
BEGIN TO DESTABILIZE...WHICH SHOULD ALLOW FOR FOG TO BREAKUP BY THAT
TIME. FRIES
OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...
WEAK RIDGING SHOULD PROVIDE GENERALLY VFR CONDITIONS MONDAY INTO
TUESDAY. A COLD FRONT WILL SAG SOUTHWARD ACROSS THE GREAT LAKES AND
THROUGH THE OHIO VALLEY TUESDAY NIGHT AND WEDNESDAY. RESTRICTIONS
CAN BE EXPECTED IN SCATTERED PREFRONTAL THUNDERSTORMS. PREVAILING
VFR WEATHER SHOULD RETURN BY THURSDAY AS A SURFACE HIGH BUILDS IN.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1121 AM EDT SUN JUL 15 2012
.UPDATE...
ISSUED AT 1119 AM EDT SUN JUL 15 2012
MORNING UPDATE MAINLY DEALS WITH TWEAKS TO THE FOG OVER LK SUPERIOR
AND CLOUD COVER THIS AFTN OVER INTERIOR LOCATIONS. FOR THE
FOG...EXTENDED THE DENSE FOG ADVY FOR NORTHERN AREAS THROUGH THIS
AFTN DUE TO RECENT WEBCAMS ALONG THE NRN KEWEENAW SHORELINE SHOWING
DENSE FOG AT THIS HOUR. FARTHER SOUTH AND EAST...WEBCAMS AND SHIP
OBS THIS MORNING SHOWING THE EXPANSE OF CLOUDS OVER THE SE LK
SUPERIOR MAINLY IN THE FORM OF LOW STRATUS. THUS...WILL LET THAT
ADVY EXPIRE AT NOON.
HIGH RES MODELS ARE ALL SHOWING DIURNAL CU AND LIGHT SHOWERS
DEVELOPING OVER THE WRN/CNTRL CWA AWAY FROM THE LK BREEZES OFF LK
SUPERIOR. AREAS FROM WRN LK SUPERIOR TO THE THUNDER BAY AND N SAW
SOME SCATTERED ACCAS EARLY THIS MORNING...WHICH SEEMS TO BE JUST E
OF THE VERY DRY AIR ON THE 12Z KINL SOUNDING. BUT WITH THE SLOW
LLVL WINDS NOT PUSHING THE DRY AIR E VERY QUICKLY...THINKING THE
LINGERING LLVL MOISTURE WILL BE ENOUGH TO DEVELOP A LARGER AREA OF
CU THAN PREVIOUSLY THOUGHT. THEREFORE...BUMPED SKIES UP TO PARTLY
CLOUDY FOR MUCH OF THE INTERIOR W AND CNTRL. SINCE WEAK
SHORTWAVE ENERGY WILL TRY TO WORK INTO THE AREA THIS AFTN FROM
MORNING SHOWERS IN NW MN...THAT MAY BE ENOUGH TO HELP PRODUCE AN
ISOLATED SHOWER OR TWO. WITH ALL OF THE HIGH RES MODELS AND THE NEW
12Z NAM KICKING OFF SHOWERS...EVEN THOUGH THEY MAY BE
OVERDOING THE LLVL TD VALUES SOME...WILL INTRODUCE THEM AROUND 18Z
OVER ERN ONTONAGON/GOGEBIC COUNTIES AND THEN DRIFT SE BEFORE
DIMINISHING IN THE LATE AFTN. SINCE THERE APPEARS TO BE PLENTY OF
DRY AIR ABOVE H750...WILL KEEP THUNDER MENTION OUT AS THIS WILL
LIKELY LIMIT CLOUD DEPTH TO A FEW KFT AND MAY EVEN HOLD OFF SHOWER
DEVELOPMENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 520 AM EDT SUN JUL 15 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW TROF JUST E OF THE FCST
AREA. SHRA/TSRA THAT ACCOMPANIED THE TROF ACROSS THE AREA YESTERDAY
HAVE RECENTLY EXITED THE SE PORTION OF THE FCST AREA. IN ITS WAKE...
CALM WIND/CLEARING SKIES AND MOISTURE FROM YESTERDAY`S RAINFALL HAS
LED TO SOME FOG DEVELOPMENT. FOG WILL QUICKLY BURN OFF WITHIN A
COUPLE HRS AFTER SUNRISE. UPSTREAM...A MID LEVEL RIDGE IS NOSING
INTO THE DAKOTAS/WRN MN. AS THE RIDGE SHIFTS E TODAY...UPPER MI WILL
FALL UNDER HEIGHT RISES/DEEP LAYER QVECTOR DIVERGENCE. MUCH DRIER
AIR...MAINLY IN THE MID LEVELS PER UPSTREAM 00Z KINL/CWPL
SOUNDINGS...WILL WORK AGAINST ANY AFTN CONVECTIVE DEVELOPMENT
DESPITE LAKE BREEZES PROVIDING LOW-LEVEL FORCING. THE K-INDEX ON THE
00Z CWPL/KINL SOUNDINGS WAS -11/-14C RESPECTIVELY DUE TO VERY DRY
AIR AROUND 700MB (DWPT DEPRESSIONS WERE IN EXCESS OF 40C). SO...
GOING DRY FCST APPEARS ON TRACK DESPITE SOME HIGH RES GUIDANCE
CONTINUING TO SHOW ISOLD CONVECTION OVER THE SCNTRL THIS AFTN.
MIXING TO AROUND 800MB ON FCST SOUNDINGS SUPPORTS MAX TEMPS UPWARDS
OF AROUND 90F. LIGHT GRADIENT WIND WILL ALLOW LAKE BREEZES OFF
LAKE SUPERIOR AND LAKE MICHIGAN TO PROVIDE SOME COOLING LAKESIDE.
SHORTWAVE ENERGY EJECTING FROM THE TROF CURRENTLY OVER THE WRN
STATES WILL HEAD INTO SCNTRL CANADA TONIGHT. IN RESPONSE...LOW-LEVEL
JET WILL INCREASE TO 45-50KT INTO THE NRN PLAINS. THIS WILL LIKELY
SUPPORT A CLUSTER OF SHRA/TSRA ON THE NOSE OF THE LOW-LEVEL JET AND
ALONG EDGE OF CAP ACROSS ND INTO SRN MANITOBA/NRN MN AND NRN
ONTARIO. AT THIS TIME...IT STILL APPEARS LOW-LEVEL JET WILL BE W OF
THE AREA AT 12Z MON...SO DO NOT ANTICIPATE ANY CONVECTION LATE
TONIGHT...EXCEPT POSSIBLY OVER NW LAKE SUPERIOR/ISLE ROYALE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 520 AM EDT SUN JUL 15 2012
BY 12Z MONDAY THE FRONTAL BOUNDARY WOULD BE ACROSS LAKE SUPERIOR
/AS A WARM FRONT/...STRETCHING FROM THE SFC LOW SET UP FROM NW MN TO
CENTRAL SD. DEPENDING ON THE AMOUNT OF MIXING /UP TO AROUND 800MB AT
SAW/ A FEW GUSTS OF 30 TO 35KTS COULD BE POSSIBLE FROM LATE MORNING
THROUGH THE REMAINDER OF THE DAYTIME HOURS. IF CLOUD COVER DOES NOT
INHIBIT MIXING...THESE STRONGER GUSTS COULD BE POSSIBLE ACROSS THE
DOWNSLOPE LOCATIONS NEAR LAKE SUPERIOR GIVEN THE STRENGTHENING SW
FLOW. AS FOR THE OFFICIAL FCST...HAVE INCREASED WINDS QUITE A BIT
FROM THE PREVIOUS FORECAST...WITH GUSTS OF 20-25KTS ACROSS MUCH OF
THE CWA BY MID AFTERNOON.
THE RECORD HIGH TEMP FOR MONDAY AT WFO MQT IS 95 DEGREES...WHICH MAY
BE BROKEN BY THE END OF THE DAY. CURRENTLY GOING ONLY A COUPLE OF
DEGREES COOLER THAN THIS RECORD...WITH 850MB TEMPS OF 22-24C
ALLOWING SEVERAL SITES ACROSS THE INTERIOR W HALF OF UPPER MI
REACHING 95 OR ABOVE.
THE SFC LOW SHOULD PUSH ACROSS THE AREA MONDAY AFTERNOON
THROUGH TUESDAY NIGHT. THE TRACK IS STILL UNCERTAIN...WITH THE
14/18Z GFS AND 15/00Z NAM PUSHING THE SFC LOW ACROSS THE KEWEENAW
PENINSULA AND ACROSS LAKE SUPERIOR BY EARLY MONDAY EVENING. THE
FARTHER SOUTH 14/12Z ECMWF INDICATES A BROADER LOW...STRETCHING
ACROSS CENTRAL AND SOUTHERN UPPER MI MONDAY NIGHT. THE 14/12Z
CANADIAN IS BEYOND CONSENSUS FROM MONDAY AFTERNOON ON...TRACKING THE
SFC LOW ACROSS ONTARIO AND N LAKE SUPERIOR...AND WILL NOT BE USED IN
THIS FORECAST UNTIL IT MOVES BACK IN LINE WITH THE REMAINDER OF
AVAILABLE GUIDANCE WEDNESDAY MORNING.
HIGH PRESSURE OVER CENTRAL CANADA TUESDAY MORNING WILL SLOWLY SHIFT
SE ACROSS LAKE SUPERIOR AND UPPER MI TUESDAY THROUGH THURSDAY. THE
COOLEST AFTERNOON TEMPS LOOK TO BE WEDNESDAY...TOPPING OUT IN THE
70S...COOLEST NEAR LAKE SUPERIOR AS DRY COOL AIR REMAINS. 850MB
TEMPS WEDNESDAY WILL BE A COOL 10-12C. THE FCST FOR THE CWA WILL
REMAIN DRY TUESDAY NIGHT THROUGH FRIDAY NIGHT. EXPECT THE SFC HIGH
TO DRIFT E TO THE LOWER GREAT LAKES AND W QUEBEC BY DAYBREAK FRIDAY
AND THE NEW ENGLAND COAST FRIDAY NIGHT...WITH A RIDGE REMAINING
ACROSS THE UPPER GREAT LAKES REGION.
A RELATIVELY WEAK SFC LOW STRETCHING FROM CENTRAL CANADA THROUGH THE
CENTRAL PLAINS LOOKS TO BECOME BETTER ORGANIZED TO OUR W SATURDAY
NIGHT...AS A SERIES OF DISTURBANCES NEAR FROM W AND CENTRAL CANADA
AS 500MB RIDGE BECOMES SUPPRESSED ACROSS THE CENTRAL AND SOUTHERN
PLAINS. KEPT CHANCE POPS FOR SATURDAY...ALTHOUGH CONFIDENCE IS
MODERATE TO LOW FOR SPECIFICS THAT FAR OUT IN THIS FCST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 749 AM EDT SUN JUL 15 2012
FOG WHICH HAS LED TO HIGHLY VARIABLE VIS/CIGS OVERNIGHT WILL BURN
OFF OVER THE NEXT HR OR TWO...LEAVING VFR CONDITIONS TO PREVAIL
TODAY AND TONIGHT AT KIWD/KCMX/KSAW. THERE IS A SMALL POTENTIAL FOR
FOG TO REDEVELOP TONIGHT...BUT A SLOW INCREASE IN NEAR SFC WINDS WILL
WORK TO LIMIT POTENTIAL. ALSO...SOIL MOISTURE WHICH PLAYED A ROLE IN
FOG DEVELOPMENT OVERNIGHT WILL HAVE A CHANCE TO DRY OUT TODAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 520 AM EDT SUN JUL 15 2012
BIGGEST CONCERN IN THE SHORT TERM WILL BE FOG. 11-3.9MICRON
SATELLITE IMAGERY INDICATES FOG (PROBABLY NOT STRATUS) EXPANDING S
AND E FROM NCNTRL LAKE SUPERIOR. MORE FOG MAY BE DEVELOPING FROM
KEWEENAW BAY TOWARD MARQUETTE/MUNISING. WITH DEVELOPING MESO HIGH
PRES OVER THE LAKE TODAY...IT`S QUITE POSSIBLE FOG MAY END UP
SPREADING TO THE SHORELINES AROUND THE ENTIRE LAKE TODAY. ALWAYS
DIFFICULT TO FCST MARINE FOG...SO TRENDS WILL NEED TO MONITORED
CLOSELY TODAY FOR MOVEMENT/DEVELOPMENT/DISSIPATION OF FOG. ONCE
DAYLIGHT ARRIVES...VIS SATELLITE IMAGERY WILL PROVIDE A BETTER LOOK
AT HOW THE FOG IS EVOLVING. QUITE POSSIBLE DENSE FOG ADVY MAY NEED
TO BE ISSUED. FOR NOW...CARRIED FOG MENTION THRU EARLY AFTN OVER
MAINLY CNTRL AND ERN LAKE SUPERIOR.
OTHERWISE...WITH HIGH PRES DEVELOPING OVER LAKE SUPERIOR TODAY...
WINDS WILL BE UNDER 15KT. ALTHOUGH WINDS WILL BECOME S-SE TONIGHT IN
ADVANCE OF APPROACHING LOW PRES...SPEEDS SHOULD REMAIN 15KT OR LESS.
THERE IS SOME UNCERTAINTY IN WHERE WARM FRONT ASSOCIATED WITH THE
LOW WILL BE POSITIONED MON. AT THIS TIME...IT APPEARS THAT AT LEAST
SRN PORTIONS OF THE LAKE WILL SEE INCREASING S-SW WINDS MON UPWARDS
OF 20KT AS WARM FRONT DRIFTS N. AS LOW PASSES ACROSS THE AREA MON
NIGHT...A COLD FRONT WILL PUSH S...BRINGING A SHIFT TO NORTHERLY
WINDS UPWARDS OF 20KT INTO TUE MORNING. HIGH PRES WILL THEN BUILD
INTO THE UPPER GREAT LAKES DURING THE MIDWEEK PERIOD...RESULTING IN
WINDS UNDER 20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 6 PM EDT THIS EVENING FOR LSZ243>245-
263-264-266.
DENSE FOG ADVISORY UNTIL NOON EDT TODAY FOR LSZ242-246>249-265.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...SRF
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
750 AM EDT SUN JUL 15 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 520 AM EDT SUN JUL 15 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW TROF JUST E OF THE FCST
AREA. SHRA/TSRA THAT ACCOMPANIED THE TROF ACROSS THE AREA YESTERDAY
HAVE RECENTLY EXITED THE SE PORTION OF THE FCST AREA. IN ITS WAKE...
CALM WIND/CLEARING SKIES AND MOISTURE FROM YESTERDAY`S RAINFALL HAS
LED TO SOME FOG DEVELOPMENT. FOG WILL QUICKLY BURN OFF WITHIN A
COUPLE HRS AFTER SUNRISE. UPSTREAM...A MID LEVEL RIDGE IS NOSING
INTO THE DAKOTAS/WRN MN. AS THE RIDGE SHIFTS E TODAY...UPPER MI WILL
FALL UNDER HEIGHT RISES/DEEP LAYER QVECTOR DIVERGENCE. MUCH DRIER
AIR...MAINLY IN THE MID LEVELS PER UPSTREAM 00Z KINL/CWPL
SOUNDINGS...WILL WORK AGAINST ANY AFTN CONVECTIVE DEVELOPMENT
DESPITE LAKE BREEZES PROVIDING LOW-LEVEL FORCING. THE K-INDEX ON THE
00Z CWPL/KINL SOUNDINGS WAS -11/-14C RESPECTIVELY DUE TO VERY DRY
AIR AROUND 700MB (DWPT DEPRESSIONS WERE IN EXCESS OF 40C). SO...
GOING DRY FCST APPEARS ON TRACK DESPITE SOME HIGH RES GUIDANCE
CONTINUING TO SHOW ISOLD CONVECTION OVER THE SCNTRL THIS AFTN.
MIXING TO AROUND 800MB ON FCST SOUNDINGS SUPPORTS MAX TEMPS UPWARDS
OF AROUND 90F. LIGHT GRADIENT WIND WILL ALLOW LAKE BREEZES OFF
LAKE SUPERIOR AND LAKE MICHIGAN TO PROVIDE SOME COOLING LAKESIDE.
SHORTWAVE ENERGY EJECTING FROM THE TROF CURRENTLY OVER THE WRN
STATES WILL HEAD INTO SCNTRL CANADA TONIGHT. IN RESPONSE...LOW-LEVEL
JET WILL INCREASE TO 45-50KT INTO THE NRN PLAINS. THIS WILL LIKELY
SUPPORT A CLUSTER OF SHRA/TSRA ON THE NOSE OF THE LOW-LEVEL JET AND
ALONG EDGE OF CAP ACROSS ND INTO SRN MANITOBA/NRN MN AND NRN
ONTARIO. AT THIS TIME...IT STILL APPEARS LOW-LEVEL JET WILL BE W OF
THE AREA AT 12Z MON...SO DO NOT ANTICIPATE ANY CONVECTION LATE
TONIGHT...EXCEPT POSSIBLY OVER NW LAKE SUPERIOR/ISLE ROYALE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 520 AM EDT SUN JUL 15 2012
BY 12Z MONDAY THE FRONTAL BOUNDARY WOULD BE ACROSS LAKE SUPERIOR
/AS A WARM FRONT/...STRETCHING FROM THE SFC LOW SET UP FROM NW MN TO
CENTRAL SD. DEPENDING ON THE AMOUNT OF MIXING /UP TO AROUND 800MB AT
SAW/ A FEW GUSTS OF 30 TO 35KTS COULD BE POSSIBLE FROM LATE MORNING
THROUGH THE REMAINDER OF THE DAYTIME HOURS. IF CLOUD COVER DOES NOT
INHIBIT MIXING...THESE STRONGER GUSTS COULD BE POSSIBLE ACROSS THE
DOWNSLOPE LOCATIONS NEAR LAKE SUPERIOR GIVEN THE STRENGTHENING SW
FLOW. AS FOR THE OFFICIAL FCST...HAVE INCREASED WINDS QUITE A BIT
FROM THE PREVIOUS FORECAST...WITH GUSTS OF 20-25KTS ACROSS MUCH OF
THE CWA BY MID AFTERNOON.
THE RECORD HIGH TEMP FOR MONDAY AT WFO MQT IS 95 DEGREES...WHICH MAY
BE BROKEN BY THE END OF THE DAY. CURRENTLY GOING ONLY A COUPLE OF
DEGREES COOLER THAN THIS RECORD...WITH 850MB TEMPS OF 22-24C
ALLOWING SEVERAL SITES ACROSS THE INTERIOR W HALF OF UPPER MI
REACHING 95 OR ABOVE.
THE SFC LOW SHOULD PUSH ACROSS THE AREA MONDAY AFTERNOON
THROUGH TUESDAY NIGHT. THE TRACK IS STILL UNCERTAIN...WITH THE
14/18Z GFS AND 15/00Z NAM PUSHING THE SFC LOW ACROSS THE KEWEENAW
PENINSULA AND ACROSS LAKE SUPERIOR BY EARLY MONDAY EVENING. THE
FARTHER SOUTH 14/12Z ECMWF INDICATES A BROADER LOW...STRETCHING
ACROSS CENTRAL AND SOUTHERN UPPER MI MONDAY NIGHT. THE 14/12Z
CANADIAN IS BEYOND CONSENSUS FROM MONDAY AFTERNOON ON...TRACKING THE
SFC LOW ACROSS ONTARIO AND N LAKE SUPERIOR...AND WILL NOT BE USED IN
THIS FORECAST UNTIL IT MOVES BACK IN LINE WITH THE REMAINDER OF
AVAILABLE GUIDANCE WEDNESDAY MORNING.
HIGH PRESSURE OVER CENTRAL CANADA TUESDAY MORNING WILL SLOWLY SHIFT
SE ACROSS LAKE SUPERIOR AND UPPER MI TUESDAY THROUGH THURSDAY. THE
COOLEST AFTERNOON TEMPS LOOK TO BE WEDNESDAY...TOPPING OUT IN THE
70S...COOLEST NEAR LAKE SUPERIOR AS DRY COOL AIR REMAINS. 850MB
TEMPS WEDNESDAY WILL BE A COOL 10-12C. THE FCST FOR THE CWA WILL
REMAIN DRY TUESDAY NIGHT THROUGH FRIDAY NIGHT. EXPECT THE SFC HIGH
TO DRIFT E TO THE LOWER GREAT LAKES AND W QUEBEC BY DAYBREAK FRIDAY
AND THE NEW ENGLAND COAST FRIDAY NIGHT...WITH A RIDGE REMAINING
ACROSS THE UPPER GREAT LAKES REGION.
A RELATIVELY WEAK SFC LOW STRETCHING FROM CENTRAL CANADA THROUGH THE
CENTRAL PLAINS LOOKS TO BECOME BETTER ORGANIZED TO OUR W SATURDAY
NIGHT...AS A SERIES OF DISTURBANCES NEAR FROM W AND CENTRAL CANADA
AS 500MB RIDGE BECOMES SUPPRESSED ACROSS THE CENTRAL AND SOUTHERN
PLAINS. KEPT CHANCE POPS FOR SATURDAY...ALTHOUGH CONFIDENCE IS
MODERATE TO LOW FOR SPECIFICS THAT FAR OUT IN THIS FCST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 749 AM EDT SUN JUL 15 2012
FOG WHICH HAS LED TO HIGHLY VARIABLE VIS/CIGS OVERNIGHT WILL BURN
OFF OVER THE NEXT HR OR TWO...LEAVING VFR CONDITIONS TO PREVAIL
TODAY AND TONIGHT AT KIWD/KCMX/KSAW. THERE IS A SMALL POTENTIAL FOR
FOG TO REDEVELOP TONIGHT...BUT A SLOW INCREASE IN NEAR SFC WINDS WILL
WORK TO LIMIT POTENTIAL. ALSO...SOIL MOISTURE WHICH PLAYED A ROLE IN
FOG DEVELOPMENT OVERNIGHT WILL HAVE A CHANCE TO DRY OUT TODAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 520 AM EDT SUN JUL 15 2012
BIGGEST CONCERN IN THE SHORT TERM WILL BE FOG. 11-3.9MICRON
SATELLITE IMAGERY INDICATES FOG (PROBABLY NOT STRATUS) EXPANDING S
AND E FROM NCNTRL LAKE SUPERIOR. MORE FOG MAY BE DEVELOPING FROM
KEWEENAW BAY TOWARD MARQUETTE/MUNISING. WITH DEVELOPING MESO HIGH
PRES OVER THE LAKE TODAY...IT`S QUITE POSSIBLE FOG MAY END UP
SPREADING TO THE SHORELINES AROUND THE ENTIRE LAKE TODAY. ALWAYS
DIFFICULT TO FCST MARINE FOG...SO TRENDS WILL NEED TO MONITORED
CLOSELY TODAY FOR MOVEMENT/DEVELOPMENT/DISSIPATION OF FOG. ONCE
DAYLIGHT ARRIVES...VIS SATELLITE IMAGERY WILL PROVIDE A BETTER LOOK
AT HOW THE FOG IS EVOLVING. QUITE POSSIBLE DENSE FOG ADVY MAY NEED
TO BE ISSUED. FOR NOW...CARRIED FOG MENTION THRU EARLY AFTN OVER
MAINLY CNTRL AND ERN LAKE SUPERIOR.
OTHERWISE...WITH HIGH PRES DEVELOPING OVER LAKE SUPERIOR TODAY...
WINDS WILL BE UNDER 15KT. ALTHOUGH WINDS WILL BECOME S-SE TONIGHT IN
ADVANCE OF APPROACHING LOW PRES...SPEEDS SHOULD REMAIN 15KT OR LESS.
THERE IS SOME UNCERTAINTY IN WHERE WARM FRONT ASSOCIATED WITH THE
LOW WILL BE POSITIONED MON. AT THIS TIME...IT APPEARS THAT AT LEAST
SRN PORTIONS OF THE LAKE WILL SEE INCREASING S-SW WINDS MON UPWARDS
OF 20KT AS WARM FRONT DRIFTS N. AS LOW PASSES ACROSS THE AREA MON
NIGHT...A COLD FRONT WILL PUSH S...BRINGING A SHIFT TO NORTHERLY
WINDS UPWARDS OF 20KT INTO TUE MORNING. HIGH PRES WILL THEN BUILD
INTO THE UPPER GREAT LAKES DURING THE MIDWEEK PERIOD...RESULTING IN
WINDS UNDER 20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL NOON EDT TODAY FOR LSZ242>249-263>266.
LAKE MICHIGAN...NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
656 AM CDT SUN JUL 15 2012
.UPDATED FOR 12Z AVIATION DISCUSSION...
&&
.DISCUSSION...
ANOTHER WARM DAY IS EXPECTED TODAY...WITH POTENTIALLY RECORD
BREAKING HEAT ON MONDAY. ON TUESDAY A FRONTAL BOUNDARY WILL SLOWLY
SLIDE SOUTHEAST THROUGH THE REGION. THIS WILL BE ACCOMPANIED BY A
FEW SHOWERS AND THUNDERSTORMS...AS WELL AS SOME SLIGHTLY COOLER
WEATHER. HOWEVER...THIS BOUNDARY WILL STRUGGLE TO MAKE IT SOUTH OF
THE IA/MN BORDER...AND EVENTUALLY SWING BACK NORTHWARD AS A WARM
FRONT...SETTING THE STAGE FOR ANOTHER HEAT WAVE FOR THE UPCOMING
WEEKEND.
TODAY THROUGH TUESDAY...SYNOPTIC ANALYSIS VIA NORTH AMERICAN WATER
VAPOR IMAGERY AND 500MB HEIGHTS AND WINDS IDENTIFIED AN UPPER LEVEL
TROUGH ACROSS THE GREAT LAKES...WITH A DOWNSTREAM RIDGE CENTERED
OVER THE HIGH PLAINS. AN H850 THERMAL RIDGE WAS LONGITUDINALLY
ORIENTED ON THE LEE SIDE OF THE ROCKIES...WHILE AT THE SURFACE A LOW
PRESSURE SYSTEM WAS LOCATED IN EASTERN MONTANA. OVER THE NEXT COUPLE
OF DAYS...A SHORTWAVE WILL ROUND THE UPPER LEVEL RIDGE AND CAUSE THE
SURFACE LOW TO TRACK EASTWARD ACROSS THE US/CANADA BORDER. AS A
RESULT...SOUTHWEST FLOW AND THE H850 THERMAL RIDGE WILL ALSO
PROPAGATE EASTWARD AND BE LOCATED OVER THE UPPER MIDWEST BY MONDAY
AFTERNOON. FROM A CONCEPTUAL MODEL PERSPECTIVE...THIS IS THE PERFECT
SETUP FOR RECORD WARMTH. FROM A NUMERICAL MODEL PERSPECTIVE...THE NAM
HAS BEEN THE WARMEST WITH WIDESPREAD HUNDREDS ACROSS THE CWA. IN
FACT...FORECAST BURR SOUNDINGS FROM THE 15.00 NAM FOR MONDAY
AFTERNOON ARE ALMOST IDENTICAL TO THE OBSERVED 00Z MSP SOUNDING FROM
JULY 4 2012...WHICH YIELDED A HIGH TEMP OF 102 AT KMSP.
THEREFORE...TEMPERATURES WERE INCREASED A COUPLE OF DEGREES FROM THE
PREVIOUS FORECAST. AFTERNOON MIXING SHOULD KEEP DEWPOINTS IN THE
UPPER 50S TO LOWER 60S...SO HEAT INDICES WILL NOT EXCEED THE ACTUAL
AIR TEMPERATURE BY MORE THAN A FEW DEGREES. THEREFORE HAVE ISSUED A
HEAT ADVISORY BEGINNING LATE MONDAY MORNING AND LASTING THROUGH LATE
MONDAY EVENING. AS THE AFOREMENTIONED SURFACE LOW CONTINUES TOWARDS
THE GREAT LAKES MONDAY NIGHT...A DIFFUSE COLD FRONT WILL GRADUALLY
SLIDE SOUTHWARD THROUGH THE REGION. THE H850 THERMAL RIDGE WILL TAKE
ON A MORE EAST/WEST ORIENTATION WITH THE WARMEST TEMPERATURES SOUTH
OF THE CWA. ALSO...WINDS WILL WEAKEN SLIGHTLY SO NOT EXPECTING AS
MUCH DYNAMICALLY INDUCED BOUNDARY LAYER HEATING DURING AFTERNOON
HOURS. WITH THAT SAID...TEMPERATURES WILL STILL REACH THE MID 90S
SOUTH OF THE FRONT ACROSS FAR SOUTHERN MINNESOTA...SO THE HEAT
ADVISORY MAY NEED TO BE EXTENDED TO COVER THIS AREA. AS FAR AS
PRECIP GOES...WARM AIR ALOFT SHOULD KEEP THE PRECIP CHANCES ACROSS
THE NORTH FOR SUNDAY AND MONDAY. AS THE FRONTAL BOUNDARY SAGS
SOUTHWARD...PRECIP CHANCES WILL INCREASE ALONG IT. LOW LEVEL
CONVERGENCE IS RELATIVELY WEAK...AND THERE IS LITTLE IN THE WAY OF
UPPER LEVEL FORCING. NONE THE LESS...A FEW ISOLATED SHOWERS AND
THUNDERSTORMS WILL LIKELY PERCOLATE ALONG THIS BOUNDARY...WITH
ISOLATED SEVERE WIND AND HAIL POSSIBLE.
WEDNESDAY THROUGH SATURDAY...AS MENTIONED EARLIER...THIS BOUNDARY
WILL STRUGGLE TO PUSH SOUTH OF THE IA/MN BORDER. BY MIDWEEK ANOTHER
UPPER LEVEL WAVE WILL CROSS THE IDAHO PANHANDLE...RESULTING IN
ANOTHER LEESIDE LOW IN SOUTHERN ALBERTA. THIS WILL DRAW THE
LINGERING FRONTAL BOUNDARY BACK NORTHWARD AS A WARM FRONT. THE
PRECIP WILL STILL REMAIN FOCUSED ALONG THIS BOUNDARY...WITH BETTER
CHANCES NEAR THE MN/DAKOTA BORDER. THE UPPER LEVEL RIDGE WILL BUILD
ACROSS THE CENTRAL CONUS...WITH HOT AND HUMID CONDITIONS RETURNING
TO THE REGION BY THE END OF THE WEEK. GIVEN THE SYNOPTIC
SETUP...INCREASED TEMPS A FEW DEGREES ABOVE GUIDANCE IN THE
EXTENDED. SO IN SUMMATION...LOOKS LIKE THE DRY AND WARM CONDITIONS
WILL STICK AROUND FOR AT LEAST THE NEXT 7 TO 10 DAYS.
&&
.AVIATION.../12Z TAF ISSUANCE/
HIGH PRESSURE IS CENTERED OVER CENTRAL MINNESOTA EARLY THIS
MORNING WITH CALM WINDS AND PATCHY FOG/HAZE AT SOME OF THE TAF
SITES. A VERY BENIGN DAY AND EVENING IN STORE FOR AVIATION
INTERESTS. NAM CU RULE INDICATES SCT050 THIS AFTERNOON IN WESTERN
WISCONSIN BUT RAP CU RULE INDICATES NO CU. WENT WITH FEW050 KSTC
EASTWARD. HIGH PRESSURE WILL EXIT THE AREA AND BY LATE MORNING
WILL SEE SE WINDS AROUND THE 10 KT RANGE INCREASING IN THE
AFTERNOON WITH...KAXN AND KRWF GUSTING UP TO 20 KNOTS IN THE
AFTERNOON. OTHER SITES WILL SEE A LIGHT WEST WIND BACK TO THE
SOUTH AND SOUTHEAST IN THE AFTERNOON WITH SPEEDS LESS THAN 10
KNOTS. FOR TONIGHT SOUTHEAST WINDS WILL REMAIN AROUND 10KTS. FOR
MONDAY SKC WITH SOUTHWEST WINDS NEAR 20 KTS.
KMSP...VFR THROUGH THE PERIOD. LIGHT WINDS BECOMING SOUTH SOUTHEAST
8-10 KNOTS SUNDAY AFTERNOON WITH A FEW GUSTS TO 13KTS.
OUTLOOK...
MONDAY...VFR. HOT. WINDS S-SW 15-20 KTS.
TUESDAY...VFR. CHANCE OF TSRA WITH FRONTAL PASSAGE. WINDS
BECOMING NE 5-10 KTS.
WEDNESDAY...VFR. EAST WINDS 5 TO 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...HEAT ADVISORY FROM 11 AM TO 9 PM CDT MONDAY FOR ANOKA-BENTON-
BLUE EARTH-BROWN-CARVER-CHIPPEWA-CHISAGO-DAKOTA-DOUGLAS-
FARIBAULT-FREEBORN-GOODHUE-HENNEPIN-ISANTI-KANABEC-
KANDIYOHI-LAC QUI PARLE-LE SUEUR-MARTIN-MCLEOD-MEEKER-MILLE
LACS-MORRISON-NICOLLET-POPE-RAMSEY-REDWOOD-RENVILLE-RICE-
SCOTT-SHERBURNE-SIBLEY-STEARNS-STEELE-STEVENS-SWIFT-TODD-
WASECA-WASHINGTON-WATONWAN-WRIGHT-YELLOW MEDICINE.
WI...HEAT ADVISORY FROM 11 AM TO 9 PM CDT MONDAY FOR BARRON-CHIPPEWA-
DUNN-EAU CLAIRE-PEPIN-PIERCE-POLK-RUSK-ST. CROIX.
&&
$$
JRB/DRL
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1107 AM EDT SUN JUL 15 2012
.SYNOPSIS...
A SOUTHWESTERLY FLOW WILL BRING INCREASINGLY HUMID AIR INTO THE
REGION TODAY ALONG WITH SOME SHOWERS AND THUNDERSTORMS. A FEW STORMS
WILL CONTAIN LOCALLY HEAVY RAINFALL...BUT ANY HEAVIER RAIN AMOUNTS
WILL BE SPOTTY. A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE LOWER
GREAT LAKES MONDAY WITH MAINLY DRY CONDITIONS.
&&
.NEAR TERM /THROUGH TONIGHT/...
TODAY THERE WILL BE SOME SPOTTY HEAVY RAIN AS CONVECTION MOVES
SLOWLY ACROSS THE AREA...HOWEVER COVERAGE OF THE BETTER RAINS WILL
BE TOO SPARSE TO OFFER MUCH RELIEF TO THE ONGOING DROUGHT. AS IS
OFTEN THE CASE...MODEL GUIDANCE IS STRUGGLING A BIT WITH
CONVECTION...WITH A FAIR SPREAD OF QPF SOLUTIONS BETWEEN THE
NAM/RGEM/GFS/EUROPEAN/SREF. THE HRRR HAS ALSO BEEN INCONSISTENT RUN
TO RUN ON SPECIFICS.
TWO MAIN AREAS OF RAIN ARE MOVING THROUGH THE AREA THIS MORNING. THE
FIRST IS NOW MOVING INTO CENTRAL NY AND OUT OF OUR CWA...WITH A
SECOND AREA OF SHOWERS MOVING INTO WESTERN NY. BOTH OF THESE AREAS
ARE WEAKENING IN INTENSITY AND AREAL COVERAGE...EXCEPT FOR THE
PORTION MOVING THROUGH CHAUTAUQUA COUNTY. EXPECT THIS TREND TO
CONTINUE THROUGH EARLY AFTERNOON...WITH HEAVY RAIN CONFINED TO THE
WESTERN SOUTHERN TIER...AND MUCH LIGHTER SHOWERS FOR THE REST OF THE
AREA. THE NORTH COUNTRY WILL REMAIN DRY THROUGH EARLY AFTERNOON
BEFORE A FEW SHOWERS POP UP LATER ON.
AS HAS BEEN THE CASE THE PAST TWO DAYS...THE FLOW ALOFT WILL BE
FAIRLY LIGHT. HOWEVER...TODAY THE PRECIPITABLE WATER VALUES WILL BE
SIGNIFICANTLY GREATER...BETWEEN 1.75 INCHES AND 2.00 INCHES. WITH
ANOMALOUSLY HIGH MOISTURE AVAILABLE IN THE COLUMN AND RELATIVELY
SLOW STORM MOTION...ANY OF THE STRONGER STORMS WILL LAY DOWN SOME
HEAVY RAIN IN ISOLATED AREAS WITH LOCAL AMOUNTS OF SEVERAL INCHES.
DESPITE THE LOCALLY HEAVY RAIN...MOST LOCATIONS WILL SEE LESS THAN A
QUARTER INCH WHICH WILL DO LITTLE OR NOTHING TO ALLEVIATE THE
PARCHED SOIL CONDITIONS.
THE UPPER TROF WILL SLOWLY MOVE ACROSS THE REGION BY THIS
EVENING...BUT BY THIS TIME...DRIER AIR SHOULD BE IN PLACE IN THE
BOUNDARY LAYER...SO SHOWER AND THUNDERSTORMS SHOULD TAPER OFF
AND/OR EXIT EAST. THE WEAK FRONTAL BOUNDARY ASSOCIATED WITH THE
TROF WILL NOT ACTUALLY CROSS THE REGION TONIGHT. THIS WILL KEEP
MOIST AIR IN PLACE...AND DEPENDING ON RAINFALL TODAY COULD RESULT
IN AREAS OF FOG TONIGHT.
TEMPERATURES WILL BE A BIT COOLER TODAY THAN THEY WERE
YESTERDAY...HOWEVER INCREASED MOISTURE WILL MAKE IT FEEL MORE MUGGY.
HIGHS SHOULD BE IN THE LOWER 80S NORTH OF THE THRU-WAY...BUT MAY
STAY IN THE UPPER 70S IN THE SOUTHERN TIER WHERE CLOUDS AND SHOWERS
SHOULD LIMIT TEMPERATURES A BIT. FOR TONIGHT...LOWS WILL RANGE FROM
THE LOWER 60S IN THE SOUTHERN TIER...TO AROUND 70 IN THE
BUFFALO/ROCHESTER METRO AREAS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
DURING THE COURSE OF MONDAY...THE AXIS OF A WEAK UPPER LEVEL TROUGH
DRAPED FROM THE NEW ENGLAND COAST TO THE MID ATLANTIC STATES WILL
SLIDE OUT TO SEA...ALLOWING THE LEADING EDGE OF BROAD/FLAT UPPER
RIDGING TO EDGE NORTHEAST INTO THE LOWER LAKES. MEANWHILE AT THE
SURFACE...LINGERING WEAK TROUGHINESS ACROSS THE LOWER LAKES AT THE
START OF THE DAY WILL ALSO SLIDE EASTWARD...GIVING WAY TO MODEST LOW
LEVEL RIDGING DURING THE AFTERNOON.
GIVEN THESE DEVELOPMENTS...EXPECT THAT MONDAY SHOULD LARGELY BE
ANOTHER DRY AND HOT/HUMID DAY...WITH 850 MB TEMPS OF +16C/+17C AGAIN
SUPPORTING WIDESPREAD HIGHS IN THE UPPER 80S/LOWER 90S GIVEN WHAT
SHOULD BE A DECENT AMOUNT OF SUNSHINE. WHILE BOTH THE GFS AND ECMWF
BOTH SPIT OUT SOME LIGHT QPF ACROSS THE AREA PRIOR TO THE DEPARTURE
OF THE LOW LEVEL TROUGH...BELIEVE THAT THIS IS OVERDONE GIVEN ONLY
WEAK LINGERING FORCING AND FAIRLY WARM MID LEVEL TEMPS...WHICH
SHOULD HELP TO KEEP ANY PRECIP ISOLATED IN COVERAGE AT BEST. HAVE
THEREFORE KEPT POPS AT THE VERY LOW END OF THE SLIGHT CHANCE RANGE
OR BELOW ON MONDAY.
MONDAY NIGHT...BROAD/FLAT UPPER RIDGING WILL REMAIN INTACT ACROSS
MUCH OF THE AREA...WHILE A SLOW MOVING COLD FRONTAL BOUNDARY OVER
CENTRAL ONTARIO PROVINCE SAGS SOUTHWARD INTO THE UPPER LAKES AND
SOUTHERN ONTARIO. WHILE I CANNOT TOTALLY RULE OUT SOME ASSOCIATED
ISOLATED CONVECTION SNEAKING INTO THE SAINT LAWRENCE VALLEY TOWARD
DAYBREAK ON TUESDAY...IT DOES APPEAR THAT THE FRONT WILL REMAIN FAR
ENOUGH TO OUR NORTH AND THAT WE WILL REMAIN CAPPED ENOUGH FOR MAINLY
DRY WEATHER TO CONTINUE AREAWIDE. WITH NO AIRMASS CHANGE AND AN
INCREASING SOUTHWESTERLY LOW LEVEL FLOW EXPECTED WITH TIME IN
RESPONSE TO THE APPROACHING FRONT...EXPECT DOWNRIGHT SULTRY
TEMPERATURES WITH OVERNIGHT LOWS RANGING FROM THE MID AND UPPER 60S
ACROSS INTERIOR SECTIONS...TO THE LOWER 70S ACROSS THE LAKE PLAINS.
ON TUESDAY...THE AFOREMENTIONED FRONT WILL CONTINUE TO SLOWLY SAG
SOUTH TOWARD OUR REGION...WITH NOTABLE TIMING DIFFERENCES SEEN
AMONGST THE VARIOUS GUIDANCE PACKAGES. THE 00Z NAM IS AN EXTREMELY
FAST OUTLIER THAT BRINGS THE FRONT COMPLETELY THROUGH THE AREA BY
THE END OF THE DAY...WHICH SEEMS HIGHLY UNLIKELY GIVEN ITS
NEAR-PARALLEL ORIENTATION TO THE UPPER LEVEL FLOW...NOT TO MENTION
THE PROPENSITY FOR SUCH BOUNDARIES TO GET HUNG UP ACROSS THE LOWER
LAKES AT THIS TIME OF YEAR. FOR THIS REASON...HAVE COMPLETELY
DISREGARDED THIS SOLUTION. OF THE REMAINING GUIDANCE...THE GFS
REMAINS A BIT ON THE FASTER SIDE THOUGH NOT AS FAST AS ITS PREVIOUS
RUNS...BRINGING THE BOUNDARY INTO NORTHERN NEW YORK/LAKE ONTARIO BY
THE END OF THE DAY...WHICH IS CLOSE ENOUGH TO GENERATE SOME
CONVECTION ACROSS BOTH THE NORTH COUNTRY AND NIAGARA/ORLEANS
COUNTIES. MEANWHILE...THE VERY CONSISTENT ECMWF REMAINS A TOUCH
SLOWER THAN THE GFS AND ONLY BRINGS A RISK OF CONVECTION INTO THE
NORTH COUNTRY...WITH THE 00Z GEM GLOBAL A BIT SLOWER STILL. AT THIS
JUNCTURE...FEEL A COMPROMISE BETWEEN THE GFS/ECMWF REPRESENTS THE
MOST PLAUSIBLE SCENARIO...WHICH WOULD BRING AT LEAST A LOW TO MODEST
CHANCE OF CONVECTION TO LAKE ONTARIO AND THE NORTH COUNTRY BY LATE
IN THE DAY.
FURTHER TO THE SOUTH...CONDITIONS SHOULD REMAIN DRY THROUGH THE DAY
ON TUESDAY...THANKS TO BOTH GREATER DISTANCE FROM THE FRONT AND
STRONG MID LEVEL CAPPING...AS EVEN HOTTER AIR RIDES EAST ALONG THE
PERIPHERY OF THE MAIN UPPER LEVEL RIDGE. A CONSENSUS OF THE
GFS/GEM/ECMWF SUPPORTS 850 MB TEMPS RISING TO THE +20/+21C RANGE
AREAWIDE DURING THE COURSE OF TUESDAY...AND THIS COUPLED WITH GOOD
MIXING AND A DECENT AMOUNT OF SUN WILL LIKELY RESULT IN A REAL
SCORCHER OF A DAY SOUTH OF LAKE ONTARIO. AT THIS POINT...WIDESPREAD
HIGHS IN THE LOWER TO MID 90S APPEAR TO BE A SOLID BET...WITH UPPER
90S NOT AT ALL OUT OF THE QUESTION FOR THE NORMAL HOT SPOTS IN
INTERIOR PORTIONS OF OUR CWA. COUPLED WITH DEWPOINTS IN THE MID TO
UPPER 60S...SOME LOCATIONS SOUTH OF LAKE ONTARIO COULD SEE APPARENT
TEMPERATURES REACHING THE 100 DEGREE MARK TUESDAY AFTERNOON...WHICH
WOULD NECESSITATE THE ISSUANCE OF A HEAT ADVISORY. AS IT REMAINS FAR
TOO EARLY FOR THAT...FOR NOW WILL JUST MENTION THIS POTENTIAL IN THE
HWO. EAST OF LAKE ONTARIO...SOMEWHAT GREATER AMOUNTS OF CLOUD COVER
WILL LIKELY HELP KEEP TEMPS A LITTLE COOLER...THOUGH IT SHOULD STILL
BE UNCOMFORTABLY HOT EVEN THERE WITH HIGHS IN THE UPPER 80S TO LOWER
90S.
TUESDAY NIGHT AND WEDNESDAY...THE COLD FRONT WILL SLOWLY SAG SOUTH
ACROSS THE REGION...BRINGING A RISK OF CONVECTION TO THE ENTIRE
CWA...ALONG WITH THE POTENTIAL FOR LOCALLY HEAVY RAINFALL GIVEN
PRECIPITABLE WATER VALUES IN THE VICINITY OF AROUND 2 INCHES. AT
THIS JUNCTURE...THE TIMING OF THIS BOUNDARY REMAINS AN ISSUE WITH
THE GFS REMAINING THE FASTEST...THE CANADIAN THE SLOWEST...AND THE
ECMWF IN THE MIDDLE...WITH FROPA TIMES RANGING BETWEEN EARLY TO MID
WEDNESDAY MORNING AND WEDNESDAY AFTERNOON. GIVEN THAT THIS FRONT
APPEARS TO BE ANAFRONTAL WITH MOST OF ITS PRECIP FALLING BEHIND THE
ACTUAL SURFACE BOUNDARY...THIS MEANS THAT ANY ASSOCIATED CONVECTION
COULD END AS EARLY AS SOMETIME WEDNESDAY MORNING...OR AS LATE AS THE
END OF THE DAY WEDNESDAY.
GIVEN THE CONTINUED UNCERTAINTIES IN TIMING AND THE AFOREMENTIONED
NEAR-PARALLEL ORIENTATION OF THE FRONT TO THE UPPER FLOW...FEEL IT
IS BEST TO SLOW DOWN THE TIMING OF THIS FRONT AND ITS ASSOCIATED
CONVECTION A BIT FROM THE PREVIOUS FORECAST...FAVORING A COMPROMISE
SOLUTION ALONG THE LINES OF THE ECMWF. AS A RESULT...CHANCES FOR
CONVECTION WILL BE IN PLACE FROM TUESDAY NIGHT THROUGH WEDNESDAY
MORNING ACROSS THE ENTIRE AREA...BEFORE DIMINISHING FROM NORTH TO
SOUTH DURING THE COURSE OF WEDNESDAY AFTERNOON. TEMPERATURE-WISE...
EXPECT ANOTHER SULTRY NIGHT IN ADVANCE OF THE FRONT TUESDAY NIGHT
WITH LOWS AGAIN RANGING FROM THE UPPER 60S TO LOWER 70S...FOLLOWED
BY SOMEWHAT COOLER HIGHS IN THE UPPER 70S TO MID 80S ON WEDNESDAY
GIVEN THE PASSAGE OF THE FRONT AND ITS ASSOCIATED CLOUD COVER/PRECIP.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
SIMPLY PUT...SPRAWLING CANADIAN HIGH PRESSURE WILL BUILD SOUTHEAST
ACROSS THE GREAT LAKES AND NORTHEAST DURING THIS PERIOD...BRINGING A
RETURN TO DRY WEATHER ALONG WITH A COOLER AND NOTICEABLY LESS HUMID
AIRMASS.
IN TERMS OF ACTUAL TEMPERATURES...EXPECT DAILY HIGHS TO FALL BACK
INTO THE MID 70S TO LOWER 80S FOR BOTH THURSDAY AND FRIDAY...BEFORE
WARMING BACK INTO THE LOWER TO MID 80S ON SATURDAY AS WARMING
COMMENCES ALOFT. MEANWHILE...NIGHTTIME LOWS WILL RANGE IN THE MID
50S TO LOWER 60S ALL THREE NIGHTS. HUMIDITY LEVELS WILL ALSO BE MUCH
MORE COMFORTABLE...WITH DEWPOINTS REMAINING IN THE MID TO UPPER 50S
DURING THE BULK OF THE PERIOD.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
AN AREA OF SHOWERS WILL CONTINUE TO MOVE EAST ACROSS THE REGION
THROUGH EARLY AFTERNOON. THUNDERSTORM COVERAGE IS VERY SPARSE
RIGHT NOW WITH JUST SOME STRIKES NEAR THE PA SATE LINE WHICH WILL
IMPACT KJHW FOR THE NEXT HOUR OR TWO. THIS AFTERNOON WITH SOME
LIMITED DAYTIME HEATING EXPECT SCATTERED STORMS TO DEVELOP ONCE
AGAIN...MAINLY ACROSS THE SOUTHERN TIER INTO THE FINGER LAKES AND
CENTRAL NY. EXPECT MAINLY VFR AND MVFR CONDITIONS MOST OF THE TIME
IN THE LIGHT RAIN...BUT ANY EMBEDDED THUNDERSTORMS WILL PRODUCE
LOCALIZED IFR.
AFTERWARD...EXPECT A GENERAL CLEARING TREND FROM WEST TO EAST
LATE THIS AFTERNOON AND EVENING. THIS SHOULD RESULT IN MAINLY VFR
CONDITIONS...BUT THERE WILL BE AN INCREASING CHANCE FOR FOG
OVERNIGHT. THE COMBINATION OF LIGHT WINDS AND LINGERING BOUNDARY
LAYER MOISTURE MAY RESULT IN FAIRLY WIDESPREAD FOG. WINDS MAY
LIMIT HOW LOW VSBY DROPS AT BUF/IAG/ROC/ART...BUT DENSE FOG MAY
DEVELOP AT JHW...IN A RELATIVELY LIGHT FLOW.
OUTLOOK...
MONDAY AND TUESDAY...MAINLY VFR.
TUESDAY NIGHT...AREAS OF MVFR IN SCATTERED -SHRA/-TSRA.
WEDNESDAY...BECOMING VFR.
THURSDAY...VFR.
&&
.MARINE...
HIGH PRESSURE WILL REMAIN ANCHORED ALONG THE MID ATLANTIC COAST
THROUGH EARLY NEXT WEEK. MEANWHILE A WEAK TROUGH WILL APPROACH THE
LOWER LAKES TODAY AND ALLOW SOUTHWEST WINDS TO INCREASE
SOMEWHAT TO THE 10-15 KNOT RANGE...WITH THE STRONGEST WINDS ON LAKE
ERIE. EXPECT CONDITIONS TO REMAIN BELOW SMALL CRAFT CRITERIA...BUT
WAVES MAY GET A LITTLE CHOPPY ON LAKE ERIE.
A RIDGE OF HIGH PRESSURE WILL NOSE INTO THE LOWER LAKES MONDAY WITH
RELATIVELY LIGHT WINDS. SOUTHWEST WINDS WILL PICK UP AGAIN TUESDAY
AHEAD OF A STRONGER COLD FRONT...ESPECIALLY ON LAKE ERIE WHERE
CONDITIONS MAY APPROACH SMALL CRAFT ADVISORY CRITERIA.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL/HITCHCOCK
MARINE...APFFEL/JJR
AREA FORECAST DISCUSSION
NWS BUFFALO NY
757 AM EDT SUN JUL 15 2012
.SYNOPSIS...
A SOUTHWESTERLY FLOW WILL BRING INCREASINGLY HUMID AIR INTO THE REGION
TODAY ALONG WITH SOME SHOWERS AND THUNDERSTORMS. A FEW STORMS WILL
CONTAIN LOCALLY HEAVY RAINFALL...BUT ANY HEAVIER RAIN AMOUNTS WILL
BE SPOTTY. A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE LOWER GREAT
LAKES MONDAY WITH MAINLY DRY CONDITIONS.
&&
.NEAR TERM /THROUGH TONIGHT/...
TODAY WILL BRING AN OPPORTUNITY FOR DROUGHT RELIEF...HOWEVER SHOWERS
AND THUNDERSTORMS WILL BE PATCHY IN NATURE...SO MANY COULD MISS
OUT. AS IS OFTEN THE CASE...MODEL GUIDANCE IS STRUGGLING A BIT
WITH CONVECTION...WITH A FAIR SPREAD OF QPF SOLUTIONS BETWEEN THE
NAM/RGEM/GFS/EUROPEAN/SREF. THE HRRR HAS ALSO BEEN INCONSISTENT
RUN TO RUN ON SPECIFICS.
DESPITE THE DIFFERENCES...THERE SEEMS TO BE A FAIR CONSENSUS THAT THE MOST
SIGNIFICANT RAINS WILL COME LATE MORNING AND EARLY AFTERNOON.
EARLY MORNING RADAR TRENDS ARE BEGINNING TO SUPPORT THIS...AS
SHOWERS AND THUNDERSTORMS EXPAND ACROSS LAKE ERIE AND SOUTHERN
ONTARIO. IT APPEARS THE TRIGGER TO THIS IS A COMBINATION OF MOIST
AIR IN THE BOUNDARY LAYER...AND THE CYCLONIC FLOW OUT AHEAD OF AN
APPROACHING UPPER TROF. FOLLOWING MODEL GUIDANCE AND RADAR
TRENDS...IT APPEARS STEADIEST RAINS WILL BE SOUTH OF LAKE
ONTARIO...ESPECIALLY IN THE SOUTHERN TIER AND FINGER LAKES
REGIONS.
AS HAS BEEN THE CASE THE PAST TWO DAYS...THE FLOW ALOFT WILL BE
FAIRLY LIGHT. HOWEVER...TODAY THE PRECIPITABLE WATER VALUES WILL BE
SIGNIFICANTLY GREATER...BETWEEN 1.75 INCHES AND 2.00 INCHES. IF IT
WERE NOT FOR THE VERY DRY CONDITIONS IN PLACE...THIS WOULD POSE A
GREATER FLOODING THREAT...BUT EVEN STILL THERE IS A REAL POTENTIAL
FOR FLOODING ALBEIT LOCALIZED. HAVE THE MOST CONCERN FOR THE
SOUTHERN TIER...WHERE TERRAIN CAN FUNNEL RUNOFF. DUE TO THE HIT OR
MISS NATURE OF CONVECTION...MEAN QPFS COULD BE A BIT MISLEADING.
WHILE BASIN-WIDE QPF FORECASTS RANGE FROM NEAR A HALF INCH EXPECTED
IN THE SOUTHERN TIER DOWN TO A TENTH OF AN INCH NORTH AND WEST OF
I-90...RAINFALL BY LOCATION SHOULD VARY SIGNIFICANTLY.
THE UPPER TROF WILL SLOWLY MOVE ACROSS THE REGION BY THIS
EVENING...BUT BY THIS TIME...DRIER AIR SHOULD BE IN PLACE IN THE
BOUNDARY LAYER...SO SHOWER AND THUNDERSTORMS SHOULD TAPER OFF
AND/OR EXIT EAST. THE WEAK FRONTAL BOUNDARY ASSOCIATED WITH THE
TROF WILL NOT ACTUALLY CROSS THE REGION TONIGHT. THIS WILL KEEP
MOIST AIR IN PLACE...AND DEPENDING ON RAINFALL TODAY COULD RESULT
IN AREAS OF FOG TONIGHT.
TEMPERATURES WILL BE A BIT COOLER TODAY THAN THEY WERE
YESTERDAY...HOWEVER INCREASED MOISTURE WILL MAKE IT FEEL MORE MUGGY.
HIGHS SHOULD BE IN THE LOWER 80S NORTH OF THE THRU-WAY...BUT MAY
STAY IN THE UPPER 70S IN THE SOUTHERN TIER WHERE CLOUDS AND SHOWERS
SHOULD LIMIT TEMPERATURES A BIT. FOR TONIGHT...LOWS WILL RANGE FROM
THE LOWER 60S IN THE SOUTHERN TIER...TO AROUND 70 IN THE
BUFFALO/ROCHESTER METRO AREAS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
DURING THE COURSE OF MONDAY...THE AXIS OF A WEAK UPPER LEVEL TROUGH
DRAPED FROM THE NEW ENGLAND COAST TO THE MID ATLANTIC STATES WILL
SLIDE OUT TO SEA...ALLOWING THE LEADING EDGE OF BROAD/FLAT UPPER
RIDGING TO EDGE NORTHEAST INTO THE LOWER LAKES. MEANWHILE AT THE
SURFACE...LINGERING WEAK TROUGHINESS ACROSS THE LOWER LAKES AT THE
START OF THE DAY WILL ALSO SLIDE EASTWARD...GIVING WAY TO MODEST LOW
LEVEL RIDGING DURING THE AFTERNOON.
GIVEN THESE DEVELOPMENTS...EXPECT THAT MONDAY SHOULD LARGELY BE
ANOTHER DRY AND HOT/HUMID DAY...WITH 850 MB TEMPS OF +16C/+17C AGAIN
SUPPORTING WIDESPREAD HIGHS IN THE UPPER 80S/LOWER 90S GIVEN WHAT
SHOULD BE A DECENT AMOUNT OF SUNSHINE. WHILE BOTH THE GFS AND ECMWF
BOTH SPIT OUT SOME LIGHT QPF ACROSS THE AREA PRIOR TO THE DEPARTURE
OF THE LOW LEVEL TROUGH...BELIEVE THAT THIS IS OVERDONE GIVEN ONLY
WEAK LINGERING FORCING AND FAIRLY WARM MID LEVEL TEMPS...WHICH
SHOULD HELP TO KEEP ANY PRECIP ISOLATED IN COVERAGE AT BEST. HAVE
THEREFORE KEPT POPS AT THE VERY LOW END OF THE SLIGHT CHANCE RANGE
OR BELOW ON MONDAY.
MONDAY NIGHT...BROAD/FLAT UPPER RIDGING WILL REMAIN INTACT ACROSS
MUCH OF THE AREA...WHILE A SLOW MOVING COLD FRONTAL BOUNDARY OVER
CENTRAL ONTARIO PROVINCE SAGS SOUTHWARD INTO THE UPPER LAKES AND
SOUTHERN ONTARIO. WHILE I CANNOT TOTALLY RULE OUT SOME ASSOCIATED
ISOLATED CONVECTION SNEAKING INTO THE SAINT LAWRENCE VALLEY TOWARD
DAYBREAK ON TUESDAY...IT DOES APPEAR THAT THE FRONT WILL REMAIN FAR
ENOUGH TO OUR NORTH AND THAT WE WILL REMAIN CAPPED ENOUGH FOR MAINLY
DRY WEATHER TO CONTINUE AREAWIDE. WITH NO AIRMASS CHANGE AND AN
INCREASING SOUTHWESTERLY LOW LEVEL FLOW EXPECTED WITH TIME IN
RESPONSE TO THE APPROACHING FRONT...EXPECT DOWNRIGHT SULTRY
TEMPERATURES WITH OVERNIGHT LOWS RANGING FROM THE MID AND UPPER 60S
ACROSS INTERIOR SECTIONS...TO THE LOWER 70S ACROSS THE LAKE PLAINS.
ON TUESDAY...THE AFOREMENTIONED FRONT WILL CONTINUE TO SLOWLY SAG
SOUTH TOWARD OUR REGION...WITH NOTABLE TIMING DIFFERENCES SEEN
AMONGST THE VARIOUS GUIDANCE PACKAGES. THE 00Z NAM IS AN EXTREMELY
FAST OUTLIER THAT BRINGS THE FRONT COMPLETELY THROUGH THE AREA BY
THE END OF THE DAY...WHICH SEEMS HIGHLY UNLIKELY GIVEN ITS
NEAR-PARALLEL ORIENTATION TO THE UPPER LEVEL FLOW...NOT TO MENTION
THE PROPENSITY FOR SUCH BOUNDARIES TO GET HUNG UP ACROSS THE LOWER
LAKES AT THIS TIME OF YEAR. FOR THIS REASON...HAVE COMPLETELY
DISREGARDED THIS SOLUTION. OF THE REMAINING GUIDANCE...THE GFS
REMAINS A BIT ON THE FASTER SIDE THOUGH NOT AS FAST AS ITS PREVIOUS
RUNS...BRINGING THE BOUNDARY INTO NORTHERN NEW YORK/LAKE ONTARIO BY
THE END OF THE DAY...WHICH IS CLOSE ENOUGH TO GENERATE SOME
CONVECTION ACROSS BOTH THE NORTH COUNTRY AND NIAGARA/ORLEANS
COUNTIES. MEANWHILE...THE VERY CONSISTENT ECMWF REMAINS A TOUCH
SLOWER THAN THE GFS AND ONLY BRINGS A RISK OF CONVECTION INTO THE
NORTH COUNTRY...WITH THE 00Z GEM GLOBAL A BIT SLOWER STILL. AT THIS
JUNCTURE...FEEL A COMPROMISE BETWEEN THE GFS/ECMWF REPRESENTS THE
MOST PLAUSIBLE SCENARIO...WHICH WOULD BRING AT LEAST A LOW TO MODEST
CHANCE OF CONVECTION TO LAKE ONTARIO AND THE NORTH COUNTRY BY LATE
IN THE DAY.
FURTHER TO THE SOUTH...CONDITIONS SHOULD REMAIN DRY THROUGH THE DAY
ON TUESDAY...THANKS TO BOTH GREATER DISTANCE FROM THE FRONT AND
STRONG MID LEVEL CAPPING...AS EVEN HOTTER AIR RIDES EAST ALONG THE
PERIPHERY OF THE MAIN UPPER LEVEL RIDGE. A CONSENSUS OF THE
GFS/GEM/ECMWF SUPPORTS 850 MB TEMPS RISING TO THE +20/+21C RANGE
AREAWIDE DURING THE COURSE OF TUESDAY...AND THIS COUPLED WITH GOOD
MIXING AND A DECENT AMOUNT OF SUN WILL LIKELY RESULT IN A REAL
SCORCHER OF A DAY SOUTH OF LAKE ONTARIO. AT THIS POINT...WIDESPREAD
HIGHS IN THE LOWER TO MID 90S APPEAR TO BE A SOLID BET...WITH UPPER
90S NOT AT ALL OUT OF THE QUESTION FOR THE NORMAL HOT SPOTS IN
INTERIOR PORTIONS OF OUR CWA. COUPLED WITH DEWPOINTS IN THE MID TO
UPPER 60S...SOME LOCATIONS SOUTH OF LAKE ONTARIO COULD SEE APPARENT
TEMPERATURES REACHING THE 100 DEGREE MARK TUESDAY AFTERNOON...WHICH
WOULD NECESSITATE THE ISSUANCE OF A HEAT ADVISORY. AS IT REMAINS FAR
TOO EARLY FOR THAT...FOR NOW WILL JUST MENTION THIS POTENTIAL IN THE
HWO. EAST OF LAKE ONTARIO...SOMEWHAT GREATER AMOUNTS OF CLOUD COVER
WILL LIKELY HELP KEEP TEMPS A LITTLE COOLER...THOUGH IT SHOULD STILL
BE UNCOMFORTABLY HOT EVEN THERE WITH HIGHS IN THE UPPER 80S TO LOWER
90S.
TUESDAY NIGHT AND WEDNESDAY...THE COLD FRONT WILL SLOWLY SAG SOUTH
ACROSS THE REGION...BRINGING A RISK OF CONVECTION TO THE ENTIRE
CWA...ALONG WITH THE POTENTIAL FOR LOCALLY HEAVY RAINFALL GIVEN
PRECIPITABLE WATER VALUES IN THE VICINITY OF AROUND 2 INCHES. AT
THIS JUNCTURE...THE TIMING OF THIS BOUNDARY REMAINS AN ISSUE WITH
THE GFS REMAINING THE FASTEST...THE CANADIAN THE SLOWEST...AND THE
ECMWF IN THE MIDDLE...WITH FROPA TIMES RANGING BETWEEN EARLY TO MID
WEDNESDAY MORNING AND WEDNESDAY AFTERNOON. GIVEN THAT THIS FRONT
APPEARS TO BE ANAFRONTAL WITH MOST OF ITS PRECIP FALLING BEHIND THE
ACTUAL SURFACE BOUNDARY...THIS MEANS THAT ANY ASSOCIATED CONVECTION
COULD END AS EARLY AS SOMETIME WEDNESDAY MORNING...OR AS LATE AS THE
END OF THE DAY WEDNESDAY.
GIVEN THE CONTINUED UNCERTAINTIES IN TIMING AND THE AFOREMENTIONED
NEAR-PARALLEL ORIENTATION OF THE FRONT TO THE UPPER FLOW...FEEL IT
IS BEST TO SLOW DOWN THE TIMING OF THIS FRONT AND ITS ASSOCIATED
CONVECTION A BIT FROM THE PREVIOUS FORECAST...FAVORING A COMPROMISE
SOLUTION ALONG THE LINES OF THE ECMWF. AS A RESULT...CHANCES FOR
CONVECTION WILL BE IN PLACE FROM TUESDAY NIGHT THROUGH WEDNESDAY
MORNING ACROSS THE ENTIRE AREA...BEFORE DIMINISHING FROM NORTH TO
SOUTH DURING THE COURSE OF WEDNESDAY AFTERNOON. TEMPERATURE-WISE...
EXPECT ANOTHER SULTRY NIGHT IN ADVANCE OF THE FRONT TUESDAY NIGHT
WITH LOWS AGAIN RANGING FROM THE UPPER 60S TO LOWER 70S...FOLLOWED
BY SOMEWHAT COOLER HIGHS IN THE UPPER 70S TO MID 80S ON WEDNESDAY
GIVEN THE PASSAGE OF THE FRONT AND ITS ASSOCIATED CLOUD COVER/PRECIP.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
SIMPLY PUT...SPRAWLING CANADIAN HIGH PRESSURE WILL BUILD SOUTHEAST
ACROSS THE GREAT LAKES AND NORTHEAST DURING THIS PERIOD...BRINGING A
RETURN TO DRY WEATHER ALONG WITH A COOLER AND NOTICEABLY LESS HUMID
AIRMASS.
IN TERMS OF ACTUAL TEMPERATURES...EXPECT DAILY HIGHS TO FALL BACK
INTO THE MID 70S TO LOWER 80S FOR BOTH THURSDAY AND FRIDAY...BEFORE
WARMING BACK INTO THE LOWER TO MID 80S ON SATURDAY AS WARMING
COMMENCES ALOFT. MEANWHILE...NIGHTTIME LOWS WILL RANGE IN THE MID
50S TO LOWER 60S ALL THREE NIGHTS. HUMIDITY LEVELS WILL ALSO BE MUCH
MORE COMFORTABLE...WITH DEWPOINTS REMAINING IN THE MID TO UPPER 50S
DURING THE BULK OF THE PERIOD.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AN AREA OF SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE REGION
THROUGH MID-AFTERNOON. RADAR TRENDS SUGGEST MOST WIDESPREAD
SHOWERS WILL BE BETWEEN 15Z AND 21Z...WITH EMBEDDED THUNDERSTORM
ACTIVITY LIKELY. OUTSIDE OF THESE...EXPECT MAINLY VFR CONDITIONS.
SHOWERS AND THUNDERSTORMS MAY LOWER VSBY TO 2SM AT TIMES IN HEAVY RAINFALL.
AFTERWARD...EXPECT A GENERAL CLEARING TREND FROM WEST TO EAST LATE THIS
AFTERNOON AND EVENING. THIS SHOULD RESULT IN MAINLY VFR
CONDITIONS...BUT THERE WILL BE AN INCREASING CHANCE FOR FOG
OVERNIGHT. THE COMBINATION OF LIGHT WINDS AND LINGERING BOUNDARY
LAYER MOISTURE MAY RESULT IN FAIRLY WIDESPREAD FOG. WINDS MAY
LIMIT HOW LOW VSBY DROPS AT BUF/IAG/ROC/ART...BUT DENSE FOG MAY
DEVELOP AT JHW...IN A RELATIVELY LIGHT FLOW.
OUTLOOK...
MONDAY AND TUESDAY...MAINLY VFR.
TUESDAY NIGHT...AREAS OF MVFR IN SCATTERED -SHRA/-TSRA.
WEDNESDAY...BECOMING VFR.
THURSDAY...VFR.
&&
.MARINE...
HIGH PRESSURE WILL REMAIN ANCHORED ALONG THE MID ATLANTIC COAST
THROUGH EARLY NEXT WEEK. MEANWHILE A WEAK TROUGH WILL APPROACH THE
LOWER LAKES TODAY AND ALLOW SOUTHWEST WINDS TO INCREASE
SOMEWHAT TO THE 10-15 KNOT RANGE...WITH THE STRONGEST WINDS ON LAKE
ERIE. EXPECT CONDITIONS TO REMAIN BELOW SMALL CRAFT CRITERIA...BUT
WAVES MAY GET A LITTLE CHOPPY ON LAKE ERIE.
A RIDGE OF HIGH PRESSURE WILL NOSE INTO THE LOWER LAKES MONDAY WITH
RELATIVELY LIGHT WINDS. SOUTHWEST WINDS WILL PICK UP AGAIN TUESDAY
AHEAD OF A STRONGER COLD FRONT...ESPECIALLY ON LAKE ERIE WHERE
CONDITIONS MAY APPROACH SMALL CRAFT ADVISORY CRITERIA.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL
MARINE...APFFEL/JJR
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1013 AM CDT SUN JUL 15 2012
.DISCUSSION...
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ALONG THE
COAST MOVING NORTHEAST. THESE HAVE PRODUCED GUSTS OF 20-27 KTS
AND .77" OF RAIN AT GLS. 00Z/06Z MODELS DID A VERY POOR JOB IN
RESOLVING THESE STORMS AS WELL AS THE TEXAS TECH WRF/4KM NAT WRF
THOUGH THE RUC HAS DONE A MARGINAL JOB BUT WITH TOO MUCH
CONVECTION OVER THE GULF. WATER VAPOR HAS A SMALL CYCLONIC
CIRCULATION EMBEDDED IN THE MOIST AXIS JUST WEST OF MATAGORDA BAY.
AREA SOUNDINGS AND ACARS SOUNDINGS INDICATE THAT CONVECTIVE TEMPS
OF 82 TO 85 SHOULD BE SUFFICIENT FOR FURTHER DEVELOPMENT. HAVE
RAISED POPS IN THE SOUTH AND NORTHEAST FOR THE SHORT TERM TRENDS
THIS MORNING AND IN THE WEST FOR THE AFTERNOON AS VORT LIFTS NORTH
AND SPEED DIVERGENCE ALOFT HAS SOME ADDITIONAL LIFT. SHEAR AXIS
CONTINUES TO MOVE WEST AND THIS TO SHOULD HELP TO DESTABILIZE THE
WESTERN AREAS THIS AFTERNOON. STILL WORRIED ABOUT THE MOIST AXIS
ACROSS THE CENTRAL GULF AND OVER LA...WV CONTINUES TO CLEARLY
DEPICT THE WESTWARD PROGRESSION...COULD MAKE FOR A WET
MONDAY/TUESDAY. 45
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 91 73 92 74 93 / 40 20 30 20 30
HOUSTON (IAH) 90 74 91 75 92 / 40 20 30 10 30
GALVESTON (GLS) 88 81 90 81 90 / 40 20 30 20 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...45
AREA FORECAST DISCUSSION
NWS TAUNTON MA
206 PM EDT SUN JUL 15 2012
.SYNOPSIS...
HOT AND HUMID WEATHER WILL CONTINUE TODAY WITH SCATTERED
THUNDERSTORMS...ESPECIALLY IN WESTERN NEW ENGLAND AS A WEAK COLD
FRONT APPROACHES THE REGION. HEAT AND HUMIDITY WILL BE WITH US
THROUGH WEDNESDAY...WHEN A STRONGER COLD FRONT MAY BRING ANOTHER
ROUND OF THUNDERSTORMS. HIGH PRESSURE WILL DOMINATE OUR WEATHER
THURSDAY INTO THE START OF NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
2 PM UPDATE...
SHOWERS/SCT TSTMS INCREASING IN COVERAGE ACROSS SE NY AND MOVING
EAST. ACTIVITY IS MOVING INTO A FAVORABLE ENVIRONMENT WITH MLCAPES
1000-1500 J/KG ACROSS SW NEW ENG SO EXPECT CONVECTION TO MOVE INTO
THE REGION NEXT 1-2 HOURS...AND HRRR INDICATING INCREASING
SHOWERS/ISOLD TSTMS 19-21Z. MID LEVEL LAPSE RATES AND DEEP LAYER
SHEAR ARE WEAK WHICH WILL LIMIT SEVERE WX POTENTIAL...BUT CANT
RULE OUT A STRONG STORM AND HEAVY RAINFALL WILL BE A CONCERN
GIVEN HIGH PWAT AIRMASS.
PREVIOUS DISCUSSION...
MID LEVEL TROF ACROSS GT LAKES WITH WV IMAGERY SHOWING MULTIPLE
SHORTWAVES MOVING THROUGH THE FLOW. MAIN IMPULSE ACROSS MI BUT
LEAD SHORTWAVE ACROSS W NY WILL BE LIFTING NE ACROSS CENTRAL NEW
ENG LATER THIS AFTERNOON WHICH SHOULD PROVIDE A TRIGGER FOR
CONVECTION TO DEVELOP.
THERE ARE A FEW SHOWERS ACROSS E NY WHICH MAY AFFECT PORTIONS OF W
NEW ENG EARLY THIS AFTERNOON...BUT MAIN FOCUS FOR STRONGER TSTMS
SHOULD BE MID TO LATE AFTERNOON ACROSS W ZONES AND EXTENDING INTO
THE EVENING FURTHER E AS DEEPER MOISTURE AND MID LEVEL OMEGA
APPROACHES FROM THE WEST. CAPES ARE FORECAST TO INCREASE TO
1000-2000 J/KG...BUT MID LEVEL LAPSE RATES ARE WEAK AND DEEP LAYER
SHEAR IS MARGINAL. STILL...IF FORECAST INSTABILITY CAN BE REALIZED
A FEW STRONG TO SEVERE STORMS WILL BE POSSIBLE GIVEN 0-6KM SHEAR
25-30 KT. PWATS INCREASE OVER 2" BY LATE TODAY SO ANY STORMS WILL
ALSO HAVE THE POTENTIAL TO PRODUCE VERY HEAVY RAINFALL. HIGHEST
POPS THIS AFTERNOON WILL BE FOCUSED ACROSS W ZONES WITH LOWEST
POPS E NEW ENG WHERE MOST OF THE DAY SHOULD REMAIN DRY.
MID/HIGH CLOUDS ARE ADVANCING ACROSS W NEW ENG AND SUNSHINE WILL
GRADUALLY FADE AS CLOUDS INCREASE FROM WEST TO EAST. TEMPS
ALREADY IN THE LOW/MID 80S ACROSS MUCH OF THE REGION. WARMEST
TEMPS WITH SOME LOWER 90S POSSIBLE WILL BE ACROSS INTERIOR E MA
AND SE NH WHERE MOST SUNSHINE...BUT INCREASING CLOUD COVER WILL
SLOW TEMP RISE ACROSS W NEW ENG. DEWPOINTS WILL BE CLIMBING TO 70+
DURING THE AFTERNOON SO VERY HUMID.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
KEPT LIKELY POPS EARLY TONIGHT ACROSS INTERIOR AS WE EXPECT
ACTIVITY TO SLOWLY DIMINISH WITH LOSS OF DAYTIME HEATING. 00Z GFS
IS MORE EMPHATIC THAT STRONGER SURFACE LOW WILL FORM ALONG FRONT
WHICH RESULTS IN MORE WIDESPREAD RAINFALL TONIGHT. NOT SURE THAT
WILL BE CASE GIVEN RATHER FLAT MID LEVEL TROUGH SO PREFER TO LEAN
MORE TOWARD DRIER NAM/SREF SOLUTION WHICH GIVES CHANCE POPS CLOSER
TO COAST. SHOULD SEE PARTIAL CLEARING AND DRIER AIR WORK ITS WAY
INTO REGION TOWARD DAYBREAK.
FRONT WILL SETTLE NEAR S COAST MON AND EVENTUALLY WASHES OUT.
ALTHOUGH CROSS SECTIONS SHOW DRYING THROUGH COLUMN...THERE MAY BE
ENOUGH LEFTOVER MOISTURE COMBINED WITH WEAK SURFACE CONVERGENCE TO
PRODUCE AN ISOLATED SHOWER OR THUNDERSTORM ALONG S COAST MON
AFTERNOON. NOT MUCH CHANGE IN AIRMASS BEHIND FRONT SO HIGHS SHOULD
ONCE AGAIN TOP OUT IN 80S AND LOWER 90S...ALTHOUGH HUMIDITY WILL
BE LOWER.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...SHORTWAVE RACES EAST OF THE AREA MONDAY...THEN A DEEPER
MID-LEVEL TROUGH APPROACHES FOR WEDNESDAY AND THURSDAY. A MID-
LEVEL RIDGE SHOULD BUILD OVER THE CENTRAL USA DURING THE LATTER
HALF OF NEXT WEEK. THIS WILL COMPLICATE OUR FORECAST AS THE
DOWNSTREAM MID-LEVEL TROUGH COULD ALSO AMPLIFY AND RETROGRADE BACK
OVER NEW ENGLAND IF IT DOES NOT REMAIN PROGRESSIVE.
SURFACE HIGH PRESSURE SITS OFFSHORE THROUGH THE EXTENDED PERIOD WITH
A SOUTHWEST FLOW INTO SOUTHERN NEW ENGLAND UNTIL WEDNESDAY. THIS
WILL MEAN HEAT AND HUMIDITY INTO MIDWEEK.
MONDAY NIGHT-TUESDAY...
SHORTWAVE MOVES OFF TO THE EAST MONDAY MORNING WITH BUILDING HEIGHTS
OVER NEW ENGLAND. MODELS CONTINUE TO SHOW SURFACE PRESSURE FIELDS
HINTING AT A LEE TROUGH ALONG THE NORTHEAST CORRIDOR. MODELS
CONTINUE TO INDICATE MARGINALLY FAVORABLE CONVECTIVE PARAMETERS
DURING THIS PERIOD. HOWEVER...THE SOUNDINGS LOOK TO BE TOO DRY
OVER TOO DEEP A LAYER TO REALLY SUPPORT SCATTERED TO WIDESPREAD
CONVECTION. HAVE KEPT THIS PORTION OF THE FORECAST DRY.
WEDNESDAY...
A COLD FRONT MOVES THROUGH AND PROVIDES A FOCUS FOR SCATTERED
SHOWERS/TSTMS.
THURSDAY-FRIDAY...
COLD FRONT MOVES OFFSHORE EARLY...WITH HIGH PRESSURE BUILDING
THROUGH THE PERIOD. THE CHANGE TO A NORTHWEST WIND WILL USHER IN
DRIER AIR.
SATURDAY...
HIGH PRESSURE CENTER BEGINS TO MOVE OFFSHORE BUT STILL LOOKS LIKE
IT WILL BE PREDOMINANT WEATHER FEATURE FOR OUR AREA. DRY FCST.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
OVERVIEW...MODERATE CONFIDENCE. SHOWERS/SCT TSTMS WILL MOVE EAST
ACROSS THE REGION LATE AFTERNOON THROUGH THIS EVENING AND WILL
LIKELY BE ACCOMPANIED BY A PERIOD OF MVFR/IFR CONDITIONS. AFTER
THE SHOWERS MOVE TO THE EAST OVERNIGHT...AREAS OF STRATUS AND FOG
WILL LIKELY DEVELOP THEN IMPROVING TO VFR DURING MON MORNING. LOW
PROB OF AN ISOLD SHOWER/TSTM DEVELOPING MON AFTERNOON.
KBOS TAF...MODERATE CONFIDENCE. EXPECT SHOWERS AND A FEW
TSTMS...MAINLY AFT 00Z WITH A PERIOD OF MVFR CONDITIONS
DEVELOPING. SHOWERS MOVE TO THE EAST AFTER MIDNIGHT...BUT AREAS OF
MVFR CIGS/VSBYS MAY DEVELOP...IMPROVING AFT 12Z. LOW PROB OF A
SEABREEZE MON AFTERNOON.
KBDL TAF...MODERATE CONFIDENCE. SHOWERS AND A FEW TSTMS EXPECTED
21-03Z WITH AREAS OF MVFR...THEN IMPROVING TO VFR OVERNIGHT.
OUTLOOK...TUESDAY THROUGH THURSDAY...
TUESDAY...MODERATE CONFIDENCE
PATCHY FOG/LOW CLOUDS DURING THE MORNING WITH IFR/LIFR
CONDITIONS. BEST CHANCE WILL BE IN THE CT VALLEY AND ALONG THE
SOUTH COAST.
WEDNESDAY...MODERATE CONFIDENCE
COLD FRONT APPROACHES DURING THE DAY. IFR/LIFR POSSIBLE IN
EARLY MORNING FOG/LOW CLOUDS...THEN VFR DURING THE DAY EXCEPT FOR
PASSAGE OF TSTMS. ANY SHOWERS/TSTMS THAT DEVELOP MAY BRING A PERIOD
OF MVFR/IFR MAINLY IN THE AFTERNOON/EVENING.
THURSDAY...MODERATE CONFIDENCE
HIGH PRESSURE BUILDS IN FROM THE NORTHWEST...VFR.
&&
.MARINE...
HIGH CONFIDENCE THROUGH MON WITH NO HEADLINES ANTICIPATED.
S/SW FLOW EXPECTED TODAY AHEAD OF WEAKENING COLD FRONT. SCATTERED
SHOWERS OR THUNDERSTORMS ARE POSSIBLE TOWARD EVENING...BEFORE
AREAS OF FOG DEVELOP IN MOIST AIRMASS. FRONT SHOULD WASH OUT
NEAR S COAST MON MORNING AND MAY BECOME FOCUS FOR AN ISOLATED
SHOWER OR THUNDERSTORM MON AFTERNOON AS FLOW REMAINS S/SW.
SEAS WILL SLOWLY BUILD ON S COASTAL WATERS THROUGH MON BUT SHOULD
NOT GET HIGHER THAN 4 FT S OF ISLANDS.
OUTLOOK...TUESDAY THROUGH THURSDAY
MODERATE CONFIDENCE DUE TO TIMING OF A COLD FRONT WEDNESDAY. THIS
WILL IMPACT THE STRENGTH OF THE SOUTHWEST FLOW.
SEAS SHOULD DIMINISH TUESDAY. INCREASING HUMIDITY IS EXPECTED
WITH DEW POINTS AROUND 70 MONDAY THROUGH WEDNESDAY. THIS COULD
MEAN AREAS OF FOG FOR THE LATE NIGHT AND EARLY MORNING PERIODS.
SEAS BUILD AGAIN TUESDAY NIGHT AND WEDNESDAY AHEAD OF AN APPROACHING
COLD FRONT...LOW RISK OF 5 FOOT SEAS ACROSS THE SOUTHERN OUTER
COASTAL WATERS. THIS FRONT IS EXPECTED TO BRING SCATTERED SHOWERS
AND THUNDERSTORMS WEDNESDAY INTO WEDNESDAY NIGHT. SEAS THEN SUBSIDE
SOMEWHAT FOR THURSDAY.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BELK/JWD
NEAR TERM...KJC
SHORT TERM...JWD
LONG TERM...BELK
AVIATION...BELK/KJC
MARINE...BELK/JWD
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
345 PM EDT Sun Jul 15 2012
.NEAR TERM [through Tonight]...
While the dry mid-upper troposphere will help limit the overall
coverage and intensity of deep moist convection through this
evening, there will be enough boundary layer moisture and influx of
moisture from the Atlantic for scattered, "more shallow" convection.
The greatest rain chance will be east of Tallahassee and Albany,
where a combination of the FL/GA east coast sea breeze front,
boundary layer moisture, and instability will be enough to support a
40-50% chance of rain. So far cloud-ground lightning and surface
wind gusts have been on the low side with the cells to our east, and
this will likely continue. One or two cells could become briefly
strong (with wind gusts to 40 MPH and brief heavy rain), but the
chance of severe storms (58 MPH+ and/or large hail) is low.
Most of the rain over land will diminish shortly after sunset, but
scattered showers and storms will likely persist over the Gulf
coastal waters as the sea breeze translates westward. Low tonight
will be typical for this time of year, in the lower to mid 70s.
&&
.SHORT TERM [Monday through Tuesday Night]...
The forecast for the early part of the week will be influenced by
the progression of a TUTT ("Tropical Upper Tropospheric Trough")
and TUTT low currently situated to the east of the area. The TUTT
low is very well defined on water vapor loops this afternoon,
spinning near 31.2N / 78.2W. The upper level trough extends SW
from there over S FL and towards the Yucatan. The TUTT low, and
associated trough, are expected to slowly drift to the west over
the next couple days, with the low near GNV by Monday afternoon,
and near Apalachee Bay by Tuesday afternoon. The question is how
fast the aforementioned pocket of mid-upper level dry air will be
eroded by the approaching trough. The GFS and RUC both indicate
that should occur overnight, with PWATS reaching values much
closer to climatological normals by Monday. So far this weekend, a
lot of the convection has been situated near or east of the TUTT
axis, which means that it could take until Tuesday for a notable
increase in PoPs across the entire area. Therefore, for Monday we
expect more isolated activity (20-30% PoPs) in the NW half of the
area, with scattered to numerous storms (45-60% PoPs) around the
Florida Big Bend near Apalachee Bay. By Tuesday, we will be more
underneath the TUTT axis, and the low-level flow pattern will be
transitioning from light and variable to southerly. Therefore, the
increased forcing for ascent in the mid and upper levels, as well
as the local sea-breeze climatology both favor higher PoPs over
the entire area. PoPs were bumped up to about 50% in most areas.
There are some hints that the atmosphere could become a little
more favorable for downbursts in stronger storms in the short term
period as well, but this remains uncertain.
.LONG TERM [Wednesday through Sunday]...
Very little change to the extended fcst this cycle as the latest
00 UTC GFS and ECMWF have remained in fairly good agreement with a
Synoptic pattern dominated by a TUTT Low which will gradually open
up into an Upper Level Trof. This should further increase fcst
confidence in above Climo Pops and near Climo Max Temps through
much of the period. Despite the fairly disturbed pattern, the MEX
High Temps appeared too high (Mid 90s in many areas away from the
coast) for the expected levels of cloud cover and rain chances, so
used a 2-1 Blend of the lower and more realistic looking HPC and
MOS Guidance grids. The Euro (and GFS to some extent) do both show
some potential for a brief break in this pattern on Friday, with
possible Upper Level Ridging moving in from the east, before the
mean Trof builds back southward over the weekend, bringing a
return to higher rain chances.
&&
.AVIATION...
[through 18z Monday] KECP and KVLD are likely to be only
terminals affected by TSRA/SHRA today, with brief IFR-MVFR
vis/cigs and gusty winds through late afternoon or early evening.
The PoP is too low elsewhere to include in this afternoon`s TAF
package. Some of the high resolution NWP indicate the potential
for low clouds/fog around KVLD early Monday morning, but our
confidence is not yet high enough to include this in the forecast.
&&
.MARINE...
Very benign weather pattern for the marine forecast in terms of
winds and seas. Weak surface pressure pattern should keep winds at
or below 10 knots, and seas should therefore be 2 feet or less.
The approaching upper level low for Monday and Tuesday may begin
to increase thunderstorm coverage over the waters early this week,
particularly during the overnight and early morning hours.
&&
.FIRE WEATHER...
Relative humidity levels are unlikely to reach critical values for
the next several days. This, along with near-climo rain chances
(40-50%) over the next several days, will make controlled burning
difficult.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 73 92 73 91 74 / 30 50 20 50 30
Panama City 75 91 76 88 76 / 20 30 20 30 30
Dothan 74 95 75 93 74 / 20 30 20 50 30
Albany 72 95 74 94 74 / 20 30 20 50 40
Valdosta 71 93 71 92 72 / 30 40 20 50 40
Cross City 71 91 72 89 72 / 50 50 20 50 30
Apalachicola 75 89 76 87 76 / 20 40 20 30 20
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...None.
FL...None.
MARINE...None.
&&
$$
Near Term...Fournier
Short Term...Lamers
Long Term...Gould
Aviation...Fournier
Marine...Lamers
Fire Weather...Fournier
AREA FORECAST DISCUSSION
NWS JACKSON KY
225 PM EDT SUN JUL 15 2012
.UPDATE...
ISSUED AT 225 PM EDT SUN JUL 15 2012
COVERAGE HAS PICKED UP ALONG AND SOUTH OF THE HAL ROGERS PARKWAY AND
HIGHWAY 80 CORRIDORS THANKS TO BUILDING INSTABILITY AS WELL AS AN
OUTFLOW BOUNDARY MOVING EAST SOUTHEAST ACROSS THE AREA. HAVE BEEFED
UP THE POPS DOWN SOUTH ALL THE WAY TO THE PORTIONS OF THE VIRGINIA
BORDER AS CONVECTION WILL LIKELY KEEP POPPING AS THE OUTFLOW BOUNDARY
CONTINUES TO MOVE THROUGH SOUTHEAST KENTUCKY. HAVE REDUCED POPS
FURTHER NORTH TO JUST SCATTERED AS THE UPPER LEVEL FORCING GRADUALLY
LESSENS.
ISSUED 1054 AM EDT SUN JUL 15 2012
SHOWERS CONTINUE TO FOCUS ALONG THE NORTHWEST PORTION OF
THE CWA THIS MORNING...AS A LOW LEVEL JET ALONG WITH SOME UPPER LEVEL
DIVERGENCE REMAIN IN PLACE NEAR THE OHIO RIVER. SOME OF THE HEAVIER
SHOWERS AND ISOLATED THUNDERSTORMS HAVE BEEN DROPPING A LOT OF RAIN
IN A SHORT PERIOD OF TIME...UP TO AN INCH IN LESS THAN 30 MINUTES.
FORTUNATELY...STORM MOTIONS ARE AROUND 15 KTS...HOWEVER WILL HAVE TO
MONITOR AT LEAST A FEW LOCATIONS FOR REPEATED ROUNDS...WHICH COULD
LEAD TO MINOR FLOODING IN LOW LYING AREAS AT A MINIMUM. HAVE
INCREASED POPS UP TO CATEGORICAL GIVEN THE RADAR TRENDS.
THE LATEST NAM SHOWS ACTIVITY PEAKING IN THE 15-18Z TIME FRAME AND
THEN SCATTERING OUT MORE FOR THE REST OF THE AFTERNOON AS SOME MID-
LEVEL CAPPING DEVELOPS. THIS IS SIMILAR TO THE 06Z RUN...SO IT MAY BE
ON TO SOMETHING. THE LAST RUN OF THE SREF CONTINUES THE HIGHER POPS
THROUGH 21Z AND THIS MAY ALSO BE A CONTENDER WITH ANY OUTFLOW
BOUNDARY INTERACTION. FOR NOW...WILL LEAN TOWARDS THE NAM IDEA.
FRESHENED UP THE REST OF THE GRIDS...MAINLY TO ALLOW FOR A FASTER
DIURNAL RISE WHERE CLOUDS ARE STARTING OUT THINNER. HIGHS RANGING
FROM THE LOWER 80S IN THE NORTH TO A FEW UPPER 80S IN THE SOUTHEAST
LOOK ON TARGET.
UPDATE ISSUED AT 700 AM EDT SUN JUL 15 2012
SHOWERS HAVE INCREASED OVER ERN KY THIS MORNING WITH A FEW RUMBLES
AS WELL...LENDING SOME CREDIBILITY TO THE HRRR AND NAM12...AND HAVE
BENT THE GRIDS IN THIS DIRECTION THROUGH THE REMAINDER OF THE
MORNING. ALSO UPDATED SKY...ALONG WITH TEMPS AND DEW PTS TO ESTABLISH
TRENDS HEADING INTO THE DAY. OTHERWISE...THE FCST IS ESSENTIALLY ON
TRACK. UPDATED ZONES WILL BE ISSUED SHORTLY.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 232 AM EDT SUN JUL 15 2012
ESSENTIALLY LOOKING AT A PERSISTENCE FORECAST FOR TODAY AND TONIGHT
WITH LITTLE CHANGE ANTICIPATED IN THE OVERALL. THE QUESTION REMAINS
WHERE AND WHEN CONVECTION WILL INITIATE...BUT THE NEAR TERM MODELS
ARE STILL PLUGGING SOME EARLY MORNING DEVELOPMENT OVER CNTRL TN AND
KY SPREADING EAST THROUGH THE MORNING AND CONTINUING THROUGH THE
AFTERNOON BEFORE DIMINISHING THIS EVENING FOLLOWING THE LOSS OF
DAYTIME HEATING.
MODELS ARE IN GENERAL AGREEMENT IN DEVELOPING SOME HEALTHY INSTABILITY
THIS MORNING...UPWARDS OF 3K J/KG MU CAPE AGAIN WITH CONVECTIVE TEMPS
IN THE LOWER 80S AND CURRENT FCST HIGHS IN THE MID 80S. FCST PWATS
CONTINUE TO RUN ABOUT 2 INCHES THROUGHOUT THE DAY...AND WITH A RIGHT
ENTRANCE REGION OF A MODEST 50-60KT UPPER LEVEL JET TRAVERSING UP THE
OHIO VALLEY THIS AFTERNOON...COUPLED WITH A MID LEVEL SHORT WAVE
MOVING UP FROM THE TN VALLEY...CAN SEE LITTLE REASON THIS MORNING
WHY WE WOULD NOT SEE SOME EFFICIENT TSTMS AGAIN LATER THIS MORNING
CONTINUING THROUGH THE AFTERNOON...WITH LOCALLY HEAVY RAINFALL AGAIN
THE PRIMARY CONCERN.
MONDAY IS LOOKING A LITTLE MORE INTERESTING THIS MORNING WITH FCST
SOUNDINGS DEPICTING A STRONGER CAP DEVELOPING BY LATE MORNING
CONTINUING THROUGH THE PEAK HEATING HOURS AS THE STRONG BERMUDA HIGH
IS PROGGED TO SHIFT WEST TOWARDS THE CENTRAL APPALACHIANS...WEAKENING
SLIGHTLY IN THE PROCESS. DRIER...BUT WARMER MID LEVEL ADVECTION WILL
EITHER SQUASH PRECIP CHANCES OR...IF THE CAP BREAKS...COULD RESULT
IN SOME STRONG STORMS AGAIN DEVELOPING DURING THE AFTERNOON WITH
DAMAGING WINDS POSSIBLE IN ADDITION TO THE THREAT FOR LOCALLY HEAVY
RAINFALL.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 232 AM EDT SUN JUL 15 2012
THE MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE GENERAL LONG WAVE
PATTERN...HOWEVER THERE ARE SOME DIFFERENCES IN THE TIMING SOME OF
THE SHORT WAVES LATER ON DURING THE PERIOD. ON MONDAY
NIGHT...KENTUCKY WILL BE DOMINATED BY THE UPPER RIDGE WITH A MAJOR
TROUGH JUST OFF THE WEST COAST. ALL THE FRONTAL ACTIVITY WILL BE
WELL NORTH OF THE AREA AND THE COAL FIELDS WILL BE DOMINATED BY THE
WARM...MOIST AND UNSTABLE AIR MASS. WITH TIME...AN UPPER TROUGH BEGINS
TO DROP SOUTH FROM AN UPPER LOW CENTER OVER THE CANADIAN MARITIMES.
THIS WILL ALLOW A COLD FRONT TO START MOVING TO THE SOUTH. BY
THURSDAY MORNING...THE FRONT WILL BE OVER NORTHERN KENTUCKY AND WILL
SLOWLY MOVE SOUTH DURING THE DAY. BY FRIDAY MORNING THE FRONT WILL
HAVE MOVED INTO CENTRAL TENNESSEE. THE 00GMT GFS IS WANTING TO SLOW
THE FRONT DOWN AND SORT OF STALL IT OVER THE AREA ON FRIDAY...WHILE
THE 12 GMT ECMWF WANTS TO MOVES IT SOUTH OF THE AREA MORE QUICKLY.
IN GENERAL...I HAVE MORE CONFIDENCE IN THE ECMWF AND WILL BE NUDGING
THE FORECAST TOWARD THE FASTER FRONTAL PASSAGE. IN EITHER CASE...AS
THE FRONT MOVES TO THE SOUTH...DRIER AIR WILL BE MOVING INTO THE
AREA AND MAKE THINGS MORE COMFORTABLE. EVEN THOUGH THE HIGHS WILL
STILL BE A LITTLE ABOVE NORMAL. THE OVERNIGHT LOWS WILL DROP DUE TO
THE DRIER AIR. IN THE MEAN TIME...KENTUCKY WILL BE UNDER A DIRTY
RIDGE WITH WARM MOIST UNSTABLE AIR OVER THE AREA WHICH WILL BE ABLE
TO PRODUCE MAINLY AFTERNOON AND EVENING CONVECTIVE THUNDERSTORMS AND
SHOWERS AND WILL KEEP TEMPERATURES WARM AND MISERABLE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 225 PM EDT SUN JUL 15 2012
SCATTERED TO NUMEROUS CONVECTION IS POPPING ACROSS THE
AREA...PARTICULARLY ALONG AND SOUTH OF THE HAL ROGERS PARKWAY AND
HIGHWAY 80 CORRIDORS. LOZ LOOKS TO SEE THE BEST CHANCE OF SEEING A
DIRECT HIT FROM THUNDERSTORMS AND HAVE INCLUDED A TEMPO BETWEEN 19
AND 21Z. HAVE HELD ONTO VCTS ELSEWHERE. FOG WILL AGAIN BE A CONCERN
TONIGHT AND HAVE GONE IFR AT MOST LOCATIONS...ALTHOUGH LIFR OR WORSE
IN LOCATIONS THAT HAVE SEEN THE HEAVIER RAIN SHOWERS IS LIKELY. ONCE
THE FOG BURNS OFF MONDAY MORNING...CONVECTION WILL LIKELY THREATEN
ONCE AGAIN...ALTHOUGH THIS MAY BE A BIT LATER IN THE DAY THAN WE HAVE
SEEN COMPARED TO THE LAST SEVERAL DAYS SO HAVE LEFT OUT ANY MENTION
FOR NOW.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...MB
LONG TERM....JJ
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
145 PM EDT SUN JUL 15 2012
.UPDATE...
ISSUED AT 1119 AM EDT SUN JUL 15 2012
MORNING UPDATE MAINLY DEALS WITH TWEAKS TO THE FOG OVER LK SUPERIOR
AND CLOUD COVER THIS AFTN OVER INTERIOR LOCATIONS. FOR THE
FOG...EXTENDED THE DENSE FOG ADVY FOR NORTHERN AREAS THROUGH THIS
AFTN DUE TO RECENT WEBCAMS ALONG THE NRN KEWEENAW SHORELINE SHOWING
DENSE FOG AT THIS HOUR. FARTHER SOUTH AND EAST...WEBCAMS AND SHIP
OBS THIS MORNING SHOWING THE EXPANSE OF CLOUDS OVER THE SE LK
SUPERIOR MAINLY IN THE FORM OF LOW STRATUS. THUS...WILL LET THAT
ADVY EXPIRE AT NOON.
HIGH RES MODELS ARE ALL SHOWING DIURNAL CU AND LIGHT SHOWERS
DEVELOPING OVER THE WRN/CNTRL CWA AWAY FROM THE LK BREEZES OFF LK
SUPERIOR. AREAS FROM WRN LK SUPERIOR TO THE THUNDER BAY AND N SAW
SOME SCATTERED ACCAS EARLY THIS MORNING...WHICH SEEMS TO BE JUST E
OF THE VERY DRY AIR ON THE 12Z KINL SOUNDING. BUT WITH THE SLOW
LLVL WINDS NOT PUSHING THE DRY AIR E VERY QUICKLY...THINKING THE
LINGERING LLVL MOISTURE WILL BE ENOUGH TO DEVELOP A LARGER AREA OF
CU THAN PREVIOUSLY THOUGHT. THEREFORE...BUMPED SKIES UP TO PARTLY
CLOUDY FOR MUCH OF THE INTERIOR W AND CNTRL. SINCE WEAK
SHORTWAVE ENERGY WILL TRY TO WORK INTO THE AREA THIS AFTN FROM
MORNING SHOWERS IN NW MN...THAT MAY BE ENOUGH TO HELP PRODUCE AN
ISOLATED SHOWER OR TWO. WITH ALL OF THE HIGH RES MODELS AND THE NEW
12Z NAM KICKING OFF SHOWERS...EVEN THOUGH THEY MAY BE
OVERDOING THE LLVL TD VALUES SOME...WILL INTRODUCE THEM AROUND 18Z
OVER ERN ONTONAGON/GOGEBIC COUNTIES AND THEN DRIFT SE BEFORE
DIMINISHING IN THE LATE AFTN. SINCE THERE APPEARS TO BE PLENTY OF
DRY AIR ABOVE H750...WILL KEEP THUNDER MENTION OUT AS THIS WILL
LIKELY LIMIT CLOUD DEPTH TO A FEW KFT AND MAY EVEN HOLD OFF SHOWER
DEVELOPMENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 520 AM EDT SUN JUL 15 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW TROF JUST E OF THE FCST
AREA. SHRA/TSRA THAT ACCOMPANIED THE TROF ACROSS THE AREA YESTERDAY
HAVE RECENTLY EXITED THE SE PORTION OF THE FCST AREA. IN ITS WAKE...
CALM WIND/CLEARING SKIES AND MOISTURE FROM YESTERDAY`S RAINFALL HAS
LED TO SOME FOG DEVELOPMENT. FOG WILL QUICKLY BURN OFF WITHIN A
COUPLE HRS AFTER SUNRISE. UPSTREAM...A MID LEVEL RIDGE IS NOSING
INTO THE DAKOTAS/WRN MN. AS THE RIDGE SHIFTS E TODAY...UPPER MI WILL
FALL UNDER HEIGHT RISES/DEEP LAYER QVECTOR DIVERGENCE. MUCH DRIER
AIR...MAINLY IN THE MID LEVELS PER UPSTREAM 00Z KINL/CWPL
SOUNDINGS...WILL WORK AGAINST ANY AFTN CONVECTIVE DEVELOPMENT
DESPITE LAKE BREEZES PROVIDING LOW-LEVEL FORCING. THE K-INDEX ON THE
00Z CWPL/KINL SOUNDINGS WAS -11/-14C RESPECTIVELY DUE TO VERY DRY
AIR AROUND 700MB (DWPT DEPRESSIONS WERE IN EXCESS OF 40C). SO...
GOING DRY FCST APPEARS ON TRACK DESPITE SOME HIGH RES GUIDANCE
CONTINUING TO SHOW ISOLD CONVECTION OVER THE SCNTRL THIS AFTN.
MIXING TO AROUND 800MB ON FCST SOUNDINGS SUPPORTS MAX TEMPS UPWARDS
OF AROUND 90F. LIGHT GRADIENT WIND WILL ALLOW LAKE BREEZES OFF
LAKE SUPERIOR AND LAKE MICHIGAN TO PROVIDE SOME COOLING LAKESIDE.
SHORTWAVE ENERGY EJECTING FROM THE TROF CURRENTLY OVER THE WRN
STATES WILL HEAD INTO SCNTRL CANADA TONIGHT. IN RESPONSE...LOW-LEVEL
JET WILL INCREASE TO 45-50KT INTO THE NRN PLAINS. THIS WILL LIKELY
SUPPORT A CLUSTER OF SHRA/TSRA ON THE NOSE OF THE LOW-LEVEL JET AND
ALONG EDGE OF CAP ACROSS ND INTO SRN MANITOBA/NRN MN AND NRN
ONTARIO. AT THIS TIME...IT STILL APPEARS LOW-LEVEL JET WILL BE W OF
THE AREA AT 12Z MON...SO DO NOT ANTICIPATE ANY CONVECTION LATE
TONIGHT...EXCEPT POSSIBLY OVER NW LAKE SUPERIOR/ISLE ROYALE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 520 AM EDT SUN JUL 15 2012
BY 12Z MONDAY THE FRONTAL BOUNDARY WOULD BE ACROSS LAKE SUPERIOR
/AS A WARM FRONT/...STRETCHING FROM THE SFC LOW SET UP FROM NW MN TO
CENTRAL SD. DEPENDING ON THE AMOUNT OF MIXING /UP TO AROUND 800MB AT
SAW/ A FEW GUSTS OF 30 TO 35KTS COULD BE POSSIBLE FROM LATE MORNING
THROUGH THE REMAINDER OF THE DAYTIME HOURS. IF CLOUD COVER DOES NOT
INHIBIT MIXING...THESE STRONGER GUSTS COULD BE POSSIBLE ACROSS THE
DOWNSLOPE LOCATIONS NEAR LAKE SUPERIOR GIVEN THE STRENGTHENING SW
FLOW. AS FOR THE OFFICIAL FCST...HAVE INCREASED WINDS QUITE A BIT
FROM THE PREVIOUS FORECAST...WITH GUSTS OF 20-25KTS ACROSS MUCH OF
THE CWA BY MID AFTERNOON.
THE RECORD HIGH TEMP FOR MONDAY AT WFO MQT IS 95 DEGREES...WHICH MAY
BE BROKEN BY THE END OF THE DAY. CURRENTLY GOING ONLY A COUPLE OF
DEGREES COOLER THAN THIS RECORD...WITH 850MB TEMPS OF 22-24C
ALLOWING SEVERAL SITES ACROSS THE INTERIOR W HALF OF UPPER MI
REACHING 95 OR ABOVE.
THE SFC LOW SHOULD PUSH ACROSS THE AREA MONDAY AFTERNOON
THROUGH TUESDAY NIGHT. THE TRACK IS STILL UNCERTAIN...WITH THE
14/18Z GFS AND 15/00Z NAM PUSHING THE SFC LOW ACROSS THE KEWEENAW
PENINSULA AND ACROSS LAKE SUPERIOR BY EARLY MONDAY EVENING. THE
FARTHER SOUTH 14/12Z ECMWF INDICATES A BROADER LOW...STRETCHING
ACROSS CENTRAL AND SOUTHERN UPPER MI MONDAY NIGHT. THE 14/12Z
CANADIAN IS BEYOND CONSENSUS FROM MONDAY AFTERNOON ON...TRACKING THE
SFC LOW ACROSS ONTARIO AND N LAKE SUPERIOR...AND WILL NOT BE USED IN
THIS FORECAST UNTIL IT MOVES BACK IN LINE WITH THE REMAINDER OF
AVAILABLE GUIDANCE WEDNESDAY MORNING.
HIGH PRESSURE OVER CENTRAL CANADA TUESDAY MORNING WILL SLOWLY SHIFT
SE ACROSS LAKE SUPERIOR AND UPPER MI TUESDAY THROUGH THURSDAY. THE
COOLEST AFTERNOON TEMPS LOOK TO BE WEDNESDAY...TOPPING OUT IN THE
70S...COOLEST NEAR LAKE SUPERIOR AS DRY COOL AIR REMAINS. 850MB
TEMPS WEDNESDAY WILL BE A COOL 10-12C. THE FCST FOR THE CWA WILL
REMAIN DRY TUESDAY NIGHT THROUGH FRIDAY NIGHT. EXPECT THE SFC HIGH
TO DRIFT E TO THE LOWER GREAT LAKES AND W QUEBEC BY DAYBREAK FRIDAY
AND THE NEW ENGLAND COAST FRIDAY NIGHT...WITH A RIDGE REMAINING
ACROSS THE UPPER GREAT LAKES REGION.
A RELATIVELY WEAK SFC LOW STRETCHING FROM CENTRAL CANADA THROUGH THE
CENTRAL PLAINS LOOKS TO BECOME BETTER ORGANIZED TO OUR W SATURDAY
NIGHT...AS A SERIES OF DISTURBANCES NEAR FROM W AND CENTRAL CANADA
AS 500MB RIDGE BECOMES SUPPRESSED ACROSS THE CENTRAL AND SOUTHERN
PLAINS. KEPT CHANCE POPS FOR SATURDAY...ALTHOUGH CONFIDENCE IS
MODERATE TO LOW FOR SPECIFICS THAT FAR OUT IN THIS FCST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 144 PM EDT SUN JUL 15 2012
MAINLY VFR CONDITIONS THROUGH THE PERIOD...AS THE DEVELOPING WARM
FRONT TONIGHT IS EXPECTED TO STAY TO THE N OF THE AREA.
THEREFORE...ALL OF THE ASSOCIATED CONVECTION SHOULD REMAIN OVER NRN
LK SUPERIOR OR SRN ONTARIO.
HAVE SOME CONCERN WITH FOG/STRATUS OVER LK SUPERIOR AND IT/S
POSSIBLE EFFECT ON KCMX/KIWD. CURRENT THINKING IS THAT IT SHOULDN/T
AFFECT KIWD DO TO INCREASING SWRLY FLOW TONIGHT. KCMX ON THE
OTHERHAND IS TRICKY. WITH WINDS BECOMING ERLY THIS EVENING AND LOSS
OF DIURNAL HEATING...COULD SEE THE FOG/STRATUS OVER LK SUPERIOR MOVE
IN AND QUICKLY BRING CIGS/VSBYS DONE. INDICATIONS ARE THAT IT IS A
STRATUS DECK...BUT THE LIGHT UPSLOPE FLOW WOULD HELP VSBYS GO DOWN.
DON/T HAVE ENOUGH CONFIDENCE TO HIT THE LOW CLOUDS/VSBYS HARD...SO
WILL MENTION OF MVFR VSBY AND SCT003 FOR NOW...BUT THINKING THAT
WILL LIKELY NEED TO BE DROPPED TO ALT LANDING MINS.
FINALLY...COULD GET QUITE GUSTY...TO 35KTS...OUT OF THE SSW AT THE
END OF THE TAF PERIOD AND FOR THE REST OF THE AFTN TOMORROW FOR KIWD
AND POTENTIALLY KCMX.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 520 AM EDT SUN JUL 15 2012
BIGGEST CONCERN IN THE SHORT TERM WILL BE FOG. 11-3.9MICRON
SATELLITE IMAGERY INDICATES FOG (PROBABLY NOT STRATUS) EXPANDING S
AND E FROM NCNTRL LAKE SUPERIOR. MORE FOG MAY BE DEVELOPING FROM
KEWEENAW BAY TOWARD MARQUETTE/MUNISING. WITH DEVELOPING MESO HIGH
PRES OVER THE LAKE TODAY...IT`S QUITE POSSIBLE FOG MAY END UP
SPREADING TO THE SHORELINES AROUND THE ENTIRE LAKE TODAY. ALWAYS
DIFFICULT TO FCST MARINE FOG...SO TRENDS WILL NEED TO MONITORED
CLOSELY TODAY FOR MOVEMENT/DEVELOPMENT/DISSIPATION OF FOG. ONCE
DAYLIGHT ARRIVES...VIS SATELLITE IMAGERY WILL PROVIDE A BETTER LOOK
AT HOW THE FOG IS EVOLVING. QUITE POSSIBLE DENSE FOG ADVY MAY NEED
TO BE ISSUED. FOR NOW...CARRIED FOG MENTION THRU EARLY AFTN OVER
MAINLY CNTRL AND ERN LAKE SUPERIOR.
OTHERWISE...WITH HIGH PRES DEVELOPING OVER LAKE SUPERIOR TODAY...
WINDS WILL BE UNDER 15KT. ALTHOUGH WINDS WILL BECOME S-SE TONIGHT IN
ADVANCE OF APPROACHING LOW PRES...SPEEDS SHOULD REMAIN 15KT OR LESS.
THERE IS SOME UNCERTAINTY IN WHERE WARM FRONT ASSOCIATED WITH THE
LOW WILL BE POSITIONED MON. AT THIS TIME...IT APPEARS THAT AT LEAST
SRN PORTIONS OF THE LAKE WILL SEE INCREASING S-SW WINDS MON UPWARDS
OF 20KT AS WARM FRONT DRIFTS N. AS LOW PASSES ACROSS THE AREA MON
NIGHT...A COLD FRONT WILL PUSH S...BRINGING A SHIFT TO NORTHERLY
WINDS UPWARDS OF 20KT INTO TUE MORNING. HIGH PRES WILL THEN BUILD
INTO THE UPPER GREAT LAKES DURING THE MIDWEEK PERIOD...RESULTING IN
WINDS UNDER 20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 6 PM EDT THIS EVENING FOR LSZ243>245-
263-264-266.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...SRF
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...SRF
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS GLASGOW MT
312 PM MDT SUN JUL 15 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH TUESDAY...
WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL LOW OVER THE PACIFIC
NORTHWEST WHICH CONTINUE TO MOVE SOUTHWARD OVER THE WEST COAST
BEFORE BECOMING STATIONARY SOMEWHERE NEAR THE NORTHERN CALIFORNIA
COAST LINE BY THE END OF THE SHORT TERM PERIOD. THIS WILL LEAVE
MONTANA IN AN OVER ALL SW FLOW ALOFT PATTERN. THIS WILL CONTINUE
THE FEEDING OF PACIFIC MOISTURE FOR THE NEXT FEW DAYS ALONG WITH
DISTURBANCES MOVING OVER MONTANA CAUGHT IN THIS FLOW.FOR
THUNDERSTORMS ACROSS THE CENTRAL AND NORTHERN ROCKIES OVERNIGHT
LAST NIGHT AND TODAY.
SO LOOKING AT THE FORECAST FOR LATE THIS AFTERNOON AND THIS
EVENING THE CHANCE OF SHOWERS AND THUNDERSTORMS IS POSSIBLE. THE
WATER VAPOR IMAGERY SHOWS TWO JET STREAKS...ONE MOVING INTO SW
MONTANA AND ONE MOVING INTO SW WYOMING WHICH SHOULD HELP AID IN
THUNDERSTORM DEVELOPMENT ACROSS CENTRAL AND EASTERN MONTANA LATE
THIS AFTERNOON AND EVENING. THUNDERSTORMS THAT ARE ALREADY THERE
COULD BE ENHANCED BY THE LEFT FRONT ENTRANCE REGION OF THE JET
STREAK ACROSS SW WYOMING ONCE IT GETS CLOSE TO CENTRAL MONTANA
LATE THIS EVENING. THE LATEST HRRR MODELS SHOWS CONVECTION
DEVELOPING ACROSS CENTRAL MONTANA AND MOVING EASTWARD INTO
NORTHEAST MONTANA THIS EVENING. SO DECIDED TO INCREASE POPS AND
MENTION BRIEF MODERATE RAINFALL ALONG WITH POSSIBLE GUSTY WINDS.
THE CHANCE OF THUNDERSTORMS WILL END AFTER MIDNIGHT BUT REDEVELOP
MONDAY AFTERNOON AS ANOTHER SHORTWAVE MOVE UP IN THE SW FLOW FROM
THE NORTHERN GREAT BASIN. THIS WAVE SEEMS TO GET STUCK OVER
CENTRAL MONTANA BEFORE GETTING PUSHED NE TUESDAY EVENING. SHOULD
PROVIDE ENOUGH LIFT AND INSTABILITY TO CONTINUE CHANCE TO SLIGHT
CHANCE POPS ACROSS THE REGION THROUGH THE SAME TIME FRAME. NO
SEVERE WEATHER IS EXPECT DURING THIS TIME FRAME BUT A FEW STRONG
THUNDERSTORMS CELL ARE POSSIBLE. SPC HAS A GENERAL THUNDERSTORM
RISK FOR MONDAY AND WE ARE PROBABLY LOOKING AT THE SAME THING
FOR TUESDAY. HIGHS ACROSS THE REGION BOTH MONDAY AND TUESDAY WILL
BE IN THE UPPER 80S AND LOWER 90S. CLOUD COVER WILL PLAY BIG
FACTOR IN THE TEMPERATURE FORECAST MORE ON TUESDAY RATHER THEN
MONDAY. RSMITH
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...
AFTERNOON UPDATE...THE ONLY REAL CHANGE TO THE EXTENDED FORECAST
IS TO ADD SOME POPS INTO THE FORECAST IN THE FRIDAY INTO SATURDAY
TIME FRAME. A SURFACE TROF SETS UP OVER THE EASTERN MT AND ND
BORDER WITH A SOUTHWEST FLOW ALOFT WHICH GENERALLY ALLOWS FOR SOME
THUNDERSTORMS TO FORM. NO BIG EVENT EXPECTED AT THIS TIME JUST
GENERAL THUNDERSTORMS. OTHERWISE TUESDAY NIGHT INTO WEDNESDAY
NIGHT IS THE EVENT OF INTEREST IN THE EXTENDED AND HAVE INCREASED
POPS A BIT ALONG THE CANADIAN BORDER AND NORTH DAKOTA BORDER
AREAS. FRANSEN
SOUTHWEST FLOW ALOFT WILL BE OVER MONTANA THROUGH FRIDAY AND NOW
ARE A DAY LATER WITH MOVING THE WEST COAST UPPER TROUGH INLAND
(FRIDAY NIGHT VERSUS THURSDAY NIGHT). WITHIN THE SOUTHWEST FLOW
ALOFT...A SHORTWAVE TUESDAY NIGHT INTO WEDNESDAY WILL BRING A
CHANCE OF SHOWERS AND THUNDERSTORMS TO THE FORECAST AREA. THEN THE
RIDGE OVER THE CENTRAL U.S. STRENGTHENS AND WARMS TEMPERATURES
INTO THE 90S FOR MOST OF THE AREA FOR THURSDAY AND FRIDAY. DRIER
AIRMASS WILL ALSO LIMIT PRECIP CHANCES ALTHOUGH WEAK WAVES COULD
BRING A SHOWER OR THUNDERSTORM WEDNESDAY NIGHT AND THURSDAY.
THE UPPER TROUGH MOVES INLAND FRIDAY AND THROUGH THE FORECAST AREA
FRIDAY NIGHT. WITH LIMITED MOISTURE...WILL MENTION A SLIGHT CHANCE
OF SHOWERS AND THUNDERSTORMS FOR NOW. THE WAVE WILL FLATTEN THE
RIDGE SO THAT THE FLOW ALOFT BECOMES ZONAL FOR NEXT WEEKEND WITH
DRY WEATHER. FORRESTER
&&
.AVIATION...
LOOK FOR VFR CONDITIONS TODAY AND TONIGHT WITH A MIX AND MID AND
HIGH LEVEL CLOUDS. MAY SEE SOME WIDELY SCATTERED SHOWERS OR
THUNDERSTORMS AFFECT THE TAF SITES BTWN 21Z THROUGH 05Z. EAST TO
SOUTHEAST WINDS EARLY THIS MORNING WILL DIMINISH AND TURN TO THE
WEST OR WEST- NORTHWEST AROUND 10 KTS AS A LOW PRESSURE SYSTEM
MOVES FROM EASTERN MT INTO WESTERN ND. FRANSEN
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
300 PM CDT SUN JUL 15 2012
.SHORT TERM...
THE MAIN CHALLENGES WILL BE CONVECTIVE CHANCES LATE THIS AFTERNOON
AND OVERNIGHT...ALONG WITH TEMPS AND RESULTANT HEAT INDICES
THROUGH MONDAY IN THE SOUTH. MODELS CONTINUE TO DIFFER IN REGARDS
TO WARM FRONTAL PLACEMENT AND CONVECTION...WITH THE GFS STILL TOO
FAR SOUTH WITH THE NAM PERHAPS TOO FAR NORTH. THE ECMWF REMAINS A
DECENT COMPROMISE ALTHOUGH IT IS MORE IN THE NORTHERLY NAM CAMP.
THE LATEST NEAR TERM HRRR AND OTHER MESOSCALE MODELS ARE ALSO IN
AGREEMENT WITH THE CAP HOLDING INTO THIS EVENT WITH A MORE
NORTHERLY MCS OVERNIGHT...SO WILL BASE POPS ON THIS SCENARIO.
FOR TONIGHT...EXPECT CONVECTION TO DEVELOP SOMEWHERE IN NC ND TO
THE WEST OF THE FORECAST AREA AROUND OR SHORTLY BEFORE 00Z. STORM
MOTION VECTORS AND INCREASE LLJ WILL LIKELY CAUSE THESE STORMS TO
TRACK NEAR THE CANADIAN BORDER THEN TURN INTO NE ND/NW MN
OVERNIGHT. THERE WILL BE AMPLE SHEAR/INSTABILITY FOR A FEW SEVERE
STORMS...AND GIVEN A VERY PRONOUNCED WARM FRONT AND HIGH
SHEAR...CAN/T RULE OUT A TORNADO EITHER IF DEWPOINTS CAN POOL
ENOUGH LOCALLY. IT STILL IS UNCERTAIN HOW CURRENT CAP WILL AFFECT
CONVECTION THOUGH...BUT POTENTIAL EXISTS FOR SEVERE STORMS SO WILL
MENTION OVERNIGHT. IT WILL BE VERY MILD OVERNIGHT...WITH THE
SOUTH REMAINING IN THE 70S.
FOR MON...THE FRONT WILL SAG INTO THE SOUTH BUT IT WILL REMAIN
VERY WARM HERE. HEAT INDICES WILL RISE TO AROUND 100...AND WE MAY
NEED SOME HEAT HEADLINES HERE. FOR NOW WILL HOLD ON HEADLINES WITH
UNCERTAINTY IN REGARDS TO CLOUD COVER/DEWPOINTS BUT SOMETHING TO
KEEP IN MIND FOR LATER SHIFTS. THERE WILL BE THE CHANCE FOR
SHOWERS OR STORMS BUT MOST AREAS WILL REMAIN DRY.
ON TUE/WED...EXPECTING A COUPLE OF DRY DAYS WITH TEMPS NEAR
NORMAL AND HIGH PRESSURE BUILDING IN. THERE COULD BE A THREAT FOR
SOME CONVECTION IN THE FAR SOUTH...BUT FEEL ITS NOT WORTH A
MENTION BUT SOMETHING TO KEEP IN MIND.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
GFS/ECMWF IN POOR AGREEMENT WEDNESDAY THROUGH NEXT WEEKEND...
BECOMING 180 DEGREES OUT OF PHASE ACROSS THE NORTHERN PLAINS BY
00 UTC SATURDAY WITH RESPECT TO THE 500 HPA HEIGHT PATTERN. DESPITE
ALLBLEND POPS OF 20 TO 30 PERCENT NEARLY EVERY PERIOD...WILL FOLLOW
PREVIOUS FORECAST CLOSELY TO MAINTAIN CONTINUITY. GIVEN RECENT
SYNOPTIC REGIME...PREFER THE HOTTER AND DRIER ECMWF SOLUTION. BEST
AGREEMENT BETWEEN GFS/ECMWF FOR PRECIPITATION IS WEDNESDAY NIGHT
INTO THURSDAY AS A WEAK SHORT-WAVE MAY MOVE THROUGH RIDGE ALOFT.
ALSO INCLUDED LOW POPS FRIDAY NIGHT INTO SATURDAY ON THE OFF-CHANCE
THE OVERLY AGGRESSIVE GFS VERIFIES WITH ANOTHER WAVE MOVING ALONG
THE CANADIAN BORDER. TEMPERATURES EXPECTED TO INCREASE SLIGHTLY EACH
DAY...WITH MANY LOCATIONS BACK IN THE 90S BY FRIDAY/SATURDAY.
OVERNIGHT LOWS MAY ALSO BE VERY WARM BY WEEK/S END...AT OR ABOVE 70
DEGREES.
&&
.AVIATION...
EXPECT VFR CONDITIONS THROUGH 18 UTC MONDAY. LATE THIS AFTERNOON AND
EVENING...SHOWERS AND THUNDERSTORMS WILL DEVELOP ALONG AND NORTH OF
A WARM FRONT STRETCHING ALONG THE HIGHWAY 2 CORRIDOR. WITH THE
EXCEPTION OF KDVL...THINK CONVECTION WILL REMAIN NORTH OF TAF
SITES...SO KEPT 18 UTC ISSUANCE DRY AT THIS TIME. WILL NEED TO WATCH
KGFK AND KTVF FOR POSSIBLE DEVELOPMENT FARTHER SOUTH. WINDS SOUTH OF
THE FRONT WILL CONTINUE FROM THE SOUTHEAST...GUSTING TO 25 KTS AT
TIMES. NORTH OF THE FRONT...WINDS WILL BE FROM THE EAST-NORTHEAST.
LATE TONIGHT...WINDS WILL SHIFT TO THE NORTHWEST AFTER SURFACE
TROUGH PASSAGE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
DK/ROGERS
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
333 PM CDT SUN JUL 15 2012
.DISCUSSION...
CURRENTLY...UPPER LEVEL RIDING IS PUSHING BACK INTO THE REGION
FROM THE EAST WHICH HAS PUSHED THE MOISTURE AXIS THAT CONTAINS
PWAT VALUES GREATER THAN 2 INCHES TO THE WESTERN HALF OF THE
MIDSOUTH. AN OUTFLOW BOUNDARY PUSHING NORTH INTO NW MS IS
PRODUCING SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WITH
ISOLATED TO SCATTERED CONVECTION ACROSS EASTERN ARKANSAS AND THE
MO BOOTHEEL. DRIER AIR WORKING INTO THE EASTERN HALF HAS SEVERELY
LIMITED AREAL COVERAGE EAST OF MEMPHIS FOR NOW. TEMPS ARE
GENERALLY IN THE MID AND UPPER 80S THOUGH A FEW READINGS ABOVE 90
CAN BE FOUND ACROSS NE MS AND SE PARTS OF WEST TN.
TONIGHT...BEST CHANCES FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE
TO BE ACROSS THE WESTERN HALF OF THE MIDSOUTH THROUGH EARLY
EVENING WITH LESS COVERAGE TO THE EAST. SOME OF STORMS WILL
CONTAIN VERY HEAVY RAINFALL AND GUSTY WINDS. CONVECTION IS MAINLY
SURFACE HEATING BASED SO ACTIVITY WILL DISSIPATE QUICKLY THIS
EVENING AND THIS IS CONFIRMED NICELY BY THE LATEST HRRR RUN.
TEMPS WILL BE SIMILAR TO THE PAST SEVERAL NIGHT WITH LOWS IN THE
70 TO 75 DEGREE RANGE.
MONDAY THROUGH WEDNESDAY...UPPER RIDGE WILL BE OVER THE AREA AND
TEMPS WILL START TO HEAT UP INTO THE MID 90S BY TUESDAY AND
WEDNESDAY. SURFACE DEWPOINTS SHOULD REMAIN IN AT LEAST THE LOWER
70S WHICH MAY PRODUCE HEAT INDEX VALUES NEAR ADVISORY LEVELS BY
MIDWEEK. EVEN WITH THE UPPER RIDGE OVER THE AREA THE MID LEVEL
CAPPING WILL NOT BE STRONG ENOUGH TO COMPLETELY SHUT OFF
CONVECTION...THOUGH AREAL COVERAGE WILL BE LOWER AS PWAT VALUES
FALL. OVERNIGHT LOWS WILL BE TRENDING UP AS WELL.
THURSDAY THROUGH SUNDAY...UPPER RIDGE MAY WEAKEN SLIGHTLY AS AN
UPPER TROF MOVING THROUGH THE NORTHEAST/EASTERN GREAT LAKES SENDS
A BACK DOOR COLD FRONT INTO THE OHIO VALLEY. 12Z MODELS ARE NOT IN
VERY GOOD AGREEMENT ATTM. THE 12Z GFS LEANS TOWARD MORE UPPER
LEVEL RIDGING. MEANWHILE THE ECMWF DEVELOPS A CLOSED 500 MB LOW
OVER THE EASTERN OHIO VALLEY BY SUNDAY AFTERNOON. HAVE GENERALLY
GONE WITH A COMPROMISE BETWEEN THE COOLER/WETTER ECMWF AND THE
WARMER/DRIER GFS.
SJM
&&
.AVIATION...
18Z TAF CYCLE
CIGS AND VSBYS AT ALL TAF SITES HAVE BECOME VFR AND SHOULD REMAIN
SO THROUGH LATE THIS EVENING. PWATS REMAIN IN EXCESS OF 2 INCHES
AT ALL SURROUNDING 12Z SOUNDING LOCATIONS (KJAN...KLZK...KOHX)
WITH THE EXCEPTION BEING KBMX WHERE DRIER AIR HAS WORKED IN WITH
PWATS AROUND 1.45 INCHES DUE TO RIDGING ALOFT SPREADING WESTWARD.
PLAN TO CARRY VCTS AT ALL SITES FOR THIS AFTERNOON...BUT KEEP
TEMPOS AT ALL SITES EXCEPT KTUP WHERE DRIER AIRMASS MAY WORK IN.
THE HIGHEST CONVECTIVE POTENTIAL SHOULD REMAIN ALONG AND WEST OF
THE MISSISSIPPI RIVER TO INCLUDE KMEM AND KJBR. IN FACT...A
PROMINANT OUTFLOW BOUNDARY CURRENTLY OVER THE DELTA COUNTIES OF
NORTH CENTRAL MISSISSIPPI SHOULD CONTINUE TO PUSH NORTH TOWARDS
KMEM LATER THIS AFTERNOON AND MAY FOCUS CONVECTIVE ACTIVITY. TEMPO
AT KMEM MAY NEED TO BE EXTENDED BEYOND CURRENT EXPIRATION OF 15/22Z.
CONVECTION SHOULD WANE IN COVERAGE AND INTENSITY LATER THIS
EVENING WITH MOST LOCATIONS RAIN FREE AFTER 16/02Z.
LOWER CIGS SHOULD ONCE AGAIN OCCUR IN MOST LOCATIONS LATE TONIGHT
WITH AT LEAST REDUCTIONS TO MVFR. THERE MAY EVEN BE IFR CIGS AT
SOME LOCATIONS BUT CONFIDENCE NOT HIGH ENOUGH TO INCLUDE IN THE
LATEST TAF. THERE MAY ALSO BE SOME MVFR VSBYS IN PATCHY FOG.
LOW CLOUDS SHOULD MIX OUT BY LATER MONDAY MORNING WITH MOST
LOCATIONS BECOMING VFR NEAR THE END OF THE TAF FORECAST PERIOD.
CONVECTIVE POTENTIAL APPEARS LOWER TOMORROW AS THE PERSISTENT
UPPER TROUGH AXIS BEGINS TO SHIFT NORTHWEST AND UPPER RIDGING
BUILDS FROM THE SOUTHEAST.
JLH
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 75 93 76 95 / 20 30 10 20
MKL 71 93 72 94 / 20 30 10 20
JBR 73 93 74 95 / 20 20 10 20
TUP 73 94 74 94 / 20 20 10 30
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1235 PM CDT SUN JUL 15 2012
.AVIATION...
18Z TAFS THROUGH 20Z...CARRYING SHRA/TSRA FOR IAH AND CXO AND UTS. GENERALLY
WENT WITH VCSH ELSEWHERE BUT WILL HAVE TO WATCH FOR ADDITIONAL AFTERNOON
DEVELOPMENT OUT WEST WHERE CONVECTIVE TEMPERATURES ARE PROBABLY GOING
TO BE REACHED AGAIN (ALREADY SEEING REDEVELOPMENT IN/AROUND THE MATAGORDA
BAY AREA). VFR OVERNIGHT WITH LIGHT WINDS. LEANING TOWARD WETTER MODEL
SOLUTIONS FOR TOMORROW...SO INTRODUCED VCSH TOWARD THE COAST IN THE
MORNING AND VCTS FURTHER INLAND IN THE AFTER4NOON. GOOD COORDINATION
CALL WITH CWSU ZHU. 42
&&
.PREV DISCUSSION... /ISSUED 1013 AM CDT SUN JUL 15 2012/
DISCUSSION...
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ALONG THE
COAST MOVING NORTHEAST. THESE HAVE PRODUCED GUSTS OF 20-27 KTS
AND .77" OF RAIN AT GLS. 00Z/06Z MODELS DID A VERY POOR JOB IN
RESOLVING THESE STORMS AS WELL AS THE TEXAS TECH WRF/4KM NAT WRF
THOUGH THE RUC HAS DONE A MARGINAL JOB BUT WITH TOO MUCH
CONVECTION OVER THE GULF. WATER VAPOR HAS A SMALL CYCLONIC
CIRCULATION EMBEDDED IN THE MOIST AXIS JUST WEST OF MATAGORDA BAY.
AREA SOUNDINGS AND ACARS SOUNDINGS INDICATE THAT CONVECTIVE TEMPS
OF 82 TO 85 SHOULD BE SUFFICIENT FOR FURTHER DEVELOPMENT. HAVE
RAISED POPS IN THE SOUTH AND NORTHEAST FOR THE SHORT TERM TRENDS
THIS MORNING AND IN THE WEST FOR THE AFTERNOON AS VORT LIFTS NORTH
AND SPEED DIVERGENCE ALOFT HAS SOME ADDITIONAL LIFT. SHEAR AXIS
CONTINUES TO MOVE WEST AND THIS TO SHOULD HELP TO DESTABILIZE THE
WESTERN AREAS THIS AFTERNOON. STILL WORRIED ABOUT THE MOIST AXIS
ACROSS THE CENTRAL GULF AND OVER LA...WV CONTINUES TO CLEARLY
DEPICT THE WESTWARD PROGRESSION...COULD MAKE FOR A WET
MONDAY/TUESDAY. 45
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 73 92 74 93 74 / 20 30 20 30 20
HOUSTON (IAH) 74 91 75 92 76 / 20 30 10 30 20
GALVESTON (GLS) 81 90 81 90 81 / 20 30 20 30 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...45
AVIATION/MARINE...42
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
236 PM CDT SUN JUL 15 2012
.SHORT TERM...TONIGHT AND MONDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE
CENTERED ON THE MONTANA-NORTH DAKOTA BORDER AND ITS ASSOCIATED WARM
FRONT EXTENDING ACROSS THE DAKOTAS. YESTERDAYS UPPER TROUGH HAS
MOVED TO THE EASTERN GREAT LAKES. WISCONSIN LIES BETWEEN THESE TWO
FEATURES IN A REGION OF BUILDING HEIGHTS ALOFT. DIURNAL CU HAS
POPPED OVER CENTRAL AND NORTH-CENTRAL WISCONSIN AND AREA RADARS HAVE
DETECTED A SOLE SPRINKLE THAT DEVELOPED EARLIER OVER THE
PORTAGE/WAUPACA BORDER. THE CU LOOKS RATHER FEISTY SO WILL ADD AN
ISOLATED SPRINKLE MENTION FOR THE REST OF THE AFTERNOON. AS THE MID-LEVEL
RIDGE BUILDS INTO OUR AREA...THE MAIN FORECAST CONCERNS INCLUDE
CLOUDS AND TEMPS INCLUDING HEAT HEADLINES OVER THE NEXT 24 HOURS.
TONIGHT...LOW PRESSURE WILL MOVE NE OVER THE NORTHERN PLAINS AND
HIGH PRESSURE WILL REMAIN CENTERED OVER THE SE CONUS. UPSTREAM
MID-DECK AND CIRRUS WILL LIKELY MAKE IT AT LEAST OVER THE NORTHERN
HALF OF THE FORECAST AREA TONIGHT AND LIGHT AND VARIABLE WINDS AT
THE SURFACE WILL PICK UP LATE. THESE CONDITIONS POINT TOWARDS
A WARMER NIGHT AND WILL GO WITH LOWS RANGING THROUGH THE 60S.
MONDAY...UPSTREAM LOW PRESSURE WILL MOVE EAST OVER NORTHERN
MINNESOTA AND WESTERN LAKE SUPERIOR. AS THIS OCCURS...A COLD FRONT
WILL SAG INTO NORTHWEST WISCONSIN LATE IN THE DAY...BUT AIRMASS
AHEAD OF THE FRONT IS PRETTY DRY...SO THINKING THERE IS SLIM CHANCES
OF A COOLING THUNDERSTORM. WILL LEAVE A SLIGHT CHANCE OVER FAR
NORTHERN VILAS IN CASE A ROGUE STORM DECIDES TO MAKE A RUN TOWARDS
THE NORTHERN TIP OF THE COUNTY. OTHERWISE...THE HEAT WILL BE THE
MAIN STORY TOMORROW. THE LATEST GUIDANCE SHOWS 850MB TEMPS IN THE
24-25C RANGE WHICH WOULD PUT HIGHS NEAR 100F. A TIGHTENING PRESSURE
GRADIENT WILL SUPPORT GOOD MIXING GREATER THAN 800MB...AND HELP TO
MIX OUT DEWPOINTS INTO THE LOW TO MID 60S. BUT THE GOOD MIXING ALSO
SUPPORTS GOING ON THE WARM SIDE OF GUIDANCE...WHICH PLACES HIGHS IN
THE MID TO UPPER 90S OVER CENTRAL AND EAST-CENTRAL WISCONSIN...AND
LOW TO MID 90S FARTHER NORTH. SOME 100S WILL LIKELY BE REACHED IN
THE HOT SPOTS AROUND WAUPACA AND WAUSHARA. ONLY CONCERN WITH TEMPS
IS THE MID AND HIGH LEVEL MOISTURE UPSTREAM...THOUGH ITS TOUGH TO
GAUGE HOW THICK IT WILL BE TOMORROW. BECAUSE DEWPOINTS WILL LIKELY
BE MIXING OUT...THINK HEAT INDICES MAY STRUGGLE TO REACH ADVISORY CRITERIA
OVER CENTRAL WISCONSIN. NONETHELESS...NO POINT IN CANCELLING
HEADLINES AT THIS POINT AS POTENTIAL WILL STILL BE THERE AND IT WILL
BE VERY HOT.
.LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY.
CONTINUE TO DEAL WITH FLUCTUATIONS IN POSITION/STRENGTH OF STRONG
CENTRAL U.S. RIDGE WITH SYSTEMS EJECTING OUT OF WESTERN TROF THROUGH
CANADA. TEMPERATURES EXPECTED TO START OUT WARM...THEN RETURN TO
NEAR NORMAL LEVELS BEFORE HEATING UP AGAIN ON THE WEEKEND.
INITIALLY WILL BE DEALING WITH COOL FRONT MOVING INTO/THROUGH CWA
MONDAY NIGHT AND TUESDAY. MAIN FORCING WITH UPPER JET REMAINS OVER
THE NORTH...PULLS OUT TUE NIGHT. SOME INSTABILITY...THOUGH
LIMITED. NAM STRONGER WITH SURFACE LOW...FASTER WITH FRONT
PASSING...AND SHOWS DRY FRONTAL PASSAGE. EC ON SLOWER END OF
GUIDANCE WITH SYSTEM AND FOR PAST TWO RUNS SUGGESTS MCS/S MAY MOVE ALONG
FRONT TUE NIGHT/WED OVER SOUTHERN HALF OF STATE. NOT SEEING ANY SIG
FORCING FOR SCENARIO...EXCEPT FOR SOME RELATIVELY WEAK WAA OVER
MN/SD. FEW TEMPS/HEAT INDICES REACH ADVISORY LEVELS TUE AFTN OVER
THE SOUTH...BUT WILL NOT EXTEND CURRENT ADVISORY GIVEN CLOUD/PCPN
CONCERNS. CWA REMAINS ON EDGE OF SEE TEXT BY SPC FOR MONDAY NIGHT
INTO TUE NIGHT. SHEAR IS LIMITED...THOUGH COULD SEE SOME GUSTY
WINDS AND MARGINAL HAIL WITH SOME TO THE STORMS IF THEY DEVELOP.
FRONT WILL SAG SOUTH INTO NORTHERN ILLINOIS ON WEDNESDAY WITH DRY
CANADIAN HIGH PRESSURE MOVING IN FOR WED-FRI PERIOD.
SPREAD SEEN IN ENSEMBLES FOR THE WEEKEND...WITH RIDGE
POSITION/STRENGTH...THOUGH MEANS SUGGEST GOING ON THE WARM
SIDE.
&&
.AVIATION...FOR 12Z TAF ISSUANCE. AFTER FG BURNS OFF EARLY TDA...
VFR CONDITIONS EXPECTED. SOME FG POSSIBLE AGAIN TNGT...BUT IT WL
BE MUCH MORE PATCHY AND PROBABLY NOT OF A CONSEQUENCE TO AVIATION
INTERESTS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TO 9 PM CDT MONDAY FOR WIZ020-021-030-
031-035>040-045-048>050-073-074.
&&
$$
MPC/TE