Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/17/13
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
739 PM MDT TUE JUL 16 2013
.UPDATE...DRY AIR AND SUBSIDENCE HAS KEPT CONVECTION FROM FORMING
OVER NORTHEAST COLORADO TODAY. AFTERNOON CUMULUS CLOUDS OVER THE
EASTERN PLAINS AND MOUNTAINS ARE DECREASING. WILL REMOVE POPS FROM
THE FORECAST FOR THE HIGHER TERRAIN. DID ADD SOME PATCHY FOG FOR
EASTERN ELBERT AND LINCOLN COUNTIES. THE RAP HAS BEEN SHOWING
SOME HERE AND EASTWARD OVER THE PAST FEW RUNS. NO OTHER CHANGES
PLANNED.
&&
.AVIATION...CLEAR SKIES WILL PREVAIL TONIGHT. SOUTHERLY WINDS
WILL CONTINUE TONIGHT AND WEDNESDAY WITH GUSTS TO 30 KNOTS
POSSIBLE WEDNESDAY AFTERNOON AT KDEN AND KAPA.
&&
.PREV DISCUSSION... /ISSUED 343 PM MDT TUE JUL 16 2013/
SHORT TERM...MID-LEVEL DRYING AND SUBSIDENCE OVER THE FORECAST
AREA HAS INHIBITED THE DEVELOPMENT OF ANY SHOWERS THROUGH THE
AFTERNOON. THERE IS STILL A SMALL CHANCE THAT ONE OR TWO
THUNDERSTORMS MAY DEVELOP OVER THE HIGHER ELEVATIONS OF GRAND AND
JACKSON COUNTIES DURING THE EVENING. WILL HOLD ON TO ISOLATED
SHOWERS FOR A FEW HOURS IN ZONES 31...33 AND 34. SKIES SHOULD
CLEAR OUT OVERNIGHT AS THE AIRMASS STABILIZES.
ON WEDNESDAY...SUBSIDENCE AND DRY AIR SHOULD REMAIN OVER THE
PLAINS AS THE SLOW MOVING UPPER LOW MAKES ITS WAY WESTWARD ACROSS
NEW MEXICO. MODELS INDICATE THAT THERE MAY BE MORE SHOWER ACTIVITY
OVER THE MOUNTAINS TOMORROW AFTERNOON. IT IS TOUGH TO TELL
WHETHER ENOUGH MOISTURE WILL RETURN TO THE MOUNTAINS TO FUEL THE
AFTERNOON SHOWERS...BUT IT IS HARD TO FIGHT AGAINST CLIMATOLOGY
FOR MORE THAN ONE OR TWO DAYS. IF THE UPPER LOW GETS FAR ENOUGH TO
THE WEST...THEN THERE WILL BE A SOUTHERLY FEED OF MOISTURE ACROSS
THE CENTRAL PART OF THE STATE...SO SCATTERED SHOWERS WILL REMAIN
IN THE FORECAST.
TEMPERATURES WILL WARM A FEW DEGREES FROM TODAY DUE TO MODERATION
OF THE AIRMASS BY ABUNDANT SUNSHINE. SOUTHERLY WINDS ON THE
PLAINS WILL BE THE OTHER FEATURE OF THE FORECAST.
LONG TERM...SOME THUNDERSTORMS WILL BE POSSIBLE OVER THE HIGHER
TERRAIN WEDNESDAY EVENING WHERE THERE WILL BE A BIT MORE MID
LEVEL MOISTURE. FORECAST SOUNDINGS SHOWING PRECIPITABLE WATER
VALUES AROUND SEVEN TENTHS OF AN INCH WITH WEAK INSTABILITY.
STORMS TO PRODUCE BRIEF MODERATE RAIN AS WELL AS GUSTY WINDS.
ACROSS PLAINS...NO STORMS EXPECTED AS SOUNDINGS INDICATE
PERSISTENT MID LEVEL CAP. STORMS TO END AROUND MIDNIGHT THOUGH A
FEW STORMS COULD LINGER OVER THE HIGHER MOUNTAINS. ON THURSDAY...
MODELS SHOW UPPER LEVEL RIDGE CENTERED ALONG WESTERN COLORADO AND
EASTERN UTAH BORDER WITH WEST NORTHWEST FLOW ALOFT ACROSS
COLORADO. FLOW OF SUBTROPICAL MOISTURE SHIFTS ACROSS CENTRAL AND
WESTERN COLORADO. THIS WILL PROVIDE FOR A BETTER CHANCE OF
THUNDERSTORMS ACROSS THE MOUNTAINS. WITH PRECIPITABLE WATER VALUES
INCHING UP TO AROUND EIGHT TENTHS OF AN INCH...SOME OF THE STORMS
COULD PRODUCE BRIEF MODERATE TO HEAVY RAINFALL. OVER THE
PLAINS...FORECAST SOUNDINGS INDICATING A WEAKER CAP WHICH ANY
BOUNDARIES FROM FOOTHILL CONVECTION SHOULD ERRODE. THUS...A FEW
STORMS WILL BE POSSIBLE...MAINLY DURING THE LATE AFTERNOON AND
EVENING HOURS. WITH PRECIPITABLE WATER VALUES CLOSE TO AN INCH...A
FEW STORMS COULD PRODUCE BRIEF MODERATE TO HEAVY RAIN. TEMPERATURE
AND THICKNESS PROGS SUGGEST HIGHS TO WARM INTO THE 90S ACROSS THE
PLAINS. MOST STORMS TO END AROUND MIDNIGHT...THOUGH SOME STORMS
WILL LINGER OVERNIGHT ACROSS THE MOUNTAINS AND FOOTHILLS. FOR
FRIDAY... UPPER LEVEL RIDGE TO BE CENTERED OVER THE GREAT BASIN
WITH NORTHWEST FLOW ALOFT CONTINUING. SUBTROPICAL MOISTURE WILL
CONTINUE TO MOVE ACROSS THE AREA...WITH A CONTINUED CHANCE FOR
THUNDERSTORMS OVER THE MOUNTAINS. MODELS SHOW WEAK MID LEVEL
DISTURBANCE MOVING ACROSS THE AREA...WHICH SHOULD HELP INCREASE
THE STORM CHANCES. THE DISTURBANCE WILL PUSH A WEAK FRONT ACROSS
THE NORTHEAST PLAINS DURING THE MORNING WITH SOME INCREASE IN LOW
LEVEL MOISTURE. THIS SHOULD INCREASE THE CHANCE FOR THUNDERSTORMS
BY THE AFTERNOON AS MID LEVEL QG ASCENT INCREASES. MODELS SHOW
PRECIPITABLE WATER VALUES INCREASING TO OVER AN INCH ACROSS THE
PLAINS WITH AROUND EIGHT TENTHS OF AN INCH. THUS SHOULD SEE SOME
STORMS PRODUCE BRIEF HEAVY RAIN. TEMPERATURES TO COOL INTO THE 80S
ACROSS THE PLAINS. ON SATURDAY...PATTERN CHANGES LITTLE WITH RIDGE
STILL CENTERED OVER NEVADA AND NORTHWEST FLOW ALOFT CONTINUING
ACROSS COLORADO. CROSS SECTIONS KEEP SOME SUBTROPICAL MOISTURE
ACROSS MOUNTAINS AND FOOTHILLS FOR A CONTINUED CHANCE OF
THUNDERSTORMS. OVER THE PLAINS...SOME OF MOISTURE APPEARS TO SHIFT
SOUTH AND EAST AS SLIGHTLY DRIER AIR MOVES INTO THE AREA. THIS
COULD RESULT IN A LOWER CHANCE FOR THUNDERSTORMS. THERE APPEARS TO
BE A BETTER MID LEVEL CAP WHICH COULD LEAD TO A LOWER CHANCE OF
STORMS. THICKNESS PROGS CHANGE LITTLE FROM FRIDAY...WITH HIGHS
REMAINING IN THE MIDDLE 80S ACROSS THE PLAINS.
FOR THE LATER DAYS SUNDAY THROUGH TUESDAY...MODELS SHOW RIDGE
BUILDING BACK ACROSS COLORADO SUNDAY WITH THE HIGH CENTERED OVER
UTAH AND WEAKER NORTHWEST FLOW ALOFT. CROSS SECTIONS SHOW
SUBTROPICAL MOISTURE DECREASING ACROSS THE AREA. THE BETTER
MOISTURE TO BE ACROSS THE MOUNTAINS...WILL KEEP A SLIGHT CHANCE OF
STORMS THERE...WITH DRY CONDITIONS ACROSS THE PLAINS. BOTH GFS AND
DGEX KEEP THE HIGH CENTERED OVER UTAH MONDAY AND TUESDAY WHILE THE
ECMWF MOVES THE HIGH ACROSS COLORADO MONDAY AND TUESDAY. THE ECMWF
SEEMS TO BE THE OUTLIER AND WILL GO WITH THE GFS/DGEX SOLUTIONS.
WILL CONTINUE A SLIGHT CHANCE OF STORMS FOR THE MOUNTAINS AND DRY
CONDITIONS ACROSS THE PLAINS. TEMPERATURES TO WARM INTO THE MIDDLE
90S BY TUESDAY.
AVIATION...NO AVIATION IMPACTS EXPECTED THROUGH THE NEXT 24
HOURS. CEILINGS AND VISIBILITIES WILL BE UNLIMITED OVERNIGHT AND
TOMORROW. SOUTHERLY WINDS GUSTING IN THE LOWER 20S WILL CONTINUE
UNTIL ABOUT 01Z THEN RE-DEVELOP TOMORROW AFTER 18Z.
HYDROLOGY...NO PRECIPITATION = NO PROBLEMS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DANKERS
LONG TERM....D-L
UPDATE/AVIATION...MEIER
AREA FORECAST DISCUSSION
NWS TAUNTON MA
958 PM EDT TUE JUL 16 2013
.SYNOPSIS...
HOT AND HUMID WEATHER WILL CONTINUE THIS WEEK WITH ONLY WIDELY
SCATTERED SHOWERS OR THUNDERSTORMS ON WED. CHANCES FOR SHOWERS
AND THUNDERSTORMS WILL INCREASE THU...FRI AND ESPECIALLY SAT AS A
COLD FRONT APPROACHES FROM THE GREAT LAKES. RELIEF FROM THE HEAT
AND HUMIDITY WILL ARRIVE ON SUNDAY BEHIND A STRONG COLD FRONT AND
LAST THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
10 PM UPDATE...
SEA BREEZE HAS DISSIPATED WITH LOSS OF DIURNAL ASSISTANCE AND AS
SUCH THE WEAK LOW TOPPED CONVECTIVE SHOWERS THAT FORMED ALONG IT
AND SLIDE THROUGH ERN MA/RI AND CT THROUGH THE EVENING ARE
DISSIPATING AS WELL. AFTER THE REMNANT CLOUDS FROM THESE DISSIPATE
AS WELL THANKS TO DRY SUBSIDENCE INVERSION...EXPECTING A MOSTLY
SKC NIGHT WHICH SHOULD ALLOW TEMPS TO DIP DOWN INTO THE UPPER 60S
TO AROUND 70. POSSIBLE A LITTLE COOLER THANKS TO SLIGHTLY DRIER
DWPTS THAN PREVIOUS DAYS.
ADJUSTED SKIES/TEMPS/DWPTS TOWARD THIS THINKING BASED ON LATEST
00Z NAM WHICH HAS STARTED TO COME IN.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
WED WILL BE SIMILAR TO TODAY...WITH A MOSTLY CLEAR START AND
TEMPERATURES RAPIDLY CLIMBING INTO THE LOWER TO MID 90S.
TEMPERATURES WILL BE A COUPLE OF DEGREES WARMER AND DEWPOINTS WILL
BE A DEGREE OR TWO HIGHER...WHICH WILL LEAD TO HEAT INDICES
REACHING 98-102 OVER MOST OF SOUTHERN NEW ENGLAND...INCLUDING
SOUTHERN NH...WITH THE ONLY EXCEPTIONS BEING CAPE COD AND THE
ISLANDS. THUS HAVE ISSUED A HEAT ADVISORY FOR MOST OF THE REGION
FOR WED AFTERNOON AND EARLY EVENING.
WINDS WILL STILL BE LIGHT...BUT SHOULD TURN TO A SOUTHERLY
DIRECTION. ALTHOUGH HIGHS REACHED 90 ON BLOCK ISLAND TODAY...WITH
LIGHT SOUTHERLY WINDS EXPECTED OFF OF THE COOLER WATERS WED...HAVE
ONLY FORECAST MID 80S THERE...IT COULD POTENTIALLY BE COOLER THAN
THAT.
THERE IS A CHANCE OF AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS
ON WED...MAINLY IN SOUTHERN NH AND NORTHERN MA...AS LOW PRESSURE
MOVES ACROSS SOUTHERN QUEBEC AND A TROUGH OF LOW PRESSURE PASSES
ACROSS NEW ENGLAND. UPPER LEVEL HIGH PRES RIDGE STILL IN CONTROL
THOUGH WITH CAP AROUND H7 AND UNFAVORABLE MID LEVEL LAPSE RATES.
SB CAPE VALUES LOOK TO BE A BIT HIGHER THANKS TO THE INCREASING
MOISTURE WITHIN THE COLUMN...AVERAGING ABOUT 1500-2000 J/KG.
THEREFORE...WENT WITH 25 TO 35 PCT CHANCE IN NORTHEAST MA/SOUTHERN
NH AND 20 PCT FARTHER TO THE SOUTH INTO NORTHERN CT/RI/SOUTHEAST
MA.
WEDNESDAY EVENING...ANY CONVECTION WILL DIMINISH AGAIN BY SUNSET.
ANOTHER WARM AND MUGGY NIGHT WITH CLEAR TO PARTLY CLOUDY SKIES IS
EXPECTED. PERHAPS A LITTLE MORE PATCHY FOG AS THE AIR MASS GETS
EVEN MORE HUMID. LOWS MAINLY UPPER 60S TO MID 70S.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
HEADLINES...
* HOT/HUMID THU INTO SAT WITH SCATTERED T-STORMS
* SEVERE STORMS POSSIBLE AHEAD OF A COLD FRONT SAT
* SEASONABLE AND DRY SUNDAY INTO THE BEGINNING OF NEXT WEEK
DETAILS...
NOT MUCH CHANGE IN OUR FORECAST THINKING FROM PREVIOUS SHIFTS.
MODELS REMAIN IN GOOD OVERALL AGREEMENT SHIFTING H5 HIGH SOUTH
AND WEST TOWARDS THE FOUR-CORNERS REGION ALLOWING FOR FALLING
HEIGHTS ACROSS NEW ENGLAND. THIS RESULTS IN THE RETURN OF THE
NORTHERN STREAM AS DOMINANT INFLUENCE AND SUBSEQUENTLY A MORE
ACTIVE PATTERN.
THURSDAY...
MODELS KEY ON LEE TROUGH BECOMING FOCUS FOR SCATTERED AFTERNOON
CONVECTION. SURFACE-BASED CAPES REACH 1500 J/KG WITH DECENT MID
LEVEL LAPSE RATES AROUND 6C/KM...BUT 0-6KM SHEAR IS MARGINAL AT
BEST. STILL NEED TO OVERCOME RATHER WARM MID LEVEL TEMPERATURES...
SO NOT CONFIDENT THAT STORM COVERAGE WILL BE ALL THAT GREAT. KEPT
CHANCE POPS FOR SCATTERED AFTERNOON THUNDERSTORMS WITH CONTINUED
MENTION OF HEAVY RAIN.
HIGH CAPE ENVIRONMENT FAVORS STRONG TO ISOLATED SEVERE STORMS...
BUT OVERALL SEVERE THREAT APPEARS TO BE LIMITED. PRECIPITABLE
WATER VALUES APPROACHING 2 INCHES...WHICH IS AROUND +2 STANDARD
DEVIATIONS...MEANS POTENTIAL FOR HEAVY RAINFALL AND ISOLATED
FLOODING IN STORMS.
HIGHS IN 90S AWAY FROM S COAST COMBINED WITH DEW POINTS IN LOWER
70S WILL ONCE AGAIN YIELD HEAT INDICES AROUND 100.
FRIDAY...
FLOW ALOFT BECOMES FLATTER WHICH SHOULD ALLOW ANY UPSTREAM
ACTIVITY TO PASS TO OUR N. HOWEVER WE REMAIN IN UNSTABLE AIRMASS
WITH BETTER CONVECTIVE POTENTIAL THAN THU. MODELS SHOW SURFACE
BASED CAPES 2000-3000 J/KG AND MID LEVEL LAPSE RATES OVER 6C/KM.
AXIS OF GREATEST 0-6KM SHEAR REMAINS ACROSS NORTHERN NEW ENGLAND
BUT SW NH AND NORTHERN MA ARE ON PERIPHERY OF THIS AXIS WITH
VALUES OF 30-35KT. IN ADDITION WE ARE IN FAVORABLE RR QUAD OF
UPPER JET. ONLY LIMITING FACTOR APPEARS TO BE WARM MID LEVEL TEMPS
/+11C AT 700 MB/ BUT COLDER AIR ALOFT SHOULD BE ABLE TO
COMPENSATE.
EXPECT SCATTERED STORMS TO DEVELOP FRI AFTERNOON ACROSS MUCH OF
SOUTHERN NEW ENGLAND...ASIDE FROM IMMEDIATE S COAST WHICH WILL BE
MORE STABLE DUE TO SW FLOW. SEVERE POTENTIAL IS SOMEWHAT BETTER
THAN THU WITH BETTER POSSIBILITY OF DAMAGING WINDS DUE TO BOWING
SEGMENTS OR LINES. ALSO HAVE CONTINUED POTENTIAL FOR HEAVY
RAINFALL AND ISOLATED FLOODING.
INCREASING SW FLOW WILL RESULT IN WARMER DAY THAN THU. HIGHS
SHOULD TOP OUT IN LOW-MID 90S /GIVEN MODEL 2M TEMPERATURES/
COMBINED WITH DEW POINTS IN LOW-MID 70S SHOULD YIELD HEAT INDICES
OF 100-105. NOT CONFIDENT ENOUGH TO ISSUE EXCESSIVE HEAT WATCH BUT
WE MAY NEED TO DO SO IF THIS BECOMES MORE CERTAIN.
SATURDAY...
BEST POTENTIAL FOR ORGANIZED CONVECTION AS STRONG COLD FRONT
APPROACHES FROM GREAT LAKES. SOME QUESTION AS TO WHETHER OR NOT
ANY EARLY MORNING CONVECTION WILL INHIBIT SIGNIFICANT
DESTABILIZATION DURING AFTERNOON. PATTERN SEEMS TO FAVOR AT LEAST
MORNING SHOWERS/STORMS NEAR S COAST...THEN WE SEE A BREAK BEFORE
ADDITIONAL STORMS FIRE DURING AFTERNOON AND EVENING.
NO REAL CHANGE IN THINKING FROM SPC DAY 4 OUTLOOK AND PREVIOUS
DISCUSSION. EXPECTED INSTABILITY COUPLED WITH BULK SOUTHWESTERLY
UNI-DIRECTIONAL SHEAR AROUND 35 KTS FAVORS MULTICELLS AND LINE
ECHO WAVE PATTERNS WITH DAMAGING WINDS MAIN THREAT. ALSO NEED TO
BE AWARE OF CONTINUED FLASH FLOOD POTENTIAL WITH PRECIPITABLE
WATER VALUES NEAR 2 INCHES.
SUNDAY INTO THE EARLY WEEK...
COLD FRONT WILL HEAD OFFSHORE SUN MORNING...PERHAPS NOT UNTIL SUN
AFTERNOON ON CAPE COD. COOLER AND DRIER AIR WILL FOLLOW ON NW
WINDS LATER SUN. FRONT MAY BECOME STATIONARY AS IT RUNS UP INTO
RIDGING OVER WESTERN ATLANTIC. THIS WOULD KEEP US IN NE FLOW
MON/TUE WITH DRY WEATHER ANTICIPATED...ALTHOUGH IT IS POSSIBLE ONE
OR TWO WEAK AREAS OF LOW PRESSURE COULD COME CLOSE ENOUGH TO BRING
AT LEAST SOME CLOUDINESS TO SE NEW ENGLAND.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE THROUGH WED NIGHT.
VFR. EXPECT LOCAL MVFR/IFR IN PATCHY FOG TONIGHT NEAR S COAST
INCLUDING KACK AND IN SOME OF INTERIOR VALLEYS. SEA BREEZES
DEVELOP ONCE AGAIN LATE WED MORNING INTO AFTERNOON...BUT WINDS
ALONG E MA COAST SHOULD TURN S LATE IN DAY. ISOLATED THUNDERSTORMS
MAY DEVELOP AFTER 18Z WED...PRIMARILY IN SOUTHERN NH AND NORTHERN
MA.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF. ISOLATED TSTMS SHOULD
REMAIN N OF AIRPORT WED AFTERNOON BUT MAY IMPACT GARDNER.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THURSDAY AND FRIDAY...MODERATE CONFIDENCE. IFR IN S COASTAL FOG
EARLY. ISOLATED SHOWERS/TSTMS WITH LOCAL IFR IN AFTERNOON.
SATURDAY...MODERATE CONFIDENCE. IFR IN S COASTAL FOG EARLY.
SCATTERED SHOWERS/TSTMS WITH LOCAL IFR IN AFTERNOON/EVENING.
SUNDAY...MODERATE CONFIDENCE. BECOMING VFR BY AFTERNOON.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE...
WINDS AND SEAS REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH
WED NIGHT. HIGH PRES REMAINS OVER THE WATERS THROUGH WED. A LOW
PRES APPROACHES THE WATERS AND WEAKENS WED NIGHT. THERE IS A
CHANCE OF SOME REDUCED VSBYS IN FOG IN SOME SPOTS.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THURSDAY AND FRIDAY...HIGH CONFIDENCE.
WEAK GRADIENT WILL RESULT IN SEA BREEZES ALONG E COAST WITH MORE
OF A SW FLOW ALONG S COAST WHERE 20KT GUSTS POSSIBLE. ISOLATED
THUNDERSTORMS POSSIBLE BOTH DAYS NEAR SHORE. EXPECT AREAS OF
NIGHTTIME AND EARLY MORNING FOG AROUND CAPE COD.
SATURDAY...MODERATE CONFIDENCE.
APPROACHING COLD FRONT WILL BRING INCREASING SW FLOW ON ALL WATERS
AS SEAS SLOWLY BUILD ON S COASTAL WATERS. STAYED BELOW WAVE WATCH
MODEL FORECAST OF 6-8 FT AS THIS MODEL IS TYPICALLY OVERDONE IN SW
FLOW DURING SUMMER...SHOULD BE MORE LIKE 4-5 FT AT MOST AND SCA
WILL PROBABLY BE NEEDED OFFSHORE.
AREAS OF NIGHTTIME AND EARLY MORNING FOG SHOULD PERSIST AROUND
CAPE COD.
SCATTERED THUNDERSTORMS POSSIBLE IN TWO ROUNDS...FIRST EARLY SAT
MORNING /PERHAPS NEAR S COAST?/ AND AGAIN TOWARD EVENING INTO SAT
NIGHT AS COLD FRONT PUSHES THROUGH NEW ENGLAND.
SUNDAY...MODERATE CONFIDENCE.
WINDS SHIFT TO NW AND DIMINISH AS COLD FRONT HEADS OFFSHORE BY
AFTERNOON. SEAS SLOWLY DIMINISH AS WELL BUT SHOULD REMAIN AT 5 OR
6 FT SE OF CAPE COD. SHOWERS/THUNDERSTORMS SHOULD LINGER
INITIALLY ON WATERS SE OF NANTUCKET BUT SHOULD BE WELL OFFSHORE BY
EARLY AFTERNOON.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...HEAT ADVISORY FROM 11 AM TO 7 PM EDT WEDNESDAY FOR CTZ002>004.
MA...HEAT ADVISORY FROM 11 AM TO 7 PM EDT WEDNESDAY FOR MAZ002>021-
026.
NH...HEAT ADVISORY FROM 11 AM TO 7 PM EDT WEDNESDAY FOR NHZ011-012-
015.
RI...HEAT ADVISORY FROM 11 AM TO 7 PM EDT WEDNESDAY FOR RIZ001>007.
MARINE...NONE.
&&
$$
SYNOPSIS...JWD/GAF
NEAR TERM...DOODY
SHORT TERM...GAF
LONG TERM...JWD
AVIATION...JWD/GAF
MARINE...JWD/GAF
AREA FORECAST DISCUSSION
NWS NEW YORK NY
747 PM EDT TUE JUL 16 2013
.SYNOPSIS...
HOT AND HUMID WEATHER WILL CONTINUE THROUGH THE END OF THE WEEK
WITH WEAK HIGH PRESSURE REMAINING ACROSS THE REGION THROUGH
WEDNESDAY NIGHT. A WEAK TROUGH OF LOW PRESSURE WILL DEVELOP ACROSS
THE AREA FOR THE REST OF THE WEEK. A COLD FRONT APPROACHES ON
SATURDAY AND MOVES SOUTH OF THE REGION ON SUNDAY AS HIGH PRESSURE
RETURNS FOR EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
MINOR TWEAKS TO GRIDS TO ACCOUNT FOR SLOWER COOLING THIS EVENING.
HOWEVER...CONSIDERING SOMEWHAT LOWER DEW POINTS COMPARED TO THE
PREVIOUS EVENING...EXPECT TEMPS TO DROP AS FORECAST AFTER SUNSET.
HEAT AND HUMIDITY STILL IN PLACE WITH INCREASING MOISTURE CONTENT
WITHIN BOUNDARY LAYER. SEA BREEZE MORE SUPPRESSED TODAY SIMILAR TO
YESTERDAY. A SHORTWAVE MOVING ACROSS NEW ENGLAND THIS EVENING WILL
ALLOW FOR A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS AHEAD AND
ALONG IT. SOME MESO MODELS SUCH AS THE HRRR AND WRF NMM ARE
INDICATING THIS POSSIBILITY. OTHERWISE...DRY AND HUMID WEATHER
CONTINUES TONIGHT. LOWS WERE PREFERRED WITH WARMER
GUIDANCE...KEEPING TEMPERATURES IN THE 70S FOR MUCH OF THE AREA
TONIGHT AND UPPER 60S FOR INTERIOR AND RURAL SECTIONS.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
UPPER LEVEL RIDGE TO OUR WEST BEGINS TO SLOWLY FLATTEN WITH HIGH
PRESSURE AT THE SURFACE CONTINUING TO WEAKEN. A SURFACE TROUGH
DEVELOPS ACROSS THE AREA WEDNESDAY...WITH A BETTER SOUTHERLY FLOW
DEVELOPING ACROSS COASTAL SECTIONS. SO A BETTER CHANCE FOR SEA
BREEZES DURING THE AFTERNOON FOR AT LEAST IMMEDIATE COASTAL
SECTIONS. FLOW TURNS MORE SOUTHWEST WEDNESDAY NIGHT. POSSIBLE
SHOWER OR THUNDERSTORM ACROSS THE INTERIOR BUT NOT ENOUGH
CONFIDENCE TO INSERT IN FORECAST.
HIGHS WILL BE WELL INTO THE 90S WITH DEWPOINTS HIGHEST ALONG THE
URBAN CORRIDOR AND THE LOWER HUDSON VALLEY AS WELL AS INTERIOR
SOUTHERN CONNECTICUT. UPPER 80S TO LOWER 90S MAX TEMPS TOWARDS THE
COASTLINE IN COMBINATION WITH THE DEWPOINT WILL KEEP HEAT INDICES
AT LEAST A FEW DEGREES BELOW 100 DEGREES...THE CRITERION FOR HEAT
ADVISORY OUTSIDE OF NYC. HOWEVER...URBAN NORTHEAST NEW JERSEY AS
WELL AS NEW YORK CITY...THE LOWER HUDSON VALLEY...AND INTERIOR
SOUTHERN CONNECTICUT WILL BE APPROACHING 100 DEGREES FOR HEAT
INDICES SO HEAT ADVISORIES EXTENDED THROUGH EARLY WEDNESDAY
EVENING FOR THESE LOCATIONS. THERE IS SOME UNCERTAINTY DEPENDING
ON DAYTIME MIXING...WHICH IS FORECAST TO BE UP TO AROUND 850 MB
AGAIN. HOWEVER...MOISTURE IS FORECAST TO INCREASE RELATIVE TO
TODAY AND THIS MAKES SENSE DUE TO A GREATER SOUTHERLY SYNOPTIC
FLOW AND LESS SYNOPTIC NORTHERLY FLOW.
FOR WEDNESDAY NIGHT...SIMILAR TEMPS TO PREVIOUS NIGHT WITH DRY
WEATHER IN PLACE.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
DEEP LAYERED RIDGING WILL REMAIN OVER THE EASTERN CONUS THROUGH
FRIDAY. BY FRIDAY NIGHT...THERE IS EXCELLENT AGREEMENT AMONG THE
OPERATIONAL AND ENSEMBLE GUIDANCE OF THE RIDGE BREAKING DOWN AND
SHIFTING OFFSHORE AS UPPER LEVEL HEIGHTS BEGIN TO FALL AHEAD OF A
TROUGHING BUILDING INTO THE NE US. THIS TROUGH SENDS A COLD FRONT
THROUGH THE AREA SATURDAY/SATURDAY NIGHT.
HOT AND HUMID CONDITIONS WILL CONTINUE INTO SATURDAY. H85 TEMPS ARE
FORECAST TO RANGE FROM 18C TO 20C ON THURSDAY AND FRIDAY HELPING TO
MAKE THESE DAYS THE HOTTEST OF THE EXTENDED PERIOD. HEAT ADVISORY
HAS BEEN EXTENDED UNTIL 8PM THURSDAY FOR NEW YORK CITY. FOR LOWER
HUDSON VALLEY...NE NJ...AND INTERIOR CT...IT IS POSSIBLE HEAT
ADVISORY CRITERIA WILL BE MET THURSDAY BUT CONFIDENCE IS LOW AT THIS
TIME. ONE POSSIBLE CAVEAT IS HOW MUCH DRIER AIR MIXES DOWN. SIMILAR
CONDITIONS/CONCERNS EXIST ON FRIDAY SO WILL NEED TO CONTINUE TO
MONITOR TRENDS. WITH A SURFACE TROUGH AND HIGH AMOUNTS OF
INSTABILITY THURS AND FRI...A SHOWER OR THUNDERSTORM CANNOT BE RULED
OUT. THESE WILL LIKELY BE PULSE IN NATURE AS SHEAR IS MINIMAL.
COLD FRONT THEN APPROACHES SATURDAY BRINGING MUCH BETTER CHANCES FOR
SHOWERS AND STORMS. WITH HEIGHT FALLS OCCURRING ALOFT AND BETTER
SYNOPTIC LIFT...THE CHANCES FOR SHOWERS AND STORMS INCREASE.
INGREDIENTS MAY BE PRESENT TO PROMOTE SEVERE WEATHER SAT WITH THE
FRONT. PRIMARY THREATS AT THIS TIME APPEAR TO BE DAMAGING WINDS. ANY
STORM MAY ALSO PRODUCE HEAVY RAINFALL AS PWATS APPROACH 2 INCHES
SATURDAY.
THE FRONT SHOULD MOVE SOUTH OF THE AREA SUNDAY. HOWEVER...12Z GFS
DOES SLOW ITS PROGRESSION WITH A WAVE DEVELOPING ALONG IT. THE
LATEST 12Z ECMWF AND 12Z CMC DO NOT DEPICT THIS SCENARIO...BUT DO
HINT AT A SLIGHTLY SLOWER PROGRESSION SOUTHWARD.
THEREFORE...LINGERED CHANCE POPS MAINLY ACROSS SOUTHERN ZONES
SUNDAY.
A RETURN TO MORE SEASONABLE CONDITIONS EXPECTED FOR EARLY NEXT WEEK
AS HIGH PRESSURE BUILDS INTO THE AREA.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
HIGH PRESSURE REMAINS IN CONTROL OVER THE REGION...WITH WEAK
TROUGHING DEVELOPING ACROSS THE AREA WEDNESDAY AFTERNOON. VFR
THROUGH THE TAF PERIOD.
LIGHT AND VARIABLE WINDS OVERNIGHT...BECOMING N/NE 5 TO 7 KT AFT
13Z. FLOW SHOULD WEAKEN ENOUGH DURING THE AFTERNOON FOR SEABREEZE
DEVELOPMENT. HIGH CONFIDENCE IN SEABREEZE ACROSS COASTAL TERMINALS...WITH
MODERATE CONFIDENCE AT KEWR/KTEB/KHPN.
SCT CU DEVELOPMENT LIKELY ALONG SEABREEZE BOUNDARY AND OFF HIGHER
TERRAIN...WITH ISOLATED AFT SHRA/TSRA DEVELOPMENT POSSIBLE ALONG
THE SAME FEATURES.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: HIGH CONFIDENCE IN AFTERNOON
SEABREEZE...AROUND 18-19Z.
KLGA FCSTER COMMENTS: HIGH CONFIDENCE IN AFTERNOON
SEABREEZE...AROUND 20-21Z.
KEWR FCSTER COMMENTS: MODERATE CONFIDENCE IN AFTERNOON
SEABREEZE...AROUND 20-21Z.
KTEB FCSTER COMMENTS: MODERATE CONFIDENCE IN AFTERNOON
SEABREEZE...AROUND 20-21Z.
KHPN FCSTER COMMENTS: MODERATE CONFIDENCE IN AFTERNOON
SEABREEZE...AROUND 20-21Z.
KISP FCSTER COMMENTS: HIGH CONFIDENCE IN AFTERNOON
SEABREEZE...AROUND 19-20Z.
.OUTLOOK FOR 00Z THURSDAY THROUGH SUNDAY...
.WEDNESDAY NIGHT...VFR.
.THURSDAY AND FRIDAY NIGHT...VFR. SLIGHT CHANCE SHRA/TSTM MAINLY
N AND W OF NYC DURING THE AFTERNOON/EVENING.
.SATURDAY...MAINLY VFR...BUT THE POTENTIAL LIES FOR WITH MVFR OR
LOWER CONDS IN STRONG TO SEVERE CONVECTION.
.SUNDAY...IMPROVING CONDS.
&&
.MARINE...
SUB SCA CONDITIONS ARE EXPECTED TO PREVAIL THROUGH WEDNESDAY NIGHT WITH
A WEAK PRESSURE GRADIENT IN PLACE.
A 15-20KT SW FLOW DEVELOPS OVER THE WATERS WITH GUSTS LIKELY
APPROACHING SCA LEVELS FRIDAY INTO SATURDAY. SEAS WILL ALSO BUILD TO
SCA LEVELS DURING THIS TIME. SUNDAY INTO MONDAY...WINDS SHOULD
REMAIN BELOW SCA LEVELS WITH MARGINAL SCA SEAS.
&&
.HYDROLOGY...
DRY CONDITIONS ARE EXPECTED THROUGH WEDNESDAY NIGHT.
A MOIST AIRMASS OVER THE AREA THURSDAY INTO FRIDAY BRINGS THE
POTENTIAL FOR HEAVY DOWNPOURS. HOWEVER...THUNDERSTORMS SHOULD REMAIN
ISOLATED LIMITING ANY FLASH FLOODING POTENTIAL. THE CHANCE FOR FLASH
FLOODING INCREASES ON SATURDAY WITH BETTER THUNDERSTORM COVERAGE AND
PRECIPITABLE WATERS INCREASING TO AROUND 2 INCHES.
&&
.CLIMATE...
TUESDAY JULY 16 2013 RECORD MAXIMUM TEMPERATURES
SITE RECORD FORECAST HIGH
BRIDGEPORT 94 (1983, 1952) 95
ISLIP 93 (1999) 95
LAGUARDIA 97 (1980) 97
KENNEDY 100 (1983) 95
CENTRAL PARK 99 (1980) 96
NEWARK 101 (1988) 97
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...HEAT ADVISORY UNTIL 8 PM EDT WEDNESDAY FOR CTZ005>008.
HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR CTZ009>012.
NY...HEAT ADVISORY UNTIL 8 PM EDT WEDNESDAY FOR NYZ067>071.
HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NYZ078-080-177-
179.
HEAT ADVISORY UNTIL 8 PM EDT THURSDAY FOR NYZ072>075-176-178.
NJ...HEAT ADVISORY UNTIL 8 PM EDT WEDNESDAY FOR NJZ006-104-106-108.
HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NJZ004-103-105-
107.
MARINE...NONE.
&&
$$
SYNOPSIS...JM/DS
NEAR TERM...JM/PICCA
SHORT TERM...JM
LONG TERM...DS
AVIATION...NV
MARINE...JM/DS
HYDROLOGY...JM/DS
CLIMATE...
AREA FORECAST DISCUSSION
NWS TAUNTON MA
715 PM EDT TUE JUL 16 2013
.SYNOPSIS...
HOT AND HUMID WEATHER WILL CONTINUE THIS WEEK WITH ONLY WIDELY
SCATTERED SHOWERS OR THUNDERSTORMS ON WED. CHANCES FOR SHOWERS
AND THUNDERSTORMS WILL INCREASE THU...FRI AND ESPECIALLY SAT AS A
COLD FRONT APPROACHES FROM THE GREAT LAKES. RELIEF FROM THE HEAT
AND HUMIDITY WILL ARRIVE ON SUNDAY BEHIND A STRONG COLD FRONT AND
LAST THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
715 PM UPDATE...
COUPLE OF SHOWERS FORMED IN MERRIMACK VALLEY BEHIND SEA BREEZE
FRONT...ONE MAKING IT ALL WAY TO BOSTON. DESPITE DECENT
INSTABILITY AND LOW LEVEL LAPSE RATES...LACK OF DEEP MOISTURE /AS
SEEN IN K-INDEX/ PREVENTED MUCH IN WAY OF DEVELOPMENT. EXPECT ANY
REMAINING SHOWERS TO DISSIPATE SHORTLY AFTER SUNSET.
OTHERWISE ANOTHER WARM AND MUGGY NIGHT AHEAD. EXPECT PATCHY FOG TO
DEVELOP NEAR S COAST AS WELL AS ACROSS SOME OF INTERIOR VALLEYS.
LOWS SHOULD FALL BACK INTO 60S TO SOME MID 70S IN URBAN AREAS.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
WED WILL BE SIMILAR TO TODAY...WITH A MOSTLY CLEAR START AND
TEMPERATURES RAPIDLY CLIMBING INTO THE LOWER TO MID 90S.
TEMPERATURES WILL BE A COUPLE OF DEGREES WARMER AND DEWPOINTS WILL
BE A DEGREE OR TWO HIGHER...WHICH WILL LEAD TO HEAT INDICES
REACHING 98-102 OVER MOST OF SOUTHERN NEW ENGLAND...INCLUDING
SOUTHERN NH...WITH THE ONLY EXCEPTIONS BEING CAPE COD AND THE
ISLANDS. THUS HAVE ISSUED A HEAT ADVISORY FOR MOST OF THE REGION
FOR WED AFTERNOON AND EARLY EVENING.
WINDS WILL STILL BE LIGHT...BUT SHOULD TURN TO A SOUTHERLY
DIRECTION. ALTHOUGH HIGHS REACHED 90 ON BLOCK ISLAND TODAY...WITH
LIGHT SOUTHERLY WINDS EXPECTED OFF OF THE COOLER WATERS WED...HAVE
ONLY FORECAST MID 80S THERE...IT COULD POTENTIALLY BE COOLER THAN
THAT.
THERE IS A CHANCE OF AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS
ON WED...MAINLY IN SOUTHERN NH AND NORTHERN MA...AS LOW PRESSURE
MOVES ACROSS SOUTHERN QUEBEC AND A TROUGH OF LOW PRESSURE PASSES
ACROSS NEW ENGLAND. UPPER LEVEL HIGH PRES RIDGE STILL IN CONTROL
THOUGH WITH CAP AROUND H7 AND UNFAVORABLE MID LEVEL LAPSE RATES.
SB CAPE VALUES LOOK TO BE A BIT HIGHER THANKS TO THE INCREASING
MOISTURE WITHIN THE COLUMN...AVERAGING ABOUT 1500-2000 J/KG.
THEREFORE...WENT WITH 25 TO 35 PCT CHANCE IN NORTHEAST MA/SOUTHERN
NH AND 20 PCT FARTHER TO THE SOUTH INTO NORTHERN CT/RI/SOUTHEAST
MA.
WEDNESDAY EVENING...ANY CONVECTION WILL DIMINISH AGAIN BY SUNSET.
ANOTHER WARM AND MUGGY NIGHT WITH CLEAR TO PARTLY CLOUDY SKIES IS
EXPECTED. PERHAPS A LITTLE MORE PATCHY FOG AS THE AIR MASS GETS
EVEN MORE HUMID. LOWS MAINLY UPPER 60S TO MID 70S.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
HEADLINES...
* HOT/HUMID THU INTO SAT WITH SCATTERED T-STORMS
* SEVERE STORMS POSSIBLE AHEAD OF A COLD FRONT SAT
* SEASONABLE AND DRY SUNDAY INTO THE BEGINNING OF NEXT WEEK
DETAILS...
NOT MUCH CHANGE IN OUR FORECAST THINKING FROM PREVIOUS SHIFTS.
MODELS REMAIN IN GOOD OVERALL AGREEMENT SHIFTING H5 HIGH SOUTH
AND WEST TOWARDS THE FOUR-CORNERS REGION ALLOWING FOR FALLING
HEIGHTS ACROSS NEW ENGLAND. THIS RESULTS IN THE RETURN OF THE
NORTHERN STREAM AS DOMINANT INFLUENCE AND SUBSEQUENTLY A MORE
ACTIVE PATTERN.
THURSDAY...
MODELS KEY ON LEE TROUGH BECOMING FOCUS FOR SCATTERED AFTERNOON
CONVECTION. SURFACE-BASED CAPES REACH 1500 J/KG WITH DECENT MID
LEVEL LAPSE RATES AROUND 6C/KM...BUT 0-6KM SHEAR IS MARGINAL AT
BEST. STILL NEED TO OVERCOME RATHER WARM MID LEVEL TEMPERATURES...
SO NOT CONFIDENT THAT STORM COVERAGE WILL BE ALL THAT GREAT. KEPT
CHANCE POPS FOR SCATTERED AFTERNOON THUNDERSTORMS WITH CONTINUED
MENTION OF HEAVY RAIN.
HIGH CAPE ENVIRONMENT FAVORS STRONG TO ISOLATED SEVERE STORMS...
BUT OVERALL SEVERE THREAT APPEARS TO BE LIMITED. PRECIPITABLE
WATER VALUES APPROACHING 2 INCHES...WHICH IS AROUND +2 STANDARD
DEVIATIONS...MEANS POTENTIAL FOR HEAVY RAINFALL AND ISOLATED
FLOODING IN STORMS.
HIGHS IN 90S AWAY FROM S COAST COMBINED WITH DEW POINTS IN LOWER
70S WILL ONCE AGAIN YIELD HEAT INDICES AROUND 100.
FRIDAY...
FLOW ALOFT BECOMES FLATTER WHICH SHOULD ALLOW ANY UPSTREAM
ACTIVITY TO PASS TO OUR N. HOWEVER WE REMAIN IN UNSTABLE AIRMASS
WITH BETTER CONVECTIVE POTENTIAL THAN THU. MODELS SHOW SURFACE
BASED CAPES 2000-3000 J/KG AND MID LEVEL LAPSE RATES OVER 6C/KM.
AXIS OF GREATEST 0-6KM SHEAR REMAINS ACROSS NORTHERN NEW ENGLAND
BUT SW NH AND NORTHERN MA ARE ON PERIPHERY OF THIS AXIS WITH
VALUES OF 30-35KT. IN ADDITION WE ARE IN FAVORABLE RR QUAD OF
UPPER JET. ONLY LIMITING FACTOR APPEARS TO BE WARM MID LEVEL TEMPS
/+11C AT 700 MB/ BUT COLDER AIR ALOFT SHOULD BE ABLE TO
COMPENSATE.
EXPECT SCATTERED STORMS TO DEVELOP FRI AFTERNOON ACROSS MUCH OF
SOUTHERN NEW ENGLAND...ASIDE FROM IMMEDIATE S COAST WHICH WILL BE
MORE STABLE DUE TO SW FLOW. SEVERE POTENTIAL IS SOMEWHAT BETTER
THAN THU WITH BETTER POSSIBILITY OF DAMAGING WINDS DUE TO BOWING
SEGMENTS OR LINES. ALSO HAVE CONTINUED POTENTIAL FOR HEAVY
RAINFALL AND ISOLATED FLOODING.
INCREASING SW FLOW WILL RESULT IN WARMER DAY THAN THU. HIGHS
SHOULD TOP OUT IN LOW-MID 90S /GIVEN MODEL 2M TEMPERATURES/
COMBINED WITH DEW POINTS IN LOW-MID 70S SHOULD YIELD HEAT INDICES
OF 100-105. NOT CONFIDENT ENOUGH TO ISSUE EXCESSIVE HEAT WATCH BUT
WE MAY NEED TO DO SO IF THIS BECOMES MORE CERTAIN.
SATURDAY...
BEST POTENTIAL FOR ORGANIZED CONVECTION AS STRONG COLD FRONT
APPROACHES FROM GREAT LAKES. SOME QUESTION AS TO WHETHER OR NOT
ANY EARLY MORNING CONVECTION WILL INHIBIT SIGNIFICANT
DESTABILIZATION DURING AFTERNOON. PATTERN SEEMS TO FAVOR AT LEAST
MORNING SHOWERS/STORMS NEAR S COAST...THEN WE SEE A BREAK BEFORE
ADDITIONAL STORMS FIRE DURING AFTERNOON AND EVENING.
NO REAL CHANGE IN THINKING FROM SPC DAY 4 OUTLOOK AND PREVIOUS
DISCUSSION. EXPECTED INSTABILITY COUPLED WITH BULK SOUTHWESTERLY
UNI-DIRECTIONAL SHEAR AROUND 35 KTS FAVORS MULTICELLS AND LINE
ECHO WAVE PATTERNS WITH DAMAGING WINDS MAIN THREAT. ALSO NEED TO
BE AWARE OF CONTINUED FLASH FLOOD POTENTIAL WITH PRECIPITABLE
WATER VALUES NEAR 2 INCHES.
SUNDAY INTO THE EARLY WEEK...
COLD FRONT WILL HEAD OFFSHORE SUN MORNING...PERHAPS NOT UNTIL SUN
AFTERNOON ON CAPE COD. COOLER AND DRIER AIR WILL FOLLOW ON NW
WINDS LATER SUN. FRONT MAY BECOME STATIONARY AS IT RUNS UP INTO
RIDGING OVER WESTERN ATLANTIC. THIS WOULD KEEP US IN NE FLOW
MON/TUE WITH DRY WEATHER ANTICIPATED...ALTHOUGH IT IS POSSIBLE ONE
OR TWO WEAK AREAS OF LOW PRESSURE COULD COME CLOSE ENOUGH TO BRING
AT LEAST SOME CLOUDINESS TO SE NEW ENGLAND.
&&
.AVIATION /23Z TUESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE THROUGH WED NIGHT.
VFR. EXPECT LOCAL MVFR/IFR IN PATCHY FOG TONIGHT NEAR S COAST
INCLUDING KACK AND IN SOME OF INTERIOR VALLEYS. SEA BREEZES
DEVELOP ONCE AGAIN LATE WED MORNING INTO AFTERNOON...BUT WINDS
ALONG E MA COAST SHOULD TURN S LATE IN DAY. ISOLATED THUNDERSTORMS
MAY DEVELOP AFTER 18Z WED...PRIMARILY IN SOUTHERN NH AND NORTHERN
MA.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF. ISOLATED TSTMS SHOULD
REMAIN N OF AIRPORT WED AFTERNOON BUT MAY IMPACT GARDNER.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THURSDAY AND FRIDAY...MODERATE CONFIDENCE. IFR IN S COASTAL FOG
EARLY. ISOLATED SHOWERS/TSTMS WITH LOCAL IFR IN AFTERNOON.
SATURDAY...MODERATE CONFIDENCE. IFR IN S COASTAL FOG EARLY.
SCATTERED SHOWERS/TSTMS WITH LOCAL IFR IN AFTERNOON/EVENING.
SUNDAY...MODERATE CONFIDENCE. BECOMING VFR BY AFTERNOON.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE...
WINDS AND SEAS REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH
WED NIGHT. HIGH PRES REMAINS OVER THE WATERS THROUGH WED. A LOW
PRES APPROACHES THE WATERS AND WEAKENS WED NIGHT. THERE IS A
CHANCE OF SOME REDUCED VSBYS IN FOG IN SOME SPOTS.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THURSDAY AND FRIDAY...HIGH CONFIDENCE.
WEAK GRADIENT WILL RESULT IN SEA BREEZES ALONG E COAST WITH MORE
OF A SW FLOW ALONG S COAST WHERE 20KT GUSTS POSSIBLE. ISOLATED
THUNDERSTORMS POSSIBLE BOTH DAYS NEAR SHORE. EXPECT AREAS OF
NIGHTTIME AND EARLY MORNING FOG AROUND CAPE COD.
SATURDAY...MODERATE CONFIDENCE.
APPROACHING COLD FRONT WILL BRING INCREASING SW FLOW ON ALL WATERS
AS SEAS SLOWLY BUILD ON S COASTAL WATERS. STAYED BELOW WAVE WATCH
MODEL FORECAST OF 6-8 FT AS THIS MODEL IS TYPICALLY OVERDONE IN SW
FLOW DURING SUMMER...SHOULD BE MORE LIKE 4-5 FT AT MOST AND SCA
WILL PROBABLY BE NEEDED OFFSHORE.
AREAS OF NIGHTTIME AND EARLY MORNING FOG SHOULD PERSIST AROUND
CAPE COD.
SCATTERED THUNDERSTORMS POSSIBLE IN TWO ROUNDS...FIRST EARLY SAT
MORNING /PERHAPS NEAR S COAST?/ AND AGAIN TOWARD EVENING INTO SAT
NIGHT AS COLD FRONT PUSHES THROUGH NEW ENGLAND.
SUNDAY...MODERATE CONFIDENCE.
WINDS SHIFT TO NW AND DIMINISH AS COLD FRONT HEADS OFFSHORE BY
AFTERNOON. SEAS SLOWLY DIMINISH AS WELL BUT SHOULD REMAIN AT 5 OR
6 FT SE OF CAPE COD. SHOWERS/THUNDERSTORMS SHOULD LINGER
INITIALLY ON WATERS SE OF NANTUCKET BUT SHOULD BE WELL OFFSHORE BY
EARLY AFTERNOON.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...HEAT ADVISORY FROM 11 AM TO 7 PM EDT WEDNESDAY FOR CTZ002>004.
MA...HEAT ADVISORY FROM 11 AM TO 7 PM EDT WEDNESDAY FOR MAZ002>021-
026.
NH...HEAT ADVISORY FROM 11 AM TO 7 PM EDT WEDNESDAY FOR NHZ011-012-
015.
RI...HEAT ADVISORY FROM 11 AM TO 7 PM EDT WEDNESDAY FOR RIZ001>007.
MARINE...NONE.
&&
$$
SYNOPSIS...JWD/GAF
NEAR TERM...JWD
SHORT TERM...GAF
LONG TERM...JWD
AVIATION...JWD/GAF
MARINE...JWD/GAF
AREA FORECAST DISCUSSION
NWS ALBANY NY
640 AM EDT MON JUL 15 2013
.SYNOPSIS...
HOT AND HUMID CONDITIONS ARE EXPECTED THROUGH MOST OF
THIS UPCOMING WEEK AS A LARGE RIDGE OF HIGH PRESSURE EXPANDS ACROSS
MOST OF THE NATION. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL
GRADUALLY INCREASE AS THE WEEK PROGRESSES WHICH COULD OCCUR DURING
THE AFTERNOON AND EVENING HOURS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM EDT...SCT-BKN AC DECK WAS DRAPED FROM WESTERN NY INTO
THE CATSKILLS AND MID HUDSON VALLEY. THIS SEEMS TO BE THE DIVISION
DEWPOINT LINE AND LATEST HRRR EXPERIMENTAL REFLECTIVITIES STILL
KEEPS OUR REGION DRY. SO NO MAJOR CHANGES TO THE CURRENT FORECAST
JUST A REFRESH OF HOURLY GRIDS.
AS OF 400 AM EDT...UPPER AIR PATTERN OVER EASTERN 2/3RDS OF THE
CONUS REMAINS SOMEWHAT RETROGRESSIVE AS LARGE UPPER HIGH WAS
CENTERED OVER THE OHIO RIVER VALLEY AND UPPER LOW OVER THE RED
RIVER VALLEY. THIS WILL KEEP OUR WEATHER PATTERN RATHER QUIET WITH
RESPECT TO CONVECTIVE POTENTIAL BUT RATHER WARM/HOT AND MUGGY
CONDITIONS. H500 TEMPS ARE EXPECTED TO BE AOA -6C WITH H700 TEMPS
AOA +10C...SO A VERY WARM AND CAPPED ENVIRONMENT. FORECAST BUFR
PROFILES TODAY POINT TOWARD EFFECTIVE MIXING LAYER HEIGHTS AROUND
H825 WHERE +17C ISOTHERM RESIDES. DRY ADIABATIC DECENT POINTS
TOWARD 90+ FOR VALLEY LOCATIONS AND 80S FOR THE HIGHER TERRAIN.
QUESTION FOR TODAY WILL BE THE DEWPOINTS AND ITS IMPACTS TO THE
APPARENT TEMPERATURE. ISODROSOTHERMS ANALYSIS REVEALS SOMEWHAT
COOLER VALUES ACROSS NEW ENGLAND AND TRAJECTORIES SUGGEST THESE
LOWER VALUES SHOULD MIGRATE INTO OUR CWFA. IF THIS REMAINS ON
TRACK...THEN HEAT INDICES SHOULD REMAIN JUST BELOW ADVISORY
CRITERIA. HOWEVER...IT WILL BE CLOSE AND PER COLLABORATION WITH
OKX...WE WILL RETAIN THE HEAT ADVISORIES FOR EASTERN ULSTER...ALL
OF DUTCHESS AND LITCHFIELD COUNTIES.
THE UPPER HIGH CONTINUES TO SLOWLY RETROGRADE FURTHER WEST BUT
KEEP OUR WEATHER TRANQUIL. MOS NUMBERS ARE FAIRLY REASONABLE WITH
MAINLY 60S FOR THE OVERNIGHT LOWS AND A MODEL BLEND WAS UTILIZED
WITH A LITTLE MORE EMPHASIS TOWARD THE MET NUMBERS. WE COULD GET
ADDITIONAL PATCHY FOG DEVELOPMENT WHERE DEWPOINT DEPRESSIONS
COLLAPSE WITH LIGHT WINDS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
AS THE LARGE UPPER HIGH CONTINUES TO SLOWLY RETROGRADE...THIS WILL
ALLOW FOR A GRADUAL HEIGHT FALLS ACROSS THE CWFA AND AN INCREASING
NORTHWEST FLOW. PER CLIMATOLOGY...THESE NORTHWEST FLOWS UNDER A
VERY WARM/HOT AND MOIST AIR MASS COULD POSE A CHALLENGE WITH
CONVECTIVE FORECASTS. LATEST MODELS SEEM TO SUGGEST THIS WITH SOME
QPF EXPECTED IN THE AFTERNOON AND EVENING ACROSS THE HIGHER
TERRAIN MAINLY TO THE NORTH AND EAST OF THE CAPITAL DISTRICT. ANY
SUBTLE SHORT WAVE ON TOP OF FORECAST SBCAPES OF 1-2K J/KG COULD
ALLOW PARCELS TO BYPASS THE CAP AOA H700 FOR ISOLATED CONVECTION
TO DEVELOP. AS PER THE PREVIOUS EXCELLENT FORECAST...WE WILL
RETAIN THE SLIGHT CHANCE POPS. HIGHS ON TUESDAY ARE EXPECTED TO BE
SIMILAR TO MONDAY/S BUT THE DEWPOINTS ARE EXPECTED TO BE A LITTLE
HIGHER. THIS MAY POSE ANOTHER OPPORTUNITY FOR HEAT ADVISORIES FOR
VALLEY LOCATIONS MAINLY SOUTH OF ALBANY.
ANY CONVECTION SHOULD QUICKLY DISSIPATE TUESDAY EVENING WITH THE
LOSS OF DAYTIME HEATING. IT WILL BE ANOTHER WARM AND MUGGY NIGHT
FOR THE REGION WITH MAINLY 60S FOR OVERNIGHT LOWS /AROUND 70F IN
THE VICINITY OF THE HUDSON RIVER SOUTH OF KGFL.
WEDNESDAY...THE NAM AND ECMWF ARE VERY SIMILAR WITH AN INJECTION
OF MUCH DRIER AIR AOB H500. WITH THAT WRITTEN...SBCAPES ARE
EXPECTED TO BE CLIMB AT OR ABOVE 2K J/KG WITH THE GFS MORE ROBUST
WITH CONVECTIVE DEVELOPMENTS IN THE AFTERNOON AND TOWARD SUNSET.
A CLOSER LOOK AT 1.5PVU SURFACE...ITS DIFFICULT TO FIND AN ANOMALY
TO RESULT IN THE GFS QPF FORECAST. BUT THE SURFACE FEATURES DO
HINT A WEAK TROUGH AXIS SLIDING THROUGH WITH A WIND SHIFT FROM THE
WESTERLY DIRECTION. FOR NOW...WE WILL RETAIN THE PREVIOUS
FORECAST FOR KEEPING POPS JUST BELOW SLIGHT CHANCE. HIGHS
WEDNESDAY AFTERNOON COULD CLIMB INTO THE MIDDLE 90S AS LOW LEVEL
FLOW BECOMES MORE WESTERLY AND A SLIGHT INCREASE IN THE H825
TEMPS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
DURING THIS PERIOD WE WILL BEGIN TO SEE A SLOW BREAKDOWN IN THE HEAT
WAVE ALTHOUGH FROM THIS VANTAGE POINT.
WE KEEP IT DRY (14 POPS) WEDNESDAY NIGHT BUT STILL MUGGY WITH
OVERNIGHT LOWS WITHIN A FEW DEGREES OF 70.
THEN...ON THURSDAY INTO FRIDAY...AS 500MB HEIGHT FALLS COMMENCE...AT
THE SURFACE...A COLD FRONT LOOK TO SLOWLY SINK SOUTHWARD FROM
CANADA. ALTHOUGH IT MIGHT STILL BE LOCATED JUST TO THE NORTH OF OUR
REGION...IT WILL SERVE TO BEGIN TO BREAK THE "CAP" IN
ATMOSPHERE...ESPECIALLY NORTH. ON THURSDAY AND FRIDAY WE INCLUDE
POPS FOR SHOWERS/THUNDERSTORMS (30 POPS FAR NORTH) ONLY 20 POPS
FURTHER SOUTH. IT WILL STILL BE HOT AND HUMID WITH TEMPERATURES
REACHING 90-95 IN VALLEY AREAS...MID TO UPPER 80S ACROSS THE HIGHER
TERRAIN. HEAT INDICES WILL REACH 95 TO 100 IN THE VALLEY AREAS
AGAIN...CONTINUING THE HEAT WAVE.
AS WE HEAD INTO THE WEEKEND...INDICATIONS ARE A SECOND STRONGER COLD
FRONT COULD FOLLOW ON THE HEELS OF THE FIRST ONE...BUT THE EXACT
TIMING IS IMPOSSIBLE TO DETERMINE THIS FALL OUT. THIS FRONT COULD
BRING PERHAPS A MORE SIGNIFICANT ROUND OF THUNDERSTORMS...ESPECIALLY
IF ARRIVES LATER SATURDAY DURING THE HEATING OF THE DAY. IT IS TOO
EARLY TO FULLY ASSESS THE SEVERE POTENTIAL OF THE THUNDERSTORMS.
THERE SHOULD BE PLENTY OF INSTABILITY OF A 1000 J/KG EACH OF THESE
DAYS TO WORK WITH. THE WIND FIELD WILL INCREASE SOMEWHAT THROUGH THE
PERIOD.
WITH MORE CLOUDS ANTICIPATED SATURDAY...HIGH TEMPERATURES WILL BE
MORE LIKE 85 TO 90 IN THE VALLEYS...WITH A FEW DEGREES OF 80 IN THE
MOUNTAINS. FINALLY...BY SUNDAY WITH RAIN OR SHINE...HIGH
TEMPERATURES LOOKS TO COOL OFF EVEN MORE...80 TO 85 IN THE
VALLEYS...ONLY 70S HIGHER TERRAIN. DEWPOINTS LOOK TO DROP INTO THE
50S.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL REMAIN IN ALL LEVELS OF THE ATMOSPHERE FOR THE
NEXT SEVERAL DAYS.
VFR CONDITIONS SHOULD PREVAIL AT KPOU AND KALB THROUGH THE DAY.
THERE HAS BEEN IFR FOG AT BOTH KPSF AND KGFL...BUT SOME MID LEVEL
CLOUDS HAVE MOVED IN AND HELPED THIN THE FOG. HOWEVER...WILL
CONTINUE WITH OCCASIONAL IFR FOG AT BOTH TAF SITES THROUGH 12Z.
ANY AND ALL FOG WILL DISSIPATE AROUND THE MORNING PEAK AT KPSF AND
KGFL (12Z). AFTER THAT VFR CONDITIONS WILL PREVAIL EVERYWHERE. A
NORTHWEST OR WEST WIND WILL INCREASE TO 5-10KTS...WITH PERHAPS A FEW
HIGHER GUSTS AT KPSF AND KALB NOT INCLUDED IN THE TAF AT THIS TIME.
THERE MIGHT BE A FEW CUMULUS WITH BASED AROUND 6000 FEET LATER BY
AFTERNOON.
MONDAY NIGHT...MAINLY VFR CONDITIONS EXPECTED DURING THE EVENING BUT
IFR FOG MIGHT ENSUE AGAIN AT KGFL AND KPSF AFTER MIDNIGHT. THE WIND
WILL BE LIGHT OR CALM.
WE ARE STARTING A NEW EXPERIMENTAL FORMAT FOR DISPLAYING THE
EXTENDED PORTION OF THE AVIATION DISCUSSION. THIS FORMAT BREAKS THE
EXTENDED PERIODS INTO 12-HOUR INCREMENTS. IT DOES NOT INCLUDE THE
POSSIBILITY OF IFR/VFR BUT THE POTENTIAL SENSIBLE WEATHER AND
"POTENTIAL" IMPACT THE WEATHER MIGHT CAUSE. WE HAVE OMITTED THE WORD
POTENTIAL TO KEEP THE VERBIAGE SHORTER.
OUTLOOK...
TUESDAY: MODERATE OPERATIONAL IMPACT. SLIGHT CHANCE OF RAIN
SHOWERS...THUNDER STORMS.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO
SIGNIFICANT WEATHER.
THURSDAY: MODERATE OPERATIONAL IMPACT. SLIGHT CHANCE OF RAIN
SHOWERS...THUNDER STORMS.
THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF RAIN
SHOWERS...THUNDER STORMS.
FRIDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF RAIN
SHOWERS...THUNDER STORMS.
&&
.FIRE WEATHER...
SIGNIFICANT RAINFALL THAT HAS OCCURRED OVER THE PAST SEVERAL
WEEKS...THERE CONTINUES TO BE NO FIRE WEATHER RELATED CONCERNS. A
FULL RECOVERY IN LOW LEVEL MOISTURE ARE EXPECTED EACH NIGHT AND RH
VALUES WILL REMAIN ELEVATED DURING THE AFTERNOON...DROPPING TO
BETWEEN 40 AND 60 PERCENT.
THE BERMUDA HIGH...AT THE SURFACE AND ALOFT...WILL DOMINATE OVER
THE EASTERN UNITED STATES RESULTING IN A WEEK WITH HOT AND HUMID
CONDITIONS. TOWARDS THE END OF THE WEEK THERE WILL BE A CHANCE OF
SHOWERS AND THUNDERSTORMS AS A FRONTAL BOUNDARY APPROACHES THE
REGION.
&&
.HYDROLOGY...
LITTLE IN THE WAY OF PRECIPITATION IS EXPECTED THROUGH MID WEEK.
LOOKING AT HOT AND HUMID WEATHER AS HIGH PRESSURE DOMINATES THE
REGION. THE OVERALL TREND FOR MAIN STEM RIVERS WILL BE FOR FLOWS TO
CONTINUE TO DECREASE. THE NEXT CHANCE OF MEASURABLE RAIN FOR MOST
AREAS WILL BE TOWARDS THE END OF THE WEEK AS A FRONTAL BOUNDARY
APPROACHES AND MOVES INTO THE REGION.
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.
&&
.CLIMATE...
TO ACCESS HEAT RELATED CLIMATE DATA INCLUDING HEAT WAVES...NUMBER
90+ DEGREES DAYS AND 100+ DEGREES DAYS...PLEASE VISIT
WWW.WEATHER.GOV/ALY/SPECIALDATAALB /ALL LOWER CASE/
NUMBER OF 90+ DEGREE DAYS AND RECORD HIGHS...
ALBANY NY...
2013 MAY: 1 DAY
2013 JUNE: 4 DAYS
2013 JULY: 3 DAYS
2012: 13 DAYS
2011: 8 DAYS
2010: 14 DAYS
NORMAL: 10 DAYS
RECORD HIGHS: (DATE BACK TO 1874)
JULY 14: 99 DEGREES 1995
JULY 15: 96 DEGREES 1997
JULY 16: 97 DEGREES 1900
JULY 17: 99 DEGREES 1900
JULY 18: 100 DEGREES 1953
JULY 19: 97 DEGREES 1904
GLENS FALLS NY...
2013 MAY: 1 DAY
2013 JUNE: 2 DAYS
2013 JULY: 1 DAY
2012: 8 DAYS
RECORD HIGHS: (DATE BACK TO 1949)
JULY 14: 98 DEGREES 1995
JULY 15: 94 DEGREES 1983
JULY 16: 95 DEGREES 1983
JULY 17: 99 DEGREES 1953
JULY 18: 97 DEGREES 1953
JULY 19: 95 DEGREES 1977
POUGHKEEPSIE NY...
2013 MAY: 3 DAY
2013 JUNE: 4 DAYS
2013 JULY: 4 DAYS
2012: 22 DAYS
RECORD HIGHS: (DATE BACK TO 1949)
JULY 14: 99 DEGREES 1954
JULY 15: 98 DEGREES 1995
JULY 16: 103 DEGREES 1995
JULY 17: 98 DEGREES 2006
JULY 18: 100 DEGREES 1991
JULY 19: 102 DEGREES 1991
BENNINGTON VT...
2013 MAY: NONE
2013 JUNE: NONE
2013 JULY: 1 DAY
2012: 7 DAYS
PITTSFIELD MA...
2013 MAY: NONE
2013 JUNE: NONE
2013 JULY: NONE
2012: 3 DAYS
&&
.EQUIPMENT...
KENX NATIONAL WEATHER SERVICE DOPPLER RADAR WILL BE UNAVAILABLE
THROUGH TUESDAY JULY 16 2013. TECHNICIANS CONTINUE TO TROUBLESHOOT
WITH PARTS ON ORDER AT THIS TIME. WE EXPECT A FULL RETURN TO
SERVICE LATE TUESDAY AFTERNOON. WE APOLOGIZE FOR THE INCONVENIENCE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
CTZ001-013.
NY...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
NYZ064>066.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...HWJIV
AVIATION...HWJIV
FIRE WEATHER...IAA/BGM
HYDROLOGY...IAA/BGM
CLIMATE...IAA
EQUIPMENT...IAA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
612 PM EDT MON JUL 15 2013
.SYNOPSIS...
AN OPPRESSIVE HIGH PRESSURE SYSTEM ALONG THE EASTERN SEABOARD IS
EXPECTED TO REMAIN NEARLY STATIONARY THROUGH FRIDAY. A SLOWLY
SOUTHWARD SAGGING COLD FRONT IS FORECAST TO REACH THE NORTHERN
GREAT LAKES ON THURSDAY, LAKE ONTARIO AND LAKE ERIE ON FRIDAY AND
THEN MOVE INTO OUR AREA ON SATURDAY. A SECOND COLD FRONT FROM
EASTERN CANADA IS THEN EXPECTED TO MOVE THROUGH OUR REGION LATER
SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THE EXCESSIVE HEAT WARNING REMAINS IN EFFECT. THE HEAT ADVISORY WILL
BE ALLOWED TO EXPIRE AT 8:00 PM.
A THERMAL SURFACE TROUGH BISECTS THE CWA EARLY THIS EVENING
BENEATH A BUILDING UPPER-LEVEL RIDGE. THERE APPEARS TO BE A SUBTLE
SHORT WAVE ROUNDING THE EASTERN SIDE OF THE RIDGE, AND DESPITE NOT
MUCH FORCING WITH IT THE COMBINATION OF HEAT AND HUMIDITY AND JUST
ENOUGH SURFACE FOCUS HAS LEAD TO A FEW ISOLATED SHOWERS AND
THUNDERSTORMS. THE MAJORITY OF THE CWA IS EXPECTED TO REMAIN RAIN-
FREE, HOWEVER THE HRRR AND THE SPC WRF INDICATE ADDITIONAL
DEVELOPMENT POSSIBLE FOR THE NEXT FEW HOURS SOUTHWARD. AS A
RESULT, WE ADDED IN A SLIGHT CHC POP TO ACCOUNT FOR THIS ACTIVITY
SLIDING SOUTHWARD.
THERE IS NOT A LOT OF WIND HOWEVER THE FLOW IS FORECAST TO BECOME
MORE NORTHERLY DURING THE NIGHT, WHICH MAY TRY AND PULL DOWN SOME
DRIER AIR. THIS MAY NOT BE REALIZED THOUGH HOWEVER ACROSS MUCH OF
THE CWA GIVEN LIGHT ENOUGH SURFACE WINDS /REDUCED VERTICAL MIXING/
AN ENOUGH LINGERING LOW-LEVEL MOISTURE IN PLACE. WE DID MAINTAIN A
SIMILAR TREND IN DEW POINTS FROM CONTINUITY, WHICH SHOWS A LITTLE
BIT OF LOWERING ESPECIALLY ACROSS THE FAR NORTH.
LOW TEMPERATURES WERE MOSTLY A GFS/NAM MOS BLEND WITH SOME MINOR
TWEAKS. THE HOURLY GRIDS WERE INITIALIZED WITH THE 21-22Z OBS AND
THEN SOME BLENDING IN OF THE LAMP/LAV GUIDANCE WAS USED.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
WITH SOME SLIGHTLY DRIER AIR IN PLACE TOMORROW, ACTUAL AIR
TEMPERATURES SHOULD EITHER BE THE SAME AS TODAY OR A DEGREE OR TWO
HIGHER. BUT WITH DEWPOINTS DROPPING 5 TO 10 DEGREES, APPARENT
TEMPERATURES SHOULD BE SLIGHTLY COOLER THAN WHAT WE`RE EXPERIENCING
TODAY. THAT SAID, THE EXCESSIVE HEAT WARNING FOR THE URBAN AREAS
WILL STICK, BUT WE WILL NOT BE ISSUING ANY OTHER ADVISORIES LIKE WE
HAVE UP TODAY.
SO TEMPS WILL TOP OUT IN THE MID 90S IN MOST SPOTS TOMORROW. THE
POCONOS SHOULD TOP OUT AROUND 90. WINDS WILL BE OUT OF THE NORTH,
LESS THAN 10 MPH UNDER MOSTLY SUNNY SKIES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
THE 500MB 12Z UA ANALYSIS HAD A BOATLOAD OF 599 DM HEIGHTS IN THE
OHIO VALLEY THIS MORNING WITH THE LATEST HEAT RIDGE. ACCORDING TO
METEOROLOGIST TOM GREEN, THE 600 DM HEIGHT OFF THE PBZ SOUNDING LAST
NIGHT IS BELIEVED (BUT NOT CONFIRMED) TO BE THE FIRST TIME THAT HAS
EVER HAPPENED THERE.
THE GFS INITIALIZATION OVERALL LOOKED PRETTY GOOD AND SLIGHTLY
BETTER THAN THE WRF-NMMB. THE LARGER GEOGRAPHICAL HEAT RIDGE LOOKS
BETTER (WELL SORT OF). DP/DTG THIS 12Z RUN IS SHOWING A ZERO SUM
GAIN AS THE RIDGE IS RETROGRADING FASTER, BUT IS ALSO LARGER LEAVING
SIMILAR HEIGHT VALUES. THE 12Z GFS ENSEMBLE MEAN IS PRETTY CLOSE TO
THE OPERATIONAL RUN, SLIGHTLY SLOWER OVERALL.
GIVEN THE ACCUMULATIVE EFFECT OF HEAT AND WHAT LOOKS LIKE 99.4%
ASSURED OF REACHING INTO THE MIDDLE 90S ALONG THE I95 URBAN CORRIDOR
INTO FRIDAY, WE DECIDED TO FORGO THE MULTIPLE HEADLINES AND EXTEND
THE EXCESSIVE HEAT WARNING THROUGH THE WORK WEEK. IN OTHER AREAS,
THURSDAY AND FRIDAY LOOK LIKE ADVISORY, POSSIBLY WARNING HEADLINE
DAYS, A LITTLE IFFIER FOR WEDNESDAY WHERE BORDERLINE HEAT ADVISORY
CRITERIA MAY BE MET. IN THESE AREAS, WE WILL CONTINUE MENTION IN THE
HWO. CONVECTIVE-WISE THE BREAK IN THE HEAT COULD COME WITH THE PRICE
OF AN ORGANIZED LINE OF STORMS ON SATURDAY. THAT IS DAYS AWAY AND
THERE IS UNCERTAINTY HOW THIS WILL AFFECT OUR AREA.
WE ARE BANKING ON A 95ISH HIGH FOR PHL TODAY AS THE TEMPLATE FOR
FUTURE DAYS MAX TEMPS. THE COMBINATION OF HOME GROWN (VS CENTRAL
CONUS BAKING) HEAT AND ALL OUR RECENT WETNESS WILL LIKELY PRECLUDE
MOST OF US FROM HITTING 100F AIR TEMPERATURES, IF THAT IS ANY
CONSOLATION.
THE SHIFT OF THE WINDS TO THE NORTH ON TUESDAY AND RELATIVE CLEAR
SKIES AND LIGHT WINDS WILL GIVE NON URBAN AREAS A BIT OF A NIGHT
TIME REPRIEVE FROM THE HEAT AS STAT GUIDANCE HAS TRENDED DOWNWARD
FROM A COUPLE OF DAYS AGO. MIN TEMPS ARE A BLEND OF CONTINUITY AND
THIS NEW GUIDANCE, STILL LIKELY FOR MINS TO ONLY FALL TO THE MID TO
UPPER 70S IN URBAN CENTERS.
ON WEDNESDAY WE ARE EXPECTING THE CAP TO HOLD WITH THE CONVECTIVE
TEMP VERY CLOSE TO THE MAX TEMP. NO THUNDER IN THE FORECAST. WE ARE
GETTING MIXED MESSAGES WITH THE THERMAL FIELDS, 1000-850MB THICK
SUGGEST EQUAL MAXES FROM TUE, WHILE 850S AND 925S SUGGEST A DEGREE
HIGHER. WE HAVE OPTED FOR ABOUT THE SAME. WE SHOULD MIX UP TO 850MB
AND WITH THE FCST AIR MASS EXPECTED TO BE RELATIVELY DRY, DEW POINT
STAT GUIDANCE DROPPING INTO THE MID TO UPPER 60S SEEMS LOGICAL. HEAT
INDEX VALUES IN URBAN CENTERS GET TO ABOUT 100F AND SERN CWA. THEY
MAY FALL JUST SHORT (POCONOS SHOULD REMAIN WELL BELOW) ELSEWHERE. SO
NO HEAT HEADLINES FOR OTHER LOCALES.
MUGGIER NIGHT WEDNESDAY NIGHT AS DEW POINTS WILL START OUT HIGHER
WITH A 1-3F BUMP UP IN MIN TEMPS FROM TUESDAY NIGHT. ON THURSDAY
BOTH THE GFS AND WRF-NMMB HAVE SUFFICIENT MOISTURE FORECAST FOR THE
CONVECTIVE TEMPERATURE TO BE REACHED. THEY ALSO HAVE A HINT OF A LEE
SIDE TROF FORMING AS A POSSIBLE CONVECTIVE FOCUS AS COULD BE THE SEA
AND BAY BREEZE FRONTS. WHILE WE ARE NOT EXPECTING ORGANIZED SEVERE,
THE POSSIBILITY OF ISOLATED PULSE TYPE SEVERE IS NOT OUT OF THE
QUESTION. THE SAME CAN BE SAID FOR FRIDAY. ON FRIDAY, AN EVEN UGLIER
COMBINATION OF TEMPERATURES AND DEW POINTS IS EXPECTED. MAX TEMPS
WERE BUMPED UP ABOUT A DEGREE, BUT HIGHER DEW POINTS ARE BRINGING
HEAT INDICES AT OR ABOVE 100F TO A LARGER PART OF OUR CWA.
AFTER ANOTHER MUGGY NIGHT, THE HEAT AND HUMIDITY MAY PEAK ON FRIDAY.
THE GFS ONCE AGAIN IS THE MOST BULLISH WITH THIS IDEA. UNLESS THERE
ARE CONSIDERABLE DEBRIS CLOUDS AROUND, AT THE LEAST MID 90S FOR
HIGHS IN THE URBAN CORRIDOR APPEAR LIKELY. COUPLED WITH WHAT SHOULD
BE HIGHER AND POOLING DEW POINTS AS THE COLD FRONT COMES CLOSER WE
HAVE THE HIEST FCST HEAT INDICES FOR THIS WEEK. MAX TEMPS WERE KEPT
ABOUT THE SAME.
SATURDAY LOOKS TO BE THE MOST CONVECTIVELY ACTIVE DAY OF THE WEEK.
SPC ALREADY HAS NORTHERN AREAS OF OUR CWA IN THEIR OUTLOOK FOR
POSSIBLE SEVERE WEATHER. AS THE JET STREAM DIPS SOUTHWARD, THE FCST
BULK SHEAR VALUES DO LOOK MORE FAVORABLE FOR ORGANIZED SEVERE AND
THE MID LEVEL LAPSE RATES AT THIS JUNCTURE ARE NOT FORECAST TO BE AN
IMPEDING FORCE. WE HAVE TO SEE HOW FRIDAY`S AND FRIDAY NIGHT`S
UPSTREAM CONVECTION AFFECTS US. FOR NOW WE CARRY THE HIEST POPS OF
THE WEEK IN THIS FORECAST PERIOD. SATURDAY COULD ALSO BE
PROBLEMATICAL FOR HEAT PENDING ON THE FRONT`S TIMING. MODELS OFTEN
GIVE CLOUDS TOO MUCH CREDIT ON THESE DAYS ON DAMPENING MAX TEMPS.
THEN FOR SUNDAY AND MONDAY WE KEPT IN LOWER CHANCES AS A SECOND FRONT
IS FORECAST TO MOVE THROUGH AND ALSO THE POSSIBILITY OF A WAVE
FORMING ON THE FRONT. THE PASSING OF THE FIRST FRONT SHOULD BRING
MORE TOLERABLE TEMPERATURES BACK INTO THE AREA.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TONIGHT...VFR. WEST-NORTHWEST WINDS AROUND 10 KNOTS EARLY, THEN BECOMING
NORTHERLY 4-8 KNOTS. AN ISOLATED SHOWER OR THUNDERSTORM THIS
EVENING. ANY LIGHT FOG LATE SHOULD BE RATHER LOCALIZED.
TUESDAY...VFR WITH FEW TO SCATTERED CUMULUS DEVELOPING WITH BASES
NEAR 5,000 FEET. NORTHERLY WINDS NEAR 10 KNOTS, ALTHOUGH PERHAPS
SHIFTING TO THE EAST OR SOUTHEAST IN THE AFTERNOON AT KACY.
OUTLOOK...
TUESDAY NIGHT THROUGH FRIDAY...MAINLY VFR WITH LATE NIGHT AND EARLY
MORNING VISIBILITY RESTRICTIONS IN HAZE POSSIBLE EACH DAY.
FRIDAY NIGHT AND ESPECIALLY SATURDAY...SOME MVFR TO IFR CONDITIONS
IN MORNING FOG AND HAZE AS WELL AS SHOWERS AND THUNDERSTORMS. GUSTY
WINDS FROM THUNDERSTORMS POSSIBLE.
&&
.MARINE...
WEST WINDS 10 KT OR LESS THIS EVENING WILL BECOME NORTHWEST BY
DAYBREAK. WINDS WILL GO NORTH TOMORROW AT THE SAME SPEEDS. SEAS
MAINLY 2 TO 3 FEET THROUGH TOMORROW AFTERNOON.
OUTLOOK...
SCA HEADLINES ARE NOT ANTICIPATED INTO FRIDAY MORNING ON THE OCEAN
AND THROUGH THE OUTLOOK PERIOD ON DELAWARE BAY. LATER FRIDAY INTO
SATURDAY ON THE OCEAN, THE INCREASING SOUTHWESTERLY FLOW PRECEDING
THE COLD FRONT COULD BRING SEAS UP TO SMALL CRAFT ADVISORY CRITERIA.
WE HAVE TAKEN AROUND A FOOT OFF OF WAVE WATCH GUIDANCE BASED ON ITS
PREVIOUS PERFORMANCE IN SIMILAR EVENTS WHICH BRINGS US NEAR THE
THRESHOLD OF SMALL CRAFT ADVISORY CRITERIA VS BEING WELL INTO IT.
&&
.CLIMATE...
BESIDE THE DAYTIME HEAT, THERE HAVE NOT BEEN TOO MANY PLEASANT
NIGHTS FOR SLEEPING. PRIOR TO THIS WEEK MORE OF THE ABOVE NORMAL
TEMPERATURE DEPARTURES THIS MONTH HAVE BEEN ATTRIBUTED TO THE NIGHTS
AS DEW POINT LEVELS HAVE NOT BEEN PLEASANT AT ALL. SO MUCH SO THAT
TO DATE, THE NIGHTMARISH AVERAGE MINIMUM TEMPERATURE IN PHILADELPHIA
OF 74.6 DEGREES IS THE WARMEST ON RECORD FOR ANY MONTH DATING BACK
TO 1874.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR PAZ060-061-101-
103-105.
EXCESSIVE HEAT WARNING UNTIL 8 PM EDT FRIDAY FOR PAZ070-071-
102-104-106.
NJ...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NJZ008>010-012-
013.
EXCESSIVE HEAT WARNING UNTIL 8 PM EDT FRIDAY FOR NJZ015-
017>019.
DE...EXCESSIVE HEAT WARNING UNTIL 8 PM EDT FRIDAY FOR DEZ001.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DRAG/GIGI
NEAR TERM...GORSE
SHORT TERM...KRUZDLO
LONG TERM...GIGI
AVIATION...DRAG/GIGI/GORSE
MARINE...GIGI/KRUZDLO
CLIMATE...GIGI
AREA FORECAST DISCUSSION
NWS MIAMI FL
141 AM EDT MON JUL 15 2013
.AVIATION...
MOSTLY VFR CONDITIONS ARE EXPECTED THROUGH THIS FORECAST PERIOD. A
BATCH OF SHOWERS OVER THE ATLANTIC HAVE BEEN WEAKENING AS THEY
APPROACH THE EAST COAST AND THIS TREND WILL CONTINUE OVER THE
FIRST COUPLE OF HOURS. ADDITIONAL DEVELOPMENT WILL OCCUR INLAND
AWAY FROM THE EAST COAST TERMINALS AND MOVE TOWARDS KAPF AFT
15-17Z. SLIGHT DRYING WILL OCCUR TODAY SO NOT EXPECTING THE
WIDESPREAD ACTIVITY FROM THE PAST COUPLE OF DAYS SO ONLY MENTIONED
VCSH ALONG THE EAST COAST AND VCTS TO KAPF WHERE THEY HAVE THE
GREATEST CHANCE FOR A BRIEF MVFR/IFR CIG OR VSBY CONCERN. EAST
SURFACE WIND WILL CONTINUE THROUGH THE PERIOD AND FLUCTUATE IN
SPEED BY A COUPLE OF KNOTS PRIOR TO AND AFTER SUNRISE.
KOB
&&
.PREV DISCUSSION... /ISSUED 1133 PM EDT SUN JUL 14 2013/
UPDATE...THE NEAR TERM FORECAST WAS JUST UPDATED. RADAR TRENDS
SUGGEST WIDESPREAD ACTIVITY WILL AFFECT THE PALM BEACHES OVER THE
NEXT HOUR OR SO, EVEN THOUGH THERE IS A GENERAL WEAKENING TREND IN
THE CONVECTION. FURTHER DOWN THE COAST, IT REMAINS TO BE SEEN HOW
MUCH ACTIVITY WILL MOVE INLAND OVERNIGHT. WINDS ARE LIGHT BUT THE
EASTERLY FLOW IMPINGING INTO THE AREA COULD ALLOW FOR SOME SHRA OR
TSTORMS TO MOVE ONSHORE OVERNIGHT. /GREGORIA
PREV DISCUSSION... /ISSUED 920 PM EDT SUN JUL 14 2013/
UPDATE...
SHOWERS AND THUNDERSTORMS CONTINUE TO DECREASE IN COVERAGE ACROSS
THE SOUTH FLORIDA AREA THIS EVENING WITH SLIGHTLY MORE ORGANIZED
CONVECTION ACROSS THE GULF WATERS. LATEST HRRR CONTINUES TO DEPICT
ACTIVITY WEAKENING THROUGH THE NEXT FEW HOURS. ADJUSTED POP AND
QPF GRIDS SLIGHTLY. UPDATE SENT.
PREV DISCUSSION... /ISSUED 800 PM EDT SUN JUL 14 2013/
AVIATION...
SHORTWAVE RIDGE BUILDING SOUTH OF EAST CST FL AS MODELS HAVE BEEN
ADVERTISING. CURRENTLY HAS YET TO SET IN ACROSS S FL TO PUSH
STORMS WEST. HENCE ACTIVITY INLAND ENDED UP PROPAGATING INTO THE
EAST COAST THIS EVENING. THIS EVENING WILL BE SEEING SOME DIMINISHING TS
OVERNIGHT ALONG EAST COAST TERMINALS WITH BRIEF PERIODS OF MVFR
CIG/VIS NEXT COUPLE OF HOURS AND EVEN VERY BRIEF IFR. OTHERWISE
VFR CONDITIONS THROUGH TOMORROW EVENING OUTSIDE DIMINISHING CHANCES
OF SHOWERS OR STORMS AFFECTING ANY GIVEN TERMINAL AS OUTLINED
NEXT.
GOING DRY FOR A SPELL OVERNIGHT. MESOANALYSIS SHOW AN AREA OF DRY
LOW LEVEL AIR TRYING TO MOVE WEST FROM BAHAMAS BUT WEAKENS AND
OTHERWISE DOESN`T QUITE MAKE IT. SOME SHRA MAY REDEVELOP COASTAL
WATERS AND THINK CHANCES ARE BETTER DURING THE LATE OVERNIGHT
PERIOD FOR EASTERN TERMINALS WHERE LOW LEVEL FLOW SHOULD BE A
LITTLE STRONGER. THIS IS ALL INDICATIVE OF AREA TRANSITIONING TO A
MORE TYPICAL EASTERLY FLOW PATTERN AND WITH THAT WILL MENTION VCSH
OVERNIGHT INTO LATE TOMORROW MORNING OR VERY EARLY AFTERNOON. WITH
LOW LEVEL RIDGE BUILDING IN, ACTIVITY SHOULD TRANSITION AND STAY
INLAND TOMORROW AFTERNOON SO WILL LEAVE VCSH OR VCTS OUT OF THE SE
TERMINALS FOR TOMORROW AFTERNOON EXCEPT AT PBI AND FXE. FOR APF,
ADDED VCSH AND VCTS FROM LATE MORNING ON.
SFC WIND...DCRG EAST FLOW LATE EVENING BCMG ENE AROUND 7KT OR LESS
ALL TERMINALS OVERNIGHT. TOMORROW EAST 7-12KT BY 14-16Z ALL SITES.
PREV DISCUSSION... /ISSUED 241 PM EDT SUN JUL 14 2013/
DISCUSSION...
THE AREA OF PERSISTENT CONVERGENCE AND THUNDERSTORMS THAT HAS
BEEN AFFECTING AREAS AROUND NAPLES THIS MORNING MOVED TO THE
NORTHEAST INTO THE EVERGLADES DURING THE LATE MORNING AND IT IS
NOW AFFECTING AREAS AROUND THE LAKE.
THE 12Z RUN OF THE GFS AND THE LATEST ECMWF PORTRAY THE SAME GENERAL
REASONING THAN THE PAST FEW DAYS: A TROUGH OF LOW PRESSURE OVER THE
CENTRAL US SURROUNDED BY TWO LARGE AREAS OF HIGH PRESSURE. THE
FORECAST STILL CALLS FOR THE AREA OF HIGH PRESSURE IN THE ATLANTIC
TO INTENSIFY AND RETROGRADE OVER THE NE US BETWEEN NOW AND THE
MONDAY-TUESDAY TIME FRAME. BY WEDNESDAY, THE ATLANTIC OCEAN IS
DOMINATED BY TWO LARGE AREAS OF HIGH PRESSURE ONE OVER NORTH AFRICA
AND THE SECOND OVER THE NORTHERN US, WITH MOST OF THE SUBTROPICAL
ATLANTIC UNDER TRADE WINDS.
BY THE MIDDLE OF THE WEEK THE AREA OF HIGH PRESSURE OVER NORTH
AMERICA BEGINS TO WEAKEN SOMEWHAT. THE WEATHER OVER SOUTH FLORIDA
WILL BE DRIVEN BY FLUCTUATIONS IN MOISTURE MOVING WESTWARD ON THE
SOUTHERN PERIPHERY OF THE ATLANTIC HIGH PRESSURE AND SLIGHT CHANGES
IN THE MID LEVEL TEMPERATURES AS SMALL POCKETS OF COOL AIR TRAVEL
AROUND THE AREA OF HIGH PRESSURE IN THE ATLANTIC.
THE INCREASED MOISTURE ASSOCIATED WITH THE REMNANTS WILL CEASE TO
AFFECT SOUTH FLORIDA AFTER TODAY.
THE STEERING WINDS ARE TRANSITIONING TO THE SOUTHEAST TODAY AND ARE
FORECAST TO REMAIN SOUTHEASTERLY FOR THE MOST OF THIS COMING WEEK. A
WEAKNESS IN THE HIGH PRESSURE WILL MOVE FROM EAST TO WEST ON MONDAY
OVER THE BAHAMA ISLANDS. THIS WILL BRING A BRIEF PERIOD OF
NORTHEASTERLY WINDS ON MONDAY MORNING. THIS COULD GENERATE AN
ENHANCEMENT OF MORNING SHOWERS FROM STREAMERS ALONG THE ATLANTIC
COASTAL WATERS AND ENHANCE MOISTURE CONVERGENCE IN THE WEST COAST
DURING THE MORNING HOURS AND POSSIBLY CONCENTRATING THE SHOWER
AND THUNDERSTORM ACTIVITY OVER COLLIER COUNTY IN THE AFTERNOON/EVENING.
WIDESPREAD SHOWERS AND THUNDERSTORMS ARE FORECAST FOR TODAY WITH THE
MAIN CONCENTRATION OVER THE NORTHERN AND WESTERN PORTIONS AS THE
EVENING PROGRESSES. THE INTERACTION OF STORMS WITH OUTFLOW
BOUNDARIES COULD STILL TRIGGER A FEW STORMS OVER THE WESTERN METRO
AREAS THIS AFTERNOON AND EVENING. FOR MONDAY AFTERNOON AND
EVENING THE MAIN CONCENTRATION OF SHOWERS AND STORMS IS EXPECTED FOR
THE INTERIOR AND WEST, AS THE EAST TO SOUTHEAST FLOW GETS
ESTABLISHED.
THE VISIBLE SATELLITE IMAGE SHOWS THE LEADING EDGE OF THE EXPANDING
SUBTROPICAL RIDGE CROSSING THE BAHAMA ISLANDS AROUND 1 PM TODAY. THIS
AREA COINCIDES WITH A DRY SLOT AT 850 MB, AROUND THE HEIGHT OF THE
BASE OF THE SUBTROPICAL INVERSION. ONCE THIS DRY AIR REACHES THE SE
COAST THE CHANCES FOR THUNDERSTORMS WILL DIMINISH SUBSTANTIALLY FOR
THE EAST COAST. HOWEVER, THIS FEATURE IS NOT EXPECTED TO ARRIVE THE
EAST COAST FOR 7 MORE HOURS. FOR NOW HAVE KEPT A 40 PERCENT OF
SHOWERS OVER THE SOUTHERN ATLANTIC WATERS AND A 50 PERCENT FOR THE
EAST COAST METRO AREAS OF MIAMI-DADE. BUT IT IS POSSIBLE THAT SOME
MIXING OF DRY AIR AHEAD OF THE FEATURE COULD START AFFECTING THE
EAST COAST IN THE NEXT FEW HOURS. AREAS TO THE INTERIOR STILL HAVE A
70 PERCENT CHANCE OF SHOWERS AND STORMS FOR THIS AFTERNOON AND
EVENING. A DECK OF MID LEVEL CLOUDS OVER PARTS OF MIAMI-DADE CAN
SLOW DOWN CONVECTION IN THE SHORT TERM. ANOTHER VARIABLE
COMPLICATING THE FORECAST FOR THIS EVENING FOR THE SOUTHEAST COAST
IS THE PRESENCE OF SAHARAN DUST WELL DETECTED BY LIDAR AND THE NAVY
AND GFS AEROSOL MODELS. THE DRY AIR ABOVE THE SURFACE MIXED WITH
THE DUST COULD DIMINISH THE WIDESPREAD CONVECTION BUT STILL ALLOW FOR ONE OR
TWO STRONG STORMS.
MARINE...
TRANQUIL WIND AND SEAS ARE EXPECTED THROUGH THE PERIOD OUTSIDE OF
ROUGHER SEAS NEAR THUNDERSTORMS. A GENERAL LIGHT TO MODERATE EAST TO
SOUTHEAST WIND IS ANTICIPATED THROUGH THE MIDDLE OF NEXT WEEK.
FIRE WEATHER...
NO FIRE WEATHER CONCERNS OR FOG IS ANTICIPATED THIS WEEK. HIGH
RELATIVE HUMIDITY AND AT LEAST SCATTERED SHOWERS WILL PREVAIL. THE
TYPICAL AREA WITH LOWER RELATIVE HUMIDITIES, GLADES AND HENDRY, WILL
MAINTAIN VALUES ABOVE 55 PERCENT AND ABOVE 48 PERCENT FOR THE
LATER PART OF THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 87 76 88 78 / 20 10 30 30
FORT LAUDERDALE 88 79 89 79 / 30 20 30 40
MIAMI 89 78 89 78 / 30 20 30 40
NAPLES 88 73 92 74 / 50 20 40 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
123 PM CDT MON JUL 15 2013
.DISCUSSION...
925 AM CDT
HAVE UPDATED GRIDS AND TEXT PRODUCTS TO HIT THUNDERSTORM CHANCES
HARDER FOR THIS AFTERNOON.
GOES IMAGERY THIS MORNING SHOWS A WEAK SHORTWAVE PUSHING NORTHWARD
INTO THE REGION ON THE SOUTHWESTERN PERIPHERY OF THE VERY STRONG
UPPER HIGH CENTERED JUST OFF TO OUR EAST. INTERESTINGLY...THIS WAVE
CAN BE TRACED BACK TO WHERE TROPICAL STORM CHANTEL DISSIPATED OFF
OFF THE SOUTH EAST COAST OVER THE WEEKEND. SCTD TSRA DEVELOPED OVER
EASTERN TN VALLEY REGION WITH THIS FEATURE SUNDAY AFTERNOON AND
BECOMING MORE CONCERNED THAT WE COULD SEE A REPEAT IN OUR CWA THIS
AFTERNOON.
THE 12Z ILX SOUNDING SAMPLED A VERY TROPICAL AIRMASS WITH PWATS OVER
2 INCHES...WITH GOES SOUNDER PWAT IMAGERY SHOWING A POOL OF 2-2.25"
PWATS EXTENDING FROM CENTRAL IL NORTHEAST INTO NORTHERN INDIANA
PUSHING NORTHWESTWARD INTO THE REGION. MODIFYING THE 12Z ILX/DVN
SOUNDINGS FOR SFC TEMPS IN THE MID-UPPER 80S AND DEWPOINTS IN THE
LOW/MID 70S YIELD MLCAPE VALUES OF 2500-3000 J/KG THIS AFTERNOON
DESPITE THE WARM MID LEVEL TEMPS/MID LAPSE RATES WITH NO CONVECTIVE
INHIBITION. RUC13 FORECAST SOUNDINGS FOR THIS AFTERNOON SHOW VERY
SIMILAR FORECAST VALUES LENDING MORE CONFIDENCE TO THE IDEA THAT IT
WILL GROW STRONGLY UNSTABLE AND UNCAPPED THIS AFTERNOON.
IN ADDITION TO THE WEAK SHORTWAVE...WHICH SEEMS AS THOUGH IT MAY
TEND TO FAVOR CONVECTION FIRING OVER WESTERN AND NORTHWESTERN CWA
THIS AFTERNOON THE OTHER AREA THAT COULD FOCUS DEVELOPMENT IS ALONG
THE ANTICIPATED LAKE BREEZE THIS AFTERNOON. WHILE THE LAKE BREEZE
AND SUBSEQUENT CONVERGENCE WILL NOT BE STRONG OR TERRIBLY DEEP...THE
THE VERY HIGH DEWPOINTS AND RESULTANT LOW LFC HEIGHTS MEAN IT WON`T
BE TOO HARD FOR PARCELS TO REACH LFC. WIND SHEAR PROFILES ARE WEAK
AND MID LEVEL TEMPS VERY WARM SO HAIL THREAT SHOULD BE VERY
LOW...BUT WITH PWATS OVER 2 INCHES AND STRONG INSTABILITY POTENTIAL
FOR BRIEF BUT TORRENTIAL RAINFALL RATES EXISTS AND CANNOT RULE OUT A
WET MICROBURST OR TWO.
IZZI
//PREV DISCUSSION...
253 AM CDT
WARMER AND MORE HUMID WEATHER WILL CONTINUE TO TAKE CENTER STAGE
THIS WEEK. WHILE THE POTENTIAL FOR A FEW ISOLATED SHOWER OR
THUNDERSTORMS WILL EXIST PARTICULARLY THIS AFTERNOON...IT APPEARS
THAT A MORE SIGNIFICANT CHANCE OF RAIN WILL HOLD OFF UNTIL LATE IN
THE WEEK WHEN A COLD FRONT EVENTUALLY SETTLES SOUTH ACROSS THE
MIDWEST.
ANALYSIS OF EVENING UPPER AIR DATA AND OVERNIGHT GOES WATER VAPOR
IMAGERY DEPICT A FAIRLY UNUSUAL WEATHER PATTERN FOR MID-SUMMER...
WITH A CLOSED LOW DRIFTING WESTWARD ACROSS THE SOUTHERN PLAINS AND A
STRONG UPPER RIDGE BUILDING WEST ACROSS THE UPPER OHIO VALLEY.
SOUTHEAST FLOW BETWEEN THESE TWO SYSTEMS WAS SPREADING LOW-LEVEL
MOISTURE INTO THE FORECAST AREA...AS NOTED IN UPSTREAM 00Z SOUNDINGS
SUCH AS NASHVILLE TN. THIS INCREASE IN LOW LEVEL MOISTURE HAS LED TO
ISOLATED AFTERNOON CONVECTION ACROSS PARTS OF THE LOWER OHIO VALLEY
OVER THE PAST COUPLE OF DAYS...AND MODEL GUIDANCE CONTINUES TO
INDICATE CONVECTION WOULD DEVELOP ACROSS PARTS OF THE WFO LOT
FORECAST AREA TODAY. GUIDANCE HAS BEEN OVER-FORECASTING THE EXTENT
OF AFTERNOON CONVECTION UPSTREAM HOWEVER...LIKELY DUE TO MODELED
BOUNDARY LAYER DEW POINT TEMPS THAT ARE TOO HIGH. WITH RELATIVELY
WEAK LOW LEVEL CONVERGENCE AND MORE CONSERVATIVE INSTABILITY
EXPECTED WILL MAINTAIN ONLY SLIGHT CHANCE POPS FOR ISOLATED
CONVECTIVE DEVELOPMENT THIS AFTERNOON...AND THAT MAINLY ALONG THE
LAKE BREEZE BOUNDARY AND NORTHERN IL WHERE LOW-LEVEL CONVERGENCE
WILL BE MORE FOCUSED AND AWAY FROM STRONGER MID/UPPER LEVEL RIDGING
FARTHER TO THE EAST. THUNDERSTORM CHANCES SHOULD BE EVEN LOWER
TUESDAY-THURSDAY AS CENTER OF UPPER RIDGE CONTINUES TO BUILD
WESTWARD ACROSS INDIANA AND ILLINOIS AND SUBSIDENCE AND WARM
MID-LEVEL TEMPS BECOME LESS FAVORABLE FOR CONVECTION.
WITH BUILDING UPPER RIDGE...850MB TEMPS SLOWLY WARM FROM +17/18C
TODAY TO +19/20C LATER IN THE WEEK. TAKING LOCAL CLIMATOLOGY AND
MODEL LOW-LEVEL THERMAL FIELDS INTO ACCOUNT...TEMPS SHOULD WARM FROM
AROUND 90 TODAY TO THE LOWER AND EVEN A FEW MID 90S WED/THURS/FRI.
WITH DEW POINT TEMPERATURES MAINLY IN THE LOWER 70S...THIS SHOULD
SUPPORT HEAT INDEX VALUES MAXING OUT IN THE MID 90S TODAY...AND
AROUND 100 TUESDAY THROUGH FRIDAY. THIS WOULD PRECLUDE ANY HEAT
ADVISORY HEADLINES AT THIS POINT...THOUGH THE PROLONGED PERIOD OF
HEAT AND HUMIDITY WILL HAVE TO BE MONITORED. LAKE COOLING WILL BE
FAIRLY MINIMAL OVER THE NEXT FEW DAYS...MAINLY CONFINED TO THE
IMMEDIATE SHORE AREAS AS LOW LEVEL FLOW BECOMES MORE
WEST-SOUTHWESTERLY.
LONGER RANGE MODEL GUIDANCE IS IN VERY DECENT AGREEMENT THAT THE
UPPER RIDGE OVER THE MIDWEST WILL EVENTUALLY DRIFT SOUTH AND BREAK
DOWN TOWARD THE END OF THE WEEK...WITH AN UPPER TROUGH DEVELOPING
OVER EASTERN CANADA AND THE GREAT LAKES/NORTHEAST STATES. THIS
SHOULD ALLOW A COLD FRONT TO SAG ACROSS THE AREA FRIDAY/FRIDAY
NIGHT...BRINGING A MORE SIGNIFICANT CHANCE OF THUNDERSTORMS
FRIDAY/FRIDAY NIGHT...AS WELL AS COOLER TEMPERATURES AND MORE
PROMINENT LAKE BREEZES TO THE AREA NEXT WEEKEND.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SHOWERS AND POSSIBLE THUNDERSTORMS THROUGH EARLY AFTERNOON.
LENNING
//DISCUSSION...UPDATED 18Z...
SHOWER ACTIVITY THAT POPPED ALONG THE LAKE BREEZE LATE THIS
MORNING IS TRENDING DOWNWARD IN COVERAGE AND STRENGTH AS WE MOVE
INTO EARLY AFTERNOON. EXPECT THE FOCUS TO MOVE WEST WITH LAKE
BREEZE AND OUTFLOW FROM EARLIER ACTIVITY. A FEW GUSTS INTO THE
TEENS WITH VARIABLE WIND DIRECTIONS ARE POSSIBLE WITH THESE
SHOWERS. OTHERWISE WILL CONTINUE THE GRADUAL VEERING OF WINDS
FROM ENE AROUND TO EAST AND THEN EVENTUALLY SOUTH.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM TO HIGH CONFIDENCE THAT SHOWER ACTIVITY WILL DIMINISH
OVER THE TERMINALS AND FOCUS MORE TO THE WEST BY LATER THIS
AFTERNOON.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUE NIGHT...MVFR VISIBILITY DUE TO HZ AND BR.
WED AND THU...MVFR VISIBILITY INTO MID MORNING DUE TO HZ AND BR.
THU...VFR VISIBILITY INTO MID MORNING DUE TO HZ AND BR.
FRI...CHANCE OF TSRA DURING THE AFTERNOON...LIKELY TSRA DURING
THE NIGHT CREATING PERIODS OF MVFR AND IFR.
SAT...CHANCE OF TSRA DURING DAYLIGHT HOURS.
SUN...VFR. NO SIG WX.
TRS
&&
.MARINE...
328 AM CDT
A BROAD AREA OF HIGH PRESSURE WILL REMAIN CENTERED OVER THE
LOWER GREAT LAKES AND THE UPPER OH VALLEY TODAY KEEPING WINDS AT
10 KT OR LESS. THE HIGH WILL START TO DRIFT SLOWLY WSW TONIGHT
AND WILL BE CENTERED OVER THE LOWER OH VALLEY AND THE MID MS
VALLEY BY THURSDAY MORNING. IN RESPONSE...WINDS WILL GENERALLY
VEER FROM SOUTHEAST AND SOUTH TO SOUTH AND SOUTHWEST AND START TO
FRESHEN. DURING THURSDAY AND THURSDAY NIGHT A COLD FRONT WILL BE
DROPPING SOUTHWARD FROM ONTARIO...CROSSING LAKE SUPERIOR BY
FRIDAY MORNING. AHEAD OF THE COLD FRONT WINDS FROM THE SOUTHWEST
WILL INCREASE TO A MODERATE BREEZE. THE COLD FRONT WILL CONTINUE
SLOWLY SOUTHWARD FRIDAY...CROSSING THE NORTHERN PORTION OF LAKE
MI BY LATE IN THE DAY...AND REACHING THE S TIP BY DAWN SATURDAY.
IL AND IN NEARSHORE WATERS WILL BE UNDER THE INFLUENCE OF A LAKE
BREEZE WITH ENHANCED ONSHORE WINDS DURING THE THIS AFTERNOON.
WINDS WILL RETURN TO ONSHORE AGAIN TUESDAY AFTERNOON...BUT MAINLY
ONLY ALONG THE IL SHORE.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
102 PM CDT MON JUL 15 2013
.DISCUSSION...
ISSUED 1047 AM CDT MON JUL 15 2013
WITH MOISTURE INCREASING FROM YESTERDAY WITH SOME SCT SPRINKLES
AND PRETTY EXPANSIVE CU FIELD...SAT IMAGERY IS ON TRACK WITH MORE
CLOUD COVER FOR THIS AFTERNOON AS WELL. SOME OF THE CU GETTING A
BIT TALL WITH SOME SHOWERS POPPING UP NORTH OF CWA. EARLY CU FIELD
IN THE FAR SE HEADED THE SAME WAY. WITH PLENTY OF MUGGY AIR TO
WORK WITH IN THE COLUMN FROM THIS MORNINGS SOUNDING...AND A
SHORTWAVE RIPPLING THROUGH THE CWA...THINK A SLIGHT UPWARD ADJUSTMENT
IN THE POPS MAY BE WARRANTED. CONCERN FOR GOING TOO HIGH OR
WIDESPREAD WITH REGARDS TO THE LOCATION OF THE BEST LIFT WITH THE
SMALL WAVE BY THE TIME PEAK HEATING HITS THIS AFTERNOON. WITH
RATHER NON EXISTENT CAP...SHOULD NOT TAKE MUCH. HAVE BOOSTED FOR
AT LEAST A MENTION TO THE SE FOR SOME ISO SHOWERS...THOUGH SHOULD
BE WELL BEHIND THE WAVE BY THIS AFTERNOON.
&&
.AVIATION...
ISSUED 1257 PM CDT MON JUL 15 2013
CU FIELD A BIT DENSE AND LACK OF CAP RESULTING IN SOME SCT SHOWERS
ACROSS THE AREA. NONE OF THE TERMINALS ARE IN THE PATH OF THE
CURRENT ECHOS...BUT WILL LIKELY SEE ONE OR TWO BEFORE THE END OF
THE DAY. VCTS TO COVER INCREASING THREAT OF THUNDER AS THE
AFTERNOON PROGRESSES. LIGHT WINDS THROUGH THE OVERNIGHT MAY RESULT
IN SOME MVFR FOG...ESP WITH THE INCREASING MOISTURE ACROSS THE
AREA AND THE LACK OF MIXING OUT LIKELY WITH CLOUD COVER
INCREASING.
HJS
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT MON JUL 15 2013
SHORT TERM...TODAY THROUGH FRIDAY
FORECAST CONCERN WILL BE THE HIGH HEAT AND HUMIDITY AS STRONG 600
DM 500 MB HIGH PRESSURE OVER EASTERN OHIO/WESTERN PA RETROGRADES
WESTWARD ACROSS THE SOUTHERN GREAT LAKES AND INTO IL BY WED. 00Z
MODELS ARE IN FAIR AGREEMENT NEXT FEW DAYS AND WILL USE A BLEND.
A WEAK SHORT WAVE AND SURFACE TROF TO LIFT NW ACROSS IL DURING
THE DAY AND INTERACT WITH UNSTABLE AIRMASS WITH CAPES 2000-3000
J/KG AND PRECIPITABLE WATER VALUES 1.75 TO 2.25 INCHES TO DEVELOP
ISOLATED SHOWERS AND THUNDERSTORMS THIS AFTERNOON WEST OF I-57.
SOME MODELS LIKE THE NAM SHOW CONVECTION DEVELOPING DURING THE
MORNING AND IF THIS OCCURS THEN ISOLATED CHANCES IN EASTERN IL
WOULD BE POSSIBLE TOO. LEANED ON THE HRRR AND RUC MODELS FOR
CONVECTION CHANCES TODAY. SCATTERED TO BROKEN CUMULUS CLOUDS TO
DEVELOP IN THE AFTERNOON. HIGHS IN THE UPPER 80S OVER CENTRAL IL
AND LOWER 90S BY THE WABASH RIVER WHICH IS DRYER TODAY. DEWPOINTS
IN THE LOWER 70S TO GIVE HEAT INDICES PEAKING IN MID TO UPPER 90S
THIS AFTERNOON.
ISOLATED CONVECTION COULD LINGER OVER THE IL RIVER VALLEY EARLY
THIS EVENING UNTIL SUNSET...OTHERWISE FAIR AND MUGGY WEATHER
EXPECTED TONIGHT WITH LOWS IN THE LOWER 70S. TEMPS GRADUALLY HEAT
UP NEXT FEW DAYS AS STRONG UPPER LEVEL HIGH PRESSURE RIDGE SETTLES
INTO IL BY WED. HIGHS TUE 89 TO 93 WITH AFTERNOON HEAT INDICES
AROUND 100F. HIGHS 90 TO 95F WED-FRI WITH AFTERNOON HEAT INDICES
PEAKING FROM 98 TO 105F AND HIGHEST IN SOUTHEAST OF I-70 IN
SOUTHEAST IL. BEEN THIS HOT BEFORE ON JUNE 12 BUT THIS WILL BE THE
LONGEST HEAT WAVE OF THE SUMMER...LASTING MUCH OF THIS WORK WEEK.
CHANCES OF SHOWERS AND THUNDERSTORMS LESS THAN 20% EACH AFTERNOON
AND EARLY EVENING DURING MID AND LATE WORK WEEK.
LONG TERM...FRIDAY NIGHT THROUGH SUNDAY
EXTENDED MODELS CONTINUE TO SHOW STRONG UPPER LEVEL RIDGE SLOWLY
WEAKENING AND SHIFTING SOUTHWARD ALLOWING COLD FRONT TO PRESS
SOUTHWARD ACROSS THE GREAT LAKES REGION FRIDAY AND THROUGH IL SAT
AND SAT NIGHT...AND INTO THE OHIO VALLEY SUNDAY. HAVE CHANCES OF
SHOWERS AND THUNDERSTORMS HIGHEST OVER NORTHERN AREAS FRI NIGHT
WITH JUST SLIGHT CHANCES IN SOUTHEAST IL. THEN CHANCE OF
CONVECTION ACROSS AREA SAT AND BEST CHANCES SHIFT INTO SE IL SAT
NIGHT AND SUNDAY. HIGHS BY SUNDAY IN THE MID TO UPPER 80S WITH
DEWPOINTS IN THE MID TO UPPER 60S SO SOME RELIEF FROM THE HIGH
HEAT AND HUMIDITY.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1102 AM CDT MON JUL 15 2013
.DISCUSSION...
925 AM CDT
HAVE UPDATED GRIDS AND TEXT PRODUCTS TO HIT THUNDERSTORM CHANCES
HARDER FOR THIS AFTERNOON.
GOES IMAGERY THIS MORNING SHOWS A WEAK SHORTWAVE PUSHING NORTHWARD
INTO THE REGION ON THE SOUTHWESTERN PERIPHERY OF THE VERY STRONG
UPPER HIGH CENTERED JUST OFF TO OUR EAST. INTERESTINGLY...THIS WAVE
CAN BE TRACED BACK TO WHERE TROPICAL STORM CHANTEL DISSIPATED OFF
OFF THE SOUTH EAST COAST OVER THE WEEKEND. SCTD TSRA DEVELOPED OVER
EASTERN TN VALLEY REGION WITH THIS FEATURE SUNDAY AFTERNOON AND
BECOMING MORE CONCERNED THAT WE COULD SEE A REPEAT IN OUR CWA THIS
AFTERNOON.
THE 12Z ILX SOUNDING SAMPLED A VERY TROPICAL AIRMASS WITH PWATS OVER
2 INCHES...WITH GOES SOUNDER PWAT IMAGERY SHOWING A POOL OF 2-2.25"
PWATS EXTENDING FROM CENTRAL IL NORTHEAST INTO NORTHERN INDIANA
PUSHING NORTHWESTWARD INTO THE REGION. MODIFYING THE 12Z ILX/DVN
SOUNDINGS FOR SFC TEMPS IN THE MID-UPPER 80S AND DEWPOINTS IN THE
LOW/MID 70S YIELD MLCAPE VALUES OF 2500-3000 J/KG THIS AFTERNOON
DESPITE THE WARM MID LEVEL TEMPS/MID LAPSE RATES WITH NO CONVECTIVE
INHIBITION. RUC13 FORECAST SOUNDINGS FOR THIS AFTERNOON SHOW VERY
SIMILAR FORECAST VALUES LENDING MORE CONFIDENCE TO THE IDEA THAT IT
WILL GROW STRONGLY UNSTABLE AND UNCAPPED THIS AFTERNOON.
IN ADDITION TO THE WEAK SHORTWAVE...WHICH SEEMS AS THOUGH IT MAY
TEND TO FAVOR CONVECTION FIRING OVER WESTERN AND NORTHWESTERN CWA
THIS AFTERNOON THE OTHER AREA THAT COULD FOCUS DEVELOPMENT IS ALONG
THE ANTICIPATED LAKE BREEZE THIS AFTERNOON. WHILE THE LAKE BREEZE
AND SUBSEQUENT CONVERGENCE WILL NOT BE STRONG OR TERRIBLY DEEP...THE
THE VERY HIGH DEWPOINTS AND RESULTANT LOW LFC HEIGHTS MEAN IT WON`T
BE TOO HARD FOR PARCELS TO REACH LFC. WIND SHEAR PROFILES ARE WEAK
AND MID LEVEL TEMPS VERY WARM SO HAIL THREAT SHOULD BE VERY
LOW...BUT WITH PWATS OVER 2 INCHES AND STRONG INSTABILITY POTENTIAL
FOR BRIEF BUT TORRENTIAL RAINFALL RATES EXISTS AND CANNOT RULE OUT A
WET MICROBURST OR TWO.
IZZI
//PREV DISCUSSION...
253 AM CDT
WARMER AND MORE HUMID WEATHER WILL CONTINUE TO TAKE CENTER STAGE
THIS WEEK. WHILE THE POTENTIAL FOR A FEW ISOLATED SHOWER OR
THUNDERSTORMS WILL EXIST PARTICULARLY THIS AFTERNOON...IT APPEARS
THAT A MORE SIGNIFICANT CHANCE OF RAIN WILL HOLD OFF UNTIL LATE IN
THE WEEK WHEN A COLD FRONT EVENTUALLY SETTLES SOUTH ACROSS THE
MIDWEST.
ANALYSIS OF EVENING UPPER AIR DATA AND OVERNIGHT GOES WATER VAPOR
IMAGERY DEPICT A FAIRLY UNUSUAL WEATHER PATTERN FOR MID-SUMMER...
WITH A CLOSED LOW DRIFTING WESTWARD ACROSS THE SOUTHERN PLAINS AND A
STRONG UPPER RIDGE BUILDING WEST ACROSS THE UPPER OHIO VALLEY.
SOUTHEAST FLOW BETWEEN THESE TWO SYSTEMS WAS SPREADING LOW-LEVEL
MOISTURE INTO THE FORECAST AREA...AS NOTED IN UPSTREAM 00Z SOUNDINGS
SUCH AS NASHVILLE TN. THIS INCREASE IN LOW LEVEL MOISTURE HAS LED TO
ISOLATED AFTERNOON CONVECTION ACROSS PARTS OF THE LOWER OHIO VALLEY
OVER THE PAST COUPLE OF DAYS...AND MODEL GUIDANCE CONTINUES TO
INDICATE CONVECTION WOULD DEVELOP ACROSS PARTS OF THE WFO LOT
FORECAST AREA TODAY. GUIDANCE HAS BEEN OVER-FORECASTING THE EXTENT
OF AFTERNOON CONVECTION UPSTREAM HOWEVER...LIKELY DUE TO MODELED
BOUNDARY LAYER DEW POINT TEMPS THAT ARE TOO HIGH. WITH RELATIVELY
WEAK LOW LEVEL CONVERGENCE AND MORE CONSERVATIVE INSTABILITY
EXPECTED WILL MAINTAIN ONLY SLIGHT CHANCE POPS FOR ISOLATED
CONVECTIVE DEVELOPMENT THIS AFTERNOON...AND THAT MAINLY ALONG THE
LAKE BREEZE BOUNDARY AND NORTHERN IL WHERE LOW-LEVEL CONVERGENCE
WILL BE MORE FOCUSED AND AWAY FROM STRONGER MID/UPPER LEVEL RIDGING
FARTHER TO THE EAST. THUNDERSTORM CHANCES SHOULD BE EVEN LOWER
TUESDAY-THURSDAY AS CENTER OF UPPER RIDGE CONTINUES TO BUILD
WESTWARD ACROSS INDIANA AND ILLINOIS AND SUBSIDENCE AND WARM
MID-LEVEL TEMPS BECOME LESS FAVORABLE FOR CONVECTION.
WITH BUILDING UPPER RIDGE...850MB TEMPS SLOWLY WARM FROM +17/18C
TODAY TO +19/20C LATER IN THE WEEK. TAKING LOCAL CLIMATOLOGY AND
MODEL LOW-LEVEL THERMAL FIELDS INTO ACCOUNT...TEMPS SHOULD WARM FROM
AROUND 90 TODAY TO THE LOWER AND EVEN A FEW MID 90S WED/THURS/FRI.
WITH DEW POINT TEMPERATURES MAINLY IN THE LOWER 70S...THIS SHOULD
SUPPORT HEAT INDEX VALUES MAXING OUT IN THE MID 90S TODAY...AND
AROUND 100 TUESDAY THROUGH FRIDAY. THIS WOULD PRECLUDE ANY HEAT
ADVISORY HEADLINES AT THIS POINT...THOUGH THE PROLONGED PERIOD OF
HEAT AND HUMIDITY WILL HAVE TO BE MONITORED. LAKE COOLING WILL BE
FAIRLY MINIMAL OVER THE NEXT FEW DAYS...MAINLY CONFINED TO THE
IMMEDIATE SHORE AREAS AS LOW LEVEL FLOW BECOMES MORE
WEST-SOUTHWESTERLY.
LONGER RANGE MODEL GUIDANCE IS IN VERY DECENT AGREEMENT THAT THE
UPPER RIDGE OVER THE MIDWEST WILL EVENTUALLY DRIFT SOUTH AND BREAK
DOWN TOWARD THE END OF THE WEEK...WITH AN UPPER TROUGH DEVELOPING
OVER EASTERN CANADA AND THE GREAT LAKES/NORTHEAST STATES. THIS
SHOULD ALLOW A COLD FRONT TO SAG ACROSS THE AREA FRIDAY/FRIDAY
NIGHT...BRINGING A MORE SIGNIFICANT CHANCE OF THUNDERSTORMS
FRIDAY/FRIDAY NIGHT...AS WELL AS COOLER TEMPERATURES AND MORE
PROMINENT LAKE BREEZES TO THE AREA NEXT WEEKEND.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* CONTINUE TO WATCH FOR POSSIBLE CONVECTIVE DEVELOPMENT. SMALL
CELLS FORMING WELL SOUTHWEST OF THE TERMINALS ARE MOVING
NORTHEAST. MOST FAVORABLE TIMEFRAME FOR ORD/MDW WOULD BE 18-21Z.
LENNING
//DISCUSSION...UPDATED 12Z...
THE LARGE ANTICYCLONE...SURFACE THROUGH THE UPPER LEVELS...WILL
CONTINUE TO RETROGRADE WESTWARD OVER THE REGION WITH IT BEING
CENTERED OVER OH DURING THE DAY. MEANWHILE THE UPPER LOW IN THE
SOUTHERN PLAINS...CURRENTLY CENTERED OVER THE RED RIVER VALLEY...
WILL ALSO RETROGRADE SLOWLY WESTWARD TO THE TX PANHANDLE DURING
THE DAY.
WITHIN THE SOUTHEASTERLY FLOW BETWEEN THESE TWO MAIN FEATURES
SATELLITE LOOPS SHOW MULTIPLE SMALL DISTURBANCES THAT HAVE BEEN
MOVING FROM THE DEEP SOUTH ACROSS THE LOWER OH VALLEY AND MID MS
VALLEY FROM SUNDAY AFTERNOON THROUGH THE OVERNIGHT HOURS.
MODELS...EVEN HI RES ONES...ARE TYPICALLY NOT VERY GOOD
POSITIONING THESE SMALLER DISTURBANCES BEYOND THE NEAR TERM SO
HAVE RELIED MORE ON OLD SCHOOL EXTRAPOLATION TO CONTINUE MOVING
THEM NORTHWEST TO NORTH-NORTHWESTWARD TODAY.
THIS METHOD HAS ONE DISTURBANCE MOVING OVER THE AREA DURING THE
PRE-DAWN AND EARLY MORNING HOURS WITH ANOTHER DURING THE EARLY
AND MID AFTERNOON. WHILE DIURNAL HEATING WILL RESULT IN A CU
FIELD TO DEVELOP BY LATE MORNING TO NOONTIME...THESE DISTURBANCES
WILL START MOVING ANTICYCLONICALLY AS THEY ROTATE THROUGH THE
EAST SIDE OF THE UPPER HIGH. WITHOUT THE AID OF DAYTIME HEATING
AND WITH NORTHWEST MOVEMENT FROM SLIGHTLY CYCLONIC UPPER FLOW TO
NEUTRAL TO SLIGHTLY ANTICYCLONIC FLOW THE FEW TS THAT DEVELOPED
IN SOUTHERN INDIANA SUNDAY EVENING ASSOCIATED WITH THE NORTHERN
MOST IMPULSE DISSIPATED BY 06Z.
WHILE CANNOT TOTALLY RULE OUT AN ISOLATED TS OR TWO WITH THESE
DISTURBANCES THE PROBABILITY OF OCCURRENCE LET ALONG AFFECTING
ORD OR MDW AND VICINITY IS SLIGHT AT BEST.
WITH THE CENTER OF THE ANTICYCLONE CREEPING WESTWARD AND THE LOW
LEVEL FLOW...WEAK AS IT WILL BE...VEERING TO SE TODAY AND THEN
TO S TO SW THE OVERNIGHT THE DEW POINTS OF AROUND 70 JUST TO THE
E THROUGH SW OF THE LOCAL AREA WILL OVERSPREAD THE AREA. WITH
LIGHT TO NIL WIND OVERNIGHT TONIGHT THROUGH DAWN TUE AND SURFACE
COOLING DURING THIS TIME WILL RESULT IN A SHALLOW SURFACE BASED
INVERSION FORMING WHICH WILL CONDUCIVE TO BR AND HZ UNTIL IT
MIXES OUT AFTER SUNRISE TUE.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* LOW CONFIDENCE ON TIMING AND LOCATION OF SHRA AND TSRA...SO
STILL OPTING TO EXCLUDE FROM LATEST TAF AMENDMENT.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUE NIGHT...MVFR VISIBILITY DUE TO HZ AND BR.
WED AND THU...MVFR VISIBILITY INTO MID MORNING DUE TO HZ AND BR.
THU...VFR VISIBILITY INTO MID MORNING DUE TO HZ AND BR.
FRI...CHANCE OF TSRA DURING THE AFTERNOON...LIKELY TSRA DURING
THE NIGHT CREATING PERIODS OF MVFR AND IFR.
SAT...CHANCE OF TSRA DURING DAYLIGHT HOURS.
SUN...VFR. NO SIG WX.
TRS
&&
.MARINE...
328 AM CDT
A BROAD AREA OF HIGH PRESSURE WILL REMAIN CENTERED OVER THE
LOWER GREAT LAKES AND THE UPPER OH VALLEY TODAY KEEPING WINDS AT
10 KT OR LESS. THE HIGH WILL START TO DRIFT SLOWLY WSW TONIGHT
AND WILL BE CENTERED OVER THE LOWER OH VALLEY AND THE MID MS
VALLEY BY THURSDAY MORNING. IN RESPONSE...WINDS WILL GENERALLY
VEER FROM SOUTHEAST AND SOUTH TO SOUTH AND SOUTHWEST AND START TO
FRESHEN. DURING THURSDAY AND THURSDAY NIGHT A COLD FRONT WILL BE
DROPPING SOUTHWARD FROM ONTARIO...CROSSING LAKE SUPERIOR BY
FRIDAY MORNING. AHEAD OF THE COLD FRONT WINDS FROM THE SOUTHWEST
WILL INCREASE TO A MODERATE BREEZE. THE COLD FRONT WILL CONTINUE
SLOWLY SOUTHWARD FRIDAY...CROSSING THE NORTHERN PORTION OF LAKE
MI BY LATE IN THE DAY...AND REACHING THE S TIP BY DAWN SATURDAY.
IL AND IN NEARSHORE WATERS WILL BE UNDER THE INFLUENCE OF A LAKE
BREEZE WITH ENHANCED ONSHORE WINDS DURING THE THIS AFTERNOON.
WINDS WILL RETURN TO ONSHORE AGAIN TUESDAY AFTERNOON...BUT MAINLY
ONLY ALONG THE IL SHORE.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
1052 AM CDT MON JUL 15 2013
.DISCUSSION...
ISSUED 1047 AM CDT MON JUL 15 2013
WITH MOISTURE INCREASING FROM YESTERDAY WITH SOME SCT SPRINKLES
AND PRETTY EXPANSIVE CU FIELD...SAT IMAGERY IS ON TRACK WITH MORE
CLOUD COVER FOR THIS AFTERNOON AS WELL. SOME OF THE CU GETTING A
BIT TALL WITH SOME SHOWERS POPPING UP NORTH OF CWA. EARLY CU FIELD
IN THE FAR SE HEADED THE SAME WAY. WITH PLENTY OF MUGGY AIR TO
WORK WITH IN THE COLUMN FROM THIS MORNINGS SOUNDING...AND A
SHORTWAVE RIPPLING THROUGH THE CWA...THINK A SLIGHT UPWARD ADJUSTMENT
IN THE POPS MAY BE WARRANTED. CONCERN FOR GOING TOO HIGH OR
WIDESPREAD WITH REGARDS TO THE LOCATION OF THE BEST LIFT WITH THE
SMALL WAVE BY THE TIME PEAK HEATING HITS THIS AFTERNOON. WITH
RATHER NON EXISTENT CAP...SHOULD NOT TAKE MUCH. HAVE BOOSTED FOR
AT LEAST A MENTION TO THE SE FOR SOME ISO SHOWERS...THOUGH SHOULD
BE WELL BEHIND THE WAVE BY THIS AFTERNOON.
HJS
&&
.AVIATION...
ISSUED 610 AM CDT MON JUL 15 2013
OTHER THAN SOME PATCHY GROUND FOG EARLY THIS MORNING (UNTIL 13Z)
AND AGAIN AFTR 09Z TONIGHT AT A FEW OF OUR TAF SITES...VFR
CONDITIONS ARE EXPECTED. LATEST FORECAST SOUNDINGS CONTINUE TO
SHOW THE POTENTIAL FOR RAPID CUMULUS DEVELOPMENT AROUND 15 TO 16Z
MOST AREAS WITH SCT-BKN CIGS EXPECTED AT OR JUST AFTR 18Z.
ATMOSPHERE BECOMES RATHER UNSTABLE BY EARLY THIS AFTN BUT COVERAGE
OF ANY CONVECTION THE FORMS IN THE HEAT OF THE DAY TOO SPOTTY TO
INCLUDE IN ANY OF THE TAFS THIS FORECAST PERIOD. CU FIELD SHOULD
QUICKLY DISSIPATE AGAIN THIS EVENING WITH MAINLY HIGH LEVEL CLOUDS
EXPECTED OVERNIGHT. ANOTHER DAY WITH LIGHT SURFACE WINDS WITH
MAINLY ESE WINDS EXPECTED AT 10 KTS OR LESS TODAY...AND FROM 5 TO
10 KTS TONIGHT. MAY SEE A BRIEF PERIOD OF GROUND FOG AGAIN LATE
TONIGHT...AFTER 10Z...BUT COVERAGE STILL APPEARS LIMITED ENOUGH
TO KEEP OUT OF THIS SET OF TAFS.
SMITH
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT MON JUL 15 2013
SHORT TERM...TODAY THROUGH FRIDAY
FORECAST CONCERN WILL BE THE HIGH HEAT AND HUMIDITY AS STRONG 600
DM 500 MB HIGH PRESSURE OVER EASTERN OHIO/WESTERN PA RETROGRADES
WESTWARD ACROSS THE SOUTHERN GREAT LAKES AND INTO IL BY WED. 00Z
MODELS ARE IN FAIR AGREEMENT NEXT FEW DAYS AND WILL USE A BLEND.
A WEAK SHORT WAVE AND SURFACE TROF TO LIFT NW ACROSS IL DURING
THE DAY AND INTERACT WITH UNSTABLE AIRMASS WITH CAPES 2000-3000
J/KG AND PRECIPITABLE WATER VALUES 1.75 TO 2.25 INCHES TO DEVELOP
ISOLATED SHOWERS AND THUNDERSTORMS THIS AFTERNOON WEST OF I-57.
SOME MODELS LIKE THE NAM SHOW CONVECTION DEVELOPING DURING THE
MORNING AND IF THIS OCCURS THEN ISOLATED CHANCES IN EASTERN IL
WOULD BE POSSIBLE TOO. LEANED ON THE HRRR AND RUC MODELS FOR
CONVECTION CHANCES TODAY. SCATTERED TO BROKEN CUMULUS CLOUDS TO
DEVELOP IN THE AFTERNOON. HIGHS IN THE UPPER 80S OVER CENTRAL IL
AND LOWER 90S BY THE WABASH RIVER WHICH IS DRYER TODAY. DEWPOINTS
IN THE LOWER 70S TO GIVE HEAT INDICES PEAKING IN MID TO UPPER 90S
THIS AFTERNOON.
ISOLATED CONVECTION COULD LINGER OVER THE IL RIVER VALLEY EARLY
THIS EVENING UNTIL SUNSET...OTHERWISE FAIR AND MUGGY WEATHER
EXPECTED TONIGHT WITH LOWS IN THE LOWER 70S. TEMPS GRADUALLY HEAT
UP NEXT FEW DAYS AS STRONG UPPER LEVEL HIGH PRESSURE RIDGE SETTLES
INTO IL BY WED. HIGHS TUE 89 TO 93 WITH AFTERNOON HEAT INDICES
AROUND 100F. HIGHS 90 TO 95F WED-FRI WITH AFTERNOON HEAT INDICES
PEAKING FROM 98 TO 105F AND HIGHEST IN SOUTHEAST OF I-70 IN
SOUTHEAST IL. BEEN THIS HOT BEFORE ON JUNE 12 BUT THIS WILL BE THE
LONGEST HEAT WAVE OF THE SUMMER...LASTING MUCH OF THIS WORK WEEK.
CHANCES OF SHOWERS AND THUNDERSTORMS LESS THAN 20% EACH AFTERNOON
AND EARLY EVENING DURING MID AND LATE WORK WEEK.
LONG TERM...FRIDAY NIGHT THROUGH SUNDAY
EXTENDED MODELS CONTINUE TO SHOW STRONG UPPER LEVEL RIDGE SLOWLY
WEAKENING AND SHIFTING SOUTHWARD ALLOWING COLD FRONT TO PRESS
SOUTHWARD ACROSS THE GREAT LAKES REGION FRIDAY AND THROUGH IL SAT
AND SAT NIGHT...AND INTO THE OHIO VALLEY SUNDAY. HAVE CHANCES OF
SHOWERS AND THUNDERSTORMS HIGHEST OVER NORTHERN AREAS FRI NIGHT
WITH JUST SLIGHT CHANCES IN SOUTHEAST IL. THEN CHANCE OF
CONVECTION ACROSS AREA SAT AND BEST CHANCES SHIFT INTO SE IL SAT
NIGHT AND SUNDAY. HIGHS BY SUNDAY IN THE MID TO UPPER 80S WITH
DEWPOINTS IN THE MID TO UPPER 60S SO SOME RELIEF FROM THE HIGH
HEAT AND HUMIDITY.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
925 AM CDT MON JUL 15 2013
.DISCUSSION...
925 AM CDT
HAVE UPDATED GRIDS AND TEXT PRODUCTS TO HIT THUNDERSTORM CHANCES
HARDER FOR THIS AFTERNOON.
GOES IMAGERY THIS MORNING SHOWS A WEAK SHORTWAVE PUSHING NORTHWARD
INTO THE REGION ON THE SOUTHWESTERN PERIPHERY OF THE VERY STRONG
UPPER HIGH CENTERED JUST OFF TO OUR EAST. INTERESTINGLY...THIS WAVE
CAN BE TRACED BACK TO WHERE TROPICAL STORM CHANTEL DISSIPATED OFF
OFF THE SOUTH EAST COAST OVER THE WEEKEND. SCTD TSRA DEVELOPED OVER
EASTERN TN VALLEY REGION WITH THIS FEATURE SUNDAY AFTERNOON AND
BECOMING MORE CONCERNED THAT WE COULD SEE A REPEAT IN OUR CWA THIS
AFTERNOON.
THE 12Z ILX SOUNDING SAMPLED A VERY TROPICAL AIRMASS WITH PWATS OVER
2 INCHES...WITH GOES SOUNDER PWAT IMAGERY SHOWING A POOL OF 2-2.25"
PWATS EXTENDING FROM CENTRAL IL NORTHEAST INTO NORTHERN INDIANA
PUSHING NORTHWESTWARD INTO THE REGION. MODIFYING THE 12Z ILX/DVN
SOUNDINGS FOR SFC TEMPS IN THE MID-UPPER 80S AND DEWPOINTS IN THE
LOW/MID 70S YIELD MLCAPE VALUES OF 2500-3000 J/KG THIS AFTERNOON
DESPITE THE WARM MID LEVEL TEMPS/MID LAPSE RATES WITH NO CONVECTIVE
INHIBITION. RUC13 FORECAST SOUNDINGS FOR THIS AFTERNOON SHOW VERY
SIMILAR FORECAST VALUES LENDING MORE CONFIDENCE TO THE IDEA THAT IT
WILL GROW STRONGLY UNSTABLE AND UNCAPPED THIS AFTERNOON.
IN ADDITION TO THE WEAK SHORTWAVE...WHICH SEEMS AS THOUGH IT MAY
TEND TO FAVOR CONVECTION FIRING OVER WESTERN AND NORTHWESTERN CWA
THIS AFTERNOON THE OTHER AREA THAT COULD FOCUS DEVELOPMENT IS ALONG
THE ANTICIPATED LAKE BREEZE THIS AFTERNOON. WHILE THE LAKE BREEZE
AND SUBSEQUENT CONVERGENCE WILL NOT BE STRONG OR TERRIBLY DEEP...THE
THE VERY HIGH DEWPOINTS AND RESULTANT LOW LFC HEIGHTS MEAN IT WON`T
BE TOO HARD FOR PARCELS TO REACH LFC. WIND SHEAR PROFILES ARE WEAK
AND MID LEVEL TEMPS VERY WARM SO HAIL THREAT SHOULD BE VERY
LOW...BUT WITH PWATS OVER 2 INCHES AND STRONG INSTABILITY POTENTIAL
FOR BRIEF BUT TORRENTIAL RAINFALL RATES EXISTS AND CANNOT RULE OUT A
WET MICROBURST OR TWO.
IZZI
&&
.PREV DISCUSSION...
253 AM CDT
WARMER AND MORE HUMID WEATHER WILL CONTINUE TO TAKE CENTER STAGE
THIS WEEK. WHILE THE POTENTIAL FOR A FEW ISOLATED SHOWER OR
THUNDERSTORMS WILL EXIST PARTICULARLY THIS AFTERNOON...IT APPEARS
THAT A MORE SIGNIFICANT CHANCE OF RAIN WILL HOLD OFF UNTIL LATE IN
THE WEEK WHEN A COLD FRONT EVENTUALLY SETTLES SOUTH ACROSS THE
MIDWEST.
ANALYSIS OF EVENING UPPER AIR DATA AND OVERNIGHT GOES WATER VAPOR
IMAGERY DEPICT A FAIRLY UNUSUAL WEATHER PATTERN FOR MID-SUMMER...
WITH A CLOSED LOW DRIFTING WESTWARD ACROSS THE SOUTHERN PLAINS AND A
STRONG UPPER RIDGE BUILDING WEST ACROSS THE UPPER OHIO VALLEY.
SOUTHEAST FLOW BETWEEN THESE TWO SYSTEMS WAS SPREADING LOW-LEVEL
MOISTURE INTO THE FORECAST AREA...AS NOTED IN UPSTREAM 00Z SOUNDINGS
SUCH AS NASHVILLE TN. THIS INCREASE IN LOW LEVEL MOISTURE HAS LED TO
ISOLATED AFTERNOON CONVECTION ACROSS PARTS OF THE LOWER OHIO VALLEY
OVER THE PAST COUPLE OF DAYS...AND MODEL GUIDANCE CONTINUES TO
INDICATE CONVECTION WOULD DEVELOP ACROSS PARTS OF THE WFO LOT
FORECAST AREA TODAY. GUIDANCE HAS BEEN OVER-FORECASTING THE EXTENT
OF AFTERNOON CONVECTION UPSTREAM HOWEVER...LIKELY DUE TO MODELED
BOUNDARY LAYER DEW POINT TEMPS THAT ARE TOO HIGH. WITH RELATIVELY
WEAK LOW LEVEL CONVERGENCE AND MORE CONSERVATIVE INSTABILITY
EXPECTED WILL MAINTAIN ONLY SLIGHT CHANCE POPS FOR ISOLATED
CONVECTIVE DEVELOPMENT THIS AFTERNOON...AND THAT MAINLY ALONG THE
LAKE BREEZE BOUNDARY AND NORTHERN IL WHERE LOW-LEVEL CONVERGENCE
WILL BE MORE FOCUSED AND AWAY FROM STRONGER MID/UPPER LEVEL RIDGING
FARTHER TO THE EAST. THUNDERSTORM CHANCES SHOULD BE EVEN LOWER
TUESDAY-THURSDAY AS CENTER OF UPPER RIDGE CONTINUES TO BUILD
WESTWARD ACROSS INDIANA AND ILLINOIS AND SUBSIDENCE AND WARM
MID-LEVEL TEMPS BECOME LESS FAVORABLE FOR CONVECTION.
WITH BUILDING UPPER RIDGE...850MB TEMPS SLOWLY WARM FROM +17/18C
TODAY TO +19/20C LATER IN THE WEEK. TAKING LOCAL CLIMATOLOGY AND
MODEL LOW-LEVEL THERMAL FIELDS INTO ACCOUNT...TEMPS SHOULD WARM FROM
AROUND 90 TODAY TO THE LOWER AND EVEN A FEW MID 90S WED/THURS/FRI.
WITH DEW POINT TEMPERATURES MAINLY IN THE LOWER 70S...THIS SHOULD
SUPPORT HEAT INDEX VALUES MAXING OUT IN THE MID 90S TODAY...AND
AROUND 100 TUESDAY THROUGH FRIDAY. THIS WOULD PRECLUDE ANY HEAT
ADVISORY HEADLINES AT THIS POINT...THOUGH THE PROLONGED PERIOD OF
HEAT AND HUMIDITY WILL HAVE TO BE MONITORED. LAKE COOLING WILL BE
FAIRLY MINIMAL OVER THE NEXT FEW DAYS...MAINLY CONFINED TO THE
IMMEDIATE SHORE AREAS AS LOW LEVEL FLOW BECOMES MORE
WEST-SOUTHWESTERLY.
LONGER RANGE MODEL GUIDANCE IS IN VERY DECENT AGREEMENT THAT THE
UPPER RIDGE OVER THE MIDWEST WILL EVENTUALLY DRIFT SOUTH AND BREAK
DOWN TOWARD THE END OF THE WEEK...WITH AN UPPER TROUGH DEVELOPING
OVER EASTERN CANADA AND THE GREAT LAKES/NORTHEAST STATES. THIS
SHOULD ALLOW A COLD FRONT TO SAG ACROSS THE AREA FRIDAY/FRIDAY
NIGHT...BRINGING A MORE SIGNIFICANT CHANCE OF THUNDERSTORMS
FRIDAY/FRIDAY NIGHT...AS WELL AS COOLER TEMPERATURES AND MORE
PROMINENT LAKE BREEZES TO THE AREA NEXT WEEKEND.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* VARIABLE WIND DIRECTION POSSIBLE BUT LIGHT FLOW GENERALLY EASTERLY.
* TSRA THIS AFTERNOON NOT OUT OF THE QUESTION. NOT EXPECTING
WIDESPREAD OR LONG LIVED ACTIVITY...BUT SOME STORMS EASILY COULD
WORK THEIR WAY INTO THE TERMINAL AREAS. ALSO THE UNUSUAL
MOVEMENT FROM SOUTHEAST TO NORTHWEST COULD ADD TO THE CONFUSION.
LENNING
//DISCUSSION...UPDATED 12Z...
THE LARGE ANTICYCLONE...SURFACE THROUGH THE UPPER LEVELS...WILL
CONTINUE TO RETROGRADE WESTWARD OVER THE REGION WITH IT BEING
CENTERED OVER OH DURING THE DAY. MEANWHILE THE UPPER LOW IN THE
SOUTHERN PLAINS...CURRENTLY CENTERED OVER THE RED RIVER VALLEY...
WILL ALSO RETROGRADE SLOWLY WESTWARD TO THE TX PANHANDLE DURING
THE DAY.
WITHIN THE SOUTHEASTERLY FLOW BETWEEN THESE TWO MAIN FEATURES
SATELLITE LOOPS SHOW MULTIPLE SMALL DISTURBANCES THAT HAVE BEEN
MOVING FROM THE DEEP SOUTH ACROSS THE LOWER OH VALLEY AND MID MS
VALLEY FROM SUNDAY AFTERNOON THROUGH THE OVERNIGHT HOURS.
MODELS...EVEN HI RES ONES...ARE TYPICALLY NOT VERY GOOD
POSITIONING THESE SMALLER DISTURBANCES BEYOND THE NEAR TERM SO
HAVE RELIED MORE ON OLD SCHOOL EXTRAPOLATION TO CONTINUE MOVING
THEM NORTHWEST TO NORTH-NORTHWESTWARD TODAY.
THIS METHOD HAS ONE DISTURBANCE MOVING OVER THE AREA DURING THE
PRE-DAWN AND EARLY MORNING HOURS WITH ANOTHER DURING THE EARLY
AND MID AFTERNOON. WHILE DIURNAL HEATING WILL RESULT IN A CU
FIELD TO DEVELOP BY LATE MORNING TO NOONTIME...THESE DISTURBANCES
WILL START MOVING ANTICYCLONICALLY AS THEY ROTATE THROUGH THE
EAST SIDE OF THE UPPER HIGH. WITHOUT THE AID OF DAYTIME HEATING
AND WITH NORTHWEST MOVEMENT FROM SLIGHTLY CYCLONIC UPPER FLOW TO
NEUTRAL TO SLIGHTLY ANTICYCLONIC FLOW THE FEW TS THAT DEVELOPED
IN SOUTHERN INDIANA SUNDAY EVENING ASSOCIATED WITH THE NORTHERN
MOST IMPULSE DISSIPATED BY 06Z.
WHILE CANNOT TOTALLY RULE OUT AN ISOLATED TS OR TWO WITH THESE
DISTURBANCES THE PROBABILITY OF OCCURRENCE LET ALONG AFFECTING
ORD OR MDW AND VICINITY IS SLIGHT AT BEST.
WITH THE CENTER OF THE ANTICYCLONE CREEPING WESTWARD AND THE LOW
LEVEL FLOW...WEAK AS IT WILL BE...VEERING TO SE TODAY AND THEN
TO S TO SW THE OVERNIGHT THE DEW POINTS OF AROUND 70 JUST TO THE
E THROUGH SW OF THE LOCAL AREA WILL OVERSPREAD THE AREA. WITH
LIGHT TO NIL WIND OVERNIGHT TONIGHT THROUGH DAWN TUE AND SURFACE
COOLING DURING THIS TIME WILL RESULT IN A SHALLOW SURFACE BASED
INVERSION FORMING WHICH WILL CONDUCIVE TO BR AND HZ UNTIL IT
MIXES OUT AFTER SUNRISE TUE.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE OF GENERALLY EASTERLY FLOW TODAY...GRADUALLY
BACKING SOUTHEAST TO SOUTH.
* CONFIDENCE OF TIMING...LOCATION...AND PROBABILITY OF CONVECTION
IS TOO LOW FOR INCLUSION IN TAFS JUST YET.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUE NIGHT...MVFR VISIBILITY DUE TO HZ AND BR.
WED AND THU...MVFR VISIBILITY INTO MID MORNING DUE TO HZ AND BR.
THU...VFR VISIBILITY INTO MID MORNING DUE TO HZ AND BR.
FRI...CHANCE OF TSRA DURING THE AFTERNOON...LIKELY TSRA DURING
THE NIGHT CREATING PERIODS OF MVFR AND IFR.
SAT...CHANCE OF TSRA DURING DAYLIGHT HOURS.
SUN...VFR. NO SIG WX.
TRS
&&
.MARINE...
328 AM CDT
A BROAD AREA OF HIGH PRESSURE WILL REMAIN CENTERED OVER THE
LOWER GREAT LAKES AND THE UPPER OH VALLEY TODAY KEEPING WINDS AT
10 KT OR LESS. THE HIGH WILL START TO DRIFT SLOWLY WSW TONIGHT
AND WILL BE CENTERED OVER THE LOWER OH VALLEY AND THE MID MS
VALLEY BY THURSDAY MORNING. IN RESPONSE...WINDS WILL GENERALLY
VEER FROM SOUTHEAST AND SOUTH TO SOUTH AND SOUTHWEST AND START TO
FRESHEN. DURING THURSDAY AND THURSDAY NIGHT A COLD FRONT WILL BE
DROPPING SOUTHWARD FROM ONTARIO...CROSSING LAKE SUPERIOR BY
FRIDAY MORNING. AHEAD OF THE COLD FRONT WINDS FROM THE SOUTHWEST
WILL INCREASE TO A MODERATE BREEZE. THE COLD FRONT WILL CONTINUE
SLOWLY SOUTHWARD FRIDAY...CROSSING THE NORTHERN PORTION OF LAKE
MI BY LATE IN THE DAY...AND REACHING THE S TIP BY DAWN SATURDAY.
IL AND IN NEARSHORE WATERS WILL BE UNDER THE INFLUENCE OF A LAKE
BREEZE WITH ENHANCED ONSHORE WINDS DURING THE THIS AFTERNOON.
WINDS WILL RETURN TO ONSHORE AGAIN TUESDAY AFTERNOON...BUT MAINLY
ONLY ALONG THE IL SHORE.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
617 AM CDT MON JUL 15 2013
.DISCUSSION...
ISSUED 330 AM CDT MON JUL 15 2013
SHORT TERM...TODAY THROUGH FRIDAY
FORECAST CONCERN WILL BE THE HIGH HEAT AND HUMIDITY AS STRONG 600
DM 500 MB HIGH PRESSURE OVER EASTERN OHIO/WESTERN PA RETROGRADES
WESTWARD ACROSS THE SOUTHERN GREAT LAKES AND INTO IL BY WED. 00Z
MODELS ARE IN FAIR AGREEMENT NEXT FEW DAYS AND WILL USE A BLEND.
A WEAK SHORT WAVE AND SURFACE TROF TO LIFT NW ACROSS IL DURING
THE DAY AND INTERACT WITH UNSTABLE AIRMASS WITH CAPES 2000-3000
J/KG AND PRECIPITABLE WATER VALUES 1.75 TO 2.25 INCHES TO DEVELOP
ISOLATED SHOWERS AND THUNDERSTORMS THIS AFTERNOON WEST OF I-57.
SOME MODELS LIKE THE NAM SHOW CONVECTION DEVELOPING DURING THE
MORNING AND IF THIS OCCURS THEN ISOLATED CHANCES IN EASTERN IL
WOULD BE POSSIBLE TOO. LEANED ON THE HRRR AND RUC MODELS FOR
CONVECTION CHANCES TODAY. SCATTERED TO BROKEN CUMULUS CLOUDS TO
DEVELOP IN THE AFTERNOON. HIGHS IN THE UPPER 80S OVER CENTRAL IL
AND LOWER 90S BY THE WABASH RIVER WHICH IS DRYER TODAY. DEWPOINTS
IN THE LOWER 70S TO GIVE HEAT INDICES PEAKING IN MID TO UPPER 90S
THIS AFTERNOON.
ISOLATED CONVECTION COULD LINGER OVER THE IL RIVER VALLEY EARLY
THIS EVENING UNTIL SUNSET...OTHERWISE FAIR AND MUGGY WEATHER
EXPECTED TONIGHT WITH LOWS IN THE LOWER 70S. TEMPS GRADUALLY HEAT
UP NEXT FEW DAYS AS STRONG UPPER LEVEL HIGH PRESSURE RIDGE SETTLES
INTO IL BY WED. HIGHS TUE 89 TO 93 WITH AFTERNOON HEAT INDICES
AROUND 100F. HIGHS 90 TO 95F WED-FRI WITH AFTERNOON HEAT INDICES
PEAKING FROM 98 TO 105F AND HIGHEST IN SOUTHEAST OF I-70 IN
SOUTHEAST IL. BEEN THIS HOT BEFORE ON JUNE 12 BUT THIS WILL BE THE
LONGEST HEAT WAVE OF THE SUMMER...LASTING MUCH OF THIS WORK WEEK.
CHANCES OF SHOWERS AND THUNDERSTORMS LESS THAN 20% EACH AFTERNOON
AND EARLY EVENING DURING MID AND LATE WORK WEEK.
LONG TERM...FRIDAY NIGHT THROUGH SUNDAY
EXTENDED MODELS CONTINUE TO SHOW STRONG UPPER LEVEL RIDGE SLOWLY
WEAKENING AND SHIFTING SOUTHWARD ALLOWING COLD FRONT TO PRESS
SOUTHWARD ACROSS THE GREAT LAKES REGION FRIDAY AND THROUGH IL SAT
AND SAT NIGHT...AND INTO THE OHIO VALLEY SUNDAY. HAVE CHANCES OF
SHOWERS AND THUNDERSTORMS HIGHEST OVER NORTHERN AREAS FRI NIGHT
WITH JUST SLIGHT CHANCES IN SOUTHEAST IL. THEN CHANCE OF
CONVECTION ACROSS AREA SAT AND BEST CHANCES SHIFT INTO SE IL SAT
NIGHT AND SUNDAY. HIGHS BY SUNDAY IN THE MID TO UPPER 80S WITH
DEWPOINTS IN THE MID TO UPPER 60S SO SOME RELIEF FROM THE HIGH
HEAT AND HUMIDITY.
07
&&
.AVIATION...
ISSUED 610 AM CDT MON JUL 15 2013
OTHER THAN SOME PATCHY GROUND FOG EARLY THIS MORNING (UNTIL 13Z)
AND AGAIN AFTR 09Z TONIGHT AT A FEW OF OUR TAF SITES...VFR
CONDITIONS ARE EXPECTED. LATEST FORECAST SOUNDINGS CONTINUE TO
SHOW THE POTENTIAL FOR RAPID CUMULUS DEVELOPMENT AROUND 15 TO 16Z
MOST AREAS WITH SCT-BKN CIGS EXPECTED AT OR JUST AFTR 18Z.
ATMOSPHERE BECOMES RATHER UNSTABLE BY EARLY THIS AFTN BUT COVERAGE
OF ANY CONVECTION THE FORMS IN THE HEAT OF THE DAY TOO SPOTTY TO
INCLUDE IN ANY OF THE TAFS THIS FORECAST PERIOD. CU FIELD SHOULD
QUICKLY DISSIPATE AGAIN THIS EVENING WITH MAINLY HIGH LEVEL CLOUDS
EXPECTED OVERNIGHT. ANOTHER DAY WITH LIGHT SURFACE WINDS WITH
MAINLY ESE WINDS EXPECTED AT 10 KTS OR LESS TODAY...AND FROM 5 TO
10 KTS TONIGHT. MAY SEE A BRIEF PERIOD OF GROUND FOG AGAIN LATE
TONIGHT...AFTER 10Z...BUT COVERAGE STILL APPEARS LIMITED ENOUGH
TO KEEP OUT OF THIS SET OF TAFS.
SMITH
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
331 AM CDT MON JUL 15 2013
.DISCUSSION...
ISSUED 330 AM CDT MON JUL 15 2013
SHORT TERM...TODAY THROUGH FRIDAY
FORECAST CONCERN WILL BE THE HIGH HEAT AND HUMIDITY AS STRONG 600
DM 500 MB HIGH PRESSURE OVER EASTERN OHIO/WESTERN PA RETROGRADES
WESTWARD ACROSS THE SOUTHERN GREAT LAKES AND INTO IL BY WED. 00Z
MODELS ARE IN FAIR AGREEMENT NEXT FEW DAYS AND WILL USE A BLEND.
A WEAK SHORT WAVE AND SURFACE TROF TO LIFT NW ACROSS IL DURING
THE DAY AND INTERACT WITH UNSTABLE AIRMASS WITH CAPES 2000-3000
J/KG AND PRECIPITABLE WATER VALUES 1.75 TO 2.25 INCHES TO DEVELOP
ISOLATED SHOWERS AND THUNDERSTORMS THIS AFTERNOON WEST OF I-57.
SOME MODELS LIKE THE NAM SHOW CONVECTION DEVELOPING DURING THE
MORNING AND IF THIS OCCURS THEN ISOLATED CHANCES IN EASTERN IL
WOULD BE POSSIBLE TOO. LEANED ON THE HRRR AND RUC MODELS FOR
CONVECTION CHANCES TODAY. SCATTERED TO BROKEN CUMULUS CLOUDS TO
DEVELOP IN THE AFTERNOON. HIGHS IN THE UPPER 80S OVER CENTRAL IL
AND LOWER 90S BY THE WABASH RIVER WHICH IS DRYER TODAY. DEWPOINTS
IN THE LOWER 70S TO GIVE HEAT INDICES PEAKING IN MID TO UPPER 90S
THIS AFTERNOON.
ISOLATED CONVECTION COULD LINGER OVER THE IL RIVER VALLEY EARLY
THIS EVENING UNTIL SUNSET...OTHERWISE FAIR AND MUGGY WEATHER
EXPECTED TONIGHT WITH LOWS IN THE LOWER 70S. TEMPS GRADUALLY HEAT
UP NEXT FEW DAYS AS STRONG UPPER LEVEL HIGH PRESSURE RIDGE SETTLES
INTO IL BY WED. HIGHS TUE 89 TO 93 WITH AFTERNOON HEAT INDICES
AROUND 100F. HIGHS 90 TO 95F WED-FRI WITH AFTERNOON HEAT INDICES
PEAKING FROM 98 TO 105F AND HIGHEST IN SOUTHEAST OF I-70 IN
SOUTHEAST IL. BEEN THIS HOT BEFORE ON JUNE 12 BUT THIS WILL BE THE
LONGEST HEAT WAVE OF THE SUMMER...LASTING MUCH OF THIS WORK WEEK.
CHANCES OF SHOWERS AND THUNDERSTORMS LESS THAN 20% EACH AFTERNOON
AND EARLY EVENING DURING MID AND LATE WORK WEEK.
LONG TERM...FRIDAY NIGHT THROUGH SUNDAY
EXTENDED MODELS CONTINUE TO SHOW STRONG UPPER LEVEL RIDGE SLOWLY
WEAKENING AND SHIFTING SOUTHWARD ALLOWING COLD FRONT TO PRESS
SOUTHWARD ACROSS THE GREAT LAKES REGION FRIDAY AND THROUGH IL SAT
AND SAT NIGHT...AND INTO THE OHIO VALLEY SUNDAY. HAVE CHANCES OF
SHOWERS AND THUNDERSTORMS HIGHEST OVER NORTHERN AREAS FRI NIGHT
WITH JUST SLIGHT CHANCES IN SOUTHEAST IL. THEN CHANCE OF
CONVECTION ACROSS AREA SAT AND BEST CHANCES SHIFT INTO SE IL SAT
NIGHT AND SUNDAY. HIGHS BY SUNDAY IN THE MID TO UPPER 80S WITH
DEWPOINTS IN THE MID TO UPPER 60S SO SOME RELIEF FROM THE HIGH
HEAT AND HUMIDITY.
07
&&
.AVIATION...
ISSUED 1146 PM CDT SUN JUL 14 2013
VFR CONDITIONS ARE EXPECTED AT ALL SITES NEXT 24HRS. SKIES SHOULD
BE CLEAR OVERNIGHT AND EARLY TOMORROW MORNING. LOW LEVEL MOISTURE
HAS INCREASED IN THE AREA SO LIGHT FOG A POSSIBILITY AGAIN IN THE
MORNING. SO WILL HAVE JUST TEMPO GROUP AT ALL SITES FOR 3-4HRS.
THEN BELIEVE CU WILL AGAIN BE POSSIBLE TOMORROW INTO TOMORROW
AFTERNOON. ISOLATED SHOWERS WILL BE POSSIBLE LATE TOMORROW
AFTERNOON...BUT COVERAGE DOES NOT WARRANT MENTION IN TAFS AT THIS
TIME. CU COULD BECOME MORE BROKEN AS IT WAS LATE THIS AFTERNOON
AND EARLY EVENING BEFORE CLEARING OUT AROUND 01-02Z. SO HAVE ADDED
A TEMPO GROUP FOR BROKEN CIGS AROUND 5KFT AND THEN BECOMING CLEAR
AROUND 02Z. WINDS WILL BE EAST TO SOUTHEAST THROUGH THE PERIOD
WITH SPEEDS LIGHT OVERNIGHT AND AGAIN TOMORROW EVENING.
AUTEN
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
630 PM CDT TUE JUL 16 2013
...UPDATE TO AVIATION...
.SYNOPSIS...
ISSUED AT 1201 PM CDT TUE JUL 16 2013
AT 12Z TUESDAY A 500MB LOW WAS LOCATED OVER EASTERN NEW MEXICO
AND A 500MB HIGH WAS LOCATED OVER THE OHIO VALLEY. ACROSS THE
SOUTHERN AND CENTRAL PLAINS A SOUTHEAST FLOW IN THE 850MB TO 500MB
LEVEL WAS DRAWING HIGHER DEWPOINTS INTO WESTERN KANSAS. ONE UPPER
LEVEL DISTURBANCE ROTATING AROUND THIS UPPER LOW WAS LOCATED
ACROSS THE PANHANDLE OF TEXAS AND WESTERN OKLAHOMA AS OF 12Z
TUESDAY WITH ANOTHER DISTURBANCE LOCATED NEAR THE BASED OF THIS
UPPER LOW ACROSS WESTERN TEXAS. WATER VAPOR LOOP AS OF 15Z
INDICATED THIS UPPER LOW WAS MOVING SLOWLY WESTWARD AS THE
PANHANDLE UPPER LEVEL WAVE APPROACHES SOUTHWEST KANSAS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 159 PM CDT TUE JUL 16 2013
RAP AND WATER VAPOR LOOP INDICATING AN UPPER LEVEL DISTURBANCE
WAS MOVING NORTHWEST ACROSS THE PANHANDLE OF TEXAS AS OF 19Z WITH
RADAR TRENDS INDICATING PRECIPITATION INCREASING IN AREA COVER
AHEAD OF THIS DISTURBANCE ACROSS PORTIONS OF SOUTHWEST KANSAS. NAM
AND RAP WERE IN DECENT AGREEMENT IN MOVING THIS UPPER WAVE ACROSS
SOUTHWEST KANSAS INTO SOUTHEAST COLORADO EARLY TONIGHT. GIVEN THE
MOISTURE FORECAST ACROSS SOUTHWEST KANSAS IN THE 850MB TO 500MB
AHEAD OF THIS UPPER SYSTEM WILL RETAIN AT LEAST A CHANCE FOR
SHOWERS ACROSS SOUTHWEST KANSAS AT AROUND 03Z AND THEN TAPER
PRECIPITATION OFF FROM NORTHEAST TO SOUTHWEST.
AFTER MIDNIGHT SUBSIDENCE APPEARS TO DEVELOP ACROSS WESTERN KANSAS
AS THE UPPER LEVEL DISTURBANCE MOVES INTO SOUTHERN COLORADO.
CLEARING SKIES MAY BRIEFLY DEVELOP AFTER MIDNIGHT, HOWEVER SOME
EARLY MORNING STATUS AND/OR FOG WILL BE POSSIBLE AROUND DAYBREAK
GIVEN THE SHALLOW LAYER OF LOW LEVEL MOISTURE FORECAST BY THE 12Z
NAM. BASED ONE THE EXPECTED DEWPOINTS OVERNIGHT THE PREVIOUS
FORECAST WITH LOWS RANGING FROM 60 TO NEAR 65 DEGREES STILL LOOKS
ON TRACK.
ON WEDNESDAY A TROUGH OF LOW PRESSURE WILL DEEPEN ALONG THE LEE
OF THE ROCKIES. BASED ON EXPECTED SKY COVER AND 00Z 850MB
TEMPERATURES RANGING FROM AROUND 20 IN SOUTH CENTRAL KANSAS TO THE
MID 20S NEAR THE COLORADO BORDER HAVE DECIDED TO TREND TOWARDS THE
SLIGHTLY COOLER ECMWF GUIDANCE FOR HIGHS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 333 PM CDT TUE JUL 16 2013
WEDNESDAY NIGHT:
LEE TROUGHING WILL CONTINUE WEDNESDAY NIGHT INTO THURSDAY MORNING.
THE UPPER LEVEL DISTURBANCE MENTIONED IN THE SYNOPSIS/SHORT TERM PERIOD
WILL CONTINUE TO DRIFT WELL AWAY FROM THE REGION BY THURSDAY MORNING.
STILL, THERE WILL BE "COOLER" LOW TO MID LEVEL TEMPERATURES ASSOCIATED
WITH THE PRESSURE PERTURBATION LINGERING ACROSS THE REGION. CONSIDERING
THIS AND THE WARM BIAS SHOWN VIA BOISE VERIFICATION...HAVE GONE WITH
COOLER MOS GUIDANCE FOR MINIMUMS INTO THURSDAY MORNING...60S DEG F.
THURSDAY:
ON THURSDAY, THE AFOREMENTIONED LEE SURFACE TROUGH WILL CONTINUE TO
DEEPEN AHEAD OF A TRAVERSING SHORTWAVE TROF ACROSS THE NORTHERN PLAINS.
THIS WILL ALLOW FOR A CONTINUED WARM AIR ADVECTION REGIME THROUGH THE
DAY. HAVE GONE WITH COOLER ECMWF RAW OUTPUT FOR MAXIMUMS - MID 90S DEG
F NORTHEAST TO AROUND 90 DEG F SOUTHWEST. NO PRECIPITATION IS EXPECTED
THROUGH THE DAY WITH PRECIPITATION PROBABILITY PERCENTAGE POINTS AOB
10 PERCENT AS THE AFOREMENTIONED SYNOPTIC SYSTEM IS WELL TO THE NORTH.
FRIDAY AND BEYOND:
A MODERATION OF TEMPERATURES IS EXPECTED WITH MAXIMUMS IN THE 90S DEG
F AND LOWS IN THE 60S AND 70S DEG F AS LEE TROUGHING CONTINUES AHEAD
OF AN APPROACHING COLD FRONT. THIS FRONT SHOULD BE IN THE REGION (PER
ECMWF) SOMETIME LATE FRIDAY NIGHT AND INTO SATURDAY. CONVECTION WILL
BE POSSIBLE ALONG THIS DENSITY GRADIENT THROUGH THE WEEKEND. THE 12Z
ECMWF SOLUTION HAS TRENDED DRIER THAN COMPARED TO THE 00Z ECMWF SOLUTION.
THE GFS, AS PER USUAL, IS WETTER AND COOLER THAN COMPARED TO THE EC.
DUE TO THE UNCERTAINTY, WILL GO WITH THE ALLBLEND SOLUTION FOR NOW.
THIS MODEL - OF COURSE - APPLIES A WEIGHTING FUNCTION TO BOTH SOLUTIONS
PLUS THE PREVIOUS NDFD GRIDS. BEYOND THIS, 500 HPA RIDGING IS INDICATED
BY BOTH MODELS BY EARLY TO MID WEEK OF NEXT WEEK, WHICH FAVORS A DRY
FORECAST AND HOT TEMPERATURES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 630 PM CDT TUE JUL 16 2013
SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE TO LIFT NORTH
ACROSS SOUTHWEST AND PORTIONS OF CENTRAL KANSAS THIS EVENING
RESULTING IN PERIODS OF MVFR CIGS/VSBYS. BRIEF PERIODS OF IFR
CIGS/VSBYS ARE POSSIBLE WITH HEAVIER SHOWERS. AREAS OF LOW LEVEL
STRATUS ARE THEN EXPECTED TO DEVELOP LATER TONIGHT ACROSS THE
REGION AS MOISTURE CONTINUES TO MOVE NORTH INTO WESTERN KANSAS.
MVFR/IFR CIGS AND VSBYS WILL BE POSSIBLE IN THE VICINITY OF KDDC
AND KGCK GENERALLY AFTER 06Z...AND POTENTIALLY AS FAR NORTH AS
KHYS TOWARD SUNRISE. AS FOR WINDS, A LARGE AREA OF HIGH PRESSURE
WILL REMAIN ACROSS THE MID MISSISSIPPI RIVER VALLEY THROUGH THE
PERIOD. THIS WILL RESULT IN SOUTH TO SOUTHEASTERLY WINDS OF 5 TO
15KT ACROSS WESTERN KANSAS THROUGH WEDNESDAY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 62 87 65 91 / 50 10 10 0
GCK 60 86 64 90 / 50 10 10 10
EHA 59 82 62 88 / 50 10 10 10
LBL 62 84 64 89 / 60 10 10 10
HYS 63 89 67 94 / 20 10 0 0
P28 65 87 68 91 / 30 20 10 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...SUGDEN
AVIATION...JJOHNSON
AREA FORECAST DISCUSSION
NWS GOODLAND KS
245 PM MDT MON JUL 15 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 138 PM MDT MON JUL 15 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW 581 DM CLOSED LOW
CENTERED OVER SW OKLAHOMA...WITH A 599 DM RIDGE ACROSS THE EASTERN
CONUS EXTENDING WEST ACROSS THE NORTHERN PLAINS. WV IMAGERY SHOWS
MOISTURE CONTINUING TO ROTATE AROUND EASTERN EXTEND OF CLOSED LOW
INTO SOUTHERN KS. RAP/LATEST NAM SHOW A CURVED JET STRUCTURE ACROSS
THE NORTHERN PART OF CLOSED LOW OVER SW KS AND SEVERAL VORT MAXES
ROTATING THROUGH THE NORTHERN EXTENT OF THIS LOW. COMPOSITE RADAR
SHOWS SHOWER ACTIVITY HAVING DEVELOPED WITH THESE FEATURES MOVING TO
ACROSS CENTRAL AND SOUTHWEST KANSAS. VIS SATELLITE SHOWS A
WIDESPREAD CU FIELD IN PLACE ACROSS OUR CWA THAT HAS DEVELOPED WITH
DAYTIME HEATING AND COLD POOL ALOFT.
LATEST SHORT RANGE GUIDANCE SHOWS THE ACTIVITY CURRENTLY SOUTH AND
EAST OF THE CWA FALLING APART BY 00Z AS IT MOVES TOWARDS OUR CWA. AT
THIS POINT I AM NOT SURE WE WILL ACTUALLY SEE ANY SHOWERS DEVELOP
WITH CU FIELD...THOUGH UNTIL WE LOOSE DAYTIME HEATING I COULDNT RULE
OUT SHOWERS SPREADING INTO THE SOUTHERN HALF CONSIDERING RADAR
TRENDS...AND AT LEAST SOME LARGE SCALE FORCING STILL IN PLACE JUST TO
OUR SOUTH. I DO NOT EXPECT THIS TO BE WIDESPREAD AND SHOULD QUICKLY
END AS WE LOOSE FAVORABLE LOW LEVEL LAPSE RATES DUE TO DIURNAL
COOLING.
SOUTHERLY FLOW WILL KEEP BL MOISTURE IN PLACE OVERNIGHT AND
TUESDAY...AND THERE IS SOME INDICATION OF A FEW SHOWERS ACROSS
SOUTHERN KS...POSSIBLY INTO OUR CWA AS UPPER LOW CONTINUES TO SLOWLY
MOVE WEST. WITH LITTLE IN THE WAY OF INSTABILITY AND STRONG
SUBSIDENCE BUILDING IN FROM THE NORTH TONIGHT I DECIDED TO KEEP
FORECAST DRY. WE DO BEGIN TO SEE A SIMILAR SET UP AS THIS AFTERNOON
REGARDING INCREASING LAPSE RATES BELOW COLD POOL...HOWEVER WITH
RIDGE BEGINNING TO HOLD MORE INFLUENCE AND DRIER AIR MOVING INTO THE
REGION ALOFT...I DECIDED TO KEEP POPS SILENT FOR NOW. I DID KEEP
PATCHY FOG MENTION IN THE FORECAST FOR TUESDAY MORNING...AND GOOD BL
MOISTURE ADVECTING IN FROM THE SOUTH. WITH BL WINDS
INCREASING...IF WE SEE SURFACE WINDS AROUND 10KT THE LOW LEVELS
MAY BE TOO MIXED FOR FOG DEVELOPMENT...SO I KEPT COVERAGE PATCHY.
THERE IS LITTLE CHANGE REGARDING THE AIR MASS OVER OUR CWA
TUESDAY...AND THERE ARE SIMILAR TRENDS REGARDING CLOUD COVER. TEMPS
ON TUESDAY SHOULD BE VERY SIMILAR TO TODAY...WITH HIGHS RANGING FROM
THE UPPER 70S WEST TO UPPER 80S EAST.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 244 PM MDT MON JUL 15 2013
DRY CONDITIONS WITH A SLOW WARMING TREND WILL BE THE DOMINANT
WEATHER PATTERN UNTIL THE OF THE WEEK AS THE HIGH PRESSURE OVER THE
EASTERN CONUS MOVES WEST TOWARD THE ROCKIES. WEDNESDAY AND THURSDAY
WILL BE WINDY AS 850MB WINDS NEAR 30KTS ARE ABLE TO MIX DOWN TO
THE GROUND AHEAD OF THE RETROGRADING RIDGE. PRECIPITATION CHANCES
RETURN FRIDAY THROUGH EARLY NEXT WEEK AS A FEW UPPER LEVEL
DISTURBANCES MOVE THROUGH THE NORTHWEST FLOW OVER THE AREA.
FRIDAY A WEAK FRONT/SURFACE TROUGH MOVES OVER THE AREA...COOLING THE
ABOVE NORMAL TEMPERATURES DOWN AND HELPING WITH PRECIP. CHANCES AS
AN UPPER LEVEL TROUGH ALSO MOVES THROUGH.
THE WEAK FRONT LINGERS OVER THE SOUTHERN PART OF THE AREA THROUGH
SATURDAY WHICH MAY AID IN CREATING SOME STORMS FOR THE AREA.
PRECIPITATION CHANCES LINGER THROUGH EARLY NEXT WEAK AS ANOTHER WEAK
UPPER LEVEL TROUGH MOVES ACROSS THE AREA.
TEMPERATURES THROUGH THE PERIOD WILL START OUT NEAR NORMAL THEN WARM
TO NEAR/ABOVE NORMAL BY THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1121 AM MDT MON JUL 15 2013
GUSTY SOUTHEAST WINDS WILL DEVELOP THIS AFTERNOON AT BOTH
TERMINALS...WITH GUSTS BETWEEN 20-25KT EXPECTED. WINDS SHOULD
DIMINISH WITH END OF DAYTIME HEATING BEFORE INCREASING AGAIN
TUESDAY MORNING. FOG WILL ONCE AGAIN BE POSSIBLE AT BOTH TERMINALS
BY SUNRISE TUESDAY WITH MOIST BL STILL IN PLACE. WITH BL WINDS
INCREASING...I AM SKEPTICAL OF THESE LOWER CONDITIONS UNLESS
SURFACE WINDS ARE MUCH LIGHTER...AND IN THAT CASE FOG LAYER WOULD
BE FAIRLY SHALLOW. KMCK IS FARTHER REMOVED FROM BEST BL MOISTURE
IN THE SOUTH...THOUGH LOCAL EFFECTS AND LINGERING LOW LEVEL
MOISTURE COULD STILL SUPPORT LIGHT FOG DEVELOPMENT. CURRENT
FORECAST IS FOR MVFR VIS/CIGS AT KGLD AND BETTER CONDITIONS AT
KMCK...THOUGH MET GUIDANCE WOULD ACTUALLY SUPPORT IFR AT BOTH
TERMINALS. I PREFER BEING CONSERVATIVE AT THIS POINT...AND WILL
ALLOW NEXT FEW SCHEDULED UPDATES TO FINE TUNE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JTL
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
138 PM MDT MON JUL 15 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 138 PM MDT MON JUL 15 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW 581 DM CLOSED LOW
CENTERED OVER SW OKLAHOMA...WITH A 599 DM RIDGE ACROSS THE EASTERN
CONUS EXTENDING WEST ACROSS THE NORTHERN PLAINS. WV IMAGERY SHOWS
MOISTURE CONTINUING TO ROTATE AROUND EASTERN EXTEND OF CLOSED LOW
INTO SOUTHERN KS. RAP/LATEST NAM SHOW A CURVED JET STRUCTURE ACROSS
THE NORTHERN PART OF CLOSED LOW OVER SW KS AND SEVERAL VORT MAXES
ROTATING THROUGH THE NORTHERN EXTENT OF THIS LOW. COMPOSITE RADAR
SHOWS SHOWER ACTIVITY HAVING DEVELOPED WITH THESE FEATURES MOVING TO
ACROSS CENTRAL AND SOUTHWEST KANSAS. VIS SATELLITE SHOWS A
WIDESPREAD CU FIELD IN PLACE ACROSS OUR CWA THAT HAS DEVELOPED WITH
DAYTIME HEATING AND COLD POOL ALOFT.
LATEST SHORT RANGE GUIDANCE SHOWS THE ACTIVITY CURRENTLY SOUTH AND
EAST OF THE CWA FALLING APART BY 00Z AS IT MOVES TOWARDS OUR CWA. AT
THIS POINT I AM NOT SURE WE WILL ACTUALLY SEE ANY SHOWERS DEVELOP
WITH CU FIELD...THOUGH UNTIL WE LOOSE DAYTIME HEATING I COULDNT RULE
OUT SHOWERS SPREADING INTO THE SOUTHERN HALF CONSIDERING RADAR
TRENDS...AND AT LEAST SOME LARGE SCALE FORCING STILL IN PLACE JUST TO
OUR SOUTH. I DO NOT EXPECT THIS TO BE WIDESPREAD AND SHOULD QUICKLY
END AS WE LOOSE FAVORABLE LOW LEVEL LAPSE RATES DUE TO DIURNAL
COOLING.
SOUTHERLY FLOW WILL KEEP BL MOISTURE IN PLACE OVERNIGHT AND
TUESDAY...AND THERE IS SOME INDICATION OF A FEW SHOWERS ACROSS
SOUTHERN KS...POSSIBLY INTO OUR CWA AS UPPER LOW CONTINUES TO SLOWLY
MOVE WEST. WITH LITTLE IN THE WAY OF INSTABILITY AND STRONG
SUBSIDENCE BUILDING IN FROM THE NORTH TONIGHT I DECIDED TO KEEP
FORECAST DRY. WE DO BEGIN TO SEE A SIMILAR SET UP AS THIS AFTERNOON
REGARDING INCREASING LAPSE RATES BELOW COLD POOL...HOWEVER WITH
RIDGE BEGINNING TO HOLD MORE INFLUENCE AND DRIER AIR MOVING INTO THE
REGION ALOFT...I DECIDED TO KEEP POPS SILENT FOR NOW. I DID KEEP
PATCHY FOG MENTION IN THE FORECAST FOR TUESDAY MORNING...AND GOOD BL
MOISTURE ADVECTING IN FROM THE SOUTH. WITH BL WINDS
INCREASING...IF WE SEE SURFACE WINDS AROUND 10KT THE LOW LEVELS
MAY BE TOO MIXED FOR FOG DEVELOPMENT...SO I KEPT COVERAGE PATCHY.
THERE IS LITTLE CHANGE REGARDING THE AIR MASS OVER OUR CWA
TUESDAY...AND THERE ARE SIMILAR TRENDS REGARDING CLOUD COVER. TEMPS
ON TUESDAY SHOULD BE VERY SIMILAR TO TODAY...WITH HIGHS RANGING FROM
THE UPPER 70S WEST TO UPPER 80S EAST.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 303 AM MDT MON JUL 15 2013
TOMORROW NIGHT-WEDNESDAY NIGHT...AS UPPER LOW EXITS THE AREA LARGE
H5 RIDGE WILL ONCE AGAIN BE THE PRIMARY SYNOPTIC SCALE FEATURE
IMPACTING THE AREA. WITH LARGE SCALE SUBSIDENCE...EXPECT DRY
CONDITIONS TO PREVAIL WITH TEMPERATURES WARMING THROUGH THE PERIOD.
A DEVELOPING SFC TROUGH WILL BRING SOME GUSTY SOUTHERLY WINDS TO THE
AREA ON WEDNESDAY WITH AFTERNOON SPEEDS AROUND 20KTS A STRONG
POSSIBILITY...WITH WINDS REMAINING UP THROUGH THE NIGHT HOLDING LOW
TEMPS UP SEVERAL DEGREES.
.EXTENDED RANGE...(THU JUL 18 THRU SUN JUL 21)
LATE WEEK THROUGH THE WEEKEND IS LOOKING LIKE TYPICAL JULY WEATHER
WITH NEAR NORMAL TEMPERATURES AND CHANCES FOR STORMS ON A FEW DAYS.
SYNOPTIC PATTERN STARTS AS A WEAK UPPER LEVEL RIDGE ACROSS MOST OF
THE CENTRAL CONUS AS AN UPPER HIGH WEAKENS IN THE EAST AND A RIDGE
BEGINS TO DEVELOP OVER THE WEST. AS THIS RIDGE IN THE WEST BUILDS
AND MOVES EAST THE GEM AND GFS DEVELOP A SMALL BUT POWERFUL VORT MAX
WEST OF THE CENTRAL ROCKIES AND EVENTUALLY MOVES IT EAST FRIDAY INTO
SATURDAY WITH AN ASSOCIATED COLD FRONT AND PLENTY OF PRECIPITATION.
THE GFS ENSEMBLES CARRIES THIS IDEA OF A COLD FRONT STRETCHING FROM
THE GREAT LAKES TO THE CENTRAL ROCKIES MOVING SOUTH WITH WIDESPREAD
PRECIPITATION ALONG THE FRONT. ECMWF DOES NOT AGREE ENTIRELY WITH
SUCH AN ORGANIZED SOLUTION...BUT IT DOES AT LEAST CARRY THE IDEA OF
THE FRONT ALBEIT WITH MUCH LESS PRECIP. THE EXTENDED INIT GAVE
QUITE HIGH POPS IN COMPARISON TO STATISTICAL GUIDANCE...SO WHILE
SOME OF THE POPS HAVE BEEN NUDGED DOWN GENERALLY WENT ALONG WITH THE
MODEL BLEND OF THE INIT. AT THIS POINT IT IS TOO FAR TO NAIL DOWN
ALL THE DETAILS...BUT MODEL SOUNDINGS ARE INDICATING A VERY MOIST
ENVIRONMENT AND SLOW STORM MOTIONS COULD LEAD TO A HEAVY
RAINFALL/FLOODING THREAT SIMILAR TO YESTERDAY. TEMPS OVER THE
PERIOD WILL BE NEAR NORMAL /HIGHS IN THE LOW 90S/ WITH THE EXCEPTION
OF BEING A BIT COOLER ON SATURDAY AFTER THE FRONT MOVES THROUGH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1121 AM MDT MON JUL 15 2013
GUSTY SOUTHEAST WINDS WILL DEVELOP THIS AFTERNOON AT BOTH
TERMINALS...WITH GUSTS BETWEEN 20-25KT EXPECTED. WINDS SHOULD
DIMINISH WITH END OF DAYTIME HEATING BEFORE INCREASING AGAIN
TUESDAY MORNING. FOG WILL ONCE AGAIN BE POSSIBLE AT BOTH TERMINALS
BY SUNRISE TUESDAY WITH MOIST BL STILL IN PLACE. WITH BL WINDS
INCREASING...I AM SKEPTICAL OF THESE LOWER CONDITIONS UNLESS
SURFACE WINDS ARE MUCH LIGHTER...AND IN THAT CASE FOG LAYER WOULD
BE FAIRLY SHALLOW. KMCK IS FARTHER REMOVED FROM BEST BL MOISTURE
IN THE SOUTH...THOUGH LOCAL EFFECTS AND LINGERING LOW LEVEL
MOISTURE COULD STILL SUPPORT LIGHT FOG DEVELOPMENT. CURRENT
FORECAST IS FOR MVFR VIS/CIGS AT KGLD AND BETTER CONDITIONS AT
KMCK...THOUGH MET GUIDANCE WOULD ACTUALLY SUPPORT IFR AT BOTH
TERMINALS. I PREFER BEING CONSERVATIVE AT THIS POINT...AND WILL
ALLOW NEXT FEW SCHEDULED UPDATES TO FINE TUNE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JRM/JJM
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1119 PM MDT SUN JUL 14 2013
.SHORT TERM...(THIS AFTERNOON THROUGH TONIGHT)
ISSUED AT 125 PM MDT SUN JUL 14 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS 579DM CLOSED LOW CENTERED
OVER NORTHEAST OKLAHOMA WITH STRONG PV HEIGHT ANOMALY IN PLACE OVER
SOUTHEAST KS. A 599DM RIDGE IS IN PLACE OVER THE NORTHEAST US WITH
AXIS EXTENDING NORTH OF CLOSED LOW INTO THE UPPER MISSISSIPPI VALLEY.
WITH GOOD MOISTURE/INSTABILITY IN PLACE AND SEVERAL WEAK CONVERGENT
AREAS WE ARE ALREADY SEEING THUNDERSTORMS DEVELOPING ALONG SEVERAL
WEAK CONVERGENT AREAS IN OUR CWA. AS LARGE SCALE FORCING INCREASES
AND THE MAIN MOISTURE PLUME MOVES OVER OUR CWA I EXPECT THUNDERSTORM
COVERAGE TO INCREASE. WHAT COULD BE DESCRIBED AS A COLD FRONT WILL
MOVE INTO THE CWA FROM THE SOUTHEAST THIS AFTERNOON AHEAD OF COLD
POOL ASSOCIATED WITH STRONG UPPER LOW. THUNDERSTORMS WILL INCREASE
IN COVERAGE AS THIS BOUNDARY MOVES NORTHWEST WITH BEST FORCING
CURRENTLY ADVERTISED IN THE 21-00Z TIME FRAME ALONG THE KS/CO BORDER
WHERE MOST GUIDANCE IS SHOWING VERY HIGH QPF VALUES. LATEST GFS IS A
LITTLE FURTHER EAST...HOWEVER SHORT RANGE GUIDANCE (RUC/HRRR)
CONTINUE TO SUPPORT THE NAM SOLUTION FURTHER WEST ALONG COLORADO
STATE LINE.
A VERY MOIST AIR MASS IS IN PLACE OVER THE CWA WITH LATEST RAP
ANALYSIS INDICATING PWAT VALUES IN EXCESS OF 1.5 INCHES AND AS HIGH
AS 1.8 INCHES IN NORTHEAST PARTS OF THE CWA. WHILE NOT UNHEARD OF
THIS IS ANOMALOUSLY HIGH FOR THIS TIME OF YEAR. SB/ML CAPE VALUES
HAVE INCREASED TO NEAR 2000 J/KG ACROSS THE NORTHEAST CWA AND THE
MAIN INSTABILITY AXIS SHOULD CONTINUE TO SPREAD SOUTH AND WEST THIS
AFTERNOON. SHEAR PROFILES ARE VERY WEAK...SO ANY SEVERE THREAT SHOULD
BE TIED TO WIND/HAIL ASSOCIATED WITH PULSE TYPE THUNDERSTORMS. STORM
MOTION WILL GENERALLY BE IN THE 5-15KT RANGE ACROSS THE AREA AND
THERE WILL BE THE POTENTIAL FOR BACK BUILDING AND SLOW PROPAGATION
ALONG THE BOUNDARY OVER OUR WESTERN CWA. WITH HIGH PRECIP RATES AND
SLOW MOVING (POSSIBLY TRAINING) THUNDERSTORM WE COULD SEE AN
ELEVATED THREAT FOR FLASH FLOODING. DESPITE OVERALL SHOWER AND
THUNDERSTORM COVERAGE LIKELY HIGH I AM NOT CONFIDENT THE FLASH FLOOD
THREAT WILL BE WIDESPREAD ENOUGH TO ISSUE A WATCH AT THIS TIME.
ACTIVITY SHOULD COME TO AN END QUICKLY FROM THE EAST TO THE WEST
THIS EVENING AS STRONG SUBSIDENCE BUILDS IN FROM THE NORTHEAST
ASSOCIATED WITH RIDGE BUILDING EAST BEHIND TROUGH. WITH LINGERING
CONVERGENCE ACROSS EASTERN COLORADO AND MOIST UPSLOPE WE COULD SEE A
FEW LINGERING SHOWERS/THUNDERSTORMS THROUGH 12Z WITH PATCHY FOG
POSSIBLY DEVELOPING IN THE 09Z-12Z TIME FRAME.
.LONG TERM...(MONDAY THROUGH SUNDAY)
ISSUED AT 158 PM MDT SUN JUL 14 2013
MONDAY MORNING MAY START OUT WITH SOME FOG OVER THE SOUTHERN AND
WESTERN PARTS OF THE AREA. ANY FOG THAT DEVELOPS SHOULD CLEAR OUT
BY MID MORNING. THE UPPER LEVEL LOW PRESSURE THAT BROUGHT RAINFALL
TO THE TRI-STATE AREA WILL CONTINUE TO MOVE SOUTH. LATE MONDAY
AFTERNOON INTO EARLY MONDAY EVENING THERE WILL BE A BAND OF MID
LEVEL LIFT THAT WILL MOVE ACROSS THE FAR SOUTHERN PART OF THE AREA.
THERE WILL BE AMBLE MOISTURE TO WORK...BUT THE LIMITING FACTOR WILL
BE THE STRENGTHEN OF THE LIFT AND THE SMALL AMOUNT OF INSTABILITY
AVAILABLE. AT THIS TIME THERE APPEARS TO BE ENOUGH LIFT AND
INSTABILITY THAT AN ISOLATED STORM CANNOT BE RULED OUT...SO WILL
KEEP THE SLIGHT CHANCES IN THE FORECAST BUT CONFINE THEM TO THE LATE
AFTERNOON AND EARLY EVENING.
TUESDAY AN UPPER LEVEL RIDGE BEGINS BUILDING OVER THE AREA.
SOUNDINGS OVER EAST CENTRAL COLORADO SHOW SOME INSTABILITY TO WORK
WITH AND LITTLE CIHN DURING THE AFTERNOON...BUT WITH NO SURFACE
CONVERGENCE OR UPPER LEVEL LIFT TO TRIGGER STORMS WILL KEEP THE DAY
DRY.
WEDNESDAY THROUGH SUNDAY AN UPPER LEVEL RIDGE WILL MOVE OVER THE
PLAINS THEN BECOME ESTABLISHED OVER THE ROCKIES. TOWARD THE END OF
THE WEEK THE UPPER LEVEL FLOW WILL STRENGTHEN AND BECOME NORTHWEST.
MODELS HAVE FLATTENED OUT THE SHORT WAVE TROUGH THAT WOULD MOVE OVER
THE AREA DURING THE WEEKEND. THE STRENGTH OF THE COLD FRONT HAS
ALSO DECREASED...WITH MODELS WASHING IT OUT ON SATURDAY OVER THE
AREA. HOWEVER MODELS STILL HAVE A SURFACE TROUGH/WEAK COLD FRONT
OVER THE AREA FOR THE WEEKEND. WITH NORTHWEST UPPER LEVEL FLOW OVER
THE AREA THERE IS STILL A POSSIBILITY FOR STORMS TO
DEVELOP...ALTHOUGH NOT AS GOOD AS PREVIOUSLY THOUGHT.
HIGH TEMPERATURES FOR THE PERIOD WILL GRADUALLY WARM TO ABOVE NORMAL
BY THE END OF THE WEEK AS THE UPPER LEVEL RIDGE BUILDS OVER THE
AREA. WITH LITTLE CHANGE IN THE AIR MASS BY THE END OF THE
WEEK...HIGHS WILL LARGELY REMAIN UNCHANGED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1113 PM MDT SUN JUL 14 2013
ISOLATED SHOWERS OVERNIGHT WILL NOT IMPACT EITHER KGLD OR KMCK.
MODELS HAVE SOMEWHAT BACKED OFF ON STRATUS/FOG POSSIBILITIES. LOW
LEVELS REMAIN QUITE MOIST AND FORECAST LOWS ARE SEVERAL DEGREES
BELOW CURRENT DEW POINTS. HOWEVER MID AND HIGH LEVEL CLOUDS ARE
PERSISTING WHICH WILL LIMIT RADIATIONAL COOLING. STILL THINK THERE
COULD BE AN HOUR OR TWO OF MVFR CIGS AND/OR VISBY RESTRICTIONS
RIGHT AROUND SUNRISE...BEFORE LIFTING LATER IN THE MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JTL
AVIATION...024
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1018 PM CDT TUE JUL 16 2013
.UPDATE...
OVERALL FCST IN GOOD SHAPE. RECENT RADAR TRENDS SHOW CONVECTION
OVER LAND HAS DIMINISHED WITH SCT ACTIVITY CONTINUING OVER THE
COASTAL WATERS. MADE SOME MINOR ADJUSTMENTS TO POPS...INCREASING
THEM OVER THE COASTAL WATERS AND IMMEDIATE COASTAL AREAS FOR THIS
EVENING. POPS AFTER MIDNIGHT STILL LOOK ON TRACK AND SEEM TO BE IN
DECENT AGREEMENT WITH RECENT NAM12 AND HRRR RUNS WITH BEST CHANCES
OVER THE WRN HALF OF THE COASTAL WATERS. TWEAKED HOURLY
TEMPS...DEWPOINTS AND WINDS TO REFLECT RECENT OBSERVATIONAL
TRENDS...BUT NO SIGNIFICANT CHANGES TO REMAINDER OF FCST. 24
&&
.PREV DISCUSSION... /ISSUED 641 PM CDT TUE JUL 16 2013/
DISCUSSION...
00Z
AVIATION...
SCATTERED SHOWERS AND THUNDERSTORMS MOVING AROUND THE PERIPHERY OF
A DEVELOPING HIGH CONTINUE ACROSS THE AREA THIS EVENING. EXPECT
THE ACTIVITY TO CONTINUE FOR THE NEXT COUPLE OF HOURS BEFORE
WANING WITH THE SETTING SUN. A FEW THUNDERSTORMS WILL LIKELY CONTINUE
OFFSHORE OVERNIGHT BUT THEY SHOULD NOT IMPACT TERMINALS. AS THE
HIGH CONTINUES TO BUILD IN...STORMS BE PUSHED FURTHER SOUTHWEST.
THEREFORE EXPECT ONLY ISOLATED THUNDERSTORMS WEDNESDAY AFTERNOON.
66
PREV DISCUSSION... /ISSUED 327 PM CDT TUE JUL 16 2013/
DISCUSSION...
SHOWERS AND THUNDERSTORMS...MORE SCATTERED THAN NUMEROUS IN NATURE
SO FAR...MOVING ACROSS THE FORECAST AREA FROM EAST TO WEST.
SCATTERED ACTIVITY WILL CONTINUE THROUGH EARLY EVENING
HOURS...THEN DIMINISH WITH THE LOSS OF DAYTIME HEATING.
UPPER LEVEL LOW MOVING INTO NEW MEXICO WILL CONTINUE TO MOVE TO
THE WEST WITH UPPER LEVEL RIDGING MOVING IN OVER THE FORECAST AREA
TO TAKE ITS PLACE. THIS SHOULD HELP CUT OFF THE DEEP MOISTURE
FETCH OVER THE FORECAST AREA. THEREFORE...RAIN CHANCES WILL BE
DECREASING OVER THE NEXT COUPLE OF DAYS. EXPECTED SCATTERED
ACTIVITY OVER IN SOUTHEAST TEXAS AND EXTREME WESTERN LOUISIANA ON
WEDNESDAY WITH ISOLATED ELSEWHERE...THEN ISOLATED POPS EVERYWHERE
ON THURSDAY.
THE MID/UPPER LEVEL RIDGE WILL BEGIN TO BREAK DOWN AT THE END OF
THE WEEK INTO THE WEEKEND...WITH THE NEXT WEAK UPPER LEVEL LOW
RETROGRADING INTO THE REGION. THEREFORE...RAIN CHANCES WILL AGAIN
INCREASE TO SCATTERED POPS...WITH NEAR CLIMO TEMPERATURES FROM
FRIDAY THROUGH THE WEEKEND INTO EARLY NEXT WEEK.
RUA
MARINE...
OCCASIONAL WINDS BETWEEN 15 AND 20 KNOTS OCCURRING OVER THE COASTAL
WATERS THIS AFTERNOON. BRIEF PERIODS OF NEAR 20 KNOT WINDS WILL
CONTINUE THROUGH THE EVENING HOURS AS A BIT OF A TIGHTER GRADIENT
AS RIDGE BEGINS TO BUILD IN FROM THE EAST. SO WILL KEEP SMALL
CRAFT EXERCISE CAUTION WORDING THROUGH ABOUT MIDNIGHT.
A LIGHT TO MODERATE EAST TO SOUTHEAST WIND FLOW WILL THEN PREVAIL
THROUGH THE REMAINDER OF THE WEEK...AS COASTAL WATERS REMAIN ON
THE PERIPHERY OF A SURFACE RIDGE LOCATED OVER THE EASTERN U.S.
RUA
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 74 91 74 92 / 20 20 20 20
KBPT 75 90 75 92 / 30 40 20 20
KAEX 72 93 73 94 / 20 20 20 20
KLFT 74 92 74 92 / 20 20 20 20
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
843 PM EDT TUE JUL 16 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 345 PM EDT TUE JUL 16 2013
UPPER AIR PATTERN CONSISTS OF A STRONG 500 MB RIDGE OVER THE LOWER
GREAT LAKES WITH A TROUGH OVER SOUTH CENTRAL CANADA WITH CLOSED LOWS
OFF THE CA COAST AND ONE OVER ERN NM. THE 500 MB RIDGE REMAINS
STATIONARY TODAY WITH THE TROUGH CONTINUING TO MOVE EAST ACROSS
CENTRAL CANADA. THIS TROUGH HELPS TO START PUSHING DOWN THE RIDGE
THIS FORECAST PERIOD WITH THE WESTERLIES ALONG THE CANADIAN/U.S.
BORDER MOVING SLOWLY SOUTH WITH A COLD FRONT MOVING SLOWLY SOUTH AS
WELL.
SPOTTY CONVECTION THAT HAS BEEN KICKED OFF THIS AFTERNOON WAS CAUSED
BY REACHING CONVECTIVE TEMPERATURE WHICH WAS IN THE UPPER 80S. 12Z
GRB SOUNDING HAD A CONVECTIVE TEMPERATURE OF 87 AND THIS SEEMS TO BE
WHAT TEMPERATURES HAVE TO GET TO TO KICK OFF CONVECTION. RUC IS ALSO
SHOWING A 500 MB SPEED MAX JUST TO THE NORTH OF THE AREA AND WITH
MOISTURE ADVECTION...THIS ALSO HELPED TO KICK OFF THE CONVECTION
THIS AFTERNOON. LOOK FOR THIS TO CONTINUE INTO THE EVENING BEFORE
INSTABILITY DIMINISHES WITH LOSS OF HEATING TO STOP THE
THUNDERSTORMS FROM CONTINUING TO DEVELOP. STUFF HAS BEEN FAIRLY
SHORT LIVED AND EXPECT THAT TREND TO CONTINUE THIS AFTERNOON INTO
THIS EVENING.
BUMPED UP SOME LOW TEMPERATURES TONIGHT WITH A SOUTHWEST WIND
ALLOWING DOWNSLOPE TO CONTINUE AND A FEW SW AFFECTED DOWNSLOPE AREAS
COULD HAVE LOWS IN THE MID 70S TONIGHT WHICH IS VERY WARM.
OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST FOR
TEMPERATURES FOR HIGHS ON WED. AGREE WITH SPC OUTLOOK FOR SLIGHT
RISK OF SEVERE THUNDERSTORMS TOMORROW WITH UNIDIRECTIONAL WINDS AND
POOLING OF MOISTURE NEAR THE FRONT TO ALLOW STORMS WITH HIGH WINDS
TO DEVELOP WHICH WOULD BE THE MAIN THREAT FOR SEVERE WEATHER. FRONT
STARTS TO SAG DOWN INTO THE AREA AS WELL SO A FOCUSING MECHANISM FOR
CONVECTION IS THERE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 345 PM EDT TUE JUL 16 2013
WEDNESDAY NIGHT...THE VERY SLOW MOVING COLD FRONT STRETCHING FROM
NORTH DAKOTA EASTWARD INTO SOUTHWESTERN QUEBEC WILL BECOME
STATIONARY OVERNIGHT WEDNESDAY NIGHT. AT THE SAME TIME HEIGHT FALLS
ASSOCIATED WITH THE UPPER LEVEL 500MB LOW OVER JAMES BAY WILL BEGIN
TO SINK SLOWLY SOUTHWARD AS IT SLOWLY WEAKENS THE HIGH PRESSURE
RIDGE THAT REMAINS OVER MUCH OF THE SOUTHEASTERN U.S. WITH THE FRONT
STRETCHING ACROSS MUCH OF LAKE SUPERIOR INTO THE NORTHERN PORTIONS
OF THE U.P. EXPECT THAT FORCING WILL BE GREAT ENOUGH TO ENHANCE THE
CHANCES FOR SHOWERS AND THUNDERSTORMS ACROSS MUCH OF THE AREA.
CONVERGENCE ASSOCIATED WITH A 25 TO 30 KNOT 850MB LLJ OVER CENTRAL
MN INTO NORTHERN WI WILL KEEP SHOWERS AND THUNDERSTORMS IN THE
FORECAST THROUGH THE OVERNIGHT HOURS...EVEN WITH THE LOSS OF DAYTIME
HEATING. DURING THE OVERNIGHT HOURS...THE CWA WILL ALSO BE UNDER
THE INFLUENCE OF THE RIGHT ENTRANCE REGION OF AN UPPER LEVEL 300MB
JET MAX...HELPING TO INCREASE FORCING FOR ASCENT. MU CAPE VALUES
OVERNIGHT ARE STILL EXPECTED TO BE AROUND 1000-1500 J/KG WITH DEEP
LAYER SHEAR VALUES ON THE ORDER OF 30 TO 35 KNOTS ACROSS THE AREA.
THE SHEAR IS UNIDIRECTIONAL...WHICH WOULD ALSO FAVOR MORE OF A WIND
THREAT. IT WOULD DEFINITELY NOT BE OUT OF THE QUESTION FOR SOME OF
THE STORMS TO BE FAIRLY STRONG OR EVEN SEVERE. THE MAIN THREAT FROM
THESE STORMS WOULD BE STRONG GUSTY WINDS AS DRY AIR REMAINS IN THE
MID LEVELS ALONG WITH AN INVERTED V TYPE SOUNDING IN THE LOW LEVELS
THROUGH THE OVERNIGHT HOURS...HELPING TO INCREASE COLD POOL
DEVELOPMENT. IT SHOULD BE KEPT IN MIND THAT MUCH OF THIS DEPENDS ON
CONVECTIVE DEVELOPMENT/TRACK THROUGH THE DAYTIME HOURS WEDNESDAY.
THURSDAY THROUGH FRIDAY...THE STATIONARY FRONT POSITIONED OVER LAKE
SUPERIOR THURSDAY MORNING IS PROGGED BY THE GFS/EC/GEM TO BEGIN
LIFTING NORTHWARD AS A WARM FRONT DURING THE AFTERNOON HOURS
THURSDAY. THIS FRONT WILL CONTINUE TO LIFT NORTHWARD INTO ONTARIO
DURING THE EVENING HOURS AS A COLD FRONT IS PUSHED SOUTHEASTWARD OUT
OF SOUTHERN MANITOBA INTO NORTHEASTERN MN DURING THE OVERNIGHT
HOURS AS THE UPPER LEVEL TROUGH BEGINS TO DIG INTO THE REGION. WITH
THE FRONT LIFTING NORTHWARD DURING THE DAY THURSDAY...IT WOULD NOT
BE OUT OF THE QUESTION TO SEE THE CLOUDS BREAK UP OVER THE
AREA...WHICH WILL HELP TO INCREASE THE CHANCES FOR SEVERE WEATHER
ACROSS THE CWA AS INSTABILITY INCREASES TO AROUND 1500-2500 J/KG.
DEEP LAYER SHEAR VALUES THROUGH THE DAY THURSDAY ARE PROGGED TO BE
AROUND 35 TO 40 KNOTS WHICH WOULD BE FAVORABLE FOR SEVERE WEATHER
DEVELOPMENT. THURSDAY AND THURSDAY EVENING WIND PROFILES INDICATED
THAT BOTH SPEED AND DIRECTIONAL SHEAR ARE AVAILABLE WHICH WOULD
SUPPORT A MORE ORGANIZED SEVERE EVENT. WHILE THE SOUNDING GAINS A
BIT MORE MOISTURE THROUGHOUT...DRY AIR REMAINS IN PORTIONS OF THE
LOWER LEVELS ALLOWING FOR AN INCREASED SEVERE WIND THREAT THROUGH
THE DAY THURSDAY INTO THE EVENING HOURS. A GREAT DEAL OF THE SEVERE
THREAT DURING THE DAY THURSDAY IS DEPENDENT UPON CLOUD COVER.
OVERNIGHT THURSDAY THROUGH FRIDAY MORNING THE COLD FRONT TO THE
NORTHWEST OF THE AREA WILL CONTINUE SOUTHEASTWARD PUSHING SOUTHEAST
OF THE AREA BY LATE FRIDAY AFTERNOON. AHEAD OF THE COLD FRONT
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO BE LIKELY. STRONG TO
SEVERE THUNDERSTORMS WILL BE POSSIBLE THROUGH EARLY FRIDAY MORNING
AS 0-6KM SHEAR VALUES ARE EXPECTED TO BE AROUND 40 TO 45 KNOTS ALONG
AND AHEAD OF THE FRONT...WITH SHEAR VECTORS BECOMING PERPENDICULAR
TO THE FORCING. THE SEVERE THREAT WILL SHIFT SOUTHEASTWARD INTO THE
LOWER GREAT LAKES BY FRIDAY AFTERNOON AS THE FRONT SHIFTS OUT OF THE
AREA. WITH THAT BEING SAID A FEW SHOWERS MAY LINGER INTO THE
AFTERNOON HOURS AS THE UPPER LEVEL 500MB THROUGH MOVES DIRECTLY
OVERHEAD.
FRIDAY NIGHT THROUGH SUNDAY NIGHT...FRIDAY NIGHT THE UPPER LEVEL
500MB TROUGH AXIS LINGERS OVER THE UPPER GREAT LAKES ALONG WITH
REMNANT MOISTURE. THIS WILL KEEP THE CHANCE OF ISOLATED SHOWERS IN
THE FORECAST THROUGH FRIDAY NIGHT. SATURDAY...HIGH PRESSURE BUILDING
OVER SOUTHERN CANADA INTO THE NORTHERN PLAINS WILL BEGIN BUILDING
EASTWARD INTO THE GREAT LAKES REGION. AS THIS HAPPENS FLOW AROUND
THE EASTERN SIDE OF THE HIGH WILL ALLOW DRY AIR FROM CANADA TO SPILL
SOUTHWARD HELPING TO CLEAR THE SKIES FOR THE WEEKEND AND DRY THINGS
OUT A BIT. THIS HIGH IS PROGGED TO REMAIN IN THE AREA THROUGH
SUNDAY NIGHT.
MONDAY THROUGH TUESDAY...DIFFERENCES REMAIN IN MODEL SOLUTIONS TO
THE WEATHER PATTERN FOR THE FIRST HALF OF NEXT WEEK. THE GFS KEEPS
ZONAL TO SLIGHTLY RIDGED FLOW AT 500MB ACROSS THE AREA THROUGH THIS
TIME PERIOD WHILE THE EC BRINGS AND UPPER LEVEL TROUGH INTO THE
REGION. AT THE SAME TIME THE GFS PLACES A SURFACE HIGH OVER THE AREA
WHILE THE EC BUILDS A SURFACE LOW INTO THE REGION OUT OF SOUTHERN
CANADA. WITH THIS CONTINUED DISCONTINUITY...WILL STICK WITH A
CONSENSUS OF THE MODELS DURING THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 838 PM EDT TUE JUL 16 2013
VFR CONDITIONS SHOULD CONTINUE THROUGH THE PERIOD AT ALL SITES. ISOLD
SHRA/TSRA ARE DISSIPATING THIS EVENING WITH LOSS OF HEATING. LOOK FOR
MORE SCT TO ISOLD SHRA/TS TO DEVELOP LATE WED MORNING/EARLY AFTERNOON
AS A FRONTAL BOUNDARY MOVES IN FM THE NW. HAVE INCLUDED PREVAILING
-SHRA AND VCTS FOR BOTH KIWD AND KSAW BUT WILL LEAVE MENTION OF SHRA
OUT OF KCMX WHERE CONDITIONS WILL BE MORE STABLE NEAR LAKE SUPERIOR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 345 PM EDT TUE JUL 16 2013
FOG WILL CONTINUE TO BE PATCHY THROUGH WED MORNING ON LAKE SUPERIOR
AS COLD WATER WITH WARM AND HUMID AIR MOVING OVER THE TOP CAUSES FOG
TO FORM. AS THE FRONT STARTS TO COME DOWN ON WED...THIS SHOULD
DISRUPT THE FOG. A LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY WILL
EFFECT THE REGION WEDNESDAY THROUGH FRIDAY...HOWEVER...WINDS SHOULD
REMAIN LIGHT AND GENERALLY LESS THAN 15 KNOTS. HIGH PRESSURE BUILDS
IN FOR MUCH OF THE WEEKEND ALLOWING WINDS TO REMAIN LIGHT AND
VARIABLE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...KEC
AVIATION...VOSS
MARINE...07
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
130 PM EDT MON JUL 15 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 427 AM EDT MON JUL 15 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SPRAWLING UPR RDG
CENTERED NEAR LAKE ERIE ON THE SRN FLANK OF FASTER WSW FLOW ALF OVER
CANADA. WITH VERY DRY MID LVLS AND SUBSIDENCE INVRN SHOWN ON THE 00Z
MPX/GRB/APX RAOBS...SKIES ARE MOCLR OVER THE CWA. RIBBON OF MSTR/
BAND OF SHRA TO THE SE OF STNRY FNT RUNNING FM MN INTO NW ONTARIO IS
JUST NW OF LK SUP...BUT ONLY SCT CLDS ARE IMPACTING THE WRN CWA.
MORE LO/MID LVL MSTR IS PRESENT OVER THE OH RIVER VALLEY/LOWER GRT LKS
AND TENDING TO DRIFT TO THE NW ARND THE CLOSED LO PER WV IMAGERY.
MAIN FCST CONCERNS THRU TNGT ARE TEMPS AND POPS...RELATED TO MSTR
RIBBON JUST TO THE NW AND AREA OF MOISTER AIR DRIFTING NWWD THRU THE
OH RIVER VALLEY/LOWER GRT LKS.
TODAY...UPR RDG IS FCST TO REMAIN DOMINANT OVER THE GREAT LKS...
WHICH SHOULD KEEP PCPN ASSOCIATED WITH MSTR RIBBON IN MN TO THE NW
OF ALL BUT NW LK SUP. THE BIGGER QUESTION IS WHETHER ENUF MSTR WL
ARRIVE FM THE S TO GENERATE SOME DIURNAL SHRA/TS IN THE ABSENCE OF
ANY DYNAMIC FORCING THAT WOULD TEND TO MAINTAIN THE STRENGTH OF THE
SUBSIDENCE INVRN. A FEW OF THE MODELS INCLUDING THE 00Z NAM GENERATE
SOME PCPN OVER THE FAR SCENTRAL THIS AFTN...MAINLY THE NAM FCST
SDNGS FOR MNM SHOW KINX INCRSG FM 15 AT 18Z TO 34 AT 00Z...BUT THE
NAM APPEARS TO WEAKEN THE SUBSIDENCE INVRN TOO MUCH. CONSIDERING THE
OBSVD STRENGTH OF THE UPR RDG/SUBSIDENCE INVRN SHOWN ON THE 00Z GRB
RAOB...PREFER THE MORE STABLE LOOK OF THE 00Z LOCAL WRF/ARW AND THE
DRY FCST IT SHOWS IN THE ABSENCE OF ANY LARGER SCALE FORCING OTHER
THAN MSTR ADVECTION. EVEN THOUGH MORE DIURNAL CU WL DVLP TODAY WITH
INFLUX OF LLVL MSTR FM THE S...EXPECT TEMPS TO RISE WELL INTO THE
80S AGAIN IN THE PRESENCE OF H85 TEMPS ARND 18C. BUT WITH RATHER
WEAK PRES GRADIENT...LK BREEZES SHOULD KEEP COASTAL AREAS COOLER.
TNGT...THE MAJORITY OF THE MODELS DO GENERATE PCPN TNGT ASSOCIATED
WITH THE RETURNING MSTR. BUT THE QUESTION REMAINS WHY THE MID LVL
INVRN WOULD WEAKEN AS MUCH AS SHOWN ON THE FCST SDNGS TO ALLOW SHRA
TO FORM IN THE PRESENCE OF NOCTURNAL COOLING. OFTEN DURING THIS TIME
OF YEAR...A STRENGTHENING OF THE NOCTURNAL LLJ RESULTS IN SOME
CONVECTION...BUT THERE IS NO SIGN OF THIS. IN FACT...THE H85 FLOW IS
FCST TO REMAIN ACYC. SO OPTED TO FOLLOW THE DRY NAM FCST AND JUST
SHOW SOME INCRSG CLDS. THIS INCRSG MSTR SHOULD RESULT IN HIER MIN
TEMPS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 427 AM EDT MON JUL 15 2013
LARGE MID-LEVEL HIGH OVER OHIO VALLEY AND LOWER GREAT LAKES EXPANDS
WESTWARD TOWARD THE CENTRAL PLAINS THROUGH MIDWEEK. MID TO LATE WEEK
HEIGHTS FM NORTHERN PLAINS TO THE UPPER GREAT LAKES ARE FORECAST
TO LOWER AS MID-LEVEL WIND CORE SETTLES ACROSS MANITOBA AND NORTHERN
ONTARIO. GOOD MODEL AGREEMENT IN THE TREND TOWARD LOWER HEIGHTS LATE
THIS WEEK.
FIRST QUANDARY FOR THE FORECAST IS ON TUESDAY. WHAT TO DO WITH ALL
THE QPF MODELS ARE KICKING OFF. AS DISCUSSED IN THE SHORT TERM
NEGATIVE LARGER SCALE FORCING WITH RIDGE NEARBY SEEMS TO OUTWEIGH
PRIMARILY MAIN DRIVER OF MOISTURE ADVECTION. ON TUESDAY MOISTURE
ADVECTION CONTINUES BUT THERE IS ALSO WEAK TEMP ADVECTION AT H85
MAINLY OVR NORTHERN LK SUPERIOR. THOUGH THERE IS MINIMAL LK BREEZE
CONVERGENCE...POSSIBLE THAT THIS AREA OF SHRA/TSRA OVER THE LAKE WILL
EXPAND OVER PARTS OF LAND AREAS OF UPR MICHIGAN DURING PEAK HEATING
OF AFTN. COVERAGE SHOULD BE PRETTY SPARSE. JUST SLIGHT CHANCE POPS
GIVEN PRIMARY NEGATIVE LARGER SCALE FORCING AND LIMITED COVERAGE.
ANY SHRA/TSRA FM AFTN WILL CEASE EARLY WITH LOSS OF DAYTIME HEATING
AND NOT MUCH OF TRIGGER OTHERWISE. SHRA/TSRA WILL BE ONGOING CLOSER
TO APPROACHING COLD FRONT/LOW-LEVEL JET OVER SOUTHERN MANITOBA INTO
NORTHWEST ONTARIO. ISLE ROYALE COULD GET CLIPPED BUT BASED ON
WESTERLY STORM MOTION THAT SEEMS TO BE PRETTY LOW CHANCE. PRIMARY
FRONTAL PASSAGE OCCURS OVR UPR MICHIGAN LATE WEDNESDAY INTO
WEDNESDAY NIGHT AS INITIAL HEIGHT FALLS BEGIN. AT THIS POINT...THINK
WEDNESDAY PM HOLDS THE HIGHEST LIKLIHOOD OF SEEING STRONG STORMS
AND POSSIBLE SEVERE WEATHER AS THE FRONT MOVES THROUGH AND INTERACTS
WITH HIGHER END INSTABILITY WITH MLCAPES OVER 1500J/KG AND STRONGER
DEEP LAYER SHEAR OVER 30 KTS. BASED ON HIGHER SHEAR AND FAVORABLE
0-1KM SHEAR...ALL MODES OF SEVERE...INCLUDING SUPERCELLS...WOULD BE
POSSIBLE WEDNESDAY AFTN INTO WEDNESDAY EVENING.
QUESTIONS THEN ON HOW FAR SOUTH THE FRONT EVENTUALLY PROGRESSES BY
THURSDAY. MODELS HAVE TRENDED A BIT FARTHER SOUTH WITH FROPA OVER
LAST COUPLE DAYS...INDICATING THE FRONT...POSSIBLY ENHANCED BY
OUTFLOW FM THE TSRA ON WEDNESDAY...WILL SET UP MORE OVER WISCONSIN
LATER WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. IF THIS OCCURS...AND
THAT IS NOT SURE THING AS FRONT WILL STILL BE PARALLEL TO MID LEVEL
HEIGHTS...BETTER CHANCES FOR SEVERE STORMS THURSDAY WOULD LIKELY
STAY TO SOUTH OF UPR MICHIGAN. HOWEVER BEFORE THAT IF TSRA FORM
UPSTREAM IN NORTHERN MINNESOTA ON WEDNESDAY AFTN/EVENING THERE IS
ADDITIONAL POTENTIAL FOR STRONGER TSRA WITH A WIND THREAT LATE
WEDNESDAY NIGHT OVR MUCH OF UPR MICHIGAN BASED ON H85-H3 THICKNESSES
AND GRADIENT OF HIGHER MUCAPE OVER UPR MICHIGAN. SINCE UPR MICHIGAN
WOULD THEN BE ON THE COOLER SIDE OF THE FRONT ON THURSDAY AND THERE
IS ABUNDANT MOISTURE INTERSECTING THE FRONT WITH PWATS NEARING 200
PCT OF NORMAL AND THERE ARE SHORTWAVES MOVING THROUGH IN WNW FLOW
ALOFT ACROSS MANITOBA AND ONTARIO...SEEMS LIKELY THAT COULD SEE
WIDESPREAD SHRA/TSRA ACROSS MUCH OF THE AREA ON THURSDAY. HEAVY
RAIN WOULD BE POSSIBLE WITH SUCH ABUNDANT MOISTURE. CONSENSUS OF
MODELS INDICATES LIKELY POPS THURSDAY INTO THURSDAY NIGHT WHICH
FITS THIS PATTERN PRETTY WELL. GIVEN POTENTIAL FOR A LOT OF
CLOUDS/FOG AND WIDESPREAD PRECIP ON THURSDAY IN ADDITION TO ONSHORE
FLOW DEVELOPING OFF LK SUPERIOR...HAVE LOWERED TEMPS ACROSS THE CWA.
GOOD AGREEMENT THAT COOLER NORTH FLOW KICKS IN BY FRIDAY AND
CONTINUES THROUGH SATURDAY. NO REAL CHANGE TO GOING FCST/CONSENSUS
WITH HIGHS STRUGGLING IN THE 60S NEAR LK SUPERIOR BOTH FRIDAY AND
SATURDAY. HIGHS AWAY FM LK SUPERIOR WILL BE IN THE 70S/LOWER
80S...COOLEST ON SATURDAY BEHIND SECONDARY RE-INFORCING COLD FRONT.
WARMER TEMPS BEGIN TO RETURN BY SUNDAY ALONG WITH A SMALL CHANCES
OF SHRA/TSRA DUE TO WARM AIR ADVECTION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 129 PM EDT MON JUL 15 2013
WITH HIGH PRESSURE IN PLACE OVER UPPER MICHIGAN...EXPECT VFR
CONDITIONS THROUGH MOST OF THE TAF PERIOD. THE ONLY CONCERN FOR
TONIGHT WILL BE POTENTIAL FOR FOG DEVELOPMENT. THOUGH THERE WILL BE
ABUNDANT LL MOISTURE AND LIMITED CLOUD COVER TONIGHT...FOG MAY NOT
DEVELOP BECAUSE OF MORE PRONOUNCED SOUTHERLY WIND FLOW. STILL FELT
CONFIDENT ENOUGH TO PLACE IN TAF. ONLY HAVE HIGH END-MVFR
VISIBILITIES AS IT WILL NOT LIKELY DROP TO LESS THAN 3 MILES LIKE
LAST NIGHT BECAUSE OF THE SLIGHTLY STRONGER WINDS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 427 AM EDT MON JUL 15 2013
WITH A WEAK PRESSURE GRADIENT AND STABLE AIR OVER THE COOL WATERS OF
LAKE SUPERIOR...EXPECT WINDS TO REMAIN LESS THAN 20 KNOTS THROUGH
THE FORECAST PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...MCD
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
705 AM EDT MON JUL 15 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 427 AM EDT MON JUL 15 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SPRAWLING UPR RDG
CENTERED NEAR LAKE ERIE ON THE SRN FLANK OF FASTER WSW FLOW ALF OVER
CANADA. WITH VERY DRY MID LVLS AND SUBSIDENCE INVRN SHOWN ON THE 00Z
MPX/GRB/APX RAOBS...SKIES ARE MOCLR OVER THE CWA. RIBBON OF MSTR/
BAND OF SHRA TO THE SE OF STNRY FNT RUNNING FM MN INTO NW ONTARIO IS
JUST NW OF LK SUP...BUT ONLY SCT CLDS ARE IMPACTING THE WRN CWA.
MORE LO/MID LVL MSTR IS PRESENT OVER THE OH RIVER VALLEY/LOWER GRT LKS
AND TENDING TO DRIFT TO THE NW ARND THE CLOSED LO PER WV IMAGERY.
MAIN FCST CONCERNS THRU TNGT ARE TEMPS AND POPS...RELATED TO MSTR
RIBBON JUST TO THE NW AND AREA OF MOISTER AIR DRIFTING NWWD THRU THE
OH RIVER VALLEY/LOWER GRT LKS.
TODAY...UPR RDG IS FCST TO REMAIN DOMINANT OVER THE GREAT LKS...
WHICH SHOULD KEEP PCPN ASSOCIATED WITH MSTR RIBBON IN MN TO THE NW
OF ALL BUT NW LK SUP. THE BIGGER QUESTION IS WHETHER ENUF MSTR WL
ARRIVE FM THE S TO GENERATE SOME DIURNAL SHRA/TS IN THE ABSENCE OF
ANY DYNAMIC FORCING THAT WOULD TEND TO MAINTAIN THE STRENGTH OF THE
SUBSIDENCE INVRN. A FEW OF THE MODELS INCLUDING THE 00Z NAM GENERATE
SOME PCPN OVER THE FAR SCENTRAL THIS AFTN...MAINLY THE NAM FCST
SDNGS FOR MNM SHOW KINX INCRSG FM 15 AT 18Z TO 34 AT 00Z...BUT THE
NAM APPEARS TO WEAKEN THE SUBSIDENCE INVRN TOO MUCH. CONSIDERING THE
OBSVD STRENGTH OF THE UPR RDG/SUBSIDENCE INVRN SHOWN ON THE 00Z GRB
RAOB...PREFER THE MORE STABLE LOOK OF THE 00Z LOCAL WRF/ARW AND THE
DRY FCST IT SHOWS IN THE ABSENCE OF ANY LARGER SCALE FORCING OTHER
THAN MSTR ADVECTION. EVEN THOUGH MORE DIURNAL CU WL DVLP TODAY WITH
INFLUX OF LLVL MSTR FM THE S...EXPECT TEMPS TO RISE WELL INTO THE
80S AGAIN IN THE PRESENCE OF H85 TEMPS ARND 18C. BUT WITH RATHER
WEAK PRES GRADIENT...LK BREEZES SHOULD KEEP COASTAL AREAS COOLER.
TNGT...THE MAJORITY OF THE MODELS DO GENERATE PCPN TNGT ASSOCIATED
WITH THE RETURNING MSTR. BUT THE QUESTION REMAINS WHY THE MID LVL
INVRN WOULD WEAKEN AS MUCH AS SHOWN ON THE FCST SDNGS TO ALLOW SHRA
TO FORM IN THE PRESENCE OF NOCTURNAL COOLING. OFTEN DURING THIS TIME
OF YEAR...A STRENGTHENING OF THE NOCTURNAL LLJ RESULTS IN SOME
CONVECTION...BUT THERE IS NO SIGN OF THIS. IN FACT...THE H85 FLOW IS
FCST TO REMAIN ACYC. SO OPTED TO FOLLOW THE DRY NAM FCST AND JUST
SHOW SOME INCRSG CLDS. THIS INCRSG MSTR SHOULD RESULT IN HIER MIN
TEMPS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 427 AM EDT MON JUL 15 2013
LARGE MID-LEVEL HIGH OVER OHIO VALLEY AND LOWER GREAT LAKES EXPANDS
WESTWARD TOWARD THE CENTRAL PLAINS THROUGH MIDWEEK. MID TO LATE WEEK
HEIGHTS FM NORTHERN PLAINS TO THE UPPER GREAT LAKES ARE FORECAST
TO LOWER AS MID-LEVEL WIND CORE SETTLES ACROSS MANITOBA AND NORTHERN
ONTARIO. GOOD MODEL AGREEMENT IN THE TREND TOWARD LOWER HEIGHTS LATE
THIS WEEK.
FIRST QUANDARY FOR THE FORECAST IS ON TUESDAY. WHAT TO DO WITH ALL
THE QPF MODELS ARE KICKING OFF. AS DISCUSSED IN THE SHORT TERM
NEGATIVE LARGER SCALE FORCING WITH RIDGE NEARBY SEEMS TO OUTWEIGH
PRIMARILY MAIN DRIVER OF MOISTURE ADVECTION. ON TUESDAY MOISTURE
ADVECTION CONTINUES BUT THERE IS ALSO WEAK TEMP ADVECTION AT H85
MAINLY OVR NORTHERN LK SUPERIOR. THOUGH THERE IS MINIMAL LK BREEZE
CONVERGENCE...POSSIBLE THAT THIS AREA OF SHRA/TSRA OVER THE LAKE WILL
EXPAND OVER PARTS OF LAND AREAS OF UPR MICHIGAN DURING PEAK HEATING
OF AFTN. COVERAGE SHOULD BE PRETTY SPARSE. JUST SLIGHT CHANCE POPS
GIVEN PRIMARY NEGATIVE LARGER SCALE FORCING AND LIMITED COVERAGE.
ANY SHRA/TSRA FM AFTN WILL CEASE EARLY WITH LOSS OF DAYTIME HEATING
AND NOT MUCH OF TRIGGER OTHERWISE. SHRA/TSRA WILL BE ONGOING CLOSER
TO APPROACHING COLD FRONT/LOW-LEVEL JET OVER SOUTHERN MANITOBA INTO
NORTHWEST ONTARIO. ISLE ROYALE COULD GET CLIPPED BUT BASED ON
WESTERLY STORM MOTION THAT SEEMS TO BE PRETTY LOW CHANCE. PRIMARY
FRONTAL PASSAGE OCCURS OVR UPR MICHIGAN LATE WEDNESDAY INTO
WEDNESDAY NIGHT AS INITIAL HEIGHT FALLS BEGIN. AT THIS POINT...THINK
WEDNESDAY PM HOLDS THE HIGHEST LIKLIHOOD OF SEEING STRONG STORMS
AND POSSIBLE SEVERE WEATHER AS THE FRONT MOVES THROUGH AND INTERACTS
WITH HIGHER END INSTABILITY WITH MLCAPES OVER 1500J/KG AND STRONGER
DEEP LAYER SHEAR OVER 30 KTS. BASED ON HIGHER SHEAR AND FAVORABLE
0-1KM SHEAR...ALL MODES OF SEVERE...INCLUDING SUPERCELLS...WOULD BE
POSSIBLE WEDNESDAY AFTN INTO WEDNESDAY EVENING.
QUESTIONS THEN ON HOW FAR SOUTH THE FRONT EVENTUALLY PROGRESSES BY
THURSDAY. MODELS HAVE TRENDED A BIT FARTHER SOUTH WITH FROPA OVER
LAST COUPLE DAYS...INDICATING THE FRONT...POSSIBLY ENHANCED BY
OUTFLOW FM THE TSRA ON WEDNESDAY...WILL SET UP MORE OVER WISCONSIN
LATER WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. IF THIS OCCURS...AND
THAT IS NOT SURE THING AS FRONT WILL STILL BE PARALLEL TO MID LEVEL
HEIGHTS...BETTER CHANCES FOR SEVERE STORMS THURSDAY WOULD LIKELY
STAY TO SOUTH OF UPR MICHIGAN. HOWEVER BEFORE THAT IF TSRA FORM
UPSTREAM IN NORTHERN MINNESOTA ON WEDNESDAY AFTN/EVENING THERE IS
ADDITIONAL POTENTIAL FOR STRONGER TSRA WITH A WIND THREAT LATE
WEDNESDAY NIGHT OVR MUCH OF UPR MICHIGAN BASED ON H85-H3 THICKNESSES
AND GRADIENT OF HIGHER MUCAPE OVER UPR MICHIGAN. SINCE UPR MICHIGAN
WOULD THEN BE ON THE COOLER SIDE OF THE FRONT ON THURSDAY AND THERE
IS ABUNDANT MOISTURE INTERSECTING THE FRONT WITH PWATS NEARING 200
PCT OF NORMAL AND THERE ARE SHORTWAVES MOVING THROUGH IN WNW FLOW
ALOFT ACROSS MANITOBA AND ONTARIO...SEEMS LIKELY THAT COULD SEE
WIDESPREAD SHRA/TSRA ACROSS MUCH OF THE AREA ON THURSDAY. HEAVY
RAIN WOULD BE POSSIBLE WITH SUCH ABUNDANT MOISTURE. CONSENSUS OF
MODELS INDICATES LIKELY POPS THURSDAY INTO THURSDAY NIGHT WHICH
FITS THIS PATTERN PRETTY WELL. GIVEN POTENTIAL FOR A LOT OF
CLOUDS/FOG AND WIDESPREAD PRECIP ON THURSDAY IN ADDITION TO ONSHORE
FLOW DEVELOPING OFF LK SUPERIOR...HAVE LOWERED TEMPS ACROSS THE CWA.
GOOD AGREEMENT THAT COOLER NORTH FLOW KICKS IN BY FRIDAY AND
CONTINUES THROUGH SATURDAY. NO REAL CHANGE TO GOING FCST/CONSENSUS
WITH HIGHS STRUGGLING IN THE 60S NEAR LK SUPERIOR BOTH FRIDAY AND
SATURDAY. HIGHS AWAY FM LK SUPERIOR WILL BE IN THE 70S/LOWER
80S...COOLEST ON SATURDAY BEHIND SECONDARY RE-INFORCING COLD FRONT.
WARMER TEMPS BEGIN TO RETURN BY SUNDAY ALONG WITH A SMALL CHANCES
OF SHRA/TSRA DUE TO WARM AIR ADVECTION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 701 AM EDT MON JUL 15 2013
EXCEPT FOR SOME FOG EARLY AT IWD...EXPECT VFR CONDITIONS TO DOMINATE
THIS FCST PERIOD AS HI PRES REMAINS IN CONTROL. THERE WL BE AN
INFLUX OF MOISTER AIR...BUT PERSISTENT UPR RDG WL RESTRICT THE CHC
FOR SHRA TDAY. SOME FOG IS PSBL TNGT WITHIN THE MOISTER AIRMASS...
BUT A STEADY S WIND WL LIMIT THIS POTENTIAL.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 427 AM EDT MON JUL 15 2013
WITH A WEAK PRESSURE GRADIENT AND STABLE AIR OVER THE COOL WATERS OF
LAKE SUPERIOR...EXPECT WINDS TO REMAIN LESS THAN 20 KNOTS THROUGH
THE FORECAST PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
430 AM EDT MON JUL 15 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 427 AM EDT MON JUL 15 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SPRAWLING UPR RDG
CENTERED NEAR LAKE ERIE ON THE SRN FLANK OF FASTER WSW FLOW ALF OVER
CANADA. WITH VERY DRY MID LVLS AND SUBSIDENCE INVRN SHOWN ON THE 00Z
MPX/GRB/APX RAOBS...SKIES ARE MOCLR OVER THE CWA. RIBBON OF MSTR/
BAND OF SHRA TO THE SE OF STNRY FNT RUNNING FM MN INTO NW ONTARIO IS
JUST NW OF LK SUP...BUT ONLY SCT CLDS ARE IMPACTING THE WRN CWA.
MORE LO/MID LVL MSTR IS PRESENT OVER THE OH RIVER VALLEY/LOWER GRT LKS
AND TENDING TO DRIFT TO THE NW ARND THE CLOSED LO PER WV IMAGERY.
MAIN FCST CONCERNS THRU TNGT ARE TEMPS AND POPS...RELATED TO MSTR
RIBBON JUST TO THE NW AND AREA OF MOISTER AIR DRIFTING NWWD THRU THE
OH RIVER VALLEY/LOWER GRT LKS.
TODAY...UPR RDG IS FCST TO REMAIN DOMINANT OVER THE GREAT LKS...
WHICH SHOULD KEEP PCPN ASSOCIATED WITH MSTR RIBBON IN MN TO THE NW
OF ALL BUT NW LK SUP. THE BIGGER QUESTION IS WHETHER ENUF MSTR WL
ARRIVE FM THE S TO GENERATE SOME DIURNAL SHRA/TS IN THE ABSENCE OF
ANY DYNAMIC FORCING THAT WOULD TEND TO MAINTAIN THE STRENGTH OF THE
SUBSIDENCE INVRN. A FEW OF THE MODELS INCLUDING THE 00Z NAM GENERATE
SOME PCPN OVER THE FAR SCENTRAL THIS AFTN...MAINLY THE NAM FCST
SDNGS FOR MNM SHOW KINX INCRSG FM 15 AT 18Z TO 34 AT 00Z...BUT THE
NAM APPEARS TO WEAKEN THE SUBSIDENCE INVRN TOO MUCH. CONSIDERING THE
OBSVD STRENGTH OF THE UPR RDG/SUBSIDENCE INVRN SHOWN ON THE 00Z GRB
RAOB...PREFER THE MORE STABLE LOOK OF THE 00Z LOCAL WRF/ARW AND THE
DRY FCST IT SHOWS IN THE ABSENCE OF ANY LARGER SCALE FORCING OTHER
THAN MSTR ADVECTION. EVEN THOUGH MORE DIURNAL CU WL DVLP TODAY WITH
INFLUX OF LLVL MSTR FM THE S...EXPECT TEMPS TO RISE WELL INTO THE
80S AGAIN IN THE PRESENCE OF H85 TEMPS ARND 18C. BUT WITH RATHER
WEAK PRES GRADIENT...LK BREEZES SHOULD KEEP COASTAL AREAS COOLER.
TNGT...THE MAJORITY OF THE MODELS DO GENERATE PCPN TNGT ASSOCIATED
WITH THE RETURNING MSTR. BUT THE QUESTION REMAINS WHY THE MID LVL
INVRN WOULD WEAKEN AS MUCH AS SHOWN ON THE FCST SDNGS TO ALLOW SHRA
TO FORM IN THE PRESENCE OF NOCTURNAL COOLING. OFTEN DURING THIS TIME
OF YEAR...A STRENGTHENING OF THE NOCTURNAL LLJ RESULTS IN SOME
CONVECTION...BUT THERE IS NO SIGN OF THIS. IN FACT...THE H85 FLOW IS
FCST TO REMAIN ACYC. SO OPTED TO FOLLOW THE DRY NAM FCST AND JUST
SHOW SOME INCRSG CLDS. THIS INCRSG MSTR SHOULD RESULT IN HIER MIN
TEMPS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 427 AM EDT MON JUL 15 2013
LARGE MID-LEVEL HIGH OVER OHIO VALLEY AND LOWER GREAT LAKES EXPANDS
WESTWARD TOWARD THE CENTRAL PLAINS THROUGH MIDWEEK. MID TO LATE WEEK
HEIGHTS FM NORTHERN PLAINS TO THE UPPER GREAT LAKES ARE FORECAST
TO LOWER AS MID-LEVEL WIND CORE SETTLES ACROSS MANITOBA AND NORTHERN
ONTARIO. GOOD MODEL AGREEMENT IN THE TREND TOWARD LOWER HEIGHTS LATE
THIS WEEK.
FIRST QUANDARY FOR THE FORECAST IS ON TUESDAY. WHAT TO DO WITH ALL
THE QPF MODELS ARE KICKING OFF. AS DISCUSSED IN THE SHORT TERM
NEGATIVE LARGER SCALE FORCING WITH RIDGE NEARBY SEEMS TO OUTWEIGH
PRIMARILY MAIN DRIVER OF MOISTURE ADVECTION. ON TUESDAY MOISTURE
ADVECTION CONTINUES BUT THERE IS ALSO WEAK TEMP ADVECTION AT H85
MAINLY OVR NORTHERN LK SUPERIOR. THOUGH THERE IS MINIMAL LK BREEZE
CONVERGENCE...POSSIBLE THAT THIS AREA OF SHRA/TSRA OVER THE LAKE WILL
EXPAND OVER PARTS OF LAND AREAS OF UPR MICHIGAN DURING PEAK HEATING
OF AFTN. COVERAGE SHOULD BE PRETTY SPARSE. JUST SLIGHT CHANCE POPS
GIVEN PRIMARY NEGATIVE LARGER SCALE FORCING AND LIMITED COVERAGE.
ANY SHRA/TSRA FM AFTN WILL CEASE EARLY WITH LOSS OF DAYTIME HEATING
AND NOT MUCH OF TRIGGER OTHERWISE. SHRA/TSRA WILL BE ONGOING CLOSER
TO APPROACHING COLD FRONT/LOW-LEVEL JET OVER SOUTHERN MANITOBA INTO
NORTHWEST ONTARIO. ISLE ROYALE COULD GET CLIPPED BUT BASED ON
WESTERLY STORM MOTION THAT SEEMS TO BE PRETTY LOW CHANCE. PRIMARY
FRONTAL PASSAGE OCCURS OVR UPR MICHIGAN LATE WEDNESDAY INTO
WEDNESDAY NIGHT AS INITIAL HEIGHT FALLS BEGIN. AT THIS POINT...THINK
WEDNESDAY PM HOLDS THE HIGHEST LIKLIHOOD OF SEEING STRONG STORMS
AND POSSIBLE SEVERE WEATHER AS THE FRONT MOVES THROUGH AND INTERACTS
WITH HIGHER END INSTABILITY WITH MLCAPES OVER 1500J/KG AND STRONGER
DEEP LAYER SHEAR OVER 30 KTS. BASED ON HIGHER SHEAR AND FAVORABLE
0-1KM SHEAR...ALL MODES OF SEVERE...INCLUDING SUPERCELLS...WOULD BE
POSSIBLE WEDNESDAY AFTN INTO WEDNESDAY EVENING.
QUESTIONS THEN ON HOW FAR SOUTH THE FRONT EVENTUALLY PROGRESSES BY
THURSDAY. MODELS HAVE TRENDED A BIT FARTHER SOUTH WITH FROPA OVER
LAST COUPLE DAYS...INDICATING THE FRONT...POSSIBLY ENHANCED BY
OUTFLOW FM THE TSRA ON WEDNESDAY...WILL SET UP MORE OVER WISCONSIN
LATER WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. IF THIS OCCURS...AND
THAT IS NOT SURE THING AS FRONT WILL STILL BE PARALLEL TO MID LEVEL
HEIGHTS...BETTER CHANCES FOR SEVERE STORMS THURSDAY WOULD LIKELY
STAY TO SOUTH OF UPR MICHIGAN. HOWEVER BEFORE THAT IF TSRA FORM
UPSTREAM IN NORTHERN MINNESOTA ON WEDNESDAY AFTN/EVENING THERE IS
ADDITIONAL POTENTIAL FOR STRONGER TSRA WITH A WIND THREAT LATE
WEDNESDAY NIGHT OVR MUCH OF UPR MICHIGAN BASED ON H85-H3 THICKNESSES
AND GRADIENT OF HIGHER MUCAPE OVER UPR MICHIGAN. SINCE UPR MICHIGAN
WOULD THEN BE ON THE COOLER SIDE OF THE FRONT ON THURSDAY AND THERE
IS ABUNDANT MOISTURE INTERSECTING THE FRONT WITH PWATS NEARING 200
PCT OF NORMAL AND THERE ARE SHORTWAVES MOVING THROUGH IN WNW FLOW
ALOFT ACROSS MANITOBA AND ONTARIO...SEEMS LIKELY THAT COULD SEE
WIDESPREAD SHRA/TSRA ACROSS MUCH OF THE AREA ON THURSDAY. HEAVY
RAIN WOULD BE POSSIBLE WITH SUCH ABUNDANT MOISTURE. CONSENSUS OF
MODELS INDICATES LIKELY POPS THURSDAY INTO THURSDAY NIGHT WHICH
FITS THIS PATTERN PRETTY WELL. GIVEN POTENTIAL FOR A LOT OF
CLOUDS/FOG AND WIDESPREAD PRECIP ON THURSDAY IN ADDITION TO ONSHORE
FLOW DEVELOPING OFF LK SUPERIOR...HAVE LOWERED TEMPS ACROSS THE CWA.
GOOD AGREEMENT THAT COOLER NORTH FLOW KICKS IN BY FRIDAY AND
CONTINUES THROUGH SATURDAY. NO REAL CHANGE TO GOING FCST/CONSENSUS
WITH HIGHS STRUGGLING IN THE 60S NEAR LK SUPERIOR BOTH FRIDAY AND
SATURDAY. HIGHS AWAY FM LK SUPERIOR WILL BE IN THE 70S/LOWER
80S...COOLEST ON SATURDAY BEHIND SECONDARY RE-INFORCING COLD FRONT.
WARMER TEMPS BEGIN TO RETURN BY SUNDAY ALONG WITH A SMALL CHANCES
OF SHRA/TSRA DUE TO WARM AIR ADVECTION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 130 AM EDT MON JUL 15 2013
HIGH PRESSURE CONTINUES TO BUILD INTO THE REGION. SOME PATCHY FOG
HAS DEVELOPED IN THE KIWD AREA AS TEMPERATURES HAVE FALLEN OFF
FASTER THERE WITH THE LOSS OF DAYTIME HEATING. AS TEMPERATURES
CONTINUE TO FALL UNDER CLEAR TO PARTLY CLOUDY SKIES PATCHY FOG WILL
EVENTUALLY IMPACT ALL THREE TAF SITES. EXPECT MVFR CONDITIONS WITH
THE FOG...BUT KIWD MAY SEE A FEW IFR VISIBILITIES DURING THE
OVERNIGHT HOURS. ONCE THE SUN RISES...THE FOG WILL QUICKLY BURN OFF
LEAVING VFR CONDITIONS FOR THE REMAINDER OF THE FORECAST. THERE IS A
VERY SLIGHT POSSIBILITY OF A SHOWER OR THUNDERSTORM AT KCMX AROUND
0Z AS A DISTURBANCE RIDES OVER THE RIDGE JUST TO THE NORTH...BUT
PROBABILITIES ARE SO LOW HAVE LEFT OUT OF THE FORECAST AT THIS TIME.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 427 AM EDT MON JUL 15 2013
WITH A WEAK PRESSURE GRADIENT AND STABLE AIR OVER THE COOL WATERS OF
LAKE SUPERIOR...EXPECT WINDS TO REMAIN LESS THAN 20 KNOTS THROUGH
THE FORECAST PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...RJT
MARINE...KC
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
910 PM CDT TUE JUL 16 2013
.UPDATE...
H5 UPPER RIDGE WITH HEIGHTS AROUND 600DM OVER THE OHIO VALLEY IS
GRADUALLY BUILDING TO THE SW OVERNIGHT. THIS HAS KEPT MOST OF THE
DEEPER MOISTURE CONFINED IN THE S/SW TONIGHT...WITH PWATS NEAR
1.7-1.8 INCHES IN THE I-20 CORRIDOR TO NEAR 2-2.25 INCHES IN CENTRAL
LA PER BLENDED TOTAL PWAT IMAGERY AND REGIONAL 00Z SOUNDINGS. THIS
HAS KEPT SHOWER/THUNDERSTORM ACTIVITY MAINLY IN THE S/SW DUE TO
INCREASED LIFT FROM S/WV IN H5 EASTERLY FLOW. DECIDED TO INCREASE
POPS IN THE S/SE DUE TO HRRR INDICATING SOME OF THE ACTIVITY IN S AL
MOVING INTO THE REGION AND SOME OF CURRENT CONVECTION S OF I-20.
ALSO EXTENDED THIS UNTIL AROUND 4Z DUE TO INCREASED FLOW AND SOME
LINGERING CONVECTION POSSIBLE. TEMPS TONIGHT WILL BE CLOSE TO MAV
BUT BUMPED UP SLIGHTLY DUE TO POSSIBILITY OF STRATUS DEVELOPMENT DUE
TO DECENT LOW LEVEL FLOW AND RESIDUAL MOISTURE IN THE REGION.
SLIGHTLY MODIFIED HOURLY TEMPS/DEWPOINTS ACCORDING TO CURRENT TRENDS
AND MADE SLIGHT MODIFICATIONS TO SKY COVER GRIDS. REST OF THE
FORECAST IS ON TRACK. /DC/
&&
.AVIATION...ISOLD SHRA/TSRA WL BE CONFINED ALONG AND S OF A LAUREL
MS TO MONROE LA LINE THIS EVENING BEFORE THIS ACTIVITY WANES OVRNGT.
MVFR/IFR CIG WL ARE XPCTD TO IMPACT THE REGION TOMORROW MORNING
10-15Z...SIMILAR TO THIS MORNING. VFR CONDS TO PREVAIL THEREAFTER.
/BK/03/
&&
.PREV DISCUSSION... /ISSUED 343 PM CDT TUE JUL 16 2013/
SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)...UPPER RIDGING IS
CONTINUING TO BUILD IN OVER MUCH OF THE EASTERN CONUS LEAVING THE
ARKLAMISS IN EASTERLY/SOUTHEASTERLY FLOW ALOFT...WHILE SURFACE HIGH
PRESSURE CENTERED OVER THE OHIO VALLEY IS ALSO BUILDING IN ACROSS THE
REGION. THIS SHOULD HELP LIMIT INSTABILITY-DRIVEN CONVECTION ACROSS
MUCH OF CWA THROUGH MUCH OF WEDNESDAY. HOWEVER...AN UPPER LEVEL
DISTURBANCE APPROACHING FROM THE EAST COULD BRING SOME SHWR/TSTM
ACTIVITY LATE WEDNESDAY FOR EASTERN PORTIONS OF THE CWA. TEMPS LOOK
TO CLIMB INTO THE LOWER AND MIDDLE 90S ACROSS THE CWA ON
WEDNESDAY...WITH HEAT INDEX READINGS POSSIBLY CREEPING ABOVE 100 IN
SOME AREAS.
THE UPPER RIDGE WILL BEGIN TO BREAK DOWN LATE ON WEDNESDAY...WITH AN
UPPER LEVEL DISTURBANCE MOVING INTO THE REGION LATE WEDNESDAY AND
INTO THURSDAY. THIS WILL BRING A RETURN TO BETTER CHANCES FOR SHOWER
AND THUNDERSTORM ACTIVITY FOR THE ENTIRE CWA. A FEW STRONG TO SEVERE
STORMS CANNOT BE RULED OUT ON THURSDAY...AS GOOD INSTABILITY AND
STEEP LAPSE RATES COULD RESULT IN SOME STORMS PRODUCING GUSTY WINDS
AND HAIL. HIGHS ON THURSDAY WILL ONCE AGAIN CLIMB INTO THE LOW TO
MID 90S ACROSS THE CWA. /27/
LONG TERM (FRIDAY THROUGH NEXT TUESDAY)...THE UPPER LEVEL HIGH WILL
KEEP A PRESENCE OVER THE REGION INTO FRIDAY. HOWEVER...HEADING INTO
THE UPCOMING WEEKEND THIS HIGH WILL GRADUALLY WEAKEN. THIS WILL ALLOW
AN UPPER TROUGH TO BEGIN SINKING INTO THE SOUTHEAST UNITED
STATES...THUS RESULTING IN NORTHWEST FLOW SETTING UP OVER THE LOWER
MISSISSIPPI RIVER VALLEY DURING THE BEGINNING OF NEXT WEEK.
MEANWHILE...A WEAKENING SURFACE BOUNDARY ASSOCIATED WITH THIS TROUGH
IS FORECAST TO ALSO SINK SOUTHEAST INTO THE CWA LATE SUNDAY AND
MEANDER ABOUT THE FORECAST AREA NEXT MONDAY INTO TUESDAY.
CHANCES FOR MAINLY AFTERNOON AND EARLY EVENING SHOWERS AND
THUNDERSTORMS WILL EXIST THROUGH THE ENTIRE FORECAST PERIOD. THIS
PARTICULARLY LOOKS TO BE THE CASE OVER THE WEEKEND AND INTO THE NEW
WORK WEEK AS THE CWA COMES MORE UNDER THE INFLUENCE OF THE
AFOREMENTIONED APPROACHING UPPER TROUGH AND SURFACE BOUNDARY.
AS FAR AS TEMPERATURES ARE CONCERNED...I STUCK PRETTY CLOSE TO
GUIDANCE FOR BOTH HIGHS AND LOWS. THE ONLY SIGNIFICANT CHANGES WERE
MADE FOR HIGHS THURSDAY WHERE I DECREASED THEM SOME 2-3 DEGREES.
WHILE SOME DRYING HAS OCCURRED...GROUND CONDITIONS REMAIN RATHER
MOIST ACROSS MUCH OF THE FORECAST AREA FROM RECENT RAINS. ALREADY
SEVERAL TIMES THIS SUMMER THIS LONE FACTOR HAS RESULTED IN KEEPING
HIGHS IN CHECK COMPARED TO GFS FORECASTED NUMBERS...WHICH CURRENTLY
SUGGEST HIGHS RANGING FROM 93-98F THURSDAY. I FEEL THIS...IN ADDITION
TO EXPECTED CLOUD COVER AND POTENTIAL FOR AFTERNOON
CONVECTION...SUPPORT LOWER HIGHS ON THIS DAY. /19/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 72 94 71 95 / 6 4 16 29
MERIDIAN 69 94 69 94 / 6 15 25 40
VICKSBURG 71 93 69 95 / 9 4 10 24
HATTIESBURG 72 94 72 94 / 15 11 21 38
NATCHEZ 72 91 70 93 / 17 10 16 30
GREENVILLE 73 96 73 96 / 5 2 10 23
GREENWOOD 71 95 72 96 / 5 2 10 24
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
DC/BK/03/27/19
AREA FORECAST DISCUSSION
NWS BILLINGS MT
908 PM MDT TUE JUL 16 2013
.UPDATE...
MONSOONAL MOISTURE WILL CONTINUE TO MOVES ACROSS THE AREA
OVERNIGHT. THIS MOISTURE ALONG WITH A SHORT WAVE WILL BRING
ISOLATED RAIN SHOWERS OVERNIGHT. A BAND OF SHOWERS WAS LOCATED
FROM MILES CITY AND EXTENDED SOUTHWEST TO NEAR FORT SMITH.
CONVECTION STILL ON GOING OVER EASTERN IDAHO THIS EVENING AND THIS
PRECIPITATION WILL WORK ITS WAY INTO OUR AREA AFTER 06Z. GFS WAS
HANDLING THE CURRENT PRECIPITATION TREND WELL AS WAS THE HRRR.
UPPER LIFT IS WEAK ACROSS WESTERN AND CENTRAL MONTANA AND EXPECT
ONLY ISOLATED RAIN SHOWERS FOR THE REMAINDER OF THE NIGHT. HAVE
LOWERED TEMPERATURES A FEW DEGREES TONIGHT AS A FEW MOUNTAIN
LOCATIONS HAD ALREADY COOLED TO FORECASTED LOWS. ALSO LOWERED
TEMPERATURES OVER THE CENTRAL ZONES A DEGREE OR TWO BUT CLOUD
COVER OVERNIGHT SHOULD KEEP TEMPS IN CHECK. RICHMOND
&&
.SHORT TERM...VALID FOR WED AND THU...
STUBBORN POST FRONTAL STRATUS DEVELOPED OVER MUCH OF THE FORECAST
AREA TODAY AIDED BY A DEEP UPSLOPE FLOW...AND BY THE TIME IT
BEGAN THINNING OUT MID LEVEL CLOUDS WERE INVADING THE REGION.
THUS...MOSTLY CLOUDY SKIES LIMITED INSOLATION AND LED TO A BUSTED
FORECAST AT MANY LOCATIONS WITH REGARDS TO SKY AND TEMPERATURES.
SHOWERS WERE SPREADING ACROSS OUR WESTERN MOUNTAINS IN A PUSH OF
MONSOONAL TYPE MOISTURE. ALSO...SOME ELEVATED WEAK THUNDERSTORMS
HAVE DEVELOPED IN ROSEBUD COUNTY. THIS LOOKS RELATED TO A THERMAL
TROUGH AT 500MB. I WILL MENTION LOW POPS IN THE EAST THIS EVENING
AS THIS THERMAL TROUGH FEATURE TRACKS ACROSS...AND EXTEND THE POPS
A BIT SOUTH BASED ON MID LEVEL LAPSE RATES ACROSS THE EASTERN
PLAINS. I ALSO PUSHED POPS IN THE WEST FURTHER EAST FOR THIS
EVENING BASED ON CURRENT SATELLITE AND RADAR IMAGERY. HRRR SEEMS
TO BE PICKING UP THESE TRENDS BEST AND USED IT AS A PROXY FOR
PLACEMENT OF POPS.
FOR WEDNESDAY...THIS SHOULD BE OUR BEST CHANCE OF WIDESPREAD AND
HEAVY PRECIPITATION FOR THE REST OF THE WEEK. A BETTER PUSH OF
MONSOONAL FLOW WILL INVADE FROM THE SOUTH OVER OUR MOUNTAIN
LOCATIONS AND ROTATE A BIT NORTHEAST. HIGH CHANCE TO LOW LIKELY
POPS SEEM GOOD FOR NOW. ONCE WE IDENTIFY A BATCH OF MOISTURE IN
THE SHORT TERM WE WILL BE ABLE TO INCREASE POPS AS APPROPRIATE.
DESPITE CLOUD COVER TOMORROW...TEMPERATURES SHOULD BE BACK AROUND
NORMAL AS 850-700 MB TEMPS INCREASE UNDER THE RIDGE.
THURSDAY...OUR RIDGE WILL BE SUPPRESSED A LARGE UPPER LOW TRACKS
OVER THE HUDSON BAY REGION. LOOK FOR A FEW THUNDERSTORMS TO LINGER
OVERNIGHT WEDNESDAY INTO THURSDAY AS THEY GRADUALLY MAKE THEIR WAY
EASTWARD. HOWEVER...THE MOISTURE TO THE SOUTH WILL BE CUT OFF
FOR THE TIME BEING. I WILL KEEP THE HIGHEST POPS IN THE SOUTH AND
EAST. TEMPERATURES WILL REMAIN AROUND NORMAL. BT
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
LITTLE IN THE WAY OF CHANGES THROUGH THE EXTENDED PERIOD...WITH
MODELS CONTINUING TO BE IN GOOD AGREEMENT. MAINLY DRY AND HOT
CONDITIONS WILL PREVAIL THROUGH THE EXTENDED PERIOD.
THE EXTENDED FORECAST PERIOD BEGINS FRIDAY AND APPEARS TOP BE THE
COOLEST DAY...WITH BEST POTENTIAL FO PRECIP. AS RIDGE BUILDS JUST
TO THE WEST...MODELS ARE HINTING AT A BACKDOOR COLD FRONT
SLIPPING IN FROM THE NORTHEAST. THE DIFFICULTY IS GAUGING JUST
HOW FAR INTO THE AREA THIS COOL AIR WILL PUSH...IF AT ALL.
CURRENTLY THIS APPEARS TO BE VERY LITTLE WITH ANY IMPACTS PUSHED OFF
TO THE EAST AND NORTHEAST..BUT WILL BARE ATTENTION IN LATER
SHIFTS. MEANWHILE MONSOONAL FLOW WILL CONTINUE FROM THE
SOUTHWEST...BUT IS GREATLY SUPPRESSED BY DEVELOPING RIDGE. SO BEST
CHANCES FOR PRECIP WILL BE IN EXTREME SOUTHERN ZONES...PRIMARILY
HIGH TERRAIN...WITH A VERY SLIGHT CHANCE AROUND KBHK.
FLAT RIDGING BEGINS TO PUSH EASTWARD OVERNIGHT FRIDAY AND
DOMINATES THE PATTERN THROUGH THE REMAINDER OF THE FORECAST
PERIOD. MONSOONAL FLOW WILL SUPPRESSED BY THE RIDGE AND PUSHED OFF
TO THE EAST OF THE AREA. THIS WILL RESULT IN INCREASINGLY DRY AND
HOT CONDITIONS THROUGH THR REMAINDER OF THE FORECAST PERIOD.
TEMPERATURES WILL BE AROUND SEASONAL FOR FRIDAY AND SATURDAY...AND
CLIMB TO MID 90S THROUGH THE REMAINDER OF THE PERIOD...WITH SOME
POTENTIAL FOR REACHING THE CENTURY MARK IN SOME AREAS IF STRONGER
DOWNSLOPE FLOW PANS OUT. AAG
&&
.AVIATION...
VFR CONDITIONS WITH MID-LEVEL CLOUDS WILL GENERALLY EXIST TONIGHT
AND WEDNESDAY. HOWEVER...WE ARE CONCERNED THAT SOME MVFR OR MAYBE
EVEN IFR CEILINGS WILL DEVELOP IN SOME AREAS DUE TO UPSLOPE FLOW.
IN ADDITION...SOME SHOWERS COULD BRING SUB-VFR WEATHER ALONG WITH
AREAS OF MOUNTAIN OBSCURATION OVERNIGHT...ESPECIALLY TO THE SOUTH
CENTRAL PART OF MT. SCATTERED THUNDERSTORMS MAY ALSO DEVELOP OVER
SOUTH CENTRAL MT AFTER 18 UTC WEDNESDAY. SCHULTZ
&&
.PRELIMINARY POINT TEMP/POPS...
WED THU FRI SAT SUN MON TUE
-----------------------------------------------------------
BIL 061/090 065/092 061/089 064/092 065/096 065/096 064/095
32/T 32/T 21/B 10/B 00/U 01/U 11/U
LVM 059/090 058/091 053/091 052/095 052/097 052/094 054/094
35/T 42/T 21/B 10/B 00/U 01/U 11/B
HDN 060/093 065/093 060/091 059/094 061/098 061/097 060/096
22/T 22/T 21/B 11/B 10/U 01/U 11/U
MLS 062/094 068/094 063/090 065/093 066/096 066/097 064/094
22/T 22/T 11/B 11/B 11/U 11/U 11/U
4BQ 060/094 062/092 059/088 060/091 060/094 061/096 060/092
11/B 12/T 11/B 11/B 11/U 11/U 11/U
BHK 059/091 063/090 059/086 061/089 061/092 062/094 061/091
11/B 12/T 21/U 11/U 12/T 21/U 11/U
SHR 057/091 060/092 057/089 057/091 057/095 057/095 057/095
12/T 22/T 32/T 21/B 10/U 01/U 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
315 PM MDT MON JUL 15 2013
.SHORT TERM...VALID FOR TUE AND WED...
I WILL FOCUS ON THIS EVENINGS WEATHER FOR THE MOST PART OF THIS
DISCUSSION DUE TO A THREAT OF SEVERE WEATHER. THE THREAT IS MAINLY
ALONG THE MONTANA/DAKOTA BORDERS REGION. THE OTHER SIGNIFICANT
WEATHER FEATURE THROUGH THE NEXT 48 HOURS IS A BRISK COLD FRONT
EXPECTED TONIGHT.
CURRENTLY...THERE IS CONVECTION ALONG THE CONVERGENCE AREA OF A
SURFACE TROUGH EXTENDING SOUTH ACROSS CUSTER COUNTY DOWN INTO
NORTH CENTRAL WYOMING. THIS CONVERGENCE REGION WILL SLOWLY SHIFT
EAST WITH TIME AS A COLD FRONT APPROACHES FROM THE NORTHWEST. AT
THE SAME TIME WE HAVE A WEAK SHORT WAVE IN THE SW FLOW ALOFT WHICH
WILL RIDE OVER THIS SURFACE TROUGH. THE GFS AND NAM ARE NOT VERY
BULLISH ON CONVECTIVE DEVELOPMENT...BUT THE HRRR UNZIPS A STRONG
LINE OF CONVECTION ALONG THE SURFACE TROUGH AND PUSHES IT EAST
INTO A RICH ENVIRONMENT WITH DEWPOINTS IN THE 60S ALONG THE
EASTERN STATELINE. IN THE SAME AREA WE HAVE A STRONGLY SHEARED
ENVIRONMENT. THIS ALL AMOUNTS TO A RISK OF SEVERE WEATHER ALONG
OUR EASTERN BORDER COUNTIES LATE TODAY THROUGH EARLY EVENING.
PRECIP WATER VALUES ARE WELL OVER AN INCH...SO ALONG WITH LARGE
HAIL AND DAMAGING WIND ANY STORMS COULD PRODUCE VERY HEAVY
RAINFALL AS WELL. AS THE FORCING FROM THE SHORT WAVE DRIFTS
NORTHEAST THE CONVECTION WILL SHIFT EAST AFTER MID EVENING.
WE THEN HAVE WHAT APPEARS TO BE A SHARP COLD FRONT MOVING IN FROM
THE NW OVERNIGHT. PRESSURE RISES ARE ON THE ORDER FROM 9 TO 13 MB
PER 6 HRS DEPENDING ON WHAT PROGG YOU LOOK AT. THIS IS A PRETTY
DECENT RIDGE CRASHING FRONT. AS A FRAME OF REFERENCE...THE FRONTAL
PASSAGE IS EXPECTED THROUGH BILLINGS AROUND MIDNIGHT. BUFKIT MIXES
SOME 20 TO 30 KT WINDS TO NEAR THE SURFACE. I EXPECT RIDGE TOPS TO
BE RATHER BREEZY BEHIND THE FRONT OVERNIGHT. THIS IS PRIMARILY A
FIRE WEATHER CONCERN AND WILL BE HIGHLIGHTED IN FIRE WEATHER
PRODUCTS.
LOOK FOR MUCH COOLER TEMPERATURES TUESDAY WITH SHOWERS POSSIBLE IN
THE EAST EARLY...SWITCHING TO THE WEST LATER IN THE DAY. BT
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
LITTLE IN THE WAY OF CHANGES FOR THE EXTENDED PERIOD FORECAST
THIS AFTERNOON...WITH MODELS IN FAIR AGREEMENT. MODELS SEEM TO
DIFFER A BIT ON STRENGTH AND IMPACTS OF MONSOONAL FLOW INTO THE
REGION...BUT GOING FORECAST SEEMS A GOOD REPRESENTATION WITH MINOR
DISCREPANCY.
SFC MOISTURE SHOULD REMAIN IN PLACE ACROSS THE REGION...WITH
RELATIVELY DEEP EASTERLY FLOW AT LOW LEVELS. ADDITIONALLY
MONSOONAL MOISTURE AT MID LEVELS WILL CONTINUE TO PUSH INTO THE
AREA KEEPING PWATS OVER AN INCH IN MOST AREAS. ALTHOUGH THE FLOW
IS MORE WESTERLY ALOFT...MULTIPLE SHORTWAVES THROUGH FRIDAY
SHOULD KEEP POTENTIAL FOR CONVECTION IN PLACE...ESPECIALLY IN THE
HIGH TERRAIN...AS UPSLOPE FLOW IMPROVES DURING THE DAY. STRONG TO
SEVERE COULD BE POSSIBLE...WITH POTENTIAL SHEAR VALUES...WHICH
HAVE BEEN IMPROVING RECENTLY. EXPECT SEASONAL TYPE TEMPS FOR
THURSDAY AND FRIDAY...AS HIGHS CLIMB TO AROUND 90 DEGREES.
SHALLOW UPPER LEVEL RIDGING AND SHIFTING OF MONSOONAL FLOW
EASTWARD...OUT OF THE AREA...SHOULD LEAD TO DRIER AND WARMER
CONDITIONS ON TAP FOR SATURDAY AND SUNDAY...WITH TEMPS BACK INTO
THE MID 90S IN MOST AREAS FOR THE WEEKEND. AAG
&&
.AVIATION...
ISOLATED SHOWERS AND THUNDERSTORMS ARE EXPECTED THROUGH THIS
EVENING...ESPECIALLY EAST OF A LINE FORM KMLS TO KSHR. SOME MAY BE
SEVERE. WINDS WILL BE GENERALLY LIGHT ACROSS THE WEST THROUGH THE
DAY...WITH SOUTHEASTERLY WINDS AROUND 15 KNOTS EAST OF A LINE FROM
FORSYTH TO KSHR. A STRONG COLD FRONT WILL MOVE THROUGH THE REGION
AROUND MIDNIGHT...BRINGING MORE THUNDERSTORMS ACROSS THE REGION
OVERNIGHT AS WELL AS STRONG AND GUSTY NORTHWEST WINDS...AND MUCH
COOLER TEMPERATURES FOR TUESDAY. VFR CONDITIONS WILL PREVAIL...BUT
LOCAL/BRIEF MVFR IS POSSIBLE WITH ANY STORMS THAT DEVELOP. ERRATIC
GUSTY WINDS CAN BE EXPECTED AROUND THUNDERSTORMS. AAG
&&
.PRELIMINARY POINT TEMP/POPS...
TUE WED THU FRI SAT SUN MON
-----------------------------------------------------------
BIL 063/082 062/089 063/091 064/091 064/094 065/095 065/093
21/B 22/T 32/T 32/T 21/B 11/B 11/U
LVM 054/082 054/090 056/090 055/092 052/095 052/096 052/093
22/T 24/T 43/T 32/T 21/B 11/B 11/B
HDN 063/084 061/091 062/092 061/093 059/095 061/097 061/094
22/T 02/T 32/T 32/T 21/B 11/B 11/U
MLS 066/087 063/092 067/093 066/093 066/094 066/095 066/092
32/T 12/T 22/T 21/B 11/U 11/U 11/U
4BQ 062/088 060/093 062/091 065/090 060/092 060/094 060/093
32/T 01/B 12/T 22/T 21/B 11/U 11/U
BHK 061/087 058/089 062/090 064/088 062/089 061/092 061/087
32/T 12/T 22/T 21/B 12/T 21/U 11/U
SHR 059/085 059/092 059/090 058/090 057/092 057/095 057/092
22/T 12/T 23/T 33/T 31/B 11/B 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...TORNADO WATCH 415 IN EFFECT UNTIL 11 PM MDT THIS EVENING FOR
ZONES 33-37.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
1138 PM MDT SUN JUL 14 2013
.UPDATE...
STRATUS DECK HAS MOVED INTO FAR EASTERN ZONES LATE THIS EVENING
BRINGING OVERCAST CONDITIONS TO FALLON AND CARTER COUNTIES. LOOKS
LIKE ADDITIONAL MOVEMENT OF THIS DECK TO THE WEST WILL OCCUR
OVERNIGHT...ENDING UP ALONG A MILES CITY TO ASHLAND LINE BY
SUNRISE. KEPT OUT OF SHERIDAN FOR NOW BUT CAN NOT RULE OUT CLOUD
COVER PUSHING UP ALONG THE BIG HORN FOOTHILLS AND MAY NEED TO
ADJUST FURTHER WITH THE MORNING FORECAST PACKAGE. ALSO ADJUSTED
POPS FOR TONIGHT INTO TOMORROW MORNING. WEAK VORTICITY IS
PRODUCING A FEW SHOWERS AND AN ISOLATED THUNDERSTORM OVER PARK AND
SWEET GRASS COUNTIES. THIS ACTIVITY LOOKS TO MOVE NORTH-NORTHEAST
OVER THE NEXT FEW HOURS. MODELS DON`T LOOKS IMPRESSIVE ENOUGH TO
KEEP POPS FURTHER EAST OF THIS ACTIVITY OUTSIDE OF THE HIGHER BIG
HORNS...SO REMOVED POP MENTION ELSEWHERE THROUGH MONDAY MORNING.
CHAMBERS
&&
.SHORT TERM...VALID FOR MON AND TUE...
ACTIVE WEATHER WILL CONTINUE TONIGHT THROUGH TUE NIGHT. A BAND OF
CONVECTION CONTINUED MOVING THROUGH SE MT THIS AFTERNOON PER RADAR
IMAGERY. THE BAND WAS BEING FUELED BY JET DIVERGENCE. OTHER
CONVECTION WAS MOVING INTO THE SW PART OF THE AREA AHEAD OF A
SHORTWAVE MOVING INTO W MT AND WEAK WAVES SW OF THE AREA. A WARM
FRONT WILL MOVE N THROUGH THE REGION TONIGHT ACCOMPANIED BY
ISENTROPIC LIFT. THE HRRR HAS BEEN GENERATING CONVECTION OVER THE
S CENTRAL PART OF THE AREA FOR THE LAST FEW RUNS DURING THE
EVENING. THE RAP SHOWED 1000 J/KG OF SURFACE CAPE IN THIS AREA AND
THE WRF HAD DECENT BULK SHEAR...SO STORMS IN THIS AREA COULD BE
STRONG. A LOW-LEVEL JET WILL HELP SUSTAIN CONVECTION IN THE E
THROUGH THE NIGHT. THUS WENT WITH CHANCE POPS S TAPERING TO SLIGHT
CHANCE N DURING THE EVENING...AND SLIGHT CHANCE E OVERNIGHT.
PRECIPITABLE WATERS AROUND AN INCH WILL SUPPORT HEAVY RAIN WITH
THE THUNDERSTORMS.
MON WILL BE A PREFRONTAL DAY. SHORTWAVES WILL CONTINUE MOVING
THROUGH THE SW FLOW ALOFT. INVERTED-V SOUNDINGS WERE FORECAST FOR
THE CENTRAL AND W ZONES. KMLS WAS CAPPED ON BUFKIT. CAPES AT KBHK
WERE 1000-1500 J/KG...BUT SOUNDINGS DID NOT SHOW MUCH IN THE WAY
OF LIFT. HAD CHANCE POPS SE IN THE MORNING NEAR SHORTWAVE ENERGY
THEN ISOLATED TO SCATTERED POPS IN THE AFTERNOON AND EVENING DUE
TO ADDITIONAL SHORTWAVES AND THE APPROACH OF THE FRONT. GOOD
MIXING WILL PROMOTE HIGH TEMPERATURES IN THE 90S IN MANY AREAS.
KEPT POPS THROUGH THE NIGHT DUE TO THE COLD FRONT.
THE FRONT WILL SETTLE OVER THE REGION ON TUE AND THE FLOW WILL
TURN E. HAD MAINLY ISOLATED POPS THROUGH THE DAY. STRONG THETA-E
RIDGE WILL HELP CONTINUE CHANCES FOR THUNDERSTORMS TUE NIGHT. TUE
WILL BE COOLER WITH READINGS IN THE 80S BUT A THERMAL RIDGE WILL
KEEP THE E WARMER WITH TEMPERATURES AROUND 90. ARTHUR
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
THE THEME IN THE EXTENDED FORECAST REMAINS SUMMER TEMPERATURES AND
ISOLATED TO SCATTERED THUNDERSTORMS EACH DAY. BROAD SUMMER RIDGING
WILL FINALLY BE ESTABLISHED ACROSS MOST OF THE CONUS WITH THE
FORECAST AREA REMAINING ON THE NORTHERN EXTENT OF THE RIDGE WITH
THE JET STREAM NEARBY TO THE NORTH.
THIS SETUP WILL ALLOW INCREASING MID-LEVEL MOISTURE ACROSS THE
FORECAST AREA FROM THE MONSOONAL FLOW OUT OF THE SOUTH.
FURTHERMORE...LOW-LEVEL MOISTURE WILL BE ON THE INCREASE THANKS TO
GULF MOISTURE BEING TRANSPORTED UP THE GREAT PLAINS AND INTO THE
FORECAST AREA FROM THE EAST AND NORTHEAST. THIS WILL KEEP PW
VALUES RUNNING BETWEEN 1 AND 1.5 INCHES ACROSS THE FORECAST AREA
WEDNESDAY THROUGH FRIDAY. THESE WILL BE THE BEST DAYS IN THE
EXTENDED FORECAST FOR THUNDERSTORM ACTIVITY. DEEP LAYER SHEER
(0-6KM) SHOULD BE WEAK ON WEDNESDAY AS THE JET STREAM REMAINS
MOSTLY NORTH OF THE FORECAST AREA...THUS EXPECT STORMS TO BE HEAVY
RAINERS BUT THE SEVERE POTENTIAL SHOULD BE VERY LIMITED. DEEP
LAYER SHEER SHOULD INCREASE TO AROUND 40 KTS FOR THURSDAY AND
FRIDAY AS THE JET SAGS FARTHER SOUTH. THIS WILL BE COUPLED WITH
COOLER 700 MB TEMPERATURES. THUS EXPECT THUNDERSTORMS ON THURSDAY
AND FRIDAY COULD BE ON THE STRONG SIDE WITH SOME ISOLATED SEVERE
POTENTIAL.
STRONGER ZONAL TO NORTHWESTERLY FLOW ESTABLISHES OVER THE FORECAST
AREA BY THE WEEKEND. THIS HELPS TO KEEP MONSOONAL MOISTURE LOCKED
TO THE SOUTH OF THE FORECAST AREA WHILE THE LOW-LEVEL MOISTURE
BECOMES SHIFTED TO THE EAST. THIS SHOULD MINIMIZED OUR CHANCES OF
PRECIPITATION THIS WEEKEND.
TEMPERATURES WILL REMAIN JUST ABOVE SEASONAL NORMALS IN THE UPPER
80S AND LOW 90S THROUGH THE EXTENDED FORECAST.
CHURCH
&&
.AVIATION...
A FEW SHOWERS AND AN ISOLATED THUNDERSTORM OR TWO ARE POSSIBLE
OVER FAR WESTERN ROUTES FOR THE NEXT FEW HOURS. OTHERWISE...VFR
CONDITIONS ARE EXPECTED THROUGH MID DAY MONDAY. STC
&&
.PRELIMINARY POINT TEMP/POPS...
MON TUE WED THU FRI SAT SUN
-----------------------------------------------------------
BIL 061/095 064/083 062/090 066/092 065/093 065/094 065/094
12/T 22/T 32/T 32/T 33/T 31/B 11/B
LVM 052/091 054/085 056/091 055/092 056/093 052/095 052/095
23/T 33/T 33/T 33/T 33/T 32/T 21/B
HDN 061/096 062/087 058/092 061/093 063/093 061/095 061/096
12/T 22/T 32/T 32/T 32/T 21/B 11/B
MLS 065/095 067/089 064/093 068/093 066/093 067/094 066/094
12/T 22/T 22/T 22/T 22/T 21/B 11/U
4BQ 062/093 062/092 061/093 063/091 065/090 061/092 060/093
12/T 22/T 21/U 12/T 22/T 21/B 11/U
BHK 060/087 062/088 059/091 064/090 064/088 062/089 061/090
12/T 22/T 21/B 22/T 22/T 22/T 21/U
SHR 058/091 058/089 058/092 058/091 058/090 057/092 057/094
12/T 22/T 22/T 22/T 33/T 31/B 11/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1249 PM CDT MON JUL 15 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 325 AM CDT MON JUL 15 2013
FORECAST CHALLENGES IN THE NEAR TERM ARE TEMPERATURES AND ENDING
TIME OF PRECIPITATION THIS MORNING. FOR TODAY...UPPER LEVEL LOW
PRESSURE WILL TRACK ALONG THE TX/OK BORDER. MID LEVEL WAA WILL
SHIFT NORTHWEST INTO THE NEBRASKA PANHANDLE AND SOUTH DAKOTA BY
MID MORNING...ENDING PRECIPITATION ACROSS THE FORECAST AREA. THE
NAM...GFS...AND HI RES RUC ALL SHIFT THIS MID LEVEL LIFT WEST...SO
CONFIDENCE IS FAIRLY HIGH IN ENDING PCPN MENTION BY MID MORNING.
DRY CONDITIONS WILL CARRY OVER INTO THE OVERNIGHT HOURS
TONIGHT...AS DRIER...MORE STABLE AIR PUSHES INTO WESTERN AND NORTH
CENTRAL NEBRASKA. TEMPERATURES TODAY WILL RANGE FROM THE LOWER 80S
IN THE WEST WITH MORE PERSISTENT CLOUD COVER...TO THE MIDDLE AND
UPPER 80S IN THE CENTRAL AND EASTERN FORECAST AREA...WITH MAINLY
CLEAR SKIES EXPECTED. WINDS WILL BE FROM THE SOUTH AND SOUTHEAST
AT 10 TO 20 MPH...DECREASING TO 10 TO 15 MPH TONIGHT. WITH MUCH
DRIER AIR PUSHING INTO THE REGION TODAY...OVERNIGHT LOWS WILL
BOTTOM OUT IN THE UPPER 50S IN THE WEST TO MID 60S IN THE EAST.
THE ONLY CAVEAT TO LOWS TONIGHT WILL BE WHETHER OR NOT WINDS WILL
TOTALLY DECOUPLE. THIS MAY BE AN ISSUE ACROSS NORTH CENTRAL
NEBRASKA WHERE H85 AND H925 WINDS REMAIN UNIDIRECTIONAL INTO THE
OVERNIGHT. WITH THIS IN MIND...HEDGED LOWS A LITTLE WARMER ACROSS
NORTH CENTRAL NEBRASKA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 325 AM CDT MON JUL 15 2013
EXPANSIVE UPPER LEVEL AREA OF HIGH PRESSURE WILL BE ANCHORED
ACROSS THE OHIO RVR VALLEY /LOWER GREAT LAKES REGION STARTING OFF
THE EXTENDED PERIOD AS A FILLING UPPER LOW CONTINUES TO RETROGRADE
SOUTHWEST ACROSS WESTERN TEXAS. WITH INCREASING SUBSIDENCE AND
RISING HEIGHTS...TEMPERATURES WILL CONTINUE TO WARM MID WEEK WITH
WIDESPREAD 90S ANTICIPATED WEDNESDAY AND ESPECIALLY THURSDAY FOR
ALL LOCATIONS ACROSS WESTERN AND NORTH CENTRAL NEBRASKA.
LOWS...UNDER MOSTLY CLEAR SKIES...SHOULD BE SEASONAL WITH 60S
PREVAILING FOR MOST LOCATIONS. BEYOND THURSDAY...MODELS REMAIN
CONSISTENT WITH THE PASSAGE OF A SHORTWAVE ACROSS THE NORTHERN
PLAINS...WHICH WILL FORCE A COLD FRONT THROUGH THE CWA ON FRIDAY.
HIGHS ARE ANTICIPATED TO BE A COUPLE TO SEVERAL DEGREES
COOLER...WITH MAINLY 80S AND LOW 90S EXPECTED. IT SEEMS THAT WITH
EACH SUCCESSIVE MODEL RUNS...QPF COVERAGE ASSOCIATED WITH THE
SHORTWAVE AND COLD FRONTAL PASSAGE IS BECOMING LESS AND
LESS...THUS WILL ONLY MAINTAIN SLIGHT CHANCES/LOW END CHANCES OF
POPS FRIDAY THROUGH EARLY SATURDAY...WITH THE HIGHEST PROBABILITY
OCCURRING ALONG OUR SOUTHERN BORDER FRIDAY EVENING AS THE FRONT
SAGS SOUTH. INTO THE WEEKEND...THERE REMAINS SOME CONSISTENCY IN
THE OPERATIONALS THAT THE FRONT WILL STALL TO THE SOUTH OF THE
CWA...WITH ADDITIONAL DISTURBANCES PASSING THROUGH NORTHWESTERLY
FLOW ALOFT. A THREAT OF STORMS WILL REMAIN THROUGH THE COMING
WEEKEND...HOWEVER SHEAR VALUES AT THIS TIME LOOK FAIRLY
WEEK...WIDESPREAD SEVERE WEATHER IS NOT ANTICIPATED IF STORMS
ACTUALLY ARE REALIZED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1246 PM CDT MON JUL 15 2013
CUMULUS CLOUDS WILL DISSIPATE THIS EVENING WITH THE LOSS OF
DAYTIME HEATING. VFR CONDITIONS WILL RULE...WITH SOUTH TO
SOUTHEAST SFC WINDS OCCASIONALLY GUSTING TO 20 KTS THIS
AFTERNOON...AND HOLD STEADY NEAR 10 KTS TONIGHT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CLB
LONG TERM...JACOBS
AVIATION...TAYLOR
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1212 PM CDT MON JUL 15 2013
.DISCUSSION...
LEFT IN A 20/30 PERCENT CHANCE FOR CONVECTION FOR THE AFTERNOON
AS WE CONTINUE TO WARM. THERE IS A WEAK CAP IN PLACE THAT WE WILL
HAVE TO OVERCOME. NAM/RAP MODELS SUGGEST BEST CHANCE MIGHT EXIST
BETWEEN KOMA/KSUX. HRRR SEEMS OVERDONE AS IT MAY JUST BE PICKING
UP ON THE CU FIELD THAT HAS DEVELOPED.
&&
.AVIATION...18Z TAFS FOR KOMA...KLNK AND KOFK. VFR CONDITIONS
EXPECTED THROUGH THE PERIOD. SOME CUMULUS CLOUDS WILL AFFECT THE
REGION THROUGH EARLY EVENING...BUT THEN SHOULD DISSIPATE BY
SUNSET. WHILE THERE IS A SMALL CHANCE THAT CONVECTION COULD
DEVELOP ACROSS EASTERN NEBRASKA/WESTERN IOWA...WILL NOT SPECIFICALLY
PUT IT IN THE FORECAST AT THIS TIME SINCE IT MAY BE NORTH OF THE
KOMA TAF SITE.
&&
.PREV DISCUSSION... /ISSUED 335 AM CDT MON JUL 15 2013/
DISCUSSION...
TEMPERATURES THROUGH THE WEEK AND THE CHANCE FOR TSTMS FOR TODAY
INTO EARLY THIS EVENING ARE THE PRIMARY FORECAST CONCERNS. UNUSUAL
UPPER LEVEL PATTERN WITH RETROGRESSIVE MID TROPOSPHERIC FLOW WILL
CONTINUE INTO MID WEEK.
CURRENT AIRMASS OVER THE AREA IS MUCH DRIER THAN 24 HOURS AGO. AT
12Z SUNDAY THE PRECIPITABLE WATER AMOUNT FROM THE KOAX SOUNDING WAS
1.80 INCHES. THAT DROPPED TO 1.03 BY 00Z MONDAY. THAT WILL BE
CHANGING AS MOISTURE MOVES BACK INTO THE AREA FROM THE SOUTHEAST.
MOST OF THE SHORT RANGE MODEL DEVELOP SOME LIGHT PCPN OVER AT
LEAST PORTIONS OF THE FORECAST AREA FROM THIS AFTERNOON INTO THE
EARLY EVENING. NAM AND RAP SHOW SOME CAPE (500-1500 J/KG)
DEVELOPING THIS AFTERNOON AND CONTINUING INTO THE EVENING.
AFTER THIS EVENING...KEPT A DRY FORECAST UNTIL LATE IN THE WEEK.
ALTHOUGH CAN NOT COMPLETELY RULE OUT SOME ISOLD LATE AFTERNOON POP
SHOWERS/THUNDERSTORMS TUESDAY OR WEDNESDAY...FELT COVERAGE WOULD
JUST BE TOO LOW TO MENTION AT THIS POINT. WILL NEED TO LOOK AT THAT
THOUGH THE NEXT SEVERAL FORECAST CYCLES.
THE CLOSED LOW INITIALLY OVER OKLAHOMA TODAY WILL MOVE INTO EASTERN
NEW MEXICO TUESDAY AND THEN INTO THE NORTHERN PART OF SONORA MEXICO
ON THURSDAY. FAIRLY HIGH 500 MB HEIGHTS FAVOR WARM TEMPERATURES AND
MAINLY DRY CONDITIONS. THE LARGE MID/UPPER TROPOSPHERIC RIDGES DOES
START TO FLATTEN THURSDAY NIGHT/FRIDAY...WHICH WILL ALLOW A WEAK
COLD FRONT TO SAG SOUTH INTO THE AREA FRIDAY/SATURDAY. THIS SHOULD
BRING A DECENT CHANCE OF PCPN. TEMPERATURES WILL BE MAINLY IN THE
90S IN THE MID AND LATER PART OF THE WEEK WITH SLIGHT COOLING FOR
THE WEEKEND.
MILLER
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
651 AM CDT MON JUL 15 2013
.AVIATION...
12Z TAFS FOR KOMA...KLNK...KOFK.
INCREASING AREA OF MID CLOUDS APPROACHING AREA FROM THE SOUTHEAST
AT 11Z WILL LIKELY CONTINUE INTO THE DAY WITH SCT-BKN LAYERS
EXPECTED AT TAF SITES. SCT CU LAYER ALSO POSSIBLE AFTER 16Z.
PATCHY MVFR VSBY AFTER 09Z WITH WEAK SURFACE FLOW STILL IN PLACE.
&&
.PREV DISCUSSION... /ISSUED 335 AM CDT MON JUL 15 2013/
DISCUSSION...
TEMPERATURES THROUGH THE WEEK AND THE CHANCE FOR TSTMS FOR TODAY
INTO EARLY THIS EVENING ARE THE PRIMARY FORECAST CONCERNS. UNUSUAL
UPPER LEVEL PATTERN WITH RETROGRESSIVE MID TROPOSPHERIC FLOW WILL
CONTINUE INTO MID WEEK.
CURRENT AIRMASS OVER THE AREA IS MUCH DRIER THAN 24 HOURS AGO. AT
12Z SUNDAY THE PRECIPITABLE WATER AMOUNT FROM THE KOAX SOUNDING WAS
1.80 INCHES. THAT DROPPED TO 1.03 BY 00Z MONDAY. THAT WILL BE
CHANGING AS MOISTURE MOVES BACK INTO THE AREA FROM THE SOUTHEAST.
MOST OF THE SHORT RANGE MODEL DEVELOP SOME LIGHT PCPN OVER AT
LEAST PORTIONS OF THE FORECAST AREA FROM THIS AFTERNOON INTO THE
EARLY EVENING. NAM AND RAP SHOW SOME CAPE (500-1500 J/KG)
DEVELOPING THIS AFTERNOON AND CONTINUING INTO THE EVENING.
AFTER THIS EVENING...KEPT A DRY FORECAST UNTIL LATE IN THE WEEK.
ALTHOUGH CAN NOT COMPLETELY RULE OUT SOME ISOLD LATE AFTERNOON POP
SHOWERS/THUNDERSTORMS TUESDAY OR WEDNESDAY...FELT COVERAGE WOULD
JUST BE TOO LOW TO MENTION AT THIS POINT. WILL NEED TO LOOK AT THAT
THOUGH THE NEXT SEVERAL FORECAST CYCLES.
THE CLOSED LOW INITIALLY OVER OKLAHOMA TODAY WILL MOVE INTO EASTERN
NEW MEXICO TUESDAY AND THEN INTO THE NORTHERN PART OF SONORA MEXICO
ON THURSDAY. FAIRLY HIGH 500 MB HEIGHTS FAVOR WARM TEMPERATURES AND
MAINLY DRY CONDITIONS. THE LARGE MID/UPPER TROPOSPHERIC RIDGES DOES
START TO FLATTEN THURSDAY NIGHT/FRIDAY...WHICH WILL ALLOW A WEAK
COLD FRONT TO SAG SOUTH INTO THE AREA FRIDAY/SATURDAY. THIS SHOULD
BRING A DECENT CHANCE OF PCPN. TEMPERATURES WILL BE MAINLY IN THE
90S IN THE MID AND LATER PART OF THE WEEK WITH SLIGHT COOLING FOR
THE WEEKEND.
MILLER
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
FOBERT
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
623 AM CDT MON JUL 15 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 325 AM CDT MON JUL 15 2013
FORECAST CHALLENGES IN THE NEAR TERM ARE TEMPERATURES AND ENDING
TIME OF PRECIPITATION THIS MORNING. FOR TODAY...UPPER LEVEL LOW
PRESSURE WILL TRACK ALONG THE TX/OK BORDER. MID LEVEL WAA WILL
SHIFT NORTHWEST INTO THE NEBRASKA PANHANDLE AND SOUTH DAKOTA BY
MID MORNING...ENDING PRECIPITATION ACROSS THE FORECAST AREA. THE
NAM...GFS...AND HI RES RUC ALL SHIFT THIS MID LEVEL LIFT WEST...SO
CONFIDENCE IS FAIRLY HIGH IN ENDING PCPN MENTION BY MID MORNING.
DRY CONDITIONS WILL CARRY OVER INTO THE OVERNIGHT HOURS
TONIGHT...AS DRIER...MORE STABLE AIR PUSHES INTO WESTERN AND NORTH
CENTRAL NEBRASKA. TEMPERATURES TODAY WILL RANGE FROM THE LOWER 80S
IN THE WEST WITH MORE PERSISTENT CLOUD COVER...TO THE MIDDLE AND
UPPER 80S IN THE CENTRAL AND EASTERN FORECAST AREA...WITH MAINLY
CLEAR SKIES EXPECTED. WINDS WILL BE FROM THE SOUTH AND SOUTHEAST
AT 10 TO 20 MPH...DECREASING TO 10 TO 15 MPH TONIGHT. WITH MUCH
DRIER AIR PUSHING INTO THE REGION TODAY...OVERNIGHT LOWS WILL
BOTTOM OUT IN THE UPPER 50S IN THE WEST TO MID 60S IN THE EAST.
THE ONLY CAVEAT TO LOWS TONIGHT WILL BE WHETHER OR NOT WINDS WILL
TOTALLY DECOUPLE. THIS MAY BE AN ISSUE ACROSS NORTH CENTRAL
NEBRASKA WHERE H85 AND H925 WINDS REMAIN UNIDIRECTIONAL INTO THE
OVERNIGHT. WITH THIS IN MIND...HEDGED LOWS A LITTLE WARMER ACROSS
NORTH CENTRAL NEBRASKA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 325 AM CDT MON JUL 15 2013
EXPANSIVE UPPER LEVEL AREA OF HIGH PRESSURE WILL BE ANCHORED
ACROSS THE OHIO RVR VALLEY /LOWER GREAT LAKES REGION STARTING OFF
THE EXTENDED PERIOD AS A FILLING UPPER LOW CONTINUES TO RETROGRADE
SOUTHWEST ACROSS WESTERN TEXAS. WITH INCREASING SUBSIDENCE AND
RISING HEIGHTS...TEMPERATURES WILL CONTINUE TO WARM MID WEEK WITH
WIDESPREAD 90S ANTICIPATED WEDNESDAY AND ESPECIALLY THURSDAY FOR
ALL LOCATIONS ACROSS WESTERN AND NORTH CENTRAL NEBRASKA.
LOWS...UNDER MOSTLY CLEAR SKIES...SHOULD BE SEASONAL WITH 60S
PREVAILING FOR MOST LOCATIONS. BEYOND THURSDAY...MODELS REMAIN
CONSISTENT WITH THE PASSAGE OF A SHORTWAVE ACROSS THE NORTHERN
PLAINS...WHICH WILL FORCE A COLD FRONT THROUGH THE CWA ON FRIDAY.
HIGHS ARE ANTICIPATED TO BE A COUPLE TO SEVERAL DEGREES
COOLER...WITH MAINLY 80S AND LOW 90S EXPECTED. IT SEEMS THAT WITH
EACH SUCCESSIVE MODEL RUNS...QPF COVERAGE ASSOCIATED WITH THE
SHORTWAVE AND COLD FRONTAL PASSAGE IS BECOMING LESS AND
LESS...THUS WILL ONLY MAINTAIN SLIGHT CHANCES/LOW END CHANCES OF
POPS FRIDAY THROUGH EARLY SATURDAY...WITH THE HIGHEST PROBABILITY
OCCURRING ALONG OUR SOUTHERN BORDER FRIDAY EVENING AS THE FRONT
SAGS SOUTH. INTO THE WEEKEND...THERE REMAINS SOME CONSISTENCY IN
THE OPERATIONALS THAT THE FRONT WILL STALL TO THE SOUTH OF THE
CWA...WITH ADDITIONAL DISTURBANCES PASSING THROUGH NORTHWESTERLY
FLOW ALOFT. A THREAT OF STORMS WILL REMAIN THROUGH THE COMING
WEEKEND...HOWEVER SHEAR VALUES AT THIS TIME LOOK FAIRLY
WEEK...WIDESPREAD SEVERE WEATHER IS NOT ANTICIPATED IF STORMS
ACTUALLY ARE REALIZED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 622 AM CDT MON JUL 15 2013
FOR THE KLBF TERMINAL...PATCHY GROUND FOG WITH VISBYS DOWN TO HALF
A MILE OR LESS WILL REMAIN POSSIBLE THROUGH 13Z. FOG IS EXPECTED TO
BURN OFF BY MID MORNING WITH CLEAR SKIES EXPECTED THEREAFTER.
WINDS WILL BE SOUTHERLY AT 10 TO 20 KTS TODAY...DIMINISHING TO
UNDER 10 KTS TONIGHT.
FOR THE KVTN TERMINAL...SCATTERED TO BROKEN CIGS AON 2000 FT AGL
ARE EXPECTED THROUGH MID MORNING...WITH MOSTLY CLEAR SKIES
EXPECTED THEREAFTER. SOUTHERLY WINDS WILL INCREASE TO 10 TO 20
KTS...WITH GUSTS TO 25 KTS POSSIBLE THIS AFTERNOON. WINDS WILL
DIMINISH TO 10 TO 15 KTS TONIGHT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CLB
LONG TERM...JACOBS
AVIATION...CLB
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
335 AM CDT MON JUL 15 2013
.DISCUSSION...
TEMPERATURES THROUGH THE WEEK AND THE CHANCE FOR TSTMS FOR TODAY
INTO EARLY THIS EVENING ARE THE PRIMARY FORECAST CONCERNS. UNUSUAL
UPPER LEVEL PATTERN WITH RETROGRESSIVE MID TROPOSPHERIC FLOW WILL
CONTINUE INTO MID WEEK.
CURRENT AIRMASS OVER THE AREA IS MUCH DRIER THAN 24 HOURS AGO. AT
12Z SUNDAY THE PRECIPITABLE WATER AMOUNT FROM THE KOAX SOUNDING WAS
1.80 INCHES. THAT DROPPED TO 1.03 BY 00Z MONDAY. THAT WILL BE
CHANGING AS MOISTURE MOVES BACK INTO THE AREA FROM THE SOUTHEAST.
MOST OF THE SHORT RANGE MODEL DEVELOP SOME LIGHT PCPN OVER AT
LEAST PORTIONS OF THE FORECAST AREA FROM THIS AFTERNOON INTO THE
EARLY EVENING. NAM AND RAP SHOW SOME CAPE (500-1500 J/KG)
DEVELOPING THIS AFTERNOON AND CONTINUING INTO THE EVENING.
AFTER THIS EVENING...KEPT A DRY FORECAST UNTIL LATE IN THE WEEK.
ALTHOUGH CAN NOT COMPLETELY RULE OUT SOME ISOLD LATE AFTERNOON POP
SHOWERS/THUNDERSTORMS TUESDAY OR WEDNESDAY...FELT COVERAGE WOULD
JUST BE TOO LOW TO MENTION AT THIS POINT. WILL NEED TO LOOK AT THAT
THOUGH THE NEXT SEVERAL FORECAST CYCLES.
THE CLOSED LOW INITIALLY OVER OKLAHOMA TODAY WILL MOVE INTO EASTERN
NEW MEXICO TUESDAY AND THEN INTO THE NORTHERN PART OF SONORA MEXICO
ON THURSDAY. FAIRLY HIGH 500 MB HEIGHTS FAVOR WARM TEMPERATURES AND
MAINLY DRY CONDITIONS. THE LARGE MID/UPPER TROPOSPHERIC RIDGES DOES
START TO FLATTEN THURSDAY NIGHT/FRIDAY...WHICH WILL ALLOW A WEAK
COLD FRONT TO SAG SOUTH INTO THE AREA FRIDAY/SATURDAY. THIS SHOULD
BRING A DECENT CHANCE OF PCPN. TEMPERATURES WILL BE MAINLY IN THE
90S IN THE MID AND LATER PART OF THE WEEK WITH SLIGHT COOLING FOR
THE WEEKEND.
MILLER
&&
.AVIATION...
06Z TAFS FOR KOMA...KLNK...KOFK.
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. GENERALLY CLEAR
SKIES ARE EXPECTED OVERNIGHT WITH LIGHT SOUTHEAST WINDS. WE EXPECT
SOME CUMULUS TO DEVELOP THROUGH THE LATE MORNING AND INTO THE
AFTERNOON AT ALL 3 SITES...BUT ESPECIALLY OMA/LNK. AN ISOLD SHOWER
APPEARS POSSIBLE AT OMA...BUT TIMING AND VERY ISOLD NATURE
PRECLUDES MENTION ATTM.
BOUSTEAD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
325 AM CDT MON JUL 15 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 325 AM CDT MON JUL 15 2013
FORECAST CHALLENGES IN THE NEAR TERM ARE TEMPERATURES AND ENDING
TIME OF PRECIPITATION THIS MORNING. FOR TODAY...UPPER LEVEL LOW
PRESSURE WILL TRACK ALONG THE TX/OK BORDER. MID LEVEL WAA WILL
SHIFT NORTHWEST INTO THE NEBRASKA PANHANDLE AND SOUTH DAKOTA BY
MID MORNING...ENDING PRECIPITATION ACROSS THE FORECAST AREA. THE
NAM...GFS...AND HI RES RUC ALL SHIFT THIS MID LEVEL LIFT WEST...SO
CONFIDENCE IS FAIRLY HIGH IN ENDING PCPN MENTION BY MID MORNING.
DRY CONDITIONS WILL CARRY OVER INTO THE OVERNIGHT HOURS
TONIGHT...AS DRIER...MORE STABLE AIR PUSHES INTO WESTERN AND NORTH
CENTRAL NEBRASKA. TEMPERATURES TODAY WILL RANGE FROM THE LOWER 80S
IN THE WEST WITH MORE PERSISTENT CLOUD COVER...TO THE MIDDLE AND
UPPER 80S IN THE CENTRAL AND EASTERN FORECAST AREA...WITH MAINLY
CLEAR SKIES EXPECTED. WINDS WILL BE FROM THE SOUTH AND SOUTHEAST
AT 10 TO 20 MPH...DECREASING TO 10 TO 15 MPH TONIGHT. WITH MUCH
DRIER AIR PUSHING INTO THE REGION TODAY...OVERNIGHT LOWS WILL
BOTTOM OUT IN THE UPPER 50S IN THE WEST TO MID 60S IN THE EAST.
THE ONLY CAVEAT TO LOWS TONIGHT WILL BE WHETHER OR NOT WINDS WILL
TOTALLY DECOUPLE. THIS MAY BE AN ISSUE ACROSS NORTH CENTRAL
NEBRASKA WHERE H85 AND H925 WINDS REMAIN UNIDIRECTIONAL INTO THE
OVERNIGHT. WITH THIS IN MIND...HEDGED LOWS A LITTLE WARMER ACROSS
NORTH CENTRAL NEBRASKA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 325 AM CDT MON JUL 15 2013
EXPANSIVE UPPER LEVEL AREA OF HIGH PRESSURE WILL BE ANCHORED
ACROSS THE OHIO RVR VALLEY /LOWER GREAT LAKES REGION STARTING OFF
THE EXTENDED PERIOD AS A FILLING UPPER LOW CONTINUES TO RETROGRADE
SOUTHWEST ACROSS WESTERN TEXAS. WITH INCREASING SUBSIDENCE AND
RISING HEIGHTS...TEMPERATURES WILL CONTINUE TO WARM MID WEEK WITH
WIDESPREAD 90S ANTICIPATED WEDNESDAY AND ESPECIALLY THURSDAY FOR
ALL LOCATIONS ACROSS WESTERN AND NORTH CENTRAL NEBRASKA.
LOWS...UNDER MOSTLY CLEAR SKIES...SHOULD BE SEASONAL WITH 60S
PREVAILING FOR MOST LOCATIONS. BEYOND THURSDAY...MODELS REMAIN
CONSISTENT WITH THE PASSAGE OF A SHORTWAVE ACROSS THE NORTHERN
PLAINS...WHICH WILL FORCE A COLD FRONT THROUGH THE CWA ON FRIDAY.
HIGHS ARE ANTICIPATED TO BE A COUPLE TO SEVERAL DEGREES
COOLER...WITH MAINLY 80S AND LOW 90S EXPECTED. IT SEEMS THAT WITH
EACH SUCCESSIVE MODEL RUNS...QPF COVERAGE ASSOCIATED WITH THE
SHORTWAVE AND COLD FRONTAL PASSAGE IS BECOMING LESS AND
LESS...THUS WILL ONLY MAINTAIN SLIGHT CHANCES/LOW END CHANCES OF
POPS FRIDAY THROUGH EARLY SATURDAY...WITH THE HIGHEST PROBABILITY
OCCURRING ALONG OUR SOUTHERN BORDER FRIDAY EVENING AS THE FRONT
SAGS SOUTH. INTO THE WEEKEND...THERE REMAINS SOME CONSISTENCY IN
THE OPERATIONALS THAT THE FRONT WILL STALL TO THE SOUTH OF THE
CWA...WITH ADDITIONAL DISTURBANCES PASSING THROUGH NORTHWESTERLY
FLOW ALOFT. A THREAT OF STORMS WILL REMAIN THROUGH THE COMING
WEEKEND...HOWEVER SHEAR VALUES AT THIS TIME LOOK FAIRLY
WEEK...WIDESPREAD SEVERE WEATHER IS NOT ANTICIPATED IF STORMS
ACTUALLY ARE REALIZED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1225 AM CDT MON JUL 15 2013
.AVIATION...
A LINE OF THUNDERSTORMS AND RAINSHOWERS WILL CONTINUE TO MOVE SLOWLY
WEST OVER THE WESTERN NEBRASKA SANDHILLS THROUGH THE EARLY MORNING
HOURS. STRATUS WITH IFR CEILINGS WILL CONTINUE OVER THE KVTN TAF
SITE THROUGH 15/12Z. MARGINAL MVFR CEILINGS ARE POSSIBLE OVER
SOUTHERN NEBRASKA BUT THE GENERAL TREND HAS BEEN FOR VFR CEILINGS
AND HAVE CONTINUED THIS TREND OVER NIGHT. CEILINGS WILL LIFT THROUGH
MID MORNING OVER NORTHERN NEBRASKA WITH SOUTHERLY WINDS INCREASING
TO 10 TO 20 MPH THROUGH THE DAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CLB
LONG TERM...JACOBS
AVIATION...POWER
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
947 PM EDT TUE JUL 16 2013
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE OVER THE OHIO VALLEY WITH VERY WARM
AND HUMID AIR WILL INFLUENCE OUR WEATHER THROUGH FRIDAY. A COLD
FRONT WILL DROP SOUTH OF THE REGION SATURDAY WITH A CHANCE FOR
STRONG THUNDERSTORMS. AFTER THIS FRONT PASSES BY...COOLER AND LESS
HUMID AIR WILL COVER THE REGION FOR EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
950 PM EDT UPDATE...
FORECAST IS IN GREAT SHAPE AND A QUITE EVENING IS ON ITS WAY
TONIGHT. VALLEY FOG IS STILL EXPECTED TO DEVELOP LATER THIS EVENING
AS CLEAR SKIES WILL CONTINUE ACROSS CENTRAL NY AND NORTHEAST PA. TEMPS
ARE IN GOOD ORDER FOR WEDNESDAY. ANOTHER HOT AND MUGGY DAY IS ON
ITS WAY.
PREVIOUS FORECAST...
SCT CUMULUS IN CLOUD STREETS COVER MUCH OF THE CWA AS THE LL FLOW
IS NWRLY. DEWPOINTS WERE A BIT LOWER THIS AFTERNOON THAN YSTA
RUNNING IN THE MID TO UPPER 60S. RAP MODEL SOUNDINGS SHOW A
CAPPING INVERSION NR 800 MB WHICH WAS KEEPING DEEP CONVECTION IN
CHECK HENCE DON/T EXPECT ANY SHRA OR TSRA FOR THE REST OF TODAY OR
THIS EVENING.
FOR OVERNIGHT...EXPECT MORE VALLEY FOG SIMILAR TO THIS MORNING IN
OUR RIVER VALLEYS.
FOR WEDNESDAY...W-NW LL FLOW WILL ADVECT SLIGHTLY HIGHER DEWPOINTS
INTO C NY AND NE PA AS PER MODEL GUIDC. NAM AND GFS BOTH SHOW
HIGHER DEWPOINTS AT 850 MB COMING SOUTHEASTWARD BY WED WHICH SHUD
MIX DOWN WITH BNDRY LAYER GROWTH FROM INSOLATION. MODEL GUIDC
SUGGESTS DEWPOINTS IN THE LOWER 70S ALONG THE LAKE ONTARIO PLAIN
AND UPPER 60S REST OF CWA. HIGH TEMPERATURES ALREADY SHUD BE IN
THE LOW 90S TODAY IN SYR AND WUD EXPECT THE SAME FOR WED. HENCE
HEAT INDICES WED PM WILL BE CLOSE TO 100F IN THE SYR-AUBURN AREAS
WHICH IS OUR HEAT ADVY CRITERIA. SO ISSUED HEAT ADVY FOR A FEW
COUNTIES ALONG THE LAKE ONTARIO PLAIN INCLUDING SYR TO COVER.
ANOTHER CONCERN FOR WED WILL BE MORE INSTABILITY WITH A BIT HIGHER
DEWPOINTS. MODEL SOUNDINGS ALL SHOW CAPES BETWEEN 1500 J/KG AND
2000 J/KG BY WED PM. FORCING WILL BE WEAK BUT WITH A LL NW FLO
SEE SOME ISLD SHRA/TSRA FORMING FROM MTN VALLY CRLCNS AND LAKE
BOUNDARIES. SO WENT WITH SLGHT CHC TSRA IN MUCH OF CNTRL NY.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
FOR THURSDAY...SHORT WAVE TRACKING ACROSS SWRN AND SC CANADA WILL
REACH SERN CANADA BY THURSDAY PM...THIS WILL TURN THE MID TO UPPER
LVL FLOW MORE NWRLY AND PRESS A FRNT DOWN TO NRN NEW ENGLAND AND THE
UPPER LAKES. AT 500 MB THE TEMPERATURES BEGIN TO FALL FROM WEAK
CAA AS WELL FROM THE NW FLOW. AT LL/S THE DEWPOINTS AGAIN WILL BE
WITHIN A FEW DEGREES OF 70F. SO THINK THERE WILL BE SCT TSRA IN
NC NY TO ISLD CONVECTION FARTHER S TO NE PA AS CAPES ARE RUNNING
BETWEEN 1000 AND 1500 J/KG AND LL FLOW AGAIN RUNS UP INTO THE
HILLS OF NY AND NRN PA.
FOR FRIDAY...LONGER WAVELENGTH UPPER LEVEL FEATURE OVER SC CANADA
TO THE UPR MIDWEST WILL TURN THE LL FLOW MORE SWRLY AND ADVECT
SOMEWHAT HIGHER LL MOISTURE INTO NY AND PA AND INCREASE
INSTABILITY. CAPES CUD EXCEED 2000 J/KG. 0-6 KM BULK SHEAR WILL
ALSO BE BETWEEN 30 AND 40 KNOTS BY AFTERNOON. POTENTIAL IS FOR
SOME CONVECTION WELL IN ADVANCE OF THE FRONT. THE REGION WILL FALL
UNDER THE RIGHT ENTRANCE REGION OF A STRG UPPER LEVEL JET IN SERN
CANADA BY FRI PM TO ENHANCE UPPER DVRG. AT LL/S THERE IS A 30-35
KNOT W-SW LLJ RUNNING FROM THE LOWER LAKES TO NRN NY STATE. THIS
IS FAVORABLE TO SUPPORT STRG TO SVR CONVECTION ACRS NC NY WHERE
POPS WILL BE HIGHEST. WILL TAPER DOWN POPS SOME INTO NE PA FRI.
BOTH THURSDAY AND FRIDAY...HEAT INDICES WILL BE CLOSE TO 100F IN
NE PA AND SRN SULLIVAN CO NY AND POSSIBLY SC NY. THE LAKE ONTARIO
PLAIN LIKELY WILL REMAIN CLOSE TO 100F HEAT INDICES BOTH DAYS. FOR
NOW WILL COVER IN HWO...BUT MAY HAVE TO EXTEND HEAT ADVISORIES UP
THERE AND EXPAND HEAT ADVISORIES FARTHER S AND E.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
LTL CHG TO THE MED RNG FCST WHICH FEATURES THE PSSG OF A CANADIAN
CDFNT ON SAT...FOLLOWED BY MUCH MORE COMFORTABLE CONDITIONS. BEST
CHCS FOR TSRA APPEAR TO BE OVER NRN SXNS ON FRI NGT...SPREADING
INTO CNTRL NY AND NE PA ON SAT. POTNL FOR STRONG/SVR TSRA ON SAT GIVEN
THE MDL FCST WIND FIELDS AND INSTABILITY...WITH TIMING OF FNT
LOOKING QUITE FVRBL FOR SRN/CNTRL NY AND NE PA ON SAT. XPCT
LINGERING ACTIVITY TO PUSH OFF TO THE SE ON SAT NGT...WITH FAIR WX
AND MORE SEASONABLE TEMPS RETURNING ON SUNDAY. EARLY NXT WEEK
LOOKING FABULOUS WITH MAXES 75-80 AND LOWS INTO THE 50S...AND MUCH
LOWER HUMIDITY.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
STRONG HIGH PRESSURE REMAINS IN CONTROL THIS EVENING WITH DIURNAL
CU RAPIDLY FADING AWAY WITH LOSS OF DAYTIME HEATING. THE
ONGOING PRESENCE OF A VERY MOIST ATMOSPHERE ALONG WITH NEARLY
CLEAR SKIES ALOFT WILL SET THE STAGE FOR VALLEY FOG FORMATION ONCE
AGAIN TONIGHT....WITH IFR POSSIBLE AT ELM AFTER 09Z. A LITTLE MORE
UNCERTAIN AT ITH AS ALL GUIDANCE SUGGESTS DEVELOPING MVFR VSBYS
TOWARDS MORNING...AND HAVE ELECTED TO OFFER A BRIEF TEMPO MVFR
MENTION FOR NOW. AT REMAINING SITES...EXPECT VFR TO CONTINUE
THROUGH THE PERIOD WITH ALL LOCATIONS SEEING SCT CU AS THE DAYTIME
HEATING CYCLE ONCE AGAIN GETS UNDER WAY. VARIABLE WINDS OVERNIGHT
WILL BECOME NORTHWESTERLY 5-10 KTS AFTER 14Z.
.OUTLOOK...
WED NGT/THU/FRI...VFR PREVAILS. CHANCE FOR LATE NGT/EARLY MRNG MVFR/IFR
FG/BR/HZ AT KELM. ISOLD OR WDLY SCT AFTN TSRA MAY ALSO PRODUCE
BRIEF RESTRICTIONS.
FRI NGT INTO SAT...MVFR IN TSRA...MOST NUMEROUS OVER NRN SITES FRI
NGT...AND AREA WIDE ON SAT.
SAT NGT...MVFR PSBL AT AVP IN SHRA/TSRA EARLY....IMPRVG TO VFR CNTRL
NY.
SUN...VFR.
&&
.CLIMATE...
BELOW ARE THE RECORD HIGHS FOR THE NEXT FEW DAYS AT OUR MAIN AIRPORTS
AND OUR FORECAST HIGHS. HIGH TEMPERATURES SHOULD FALL SHORT OF THE DAILY
RECORDS...
SYRACUSE HANCOCK FIELD...
TODAY 97 SET IN 1988. FORECAST 92
WEDNESDAY 101 SET IN 2012. FORECAST 92
THURSDAY 97 SET IN 1953. FORECAST 91
GREATER BINGHAMTON AIRPORT...
TODAY 98 SET IN 1988. TODAY`S FORECAST 88
WEDNESDAY 91 SET IN 1991. FORECAST 88
THURSDAY 93 SET IN 1953. FORECAST 88
SCRANTON/WILKES-BARRE INTERNATIONAL AIRPORT...
TODAY 101 SET IN 1988. TODAY`S FORECAST 91
WEDNESDAY 96 SET IN 1999. FORECAST 93
THURSDAY 98 SET IN 1953. FORECAST 93
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...HEAT ADVISORY FROM NOON TO 8 PM EDT WEDNESDAY FOR NYZ016>018.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN/KAH
SHORT TERM...DJN
LONG TERM...
AVIATION...CMG
CLIMATE...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
745 PM EDT TUE JUL 16 2013
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE OVER THE OHIO VALLEY WITH VERY WARM
AND HUMID AIR WILL INFLUENCE OUR WEATHER THROUGH FRIDAY. A COLD
FRONT WILL DROP SOUTH OF THE REGION SATURDAY WITH A CHANCE FOR
STRONG THUNDERSTORMS. AFTER THIS FRONT PASSES BY...COOLER AND LESS
HUMID AIR WILL COVER THE REGION FOR EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
SCT CUMULUS IN CLOUD STREETS COVER MUCH OF THE CWA AS THE LL FLOW
IS NWRLY. DEWPOINTS WERE A BIT LOWER THIS AFTERNOON THAN YSTA
RUNNING IN THE MID TO UPPER 60S. RAP MODEL SOUNDINGS SHOW A
CAPPING INVERSION NR 800 MB WHICH WAS KEEPING DEEP CONVECTION IN
CHECK HENCE DON/T EXPECT ANY SHRA OR TSRA FOR THE REST OF TODAY OR
THIS EVENING.
FOR OVERNIGHT...EXPECT MORE VALLEY FOG SIMILAR TO THIS MORNING IN
OUR RIVER VALLEYS.
FOR WEDNESDAY...W-NW LL FLOW WILL ADVECT SLIGHTLY HIGHER DEWPOINTS
INTO C NY AND NE PA AS PER MODEL GUIDC. NAM AND GFS BOTH SHOW
HIGHER DEWPOINTS AT 850 MB COMING SOUTHEASTWARD BY WED WHICH SHUD
MIX DOWN WITH BNDRY LAYER GROWTH FROM INSOLATION. MODEL GUIDC
SUGGESTS DEWPOINTS IN THE LOWER 70S ALONG THE LAKE ONTARIO PLAIN
AND UPPER 60S REST OF CWA. HIGH TEMPERATURES ALREADY SHUD BE IN
THE LOW 90S TODAY IN SYR AND WUD EXPECT THE SAME FOR WED. HENCE
HEAT INDICES WED PM WILL BE CLOSE TO 100F IN THE SYR-AUBURN AREAS
WHICH IS OUR HEAT ADVY CRITERIA. SO ISSUED HEAT ADVY FOR A FEW
COUNTIES ALONG THE LAKE ONTARIO PLAIN INCLUDING SYR TO COVER.
ANOTHER CONCERN FOR WED WILL BE MORE INSTABILITY WITH A BIT HIGHER
DEWPOINTS. MODEL SOUNDINGS ALL SHOW CAPES BETWEEN 1500 J/KG AND
2000 J/KG BY WED PM. FORCING WILL BE WEAK BUT WITH A LL NW FLO
SEE SOME ISLD SHRA/TSRA FORMING FROM MTN VALLY CRLCNS AND LAKE
BOUNDARIES. SO WENT WITH SLGHT CHC TSRA IN MUCH OF CNTRL NY.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
FOR THURSDAY...SHORT WAVE TRACKING ACROSS SWRN AND SC CANADA WILL
REACH SERN CANADA BY THURSDAY PM...THIS WILL TURN THE MID TO UPPER
LVL FLOW MORE NWRLY AND PRESS A FRNT DOWN TO NRN NEW ENGLAND AND THE
UPPER LAKES. AT 500 MB THE TEMPERATURES BEGIN TO FALL FROM WEAK
CAA AS WELL FROM THE NW FLOW. AT LL/S THE DEWPOINTS AGAIN WILL BE
WITHIN A FEW DEGREES OF 70F. SO THINK THERE WILL BE SCT TSRA IN
NC NY TO ISLD CONVECTION FARTHER S TO NE PA AS CAPES ARE RUNNING
BETWEEN 1000 AND 1500 J/KG AND LL FLOW AGAIN RUNS UP INTO THE
HILLS OF NY AND NRN PA.
FOR FRIDAY...LONGER WAVELENGTH UPPER LEVEL FEATURE OVER SC CANADA
TO THE UPR MIDWEST WILL TURN THE LL FLOW MORE SWRLY AND ADVECT
SOMEWHAT HIGHER LL MOISTURE INTO NY AND PA AND INCREASE
INSTABILITY. CAPES CUD EXCEED 2000 J/KG. 0-6 KM BULK SHEAR WILL
ALSO BE BETWEEN 30 AND 40 KNOTS BY AFTERNOON. POTENTIAL IS FOR
SOME CONVECTION WELL IN ADVANCE OF THE FRONT. THE REGION WILL FALL
UNDER THE RIGHT ENTRANCE REGION OF A STRG UPPER LEVEL JET IN SERN
CANADA BY FRI PM TO ENHANCE UPPER DVRG. AT LL/S THERE IS A 30-35
KNOT W-SW LLJ RUNNING FROM THE LOWER LAKES TO NRN NY STATE. THIS
IS FAVORABLE TO SUPPORT STRG TO SVR CONVECTION ACRS NC NY WHERE
POPS WILL BE HIGHEST. WILL TAPER DOWN POPS SOME INTO NE PA FRI.
BOTH THURSDAY AND FRIDAY...HEAT INDICES WILL BE CLOSE TO 100F IN
NE PA AND SRN SULLIVAN CO NY AND POSSIBLY SC NY. THE LAKE ONTARIO
PLAIN LIKELY WILL REMAIN CLOSE TO 100F HEAT INDICES BOTH DAYS. FOR
NOW WILL COVER IN HWO...BUT MAY HAVE TO EXTEND HEAT ADVISORIES UP
THERE AND EXPAND HEAT ADVISORIES FARTHER S AND E.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
LTL CHG TO THE MED RNG FCST WHICH FEATURES THE PSSG OF A CANADIAN
CDFNT ON SAT...FOLLOWED BY MUCH MORE COMFORTABLE CONDITIONS. BEST
CHCS FOR TSRA APPEAR TO BE OVER NRN SXNS ON FRI NGT...SPREADING
INTO CNTRL NY AND NE PA ON SAT. POTNL FOR STRONG/SVR TSRA ON SAT GIVEN
THE MDL FCST WIND FIELDS AND INSTABILITY...WITH TIMING OF FNT
LOOKING QUITE FVRBL FOR SRN/CNTRL NY AND NE PA ON SAT. XPCT
LINGERING ACTIVITY TO PUSH OFF TO THE SE ON SAT NGT...WITH FAIR WX
AND MORE SEASONABLE TEMPS RETURNING ON SUNDAY. EARLY NXT WEEK
LOOKING FABULOUS WITH MAXES 75-80 AND LOWS INTO THE 50S...AND MUCH
LOWER HUMIDITY.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
STRONG HIGH PRESSURE REMAINS IN CONTROL THIS EVENING WITH DIURNAL
CU RAPIDLY FADING AWAY WITH LOSS OF DAYTIME HEATING. THE
ONGOING PRESENCE OF A VERY MOIST ATMOSPHERE ALONG WITH NEARLY
CLEAR SKIES ALOFT WILL SET THE STAGE FOR VALLEY FOG FORMATION ONCE
AGAIN TONIGHT....WITH IFR POSSIBLE AT ELM AFTER 09Z. A LITTLE MORE
UNCERTAIN AT ITH AS ALL GUIDANCE SUGGESTS DEVELOPING MVFR VSBYS
TOWARDS MORNING...AND HAVE ELECTED TO OFFER A BRIEF TEMPO MVFR
MENTION FOR NOW. AT REMAINING SITES...EXPECT VFR TO CONTINUE
THROUGH THE PERIOD WITH ALL LOCATIONS SEEING SCT CU AS THE DAYTIME
HEATING CYCLE ONCE AGAIN GETS UNDER WAY. VARIABLE WINDS OVERNIGHT
WILL BECOME NORTHWESTERLY 5-10 KTS AFTER 14Z.
.OUTLOOK...
WED NGT/THU/FRI...VFR PREVAILS. CHANCE FOR LATE NGT/EARLY MRNG MVFR/IFR
FG/BR/HZ AT KELM. ISOLD OR WDLY SCT AFTN TSRA MAY ALSO PRODUCE
BRIEF RESTRICTIONS.
FRI NGT INTO SAT...MVFR IN TSRA...MOST NUMEROUS OVER NRN SITES FRI
NGT...AND AREA WIDE ON SAT.
SAT NGT...MVFR PSBL AT AVP IN SHRA/TSRA EARLY....IMPRVG TO VFR CNTRL
NY.
SUN...VFR.
&&
.CLIMATE...
BELOW ARE THE RECORD HIGHS FOR THE NEXT FEW DAYS AT OUR MAIN AIRPORTS
AND OUR FORECAST HIGHS. HIGH TEMPERATURES SHOULD FALL SHORT OF THE DAILY
RECORDS...
SYRACUSE HANCOCK FIELD...
TODAY 97 SET IN 1988. FORECAST 92
WEDNESDAY 101 SET IN 2012. FORECAST 92
THURSDAY 97 SET IN 1953. FORECAST 91
GREATER BINGHAMTON AIRPORT...
TODAY 98 SET IN 1988. TODAY`S FORECAST 88
WEDNESDAY 91 SET IN 1991. FORECAST 88
THURSDAY 93 SET IN 1953. FORECAST 88
SCRANTON/WILKES-BARRE INTERNATIONAL AIRPORT...
TODAY 101 SET IN 1988. TODAY`S FORECAST 91
WEDNESDAY 96 SET IN 1999. FORECAST 93
THURSDAY 98 SET IN 1953. FORECAST 93
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...HEAT ADVISORY FROM NOON TO 8 PM EDT WEDNESDAY FOR NYZ016>018.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...DJN
LONG TERM...
AVIATION...CMG
CLIMATE...
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
135 AM EDT MON JUL 15 2013
.SYNOPSIS...
A LARGE MID LEVEL RIDGE OVER THE OHIO VALLEY WILL GROW IN SIZE
AND DRIFT SOUTH THROUGH THE MIDDLE OF THE WEEK. THE RIDGE WILL
WEAKEN LATE IN THE WEEK WHILE BERMUDA HIGH PRESSURE BUILDS BACK FROM
THE EAST AND THE PIEDMONT TROUGH STRENGTHENS. NEXT WEEKEND...A COLD
FRONT WILL APPROACH FROM THE NORTHWEST...POTENTIALLY BRINGING AN
INCREASED CHANCE OF SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 11 PM SUNDAY...HAVE ADJUSTED POPS TO A LOW CHANCE FOR
MAINLY THE PRE-DAWN HRS OF MONDAY TO ACCOUNT FOR ANY ONSHORE
MOVEMENT OF NOCTURNAL SHRA ACTIVITY FROM OFF THE ADJ ATLANTIC.
LATEST ADJACENT NWS 88D RADARS DEPICT THE INCREASING WIDELY
SCATTERED SHRA DEVELOPMENT OVER THE ADJACENT ATLANTIC WATERS.
NAMBUFR SOUNDINGS ACROSS THE COASTAL FA...INDICATE AN EASTERLY
FLOW THRUOUT THE ATM COLUMN. AS A RESULT...THIS DEEP ONSHORE FLOW
WILL PERIODICALLY PUSH ANY ATLANTIC PCPN ACTIVITY ONSHORE. A
MODEST CAP WILL EXIST IN THE 800-750 MB RANGE VIA PROGGED NAMBUFR
HOURLY SOUNDINGS...THUS PUTTING A LID ON ANY FURTHER VERTICAL
DEVELOPMENT OF THE OVERNIGHTS PCPN. THEREFORE...DO NOT EXPECT
MUCH IF ANY THUNDERSTORM ACTIVITY TO ACCOMPANY THIS PCPN. THE
LATEST MIN TEMP FORECAST OF 70 TO 75 DEGREES STILL LOOKING
AOK...WITH 74 TO 78 DEGREE READINGS RESERVED FOR ALONG THE
IMMEDIATE COAST.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...SURFACE AND MID LEVEL RIDGING OVER THE OH VALLEY
WILL GRADUALLY EXPAND SOUTH DURING THE PERIOD. EAST FLOW AROUND THE
SOUTHERN EDGE OF THE SURFACE HIGH WILL HELP KEEP TEMPERATURES A
LITTLE COOLER THAN WHAT IS TYPICAL FOR MID JULY...ESPECIALLY NEAR
THE COAST. EASTERLY FLOW WILL ALSO MAINTAIN THE SUPPLY OF LOW LEVEL
MOISTURE. CONVERGENCE ALONG THE EASTERLY WIND ENHANCED SEA BREEZE
MAY TRIGGER SOME WEAK CONVECTION ACROSS INLAND AREAS MON AFTERNOON.
ALTHOUGH THERE WILL BE SOME MID LEVEL SUBSIDENCE ON THE PERIPHERY OF
THE 5H RIDGE MON IT WILL BE ON THE WEAK SIDE AND PROBABLY NOT STRONG
ENOUGH TO SUPPRESS ALL DEEPER CONVECTION. SOUTHWARD EXPANSION OF 5H
RIDGE ON TUE INCREASES SUBSIDENCE WHICH SHOULD KEEP THE REGION DRY.
HAVE TWEAKED POP FORECAST FOR MON WITH VALUES RANGING FROM SLIGHT
CHANCE TO LOW CHANCE ACROSS INLAND SC...WHERE SUBSIDENCE SHOULD BE
WEAKEST. MAINTAIN THE DRY FORECAST BUT HAVE NON ZERO POP TUE/TUE
NIGHT.
EASTERLY FLOW ON MON WILL KEEP TEMPERATURES ACROSS MUCH OF THE
REGION BELOW CLIMO AND MOST AREAS WILL STRUGGLE TO REACH 90. SUBTLE
WIND SHIFT...TO SOUTHEAST...ON TUE WILL KEEP COASTAL LOCATIONS COOL
BUT ALLOW INLAND AREAS TO WARM UP. LOW 90S ARE EXPECTED WITH
POTENTIAL FOR ISOLATED MID 90S. LOWS WILL RUN NEAR TO SLIGHTLY ABOVE
CLIMO. TUE NIGHT WILL BE WARMER OF THE TWO NIGHTS AS BERMUDA HIGH
STARTS TO REASSERT ITSELF AND SOUTHERLY FLOW DEVELOPS. ADDITIONALLY
GUIDANCE IS SHOWING A WEAK SHORTWAVE DROPPING SOUTH ALONG THE EAST
COAST TUE NIGHT. NOT SOLD ON STRENGTH...TIMING...AND LOCATION OF
THIS FEATURE BUT IT COULD PRODUCE A MID LEVEL CLOUD DECK TUE NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 3 PM SUNDAY...STRONG RIDGE OVER THE OHIO VALLEY SINKS SOUTH
AND WEAKENS BY THE WEEKEND AS A MID TO UPPER TROUGH DIGS DOWN FROM
CANADA AND RIDES THROUGH THE NORTHEAST INTO THE MID ATLANTIC STATES
THROUGH THE WEEKEND. THE RIDGE ALOFT WILL BE ELONGATED NORTH OF OUR
LOCAL AREA AS IT REACHES UP THROUGH THE LOW AND MID TO UPPER LEVELS
OF THE ATMOSPHERE. THEREFORE THERE WILL BE A DEEP EAST TO NORTHEAST
FLOW INITIALLY THROUGH WED. OVERALL EXPECT A FAIRLY DRY ATMOSPHERE
WITH MID TO UPPER RIDGE REACHING DOWN INTO AREA LEADING TO LITTLE TO
NO UPPER LEVEL DYNAMICS TO SUPPORT MUCH IN THE WAY OF SHWRS/TSTM
ACTIVITY BUT MODELS DO SHOW A MINOR PERTURBATION MAKING ITS WAY
AROUND THE BASE OF THE H5 RIDGE INTO THE CAROLINAS ON WED. THESE
FEATURES ARE TOUGH TO TIME BUT IT MAY LEAD TO A SLIGHT ENHANCEMENT
OF CLOUDS AND/OR CONVECTIVE DEVELOPMENT ON WED...MAINLY
INLAND...ESPECIALLY AS PIEDMONT TROUGH BECOMES MORE PRONOUNCED
THROUGH MID TO LATE WEEK. GFS SHOWING PCP WATER VALUES REACHING UP
OVER 2 INCHES INLAND WED AFTN.
BY THURSDAY THE LOW LEVEL FLOW BECOMES MORE SOUTHWESTERLY AS BERMUDA
RIDGE AND PIEDMONT TROUGH BECOME DOMINANT FEATURES. A FAIR AMOUNT OF
SUBSIDENCE AND DRY AIR WILL CONTINUE THROUGH THURS AND FRI AS MID TO
UPPER RIDGE MOVES CLOSER OVERHEAD. AT THE LOW LEVELS MODELS SHOW
DRIER AIR UPSTREAM BRINGING PCP WATER VALUES DOWN NEAR 1.5 INCHES
THURS INTO FRI. BY FRI NIGHT INTO SATURDAY THE SOUTHWEST FLOW
CONTINUES WITH A SLIGHT INCREASE IN MOISTURE BUT OVERALL A MODEST
AMOUNT FOR THIS TIME OF YEAR.
BASICALLY EXPECT MORE ISOLATED AND LOCALIZED SHOWER ACTIVITY THROUGH
MOST OF THE PERIOD...WITH MAIN FOCUS ALONG SEA BREEZE CONVERGENT
BOUNDARY AND FURTHER INLAND ALONG PIEDMONT TROUGH. BY SUNDAY THE MID
TO UPPER TROUGH MAY PUSH A COLD FRONT INTO THE CAROLINAS WITH PLENTY
OF MOISTURE AND GREATER INSTABILITY AHEAD OF THE FRONT ACROSS THE
CAROLINAS.
TEMPERATURES CLOSE TO OR A FEW DEGREES ABOVE CLIMO THROUGH AT LEAST
THE FIRST HALF OF THE PERIOD AS RIDGE KEEPS HIGHER H5 HEIGHTS AND
LOW LEVEL THICKNESSES ACROSS THE AREA. EXPECT READINGS 90 TO 95 MOST
PLACES DURING THE DAY AND LOWER 70S AT NIGHT.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...NO SIGNIFICANT CHANGE TO THE CURRENT TAFS. ISOLATED
SHOWERS WILL CONTINUE THIS MORNING...BUT THE CHANCE OF ANY TERMINAL
BEING AFFECTED IS LOW.
THERE IS MODERATE CONFIDENCE FOR IFR CIGS EARLY THIS MORNING AT
KFLO/KLBT WITH MVFR CIGS AT THE COASTAL TERMINALS. CIGS COULD DROP
INTO THE LIFR LEVEL AT TIMES IN THE PRE-DAWN HOURS AT KLBT/KFLO. FOG
POTENTIAL WILL BE HINDERED BY BOUNDARY LAYER WINDS AROUND 16 KT...
BUT ABUNDANT LOW LEVEL MOISTURE SHOULD ALLOW VSBYS TO POTENTIALLY
DROP TO AT LEAST MVFR LEVELS AT KFLO/KLBT. VSBYS SHOULD REMAIN VFR
AT THE COASTAL TERMINALS. AFTER SUNRISE VFR EXPECTED AT THE COASTAL
TERMINALS. AT KFLO/KLBT ANY SUB-VFR VSBYS INCREASE TO VFR FAIRLY
RAPIDLY...BUT CIGS SLOWLY RISE TO MVFR BY 14Z THEN TO VFR 16Z. WINDS
WILL BE E 10-15 KT...HIGHEST AT THE SOUTHERN COASTAL TERMINALS. ANY
SHOWER DEVELOPMENT SHOULD BE ISOLATED AT THE COASTAL TERMINALS
DURING THE MORNING. THIS ACTIVITY WILL MOVE WNW TOWARDS THE KFLO
TERMINAL BY MID TO LATE MORNING.
EXTENDED OUTLOOK...A CHANCE OF EARLY MORNING IFR CIGS AND TEMPO MVFR
MORNING/AFTERNOON CIGS THROUGH THE PERIOD. ISOLATED SHOWERS AND
THUNDERSTORMS WEDNESDAY THROUGH FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1130 PM SUNDAY...SCEC FOR ALL WATERS EXCEPT AMZ254...VALID
THROUGH MONDAY MID-MORNING. SFC PRESSURE PATTERN AND TIGHTENED
GRADIENT WILL YIELD ENE TO ESE WIND DIRECTIONS AT 10 TO 20
KT...WITH A FEW GUSTS UP TO 25 KT. THIS WELL SUPPORTED BY THE
LATEST HRRR HOURLY PROGGED SFC WIND DATA AND THE CURRENT NAM AND
GFS SFC FIELDS. THE LATTER 2 MODELS INDICATE A WESTWARD MOVING
INVERTED SFC TROF TO PROGRESS ACROSS THE ATL WATERS FROM WELL OFF
THE SE U.S. COAST...TO THE ATL WATERS JUST OFFSHORE FROM THE GA-FL
COAST BY DAYBREAK MONDAY. WAVEWATCH3 INDICATES A SWATH OR BUBBLE
OF HIER SEAS...AN EASTERLY SWELL EXHIBITING 8 SECOND
PERIODS...ASSOCIATED WITH THIS TROF THAT PARTIALLY PUSHES ACROSS
THE ILM AREA WATERS. AS A RESULT...SIGNIFICANT SEAS WILL REMAIN OR
HOLD IN THE 3 TO 5 FOOT RANGE OVERNIGHT...AND TRANSITION FROM THE
INITIAL DOMINANT WIND DRIVEN WAVE EXHIBITING AVERAGE PERIODS IN
THE 5.0 TO 6.0 SECOND RANGE...TO AN INCREASING AND MORE DOMINANT E
TO ESE SWELL AT 7 TO 8 SECOND PERIODS. WIDELY SCATTERED NOCTURNAL
SHRA TO PUSH ACROSS THE AREA WATERS...WITH THE BEST COVERAGE TO
OCCUR FROM CAPE FEAR SOUTHWARD.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...GRADIENT OVER THE WATERS WILL WEAKEN DURING THE
PERIOD AS SURFACE HIGH NORTHWEST OF THE WATERS SETTLES SOUTH. FLOW
WILL REMAIN EAST TO NORTHEAST INTO TUE BEFORE BERMUDA HIGH STARTS TO
EXTEND WEST...SETTING UP RETURN FLOW. NORTHEAST FLOW STARTS OUT ON
THE HIGH END OF THE 10 TO 15 KT RANGE MON MORNING BUT SHOULD BE 10
KT OR LESS BY MID AFTERNOON. RELAXED GRADIENT KEEPS SOUTHERLY FLOW
10 KT OR LESS THROUGH TUE NIGHT. SEAS WILL SLOWLY SUBSIDE ON
MON...FALLING FROM 3 TO 5 FT AT THE START OF THE PERIOD TO 2 TO 4 FT
MON NIGHT. SEAS CONTINUE TO DECREASE TUE AND TUE NIGHT IN THE
PRESENCE OF LIGHT WINDS...FALLING TO 2 FT BY THE END OF THE PERIOD.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 3 PM SUNDAY...WHILE RIDGE SHIFTS FURTHER SOUTH ALOFT
CREATING A MORE EASTERLY FLOW ABOVE THE SURFACE...THE FLOW AT THE
SURFACE WILL BACK FROM WESTERLY ON WED AS HIGH PRESSURE CENTERED
SOUTH OF AREA WEAKENS TO MORE SOUTHWEST TO SOUTHERLY AS BERMUDA
HIGH TAKES CONTROL THURS INTO NEXT WEEKEND. OVERALL FAIRLY TYPICAL
SUMMERTIME PATTERN SETS UP THURS INTO THE WEEKEND WITH HIGH
PRESSURE TO THE EAST AND PIEDMONT TROUGH OVER THE INLAND CAROLINAS
TO PRODUCE PERSISTENT S-SW FLOW. INITIALLY A LIGHTER OFF SHORE
FLOW WILL ALLOW SEAS TO SUBSIDE TO LESS THAN 3 FT MOST WATERS. THE
PERSISTENT AND INCREASING S-SW FLOW UP TO 15 KTS OR SO THAT SETS
UP THURS INTO THE WEEKEND WILL PUSH SEAS UP 3 TO 4 FT BY LATE FRI.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...III
NEAR TERM...DCH
SHORT TERM...III
LONG TERM...RGZ
AVIATION...MRR/RJD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1147 PM CDT SUN JUL 14 2013
.UPDATE...
ISSUED AT 1144 PM CDT SUN JUL 14 2013
NO ADDITIONAL CHANGES OVERNIGHT.
UPDATE ISSUED AT 1000 PM CDT SUN JUL 14 2013
SHOWER ACTIVITY IN FAR SOUTHEASTERN FCST AREA CONTINUES TO WEAKEN
IN COVERAGE AND MOSTLY AREAS OF LIGHT RAIN/DRIZZLE. KEPT SCT
SHOWERS IN THRU THE NIGHT. COORD WITH WFO BIS AND REMOVED ANY POPS
FOR AREAS NORTH AND WEST OF DEVILS LAKE. SHOWERS WEST AND NORTH OF
MINOT HEADED NORTHEAST AND LATEST 00Z NAM/RUC/HRRR ALL HAVE DRY IN
DVL BASIN TONIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 306 PM CDT SUN JUL 14 2013
VERY INTERESTING SYNOPTIC PATTERN WITH WELL ADVERTISED
RETROGRESSION OF UPPER LOW ACROSS MIDWEST. AS THIS SYSTEM MOVES
WEST-SOUTHWEST A SHORT WAVE OVER BRITISH COLUMBIA WILL MOVE EAST-
NORTHEAST. ANOTHER SHORTWAVE OVER NORTH CENTRAL MONTANA IS
GENERATING TSRA OVER EASTERN MONTANA AND WESTERN ND. THE LOW TO OUR
SOUTH HAS HELPED PRODUCE MULTIPLE FEEDS OF DEEP LAYERED MOISTURE
INTO THE CONVERGENT ZONE ALONG A BDE...BJI TO BWP LINE. THIS HAS
KEPT CONVECTION GOING ACROSS PARTS OF THE CWFA TODAY.
TONIGHT...DRIER SURFACE AIR AND UPPER CONVERGENCE IS HELPING TO
STABILIZE THE LOWER LAYERS AND SHRINK THE AREA OF CONVECTION. HAVE
FOLLOWED THE THE HRRR IN THE OVERNIGHT WHICH DECREASES POPS OVER
THE SOUTH WHILE INCREASING THEM IN THE DEVILS LAKE BASIN AFTER
06Z. EXPECT ONLY ISOLD TO WDLY SCATTERED SHRA/TSRA TONIGHT.
MONDAY...BOUNDARY BEGINS TO LIFT NORTH DURING THE MORNING. THERE
COULD BE LINGERING LIFT FROM THE MONTANA WAVE TO INTERACT WITH THE
NORTHWARD MOVING BOUNDARY TO MAINTAIN / REGENERATE TSRA MONDAY.
INSTABILITY AND LIFT MARGINAL AS FRONT MOVES NORTH...850 JET
FORECAST 20 TO 25 KTS...SHOWALTERS -2 TO -4 AND MU-CAPES AROUND
1500 J/KG SUGGEST LOW RISK SEVERE.
MONDAY NIGHT...BOUNDARY LIFTS NORTH TOWARDS INTERNATIONAL BORDER.
DRIER AIR MOVING IN FROM THE SOUTH...COURTESY OF LOWER PLAINS
CIRCULATION... REDUCES THE CONVECTIVE RISK. HAVE CONFINED POPS
NORTH OF THE U.S. 2 CORRIDOR AFTER 00Z MONDAY.
TUESDAY...BOUNDARY FORECAST TO CLEAR THE CWFA FOR THE MORNING
TUESDAY. ATMOSPHERE REMAINS RELATIVELY STABLE UNTIL LATER IN THE
DAY SO HAVE KEPT THE FORENOON PERIOD PRECIPITATION FREE. SHORTWAVE
MOVING FROM ALBERTA TO NORTHERN MANITOBA BUILDS A WEAK SURFACE
HIGH PUSHING THE FRONT BACK SOUTH. AS BOUNDARY BEGINS TO DROP
ACROSS THE AREA...DAYTIME HEATING AND MARGINAL MOISTURE SHOULD
RESULT IN TSRA LATER TUESDAY AFTERNOON AND EVENING.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 306 PM CDT SUN JUL 14 2013
TUESDAY NIGHT AND WEDNESDAY SHOULD SEE A FRONTAL BOUNDARY MOVING
INTO THE NORTHERN CWA AND STALLING OUT AS A LARGE UPPER RIDGE
CONTINUES OVER MUCH OF THE CENTRAL CONUS AND TROUGHING SETTING UP
OVER CANADA. THE FRONT MAY START TO WASH OUT A BIT DURING THE DAY
ON WEDNESDAY...BUT THINK THERE WILL BE ENOUGH CONVERGENCE REMAINING
ALONG IT TO ALLOW THUNDERSTORMS TO CONTINUE TO DEVELOP. CONTINUED TO
KEEP 20-40 POPS TUESDAY NIGHT AND WEDNESDAY NEAR THE CANADIAN BORDER
WHERE THE FRONT SEEMS LIKELY TO SET UP.
THURSDAY...AN UPPER SHORTWAVE WILL BEGIN TO DIG INTO
SASKATCHEWAN...AND THE BOUNDARY SHOULD MOVE SOUTH. THINK WITH THE
FRONT COMING THROUGH AND DECREASING 500MB HEIGHTS THERE WILL BE A
GOOD CHANCE FOR PRECIPITATION SO KEPT PRETTY HIGH POPS GOING. THE
SHORTWAVE WILL DIG DOWN INTO THE CWA ON FRIDAY...WITH PRECIP
STARTING TO TAPER OFF AND TEMPERATURES DROPPING BACK TO NEAR
SEASONAL NORMALS.
FOR NEXT WEEKEND...THE MODELS ARE IN PRETTY GOOD AGREEMENT ON
NORTHWESTERLY FLOW ALOFT SETTING UP...ALTHOUGH DIFFER QUITE A BIT ON
THE TIMING OF VARIOUS WEAK SHORTWAVES COMING THROUGH. THUS...SEE
LITTLE REASON TO DEVIATE MUCH FROM ALLBLEND POPS. TEMPS SHOULD BE
CLOSE TO AVERAGE FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1144 PM CDT SUN JUL 14 2013
ISSUE FOR THIS TAF PERIOD WILL BE CIGS. AREA OF 900-800 MB
MOISTURE WILL REMAIN IN PLACE FROM INL-BDE TO FARGO-FERGUS FALLS
AND INTO SOUTH DAKOTA. WITHIN THIS REGION THERE ARE POCKETS OF IFR
CIGS IN SOME DRIZZLE/LIGHT RAIN AND LIGHT FOG. EXPECT THESE
CONDITIONS TO HOLD THRU 15Z MON...WITH BEST CHC OF IFR VSBY/CIGS
IN HIGHER TERRAIN BJI-PKD-DTL REGION. DO EXPECT MOSTLY VFR CIGS TO
CONTINUE OR SLOWLY SPREAD NORTHWEST THRU MONDAY AS FRONTAL
BOUNDARY LIFTS NORTHEAST. PRECIP CHANCES AT ANY TAF SITE BLO 20
PCT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...EWENS
LONG TERM...JR
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
400 PM EDT MON JUL 15 2013
.SYNOPSIS...
A SPRAWLING AREA OF HIGH PRESSURE WILL STAY IN POSITION OVER THE
REGION THROUGH FRIDAY...PROVIDING ABOVE-NORMAL TEMPERATURES. ON
FRIDAY NIGHT AND INTO SATURDAY...A COLD FRONT WILL MOVE SOUTH FROM
THE GREAT LAKES...PASSING THROUGH THE OHIO VALLEY. THIS WILL
PROVIDE A CHANCE OF SHOWERS AND STORMS. WITH HIGH PRESSURE
BUILDING IN BEHIND THE FRONT...SLIGHTLY COOLER AND DRIER
CONDITIONS ARE EXPECTED FOR SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
WITH HIGH PRESSURE PROVIDING GENERALLY TRANQUIL (THOUGH WARM)
CONDITIONS ACROSS THE CWA TODAY...THE ONLY SIGNIFICANT FORECAST
QUESTION FOR TONIGHT IS THE POSSIBILITY OF A POP-UP SHOWER OR
THUNDERSTORM. CONVECTION IS DEVELOPING FAIRLY READILY ALONG AND
NORTH OF THE MICHIGAN BORDER...AND A FEW LIGHT ECHOES HAVE BEEN
OBSERVED JUST A COUPLE COUNTIES NORTH OF THE ILN CWA IN OHIO. LAPS
DATA SUGGESTS A FAIRLY UNIFORM FIELD OF AROUND 1500-2000 J/KG
CAPE (SURFACE BASED) ACROSS THE CWA...WITH SLIGHTLY MORE FURTHER
NORTH. WIND FLOW IS VERY LIGHT AND THERE IS VERY LITTLE IF ANY
FORCING...AND THERE IS ALSO A BIT OF INHIBITION (AS ALSO SUGGESTED
WITH A SMALL CAP ON RAP SOUNDINGS). THE FORECAST WILL CARRY A 10
PERCENT CHANCE OF A SHOWER OR STORM CWA-WIDE (10-POPS DO NOT SHOW
UP IN THE TEXT PRODUCTS) WITH A SLIGHT CHANCE IN THE FAR
NORTH...CLOSER TO THE SLIGHTLY HIGHER INSTABILITY AND A REALLY
SLIGHT AMOUNT OF 850MB CONVERGENCE IN THE TURNING FLOW AROUND THE
CENTER OF THE HIGH.
MIN TEMPS ARE NOT FAR FROM PERSISTENCE FROM LAST NIGHT...PERHAPS A
DEGREE OR TWO WARMER AS THE AIR MASS GRADUALLY ADJUSTS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
THE CENTER OF THE LARGE STACKED HIGH PRESSURE AREA WILL PARK
ITSELF OVER THE ILN CWA ON TUESDAY...REMAINING IN PLACE BEFORE IT
IS FINALLY SUPPRESSED ON FRIDAY. THE HEIGHTS ASSOCIATED WITH THIS
HIGH ARE POSSIBLY HISTORIC...BUT THE HEAT (THOUGH WELL ABOVE
NORMAL) IS NOT. 850MB TEMP ANOMALIES PEAK OUT AT ABOUT ONE
STANDARD DEVIATION ABOVE NORMAL OVER THE NEXT FEW DAYS.
HOWEVER...500MB HEIGHT ANOMALIES ARE EXPECTED TO BE TWO TO TWO AND
A HALF STANDARD DEVIATIONS ABOVE NORMAL. DESPITE THE STRENGTH OF
THE HIGH...MOIST CONDITIONS ARE ONE FACTOR KEEPING THE HEAT
DOWN...AND PROVIDING CUMULUS DEVELOPMENT AND A SLIM CHANCE FOR A
SHOWER OR STORM ON JUST ABOUT EVERY DAY THIS WEEK.
LOOKING AT PRECIPITATION CHANCES...WEAK TO ALMOST NON-EXISTENT
FORCING WILL KEEP THE THREAT FOR ORGANIZED STORMS AWAY UNTIL THE
WEEKEND. INSTABILITY WILL DRIVE ANYTHING THAT DEVELOPS OVER THE
NEXT FEW DAYS...AS CAPE VALUES CLIMB TO AROUND 2000 J/KG
(POTENTIALLY AS HIGH AS 3000 J/KG) TUESDAY AND WEDNESDAY. THE SREF
FAVORS CONVECTIVE POTENTIAL TUESDAY FROM LOWER MICHIGAN SSE TOWARD
LAKE ERIE...AND PERHAPS AS FAR SOUTH AS CENTRAL OHIO. A 20-POP
WILL BE USED IN THE NORTHEAST HALF OF THE CWA. WEDNESDAY...AS THE
CENTER OF THE HIGH SLOWLY DRIFTS WEST...CONDITIONS WILL BE A
LITTLE MORE FAVORABLE CWA-WIDE (WITH UP TO A 30 PERCENT CHANCE IN
THE FAR EASTERN CWA). THE EXPECTATION ON EACH DAY IS TYPICAL FOR
THIS SORT OF PATTERN...WITH SPARSE COVERAGE...SLOW
MOTIONS...DOWNPOURS AND GUSTY WINDS.
AS OF NOW...IT LOOKS LIKE THE HEAT (THROUGH WEDNESDAY) WILL HOLD
OFF JUST SHY OF ADVISORY CRITERIA. WITH 925MB TEMPS IN THE 22C-24C
RANGE...AND 850MB TEMPS IN THE 18C-19C RANGE...SURFACE TEMPS OF
AROUND 90 TO THE LOWER 90S ARE SUPPORTED. DEWPOINTS IN THE LOWER
70S (APPROACHING MID-70S BY WEDNESDAY) ARE EXPECTED...WHICH SHOULD
ALLOW FOR HEAT INDICES IN THE MIDDLE TO UPPER 90S. A FEW LOCATIONS
WILL PROBABLY BRIEFLY MAKE IT TO AROUND 100 FOR A HEAT INDEX...BUT
THIS IS NOT EXPECTED TO BE WIDESPREAD. THE LACK OF WIND MAY MAKE
CONDITIONS RATHER UNCOMFORTABLE...BUT MIXING POTENTIAL MAY ONLY BE
TO AROUND 850MB (THERE DOES NOT SEEM TO BE MUCH SUPPORT IN THE
FORECAST SOUNDINGS FOR ANYTHING HIGHER THAN THAT). MIN TEMPS WERE
RAISED A DEGREE OR TWO FOR TUESDAY AND WEDNESDAY NIGHT.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
COMPUTER MODELS ARE IN GOOD AGREEMENT THROUGH SATURDAY NECESSITATING
FEW CHANGES TO THE GOING FORECAST.
VERTICALLY STACKED HIGH PRESSURE STRETCHING FROM THE CENTRAL PLAINS
TO THE CENTRAL APPALACHIANS WILL CONTINUE TO DOMINATE ON THURSDAY.
A TROUGH MOVING ACROSS HUDSON BAY WILL ACT TO BEGIN SUPPRESSING THE
RIDGE...HOWEVER LOW LEVEL THERMAL PROFILES WILL CONTINUE TO SUPPORT
HIGH TEMPERATURES IN THE LOWER 90S AREA-WIDE. DEW POINTS IN THE
LOWER 70S WILL BRING ANOTHER DAY WITH HEAT INDICES NEAR OR POSSIBLY
EXCEEDING 100F. A STRAY THUNDERSTORM WILL BE POSSIBLE IN THIS
AIRMASS...ALTHOUGH THE LACK OF FORCING AND AT LEAST SOME CAPPING IN
PLACE SUGGEST MODEL QPF OUTPUT IS PROBABLY OVERDONE.
ON FRIDAY...UPPER HEIGHTS WILL BEGIN FALLING AS A VIGOROUS TROUGH
BEGINS DIVING THROUGH CENTRAL CANADA. A LITTLE HIGHER COVERAGE OF
THUNDERSTORMS MAY RESULT...AND WE WILL HAVE TO WATCH OUR NORTHERN
COUNTIES TO SEE WHAT EVOLVES FROM WHAT COULD BE AN ACTIVE WEATHER
DAY OVER THE GREAT LAKES. HIGH TEMPERATURES WILL STILL REACH THE 90S
FOR MANY...ALTHOUGH THE HEAT INDEX MAY BE A FEW DEGREES LOWER.
A COLD FRONT WILL DROP SOUTHWARD INTO THE AREA ON SATURDAY...LEADING
TO A FAIRLY HIGH CHANCES OF PRECIPITATION. OBVIOUSLY THIS FAR OUT
THE CONVECTIVE EVOLUTION REMAINS IN QUESTION THOUGH. SPC HAS
HIGHLIGHTED AREAS TO OUR NORTH (DAY 5/FRIDAY) AND EAST (DAY
6/SATURDAY) FOR SEVERE WEATHER...AND THIS COINCIDES WITH HIGHER WIND
SHEAR VALUES. HOWEVER...IT IS CERTAINLY POSSIBLE THE COLD FRONT
COULD BRING STRONG TO SEVERE STORMS TO OUR AREA AS WELL ON SATURDAY.
CONFIDENCE IS LOW ENOUGH TO LEAVE OUT OF THE HWO FOR NOW.
TEMPERATURES ON SATURDAY WILL BE TRICKY DEPENDING ON PRECIPITATION
TIMING.
EVEN THOUGH UPPER LEVEL HEIGHT PATTERNS ARE FAIRLY CONSISTENT...
THERE HAS BEEN DISAGREEMENT BETWEEN MODELS AND MODEL RUNS ON HOW FAR
SOUTH THE LOW LEVEL COLD FRONT WILL MAKE IT LATE IN THE WEEKEND.
GIVEN THE FRONT IS SOMEWHAT PARALLEL TO THE UPPER FLOW...FELT IT WAS
PRUDENT TO LINGER SOME POPS IN THE SOUTH FOR SUNDAY. RIGHT
NOW...HIGH PRESSURE TO THE NORTH APPEARS STRONG ENOUGH TO PROVIDE
DRY WEATHER FOR MONDAY. AFTER THE FRONT PASSES...TEMPERATURES WILL
RETURN CLOSER TO SEASONAL NORMALS (HIGHS IN LOWER TO MID 80S...LOWS
IN MID 60S).
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
VFR CONDITIONS WILL PREVAIL AS DAYTIME CU DEVELOPMENT RAPIDLY CUTS
OFF WITH THE COMING OF NIGHT. CLEAR SKIES AND LIGHT WINDS SHOULD
ALLOW FOR SOME PREDAWN OBSERVATIONS OF BR...GENERALLY LIGHT.
FAIR WX CU ARE EXPECTED AGAIN TOMORROW AS HIGH PRESSURE CONTINUES
TO GIVE A GENERAL DOWNWARD MOTION TO THE REGION.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...SNYDER
AVIATION...FRANKS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
147 PM EDT MON JUL 15 2013
.SYNOPSIS...
HIGH PRESSURE BRINGS ABOVE NORMAL TEMPERATURES THROUGH MUCH OF THE
WORK WEEK. A COLD FRONT SAGS SLOWLY SOUTHWARD TOWARD THE AREA NEAR
THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
UPDATE...
NO CHANGES TO THE LATEST FORECAST.
PREVIOUS DISCUSSION...
MODELS ARE SHOWING A BIT OF MID LEVEL MOISTURE MOVING INTO THE
REGION FROM THE SOUTHEAST TODAY. THIS SEEMS TO BE VALID BASED ON AN
AREA OF SHOWERS AND CLOUDS CURRENTLY IN SOUTHERN VA. BIG PROBLEM IS
THE EXTENT OF THE MOISTURE AND EXACTLY WHERE IT ENDS UP THIS
AFTERNOON. THIS IS WHERE THE MODELS DIFFER. RUC IS A BIT MORE
GENEROUS WITH THE MOISTURE...WHILE NAM KEEPS IT MORE
CONCENTRATED...AND GFS IS LEAST GENEROUS WITH IT. THIS FEATURE WAS
IN AN AREA WITHOUT SOUNDINGS AT 00Z...SO NOT SURPRISED BY MODEL
DIFFERENCES. HRRR ALSO SHOWS SOME SHOWERS IN THE WESTERN LOWLANDS
THIS AFTERNOON. DUE TO MODEL DIFFERENCES...WILL GO WITH A GENERIC
SLIGHT CHANCE.
MOS GUIDANCE FOR HIGHS TODAY SEEMS A BIT TOO WARM BASED ON THE AREA
STILL BEING FAIRLY WET. WILL UNCUT SLIGHTLY.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
UPR RIDGE AXIS WILL GRADUALLY SHIFT W OF THE AREA IN THE SHORT TERM
PERIODS. IT APPEARS THERE WILL BE SOME MOISTURE THAT ADVECTS IN FROM
NE AS IT DOES SO. AS SUCH...APPEARS MORE LIKE A TYPICAL DIRTY RIDGE
ARND THESE PARTS WHICH WILL ALLOW FOR DAILY AFTN/EVE THREAT FOR
SHRA/TSRA. WENT WITH COVERAGE WORDING IN WX GRIDS. THINK THESE
INITIALLY FIRE ACROSS THE MTNS...AIDED BY SOME TERRAIN INDUCED
CONVERGENCE. FEEL CAP HOLDS ON TUE W OF THE MTNS EXCEPT ACROSS N
LOWLANDS AND PORTIONS OF SE OH WHERE SOME SCHC POPS WERE MAINTAINED.
HAVE LOW CHC IN THE MTNS TUE AFTN/EVE. WED MDLS ARE TRYING TO
INDICATE AFTN MTN CONVECTION SLIDES OFF THE RIDGES INTO THE CENTRAL
LOWLANDS. STORM MOTIONS OFF MDLS SUPPORT THIS AND PERHAPS AIDED BY
COLD POOL PROPAGATION. NAM IN PARTICULAR ALLOWS THIS TO REACH INTO
COAL FIELDS AND KANAWHA VALLEY LATE WED AFTN. PREV FCST SEEMED TO
REFLECT THIS GENERAL THINKING AND ONLY SOME TWEAKS TO POPS TO ALLOW
W PENETRATION WAS NEEDED. HOLD IN CHC RANGE FOR NOW WITH THIS.
ELSEWHERE KEEP IT DRY. SAME GENERAL IDEA HOLDS FOR THU AS
WELL...WITH MTN CONVECTION PERHAPS SLIDING OFF THE HILLS INTO THE
CENTRAL LOWLANDS. THESE MAY BE SLOW TO DIE OFF AFTER SUNSET...HENCE
KEEP SOME SCHC IN UNTIL ARND 05Z. ANY STORMS THAT FIRE TUE-THU
COULD BE ON THE STRONG SIDE GIVEN CAPE BUILDUP EXPECTED. WIND WOULD
BE THE CONCERN AND HEAVY DOWNPOURS.
AS FOR TEMPS...FEEL MAV IS TOO WARM ACROSS THE LOWLANDS AND HEDGED
TOWARD COOLER MET. THIS RESULTS IN GENERALLY LWR 90S OUTSIDE OF THE
MTNS. DWPTS 70 TO 72F WILL PRODUCE HEAT INDICES IN THE MID TO UPR
90S TUE...PUSHING 100 WED AND THU OUTSIDE OF THE MTNS. A HEAT ADV
MAY BE NEEDED FOR WED AND THU. WILL PUT A MENTION IN HWO.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
UPPER RIDGE GRADUALLY FLATTENS THIS PERIOD...ALLOWING EASTERN
CANADIAN TROUGHING TO GRADUALLY SETTLE S INTO THE NERN CONUS. THIS
DRIVES A COLD FRONT SWD TOWARD THE AREA AS EARLY AS FRI NT...AND
GRADUALLY INCREASES THE CHANCE FOR SHOWERS AND THUNDERSTORMS GOING
INTO NEXT WEEKEND...ESPECIALLY LATE DAY. HAVE THE FRONT PUSHING ON
THROUGH SUN / SUN NT THOUGH THIS WILL DEPEND UPON HOW DEEP THE NE
CONUS TROUGH GETS.
BLENDED IN A LITTLE OF ADJMEXBC ON HIGHS FOR SLIGHTLY HIGHER VALUES
AND USED PREVIOUS/ADJMEXBC/WPC BLEND ON LOWS WITH LITTLE CHANGE OR
SLIGHTLY HIGHER VALUES THERE.
&&
.AVIATION /17Z MONDAY THROUGH FRIDAY/...
VFR THROUGH TODAY UNDER DOMINANT HIGH PRESSURE ALOFT. HIT THE
IFR/LIFR CONDITIONS A LITTLE HARDER TONIGHT BASED ON CONSENSUS
GUIDANCE FROM THE MET/MAV/LAMP. SOME CONFIDENCE LACKS HOWEVER DUE
TO VERY HIGH DEWPOINTS. EXPECT THE WIND TO GO CALM LATE THIS
EVENING AND TONIGHT.
MAY HAVE A SHOWER NEAR BKW TODAY...BUT NOT ENOUGH OF A CHANCE TO
WARRANT SHRA IN THE PREVAILING...OR VCSH FOR THAT MATTER.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY...
FORECAST CONFIDENCE: HIGH TODAY...MEDIUM TO HIGH TONIGHT.
ALTERNATE SCENARIOS: LOCATION OF THUNDERSTORMS THIS AFTERNOON
COULD VARY. NOT SOLD ON IFR CHANCES TONIGHT...AND LATE TEMPOS MAY
BE A BETTER BET.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z TUESDAY...
NO IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/RPY/30
NEAR TERM...RPY/26
SHORT TERM...30
LONG TERM...TRM
AVIATION...26
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1031 AM EDT MON JUL 15 2013
.SYNOPSIS...
HIGH PRESSURE BRINGS ABOVE NORMAL TEMPERATURES THROUGH MUCH OF THE
WORK WEEK. A COLD FRONT SAGS SLOWLY SOUTHWARD TOWARD THE AREA NEAR
THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
TWEAKED THE POPS...AND DI GAMBLE ON REMOVING SOME OF THE SLIGHT
CHANCE POPS TODAY ACROSS THE NORTHWESTERN ZONES. OTHERWISE...NO
MAJOR CHANGES. HEAT AND HUMIDITY WILL BE PLENTIFUL TODAY.
PREVIOUS DISCUSSION...
MODELS ARE SHOWING A BIT OF MID LEVEL MOISTURE MOVING INTO THE
REGION FROM THE SOUTHEAST TODAY. THIS SEEMS TO BE VALID BASED ON AN
AREA OF SHOWERS AND CLOUDS CURRENTLY IN SOUTHERN VA. BIG PROBLEM IS
THE EXTENT OF THE MOISTURE AND EXACTLY WHERE IT ENDS UP THIS
AFTERNOON. THIS IS WHERE THE MODELS DIFFER. RUC IS A BIT MORE
GENEROUS WITH THE MOISTURE...WHILE NAM KEEPS IT MORE
CONCENTRATED...AND GFS IS LEAST GENEROUS WITH IT. THIS FEATURE WAS
IN AN AREA WITHOUT SOUNDINGS AT 00Z...SO NOT SURPRISED BY MODEL
DIFFERENCES. HRRR ALSO SHOWS SOME SHOWERS IN THE WESTERN LOWLANDS
THIS AFTERNOON. DUE TO MODEL DIFFERENCES...WILL GO WITH A GENERIC
SLIGHT CHANCE.
MOS GUIDANCE FOR HIGHS TODAY SEEMS A BIT TOO WARM BASED ON THE AREA
STILL BEING FAIRLY WET. WILL UNCUT SLIGHTLY.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
UPR RIDGE AXIS WILL GRADUALLY SHIFT W OF THE AREA IN THE SHORT TERM
PERIODS. IT APPEARS THERE WILL BE SOME MOISTURE THAT ADVECTS IN FROM
NE AS IT DOES SO. AS SUCH...APPEARS MORE LIKE A TYPICAL DIRTY RIDGE
ARND THESE PARTS WHICH WILL ALLOW FOR DAILY AFTN/EVE THREAT FOR
SHRA/TSRA. WENT WITH COVERAGE WORDING IN WX GRIDS. THINK THESE
INITIALLY FIRE ACROSS THE MTNS...AIDED BY SOME TERRAIN INDUCED
CONVERGENCE. FEEL CAP HOLDS ON TUE W OF THE MTNS EXCEPT ACROSS N
LOWLANDS AND PORTIONS OF SE OH WHERE SOME SCHC POPS WERE MAINTAINED.
HAVE LOW CHC IN THE MTNS TUE AFTN/EVE. WED MDLS ARE TRYING TO
INDICATE AFTN MTN CONVECTION SLIDES OFF THE RIDGES INTO THE CENTRAL
LOWLANDS. STORM MOTIONS OFF MDLS SUPPORT THIS AND PERHAPS AIDED BY
COLD POOL PROPAGATION. NAM IN PARTICULAR ALLOWS THIS TO REACH INTO
COAL FIELDS AND KANAWHA VALLEY LATE WED AFTN. PREV FCST SEEMED TO
REFLECT THIS GENERAL THINKING AND ONLY SOME TWEAKS TO POPS TO ALLOW
W PENETRATION WAS NEEDED. HOLD IN CHC RANGE FOR NOW WITH THIS.
ELSEWHERE KEEP IT DRY. SAME GENERAL IDEA HOLDS FOR THU AS
WELL...WITH MTN CONVECTION PERHAPS SLIDING OFF THE HILLS INTO THE
CENTRAL LOWLANDS. THESE MAY BE SLOW TO DIE OFF AFTER SUNSET...HENCE
KEEP SOME SCHC IN UNTIL ARND 05Z. ANY STORMS THAT FIRE TUE-THU
COULD BE ON THE STRONG SIDE GIVEN CAPE BUILDUP EXPECTED. WIND WOULD
BE THE CONCERN AND HEAVY DOWNPOURS.
AS FOR TEMPS...FEEL MAV IS TOO WARM ACROSS THE LOWLANDS AND HEDGED
TOWARD COOLER MET. THIS RESULTS IN GENERALLY LWR 90S OUTSIDE OF THE
MTNS. DWPTS 70 TO 72F WILL PRODUCE HEAT INDICES IN THE MID TO UPR
90S TUE...PUSHING 100 WED AND THU OUTSIDE OF THE MTNS. A HEAT ADV
MAY BE NEEDED FOR WED AND THU. WILL PUT A MENTION IN HWO.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
UPPER RIDGE GRADUALLY FLATTENS THIS PERIOD...ALLOWING EASTERN
CANADIAN TROUGHING TO GRADUALLY SETTLE S INTO THE NERN CONUS. THIS
DRIVES A COLD FRONT SWD TOWARD THE AREA AS EARLY AS FRI NT...AND
GRADUALLY INCREASES THE CHANCE FOR SHOWERS AND THUNDERSTORMS GOING
INTO NEXT WEEKEND...ESPECIALLY LATE DAY. HAVE THE FRONT PUSHING ON
THROUGH SUN / SUN NT THOUGH THIS WILL DEPEND UPON HOW DEEP THE NE
CONUS TROUGH GETS.
BLENDED IN A LITTLE OF ADJMEXBC ON HIGHS FOR SLIGHTLY HIGHER VALUES
AND USED PREVIOUS/ADJMEXBC/WPC BLEND ON LOWS WITH LITTLE CHANGE OR
SLIGHTLY HIGHER VALUES THERE.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE AND LIGHT WINDS WILL DOMINATE THE WEATHER. AFTER SOME
EARLY MORNING VALLEY FOG BURNS OFF...VFR CONDITIONS WILL GENERALLY
PREVAIL...ALTHOUGH A COUPLE OF AFTERNOON THUNDERSTORMS CREATING
RESTRICTIONS CAN NOT BE RULED OUT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
ALTERNATE SCENARIOS THROUGH 06Z TUESDAY...LOCATION OF THUNDERSTORMS
THIS AFTERNOON COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H H M H H H H H H H H H
HTS CONSISTENCY H H M H H H H H H H H H
BKW CONSISTENCY H H M M H H H H H H H H
EKN CONSISTENCY H H M H H H H H H H H H
PKB CONSISTENCY H H M H H H H H H H H H
CKB CONSISTENCY H H M H H H H H H H H H
AFTER 12Z TUESDAY...
NO IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/RPY/30
NEAR TERM...RPY/26
SHORT TERM...30
LONG TERM...TRM
AVIATION...RPY
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
602 AM EDT MON JUL 15 2013
.SYNOPSIS...
HIGH PRESSURE BRINGS ABOVE NORMAL TEMPERATURES THROUGH MUCH OF THE
WORK WEEK. A COLD FRONT SAGS SLOWLY SOUTHWARD TOWARD THE AREA NEAR
THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
MODELS ARE SHOWING A BIT OF MID LEVEL MOISTURE MOVING INTO THE
REGION FROM THE SOUTHEAST TODAY. THIS SEEMS TO BE VALID BASED ON AN
AREA OF SHOWERS AND CLOUDS CURRENTLY IN SOUTHERN VA. BIG PROBLEM IS
THE EXTENT OF THE MOISTURE AND EXACTLY WHERE IT ENDS UP THIS
AFTERNOON. THIS IS WHERE THE MODELS DIFFER. RUC IS A BIT MORE
GENEROUS WITH THE MOISTURE...WHILE NAM KEEPS IT MORE
CONCENTRATED...AND GFS IS LEAST GENEROUS WITH IT. THIS FEATURE WAS
IN AN AREA WITHOUT SOUNDINGS AT 00Z...SO NOT SURPRISED BY MODEL
DIFFERENCES. HRRR ALSO SHOWS SOME SHOWERS IN THE WESTERN LOWLANDS
THIS AFTERNOON. DUE TO MODEL DIFFERENCES...WILL GO WITH A GENERIC
SLIGHT CHANCE.
MOS GUIDANCE FOR HIGHS TODAY SEEMS A BIT TOO WARM BASED ON THE AREA
STILL BEING FAIRLY WET. WILL UNCUT SLIGHTLY.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
UPR RIDGE AXIS WILL GRADUALLY SHIFT W OF THE AREA IN THE SHORT TERM
PERIODS. IT APPEARS THERE WILL BE SOME MOISTURE THAT ADVECTS IN FROM
NE AS IT DOES SO. AS SUCH...APPEARS MORE LIKE A TYPICAL DIRTY RIDGE
ARND THESE PARTS WHICH WILL ALLOW FOR DAILY AFTN/EVE THREAT FOR
SHRA/TSRA. WENT WITH COVERAGE WORDING IN WX GRIDS. THINK THESE
INITIALLY FIRE ACROSS THE MTNS...AIDED BY SOME TERRAIN INDUCED
CONVERGENCE. FEEL CAP HOLDS ON TUE W OF THE MTNS EXCEPT ACROSS N
LOWLANDS AND PORTIONS OF SE OH WHERE SOME SCHC POPS WERE MAINTAINED.
HAVE LOW CHC IN THE MTNS TUE AFTN/EVE. WED MDLS ARE TRYING TO
INDICATE AFTN MTN CONVECTION SLIDES OFF THE RIDGES INTO THE CENTRAL
LOWLANDS. STORM MOTIONS OFF MDLS SUPPORT THIS AND PERHAPS AIDED BY
COLD POOL PROPAGATION. NAM IN PARTICULAR ALLOWS THIS TO REACH INTO
COAL FIELDS AND KANAWHA VALLEY LATE WED AFTN. PREV FCST SEEMED TO
REFLECT THIS GENERAL THINKING AND ONLY SOME TWEAKS TO POPS TO ALLOW
W PENETRATION WAS NEEDED. HOLD IN CHC RANGE FOR NOW WITH THIS.
ELSEWHERE KEEP IT DRY. SAME GENERAL IDEA HOLDS FOR THU AS
WELL...WITH MTN CONVECTION PERHAPS SLIDING OFF THE HILLS INTO THE
CENTRAL LOWLANDS. THESE MAY BE SLOW TO DIE OFF AFTER SUNSET...HENCE
KEEP SOME SCHC IN UNTIL ARND 05Z. ANY STORMS THAT FIRE TUE-THU
COULD BE ON THE STRONG SIDE GIVEN CAPE BUILDUP EXPECTED. WIND WOULD
BE THE CONCERN AND HEAVY DOWNPOURS.
AS FOR TEMPS...FEEL MAV IS TOO WARM ACROSS THE LOWLANDS AND HEDGED
TOWARD COOLER MET. THIS RESULTS IN GENERALLY LWR 90S OUTSIDE OF THE
MTNS. DWPTS 70 TO 72F WILL PRODUCE HEAT INDICES IN THE MID TO UPR
90S TUE...PUSHING 100 WED AND THU OUTSIDE OF THE MTNS. A HEAT ADV
MAY BE NEEDED FOR WED AND THU. WILL PUT A MENTION IN HWO.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
UPPER RIDGE GRADUALLY FLATTENS THIS PERIOD...ALLOWING EASTERN
CANADIAN TROUGHING TO GRADUALLY SETTLE S INTO THE NERN CONUS. THIS
DRIVES A COLD FRONT SWD TOWARD THE AREA AS EARLY AS FRI NT...AND
GRADUALLY INCREASES THE CHANCE FOR SHOWERS AND THUNDERSTORMS GOING
INTO NEXT WEEKEND...ESPECIALLY LATE DAY. HAVE THE FRONT PUSHING ON
THROUGH SUN / SUN NT THOUGH THIS WILL DEPEND UPON HOW DEEP THE NE
CONUS TROUGH GETS.
BLENDED IN A LITTLE OF ADJMEXBC ON HIGHS FOR SLIGHTLY HIGHER VALUES
AND USED PREVIOUS/ADJMEXBC/WPC BLEND ON LOWS WITH LITTLE CHANGE OR
SLIGHTLY HIGHER VALUES THERE.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE AND LIGHT WINDS WILL DOMINATE THE WEATHER. AFTER SOME
EARLY MORNING VALLEY FOG BURNS OFF...VFR CONDITIONS WILL GENERALLY
PREVAIL...ALTHOUGH A COUPLE OF AFTERNOON THUNDERSTORMS CREATING
RESTRICTIONS CAN NOT BE RULED OUT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
ALTERNATE SCENARIOS THROUGH 06Z TUESDAY...LOCATION OF THUNDERSTORMS
THIS AFTERNOON COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 07/15/13
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EDT 1HRLY 04 05 06 07 08 09 10 11 12 13 14 15
CRW CONSISTENCY H H H H H H H H M H H H
HTS CONSISTENCY H H H H H H H H M H H H
BKW CONSISTENCY H H H H H H H H M M H H
EKN CONSISTENCY M M H H H H H H M H H H
PKB CONSISTENCY H H H H H H H H M H H H
CKB CONSISTENCY H H H H H H H H M H H H
AFTER 12Z TUESDAY...
NO IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/RPY/30
NEAR TERM...RPY
SHORT TERM...30
LONG TERM...TRM
AVIATION...RPY
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
244 AM EDT MON JUL 15 2013
.SYNOPSIS...
HIGH PRESSURE BRINGS ABOVE NORMAL TEMPERATURES THROUGH MUCH OF THE
WORK WEEK. A COLD FRONT SAGS SLOWLY SOUTHWARD TOWARD THE AREA NEAR
THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
MODELS ARE SHOWING A BIT OF MID LEVEL MOISTURE MOVING INTO THE
REGION FROM THE SOUTHEAST TODAY. THIS SEEMS TO BE VALID BASED ON AN
AREA OF SHOWERS AND CLOUDS CURRENTLY IN SOUTHERN VA. BIG PROBLEM IS
THE EXTENT OF THE MOISTURE AND EXACTLY WHERE IT ENDS UP THIS
AFTERNOON. THIS IS WHERE THE MODELS DIFFER. RUC IS A BIT MORE
GENEROUS WITH THE MOISTURE...WHILE NAM KEEPS IT MORE
CONCENTRATED...AND GFS IS LEAST GENEROUS WITH IT. THIS FEATURE WAS
IN AN AREA WITHOUT SOUNDINGS AT 00Z...SO NOT SURPRISED BY MODEL
DIFFERENCES. HRRR ALSO SHOWS SOME SHOWERS IN THE WESTERN LOWLANDS
THIS AFTERNOON. DUE TO MODEL DIFFERENCES...WILL GO WITH A GENERIC
SLIGHT CHANCE.
MOS GUIDANCE FOR HIGHS TODAY SEEMS A BIT TOO WARM BASED ON THE AREA
STILL BEING FAIRLY WET. WILL UNCUT SLIGHTLY.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
UPR RIDGE AXIS WILL GRADUALLY SHIFT W OF THE AREA IN THE SHORT TERM
PERIODS. IT APPEARS THERE WILL BE SOME MOISTURE THAT ADVECTS IN FROM
NE AS IT DOES SO. AS SUCH...APPEARS MORE LIKE A TYPICAL DIRTY RIDGE
ARND THESE PARTS WHICH WILL ALLOW FOR DAILY AFTN/EVE THREAT FOR
SHRA/TSRA. WENT WITH COVERAGE WORDING IN WX GRIDS. THINK THESE
INITIALLY FIRE ACROSS THE MTNS...AIDED BY SOME TERRAIN INDUCED
CONVERGENCE. FEEL CAP HOLDS ON TUE W OF THE MTNS EXCEPT ACROSS N
LOWLANDS AND PORTIONS OF SE OH WHERE SOME SCHC POPS WERE MAINTAINED.
HAVE LOW CHC IN THE MTNS TUE AFTN/EVE. WED MDLS ARE TRYING TO
INDICATE AFTN MTN CONVECTION SLIDES OFF THE RIDGES INTO THE CENTRAL
LOWLANDS. STORM MOTIONS OFF MDLS SUPPORT THIS AND PERHAPS AIDED BY
COLD POOL PROPAGATION. NAM IN PARTICULAR ALLOWS THIS TO REACH INTO
COAL FIELDS AND KANAWHA VALLEY LATE WED AFTN. PREV FCST SEEMED TO
REFLECT THIS GENERAL THINKING AND ONLY SOME TWEAKS TO POPS TO ALLOW
W PENETRATION WAS NEEDED. HOLD IN CHC RANGE FOR NOW WITH THIS.
ELSEWHERE KEEP IT DRY. SAME GENERAL IDEA HOLDS FOR THU AS
WELL...WITH MTN CONVECTION PERHAPS SLIDING OFF THE HILLS INTO THE
CENTRAL LOWLANDS. THESE MAY BE SLOW TO DIE OFF AFTER SUNSET...HENCE
KEEP SOME SCHC IN UNTIL ARND 05Z. ANY STORMS THAT FIRE TUE-THU
COULD BE ON THE STRONG SIDE GIVEN CAPE BUILDUP EXPECTED. WIND WOULD
BE THE CONCERN AND HEAVY DOWNPOURS.
AS FOR TEMPS...FEEL MAV IS TOO WARM ACROSS THE LOWLANDS AND HEDGED
TOWARD COOLER MET. THIS RESULTS IN GENERALLY LWR 90S OUTSIDE OF THE
MTNS. DWPTS 70 TO 72F WILL PRODUCE HEAT INDICES IN THE MID TO UPR
90S TUE...PUSHING 100 WED AND THU OUTSIDE OF THE MTNS. A HEAT ADV
MAY BE NEEDED FOR WED AND THU. WILL PUT A MENTION IN HWO.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
UPPER RIDGE GRADUALLY FLATTENS THIS PERIOD...ALLOWING EASTERN
CANADIAN TROUGHING TO GRADUALLY SETTLE S INTO THE NERN CONUS. THIS
DRIVES A COLD FRONT SWD TOWARD THE AREA AS EARLY AS FRI NT...AND
GRADUALLY INCREASES THE CHANCE FOR SHOWERS AND THUNDERSTORMS GOING
INTO NEXT WEEKEND...ESPECIALLY LATE DAY. HAVE THE FRONT PUSHING ON
THROUGH SUN / SUN NT THOUGH THIS WILL DEPEND UPON HOW DEEP THE NE
CONUS TROUGH GETS.
BLENDED IN A LITTLE OF ADJMEXBC ON HIGHS FOR SLIGHTLY HIGHER VALUES
AND USED PREVIOUS/ADJMEXBC/WPC BLEND ON LOWS WITH LITTLE CHANGE OR
SLIGHTLY HIGHER VALUES THERE.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL DOMINATE THE WEATHER. VFR CONDITIONS WILL
GENERALLY PREVAIL...ALTHOUGH CAN NOT RULE OUT SOME FOG IN MOUNTAIN
VALLEYS EARLY THIS MORNING...AND A COUPLE OF AFTERNOON THUNDERSTORMS
CREATING RESTRICTIONS.
FORECAST CONFIDENCE: HIGH
ALTERNATE SCENARIOS THROUGH 06Z TUESDAY...FOG LOCATION AND DENSITY
COULD VARY EARLY THIS MORNING. LOCATION OF THUNDERSTORMS THIS
AFTERNOON COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 07/15/13
UTC 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
EDT 1HRLY 22 23 00 01 02 03 04 05 06 07 08 09
CRW CONSISTENCY H H H H M M H H L L H H
HTS CONSISTENCY H H H H H H H H H M H H
BKW CONSISTENCY H M M M M M H H H M M H
EKN CONSISTENCY H H M M L L L L L L M H
PKB CONSISTENCY H H H H H H H H L L H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 06Z TUESDAY...
NO IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/RPY/30
NEAR TERM...RPY
SHORT TERM...30
LONG TERM...TRM
AVIATION...RPY
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
510 PM MDT TUE JUL 16 2013
.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 253 PM MDT TUE JUL 16 2013
AT 20Z A MODERATE AMOUNT OF CU DEVELOPMENT WAS TAKING
PLACE ALONG THE COOL FRONT BOUNDAY ACROSS EXTREME NORTHWESTERN SOUTH
DAKOTA THIS AFTERNOON. NO LIGHTNING YET, BUT THE HRRR 17Z UPDATE
SHOWED SOME MINIMAL RW- ACTIVITY BETWEEN 00Z AND 02Z JUST BARELY
ACROSS THE NORTHWEST CORNER OF THE STATE. THE SOUTHEASTERN EDGE OF
THE SOUTHEASTERN MONTANA LOW ST FIELD MENTIONED IN THE MORNING
UPDATE WAS DISSIPATING AND RETREATING NORTHWARD AS THE CYCLONIC
CIRCULATION AROUND THE WEAK SURFACE LOW BECAME MORE EASTERLY IN THIS
REGION.
ON A LARGER SCALE THE RIDGE EXTENDING WESTWARD INTO THE CENTRAL
PLAINS HAS PRETTY MUCH CUT OFF SIGNIFICANT MOIST RETURN FLOW TO THE
DAKOTAS THIS AFTERNOON IN THE MID AND UPPER LEVELS . DEWPOINTS ARE
DOWN 10 TO 12 DEGREES FROM YESTERDAY AFTERNOON AND MODEL SOUNDINGS
SHOW A VERY DRY STABLE AIR MASS.
FOR WEDNESDAY THE WEAK COOL FRONT IS FORECAST TO DRIFT SOUTHWARD
ACROSS NORTHWEST SOUTH DAKOTA. HOWEVER THE WESTERLYS AND ANY UPPER
LEVEL IMPULSES WILL REMAIN WELL NORTH OF THE FORECAST AREA AND
AIRMASS MOISTURE WILL CONTINUE TO BE MINIMAL. TEMPERATURES ARE
FORECAST TO BE A DEGREE OR SO WARMER THAN THIS AFTERNOON.
&&
.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 253 PM MDT TUE JUL 16 2013
VERY BROAD...FLAT LONG WAVE RIDGE OVER THE GREAT LAKES WILL
RETROGRESS TO THE PACIFIC COAST BY 12Z FRIDAY AND INCREASE SOMEWHAT
IN AMPLITUDE. GFS AND ECMWF BOTH SHOW THIS TREND. RESULT IS THAT
WEAK NORTHWESTERLY FLOW DEVELOPS OVER OUR CWA ON THURSDAY AND
FRIDAY ALLOWING A COLD FRONT TO MOVE ACROSS THE AREA. THIS WILL DROP
TEMPERATURES A BIT AND RESULT IN CHANCES FOR SCATTERED TSTM
DEVELOPMENT. UNCERTAINTY IN THE EXACT LOCATION OF THE RIDGE...THE
STRENGTH OF THE NORTHWESTERLY FLOW EAST OF IT...AND THE POSITION AND
TIMING OF SHORT WAVES EMBEDDED IN THIS FLOW ALL LEAD TO SUBSTANTIAL
UNCERTAINTY IN THE FORECAST FOR THE WEEKEND AND BEYOND. STAYED CLOSE
TO GUIDANCE WITH TEMPS AND PROBS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 509 PM MDT TUE JUL 16 2013
VFR CONDITIONS EXPECTED THROUGH WEDNESDAY AFTERNOON.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...CARPENTER
LONG TERM...BARBER
AVIATION...
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
832 PM CDT TUE JUL 16 2013
.UPDATE...
SEE EVENING UPDATE.
&&
.DISCUSSION...
00Z SOUNDINGS WERE VERY MOIST WITH PW VALUES 2.36 AT CRP AND 2.22
AT LCH. 850 MB MOISTURE WAS ALSO ROBUST WITH 850 TD BETWEEN 15 C
AND 19 C. A LARGE UPPER LOW WAS LOCATED OVER EAST CENTRAL NEW
MEXICO AND A SMALL SCALE WEAK UPPER LOW WAS NOTED NEAR MATAGORDA
BAY. FEEL THE WEAKER SYSTEM NEAR MATAGORDA BAY WAS ENHANCING THE
INFLOW AND HELPING TO FOCUS THE MOISTURE INTO A NARROW CHANNEL
FEEDING INTO SE TX. ALREADY BUMPED POPS UP IN THE COASTAL COUNTIES
FROM 00-06Z AND WILL CARRY CHANCE POPS FROM 06-12Z. THE RAP AND
HRR ARE ONCE AGGRESSIVE WITH MORNING SHRA/TSRA ALONG THE COAST.
WILL LEAVE HIGH END CHANCE POPS IN PLACE AND RE-EVALUATE ONCE 00Z
MODELS COME IN. 43
&&
.PREV DISCUSSION... /ISSUED 643 PM CDT TUE JUL 16 2013/
DISCUSSION...
SEE THE 00Z AVIATION DISCUSSION BELOW.
40
AVIATION...
A MOIST AND UNSTABLE AIRMASS WILL CONTINUE TO PROVIDE FOR
SCATTERED SHOWERS AT LEAST THROUGH THE FIRST HALF OF THE EVENING.
THE MODEL FORECAST SOUNDINGS SHOWED THE CHANCES FOR RAIN WILL
PERSIST THROUGH WEDNESDAY AFTERNOON. ALTHOUGH THE UPPER LOW OVER
THE SOUTHERN HIGH PLAINS WILL DRIFT WESTWARD...ENOUGH INSTABILITY
WILL LIKELY BE PRESENT FOR THUNDERSTORMS TO RETURN DURING THE MID
AND LATE AFTERNOON PERIOD.
OTHERWISE...AM EXPECTING VFR CONDITIONS WITH A SLIGHT CHANCE OF
MVFR FOG TONIGHT. IF PATCHY FOG DOES DEVELOP...IT SHOULD LIFT BY
THE MID MORNING.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 73 90 73 93 73 / 40 50 30 20 10
HOUSTON (IAH) 74 90 75 93 74 / 40 50 20 20 20
GALVESTON (GLS) 79 89 80 91 79 / 50 50 20 20 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 2 AM CDT WEDNESDAY FOR
THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA
SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...43
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1232 PM CDT MON JUL 15 2013
.DISCUSSION...
SEE AVIATION FOR 18Z TAF DISCUSSION.
&&
.AVIATION...
DIFFICULT FORECAST THIS AFTERNOON WITH REGARDS TO PRECIPITATION
COVERAGE AND TIMING. ACTIVITY HAS DIMINISHED ACROSS MUCH OF THE
REGION EXCEPT FOR AN AREA EAST OF GALVESTON BAY. THIS ACTIVITY
LOOKS TO REMAIN EAST OF THE MAIN TAF CORRIDOR FOR THE NEXT FEW
HOURS SO WILL MAINLY CARRY VCSH FOR AREA SITES. GIVEN THE LOW
CONFIDENCE IN EXACT TIMING HAVE HELD OFF ON ANY TEMPO GROUPS FOR
NOW. OTHERWISE ONLY MAJOR CHANGE TO THE PREVIOUS TAF WAS TO REMOVE
THE MENTION OF FOG FOR THE EARLY MORNING HOURS. EXPECTED OVERCAST
HIGH CLOUDS SHOULD ACT TO LIMIT THE THREAT FOR FOG TONIGHT. IF
BREAKS CAN DEVELOP IN THE HIGH COVER THEN FOG THREAT MAY BE
INCREASED. 38
&&
.PREV DISCUSSION... /ISSUED 1041 AM CDT MON JUL 15 2013/
UPDATE...
MORNING FORECAST UPDATE.
DISCUSSION...
AREA RADAR SHOWING A BROAD SHIELD OF PRECIP OVER C TX INTO THE
BRAZOS VALLEY. WIDELY SCATTERED SHOWERS AND A FEW THUNDERSTORMS
NOW OVER SE TX AND ALONG THE UPPER TX COAST SHOULD CONTINUE TO
MOVE INLAND. THERE SEEMS TO BE A TREND IN THE SHOWER AND
THUNDERSTORM ACTIVITY DECREASING IN COVERAGE. THIS LOOKS TO BE
SUPPORTED BY LATEST HRRR MODEL RUNS WHICH ALSO SHOW MORE ACTIVITY
DEVELOPING DURING THE EARLY AFTERNOON. THINK IF THIS LULL IN
ACTIVITY DOES OCCUR AND CLOUD COVER LESSENS...MAY GET MORE HEATING
TO INITIATE ANOTHER ROUND OF STORMS THIS AFTERNOON. AS SUCH THINK
HOLDING ONTO 50/60 POPS THIS AFTERNOON LOOKS ON TRACK. MAX TEMP
FORECAST WILL BE TRICKY AS MOST INLAND AREAS ARE STILL IN THE 70S
AND MAY BE HARD PRESSED TO REACH THE LOW/MID 80S. GETTING SOME LOW
80S ALONG THE COAST WHERE CLOUDS ARE LESS SO FOR NOW THINK MAX
TEMPS FORECAST IS OKAY BUT LARGELY DEPENDS ON CLOUD COVER. IT
CERTAINLY WILL NOT GET ANY WARMER. UPDATED FORECAST HAS BEEN SENT.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 72 90 72 90 72 / 40 40 30 40 20
HOUSTON (IAH) 74 90 74 90 74 / 40 50 30 40 20
GALVESTON (GLS) 79 88 79 88 79 / 40 50 30 40 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...39
AVIATION/MARINE...38
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1041 AM CDT MON JUL 15 2013
.UPDATE...
MORNING FORECAST UPDATE.
&&
.DISCUSSION...
AREA RADAR SHOWING A BROAD SHIELD OF PRECIP OVER C TX INTO THE
BRAZOS VALLEY. WIDELY SCATTERED SHOWERS AND A FEW THUNDERSTORMS
NOW OVER SE TX AND ALONG THE UPPER TX COAST SHOULD CONTINUE TO
MOVE INLAND. THERE SEEMS TO BE A TREND IN THE SHOWER AND
THUNDERSTORM ACTIVITY DECREASING IN COVERAGE. THIS LOOKS TO BE
SUPPORTED BY LATEST HRRR MODEL RUNS WHICH ALSO SHOW MORE ACTIVITY
DEVELOPING DURING THE EARLY AFTERNOON. THINK IF THIS LULL IN
ACTIVITY DOES OCCUR AND CLOUD COVER LESSENS...MAY GET MORE HEATING
TO INITIATE ANOTHER ROUND OF STORMS THIS AFTERNOON. AS SUCH THINK
HOLDING ONTO 50/60 POPS THIS AFTERNOON LOOKS ON TRACK. MAX TEMP
FORECAST WILL BE TRICKY AS MOST INLAND AREAS ARE STILL IN THE 70S
AND MAY BE HARD PRESSED TO REACH THE LOW/MID 80S. GETTING SOME LOW
80S ALONG THE COAST WHERE CLOUDS ARE LESS SO FOR NOW THINK MAX
TEMPS FORECAST IS OKAY BUT LARGELY DEPENDS ON CLOUD COVER. IT
CERTAINLY WILL NOT GET ANY WARMER. UPDATED FORECAST HAS BEEN SENT.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 85 72 90 72 90 / 80 40 40 30 40
HOUSTON (IAH) 87 74 90 74 90 / 60 40 50 30 40
GALVESTON (GLS) 88 79 88 79 88 / 50 40 50 30 40
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...39
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
710 AM CDT MON JUL 15 2013
.AVIATION...
MANY FACTORS COMING TOGETHER THIS MORNING IN SUPPORTING THIS
RECENTLY MORE-ACTIVE WET PATTERN. RADAR DETECTING PRIMARILY
SHOWERS MOVING NORTH AT 20 MPH TOWARDS A NORTHERN COUNTY -RA
SHIELD. SHOWERS WITH ISOLATED STORMS AFFECTING APPROXIMATELY 60
PERCENT OF THE FORECAST AREA. ALL TERMINALS IN THE FORECAST AREA
WILL BE AFFECTED BY NORTHERN-PASSING CONVECTION THROUGH THE
AFTERNOON. A WESTWARD DRIFTING UPPER LOW WITH AN ASSOCIATED
CENTRAL TEXAS SURFACE LOW/STATIONARY BOUNDARY PROVIDING THIS
DECENT INFLOW OF DEEPER GULF MOISTURE OVER AN UNCAPPED ENVIRONMENT.
VCSH OR VCTS...WITH PERIODS OF SHRA OR TSRA...THROUGH AT LEAST
MID-DAY...AN EVENING BREAK WITH LINGERING A MID-HIGH LEVEL BKN-OVC
DECK. ANOTHER WEAK DISTURBANCE MOVING ONSHORE THIS TIME TOMORROW
MORNING...WITH DECENT LAND-SEA SPEED CONVERGENCE...MAY INITIATE
RETURN (NEAR) COASTAL PRECIPITATION. 31
&&
.PREV DISCUSSION... /ISSUED 427 AM CDT MON JUL 15 2013/
DISCUSSION...
THE UPPER LEVEL LOW IS CURRENTLY LOCATED OVER CENTRAL OKLAHOMA
THIS MORNING AS HAS BEEN FORECASTED THE LAST COUPLE OF DAYS.
RAINFALL HAS BEEN FALLING THIS MORNING MAINLY FROM A BRENHAM TO
HUNTSVILLE TO CROCKETT LINE. CURRENT HRRR MODEL RUNS SHOW THE
PRECIP FIELD ASSOCIATED WITH THE UPPER LOW MOVING OFF TO THE WEST
AS THE DAY PROGESSES BUT ALSO HINTS AT REDEVELOPMENT AS MOISTURE
POOLS INTO SOUTHEAST TEXAS. THE EXTENT OF REDEVELOPMENT WILL BE
DEPENDENT ON THE POSITION OF THE UPPER LEVEL LOW. IF THE LOW IS
FAR ENOUGH WEST HIGH PWAT AIR WILL MOVE INTO SOUTHEAST TEXAS. IF
THE LOW IS SLIGHTLY SLOWER THE DEEPER MOISTURE WILL BE PUSHED MORE
INTO THE LAKE CHARLES AREA. GIVEN THAT REDEVELOPMENT IS ALREADY
OCCURRING SEEMS LIKE TODAY WE SHOULD SEE GOOD COVERAGE.
BY LATE MONDAY THE LOW WILL CONTINUE PUSHING TO THE WEST ALLOWING
FOR DEEP TROPICAL MOISTURE TO REMAIN IN PLACE. THIS IN COMBINATION
WITH NO REAL LARGE SCALE SUBSIDENCE IN PLACE WILL ALLOW FOR RAIN
CHANCES TO CONTINUE THROUGH THE WORK WEEK. BY THURSDAY THE GFS
HAS SLIGHTLY DRIER AIR (~1.6" PWAT) MOVING IN WHICH COULD HINDER
SOME PRECIP DEVELOPMENT. THE NAM ON THE OTHER HAND STILL HAS PWAT
VALUES AROUND 1.9" EARLY THURSDAY. THE GFS...EUROPEAN AND CANADIAN
ARE ALL SIMILAR WITH KEEPING THE UPPER LEVEL RIDGE OFF TOWARDS THE
NORTH FOR THE SECOND PART OF THIS WEEK. THE RIDGE IS THEN EXPECTED
TO ERODE NEXT WEEKEND. 23
MARINE...
AS WEAK DISTURBANCES/EASTERLY GULF WAVES COME ASHORE THROUGH
TUESDAY...MARINERS WILL EXPERIENCE PERIODS OF RAIN SHOWERS WITH
EMBEDDED STORMS. U.S. PLAINS HIGH PRESSURE IN RELATION TO LOWER
MEXICO PRESSURE WILL MAINTAIN A TIGHT ENOUGH COASTAL GRADIENT IN
SUPPORTING MODERATE ONSHORE WINDS THROUGH TUESDAY. THIS ENHANCED
SOUTHEASTERLY FETCH WILL DRAW UP A SOUTHWESTERN GULF SWELL LATE
TUESDAY INTO EARLY WEDNESDAY THAT WILL ULTIMATELY INCREASE SEA
HEIGHTS BY A COUPLE OF FEET (UPON TODAY`S HEIGHTS). MID TO LATE WEEK
EAST TO SOUTHEASTERLY FLOW WILL TAME...LOWERING SEA HEIGHTS. AS
BERMUDA-BASED SURFACE HIGH PRESSURE EXPANDS WESTWARD...THE ONSHORE
GRADIENT WILL TIGHTEN UP ONCE AGAIN OVER THE WEEKEND THAT EQUATES TO
STRENGTHENING SOUTHEASTERLY WINDS AND RETURN OFFSHORE SWELL. 31
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 85 72 90 72 90 / 80 40 40 30 40
HOUSTON (IAH) 87 74 90 74 90 / 60 40 50 30 40
GALVESTON (GLS) 88 79 88 79 88 / 50 40 50 30 40
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 9 AM CDT THIS MORNING
FOR THE FOLLOWING ZONES: MATAGORDA BAY...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...
WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20
NM.
&&
$$
DISCUSSION...23
AVIATION/MARINE...31
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
630 AM CDT MON JUL 15 2013
.DISCUSSION...UPDATED FOR 12Z AVIATION.
&&
.AVIATION...MAINLY VFR CONDITIONS CONTINUE THIS MORNING WITH
SCATTERED STRATO CU. A BRIEF MVFR CIG WILL BE POSSIBLE AT TAF
SITES FOR THE NEXT COUPLE OF HOURS. EVERYONE SHOULD INCREASE CLOUD
HEIGHTS THROUGH THE MORNING AND FOR THE AFTERNOON. THUNDERSTORM
CHANCES ARE GREATEST TODAY AROUND THE VCT TAF SITE. OTHER SITES
WILL ALSO HAVE A SLIGHT CHANCE OF SHOWERS AND STORMS...BUT TOO
SMALL TO INCLUDE IN TAFS AT THIS TIME. STRATO CU SHOULD RETURN
AGAIN TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 356 AM CDT MON JUL 15 2013/
SHORT TERM (TODAY THROUGH TUESDAY)...ONGOING MCS NORTH OF
FORECAST AREA SHOULD REMAIN MAINLY NORTH TODAY. UPPER LEVEL LOW
SPINNING CURRENTLY LOCATED OVER SOUTHERN OKLAHOMA...WILL CONTINUE
TO PULL BULK OF ENERGY RESPONSIBLE FOR CURRENT MCS TOWARD THE
EAST. HAVE SOME STREAMER ACTIVITY OVER NEARSHORE WATERS AND
COASTAL COUNTIES THIS MORNING...WELL REPRESENTED IN MESO MODEL
GUIDANCE...INDICATIVE OF INCREASING MOISTURE IN THE AREA.
SATELLITE DERIVED PW SAMPLES INDICATE WE ARE APPROACHING 2 INCH
PWAT ACROSS THE AREA. WILL SEE IF SOUNDING THIS AM CAN CONFIRM
THAT.
BEST MOISTURE TODAY STILL EXPECTED TO BE IN NORTHEAST PORTION OF
CWA...AND WOULD EXPECT BEST CHANCES FOR AFTERNOON CONVECTION TO BE
IN THAT AREA. WITH NO CAP TO SPEAK OF...AND MODERATE CAPE AND
LAPSE RATES THIS AFTERNOON HAVE KEPT A 50 POP WITH THUNDERSTORM
WORDING. DID INCREASE POPS OVER REMAINDER OF NORTHERN FORECAST AREA
AS SOME MESO GUIDANCE...PARTICULARLY THE HRRR INDICATES A BAND OF
SHOWERS DEVELOPING SEPARATE FROM CURRENT MCS AND DRIFTING INTO THE
AREA. THIS BAND IS SHOWING UP ON RADAR AT THIS TIME...BUT DPT
DEPRESSION AT THE SURFACE STILL TOO HIGH FOR RAIN AT THE SURFACE.
IF THIS AREA CAN CONTINUE TO POOL MOISTURE WOULD SEE SOME SHOWERS
NORTH...AND POSSIBLY WEST LATE THIS MORNING OR AFTERNOON.
ADDITIONALLY...GUIDANCE (GLOBAL AND MESO) IN PRETTY GOOD
AGREEMENT IN BRINGING AN MCS THROUGH CENTRAL TEXAS INTO THE RIO
GRANDE VALLEY TONIGHT. MOST GUIDANCE KEEPS THE BULK OF THE PRECIP
NORTH OF THE CWA...JUST SKIMMING LA SALLE AND WEBB COUNTIES. HAVE
INCREASE TO A 40 POP OUT THERE TONIGHT TO ACCOUNT FOR THE
PROXIMITY OF THIS POTENTIAL SYSTEM.
MOVING ON TO TUESDAY...GREATER MOISTURE EXPECTED TO PUSH EAST TO
WEST ACROSS THE AREA DURING THE DAY ON TUESDAY. KEPT PRETTY CLOSE
TO PREVIOUS FORECAST FOR TUESDAY...WITH 40 TO 50 POP ACROSS THE
AREA AS THE UPPER LOW CONTINUES TO RETROGRADE ACROSS NORTH TEXAS.
KEPT TEMPS PRETTY CLOSE TO PREVIOUS FORECAST...THINKING SLIGHTLY
COOLER THAN RECENT DAYS ATTRIBUTED TO INCREASING MOISTURE AND
CLOUD COVER. HIGHS IN THE LOWER TO MID 90S FOR MOST AREAS BOTH
TODAY AND TUESDAY...WITH LOWS TONIGHT IN THE 70S.
LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...THE INFLUENCE OF THE
UPPER LOW/TROUGH OVER THE CWA WL DIMINISH EARLY IN THE PERIOD
FOLLOWED BY A WEAKNESS IN THE 500MB HEIGHT FIELD OVER THE CWA/MSA
THURSDAY/FRIDAY WITH AN APPROXIMATELY E-W UPPER RIDGE AXIS ACRS THE
CONUS YET NORTH OF THE CWA/MSA (GFS/ECMWF/NAM DETERMINISTIC.) THIS
RIDGE AXIS IS PROGD TO MOVE SWD AND OVER THE CWA/MSA LATE
SATURDAY/SUNDAY (GFS/ECMWF DETERMINISTIC)...YET THE AXIS IS EXPECTED
TO BE WEAK. ALSO DRG THE PERIOD...PERSISTENT ONSHORE FLOW WITH
COPIOUS MSTR/HIGH PWAT VALUES EXPECTED DURING THE PERIOD (GFS
DETERMINISTIC.) THE COMBINATION OF DECREASING UPPER DYNAMICS/MSTR/
INSTABILITY SHOULD RESULT IN SCT CONVECTION WEDNESDAY. THE LACK OF
SIGNIFICANT UPPER FORCING THURSDAY/FRIDAY COMBINED WITH COPIOUS
MSTR SUGGEST DIURNAL CONVECTION MAINLY OVER LAND AND NOCTURNAL
CONVECTION MAINLY OVER THE COASTAL WATERS.
SATURDAY/SUNDAY...ALTHOUGH THE GFS MAINTAINS HIGH PWAT VALUES DRG
THIS PERIOD...ANTICIPATE THAT THE FOREGOING UPPER RIDGE...ALTHOUGH
WEAK...WL DECREASE THE LIKELIHOOD FOR CONVECTION. THUS ANTICIPATE
ONLY ISOLATED CONVECTION. WL FCST LOWER MAX TEMPS THAN GFS MOS
WEDNESDAY-FRIDAY OWING TO EXPECTATION OF EXTREMELY MOIST VERTICAL
COLUMN. ANTICIPATE WARMER MAX TEMPS SATURDAY/SUNDAY CONSIDERING
THE UPPER RIDGE (SLIGHTLY GREATER THICKNESS.)
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 96 77 93 77 88 / 30 30 50 20 40
VICTORIA 94 74 94 73 90 / 50 40 50 20 40
LAREDO 98 78 96 77 93 / 20 30 40 30 50
ALICE 96 75 94 74 90 / 20 30 50 20 40
ROCKPORT 92 78 90 78 87 / 30 40 50 20 40
COTULLA 97 76 96 74 91 / 40 40 50 30 50
KINGSVILLE 97 76 94 76 90 / 20 30 50 20 40
NAVY CORPUS 92 79 90 78 86 / 30 30 50 20 40
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
PZ/83...AVIATION
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
427 AM CDT MON JUL 15 2013
.DISCUSSION...
THE UPPER LEVEL LOW IS CURRENTLY LOCATED OVER CENTRAL OKLAHOMA
THIS MORNING AS HAS BEEN FORECASTED THE LAST COUPLE OF DAYS.
RAINFALL HAS BEEN FALLING THIS MORNING MAINLY FROM A BRENHAM TO
HUNTSVILLE TO CROCKETT LINE. CURRENT HRRR MODEL RUNS SHOW THE
PRECIP FIELD ASSOCIATED WITH THE UPPER LOW MOVING OFF TO THE WEST
AS THE DAY PROGESSES BUT ALSO HINTS AT REDEVELOPMENT AS MOISTURE
POOLS INTO SOUTHEAST TEXAS. THE EXTENT OF REDEVELOPMENT WILL BE
DEPENDENT ON THE POSITION OF THE UPPER LEVEL LOW. IF THE LOW IS
FAR ENOUGH WEST HIGH PWAT AIR WILL MOVE INTO SOUTHEAST TEXAS. IF
THE LOW IS SLIGHTLY SLOWER THE DEEPER MOISTURE WILL BE PUSHED MORE
INTO THE LAKE CHARLES AREA. GIVEN THAT REDEVELOPMENT IS ALREADY
OCCURRING SEEMS LIKE TODAY WE SHOULD SEE GOOD COVERAGE.
BY LATE MONDAY THE LOW WILL CONTINUE PUSHING TO THE WEST ALLOWING
FOR DEEP TROPICAL MOISTURE TO REMAIN IN PLACE. THIS IN COMBINATION
WITH NO REAL LARGE SCALE SUBSIDENCE IN PLACE WILL ALLOW FOR RAIN
CHANCES TO CONTINUE THROUGH THE WORK WEEK. BY THURSDAY THE GFS
HAS SLIGHTLY DRIER AIR (~1.6" PWAT) MOVING IN WHICH COULD HINDER
SOME PRECIP DEVELOPMENT. THE NAM ON THE OTHER HAND STILL HAS PWAT
VALUES AROUND 1.9" EARLY THURSDAY. THE GFS...EUROPEAN AND CANADIAN
ARE ALL SIMILAR WITH KEEPING THE UPPER LEVEL RIDGE OFF TOWARDS THE
NORTH FOR THE SECOND PART OF THIS WEEK. THE RIDGE IS THEN EXPECTED
TO ERODE NEXT WEEKEND. 23
&&
.MARINE...
AS WEAK DISTURBANCES/EASTERLY GULF WAVES COME ASHORE THROUGH
TUESDAY...MARINERS WILL EXPERIENCE PERIODS OF RAIN SHOWERS WITH
EMBEDDED STORMS. U.S. PLAINS HIGH PRESSURE IN RELATION TO LOWER
MEXICO PRESSURE WILL MAINTAIN A TIGHT ENOUGH COASTAL GRADIENT IN
SUPPORTING MODERATE ONSHORE WINDS THROUGH TUESDAY. THIS ENHANCED
SOUTHEASTERLY FETCH WILL DRAW UP A SOUTHWESTERN GULF SWELL LATE
TUESDAY INTO EARLY WEDNESDAY THAT WILL ULTIMATELY INCREASE SEA
HEIGHTS BY A COUPLE OF FEET (UPON TODAY`S HEIGHTS). MID TO LATE WEEK
EAST TO SOUTHEASTERLY FLOW WILL TAME...LOWERING SEA HEIGHTS. AS
BERMUDA-BASED SURFACE HIGH PRESSURE EXPANDS WESTWARD...THE ONSHORE
GRADIENT WILL TIGHTEN UP ONCE AGAIN OVER THE WEEKEND THAT EQUATES TO
STRENGTHENING SOUTHEASTERLY WINDS AND RETURN OFFSHORE SWELL. 31
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 85 72 90 72 90 / 80 40 40 30 40
HOUSTON (IAH) 87 74 90 74 90 / 60 40 50 30 40
GALVESTON (GLS) 88 79 88 79 88 / 60 40 50 30 40
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 9 AM CDT THIS MORNING
FOR THE FOLLOWING ZONES: MATAGORDA BAY...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...
WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20
NM.
&&
$$
DISCUSSION...23
AVIATION/MARINE...31
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
356 AM CDT MON JUL 15 2013
.SHORT TERM (TODAY THROUGH TUESDAY)...ONGOING MCS NORTH OF
FORECAST AREA SHOULD REMAIN MAINLY NORTH TODAY. UPPER LEVEL LOW
SPINNING CURRENTLY LOCATED OVER SOUTHERN OKLAHOMA...WILL CONTINUE
TO PULL BULK OF ENERGY RESPONSIBLE FOR CURRENT MCS TOWARD THE
EAST. HAVE SOME STREAMER ACTIVITY OVER NEARSHORE WATERS AND
COASTAL COUNTIES THIS MORNING...WELL REPRESENTED IN MESO MODEL
GUIDANCE...INDICATIVE OF INCREASING MOISTURE IN THE AREA.
SATELLITE DERIVED PW SAMPLES INDICATE WE ARE APPROACHING 2 INCH
PWAT ACROSS THE AREA. WILL SEE IF SOUNDING THIS AM CAN CONFIRM
THAT.
BEST MOISTURE TODAY STILL EXPECTED TO BE IN NORTHEAST PORTION OF
CWA...AND WOULD EXPECT BEST CHANCES FOR AFTERNOON CONVECTION TO BE
IN THAT AREA. WITH NO CAP TO SPEAK OF...AND MODERATE CAPE AND
LAPSE RATES THIS AFTERNOON HAVE KEPT A 50 POP WITH THUNDERSTORM
WORDING. DID INCREASE POPS OVER REMAINDER OF NORTHERN FORECAST AREA
AS SOME MESO GUIDANCE...PARTICULARLY THE HRRR INDICATES A BAND OF
SHOWERS DEVELOPING SEPARATE FROM CURRENT MCS AND DRIFTING INTO THE
AREA. THIS BAND IS SHOWING UP ON RADAR AT THIS TIME...BUT DPT
DEPRESSION AT THE SURFACE STILL TOO HIGH FOR RAIN AT THE SURFACE.
IF THIS AREA CAN CONTINUE TO POOL MOISTURE WOULD SEE SOME SHOWERS
NORTH...AND POSSIBLY WEST LATE THIS MORNING OR AFTERNOON.
ADDITIONALLY...GUIDANCE (GLOBAL AND MESO) IN PRETTY GOOD
AGREEMENT IN BRINGING AN MCS THROUGH CENTRAL TEXAS INTO THE RIO
GRANDE VALLEY TONIGHT. MOST GUIDANCE KEEPS THE BULK OF THE PRECIP
NORTH OF THE CWA...JUST SKIMMING LA SALLE AND WEBB COUNTIES. HAVE
INCREASE TO A 40 POP OUT THERE TONIGHT TO ACCOUNT FOR THE
PROXIMITY OF THIS POTENTIAL SYSTEM.
MOVING ON TO TUESDAY...GREATER MOISTURE EXPECTED TO PUSH EAST TO
WEST ACROSS THE AREA DURING THE DAY ON TUESDAY. KEPT PRETTY CLOSE
TO PREVIOUS FORECAST FOR TUESDAY...WITH 40 TO 50 POP ACROSS THE
AREA AS THE UPPER LOW CONTINUES TO RETROGRADE ACROSS NORTH TEXAS.
KEPT TEMPS PRETTY CLOSE TO PREVIOUS FORECAST...THINKING SLIGHTLY
COOLER THAN RECENT DAYS ATTRIBUTED TO INCREASING MOISTURE AND
CLOUD COVER. HIGHS IN THE LOWER TO MID 90S FOR MOST AREAS BOTH
TODAY AND TUESDAY...WITH LOWS TONIGHT IN THE 70S.
&&
.LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...THE INFLUENCE OF THE
UPPER LOW/TROUGH OVER THE CWA WL DIMINISH EARLY IN THE PERIOD
FOLLOWED BY A WEAKNESS IN THE 500MB HEIGHT FIELD OVER THE CWA/MSA
THURSDAY/FRIDAY WITH AN APPROXIMATELY E-W UPPER RIDGE AXIS ACRS THE
CONUS YET NORTH OF THE CWA/MSA (GFS/ECMWF/NAM DETERMINISTIC.) THIS
RIDGE AXIS IS PROGD TO MOVE SWD AND OVER THE CWA/MSA LATE
SATURDAY/SUNDAY (GFS/ECMWF DETERMINISTIC)...YET THE AXIS IS EXPECTED
TO BE WEAK. ALSO DRG THE PERIOD...PERSISTENT ONSHORE FLOW WITH
COPIOUS MSTR/HIGH PWAT VALUES EXPECTED DURING THE PERIOD (GFS
DETERMINISTIC.) THE COMBINATION OF DECREASING UPPER DYNAMICS/MSTR/
INSTABILITY SHOULD RESULT IN SCT CONVECTION WEDNESDAY. THE LACK OF
SIGNIFICANT UPPER FORCING THURSDAY/FRIDAY COMBINED WITH COPIOUS
MSTR SUGGEST DIURNAL CONVECTION MAINLY OVER LAND AND NOCTURNAL
CONVECTION MAINLY OVER THE COASTAL WATERS.
SATURDAY/SUNDAY...ALTHOUGH THE GFS MAINTAINS HIGH PWAT VALUES DRG
THIS PERIOD...ANTICIPATE THAT THE FOREGOING UPPER RIDGE...ALTHOUGH
WEAK...WL DECREASE THE LIKELIHOOD FOR CONVECTION. THUS ANTICIPATE
ONLY ISOLATED CONVECTION. WL FCST LOWER MAX TEMPS THAN GFS MOS
WEDNESDAY-FRIDAY OWING TO EXPECTATION OF EXTREMELY MOIST VERTICAL
COLUMN. ANTICIPATE WARMER MAX TEMPS SATURDAY/SUNDAY CONSIDERING
THE UPPER RIDGE (SLIGHTLY GREATER THICKNESS.)
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 96 77 93 77 88 / 30 30 50 20 40
VICTORIA 94 74 94 73 90 / 50 40 50 20 40
LAREDO 98 78 96 77 93 / 20 30 40 30 50
ALICE 96 75 94 74 90 / 20 30 50 20 40
ROCKPORT 92 78 90 78 87 / 30 40 50 20 40
COTULLA 97 76 96 74 91 / 40 40 50 30 50
KINGSVILLE 97 76 94 76 90 / 20 30 50 20 40
NAVY CORPUS 92 79 90 78 86 / 30 30 50 20 40
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
PZ/83...SHORT TERM
WC/87...LONG TERM
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1252 AM CDT MON JUL 15 2013
.DISCUSSION...UPDATED FOR 06Z TAFS.
&&
.AVIATION...SCATTERED STRATO CU ACROSS THE AREA TONIGHT...COULD GO
BROKEN TEMPORARILY...WITH THE MAIN RISK BEING CRP TAF SITE.
TOMORROW...AS UPPER LOW TRACKS CLOSER TO THE AREA COULD GET SOME
SHOWER ACTIVITY AROUND THE VCT...SMALLER CHANCES AT OTHER SITES.
ALSO SOME CONCERN THAT VCT WILL HAVE PERIODS OF MFVR CIGS DURING
THE DAY...BUT FOR NOW HAVE CIG HEIGHT AT VFR LEVELS.
&&
.PREV DISCUSSION... /ISSUED 912 PM CDT SUN JUL 14 2013/
DISCUSSION...LOWERED (BUT DID NOT REMOVE) RAIN OVER THE NORTHEAST
FOR TONIGHT. ALTHOUGH CONVECTION IS ON THE WANE...SURFACE
CONVERGENCE TONIGHT NEAR THE COAST AND LACK OF CIN COULD RESULT IN
OVERNIGHT SHOWERS/THUNDER OVER THE NORTHEAST ERGO THE POPS IN THAT
AREA. INCREASED CLOUD COVER AND ADJUSTED OTHER FIRST PERIOD
PARAMETERS WHERE NEEDED. DID NOT MESS WITH OVERNIGHT LOWS. REST OF
FORECAST FINE FOR NOW.
PREV DISCUSSION... /ISSUED 631 PM CDT SUN JUL 14 2013/
DISCUSSION...SEE AVIATION DISCUSSION BELOW FOR THE 00Z TAFS.
AVIATION...AS OF 625 PM CDT...RADAR WAS INDICATING SHRA/TSRA`S N
OF THE CWA MOVG S. THERE IS SOME UNCERTAINTY AS TO HOW FAR S THIS
ACTIVITY WILL MOVE DUE TO THE AFFOREMENTIONED REASONS IN THE
PREVIOUS DISCUSSION BELOW. GIVEN THE PROXIMITY OF THE CONVECTION
TO VCT...DECIDED TO INCLUDE A TEMPO WITH TSRA UNTIL 02Z.
OTHERWISE...CIGS/VSBYS ARE EXPECTED TO BE AT VFR LEVELS THROUGH
MUCH OF THE TAF PERIOD. INCREASING MOISTURE THROUGH MON MAY LEAD
TO ISOLD/SCT SHRA`S ALONG THE SEA BREEZE AND ADDITIONAL CONVECTION
POSSIBLY MOVING INTO THE NRN CWA FROM THE HILL COUNTRY. FOR NOW
WENT WITH VCSH FOR THE LATTER PART OF THE VCT TAF WHERE CHCS ARE
BEST.
PREV DISCUSSION... /ISSUED 619 PM CDT SUN JUL 14 2013/
DISCUSSION...LAPS DATA AND HRRR MODEL DATA STILL SUGGESTING THAT
CONVECTION ALONG THE BOUNDARY SHOULD WEAKEN AND DISSIPATE BEFORE
IT GETS MUCH FARTHER EAST. STILL...ACTIVITY STILL GETTING A BIT
TOO CLOSE TO VICTORIA AREA NOT TO INCREASE POPS AT LEAST INTO THE
CHANCE CATEGORY. LAPS NOW SHOWING A BIT OF A CAP STARTING TO FORM
JUST SOUTH OF VICTORIA...WE WILL SEE IF THIS IS ENOUGH. IN ANY
CASE...DECIDED TO UPDATE FORECAST FOR AFOREMENTIONED ACTIVITY.
WILL MONITOR FOR FURTHER UPDATES AS NEEDED. PRODUCTS ARE OUT.
PREV DISCUSSION... /ISSUED 328 PM CDT SUN JUL 14 2013/
SHORT TERM (TONIGHT THROUGH MONDAY NIGHT)...MAIN AREA OF SHOWERS
AND THUNDERSTORMS IS CURRENTLY LOCATED OVER EAST CENTRAL TEXAS.
ADDITIONAL CONVECTION HAS DEVELOPED ALONG SOUTHWARD MOVING
BOUNDARY OVER SOUTH CENTRAL TEXAS...AND THIS ACTIVITY MAY MOVE
INTO THE REGION LATER THIS AFTERNOON/EVENING. LATEST LAPS DATA
SHOWS CAPE VALUES BETWEEN 1500 AND 2000 J/KG OVER THE EASTERN
PARTS OF THE CWA. IF CONVECTION CAN CONTINUE TO MOVE SOUTHWARD
INTO THE AREA...THEN A FEW STRONGER STORMS WITH LOCALLY HEAVY
RAINFALL COULD BE POSSIBLE LATE THIS AFTERNOON/EARLY EVENING
MAINLY OVER THE NORTHERN AND NORTHEAST ZONES. CURRENT FORECAST HAS
THIS ACCOUNTED FOR THE SLIGHT END POPS OVER THESE LOCATIONS.
MOISTURE AND CLOUD COVER INCREASES FURTHER TONIGHT AND ALONG WITH
CONTINUED SOUTHERLY WINDS SHOULD LEAD TO A WARM NIGHT ACROSS SOUTH
TEXAS. OVERNIGHT LOWS WILL BE IN THE MID/UPPER 70S AND INCREASED
TEMPS OVER MAVMOS VALUES. UPPER LOW WILL CONTINUE TO TRACK
WESTWARD ACROSS OKLAHOMA AND NORTH TEXAS ON MONDAY. WEAKNESS IN
FLOW ALOFT WITH LITTLE TO NO CAPPING SHOULD ONCE AGAIN PROVE
SUFFICIENT FOR SHOWER AND THUNDERSTORM DEVELOPMENT. HIGHEST
CHANCES WILL BE OVER THE VICTORIA CROSSROADS WHERE BETTER MOISTURE
WILL RESIDE. HIGHS ON MONDAY WILL BE SET BACK A FEW DEGREES
(THOUGHT STILL IN THE 90S) DUE TO CLOUD COVER AND RAIN CHANCES...
AND HAVE EITHER GONE WITH OR UNDERCUT GUIDANCE BY A FEW DEGREES.
LONG TERM (TUESDAY THROUGH SUNDAY)...MAIN FORECAST CHALLENGE FOR
TODAY CONTINUES TO BE POP PLACEMENT/COVERAGE THROUGH THE WORK WEEK.
ALL GUIDANCE SUITES CONTINUE TO ADVERTISE POTENTIALLY WET WEEK FOR
SOUTH TEXAS AS DEEP TROPICAL MOISTURE IS PROG TO EXIST FROM TUESDAY
THROUGH THURS/FRI. THE INTERACTION BETWEEN THE DEEP MOISTURE...
PERIODIC POS VORT ADVECTION...WEAK ELONGATED TUTT SIGNATURE...WEAK
SURFACE TROUGHING...AND ANY MESOSCALE BOUNDARIES /OUTFLOW
BOUNDARIES AND SEABREEZE...SHOULD ALL LEAD TO A SCATTERING OF
SHOWERS AND THUNDERSTORMS FROM TUESDAY THROUGH THURSDAY. TUESDAY/S
PRECIP CHANCES SHOULD BE BASED ON PIECE OF H5 VORTICITY DRIFTING
OUT OF OLD MEX AND INTERACTING WITH UNSTABLE AIRMASS AND DEEP
MOISTURE THAT SHOULD ALREADY BE IN PLACE. WED AND THURSDAY/S
CHANCES ARE BASED ON WEAK INVERTED SURFACE TROUGH AND WEAK TUTT
STRETCHING INTO THE REGION...WHICH ONCE AGAIN SHOULD LEAD TO A
SCATTERING OF SHOWERS AND THUNDERSTORMS. GIVEN DEEP MOISTURE OF
AOA 2 INCHES...LOCALLY HEAVY RAINFALL WILL BE POSSIBLE THIS
WEEK...BUT AT THIS TIME WIDESPREAD FLOODING RAINS ARE NOT
EXPECTED. SLIGHT CHANCES OF PRECIP MAY CONTINUE FRIDAY AND INTO
NEXT WEEKEND...BUT WILL BE DEPENDENT ON HOW MUCH DRIER AIR CAN
WORK ITS WAY INTO THE AREA AS H85 HIGH SHIFTS FARTHER EAST FROM
THE MIDWEST TO THE SE COAST. MAX TEMPS THIS WEEK WILL BE STRONGLY
DEPENDENT ON COVERAGE OF PRECIP AND CLOUD COVER...FOR NOW HAVE
GONE A LITTLE ON THE WARM SIDE GIVEN THAT WE SHOULD NOT HAVE
WIDESPREAD CLOUD COVER EVERY DAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 94 77 94 77 95 / 30 30 50 30 50
VICTORIA 91 75 93 74 94 / 50 30 50 30 50
LAREDO 98 78 97 78 97 / 20 30 50 30 50
ALICE 96 76 94 75 96 / 20 30 50 30 50
ROCKPORT 88 79 92 77 92 / 30 30 50 40 50
COTULLA 96 76 97 75 97 / 20 30 50 30 50
KINGSVILLE 96 77 94 77 95 / 20 30 50 30 50
NAVY CORPUS 88 80 91 78 91 / 30 30 50 40 50
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
PZ/83...AVIATION
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1117 PM CDT SUN JUL 14 2013
.AVIATION...
ANY SHOWERS AND THUNDERSTORMS SHOULD BE SOUTHWEST OF THE TAF SITES AT
THE START OF THIS FORECAST. STILL BELIEVE THAT CIGS WILL FALL INTO
THE MVFR RANGE AT ALL SITES AFTER ABOUT 10Z. THE CIGS SHOULD THEN
LIFT INTO THE VFR RANGE BY LATE MORNING ON MONDAY. SOME SHOWERS AND
THUNDERSTORMS MAY BE FOUND ACROSS THE AREA MONDAY AFTERNOON INTO
MONDAY EVENING...BUT CONFIDENCE IS NOT HIGH ENOUGH THAT ANY ONE THESE
WILL AFFECT A TAF SITE...SO WILL LEAVE THE MENTION OF THEM OUT OF
THIS FORECAST. SOUTHEAST WINDS WILL TURN MORE EASTERLY DURING THE DAY
ON MONDAY. WIND SPEEDS SHOULD GENERALLY BE IN THE 10 TO 15 KNOT RANGE.
&&
.PREV DISCUSSION... /ISSUED 605 PM CDT SUN JUL 14 2013/
AVIATION...
ANOTHER BAND OF SHOWERS AND ISOLATED THUNDERSTORMS MAY DEVELOP NORTH
OF THE CWA AND TRANSLATE SOUTHWARD THIS EVENING. HAVE GONE AHEAD AND
ADDED A TEMPO GROUP AT ALL TAF SITES FOR -SHRA AND MVFR CIGS THIS
EVENING FOR A 4 HOUR TIME PERIOD. AFTER THE SHOWERS PASS...MVFR CIGS
WILL PREVAIL AT GUY AND DHT WITH IFR CIGS AT AMA. THE LOW CLOUDS ARE
EXPECTED TO DECREASE BY LATE MORNING ON MONDAY AND A VFR CLOUD LAYER
WILL PREVAIL FOR THE REST OF THE FORECAST. GUSTY SOUTHEAST WINDS WILL
DECREASE LATE THIS EVENING AND THEN THEY WILL BECOME MORE EASTERLY
AFTER 06Z. MORE SHOWERS AND THUNDERSTORMS MAY DEVELOP MONDAY
AFTERNOON WITH AMA BEING THE MOST FAVORED...BUT CONFIDENCE IS NOT
HIGH ENOUGH TO ADD TO THE TAF AT THIS POINT.
PREV DISCUSSION... /ISSUED 310 PM CDT SUN JUL 14 2013/
SHORT TERM...
COLD FRONT NOW THROUGH ALL OF THE PANHANDLES AS OF 3 PM CDT. IN ITS
WAKE...DECREASING TEMPERATURES AND SCATTERED SHOWERS ACROSS.
FOR TONIGHT...SHOULD SEE COVERAGE OF SHOWERS INCREASE A BIT AND HIGH
RESOLUTION MODELS LIKE THE HRRR AND TTU WRF CONTINUE TO SHOW THIS
TREND. WITH VERY LIMITED INSTABILITY...EXPECT THE ACTIVITY TO
PRIMARILY BE LIGHT RAIN SHOWERS...THOUGH AN ISOLATED THUNDERSTORM IS
POSSIBLE.
TOMORROW THROUGH TUESDAY...EXPECT A LULL IN THE PRECIP STARTING SOMETIME
EARLY TOMORROW MORNING AND CONTINUING THROUGH MID DAY AS THE REGION
WILL BE ON THE DRIER NW SIDE OF THE LOW. AS THE LOW CONTINUES TO
SLIDE EAST TOMORROW NIGHT...EXPECT PRECIP TO SPREAD FROM EAST TO WEST
ONCE AGAIN...AS BETTER LIFT IS EXPECTED ON THE EASTERN SIDE OF THE
UPPER LEVEL LOW. STILL SOME QUESTION AS TO HOW FAR NORTH MOISTURE
WILL ADVECT AND IF CONVECTION FURTHER DOWN STATE WILL ROB SOME OF THE
MOISTURE ADVECTION FOR THE PANHANDLES. STILL THINK THE BEST CHANCE
WILL BE TOMORROW NIGHT...WITH CHANCES DECREASING AFTER THAT.
LONG TERM...
WEDNESDAY THROUGH THURSDAY...COULD STILL SEE SOME LINGERING
CONVECTION EVEN THOUGH THE LOW WILL BE PROPAGATING OVER NORTHERN
MEXICO BY THIS POINT...THE RESULTING MID AND UPPER LEVEL
SOUTHEASTERLY FLOW SHOULD RESULT IN A MOIST FETCH FROM THE GULF.
FRIDAY THROUGH SUNDAY...CONSIDERABLE UNCERTAINTY IN THE UPPER LEVEL
PATTERN THROUGH THIS PERIOD. GFS SHOWS VERY WEAK FLOW OVER THE REGION
THROUGH THIS PERIOD...WITH THE HIGH BUILDING OVER THE WESTERN U.S.
WHILE THE ECMWF SHOWS THE HIGH BUILDING OVER THE ROCKIES THEN SLIDING
SE TOWARDS THE PANHANDLES. EITHER WAY...IT SHOULD BE A DRIER
PATTERN...WITH THE POSSIBLE EXCEPTION OF SOME MOUNTAIN CONVECTION
SLIDING INTO THE NW CORNER ON SATURDAY UNDER VERY WEAK NW FLOW.
JOHNSON
FIRE WEATHER...
MUCH COOLER WEATHER...RAIN CHANCES...AND RELATIVE HUMIDITY VALUES
WELL ABOVE 20 PERCENT WILL PRECLUDE ANY ELEVATED OR CRITICAL FIRE
WEATHER CONDITIONS FOR THE NEXT SEVERAL DAYS.
JOHNSON
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
15/11
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1150 PM EDT TUE JUL 16 2013
.SYNOPSIS...
STRONG UPPER LEVEL HIGH PRESSURE ACROSS THE REGION WILL CONTINUE
TO DRIFT WEST AND WEAKEN THROUGH THE WEEK. WEAK UPPER LEVEL
DISTURBANCES WILL ROTATE SOUTH INTO THE AREA THIS EVENING THROUGH
THURSDAY RESULTING IN WIDELY SCATTERED SHOWERS AND STORMS AT
TIMES. A COLD FRONT WILL SINK INTO THE OHIO VALLEY NEAR THE END
OF THE WEEK BEFORE SLIDING SOUTH ACROSS THE REGION LATER THIS
WEEKEND.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 1145 PM EDT TUESDAY...
NW-SE ORIENTED BAND OF ISOLD-SCT CONVECTION CONTINUING ACROSS THE
N-E PART OF THE CWA. HRRR MODEL SHOWS THIS CONTINUING FOR A COUPLE
MORE HOURS...THEN IT SHOULD DISSIPATE. IT COULD MAKE IT TO DAN/MTV
AREA AND ADJACENT NC COUNTIES...AS WELL AS PARTS OF GREENBRIER
COUNTY WV BEFORE DISSIPATING...SO HAVE ADJUSTED POPS UP
ACCORDINGLY IN THESE AREAS. DO NOT EXPECT ANY MORE SEVERE TONIGHT.
TOMORROW LIKES LIKE A FAIRLY ACTIVE AFTERNOON AS WELL...BUT THE
EMPHASIS SHOULD BE SHIFTED SOMEWHAT TO THE WEST AND MAY TEND TO BE
WEST OF THE ALLEGHANY FRONT MORE THAN EAST OF IT AS IT WAS
TODAY...THUS MORE INTO EASTERN WV AND SW VA THAN IT WAS TODAY.
BECAUSE SEVERAL LOCATIONS HAD THUNDERSTORMS LATE THIS
EVENING...TEMPERATURES HAVE COOLED QUICKER THAN EXPECTED.
HOWEVER...DO NOT EXPECT MUCH ADDITIONAL DROP IN TEMPERATURES
BECAUSE OF HIGH DEWPOINTS. MODIFIED INITIAL TRENDS TO ACCOUNT FOR
COOLER CURRENT READINGS...BUT TRENDED TOWARD EARLIER ADVERTISED
MIDS. IT APPEARS FOG COULD BE A BIGGER PROBLEM THAN EARLIER
EXPECTED AS WELL.
AS OF 910 PM EDT TUESDAY...
THE INTENSITY AND COVERAGE OF THE SHOWERS AND THUNDERSTORMS ARE
DECREASING THIS EVENING INTO TONIGHT WITH THE LOSS OF SOLAR
HEATING. BUT...SHOWERS AND ISOLATED THUNDERSTORMS WILL PERSIST FOR
THE NEXT COUPLE OF HOURS TONIGHT. INCREASED POPS IN THE EAST TO
ALLOW BAND OF STORMS IN THE RICHER CAPES TO OUR EAST TO MOVE INTO
THE PIEDMONT. THE 18Z NAM AND GFS HINT THAT SHOWERS COULD PERSIST
INTO THE OVERNIGHT IN THE SOUTH. EXPECTED AREAS OF FOG TO DEVELOP
OVERNIGHT INTO WEDNESDAY MORNING ESPECIALLY WHERE THUNDERSTORMS
OCCURRED. LOW TEMPERATURES OVERNIGHT WILL RANGE FROM THE LOWER
60S IN THE MOUNTAINS TO THE LOWER 70S IN THE SOUTHEAST. SCATTERED
SHOWERS AND THUNDERSTORMS WILL DEVELOP AGAIN WEDNESDAY AFTERNOON.
THERE IS THE POTENTIAL FOR STRONG TO SEVERE STORMS AND LOCALIZED
FLOOD ISSUES AGAIN. HIGHS WEDNESDAY WILL RANGE FROM THE LOWER 80S
IN THE MOUNTAINS TO THE LOWER 90S IN THE PIEDMONT.
AS OF 630 PM EDT TUESDAY...
SCATTERED STRONG TO SEVERE THUNDERSTORMS WILL CONTINUE INTO
THIS EVENING. ROANOKE AIRPORT REPORT 61 MPH WIND GUST AT 630 PM.
INCREASED POPS FOR LATE AFTERNOON INTO THIS EVENING. ADJUSTED
TEMPERATURES AND DEWPOINTS. EXPECT SHOWERS AND THUNDERSTORMS TO
WEAKEN WITH LOSS OF SOLAR HEATING TONIGHT. MORE ADJUSTMENTS LATER
THIS EVENING.
AS OF 315 PM EDT TUESDAY...
UNUSUALLY STRONG UPPER RIDGE CENTERED OVER INDIANA THIS AFTERNOON
WITH A CLOSED 600DM ISOLINE ANALYZED...SOMETHING SEEN BUT RARELY
IN THE CONUS. SEVERAL IMPULSES CONTINUE TO ROUND THIS BROAD UPPER
CIRCULATION AND DROP SOUTHEASTWARD TOWARD THE ATLANTIC COAST
PROVIDING ENOUGH LIFT FOR CLUSTERS OF STORMS TO DEVELOP WITHIN
WHAT HAS BECOME A VERY WARM AND HUMID AIR MASS. H85 TEMPS ROUGHLY
+20C OVER MUCH OF THE MID-ATLANTIC/APPALACHIAN REGION WITH STRONG
HEATING PUSHING SURFACE TEMPS INTO MID-90S OVER PIEDMONT AND UPPER
80S AND A FEW LOW 90S EVEN IN THE MOUNTAINS. PLENTY OF MOISTURE
INDICATED BY SURFACE DEWPOINTS UPPER 60S TO LOW 70S AND PWATS 1.2
TO 1.5 INCHES. THUNDERSTORMS HAVE DEVELOPED THIS AFTERNOON NORTH
OVER THE HIGHER TERRAIN OF WV AND THE BLUE RIDGE AND ARE DRIFTING
SLOWLY SOUTHWARD WITH THE MEAN STEERING FLOW INTO THE NORTHERN
CWA. THIS DIURNAL PATTERN OF THUNDERSTORM ACTIVITY SHOULD WEAKEN
LATER IN THE EVENING BUT MAY MAINTAIN ITSELF FOR SOME TIME BEYOND
SUNSET WITH THE VERY HIGH INSTABILITY IN PLACE...MESOANYALYSIS
CAPES/LIS ARE 2K-3K J/KG ACROSS MOST OF THE CWA BUT HIGHER JUST
NORTH WITH 4K-5K J/KG AND -6 TO -8 LIFTED INDEX ANALYZED. A FEW
STORMS COULD BECOME SEVERE WITH THESE PARAMETERS IN PLACE AND
DCAPES NEAR 1K. LOCALIZED FLASH FLOOD ISSUES ALSO POSSIBLE WITH
THE RELATIVELY SLOW MOVEMENT OF STORMS AND LIKELY HIGH RAINFALL
RATES. OVERNIGHT TEMPS WILL BE MUGGY AND WARM WITH UPPER 60S TO
LOW 70S AND PATCHY FOG LIKELY IN SOME AREAS.
NOT MUCH CHANGE IN OVERALL SYNOPTIC PATTERN OR TEMP REGIME ON
WEDNESDAY AS UPPER HIGH REMAINS QUASI-STATIONARY AND SURFACE
FEATURES WEAK AND DIFFUSE. TEMPS WILL BE SIMILAR AND EXPECT A
RENEWAL OF THE DIURNALLY ENHANCED CONVECTION. BEST FORCING FOR
ORGANIZED ACTIVITY REMAINS OVER THE NORTHEASTERN U.S. BUT
SCATTERED SEVERE ACTIVITY AND LOCALIZED FLOOD ISSUES AGAIN A
STRONG POSSIBILITY ESPECIALLY ALONG BOUNDARIES CREATED BY
EARLIER CONVECTION OR DUE TO TERRAIN INTERACTIONS.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
AS OF 220 PM EDT TUESDAY...
NOT A LOT OF CHANGE WITH UPPER HEIGHTS SLOWLY LOWERING THROUGH
THE PERIOD WHILE MAINTAINING AN OVERALL MEAN FLAT RIDGE ACROSS
THE REGION THROUGH THE END OF THE WEEK. FAINT VORT LOBES ROTATING
AROUND THE PARENT 5H HIGH TO THE WEST MAY HELP SPARK ANOTHER
ROUND OF MAINLY MOUNTAIN CONVECTION THU AFTERNOON WITH BEST
COVERAGE SW ZONES WHERE WILL SEE A LITTLE MORE IN THE WAY OF
LIGHT SE FLOW. OTRW EXPECT WEAK NORTHERLY FLOW TO ALLOW ENOUGH
LOCAL CONVERGENCE TO SUPPORT SCTD POPS WED EVENING...AND AGAIN
THURSDAY AFTERNOON PER GOOD INSTABILITY WHEN STORMS SHOULD AGAIN
BE SLOW MOVERS AS WELL. COVERAGE LIKELY TO TAPER PRETTY QUICK
THU EVENING UNDER LACK OF SUPPORT BEFORE REDEVELOPING WEST FRIDAY
AS RIDGING ERODES EVEN MORE. WITH THE FLOW TURNING AROUND TO THE
SW...EXPECT SHRA/TSRA TO DEVELOP FARTHER EAST AND BE A BIT MORE
ORGANIZED BUT MAINLY BLUE RIDGE AS THE LEE TROF APPEARS TOO FAR
EAST TO AID IN DEVELOPMENT AT THIS POINT. OTRW CONTINUED PC
DAYTIME TO MOSTLY CLEAR AT NIGHT BUT STILL HOT/WARM AND HUMID
WITH PERSISTENCE OF UPR 80S-MID 90S FOR HIGHS AND 60S TO LOWER
70S FOR LOWS.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 1235 PM EDT TUESDAY...
RETURN TO THE EASTERN UPPER TROF REGIME WILL BE UNDERWAY STARTING
THIS WEEKEND WITH THE AXIS OF THE 5H COOL POOL CROSSING THE
REGION FROM THE NW BY EARLY MONDAY. WEAK COLD FRONT AHEAD OF THE
FALLING HEIGHTS ALOFT LOOKS TO CROSS THE OHIO VALLEY SAT AFTERNOON
BEFORE BECOMING MORE EAST-WEST ORIENTED IN BACKDOOR FASHION JUST
NORTH OF THE AREA SUNDAY. INITIAL WESTERLY FLOW AHEAD OF THE FRONT
SHOULD ACT TO CAP CONVECTION SAT UNTIL LATER IN THE
AFTERNOON/EARLY EVENING WHEN MAY SEE A PRE-FRONTAL LINE OF TSRA
ARRIVE FROM THE NW PER LATEST EC. THUS RUNNING WITH HIGH CHC/LOW
LIKELYS NW TIER SAT WITH CHANCES ELSW WITH THE LEAST SE UNTIL
EVENING. FORECAST PWATS QUICKLY INCREASE BY SUNDAY AS THE FRONT
SLOWS AND THE FLOW TURNS MORE SW. INTERACTION WITH AN EASTERN LEE
TROF AND HEATING AHEAD OF THE PREVIOUS PRE-FRONTAL BAND SHOULD
HELP ENERGIZE CONVECTION ALONG/EAST OF THE BLUE RIDGE SUNDAY SO
BUMPING POPS TO HIGH CHC/LOW LIKELYS ESPCLY SE INCLUDING DECENT
CHANCES ACROSS THE WEST. SHOULD BE QUITE HOT AHEAD OF THE FRONT
SAT GIVEN WESTERLY COMPRESSION AND EARLY INSOLATION WITH MUCH OF
THE EAST STILL IN THE 90S AND 80S WEST. SOME COOLING LIKELY SUNDAY
UNDER MORE MOISTURE/SW FLOW AND A QUICKER INIT TO CONVECTION
DURING THE AFTERNOON.
LOTS OF UNCERTAINTY THEN EARLY NEXT IN JUST HOW FAR SOUTH THE
LOW LEVEL BOUNDARY WILL GET GIVEN THE EXITING/WEAKENING 5H TROF.
APPEARS WITH AT LEAST SCTD CONVECTION MONDAY...PER THE ACTUAL
FRONT OVERHEAD...MAY SEE ENOUGH PUSH TO PERHAPS DRIFT THE
BOUNDARY INTO THE CAROLINAS MONDAY NIGHT BEFORE IT STARTS TO HEAD
BACK NORTH TUESDAY AHEAD OF THE NEXT UPSTREAM WAVE. GIVEN
POTENTIAL FOR MOISTURE TO LINGER LONGER...WONT LEAN TOWARD THE
DRIER GFS...AND KEEP SOME COVERAGE OF POPS GOING MONDAY INTO
TUESDAY WITH LESS CHANCES NORTH-NW SECTIONS MONDAY NIGHT WHERE
SOME DRYING ALOFT MAY SNEAK IN. EXPECT WILL BE BLEEDING IN SOME
SLIGHTLY COOLER AIR AS WELL EARLY NEXT WEEK ALLOWING HIGHS
TO FALL TO SLIGHTLY BELOW NORMAL WITH LOWS INTO THE 60S MOST
SPOTS.
&&
.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
AS OF 730 PM EDT TUESDAY...
SCATTERED MVFR SHOWERS AND THUNDERSTORMS WILL SLOWLY DIMINISH
THIS EVENING INTO TONIGHT. LOCAL IFR/LIFR CONDITIONS IN
CONVECTION AND AREAS OF FOG TONIGHT.
AFTER THE SHOWERS/STORMS END AND SKIES CLEAR EXPECT AREAS OF
FOG SITUATED ACROSS THE VALLEYS/BCB/LWB/LYH/DAN...WITH A
POTENTIAL FOR DENSE FOG AT BCB/LWB/ROA.
ON WEDNESDAY... GENERALLY VFR CONDITIONS EXPECTED OUTSIDE OF THE
SCATTERED DIURNALLY DRIVEN THUNDERSTORMS. BRIEF PERIODS OF
MVFR/IFR CONDITIONS ASSOC WITH THESE STORMS.
EXTENDED AVIATION DISCUSSION...
AFTER WEDNESDAY...PROGRESSIVELY MORE COVERAGE OF STORMS THROUGH
THE WEEK AS THE UPPER RIDGE FLATTENS AND A TROUGH STARTS TO BUILD
SOUTH INTO THE GREAT LAKES. ALSO...THE COASTAL TROUGH WILL
STRENGTHEN A BIT WITH THE UPPER HIGH CENTERING OVER THE ROCKIES. A
BOUNDARY WILL BE SINKING INTO THE OHIO VALLEY THIS WEEKEND. SOME
MVFR/IFR VIS/CIG CAN BE EXPECTED AT BCB/LWB EACH DAY...POTENTIALLY
REDUCED CIG/VIS DUE TO THUNDERSTORMS AT THE END OF THE WEEK.
&&
.EQUIPMENT...
AS OF 735 PM EDT TUESDAY...
VISIBILITY SENSOR AT DANVILLE ASOS HAS BEEN FIXED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/WP
NEAR TERM...KK/PC/RAB
SHORT TERM...JH
LONG TERM...JH
AVIATION...KK/PC/WP
EQUIPMENT...KK/RAB
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1100 PM CDT TUE JUL 16 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 300 PM CDT TUE JUL 16 2013
CURRENTLY AS OF 20Z...
WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED AN UPPER LOW
JUST OFF THE NORTHERN CALIFORNIA COAST...TROUGHING OVER SASKATCHEWAN
AND MANITOBA...AND A 600 DAM SUBTROPICAL HIGH NEAR SOUTH BEND
INDIANA. 500MB HEIGHTS ARE 2-3 STANDARD DEVIATIONS ABOVE NORMAL FROM
THE FORECAST AREA EASTWARD INTO NEW ENGLAND. DESPITE THE HIGH 500MB
HEIGHTS...850MB TEMPS AT 12Z WERE GENERALLY 17-18C PER SOUNDING
DATA. PLENTY OF SUNSHINE HAS ALLOWED FULL MIXING TO 850MB...YIELDING
TEMPERATURES IN THE UPPER 80S TO MID 90S. ACCOMPANYING THE
SUBTROPICAL HIGH IS PLENTY OF DEEP MOISTURE...NOTED BY PRECIPITABLE
WATER VALUES OF 1.75 TO 2 INCHES FROM EASTERN OKLAHOMA INTO THE
FORECAST AREA. ITS WORTH NOTING THAT THE 12Z GRB SOUNDING
PRECIPITABLE WATER VALUES OF 2.07 INCHES IS AT THE 99TH PERCENTILE.
THIS DEEP MOISTURE IS ALSO REFLECTED AT THE SURFACE WITH DEWPOINTS
IN THE UPPER 60S/LOWER 70S...A LITTLE LOWER THAN AT 15Z DUE TO
MIXING AND DRIER SOILS. PLENTY OF CUMULUS HAS DEVELOPED IN THIS
MOIST AIRMASS. DESPITE HIGHER 500MB HEIGHTS TODAY COMPARED TO
YESTERDAY...THE HIGHER PRECIPITABLE WATER VALUES COMPARED TO MODEL
FORECASTS FROM YESTERDAY AND DAYTIME INSTABILITY HAS LED TO SOME
SHOWER DEVELOPMENT. TO THE NORTHWEST...A COLD FRONTAL BOUNDARY
ACCOMPANYING THE SOUTH CENTRAL CANADA TROUGH STRETCHED FROM
NORTHWEST ONTARIO BACK INTO THE BLACK HILLS OF SOUTH DAKOTA.
SYNOPTIC OVERVIEW...
THE SUBTROPICAL HIGH LOOKS TO SLOWLY DRIFT SOUTH DURING THE NEXT 24
HOURS IN RESPONSE TO THE SOUTH CENTRAL CANADA TROUGH PUSHING EAST
AND FLATTENING THE RIDGE. AS THIS OCCURS...THE COLD FRONTAL BOUNDARY
LOOKS TO LAY UP EAST TO WEST FROM NEAR THE NORTH DAKOTA/SOUTH DAKOTA
STATE LINE INTO UPPER MICHIGAN.
TONIGHT...
DIURNAL CUMULUS CLOUDS AS WELL AS ANY SHOWER ACTIVITY WILL DISSIPATE
THIS EVENING WITH LOSS OF HEATING...AND THEN THE REST OF NIGHT
SHOULD BE MOSTLY CLEAR. ANY POTENTIAL FOR ELEVATED CONVECTION LOOKS
TO OCCUR WELL OFF TO OUR NORTH ALONG THE FRONTAL BOUNDARY. A WARM
AND MUGGY NIGHT IS LIKELY AS DEWPOINTS JUMP BACK UP WITH LOSS OF
MIXING.
WEDNESDAY...
WITH A SOUTHWEST SURFACE FLOW AND THE COLD FRONTAL BOUNDARY STILL
OFF TO OUR NORTH...ANTICIPATING ANOTHER DRY DAY. ADDITIONALLY...
16.12Z NAM/GFS PRECIPITABLE WATER FORECASTS SUGGEST SLIGHTLY DRIER
VALUES IN THE 1.5 TO 1.8 INCH RANGE. THESE DRIER PRECIPITABLE WATER
VALUES SUPPORT A DRIER FORECAST...IN AGREEMENT TOO WITH THE 16.12Z
NAM AND HIRES-ARW. SHOULD SEE DEWPOINTS MIX DOWN A LITTLE MORE DUE
TO THOSE LOWER VALUES AND SOILS CONTINUING TO DRY OUT. 850MB TEMPS
ARE PROGGED SLIGHTLY WARMER THAN TODAY...18-19C...SO WE SHOULD BE
ABLE TO TACK ON 1-2F FOR HIGHS COMPARED TO TODAY. WITH THE
DEWPOINTS MIXING OUT...ANTICIPATING HEAT INDICES IN THE 95-102F
RANGE FOR A MAX.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 300 PM CDT TUE JUL 16 2013
SYNOPTIC OVERVIEW...
MODELS REMAIN IN GOOD AGREEMENT SHOWING THE SUBTROPICAL HIGH
CONTINUING TO GET SUPPRESSED TO THE SOUTH...IN RESPONSE TO TROUGHING
EVENTUALLY DEVELOPING OVER THE WESTERN GREAT LAKES BY SATURDAY. THIS
TROUGHING IS A COMBINATION OF TWO FEATURES:
1. THE CURRENT UPPER LOW OFF THE NORTHERN CALIFORNIA COAST DROPPING
THROUGH THE AREA AS A SHORTWAVE TROUGH LATE FRIDAY.
2. A POTENT TROUGH DROPPING THROUGH CENTRAL CANADA ON FRIDAY AND
POSSIBLY PHASING WITH THE AFOREMENTIONED SHORTWAVE TROUGH.
THE FORECAST AREA GENERALLY LOOKS TO STAY IN A NORTHWEST FLOW
HEADING INTO EARLY NEXT WEEK ACCORDING TO THE 16.12Z GFS/ECMWF.
HAZARDS...
EARLIER TODAY ISSUED A HEAT ADVISORY THROUGH FRIDAY. PART OF THE
UPGRADE WAS RELATED TO HOW QUICKLY WE WARMED THIS MORNING...
DEWPOINTS TAKING LONGER TO MIX OUT THAN EXPECTED...SLIGHTLY WARMER
TEMPERATURES THAN PREVIOUSLY FORECAST FOR WEDNESDAY THROUGH
THURSDAY...AND CONCERN FRIDAY WILL BE WARMER TOO. HEAT INDICES
GENERALLY SHOULD RANGE BETWEEN 95-100 EACH DAY ACROSS THE ENTIRE
FORECAST AREA...UNTIL THE FRONTAL PASSAGE FRIDAY...WITH VALLEY
LOCATIONS LIKELY AT OR ABOVE 100. NORMALLY 100 DEGREES IS THE
CRITERIA FOR HEAT ADVISORY...BUT IF A LONG DURATION EVENT OF 4 OR
MORE DAYS OCCUR WITH SLIGHTLY BELOW 100 DEGREE READINGS...AN
ADVISORY CAN BE ISSUED. ONLY TAYLOR COUNTY IS NOT IN A HEAT ADVISORY
BECAUSE OF CONVECTION CONCERNS WED NIGHT THROUGH FRIDAY.
CANNOT RULE OUT SOME SEVERE WEATHER ACROSS TAYLOR COUNTY THURSDAY
NIGHT OR POSSIBLY ON THE FRONT ON FRIDAY...BUT CONFIDENCE OF
PRECIPITATION IS LOWER AS DISCUSSED IN THE DAILY DETAILS BELOW.
DAILY DETAILS...
WEDNESDAY NIGHT THROUGH FRIDAY...
CONFIDENCE CONTINUES TO DECREASE OF PRECIPITATION AFFECTING THE
FORECAST AREA. THERE ARE NUMEROUS ISSUES THAT POINT TO A DRIER
FORECAST MORE LIKELY:
1. LOOKING AT ELEVATED CONVECTION POTENTIAL WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT...THE 16.12Z NAM/ECMWF POINT THE NOSE OF THE 850MB
MOISTURE TRANSPORT NORTH OF THE FORECAST AREA...AND BY THURSDAY
NIGHT EVEN NORTHEAST OF LAKE SUPERIOR.
2. NOT CONNECTED TO A DRIER FORECAST MORE LIKELY...BUT THE GFS IS
PRODUCING WAY TOO MUCH PRECIPITATION IN THIS VERY WARM AND HUMID
ENVIRONMENT. ITS ALMOST LIKE IT CANNOT THE INSTABILITY. THIS
PRECIPITATION FEEDS BACK INTO OTHER FIELDS LIKE 850MB MOISTURE
TRANSPORT...MAKING THAT UNUSABLE.
3. AS THE FRONT AND SHORTWAVE APPROACH FRIDAY...THERE IS A DEFINITE
WARM SURGE AT 800MB COMING ACROSS THE AREA ON TOP OF THE FRONT. THIS
WARM SURGE COULD EFFECTIVELY CAP CONVECTION...BRINGING THE FRONT
THROUGH DRY. THE 16.12Z NAM/ECMWF DEPICT ISOLATED/SCATTERED
DEVELOPMENT AT MOST.
4. FRONTAL TIMING IS A BIG ISSUE...WITH MODELS SUGGESTING THE COLD
FRONT IS INTO LA CROSSE AT 18Z FRIDAY. DRY CONDITIONS ARE LIKELY
ONCE THE FRONT PASSES.
GIVEN ALL OF THE ABOVE ISSUES...HAVE SHIFTED PRECIPITATION CHANCES
FARTHER NORTH WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...AND KNOCKED
PRECIPITATION CHANCES DOWN FOR FRIDAY. PRECIPITATION STILL SEEMS
LIKELY TO IMPACT TAYLOR AND POSSIBLY CLARK COUNTIES DURING THIS TIME
FRAME...THOUGH.
TEMPERATURES ARE TRICKY TOO. GIVEN HOW WARM WE GOT TODAY AND THE
AIRMASS CONTINUING TO MODIFY...THINKING EACH DAY SHOULD BE JUST
SLIGHTLY WARMER THAN THE PREVIOUS. RAISED HIGHS THURSDAY AND
FRIDAY...AND DEPENDING ON FRONTAL TIMING FRIDAY COULD BE THE WARMEST
AS THAT WARM SURGE OF AIR MENTIONED IN POINT 3 ABOVE COMES IN.
FRIDAY NIGHT THROUGH TUESDAY...
HIGH PRESSURE LOOKS TO BUILD INTO THE FORECAST AREA FOR FRIDAY NIGHT
THROUGH SATURDAY NIGHT BEHIND THE FRONT...PROVIDING COOLER AND DRIER
CONDITIONS. STILL MAINTAINED A 20 PERCENT CHANCE IN THE EVENING IN
THE SOUTHEASTERN PORTION OF THE FORECAST AREA IN THE EVENT
CONVECTION/FRONT IS SLOWER. AS WE HEAD INTO SUNDAY AND THROUGH EARLY
NEXT WEEK...FORECAST BECOMES A BIT MORE PROBLEMATIC. MODELS ARE
SHOWING A VARIETY OF SHORTWAVES DROPPING THROUGH THE NORTHWEST
FLOW...WHILE AT THE SAME TIME 500MB HEIGHTS ARE RISING WITH WARM
ADVECTION IN THE LOWER LEVELS. THIS BECOMES A FAVORABLE PATTERN FOR
MULTIPLE ROUNDS OF CONVECTION. HAVE 20 PERCENT CHANCES IN THE
FORECAST FOR SUNDAY OVER WESTERN PORTIONS OF THE FORECAST
AREA...WHICH THEN EXPAND EAST AND BEGIN TO INCREASE ACROSS THE REST
OF THE AREA FOR SUNDAY NIGHT THROUGH TUESDAY. WE MAY HAVE TO WATCH
TEMPERATURES AGAIN AS WE APPROACH TUESDAY AS WELL...WITH THE
16.00Z/16.12Z ECMWF BRINGING 850MB TEMPS UP TO 24C WEST OF THE MS
RIVER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1100 PM CDT TUE JUL 16 2013
MUGGY OVERNIGHT CONDITIONS HAVE RESULTED IN SOME LIGHT BR DURING THE
NEAR DAYBREAK HOURS AT KRST/KLSE...AND CONDITIONS SEEM RIPE FOR WED
AND THU MORNINGS FOR SOME OF THIS LIGHT FUZZ. DON/T SEE A THICKER FG
THREAT AT KLSE AT THE TIME...TOO MUCH MIXING IN THE NEAR SFC LAYER
AND T/TD SPREAD WAS 13 DEGREES AT 03Z. EXPECT SOME CU FOR THE
AFTERNOON HOURS WED...LIKELY BKN FOR A PERIOD. COULD SEE AN ISOLD
AIRMASS SHRA/TS POP UP LATE IN THE DAY...BUT WITHOUT A TRIGGER TO
FOCUS IT ON...NO CONFIDENCE IN ADDING TO THE TAFS. OVERALL...VFR
CIGS/VSBYS SHOULD BE THE RULE INTO THU.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...HEAT ADVISORY UNTIL 7 PM CDT FRIDAY FOR WIZ029-032>034-041>044-
053>055-061.
MN...HEAT ADVISORY UNTIL 7 PM CDT FRIDAY FOR MNZ079-086>088-094>096.
IA...HEAT ADVISORY UNTIL 7 PM CDT FRIDAY FOR IAZ008>011-018-019-029-
030.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
919 PM CDT TUE JUL 16 2013
.UPDATE...
IT WILL BE A QUIET NIGHT WITH CLEAR SKIES AND LIGHT SOUTHWEST WINDS
UNDER A STRONG RIDGE OF HIGH PRESSURE. PATCHY FOG IS EXPECTED TO
DEVELOP ONCE AGAIN IN THE FAVORABLE LOCATIONS SUCH AS RIVER
VALLEYS...MARSHES AND OTHER LOW LYING AREAS.
HOT AND HUMID CONDITIONS WILL CONTINUE AGAIN WEDNESDAY WITH HIGH
PRESSURE FIRMLY IN PLACE OVER THE EAST HALF OF THE UNITED STATES.
THE HEAT ADVISORY IS IN EFFECT THROUGH FRIDAY. WITH THE HIGH
DEWPOINTS AND DECENT AFTERNOON INSTABILITY...CANNOT RULE OUT A STRAY
SHOWER/THUNDERSTORM AGAIN TOMORROW AFTERNOON...JUST LIKE THE PAST
TWO DAYS.
&&
.AVIATION/06Z TAFS/...
SURFACE WINDS WILL BE LIGHT AND PATCHY FOG DEVELOPMENT IS EXPECTED
ONCE AGAIN TONIGHT/EARLY TUESDAY MORNING.
WEDNESDAY WILL BE A REPEAT OF MONDAY AND TUESDAY...EXCEPT WINDS WILL
BE PRIMARILY OUT OF THE WEST/SOUTHWEST. BROKEN VFR CUMULUS EXPECTED
BY LATE MORNING...AND THERE WILL BE A VERY ISOLATED THREAT OF
SHOWERS/THUNDERSTORMS FOR THE AFTERNOON INTO EARLY EVENING.
&&
.PREV DISCUSSION... /ISSUED 240 PM CDT TUE JUL 16 2013/
TONIGHT AND WEDNESDAY - CONFIDENCE...MEDIUM TO HIGH
HOISTED HEAT ADVISORY WITH LIKELIHOOD OF DAYTIME HEAT INDICES
REACHING 95 TO 100 THROUGH FRIDAY. WARM AND TROPICAL NIGHT WITH ANY
LINGERING CU/ISOLD SHRA OR TSRA DISSIPATING THIS EVENING. 6000 METER
HEIGHT CONTOUR INTO SE WI PER RUC ANALYSIS. GREATER COVERAGE OF TSRA
ON NW PERIPHERY OF THE RIDGE. STILL THINK THERE IS POTENTIAL FOR
ISOLATED DEVELOPMENT ALONG THE LAKE BREEZE BOUNDARY INTO THE EVENING
HOURS. 925 TEMPS AROUND 25-26C WEDNESDAY SO UPPER 80S/LOWER 90S LOOK
GOOD WITH TROPICAL DEW POINTS IN THE MID 70S. WILL CARRY A VERY
SMALL POP FOR THE AFTERNOON HOURS TO ACKNOWLEDGE A BLEND OF ALL THE
MODEL SOLUTIONS. A TRIGGER MAY BE HARD TO COME BY.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...FORECAST CONFIDENCE IS
MEDIUM TO HIGH.
THE BIG SURFACE HIGH PRESSURE SYSTEM WILL BE DRIFTING TO THE
SOUTH WITH TIME. BY THURSDAY WE/LL START TO GET INTO A BETTER
SOUTHWEST GRADIENT FLOW BETWEEN THE HIGH TO THE SOUTH AND THE
APPROACHING COLD FRONT/TROUGH TO THE NORTHWEST. WILL ONLY CARRY
SOME SMALL POPS ACROSS MY FAR NORTH FOR ANYTHING THAT MAY SNEAK IN
WITH THE RING OF FIRE GETTING CLOSER. LOOK FOR HIGHS ON THURSDAY
AROUND 90 MOST PLACES WITH HEAT INDICES APPROACHING OR REACHING
100 IN SOME SPOTS.
FRIDAY AND FRIDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM TO HIGH.
THE HEAT WILL REMAIN IN PLACE WITH FRIDAY NOW LOOKING A TOUCH
WARMER. 925MB TEMPS ON FRIDAY WILL BE PUSHING 26C IN A NARROW
WEDGE AHEAD OF THE APPROACHING FRONT...WHICH IS WARMER THAN
PREVIOUS RUNS. CLOUDS WILL BE INCREASING...SO WE WON/T REALIZE
THAT FULL POTENTIAL OF HEAT IF WE HAD GOOD MIXING WITH SUNSHINE.
HEAT INDICES AGAIN 95 TO 98. THE TIMING OF THE FRONT HASN/T CHANGED
MUCH WITH THE NEW RUNS...STILL REACHING THE WI/IL BORDER BY OR
SHORTLY AFTER 00Z SAT.
IT APPEARS THE BEST CHANCE FOR THUNDERSTORMS...AND SOME MAY BE
SEVERE...WITH THE FRONT WILL BE ACROSS THE EASTERN FORECAST AREA.
THE ORIENTATION OF THE ADVANCING FRONT WITH THE LAKE SHORE WILL
RESULT IN A MOVING TRIPLE POINT OF CONVERGENCE WHERE THE COLD
FRONT INTERSECTS THE STATIONARY COOL LAKE BNDRY. THE LAKE WILL
ESSENTIALLY BE ANOTHER LLV COLD FRONT WITH WARM ADVECTION/LIFT
OCCURRING JUST AHEAD OF THE FRONT...OVER THE COOLER DOME OF THE
LAKE. UPWELLING WITH THE INCREASING SOUTHWEST WINDS MAY HELP TO
ENHANCE THE BAROCLINIC ZONE. THE CIPS ANALOGS SHOW THE EAST WITH
THE BIGGEST THREAT FOR SEVERE WEATHER...MAINLY WIND AND HAIL. BACK
TO THE WEST TOWARD MADISON...THERE IS SOME LOW LEVEL CAPPING THAT
MAY BE HARD TO BUST...SO THE SEVERE THREAT DIMINISHES AS YOU GET
TO MADISON AND POINTS WEST.
THE RAIN SHOULD BE EXITING QUICKLY DURING THE EVENING WITH DRY
CONDITIONS RETURNING AFTER MIDNIGHT.
SATURDAY AND SUNDAY...FORECAST CONFIDENCE IS HIGH.
A MUCH COOLER AND DRIER AIRMASS RETURNS FOR THE WEEKEND BRINGING
VERY PLEASANT TEMPERATURES. LOOK FOR HIGHS IN THE 70S AND NO RAIN.
MONDAY AND TUESDAY...FORECAST CONFIDENCE IS MEDIUM.
WARM ADVECTION KICKS IN FOR MONDAY NIGHT INTO MONDAY AHEAD OF AN
APPROACHING LOW PRESSURE FROM THE NORTHWEST. THE WAA AND LOW
PRESSURE WILL BRING ANOTHER CHANCE FOR SHOWERS AND STORMS...ALONG
WITH SOME WARMER TEMPS.
AVIATION/00Z TAFS/...BKN VFR CU FIELD WILL DISSIPATE DIURNALLY ONCE
AGAIN THIS EVENING. VRY ISOLD TSRA THREAT INTO THE EARLY EVENING.
WITH LIGHT WIND REGIME PATCHY FOG DEVELOPMENT LOOKS REASONABLE
TONIGHT AS SUGGESTED BY MOS. LIKELY TO SEE MORE CU WEDNESDAY WITH
POTENTIAL FOR AN ISOLATED TSRA. ALTHOUGH MODEL COVERAGE AND
CONSENSUS NOT TOO CONVINCING.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...HEAT ADVISORY UNTIL 7 PM CDT FRIDAY FOR WIZ046-047-051-052-
056>060-062>072.
LM...NONE.
&&
$$
UPDATE...MRC
TONIGHT/WEDNESDAY AND AVIATION/MARINE...COLLAR
WEDNESDAY NIGHT THROUGH TUESDAY...DAVIS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
627 PM CDT TUE JUL 16 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 300 PM CDT TUE JUL 16 2013
CURRENTLY AS OF 20Z...
WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED AN UPPER LOW
JUST OFF THE NORTHERN CALIFORNIA COAST...TROUGHING OVER SASKATCHEWAN
AND MANITOBA...AND A 600 DAM SUBTROPICAL HIGH NEAR SOUTH BEND
INDIANA. 500MB HEIGHTS ARE 2-3 STANDARD DEVIATIONS ABOVE NORMAL FROM
THE FORECAST AREA EASTWARD INTO NEW ENGLAND. DESPITE THE HIGH 500MB
HEIGHTS...850MB TEMPS AT 12Z WERE GENERALLY 17-18C PER SOUNDING
DATA. PLENTY OF SUNSHINE HAS ALLOWED FULL MIXING TO 850MB...YIELDING
TEMPERATURES IN THE UPPER 80S TO MID 90S. ACCOMPANYING THE
SUBTROPICAL HIGH IS PLENTY OF DEEP MOISTURE...NOTED BY PRECIPITABLE
WATER VALUES OF 1.75 TO 2 INCHES FROM EASTERN OKLAHOMA INTO THE
FORECAST AREA. ITS WORTH NOTING THAT THE 12Z GRB SOUNDING
PRECIPITABLE WATER VALUES OF 2.07 INCHES IS AT THE 99TH PERCENTILE.
THIS DEEP MOISTURE IS ALSO REFLECTED AT THE SURFACE WITH DEWPOINTS
IN THE UPPER 60S/LOWER 70S...A LITTLE LOWER THAN AT 15Z DUE TO
MIXING AND DRIER SOILS. PLENTY OF CUMULUS HAS DEVELOPED IN THIS
MOIST AIRMASS. DESPITE HIGHER 500MB HEIGHTS TODAY COMPARED TO
YESTERDAY...THE HIGHER PRECIPITABLE WATER VALUES COMPARED TO MODEL
FORECASTS FROM YESTERDAY AND DAYTIME INSTABILITY HAS LED TO SOME
SHOWER DEVELOPMENT. TO THE NORTHWEST...A COLD FRONTAL BOUNDARY
ACCOMPANYING THE SOUTH CENTRAL CANADA TROUGH STRETCHED FROM
NORTHWEST ONTARIO BACK INTO THE BLACK HILLS OF SOUTH DAKOTA.
SYNOPTIC OVERVIEW...
THE SUBTROPICAL HIGH LOOKS TO SLOWLY DRIFT SOUTH DURING THE NEXT 24
HOURS IN RESPONSE TO THE SOUTH CENTRAL CANADA TROUGH PUSHING EAST
AND FLATTENING THE RIDGE. AS THIS OCCURS...THE COLD FRONTAL BOUNDARY
LOOKS TO LAY UP EAST TO WEST FROM NEAR THE NORTH DAKOTA/SOUTH DAKOTA
STATE LINE INTO UPPER MICHIGAN.
TONIGHT...
DIURNAL CUMULUS CLOUDS AS WELL AS ANY SHOWER ACTIVITY WILL DISSIPATE
THIS EVENING WITH LOSS OF HEATING...AND THEN THE REST OF NIGHT
SHOULD BE MOSTLY CLEAR. ANY POTENTIAL FOR ELEVATED CONVECTION LOOKS
TO OCCUR WELL OFF TO OUR NORTH ALONG THE FRONTAL BOUNDARY. A WARM
AND MUGGY NIGHT IS LIKELY AS DEWPOINTS JUMP BACK UP WITH LOSS OF
MIXING.
WEDNESDAY...
WITH A SOUTHWEST SURFACE FLOW AND THE COLD FRONTAL BOUNDARY STILL
OFF TO OUR NORTH...ANTICIPATING ANOTHER DRY DAY. ADDITIONALLY...
16.12Z NAM/GFS PRECIPITABLE WATER FORECASTS SUGGEST SLIGHTLY DRIER
VALUES IN THE 1.5 TO 1.8 INCH RANGE. THESE DRIER PRECIPITABLE WATER
VALUES SUPPORT A DRIER FORECAST...IN AGREEMENT TOO WITH THE 16.12Z
NAM AND HIRES-ARW. SHOULD SEE DEWPOINTS MIX DOWN A LITTLE MORE DUE
TO THOSE LOWER VALUES AND SOILS CONTINUING TO DRY OUT. 850MB TEMPS
ARE PROGGED SLIGHTLY WARMER THAN TODAY...18-19C...SO WE SHOULD BE
ABLE TO TACK ON 1-2F FOR HIGHS COMPARED TO TODAY. WITH THE
DEWPOINTS MIXING OUT...ANTICIPATING HEAT INDICES IN THE 95-102F
RANGE FOR A MAX.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 300 PM CDT TUE JUL 16 2013
SYNOPTIC OVERVIEW...
MODELS REMAIN IN GOOD AGREEMENT SHOWING THE SUBTROPICAL HIGH
CONTINUING TO GET SUPPRESSED TO THE SOUTH...IN RESPONSE TO TROUGHING
EVENTUALLY DEVELOPING OVER THE WESTERN GREAT LAKES BY SATURDAY. THIS
TROUGHING IS A COMBINATION OF TWO FEATURES:
1. THE CURRENT UPPER LOW OFF THE NORTHERN CALIFORNIA COAST DROPPING
THROUGH THE AREA AS A SHORTWAVE TROUGH LATE FRIDAY.
2. A POTENT TROUGH DROPPING THROUGH CENTRAL CANADA ON FRIDAY AND
POSSIBLY PHASING WITH THE AFOREMENTIONED SHORTWAVE TROUGH.
THE FORECAST AREA GENERALLY LOOKS TO STAY IN A NORTHWEST FLOW
HEADING INTO EARLY NEXT WEEK ACCORDING TO THE 16.12Z GFS/ECMWF.
HAZARDS...
EARLIER TODAY ISSUED A HEAT ADVISORY THROUGH FRIDAY. PART OF THE
UPGRADE WAS RELATED TO HOW QUICKLY WE WARMED THIS MORNING...
DEWPOINTS TAKING LONGER TO MIX OUT THAN EXPECTED...SLIGHTLY WARMER
TEMPERATURES THAN PREVIOUSLY FORECAST FOR WEDNESDAY THROUGH
THURSDAY...AND CONCERN FRIDAY WILL BE WARMER TOO. HEAT INDICES
GENERALLY SHOULD RANGE BETWEEN 95-100 EACH DAY ACROSS THE ENTIRE
FORECAST AREA...UNTIL THE FRONTAL PASSAGE FRIDAY...WITH VALLEY
LOCATIONS LIKELY AT OR ABOVE 100. NORMALLY 100 DEGREES IS THE
CRITERIA FOR HEAT ADVISORY...BUT IF A LONG DURATION EVENT OF 4 OR
MORE DAYS OCCUR WITH SLIGHTLY BELOW 100 DEGREE READINGS...AN
ADVISORY CAN BE ISSUED. ONLY TAYLOR COUNTY IS NOT IN A HEAT ADVISORY
BECAUSE OF CONVECTION CONCERNS WED NIGHT THROUGH FRIDAY.
CANNOT RULE OUT SOME SEVERE WEATHER ACROSS TAYLOR COUNTY THURSDAY
NIGHT OR POSSIBLY ON THE FRONT ON FRIDAY...BUT CONFIDENCE OF
PRECIPITATION IS LOWER AS DISCUSSED IN THE DAILY DETAILS BELOW.
DAILY DETAILS...
WEDNESDAY NIGHT THROUGH FRIDAY...
CONFIDENCE CONTINUES TO DECREASE OF PRECIPITATION AFFECTING THE
FORECAST AREA. THERE ARE NUMEROUS ISSUES THAT POINT TO A DRIER
FORECAST MORE LIKELY:
1. LOOKING AT ELEVATED CONVECTION POTENTIAL WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT...THE 16.12Z NAM/ECMWF POINT THE NOSE OF THE 850MB
MOISTURE TRANSPORT NORTH OF THE FORECAST AREA...AND BY THURSDAY
NIGHT EVEN NORTHEAST OF LAKE SUPERIOR.
2. NOT CONNECTED TO A DRIER FORECAST MORE LIKELY...BUT THE GFS IS
PRODUCING WAY TOO MUCH PRECIPITATION IN THIS VERY WARM AND HUMID
ENVIRONMENT. ITS ALMOST LIKE IT CANNOT THE INSTABILITY. THIS
PRECIPITATION FEEDS BACK INTO OTHER FIELDS LIKE 850MB MOISTURE
TRANSPORT...MAKING THAT UNUSABLE.
3. AS THE FRONT AND SHORTWAVE APPROACH FRIDAY...THERE IS A DEFINITE
WARM SURGE AT 800MB COMING ACROSS THE AREA ON TOP OF THE FRONT. THIS
WARM SURGE COULD EFFECTIVELY CAP CONVECTION...BRINGING THE FRONT
THROUGH DRY. THE 16.12Z NAM/ECMWF DEPICT ISOLATED/SCATTERED
DEVELOPMENT AT MOST.
4. FRONTAL TIMING IS A BIG ISSUE...WITH MODELS SUGGESTING THE COLD
FRONT IS INTO LA CROSSE AT 18Z FRIDAY. DRY CONDITIONS ARE LIKELY
ONCE THE FRONT PASSES.
GIVEN ALL OF THE ABOVE ISSUES...HAVE SHIFTED PRECIPITATION CHANCES
FARTHER NORTH WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...AND KNOCKED
PRECIPITATION CHANCES DOWN FOR FRIDAY. PRECIPITATION STILL SEEMS
LIKELY TO IMPACT TAYLOR AND POSSIBLY CLARK COUNTIES DURING THIS TIME
FRAME...THOUGH.
TEMPERATURES ARE TRICKY TOO. GIVEN HOW WARM WE GOT TODAY AND THE
AIRMASS CONTINUING TO MODIFY...THINKING EACH DAY SHOULD BE JUST
SLIGHTLY WARMER THAN THE PREVIOUS. RAISED HIGHS THURSDAY AND
FRIDAY...AND DEPENDING ON FRONTAL TIMING FRIDAY COULD BE THE WARMEST
AS THAT WARM SURGE OF AIR MENTIONED IN POINT 3 ABOVE COMES IN.
FRIDAY NIGHT THROUGH TUESDAY...
HIGH PRESSURE LOOKS TO BUILD INTO THE FORECAST AREA FOR FRIDAY NIGHT
THROUGH SATURDAY NIGHT BEHIND THE FRONT...PROVIDING COOLER AND DRIER
CONDITIONS. STILL MAINTAINED A 20 PERCENT CHANCE IN THE EVENING IN
THE SOUTHEASTERN PORTION OF THE FORECAST AREA IN THE EVENT
CONVECTION/FRONT IS SLOWER. AS WE HEAD INTO SUNDAY AND THROUGH EARLY
NEXT WEEK...FORECAST BECOMES A BIT MORE PROBLEMATIC. MODELS ARE
SHOWING A VARIETY OF SHORTWAVES DROPPING THROUGH THE NORTHWEST
FLOW...WHILE AT THE SAME TIME 500MB HEIGHTS ARE RISING WITH WARM
ADVECTION IN THE LOWER LEVELS. THIS BECOMES A FAVORABLE PATTERN FOR
MULTIPLE ROUNDS OF CONVECTION. HAVE 20 PERCENT CHANCES IN THE
FORECAST FOR SUNDAY OVER WESTERN PORTIONS OF THE FORECAST
AREA...WHICH THEN EXPAND EAST AND BEGIN TO INCREASE ACROSS THE REST
OF THE AREA FOR SUNDAY NIGHT THROUGH TUESDAY. WE MAY HAVE TO WATCH
TEMPERATURES AGAIN AS WE APPROACH TUESDAY AS WELL...WITH THE
16.00Z/16.12Z ECMWF BRINGING 850MB TEMPS UP TO 24C WEST OF THE MS
RIVER.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 627 PM CDT TUE JUL 16 2013
OVERALL VFR CONDITIONS TO PREVAIL THROUGH WEDNESDAY EVENING...AND
THE MAIN CONCERN IS FOR THE OVERNIGHT AS WARM MUGGY NIGHT COMBINED
WITH LIGHT WINDS COULD LEAD TO SOME LIGHT FOG AT KRST/KLSE. THE
PAST FEW NIGHTS / EARLY MORNINGS HAVE SEEN 6 TO 8 MILE
VISIBILITIES...AND TONIGHT SEEMS TO BE ON TRACK FOR SIMILAR
CONDITIONS. OTHERWISE...FOR WEDNESDAY ANOTHER ROUND OF STRONG
DAYTIME HEATING WILL GIVE WAY TO EXPANSIVE CUMULUS FIELD. A STRAY
SHOWER OR THUNDERSTORM IS POSSIBLE...BUT CHANCES ARE TOO LOW TO
CONSIDER IN TAF.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...HEAT ADVISORY UNTIL 7 PM CDT FRIDAY FOR WIZ029-032>034-041>044-
053>055-061.
MN...HEAT ADVISORY UNTIL 7 PM CDT FRIDAY FOR MNZ079-086>088-094>096.
IA...HEAT ADVISORY UNTIL 7 PM CDT FRIDAY FOR IAZ008>011-018-019-029-
030.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...ZT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
249 PM CDT MON JUL 15 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 249 PM CDT MON JUL 15 2013
CURRENTLY AS OF 19Z...
WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED TROUGHING OVER
SOUTHWEST CANADA...AN UPPER LOW OVER THE TEXAS PANHANDLE
RETROGRADING WESTWARD...AND A NEAR 600 DAM HIGH NEAR TOLEDO OHIO
ALSO RETROGRADING WESTWARD. STANDARD DEVIATIONS AGAIN WITH THIS HIGH
ARE RUNNING 2.5 ABOVE NORMAL. BETWEEN THE UPPER LOW AND SUBTROPICAL
HIGH...DEEP LAYER SOUTH TO SOUTHEAST WINDS ARE ADVECTING HIGHER
PRECIPITABLE WATER VALUES TOWARDS THE FORECAST AREA. 12Z DVN AND ILX
REPORTED VALUES OF 1.89 AND 2.04 INCHES RESPECTIVELY. HIGHER SURFACE
DEWPOINTS IN THE LOW 70S HAVE ACCOMPANIED THIS DEEP MOISTURE. WITH
TEMPERATURES THAT HAVE CLIMBED INTO THE UPPER 80S/LOW 90S...
RESULTING IN MLCAPE VALUES OF 500-1000 J/KG...ISOLATED SHOWERS HAVE
FORMED. NO LIGHTNING YET...WHICH MAY BE A RESULT OF THE SHALLOW
NATURE OF THE SHOWERS AND DEEP WARM CLOUD DEPTHS PREVENTING ICE
PRODUCTION. DESPITE THE HIGH 500MB HEIGHTS OVER THE FORECAST
AREA...ON THE ORDER OF 594-597 DAM...850MB TEMPS ARE ONLY 16-17C.
THE REASON THESE ARE COOL COMPARED TO THE 500MB HEIGHT IS A RESULT
OF THE SUBTROPICAL HIGH BEING OF ATLANTIC OCEAN ORIGIN. HAD IT COME
OUT OF THE WESTERN U.S....THE 850MB TEMPS WOULD BE A LOT HIGHER.
SYNOPTIC OVERVIEW...
MODELS CONTINUE TO SHOW THE STRONG SUBTROPICAL HIGH DRIFTING
WESTWARD THROUGH TUESDAY...REACHING NEAR GARY INDIANA BY 00Z
WEDNESDAY. THUS...500MB HEIGHTS WILL CONTINUE TO RISE OVER THE
FORECAST AREA...IMPLYING INCREASING MID-LEVEL SUBSIDENCE.
FOR TONIGHT...
ANY AFTERNOON CONVECTION THAT IS SPREADING NORTHWARD...ACCOMPANYING
THE HIGHER PRECIPITABLE WATER...WILL DIMINISH BY 03Z THIS EVENING
WITH LOSS OF HEATING SINCE IT IS HIGHLY DIURNALLY DRIVEN. THE REST
OF THE NIGHT LOOKS DRY WITH ANY FORCING FOR NOCTURNAL CONVECTION
WELL NORTH OF THE FORECAST AREA.
ON TUESDAY...
THE BATTLE CONTINUES OF WHETHER OR NOT TO NEED A MENTION OF SHOWERS
AND THUNDERSTORMS IN THE AFTERNOON. MODELS WERE A LITTLE HYPERACTIVE
WITH DIURNAL CONVECTION TODAY...ESPECIALLY THE 15.12Z NAM SHOWING
PRECIP ACROSS ALL OF ILLINOIS BY 15Z AND THERE WAS NONE IN REALITY.
ALL MODELS ARE IN AGREEMENT OF MUCH LESS QPF...AND THE 15.12Z NAM
CONTINUES TO SHOW A DRY FORECAST FOR THE FORECAST AREA. THERE ARE
OTHER NEGATIVES TOO FOR CONVECTION...BEING CLOSER TO THE SUBTROPICAL
HIGH...AND 0.25-0.5 INCH DRYING OF PRECIPITABLE WATER VALUES
ORIGINATING FROM EASTERN KY/TN THIS MORNING. SEEING THE DRY FORECAST
FROM THE NAM...THE 15.12Z CANADIAN WHICH DID A GOOD JOB WITH PRECIP
TODAY AND IS DRY FOR TUESDAY...ALONG WITH OTHER MODELS SHOWING VERY
LITTLE IF ANY QPF...WENT BACK TO A DRY FORECAST. 850MB TEMPS ARE 2C
HIGHER TOMORROW...BETWEEN 18-19C...SO WE SHOULD SEE ABOUT A SIMILAR
INCREASE IN HIGH TEMPERATURES INTO UPPER 80S/LOW 90S. DEWPOINTS UP
IN THE UPPER 60S/LOW 70S AND THE FORECAST HIGH TEMPERATURES WILL
LIKELY LEAD TO PLENTY OF CUMULUS...BUT MORE IMPORTANTLY MAKE IT FEEL
MUGGY. HEAT INDICES ARE STILL FORECAST TO TOP OUT IN THE 95-100
RANGE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 249 PM CDT MON JUL 15 2013
SYNOPTIC OVERVIEW...
MODELS REMAIN CONSISTENT IN THE STRONG SUBTROPICAL HIGH RETROGRADING
ACTUALLY SOUTHWESTWARD THROUGH THE REST OF THE WEEK. THIS IS IN
RESPONSE TO FIRST THE TROUGH IN SOUTHWEST CANADA MARCHING
EAST-NORTHEAST AND FLATTENING THE RIDGE...AND FINALLY AN UPPER LOW
CURRENTLY OFF THE COAST OF SAN FRANSISCO DROPPING SOUTHEAST THROUGH
THE FORECAST AREA AS A SHORTWAVE TROUGH. BY SATURDAY WE SHOULD BE
LOOKING AT TROUGHING OVER THE WESTERN GREAT LAKES VERSUS THE CURRENT
RIDGING. HEADING INTO SUNDAY AND MONDAY...INDICATIONS ARE THAT A
MORE POTENT SHORTWAVE TROUGH WILL BE APPROACHING THE AREA IN THE
NORTHWEST FLOW.
HAZARDS...
HEAT INDICES REMAIN THE BIG CONCERN. TUESDAY THROUGH THURSDAY LOOK
SOLID TO HAVE AFTERNOON HEAT INDICES BETWEEN 95-100...ESPECIALLY IN
THE VALLEYS. HEAT ADVISORY CRITERIA REQUIRES 100 OR GREATER FOR 1
DAY OR GREATER THAN 95 FOR 4 OR MORE DAYS. THE MORE LIKELY OF THE
TWO OPTIONS TO HIT WOULD BE DURATION. HEAT INDICES ONLY TOPPED OUT
IN THE UPPER 80S TO MID 90S TODAY...SO THAT MEANS FRIDAY WOULD NEED
95 OR GREATER. WITH CONCERN OF THE FRONT AND CONVECTION COMING
THROUGH FRIDAY...HAVE REFRAINED AT THIS TIME FROM ISSUING A HEAT
ADVISORY. HOWEVER...WE WILL ISSUE A SPECIAL WEATHER STATEMENT TO
DISCUSS THE HEAT. NOTE THAT THIS TIME PERIOD OF 15TH THROUGH 18TH
OF JULY IS COMMONLY THE TIME TO GET HEAT.
THERE IS A POSSIBILITY OF SEVERE WEATHER TOO IN THE THURSDAY THROUGH
FRIDAY TIME PERIOD. THURSDAY/THURSDAY NIGHT WOULD BE MORE TO THE
NORTH...PERHAPS JUST TAYLOR/CLARK COUNTIES AS ALSO SHOWN IN THE SPC
DAY 4-8 OUTLOOK. FRIDAY IT ALL DEPENDS ON THE FRONTAL TIMING.
ADDITIONALLY...THE BEST 0-6KM SHEAR IS BEHIND THE FRONT...WITH ONLY
30-35 KT ON THE FRONT. SO IT WOULD SEEM THAT OVERALL ANY SEVERE
WEATHER WOULD BE ISOLATED WITH DAMAGING WINDS AND HEAVY RAIN THE
MAIN HAZARDS.
DAILY DETAILS...
TUESDAY NIGHT AND WEDNESDAY...
A COLD FRONT ACCOMPANYING THE SOUTHWEST CANADA TROUGH IS PROGGED TO
DROP INTO NORTHERN MN BY 12Z WED AND THEN LAY UP BETWEEN ST CLOUD MN
AND UPPER MI LATE WEDNESDAY. ENVISIONING CONVECTION ON THIS
BOUNDARY...DUE TO PLENTIFUL MOISTURE AND INSTABILITY AROUND IT...
ALONG WITH LAKE BREEZE ENHANCED CONVERGENCE. GIVEN ITS LOCATION...
ANTICIPATING ANY CONVECTION TO STAY UP TO THE NORTH THROUGH
WEDNESDAY. WILL NEED TO MONITOR TAYLOR COUNTY FOR A NEED FOR SOME
CHANCES OF PRECIPITATION IN LATER FORECASTS SHOULD THE BOUNDARY DROP
FARTHER SOUTH. OTHERWISE...PRECIPITABLE WATER VALUES ARE PROGGED TO
HOLD STEADY OR EVEN FALL A LITTLE MORE COMPARED TO TUESDAY...SO NOT
ANTICIPATING ANY DIURNAL CONVECTION. WITH CONTINUED AIRMASS
MODIFICATION OF THE SUBTROPICAL HIGH...850MB TEMPS CLIMB ABOUT
ANOTHER 1C...WHICH WITH PLENTY OF SUN SHOULD YIELD ANOTHER DAY OF
HIGHS IN THE UPPER 80S/LOW 90S.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...
THIS PERIOD APPEARS A BIT MORE MUDDLED / LESS CONFIDENCE / THAN
BEFORE. WITH A ZONAL UPPER FLOW PATTERN THROUGH THURSDAY...THE COLD
FRONT SITUATED UP TO OUR NORTH APPEARS LIKELY TO STAY IN PLACE. IN
FACT...ON THURSDAY NIGHT WHEN THE SHORTWAVE TROUGH DROPS INTO THE
DAKOTAS...THE FRONT COULD EVEN GET PROPELLED NORTHWARD. 15.12Z
ECMWF/GFS/NAM/UKMET/CANADIAN ALL DEPICT THE NOSE/GRADIENT OF THE
850MB MOISTURE TRANSPORT STAYING FOCUSED FROM NORTHERN MN INTO
NORTHERN WI/UPPER MI AND LOWER MI FROM WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT. FIGURE CONVECTION WOULD EITHER BE TIED TO THE FRONT
OR NOSE OF THE MOISTURE TRANSPORT...WHICH BOTH SUGGEST NORTH OF THE
FORECAST AREA. CORFIDI VECTORS ARE FAIRLY LIGHT TOO IN TERMS OF
SPEEDS WITH DIRECTIONS MAINLY WEST OR WEST-NORTHWEST...SO IF AN MCS
FORMS IT COULD END UP STAYING NORTH OF THE AREA AS WELL. GIVEN ALL
OF THIS...HAVE DECIDED TO SHIFT ALL OF THE PRECIPITATION CHANCES
NORTHWARD...WHICH MEANS A REDUCTION ACROSS THE BOARD. WOULD NOT BE
SURPRISED IF ALL STORMS DURING THIS PERIOD STAY NORTH OF HIGHWAY 29.
TEMPERATURES THURSDAY LOOK SIMILAR TO TUESDAY AND WEDNESDAY WITH
850MB TEMPS OF 18-20C.
FRIDAY THROUGH MONDAY...
GOOD AGREEMENT REMAINS ABOUT THE COLD FRONT COMING THROUGH THE AREA
ON FRIDAY...AHEAD OF THE SHORTWAVE TROUGH. HAVE SOME CONCERN THAT
THIS FRONT COULD COME THROUGH DRY SEEING THE 15.00Z ECMWF. THREE
NEGATIVES WITH THIS FRONT FOR CONVECTION IS THE POSITIVELY TITLED
NATURE OF THE SHORTWAVE...WEAK CONVERGENCE AND THAT THE TIMING MAY
BE MESSED UP. FOR NOW LEFT A MODEL CONSENSUS 20-40 PERCENT CHANCES
IN THE FORECAST INTO FRIDAY EVENING. HIGH PRESSURE IS STILL
INDICATED TO BUILD INTO THE AREA FOR THE WEEKEND. HOWEVER...BEING
UNDER UPPER TROUGHING YIELDS CONCERNS FOR SHORTWAVES COMING THROUGH
AT PEAK HEATING AND INITIATING CONVECTION. THE 15.00Z ECMWF HINTED
AT THIS FOR SATURDAY...BUT THE 15.12Z RUN IS NOW DRY. WITH A DRY GFS
FORECAST...HAVE KEPT SATURDAY INTO SATURDAY NIGHT DRY. MUCH OF
SUNDAY MAY BE DRY TOO...THOUGH THERE ARE INDICATIONS FROM THE 15.12Z
ECMWF OF A SHORTWAVE MOVING INTO MN BRINGING CONVECTION TO LOCATIONS
MAINLY WEST OF THE MS RIVER. THUS...HAD TO KEEP SOME LOW CHANCES
THERE. ADDITIONAL CHANCES IN THE 20-40 RANGE ARE FORECAST INTO
MONDAY ASSOCIATED WITH THE MORE POTENT SHORTWAVE. TIMING IS STILL
YET TO BE DETERMINED ON THIS SHORTWAVE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1211 PM CDT MON JUL 15 2013
NOT MUCH OF A FOCUS FOR CONVECTION TO DEVELOP THIS AFTERNOON...BUT
STILL POSSIBLE. THE 15.15Z RAP CONTINUES TO SUGGEST THE
POSSIBILITY OF A WEAK MID LEVEL SHORT WAVE TROUGH TO MOVE ACROSS
THE AREA ON THE WEST SIDE OF THE ATLANTIC RIDGE ALONG WITH SOME
WEAKENING LOW TO MID LEVEL MOISTURE TRANSPORT ASSOCIATED WITH THE
WAVE. A FEW SHOWERS HAVE ALREADY POPPED UP NORTH OF THE TAF SITES
WHERE THERE IS SOME WEAK SURFACE CONVERGENCE. HIGHER CONFIDENCE
THAT ANY SHOWERS THAT DEVELOP THROUGH THE AFTERNOON WILL MISS THE
TAF SITES BUT SINCE VCSH ALREADY INCLUDED IN THE FORECAST WILL
LEAVE IT IN. WILL INCLUDE SOME MVFR VISIBILITY FOR FOG OVERNIGHT
AS THE 15.12Z NAM BUFKIT SOUNDING SHOWS SATURATION OCCURRING AT
THE SURFACE FOR BOTH SITES. HOWEVER...THE 15.15Z RAP DOES NOT SHOW
THIS AND BOTH MODELS ALSO HAVE WINDS OF 10+ KNOTS NOT FAR ABOVE
THE SURFACE. BETTER CHANCE FOR THE VALLEY TO DECOUPLE AT KLSE SO
HAVE GONE WITH A CATEGORICAL VISIBILITY RESTRICTION THERE WHILE
JUST INCLUDING IT IN A TEMPO GROUP AT KLSE. SHOULD SEE SOME LATE
MORNING CUMULUS CLOUDS DEVELOP AGAIN TUESDAY BUT WILL LET LATER
FORECASTS DETAIL THIS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1145 PM CDT SUN JUL 14 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 250 PM CDT SUN JUL 14 2013
MAIN FORECAST CONCERN IS ON THUNDERSTORM POTENTIAL FOR MONDAY.
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A SHARP SHORTWAVE TROUGH OVER BRITISH COLUMBIA...AN UPPER LOW
OVER EASTERN OKLAHOMA...A SHORTWAVE TROUGH STRETCHING FROM NORTHERN
MN INTO EASTERN SOUTH DAKOTA...AND THE BERMUDA HIGH OVER THE EASTERN
GREAT LAKES. 500MB HEIGHTS ASSOCIATED WITH THE BERMUDA HIGH ARE
QUITE IMPRESSIVE...NEARING 600 DAM OR 2.5 STANDARD DEVIATIONS ABOVE
NORMAL. DESPITE THE SUBSTANTIAL 500MB HEIGHTS...850MB TEMPS ARE ONLY
IN THE 15-18C UNDERNEATH IT PER 12Z RAOBS OR NEAR 1 STANDARD
DEVIATION ABOVE NORMAL. THE WESTERN EXTENT OF THE SUBTROPICAL RIDGE
HAS BEEN PROVIDING SUBSIDENCE OVER THE FORECAST AREA...RESULTING IN
DRY CONDITIONS WITH JUST SOME DIURNAL CUMULUS CLOUDS. TO OUR
WEST...A STREAM OF PRECIPITABLE WATER VALUES OF 1.65 TO 2 INCHES
PER GOES DERIVED IMAGERY STRETCHED FROM CENTRAL OKLAHOMA TO
EASTERN SOUTH DAKOTA AND NORTHERN MN. THIS STREAM OF HIGH MOISTURE
IS CO-LOCATED WITH THAT SHORTWAVE TROUGH IN THE NORTHERN PLAINS
AND DEFORMATION ON THE WEST SIDE OF THE UPPER LOW. NUMEROUS
SHOWERS AND THUNDERSTORMS WERE PRESENT IN THE STREAM.
EXPECT THE RETROGRADING 500MB PATTERN TO CONTINUE THROUGH THE SHORT
TERM PERIOD...SUCH THAT BY 00Z TUESDAY MODELS FORECAST THE BERMUDA
HIGH TO BE SITUATED NEAR THE OHIO/INDIANA BORDER. THIS RETROGRESSION
MEANS 500MB HEIGHTS ARE GOING TO RISE OVER THE FORECAST AREA...
IMPLYING SUBSIDENCE. NOT ANTICIPATING ANY PRECIPITATION TONIGHT
BEING IN THE NOCTURNAL COOLING PERIOD AND RISING HEIGHTS ALOFT. ON
MONDAY...DESPITE BEING UNDER THE SUBSIDENCE OF THE RISING HEIGHTS
ALOFT...NEARLY EVERY MODEL DEPICTS ISOLATED TO SCATTERED SHOWER AND
THUNDERSTORM DEVELOPMENT BETWEEN 18Z-00Z OVER THE FORECAST AREA.
THE REASONING FOR THE PRECIPITATION IS A COMBINATION OF FACTORS:
1. SOUTHEAST WINDS ADVECTING IN 70+ SURFACE DEWPOINTS...WHICH ARE
ACCOMPANYING THE BERMUDA HIGH AND ENHANCED BY EVAPOTRANSPIRATION
FROM VEGETATION.
2. STREAM OF HIGHER PRECIPITABLE WATER VALUES OF 1.8 TO 2 INCHES
COMING UP OUT OF GEORGIA AND ALABAMA CURRENTLY.
3. DAYTIME HEATING COMBINING WITH THE HIGHER DEWPOINTS TO BUILD UP
INSTABILITY. MIXING TO 850MB TEMPS OF 16-17C SHOULD YIELD HIGHS IN
THE MID TO UPPER 80S.
4. SOUNDINGS DEPICT NO CAPPING
LOOKING AT VARIOUS PRESSURE LEVELS FOR CONVERGENCE...IT IS VERY
DIFFICULT TO FIND ANY. THUS...IT APPEARS THE LACK OF CAPPING AND THE
HIGHER DEEPER MOISTURE ITSELF WILL RESULT IN POP UP SHOWERS AND
THUNDERSTORMS. 0-6KM SHEAR VALUES OF LESS THAN 20 KT MEANS THESE
STORMS ARE GOING TO BE PULSE AND NON-SEVERE...WITH OUTFLOWS
PRODUCING ADDITIONAL SHOWERS AND THUNDERSTORMS. MAIN CONCERN WITH
THIS PRECIPITATION IS BRIEF HEAVY RAIN GIVEN THE PRECIPITABLE WATER
VALUES AND DEEP WARM CLOUD DEPTHS.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 250 PM CDT SUN JUL 14 2013
THE RETROGRESSION 500MB PATTERN CONTINUES FROM THE SHORT TERM PERIOD
RIGHT INTO NEXT WEEKEND. 14.12Z ECMWF/CANADIAN/GFS AND 14.00Z ECMWF
ENSEMBLE MEAN ALL SHOW THAT THE BERMUDA HIGH WILL SLOWLY MOVE
WESTWARD THROUGH THE WEEK...SUCH THAT BY LATE FRIDAY INTO THE
WEEKEND TROUGHING DOMINATES MUCH OF CANADA INTO THE WESTERN GREAT
LAKES REGION.
MONDAY NIGHT THROUGH WEDNESDAY...
CONVECTION THAT FORMED MONDAY AFTERNOON SHOULD DISSIPATE PRETTY
QUICK IN THE EVENING...LIKELY BY 03Z...AS THE LOSS OF DAYTIME
HEATING DIMINISHES THE INSTABILITY. THE REST OF THE NIGHT INTO
TUESDAY MORNING LOOKS DRY WITH THE MAIN FORCING FOR NOCTURNAL
CONVECTION WELL OFF TO THE NORTHWEST IN THE DAKOTAS. A SIMILAR SETUP
TO MONDAY AFTERNOON LOOKS TO OCCUR FOR TUESDAY AFTERNOON WITH
DEWPOINTS IN THE UPPER 60S TO LOW 70S...HIGHS A FEW DEGREES WARMER
GIVEN 850MB TEMPS PROGGED BETWEEN 18-19C...AND HIGHER CAPE VALUES
DUE TO THESE READINGS. HOWEVER...MODELS ARE MUCH LESS AGGRESSIVE
WITH QPF...AND THIS APPEARS TO STEM FROM PRECIPITABLE WATER VALUES
THAT ARE 0.25-0.5 INCH LOWER. GIVEN THAT THE 14.12Z NAM WHICH IS
USUALLY AGGRESSIVE IN THESE SCENARIOS AND HAPPENS TO BE DRY...AND
COLLABORATION WITH SURROUNDING OFFICES...WENT DRY FOR TUESDAY.
SHOWERS AND THUNDERSTORMS STILL LOOK POSSIBLE NORTH AND EAST OF THE
FORECAST AREA...ASSOCIATED WITH LAKE BREEZES RUNNING INTO THE
UNSTABLE AIR. A COMPLETE REPEAT OF THE WEATHER HAPPENS TUESDAY NIGHT
AND WEDNESDAY...AND HERE AGAIN MODELS ARE NOT THAT AGGRESSIVE WITH
QPF WEDNESDAY AFTERNOON STEMMING FROM SIMILAR PRECIPITABLE WATER
VALUES TO TUESDAY. REMOVED THE 20 PERCENT CHANCES FOR WEDNESDAY.
SAFE TO SAY THAT IF INDEED NO PRECIPITATION HAPPENS TUESDAY...
WEDNESDAY WILL END UP DRY TOO. HIGHS ON WEDNESDAY ARE LIKELY TO BE
SIMILAR TO TUESDAY WITH 850MB TEMPS HOVERING AROUND 19C...YIELDING
READINGS IN THE UPPER 80S TO LOWER 90S.
WITH TUESDAY AND WEDNESDAY AFTERNOON DEWPOINTS IN THE UPPER 60S TO
LOWER 70S AND HIGHS IN UPPER 80S TO LOWER 90S...HEAT INDICES ARE
LIKELY TO CLIMB INTO THE 95-100 RANGE. THESE ARE JUST UNDER HEAT
ADVISORY CRITERIA. SHOULD EITHER DEWPOINTS OR TEMPERATURES GET
HIGHER THAN FORECAST...HEAT ADVISORIES MAY BE REQUIRED.
WEDNESDAY NIGHT THROUGH SUNDAY...
THE PROGGED SWITCH IN THE UPPER FLOW TO MORE NORTHWESTERLY ALLOWS
A COLD FRONT SITUATED OVER NORTHERN MN AND UPPER MI ON WEDNESDAY
TO SLOWLY DRIFT SOUTH. THE TIMING OF WHEN THIS BOUNDARY CROSSES
THE FORECAST AREA LOOKS TO BE MODULATED BY A SHORTWAVE DROPPING
THROUGH NORTH DAKOTA...WHICH COULD STALL OR EVEN SEND THE FRONT
BACK NORTHWARD THURSDAY NIGHT AS SUGGESTED BY THE 14.00Z/14.12Z
ECMWF. MOST MODELS AGREE ON A TIMING OF THE COLD FRONT CROSSING
THE AREA FRIDAY INTO FRIDAY EVENING...WITH PERHAPS THE FRONT
COMING INTO NORTHERN SECTIONS OF THE FORECAST AREA WEDNESDAY
NIGHT. GIVEN PLENTIFUL INSTABILITY IN PLACE AHEAD OF AND AROUND
THE BOUNDARY...AS WELL AS A PLUME OF HIGHER PRECIPITABLE WATER
VALUES ON THE ORDER OF 1.75-2 INCHES...DEFINITELY NEED CHANCES OF
SHOWERS AND THUNDERSTORMS. THERE ARE INDICATIONS OF POSSIBLE MCS
ACTIVITY TOO...ESPECIALLY THURSDAY AFTERNOON AND NIGHT NORTH OF
I-90 WHICH IS WHERE CHANCES OF PRECIPITATION ARE ON THE ORDER OF
50-60. ONE PORTION OF THE FORECAST WHERE CHANCES MAY BE ABLE TO BE
REMOVED IS FRIDAY NIGHT...SINCE THERE ARE SOME INDICATIONS OF THE
FRONT AND ASSOCIATED CONVECTION GETTING OUT OF THE AREA IN TIME.
HIGH PRESSURE BUILDS IN FOR SATURDAY AND SATURDAY NIGHT...BRINGING
DRIER CONDITIONS. UNCERTAINTY INCREASES FOR SUNDAY WITH
INDICATIONS OF SOME SHORTWAVE TROUGH DROPPING THROUGH IN THE
NORTHWEST FLOW. HAVE FOLLOWED A MODEL CONSENSUS OF 20-40 PERCENT
CHANCES FOR NOW.
SOME SEVERE WEATHER IS POSSIBLE THURSDAY THROUGH FRIDAY...WITH 0-6KM
SHEAR VALUES PROGGED OF 30-35 KT ALONG THE COLD FRONT. DAMAGING
WINDS AND HEAVY RAIN WOULD APPEAR TO BE THE MAIN HAZARDS. LOCATIONS
NORTH OF I-90 SEEM TO BE CENTERED ON HAVING THE MOST RAIN DURING
THIS PERIOD...WHICH IS AN AREA THAT NOT ONLY CAN HANDLE THE RAIN BUT
NEEDS IT.
TEMPERATURES THURSDAY THROUGH FRIDAY ARE QUITE TRICKY. 850MB TEMPS
UPWARDS OF 20C COULD EASILY SUPPORT HIGHS IN THE LOW TO EVEN PERHAPS
MID 90S...AND WITH DEWPOINTS UP IN THE LOW 70S WOULD YIELD HEAT
INDICES AGAIN IN THE 95-100 RANGE. HOWEVER...THERE IS CONVECTION TO
WORRY ABOUT...ESPECIALLY ON FRIDAY. THUS...HIGH TEMPERATURES ARE
ONLY FORECAST IN THE MID 80S TO LOW 90S AT THIS TIME. 850MB TEMPS
FALLING INTO THE 13-15C RANGE FOR SATURDAY AND ONLY CLIMBING ABOUT
1C HIGHER ON SUNDAY WILL RESULT IN COOLER TEMPERATURES...UPPER 70S
TO MID 80S.
&&
.AVIATION...THROUGH 06Z TUESDAY
1145 PM CDT SUN JUL 14 2013
HIGH PRESSURE IN PLACE OVER THE AREA...RETROGRADING WESTWARD INTO
THE REGION. AS GRADIENT WEAKENED THIS EVENING FLOW BECAME MORE
EASTERLY AND SLACKENED. WITH LIGHT WINDS...COOLING TEMPS...AND
INCREASING LOW LEVEL MOISTURE...FEEL SOME PATCHES OF LIGHT
FOG/MIST WILL BE SEEN FOR A FEW HOURS AROUND SUNRISE. LATEST
SURFACE OBSERVATIONS AND SATELLITE FOG ENHANCEMENT SHOWING SOME
SCATTERED CLOUD DEVELOPING AROUND 5KFT IN A SOUTHWEST TO NORTHEAST
BAND. MODELS DID HINT AT THIS...AND PROPAGATE IT TO THE NORTH AND
NORTHEAST OVERNIGHT.
AS MOISTURE AND INSTABILITY BUILDS ON MONDAY...ANTICIPATE SOME
SHOWERS TO BREAK OUT FOR THE AFTERNOON AND EARLY EVENING HOURS.
MAIN FOCUS FOR THIS ACTIVITY WILL BE ACROSS IOWA/ILLINOIS...BUT
SOME SHOULD DRIFT NORTH INTO BOTH TAF LOCATIONS AND ADDED THIS TO
THE FORECASTS. ACTIVITY SHOULD DIMINISH DIURNALLY IN THE EVENING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...MW
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1124 PM MDT SUN JUL 14 2013
.UPDATE...
ISSUED AT 848 PM MDT SUN JUL 14 2013
OVERALL AN UNEVENTFUL EVENING ACROSS THE CWA...DESPITE THE SURFACE
DEWPOINTS IN THE 60S AND PRECIPITABLE WATER VALUES THAT ARE
RUNNING 150 TO 200 PERCENT OF NORMAL. THICKER DAYTIME CLOUD COVER
CERTAINLY THWARTED SOME OF THE INSTABILITY. BUT THE PRIMARY
HINDRANCE HAS BEEN THE LACK OF A TRIGGER. THE ORIGINAL THOUGHT WAS
THAT OROGRAPHIC ASCENT WOULD BE SUFFICIENT IN CONVECTIVE
DEVELOPMENT...WHICH OBVIOUSLY HAS NOT BEEN THE CASE. OUTSIDE OF
A FEW ISOLATED THUNDERSTORMS...MUCH OF THE CWFA HAS REMAINED DRY.
INITIAL LOOK AT 00Z GUIDANCE SHOWS ANY HOPE OF CONVECTION FADING
THROUGH THE OVERNIGHT HOURS AS RIBBON OF MOISTURE THINS AS IT
BACKS TO THE WEST THROUGH THE CWA. COULD STILL SEE SOME SHOWERS
AND EVEN EMBEDDED THUNDER DEVELOP THRU THE NIGHT...BUT ANY HOPE IS
QUICKLY FADING. SO...IN AN EARLIER UPDATE BEGAN SCALING BACK
PRECIPITATION CHANCES ACROSS THE ENTIRE AREA TONIGHT. THE OTHER
CONCERN IS THE POTENTIAL FOR FOG DEVELOPMENT AFTER MIDNIGHT GIVEN
THE VERY MOIST LLVLS. BOTH THE SREF AND HRRR ARE POINTING TO ITS
DEVELOPMENT ALONG THE LARAMIE RANGE AND ADJACENT EASTERN
FOOTHILLS. GIVEN ESE LLVL FLOW...THIS SEEMS TO BE PLAUSIBLE. SO
HAVE ADDED AREAS OF FOG ACROSS MOST OF THE EASTERN PLAINS FOR LATE
TONIGHT AND EARLY MONDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 350 PM MDT SUN JUL 14 2013
VERY MOIST AIRMASS IS CURRENTLY OVER THE CWA WITH MANY AREAS TO
THE EAST OF THE LARAMIE RANGE SEEING 60S DEWPOINTS. THE EXTENSIVE
LOW AND MIDLEVEL CLOUD COVER THAT HAS OCCURRED THROUGH THE EARLY
AFTERNOON HAS LIMITED SFC HEATING AND INSTABILITY. HOWEVER...VISIBLE
IMAGERY SHOWS THE PLAINS STARTING TO CLEAR AND LAPS ANALYSIS
INDICATES WIDESPREAD 500-1000 J/KG OF CAPE. BELIEVE THERE COULD BE
AN UPTICK IN CONVECTIVE ACTIVITY DURING THE EARLY EVENING OVER THE
SOUTHERN ZONES DESPITE THE LATE START. THE SFC TROUGH AND
ASSOCIATED HIGHEST DEWPOINT/PW VALUES IS JUST TO THE EAST OF THE
CWA AND IS PROGGED TO CONTINUE MOVING WESTWARD THROUGH THE NIGHT.
THE MOST IMPRESSIVE CONVECTION IS CURRENTLY IN THE CONVERGENCE
ALONG THAT TROUGH...OUTFLOW FROM THIS CONVECTION SHOULD BE ABLE TO
INITIATE CONVECTION IN THE SOUTHERN PANHANDLE DURING THE EVENING.
STILL HAVE HEAVY RAIN IN THE GRIDS THROUGH THE NIGHT WITH PW
VALUES AROUND 1.3 INCHES AND SLOW STEERING FLOW (700-300MB FLOW IS
AROUND 5-10 KTS). AREAS IN SCOTTS BLUFF COUNTY PICKED UP AROUND 2
INCHES OF RAINFALL IN A FEW HOURS EARLIER THIS AFTERNOON...A
TESTAMENT TO THE HEAVY RAIN POTENTIAL. THE PW RIDGE AXIS IS IN
EXTREME SOUTHEAST WY BY MONDAY MORNING SO CONTINUED THE THREAT OF
SHOWERS THROUGH THE NIGHT ACROSS MUCH OF THE PLAINS.
UPPER LOW AND ITS ASSOCIATED MIDLEVEL MOISTURE PLUME CONTINUE TO
MOVE WESTWARD ON MONDAY. PW VALUES ARE HIGHEST (AROUND 1 INCH)
ACROSS SOUTHEAST WY WITH A CONSIDERABLE DROP IN THE PANHANDLE.
HAVE CHANCE POPS MAINLY ALONG AND WEST OF THE LARAMIE RANGE DURING
THE AFTN AND EVENING...NOT EXPECTING MUCH FURTHER EAST. STEERING
FLOW CONTINUES TO BE WEAK SO THE HEAVY RAIN THREAT WILL BE
THERE...ESPECIALLY IN THE HIGHER TERRAIN WHERE COVERAGE OF STORMS
WILL BE BEST. TEMPS WARM AROUND 5 DEGREES ON MONDAY WITH LESS
CLOUD COVER...ESPECIALLY IN NEBRASKA. THE DRYING TREND THAT HAS
BEEN PROGGED FOR TUESDAY CONTINUES TO LOOK ON TRACK. WITH PW
VALUES AT 0.5-0.75 INCHES AND LI VALUES ON THE GFS STRUGGLING TO
GET NEGATIVE...STORM POTENTIAL WILL REALLY DROP OFF. SLIGHT CHANCE
POPS ARE CONFINED TO THE SIERRA MADRE AND SNOWY RANGES.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 350 PM MDT SUN JUL 14 2013
TUESDAY NIGHT...EVENING THUNDERSTORMS ACROSS THE SIERRA MADRE RANGE
IN UPSLOPE...OTHERWISE DRY.
WEDNESDAY...UPPER RIDGE AXIS OVER OUR COUNTIES. SURFACE LOW AND LOW
LEVEL CONVERGENCE AXIS OVER OUR SNOWY AND SIERRA MADRE RANGES...
WHERE SCATTERED AFTERNOON THUNDERSTORMS ON TAP...DRY ELSEWHERE WITH
SUBSIDENCE AND CONVECTIVE INHIBITION.
THURSDAY...RIDGE ALOFT WEAKENS SLIGHTLY AND WITH SLIGHTLY MORE LOW
AND MID LEVEL MOISTURE...EXPECT SCATTERED AFTERNOON THUNDERSTORMS
OVER THE NORTHERN...SNOWY AND SIERRA MADRE RANGES...DRY ELSEWHERE.
FRIDAY...MONSOONAL MOISTURE TAP RETURNS OVER OUR COUNTIES AND WITH
LOW LEVEL UPSLOPE WINDS AND PLENTY OF LOW AND MID LEVEL MOISTURE...
WILL SEE SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS...MOST
NUMEROUS OVER THE MOUNTAINS.
SATURDAY...DEEPER MONSOONAL MOISTURE FEED TRANSLATES SOUTH ACROSS
COLORADO...THOUGH STILL ENOUGH MOISTURE FOR ISOLATED TO SCATTERED
LATE DAY THUNDERSTORMS FOCUSED NEAR THE MOUNTAINS.
SUNDAY...DRIER AIRMASS ADVECTS IN ON NORTHWEST FLOW ALOFT...THUS
ONLY ISOLATED LATE DAY THUNDERSTORMS ON TAP OVER THE MOUNTAINS...DRY
ELSEWHERE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY EVENING)
ISSUED AT 1124 PM MDT SUN JUL 14 2013
FAIRLY WIDESPREAD IFR/LIFR CIGS EXPECTED ACROSS MUCH OF THE NEB
PANHANDLE INTO FAR ERN WYOMING INTO MONDAY MORNING IN MOIST UPSLOPE
FLOW. AREAS OF FOG AS WELL LOWERING VSBYS TO LESS THAN 3 MILES IN
SOME SPOTS. CONDITIONS SHOULD IMPROVE SLOWLY AFTER SUNRISE.
ISOLATED SHOWERS AND A FEW TSTRMS POSSIBLE MONDAY AFTERNOON INTO
MONDAY EVENING MAINLY OVER AND EAST OF THE MTNS.
&&
.FIRE WEATHER...
ISSUED AT 350 PM MDT SUN JUL 14 2013
NO FIRE WEATHER CONCERNS THROUGH EARLY NEXT WEEK. A VERY MOIST
AIRMASS IS CURRENTLY AFFECTING THE REGION WITH SCATTERED SHOWERS
AND THUNDERSTORMS POSSIBLE THROUGH THE EARLY NIGHT. THIS MOIST
AIRMASS WILL CONTINUE MOVING WESTWARD WITH ANOTHER CHANCE OF
SHOWERS AND THUNDERSTORMS ON MONDAY AFTERNOON AND EVENING...MAINLY
ALONG AND WEST OF THE LARAMIE RANGE. STORM CHANCES WILL REALLY
DROP BY TUESDAY AS MIDLEVEL MOISTURE PUSHES OUT OF THE REGION.
WINDS WILL GENERALLY BE BELOW 20 MPH THROUGH TUESDAY...EXCEPT IN
THE VICINITY OF STORMS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...HAHN
SHORT TERM...FINCH
LONG TERM...RUBIN
AVIATION...RE
FIRE WEATHER...FINCH
AREA FORECAST DISCUSSION
NWS TAUNTON MA
134 AM EDT WED JUL 17 2013
.SYNOPSIS...
HOT AND HUMID WEATHER WILL CONTINUE THIS WEEK WITH ONLY WIDELY
SCATTERED SHOWERS OR THUNDERSTORMS ON WED. CHANCES FOR SHOWERS
AND THUNDERSTORMS WILL INCREASE THU...FRI AND ESPECIALLY SAT AS A
COLD FRONT APPROACHES FROM THE GREAT LAKES. RELIEF FROM THE HEAT
AND HUMIDITY WILL ARRIVE ON SUNDAY BEHIND A STRONG COLD FRONT AND
LAST THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
130 AM UPDATE...
MAINLY SKC CONDITIONS ACROSS THE REGION THIS HOUR AS REMNANT
CONVECTIVE CLOUDS HAVE ALREADY DISSIPATED. NOT EXPECTING ANY MORE
CLOUD COVER THROUGH THE MORNING...SO TEMPS MAY CONTINUE TO DECLINE
A FEW MORE HOURS AND DIP TO THE UPPER 60S IN SEVERAL LOCATIONS
BEFORE REBOUNDING AFTER SUNRISE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
WED WILL BE SIMILAR TO TODAY...WITH A MOSTLY CLEAR START AND
TEMPERATURES RAPIDLY CLIMBING INTO THE LOWER TO MID 90S.
TEMPERATURES WILL BE A COUPLE OF DEGREES WARMER AND DEWPOINTS WILL
BE A DEGREE OR TWO HIGHER...WHICH WILL LEAD TO HEAT INDICES
REACHING 98-102 OVER MOST OF SOUTHERN NEW ENGLAND...INCLUDING
SOUTHERN NH...WITH THE ONLY EXCEPTIONS BEING CAPE COD AND THE
ISLANDS. THUS HAVE ISSUED A HEAT ADVISORY FOR MOST OF THE REGION
FOR WED AFTERNOON AND EARLY EVENING.
WINDS WILL STILL BE LIGHT...BUT SHOULD TURN TO A SOUTHERLY
DIRECTION. ALTHOUGH HIGHS REACHED 90 ON BLOCK ISLAND TODAY...WITH
LIGHT SOUTHERLY WINDS EXPECTED OFF OF THE COOLER WATERS WED...HAVE
ONLY FORECAST MID 80S THERE...IT COULD POTENTIALLY BE COOLER THAN
THAT.
THERE IS A CHANCE OF AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS
ON WED...MAINLY IN SOUTHERN NH AND NORTHERN MA...AS LOW PRESSURE
MOVES ACROSS SOUTHERN QUEBEC AND A TROUGH OF LOW PRESSURE PASSES
ACROSS NEW ENGLAND. UPPER LEVEL HIGH PRES RIDGE STILL IN CONTROL
THOUGH WITH CAP AROUND H7 AND UNFAVORABLE MID LEVEL LAPSE RATES.
SB CAPE VALUES LOOK TO BE A BIT HIGHER THANKS TO THE INCREASING
MOISTURE WITHIN THE COLUMN...AVERAGING ABOUT 1500-2000 J/KG.
THEREFORE...WENT WITH 25 TO 35 PCT CHANCE IN NORTHEAST MA/SOUTHERN
NH AND 20 PCT FARTHER TO THE SOUTH INTO NORTHERN CT/RI/SOUTHEAST
MA.
WEDNESDAY EVENING...ANY CONVECTION WILL DIMINISH AGAIN BY SUNSET.
ANOTHER WARM AND MUGGY NIGHT WITH CLEAR TO PARTLY CLOUDY SKIES IS
EXPECTED. PERHAPS A LITTLE MORE PATCHY FOG AS THE AIR MASS GETS
EVEN MORE HUMID. LOWS MAINLY UPPER 60S TO MID 70S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HEADLINES...
* HOT/HUMID THU INTO SAT WITH SCATTERED T-STORMS
* SEVERE STORMS POSSIBLE AHEAD OF A COLD FRONT SAT
* SEASONABLE AND DRY SUNDAY INTO THE BEGINNING OF NEXT WEEK
DETAILS...
NOT MUCH CHANGE IN OUR FORECAST THINKING FROM PREVIOUS SHIFTS.
MODELS REMAIN IN GOOD OVERALL AGREEMENT SHIFTING H5 HIGH SOUTH
AND WEST TOWARDS THE FOUR-CORNERS REGION ALLOWING FOR FALLING
HEIGHTS ACROSS NEW ENGLAND. THIS RESULTS IN THE RETURN OF THE
NORTHERN STREAM AS DOMINANT INFLUENCE AND SUBSEQUENTLY A MORE
ACTIVE PATTERN.
THURSDAY...
MODELS KEY ON LEE TROUGH BECOMING FOCUS FOR SCATTERED AFTERNOON
CONVECTION. SURFACE-BASED CAPES REACH 1500 J/KG WITH DECENT MID
LEVEL LAPSE RATES AROUND 6C/KM...BUT 0-6KM SHEAR IS MARGINAL AT
BEST. STILL NEED TO OVERCOME RATHER WARM MID LEVEL TEMPERATURES...
SO NOT CONFIDENT THAT STORM COVERAGE WILL BE ALL THAT GREAT. KEPT
CHANCE POPS FOR SCATTERED AFTERNOON THUNDERSTORMS WITH CONTINUED
MENTION OF HEAVY RAIN.
HIGH CAPE ENVIRONMENT FAVORS STRONG TO ISOLATED SEVERE STORMS...
BUT OVERALL SEVERE THREAT APPEARS TO BE LIMITED. PRECIPITABLE
WATER VALUES APPROACHING 2 INCHES...WHICH IS AROUND +2 STANDARD
DEVIATIONS...MEANS POTENTIAL FOR HEAVY RAINFALL AND ISOLATED
FLOODING IN STORMS.
HIGHS IN 90S AWAY FROM S COAST COMBINED WITH DEW POINTS IN LOWER
70S WILL ONCE AGAIN YIELD HEAT INDICES AROUND 100.
FRIDAY...
FLOW ALOFT BECOMES FLATTER WHICH SHOULD ALLOW ANY UPSTREAM
ACTIVITY TO PASS TO OUR N. HOWEVER WE REMAIN IN UNSTABLE AIRMASS
WITH BETTER CONVECTIVE POTENTIAL THAN THU. MODELS SHOW SURFACE
BASED CAPES 2000-3000 J/KG AND MID LEVEL LAPSE RATES OVER 6C/KM.
AXIS OF GREATEST 0-6KM SHEAR REMAINS ACROSS NORTHERN NEW ENGLAND
BUT SW NH AND NORTHERN MA ARE ON PERIPHERY OF THIS AXIS WITH
VALUES OF 30-35KT. IN ADDITION WE ARE IN FAVORABLE RR QUAD OF
UPPER JET. ONLY LIMITING FACTOR APPEARS TO BE WARM MID LEVEL TEMPS
/+11C AT 700 MB/ BUT COLDER AIR ALOFT SHOULD BE ABLE TO
COMPENSATE.
EXPECT SCATTERED STORMS TO DEVELOP FRI AFTERNOON ACROSS MUCH OF
SOUTHERN NEW ENGLAND...ASIDE FROM IMMEDIATE S COAST WHICH WILL BE
MORE STABLE DUE TO SW FLOW. SEVERE POTENTIAL IS SOMEWHAT BETTER
THAN THU WITH BETTER POSSIBILITY OF DAMAGING WINDS DUE TO BOWING
SEGMENTS OR LINES. ALSO HAVE CONTINUED POTENTIAL FOR HEAVY
RAINFALL AND ISOLATED FLOODING.
INCREASING SW FLOW WILL RESULT IN WARMER DAY THAN THU. HIGHS
SHOULD TOP OUT IN LOW-MID 90S /GIVEN MODEL 2M TEMPERATURES/
COMBINED WITH DEW POINTS IN LOW-MID 70S SHOULD YIELD HEAT INDICES
OF 100-105. NOT CONFIDENT ENOUGH TO ISSUE EXCESSIVE HEAT WATCH BUT
WE MAY NEED TO DO SO IF THIS BECOMES MORE CERTAIN.
SATURDAY...
BEST POTENTIAL FOR ORGANIZED CONVECTION AS STRONG COLD FRONT
APPROACHES FROM GREAT LAKES. SOME QUESTION AS TO WHETHER OR NOT
ANY EARLY MORNING CONVECTION WILL INHIBIT SIGNIFICANT
DESTABILIZATION DURING AFTERNOON. PATTERN SEEMS TO FAVOR AT LEAST
MORNING SHOWERS/STORMS NEAR S COAST...THEN WE SEE A BREAK BEFORE
ADDITIONAL STORMS FIRE DURING AFTERNOON AND EVENING.
NO REAL CHANGE IN THINKING FROM SPC DAY 4 OUTLOOK AND PREVIOUS
DISCUSSION. EXPECTED INSTABILITY COUPLED WITH BULK SOUTHWESTERLY
UNI-DIRECTIONAL SHEAR AROUND 35 KTS FAVORS MULTICELLS AND LINE
ECHO WAVE PATTERNS WITH DAMAGING WINDS MAIN THREAT. ALSO NEED TO
BE AWARE OF CONTINUED FLASH FLOOD POTENTIAL WITH PRECIPITABLE
WATER VALUES NEAR 2 INCHES.
SUNDAY INTO THE EARLY WEEK...
COLD FRONT WILL HEAD OFFSHORE SUN MORNING...PERHAPS NOT UNTIL SUN
AFTERNOON ON CAPE COD. COOLER AND DRIER AIR WILL FOLLOW ON NW
WINDS LATER SUN. FRONT MAY BECOME STATIONARY AS IT RUNS UP INTO
RIDGING OVER WESTERN ATLANTIC. THIS WOULD KEEP US IN NE FLOW
MON/TUE WITH DRY WEATHER ANTICIPATED...ALTHOUGH IT IS POSSIBLE ONE
OR TWO WEAK AREAS OF LOW PRESSURE COULD COME CLOSE ENOUGH TO BRING
AT LEAST SOME CLOUDINESS TO SE NEW ENGLAND.
&&
.AVIATION /05Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE THROUGH THURSDAY.
MAINLY VFR THROUGH THE DAY TODAY. SEA BREEZES LIKELY ALONG
EASTERN SHORE BUT WINDS WILL GRADUALLY SHIFT BACK TO THE
SOUTH/SOUTHWEST BY LATE IN THE DAY. MOST OF THE AFTERNOON SHOWERS
AND THUNDERSHOWERS REMAIN IN NORTHERN NEW ENGLAND...BUT AN
ISOLATES SHOWER OR STORM MAY SNEAK INTO SOUTHERN NH OR NORTHERN MA
BY LATE DAY/EVENING.
OVERNIGHT...MAY SEE A BIT MORE FOG THAN PREVIOUS NIGHTS WITH SOME
MVFR VSBYS...BUT THIS WILL LIKELY BE AT THE TYPICALLY PRONE
AIRPORTS.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF. SEA BREEZES LIKELY SHIFT
SOUTH BY LATE DAY.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THURSDAY AND FRIDAY...MODERATE CONFIDENCE. IFR IN S COASTAL FOG
EARLY. ISOLATED SHOWERS/TSTMS WITH LOCAL IFR IN AFTERNOON.
SATURDAY...MODERATE CONFIDENCE. IFR IN S COASTAL FOG EARLY.
SCATTERED SHOWERS/TSTMS WITH LOCAL IFR IN AFTERNOON/EVENING.
SUNDAY...MODERATE CONFIDENCE. BECOMING VFR BY AFTERNOON.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE...
WINDS AND SEAS REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH
WED NIGHT. HIGH PRES REMAINS OVER THE WATERS THROUGH WED. A LOW
PRES APPROACHES THE WATERS AND WEAKENS WED NIGHT. THERE IS A
CHANCE OF SOME REDUCED VSBYS IN FOG IN SOME SPOTS.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THURSDAY AND FRIDAY...HIGH CONFIDENCE.
WEAK GRADIENT WILL RESULT IN SEA BREEZES ALONG E COAST WITH MORE
OF A SW FLOW ALONG S COAST WHERE 20KT GUSTS POSSIBLE. ISOLATED
THUNDERSTORMS POSSIBLE BOTH DAYS NEAR SHORE. EXPECT AREAS OF
NIGHTTIME AND EARLY MORNING FOG AROUND CAPE COD.
SATURDAY...MODERATE CONFIDENCE.
APPROACHING COLD FRONT WILL BRING INCREASING SW FLOW ON ALL WATERS
AS SEAS SLOWLY BUILD ON S COASTAL WATERS. STAYED BELOW WAVE WATCH
MODEL FORECAST OF 6-8 FT AS THIS MODEL IS TYPICALLY OVERDONE IN SW
FLOW DURING SUMMER...SHOULD BE MORE LIKE 4-5 FT AT MOST AND SCA
WILL PROBABLY BE NEEDED OFFSHORE.
AREAS OF NIGHTTIME AND EARLY MORNING FOG SHOULD PERSIST AROUND
CAPE COD.
SCATTERED THUNDERSTORMS POSSIBLE IN TWO ROUNDS...FIRST EARLY SAT
MORNING /PERHAPS NEAR S COAST?/ AND AGAIN TOWARD EVENING INTO SAT
NIGHT AS COLD FRONT PUSHES THROUGH NEW ENGLAND.
SUNDAY...MODERATE CONFIDENCE.
WINDS SHIFT TO NW AND DIMINISH AS COLD FRONT HEADS OFFSHORE BY
AFTERNOON. SEAS SLOWLY DIMINISH AS WELL BUT SHOULD REMAIN AT 5 OR
6 FT SE OF CAPE COD. SHOWERS/THUNDERSTORMS SHOULD LINGER
INITIALLY ON WATERS SE OF NANTUCKET BUT SHOULD BE WELL OFFSHORE BY
EARLY AFTERNOON.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...HEAT ADVISORY FROM 11 AM THIS MORNING TO 7 PM EDT THIS EVENING
FOR CTZ002>004.
MA...HEAT ADVISORY FROM 11 AM THIS MORNING TO 7 PM EDT THIS EVENING
FOR MAZ002>021-026.
NH...HEAT ADVISORY FROM 11 AM THIS MORNING TO 7 PM EDT THIS EVENING
FOR NHZ011-012-015.
RI...HEAT ADVISORY FROM 11 AM THIS MORNING TO 7 PM EDT THIS EVENING
FOR RIZ001>007.
MARINE...NONE.
&&
$$
SYNOPSIS...JWD/GAF
NEAR TERM...DOODY
SHORT TERM...GAF
LONG TERM...JWD
AVIATION...DOODY/JWD
MARINE...JWD/GAF
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1241 AM CDT WED JUL 17 2013
...UPDATED AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1201 PM CDT TUE JUL 16 2013
AT 12Z TUESDAY A 500MB LOW WAS LOCATED OVER EASTERN NEW MEXICO
AND A 500MB HIGH WAS LOCATED OVER THE OHIO VALLEY. ACROSS THE
SOUTHERN AND CENTRAL PLAINS A SOUTHEAST FLOW IN THE 850MB TO 500MB
LEVEL WAS DRAWING HIGHER DEWPOINTS INTO WESTERN KANSAS. ONE UPPER
LEVEL DISTURBANCE ROTATING AROUND THIS UPPER LOW WAS LOCATED
ACROSS THE PANHANDLE OF TEXAS AND WESTERN OKLAHOMA AS OF 12Z
TUESDAY WITH ANOTHER DISTURBANCE LOCATED NEAR THE BASED OF THIS
UPPER LOW ACROSS WESTERN TEXAS. WATER VAPOR LOOP AS OF 15Z
INDICATED THIS UPPER LOW WAS MOVING SLOWLY WESTWARD AS THE
PANHANDLE UPPER LEVEL WAVE APPROACHES SOUTHWEST KANSAS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 159 PM CDT TUE JUL 16 2013
RAP AND WATER VAPOR LOOP INDICATING AN UPPER LEVEL DISTURBANCE
WAS MOVING NORTHWEST ACROSS THE PANHANDLE OF TEXAS AS OF 19Z WITH
RADAR TRENDS INDICATING PRECIPITATION INCREASING IN AREA COVER
AHEAD OF THIS DISTURBANCE ACROSS PORTIONS OF SOUTHWEST KANSAS. NAM
AND RAP WERE IN DECENT AGREEMENT IN MOVING THIS UPPER WAVE ACROSS
SOUTHWEST KANSAS INTO SOUTHEAST COLORADO EARLY TONIGHT. GIVEN THE
MOISTURE FORECAST ACROSS SOUTHWEST KANSAS IN THE 850MB TO 500MB
AHEAD OF THIS UPPER SYSTEM WILL RETAIN AT LEAST A CHANCE FOR
SHOWERS ACROSS SOUTHWEST KANSAS AT AROUND 03Z AND THEN TAPER
PRECIPITATION OFF FROM NORTHEAST TO SOUTHWEST.
AFTER MIDNIGHT SUBSIDENCE APPEARS TO DEVELOP ACROSS WESTERN KANSAS
AS THE UPPER LEVEL DISTURBANCE MOVES INTO SOUTHERN COLORADO.
CLEARING SKIES MAY BRIEFLY DEVELOP AFTER MIDNIGHT, HOWEVER SOME
EARLY MORNING STATUS AND/OR FOG WILL BE POSSIBLE AROUND DAYBREAK
GIVEN THE SHALLOW LAYER OF LOW LEVEL MOISTURE FORECAST BY THE 12Z
NAM. BASED ONE THE EXPECTED DEWPOINTS OVERNIGHT THE PREVIOUS
FORECAST WITH LOWS RANGING FROM 60 TO NEAR 65 DEGREES STILL LOOKS
ON TRACK.
ON WEDNESDAY A TROUGH OF LOW PRESSURE WILL DEEPEN ALONG THE LEE
OF THE ROCKIES. BASED ON EXPECTED SKY COVER AND 00Z 850MB
TEMPERATURES RANGING FROM AROUND 20 IN SOUTH CENTRAL KANSAS TO THE
MID 20S NEAR THE COLORADO BORDER HAVE DECIDED TO TREND TOWARDS THE
SLIGHTLY COOLER ECMWF GUIDANCE FOR HIGHS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 333 PM CDT TUE JUL 16 2013
WEDNESDAY NIGHT:
LEE TROUGHING WILL CONTINUE WEDNESDAY NIGHT INTO THURSDAY MORNING.
THE UPPER LEVEL DISTURBANCE MENTIONED IN THE SYNOPSIS/SHORT TERM PERIOD
WILL CONTINUE TO DRIFT WELL AWAY FROM THE REGION BY THURSDAY MORNING.
STILL, THERE WILL BE "COOLER" LOW TO MID LEVEL TEMPERATURES ASSOCIATED
WITH THE PRESSURE PERTURBATION LINGERING ACROSS THE REGION. CONSIDERING
THIS AND THE WARM BIAS SHOWN VIA BOISE VERIFICATION...HAVE GONE WITH
COOLER MOS GUIDANCE FOR MINIMUMS INTO THURSDAY MORNING...60S DEG F.
THURSDAY:
ON THURSDAY, THE AFOREMENTIONED LEE SURFACE TROUGH WILL CONTINUE TO
DEEPEN AHEAD OF A TRAVERSING SHORTWAVE TROF ACROSS THE NORTHERN PLAINS.
THIS WILL ALLOW FOR A CONTINUED WARM AIR ADVECTION REGIME THROUGH THE
DAY. HAVE GONE WITH COOLER ECMWF RAW OUTPUT FOR MAXIMUMS - MID 90S DEG
F NORTHEAST TO AROUND 90 DEG F SOUTHWEST. NO PRECIPITATION IS EXPECTED
THROUGH THE DAY WITH PRECIPITATION PROBABILITY PERCENTAGE POINTS AOB
10 PERCENT AS THE AFOREMENTIONED SYNOPTIC SYSTEM IS WELL TO THE NORTH.
FRIDAY AND BEYOND:
A MODERATION OF TEMPERATURES IS EXPECTED WITH MAXIMUMS IN THE 90S DEG
F AND LOWS IN THE 60S AND 70S DEG F AS LEE TROUGHING CONTINUES AHEAD
OF AN APPROACHING COLD FRONT. THIS FRONT SHOULD BE IN THE REGION (PER
ECMWF) SOMETIME LATE FRIDAY NIGHT AND INTO SATURDAY. CONVECTION WILL
BE POSSIBLE ALONG THIS DENSITY GRADIENT THROUGH THE WEEKEND. THE 12Z
ECMWF SOLUTION HAS TRENDED DRIER THAN COMPARED TO THE 00Z ECMWF SOLUTION.
THE GFS, AS PER USUAL, IS WETTER AND COOLER THAN COMPARED TO THE EC.
DUE TO THE UNCERTAINTY, WILL GO WITH THE ALLBLEND SOLUTION FOR NOW.
THIS MODEL - OF COURSE - APPLIES A WEIGHTING FUNCTION TO BOTH SOLUTIONS
PLUS THE PREVIOUS NDFD GRIDS. BEYOND THIS, 500 HPA RIDGING IS INDICATED
BY BOTH MODELS BY EARLY TO MID WEEK OF NEXT WEEK, WHICH FAVORS A DRY
FORECAST AND HOT TEMPERATURES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1241 AM CDT WED JUL 17 2013
VFR CIGS AND VSBYS AT THE BEGINNING OF THIS TAF PERIOD ARE
EXPECTED TO DETERIORATE TO MVFR/IFR FROM AROUND 10Z-15Z AS LOW
LEVEL MOISTURE REMAINS ACROSS WESTERN KANSAS. THE LOW CIGS WILL
MIX OUT THROUGH THE MORNING HOURS WITH VFR CONDITIONS RETURNING.
THERE COULD BE SOME ISOLATED SHOWERS AND POSSIBLE THUNDERSTORMS
DEVELOPING ACROSS SOUTHWEST KANSAS WEDNESDAY AFTERNOON BUT THE
ISOLATED NATURE PRECLUDES MENTIONING IN THE TAFS AT THIS TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 65 91 68 94 / 10 0 10 40
GCK 64 90 68 94 / 10 10 10 40
EHA 62 88 66 94 / 10 10 10 40
LBL 64 89 67 94 / 10 10 10 40
HYS 67 94 72 94 / 0 0 10 30
P28 68 91 70 95 / 10 0 10 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...SUGDEN
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1138 PM CDT TUE JUL 16 2013
.DISCUSSION...
06Z TAFS
&&
.AVIATION...
SHOWERS AND THUNDERSTORMS HAVE LARGELY CONFINED THEMSELVES TO THE
OFFSHORE WATERS VERY SIMILAR TO LAST NIGHT. THE MAIN EXCEPTION IS
ACROSS PARTS OF SOUTHEAST TEXAS WHERE A FEW SHOWERS HAVE BEEN
STREAMING ONSHORE OVER THE LAST HOUR. A COUPLE OF STRAY LIGHTNING
STRIKES CANT BE RULED OUT BUT GIVEN THE GENERAL WEAKENING TREND OF
CELLS AS THEY MOVE INLAND OPTED TO JUST INCLUDE VCSH AT BPT
THROUGH THE EARLY MORNING. KEPT OTHER SITES DRY AND VFR THROUGH
THE PERIOD ALTHOUGH A FEW ISOLATED THUNDERSTORMS COULD DEVELOP
DURING THE AFTERNOON HOURS.
&&
66
.PREV DISCUSSION... /ISSUED 1018 PM CDT TUE JUL 16 2013/
UPDATE...
OVERALL FCST IN GOOD SHAPE. RECENT RADAR TRENDS SHOW CONVECTION
OVER LAND HAS DIMINISHED WITH SCT ACTIVITY CONTINUING OVER THE
COASTAL WATERS. MADE SOME MINOR ADJUSTMENTS TO POPS...INCREASING
THEM OVER THE COASTAL WATERS AND IMMEDIATE COASTAL AREAS FOR THIS
EVENING. POPS AFTER MIDNIGHT STILL LOOK ON TRACK AND SEEM TO BE IN
DECENT AGREEMENT WITH RECENT NAM12 AND HRRR RUNS WITH BEST CHANCES
OVER THE WRN HALF OF THE COASTAL WATERS. TWEAKED HOURLY
TEMPS...DEWPOINTS AND WINDS TO REFLECT RECENT OBSERVATIONAL
TRENDS...BUT NO SIGNIFICANT CHANGES TO REMAINDER OF FCST. 24
PREV DISCUSSION... /ISSUED 641 PM CDT TUE JUL 16 2013/
DISCUSSION...
00Z
AVIATION...
SCATTERED SHOWERS AND THUNDERSTORMS MOVING AROUND THE PERIPHERY OF
A DEVELOPING HIGH CONTINUE ACROSS THE AREA THIS EVENING. EXPECT
THE ACTIVITY TO CONTINUE FOR THE NEXT COUPLE OF HOURS BEFORE
WANING WITH THE SETTING SUN. A FEW THUNDERSTORMS WILL LIKELY CONTINUE
OFFSHORE OVERNIGHT BUT THEY SHOULD NOT IMPACT TERMINALS. AS THE
HIGH CONTINUES TO BUILD IN...STORMS BE PUSHED FURTHER SOUTHWEST.
THEREFORE EXPECT ONLY ISOLATED THUNDERSTORMS WEDNESDAY AFTERNOON.
66
PREV DISCUSSION... /ISSUED 327 PM CDT TUE JUL 16 2013/
DISCUSSION...
SHOWERS AND THUNDERSTORMS...MORE SCATTERED THAN NUMEROUS IN NATURE
SO FAR...MOVING ACROSS THE FORECAST AREA FROM EAST TO WEST.
SCATTERED ACTIVITY WILL CONTINUE THROUGH EARLY EVENING
HOURS...THEN DIMINISH WITH THE LOSS OF DAYTIME HEATING.
UPPER LEVEL LOW MOVING INTO NEW MEXICO WILL CONTINUE TO MOVE TO
THE WEST WITH UPPER LEVEL RIDGING MOVING IN OVER THE FORECAST AREA
TO TAKE ITS PLACE. THIS SHOULD HELP CUT OFF THE DEEP MOISTURE
FETCH OVER THE FORECAST AREA. THEREFORE...RAIN CHANCES WILL BE
DECREASING OVER THE NEXT COUPLE OF DAYS. EXPECTED SCATTERED
ACTIVITY OVER IN SOUTHEAST TEXAS AND EXTREME WESTERN LOUISIANA ON
WEDNESDAY WITH ISOLATED ELSEWHERE...THEN ISOLATED POPS EVERYWHERE
ON THURSDAY.
THE MID/UPPER LEVEL RIDGE WILL BEGIN TO BREAK DOWN AT THE END OF
THE WEEK INTO THE WEEKEND...WITH THE NEXT WEAK UPPER LEVEL LOW
RETROGRADING INTO THE REGION. THEREFORE...RAIN CHANCES WILL AGAIN
INCREASE TO SCATTERED POPS...WITH NEAR CLIMO TEMPERATURES FROM
FRIDAY THROUGH THE WEEKEND INTO EARLY NEXT WEEK.
RUA
MARINE...
OCCASIONAL WINDS BETWEEN 15 AND 20 KNOTS OCCURRING OVER THE COASTAL
WATERS THIS AFTERNOON. BRIEF PERIODS OF NEAR 20 KNOT WINDS WILL
CONTINUE THROUGH THE EVENING HOURS AS A BIT OF A TIGHTER GRADIENT
AS RIDGE BEGINS TO BUILD IN FROM THE EAST. SO WILL KEEP SMALL
CRAFT EXERCISE CAUTION WORDING THROUGH ABOUT MIDNIGHT.
A LIGHT TO MODERATE EAST TO SOUTHEAST WIND FLOW WILL THEN PREVAIL
THROUGH THE REMAINDER OF THE WEEK...AS COASTAL WATERS REMAIN ON
THE PERIPHERY OF A SURFACE RIDGE LOCATED OVER THE EASTERN U.S.
RUA
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 89 75 91 74 92 / 60 20 30 20 20
KBPT 88 75 90 75 92 / 60 30 40 20 20
KAEX 90 72 93 73 94 / 60 20 20 20 20
KLFT 88 74 91 74 92 / 60 20 20 20 20
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
132 AM EDT WED JUL 17 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 345 PM EDT TUE JUL 16 2013
UPPER AIR PATTERN CONSISTS OF A STRONG 500 MB RIDGE OVER THE LOWER
GREAT LAKES WITH A TROUGH OVER SOUTH CENTRAL CANADA WITH CLOSED LOWS
OFF THE CA COAST AND ONE OVER ERN NM. THE 500 MB RIDGE REMAINS
STATIONARY TODAY WITH THE TROUGH CONTINUING TO MOVE EAST ACROSS
CENTRAL CANADA. THIS TROUGH HELPS TO START PUSHING DOWN THE RIDGE
THIS FORECAST PERIOD WITH THE WESTERLIES ALONG THE CANADIAN/U.S.
BORDER MOVING SLOWLY SOUTH WITH A COLD FRONT MOVING SLOWLY SOUTH AS
WELL.
SPOTTY CONVECTION THAT HAS BEEN KICKED OFF THIS AFTERNOON WAS CAUSED
BY REACHING CONVECTIVE TEMPERATURE WHICH WAS IN THE UPPER 80S. 12Z
GRB SOUNDING HAD A CONVECTIVE TEMPERATURE OF 87 AND THIS SEEMS TO BE
WHAT TEMPERATURES HAVE TO GET TO TO KICK OFF CONVECTION. RUC IS ALSO
SHOWING A 500 MB SPEED MAX JUST TO THE NORTH OF THE AREA AND WITH
MOISTURE ADVECTION...THIS ALSO HELPED TO KICK OFF THE CONVECTION
THIS AFTERNOON. LOOK FOR THIS TO CONTINUE INTO THE EVENING BEFORE
INSTABILITY DIMINISHES WITH LOSS OF HEATING TO STOP THE
THUNDERSTORMS FROM CONTINUING TO DEVELOP. STUFF HAS BEEN FAIRLY
SHORT LIVED AND EXPECT THAT TREND TO CONTINUE THIS AFTERNOON INTO
THIS EVENING.
BUMPED UP SOME LOW TEMPERATURES TONIGHT WITH A SOUTHWEST WIND
ALLOWING DOWNSLOPE TO CONTINUE AND A FEW SW AFFECTED DOWNSLOPE AREAS
COULD HAVE LOWS IN THE MID 70S TONIGHT WHICH IS VERY WARM.
OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST FOR
TEMPERATURES FOR HIGHS ON WED. AGREE WITH SPC OUTLOOK FOR SLIGHT
RISK OF SEVERE THUNDERSTORMS TOMORROW WITH UNIDIRECTIONAL WINDS AND
POOLING OF MOISTURE NEAR THE FRONT TO ALLOW STORMS WITH HIGH WINDS
TO DEVELOP WHICH WOULD BE THE MAIN THREAT FOR SEVERE WEATHER. FRONT
STARTS TO SAG DOWN INTO THE AREA AS WELL SO A FOCUSING MECHANISM FOR
CONVECTION IS THERE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 345 PM EDT TUE JUL 16 2013
WEDNESDAY NIGHT...THE VERY SLOW MOVING COLD FRONT STRETCHING FROM
NORTH DAKOTA EASTWARD INTO SOUTHWESTERN QUEBEC WILL BECOME
STATIONARY OVERNIGHT WEDNESDAY NIGHT. AT THE SAME TIME HEIGHT FALLS
ASSOCIATED WITH THE UPPER LEVEL 500MB LOW OVER JAMES BAY WILL BEGIN
TO SINK SLOWLY SOUTHWARD AS IT SLOWLY WEAKENS THE HIGH PRESSURE
RIDGE THAT REMAINS OVER MUCH OF THE SOUTHEASTERN U.S. WITH THE FRONT
STRETCHING ACROSS MUCH OF LAKE SUPERIOR INTO THE NORTHERN PORTIONS
OF THE U.P. EXPECT THAT FORCING WILL BE GREAT ENOUGH TO ENHANCE THE
CHANCES FOR SHOWERS AND THUNDERSTORMS ACROSS MUCH OF THE AREA.
CONVERGENCE ASSOCIATED WITH A 25 TO 30 KNOT 850MB LLJ OVER CENTRAL
MN INTO NORTHERN WI WILL KEEP SHOWERS AND THUNDERSTORMS IN THE
FORECAST THROUGH THE OVERNIGHT HOURS...EVEN WITH THE LOSS OF DAYTIME
HEATING. DURING THE OVERNIGHT HOURS...THE CWA WILL ALSO BE UNDER
THE INFLUENCE OF THE RIGHT ENTRANCE REGION OF AN UPPER LEVEL 300MB
JET MAX...HELPING TO INCREASE FORCING FOR ASCENT. MU CAPE VALUES
OVERNIGHT ARE STILL EXPECTED TO BE AROUND 1000-1500 J/KG WITH DEEP
LAYER SHEAR VALUES ON THE ORDER OF 30 TO 35 KNOTS ACROSS THE AREA.
THE SHEAR IS UNIDIRECTIONAL...WHICH WOULD ALSO FAVOR MORE OF A WIND
THREAT. IT WOULD DEFINITELY NOT BE OUT OF THE QUESTION FOR SOME OF
THE STORMS TO BE FAIRLY STRONG OR EVEN SEVERE. THE MAIN THREAT FROM
THESE STORMS WOULD BE STRONG GUSTY WINDS AS DRY AIR REMAINS IN THE
MID LEVELS ALONG WITH AN INVERTED V TYPE SOUNDING IN THE LOW LEVELS
THROUGH THE OVERNIGHT HOURS...HELPING TO INCREASE COLD POOL
DEVELOPMENT. IT SHOULD BE KEPT IN MIND THAT MUCH OF THIS DEPENDS ON
CONVECTIVE DEVELOPMENT/TRACK THROUGH THE DAYTIME HOURS WEDNESDAY.
THURSDAY THROUGH FRIDAY...THE STATIONARY FRONT POSITIONED OVER LAKE
SUPERIOR THURSDAY MORNING IS PROGGED BY THE GFS/EC/GEM TO BEGIN
LIFTING NORTHWARD AS A WARM FRONT DURING THE AFTERNOON HOURS
THURSDAY. THIS FRONT WILL CONTINUE TO LIFT NORTHWARD INTO ONTARIO
DURING THE EVENING HOURS AS A COLD FRONT IS PUSHED SOUTHEASTWARD OUT
OF SOUTHERN MANITOBA INTO NORTHEASTERN MN DURING THE OVERNIGHT
HOURS AS THE UPPER LEVEL TROUGH BEGINS TO DIG INTO THE REGION. WITH
THE FRONT LIFTING NORTHWARD DURING THE DAY THURSDAY...IT WOULD NOT
BE OUT OF THE QUESTION TO SEE THE CLOUDS BREAK UP OVER THE
AREA...WHICH WILL HELP TO INCREASE THE CHANCES FOR SEVERE WEATHER
ACROSS THE CWA AS INSTABILITY INCREASES TO AROUND 1500-2500 J/KG.
DEEP LAYER SHEAR VALUES THROUGH THE DAY THURSDAY ARE PROGGED TO BE
AROUND 35 TO 40 KNOTS WHICH WOULD BE FAVORABLE FOR SEVERE WEATHER
DEVELOPMENT. THURSDAY AND THURSDAY EVENING WIND PROFILES INDICATED
THAT BOTH SPEED AND DIRECTIONAL SHEAR ARE AVAILABLE WHICH WOULD
SUPPORT A MORE ORGANIZED SEVERE EVENT. WHILE THE SOUNDING GAINS A
BIT MORE MOISTURE THROUGHOUT...DRY AIR REMAINS IN PORTIONS OF THE
LOWER LEVELS ALLOWING FOR AN INCREASED SEVERE WIND THREAT THROUGH
THE DAY THURSDAY INTO THE EVENING HOURS. A GREAT DEAL OF THE SEVERE
THREAT DURING THE DAY THURSDAY IS DEPENDENT UPON CLOUD COVER.
OVERNIGHT THURSDAY THROUGH FRIDAY MORNING THE COLD FRONT TO THE
NORTHWEST OF THE AREA WILL CONTINUE SOUTHEASTWARD PUSHING SOUTHEAST
OF THE AREA BY LATE FRIDAY AFTERNOON. AHEAD OF THE COLD FRONT
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO BE LIKELY. STRONG TO
SEVERE THUNDERSTORMS WILL BE POSSIBLE THROUGH EARLY FRIDAY MORNING
AS 0-6KM SHEAR VALUES ARE EXPECTED TO BE AROUND 40 TO 45 KNOTS ALONG
AND AHEAD OF THE FRONT...WITH SHEAR VECTORS BECOMING PERPENDICULAR
TO THE FORCING. THE SEVERE THREAT WILL SHIFT SOUTHEASTWARD INTO THE
LOWER GREAT LAKES BY FRIDAY AFTERNOON AS THE FRONT SHIFTS OUT OF THE
AREA. WITH THAT BEING SAID A FEW SHOWERS MAY LINGER INTO THE
AFTERNOON HOURS AS THE UPPER LEVEL 500MB THROUGH MOVES DIRECTLY
OVERHEAD.
FRIDAY NIGHT THROUGH SUNDAY NIGHT...FRIDAY NIGHT THE UPPER LEVEL
500MB TROUGH AXIS LINGERS OVER THE UPPER GREAT LAKES ALONG WITH
REMNANT MOISTURE. THIS WILL KEEP THE CHANCE OF ISOLATED SHOWERS IN
THE FORECAST THROUGH FRIDAY NIGHT. SATURDAY...HIGH PRESSURE BUILDING
OVER SOUTHERN CANADA INTO THE NORTHERN PLAINS WILL BEGIN BUILDING
EASTWARD INTO THE GREAT LAKES REGION. AS THIS HAPPENS FLOW AROUND
THE EASTERN SIDE OF THE HIGH WILL ALLOW DRY AIR FROM CANADA TO SPILL
SOUTHWARD HELPING TO CLEAR THE SKIES FOR THE WEEKEND AND DRY THINGS
OUT A BIT. THIS HIGH IS PROGGED TO REMAIN IN THE AREA THROUGH
SUNDAY NIGHT.
MONDAY THROUGH TUESDAY...DIFFERENCES REMAIN IN MODEL SOLUTIONS TO
THE WEATHER PATTERN FOR THE FIRST HALF OF NEXT WEEK. THE GFS KEEPS
ZONAL TO SLIGHTLY RIDGED FLOW AT 500MB ACROSS THE AREA THROUGH THIS
TIME PERIOD WHILE THE EC BRINGS AND UPPER LEVEL TROUGH INTO THE
REGION. AT THE SAME TIME THE GFS PLACES A SURFACE HIGH OVER THE AREA
WHILE THE EC BUILDS A SURFACE LOW INTO THE REGION OUT OF SOUTHERN
CANADA. WITH THIS CONTINUED DISCONTINUITY...WILL STICK WITH A
CONSENSUS OF THE MODELS DURING THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 131 AM EDT WED JUL 17 2013
VFR CONDITIONS SHOULD CONTINUE THROUGH THE PERIOD AT ALL SITES.
LOOK FOR MORE SCT TO ISOLD SHRA/TS TO DEVELOP LATE WED MORNING/EARLY
AFTERNOON AS A FRONTAL BOUNDARY MOVES IN FM THE NW. HAVE INCLUDED
PREVAILING -SHRA AND VCTS FOR BOTH KIWD AND KSAW INTO EARLY WED
EVENING BUT WILL LEAVE MENTION OF PREVAILING SHRA OUT OF KCMX WHERE
CONDITIONS WILL BE MORE STABLE NEAR LAKE SUPERIOR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 345 PM EDT TUE JUL 16 2013
FOG WILL CONTINUE TO BE PATCHY THROUGH WED MORNING ON LAKE SUPERIOR
AS COLD WATER WITH WARM AND HUMID AIR MOVING OVER THE TOP CAUSES FOG
TO FORM. AS THE FRONT STARTS TO COME DOWN ON WED...THIS SHOULD
DISRUPT THE FOG. A LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY WILL
EFFECT THE REGION WEDNESDAY THROUGH FRIDAY...HOWEVER...WINDS SHOULD
REMAIN LIGHT AND GENERALLY LESS THAN 15 KNOTS. HIGH PRESSURE BUILDS
IN FOR MUCH OF THE WEEKEND ALLOWING WINDS TO REMAIN LIGHT AND
VARIABLE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...KEC
AVIATION...VOSS
MARINE...07
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
550 AM EDT WED JUL 17 2013
.SYNOPSIS...
HOT AND HUMID WEATHER IS EXPECTED THROUGH FRIDAY ALONG WITH AN
INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS. A FEW OF THE
STORMS COULD BE STRONG TO SEVERE LATER THIS AFTERNOON AND
EVENING. SHOWERS AND STORMS WILL END NORTH TO SOUTH DURING
SATURDAY AS A STRONG COLD FRONT PUSHES THROUGH THE AREA. BEHIND
THIS FRONT...A MORE SEASONABLE AND PLEASANTLY DRIER AIRMASS WILL
SETTLE ACROSS THE REGION FROM SUNDAY INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 550 AM EDT WEDNESDAY...QUICK UPDATE TO ACCOUNT FOR ISOLATED
SHOWERS FAR NERN VT OVER THE NEXT FEW HOURS...AND TO INCORPORATE
LATEST T/TD/SKY DATA INTO EXISTENT DATASETS. OTW FORECAST IN GOOD
SHAPE. HAVE A GREAT DAY. PRIOR DISCUSSION FOLLOWS...
FORECAST MORE OR LESS REMAINS ON TRACK FOR TODAY AS LARGE-SCALE H5
HEAT RIDGE MAINTAINS ITS HOLD ON REGIONAL WEATHER. MEAN 18Z 925MB
OF 23-25C SUPPORT HIGHS IN THE UPPER 80S TO MID 90S ACROSS THE
REGION ALONG WITH HIGH HUMIDITY...NOT A PLEASANT DAY. HEAT INDEX
VALUES TO PEAK JUST BELOW ADVISORY CRITERIA...GENERALLY IN THE
92-98 RANGE IN LOWER ELEVATIONS BELOW 1000 FEET. THIS WILL BE DAY
3 OF 90F+ AT KBTV SO OFFICIAL NEW ENGLAND HEAT WAVE CRITERIA WILL
BE MET. OF COURSE NOT ALL AREAS HAVE SEEN 3 CONSECUTIVE DAYS OF
90F+...ESP IN SOME OF OUR NRN MTN LOCALES...BUT EVERYONE GETS THE
POINT THAT WE`RE IN A VERY WARM AND UNCOMFORTABLE STRETCH OF WX.
COULD SEE SOME ISOLATED AFTERNOON PULSE-TYPE STORMS IN THE 1 TO 4
PM TIME FRAME OF SO...BUT INITIALLY MID LEVELS WILL BE SLIGHTLY
CAPPED SUCH THAT UPDRAFTS WILL BE INHIBITED. MORE IMPORTANTLY
HOWEVER WILL BE THE POTENTIAL FOR A LINE OF STRONG TO LOCALLY
SEVERE STORMS TO DROP SOUTHWARD INTO OUR NORTHERN COUNTIES LATER
THIS AFTERNOON OR EARLY EVENING AS A WEAK SURFACE FRONT
APPROACHES FROM THE NORTHWEST. WITH SLIGHT MID LEVEL HEIGHT FALLS
AMPLE PBL INSTABILITY AND MODEST 0-6KM SHEAR VALUES INCREASING
INTO THE 30-40 KT RANGE ACROSS THE NORTH...THE THREAT FOR STRONG
TO LOCALLY SEVERE STORMS TO DEVELOP ALONG THIS LINE IS
INCREASING. VERY TALL STORMS WITH TOPS TO NEAR 50 KFT POSSIBLE
WITH EQ LEVELS VERY HIGH. MODIFIED KMSS AND KFSO SOUNDINGS
CENTERED AROUND 00Z SHOW QUITE ROBUST SWEAT AND DCAPE VALUES...SO
STRONG OUTFLOW/DAMAGING WINDS LOOK LIKE THE PRIMARY
THREAT...ESPECIALLY IF ACTIVITY CAN ORGANIZE ENOUGH TO GENERATE
AN AMPLE COLD POOL. HAIL NOT SO MUCH AN ISSUE GIVEN MEAN WBZ
VALUES ABOVE 12 KFT. STORMS WILL TEND TO WEAKEN AS THEY PROGRESS
SOUTHWARD THROUGH OUR REGION...SO HIGHEST THREAT WILL BE ACROSS
OUR NORTHERN COUNTIES WITH LESS OF A THREAT THE FURTHER SOUTH YOU
GO. WILL ALSO CONTINUE MENTION OF HEAVY RAINFALL AS PWATS CLIMB
TO NEAR 1.9 INCHES ALONG WITH LOW TO MID LEVEL MOISTURE POOLING
IN ADVANCE OF THE SURFACE BOUNDARY.
BY LATER THIS EVENING INTO TONIGHT ACTIVITY SLOWLY WANES AND
TAPERS TO SCATTERED SHOWERS ACROSS OUR CENTRAL AND NORTHERN
COUNTIES AS WEAK FRONTAL BOUNDARY SAGS INTO THE REGION AND
STALLS. PATCHY FOG ALSO A GOOD BET IF WE SEE HEAVIER WETTING
RAINFALL. LOWS MILD AND HUMID...MID 60S TO LOWER 70S...OR SIMILAR
TO THE PAST FEW NIGHTS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 420 AM EDT WEDNESDAY...BY THURSDAY STALLED WEAK SURFACE
BOUNDARY REMAINS DRAPED ACROSS OUR AREA ALONG WITH CONTINUED
WARMTH AND HUMIDITY. SCATTERED SHOWERS AND STORMS ALSO A GOOD BET
WITH LOCALLY HEAVY RAINFALL ONCE AGAIN. MBE VECTOR VALUES ARE
GENERALLY GREATER THAN 10 KTS HOWEVER...SO MY FEELING IS STORMS
MAY BE MOVING ENOUGH TO PRECLUDE A MORE ORGANIZED FLASH FLOOD
THREAT. NONETHELESS WE`LL HAVE TO KEEP AN EYE ON THINGS WITH PWAT
VALUES HOVERING AROUND 2.0 INCHES. DESPITE AMPLE SHEAR AND
INSTABILITY...FEEL ANY SEVERE THREAT SHOULD BE FAIRLY MARGINAL AS
WE REALLY DON`T HAVE A STRONG MECHANISM FOR LIFT OTHER THAN THE
SFC HEATING AND THE WEAK BOUNDARY. TIME WILL TELL. HIGHS ABOUT
2-4 DEGREES COOLER THAN TODAY SO SOME SLIGHT RELIEF BUT NOT MUCH.
SPOT HIGH FOR KBTV AT 89-90F LOOKS REASONABLE.
FRONT THEN REMAINS ATOP OUR REGION THURSDAY NIGHT INTO
FRIDAY...LIFTING SLOWLY NORTHWARD AND DISSIPATING THROUGH TIME IN
RESPONSE TO LARGE-SCALE BACKING OF THE MID LEVEL FLOW AHEAD OF A
MORE ROBUST NRN STREAM UPPER TROUGH OFF TO OUR NORTHWEST. THUS
CHANCE OF SHOWERS AND STORMS CONTINUE...BUT HIGHER CHANCES TREND
MORE ACROSS OUR NORTHERN COUNTIES. LIKELY A REPEAT OF TODAYS HOT
VALUES BY FRIDAY WITH MODELS HAVING CONSISTENTLY TRENDED WARMER
OVER THE PAST 24-HOURS. INDEED...WITH MEAN 925MB TEMPS AVERAGING
FROM 24-26C FRIDAY COULD END UP AS HOT IF NOT A DEGREE OR TWO
HOTTER THAN TODAY...ESPECIALLY IF WE SEE AMPLE SUNSHINE. SO IT`S
NOT ENTIRELY UNREASONABLE TO SUGGEST IF WE HIT 90F AT KBTV ON
THURSDAY...A FIVE DAY STRETCH OF 90F+ WILL BE IN REACH. THE LAST
TIME THIS OCCURRED WAS BACK IN AUGUST 2002.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 436 AM EDT WEDNESDAY...SFC LOW PRESSURE SYSTEM WILL START
THE PERIOD WITH SHOWERS/THUNDERSTORMS AND WARM TEMPERATURES...
FOLLOWED BY HIGH PRESSURE AND A COOLER...DRIER AIRMASS. FRIDAY
NIGHT WILL SEE THE NORTH COUNTRY STILL IN THE WARM SECTOR AND SW
FLOW AS A PREFRONTAL TROUGH AT THE SFC TRIGGERS
SHOWERS/THUNDERSTORMS FOLLOWED BY ASSOCIATED COLD FRONT ON
SATURDAY CONTINUING THE THREAT FOR SHOWERS AND THUNDERSTORMS.
FAVORABLE UPPER LEVEL JET DYNAMICS WILL ACCOMPANY THE COLD FRONT
WITH RR QUADRANT OF 250MB JET MOVES OVER THE NORTH COUNTRY MAINLY
ON SATURDAY...COINCIDING WITH STRONG FGEN AT 850MB...LINGERING
INTO SATURDAY NIGHT. PWATS OF 1.5-2 INCHES WILL PEAK EARLY
SATURDAY AS THE FRONT MOVES FROM SE ONTARIO...SEWD AND EVENTUALLY
EXIT VT EARLY SUNDAY AS ASSOCIATED UPPER LEVEL TROUGH PUSHES NEWD
SATURDAY NIGHT. HIGH PRESSURE WILL BUILD IN OVER THE REGION
FOLLOWING THE FRONT SUNDAY THROUGH AT LEAST MONDAY. MONDAY NIGHT
INTO TUESDAY...THE 00Z ECMWF BRINGS ANOTHER UPPER LEVEL TROUGH
OVER THE REGION...PRODUCING SHOWERS WHILE THE GFS KEEPS THE HIGH
PRESSURE ENTRENCHED OVER NRN NEW ENGLAND THROUGH THE MIDDLE OF
THE WEEK.
TEMPERATURES WILL BE WARM AND MUGGY...WITH MIN TEMPS FRIDAY NIGHT
IN THE 60S-L70S AND MAX TEMPS ON SATURDAY RANGING FORM M70S TO
M80S. COOLER AIR WILL FILTER IN FOR THE REST OF THE PERIOD WITH
MIN TEMPS TRENDING COOLER. SATURDAY NIGHT WILL BE IN THE 50S-
L60S...WITH SUNDAY NT THRU TUES NT IN THE M40S-U50S. MAX TEMPS
WILL GENERALLY BE IN THE 70S.
&&
.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 06Z THURSDAY...VFR CONDITIONS WILL PERSIST THROUGH AT
LEAST THE LATE AFTN/EARLY EVENING HOURS...WITH EXCEPTION OF KSLK
AND KMPV THIS MORNING EXPERIENCING SOME MVFR AND PSBL IFR AT KSLK
THROUGH 12Z. DIURNALLY DRIVEN VFR CLOUDS WILL DEVELOP IN THE HOT
HUMID DAYTIME...WITH INSTABILITY INCREASING THROUGHOUT THE LATE
AFTN/EVENING HRS. LGT TO CALM WINDS THIS MORNING WILL INCREASE TO
8-12KTS OUT OF THE S-SW IN THE MID-LATE MORNING...SHIFTING SW-W
THIS AFTN.
A PACKET OF VORTICITY WILL TRIGGER SHOWERS AND THUNDERSTORMS
NORTH OF THE INTERNATIONAL BORDER IN THE LATE AFTN...TRAVEL LING
SOUTH AND MOST LIKELY AFFECTING KMSS/KPBG/KBTV AND PSBLY
KSLK/KMPV. HAVE INCLUDED VCSH AT ALL BUT KRUT AS WESTERLY WINDS
WILL HELP SHOWERS AND THUNDERSTORMS LOSE MOMENTUM SWD...WHILE
LOSS OF DIURNAL HEATING AFTER SUNSET WEAKENS CONVECTIVE ACTIVITY.
EXPECT SHOWERS AND THUNDERSTORMS TO DISSIPATE AFTER 04Z.
THUNDERSTORMS MAY CONTAIN STRONG GUSTY WINDS. ANY AREA THAT
RECEIVES RAINFALL COULD DEVELOP FG/BR MAINLY AFTER 04Z THURSDAY.
OUTLOOK 06Z THURSDAY THROUGH SUNDAY...
06Z THURSDAY THROUGH SATURDAY...PRIMARILY VFR CONDITIONS EXPECTED
DURING THE DAY WITH ISOLATED PATCHY FG/BR OVERNIGHT...MAINLY AT
KSLK/KMPV. HOWEVER...CHANCES INCREASE FOR SCATTERED
SHOWERS/THUNDERSTORMS THROUGH THE PERIOD WHICH MAY BRING BRIEF
PERIODS OF MVFR/IFR IN SHOWERS AND THUNDERSTORMS.
SUNDAY...VFR WITH HIGH PRESSURE BUILDING IN AT THE SFC.
&&
.MARINE...
AS OF 420 AM EDT WEDNESDAY...STRONG TO LOCALLY SEVERE
THUNDERSTORMS MAY EFFECT THE LAKE CHAMPLAIN WATERS LATER THIS
AFTERNOON AND EVENING. IF STORMS DO DEVELOP...THEY WILL LIKELY
APPROACH FROM THE NORTH AND NORTHWEST AFTER 3 PM AND MAY BE
ACCOMPANIED BY VERY STRONG GUSTY WINDS AND FREQUENT CLOUD TO
GROUND LIGHTNING. IF PLANNING ACTIVITIES ON THE LAKE THIS
AFTERNOON AND EVENING...PLEASE KEEP ABREAST OF THE LATEST WEATHER
INFORMATION AND BE PREPARED TO SEEK SAFE HARBOR QUICKLY SHOULD
STRONGER STORMS APPROACH. WINDS GENERALLY LIGHT SOUTHERLY THIS
MORNING...TRENDING WEST TO SOUTHWESTERLY 5 TO 15 KNOTS THIS
AFTERNOON AND EVENING OUTSIDE ANY STORMS.
&&
.CLIMATE...
MAX TEMP RECORDS TODAY THROUGH FRIDAY. BEST SHOT TODAY AT
KMSS...THEN ON FRIDAY AT KMPV AND KMSS. SHORTER PERIOD OF RECORD AT
THESE SITES THAN AT K1V4 AND KBTV.
07/17/2013 07/18/2013 07/19/2013
KBTV 97/1999 99/1953 98/1942
KMPV 93/1982 96/1953 92/1991
K1V4 94/1953 99/1953 95/1991
KMSS 92/2012 95/1953 93/1991
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...KGM
MARINE...JMG
CLIMATE...JMG
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
436 AM EDT WED JUL 17 2013
.SYNOPSIS...
HOT AND HUMID WEATHER IS EXPECTED THROUGH FRIDAY ALONG WITH AN
INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS. A FEW OF THE
STORMS COULD BE STRONG TO SEVERE LATER THIS AFTERNOON AND
EVENING. SHOWERS AND STORMS WILL END NORTH TO SOUTH DURING
SATURDAY AS A STRONG COLD FRONT PUSHES THROUGH THE AREA. BEHIND
THIS FRONT...A MORE SEASONABLE AND PLEASANTLY DRIER AIRMASS WILL
SETTLE ACROSS THE REGION FROM SUNDAY INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 420 AM EDT WEDNESDAY...FORECAST MORE OR LESS REMAINS ON
TRACK FOR TODAY AS LARGE-SCALE H5 HEAT RIDGE MAINTAINS ITS HOLD
ON REGIONAL WEATHER. MEAN 18Z 925MB OF 23-25C SUPPORT HIGHS IN
THE UPPER 80S TO MID 90S ACROSS THE REGION ALONG WITH HIGH
HUMIDITY...NOT A PLEASANT DAY. HEAT INDEX VALUES TO PEAK JUST
BELOW ADVISORY CRITERIA...GENERALLY IN THE 92-98 RANGE IN LOWER
ELEVATIONS BELOW 1000 FEET. THIS WILL BE DAY 3 OF 90F+ AT KBTV SO
OFFICIAL NEW ENGLAND HEAT WAVE CRITERIA WILL BE MET. OF COURSE
NOT ALL AREAS HAVE SEEN 3 CONSECUTIVE DAYS OF 90F+...ESP IN SOME
OF OUR NRN MTN LOCALES...BUT EVERYONE GETS THE POINT THAT WE`RE
IN A VERY WARM AND UNCOMFORTABLE STRETCH OF WX.
COULD SEE SOME ISOLATED AFTERNOON PULSE-TYPE STORMS IN THE 1 TO 4
PM TIME FRAME OF SO...BUT INITIALLY MID LEVELS WILL BE SLIGHTLY
CAPPED SUCH THAT UPDRAFTS WILL BE INHIBITED. MORE IMPORTANTLY
HOWEVER WILL BE THE POTENTIAL FOR A LINE OF STRONG TO LOCALLY
SEVERE STORMS TO DROP SOUTHWARD INTO OUR NORTHERN COUNTIES LATER
THIS AFTERNOON OR EARLY EVENING AS A WEAK SURFACE FRONT
APPROACHES FROM THE NORTHWEST. WITH SLIGHT MID LEVEL HEIGHT FALLS
...AMPLE PBL INSTABILITY AND MODEST 0-6KM SHEAR VALUES INCREASING
INTO THE 30-40 KT RANGE ACROSS THE NORTH...THE THREAT FOR STRONG
TO LOCALLY SEVERE STORMS TO DEVELOP ALONG THIS LINE IS
INCREASING. VERY TALL STORMS WITH TOPS TO NEAR 50 KFT POSSIBLE
WITH EQ LEVELS VERY HIGH. MODIFIED KMSS AND KFSO SOUNDINGS
CENTERED AROUND 00Z SHOW QUITE ROBUST SWEAT AND DCAPE VALUES...SO
STRONG OUTFLOW/DAMAGING WINDS LOOK LIKE THE PRIMARY
THREAT...ESPECIALLY IF ACTIVITY CAN ORGANIZE ENOUGH TO GENERATE
AN AMPLE COLD POOL. HAIL NOT SO MUCH AN ISSUE GIVEN MEAN WBZ
VALUES ABOVE 12 KFT. STORMS WILL TEND TO WEAKEN AS THEY PROGRESS
SOUTHWARD THROUGH OUR REGION...SO HIGHEST THREAT WILL BE ACROSS
OUR NORTHERN COUNTIES WITH LESS OF A THREAT THE FURTHER SOUTH YOU
GO. WILL ALSO CONTINUE MENTION OF HEAVY RAINFALL AS PWATS CLIMB
TO NEAR 1.9 INCHES ALONG WITH LOW TO MID LEVEL MOISTURE POOLING
IN ADVANCE OF THE SURFACE BOUNDARY.
BY LATER THIS EVENING INTO TONIGHT ACTIVITY SLOWLY WANES AND
TAPERS TO SCATTERED SHOWERS ACROSS OUR CENTRAL AND NORTHERN
COUNTIES AS WEAK FRONTAL BOUNDARY SAGS INTO THE REGION AND
STALLS. PATCHY FOG ALSO A GOOD BET IF WE SEE HEAVIER WETTING
RAINFALL. LOWS MILD AND HUMID...MID 60S TO LOWER 70S...OR SIMILAR
TO THE PAST FEW NIGHTS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 420 AM EDT WEDNESDAY...BY THURSDAY STALLED WEAK SURFACE
BOUNDARY REMAINS DRAPED ACROSS OUR AREA ALONG WITH CONTINUED
WARMTH AND HUMIDITY. SCATTERED SHOWERS AND STORMS ALSO A GOOD BET
WITH LOCALLY HEAVY RAINFALL ONCE AGAIN. MBE VECTOR VALUES ARE
GENERALLY GREATER THAN 10 KTS HOWEVER...SO MY FEELING IS STORMS
MAY BE MOVING ENOUGH TO PRECLUDE A MORE ORGANIZED FLASH FLOOD
THREAT. NONETHELESS WE`LL HAVE TO KEEP AN EYE ON THINGS WITH PWAT
VALUES HOVERING AROUND 2.0 INCHES. DESPITE AMPLE SHEAR AND
INSTABILITY...FEEL ANY SEVERE THREAT SHOULD BE FAIRLY MARGINAL AS
WE REALLY DON`T HAVE A STRONG MECHANISM FOR LIFT OTHER THAN THE
SFC HEATING AND THE WEAK BOUNDARY. TIME WILL TELL. HIGHS ABOUT
2-4 DEGREES COOLER THAN TODAY SO SOME SLIGHT RELIEF BUT NOT MUCH.
SPOT HIGH FOR KBTV AT 89-90F LOOKS REASONABLE.
FRONT THEN REMAINS ATOP OUR REGION THURSDAY NIGHT INTO
FRIDAY...LIFTING SLOWLY NORTHWARD AND DISSIPATING THROUGH TIME IN
RESPONSE TO LARGE-SCALE BACKING OF THE MID LEVEL FLOW AHEAD OF A
MORE ROBUST NRN STREAM UPPER TROUGH OFF TO OUR NORTHWEST. THUS
CHANCE OF SHOWERS AND STORMS CONTINUE...BUT HIGHER CHANCES TREND
MORE ACROSS OUR NORTHERN COUNTIES. LIKELY A REPEAT OF TODAYS HOT
VALUES BY FRIDAY WITH MODELS HAVING CONSISTENTLY TRENDED WARMER
OVER THE PAST 24-HOURS. INDEED...WITH MEAN 925MB TEMPS AVERAGING
FROM 24-26C FRIDAY COULD END UP AS HOT IF NOT A DEGREE OR TWO
HOTTER THAN TODAY...ESPECIALLY IF WE SEE AMPLE SUNSHINE. SO IT`S
NOT ENTIRELY UNREASONABLE TO SUGGEST IF WE HIT 90F AT KBTV ON
THURSDAY...A FIVE DAY STRETCH OF 90F+ WILL BE IN REACH. THE LAST
TIME THIS OCCURRED WAS BACK IN AUGUST 2002.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 436 AM EDT WEDNESDAY...SFC LOW PRESSURE SYSTEM WILL START
THE PERIOD WITH SHOWERS/THUNDERSTORMS AND WARM TEMPERATURES...
FOLLOWED BY HIGH PRESSURE AND A COOLER...DRIER AIRMASS. FRIDAY
NIGHT WILL SEE THE NORTH COUNTRY STILL IN THE WARM SECTOR AND SW
FLOW AS A PREFRONTAL TROUGH AT THE SFC TRIGGERS
SHOWERS/THUNDERSTORMS FOLLOWED BY ASSOCIATED COLD FRONT ON
SATURDAY CONTINUING THE THREAT FOR SHOWERS AND THUNDERSTORMS.
FAVORABLE UPPER LEVEL JET DYNAMICS WILL ACCOMPANY THE COLD FRONT
WITH RR QUADRANT OF 250MB JET MOVES OVER THE NORTH COUNTRY MAINLY
ON SATURDAY...COINCIDING WITH STRONG FGEN AT 850MB...LINGERING
INTO SATURDAY NIGHT. PWATS OF 1.5-2 INCHES WILL PEAK EARLY
SATURDAY AS THE FRONT MOVES FROM SE ONTARIO...SEWD AND EVENTUALLY
EXIT VT EARLY SUNDAY AS ASSOCIATED UPPER LEVEL TROUGH PUSHES NEWD
SATURDAY NIGHT. HIGH PRESSURE WILL BUILD IN OVER THE REGION
FOLLOWING THE FRONT SUNDAY THROUGH AT LEAST MONDAY. MONDAY NIGHT
INTO TUESDAY...THE 00Z ECMWF BRINGS ANOTHER UPPER LEVEL TROUGH
OVER THE REGION...PRODUCING SHOWERS WHILE THE GFS KEEPS THE HIGH
PRESSURE ENTRENCHED OVER NRN NEW ENGLAND THROUGH THE MIDDLE OF
THE WEEK.
TEMPERATURES WILL BE WARM AND MUGGY...WITH MIN TEMPS FRIDAY NIGHT
IN THE 60S-L70S AND MAX TEMPS ON SATURDAY RANGING FORM M70S TO
M80S. COOLER AIR WILL FILTER IN FOR THE REST OF THE PERIOD WITH
MIN TEMPS TRENDING COOLER. SATURDAY NIGHT WILL BE IN THE 50S-
L60S...WITH SUNDAY NT THRU TUES NT IN THE M40S-U50S. MAX TEMPS
WILL GENERALLY BE IN THE 70S.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 06Z THURSDAY...VFR CONDITIONS WILL PERSIST THROUGH AT
LEAST THE LATE AFTN/EARLY EVENING HOURS...WITH EXCEPTION OF KSLK
AND KMPV THIS MORNING EXPERIENCING SOME MVFR AND PSBL IFR AT KSLK
THROUGH 12Z. DIURNALLY DRIVEN VFR CLOUDS WILL DEVELOP IN THE HOT
HUMID DAYTIME...WITH INSTABILITY INCREASING THROUGHOUT THE LATE
AFTN/EVENING HRS. LGT TO CALM WINDS THIS MORNING WILL INCREASE TO
8-12KTS OUT OF THE S-SW IN THE MID-LATE MORNING...SHIFTING SW-W
THIS AFTN.
A PACKET OF VORTICITY WILL TRIGGER SHOWERS AND THUNDERSTORMS
NORTH OF THE INTERNATIONAL BORDER IN THE LATE AFTN...TRAVEL LING
SOUTH AND MOST LIKELY AFFECTING KMSS/KPBG/KBTV AND PSBLY
KSLK/KMPV. HAVE INCLUDED VCSH AT ALL BUT KRUT AS WESTERLY WINDS
WILL HELP SHOWERS AND THUNDERSTORMS LOSE MOMENTUM SWD...WHILE
LOSS OF DIURNAL HEATING AFTER SUNSET WEAKENS CONVECTIVE ACTIVITY.
EXPECT SHOWERS AND THUNDERSTORMS TO DISSIPATE AFTER 04Z.
THUNDERSTORMS MAY CONTAIN STRONG GUSTY WINDS. ANY AREA THAT
RECEIVES RAINFALL COULD DEVELOP FG/BR MAINLY AFTER 04Z THURSDAY.
OUTLOOK 06Z THURSDAY THROUGH SUNDAY...
06Z THURSDAY THROUGH SATURDAY...PRIMARILY VFR CONDITIONS EXPECTED
DURING THE DAY WITH ISOLATED PATCHY FG/BR OVERNIGHT...MAINLY AT
KSLK/KMPV. HOWEVER...CHANCES INCREASE FOR SCATTERED
SHOWERS/THUNDERSTORMS THROUGH THE PERIOD WHICH MAY BRING BRIEF
PERIODS OF MVFR/IFR IN SHOWERS AND THUNDERSTORMS.
SUNDAY...VFR WITH HIGH PRESSURE BUILDING IN AT THE SFC.
&&
.MARINE...
AS OF 420 AM EDT WEDNESDAY...STRONG TO LOCALLY SEVERE
THUNDERSTORMS MAY EFFECT THE LAKE CHAMPLAIN WATERS LATER THIS
AFTERNOON AND EVENING. IF STORMS DO DEVELOP...THEY WILL LIKELY
APPROACH FROM THE NORTH AND NORTHWEST AFTER 3 PM AND MAY BE
ACCOMPANIED BY VERY STRONG GUSTY WINDS AND FREQUENT CLOUD TO
GROUND LIGHTNING. IF PLANNING ACTIVITIES ON THE LAKE THIS
AFTERNOON AND EVENING...PLEASE KEEP ABREAST OF THE LATEST WEATHER
INFORMATION AND BE PREPARED TO SEEK SAFE HARBOR QUICKLY SHOULD
STRONGER STORMS APPROACH. WINDS GENERALLY LIGHT SOUTHERLY THIS
MORNING...TRENDING WEST TO SOUTHWESTERLY 5 TO 15 KNOTS THIS
AFTERNOON AND EVENING OUTSIDE ANY STORMS.
&&
.CLIMATE...
MAX TEMP RECORDS TODAY THROUGH FRIDAY. BEST SHOT TODAY AT
KMSS...THEN ON FRIDAY AT KMPV AND KMSS. SHORTER PERIOD OF RECORD AT
THESE SITES THAN AT K1V4 AND KBTV.
07/17/2013 07/18/2013 07/19/2013
KBTV 97/1999 99/1953 98/1942
KMPV 93/1982 96/1953 92/1991
K1V4 94/1953 99/1953 95/1991
KMSS 92/2012 95/1953 93/1991
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...KGM
MARINE...JMG
CLIMATE...JMG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1148 PM CDT TUE JUL 16 2013
.UPDATE...
ISSUED AT 1144 PM CDT TUE JUL 16 2013
WILL CONTINUE WITH ISOLD-SCT SHRA/TSRA IN THE ZONE VERY NEAR THE
850 MB FRONT WHERE WEAK CONVERGENCE WILL CONTINUE OVERNIGHT...THIS
REGION RUNS ROUGHLY EITHER SIDE OF HWY 2. HRRR CONTINUES TO
DEVELOP AREA BUT PAST RUNS HAVE BEEN VERY BULLISH FOR THIS EVE AND
THAT DIDNT MATERIALIZE. DO HAVE ONE DECENT STORM BTWN MOT/BIS
MOVING EAST-SOUTHEAST THRU FAR EASTERN MCLEAN CO ND.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 336 PM CDT TUE JUL 16 2013
PCPN CHANCES WILL BE THE MAIN CHALLENGE THROUGHOUT THE ENTIRE
SHORT TERM. NOT SEEING ANY REASON TO DEVIATE TOO MUCH FROM THE
INHERITED FORECAST AT THIS POINT. LATE THIS AFTERNOON SEVERAL
LINES OF SHOWERS/TSTMS HAD FORMED WELL BEHIND THE SFC BOUNDARY.
THE CLOSEST BAND OF SHOWERS/TSTMS RUNS FROM WINNIPEG DOWN THROUGH
THE RUGBY AREA WITH THE OTHERS BACK OVER NORTHWEST ND. THE HIGH
RESOLUTION MODELS DIFFER ON WHERE THEY PLACE THESE SHOWERS/TSTMS
TONIGHT. HOWEVER THEY ALL SEEM TO AGREE WITH THE GENERAL IDEA OF
ISOLATED TO SCATTERED CONVECTION ALONG AND NORTH HIGHWAY 2. THE
SFC BOUNDARY CURRENTLY LIES ALONG A LINE FROM KROX TO JUST NORTH
OF GRAND FORKS TO NEAR KBIS. THIS BOUNDARY IS EXPECTED TO SLOWLY
SAG SOUTHWARD MAYBE ANOTHER 20 MILES OR SO AND EITHER WASH OUT OR
STAGNATE. THE UPPER JET IS EXPECTED TO REMAIN MAINLY NORTH OF THE
CANADIAN BORDER AND MODELS DO NOT SHOW ANY STRONG UPPER LEVEL
DISTURBANCES COMING THROUGH EITHER. HOWEVER WITH MODEST CAPE AND
THE SFC BOUNDARY THERE APPEARS TO BE JUST ENOUGH FORCING. LATEST
SPC DAY1 DISCUSSION MENTIONS A LIMITED SEVERE THREAT DUE TO THE
ABOVE MENTIONED FEATURES. THE WEAK WARM ADVECTION TONIGHT AND NO
REAL FOCUSED LOW LEVEL JET WILL LIKELY LIMIT THE TSTM THREAT
AFTER DARK AS WELL.
FOR WED A WEAK SFC HIGH WILL TRY TO BUILD DOWN INTO THE NORTHERN
FA. DO NOT SEE A LOT OF CHANGE FROM CONDITIONS TODAY WITH THE
WASHED OUT OR STAGNANT SFC BOUNDARY STILL HANGING ACROSS THE
CENTRAL FA AND THE UPPER JET ALONG OR NORTH OF THE CANADIAN
BORDER. FORECAST WILL MAINTAIN THE LOW CHANCES FOR PCPN MAINLY
ALONG AND NORTH OF HIGHWAY 200. SPC DAY2 DISCUSSION MENTIONS THE
POSSIBILITY OF ELEVATED STORMS ON WED NIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 336 PM CDT TUE JUL 16 2013
STILL LOOKING LIKE THE BEST CHANCE FOR TSTMS MAY BE ON THU AS THE
SFC LOW LIFTS UP INTO SOUTH CENTRAL ND. WILL UP CHANCES INTO THE
LIKELY CATEGORY FOR NORTHEAST ND INTO NORTHWEST MN. COULD STILL
SOME LOWER CHANCES FOR PCPN THU NIGHT INTO FRI.
FRIDAY NIGHT-TUESDAY...SOME LOW-LEVEL COLD AIR ADVECTION WILL
PERSIST FRIDAY NIGHT INTO SATURDAY AS A CANADIAN HIGH PRESSURE
SYSTEM DROPS SOUTHWARD. A DRY AND COOL JULY AIR MASS IS EXPECTED FOR
THE START OF THE WEEKEND AS 925 MB TEMPS FALL INTO THE 10-15C RANGE
BY SATURDAY MORNING. AS A RESULT...HIGHS ON SATURDAY LOOK TO REMAIN
IN THE UPPER 60S TO MID 70S. LOWS FRIDAY NIGHT AND SATURDAY NIGHT
WILL BE IN THE 50S...WITH SOME UPPER 40S POSSIBLE. TEMPS SHOULD WARM
CLOSER TO AVERAGE BY SUNDAY AS THE SFC HIGH SLIPS EASTWARD.
BEYOND SUNDAY...MODEL DIFFERENCES BECOME MAGNIFIED. THE 12Z GFS
MAINTAINS NORTHWESTERLY FLOW ALOFT...WITH THE MEAN RIDGE ACROSS THE
SOUTHWEST CONUS AND PERIODIC CHANCES FOR CONVECTION AS SHORTWAVE
DISTURBANCES DIVE SOUTHEASTWARD WITHIN THE STRONGER WESTERLIES. IN
CONTRAST...THE 12Z ECMWF SHOWS A STRONGER DISTURBANCE LIFTING ACROSS
THE PACIFIC NORTHWEST ON MONDAY INTO TUESDAY...WITH DOWNSTREAM
RIDGING MAINTAINING MORE ZONAL FLOW ACROSS THE NORTHERN PLAINS. WITH
THESE DIFFERENCES IN MIND...WILL MAINTAIN SOME POPS SUNDAY
NIGHT-TUESDAY...WITH SEASONABLE TEMPS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1144 PM CDT TUE JUL 16 2013
VFR CONDITIONS EXPECTED AT TAF SITES THRU THIS PD. SOME SC/AC WILL
BE AROUND ESP NORTH OF THE SFC BOUNDARY OVER NRN-CNTRL ND INTO FAR
NRN MN...BUT EXPECT THIS TO RANGE IN THE 5-10K FT RANGE. WINDS
WILL BE NORTH-NORTHEAST DVL-GFK-TVF TONIGHT TURNING A BIT MORE
EAST NR 10 KTS WED. FAR-BJI TO BE VERY NEAR THE BOUNDARY AND
LIKELY SEE MORE OF A VARIABLE WIND SITUATION...BRIEFLY NORTHEAST
OR EAST LATE TONIGHT-WED AM MAYBE TURNING BACK SOUTHEAST LATER
WED. SPEEDS 10 KTS OR LESS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...GODON
LONG TERM...MAKOWSKI
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS PORTLAND OR
859 PM PDT TUE JUL 16 2013
.SYNOPSIS...AN UPPER LEVEL LOW OFF THE CALIFORNIA COAST WILL MOVE
NORTHEAST OVER WESTERN OREGON AND SOUTHWEST WASHINGTON TONIGHT AND
POSSIBLY TRIGGER ELEVATED THUNDERSTORMS ACROSS THE REGION. COOLER
MARINE AIR WILL FILL IN ALONG THE COAST THIS EVENING SPREADING INLAND
OVERNIGHT. THIS WILL RESULT IN SIGNIFICANT COOLING WEDNESDAY. HIGH
PRESSURE WILL REBUILD THURSDAY AND TEMPERATURES WILL REBOUND THURSDAY
AND FRIDAY.
&&
.SHORT TERM...VISIBLE SATELLITE IMAGERY AND AREA WEBCAM LOOPS BOTH
SHOWED TODAYS CLOUD STORM QUITE WELL. ASIDE FROM SOME SPRINKLES AND
A COUPLE VERY ISOLATED RAIN SHOWERS THAT BROUGHT MEASURABLE
RAIN...MOST PRECIPITATION EVAPORATED BEFORE REACHING THE GROUND.
EARLIER THIS AFTERNOON...A FEW PUNY STORMS LAID DOWN A HANDFUL OF
LIGHTNING STRIKES ACROSS THE SOUTH WASHINGTON CASCADES...AND FOR
SEVERAL HOURS...LITTLE ACTIVITY FOLLOWED. HOWEVER...AN ISOLATED CELL
POPPED NEAR LINCOLN CITY THIS EVENING WITH ADDITIONAL CONVECTION
DEVELOPING OFFSHORE AROUND 7-8PM...LAYING DOWN ANOTHER HANDFUL OF
STRIKES OFF TILLAMOOK. THIS CONVECTION HAS EXPANDED NORTHWARD WITH
CELLS DEVELOPING NEAR ASTORIA THIS EVENING...BUT IT APPEARS ALL THE
LIGHTNING ASSOCIATED WITH THIS BAND OF CONVECTION WILL LIKELY STAY
OFFSHORE. AS PURELY AN ASIDE...IT PROBABLY WOULD HAVE MADE FOR SOME
INTERESTING PHOTOGRAPHY FOR ANYONE ON ONE OF THE HIGHER PEAKS OF THE
COAST RANGE...AS THEY LOOKED WEST OVER THE MARINE LAYER WITH A
THUNDERSTORM BACK LIT BY THE SETTING SUN.
ANYWAY...THE HRRR HAS VARIED WIDELY WITH ITS DEPICTION OF CONVECTION
ACROSS THE REGION TONIGHT...AND AS A RESULT...CONFIDENCE REMAINS LOW
IN ANY PARTICULAR SCENARIO IT PRODUCES...AT LEAST FOR NOW.
AS FOR THUNDER CHANCES TONIGHT...IT STILL SEEMS LIKE A LOW
PROBABILITY THREAT...BUT IT EXISTS NONETHELESS. THIS IS PRIMARILY DUE
TO THE UPPER LEVEL LOW PRESSURE CURRENTLY NEAR CAPE MENDOCINO AND THE
FACT THAT ITS HEADED STRAIGHT INTO WESTERN OREGON...MAINLY TOWARDS
THE WILLAMETTE VALLEY AND CASCADES. IN ADDITION...INCREASING UPPER
LEVEL LIFT AHEAD OF THIS FEATURE DUE TO MID LEVEL VORTICITY
ADVECTION...AND THE REGION BEING IN THE LEFT EXIT REGION OF A
70-80KT JET...COMBINED WITH A SWATH OF NEGATIVE 700-500MB THETAE
LAPSE RATES...AND STEEPENING MID LEVEL LAPSE RATES PER SPC ANALYSIS
MOVING OVERHEAD ALL SEEM FAVORABLE FOR NOCTURNAL CONVECTION TO
DEVELOP...PRIMARILY BETWEEN 06Z-15Z. THE THREAT APPEARS HIGHEST
NORTH AND EAST OF THE PORTLAND METRO AREA.
HOWEVER...A COUPLE MAJOR WRENCHES IN THE DEVELOPMENT OF CONVECTION
EXIST. FIRST...THE MAIN 700-500MB THETAE RIDGE IS NOW WELL NORTH OF
THE CWA...AND DRIER AIR ALOFT CONTINUES TO FEED INTO THE REGION.
MODEL SOUNDINGS ALSO SHOW ANY ADDITIONAL MOISTURE FEEDING INTO THE
REGION OVERNIGHT COMING IN AWFULLY CLOSE TO -10C WITH POSSIBLE
EQUILIBRIUM LEVELS NEAR -30C...NEITHER OF WHICH ARE TERRIBLY
FAVORABLE TO ACTUALLY PRODUCE THUNDER. CONFIDENCE IN THESE DETAILS
REMAINS LOW SO GIVEN THE SYNOPTIC PATTERN APPEARS AT LEAST
MODERATELY FAVORABLE...WILL OPT TO KEEP THE MENTION OF THUNDER GOING
THROUGH THE NIGHT TIME HOURS EVEN THOUGH CONFIDENCE IS STILL RATHER
LOW.
I DID TRIM THE MENTION OF THUNDER AS THE NIGHT WEARS ON FROM SOUTH TO
NORTH WITH THE USE OF 3 HR WX GRIDS. BY THURSDAY MORNING...TSTORM
CHANCES WILL LIKELY BE EAST OF OUR CWA...BUT I DID KEEP A MENTION
GOING ACROSS THE SOUTH WASHINGTON CASCADES WHERE UPPER LEVEL SUPPORT
COULD CAUSE STORMS TO LINGER INTO THE MORNING HOURS IF THEY IN FACT
DEVELOP.
MEANWHILE...A SIGNIFICANT SOUTHWEST MARINE PUSH IS UNDERWAY ACROSS
THE AREA THIS EVENING. MARINE CLOUDS ARE ON THE DOORSTEP OF CORVALLIS
AND EUGENE...BOTH OF WHICH HAVE BEEN QUITE GUSTY THIS EVENING...AND
HAVE COOLED DRAMATICALLY. THE INITIAL SURGE OF MARINE AIR COULD EVEN
BE SEEN ON THE KRTX RADAR ACROSS THE NORTHERN WILLAMETTE VALLEY THIS
EVENING AS A DISTINCT BOUNDARY MOVED NORTHWARD FROM SALEM/AURORA
INTO THE PORTLAND METRO AREA...CAUSING WINDS TO SHIFT TO A MORE
SOUTHERLY DIRECTION BETWEEN 00-02Z. GIVEN THE CURRENT EXTENT OF MARINE
CLOUDS AND LAYOUT OF THE PRESSURE GRADIENT...I INCREASED SKY COVER
ACROSS THE WILLAMETTE VALLEY FOR WEDNESDAY MORNING. THE INTRUSION OF
COOLER MARINE AIR SHOULD KEEP HIGH TEMPERATURES IN THE LOWER 80S FOR
INTERIOR LOCATIONS WEDNESDAY.
OTHERWISE...THE REST OF THE FORECAST APPEARS ON TRACK AND FEW CHANGES
WERE MADE. EXPECT HIGHS IN THE UPPER 80S AND SUNSHINE FOR INTERIOR
LOCATIONS WITH PERIODS OF CLOUDS AND COOLER TEMPERATURES ALONG THE
COAST FOR THURSDAY AND FRIDAY. /NEUMAN
.LONG TERM...HIGH PRESSURE WILL HOLD OVER THE AREA FRIDAY AND
CONTINUE ABOVE NORMAL TEMPERATURES ACROSS THE INTERIOR. MODELS
DIVERGE ON SOLUTIONS FOR SATURDAY AND BEYOND. THE GFS FORECASTS AN
UPPER LEVEL TROUGH TO MOVE NORTH OF THE AREA AND FLATTEN THE RIDGE
OVER THE WEEKEND...WHEREAS THE ECMWF FORECASTS AN UPPER LEVEL TROUGH
WILL MOVE DIRECTLY OVER NW OREGON SUNDAY AND MONDAY. MADE NO MAJOR
CHANGES TO THE LONG TERM AND CONTINUED WITH THE PREVIOUS THINKING
THAT THE TROUGH WILL RIDE OVER THE TOP OF THE RIDGE. WOULD LIKE TO
SEE GREATER MODEL CONSENSUS AND CONSISTENCY BEFORE JUMPING ON BOARD
WITH THE ECMWF. TH
&&
.AVIATION...IFR CONDITIONS WILL CONTINUE TO MOVE UP THE COAST
TONIGHT. IFR CIGS AT THE COAST WILL CONTINUE OVERNIGHT THEN
LIKELY LIFT TO MVFR ON WEDNESDAY. VISIBILITY AT THE COAST MAY
RISE TO MVFR LATE TONIGHT AND LIKELY TO VFR BY WEDNESDAY
AFTERNOON. EXPECT A SOUTHWEST MARINE PUSH TONIGHT TO BRING MVFR
CIGS INLAND FROM SOUTH TO NORTH AFTER MIDNIGHT...BREAKING UP AND
LIFTING TO VFR BY EARLY WEDNESDAY AFTERNOON. PT/BURGESS
KPDX AND APPROACHES...VFR THROUGH 12Z. A SLIGHT CHANCE OF THUNDER
REMAINS OVERNIGHT...WITH THE BEST CHANCE FROM 05Z- 12Z. A SURGE OF
MARINE MOISTURE IS EXPECTED TO BRING MVFR CLOUDS OVER THE AIRPORT
AFTER 12Z. PT/BURGESS
&&
.MARINE...NO CHANGES. SOUTHERLY WIND OVER THE INNER WATERS WILL
PERSIST THROUGH WEDNESDAY MORNING. EXPECT OCCASIONAL GUSTS TO 20
KT OVER THE NORTHERN INNER WATERS THROUGH WEDNESDAY MORNING.
NORTHERLY WINDS IN THE OUTER WATERS WILL CONTINUE TO TURN WEST OR
SOUTHWEST TONIGHT. THESE WINDS WILL CONTINUE INTO WEDNESDAY
MORNING THEN SHIFT MORE NORTHWESTERLY LATE WEDNESDAY AND
WEDNESDAY NIGHT. EXPECT SMALL CRAFT NORTHERLIES TO RECUR THURSDAY
AND FRIDAY.
EXPECT SEAS TO CONTINUE TO DIMINISH TONIGHT AND WEDNESDAY. PERIODS
WILL CONTINUE TO RUN AROUND 8 SECONDS SO SEAS WILL BE ON THE
CHOPPY SIDE. THERE IS SOME BACKGROUND SOUTHERLY SWELL BUT ONLY
AROUND 1 FOOT OR SO...SO WILL EMPHASIZE THE FRESH NORTHWESTERLY
SWELL. AT THIS POINT SEAS LOOK TO STAY BELOW 10 FT THROUGH THE
FORECAST PERIOD. PT/BURGESS
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WA...NONE.
PZ...NONE.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1115 PM MDT TUE JUL 16 2013
.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 253 PM MDT TUE JUL 16 2013
AT 20Z A MODERATE AMOUNT OF CU DEVELOPMENT WAS TAKING
PLACE ALONG THE COOL FRONT BOUNDAY ACROSS EXTREME NORTHWESTERN SOUTH
DAKOTA THIS AFTERNOON. NO LIGHTNING YET, BUT THE HRRR 17Z UPDATE
SHOWED SOME MINIMAL RW- ACTIVITY BETWEEN 00Z AND 02Z JUST BARELY
ACROSS THE NORTHWEST CORNER OF THE STATE. THE SOUTHEASTERN EDGE OF
THE SOUTHEASTERN MONTANA LOW ST FIELD MENTIONED IN THE MORNING
UPDATE WAS DISSIPATING AND RETREATING NORTHWARD AS THE CYCLONIC
CIRCULATION AROUND THE WEAK SURFACE LOW BECAME MORE EASTERLY IN THIS
REGION.
ON A LARGER SCALE THE RIDGE EXTENDING WESTWARD INTO THE CENTRAL
PLAINS HAS PRETTY MUCH CUT OFF SIGNIFICANT MOIST RETURN FLOW TO THE
DAKOTAS THIS AFTERNOON IN THE MID AND UPPER LEVELS . DEWPOINTS ARE
DOWN 10 TO 12 DEGREES FROM YESTERDAY AFTERNOON AND MODEL SOUNDINGS
SHOW A VERY DRY STABLE AIR MASS.
FOR WEDNESDAY THE WEAK COOL FRONT IS FORECAST TO DRIFT SOUTHWARD
ACROSS NORTHWEST SOUTH DAKOTA. HOWEVER THE WESTERLYS AND ANY UPPER
LEVEL IMPULSES WILL REMAIN WELL NORTH OF THE FORECAST AREA AND
AIRMASS MOISTURE WILL CONTINUE TO BE MINIMAL. TEMPERATURES ARE
FORECAST TO BE A DEGREE OR SO WARMER THAN THIS AFTERNOON.
&&
.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 253 PM MDT TUE JUL 16 2013
VERY BROAD...FLAT LONG WAVE RIDGE OVER THE GREAT LAKES WILL
RETROGRESS TO THE PACIFIC COAST BY 12Z FRIDAY AND INCREASE SOMEWHAT
IN AMPLITUDE. GFS AND ECMWF BOTH SHOW THIS TREND. RESULT IS THAT
WEAK NORTHWESTERLY FLOW DEVELOPS OVER OUR CWA ON THURSDAY AND
FRIDAY ALLOWING A COLD FRONT TO MOVE ACROSS THE AREA. THIS WILL DROP
TEMPERATURES A BIT AND RESULT IN CHANCES FOR SCATTERED TSTM
DEVELOPMENT. UNCERTAINTY IN THE EXACT LOCATION OF THE RIDGE...THE
STRENGTH OF THE NORTHWESTERLY FLOW EAST OF IT...AND THE POSITION AND
TIMING OF SHORT WAVES EMBEDDED IN THIS FLOW ALL LEAD TO SUBSTANTIAL
UNCERTAINTY IN THE FORECAST FOR THE WEEKEND AND BEYOND. STAYED CLOSE
TO GUIDANCE WITH TEMPS AND PROBS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1113 PM MDT TUE JUL 16 2013
AREA OF MVFR CIGS WILL PERSIST THROUGH THE NIGHT ACROSS PORTIONS
OF NORTHEAST WYOMING INTO NORTHWEST SOUTH DAKOTA. OTHERWISE VFR
CONDITIONS EXPECTED THROUGH WEDNESDAY EVENING.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...CARPENTER
LONG TERM...BARBER
AVIATION...7
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1150 PM CDT TUE JUL 16 2013
.DISCUSSION...
SEE THE 06Z AVIATION DISCUSSION BELOW.
40
&&
.AVIATION...
PLENTY OF EARLIER RAINFALL MAY LEAD TO AT LEAST MVFR CONDITIONS
LATER TONIGHT. FOR NOW...THE GUIDANCE AND CURRENT OBSERVATIONS
INDICATE WIDESPREAD VFR IS MORE LIKELY. IF MVFR CONDITIONS DO
DEVELOP...EXPECT THESE TO IMPROVE BY AROUND 14Z. OTHERWISE...AN
UPPER LOW OVER THE WESTERN GULF WAS APPEARING TO SHEAR OUT ON THE
WATER VAPOR. MOISTURE WAS BEING FOCUSED ACROSS THE NORTHWESTERN
GULF INTO SE TX AROUND THIS SYSTEM TOWARD A STRONGER UPPER LOW
OVER NORTHERN NM. THE MODELS ARE NOT IN GOOD AGREEMENT AS TO THE
DETAILS...BUT DO EXPECT SHOWERS TO PERSIST THROUGH MIDDAY ON
WEDNESDAY WITH ANOTHER CHANCE FOR THUNDERSTORMS DURING THE
AFTERNOON. THE MODELS THEN AGREE WITH DRYING WEDNESDAY EVENING.
40
&&
.PREV DISCUSSION... /ISSUED 832 PM CDT TUE JUL 16 2013/
UPDATE...
SEE EVENING UPDATE.
DISCUSSION...
00Z SOUNDINGS WERE VERY MOIST WITH PW VALUES 2.36 AT CRP AND 2.22
AT LCH. 850 MB MOISTURE WAS ALSO ROBUST WITH 850 TD BETWEEN 15 C
AND 19 C. A LARGE UPPER LOW WAS LOCATED OVER EAST CENTRAL NEW
MEXICO AND A SMALL SCALE WEAK UPPER LOW WAS NOTED NEAR MATAGORDA
BAY. FEEL THE WEAKER SYSTEM NEAR MATAGORDA BAY WAS ENHANCING THE
INFLOW AND HELPING TO FOCUS THE MOISTURE INTO A NARROW CHANNEL
FEEDING INTO SE TX. ALREADY BUMPED POPS UP IN THE COASTAL COUNTIES
FROM 00-06Z AND WILL CARRY CHANCE POPS FROM 06-12Z. THE RAP AND
HRR ARE ONCE AGGRESSIVE WITH MORNING SHRA/TSRA ALONG THE COAST.
WILL LEAVE HIGH END CHANCE POPS IN PLACE AND RE-EVALUATE ONCE 00Z
MODELS COME IN. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 73 90 73 93 73 / 40 50 30 20 10
HOUSTON (IAH) 74 90 75 93 74 / 40 50 20 20 20
GALVESTON (GLS) 79 89 80 91 79 / 50 50 20 20 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...43
AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
332 AM EDT WED JUL 17 2013
.SYNOPSIS...
STRONG UPPER LEVEL HIGH PRESSURE ACROSS THE REGION WILL CONTINUE
TO DRIFT WEST AND WEAKEN THROUGH THE WEEK. WEAK UPPER LEVEL
DISTURBANCES WILL ROTATE SOUTH INTO THE AREA THROUGH THURSDAY
RESULTING IN WIDELY SCATTERED SHOWERS AND STORMS AT TIMES. A COLD
FRONT WILL SINK INTO THE OHIO VALLEY NEAR THE END OF THE WEEK
BEFORE SLIDING SOUTH ACROSS THE REGION LATER THIS WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM EDT WEDNESDAY...
OUTFLOW BOUNDARY...DEEP MOISTURE CONVERGENCE AND HIGHER THETA-E
RIDGE REFIRING CONVECTION IN THE VA PIEDMONT EARLY THIS MORNING. 00Z
NAM WAS ABOUT THE ONLY MODEL TO KEEP CONVECTION GOING
OVERNIGHT...BUT USUAL BIAS OF TOO MUCH COVERAGE. LATEST HRRR HAS
NOTHING AT THE MOMENT BUT FIRES UP SOME TOWARD 08Z ACROSS SOUTHSIDE
VA/NW NC PIEDMONT. WILL HANG ONTO ISOLATED SHRA/TSRA TO JUST BEFORE
DAWN BUT EXPECT THINGS TO WEAKEN AGAIN BY THEN.
FOR TODAY...MODELS SHOW MAIN FOCUS FOR CONVECTION ACROSS THE
MOUNTAINS WITH LESS COVERAGE IN THE PIEDMONT. WENT CLOSER TOWARD THE
GFS/LOCAL WRF AND NAM...WITH HIGHER POPS ALONG THE SRN BLUE RIDGE
AND POINTS WEST WITH THINGS FIRING UP BY MIDDAY. STORM MOTION STILL
SHOULD BE IN A NE TO SW PATTERN AROUND 10-20 KNOTS...ALTHOUGH HEAVY
RAINERS ARE EXPECTED WITH PWATS RUNNING FROM 1.5 TO 1.75 INCHES.
THERE WILL BE ENOUGH INSTABILITY AROUND THAT SIMILAR TO
TUESDAY...SOME SVR PULSE STORMS ARE POSSIBLE WITH DAMAGING DOWNBURST
WINDS AND MARGINAL SVR HAIL POSSIBLE. AT THIS TIME...LOOKS LIKE THE
AREAS FROM SRN WV INTO THE NC MTNS AND EAST ACROSS THE NC/VA
PIEDMONT HAVE THE BETTER THREAT FOR SVR ALBEIT ISOLATED. WILL
MAINTAIN MENTION OF THIS THREAT IN THE HWO.
KEPT HIGH TEMPS CLOSE TO TUESDAY/S ALTHOUGH SOME CIRRUS THIS MORNING
PLUS STORMS FIRING UP EARLIER MAY KEEP A FEW AREA TEMPS DOWN A FEW
DEGREES. WITH THE FORECAST HIGHS IN THE MID 90S EAST OF THE DAN/LYH
AREA...HEAT INDICES ARE GOING TO TOP AROUND 100 THIS AFTERNOON
OUTSIDE ANY STORM. THIS WILL ALSO BE KEPT IN THE HWO.
TONIGHT...THE THINKING IS THE STORMS WEAKEN AGAIN AND FADE BY
MIDNIGHT AS THEY EXIT TO THE SOUTHWEST. MAY STILL SEE SOME POP UPS
OVER THE SWRN CWA AFTER MIDNIGHT. LOWS TONIGHT WILL STAY MUGGY WITH
NO CHANGE IN AIRMASS...MID TO UPPER 60S MOUNTAINS TO LOWER TO MID
70S EAST.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 310 AM EDT WEDNESDAY...
THIS MORNING THE FORECAST WILL NOT INTRODUCE MUCH CHANGE TO THIS
SEGMENT OF THE FORECAST AS COMPARED TO WHAT WAS OFFERED ON TUESDAY
AFTERNOON. THE PATTERN TREND THROUGH THE PERIOD WILL REFLECT HIGH
PRESSURE OVER THE OHIO VALLEY REGION BEING DISPLACED TO THE
SOUTHWEST IN RESPONSE TO AN APPROACHING TROUGH ALONG THE
U.S/CANADIAN BORDER. THE RESULT WILL BE A GRADUAL TREND TOWARD
SLIGHTLY COOLER TEMPERATURES...BUT STILL A COUPLE DEGREES ABOVE
NORMAL FOR THIS TIME OF THE YEAR. ALSO...WE ANTICIPATE DAILY
SCATTERED SHOWERS AND STORMS TO DEVELOP AS LOW LEVEL FLOW BECOMES
MORE SOUTHERLY AND CAN TAP THE EASTERN PART OF THE GULF OF MEXICO.
AS WE PROGRESS INTO THE WEEKEND....THE NORTHERN STREAM UPPER TROUGH
WILL BRING AN ASSOCIATED SURFACE COLD FRONT INTO THE REGION. THIS
WILL ALLOW FOR COVERAGE TO BE MORE THAN SCATTERED ACROSS THE
REGION...ESPECIALLY ACROSS SOUTHEAST WEST VIRGINIA WEST WHERE LIKELY
PROBABILITIES OF PRECIPITATION ARE ALREADY BEING OFFERED IN THE
FORECAST SATURDAY AFTERNOON THROUGH THE EVENING HOURS.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 1235 PM EDT TUESDAY...
RETURN TO THE EASTERN UPPER TROF REGIME WILL BE UNDERWAY STARTING
THIS WEEKEND WITH THE AXIS OF THE 5H COOL POOL CROSSING THE
REGION FROM THE NW BY EARLY MONDAY. WEAK COLD FRONT IN BACKDOOR
FASHION JUST NORTH OF THE AREA SUNDAY. FORECAST PWATS QUICKLY
INCREASE BY SUNDAY AS THE FRONT SLOWS AND THE FLOW TURNS MORE SW.
INTERACTION WITH AN EASTERN LEE TROF AND HEATING AHEAD OF THE
PREVIOUS PRE-FRONTAL BAND SHOULD HELP ENERGIZE CONVECTION
ALONG/EAST OF THE BLUE RIDGE SUNDAY SO BUMPING POPS TO HIGH
CHC/LOW LIKELYS ESPCLY SE INCLUDING DECENT CHANCES ACROSS THE
WEST. SOME COOLING LIKELY SUNDAY UNDER MORE MOISTURE/SW FLOW AND
A QUICKER INIT TO CONVECTION DURING THE AFTERNOON.
LOTS OF UNCERTAINTY THEN EARLY NEXT IN JUST HOW FAR SOUTH THE
LOW LEVEL BOUNDARY WILL GET GIVEN THE EXITING/WEAKENING 5H TROF.
APPEARS WITH AT LEAST SCTD CONVECTION MONDAY...PER THE ACTUAL
FRONT OVERHEAD...MAY SEE ENOUGH PUSH TO PERHAPS DRIFT THE
BOUNDARY INTO THE CAROLINAS MONDAY NIGHT BEFORE IT STARTS TO HEAD
BACK NORTH TUESDAY AHEAD OF THE NEXT UPSTREAM WAVE. GIVEN
POTENTIAL FOR MOISTURE TO LINGER LONGER...WONT LEAN TOWARD THE
DRIER GFS...AND KEEP SOME COVERAGE OF POPS GOING MONDAY INTO
TUESDAY WITH LESS CHANCES NORTH-NW SECTIONS MONDAY NIGHT WHERE
SOME DRYING ALOFT MAY SNEAK IN. EXPECT WILL BE BLEEDING IN SOME
SLIGHTLY COOLER AIR AS WELL EARLY NEXT WEEK ALLOWING HIGHS
TO FALL TO SLIGHTLY BELOW NORMAL WITH LOWS INTO THE 60S MOST
SPOTS.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
AS OF 130 AM EDT WEDNESDAY...
NOT EXPECTING ANY SHOWERS THIS MORNING WITH LONE ONE 30 MILES
NORTH OF LYH STARTING TO FADE.
AREA OF DENSE CIRRUS FROM CONVECTION WILL KEEP FOG FORMATION AT
TIMES LIMITED...AND THE DENSE FOG WE HAVE AT LWB NOW WILL IMPROVE
SOME TO IFR...BUT THEN AS THE CIRRUS STARTS TO FADE WILL DROP BACK
DOWN AGAIN...SO ONLY HAVE TEMPO GROUP FOR THE IMPROVED VSBYS.
WHERE IT RAINED TUESDAY EVENING...EXPECT FOG FORMATION AROUND
09Z-12Z WITH ALL SITES BUT BLF GETTING AT TIMES INTO IFR WHILE
LWB/BCB FALL MORE.
AS WITH THE LAST COUPLE MORNINGS...FOG WILL LIFT AND BURN OFF
AROUND 12-14Z. GENERALLY VFR CONDITIONS EXPECTED OUTSIDE OF THE
SCATTERED DIURNALLY DRIVEN THUNDERSTORMS. BRIEF PERIODS OF
MVFR/IFR CONDITIONS ASSOC WITH THESE STORMS. CONFIDENCE HIGH
ENOUGH TO HAVE VCTS IN THE TAFS BUT EMPHASIS FOR CONVECTION WILL
MORE OVER THE WV MTNS WED AFTERNOON FADING AGAIN BY 01-03Z.
CYCLE OF FOG CONTINUES WED NIGHT-THU MORNING AT THE USUAL
LOCATIONS AND IN AREAS THAT RECEIVE RAIN WED AFTN.
FOR THURSDAY AND BEYOND...PROGRESSIVELY MORE COVERAGE OF STORMS
THROUGH THE WEEK AS THE UPPER RIDGE FLATTENS AND A TROUGH STARTS
TO BUILD SOUTH INTO THE GREAT LAKES. ALSO...THE COASTAL TROUGH
WILL STRENGTHEN A BIT WITH THE UPPER HIGH CENTERING OVER THE
ROCKIES. A BOUNDARY WILL BE SINKING INTO THE OHIO VALLEY THIS
WEEKEND. SOME MVFR/IFR VIS/CIG CAN BE EXPECTED AT BCB/LWB EACH
DAY...POTENTIALLY REDUCED CIG/VIS DUE TO THUNDERSTORMS AT THE END
OF THE WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WP
NEAR TERM...WP
SHORT TERM...DS
LONG TERM...JH
AVIATION...KK/WP
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
933 AM EDT WED JUL 17 2013
.DISCUSSION...
TODAY/TONIGHT...THE LATEST RAP ANALYSIS SHOWS THE CENTER OF AN UPPER
LEVEL LOW JUST WEST OF TAMPA. SEVERAL CLUSTERS OF CONVECTION WERE
OCCURRING ON THE EAST SIDE OF THIS CIRCULATION FROM THE KEYS AND
FLORIDA STRAITS TO THE NORTHERN BAHAMAS IN DIFFLUENT/DIVERGENT
FLOW. A LOW LEVEL TROUGH PRODUCING CONVERGENCE WAS ALSO ALIGNED
FROM THE KEYS TO NEAR GRAND BAHAMA. GPS PRECIPITABLE WATER DATA
SHOWED NEAR 2 INCHES IN THE SOUTH AND 1.6 INCHES IN OUR FAR NORTH.
A GRADUAL WEST/NORTHWEST MOTION OF THE UPPER LOW AND LOW LEVEL
TROUGH WILL NUDGE DEEP MOISTURE SLOWLY NORTHWARD ACROSS THE
PENINSULA. HIGHEST POPS SHOULD AGAIN BE ALONG THE TREASURE COAST
AND OKEECHOBEE. EVEN THOUGH THERE WILL BE MORE CLOUDINESS THERE
TODAY...WILL HAVE TO WATCH FOR SOME POSSIBLE HEAVY RAINFALL. 15 TO
20 KNOT LOW LEVEL FLOW IN THE PRESENCE OF UPPER LEVEL DIVERGENCE
COULD LEAD TO TRAINING OF CELLS.
CENTRAL SECTIONS WILL HAVE SOME MORNING HEATING AND EXPECT
BOUNDARIES TO GENERATE A FEW ROUNDS OF SHOWERS AND ISOLATED STORMS.
IT REMAINS COOL ALOFT (MINUS 9 DEGREES CELSIUS AT 500MB) SO A FEW
STORMS WITH GUSTY WINDS TO 40 MPH SHOULD OCCUR AGAIN. THE DRIER AIR
ACROSS THE NORTH WILL HOLD ON AT LEAST ONE MORE DAY AND KEEP RAIN
CHANCES LOW.
NO CHANGES PLANNED TO CURRENT FORECAST.
&&
.AVIATION...
DAYTIME HEATING WILL SPARK AN INCREASE IN SHOWERS/STORMS ESPECIALLY
KTIX-KMCO SOUTHWARD. MORE THAN ONE ROUND OF MVFR-IFR CONDITIONS WITH
GUSTY WINDS TO AROUND 30 KNOTS WILL BE POSSIBLE. THE ACTIVITY MAY
PERSIST INTO THE EVENING AS UPPER LEVEL DIVERGENCE SETS UP FROM
ABOUT CANAVERAL TO OKEECHOBEE.
&&
.MARINE...
TODAY/TONIGHT...STILL POOR CONDITIONS FOR SMALL CRAFT AS EASTERLY
WINDS REMAIN 10-15 KNOTS WITH A DOMINANT SHORTER WAVE PERIOD AROUND
6 SECONDS. SHOWERS/STORMS ALSO EXPECTED TO INCREASE AS THE
AFTERNOON PROGRESSES WITH TORRENTIAL DOWNPOURS AND GUSTY WINDS 30-35
KNOTS.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECASTS...LASCODY
IMPACT WEATHER...MOSES
AREA FORECAST DISCUSSION
NWS GRAY ME
928 AM EDT WED JUL 17 2013
.SYNOPSIS...
A WEAK COLD FRONT WILL APPROACH FROM THE NORTH TODAY AND WILL DROP
SOUTH THROUGH THE REGION TONIGHT. THE FRONT WILL STALL OVER SOUTHERN
NEW ENGLAND ON THURSDAY AND WILL LIFT BACK TO THE NORTH AS A WARM
FRONT THURSDAY NIGHT. THE WARM FRONT WILL LIFT INTO SOUTHERN CANADA
ON FRIDAY. ANOTHER COLD FRONT WILL DROP SOUTH FROM CANADA FRIDAY
NIGHT AND WILL CROSS THE REGION ON SATURDAY. HIGH PRESSURE WILL
BUILD IN FROM THE NORTHWEST SATURDAY NIGHT THROUGH TUESDAY. HIGH
PRESSURE WILL SHIFT OFFSHORE ON TUESDAY NIGHT AND WILL REMAIN
ANCHORED OFF THE COAST THROUGH WEDNESDAY.
&&
.NEAR TERM /TODAY/...
930AM UPDATE...FORECAST THINKING HAS CHANGED A BIT WITH THIS
UPDATE REGARDING CONVECTION THROUGH TODAY AND TONIGHT. NAM MODEL
HAS BEEN RUNNING VERY WARM ON DEW POINTS RECENTLY... AND AS A
RESULT HAS BEEN GENERATING MORE CAPE THAN HAS BEEN REALIZED THE
PAST FEW DAYS. NAM IS FORECASTING 70 TO 73 DEW POINTS WIDESPREAD
ACROSS THE FORECAST AREA THIS MORNING... AND THIS DOES NOT APPEAR
TO BE LIKELY. CMC MODEL IS MUCH LOWER... WITH MOST AREAS IN THE
MID 60S AWAY FROM THE IMMEDIATE COAST. THE CMC IS IN GOOD
AGREEMENT WITH THE HRRR AS WELL. WITH THE LOWER DEW POINTS...
AFTERNOON SURFACE-BASED CAPE VALUES ARE NOT AS HIGH AND IT WILL BE
HARDER TO BUST THE CAP AND GENERATE CONVECTION. STILL EXPECT A LOW
CHANCE FOR A STRAY SHOWER OR THUNDERSTORM ACROSS THE AREA FROM
AROUND NOON TO 6 PM. BUT THE GREATER THREAT FOR THUNDERSTORMS AND
SEVERE WEATHER WILL NOT ARRIVE UNTIL CLOSER TO 00Z OR 8 PM WHEN
THUNDERSTORMS WHICH FORM OVER ONTARIO AND QUEBEC WITH A SHORTWAVE
TROUGH TRAVEL SOUTHEAST AND CROSS THE CANADIAN BORDER INTO
NORTHERN NEW ENGLAND. HRRR IS SHOWING THIS PROGRESSION VERY WELL
AND THIS WAS USED HEAVILY IN THE FORECAST FOR TODAY. EVEN THE NAM
DOES NOT GENERATE PRECIPITATION UNTIL LATE AFTERNOON... GIVING
MORE CREDENCE TO THE DELAYED THUNDERSTORM FORECAST. DAMAGING WINDS
WILL BE POSSIBLE WITH THIS LINE OF STORMS AS IT MOVES INTO THE
AREA... AND THE STORM PREDICTION CENTER FORECAST AGREES WITH
THIS THREAT. PRIMARY CHANGE WITH THIS UPDATE WAS TO LOWER FORECAST
POPS AND THUNDERSTORM CHANCES THROUGH THE AFTERNOON... AND
INCREASE THEM THIS EVENING.
530 AM UPDATE...THE FIRST SHOWERS OF THE DAY POPPING AROUND
SHERBROOKE THIS MORNING AND HEADING FOR COOS COUNTY. NOTHING
SPECTACULAR TO THIS UPDATE -- JUST SOME REJIGGERING OF THE SKY,
POP AND TEMPERATURE FORECASTS FOR THIS MORNING. REMAINDER OF
FORECAST UNCHANGED.
SEVERE WEATHER THREAT TODAY MAINLY NORTHERN NEW HAMPSHIRE
AND WESTERN MAINE AWAY FROM THE COAST. APPROACHING SHORTWAVE THIS
AFTERNOON WILL DEPRESS THE WESTERLIES AND A FRONTAL BOUNDARY OVER
THE AREA, INCREASING SHEAR WHILE MAINTAINING INSTABILITY. THE
FRONTAL BOUNDARY WILL BE THE FOCUS FOR CONVECTION TODAY BEGINNING
ALONG THE CANADIAN BORDER MIDDAY THEN SHIFTING SOUTHWARD THROUGH
THE AFTERNOON INTO THE EVENING HOURS. STORM PREDICTION CENTER HAS
OUTLINED DAMAGING WIND AS THE BIGGEST THREAT TODAY, WITH A
POSSIBLY ORGANIZED MESOSCALE CONVECTIVE SYSTEM TAKING SHAPE LATER
TODAY AS THE SHEAR PROFILES INCREASE. PRECIPITABLE WATER VALUES
ARE FORECAST TO BE IN THE 1.75-1.90 RANGE THIS AFTERNOON AS WELL
SO WE WILL HAVE TO BE ON THE LOOKOUT FOR TRAINING CELLS AS EACH
STORM WILL PACK HEAVY DOWNPOURS. MAX TEMPERATURES TODAY ABOUT 1-4F
COOLER THAN THE PAST FEW DAYS GIVEN CLOUD COVER EXPECTED THIS
AFTERNOON AND SEA BREEZE PENETRATION ALONG THE COAST.
&&
.SHORT TERM /TONIGHT AND THURSDAY/...
THUNDERSTORMS WIND DOWN AFTER DARK TONIGHT WITH ONLY A CHANCE OF
SHOWERS OVERNIGHT AS THE FRONTAL BOUNDARY WEAKENS IN SOUTHERN NEW
ENGLAND. EXPECT WIDESPREAD PATCHY FOG DEVELOPING OVERNIGHT WITH
LOWS IN THE 60S. THEN ON THURSDAY ANOTHER WARM DAY WITH
TEMPERATURES MAXING OUT FROM THE LOWER 80S IN MOUNTAINS TO THE
LOWER 90S IN SOUTHERN NEW HAMPSHIRE. NOT MUCH FORCING FOR
CONVECTION THURSDAY WITH MODELS SLOW TO PUSH THE DIFFUSE WARM
FRONT BACK NORTH OF OUR REGION UNTIL THURSDAY NIGHT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
STALLED FRONTAL BOUNDARY WILL LIFT BACK NORTH INTO THE REGION AS A
WARM FRONT THURSDAY NIGHT. WILL SEE A CHANCE OF EVENING SHOWERS AND
THUNDERSTORMS MAINLY OVER SOUTHWEST ZONES AND THEN A CHANCE OF
SHOWERS OVERNIGHT THROUGHOUT THE FORECAST AREA. OVERNIGHT LOWS WILL
BE IN THE 60S TO NEAR 70.
WARM FRONT WILL LIFT NORTH OF THE REGION EARLY FRIDAY AND HEAT AND
HUMIDITY WILL BUILD ONCE AGAIN. WILL SEE A CHANCE OF AFTERNOON
THUNDERSTORMS. EXPECT HIGHS IN THE UPPER 80S TO MID 90S IN MOST
AREAS WITH THE EXCEPTION OF MID COAST MAINE WHERE SOMEWHAT OF AN
ONSHORE FLOW WILL HOLD TEMPS IN THE LOWER TO MID 80S.
VERY WARM AND MUGGY FRIDAY NIGHT WITH ANY CONVECTION TAPERING OFF
WITH THE LOSS OF HEATING. COLD FRONT APPROACHING FROM THE NORTH WILL
BRING A CHANCE OF SHOWERS AND THUNDERSTORM TO NORTHERN ZONES AFTER
MIDNIGHT.
SATURDAY STILL LOOKING LIKE A BUSY SEVERE WEATHER DAY. TIMING OF THE
COLD FRONT LOOKING PRIME. FAIRLY STRONG SHEAR FOR THIS TIME OF YEAR
WILL LIKELY RESULT IN STRONG TO SEVERE THUNDERSTORMS WITH THE MAIN
THREAT BEING WIND DAMAGE DURING THE EARLY TO MID AFTERNOON TIME
FRAME. WILL CONTINUE TO HIGHLIGHT THIS THREAT IN THE HWO.
COLD FRONT WILL PUSH OFFSHORE SATURDAY EVENING FINALLY BRINGING SOME
RELIEF FROM THE HEAT AND HUMIDITY. EXPECT ANY LINGERING SHOWERS AND
THUNDERSTORMS TO PUSH OFFSHORE BEFORE MIDNIGHT. LOW TEMPS WILL
BOTTOM OUT IN THE MID TO UPPER 50S IN THE NORTH AND LOWER TO MID 60S
IN THE SOUTH.
HIGH PRESSURE BUILDING IN FROM THE NORTHWEST WILL PROVIDE SEVERAL
DAYS OF NICE SUMMER WEATHER SUNDAY THROUGH TUESDAY. HIGH PRESSURE
WILL SHIFT OFFSHORE TUESDAY NIGHT AND RETURN FLOW WILL BRING WARM
AND MUGGY AIR BACK INTO THE REGION FOR MIDWEEK.
&&
.AVIATION /13Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM...PATCHY VALLEY FOG THIS MORNING THEN VFR THIS
AFTERNOON WITH AREAS OF MVFR/IFR IN SHOWERS AND THUNDERSTORMS
THROUGH LATE EVENING. PATCHY MVFR AGAIN IN FOG AND HAZE OVERNIGHT
TONIGHT.
LONG TERM...VFR THURSDAY THROUGH SATURDAY WITH AREAS OF IFR/LIFR
VSBY/CEILINGS IN MORNING FOG. AREAS OF MVFR/IFR CONDITIONS DURING
THE DAY IN AFTERNOON SHOWERS AND THUNDERSTORMS.
&&
.MARINE...
SHORT TERM...SOUTHWESTERLY FLOW INCREASES TODAY BUT NOT ENOUGH TO
DRIVE SEAS TO SMALL CRAFT ADVISORY LEVELS, MAXING OUT AT 2 TO 4
FEET IN THE OUTER WATERS.
LONG TERM...SCA LIKELY ON FRIDAY AND FRIDAY NIGHT.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
NEAR TERM UPDATE...KIMBLE
SHORT TERM...STJEAN
LONG TERM...SINSABAUGH
AVIATION...STJEAN/SINSABAUGH
MARINE...STJEAN/SINSABAUGH
AREA FORECAST DISCUSSION
NWS GLASGOW MT
914 AM MDT WED JUL 17 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH FRIDAY...
900AM UPDATE...
NUMEROUS TO WIDESPREAD SHOWERS CONTINUE TO SPILL ACROSS THE CWA
FROM SOUTHWEST TO NORTHEAST. THEY ARE HOLDING TOGETHER RATHER WELL
AND SO INCREASED POPS FURTHER FOR THE NEXT FEW HOURS. THE HRRR
CONTINUES TO INDICATE THAT THEY WILL MOVE INTO THE NORTHEASTERN
ZONES LATER THIS MORNING AND THIS AFTERNOON AND SO INCLUDED
SCATTERED SHOWERS FOR THOSE LOCATIONS AS WELL. WILL MAINTAIN
ISOLATED MENTION OF THUNDER FOR NOW. OTHER CHANGES INCLUDED TWEAKS
TO TEMPERATURES AND SKY COVER. HIGH TEMPERATURES MAY WIND UP BEING
A DEGREE OR TWO COOLER THAN FORECAST IF SHOWERS AND HEAVY CLOUD
COVER PERSIST. CONCERNS CONTINUE FOR POTENTIAL LAKE WIND ADVISORY
FOR TOMORROW. WILL PUT MORE FOCUS ON THAT WITH THE AFTERNOON
PACKAGE. MALIAWCO
800AM UPDATE...
RAN A QUICK UPDATE AS A BAND OF SHOWERS AND POSSIBLY AN ISOLATED
THUNDERSTORM WERE MOVING NORTHEAST INTO PETROLEUM AND PHILLIPS
COUNTY. WITH A VERY MOIST ATMOSPHERE IN PLACE...THESE WILL AFFECT
THE NW TWO-THIRDS OF THE CWA WITH AMOUNTS OF A TENTH OF AN INCH IN
PLACES. 11Z HRRR MODEL SEEMED TO CAPTURE THIS FEATURE BEST. JAMBA
PREVIOUS DISCUSSION...
A SHORTWAVE TROUGH CURRENTLY OVER SW MONTANA WILL MOVE THROUGH
EASTERN MONTANA TODAY ON SW FLOW ALOFT. THIS WAVE HAS SOME SHOWERS
AND ISOLATED THUNDERSTORMS WITH IT AT 08Z. AT THIS POINT...SOME
THE MODELS ARE HAVING TROUBLE BRINGING THE PRECIP NORTHEAST WITH
THE WAVE WHICH LOOKS UNREASONABLE WITH PRECIPITABLE WATER AROUND
1.6 INCHES. AT THE SAME TIME...A WARM FRONT WILL MOVE NORTH FROM
WYOMING INTO SOUTHERN MONTANA. THE WAVE AND FRONT SHOULD BE ABLE
TRIGGER A FEW SHOWERS AND THUNDERSTORMS SOMEWHERE IN THE FORECAST
AREA TODAY.
TONIGHT...A SURFACE LOW DEVELOPS OVER EASTERN MONTANA WITH THE
WARM FRONT LIFTING NORTH. WILL MAINTAIN A CHANCE OF SHOWERS AND
THUNDERSTORMS.
BY THURSDAY...FLOW ALOFT TURNS ZONAL AHEAD OF A SHORTWAVE TROUGH
MOVING THROUGH ALBERTA IN THE MORNING. THEN THE WAVE CLIPS NE MT
IN THE AFTERNOON AS IT MOVES TOWARDS NORTH DAKOTA. THIS WILL BRING
A COLD FRONT THROUGH THE AREA IN THE MORNING WITH NORTHWEST WINDS
DEVELOPING BEHIND THE FRONT. WIND SPEEDS SHOULD REACH LAKE WIND
ADVISORY CRITERIA (20 MPH) BY AFTERNOON. SHOWERS AND THUNDERSTORMS
REMAIN A POSSIBILITY WITH THE WAVE AND FRONT.
FLOW ALOFT TURNS TO THE NORTHWEST THURSDAY NIGHT AND REMAINS THAT
WAY FOR FRIDAY. IT WILL BE DRY FOR THE MOST PART BUT A SHORTWAVE
FRIDAY COULD BRING A CHANCE OF SHOWERS AND THUNDERSTORMS TO THE
NORTHEAST HALF OF THE FORECAST AREA. FORRESTER
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...
BOTH THE EC AND THE GFS SHOW NORTHEAST MONTANA REMAINING UNDER A
NORTHWESTERLY FLOW ALOFT...AT LEAST THROUGH SUNDAY NIGHT...DUE TO
A PERSISTENT HEAT DOME OF HIGH PRESSURE CENTERED OVER THE GREAT
BASIN SUPPORTING A RIDGE IN THE WEST.
HOWEVER BEGINNING SUNDAY NIGHT THE 2 MODELS QUIT RESEMBLING EACH
OTHER. THE BIG DIFFERENCE IS THAT THE 12Z EC PICKS UP A COMPACT
CYCLONE OFF THE PACIFIC NORTHWEST COAST AND EJECTS IT ACROSS THE
INTER-MOUNTAIN WEST AND CANADIAN ROCKIES INTO ALBERTA AND
SASKATCHEWAN. THIS ACTION WOULD BACK FLOW ALOFT TO THE SOUTHWEST
AND SEND A COLD FRONT ACROSS THE DIVIDE TO REACH NEMONT AROUND
MONDAY NIGHT. THE GFS SHOWS NO HINT OF THIS WAVE. THEREFORE AFTER
THE WEEKEND THERE IS MORE UNCERTAINTY AS TO WHICH MODEL WILL PLAY
OUT. LATER IN THE SHIFT THE DELAYED 00Z EC STILL HOLDS ONTO THE
SHORTWAVE DISTURBANCE BUT RUNS IT EAST THROUGH MONTANA. WITH MORE
CONSISTENCY...REMAINED MOSTLY WITH THE GFS SOLUTION FOR THE REST
OF THE FORECAST.
FRIDAY NIGHT THROUGH SUNDAY NIGHT...WITH HIGH PRESSURE TO THE
SOUTHWEST AND A STRONG CLOSED UPPER LOW ROTATING AROUND HUDSON
BAY...NORTHEAST MONTANA WILL HAVE THE STATIONARY COLD BOUNDARY TO
THE NORTHEAST AND DESERT AIR TRYING TO PUSH IN FROM THE SOUTH.
THIS PATTERN MIGHT SEE SOME OVERRUNNING MOISTURE NEAR THIS
BOUNDARY FIRING OFF A FEW THUNDERSTORMS. BUT FOR THE MOST
PART...DRY WARM AIR WILL BE THE MAIN FEATURE OF THE WEEKEND.
MONDAY AND BEYOND...WITH BOTH MODELS OUT OF PHASE WITH EACH
OTHER...WILL NOT MOVE MUCH ONE WAY OR THE OTHER FROM THE
INHERITED GRIDS. TEMPERATURE SHOULD BE VERY WARM ON MONDAY...AND
IF THE RIDGE HOLDS THE HIGHS WILL REMAIN VERY WARM. THE EC BRINGS
IN A FRONT AROUND MONDAY NIGHT WHICH WILL TEND TO COOL
TEMPERATURES AND ALSO BRING A BETTER CHANCE FOR STRONG
THUNDERSTORMS. SO FEW CHANGES MADE BEYOND MONDAY. SCT
&&
.AVIATION...
AN AREA OF SHOWERS WERE MOVING NORTHEAST INTO THE AREA THIS
MORNING. VISIBILITIES WERE PROBABLY DROPPING INTO THE MVFR RANGE
UNDER THE HEAVIEST SHOWERS WEST OF GLASGOW. CONDITIONS ARE
EXPECTED TO IMPROVE THIS AFTERNOON WITH THE SHOWERS MOVING TO THE
NORTH. A MODERATE EAST WIND IS THEN EXPECTED TO PICK UP IN IT/S
WAKE FOR LATER TODAY. JAMBA
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS GLASGOW MT
754 AM MDT WED JUL 17 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH FRIDAY...
RAN A QUICK UPDATE AS A BAND OF SHOWERS AND POSSIBLY AN ISOLATED
THUNDERSTORM WERE MOVING NORTHEAST INTO PETROLEUM AND PHILLIPS
COUNTY. WITH A VERY MOIST ATMOSPHERE IN PLACE...THESE WILL AFFECT
THE NW TWO-THIRDS OF THE CWA WITH AMOUNTS OF A TENTH OF AN INCH IN
PLACES. 11Z HRRR MODEL SEEMED TO CAPTURE THIS FEATURE BEST. JAMBA
PREVIOUS DISCUSSION...
A SHORTWAVE TROUGH CURRENTLY OVER SW MONTANA WILL MOVE THROUGH
EASTERN MONTANA TODAY ON SW FLOW ALOFT. THIS WAVE HAS SOME SHOWERS
AND ISOLATED THUNDERSTORMS WITH IT AT 08Z. AT THIS POINT...SOME
THE MODELS ARE HAVING TROUBLE BRINGING THE PRECIP NORTHEAST WITH
THE WAVE WHICH LOOKS UNREASONABLE WITH PRECIPITABLE WATER AROUND
1.6 INCHES. AT THE SAME TIME...A WARM FRONT WILL MOVE NORTH FROM
WYOMING INTO SOUTHERN MONTANA. THE WAVE AND FRONT SHOULD BE ABLE
TRIGGER A FEW SHOWERS AND THUNDERSTORMS SOMEWHERE IN THE FORECAST
AREA TODAY.
TONIGHT...A SURFACE LOW DEVELOPS OVER EASTERN MONTANA WITH THE
WARM FRONT LIFTING NORTH. WILL MAINTAIN A CHANCE OF SHOWERS AND
THUNDERSTORMS.
BY THURSDAY...FLOW ALOFT TURNS ZONAL AHEAD OF A SHORTWAVE TROUGH
MOVING THROUGH ALBERTA IN THE MORNING. THEN THE WAVE CLIPS NE MT
IN THE AFTERNOON AS IT MOVES TOWARDS NORTH DAKOTA. THIS WILL BRING
A COLD FRONT THROUGH THE AREA IN THE MORNING WITH NORTHWEST WINDS
DEVELOPING BEHIND THE FRONT. WIND SPEEDS SHOULD REACH LAKE WIND
ADVISORY CRITERIA (20 MPH) BY AFTERNOON. SHOWERS AND THUNDERSTORMS
REMAIN A POSSIBILITY WITH THE WAVE AND FRONT.
FLOW ALOFT TURNS TO THE NORTHWEST THURSDAY NIGHT AND REMAINS THAT
WAY FOR FRIDAY. IT WILL BE DRY FOR THE MOST PART BUT A SHORTWAVE
FRIDAY COULD BRING A CHANCE OF SHOWERS AND THUNDERSTORMS TO THE
NORTHEAST HALF OF THE FORECAST AREA. FORRESTER
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...
BOTH THE EC AND THE GFS SHOW NORTHEAST MONTANA REMAINING UNDER A
NORTHWESTERLY FLOW ALOFT...AT LEAST THROUGH SUNDAY NIGHT...DUE TO
A PERSISTENT HEAT DOME OF HIGH PRESSURE CENTERED OVER THE GREAT
BASIN SUPPORTING A RIDGE IN THE WEST.
HOWEVER BEGINNING SUNDAY NIGHT THE 2 MODELS QUIT RESEMBLING EACH
OTHER. THE BIG DIFFERENCE IS THAT THE 12Z EC PICKS UP A COMPACT
CYCLONE OFF THE PACIFIC NORTHWEST COAST AND EJECTS IT ACROSS THE
INTER-MOUNTAIN WEST AND CANADIAN ROCKIES INTO ALBERTA AND
SASKATCHEWAN. THIS ACTION WOULD BACK FLOW ALOFT TO THE SOUTHWEST
AND SEND A COLD FRONT ACROSS THE DIVIDE TO REACH NEMONT AROUND
MONDAY NIGHT. THE GFS SHOWS NO HINT OF THIS WAVE. THEREFORE AFTER
THE WEEKEND THERE IS MORE UNCERTAINTY AS TO WHICH MODEL WILL PLAY
OUT. LATER IN THE SHIFT THE DELAYED 00Z EC STILL HOLDS ONTO THE
SHORTWAVE DISTURBANCE BUT RUNS IT EAST THROUGH MONTANA. WITH MORE
CONSISTENCY...REMAINED MOSTLY WITH THE GFS SOLUTION FOR THE REST
OF THE FORECAST.
FRIDAY NIGHT THROUGH SUNDAY NIGHT...WITH HIGH PRESSURE TO THE
SOUTHWEST AND A STRONG CLOSED UPPER LOW ROTATING AROUND HUDSON
BAY...NORTHEAST MONTANA WILL HAVE THE STATIONARY COLD BOUNDARY TO
THE NORTHEAST AND DESERT AIR TRYING TO PUSH IN FROM THE SOUTH.
THIS PATTERN MIGHT SEE SOME OVERRUNNING MOISTURE NEAR THIS
BOUNDARY FIRING OFF A FEW THUNDERSTORMS. BUT FOR THE MOST
PART...DRY WARM AIR WILL BE THE MAIN FEATURE OF THE WEEKEND.
MONDAY AND BEYOND...WITH BOTH MODELS OUT OF PHASE WITH EACH
OTHER...WILL NOT MOVE MUCH ONE WAY OR THE OTHER FROM THE
INHERITED GRIDS. TEMPERATURE SHOULD BE VERY WARM ON MONDAY...AND
IF THE RIDGE HOLDS THE HIGHS WILL REMAIN VERY WARM. THE EC BRINGS
IN A FRONT AROUND MONDAY NIGHT WHICH WILL TEND TO COOL
TEMPERATURES AND ALSO BRING A BETTER CHANCE FOR STRONG
THUNDERSTORMS. SO FEW CHANGES MADE BEYOND MONDAY. SCT
&&
.AVIATION...
A WEAK FRONTAL BOUNDARY AND OVERRUNNING MOISTURE IN THE SW WILL
CONTINUE TO PRODUCE ISOLATED TO SCATTERED RAIN SHOWERS AND GENERAL
THUNDERSTORMS TODAY. A WEAK SURFACE LOW IN THE LEE OF THE NORTHERN
ROCKIES WILL MAINTAIN A LIGHT TO MODERATE EASTERLY SURFACE BREEZE.
SCT
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1023 AM EDT WED JUL 17 2013
.SYNOPSIS...
HOT AND HUMID WEATHER IS EXPECTED THROUGH FRIDAY ALONG WITH AN
INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS. A FEW OF THE
STORMS COULD BE STRONG TO SEVERE LATER THIS AFTERNOON AND
EVENING. SHOWERS AND STORMS WILL END NORTH TO SOUTH DURING
SATURDAY AS A STRONG COLD FRONT PUSHES THROUGH THE AREA. BEHIND
THIS FRONT...A MORE SEASONABLE AND PLEASANTLY DRIER AIRMASS WILL
SETTLE ACROSS THE REGION FROM SUNDAY INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 11 PM THIS EVENING/...
AS OF 1020 AM EDT WEDNESDAY...ACTIVE WEATHER DAY ANTICIPATED ACRS
THE NORTH COUNTRY...WITH THE NEAR TERM CHALLENGE BEING
TIMING/EVOLUTION OF CONVECTION THIS AFTN/EVENING. WATER VAPOR
SHOWS TWO PIECES OF ENERGY...FIRST IS LOCATED JUST NORTH OF LAKE
ONTARIO AND ANOTHER MUCH STRONGER ONE IS LOCATED JUST NORTHEAST OF
LAKE SUPERIOR. THINKING FIRST S/W WL HELP IN THE DEVELOPMENT OF
SHOWERS/STORMS ACRS THE DACKS/SLV BTWN 1PM AND 4PM THIS
AFTN...WITH SOME STRONG STORMS POSSIBLE...GIVEN CAPE VALUES BTWN
2000 AND 2500 J/KG AND DEEP LAYER SHEAR VALUES BTWN 25 AND 30
KNTS. MEANWHILE...BETTER DYNAMICS/MOISTURE ASSOCIATED WITH 2ND S/W
WL ARRIVE ACRS THE OTTAWA AND SLV VALLEY`S BTWN 21Z-00Z...WITH A
LINE OF STRONG TO SEVERE STORMS LIKELY. GIVEN THE AVAILABLE SHEAR
AND INSTABILITY...THINKING LINE SEGMENTS WITH ENHANCED BOW ECHOES
WL BE POSSIBLE...WITH PRIMARY THREAT BEING STRONG/DAMAGING WINDS
GUSTS. CRNT SPC HAS OUR REGION IN SLGHT RISK...WHICH LOOKS GOOD.
ACTIVITY SHOULD WEAKEN TWD 03Z ACRS CENTRAL/EASTERN VT. CWMW
SOUNDINGS SHOW PW VALUES OF 1.66"...500MB WINDS OF 50 KNOTS...AND
VERY HIGH EL AROUND 43KFT...SO EXPECT OVERSHOOTING STORM TOPS NEAR
50KFT THIS AFTN/EVENING WITH GREATEST POTENTIAL BEING WINDS. 0 TO
6 KM STORM MOTIONS OF 20 TO 25 KNOTS SHOULD LIMIT FLASH FLOOD
THREAT...BUT WESTERN/SOUTHERN FLANK ACRS THE DACKS WL HAVE TO BE
WATCHED FOR POTENTIAL TRAINING...GIVEN VECTOR ANALYSIS.
OTHERWISE...HIGHS IN THE L/M 90S WITH DWPTS BTWN 65 AND 70 WL
RESULT IN HEAT INDEX VALUES IN THE MID TO UPPER 90S. ALL IS
COVERED VERY WELL IN CRNT FCST AND ONLY MINOR CHANGES MADE BASED
ON CRNT OBS.
PRIOR DISCUSSION FOLLOWS...
FORECAST MORE OR LESS REMAINS ON TRACK FOR TODAY AS LARGE-SCALE
H5 HEAT RIDGE MAINTAINS ITS HOLD ON REGIONAL WEATHER. MEAN 18Z
925MB OF 23-25C SUPPORT HIGHS IN THE UPPER 80S TO MID 90S ACROSS
THE REGION ALONG WITH HIGH HUMIDITY...NOT A PLEASANT DAY. HEAT
INDEX VALUES TO PEAK JUST BELOW ADVISORY CRITERIA...GENERALLY IN
THE 92-98 RANGE IN LOWER ELEVATIONS BELOW 1000 FEET. THIS WILL BE
DAY 3 OF 90F+ AT KBTV SO OFFICIAL NEW ENGLAND HEAT WAVE CRITERIA
WILL BE MET. OF COURSE NOT ALL AREAS HAVE SEEN 3 CONSECUTIVE DAYS
OF 90F+...ESP IN SOME OF OUR NRN MTN LOCALES...BUT EVERYONE GETS
THE POINT THAT WE`RE IN A VERY WARM AND UNCOMFORTABLE STRETCH OF
WX.
COULD SEE SOME ISOLATED AFTERNOON PULSE-TYPE STORMS IN THE 1 TO 4
PM TIME FRAME OF SO...BUT INITIALLY MID LEVELS WILL BE SLIGHTLY
CAPPED SUCH THAT UPDRAFTS WILL BE INHIBITED. MORE IMPORTANTLY
HOWEVER WILL BE THE POTENTIAL FOR A LINE OF STRONG TO LOCALLY
SEVERE STORMS TO DROP SOUTHWARD INTO OUR NORTHERN COUNTIES LATER
THIS AFTERNOON OR EARLY EVENING AS A WEAK SURFACE FRONT
APPROACHES FROM THE NORTHWEST. WITH SLIGHT MID LEVEL HEIGHT FALLS
AMPLE PBL INSTABILITY AND MODEST 0-6KM SHEAR VALUES INCREASING
INTO THE 30-40 KT RANGE ACROSS THE NORTH...THE THREAT FOR STRONG
TO LOCALLY SEVERE STORMS TO DEVELOP ALONG THIS LINE IS
INCREASING. VERY TALL STORMS WITH TOPS TO NEAR 50 KFT POSSIBLE
WITH EQ LEVELS VERY HIGH. MODIFIED KMSS AND KFSO SOUNDINGS
CENTERED AROUND 00Z SHOW QUITE ROBUST SWEAT AND DCAPE VALUES...SO
STRONG OUTFLOW/DAMAGING WINDS LOOK LIKE THE PRIMARY
THREAT...ESPECIALLY IF ACTIVITY CAN ORGANIZE ENOUGH TO GENERATE
AN AMPLE COLD POOL. HAIL NOT SO MUCH AN ISSUE GIVEN MEAN WBZ
VALUES ABOVE 12 KFT. STORMS WILL TEND TO WEAKEN AS THEY PROGRESS
SOUTHWARD THROUGH OUR REGION...SO HIGHEST THREAT WILL BE ACROSS
OUR NORTHERN COUNTIES WITH LESS OF A THREAT THE FURTHER SOUTH YOU
GO. WILL ALSO CONTINUE MENTION OF HEAVY RAINFALL AS PWATS CLIMB
TO NEAR 1.9 INCHES ALONG WITH LOW TO MID LEVEL MOISTURE POOLING
IN ADVANCE OF THE SURFACE BOUNDARY.
BY LATER THIS EVENING INTO TONIGHT ACTIVITY SLOWLY WANES AND
TAPERS TO SCATTERED SHOWERS ACROSS OUR CENTRAL AND NORTHERN
COUNTIES AS WEAK FRONTAL BOUNDARY SAGS INTO THE REGION AND
STALLS. PATCHY FOG ALSO A GOOD BET IF WE SEE HEAVIER WETTING
RAINFALL. LOWS MILD AND HUMID...MID 60S TO LOWER 70S...OR SIMILAR
TO THE PAST FEW NIGHTS.
&&
.SHORT TERM /11 PM THIS EVENING THROUGH FRIDAY/...
AS OF 420 AM EDT WEDNESDAY...BY THURSDAY STALLED WEAK SURFACE
BOUNDARY REMAINS DRAPED ACROSS OUR AREA ALONG WITH CONTINUED
WARMTH AND HUMIDITY. SCATTERED SHOWERS AND STORMS ALSO A GOOD BET
WITH LOCALLY HEAVY RAINFALL ONCE AGAIN. MBE VECTOR VALUES ARE
GENERALLY GREATER THAN 10 KTS HOWEVER...SO MY FEELING IS STORMS
MAY BE MOVING ENOUGH TO PRECLUDE A MORE ORGANIZED FLASH FLOOD
THREAT. NONETHELESS WE`LL HAVE TO KEEP AN EYE ON THINGS WITH PWAT
VALUES HOVERING AROUND 2.0 INCHES. DESPITE AMPLE SHEAR AND
INSTABILITY...FEEL ANY SEVERE THREAT SHOULD BE FAIRLY MARGINAL AS
WE REALLY DON`T HAVE A STRONG MECHANISM FOR LIFT OTHER THAN THE
SFC HEATING AND THE WEAK BOUNDARY. TIME WILL TELL. HIGHS ABOUT
2-4 DEGREES COOLER THAN TODAY SO SOME SLIGHT RELIEF BUT NOT MUCH.
SPOT HIGH FOR KBTV AT 89-90F LOOKS REASONABLE.
FRONT THEN REMAINS ATOP OUR REGION THURSDAY NIGHT INTO
FRIDAY...LIFTING SLOWLY NORTHWARD AND DISSIPATING THROUGH TIME IN
RESPONSE TO LARGE-SCALE BACKING OF THE MID LEVEL FLOW AHEAD OF A
MORE ROBUST NRN STREAM UPPER TROUGH OFF TO OUR NORTHWEST. THUS
CHANCE OF SHOWERS AND STORMS CONTINUE...BUT HIGHER CHANCES TREND
MORE ACROSS OUR NORTHERN COUNTIES. LIKELY A REPEAT OF TODAYS HOT
VALUES BY FRIDAY WITH MODELS HAVING CONSISTENTLY TRENDED WARMER
OVER THE PAST 24-HOURS. INDEED...WITH MEAN 925MB TEMPS AVERAGING
FROM 24-26C FRIDAY COULD END UP AS HOT IF NOT A DEGREE OR TWO
HOTTER THAN TODAY...ESPECIALLY IF WE SEE AMPLE SUNSHINE. SO IT`S
NOT ENTIRELY UNREASONABLE TO SUGGEST IF WE HIT 90F AT KBTV ON
THURSDAY...A FIVE DAY STRETCH OF 90F+ WILL BE IN REACH. THE LAST
TIME THIS OCCURRED WAS BACK IN AUGUST 2002.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 436 AM EDT WEDNESDAY...SFC LOW PRESSURE SYSTEM WILL START
THE PERIOD WITH SHOWERS/THUNDERSTORMS AND WARM TEMPERATURES...
FOLLOWED BY HIGH PRESSURE AND A COOLER...DRIER AIRMASS. FRIDAY
NIGHT WILL SEE THE NORTH COUNTRY STILL IN THE WARM SECTOR AND SW
FLOW AS A PREFRONTAL TROUGH AT THE SFC TRIGGERS
SHOWERS/THUNDERSTORMS FOLLOWED BY ASSOCIATED COLD FRONT ON
SATURDAY CONTINUING THE THREAT FOR SHOWERS AND THUNDERSTORMS.
FAVORABLE UPPER LEVEL JET DYNAMICS WILL ACCOMPANY THE COLD FRONT
WITH RR QUADRANT OF 250MB JET MOVES OVER THE NORTH COUNTRY MAINLY
ON SATURDAY...COINCIDING WITH STRONG FGEN AT 850MB...LINGERING
INTO SATURDAY NIGHT. PWATS OF 1.5-2 INCHES WILL PEAK EARLY
SATURDAY AS THE FRONT MOVES FROM SE ONTARIO...SEWD AND EVENTUALLY
EXIT VT EARLY SUNDAY AS ASSOCIATED UPPER LEVEL TROUGH PUSHES NEWD
SATURDAY NIGHT. HIGH PRESSURE WILL BUILD IN OVER THE REGION
FOLLOWING THE FRONT SUNDAY THROUGH AT LEAST MONDAY. MONDAY NIGHT
INTO TUESDAY...THE 00Z ECMWF BRINGS ANOTHER UPPER LEVEL TROUGH
OVER THE REGION...PRODUCING SHOWERS WHILE THE GFS KEEPS THE HIGH
PRESSURE ENTRENCHED OVER NRN NEW ENGLAND THROUGH THE MIDDLE OF
THE WEEK.
TEMPERATURES WILL BE WARM AND MUGGY...WITH MIN TEMPS FRIDAY NIGHT
IN THE 60S-L70S AND MAX TEMPS ON SATURDAY RANGING FORM M70S TO
M80S. COOLER AIR WILL FILTER IN FOR THE REST OF THE PERIOD WITH
MIN TEMPS TRENDING COOLER. SATURDAY NIGHT WILL BE IN THE 50S-
L60S...WITH SUNDAY NT THRU TUES NT IN THE M40S-U50S. MAX TEMPS
WILL GENERALLY BE IN THE 70S.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 12Z THURSDAY...VFR CONDITIONS WILL PERSIST THROUGH AT
LEAST THE EARLY EVENING HOURS...AS KMPV RECOVERS FROM VLIFR THIS
MORNING. SFC TROUGH GENERATING SCT-BKN MID LEVEL CLOUDS THIS
MORNING BEFORE DIURNALLY DRIVEN VFR CLOUDS DEVELOP IN THE HOT
HUMID DAYTIME...WITH INSTABILITY INCREASING THROUGHOUT THE LATE
AFTN/EVENING HRS. LGT TO CALM WINDS THIS MORNING WILL INCREASE TO
8-12KTS OUT OF THE S-SW IN THE MID-LATE MORNING...SHIFTING SW-W
THIS AFTN WITH GUSTS PSBL.
A BOUNDARY ASSOCIATED UPPER LEVEL VORTICITY WILL TRIGGER SCT
SHOWERS AND THUNDERSTORMS NORTH OF THE INTERNATIONAL BORDER IN
THE LATE AFTN...TRAVELING S/SE AND MOST LIKELY AFFECTING
KMSS/KPBG/KBTV AND PSBLY KSLK/KMPV. EXPECT SCT SHOWERS AND
THUNDERSTORMS TO TRAVEL FROM NW TO SSE...AFFECTING KMSS AROUND
20Z...KPBG/KBTV/KMPV AROUND 23Z/00Z. HAVE INCLUDED VCSH AT ALL
BUT KRUT AS WESTERLY WINDS WILL HELP SHOWERS AND THUNDERSTORMS
LOSE MOMENTUM SWD...WHILE LOSS OF DIURNAL HEATING AFTER SUNSET
WEAKENS CONVECTIVE ACTIVITY. EXPECT SHOWERS AND THUNDERSTORMS TO
DISSIPATE AFTER 04Z. THUNDERSTORMS MAY CONTAIN STRONG GUSTY
WINDS. ANY AREA THAT RECEIVES RAINFALL COULD DEVELOP FG/BR MAINLY
AFTER 04Z THURSDAY. EXPECT PATCHY FG TO DEVELOP AT MOST TAF SITES
OVERNIGHT...RECOVERING TO VFR MID TO LATE THURSDAY MORNING.
OUTLOOK 12Z THURSDAY THROUGH SUNDAY...
12Z THURSDAY THROUGH SATURDAY...PRIMARILY VFR CONDITIONS EXPECTED
DURING THE DAY WITH ISOLATED PATCHY FG/BR OVERNIGHT...MAINLY AT
KSLK/KMPV. HOWEVER...CHANCES INCREASE FOR SCATTERED
SHOWERS/THUNDERSTORMS THROUGH THE PERIOD WHICH MAY BRING BRIEF
PERIODS OF MVFR/IFR IN SHOWERS AND THUNDERSTORMS.
SUNDAY...VFR WITH HIGH PRESSURE BUILDING IN AT THE SFC.
&&
.MARINE...
AS OF 420 AM EDT WEDNESDAY...STRONG TO LOCALLY SEVERE
THUNDERSTORMS MAY EFFECT THE LAKE CHAMPLAIN WATERS LATER THIS
AFTERNOON AND EVENING. IF STORMS DO DEVELOP...THEY WILL LIKELY
APPROACH FROM THE NORTH AND NORTHWEST AFTER 3 PM AND MAY BE
ACCOMPANIED BY VERY STRONG GUSTY WINDS AND FREQUENT CLOUD TO
GROUND LIGHTNING. IF PLANNING ACTIVITIES ON THE LAKE THIS
AFTERNOON AND EVENING...PLEASE KEEP ABREAST OF THE LATEST WEATHER
INFORMATION AND BE PREPARED TO SEEK SAFE HARBOR QUICKLY SHOULD
STRONGER STORMS APPROACH. WINDS GENERALLY LIGHT SOUTHERLY THIS
MORNING...TRENDING WEST TO SOUTHWESTERLY 5 TO 15 KNOTS THIS
AFTERNOON AND EVENING OUTSIDE ANY STORMS.
&&
.CLIMATE...
MAX TEMP RECORDS TODAY THROUGH FRIDAY. BEST SHOT TODAY AT
KMSS...THEN ON FRIDAY AT KMPV AND KMSS. SHORTER PERIOD OF RECORD AT
THESE SITES THAN AT K1V4 AND KBTV.
07/17/2013 07/18/2013 07/19/2013
KBTV 97/1999 99/1953 98/1942
KMPV 93/1982 96/1953 92/1991
K1V4 94/1953 99/1953 95/1991
KMSS 92/2012 95/1953 93/1991
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG/TABER
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...KGM
MARINE...
CLIMATE...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
738 AM EDT WED JUL 17 2013
.SYNOPSIS...
HOT AND HUMID WEATHER IS EXPECTED THROUGH FRIDAY ALONG WITH AN
INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS. A FEW OF THE
STORMS COULD BE STRONG TO SEVERE LATER THIS AFTERNOON AND
EVENING. SHOWERS AND STORMS WILL END NORTH TO SOUTH DURING
SATURDAY AS A STRONG COLD FRONT PUSHES THROUGH THE AREA. BEHIND
THIS FRONT...A MORE SEASONABLE AND PLEASANTLY DRIER AIRMASS WILL
SETTLE ACROSS THE REGION FROM SUNDAY INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 550 AM EDT WEDNESDAY...QUICK UPDATE TO ACCOUNT FOR ISOLATED
SHOWERS FAR NERN VT OVER THE NEXT FEW HOURS...AND TO INCORPORATE
LATEST T/TD/SKY DATA INTO EXISTENT DATASETS. OTW FORECAST IN GOOD
SHAPE. HAVE A GREAT DAY. PRIOR DISCUSSION FOLLOWS...
FORECAST MORE OR LESS REMAINS ON TRACK FOR TODAY AS LARGE-SCALE H5
HEAT RIDGE MAINTAINS ITS HOLD ON REGIONAL WEATHER. MEAN 18Z 925MB
OF 23-25C SUPPORT HIGHS IN THE UPPER 80S TO MID 90S ACROSS THE
REGION ALONG WITH HIGH HUMIDITY...NOT A PLEASANT DAY. HEAT INDEX
VALUES TO PEAK JUST BELOW ADVISORY CRITERIA...GENERALLY IN THE
92-98 RANGE IN LOWER ELEVATIONS BELOW 1000 FEET. THIS WILL BE DAY
3 OF 90F+ AT KBTV SO OFFICIAL NEW ENGLAND HEAT WAVE CRITERIA WILL
BE MET. OF COURSE NOT ALL AREAS HAVE SEEN 3 CONSECUTIVE DAYS OF
90F+...ESP IN SOME OF OUR NRN MTN LOCALES...BUT EVERYONE GETS THE
POINT THAT WE`RE IN A VERY WARM AND UNCOMFORTABLE STRETCH OF WX.
COULD SEE SOME ISOLATED AFTERNOON PULSE-TYPE STORMS IN THE 1 TO 4
PM TIME FRAME OF SO...BUT INITIALLY MID LEVELS WILL BE SLIGHTLY
CAPPED SUCH THAT UPDRAFTS WILL BE INHIBITED. MORE IMPORTANTLY
HOWEVER WILL BE THE POTENTIAL FOR A LINE OF STRONG TO LOCALLY
SEVERE STORMS TO DROP SOUTHWARD INTO OUR NORTHERN COUNTIES LATER
THIS AFTERNOON OR EARLY EVENING AS A WEAK SURFACE FRONT
APPROACHES FROM THE NORTHWEST. WITH SLIGHT MID LEVEL HEIGHT FALLS
AMPLE PBL INSTABILITY AND MODEST 0-6KM SHEAR VALUES INCREASING
INTO THE 30-40 KT RANGE ACROSS THE NORTH...THE THREAT FOR STRONG
TO LOCALLY SEVERE STORMS TO DEVELOP ALONG THIS LINE IS
INCREASING. VERY TALL STORMS WITH TOPS TO NEAR 50 KFT POSSIBLE
WITH EQ LEVELS VERY HIGH. MODIFIED KMSS AND KFSO SOUNDINGS
CENTERED AROUND 00Z SHOW QUITE ROBUST SWEAT AND DCAPE VALUES...SO
STRONG OUTFLOW/DAMAGING WINDS LOOK LIKE THE PRIMARY
THREAT...ESPECIALLY IF ACTIVITY CAN ORGANIZE ENOUGH TO GENERATE
AN AMPLE COLD POOL. HAIL NOT SO MUCH AN ISSUE GIVEN MEAN WBZ
VALUES ABOVE 12 KFT. STORMS WILL TEND TO WEAKEN AS THEY PROGRESS
SOUTHWARD THROUGH OUR REGION...SO HIGHEST THREAT WILL BE ACROSS
OUR NORTHERN COUNTIES WITH LESS OF A THREAT THE FURTHER SOUTH YOU
GO. WILL ALSO CONTINUE MENTION OF HEAVY RAINFALL AS PWATS CLIMB
TO NEAR 1.9 INCHES ALONG WITH LOW TO MID LEVEL MOISTURE POOLING
IN ADVANCE OF THE SURFACE BOUNDARY.
BY LATER THIS EVENING INTO TONIGHT ACTIVITY SLOWLY WANES AND
TAPERS TO SCATTERED SHOWERS ACROSS OUR CENTRAL AND NORTHERN
COUNTIES AS WEAK FRONTAL BOUNDARY SAGS INTO THE REGION AND
STALLS. PATCHY FOG ALSO A GOOD BET IF WE SEE HEAVIER WETTING
RAINFALL. LOWS MILD AND HUMID...MID 60S TO LOWER 70S...OR SIMILAR
TO THE PAST FEW NIGHTS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 420 AM EDT WEDNESDAY...BY THURSDAY STALLED WEAK SURFACE
BOUNDARY REMAINS DRAPED ACROSS OUR AREA ALONG WITH CONTINUED
WARMTH AND HUMIDITY. SCATTERED SHOWERS AND STORMS ALSO A GOOD BET
WITH LOCALLY HEAVY RAINFALL ONCE AGAIN. MBE VECTOR VALUES ARE
GENERALLY GREATER THAN 10 KTS HOWEVER...SO MY FEELING IS STORMS
MAY BE MOVING ENOUGH TO PRECLUDE A MORE ORGANIZED FLASH FLOOD
THREAT. NONETHELESS WE`LL HAVE TO KEEP AN EYE ON THINGS WITH PWAT
VALUES HOVERING AROUND 2.0 INCHES. DESPITE AMPLE SHEAR AND
INSTABILITY...FEEL ANY SEVERE THREAT SHOULD BE FAIRLY MARGINAL AS
WE REALLY DON`T HAVE A STRONG MECHANISM FOR LIFT OTHER THAN THE
SFC HEATING AND THE WEAK BOUNDARY. TIME WILL TELL. HIGHS ABOUT
2-4 DEGREES COOLER THAN TODAY SO SOME SLIGHT RELIEF BUT NOT MUCH.
SPOT HIGH FOR KBTV AT 89-90F LOOKS REASONABLE.
FRONT THEN REMAINS ATOP OUR REGION THURSDAY NIGHT INTO
FRIDAY...LIFTING SLOWLY NORTHWARD AND DISSIPATING THROUGH TIME IN
RESPONSE TO LARGE-SCALE BACKING OF THE MID LEVEL FLOW AHEAD OF A
MORE ROBUST NRN STREAM UPPER TROUGH OFF TO OUR NORTHWEST. THUS
CHANCE OF SHOWERS AND STORMS CONTINUE...BUT HIGHER CHANCES TREND
MORE ACROSS OUR NORTHERN COUNTIES. LIKELY A REPEAT OF TODAYS HOT
VALUES BY FRIDAY WITH MODELS HAVING CONSISTENTLY TRENDED WARMER
OVER THE PAST 24-HOURS. INDEED...WITH MEAN 925MB TEMPS AVERAGING
FROM 24-26C FRIDAY COULD END UP AS HOT IF NOT A DEGREE OR TWO
HOTTER THAN TODAY...ESPECIALLY IF WE SEE AMPLE SUNSHINE. SO IT`S
NOT ENTIRELY UNREASONABLE TO SUGGEST IF WE HIT 90F AT KBTV ON
THURSDAY...A FIVE DAY STRETCH OF 90F+ WILL BE IN REACH. THE LAST
TIME THIS OCCURRED WAS BACK IN AUGUST 2002.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 436 AM EDT WEDNESDAY...SFC LOW PRESSURE SYSTEM WILL START
THE PERIOD WITH SHOWERS/THUNDERSTORMS AND WARM TEMPERATURES...
FOLLOWED BY HIGH PRESSURE AND A COOLER...DRIER AIRMASS. FRIDAY
NIGHT WILL SEE THE NORTH COUNTRY STILL IN THE WARM SECTOR AND SW
FLOW AS A PREFRONTAL TROUGH AT THE SFC TRIGGERS
SHOWERS/THUNDERSTORMS FOLLOWED BY ASSOCIATED COLD FRONT ON
SATURDAY CONTINUING THE THREAT FOR SHOWERS AND THUNDERSTORMS.
FAVORABLE UPPER LEVEL JET DYNAMICS WILL ACCOMPANY THE COLD FRONT
WITH RR QUADRANT OF 250MB JET MOVES OVER THE NORTH COUNTRY MAINLY
ON SATURDAY...COINCIDING WITH STRONG FGEN AT 850MB...LINGERING
INTO SATURDAY NIGHT. PWATS OF 1.5-2 INCHES WILL PEAK EARLY
SATURDAY AS THE FRONT MOVES FROM SE ONTARIO...SEWD AND EVENTUALLY
EXIT VT EARLY SUNDAY AS ASSOCIATED UPPER LEVEL TROUGH PUSHES NEWD
SATURDAY NIGHT. HIGH PRESSURE WILL BUILD IN OVER THE REGION
FOLLOWING THE FRONT SUNDAY THROUGH AT LEAST MONDAY. MONDAY NIGHT
INTO TUESDAY...THE 00Z ECMWF BRINGS ANOTHER UPPER LEVEL TROUGH
OVER THE REGION...PRODUCING SHOWERS WHILE THE GFS KEEPS THE HIGH
PRESSURE ENTRENCHED OVER NRN NEW ENGLAND THROUGH THE MIDDLE OF
THE WEEK.
TEMPERATURES WILL BE WARM AND MUGGY...WITH MIN TEMPS FRIDAY NIGHT
IN THE 60S-L70S AND MAX TEMPS ON SATURDAY RANGING FORM M70S TO
M80S. COOLER AIR WILL FILTER IN FOR THE REST OF THE PERIOD WITH
MIN TEMPS TRENDING COOLER. SATURDAY NIGHT WILL BE IN THE 50S-
L60S...WITH SUNDAY NT THRU TUES NT IN THE M40S-U50S. MAX TEMPS
WILL GENERALLY BE IN THE 70S.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 12Z THURSDAY...VFR CONDITIONS WILL PERSIST THROUGH AT
LEAST THE EARLY EVENING HOURS...AS KMPV RECOVERS FROM VLIFR THIS
MORNING. SFC TROUGH GENERATING SCT-BKN MID LEVEL CLOUDS THIS
MORNING BEFORE DIURNALLY DRIVEN VFR CLOUDS DEVELOP IN THE HOT
HUMID DAYTIME...WITH INSTABILITY INCREASING THROUGHOUT THE LATE
AFTN/EVENING HRS. LGT TO CALM WINDS THIS MORNING WILL INCREASE TO
8-12KTS OUT OF THE S-SW IN THE MID-LATE MORNING...SHIFTING SW-W
THIS AFTN WITH GUSTS PSBL.
A BOUNDARY ASSOCIATED UPPER LEVEL VORTICITY WILL TRIGGER SCT
SHOWERS AND THUNDERSTORMS NORTH OF THE INTERNATIONAL BORDER IN
THE LATE AFTN...TRAVELING S/SE AND MOST LIKELY AFFECTING
KMSS/KPBG/KBTV AND PSBLY KSLK/KMPV. EXPECT SCT SHOWERS AND
THUNDERSTORMS TO TRAVEL FROM NW TO SSE...AFFECTING KMSS AROUND
20Z...KPBG/KBTV/KMPV AROUND 23Z/00Z. HAVE INCLUDED VCSH AT ALL
BUT KRUT AS WESTERLY WINDS WILL HELP SHOWERS AND THUNDERSTORMS
LOSE MOMENTUM SWD...WHILE LOSS OF DIURNAL HEATING AFTER SUNSET
WEAKENS CONVECTIVE ACTIVITY. EXPECT SHOWERS AND THUNDERSTORMS TO
DISSIPATE AFTER 04Z. THUNDERSTORMS MAY CONTAIN STRONG GUSTY
WINDS. ANY AREA THAT RECEIVES RAINFALL COULD DEVELOP FG/BR MAINLY
AFTER 04Z THURSDAY. EXPECT PATCHY FG TO DEVELOP AT MOST TAF SITES
OVERNIGHT...RECOVERING TO VFR MID TO LATE THURSDAY MORNING.
OUTLOOK 12Z THURSDAY THROUGH SUNDAY...
12Z THURSDAY THROUGH SATURDAY...PRIMARILY VFR CONDITIONS EXPECTED
DURING THE DAY WITH ISOLATED PATCHY FG/BR OVERNIGHT...MAINLY AT
KSLK/KMPV. HOWEVER...CHANCES INCREASE FOR SCATTERED
SHOWERS/THUNDERSTORMS THROUGH THE PERIOD WHICH MAY BRING BRIEF
PERIODS OF MVFR/IFR IN SHOWERS AND THUNDERSTORMS.
SUNDAY...VFR WITH HIGH PRESSURE BUILDING IN AT THE SFC.
&&
.MARINE...
AS OF 420 AM EDT WEDNESDAY...STRONG TO LOCALLY SEVERE
THUNDERSTORMS MAY EFFECT THE LAKE CHAMPLAIN WATERS LATER THIS
AFTERNOON AND EVENING. IF STORMS DO DEVELOP...THEY WILL LIKELY
APPROACH FROM THE NORTH AND NORTHWEST AFTER 3 PM AND MAY BE
ACCOMPANIED BY VERY STRONG GUSTY WINDS AND FREQUENT CLOUD TO
GROUND LIGHTNING. IF PLANNING ACTIVITIES ON THE LAKE THIS
AFTERNOON AND EVENING...PLEASE KEEP ABREAST OF THE LATEST WEATHER
INFORMATION AND BE PREPARED TO SEEK SAFE HARBOR QUICKLY SHOULD
STRONGER STORMS APPROACH. WINDS GENERALLY LIGHT SOUTHERLY THIS
MORNING...TRENDING WEST TO SOUTHWESTERLY 5 TO 15 KNOTS THIS
AFTERNOON AND EVENING OUTSIDE ANY STORMS.
&&
.CLIMATE...
MAX TEMP RECORDS TODAY THROUGH FRIDAY. BEST SHOT TODAY AT
KMSS...THEN ON FRIDAY AT KMPV AND KMSS. SHORTER PERIOD OF RECORD AT
THESE SITES THAN AT K1V4 AND KBTV.
07/17/2013 07/18/2013 07/19/2013
KBTV 97/1999 99/1953 98/1942
KMPV 93/1982 96/1953 92/1991
K1V4 94/1953 99/1953 95/1991
KMSS 92/2012 95/1953 93/1991
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...KGM
MARINE...JMG
CLIMATE...JMG
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
931 AM EDT WED JUL 17 2013
.DISCUSSION...
HIGH PRESSURE WILL REMAIN CENTERED OVER THE OHIO VALLEY
TODAY...PRODUCING A NE FLOW ALOFT OVER THE SOUTHERN APPALACHIANS.
WITH A LACK OF SYNOPTIC FORCING...CONVECTIVE DEVELOPMENT WILL FAVOR
THE HIGHER TERRAIN OF THE MOUNTAINS AND PLATEAU. LIKE
YESTERDAY...CONVECTION IS EXPECTED TO DEVELOP OVER WESTERN
NC...AND DRIFT W-SW. THE RUC AND NAM ARE IN AGREEMENT WITH THIS
SCENARIO. POPS WILL BE ADJUSTED UPWARD SLIGHTLY IN THE MOUNTAINS
AND PLATEAU...AND LOWERED SLIGHTLY IN THE VALLEY.
BASED ON THE 1000-850 THICKNESS VALUES FROM THE 12Z OHX
SOUNDING...WHICH ARE HIGHER TODAY THAN YESTERDAY...AND CURRENT OBS
WHICH ARE RUNNING A BIT ABOVE FORECAST...WILL RAISE HIGH TEMPS A
FEW DEGREES.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS
AREA FORECAST DISCUSSION...UPDATED
NWS PHOENIX AZ
235 PM MST WED JUL 17 2013
.SYNOPSIS...
DEEP MONSOON MOISTURE WILL CONTINUE OVER ARIZONA...BUT SLOWLY EXPAND
WEST INTO THE SOUTHEAST CALIFORNIA DESERTS BY FRIDAY. THIS WILL
PROVIDE A THREAT OF AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS
OVER ARIZONA TODAY AND THURSDAY...THEN INTO THE SOUTHEAST CALIFORNIA
DESERTS BY FRIDAY AND THE WEEKEND.
&&
.DISCUSSION...
CURRENT RADAR IMAGERY AS OF 2PM LOOKS MODERATELY ACTIVE OVER THE
MOGOLLON RIM AREA AND LOCATIONS FARTHER NORTHEAST.
NORTH-NORTHEASTERLY FLOW ALOFT IS CREATING DIFLUENCE FROM NORTHERN
ARIZONA STRETCHING SOUTHWARD ACROSS CENTRAL AND SOUTHERN ARIZONA.
COOLER AIR FROM NORTHEASTERN PORTIONS OF AZ IS BEING DRAWN SOUTHWEST
ACROSS THE DESERTS...INTO AMPLE MOISTURE LOADING ENVIRONMENTS.
PAIRED WITH SUFFICIENT DAYTIME HEATING TAKING PLACE...THIS SHOULD
CREATE A FAVORABLE ENVIRONMENT FOR THUNDERSTORM ACTIVITY AND
INCREASED MONSOON ACTIVITY THIS EVENING. FORECAST MODELS ARE SHOWING
15-25KT OF STEERING FLOW...WHICH WOULD TRANSLATE TO FASTER MOVING
STORMS AND NOT SO MUCH THE THREAT OF HEAVY RAIN PRODUCING STORMS.
LOCATIONS THAT ARE OF INTEREST FOR TONIGHT ARE LA PAZ AND YUMA
COUNTIES AND THE WESTERN PORTION OF MARICOPA COUNTY...WHERE A MORE
FAVORABLE INSTABILITY AXIS RESIDES. GUSTY WINDS GENERATED FROM
OUTFLOWS ARE ALSO CONCERNS.
RAOB SOUNDING PRECIPITABLE WATER VALUES REMAIN PRETTY MOIST...VALUES
RANGING FROM 1 TO 1.8 INCHES ACROSS ARIZONA...WITH INCREASING
MOISTURE ALONG THE WESTERN PORTIONS OF THE STATE. AIRCRAFT SOUNDINGS
INDICATE A SHALLOW WARM LAYER INVERSION AROUND 700HPA EXISTED AT
19Z AND HAS SINCE ERODED AWAY. DEWPOINT READINGS ACROSS THE CENTRAL
DESERTS HAVE TRENDED DOWNWARD 4-5F DEGREES OVER THE PAST 24
HOURS...WHILE STILL REMAINING NEAR 60F. SKIES HAVE CLEARED
CONSIDERABLY TODAY...ALLOWING TEMPERATURES A LONGER DURATION TO WARM
AND MORE INSTABILITY TO DEVELOP. THE HRRR AND WRF LOCAL FORECAST
MODELS HAVE BEEN PERFORMING WELL IN REGARDS TO THE GENERAL LOCATION
AND MOVEMENT WITH CONVECTION INITIATION. THIS SAID...THESE MODELS
INDICATE A LATER ONSET OF ACTIVITY THIS AFTERNOON. WHILE WIDESPREAD
THUNDERSTORM ACTIVITY IS NOT ANTICIPATED...ANOTHER ACTIVE MONSOON
DAY IS EXPECTED. SKY HARBOR HAS REACHED 99 DAYS WITHOUT MEASURABLE
PRECIPITATION AS OF TUESDAY 16 JULY.
THE NEXT FEW DAYS LOOK FAVORABLE FOR AFTERNOON THUNDERSTORM ACTIVITY
AS WELL...AS THE UPPER LEVEL CLOSED LOW CONTINUES TO TREK
WEST-SOUTHWESTWARD INTO NORTHWEST MEXICO/GULF OF CA. SOUTHWEST AZ
WILL SEE AN INCREASE IN THE THREAT FOR STORMS THURSDAY AFTERNOON.
AS MENTIONED BY THE PREVIOUS SHIFT...FRIDAY THROUGH EARLY NEXT
WEEK...THERE WILL BE AN INCREASING THREAT OF SHOWERS AND
THUNDERSTORMS OVER THE SOUTHEAST CA DESERTS AND MOUNTAINS THIS
PERIOD. THE NORTHWEST MEXICO CLOSED LOW WILL EVENTUALLY MOVE TO A
POSITION OFF THE SAN DIEGO COAST BY MONDAY. IN THIS POSITION...UPPER
LEVEL WINDS BECOME SOUTHEASTERLY WITH A SERIES OF EMBEDDED AND HARD
TO TIME DISTURBANCES. THEREFORE A THREAT OF STORMS IN GENERAL WILL
EXIST REGION WIDE...WITH DAY TO DAY CHANGES IN COVERAGE AND
INTENSITY.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL...
EXPECT MID AND HIGH CLOUDS TO GRADUALLY THICKEN AND LOWER AS THE
AFTERNOON PROGRESSES AND AS STORMS MAKE THEIR WAY INTO THE VALLEY
FROM THE RIM. WILL MAINTAIN VCSH/VCTS AT ALL PHOENIX SITES SHORTLY
AFTER 00-02Z...CONFIDENCE IN RAIN AT ANY GIVEN AIRPORT SHAKY AT
BEST. VERY TOUGH CALL IF WE WILL GET A WEST WIND TODAY...MODEL
GUIDANCE SUGGESTS IF WE DO IT WILL BE VERY BRIEF. WINDS WILL QUICKLY
RETURN TO EAST BY MID EVENING WITH CLOUDS LINGERING INTO THURSDAY
MORNING.
SOUTHEAST CA AND SOUTHWEST AZ...INCLUDING KIPL AND KBLH...
SCT-BKN HIGH CLOUDS JUST ABOUT THE ONLY AVIATION CONCERN ACROSS SE
CA. PRECIP CHANCES REMAIN SLIM TO NIL. WINDS WILL BE LIGHT AND WILL
FAVOR TYPICAL DIURNAL TRENDS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
ABOVE NORMAL PRECIP CHANCES WILL REMAIN A POSSIBILITY THROUGH THE
WEEKEND AS A QUASI-STATIONARY AREA OF LOW PRESSURE REMAINS OVER THE
AREA. DEEPER MONSOONAL MOISTURE WILL WORK WESTWARD THROUGH THE
WEEKEND...GENERATING SLIGHTLY COOLER TEMPERATURES AND EXPANDING
PRECIPITATION CHANCES INTO THE SOUTHEAST CALIFORNIA DISTRICTS.
HUMIDITIES WILL ALSO REMAIN ELEVATED WITH AFTERNOON HUMIDITIES ONLY
DROPPING INTO THE 20-30 PERCENT RANGE WITH GOOD OVERNIGHT RECOVERY.
STORM COVERAGE AND INTENSITY WILL VARY FROM DAY TO DAY WHICH WILL
IMPACT FORECAST WINDS...DISRUPTING NORMAL DIURNAL PATTERNS.
$$
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...CDEWEY
AVIATION...LEINS
FIRE WEATHER...NOLTE/LEINS
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
303 PM EDT WED JUL 17 2013
.DISCUSSION...
CURRENTLY-TONIGHT...DAYTIME HEATING CONVECTION WILL PUSH ACROSS
THE INTERIOR TO THE WEST COAST THROUGH LATE AFTERNOON. WILL CARRY
SMALL POPS ACROSS THE INTERIOR THROUGH EVENING FOR THIS ACTIVITY.
THE LATEST RAP ANALYSIS SHOWS THE CENTER OF UPPER LEVEL LOW
CONTINUING TO PUSH SLOWLY WEST/NORTHWEST OVER THE NORTHEAST GULF.
EXPECT THIS WILL CAUSE AREAS OF DIVERGENCE ALOFT THAT HAVE BEEN
OVER THE ATLANTIC TO GET CLOSER TO THE LOCAL AREA THIS EVENING
AND OVERNIGHT.
ADDITIONALLY A WEAK LOW LEVEL TROUGH SHOULD NUDGE INTO OUR
SOUTHERN AREAS OVERNIGHT. THE COMBINATION OF LOW LEVEL CONVERGENCE
AND UPPER LEVEL DIVERGENCE SHOULD CAUSE CONVECTION TO FLARE UP AND
AFFECT A PORTION OF OUR COAST...MAINLY FROM THE CAPE SOUTHWARD TO
THE TREASURE COAST. A CHANCE FOR LOCALLY HEAVY RAINFALL EXISTS.
WILL CARRY 30 POPS IN BREVARD AND INCREASE TO 50 PERCENT IN MARTIN
FOR THIS EVENING/OVERNIGHT CONVECTION.
PREVIOUS DISCUSSION...
THU-FRI...STRONG RIDGE EXTENDING ACROSS THE CENTRAL TO EASTERN
U.S. WILL BREAK DOWN AS UPPER LEVEL TROUGH BUILDS SOUTHWARD FROM
THE GREAT LAKES REGION. AT THE SFC AN INVERTED TROUGH WILL SHIFT
WESTWARD INTO FLORIDA THURSDAY AND USHER IN A WETTER PATTERN INTO
LATE WEEK. BOTH GFS AND NAM SHOW PW VALUES INCREASING TO ABOVE 2
INCHES WHICH WILL KEEP HIGHER RAIN CHANCES OVER THE REGION. HAVE
INCREASED POPS TO 50-60% THURSDAY AND AROUND 50% FRIDAY. A FEW
SHOWERS EXPECTED EARLY IN THE MORNING WITH INCREASING COVERAGE OF
SHOWERS AND STORMS INTO THE LATE MORNING AND AFTERNOON.
SAT-TUE...UPPER LEVEL TROUGH DIGS FARTHER SOUTH THIS WEEKEND AND
REMAINS ACROSS THE EASTERN CONUS INTO EARLY NEXT WEEK. THIS WILL KEEP
THE AXIS OF THE SUBTROPICAL RIDGE ACROSS SOUTH FLORIDA FOR MUCH OF
THE PERIOD. DEEP MOISTURE AND A MORE PREVALENT LOW TO MID LEVEL W/SW
FLOW WILL FAVOR BEST RAIN CHANCES OVER EAST CENTRAL FLORIDA
ESPECIALLY WITH ANY BOUNDARY INTERACTIONS WHERE THE EAST COAST SEA
BREEZE IS ABLE TO DEVELOP IN THE AFTERNOON. TEMPERATURES WILL REMAIN
NEAR TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION...
A BIT MORE OF A TYPICAL DIURNAL REGIME WITH SCATTERED SHOWERS AND
ISOLATED STORMS MOSTLY PUSHING ACROSS THE INTERIOR FROM KMCO-KISM
SOUTHWARD. EXPECT A FEW SHOWERS TO MOVE ACROSS AREAS NORTH OF
THIS AND TO THE COAST AROUND KTIX.
FOR COASTAL SITES FROM KMLB-KSUA...THERE SHOULD BE A FLARE UP OF
CONVECTION OVER THE ATLANTIC THIS EVENING OR OVERNIGHT. WHILE IT
IS TOO EARLY TO PUT DETERIORATING CONDITIONS INTO THE TAFS...
EXPECT SOME PORTION OF THIS AREA TO BE AFFECTED WITH PERIODS OF
MVFR-IFR CONDITIONS...WHICH MAY LINGER INTO EARLY THU. EXPECT
CONVECTION DURING DAYTIME HEATING ON THU TO BE FOCUSED ON THE
INTERIOR TERMINALS.
&&
.MARINE...
TONIGHT...WEAK LOW LEVEL TROUGH IS FORECAST TO LIFT NORTH INTO THE
WATERS. THIS WILL START TO EASE THE PRESSURE GRADIENT AND VEER
WINDS MORE TO THE SOUTHEAST. MORE IMPORTANTLY SHOULD BE A
POTENTIAL FOR A FLARE UP OF CONVECTION OVER THE ATLANTIC WATERS
WHICH MAY LINGER MUCH OF THE NIGHT ESPECIALLY SOUTH OF CANAVERAL.
THU-SUN...A WEAK INVERTED TROUGH IS FORECAST TO PUSH INTO THE GULF
ON THU WITH THE ATLANTIC SURFACE RIDGE NOSING BACK TOWARDS THE
FLORIDA PENINSULA. THIS WILL CAUSE A SOUTHEAST WIND FLOW ON THU TO
BECOME MOSTLY SOUTHERLY ON FRI AND CONTINUE OVER THE WEEKEND.
SPEEDS SHOULD BE LESS THAN 15 KNOTS. QUITE HIGH MOISTURE WILL LEAD
TO A GREATER THAN NORMAL CHANCE OF ATLANTIC SHOWERS/STORMS THROUGH
THE PERIOD. DAYTIME HEATING STORMS OVER THE MAINLAND SHOULD START
TO PUSH TO THE COAST FRI AND THEN ACROSS THE COAST THIS WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 73 87 74 90 / 20 40 30 50
MCO 73 90 74 92 / 20 50 30 50
MLB 74 87 74 90 / 20 50 30 50
VRB 71 88 73 89 / 30 60 30 50
LEE 73 91 75 92 / 20 50 30 50
SFB 74 91 75 92 / 20 40 30 50
ORL 74 91 75 92 / 20 50 30 50
FPR 71 87 72 89 / 30 60 30 50
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECASTS...LASCODY
IMPACT WEATHER/RADAR...MOSES/CRISTALDI
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
337 PM EDT WED JUL 17 2013
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
CURRENT SATELLITE LOOP SHOWS MAIN EASTERN WAVE MOVING INTO NE GA AT
THE MOMENT. THE CURRENT RADAR LOP SHOWS SHOWERS AND ISOLATED
THUNDERSTORMS POPPING UP ACROSS NE GA WHICH IS DEFINITELY BEING GENERATED
BY THIS WAVE. THE MAIN ENERGY FROM THIS WAVE IS EXPECTED TO STAY
ACROSS NORTH GA BUT BOTH OUR LOCAL WRF AND THE HRRR SHOW A BIT MORE
DIURNALLY DRIVEN POP UP SHRA/TSRA ACROSS THE STATE THROUGH 02-04Z
TONIGHT. THE SURFACE TO UPPER LEVEL RIDGE KEEPS OUR AREA IN MOIST
EASTERLY FLOW THROUGH THE SHORT TERM. THE MODELS ARE SHOWING ANOTHER
WEAKER WAVE MOVING ACROSS THE AREA THU IN THIS EASTERLY FLOW. WITH
THIS IN MIND SHOULD SEE ANOTHER DIURNALLY DRIVEN CONVECTIVE DAY THU.
THERE IS VERY LITTLE SHEAR IN THIS ATMOSPHERE BUT THE CAPES AND LIS
BOTH PEAK BETWEEN 18Z AND 00Z THIS AFTERNOON AND THURSDAY. TODAY
SHOULD BE THE WARMEST DAY THIS WEEK WITH RISING THICKNESSES TODAY
HOWEVER PRECIP/CLOUDS MAY OFFSET THE WARMING A LITTLE. H5 HEIGHTS
WILL BE DROPPING THURSDAY YIELDING A SLIGHTLY COOLER TEMPS. STAYING
CLOSE TO CURRENT FORECAST TEMPS AS THEY STILL LOOKS GOOD.
01
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
NO SIG CHANGES TO THE EXTENDED. ONLY CHANGE WERE TO THE POPS ON
SUNDAY WHERE OUR NEIGHBORS AND GUIDANCE SUGGESTS A LIKELY CHANCE
OF POPS. DECIDED TO GO WITH THAT FOR SUNDAY AFTERNOON. OTHERWISE
UPDATED THE DEWPOINTS...WINDS AND TEMPERATURES WITH NEW GUIDANCE.
HAVE ATTACHED PREVIOUS DISCUSSION FOR BREVITY.
ARG
&&
.PREV DISCUSSION... /ISSUED 730 AM EDT WED JUL 17 2013/
LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
/ISSUED AT 355 AM EDT WED JUL 17 2013/
A TRANSITION TAKES PLACE THIS PERIOD FROM EAST FLOW ALOFT TO
WESTERLY FLOW WITH A UPPER TROUGH DEVELOPING OVER THE EASTERN
STATES. GFS AND EUROPEAN ARE SIMILAR WITH THIS CHANGE UNTIL THE
MONDAY TO WEDNESDAY TIME FRAME WHEN THE EUROPEAN MOVES THE TROUGH
TO THE WESTERN ATLANTIC AND THE GFS KEEPS THE UPPER TROUGH OVER THE
OH/TN VALLEYS AS A STRONGER UPPER SHORT WAVE MOVES OVER THE MID U.S.
PLENTY OF MOISTURE AND INSTABILITY THIS PERIOD FOR AT LEAST
SCATTERED SHOWERS AND THUNDERSTORMS FOR MOST AREAS...TENDING TO
MAXIMIZE IN THE AFTERNOON AND EVENING HOURS. DEEPER MOISTURE MOVES
ACROSS THE AREA WITH THE INITIAL ONSET OF THE UPPER TROUGH
SUNDAY/MONDAY AS A FRONT BECOMES STATIONARY JUST N OF GA AND A
SURFACE TROUGH SETS UP FROM THE CAROLINAS INTO GA. TEMPERATURES
GENERALLY CLOSE TO NORMAL EXCEPT HIGH TEMPERATURES WILL RUN
SLIGHTLY BELOW NORMAL FROM SATURDAY ON.
BDL
AVIATION...
18Z UPDATE...
SOME FEW TO SCT CLOUDS FORMING ACROSS THE AREA THIS AFTERNOON.
CLOUDS MAINLY IN THE 4000-6000FT RANGE AND NOT EXPECTING THINGS TO
GO BKN OR OVC. SHRA/TSRA HAVE BEGUN POPPING UP AND SHOULD SEE MORE
COVERAGE OVER THE NEXT FEW HOURS. THESE SHOWER AND THUNDERSTORMS
SHOULD STA OUT OF THE TAF SITES TILL 21Z. THIS CONVECTIVE ACTIVITY
IS DIURNALLY DRIVEN SO SHOULD SEE SHRA/TSRA DIMINISH BY 02-04Z.
WINDS ARE TURNING TO THE EAST AND SHOULD STAY THERE THROUGH THE
TAF PERIOD. NO RESTRICTIONS TO VSBYS EXPECTED EXCEPT IN AND AROUND
TSRA DEVELOPMENT.
//ATL CONFIDENCE...18Z UPDATE...
CONFIDENCE HIGH ON ALL ELEMENTS.
01
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 71 92 71 90 / 40 30 30 40
ATLANTA 74 91 73 88 / 40 30 30 50
BLAIRSVILLE 69 88 68 84 / 40 50 30 50
CARTERSVILLE 70 91 71 89 / 40 40 30 50
COLUMBUS 73 94 73 90 / 20 30 30 50
GAINESVILLE 73 90 73 88 / 40 40 30 50
MACON 71 92 71 90 / 30 30 20 40
ROME 71 92 71 90 / 40 40 30 50
PEACHTREE CITY 71 91 70 89 / 40 30 30 50
VIDALIA 72 93 72 89 / 20 30 20 40
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...01
LONG TERM....ARG
AVIATION...01
AREA FORECAST DISCUSSION
NWS GRAY ME
645 PM EDT WED JUL 17 2013
.SYNOPSIS...
A WEAK COLD FRONT WILL SLOWLY CROSS NORTHERN MAINE TONIGHT...
PRODUCING A TREAT FOR SHOWERS AND THUNDERSTORMS. THE FRONT WILL
PUSH BACK TO THE NORTH ON THURSDAY...MAKING FOR A RETURN TO HOT
AND HUMID WEATHER ON FRIDAY. A COLD FRONT WILL DROP SOUTH FROM
CANADA FRIDAY NIGHT AND WILL CROSS THE REGION ON
SATURDAY...POSSIBLY SETTING OFF A ROUND OF STRONG TO SEVERE
THUNDERSTORMS. COOLER AND LESS HUMID HIGH PRESSURE BUILDS IN ON
SUNDAY AND LINGERS INTO EARLY NEXT WEEK...BEFORE THINGS START
SHOW SIGNS OF WARMING UP AGAIN.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
WILL UPDATE TO SLOW DOWN ONSET OF SHOWERS AND THUNDERSTORMS THIS
EVENING PER LATEST RADAR MOSAIC LOOP. STILL EXPECTING CONVECTIVE
ACTIVITY TO ARRIVE THROUGH THE COURSE OF THE EVENING HOURS...
LIKELY HOLDING OFF UNTIL LATE EVENING ALONG THE COAST. ANY OTHER
CHANGES VERY MINIMAL AT THIS TIME.
ZONES UPDATED TO ADD THE SEVERE THUNDERSTORM WATCH THROUGH
MIDNIGHT TONIGHT. ALREADY HAVE POSSIBLE SEVERE THUNDERSTORMS IN
THE FORECAST FOR THIS EVENING.
SHOWERS AND THUNDERSTORMS DEVELOPING OVER ONTARIO WILL MOVE
SOUTHEAST AND INTO NORTHERN NEW ENGLAND TONIGHT. THIS ACTIVITY
WILL BE PRIMARILY DRIVEN BY A SHORTWAVE TROUGH AND SURFACE COLD
FRONT INTERACTING WITH A VERY WARM/MOIST PRE-FRONTAL ENVIRONMENT.
HRRR MODEL SEEMS TO BE HANDLING THE FORECAST VERY WELL TODAY AND
THIS WAS USED EXTENSIVELY IN THE NEAR TERM FORECAST FOR TONIGHT.
AS COORDINATED WITH THE STORM PREDICTION CENTER... IT APPEARS THAT
INITIALLY ISOLATED CONVECTIVE ACTIVITY OVER CANADA AND UPSTATE NEW
YORK WILL LIKELY EVOLVE INTO A SQUALL LINE AND MOVE SOUTHEAST
THROUGH VERMONT AND NEW HAMPSHIRE AND INTO MAINE. HRRR MODEL SEEMS
TO BE SHOWING THE SIGNS OF AN MESOSCALE CONVECTIVE SYSTEM WITH
TRAILING STRATIFORM RAIN REGION BEHIND IT ARRIVING IN NEW
HAMPSHIRE AROUND 7 TO 8 PM AND HOLDING TOGETHER ALL THE WAY TO THE
COAST BY MIDNIGHT. DAMAGING WINDS WILL BE THE BIGGEST THREAT WITH
THIS SCENARIO TONIGHT... ALTHOUGH VERY MOIST ENVIRONMENT WILL
ALLOW FOR EFFICIENT RAINFALL PRODUCTION. WIDESPREAD RAINFALL OF
OVER ONE INCH ARE POSSIBLE WITH THE LEADING CONVECTIVE BAND AND
TRAILING RAIN REGION.
STORMS SHOULD MOVE OFF THE COAST AROUND MIDNIGHT... WITH CLEARING
BEHIND IT. COULD SEE SOME FOG ESPECIALLY IF RAIN IS WIDESPREAD.
HUMIDITY WILL KEEP TEMPERATURES IN THE UPPER 60S AND LOW 70S.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
COLD FRONT / OUTFLOW FROM OVERNIGHT CONVECTION WILL STALL AND WASH
OUT OFFSHORE ON THURSDAY. MAY SEE A RETURN FLOW OF WARM/MOIST AIR
INTO THE AREA WITH TEMPERATURES WARMING INTO THE UPPER 80S AND LOW
90S. DEW POINTS NEAR 70 WILL ALLOW HEAT INDEX VALUES TO RISE INTO
THE UPPER 90S. DO NOT ANTICIPATE NEEDING A HEAT ADVISORY FOR
THURSDAY AS THERE WILL NOT BE A LARGE AREA OF EXTENDED HEAT INDEX
READINGS ABOVE 100. IF HIGHER DEW POINTS OR HIGHER TEMPERATURES
ARE ACHIEVED... THEN THIS CRITERIA COULD BE MET. CONDITIONS WILL
BE CLOSE TO ADVISORY CRITERIA... BUT CONSIDERING THAT THE HOT AND
HUMID WEATHER HAS BEEN AROUND FOR SEVERAL WEEKS THIS SUMMER... DID
NOT THINK A MARGINAL ADVISORY WAS NEEDED AS THE AWARENESS OF THE
HOT AND HUMID WEATHER IS ALREADY HIGH.
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE DURING THE AFTERNOON
TOMORROW... PRIMARILY OVER THE SOUTHWESTERN HALF OF THE AREA WHERE
BETTER INSTABILITY EXISTS. A SHORTWAVE TROUGH WILL ALSO ADD LIFT
IN THIS AREA TO INCREASE THE CHANCE OF CONVECTION. ALTHOUGH WE
CANNOT RULE OUT THE THREAT FOR DAMAGING WINDS WITH ANY STORMS THAT
FORM... THE THREAT DOES NOT APPEAR WIDESPREAD.
EXPECT SHOWERS AND THUNDERSTORMS TO DISSIPATE THURSDAY EVENING.
ANOTHER HUMID NIGHT WILL KEEP TEMPERATURES IN THE UPPER 60S AND
LOW 70S.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
500 MB HEIGHTS RISE ON FRIDAY AS RIDGING BUILDS IN BRIEFLY...AND
850 TEMPS APPROACH 20 C. EXPECTING THIS BE ONE OF THE MORE HOT AND
HUMID DAYS WE HAVE SEEN THIS SUMMER...AND HEAT INDEX VALUES WILL
LIKELY REACH 100 IN PARTS OF THE SOUTHERN ZONES...AND A HEAT
ADVISORY MAY BE NEEDED THERE. CANNOT RULE OUT A FEW AIR MASS
THUNDERSTORMS...BUT BETTER CHANCE WILL BE IN NORTHERN
ZONES...WHERE STRONGER WINDS ALOFT...AND APPROACHING COLD FRONT
WILL CREATE BETTER DYNAMICS...AND COULD PRODUCE SOME STRONGER
STORMS. LOOK FOR A WARM AND UNCOMFORTABLE NIGHT FRIDAY NIGHT AS
HUMIDITIES REMAIN HIGH AND INCREASED SW FLOW PREVENTS MIN FROM
DROPPING OFF MUCH. COLD FRONT WILL APPROACH NORTHERN ZONES LATE
FRIDAY NIGHT...AND THE THREAT FOR THUNDERSTORMS WILL INCREASE
TOWARD DAYBREAK...AND SHIFT SOUTHWARD TOWARD THROUGH THE DAY.
GIVEN THE GREAT SURFACE INSTABILITY AND THE STRONG MID-UPPER LEVEL
WINDS DROPPING SOUTHWARD AHEAD OF THE FRONT SATURDAY...THE THREAT
FOR SEVERE CONVECTION REMAINS A CONCERN ON SATURDAY...AND THIS
COULD LINGER INTO THE EVENING.
THE FRONT IS EXPECTED TO CLEAR THE COAST LATE SATURDAY NIGHT OR
EARLY SUNDAY...WITH CLEARING AND NOTICEABLY COOLER AND LESS
HUMID CONDITIONS. THE HIGH THAT BUILDS IN BEHIND THE FRONT WILL
LINGER INTO TUESDAY...WITH TEMPS CLOSE TO OR A LITTLE BELOW NORMAL
DURING THIS PERIOD. AN INCREASE IN HUMIDITY AND TEMPS IS POSSIBLE
BY MID-WEEK.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
SHORT TERM /THROUGH THURSDAY NIGHT/...SCATTERED WITH POSSIBLY MORE
NUMEROUS SHOWERS AND THUNDERSTORMS MOVE THROUGH OVERNIGHT WITH
POSSIBLE IFR CIG/VSBY...REACHING NW AREAS FIRST BY 00Z THEN ALONG
THE COAST LAST...MOST LIKELY AFTER 02Z. SHOWERS AND THUNDERSTORMS
END FROM NW TO SE FROM ROUGHLY 04Z TO 06Z. POSSIBLE SEVERE WX WITH
THUNDERSTORMS WITH A SEVERE THUNDERSTORM WATCH IN EFFECT THROUGH
MIDNIGHT ACROSS THE MOUNTAINS AND FOOTHILLS OF WESTERN MAINE AND
ALL OF NEW HAMPSHIRE EXCEPT SOUTHEAST PORTIONS. VALLEY FOG WITH
POSSIBLE IFR/LIFR CIG/VSBY FORMS OVERNIGHT MAINLY WHERE RAIN HAS
FALLEN AND IN MORE FAVORABLE LOCATIONS. VFR THURSDAY AND THURSDAY
NIGHT...EXCEPT LOWER IN SCATTERED AFTERNOON AND EVENING SHOWERS
AND THUNDERSTORMS. AGAIN...PATCHY FOG POSSIBLE THURSDAY NIGHT.
LONG TERM...MAINLY VFR FRIDAY AND FRIDAY NIGHT...WITH FLIGHT
RESTRICTIONS IS CONVECTION EXPECTED ON SATURDAY INTO SATURDAY
EVENING. VFR RETURNS SUNDAY AND MONDAY.
&&
.MARINE...
SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...WILL UPDATE PER
LATEST BUOY OBSERVATIONS. A FEW GUSTS UP TO 25 KT AT THIS TIME
WILL CONTINUE THROUGH THE EVENING HOURS BUT WON`T BE FREQUENT
ENOUGH TO WARRANT AN SCA. WINDS DROP OFF OVERNIGHT. WILL HOLD SEAS
BELOW 5 FEET OVERNIGHT AS THEY TRY TO BUILD THIS EVENING BUT
SLACKEN OFF OVERNIGHT AS WINDS LET UP. WINDS AND SEAS STAY BELOW
SCA LEVELS THURSDAY AND THURSDAY NIGHT.
LONG TERM...SW FLOW INCREASES AHEAD OF A COLD FRONT FRIDAY NIGHT
INTO SATURDAY WITH SEAS IN EXCESS AROUND 5 FT...AND WINDS APPROACHING
SCA LEVELS. WINDS WILL SHIFT TO NW SATURDAY NIGHT AND DIMINISH.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
424 PM EDT WED JUL 17 2013
.SYNOPSIS...
A WEAK COLD FRONT WILL SLOWLY CROSS NORTHERN MAINE TONIGHT...
PRODUCING A TREAT FOR SHOWERS AND THUNDERSTORMS. THE FRONT WILL
PUSH BACK TO THE NORTH ON THURSDAY...MAKING FOR A RETURN TO HOT
AND HUMID WEATHER ON FRIDAY. A COLD FRONT WILL DROP SOUTH FROM
CANADA FRIDAY NIGHT AND WILL CROSS THE REGION ON
SATURDAY...POSSIBLY SETTING OFF A ROUND OF STRONG TO SEVERE
THUNDERSTORMS. COOLER AND LESS HUMID HIGH PRESSURE BUILDS IN ON
SUNDAY AND LINGERS INTO EARLY NEXT WEEK...BEFORE THINGS START
SHOW SIGNS OF WARMING UP AGAIN.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
ZONES UPDATED TO ADD THE SEVERE THUNDERSTORM WATCH THROUGH
MIDNIGHT TONIGHT. ALREADY HAVE POSSIBLE SEVERE THUNDERSTORMS IN
THE FORECAST FOR THIS EVENING.
SHOWERS AND THUNDERSTORMS DEVELOPING OVER ONTARIO WILL MOVE
SOUTHEAST AND INTO NORTHERN NEW ENGLAND TONIGHT. THIS ACTIVITY
WILL BE PRIMARILY DRIVEN BY A SHORTWAVE TROUGH AND SURFACE COLD
FRONT INTERACTING WITH A VERY WARM/MOIST PRE-FRONTAL ENVIRONMENT.
HRRR MODEL SEEMS TO BE HANDLING THE FORECAST VERY WELL TODAY AND
THIS WAS USED EXTENSIVELY IN THE NEAR TERM FORECAST FOR TONIGHT.
AS COORDINATED WITH THE STORM PREDICTION CENTER... IT APPEARS THAT
INITIALLY ISOLATED CONVECTIVE ACTIVITY OVER CANADA AND UPSTATE NEW
YORK WILL LIKELY EVOLVE INTO A SQUALL LINE AND MOVE SOUTHEAST
THROUGH VERMONT AND NEW HAMPSHIRE AND INTO MAINE. HRRR MODEL SEEMS
TO BE SHOWING THE SIGNS OF AN MESOSCALE CONVECTIVE SYSTEM WITH
TRAILING STRATIFORM RAIN REGION BEHIND IT ARRIVING IN NEW
HAMPSHIRE AROUND 7 TO 8 PM AND HOLDING TOGETHER ALL THE WAY TO THE
COAST BY MIDNIGHT. DAMAGING WINDS WILL BE THE BIGGEST THREAT WITH
THIS SCENARIO TONIGHT... ALTHOUGH VERY MOIST ENVIRONMENT WILL
ALLOW FOR EFFICIENT RAINFALL PRODUCTION. WIDESPREAD RAINFALL OF
OVER ONE INCH ARE POSSIBLE WITH THE LEADING CONVECTIVE BAND AND
TRAILING RAIN REGION.
STORMS SHOULD MOVE OFF THE COAST AROUND MIDNIGHT... WITH CLEARING
BEHIND IT. COULD SEE SOME FOG ESPECIALLY IF RAIN IS WIDESPREAD.
HUMIDITY WILL KEEP TEMPERATURES IN THE UPPER 60S AND LOW 70S.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
COLD FRONT / OUTFLOW FROM OVERNIGHT CONVECTION WILL STALL AND WASH
OUT OFFSHORE ON THURSDAY. MAY SEE A RETURN FLOW OF WARM/MOIST AIR
INTO THE AREA WITH TEMPERATURES WARMING INTO THE UPPER 80S AND LOW
90S. DEW POINTS NEAR 70 WILL ALLOW HEAT INDEX VALUES TO RISE INTO
THE UPPER 90S. DO NOT ANTICIPATE NEEDING A HEAT ADVISORY FOR
THURSDAY AS THERE WILL NOT BE A LARGE AREA OF EXTENDED HEAT INDEX
READINGS ABOVE 100. IF HIGHER DEW POINTS OR HIGHER TEMPERATURES
ARE ACHIEVED... THEN THIS CRITERIA COULD BE MET. CONDITIONS WILL
BE CLOSE TO ADVISORY CRITERIA... BUT CONSIDERING THAT THE HOT AND
HUMID WEATHER HAS BEEN AROUND FOR SEVERAL WEEKS THIS SUMMER... DID
NOT THINK A MARGINAL ADVISORY WAS NEEDED AS THE AWARENESS OF THE
HOT AND HUMID WEATHER IS ALREADY HIGH.
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE DURING THE AFTERNOON
TOMORROW... PRIMARILY OVER THE SOUTHWESTERN HALF OF THE AREA WHERE
BETTER INSTABILITY EXISTS. A SHORTWAVE TROUGH WILL ALSO ADD LIFT
IN THIS AREA TO INCREASE THE CHANCE OF CONVECTION. ALTHOUGH WE
CANNOT RULE OUT THE THREAT FOR DAMAGING WINDS WITH ANY STORMS THAT
FORM... THE THREAT DOES NOT APPEAR WIDESPREAD.
EXPECT SHOWERS AND THUNDERSTORMS TO DISSIPATE THURSDAY EVENING.
ANOTHER HUMID NIGHT WILL KEEP TEMPERATURES IN THE UPPER 60S AND
LOW 70S.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
500 MB HEIGHTS RISE ON FRIDAY AS RIDGING BUILDS IN BRIEFLY...AND
850 TEMPS APPROACH 20 C. EXPECTING THIS BE ONE OF THE MORE HOT AND
HUMID DAYS WE HAVE SEEN THIS SUMMER...AND HEAT INDEX VALUES WILL
LIKELY REACH 100 IN PARTS OF THE SOUTHERN ZONES...AND A HEAT
ADVISORY MAY BE NEEDED THERE. CANNOT RULE OUT A FEW AIR MASS
THUNDERSTORMS...BUT BETTER CHANCE WILL BE IN NORTHERN
ZONES...WHERE STRONGER WINDS ALOFT...AND APPROACHING COLD FRONT
WILL CREATE BETTER DYNAMICS...AND COULD PRODUCE SOME STRONGER
STORMS. LOOK FOR A WARM AND UNCOMFORTABLE NIGHT FRIDAY NIGHT AS
HUMIDITIES REMAIN HIGH AND INCREASED SW FLOW PREVENTS MIN FROM
DROPPING OFF MUCH. COLD FRONT WILL APPROACH NORTHERN ZONES LATE
FRIDAY NIGHT...AND THE THREAT FOR THUNDERSTORMS WILL INCREASE
TOWARD DAYBREAK...AND SHIFT SOUTHWARD TOWARD THROUGH THE DAY.
GIVEN THE GREAT SURFACE INSTABILITY AND THE STRONG MID-UPPER LEVEL
WINDS DROPPING SOUTHWARD AHEAD OF THE FRONT SATURDAY...THE THREAT
FOR SEVERE CONVECTION REMAINS A CONCERN ON SATURDAY...AND THIS
COULD LINGER INTO THE EVENING.
THE FRONT IS EXPECTED TO CLEAR THE COAST LATE SATURDAY NIGHT OR
EARLY SUNDAY...WITH CLEARING AND NOTICEABLY COOLER AND LESS
HUMID CONDITIONS. THE HIGH THAT BUILDS IN BEHIND THE FRONT WILL
LINGER INTO TUESDAY...WITH TEMPS CLOSE TO OR A LITTLE BELOW NORMAL
DURING THIS PERIOD. AN INCREASE IN HUMIDITY AND TEMPS IS POSSIBLE
BY MID-WEEK.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
SHORT TERM...THUNDERSTORMS WILL BE POSSIBLE AROUND 00Z IN WESTERN
NEW HAMPSHIRE... SPREADING SOUTH AND EAST THROUGH AROUND 4 OR 6 Z.
THE GREATER CHANCE OF THUNDER WILL BE IN NORTHWEST NEW HAMPSHIRE.
OTHERWISE VFR CONDITIONS EXPECTED OUTSIDE OF VALLEY FOG IN THE
CONNECTICUT RIVER VALLEY.
LONG TERM...MAINLY VFR FRIDAY AND FRIDAY NIGHT...WITH FLIGHT
RESTRICTIONS IS CONVECTION EXPECTED ON SATURDAY INTO SATURDAY
EVENING. VFR RETURNS SUNDAY AND MONDAY.
&&
.MARINE...
SHORT TERM...LIGHT WINDS WILL KEEP CONDITIONS QUIET OVER THE WATERS.
LONG TERM...SW FLOW INCREASES AHEAD OF A COLD FRONT FRIDAY NIGHT
INTO SATURDAY WITH SEAS IN EXCESS AROUND 5 FT...AND WINDS APPROACHING
SCA LEVELS. WINDS WILL SHIFT TO NW SATURDAY NIGHT AND DIMINISH.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
351 PM EDT WED JUL 17 2013
.SYNOPSIS...
A WEAK COLD FRONT WILL SLOWLY CROSS NORTHERN MAINE TONIGHT...
PRODUCING A TREAT FOR SHOWERS AND THUNDERSTORMS. THE FRONT WILL
PUSH BACK TO THE NORTH ON THURSDAY...MAKING FOR A RETURN TO HOT
AND HUMID WEATHER ON FRIDAY. A COLD FRONT WILL DROP SOUTH FROM
CANADA FRIDAY NIGHT AND WILL CROSS THE REGION ON
SATURDAY...POSSIBLY SETTING OFF A ROUND OF STRONG TO SEVERE
THUNDERSTORMS. COOLER AND LESS HUMID HIGH PRESSURE BUILDS IN ON
SUNDAY AND LINGERS INTO EARLY NEXT WEEK...BEFORE THINGS START SHOW
SIGNS OF WARMING UP AGAIN.
&&
.NEAR TERM /TONIGHT/...
SHOWERS AND THUNDERSTORMS DEVELOPING OVER ONTARIO WILL MOVE
SOUTHEAST AND INTO NORTHERN NEW ENGLAND TONIGHT. THIS ACTIVITY
WILL BE PRIMARILY DRIVEN BY A SHORTWAVE TROUGH AND SURFACE COLD
FRONT INTERACTING WITH A VERY WARM/MOIST PRE-FRONTAL ENVIRONMENT.
HRRR MODEL SEEMS TO BE HANDLING THE FORECAST VERY WELL TODAY AND
THIS WAS USED EXTENSIVELY IN THE NEAR TERM FORECAST FOR TONIGHT.
AS COORDINATED WITH THE STORM PREDICTION CENTER... IT APPEARS THAT
INITIALLY ISOLATED CONVECTIVE ACTIVITY OVER CANADA AND UPSTATE NEW
YORK WILL LIKELY EVOLVE INTO A SQUALL LINE AND MOVE SOUTHEAST
THROUGH VERMONT AND NEW HAMPSHIRE AND INTO MAINE. HRRR MODEL SEEMS
TO BE SHOWING THE SIGNS OF AN MESOSCALE CONVECTIVE SYSTEM WITH
TRAILING STRATIFORM RAIN REGION BEHIND IT ARRIVING IN NEW
HAMPSHIRE AROUND 7 TO 8 PM AND HOLDING TOGETHER ALL THE WAY TO THE
COAST BY MIDNIGHT. DAMAGING WINDS WILL BE THE BIGGEST THREAT WITH
THIS SCENARIO TONIGHT... ALTHOUGH VERY MOIST ENVIRONMENT WILL
ALLOW FOR EFFICIENT RAINFALL PRODUCTION. WIDESPREAD RAINFALL OF
OVER ONE INCH ARE POSSIBLE WITH THE LEADING CONVECTIVE BAND AND
TRAILING RAIN REGION.
STORMS SHOULD MOVE OFF THE COAST AROUND MIDNIGHT... WITH CLEARING
BEHIND IT. COULD SEE SOME FOG ESPECIALLY IF RAIN IS WIDESPREAD.
HUMIDITY WILL KEEP TEMPERATURES IN THE UPPER 60S AND LOW 70S.
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
COLD FRONT / OUTFLOW FROM OVERNIGHT CONVECTION WILL STALL AND WASH
OUT OFFSHORE ON THURSDAY. MAY SEE A RETURN FLOW OF WARM/MOIST AIR
INTO THE AREA WITH TEMPERATURES WARMING INTO THE UPPER 80S AND LOW
90S. DEW POINTS NEAR 70 WILL ALLOW HEAT INDEX VALUES TO RISE INTO
THE UPPER 90S. DO NOT ANTICIPATE NEEDING A HEAT ADVISORY FOR
THURSDAY AS THERE WILL NOT BE A LARGE AREA OF EXTENDED HEAT INDEX
READINGS ABOVE 100. IF HIGHER DEW POINTS OR HIGHER TEMPERATURES
ARE ACHIEVED... THEN THIS CRITERIA COULD BE MET. CONDITIONS WILL
BE CLOSE TO ADVISORY CRITERIA... BUT CONSIDERING THAT THE HOT AND
HUMID WEATHER HAS BEEN AROUND FOR SEVERAL WEEKS THIS SUMMER... DID
NOT THINK A MARGINAL ADVISORY WAS NEEDED AS THE AWARENESS OF THE
HOT AND HUMID WEATHER IS ALREADY HIGH.
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE DURING THE AFTERNOON
TOMORROW... PRIMARILY OVER THE SOUTHWESTERN HALF OF THE AREA WHERE
BETTER INSTABILITY EXISTS. A SHORTWAVE TROUGH WILL ALSO ADD LIFT
IN THIS AREA TO INCREASE THE CHANCE OF CONVECTION. ALTHOUGH WE
CANNOT RULE OUT THE THREAT FOR DAMAGING WINDS WITH ANY STORMS THAT
FORM... THE THREAT DOES NOT APPEAR WIDESPREAD.
EXPECT SHOWERS AND THUNDERSTORMS TO DISSIPATE THURSDAY EVENING.
ANOTHER HUMID NIGHT WILL KEEP TEMPERATURES IN THE UPPER 60S AND
LOW 70S.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
500 MB HEIGHTS RISE ON FRIDAY AS RIDGING BUILDS IN BRIEFLY...AND
850 TEMPS APPROACH 20 C. EXPECTING THIS BE ONE OF THE MORE HOT AND
HUMID DAYS WE HAVE SEEN THIS SUMMER...AND HEAT INDEX VALUES WILL
LIKELY REACH 100 IN PARTS OF THE SOUTHERN ZONES...AND A HEAT
ADVISORY MAY BE NEEDED THERE. CANNOT RULE OUT A FEW AIR MASS
THUNDERSTORMS...BUT BETTER CHANCE WILL BE IN NORTHERN
ZONES...WHERE STRONGER WINDS ALOFT...AND APPROACHING COLD FRONT
WILL CREATE BETTER DYNAMICS...AND COULD PRODUCE SOME STRONGER
STORMS. LOOK FOR A WARM AND UNCOMFORTABLE NIGHT FRIDAY NIGHT AS
HUMIDITIES REMAIN HIGH AND INCREASED SW FLOW PREVENTS MIN FROM
DROPPING OFF MUCH. COLD FRONT WILL APPROACH NORTHERN ZONES LATE
FRIDAY NIGHT...AND THE THREAT FOR THUNDERSTORMS WILL INCREASE
TOWARD DAYBREAK...AND SHIFT SOUTHWARD TOWARD THROUGH THE DAY.
GIVEN THE GREAT SURFACE INSTABILITY AND THE STRONG MID-UPPER LEVEL
WINDS DROPPING SOUTHWARD AHEAD OF THE FRONT SATURDAY...THE THREAT
FOR SEVERE CONVECTION REMAINS A CONCERN ON SATURDAY...AND THIS
COULD LINGER INTO THE EVENING.
THE FRONT IS EXPECTED TO CLEAR THE COAST LATE SATURDAY NIGHT OR
EARLY SUNDAY...WITH CLEARING AND NOTICEABLY COOLER AND LESS
HUMID CONDITIONS. THE HIGH THAT BUILDS IN BEHIND THE FRONT WILL
LINGER INTO TUESDAY...WITH TEMPS CLOSE TO OR A LITTLE BELOW NORMAL
DURING THIS PERIOD. AN INCREASE IN HUMIDITY AND TEMPS IS POSSIBLE
BY MID-WEEK.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
SHORT TERM...THUNDERSTORMS WILL BE POSSIBLE AROUND 00Z IN WESTERN
NEW HAMPSHIRE... SPREADING SOUTH AND EAST THROUGH AROUND 4 OR 6 Z.
THE GREATER CHANCE OF THUNDER WILL BE IN NORTHWEST NEW HAMPSHIRE.
OTHERWISE VFR CONDITIONS EXPECTED OUTSIDE OF VALLEY FOG IN THE
CONNECTICUT RIVER VALLEY.
LONG TERM...MAINLY VFR FRIDAY AND FRIDAY NIGHT...WITH FLIGHT
RESTRICTIONS IS CONVECTION EXPECTED ON SATURDAY INTO SATURDAY
EVENING. VFR RETURNS SUNDAY AND MONDAY.
&&
.MARINE...
SHORT TERM...LIGHT WINDS WILL KEEP CONDITIONS QUIET OVER THE WATERS.
LONG TERM...SW FLOW INCREASES AHEAD OF A COLD FRONT FRIDAY NIGHT
INTO SATURDAY WITH SEAS IN EXCESS AROUND 5 FT...AND WINDS APPROACHING
SCA LEVELS. WINDS WILL SHIFT TO NW SATURDAY NIGHT AND DIMINISH.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CEMPA
NEAR TERM...KIMBLE
SHORT TERM...KIMBLE
LONG TERM...CEMPA
AVIATION...CEMPA/KIMBLE
MARINE...CEMPA/KIMBLE
AREA FORECAST DISCUSSION
NWS JACKSON MS
412 PM CDT WED JUL 17 2013
.DISCUSSION...
...STRONG TO SEVERE STORMS POSSIBLE TOMORROW AFTN/ERLY EVE...
SHOWERS AND A FEW THUNDERSTORMS ARE ONGOING ACROSS SOUTH MS AND
PORTIONS OF NE LA AS AFTERNOON CONVECTIVE TEMPERATURES ARE BEING
REACHED IN THE LOW TO MID 90S. SHOWER/STORM COVERAGE IS NOT GREAT
ACROSS THE REGION, AS EXPECTED, WITH SYNOPTIC SUBSIDENCE PREVAILING
AS A RESULT OF H5 RIDGE INFLUENCE CENTERED OVER THE OHIO VALLEY.
ANOTHER NOTABLE FEATURE IS A DEVELOPING TUTT LOW AND ASSOCIATED S/WV
VORTICITY IMPULSES TRAPPED IN THE EASTERLY MID-LVL FLOW ON THE
SOUTHERN PERIPHERY OF THE LARGE H5 RIDGE ACROSS THE WRN GOM AND
SOUTHERN ATLANTIC SEABOARD. THIS TUTT WILL AID IN THE STORMS
TOMORROW.
CURRENT SHOWER AND THUNDERSTORM ACTIVITY WILL SLOWLY DIMINISH
THROUGH THE EARLY EVENING HOURS AS THE ATMOSPHERE DESTABILIZES BUT AN
OUTSIDE STRONG STORM MAY BE POSSIBLE IF MERGERS OCCUR. THE POTENTIAL
FOR STRONG STORMS ACROSS FAR EAST MS TONIGHT HAS BEEN DECREASING WITH
ACTIVITY REMAINING CONFINED IN GA THIS AFTN AND STRUGGLING FARTHER
WEST IN AL WITH A DIMINISHING CU FIELD. LOCAL WRF AND HRRR SUPPORT
THIS THINKING AND HAVE ADJUSTED POPS/WX FOR THE OVRNGT PERIOD
ACCORDINGLY.
AS TUTT LOW INFLUENCE INCREASES TOMORROW, A NOTABLE LOW-LVL
CONVERGENT WIND FIELD LOOKS TO DEVELOP, CREATING AN INITIAL
CONVECTIVE TRIGGERING MECHANISM. A MORE THAN SUPPORTIVE THERMO
ENVIRONMENT LOOKS TO BE IN PLACE WITH >3000 J/KG SBCAPE, 27-28C
VERTICAL TOTALS AND STEEP LOW-LVL LAPSE RATES WITH TOMORROW LIKELY
THE WARMEST OF THE WEEK AS READINGS CLIMB INTO THE MID 90S. IT`S
TOUGH TO PINPOINT WHAT AREA WILL BE MORE FAVORED FOR SCATTERED TO
NUMEROUS STORM DEVELOPMENT AS IT WILL DEPEND ON H5 INVERTED TROUGH
AXIS LOCATION AND SPEED. NAM AND SUBSEQUENT HI-RES OUTPUT BASED ON
ITS INITIAL CONDITIONS ARE A BIT FASTER THAN GFS AND DEPICT BEST
COVERAGE IN CENTRAL AND WEST AREAS WITH GFS A TOUCH SLOWER WITH
POTENTIAL GREATER COVERAGE IN THE EAST. HAVE BLENDED THE TWO (WHICH
IS MUCH HIGHER THAN MAV POPS SUGGEST AND FOLLOWED MUCH CLOSER TO MET
GUIDANCE FOR THURS AFTN PERIOD. GIVEN HIGH LAPSE RATES AND ADEQUATE
INSTABILITY, STRAIGHT LINE WINDS OF 60 MPH, HAIL, AND HEAVY
DOWNPOURS WILL BE LIKELY INVOF STRONGEST STORMS. STORM MOTION WILL
BE SLOW AS ATM COLUMN HAS LITTLE FLOW, FURTHER AIDING IN LOCALIZED
POTENTIAL FOR FLASH FLOODING. ACTIVITY WILL SLOWLY DIMINISH THROUGH
THE MID TO LATE LATE EVE AS THE MID-UPPER LOW TRAVERSES WEST ACROSS
THE SABINE RIVER.
FOR FRIDAY...ANOTHER ROUND OF DECENT COVERAGE OF SHOWERS AND STORMS
AS CONTINUED FAVORABLE LIFT AND INSTABILITY REMAIN IN THE AREA WITH
THE TUTT LOW OVER ERN TX. SOME STORMS DURING FRI AFTN COULD AT LEAST
BE ON THE STRONG SIDE AND WILL HAVE TO MONITOR MESOSCALE EVOLUTION
THURSDAY TO SEE IF SEVERE STORMS COULD BE ATTAINED FRIDAY. HAVE
ADDED WORDING TO THE HWO/GRAPHICS FOR FRIDAY AFTN FOR THIS STRONG
STORM POTENTIAL.
FOR FORECAST ELEMENTS...MET POPS WERE USED AS A STARTING POINT FOR
TOMORROW IN LIEU OF LOW MAV POPS. POPS WERE ALSO BOOSTED FRIDAY WITH
WEAKNESS IN THE RIDGE AND TUTT LOW INFLUENCE. MAV LOW TEMPS WERE
BUMPED UP 1-3F DEGREES WITH HIGHS BUMPED DOWN 2F DEGREES BASED ON
RECENT TRENDS. /ALLEN/
&&
.AVIATION...VFR CONDS TO PERSIST THRU THE REST OF TODAY AND INTO
TONIGHT...ACCOMPANIED BY ELY/SELY SFC WINDS. ISOLD/SCT SHRA/TSRA WL
PERSIST ACROSS S/SW MS AND PORTIONS OF NE LA THIS AFTN BEFORE WANING
THIS EVENING. ISOLD SHRA/TSRA WL BE PSBL ACROSS ERN MS LATE THIS
AFTN/EVENING WHERE A FEW CELLS COULD MOVE INTO MS FROM OVER AL.
QUIET CONDS TO PREVAIL AREAWIDE BY 02Z...CONTINUING OVRNGT. PATCHY
MVFR VSBY WL BE PSBL 09-13Z TOMORROW. /BK/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 71 93 72 93 / 10 39 21 39
MERIDIAN 71 93 72 93 / 20 30 21 38
VICKSBURG 71 93 72 93 / 15 46 22 38
HATTIESBURG 71 93 73 93 / 14 42 21 44
NATCHEZ 71 91 72 91 / 16 46 21 48
GREENVILLE 73 95 74 94 / 10 46 20 37
GREENWOOD 71 94 72 94 / 10 30 17 40
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
ALLEN/BK
AREA FORECAST DISCUSSION...CORRECTED
NWS GLASGOW MT
332 PM MDT WED JUL 17 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH FRIDAY...
MAIN CHALLENGE THIS AFTERNOON AND EVENING IS THE HIGH TEMPERATURE
FORECAST ACROSS THE CWA. ACROSS THE NORTHEAST...DECIDED TO LOWER
TEMPERATURES BY SEVERAL DEGREES BELOW 17/12Z GUIDANCE GIVEN THE
PERSISTENT STEADY SHOWERS AND CLOUD COVER THERE. ACROSS CENTRAL
PORTIONS OF THE CWA...AREAS SHOULD START TO SEE BREAKS OF SUNSHINE
WHICH WILL RESULT IN TEMPERATURES RESPONDING. DID LOWER HIGHS IN A
FEW LOCATIONS AS THERE ARE ONLY A FEW HOURS OF DAYTIME HEATING
REMAINING. IN SHORT...EXPECT 80 DEGREES OR BETTER LATE AFTERNOON
OR EVENING ACROSS THE SOUTHERN ZONES. TEMPERATURES SHOULD MAKE IT
TO THE LOWER TO MIDDLE 70S ACROSS CENTRAL PORTIONS OF THE FORECAST
AREA. ONLY EXPECT HIGHS TO REACH UPPER 60S AND NEAR 70 ACROSS THE
INTERNATIONAL BORDER AND IN THE FAR NORTHEAST.
TONIGHT...TRICKY FORECAST REGARDING POTENTIAL SHOWER ACTIVITY
DEVELOPING...PRIMARILY SOUTH OF THE MISSOURI RIVER. WILL INSERT
LOW END CHANCE POPS FOR NOW BUT THE NEXT SHIFT WILL HAVE TO
MONITOR FAIRLY CAREFULLY FOR UPDATES. THE LATEST GFS/ECMWF MODELS
ARE DRY BUT THE NAM AND HRRR SHOWS POTENTIAL FOR PRECIPITATION
TONIGHT ACROSS THE SOUTH. GIVEN MORE SUNSHINE DURING THE DAYTIME
ACROSS THOSE LOCATIONS THERE COULD BE A BIT MORE INSTABILITY TO
TAP AS WEAK SHORTWAVE ENERGY PUSHES THROUGH OVERNIGHT. GIVEN LACK
OF CONFIDENCE HOWEVER...DID NOT GO TOO AGGRESSIVE AT THIS TIME.
THURSDAY...UPPER LEVEL ZONAL FLOW IN THE MORNING WILL TRANSITION
TO NORTHWEST FLOW ALOFT AS A SHORTWAVE TRAVELING ACROSS THE
INTERNATIONAL BORDER CLIPS THE NORTHEASTERN ZONES AND SWEEPS A
SURFACE COLD FRONT THROUGH THE CWA. WILL EXPECT STRONG GUSTY WINDS
TO DEVELOP BEHIND THE FRONTAL PASSAGE. NAM BUFKIT SOUNDINGS
INDICATE 40 KTS IN THE MID LEVELS. GIVEN VERY GOOD LOW AND MID
LEVEL LAPSE RATES...SOME OF THESE GUSTS MAY MIX DOWN TO THE
SURFACE. EXPECT 20-25 MPH SUSTAINED WINDS WITH GUSTS TO 35 MPH TO
BE QUITE POSSIBLE...WITH ISOLATED HIGHER GUSTS. THEREFORE...WILL
HOIST A LAKE WIND ADVISORY BEGINNING AT 15Z AND HAVE IT EXPIRE AT
MIDNIGHT WHEN WINDS ARE EXPECTED TO RELAX. MAINTAINED CHANCE POPS
IN THE NORTHEAST CLOSER TO THE WAVE AND THE AREA OF BEST PVA.
DESPITE THE FRONTAL PASSAGE...HIGHS MAY PROVE TO BE WARMER ACROSS
THE NORTHEAST DUE TO MORE IN THE WAY OF SUNSHINE.
THURSDAY NIGHT AND FRIDAY...NORTHWEST FLOW ALOFT WILL CONTINUE
ACROSS THE FORECAST REGION AND SHORTWAVE ENERGY WILL PROPAGATE
THROUGH ON FRIDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND
POSSIBLY THUNDER IN THE NORTHEAST. IT SHOULD REMAIN FAIRLY DRY
THURSDAY NIGHT AND FRIDAY ACROSS A ROBUST PORTION OF THE FORECAST
AREA HOWEVER AS THE CWA IS EXPECTED TO SIT ON THE EXTREME
NORTHEAST PERIPHERY OF A RIDE DOMINATING THE SOUTHWESTERN STATES.
THE ONLY AREA OF CONCERN WILL BE THE NORTHEAST CORNER OF THE
FORECAST AREA WHERE SHORTWAVE ENERGY RIDING AROUND THE RIDGE MAY
LEAD TO ENHANCED VERTICAL ASCENT AND TRIGGER A FEW SHOWERS AND/OR
THUNDERSTORMS. THIS IS STILL A COUPLE OF DAYS OUT AND FUTURE
SHIFTS CAN EVALUATE POTENTIAL FURTHER. MALIAWCO
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...
GOING FORECAST WAS IN GREAT SHAPE AND ONLY TWEAK MADE WAS TO
INCREASE POPS SLIGHTLY FOR MONDAY. JAMBA
PREVIOUS DISCUSSION...
BOTH THE EC AND THE GFS SHOW NORTHEAST MONTANA REMAINING UNDER A
NORTHWESTERLY FLOW ALOFT...AT LEAST THROUGH SUNDAY NIGHT...DUE TO
A PERSISTENT HEAT DOME OF HIGH PRESSURE CENTERED OVER THE GREAT
BASIN SUPPORTING A RIDGE IN THE WEST.
HOWEVER BEGINNING SUNDAY NIGHT THE 2 MODELS QUIT RESEMBLING EACH
OTHER. THE BIG DIFFERENCE IS THAT THE 12Z EC PICKS UP A COMPACT
CYCLONE OFF THE PACIFIC NORTHWEST COAST AND EJECTS IT ACROSS THE
INTER-MOUNTAIN WEST AND CANADIAN ROCKIES INTO ALBERTA AND
SASKATCHEWAN. THIS ACTION WOULD BACK FLOW ALOFT TO THE SOUTHWEST
AND SEND A COLD FRONT ACROSS THE DIVIDE TO REACH NEMONT AROUND
MONDAY NIGHT. THE GFS SHOWS NO HINT OF THIS WAVE. THEREFORE AFTER
THE WEEKEND THERE IS MORE UNCERTAINTY AS TO WHICH MODEL WILL PLAY
OUT. LATER IN THE SHIFT THE DELAYED 00Z EC STILL HOLDS ONTO THE
SHORTWAVE DISTURBANCE BUT RUNS IT EAST THROUGH MONTANA. WITH MORE
CONSISTENCY...REMAINED MOSTLY WITH THE GFS SOLUTION FOR THE REST
OF THE FORECAST.
FRIDAY NIGHT THROUGH SUNDAY NIGHT...WITH HIGH PRESSURE TO THE
SOUTHWEST AND A STRONG CLOSED UPPER LOW ROTATING AROUND HUDSON
BAY...NORTHEAST MONTANA WILL HAVE THE STATIONARY COLD BOUNDARY TO
THE NORTHEAST AND DESERT AIR TRYING TO PUSH IN FROM THE SOUTH.
THIS PATTERN MIGHT SEE SOME OVERRUNNING MOISTURE NEAR THIS
BOUNDARY FIRING OFF A FEW THUNDERSTORMS. BUT FOR THE MOST
PART...DRY WARM AIR WILL BE THE MAIN FEATURE OF THE WEEKEND.
MONDAY AND BEYOND...WITH BOTH MODELS OUT OF PHASE WITH EACH
OTHER...WILL NOT MOVE MUCH ONE WAY OR THE OTHER FROM THE
INHERITED GRIDS. TEMPERATURE SHOULD BE VERY WARM ON MONDAY...AND
IF THE RIDGE HOLDS THE HIGHS WILL REMAIN VERY WARM. THE EC BRINGS
IN A FRONT AROUND MONDAY NIGHT WHICH WILL TEND TO COOL
TEMPERATURES AND ALSO BRING A BETTER CHANCE FOR STRONG
THUNDERSTORMS. SO FEW CHANGES MADE BEYOND MONDAY. SCT
&&
.AVIATION...
MVFR CONDITIONS WILL CONTINUE TO BE A POSSIBILITY ACROSS THE AREA
TONIGHT IN THE FORM OF LOW CLOUDS. PATCHY FOG MAY FORM IN A FEW
SPOTS AS WELL. CONDITIONS ARE EXPECTED TO QUICKLY IMPROVE THURSDAY
MORNING WITH A COLD FRONTAL PASSAGE. NORTHWEST WINDS BY THURSDAY
AFTERNOON WILL BE STRONG WITH SUSTAINED SPEEDS OF 20 TO 30 KTS
POSSIBLE. JAMBA
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 9 AM THURSDAY TO MIDNIGHT MDT THURSDAY
NIGHT FOR FORT PECK LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...
CENTRAL AND SOUTHERN VALLEY...GARFIELD...MCCONE...PETROLEUM.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS GLASGOW MT
259 PM MDT WED JUL 17 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH FRIDAY...
MAIN CHALLENGE THIS AFTERNOON AND EVENING IS THE HIGH TEMPERATURE
FORECAST ACROSS THE CWA. ACROSS THE NORTHEAST...DECIDED TO LOWER
TEMPERATURES BY SEVERAL DEGREES BELOW 17/12Z GUIDANCE GIVEN THE
PERSISTENT STEADY SHOWERS AND CLOUD COVER THERE. ACROSS CENTRAL
PORTIONS OF THE CWA...AREAS SHOULD START TO SEE BREAKS OF SUNSHINE
WHICH WILL RESULT IN TEMPERATURES RESPONDING. DID LOWER HIGHS IN A
FEW LOCATIONS AS THERE ARE ONLY A FEW HOURS OF DAYTIME HEATING
REMAINING. IN SHORT...EXPECT 80 DEGREES OR BETTER LATE AFTERNOON
OR EVENING ACROSS THE SOUTHERN ZONES. TEMPERATURES SHOULD MAKE IT
TO THE LOWER TO MIDDLE 70S ACROSS CENTRAL PORTIONS OF THE FORECAST
AREA. ONLY EXPECT HIGHS TO REACH UPPER 60S AND NEAR 70 ACROSS THE
INTERNATIONAL BORDER AND IN THE FAR NORTHEAST.
TONIGHT...TRICKY FORECAST REGARDING POTENTIAL SHOWER ACTIVITY
DEVELOPING...PRIMARILY SOUTH OF THE MISSOURI RIVER. WILL INSERT
LOW END SLIGHT CHANCE POPS FOR NOW BUT THE NEXT SHIFT WILL HAVE TO
MONITOR FAIRLY CAREFULLY FOR UPDATES. THE LATEST GFS/ECMWF MODELS
ARE DRY BUT THE NAM AND HRRR SHOWS POTENTIAL FOR PRECIPITATION
TONIGHT ACROSS THE SOUTH. GIVEN MORE SUNSHINE DURING THE DAYTIME
ACROSS THOSE LOCATIONS THERE COULD BE A BIT MORE INSTABILITY TO
TAP AS WEAK SHORTWAVE ENERGY PUSHES THROUGH OVERNIGHT. GIVEN LACK
OF CONFIDENCE HOWEVER...DID NOT GO TOO AGGRESSIVE AT THIS TIME.
THURSDAY...UPPER LEVEL ZONAL FLOW IN THE MORNING WILL TRANSITION
TO NORTHWEST FLOW ALOFT AS A SHORTWAVE TRAVELING ACROSS THE
INTERNATIONAL BORDER CLIPS THE NORTHEASTERN ZONES AND SWEEPS A
SURFACE COLD FRONT THROUGH THE CWA. WILL EXPECT STRONG GUSTY WINDS
TO DEVELOP BEHIND THE FRONTAL PASSAGE. NAM BUFKIT SOUNDINGS
INDICATE 40 KTS IN THE MID LEVELS. GIVEN VERY GOOD LOW AND MID
LEVEL LAPSE RATES...SOME OF THESE GUSTS MAY MIX DOWN TO THE
SURFACE. EXPECT 20-25 MPH SUSTAINED WINDS WITH GUSTS TO 35 MPH TO
BE QUITE POSSIBLE...WITH ISOLATED HIGHER GUSTS. THEREFORE...WILL
HOIST A LAKE WIND ADVISORY BEGINNING AT 15Z AND HAVE IT EXPIRE AT
MIDNIGHT WHEN WINDS ARE EXPECTED TO RELAX. MAINTAINED CHANCE POPS
IN THE NORTHEAST CLOSER TO THE WAVE AND THE AREA OF BEST PVA.
DESPITE THE FRONTAL PASSAGE...HIGHS MAY PROVE TO BE WARMER ACROSS
THE NORTHEAST DUE TO MORE IN THE WAY OF SUNSHINE.
THURSDAY NIGHT AND FRIDAY...NORTHWEST FLOW ALOFT WILL CONTINUE
ACROSS THE FORECAST REGION AND SHORTWAVE ENERGY WILL PROPAGATE
THROUGH ON FRIDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND
POSSIBLY THUNDER IN THE NORTHEAST. IT SHOULD REMAIN FAIRLY DRY
THURSDAY NIGHT AND FRIDAY ACROSS A ROBUST PORTION OF THE FORECAST
AREA HOWEVER AS THE CWA IS EXPECTED TO SIT ON THE EXTREME
NORTHEAST PERIPHERY OF A RIDE DOMINATING THE SOUTHWESTERN STATES.
THE ONLY AREA OF CONCERN WILL BE THE NORTHEAST CORNER OF THE
FORECAST AREA WHERE SHORTWAVE ENERGY RIDING AROUND THE RIDGE MAY
LEAD TO ENHANCED VERTICAL ASCENT AND TRIGGER A FEW SHOWERS AND/OR
THUNDERSTORMS. THIS IS STILL A COUPLE OF DAYS OUT AND FUTURE
SHIFTS CAN EVALUATE POTENTIAL FURTHER. MALIAWCO
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...
GOING FORECAST WAS IN GREAT SHAPE AND ONLY TWEAK MADE WAS TO
INCREASE POPS SLIGHTLY FOR MONDAY. JAMBA
PREVIOUS DISCUSSION...
BOTH THE EC AND THE GFS SHOW NORTHEAST MONTANA REMAINING UNDER A
NORTHWESTERLY FLOW ALOFT...AT LEAST THROUGH SUNDAY NIGHT...DUE TO
A PERSISTENT HEAT DOME OF HIGH PRESSURE CENTERED OVER THE GREAT
BASIN SUPPORTING A RIDGE IN THE WEST.
HOWEVER BEGINNING SUNDAY NIGHT THE 2 MODELS QUIT RESEMBLING EACH
OTHER. THE BIG DIFFERENCE IS THAT THE 12Z EC PICKS UP A COMPACT
CYCLONE OFF THE PACIFIC NORTHWEST COAST AND EJECTS IT ACROSS THE
INTER-MOUNTAIN WEST AND CANADIAN ROCKIES INTO ALBERTA AND
SASKATCHEWAN. THIS ACTION WOULD BACK FLOW ALOFT TO THE SOUTHWEST
AND SEND A COLD FRONT ACROSS THE DIVIDE TO REACH NEMONT AROUND
MONDAY NIGHT. THE GFS SHOWS NO HINT OF THIS WAVE. THEREFORE AFTER
THE WEEKEND THERE IS MORE UNCERTAINTY AS TO WHICH MODEL WILL PLAY
OUT. LATER IN THE SHIFT THE DELAYED 00Z EC STILL HOLDS ONTO THE
SHORTWAVE DISTURBANCE BUT RUNS IT EAST THROUGH MONTANA. WITH MORE
CONSISTENCY...REMAINED MOSTLY WITH THE GFS SOLUTION FOR THE REST
OF THE FORECAST.
FRIDAY NIGHT THROUGH SUNDAY NIGHT...WITH HIGH PRESSURE TO THE
SOUTHWEST AND A STRONG CLOSED UPPER LOW ROTATING AROUND HUDSON
BAY...NORTHEAST MONTANA WILL HAVE THE STATIONARY COLD BOUNDARY TO
THE NORTHEAST AND DESERT AIR TRYING TO PUSH IN FROM THE SOUTH.
THIS PATTERN MIGHT SEE SOME OVERRUNNING MOISTURE NEAR THIS
BOUNDARY FIRING OFF A FEW THUNDERSTORMS. BUT FOR THE MOST
PART...DRY WARM AIR WILL BE THE MAIN FEATURE OF THE WEEKEND.
MONDAY AND BEYOND...WITH BOTH MODELS OUT OF PHASE WITH EACH
OTHER...WILL NOT MOVE MUCH ONE WAY OR THE OTHER FROM THE
INHERITED GRIDS. TEMPERATURE SHOULD BE VERY WARM ON MONDAY...AND
IF THE RIDGE HOLDS THE HIGHS WILL REMAIN VERY WARM. THE EC BRINGS
IN A FRONT AROUND MONDAY NIGHT WHICH WILL TEND TO COOL
TEMPERATURES AND ALSO BRING A BETTER CHANCE FOR STRONG
THUNDERSTORMS. SO FEW CHANGES MADE BEYOND MONDAY. SCT
&&
.AVIATION...
MVFR CONDITIONS WILL CONTINUE TO BE A POSSIBILITY ACROSS THE AREA
TONIGHT IN THE FORM OF LOW CLOUDS. PATCHY FOG MAY FORM IN A FEW
SPOTS AS WELL. CONDITIONS ARE EXPECTED TO QUICKLY IMPROVE THURSDAY
MORNING WITH A COLD FRONTAL PASSAGE. NORTHWEST WINDS BY THURSDAY
AFTERNOON WILL BE STRONG WITH SUSTAINED SPEEDS OF 20 TO 30 KTS
POSSIBLE. JAMBA
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 9 AM THURSDAY TO MIDNIGHT MDT THURSDAY
NIGHT FOR FORT PECK LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...
CENTRAL AND SOUTHERN VALLEY...GARFIELD...MCCONE...PETROLEUM.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
339 PM EDT WED JUL 17 2013
.SYNOPSIS...
AN ACTIVE WEATHER PATTERN WILL CONTINUE ACROSS THE NORTH COUNTRY
WITH DAILY CHANCES FOR SCATTERED SHOWERS AND THUNDERSTORMS THROUGH
SATURDAY. SOME STORMS COULD BE STRONG TO SEVERE THROUGH THE PERIOD.
IN ADDITION...THE HOT AND HUMID WEATHER WILL CONTINUE UNTIL
SATURDAY...BEFORE MUCH DRIER AND COOLER AIR ARRIVES ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 250 PM EDT WEDNESDAY...SVR WATCH #416 CONTINUES UNTIL
MIDNIGHT FOR ENTIRE CWA. EXPECTING SEVERAL ROUNDS OF
STORMS...FIRST ACRS THE SLV/OTTAWA VALLEY AND NORTHERN NY BTWN 4PM
AND 6PM...THEN SECONDARY AND MORE POTENT LINE OF STORMS APPROACHES
NORTHERN ZNS BTWN 22-00Z THIS EVENING. THIS WL HAVE POTENTIAL FOR
A WELL ORGANIZED LINE OF STORMS WITH ENHANCED BOWING SEGMENTS
POSSIBLE. STILL THINKING THE PRIMARY THREAT WL BE STRONG/DAMAGING
WINDS...WITH ISOLATED/SCATTERED POWER OUTAGES/TREES DOWN. THINKING
LINE WL ENTER CPV BTWN 01-02Z...AND DISSIPATE BY 03Z ACRS OUR
EASTERN CWA. THE MAIN CONCENTRATION WL BE ACRS NORTHERN NY INTO
CENTRAL/NORTHERN VT.
FCST CHALLENGE WL BE TIMING OF THE CONVECTION WEAKENING/MOVING EAST
OF OUR CWA LATE THIS EVENING...FOLLOWED BY FOG POTENTIAL OVERNIGHT.
WATER VAPOR SHOWS POTENT S/W ENERGY ENTERING THE OTTAWA VALLEY
ATTM...WHICH WL CONT TO DEVELOP A LINE OF SVR STORMS ACRS OUR
CENTRAL/NORTHERN CWA THIS EVENING. THIS SYSTEM IS PROGGED TO BE EAST
OF CWA BY 06Z TONIGHT...WHICH COMBINED WITH LOSS OF DAYTIME
HEATING/INSTABILITY WL RESULT IN A DECREASE IN SHOWERS/STORMS. WL
MENTION CHC/LIKELY POPS THRU 03Z...ALONG WITH ENHANCED WORDING FOR
WINDS/HEAVY RAINFALL. RAP 13 SHOWS DEEP LAYER SHEAR VALUES BTWN 35
AND 40 KNOTS ACRS OUR NORTHERN CWA...ALONG WITH SFC BASED CAPE
AROUND 2000 J/KG...PERSISTING THRU THE EVENING HRS. THIS WL PROVIDE
ENOUGH INSTABILITY TO KEEP STORMS STRONG/SVR INTO THE EVENING
HOURS...WITH PRIMARY THREAT BEING DAMAGING WINDS. GIVEN...VERY WARM
DWPTS AND SOUTHERLY WINDS...EXPECT LOWS MAINLY IN THE M60S MTNS TO
L70S WARMER VALLEYS WITH PATCHY FOG POSSIBLE.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 340 PM EDT WEDNESDAY...THE FCST CHALLENGE WL BE AREAL COVERAGE/INTENSITY
OF STORMS EACH AFTN/EVENING THRU FRI NIGHT. OVERALL...EXPECTING
AN ACTIVE COUPLE DAYS WITH SEVERAL ROUNDS OF STRONG TO POSSIBLY
SEVERE STORMS...ALONG WITH VERY HOT AND HUMID CONDITIONS...PERSISTING
THRU FRIDAY.
THURS INTO THURS NIGHT...A LITTLE MORE UNCERTAINTY ON PLACEMENT OF
ULVL SUPPORT...POSITION OF DEEPEST MOISTURE...AND ASSOCIATED SFC
BOUNDARY...ESPECIALLY GIVEN THIS EVENINGS CONVECTION. LATEST 12Z
GFS SHOWS BETTER DYNAMICS AND RH FIELDS...ALONG WITH THE
ASSOCIATED CONVECTION ACRS OUR SOUTHERN CWA...WHILE NAM12 SHOWS
POTENT 5H ENERGY AND GOOD RH ENTERING THE SLV BY 18Z AND MOVING INTO
THE CPV BY 21Z...AND THRU VT BY 03Z FRIDAY. BOTH NAM/GFS SHOW
FAVORABLE SHEAR/INSTABILITY PARAMETERS FOR ORGANIZED
CONVECTION...ALONG WITH A LEFTOVER SFC BOUNDARY/TRRN FOR LLVL
TRIGGER...BUT ULVL SUPPORT IS WEAKER. SOUNDING PROFILES SHOW CAPE
VALUES BTWN 2000 AND 2500 J/KG AND BEST 0 TO 6KM SHEAR OF 40 NEAR
NEAR THE INTERNATIONAL BORDER...CLOSEST TO THE MID LVL WIND MAX.
ONCE AGAIN...PRIMARY SVR WEATHER THREAT WL BE ISOLATED PULSE STRONG
AND DAMAGING WINDS. IN ADDITION...LOCAL 2KM AND 4KM ARE VERY ROBUST
WITH DEVELOPMENT OF COMPOSITE REFLECTIVITY FIELDS...BUT MAYBE A BIT
OVERDONE ON AREAL COVERAGE...BASED ON PREVIOUS EXPERIENCE. WL CONT
TO MENTION CHC POPS FROM 16Z THRU 03Z...THINKING ACTIVITY WL START
EARLIER ON THURS...BASED ON POSITION OF S/W ENERGY AND DISSIPATE BY
EARLY EVENING. PROGGED 85H AND 925MB TEMPS COOLER SLIGHTLY AND
SUPPORT HIGHS IN THE M80S MTNS TO L90S WARMER VALLEY
LOCATIONS...WITH VERY SIMILAR OVERNIGHT LOWS TO RECENT NIGHTS...M60S
TO L70S.
ON FRIDAY...MID/UPPER LVL TROF ACRS THE GREAT LAKES APPROACHES OUR
WESTERN CWA...ALONG WITH SEVERAL EMBEDDED S/W`S IN THE FAST
WEST/SOUTHWEST FLW ALOFT. THIS ENERGY/HGHT FALLS...COMBINED WITH
BETTER 850 TO 500MB RH PROFILES WL RESULT IN MORE AFTN/EVENING
SHOWERS/STORMS ON FRIDAY. NAM/GFS CONT TO SHOW BEST 0 TO 6 KM SHEAR
VALUES BTWN 40 AND 45 KNOTS ACRS OUR CENTRAL/NORTHERN CWA...ALONG
WITH CAPE VALUES AROUND 2000 J/KG. SO A FEW STRONG/SVR STORMS WL BE
POSSIBLE. SOME UNCERTAINTY ON OVERALL ORGANIZATION AND TIMING OF
INDIVIDUAL S/W`S IN FAST FLW ALOFT...ALONG WITH PLACEMENT OF
PRE-FRONTAL TROFS. SPC DAY 3 HIGHLIGHTS OUR CENTRAL/NORTHERN CWA IN
SLIGHT RISK. PWS BTWN 1.50 AND 2.0" SUPPORTS THE POTENTIAL FOR HEAVY
RAINFALL...BUT WITH STORM MOTION OF 20 TO 30 KNTS...NOT ANTICIPATING
ANY SIGNIFICANT HYDRO PROBLEMS. MAYBE SOME MINOR POOR DRAINAGE/URBAN
TYPE STUFF. PROGGED 85H TEMPS BTWN 16-18C AND 925MB TEMPS BTWN
22-24C...SUPPORT HIGHS ONCE AGAIN WELL INTO THE M/U 80S MTNS TO M90S
WARMER VALLEY LOCATIONS...ESPECIALLY SW DOWNSLOPE AREAS LIKE PBG.
HEAT INDEX VALUES WL ONCE AGAIN APPROACH 100 DEGREES IN A FEW
LOCATIONS.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 310 PM EDT WEDNESDAY...COLD FRONT EXPECTED TO OPEN THE
EXTENDED PORTION OF THE FORECAST NEAR THE SAINT LAWRENCE VALLEY.
DUE TO THE UPPER-LEVEL GEOSTROPHIC FLOW ROUGHLY PARALLEL TO THE
ORIENTATION OF THE SFC FRONT...HAVE OPTED TO SLOW THE APPROACHING
COLD FRONT`S PROGRESSION THROUGH THE NORTH COUNTRY. THUS HAVE
MAINTAINED HIGH CHANCE TO LIKELY POPS ON SATURDAY...GRADUALLY
TAPERING TO SLIGHT CHANCE/CHANCE ON SATURDAY NIGHT. NOT QUITE THE
DEGREE OF INSTABILITY AS EXPECTED ON FRIDAY BUT PWATS STILL IN THE
1.5-2.0" RANGE SUGGEST THAT ANY STORMS COULD PRODUCE SOME LOCALLY
HEAVY RAIN. WENT WITH HIGHS IN THE UPPER 70S TO LOW/MID 80S BASED
ON EXPECTED CLOUD COVER AND PRE-FRONTAL 925 MB TEMPERATURES AROUND
18-21C...WENT WITH HIGHS IN THE UPPER 70S TO MID-80S.
A NOTICEABLY COOLER AND DRIER SUNDAY AND MONDAY IS EXPECTED AS
BROAD CANADIAN HIGH PRESSURE SETTLES INTO THE REGION. TEMPERATURES
RETURN CLOSER TO NORMAL/BELOW NORMAL FOR MID JULY. GIVEN ONGOING
ACTIVE WEATHER I DIDN`T LOOK TOO CLOSELY INTO NEXT WEEK...THOUGH IT
DOES APPEAR TO TURN MORE ACTIVE WEATHER-WISE WITH TEMPERATURES AND
HUMIDITY LEVELS BEGINNING TO REBOUND. THERFORE HAVE KEPT A TOKEN
SLIGHT CHANCE/CHANCE POPS GOING.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
THROUGH 18Z THURSDAY...ACTIVE AVIATION FORECAST FOR THIS AFTERNOON
AND EVENING WITH POTENTIAL FOR LOCALLY STG THUNDERSTORMS.
THUNDERSTORMS ARE CURRENTLY DEVELOPING IN THE OTTAWA AND THE
WESTERN SAINT LAWRENCE VALLEYS MOVING EAST-SOUTHEASTWARD. VFR
CONDITIONS EXPECTED TO PREVAIL UNTIL THUNDERSTORMS APPROACH WITH
GENERAL TIMING BETWEEN 18-05Z. ACTIVITY TO BEGIN WITHIN THE NEXT
HOUR OR TWO AT MSS AND SLK...INTO PBG AND BTV AROUND 23-00Z AND
AFTER 01Z FOR RUT AND MPV. POTENTIAL FOR STRONG TO LOCALLY
DAMAGING WINDS AND ASSOCIATED LLVL TURBULENCE...BRIEF PERIOD OF
MVFR TO IFR VISIBILITIES...AND LIGHTNING WITH THUNDERSTORMS.
WINDS WILL BE SOUTH AROUND 5-9KTS. WILL TREAT WITH VCSH FOR NOW
AND USE TEMPOS ACCORDINGLY. THUNDERSTORM ACTIVITY LOOKS TO END
AFTER 05Z WITH FOG/MIST POTENTIAL TONIGHT GIVEN SATURATED LOW-
LEVELS AND LIGHT SFC WINDS TONIGHT. AREAS THAT RECEIVE RAIN TODAY
WILL STAND A GREATER CHANCE AT FOG/MIST TONIGHT...SO FOR NOW HAVE
JUST KEPT 3-6SM BR DURING THE 06-13Z THURSDAY PERIOD. VFR
CONDITIONS THRU 18Z THURSDAY WITH SOUTHWEST/WEST WINDS UNDER
10KTS.
OUTLOOK 18Z THURSDAY THROUGH SUNDAY...
18Z THURSDAY THROUGH SATURDAY...MAINLY VFR CONDITIONS EXPECTED
DURING THE DAY WITH ISOLATED PATCHY FG/BR OVERNIGHT...MAINLY AT
KSLK/KMPV. SCATTERED AFTERNOOON SHOWERS/THUNDERSTORMS EACH DAY
THROUGH THE PERIOD WHICH MAY BRING BRIEF PERIODS OF MVFR/IFR
VISIBILITIES.
SUNDAY...VFR UNDER BUILDING HIGH PRESSURE.
&&
.MARINE...
AS OF 310 PM EDT WEDNESDAY...STRONG THUNDERSTORMS WILL LIKELY
AFFECT THE LAKE CHAMPLAIN WATERS LATER THIS AFTERNOON AND EVENING.
A LAKE THUNDERSTORM ADVISORY IS IN EFFECT UNTIL FURTHER NOTICE.
WATCHING TWO LINES OF STRONG THUNDERSTORMS NOW OVER NORTHERN AND
EASTERN ONTARIO WHICH WILL SLIDE SOUTHEASTWARD ACROSS LAKE
CHAMPLAIN TONIGHT...WITH ADDITIONAL DEVELOPMENT POSSIBLE AHEAD OF
THE LINES OF ONGOING STORMS. STORMS WILL BE CAPABLE OF GUSTY TO
LOCALLY DAMAGING WINDS...ROUGH WAVES...AND CLOUD TO GROUND
LIGHTNING.
&&
.CLIMATE...
MAX TEMP RECORDS TODAY THROUGH FRIDAY. BEST SHOT TODAY AT
KMSS...THEN ON FRIDAY AT KMPV AND KMSS. SHORTER PERIOD OF RECORD AT
THESE SITES THAN AT K1V4 AND KBTV.
07/17/2013 07/18/2013 07/19/2013
KBTV 97/1999 99/1953 98/1942
KMPV 93/1982 96/1953 92/1991
K1V4 94/1953 99/1953 95/1991
KMSS 92/2012 95/1953 93/1991
&&
.EQUIPMENT...
WE CONTINUE TO EXPERIENCE LOSS OF SIGNAL/POWER WITH THE KTYX
RADAR...ALONG WITH IT GOING IN AND OUT OF SERVICE. TECHS HAVE BEEN
AT THE SITE LOOKING INTO THE PROBLEM AND HAVE OPENED A TICKET WITH
THE RADAR OPERATION CENTER. BOTTOM LINE EXPECT VERY LIMITED DATA
FROM THE KTYX RADAR.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...LOCONTO
AVIATION...LOCONTO
MARINE...
CLIMATE...
EQUIPMENT...WFO BTV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
253 PM EDT WED JUL 17 2013
.SYNOPSIS...
HOT AND HUMID WEATHER IS EXPECTED THROUGH FRIDAY ALONG WITH AN
INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS. A FEW OF THE
STORMS COULD BE STRONG TO SEVERE LATER THIS AFTERNOON AND
EVENING. SHOWERS AND STORMS WILL END NORTH TO SOUTH DURING
SATURDAY AS A STRONG COLD FRONT PUSHES THROUGH THE AREA. BEHIND
THIS FRONT...A MORE SEASONABLE AND PLEASANTLY DRIER AIRMASS WILL
SETTLE ACROSS THE REGION FROM SUNDAY INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 11 PM THIS EVENING/...
AS OF 250 PM EDT WEDNESDAY...UPDATE TO ZONES FOR SVR WATCH BOX
#416. EXPECTING SEVERAL ROUNDS OF STORMS...FIRST ACRS THE
SLV/OTTAWA VALLEY AND NORTHERN NY BTWN 3PM AND 5PM...THEN
SECONDARY AND MORE POTENT LINE OF STORMS APPROACHES NORTHERN ZNS
BTWN 22-00Z THIS EVENING. THIS WL HAVE POTENTIAL FOR A WELL
ORGANIZED LINE OF STORMS WITH ENHANCED BOWING SEGMENTS POSSIBLE.
STILL THINKING THE PRIMARY THREAT WL BE STRONG/DAMAGING
WINDS...WITH ISOLATED/SCATTERED POWER OUTAGES/TREES DOWN. THINKING
LINE WL ENTER CPV BTWN 01-02Z...AND DISSIPATE BY 03Z ACRS OUR
EASTERN CWA. THE MAIN CONCENTRATION WL BE ACRS NORTHERN NY INTO
CENTRAL/NORTHERN VT.
FCST IN GOOD SHAPE WITH A FEW MINOR ADJUSTMENTS. HAVE INCREASED
TEMPS AT PBG DUE TO DOWNSLOPE SW FLW OFF THE DACKS...ADJUSTED
SEVERAL DWPTS...AND SKY COVER GRIDS. BOTTOM LINE EXPECT HEAT INDEX
VALUES TO APPROACH 100 DEGREES IN THE WARMER VALLEY LOCATIONS AND
THUNDERSTORM ACTIVITY TO INCREASE IN AREAL COVERAGE/INTENSITY THIS
AFTN/EVENING.
CRNT RADAR SHOWS STORMS DEVELOPING NORTH OF LAKE ONTARIO AND
ANOTHER BATCH APPROACHING THE OTTAWA VALLEY. THESE STORMS WL
APPROACH THE SLV BY MID/LATE AFTN AND EVOLVE INTO A LINE OF SVR
STORMS...WITH DAMAGING WINDS AS THE PRIMARY SVR WX THREAT. GIVEN
WIND PROFILES AND INSTABILITY WOULD EXPECT SVR STORMS WITH THE
POTENTIAL FOR SCATTERED POWER OUTAGES/TREES DOWN ACRS NORTHERN NY
INTO PARTS OF CENTRAL/NORTHERN VT AS THIS LINE OF STORMS MOVES
ACRS THE REGION THIS EVENING.
ACTIVE WEATHER DAY ANTICIPATED ACRS THE NORTH COUNTRY...WITH THE
NEAR TERM CHALLENGE BEING TIMING/EVOLUTION OF CONVECTION THIS
AFTN/EVENING. WATER VAPOR SHOWS TWO PIECES OF ENERGY...FIRST IS
LOCATED JUST NORTH OF LAKE ONTARIO AND ANOTHER MUCH STRONGER ONE
IS LOCATED JUST NORTHEAST OF LAKE SUPERIOR. THINKING FIRST S/W WL
HELP IN THE DEVELOPMENT OF SHOWERS/STORMS ACRS THE DACKS/SLV BTWN
1PM AND 4PM THIS AFTN...WITH SOME STRONG STORMS POSSIBLE...GIVEN
CAPE VALUES BTWN 2000 AND 2500 J/KG AND DEEP LAYER SHEAR VALUES
BTWN 25 AND 30 KNTS. MEANWHILE...BETTER DYNAMICS/MOISTURE
ASSOCIATED WITH 2ND S/W WL ARRIVE ACRS THE OTTAWA AND SLV VALLEY`S
BTWN 21Z-00Z...WITH A LINE OF STRONG TO SEVERE STORMS LIKELY.
GIVEN THE AVAILABLE SHEAR AND INSTABILITY...THINKING LINE SEGMENTS
WITH ENHANCED BOW ECHOES WL BE POSSIBLE...WITH PRIMARY THREAT
BEING STRONG/DAMAGING WINDS GUSTS. CRNT SPC HAS OUR REGION IN
SLGHT RISK...WHICH LOOKS GOOD. ACTIVITY SHOULD WEAKEN TWD 03Z ACRS
CENTRAL/EASTERN VT. CWMW SOUNDINGS SHOW PW VALUES OF 1.66"...500MB
WINDS OF 50 KNOTS...AND VERY HIGH EL AROUND 43KFT...SO EXPECT
OVERSHOOTING STORM TOPS NEAR 50KFT THIS AFTN/EVENING WITH GREATEST
POTENTIAL BEING WINDS. 0 TO 6 KM STORM MOTIONS OF 20 TO 25 KNOTS
SHOULD LIMIT FLASH FLOOD THREAT...BUT WESTERN/SOUTHERN FLANK ACRS
THE DACKS WL HAVE TO BE WATCHED FOR POTENTIAL TRAINING...GIVEN
VECTOR ANALYSIS.
OTHERWISE...HIGHS IN THE L/M 90S WITH DWPTS BTWN 65 AND 70 WL
RESULT IN HEAT INDEX VALUES IN THE MID TO UPPER 90S. ALL IS
COVERED VERY WELL IN CRNT FCST AND ONLY MINOR CHANGES MADE BASED
ON CRNT OBS.
PRIOR DISCUSSION FOLLOWS...
FORECAST MORE OR LESS REMAINS ON TRACK FOR TODAY AS LARGE-SCALE
H5 HEAT RIDGE MAINTAINS ITS HOLD ON REGIONAL WEATHER. MEAN 18Z
925MB OF 23-25C SUPPORT HIGHS IN THE UPPER 80S TO MID 90S ACROSS
THE REGION ALONG WITH HIGH HUMIDITY...NOT A PLEASANT DAY. HEAT
INDEX VALUES TO PEAK JUST BELOW ADVISORY CRITERIA...GENERALLY IN
THE 92-98 RANGE IN LOWER ELEVATIONS BELOW 1000 FEET. THIS WILL BE
DAY 3 OF 90F+ AT KBTV SO OFFICIAL NEW ENGLAND HEAT WAVE CRITERIA
WILL BE MET. OF COURSE NOT ALL AREAS HAVE SEEN 3 CONSECUTIVE DAYS
OF 90F+...ESP IN SOME OF OUR NRN MTN LOCALES...BUT EVERYONE GETS
THE POINT THAT WE`RE IN A VERY WARM AND UNCOMFORTABLE STRETCH OF
WX.
COULD SEE SOME ISOLATED AFTERNOON PULSE-TYPE STORMS IN THE 1 TO 4
PM TIME FRAME OF SO...BUT INITIALLY MID LEVELS WILL BE SLIGHTLY
CAPPED SUCH THAT UPDRAFTS WILL BE INHIBITED. MORE IMPORTANTLY
HOWEVER WILL BE THE POTENTIAL FOR A LINE OF STRONG TO LOCALLY
SEVERE STORMS TO DROP SOUTHWARD INTO OUR NORTHERN COUNTIES LATER
THIS AFTERNOON OR EARLY EVENING AS A WEAK SURFACE FRONT
APPROACHES FROM THE NORTHWEST. WITH SLIGHT MID LEVEL HEIGHT FALLS
AMPLE PBL INSTABILITY AND MODEST 0-6KM SHEAR VALUES INCREASING
INTO THE 30-40 KT RANGE ACROSS THE NORTH...THE THREAT FOR STRONG
TO LOCALLY SEVERE STORMS TO DEVELOP ALONG THIS LINE IS
INCREASING. VERY TALL STORMS WITH TOPS TO NEAR 50 KFT POSSIBLE
WITH EQ LEVELS VERY HIGH. MODIFIED KMSS AND KFSO SOUNDINGS
CENTERED AROUND 00Z SHOW QUITE ROBUST SWEAT AND DCAPE VALUES...SO
STRONG OUTFLOW/DAMAGING WINDS LOOK LIKE THE PRIMARY
THREAT...ESPECIALLY IF ACTIVITY CAN ORGANIZE ENOUGH TO GENERATE
AN AMPLE COLD POOL. HAIL NOT SO MUCH AN ISSUE GIVEN MEAN WBZ
VALUES ABOVE 12 KFT. STORMS WILL TEND TO WEAKEN AS THEY PROGRESS
SOUTHWARD THROUGH OUR REGION...SO HIGHEST THREAT WILL BE ACROSS
OUR NORTHERN COUNTIES WITH LESS OF A THREAT THE FURTHER SOUTH YOU
GO. WILL ALSO CONTINUE MENTION OF HEAVY RAINFALL AS PWATS CLIMB
TO NEAR 1.9 INCHES ALONG WITH LOW TO MID LEVEL MOISTURE POOLING
IN ADVANCE OF THE SURFACE BOUNDARY.
BY LATER THIS EVENING INTO TONIGHT ACTIVITY SLOWLY WANES AND
TAPERS TO SCATTERED SHOWERS ACROSS OUR CENTRAL AND NORTHERN
COUNTIES AS WEAK FRONTAL BOUNDARY SAGS INTO THE REGION AND
STALLS. PATCHY FOG ALSO A GOOD BET IF WE SEE HEAVIER WETTING
RAINFALL. LOWS MILD AND HUMID...MID 60S TO LOWER 70S...OR SIMILAR
TO THE PAST FEW NIGHTS.
&&
.SHORT TERM /11 PM THIS EVENING THROUGH FRIDAY/...
AS OF 420 AM EDT WEDNESDAY...BY THURSDAY STALLED WEAK SURFACE
BOUNDARY REMAINS DRAPED ACROSS OUR AREA ALONG WITH CONTINUED
WARMTH AND HUMIDITY. SCATTERED SHOWERS AND STORMS ALSO A GOOD BET
WITH LOCALLY HEAVY RAINFALL ONCE AGAIN. MBE VECTOR VALUES ARE
GENERALLY GREATER THAN 10 KTS HOWEVER...SO MY FEELING IS STORMS
MAY BE MOVING ENOUGH TO PRECLUDE A MORE ORGANIZED FLASH FLOOD
THREAT. NONETHELESS WE`LL HAVE TO KEEP AN EYE ON THINGS WITH PWAT
VALUES HOVERING AROUND 2.0 INCHES. DESPITE AMPLE SHEAR AND
INSTABILITY...FEEL ANY SEVERE THREAT SHOULD BE FAIRLY MARGINAL AS
WE REALLY DON`T HAVE A STRONG MECHANISM FOR LIFT OTHER THAN THE
SFC HEATING AND THE WEAK BOUNDARY. TIME WILL TELL. HIGHS ABOUT
2-4 DEGREES COOLER THAN TODAY SO SOME SLIGHT RELIEF BUT NOT MUCH.
SPOT HIGH FOR KBTV AT 89-90F LOOKS REASONABLE.
FRONT THEN REMAINS ATOP OUR REGION THURSDAY NIGHT INTO
FRIDAY...LIFTING SLOWLY NORTHWARD AND DISSIPATING THROUGH TIME IN
RESPONSE TO LARGE-SCALE BACKING OF THE MID LEVEL FLOW AHEAD OF A
MORE ROBUST NRN STREAM UPPER TROUGH OFF TO OUR NORTHWEST. THUS
CHANCE OF SHOWERS AND STORMS CONTINUE...BUT HIGHER CHANCES TREND
MORE ACROSS OUR NORTHERN COUNTIES. LIKELY A REPEAT OF TODAYS HOT
VALUES BY FRIDAY WITH MODELS HAVING CONSISTENTLY TRENDED WARMER
OVER THE PAST 24-HOURS. INDEED...WITH MEAN 925MB TEMPS AVERAGING
FROM 24-26C FRIDAY COULD END UP AS HOT IF NOT A DEGREE OR TWO
HOTTER THAN TODAY...ESPECIALLY IF WE SEE AMPLE SUNSHINE. SO IT`S
NOT ENTIRELY UNREASONABLE TO SUGGEST IF WE HIT 90F AT KBTV ON
THURSDAY...A FIVE DAY STRETCH OF 90F+ WILL BE IN REACH. THE LAST
TIME THIS OCCURRED WAS BACK IN AUGUST 2002.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 436 AM EDT WEDNESDAY...SFC LOW PRESSURE SYSTEM WILL START
THE PERIOD WITH SHOWERS/THUNDERSTORMS AND WARM TEMPERATURES...
FOLLOWED BY HIGH PRESSURE AND A COOLER...DRIER AIRMASS. FRIDAY
NIGHT WILL SEE THE NORTH COUNTRY STILL IN THE WARM SECTOR AND SW
FLOW AS A PREFRONTAL TROUGH AT THE SFC TRIGGERS
SHOWERS/THUNDERSTORMS FOLLOWED BY ASSOCIATED COLD FRONT ON
SATURDAY CONTINUING THE THREAT FOR SHOWERS AND THUNDERSTORMS.
FAVORABLE UPPER LEVEL JET DYNAMICS WILL ACCOMPANY THE COLD FRONT
WITH RR QUADRANT OF 250MB JET MOVES OVER THE NORTH COUNTRY MAINLY
ON SATURDAY...COINCIDING WITH STRONG FGEN AT 850MB...LINGERING
INTO SATURDAY NIGHT. PWATS OF 1.5-2 INCHES WILL PEAK EARLY
SATURDAY AS THE FRONT MOVES FROM SE ONTARIO...SEWD AND EVENTUALLY
EXIT VT EARLY SUNDAY AS ASSOCIATED UPPER LEVEL TROUGH PUSHES NEWD
SATURDAY NIGHT. HIGH PRESSURE WILL BUILD IN OVER THE REGION
FOLLOWING THE FRONT SUNDAY THROUGH AT LEAST MONDAY. MONDAY NIGHT
INTO TUESDAY...THE 00Z ECMWF BRINGS ANOTHER UPPER LEVEL TROUGH
OVER THE REGION...PRODUCING SHOWERS WHILE THE GFS KEEPS THE HIGH
PRESSURE ENTRENCHED OVER NRN NEW ENGLAND THROUGH THE MIDDLE OF
THE WEEK.
TEMPERATURES WILL BE WARM AND MUGGY...WITH MIN TEMPS FRIDAY NIGHT
IN THE 60S-L70S AND MAX TEMPS ON SATURDAY RANGING FORM M70S TO
M80S. COOLER AIR WILL FILTER IN FOR THE REST OF THE PERIOD WITH
MIN TEMPS TRENDING COOLER. SATURDAY NIGHT WILL BE IN THE 50S-
L60S...WITH SUNDAY NT THRU TUES NT IN THE M40S-U50S. MAX TEMPS
WILL GENERALLY BE IN THE 70S.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
THROUGH 18Z THURSDAY...ACTIVE AVIATION FORECAST FOR THIS AFTERNOON
AND EVENING WITH POTENTIAL FOR LOCALLY STG THUNDERSTORMS.
THUNDERSTORMS ARE CURRENTLY DEVELOPING IN THE OTTAWA AND THE
WESTERN SAINT LAWRENCE VALLEYS MOVING EAST-SOUTHEASTWARD. VFR
CONDITIONS EXPECTED TO PREVAIL UNTIL THUNDERSTORMS APPROACH WITH
GENERAL TIMING BETWEEN 18-05Z. ACTIVITY TO BEGIN WITHIN THE NEXT
HOUR OR TWO AT MSS AND SLK...INTO PBG AND BTV AROUND 23-00Z AND
AFTER 01Z FOR RUT AND MPV. POTENTIAL FOR STRONG TO LOCALLY
DAMAGING WINDS AND ASSOCIATED LLVL TURBULENCE...BRIEF PERIOD OF
MVFR TO IFR VISIBILITIES...AND LIGHTNING WITH THUNDERSTORMS.
WINDS WILL BE SOUTH AROUND 5-9KTS. WILL TREAT WITH VCSH FOR NOW
AND USE TEMPOS ACCORDINGLY. THUNDERSTORM ACTIVITY LOOKS TO END
AFTER 05Z WITH FOG/MIST POTENTIAL TONIGHT GIVEN SATURATED LOW-
LEVELS AND LIGHT SFC WINDS TONIGHT. AREAS THAT RECEIVE RAIN TODAY
WILL STAND A GREATER CHANCE AT FOG/MIST TONIGHT...SO FOR NOW HAVE
JUST KEPT 3-6SM BR DURING THE 06-13Z THURSDAY PERIOD. VFR
CONDITIONS THRU 18Z THURSDAY WITH SOUTHWEST/WEST WINDS UNDER
10KTS.
OUTLOOK 18Z THURSDAY THROUGH SUNDAY...
18Z THURSDAY THROUGH SATURDAY...MAINLY VFR CONDITIONS EXPECTED
DURING THE DAY WITH ISOLATED PATCHY FG/BR OVERNIGHT...MAINLY AT
KSLK/KMPV. SCATTERED AFTERNOOON SHOWERS/THUNDERSTORMS EACH DAY
THROUGH THE PERIOD WHICH MAY BRING BRIEF PERIODS OF MVFR/IFR
VISIBILITIES.
SUNDAY...VFR UNDER BUILDING HIGH PRESSURE.
&&
.MARINE...
AS OF 420 AM EDT WEDNESDAY...STRONG TO LOCALLY SEVERE
THUNDERSTORMS MAY EFFECT THE LAKE CHAMPLAIN WATERS LATER THIS
AFTERNOON AND EVENING. IF STORMS DO DEVELOP...THEY WILL LIKELY
APPROACH FROM THE NORTH AND NORTHWEST AFTER 3 PM AND MAY BE
ACCOMPANIED BY VERY STRONG GUSTY WINDS AND FREQUENT CLOUD TO
GROUND LIGHTNING. IF PLANNING ACTIVITIES ON THE LAKE THIS
AFTERNOON AND EVENING...PLEASE KEEP ABREAST OF THE LATEST WEATHER
INFORMATION AND BE PREPARED TO SEEK SAFE HARBOR QUICKLY SHOULD
STRONGER STORMS APPROACH. WINDS GENERALLY LIGHT SOUTHERLY THIS
MORNING...TRENDING WEST TO SOUTHWESTERLY 5 TO 15 KNOTS THIS
AFTERNOON AND EVENING OUTSIDE ANY STORMS.
&&
.CLIMATE...
MAX TEMP RECORDS TODAY THROUGH FRIDAY. BEST SHOT TODAY AT
KMSS...THEN ON FRIDAY AT KMPV AND KMSS. SHORTER PERIOD OF RECORD AT
THESE SITES THAN AT K1V4 AND KBTV.
07/17/2013 07/18/2013 07/19/2013
KBTV 97/1999 99/1953 98/1942
KMPV 93/1982 96/1953 92/1991
K1V4 94/1953 99/1953 95/1991
KMSS 92/2012 95/1953 93/1991
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG/TABER
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...LOCONTO
MARINE...
CLIMATE...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
141 PM EDT WED JUL 17 2013
.SYNOPSIS...
HOT AND HUMID WEATHER IS EXPECTED THROUGH FRIDAY ALONG WITH AN
INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS. A FEW OF THE
STORMS COULD BE STRONG TO SEVERE LATER THIS AFTERNOON AND
EVENING. SHOWERS AND STORMS WILL END NORTH TO SOUTH DURING
SATURDAY AS A STRONG COLD FRONT PUSHES THROUGH THE AREA. BEHIND
THIS FRONT...A MORE SEASONABLE AND PLEASANTLY DRIER AIRMASS WILL
SETTLE ACROSS THE REGION FROM SUNDAY INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 11 PM THIS EVENING/...
AS OF 113 PM EDT WEDNESDAY...FCST IN GOOD SHAPE WITH A FEW MINOR
ADJUSTMENTS. HAVE INCREASED TEMPS AT PBG DUE TO DOWNSLOPE SW FLW
OFF THE DACKS...ADJUSTED SEVERAL DWPTS...AND SKY COVER GRIDS.
BOTTOM LINE EXPECT HEAT INDEX VALUES TO APPROACH 100 DEGREES IN
THE WARMER VALLEY LOCATIONS AND THUNDERSTORM ACTIVITY TO INCREASE
IN AREAL COVERAGE/INTENSITY THIS AFTN/EVENING.
CRNT RADAR SHOWS STORMS DEVELOPING NORTH OF LAKE ONTARIO AND
ANOTHER BATCH APPROACHING THE OTTAWA VALLEY. THESE STORMS WL
APPROACH THE SLV BY MID/LATE AFTN AND EVOLVE INTO A LINE OF SVR
STORMS...WITH DAMAGING WINDS AS THE PRIMARY SVR WX THREAT. GIVEN
WIND PROFILES AND INSTABILITY WOULD EXPECT SVR STORMS WITH THE
POTENTIAL FOR SCATTERED POWER OUTAGES/TREES DOWN ACRS NORTHERN NY
INTO PARTS OF CENTRAL/NORTHERN VT AS THIS LINE OF STORMS MOVES
ACRS THE REGION THIS EVENING.
ACTIVE WEATHER DAY ANTICIPATED ACRS THE NORTH COUNTRY...WITH THE
NEAR TERM CHALLENGE BEING TIMING/EVOLUTION OF CONVECTION THIS
AFTN/EVENING. WATER VAPOR SHOWS TWO PIECES OF ENERGY...FIRST IS
LOCATED JUST NORTH OF LAKE ONTARIO AND ANOTHER MUCH STRONGER ONE
IS LOCATED JUST NORTHEAST OF LAKE SUPERIOR. THINKING FIRST S/W WL
HELP IN THE DEVELOPMENT OF SHOWERS/STORMS ACRS THE DACKS/SLV BTWN
1PM AND 4PM THIS AFTN...WITH SOME STRONG STORMS POSSIBLE...GIVEN
CAPE VALUES BTWN 2000 AND 2500 J/KG AND DEEP LAYER SHEAR VALUES
BTWN 25 AND 30 KNTS. MEANWHILE...BETTER DYNAMICS/MOISTURE
ASSOCIATED WITH 2ND S/W WL ARRIVE ACRS THE OTTAWA AND SLV VALLEY`S
BTWN 21Z-00Z...WITH A LINE OF STRONG TO SEVERE STORMS LIKELY.
GIVEN THE AVAILABLE SHEAR AND INSTABILITY...THINKING LINE SEGMENTS
WITH ENHANCED BOW ECHOES WL BE POSSIBLE...WITH PRIMARY THREAT
BEING STRONG/DAMAGING WINDS GUSTS. CRNT SPC HAS OUR REGION IN
SLGHT RISK...WHICH LOOKS GOOD. ACTIVITY SHOULD WEAKEN TWD 03Z ACRS
CENTRAL/EASTERN VT. CWMW SOUNDINGS SHOW PW VALUES OF 1.66"...500MB
WINDS OF 50 KNOTS...AND VERY HIGH EL AROUND 43KFT...SO EXPECT
OVERSHOOTING STORM TOPS NEAR 50KFT THIS AFTN/EVENING WITH GREATEST
POTENTIAL BEING WINDS. 0 TO 6 KM STORM MOTIONS OF 20 TO 25 KNOTS
SHOULD LIMIT FLASH FLOOD THREAT...BUT WESTERN/SOUTHERN FLANK ACRS
THE DACKS WL HAVE TO BE WATCHED FOR POTENTIAL TRAINING...GIVEN
VECTOR ANALYSIS.
OTHERWISE...HIGHS IN THE L/M 90S WITH DWPTS BTWN 65 AND 70 WL
RESULT IN HEAT INDEX VALUES IN THE MID TO UPPER 90S. ALL IS
COVERED VERY WELL IN CRNT FCST AND ONLY MINOR CHANGES MADE BASED
ON CRNT OBS.
PRIOR DISCUSSION FOLLOWS...
FORECAST MORE OR LESS REMAINS ON TRACK FOR TODAY AS LARGE-SCALE
H5 HEAT RIDGE MAINTAINS ITS HOLD ON REGIONAL WEATHER. MEAN 18Z
925MB OF 23-25C SUPPORT HIGHS IN THE UPPER 80S TO MID 90S ACROSS
THE REGION ALONG WITH HIGH HUMIDITY...NOT A PLEASANT DAY. HEAT
INDEX VALUES TO PEAK JUST BELOW ADVISORY CRITERIA...GENERALLY IN
THE 92-98 RANGE IN LOWER ELEVATIONS BELOW 1000 FEET. THIS WILL BE
DAY 3 OF 90F+ AT KBTV SO OFFICIAL NEW ENGLAND HEAT WAVE CRITERIA
WILL BE MET. OF COURSE NOT ALL AREAS HAVE SEEN 3 CONSECUTIVE DAYS
OF 90F+...ESP IN SOME OF OUR NRN MTN LOCALES...BUT EVERYONE GETS
THE POINT THAT WE`RE IN A VERY WARM AND UNCOMFORTABLE STRETCH OF
WX.
COULD SEE SOME ISOLATED AFTERNOON PULSE-TYPE STORMS IN THE 1 TO 4
PM TIME FRAME OF SO...BUT INITIALLY MID LEVELS WILL BE SLIGHTLY
CAPPED SUCH THAT UPDRAFTS WILL BE INHIBITED. MORE IMPORTANTLY
HOWEVER WILL BE THE POTENTIAL FOR A LINE OF STRONG TO LOCALLY
SEVERE STORMS TO DROP SOUTHWARD INTO OUR NORTHERN COUNTIES LATER
THIS AFTERNOON OR EARLY EVENING AS A WEAK SURFACE FRONT
APPROACHES FROM THE NORTHWEST. WITH SLIGHT MID LEVEL HEIGHT FALLS
AMPLE PBL INSTABILITY AND MODEST 0-6KM SHEAR VALUES INCREASING
INTO THE 30-40 KT RANGE ACROSS THE NORTH...THE THREAT FOR STRONG
TO LOCALLY SEVERE STORMS TO DEVELOP ALONG THIS LINE IS
INCREASING. VERY TALL STORMS WITH TOPS TO NEAR 50 KFT POSSIBLE
WITH EQ LEVELS VERY HIGH. MODIFIED KMSS AND KFSO SOUNDINGS
CENTERED AROUND 00Z SHOW QUITE ROBUST SWEAT AND DCAPE VALUES...SO
STRONG OUTFLOW/DAMAGING WINDS LOOK LIKE THE PRIMARY
THREAT...ESPECIALLY IF ACTIVITY CAN ORGANIZE ENOUGH TO GENERATE
AN AMPLE COLD POOL. HAIL NOT SO MUCH AN ISSUE GIVEN MEAN WBZ
VALUES ABOVE 12 KFT. STORMS WILL TEND TO WEAKEN AS THEY PROGRESS
SOUTHWARD THROUGH OUR REGION...SO HIGHEST THREAT WILL BE ACROSS
OUR NORTHERN COUNTIES WITH LESS OF A THREAT THE FURTHER SOUTH YOU
GO. WILL ALSO CONTINUE MENTION OF HEAVY RAINFALL AS PWATS CLIMB
TO NEAR 1.9 INCHES ALONG WITH LOW TO MID LEVEL MOISTURE POOLING
IN ADVANCE OF THE SURFACE BOUNDARY.
BY LATER THIS EVENING INTO TONIGHT ACTIVITY SLOWLY WANES AND
TAPERS TO SCATTERED SHOWERS ACROSS OUR CENTRAL AND NORTHERN
COUNTIES AS WEAK FRONTAL BOUNDARY SAGS INTO THE REGION AND
STALLS. PATCHY FOG ALSO A GOOD BET IF WE SEE HEAVIER WETTING
RAINFALL. LOWS MILD AND HUMID...MID 60S TO LOWER 70S...OR SIMILAR
TO THE PAST FEW NIGHTS.
&&
.SHORT TERM /11 PM THIS EVENING THROUGH FRIDAY/...
AS OF 420 AM EDT WEDNESDAY...BY THURSDAY STALLED WEAK SURFACE
BOUNDARY REMAINS DRAPED ACROSS OUR AREA ALONG WITH CONTINUED
WARMTH AND HUMIDITY. SCATTERED SHOWERS AND STORMS ALSO A GOOD BET
WITH LOCALLY HEAVY RAINFALL ONCE AGAIN. MBE VECTOR VALUES ARE
GENERALLY GREATER THAN 10 KTS HOWEVER...SO MY FEELING IS STORMS
MAY BE MOVING ENOUGH TO PRECLUDE A MORE ORGANIZED FLASH FLOOD
THREAT. NONETHELESS WE`LL HAVE TO KEEP AN EYE ON THINGS WITH PWAT
VALUES HOVERING AROUND 2.0 INCHES. DESPITE AMPLE SHEAR AND
INSTABILITY...FEEL ANY SEVERE THREAT SHOULD BE FAIRLY MARGINAL AS
WE REALLY DON`T HAVE A STRONG MECHANISM FOR LIFT OTHER THAN THE
SFC HEATING AND THE WEAK BOUNDARY. TIME WILL TELL. HIGHS ABOUT
2-4 DEGREES COOLER THAN TODAY SO SOME SLIGHT RELIEF BUT NOT MUCH.
SPOT HIGH FOR KBTV AT 89-90F LOOKS REASONABLE.
FRONT THEN REMAINS ATOP OUR REGION THURSDAY NIGHT INTO
FRIDAY...LIFTING SLOWLY NORTHWARD AND DISSIPATING THROUGH TIME IN
RESPONSE TO LARGE-SCALE BACKING OF THE MID LEVEL FLOW AHEAD OF A
MORE ROBUST NRN STREAM UPPER TROUGH OFF TO OUR NORTHWEST. THUS
CHANCE OF SHOWERS AND STORMS CONTINUE...BUT HIGHER CHANCES TREND
MORE ACROSS OUR NORTHERN COUNTIES. LIKELY A REPEAT OF TODAYS HOT
VALUES BY FRIDAY WITH MODELS HAVING CONSISTENTLY TRENDED WARMER
OVER THE PAST 24-HOURS. INDEED...WITH MEAN 925MB TEMPS AVERAGING
FROM 24-26C FRIDAY COULD END UP AS HOT IF NOT A DEGREE OR TWO
HOTTER THAN TODAY...ESPECIALLY IF WE SEE AMPLE SUNSHINE. SO IT`S
NOT ENTIRELY UNREASONABLE TO SUGGEST IF WE HIT 90F AT KBTV ON
THURSDAY...A FIVE DAY STRETCH OF 90F+ WILL BE IN REACH. THE LAST
TIME THIS OCCURRED WAS BACK IN AUGUST 2002.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 436 AM EDT WEDNESDAY...SFC LOW PRESSURE SYSTEM WILL START
THE PERIOD WITH SHOWERS/THUNDERSTORMS AND WARM TEMPERATURES...
FOLLOWED BY HIGH PRESSURE AND A COOLER...DRIER AIRMASS. FRIDAY
NIGHT WILL SEE THE NORTH COUNTRY STILL IN THE WARM SECTOR AND SW
FLOW AS A PREFRONTAL TROUGH AT THE SFC TRIGGERS
SHOWERS/THUNDERSTORMS FOLLOWED BY ASSOCIATED COLD FRONT ON
SATURDAY CONTINUING THE THREAT FOR SHOWERS AND THUNDERSTORMS.
FAVORABLE UPPER LEVEL JET DYNAMICS WILL ACCOMPANY THE COLD FRONT
WITH RR QUADRANT OF 250MB JET MOVES OVER THE NORTH COUNTRY MAINLY
ON SATURDAY...COINCIDING WITH STRONG FGEN AT 850MB...LINGERING
INTO SATURDAY NIGHT. PWATS OF 1.5-2 INCHES WILL PEAK EARLY
SATURDAY AS THE FRONT MOVES FROM SE ONTARIO...SEWD AND EVENTUALLY
EXIT VT EARLY SUNDAY AS ASSOCIATED UPPER LEVEL TROUGH PUSHES NEWD
SATURDAY NIGHT. HIGH PRESSURE WILL BUILD IN OVER THE REGION
FOLLOWING THE FRONT SUNDAY THROUGH AT LEAST MONDAY. MONDAY NIGHT
INTO TUESDAY...THE 00Z ECMWF BRINGS ANOTHER UPPER LEVEL TROUGH
OVER THE REGION...PRODUCING SHOWERS WHILE THE GFS KEEPS THE HIGH
PRESSURE ENTRENCHED OVER NRN NEW ENGLAND THROUGH THE MIDDLE OF
THE WEEK.
TEMPERATURES WILL BE WARM AND MUGGY...WITH MIN TEMPS FRIDAY NIGHT
IN THE 60S-L70S AND MAX TEMPS ON SATURDAY RANGING FORM M70S TO
M80S. COOLER AIR WILL FILTER IN FOR THE REST OF THE PERIOD WITH
MIN TEMPS TRENDING COOLER. SATURDAY NIGHT WILL BE IN THE 50S-
L60S...WITH SUNDAY NT THRU TUES NT IN THE M40S-U50S. MAX TEMPS
WILL GENERALLY BE IN THE 70S.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
THROUGH 18Z THURSDAY...ACTIVE AVIATION FORECAST FOR THIS AFTERNOON
AND EVENING WITH POTENTIAL FOR LOCALLY STG THUNDERSTORMS.
THUNDERSTORMS ARE CURRENTLY DEVELOPING IN THE OTTAWA AND THE
WESTERN SAINT LAWRENCE VALLEYS MOVING EAST-SOUTHEASTWARD. VFR
CONDITIONS EXPECTED TO PREVAIL UNTIL THUNDERSTORMS APPROACH WITH
GENERAL TIMING BETWEEN 18-05Z. ACTIVITY TO BEGIN WITHIN THE NEXT
HOUR OR TWO AT MSS AND SLK...INTO PBG AND BTV AROUND 23-00Z AND
AFTER 01Z FOR RUT AND MPV. POTENTIAL FOR STRONG TO LOCALLY
DAMAGING WINDS AND ASSOCIATED LLVL TURBULENCE...BRIEF PERIOD OF
MVFR TO IFR VISIBILITIES...AND LIGHTNING WITH THUNDERSTORMS.
WINDS WILL BE SOUTH AROUND 5-9KTS. WILL TREAT WITH VCSH FOR NOW
AND USE TEMPOS ACCORDINGLY. THUNDERSTORM ACTIVITY LOOKS TO END
AFTER 05Z WITH FOG/MIST POTENTIAL TONIGHT GIVEN SATURATED LOW-
LEVELS AND LIGHT SFC WINDS TONIGHT. AREAS THAT RECEIVE RAIN TODAY
WILL STAND A GREATER CHANCE AT FOG/MIST TONIGHT...SO FOR NOW HAVE
JUST KEPT 3-6SM BR DURING THE 06-13Z THURSDAY PERIOD. VFR
CONDITIONS THRU 18Z THURSDAY WITH SOUTHWEST/WEST WINDS UNDER
10KTS.
OUTLOOK 18Z THURSDAY THROUGH SUNDAY...
18Z THURSDAY THROUGH SATURDAY...MAINLY VFR CONDITIONS EXPECTED
DURING THE DAY WITH ISOLATED PATCHY FG/BR OVERNIGHT...MAINLY AT
KSLK/KMPV. SCATTERED AFTERNOOON SHOWERS/THUNDERSTORMS EACH DAY
THROUGH THE PERIOD WHICH MAY BRING BRIEF PERIODS OF MVFR/IFR
VISIBILITIES.
SUNDAY...VFR UNDER BUILDING HIGH PRESSURE.
&&
.MARINE...
AS OF 420 AM EDT WEDNESDAY...STRONG TO LOCALLY SEVERE
THUNDERSTORMS MAY EFFECT THE LAKE CHAMPLAIN WATERS LATER THIS
AFTERNOON AND EVENING. IF STORMS DO DEVELOP...THEY WILL LIKELY
APPROACH FROM THE NORTH AND NORTHWEST AFTER 3 PM AND MAY BE
ACCOMPANIED BY VERY STRONG GUSTY WINDS AND FREQUENT CLOUD TO
GROUND LIGHTNING. IF PLANNING ACTIVITIES ON THE LAKE THIS
AFTERNOON AND EVENING...PLEASE KEEP ABREAST OF THE LATEST WEATHER
INFORMATION AND BE PREPARED TO SEEK SAFE HARBOR QUICKLY SHOULD
STRONGER STORMS APPROACH. WINDS GENERALLY LIGHT SOUTHERLY THIS
MORNING...TRENDING WEST TO SOUTHWESTERLY 5 TO 15 KNOTS THIS
AFTERNOON AND EVENING OUTSIDE ANY STORMS.
&&
.CLIMATE...
MAX TEMP RECORDS TODAY THROUGH FRIDAY. BEST SHOT TODAY AT
KMSS...THEN ON FRIDAY AT KMPV AND KMSS. SHORTER PERIOD OF RECORD AT
THESE SITES THAN AT K1V4 AND KBTV.
07/17/2013 07/18/2013 07/19/2013
KBTV 97/1999 99/1953 98/1942
KMPV 93/1982 96/1953 92/1991
K1V4 94/1953 99/1953 95/1991
KMSS 92/2012 95/1953 93/1991
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG/TABER
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...LOCONTO
MARINE...
CLIMATE...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
123 PM EDT WED JUL 17 2013
.SYNOPSIS...
HOT AND HUMID WEATHER IS EXPECTED THROUGH FRIDAY ALONG WITH AN
INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS. A FEW OF THE
STORMS COULD BE STRONG TO SEVERE LATER THIS AFTERNOON AND
EVENING. SHOWERS AND STORMS WILL END NORTH TO SOUTH DURING
SATURDAY AS A STRONG COLD FRONT PUSHES THROUGH THE AREA. BEHIND
THIS FRONT...A MORE SEASONABLE AND PLEASANTLY DRIER AIRMASS WILL
SETTLE ACROSS THE REGION FROM SUNDAY INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 11 PM THIS EVENING/...
AS OF 113 PM EDT WEDNESDAY...FCST IN GOOD SHAPE WITH A FEW MINOR
ADJUSTMENTS. HAVE INCREASED TEMPS AT PBG DUE TO DOWNSLOPE SW FLW
OFF THE DACKS...ADJUSTED SEVERAL DWPTS...AND SKY COVER GRIDS.
BOTTOM LINE EXPECT HEAT INDEX VALUES TO APPROACH 100 DEGREES IN
THE WARMER VALLEY LOCATIONS AND THUNDERSTORM ACTIVITY TO INCREASE
IN AREAL COVERAGE/INTENSITY THIS AFTN/EVENING.
CRNT RADAR SHOWS STORMS DEVELOPING NORTH OF LAKE ONTARIO AND
ANOTHER BATCH APPROACHING THE OTTAWA VALLEY. THESE STORMS WL
APPROACH THE SLV BY MID/LATE AFTN AND EVOLVE INTO A LINE OF SVR
STORMS...WITH DAMAGING WINDS AS THE PRIMARY SVR WX THREAT. GIVEN
WIND PROFILES AND INSTABILITY WOULD EXPECT SVR STORMS WITH THE
POTENTIAL FOR SCATTERED POWER OUTAGES/TREES DOWN ACRS NORTHERN NY
INTO PARTS OF CENTRAL/NORTHERN VT AS THIS LINE OF STORMS MOVES
ACRS THE REGION THIS EVENING.
ACTIVE WEATHER DAY ANTICIPATED ACRS THE NORTH COUNTRY...WITH THE
NEAR TERM CHALLENGE BEING TIMING/EVOLUTION OF CONVECTION THIS
AFTN/EVENING. WATER VAPOR SHOWS TWO PIECES OF ENERGY...FIRST IS
LOCATED JUST NORTH OF LAKE ONTARIO AND ANOTHER MUCH STRONGER ONE
IS LOCATED JUST NORTHEAST OF LAKE SUPERIOR. THINKING FIRST S/W WL
HELP IN THE DEVELOPMENT OF SHOWERS/STORMS ACRS THE DACKS/SLV BTWN
1PM AND 4PM THIS AFTN...WITH SOME STRONG STORMS POSSIBLE...GIVEN
CAPE VALUES BTWN 2000 AND 2500 J/KG AND DEEP LAYER SHEAR VALUES
BTWN 25 AND 30 KNTS. MEANWHILE...BETTER DYNAMICS/MOISTURE
ASSOCIATED WITH 2ND S/W WL ARRIVE ACRS THE OTTAWA AND SLV VALLEY`S
BTWN 21Z-00Z...WITH A LINE OF STRONG TO SEVERE STORMS LIKELY.
GIVEN THE AVAILABLE SHEAR AND INSTABILITY...THINKING LINE SEGMENTS
WITH ENHANCED BOW ECHOES WL BE POSSIBLE...WITH PRIMARY THREAT
BEING STRONG/DAMAGING WINDS GUSTS. CRNT SPC HAS OUR REGION IN
SLGHT RISK...WHICH LOOKS GOOD. ACTIVITY SHOULD WEAKEN TWD 03Z ACRS
CENTRAL/EASTERN VT. CWMW SOUNDINGS SHOW PW VALUES OF 1.66"...500MB
WINDS OF 50 KNOTS...AND VERY HIGH EL AROUND 43KFT...SO EXPECT
OVERSHOOTING STORM TOPS NEAR 50KFT THIS AFTN/EVENING WITH GREATEST
POTENTIAL BEING WINDS. 0 TO 6 KM STORM MOTIONS OF 20 TO 25 KNOTS
SHOULD LIMIT FLASH FLOOD THREAT...BUT WESTERN/SOUTHERN FLANK ACRS
THE DACKS WL HAVE TO BE WATCHED FOR POTENTIAL TRAINING...GIVEN
VECTOR ANALYSIS.
OTHERWISE...HIGHS IN THE L/M 90S WITH DWPTS BTWN 65 AND 70 WL
RESULT IN HEAT INDEX VALUES IN THE MID TO UPPER 90S. ALL IS
COVERED VERY WELL IN CRNT FCST AND ONLY MINOR CHANGES MADE BASED
ON CRNT OBS.
PRIOR DISCUSSION FOLLOWS...
FORECAST MORE OR LESS REMAINS ON TRACK FOR TODAY AS LARGE-SCALE
H5 HEAT RIDGE MAINTAINS ITS HOLD ON REGIONAL WEATHER. MEAN 18Z
925MB OF 23-25C SUPPORT HIGHS IN THE UPPER 80S TO MID 90S ACROSS
THE REGION ALONG WITH HIGH HUMIDITY...NOT A PLEASANT DAY. HEAT
INDEX VALUES TO PEAK JUST BELOW ADVISORY CRITERIA...GENERALLY IN
THE 92-98 RANGE IN LOWER ELEVATIONS BELOW 1000 FEET. THIS WILL BE
DAY 3 OF 90F+ AT KBTV SO OFFICIAL NEW ENGLAND HEAT WAVE CRITERIA
WILL BE MET. OF COURSE NOT ALL AREAS HAVE SEEN 3 CONSECUTIVE DAYS
OF 90F+...ESP IN SOME OF OUR NRN MTN LOCALES...BUT EVERYONE GETS
THE POINT THAT WE`RE IN A VERY WARM AND UNCOMFORTABLE STRETCH OF
WX.
COULD SEE SOME ISOLATED AFTERNOON PULSE-TYPE STORMS IN THE 1 TO 4
PM TIME FRAME OF SO...BUT INITIALLY MID LEVELS WILL BE SLIGHTLY
CAPPED SUCH THAT UPDRAFTS WILL BE INHIBITED. MORE IMPORTANTLY
HOWEVER WILL BE THE POTENTIAL FOR A LINE OF STRONG TO LOCALLY
SEVERE STORMS TO DROP SOUTHWARD INTO OUR NORTHERN COUNTIES LATER
THIS AFTERNOON OR EARLY EVENING AS A WEAK SURFACE FRONT
APPROACHES FROM THE NORTHWEST. WITH SLIGHT MID LEVEL HEIGHT FALLS
AMPLE PBL INSTABILITY AND MODEST 0-6KM SHEAR VALUES INCREASING
INTO THE 30-40 KT RANGE ACROSS THE NORTH...THE THREAT FOR STRONG
TO LOCALLY SEVERE STORMS TO DEVELOP ALONG THIS LINE IS
INCREASING. VERY TALL STORMS WITH TOPS TO NEAR 50 KFT POSSIBLE
WITH EQ LEVELS VERY HIGH. MODIFIED KMSS AND KFSO SOUNDINGS
CENTERED AROUND 00Z SHOW QUITE ROBUST SWEAT AND DCAPE VALUES...SO
STRONG OUTFLOW/DAMAGING WINDS LOOK LIKE THE PRIMARY
THREAT...ESPECIALLY IF ACTIVITY CAN ORGANIZE ENOUGH TO GENERATE
AN AMPLE COLD POOL. HAIL NOT SO MUCH AN ISSUE GIVEN MEAN WBZ
VALUES ABOVE 12 KFT. STORMS WILL TEND TO WEAKEN AS THEY PROGRESS
SOUTHWARD THROUGH OUR REGION...SO HIGHEST THREAT WILL BE ACROSS
OUR NORTHERN COUNTIES WITH LESS OF A THREAT THE FURTHER SOUTH YOU
GO. WILL ALSO CONTINUE MENTION OF HEAVY RAINFALL AS PWATS CLIMB
TO NEAR 1.9 INCHES ALONG WITH LOW TO MID LEVEL MOISTURE POOLING
IN ADVANCE OF THE SURFACE BOUNDARY.
BY LATER THIS EVENING INTO TONIGHT ACTIVITY SLOWLY WANES AND
TAPERS TO SCATTERED SHOWERS ACROSS OUR CENTRAL AND NORTHERN
COUNTIES AS WEAK FRONTAL BOUNDARY SAGS INTO THE REGION AND
STALLS. PATCHY FOG ALSO A GOOD BET IF WE SEE HEAVIER WETTING
RAINFALL. LOWS MILD AND HUMID...MID 60S TO LOWER 70S...OR SIMILAR
TO THE PAST FEW NIGHTS.
&&
.SHORT TERM /11 PM THIS EVENING THROUGH FRIDAY/...
AS OF 420 AM EDT WEDNESDAY...BY THURSDAY STALLED WEAK SURFACE
BOUNDARY REMAINS DRAPED ACROSS OUR AREA ALONG WITH CONTINUED
WARMTH AND HUMIDITY. SCATTERED SHOWERS AND STORMS ALSO A GOOD BET
WITH LOCALLY HEAVY RAINFALL ONCE AGAIN. MBE VECTOR VALUES ARE
GENERALLY GREATER THAN 10 KTS HOWEVER...SO MY FEELING IS STORMS
MAY BE MOVING ENOUGH TO PRECLUDE A MORE ORGANIZED FLASH FLOOD
THREAT. NONETHELESS WE`LL HAVE TO KEEP AN EYE ON THINGS WITH PWAT
VALUES HOVERING AROUND 2.0 INCHES. DESPITE AMPLE SHEAR AND
INSTABILITY...FEEL ANY SEVERE THREAT SHOULD BE FAIRLY MARGINAL AS
WE REALLY DON`T HAVE A STRONG MECHANISM FOR LIFT OTHER THAN THE
SFC HEATING AND THE WEAK BOUNDARY. TIME WILL TELL. HIGHS ABOUT
2-4 DEGREES COOLER THAN TODAY SO SOME SLIGHT RELIEF BUT NOT MUCH.
SPOT HIGH FOR KBTV AT 89-90F LOOKS REASONABLE.
FRONT THEN REMAINS ATOP OUR REGION THURSDAY NIGHT INTO
FRIDAY...LIFTING SLOWLY NORTHWARD AND DISSIPATING THROUGH TIME IN
RESPONSE TO LARGE-SCALE BACKING OF THE MID LEVEL FLOW AHEAD OF A
MORE ROBUST NRN STREAM UPPER TROUGH OFF TO OUR NORTHWEST. THUS
CHANCE OF SHOWERS AND STORMS CONTINUE...BUT HIGHER CHANCES TREND
MORE ACROSS OUR NORTHERN COUNTIES. LIKELY A REPEAT OF TODAYS HOT
VALUES BY FRIDAY WITH MODELS HAVING CONSISTENTLY TRENDED WARMER
OVER THE PAST 24-HOURS. INDEED...WITH MEAN 925MB TEMPS AVERAGING
FROM 24-26C FRIDAY COULD END UP AS HOT IF NOT A DEGREE OR TWO
HOTTER THAN TODAY...ESPECIALLY IF WE SEE AMPLE SUNSHINE. SO IT`S
NOT ENTIRELY UNREASONABLE TO SUGGEST IF WE HIT 90F AT KBTV ON
THURSDAY...A FIVE DAY STRETCH OF 90F+ WILL BE IN REACH. THE LAST
TIME THIS OCCURRED WAS BACK IN AUGUST 2002.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 436 AM EDT WEDNESDAY...SFC LOW PRESSURE SYSTEM WILL START
THE PERIOD WITH SHOWERS/THUNDERSTORMS AND WARM TEMPERATURES...
FOLLOWED BY HIGH PRESSURE AND A COOLER...DRIER AIRMASS. FRIDAY
NIGHT WILL SEE THE NORTH COUNTRY STILL IN THE WARM SECTOR AND SW
FLOW AS A PREFRONTAL TROUGH AT THE SFC TRIGGERS
SHOWERS/THUNDERSTORMS FOLLOWED BY ASSOCIATED COLD FRONT ON
SATURDAY CONTINUING THE THREAT FOR SHOWERS AND THUNDERSTORMS.
FAVORABLE UPPER LEVEL JET DYNAMICS WILL ACCOMPANY THE COLD FRONT
WITH RR QUADRANT OF 250MB JET MOVES OVER THE NORTH COUNTRY MAINLY
ON SATURDAY...COINCIDING WITH STRONG FGEN AT 850MB...LINGERING
INTO SATURDAY NIGHT. PWATS OF 1.5-2 INCHES WILL PEAK EARLY
SATURDAY AS THE FRONT MOVES FROM SE ONTARIO...SEWD AND EVENTUALLY
EXIT VT EARLY SUNDAY AS ASSOCIATED UPPER LEVEL TROUGH PUSHES NEWD
SATURDAY NIGHT. HIGH PRESSURE WILL BUILD IN OVER THE REGION
FOLLOWING THE FRONT SUNDAY THROUGH AT LEAST MONDAY. MONDAY NIGHT
INTO TUESDAY...THE 00Z ECMWF BRINGS ANOTHER UPPER LEVEL TROUGH
OVER THE REGION...PRODUCING SHOWERS WHILE THE GFS KEEPS THE HIGH
PRESSURE ENTRENCHED OVER NRN NEW ENGLAND THROUGH THE MIDDLE OF
THE WEEK.
TEMPERATURES WILL BE WARM AND MUGGY...WITH MIN TEMPS FRIDAY NIGHT
IN THE 60S-L70S AND MAX TEMPS ON SATURDAY RANGING FORM M70S TO
M80S. COOLER AIR WILL FILTER IN FOR THE REST OF THE PERIOD WITH
MIN TEMPS TRENDING COOLER. SATURDAY NIGHT WILL BE IN THE 50S-
L60S...WITH SUNDAY NT THRU TUES NT IN THE M40S-U50S. MAX TEMPS
WILL GENERALLY BE IN THE 70S.
&&
.AVIATION /17Z WEDNESDAY THROUGH MONDAY/...
THROUGH 12Z THURSDAY...VFR CONDITIONS WILL PERSIST THROUGH AT
LEAST THE EARLY EVENING HOURS...AS KMPV RECOVERS FROM VLIFR THIS
MORNING. SFC TROUGH GENERATING SCT-BKN MID LEVEL CLOUDS THIS
MORNING BEFORE DIURNALLY DRIVEN VFR CLOUDS DEVELOP IN THE HOT
HUMID DAYTIME...WITH INSTABILITY INCREASING THROUGHOUT THE LATE
AFTN/EVENING HRS. LGT TO CALM WINDS THIS MORNING WILL INCREASE TO
8-12KTS OUT OF THE S-SW IN THE MID-LATE MORNING...SHIFTING SW-W
THIS AFTN WITH GUSTS PSBL.
A BOUNDARY ASSOCIATED UPPER LEVEL VORTICITY WILL TRIGGER SCT
SHOWERS AND THUNDERSTORMS NORTH OF THE INTERNATIONAL BORDER IN
THE LATE AFTN...TRAVELING S/SE AND MOST LIKELY AFFECTING
KMSS/KPBG/KBTV AND PSBLY KSLK/KMPV. EXPECT SCT SHOWERS AND
THUNDERSTORMS TO TRAVEL FROM NW TO SSE...AFFECTING KMSS AROUND
20Z...KPBG/KBTV/KMPV AROUND 23Z/00Z. HAVE INCLUDED VCSH AT ALL
BUT KRUT AS WESTERLY WINDS WILL HELP SHOWERS AND THUNDERSTORMS
LOSE MOMENTUM SWD...WHILE LOSS OF DIURNAL HEATING AFTER SUNSET
WEAKENS CONVECTIVE ACTIVITY. EXPECT SHOWERS AND THUNDERSTORMS TO
DISSIPATE AFTER 04Z. THUNDERSTORMS MAY CONTAIN STRONG GUSTY
WINDS. ANY AREA THAT RECEIVES RAINFALL COULD DEVELOP FG/BR MAINLY
AFTER 04Z THURSDAY. EXPECT PATCHY FG TO DEVELOP AT MOST TAF SITES
OVERNIGHT...RECOVERING TO VFR MID TO LATE THURSDAY MORNING.
OUTLOOK 12Z THURSDAY THROUGH SUNDAY...
12Z THURSDAY THROUGH SATURDAY...PRIMARILY VFR CONDITIONS EXPECTED
DURING THE DAY WITH ISOLATED PATCHY FG/BR OVERNIGHT...MAINLY AT
KSLK/KMPV. HOWEVER...CHANCES INCREASE FOR SCATTERED
SHOWERS/THUNDERSTORMS THROUGH THE PERIOD WHICH MAY BRING BRIEF
PERIODS OF MVFR/IFR IN SHOWERS AND THUNDERSTORMS.
SUNDAY...VFR WITH HIGH PRESSURE BUILDING IN AT THE SFC.
&&
.MARINE...
AS OF 420 AM EDT WEDNESDAY...STRONG TO LOCALLY SEVERE
THUNDERSTORMS MAY EFFECT THE LAKE CHAMPLAIN WATERS LATER THIS
AFTERNOON AND EVENING. IF STORMS DO DEVELOP...THEY WILL LIKELY
APPROACH FROM THE NORTH AND NORTHWEST AFTER 3 PM AND MAY BE
ACCOMPANIED BY VERY STRONG GUSTY WINDS AND FREQUENT CLOUD TO
GROUND LIGHTNING. IF PLANNING ACTIVITIES ON THE LAKE THIS
AFTERNOON AND EVENING...PLEASE KEEP ABREAST OF THE LATEST WEATHER
INFORMATION AND BE PREPARED TO SEEK SAFE HARBOR QUICKLY SHOULD
STRONGER STORMS APPROACH. WINDS GENERALLY LIGHT SOUTHERLY THIS
MORNING...TRENDING WEST TO SOUTHWESTERLY 5 TO 15 KNOTS THIS
AFTERNOON AND EVENING OUTSIDE ANY STORMS.
&&
.CLIMATE...
MAX TEMP RECORDS TODAY THROUGH FRIDAY. BEST SHOT TODAY AT
KMSS...THEN ON FRIDAY AT KMPV AND KMSS. SHORTER PERIOD OF RECORD AT
THESE SITES THAN AT K1V4 AND KBTV.
07/17/2013 07/18/2013 07/19/2013
KBTV 97/1999 99/1953 98/1942
KMPV 93/1982 96/1953 92/1991
K1V4 94/1953 99/1953 95/1991
KMSS 92/2012 95/1953 93/1991
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG/TABER
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...KGM
MARINE...
CLIMATE...
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
613 PM EDT WED JUL 17 2013
.SYNOPSIS...
A WEAK UPPER DISTURBANCE OVER THE EASTERN CAROLINAS ALONG WITH A
WARM AND HUMID AIR MASS OVER THE REGION WILL BRING ISOLATED SHOWERS
AND THUNDERSTORMS THIS EVENING. A WEAK INLAND TROUGH WILL RESIDE
OVER THE INTERIOR THURSDAY AND INTO THE WEEKEND. A FRONTAL
BOUNDARY WILL STALL ACROSS THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 6:10 PM WEDNESDAY...STRONGEST CONVECTION HAS EXITED THE
FORECAST AREA TO THE SOUTH...WITH SOME MODERATE THUNDERSTORMS
LINGERING OVER EXTREME SOUTHERN GEORGETOWN AND WILLIAMSBURG
COUNTIES. HAVE TWEAKED FORECAST TO ADJUST POPS...OTHERWISE
FORECAST REMAINS ON TRACK AS PER DISCUSSION BELOW:
PLENTY OF HEAT AND HUMIDITY ABOUNDS ACROSS THE AREA WITH THE
STRONGEST CONVECTION ISOLATED OVER CENTRAL AND WESTERN NORTH
CAROLINA. WEAK SUBSIDENCE WAS APPARENTLY AT WORK OVER VERY EASTERN
NORTH CAROLINA...WITH ANVIL DEBRIS CLOUDS BEGINNING TO CUT DOWN ON
SURFACE HEATING ACROSS OUR NE ZONES AT PRESENT. SHOWERS AND TSTMS
WERE FIRING ALONG THE SEA BREEZE FRONT ACROSS EASTERN SC WHERE
CONVECTIVE INHIBITION WAS A BIT WEAKER. STEERING WINDS WILL PUSH
TSTMS GENERALLY TOWARD THE SOUTHWEST THROUGH THE AFTERNOON AND
EVENING HOURS. AN ISOLATED THREAT REMAINS FOR THE STRONGER CELLS
TO GENERATE DAMAGING WIND GUSTS AND LARGE HAIL. THE STORM THAT
MOVED WEST ACROSS RICHMOND AND ANSON COUNTIES EARLIER MANAGED TO
TOPPLE TREES AND DROP 1 INCH HAILSTONES.
TRAINING OF CELLS ALONG THE SEA BREEZE WILL BE POSSIBLE OVER THE
INTERIOR OF GEORGETOWN COUNTY THROUGH AFTERNOON...POSING A LOW-END
THREAT OF LOCALIZED FLOODING.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 230 PM WEDNESDAY...H5 RIDGE AXIS WILL SPRAWL FROM THE
MID-ATLANTIC WESTWARD ACROSS THE CENTRAL PLAINS INTO THE WESTERN
UNITED STATES THURSDAY. THE ORIENTATION OF THE RIDGE WILL SUPPRESS
MOST OF THE SHORT WAVE ENERGY TO CANADA...WITH WEAKER ENERGY
SHIFTING ALONG ITS SOUTHERN PERIPHERY ALONG THE GULF COAST. THE
OVERALL PATTERN BEGINS TO CHANGE DURING FRIDAY AS THE RIDGE
CONSOLIDATES ACROSS THE WESTERN UNITED STATES AND OFF THE EAST COAST
WITH A WEAKNESS EVOLVING ACROSS THE MS VALLEY AND EASTERN UNITED
STATES. LIFT WILL REMAIN LACKING DURING THE SHORT TERM PERIOD WITH
THE SEA BREEZE AS THE MAIN CULPRIT ALONG WITH WEAK INLAND TROUGHING.
AS A RESULT...CAN/T ENTIRELY RULE OUT AN ISOLATED SHRA/TSRA OR
WIDELY SCATTERED STORMS EACH DAY. A BLEND OF MAV/MET NUMBERS APPEARS
REASONABLE THROUGH THE PERIOD AND THESE TEMPERATURES WHICH ARE VERY
CLOSE TO CLIMO.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 230 PM WEDNESDAY...A QUICK UPDATE TO THE EXTENDED FORECAST
THIS AFTERNOON SHOWS MOST GUIDANCE REMAINS CONSISTENT WITH THE MID
LEVEL PATTERN TRANSITIONING FROM A WEAKLY FORCED CLASSIC SUMMER
PATTERN TO MID LEVEL TROUGHING ACROSS THE EAST. THE BIGGEST CHANGE
IN WPC SURFACE PROGS SHOWS THE ASSOCIATED SURFACE FRONT REMAINS TO
THE NORTH OF THE AREA ACROSS THE NC/VA BORDER AND I WOULD NOT BE
SURPRISED TO SEE THE POSITION OF THIS BOUNDARY VACILLATE NORTH TO
SOUTH OVER THE COMING DAYS. REGARDLESS OF POSITION...AN INCREASE IN
POPS IN COVERAGE REMAINS IN THE FORECAST MOST NOTABLY FROM MONDAY
THROUGH THE NEW DAY WEDNESDAY.
&&
.AVIATION /22Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...THE INTERACTION OF AN UPPER IMPULSE WITH SEA BREEZE AND
MESOSCALE SFC BOUNDARIES SHOULD RESULT IN SCATTERED SHOWERS/T-STORMS
THIS AFTN. CONVECTIVE ACTIVITY MAY BE FOCUSED MORE OVER THE SOUTHERN
TERMS...KFLO/KMYR/KCRE...WHERE BETTER SFC HEATING IS OCCURRING. THE
LATEST HRRR RUNS FAVOR THIS SOLUTION...SO WILL INCLUDE VCTS FOR
THESE TERMS THRU THE AFTN HOURS. VFR WILL PREVAIL TODAY WITH THE
POSSIBILITY OF TEMPO MVFR/IFR IN STORMS. THE WINDS WILL BECOME
LIGHT/CALM OVERNIGHT...BUT RESIDUAL LOW/MID-LEVEL MOISTURE MAY
SOMEWHAT INHIBIT FOG FORMATION. WILL STILL INCLUDE MVFR VSBYS AT ALL
TERMS EARLY THURSDAY...WITH THE BEST CHANCES FOR IFR FOG INLAND AT
KFLO AND KLBT.
EXTENDED OUTLOOK...EARLY MORNING FOG POSSIBLE DURING THE EXTENDED
PERIOD. INCREASING CHANCES FOR SHOWERS/T-STORMS SATURDAY THROUGH
MONDAY. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 6:10 PM WEDNESDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS BELOW:
LIGHT WINDS AND LOW SEA-HEIGHTS WILL POSE LITTLE HAZARD FOR
MARINERS THROUGH THE NEAR TERM PERIOD. ISOLATED TSTMS HOWEVER WILL
REMAIN POSSIBLE AS STEERING WINDS ALOFT POTENTIALLY GUIDE A FEW
STORMS OVER THE NEAR-SHORE WATERS. SEAS OF AROUND 2 FEET WILL BE
COMPOSED OF SE WAVES 1-2 FEET EVERY 7-8 SECONDS ACCOMPANIED A
LIGHT SSW CHOP. WINDS AND SEAS WILL BE NOTABLY HIGHER IN AND NEAR
TSTMS.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 PM WEDNESDAY...INLAND TROUGH WILL PROMOTE W-SW FLOW ACROSS
THE COASTAL WATERS EARLY THURSDAY...THEN THE WIND WILL BACK TO S TO
SW AS THE TROUGH DRIFTS WEST AND THE SEA BREEZE PUSHES INLAND.
SOUTHWESTERLY FLOW WILL PREVAIL THURSDAY NIGHT THROUGH FRIDAY NIGHT
WITH BERMUDA HIGH PRESSURE OFF THE COAST AND WEAK INLAND TROUGH. THE
WIND SPEED WILL UNDULATE EACH DAY...WITH SPEEDS GENERALLY 15 KNOTS
OR LESS THROUGH THE PERIOD AND SEAS WILL AVERAGE 3 FT
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 230 PM WEDNESDAY...SOUTHWEST FLOW OF 10-15 KNOTS SATURDAY WILL
INCREASE TO 15-20 KNOTS SUNDAY AS THE GRADIENT INCREASES. LOW LEVEL
WIND FIELDS DECREASE SLIGHTLY MONDAY AS THE APPROACHING FRONT
WEAKENS. SEAS COULD STILL REACH SCEC CRITERIA LATE SUNDAY BASED ON
THE INCREASE IN WINDS...OTHERWISE...2-4 FEET WILL PREVAIL.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
230 PM EDT WED JUL 17 2013
.SYNOPSIS...
A WEAK UPPER DISTURBANCE OVER THE EASTERN CAROLINAS ALONG WITH A
WARM AND HUMID AIR MASS OVER THE REGION...WILL BRING SCATTERED
SHOWERS AND THUNDERSTORMS TODAY. A WEAK INLAND TROUGH WILL RESIDE
OVER THE INTERIOR THURSDAY INTO THE WEEKEND. A FRONTAL BOUNDARY WILL
STALL ACROSS THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM WEDNESDAY...PLENTY OF HEAT AND HUMIDITY ABOUNDS ACROSS
THE AREA WITH THE STRONGEST CONVECTION ISOLATED OVER CENTRAL AND
WESTERN NORTH CAROLINA. WEAK SUBSIDENCE WAS APPARENTLY AT WORK OVER
VERY EASTERN NORTH CAROLINA...WITH ANVIL DEBRIS CLOUDS BEGINNING TO
CUT DOWN ON SURFACE HEATING ACROSS OUR NE ZONES AT PRESENT. SHOWERS
AND TSTMS WERE FIRING ALONG THE SEA BREEZE FRONT ACROSS EASTERN SC
WHERE CONVECTIVE INHIBITION WAS A BIT WEAKER. STEERING WINDS WILL
PUSH TSTMS GENERALLY TOWARD THE SOUTHWEST THROUGH THE AFTERNOON AND
EVENING HOURS. AN ISOLATED THREAT REMAINS FOR THE STRONGER CELLS TO
GENERATE DAMAGING WIND GUSTS AND LARGE HAIL. THE STORM THAT MOVED
WEST ACROSS RICHMOND AND ANSON COUNTIES EARLIER MANAGED TO TOPPLE
TREES AND DROP 1 INCH HAILSTONES.
TRAINING OF CELLS ALONG THE SEA BREEZE WILL BE POSSIBLE OVER THE
INTERIOR OF GEORGETOWN COUNTY THROUGH AFTERNOON...POSING A LOW-END
THREAT OF LOCALIZED FLOODING.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 PM WEDNESDAY...H5 RIDGE AXIS WILL SPRAWL FROM THE
MID-ATLANTIC WESTWARD ACROSS THE CENTRAL PLAINS INTO THE WESTERN
UNITED STATES THURSDAY. THE ORIENTATION OF THE RIDGE WILL SUPPRESS
MOST OF THE SHORT WAVE ENERGY TO CANADA...WITH WEAKER ENERGY
SHIFTING ALONG ITS SOUTHERN PERIPHERY ALONG THE GULF COAST. THE
OVERALL PATTERN BEGINS TO CHANGE DURING FRIDAY AS THE RIDGE
CONSOLIDATES ACROSS THE WESTERN UNITED STATES AND OFF THE EAST COAST
WITH A WEAKNESS EVOLVING ACROSS THE MS VALLEY AND EASTERN UNITED
STATES. LIFT WILL REMAIN LACKING DURING THE SHORT TERM PERIOD WITH
THE SEA BREEZE AS THE MAIN CULPRIT ALONG WITH WEAK INLAND TROUGHING.
AS A RESULT...CAN/T ENTIRELY RULE OUT AN ISOLATED SHRA/TSRA OR
WIDELY SCATTERED STORMS EACH DAY. A BLEND OF MAV/MET NUMBERS APPEARS
REASONABLE THROUGH THE PERIOD AND THESE TEMPERATURES WHICH ARE VERY
CLOSE TO CLIMO.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 230 PM WEDNESDAY...A QUICK UPDATE TO THE EXTENDED FORECAST
THIS AFTERNOON SHOWS MOST GUIDANCE REMAINS CONSISTENT WITH THE MID
LEVEL PATTERN TRANSITIONING FROM A WEAKLY FORCED CLASSIC SUMMER
PATTERN TO MID LEVEL TROUGHING ACROSS THE EAST. THE BIGGEST CHANGE
IN WPC SURFACE PROGS SHOWS THE ASSOCIATED SURFACE FRONT REMAINS TO
THE NORTH OF THE AREA ACROSS THE NC/VA BORDER AND I WOULD NOT BE
SURPRISED TO SEE THE POSITION OF THIS BOUNDARY VACILLATE NORTH TO
SOUTH OVER THE COMING DAYS. REGARDLESS OF POSITION...AN INCREASE IN
POPS IN COVERAGE REMAINS IN THE FORECAST MOST NOTABLY FROM MONDAY
THROUGH THE NEW DAY WEDNESDAY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...THE INTERACTION OF AN UPPER IMPULSE WITH SEA BREEZE AND
MESOSCALE SFC BOUNDARIES SHOULD RESULT IN SCATTERED SHOWERS/T-STORMS
THIS AFTN. CONVECTIVE ACTIVITY MAY BE FOCUSED MORE OVER THE SOUTHERN
TERMS...KFLO/KMYR/KCRE...WHERE BETTER SFC HEATING IS OCCURRING. THE
LATEST HRRR RUNS FAVOR THIS SOLUTION...SO WILL INCLUDE VCTS FOR
THESE TERMS THRU THE AFTN HOURS. VFR WILL PREVAIL TODAY WITH THE
POSSIBILITY OF TEMPO MVFR/IFR IN STORMS. THE WINDS WILL BECOME
LIGHT/CALM OVERNIGHT...BUT RESIDUAL LOW/MID-LEVEL MOISTURE MAY
SOMEWHAT INHIBIT FOG FORMATION. WILL STILL INCLUDE MVFR VSBYS AT ALL
TERMS EARLY THURSDAY...WITH THE BEST CHANCES FOR IFR FOG INLAND AT
KFLO AND KLBT.
EXTENDED OUTLOOK...EARLY MORNING FOG POSSIBLE DURING THE EXTENDED
PERIOD. INCREASING CHANCES FOR SHOWERS/T-STORMS SATURDAY THROUGH
MONDAY. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM WEDNESDAY...LIGHT WINDS AND LOW SEA-HEIGHTS WILL POSE
LITTLE HAZARD FOR MARINERS THROUGH THE NEAR TERM PERIOD. ISOLATED
TSTMS HOWEVER WILL REMAIN POSSIBLE AS STEERING WINDS ALOFT
POTENTIALLY GUIDE A FEW STORMS OVER THE NEAR-SHORE WATERS. SEAS OF
AROUND 2 FEET WILL BE COMPOSED OF SE WAVES 1-2 FEET EVERY 7-8
SECONDS ACCOMPANIED A LIGHT SSW CHOP. WINDS AND SEAS WILL BE NOTABLY
HIGHER IN AND NEAR TSTMS.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 PM WEDNESDAY...INLAND TROUGH WILL PROMOTE W-SW FLOW ACROSS
THE COASTAL WATERS EARLY THURSDAY...THEN THE WIND WILL BACK TO S TO
SW AS THE TROUGH DRIFTS WEST AND THE SEA BREEZE PUSHES INLAND.
SOUTHWESTERLY FLOW WILL PREVAIL THURSDAY NIGHT THROUGH FRIDAY NIGHT
WITH BERMUDA HIGH PRESSURE OFF THE COAST AND WEAK INLAND TROUGH. THE
WIND SPEED WILL UNDULATE EACH DAY...WITH SPEEDS GENERALLY 15 KNOTS
OR LESS THROUGH THE PERIOD AND SEAS WILL AVERAGE 3 FT
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 230 PM WEDNESDAY...SOUTHWEST FLOW OF 10-15 KNOTS SATURDAY WILL
INCREASE TO 15-20 KNOTS SUNDAY AS THE GRADIENT INCREASES. LOW LEVEL
WIND FIELDS DECREASE SLIGHTLY MONDAY AS THE APPROACHING FRONT
WEAKENS. SEAS COULD STILL REACH SCEC CRITERIA LATE SUNDAY BASED ON
THE INCREASE IN WINDS...OTHERWISE...2-4 FEET WILL PREVAIL.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MJC
SHORT TERM...SRP
LONG TERM...SHK
AVIATION...BJR/MJC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
100 PM EDT WED JUL 17 2013
.SYNOPSIS...
A WEAK UPPER DISTURBANCE OVER THE EASTERN CAROLINAS ALONG WITH
A WARM AND HUMID AIR MASS OVER THE REGION...WILL BRING SCATTERED
SHOWERS AND THUNDERSTORMS TODAY. A WEAK INLAND TROUGH WILL RESIDE
OVER THE INTERIOR THURSDAY INTO THE WEEKEND. A FRONTAL BOUNDARY
WILL STALL ACROSS THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM WEDNESDAY...AN OUTFLOW BOUNDARY FROM AN EARLY MORNING
THUNDERSTORM COMPLEX WILL RESULT IN ISOLATED TO SCATTERED CONVECTION
OVER THE NC ZONES THROUGH THE MORNING HOURS. AFTERNOON HEATING WILL
SHIFT THE FOCUS TO RE-NEWED CONVECTION AS A WEAK SURFACE TROUGH
AND A STRENGTHENING SEA BREEZE INTERACT. PWAT VALUES OF 1.85 INCHES
AND VERY HIGH COLUMN BUOYANCY WILL MAKE FOR ACTIVE CONVECTION DURING
THE PEAK IN SURFACE HEATING LATER TODAY. THE STEERING FLOW WILL
GUIDE CONVECTION GENERALLY SOUTHWARD TODAY...GIVING COASTAL LOCALS
A SHOT AT STORMS AS WELL. SOME STORMS WILL BE CAPABLE OF DAMAGING
WINDS BUT SHOULD REMAIN ISOLATED IN NATURE. THE SEA BREEZE MAY
REMAIN RELATIVELY CLOSE TO THE COAST GIVEN THE NW WIND FLOW IN THE
BOUNDARY LAYER. A FAIRLY FLAT SURFACE PRESSURE PATTERN WILL KEEP
SYNOPTIC WINDS LIGHT AND ALLOW A GOOD WARM UP EVEN AT THE COAST AS
AN UPPER RIDGE MAINTAINS AN INFLUENCE ON THE REGION.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 400 AM WEDNESDAY...BERMUDA HIGH WILL EXPAND INTO OUR AREA
FROM THE EAST WHILE RIDGE IN THE MID TO UPPER LEVELS WEAKENS AND
GETS PUSHED EAST BY DIGGING TROUGH. BASICALLY THERE WILL BE ENOUGH
SUBSIDENCE AND DRY AIR IN THE MID TO UPPER LEVELS TO ALLOW FOR
ONLY ISOLATED AND LOCALIZED SHOWER ACTIVITY THROUGH MUCH OF THE
PERIOD. THE FOCUS OF CONVECTION WILL BE ALONG SEA BREEZE BOUNDARY
AND FURTHER INLAND ALONG PIEDMONT TROUGH. THE INCREASING SOUTHERLY
COMPONENT TO THE WIND WILL HELP GUIDE ANY STORMS FROM SOUTH TO
NORTH. THE MODELS AREA SHOWING AN AREA OF MUCH DRIER AIR MOVING
OVER THE CAROLINAS LATE THURS INTO FRIDAY WITH VALUES DOWN AS LOW
AS 1.4 INCHES. BY LATE FRI INTO EARLY SAT THE VALUES SHOOT BACK UP
TO CLOSE TO 2 INCHES.
OVERALL WARM AND HUMID SUMMERTIME WEATHER WILL PREVAIL WITH RETURN
FLOW AROUND BERMUDA HIGH. THIS WILL KEEP TEMPS AT OR ABOVE
NORMAL...ESPECIALLY OVERNIGHT WITH TEMPS RUNNING IN THE LOWER 70S
MOST PLACES. DAYTIME HIGH TEMPS WILL BE WITHIN A FEW DEGREES OF
90. THE COMBINATION OF VERY WARM TEMPS AND HIGH HUMIDITY WILL MAKE
IT FEEL AS IF TEMPS WILL BE OVER 100 DEGREES EACH AFTERNOON FOR A
FEW HOURS.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 400 AM WEDNESDAY...DEEP SOUTHERLY RETURN FLOW WILL INCREASE AS
MID TO UPPER TROUGH DIGS DOWN FROM THE GREAT LAKES INTO THE
TENNESSEE VALLEY THROUGH THE WEEKEND. THIS WILL PUSH A COLD FRONT
INTO THE CAROLINAS BY LATE SUNDAY. INITIALLY THE GRADIENT WILL
TIGHTEN BETWEEN A MORE PRONOUNCED PIEDMONT TROUGH AND BERMUDA HIGH
BUT THIS WILL BE FURTHER ENHANCED AS FRONT APPROACHES FROM THE
NORTHWEST. WE WILL LOSE THE SUBSIDENCE AND DRIER AIR THROUGH THE
MID LEVELS GIVING WAY TO A GREATER CHC OF CONVECTION THROUGH THE
WEEKEND INTO EARLY NEXT WEEK. THE GFS SHOWS A MINOR PERTURBATION
RIDING UP THROUGH THE AREA IN THE SW FLOW ON SAT AFTN AND THEN THE
MAIN TROUGH APPROACHES LATE SUN INTO MON. THE ACTUAL BOUNDARY
LOOKS LIKE IT WILL WEAKEN AS IT MOVES TOWARD THE AREA WITHOUT
ACTUALLY MAKING IT THROUGH BUT IT WILL SEE INCREASED CONVECTIVE
ACTIVITY ALONG AND AHEAD OF IT THROUGH EARLY NEXT WEEK IN A VERY
MOIST AND MORE UNSTABLE ATMOSPHERE. THE WINDS WILL INCREASE OUT
OF THE SW TO WEST STEERING THE CONVECTION TOWARD THE COAST.
OVERALL EXPECT A MORE ACTIVE PERIOD SUNDAY THROUGH TUES.
WARM AND HUMID WEATHER CONTINUES WITH TEMPS REMAINING RIGHT AROUND
NORMAL WITH OVERNIGHT LOWS ON THE WARM SIDE. TEMPS MAY BE MODIFIED
BY DAILY CONVECTION AND CLOUDS IN A MORE ACTIVE PERIOD OF
CONVECTION...ESPECIALLY LATE SUNDAY THROUGH MONDAY.
&&
.AVIATION /18Z WEDNESDAY THROUGH SUNDAY/...
AS OF 18Z...THE INTERACTION OF AN UPPER IMPULSE WITH SEA BREEZE AND
MESOSCALE SFC BOUNDARIES SHOULD RESULT IN SCATTERED SHOWERS/T-STORMS
THIS AFTN. CONVECTIVE ACTIVITY MAY BE FOCUSED MORE OVER THE SOUTHERN
TERMS...KFLO/KMYR/KCRE...WHERE BETTER SFC HEATING IS OCCURRING. THE
LATEST HRRR RUNS FAVOR THIS SOLUTION...SO WILL INCLUDE VCTS FOR
THESE TERMS THRU THE AFTN HOURS. VFR WILL PREVAIL TODAY WITH THE
POSSIBILITY OF TEMPO MVFR/IFR IN STORMS. THE WINDS WILL BECOME
LIGHT/CALM OVERNIGHT...BUT RESIDUAL LOW/MID-LEVEL MOISTURE MAY
SOMEWHAT INHIBIT FOG FORMATION. WILL STILL INCLUDE MVFR VSBYS AT ALL
TERMS EARLY THURSDAY...WITH THE BEST CHANCES FOR IFR FOG INLAND AT
KFLO AND KLBT.
EXTENDED OUTLOOK...EARLY MORNING FOG POSSIBLE DURING THE EXTENDED
PERIOD. INCREASING CHANCES FOR SHOWERS/T-STORMS SATURDAY THROUGH
MONDAY. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM WEDNESDAY...SOMEWHAT VARIABLE WINDS ARE EXPECTED TODAY
AND TONIGHT UNDER A BIT OF A WEAK GRADIENT. EXPECT LIGHT W TO NW
WINDS THIS MORNING TO BECOME SE TO S THIS AFTERNOON THEN S TO SW
TONIGHT. SPEEDS LOOK TO BE 10 KT OR LESS WITH SEAS AROUND 2 FT.
SEAS COMPRISED OF SE WAVES 2 FEET AT 7-8 SECONDS WITH ONLY LIGHT
CHOP ANTICIPATED...AND MOSTLY NEAR SHORE IN THE AFTERNOON. TSTMS
MAY IMPACT THE WATERS TODAY AND TONIGHT...WITH STEERING WINDS
GUIDING ANY STORMS THAT DEVELOP FROM THE NORTH TO THE SOUTH.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 400 AM WEDNESDAY...BERMUDA HIGH TAKES HOLD AS IT EXPANDS
WESTWARD OVER LOCAL WATERS. THIS WILL PRODUCE A SOUTHERLY RETURN
FLOW THROUGH THE PERIOD. THURSDAY WILL START OUT WITH LIGHTER FLOW
OF 10 KTS OR SO BUT AS GRADIENT TIGHTENS BETWEEN PIEDMONT TROUGH
OF INLAND CAROLINAS AND BERMUDA HIGH...WIND WILL INCREASE OUT OF
THE SOUTH THROUGH LATE FRI INTO SAT. THE PERSISTENT AND INCREASING
SOUTHERLY FLOW WILL PUSH SEAS UP FROM 2 TO 3 FT THURS INTO FRI TO
3 TO 5 FT BY FRI NIGHT AND POSSIBLY TOPPING SCA THRESHOLDS BY SAT
MORNING. WINDS WILL BE GUSTY AND HIGHER EACH AFTERNOON IN SEA
BREEZE.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 400 AM WEDNESDAY...INCREASING AND PERSISTENT SOUTHERLY FLOW
AROUND BERMUDA HIGH WILL DRIVE SEAS UP TOWARD SCA THRESHOLDS EARLY
SATURDAY. THE GRADIENT WILL REMAIN TIGHT THROUGH SATURDAY INTO
SUNDAY AS COLD FRONT APPROACHES THE CAROLINAS FROM THE NORTHWEST
AND PIEDMONT TROUGH REMAINS ACROSS INLAND CAROLINAS. THE WINDS
INITIALLY WILL BE 15 KTS OR LESS BUT WILL INCREASE UP TO 15 TO 20
KTS...ESPECIALLY IN THE OUTER WATERS THROUGH SATURDAY INTO SUNDAY.
THIS INCREASING SOUTHERLY PUSH WILL KEEP SEAS UP RIGHT AROUND
ADVISORY LEVELS...NEAR 6 FT IN OUTER WATERS AND 3 TO 5 ELSEWHERE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...8
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...BJR/8
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
142 PM EDT WED JUL 17 2013
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE WILL BE THE DOMINATING WEATHER FEATURE
THROUGH FRIDAY. THE HIGH PRESSURE WAS CENTERED OVER OHIO AND WILL
GRADUALLY SLIDE SOUTHEAST INTO THE CAROLINAS BY FRIDAY. A COLD FRONT
WILL MOVE SOUTHEAST ACROSS THE AREA SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BOOSTED PARTS OF THE NW TO CHANCE POPS. SUBSTANTIAL CU FIELD IS
DEVELOPING INTO SCATTERED SHOWERS AND STORMS ACROSS SRN LWR MI AS
PRE THE HRRR MODEL FORECAST. BELIEVE THIS WILL EXTEND INTO PARTS
OF NWRN OHIO AS WELL. ALSO EXTENDED THE SLIGHT CHANCE FOR NERN
OHIO INTO CRAWFORD COUNTY PA AND THEN IN TIME INTO THE AFTERNOON.
PREVIOUS DISCUSSION...
THE HEAT IS ON. THE DOG DAYS OF SUMMER HAVE ARRIVED AS A
VERTICALLY STACKED DOME OF HIGH PRESSURE FROM 500 MB DOWN THE
SURFACE REMAINS IN PLACE TODAY. THE HIGH PRESSURE WILL CONTINUE TO
PUMP HIGH DEW POINT AIR INTO THE FORECAST AREA TODAY WITH DEW
POINTS REACHING THE MIDDLE 70S...ESPECIALLY NEAR LAKE ERIE AND
WESTERN THIRD OF THE FORECAST AREA. THE COMBINATION OF THE HIGH
DEW POINTS AND RESULTING HIGH HUMIDITY ALONG WITH HOT AIR
TEMPERATURES WILL CAUSE HEAT INDEX VALUES TO REACH BETWEEN 100 AND
104 THIS AFTERNOON INTO THE EVENING HOURS. SO...WE DECIDED TO
HOIST A HEAT ADVISORY FOR THE WESTERN THIRD OF THE FORECAST AREA
FOR TODAY. THE REST OF THE FORECAST AREA WILL STILL BE HOT AND
HUMID BUT WILL KEEP HEAT INDEXES DOWN TO BETWEEN 98 AND 99 DURING
THE AFTERNOON AND EVENING.
AS FAR AS THUNDERSTORMS GO...THE SUPPRESSION OF THE HIGH PRESSURE
OVERHEAD...DECIDED TO NOT MENTION THUNDERSTORMS ANY PLACE IN THE
FORECAST AREA. THERE COULD BE AN ISOLATED THUNDERSTORM THAT DEVELOPS
BUT AREAL COVERAGE SHOULD BE SO MINIMAL THAT IT IS NOT WORTH
MENTIONING AT THIS TIME.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
THE DOME OF HIGH PRESSURE IS EXPECTED TO MOVE SLOWLY SOUTHEAST
TONIGHT INTO FRIDAY. THIS WILL SHIFT THE SUPPRESSION FROM THE HIGH
TO THE SOUTH. HOWEVER...THE HEAT AND HUMIDITY WILL CONTINUE TONIGHT
MAKING IT FEEL VERY UNCOMFORTABLE FOR SLEEPING. THE HEAT CONTINUES
TOMORROW WITH A GOOD CHANCE THAT WE WILL NEED TO HOIST ANOTHER HEAT
ADVISORY FOR A MUCH LARGER AREA. HEAT INDEX VALUES ONCE AGAIN REACH
BETWEEN 100 AND 104 DURING THE AFTERNOON AND EVENING HOURS ON
THURSDAY. LITTLE CHANGE IF ANY IS EXPECTED THURSDAY NIGHT INTO
FRIDAY AS HOT MUGGY CONDITIONS CONTINUE.
A REPRIEVE ARRIVES ON SATURDAY AS A COLD FRONT SLIPS SOUTH ACROSS
THE AREA. THIS SHOULD KNOCK TEMPERATURES DOWN A FEW PEGS AND
DEFINITELY LOWER DEW POINT TEMPERATURES AS WELL. THIS SHOULD RESULT
IN NOTICEABLY COOLER TEMPERATURES AND HUMIDITY LEVELS.
AS THE FRONT MOVES THROUGH THE AREA...THE POTENTIAL EXISTS FOR THE
THREAT OF SHOWERS AND THUNDERSTORMS ACROSS THE AREA.
THEREFORE...WILL HOLD ON TO THE LIKELY CATEGORY. MOISTURE ASSOCIATED
WITH THE COLD FRONT EXITS TO THE SOUTH FAIRLY QUICKLY AND WILL GO
AHEAD AND END THE THREAT FOR SHOWERS AND THUNDERSTORMS FROM NORTH TO
SOUTH IN THE AFTERNOON. FAIR WEATHER RETURNS AGAIN FOR SATURDAY
NIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
A COOLER AREA OF HIGH PRESSURE WILL BE BUILDING INTO THE REGION ON
SUNDAY IN THE WAKE OF A COLD FRONT THAT SHOULD BE NEAR THE EAST
COAST. AN UPPER LEVEL TROUGH WILL THEN TAKE UP RESIDENCE ACROSS THE
GREAT LAKES REGION FOR MONDAY INTO TUESDAY. THERE MAY BE A PIECE OF
JET ENERGY THAT MOVES THROUGH THIS TROUGH FROM LATE MONDAY INTO
TUESDAY. THIS WILL BRING INCREASING CHANCES OF THUNDERSTORMS. THE
STRONGER PIECE OF ENERGY WILL LIKELY NOT ARRIVE UNTIL WEDNESDAY.
TEMPERATURES SUNDAY INTO MONDAY MAY BE SLIGHTLY BELOW SEASONAL
AVERAGES BUT WE WILL WARM AHEAD OF THE NEXT COLD FRONT THAT WILL
ARRIVE WEDNESDAY INTO THURSDAY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
CONTINUED VFR CONDITIONS. ISOLATED AFTERNOON SHRA/TS WOULD LIKELY
BE ISOLATED TO JUST THE TOLEDO AREA. OTHERWISE FOCUS IS SOUTHEAST
OF OUR SITES. MAY HAVE SOME PATCHY MVFR BR/HZ TOWARD THU MORNING
BUT NOT MUCH. VFR AGAIN THURSDAY WITH EVEN LESS OF A CHANCE FOR
SHRA/TS.
.OUTLOOK...NON VFR IN PATCHY EARLY MORNING FOG.
&&
.MARINE...
HIGH PRESSURE CENTERED OVER THE WESTERN OHIO RIVER VALLEY WILL
GRADUALLY WEAKEN AS IT SHIFTS SOUTHEAST THROUGH FRIDAY. AS A COLD
FRONT APPROACHES ON FRIDAY IT APPEARS THAT SOUTHWESTERLY WINDS WILL
BE ON THE INCREASE. WINDS MAY INCREASE TO 15 TO 25 KNOTS ALLOWING
WAVES TO BUILD TO 3 TO 5 FEET FOR THE OPEN WATERS AND EASTERN HALF
OF THE LAKE. THESE STRONGER WINDS WILL PERSIST UNTIL A COLD FRONT
PASSES FRIDAY NIGHT INTO EARLY SATURDAY. SO WITH THAT SAID IT
APPEARS A SMALL CRAFT ADVISORY WILL BE NEEDED FRIDAY INTO AT LEAST
SATURDAY MORNING. HIGH PRESSURE WILL BUILD OVER THE LAKE SATURDAY
NIGHT INTO SUNDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR OHZ003-006>011-
013-017>023-027>033-036>038-047.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...TK/LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...MULLEN
AVIATION...OUDEMAN
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1216 PM EDT WED JUL 17 2013
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE WILL BE THE DOMINATING WEATHER FEATURE
THROUGH FRIDAY. THE HIGH PRESSURE WAS CENTERED OVER OHIO AND WILL
GRADUALLY SLIDE SOUTHEAST INTO THE CAROLINAS BY FRIDAY. A COLD FRONT
WILL MOVE SOUTHEAST ACROSS THE AREA SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BOOSTED PARTS OF THE NW TO CHANCE POPS. SUBSTANTIAL CU FIELD IS
DEVELOPING INTO SCATTERED SHOWERS AND STORMS ACROSS SRN LWR MI AS
PRE THE HRRR MODEL FORECAST. BELIEVE THIS WILL EXTEND INTO PARTS
OF NWRN OHIO AS WELL. ALSO EXTENDED THE SLIGHT CHANCE FOR NERN
OHIO INTO CRAWFORD COUNTY PA AND THEN IN TIME INTO THE AFTERNOON.
PREVIOUS DISCUSSION...
THE HEAT IS ON. THE DOG DAYS OF SUMMER HAVE ARRIVED AS A
VERTICALLY STACKED DOME OF HIGH PRESSURE FROM 500 MB DOWN THE
SURFACE REMAINS IN PLACE TODAY. THE HIGH PRESSURE WILL CONTINUE TO
PUMP HIGH DEW POINT AIR INTO THE FORECAST AREA TODAY WITH DEW
POINTS REACHING THE MIDDLE 70S...ESPECIALLY NEAR LAKE ERIE AND
WESTERN THIRD OF THE FORECAST AREA. THE COMBINATION OF THE HIGH
DEW POINTS AND RESULTING HIGH HUMIDITY ALONG WITH HOT AIR
TEMPERATURES WILL CAUSE HEAT INDEX VALUES TO REACH BETWEEN 100 AND
104 THIS AFTERNOON INTO THE EVENING HOURS. SO...WE DECIDED TO
HOIST A HEAT ADVISORY FOR THE WESTERN THIRD OF THE FORECAST AREA
FOR TODAY. THE REST OF THE FORECAST AREA WILL STILL BE HOT AND
HUMID BUT WILL KEEP HEAT INDEXES DOWN TO BETWEEN 98 AND 99 DURING
THE AFTERNOON AND EVENING.
AS FAR AS THUNDERSTORMS GO...THE SUPPRESSION OF THE HIGH PRESSURE
OVERHEAD...DECIDED TO NOT MENTION THUNDERSTORMS ANY PLACE IN THE
FORECAST AREA. THERE COULD BE AN ISOLATED THUNDERSTORM THAT DEVELOPS
BUT AREAL COVERAGE SHOULD BE SO MINIMAL THAT IT IS NOT WORTH
MENTIONING AT THIS TIME.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
THE DOME OF HIGH PRESSURE IS EXPECTED TO MOVE SLOWLY SOUTHEAST
TONIGHT INTO FRIDAY. THIS WILL SHIFT THE SUPPRESSION FROM THE HIGH
TO THE SOUTH. HOWEVER...THE HEAT AND HUMIDITY WILL CONTINUE TONIGHT
MAKING IT FEEL VERY UNCOMFORTABLE FOR SLEEPING. THE HEAT CONTINUES
TOMORROW WITH A GOOD CHANCE THAT WE WILL NEED TO HOIST ANOTHER HEAT
ADVISORY FOR A MUCH LARGER AREA. HEAT INDEX VALUES ONCE AGAIN REACH
BETWEEN 100 AND 104 DURING THE AFTERNOON AND EVENING HOURS ON
THURSDAY. LITTLE CHANGE IF ANY IS EXPECTED THURSDAY NIGHT INTO
FRIDAY AS HOT MUGGY CONDITIONS CONTINUE.
A REPRIEVE ARRIVES ON SATURDAY AS A COLD FRONT SLIPS SOUTH ACROSS
THE AREA. THIS SHOULD KNOCK TEMPERATURES DOWN A FEW PEGS AND
DEFINITELY LOWER DEW POINT TEMPERATURES AS WELL. THIS SHOULD RESULT
IN NOTICEABLY COOLER TEMPERATURES AND HUMIDITY LEVELS.
AS THE FRONT MOVES THROUGH THE AREA...THE POTENTIAL EXISTS FOR THE
THREAT OF SHOWERS AND THUNDERSTORMS ACROSS THE AREA.
THEREFORE...WILL HOLD ON TO THE LIKELY CATEGORY. MOISTURE ASSOCIATED
WITH THE COLD FRONT EXITS TO THE SOUTH FAIRLY QUICKLY AND WILL GO
AHEAD AND END THE THREAT FOR SHOWERS AND THUNDERSTORMS FROM NORTH TO
SOUTH IN THE AFTERNOON. FAIR WEATHER RETURNS AGAIN FOR SATURDAY
NIGHT.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
A COOLER AREA OF HIGH PRESSURE WILL BE BUILDING INTO THE REGION ON
SUNDAY IN THE WAKE OF A COLD FRONT THAT SHOULD BE NEAR THE EAST
COAST. AN UPPER LEVEL TROUGH WILL THEN TAKE UP RESIDENCE ACROSS THE
GREAT LAKES REGION FOR MONDAY INTO TUESDAY. THERE MAY BE A PIECE OF
JET ENERGY THAT MOVES THROUGH THIS TROUGH FROM LATE MONDAY INTO
TUESDAY. THIS WILL BRING INCREASING CHANCES OF THUNDERSTORMS. THE
STRONGER PIECE OF ENERGY WILL LIKELY NOT ARRIVE UNTIL WEDNESDAY.
TEMPERATURES SUNDAY INTO MONDAY MAY BE SLIGHTLY BELOW SEASONAL
AVERAGES BUT WE WILL WARM AHEAD OF THE NEXT COLD FRONT THAT WILL
ARRIVE WEDNESDAY INTO THURSDAY.
&&
.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
PATCHY MVFR FOG WILL OCCUR THROUGH 13Z...MAINLY WHERE IT RAINED
YESTERDAY AFTERNOON. OTHERWISE EXPECT TO SEE VFR CONDITIONS
THROUGH THE DAY. THERE ARE A FEW SHOWERS OVER NE OHIO MOVING
TOWARD KYNG SO WE HAVE PLACED A VICINITY SHOWER IN THE TAF THROUGH
15Z.
OTHERWISE THERE IS A DECENT CAP ACROSS THE AREA TODAY. HOWEVER A
COUPLE OF THE MODELS ARE INDICATING SOME WEAK CONVERGENCE ACROSS
THE WESTERN COUNTY WARNING AREA. SO WE CANT COMPLETELY RULE OUT AN
ISOLATED STORM OR TWO NEAR KFDY BUT CHANCES OF THIS OCCURRING ARE
WAY TOO LOW TO MENTION IN THE TAF.
.OUTLOOK...NON VFR IN PATCHY EARLY MORNING FOG.
&&
.MARINE...
HIGH PRESSURE CENTERED OVER THE WESTERN OHIO RIVER VALLEY WILL
GRADUALLY WEAKEN AS IT SHIFTS SOUTHEAST THROUGH FRIDAY. AS A COLD
FRONT APPROACHES ON FRIDAY IT APPEARS THAT SOUTHWESTERLY WINDS WILL
BE ON THE INCREASE. WINDS MAY INCREASE TO 15 TO 25 KNOTS ALLOWING
WAVES TO BUILD TO 3 TO 5 FEET FOR THE OPEN WATERS AND EASTERN HALF
OF THE LAKE. THESE STRONGER WINDS WILL PERSIST UNTIL A COLD FRONT
PASSES FRIDAY NIGHT INTO EARLY SATURDAY. SO WITH THAT SAID IT
APPEARS A SMALL CRAFT ADVISORY WILL BE NEEDED FRIDAY INTO AT LEAST
SATURDAY MORNING. HIGH PRESSURE WILL BUILD OVER THE LAKE SATURDAY
NIGHT INTO SUNDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR OHZ003-006>011-
013-017>023-027>033-036>038-047.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...TK/LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...MULLEN
AVIATION...MULLEN
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1155 AM CDT WED JUL 17 2013
.AVIATION...
A VERY MOIST SELY TROPICAL INFLOW FROM THE GULF INTO S TX WILL
PERSIST FOR THE NEXT 24 HOURS. THEREFORE VARIABLE CONDITIONS
PREVAILING WITH IFR-MVFR CIGS OFTEN GIVING WAY TO VFR CONDITIONS IN
THE AFTERNOON...WITH MVFR-IFR CONDITIONS GENERALLY PREVAILING IN
THE OVERNIGHT INTO THE MID MORNING HOURS. CIGS AND VSBYS WILL
QUICKLY LOWER TO MVFR-IFR IN THE SCT SHRA/ISOLD TSRA THRU THE
PERIOD. E-SELY WINDS PREVAILING AT 5-15 KNOTS.
&&
.PREV DISCUSSION... /ISSUED 1122 AM CDT WED JUL 17 2013/
UPDATE...
POPS CURRENTLY APPEAR A BIT OVERDONE FOR SOUTH CENTRAL TEXAS BASED
ON LATE MORNING RADAR LOOPS...BUT CONVECTION BUILDING OVER THE
COASTAL BEND SUGGESTS MUCH MORE RAIN COVERAGE WILL DEVELOP THIS
AFTERNOON. FINER RESOLUTION MODELS SUCH AS THE HRRR CONTINUE TO
INDICATE A HIGH CHANCE OF RAIN IN THE AFTERNOON HOURS. THUS THE
MORNING PACKAGE FOR RAIN AND TEMPERATURES APPEARS ON TRACK.
PREV DISCUSSION... /ISSUED 635 AM CDT WED JUL 17 2013/
AVIATION...
SCT-NUMEROUS SHRA/ISOLD TSRA CAN BE EXPECTED TODAY INTO EVENING.
HAVE TEMPO GROUPS I-35 TAFS 14Z-21Z AND KDRT 19Z-23Z. SHRA/TSRA
DECREASE LATE EVENING INTO OVERNIGHT AS AIRMASS STABILIZES AND
THEN ISOLD-SCT SHRA/TSRA REDEVELOP THURSDAY. ALTHOUGH HAVE LEFT
MENTION OUT OF TAFS DUE UNCERTAINTY ON LOCATION...CAN NOT RULE
OUT SHRA/TSRA AT TAF SITES TONIGHT OR THURSDAY AS AIRMASS REMAINS
MOIST. LIFR/IFR CIGS EARLY THIS MORNING LIFT TO VFR THIS AFTERNOON
INTO EVENING...EXCEPT LOCAL MVFR CIGS IN/NEAR SHRA/TSRA.
REDEVELOPMENT OF IFR/MVFR CIGS EXPECTED OVERNIGHT INTO THURSDAY
MORNING. ELY WINDS 5 TO 12 KTS WILL PREVAIL. EXCEPT GUSTS TO 30
KTS IN AND NEAR SHRA/TSRA THIS AFTERNOON INTO EVENING.
PREV DISCUSSION... /ISSUED 409 AM CDT WED JUL 17 2013/
SHORT TERM (TODAY THROUGH THURSDAY)...
ANOTHER ROUND OF HEAVY SHOWERS AND ISOLATED THUNDERSTORMS IS
EXPECTED ALONG THE I-35 CORRIDOR LATE THIS MORNING INTO THE
AFTERNOON HOURS AND THEN OVER THE EDWARDS PLATEAU AND RIO GRANDE
PLAINS LATE THIS AFTERNOON AND EVENING. RAINFALL AMOUNTS WILL RANGE
FROM 1/4 TO 3/4 INCH WITH LOCALIZED 1 TO 2 INCHES.
AS THE UPPER LOW LEVEL SYSTEM OVER CENTRAL NEW MEXICO EARLY THIS
MORNING MOVES TO THE SOUTHWEST AND AWAY FROM SOUTH CENTRAL TEXAS...
ANOTHER LOW TO MID LEVEL DISTURBANCE ACROSS THE NORTHWEST PORTION
OF THE GULF OF MEXICO WILL MOVE NORTHWESTWARD AND OVER SOUTH TEXAS
THROUGHOUT THE DAY. WITH PRECIPITABLE WATER VALUES RANGING FROM 2
TO 2.15 INCHES ACROSS THE I-35 CORRIDOR AND OVER THE COASTAL
PLAINS PER GROUND-BASED SATELLITE READINGS AND MODERATE
INSTABILITY...EXPECT SHOWERS AND THUNDERSTORMS TO FORM ACROSS THE
COASTAL PLAINS AND MOVE INLAND FOR MUCH OF THE DAY. LATER THIS
AFTERNOON...SHOWERS AND THUNDERSTORMS WILL BE MAINLY OVER THE
WESTERN HALF OF SOUTH CENTRAL TEXAS AS AN UPPER LEVEL RIDGE OF
HIGH PRESSURE BUILDS FROM THE NORTHEAST. THERE MAY BE SOME
LINGERING SHOWERS AND ISOLATED THUNDERSTORMS LATER TONIGHT INTO
THE OVERNIGHT HOURS...BUT OVERALL...WEATHER CONDITIONS WILL BE
IMPROVING ON THURSDAY ACROSS MOST AREAS WITH THE EXCEPTION OF
SEA-BREEZE ENHANCED CONVECTION ACROSS THE COASTAL AND RIO GRANDE
PLAINS.
LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)...
UPPER LEVEL RIDGING WILL BE DOMINATING THE REGION LATER IN THE
WEEK INTO THE UPCOMING WEEKEND WITH ONLY SEA-BREEZE ENHANCED
ACTIVITY ACROSS THE SOUTHEASTERN COUNTIES OF SOUTH CENTRAL TEXAS
EACH AFTERNOON THROUGH SUNDAY. A WARMING TREND IS ON THE WAY FOR THE
NEXT SEVERAL DAYS THANKS TO THE UPPER RIDGE. MOSTLY DRY WEATHER
CONDITIONS ARE EXPECTED FROM MONDAY AND TUESDAY OF NEXT WEEK WITH
HIGHS IN THE UPPER 90S TO NEAR 100.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 88 74 95 74 98 / 60 30 20 10 10
AUSTIN BERGSTROM INTL AIRPORT 89 72 95 71 97 / 60 30 20 10 10
NEW BRAUNFELS MUNI AIRPORT 85 71 93 71 95 / 60 30 20 10 -
BURNET MUNI AIRPORT 81 72 91 73 92 / 60 30 20 10 10
DEL RIO INTL AIRPORT 87 74 89 75 92 / 70 50 40 20 10
GEORGETOWN MUNI AIRPORT 86 72 94 73 95 / 60 30 20 10 10
HONDO MUNI AIRPORT 88 73 93 73 95 / 70 40 30 10 -
SAN MARCOS MUNI AIRPORT 85 73 93 72 96 / 60 30 20 10 10
LA GRANGE - FAYETTE REGIONAL 90 74 98 74 96 / 60 30 20 10 20
SAN ANTONIO INTL AIRPORT 85 75 93 75 95 / 60 30 20 10 -
STINSON MUNI AIRPORT 85 73 93 74 95 / 70 30 30 10 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...01
SYNOPTIC/GRIDS...08
PUBLIC SERVICE/DATA COLLECTION...12
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1122 AM CDT WED JUL 17 2013
.UPDATE...
POPS CURRENTLY APPEAR A BIT OVERDONE FOR SOUTH CENTRAL TEXAS BASED
ON LATE MORNING RADAR LOOPS...BUT CONVECTION BUILDING OVER THE
COASTAL BEND SUGGESTS MUCH MORE RAIN COVERAGE WILL DEVELOP THIS
AFTERNOON. FINER RESOLUTION MODELS SUCH AS THE HRRR CONTINUE TO
INDICATE A HIGH CHANCE OF RAIN IN THE AFTERNOON HOURS. THUS THE
MORNING PACKAGE FOR RAIN AND TEMPERATURES APPEARS ON TRACK.
&&
.PREV DISCUSSION... /ISSUED 635 AM CDT WED JUL 17 2013/
AVIATION...
SCT-NUMEROUS SHRA/ISOLD TSRA CAN BE EXPECTED TODAY INTO EVENING.
HAVE TEMPO GROUPS I-35 TAFS 14Z-21Z AND KDRT 19Z-23Z. SHRA/TSRA
DECREASE LATE EVENING INTO OVERNIGHT AS AIRMASS STABILIZES AND
THEN ISOLD-SCT SHRA/TSRA REDEVELOP THURSDAY. ALTHOUGH HAVE LEFT
MENTION OUT OF TAFS DUE UNCERTAINTY ON LOCATION...CAN NOT RULE
OUT SHRA/TSRA AT TAF SITES TONIGHT OR THURSDAY AS AIRMASS REMAINS
MOIST. LIFR/IFR CIGS EARLY THIS MORNING LIFT TO VFR THIS AFTERNOON
INTO EVENING...EXCEPT LOCAL MVFR CIGS IN/NEAR SHRA/TSRA.
REDEVELOPMENT OF IFR/MVFR CIGS EXPECTED OVERNIGHT INTO THURSDAY
MORNING. ELY WINDS 5 TO 12 KTS WILL PREVAIL. EXCEPT GUSTS TO 30
KTS IN AND NEAR SHRA/TSRA THIS AFTERNOON INTO EVENING.
PREV DISCUSSION... /ISSUED 409 AM CDT WED JUL 17 2013/
SHORT TERM (TODAY THROUGH THURSDAY)...
ANOTHER ROUND OF HEAVY SHOWERS AND ISOLATED THUNDERSTORMS IS
EXPECTED ALONG THE I-35 CORRIDOR LATE THIS MORNING INTO THE
AFTERNOON HOURS AND THEN OVER THE EDWARDS PLATEAU AND RIO GRANDE
PLAINS LATE THIS AFTERNOON AND EVENING. RAINFALL AMOUNTS WILL RANGE
FROM 1/4 TO 3/4 INCH WITH LOCALIZED 1 TO 2 INCHES.
AS THE UPPER LOW LEVEL SYSTEM OVER CENTRAL NEW MEXICO EARLY THIS
MORNING MOVES TO THE SOUTHWEST AND AWAY FROM SOUTH CENTRAL TEXAS...
ANOTHER LOW TO MID LEVEL DISTURBANCE ACROSS THE NORTHWEST PORTION
OF THE GULF OF MEXICO WILL MOVE NORTHWESTWARD AND OVER SOUTH TEXAS
THROUGHOUT THE DAY. WITH PRECIPITABLE WATER VALUES RANGING FROM 2
TO 2.15 INCHES ACROSS THE I-35 CORRIDOR AND OVER THE COASTAL
PLAINS PER GROUND-BASED SATELLITE READINGS AND MODERATE
INSTABILITY...EXPECT SHOWERS AND THUNDERSTORMS TO FORM ACROSS THE
COASTAL PLAINS AND MOVE INLAND FOR MUCH OF THE DAY. LATER THIS
AFTERNOON...SHOWERS AND THUNDERSTORMS WILL BE MAINLY OVER THE
WESTERN HALF OF SOUTH CENTRAL TEXAS AS AN UPPER LEVEL RIDGE OF
HIGH PRESSURE BUILDS FROM THE NORTHEAST. THERE MAY BE SOME
LINGERING SHOWERS AND ISOLATED THUNDERSTORMS LATER TONIGHT INTO
THE OVERNIGHT HOURS...BUT OVERALL...WEATHER CONDITIONS WILL BE
IMPROVING ON THURSDAY ACROSS MOST AREAS WITH THE EXCEPTION OF
SEA-BREEZE ENHANCED CONVECTION ACROSS THE COASTAL AND RIO GRANDE
PLAINS.
LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)...
UPPER LEVEL RIDGING WILL BE DOMINATING THE REGION LATER IN THE
WEEK INTO THE UPCOMING WEEKEND WITH ONLY SEA-BREEZE ENHANCED
ACTIVITY ACROSS THE SOUTHEASTERN COUNTIES OF SOUTH CENTRAL TEXAS
EACH AFTERNOON THROUGH SUNDAY. A WARMING TREND IS ON THE WAY FOR THE
NEXT SEVERAL DAYS THANKS TO THE UPPER RIDGE. MOSTLY DRY WEATHER
CONDITIONS ARE EXPECTED FROM MONDAY AND TUESDAY OF NEXT WEEK WITH
HIGHS IN THE UPPER 90S TO NEAR 100.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 88 74 95 74 98 / 60 30 20 10 10
AUSTIN BERGSTROM INTL AIRPORT 89 72 95 71 97 / 60 30 20 10 10
NEW BRAUNFELS MUNI AIRPORT 85 71 93 71 95 / 60 30 20 10 -
BURNET MUNI AIRPORT 81 72 91 73 92 / 60 30 20 10 10
DEL RIO INTL AIRPORT 87 74 89 75 92 / 70 50 40 20 10
GEORGETOWN MUNI AIRPORT 86 72 94 73 95 / 60 30 20 10 10
HONDO MUNI AIRPORT 88 73 93 73 95 / 70 40 30 10 -
SAN MARCOS MUNI AIRPORT 85 73 93 72 96 / 60 30 20 10 10
LA GRANGE - FAYETTE REGIONAL 90 74 98 74 96 / 60 30 20 10 20
SAN ANTONIO INTL AIRPORT 85 75 93 75 95 / 60 30 20 10 -
STINSON MUNI AIRPORT 85 73 93 74 95 / 70 30 30 10 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...01
SYNOPTIC/GRIDS...18
PUBLIC SERVICE/DATA COLLECTION...12
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1146 AM CDT WED JUL 17 2013
NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 1145 AM CDT WED JUL 17 2013
NOTICED A FEW SMALL ECHOES ON RADAR AROUND 16Z. HRRR FROM 13Z
INDICATED QUITE A FEW SPECKLES ACROSS THE AREA AROUND THIS TIME.
IN ADDITION...LOCAL MESOANALYSIS GRAPHICS INDICATED LITTLE OR NO
CONVECTIVE INHIBITION AT 16Z WITH SBCAPES OF 1000-2000J/KG IN THE
NORTH AND IN EXCESS OF 3000J/KG IN EAST CENTRAL WISCONSIN. HAVE
GONE WITH AT LEAST ISOLATED THUNDERSTORMS ACROSS THE ENTIRE AREA
FOR THESE REASONS. SPC UPDATED DAY 1 OUTLOOK TO INCLUDE A SLIGHT
RISK OF SEVERE STORMS IN THE FAR NORTH.
&&
.SHORT TERM...TODAY...TONIGHT...AND THURSDAY
ISSUED AT 407 AM CDT WED JUL 17 2013
UPPER RIDGE CENTERED OVER NORTHERN INDIANA AND
ILLINOIS IS FORECAST TO REMAIN NEARLY STATIONARY TODAY AND TONIGHT
BEFORE BEING PUSHED TO THE SOUTHEAST THURSDAY AS THE SOUTHERN EDGE OF
THE WESTERLIES MOVES SOUTHWARD. THE 500MB HEIGHTS OF 599 DM ARE
SOME OF THE HIGHEST IN RECENT MEMORY AND WOULD GENERALLY BE AT THE
CENTER OF A WELL CAPPED ENVIRONMENT THAT WOULD INHIBIT MOST CLOUD
FORMATION AND PRECIPITATION. NOT SO THIS TIME AS 850MB AND 500MB
TEMPERATURES ARE NOT THAT WARM GIVEN THE 500MB HEIGHTS. SOME
EVENTS WITH SIMILAR UPPER AIR AND SURFACE PATTERNS WERE AUGUST 1ST
AND 12TH OF 1988 AND JULY 21ST OF 1987. THOSE DATES HAD HEAT
INDICES OF 100+ GENERALLY SOUTH OF WAUSAU TO GREEN BAY...SO WILL
EXPAND HEAT ADVISORY TO INCLUDE MARATHON...SHAWANO AND MENOMINEE
COUNTIES.
LOTS OF MOISTURE AVAILABLE FOR PRECIPITATION TODAY AND TONIGHT BUT
NOT MUCH IN THE WAY OF TRIGGERS. SOME WEAK FORCING WAS PRODUCING
MIDDLE CLOUDS OVER CENTRAL AND EAST CENTRAL WISCONSIN AT 09Z.
THINK THERE WILL BE AT LEAST ISOLATED CONVECTION TODAY AND MODEL
SEEM TO FAVOR EASTERN WISCONSIN LIKELY DUE TO LAKE BREEZES AND
CONVERGENCE NEAR THE LAKE AND BAY SHORES. HIGHS TODAY SHOULD BE A
DEGREE OR SO ABOVE YESTERDAY.
UPPER HEIGHTS BEGIN TO FALL OVER NORTHERN WISCONSIN TONIGHT AS AN
ASSOCIATED SURFACE BOUNDARY DRIFTS SOUTH. THINK THIS BOUNDARY WILL
NOT MAKE AS MUCH SOUTHWARD PROGRESS AS THE UPPER FLOW IS NEARLY
PARALLEL TO THE SURFACE BOUNDARY. THAT SET UP MIGHT SET THE STAGE
FOR SOME TRAINING OF THUNDERSTORMS OVER FAR NORTHERN WISCONSIN
TONIGHT.
AN APPROACHING UPPER TROUGH SHOULD HELP PRODUCE AT LEAST SCATTERED
THUNDERSTORMS THURSDAY. CLOUD COVER AND SCATTERED STORMS MAY HOLD
TEMPERATURES DOWN A BIT BUT FOR NOW AM KEEPING THEM CLOSE TO WHAT
WE HAVE TODAY.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY
ISSUED AT 407 AM CDT WED JUL 17 2013
POTENTIAL FOR STRONG TO SEVERE THUNDERSTORMS IS THE MAIN ISSUE
THURSDAY NIGHT AND FRIDAY. INCREASING 0-6 KM SHEAR OF 30 TO 45 KNOTS
WILL SUPPORT STRONG OR SEVERE THUNDERSTORMS...ESPECIALLY ACROSS
THE NORTH THURSDAY EVENING AND INTO THE OVERNIGHT HOURS. QUESTION
IS HOW FAR SOUTH CONVECTION WILL SAG OVERNIGHT. THE MAIN THREAT WOULD
BE DAMAGING WINDS...ALTHOUGH SOME SUPER CELLS COULD PRODUCE MARGINALLY
LARGE HAIL. PRECIPITABLE WATER SHOULD BE 150 TO 200 PERCENT OF NORMAL...
THUS TORRENTIAL RAINS SHOULD BE EXPECTED WITH THE STRONGER STORMS.
SEVERE POTENTIAL FOR FRIDAY IS MUDDLED DUE TO ONGOING CONVECTION/OUTFLOW
BOUNDARIES...CLOUD COVER AND IF WE WOULD RECOVER LATER IN THE AFTERNOON.
STILL SOME UNCERTAINTY IF ONGOING CONVECTION WILL CONTINUE FRIDAY MORNING
OR WANE AND THEN REDEVELOP FRIDAY AFTERNOON. IF WE DO GET SOME SUNSHINE...
LOWERING WET BULB HEIGHTS BETWEEN 10 AND 11 THOUSAND FEET...AND 0-6KM
SHEAR OF 35 TO 45 KNOTS WOULD SUPPORT SUPER CELLS WITH LARGE HAIL...DAMAGING
WINDS. COULD NOT RULE OUT AN ISOLATED TORNADO DUE TO THE STRONG SHEAR
AND LINGERING OUTFLOW BOUNDARIES/LAKE BREEZE INTERACTIONS.
CONTINUED A LINGERING CHANCE OF SHOWERS AND STORMS ACROSS THE EAST
FRIDAY EVENING. MUCH COOLER AND MUCH LESS HUMID AIR WILL WORK INTO
THE REGION SATURDAY. DEW POINTS BY SUNDAY WILL BE IN THE MIDDLE 40S
TO LOWER 50S...OR ABOUT 20 DEGREES LOWER THAN DEW POINTS ON
WEDNESDAY AND THURSDAY.
FORECAST BECOMES MUDDLED AGAIN LATER IN THE WEEKEND INTO THE
MIDDLE PORTION OF NEXT WEEK. SOME TIMING DIFFERENCES NOTED IN THE MODELS
WITH RETURN FLOW PRECIPITATION. HELD OFF PRECIPITATION UNTIL
SUNDAY NIGHT FOR NOW. PREVAILING NORTHWEST FLOW AND RIPPLES MOVING THROUGH
THE MEAN FLOW COULD BRING A CHANCE OF SHOWERS AND STORMS EACH DAY
MONDAY THROUGH WEDNESDAY. AFTER SLIGHTLY BELOW NORMAL TEMPERATURES THIS
WEEKEND...TEMPERATURES SHOULD RETURN CLOSE TO NORMAL EARLY NEXT
WEEK.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1037 PM CDT TUE JUL 16 2013
NO REAL CHG TO AVIATION FCST REASONING. EXPECT MVFR FG TO DEVELOP
AGAIN TNGT...WITH MAYBE SOME BRIELY LOWER CONDITIONS AT GRB/ATW
WHERE RAINS OCCURED LATE THIS AFTN.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 5 PM CDT FRIDAY FOR WIZ020-030-031-035>040-
045-048>050.
&&
$$
UPDATE.........MG
SHORT TERM.....RDM
LONG TERM......KALLAS
AVIATION.......SKOWRONSKI