Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/17/15
AREA FORECAST DISCUSSION
NWS TUCSON AZ
340 AM MST WED JUL 15 2015
.SYNOPSIS...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS MOSTLY FROM
TUCSON EAST AND SOUTH THROUGH THURSDAY. THE COVERAGE OF SHOWERS AND
THUNDERSTORMS WILL EXPAND WEST OF TUCSON FRIDAY THROUGH SUNDAY DUE
TO INCREASED MOISTURE FROM TROPICAL SYSTEM DOLORES. NEAR NORMAL
DAYTIME TEMPERATURES WILL CONTINUE THROUGH THURSDAY FOLLOWED BY A
COOLING TREND FRIDAY INTO THIS WEEKEND. WARMER DAYTIME TEMPERATURES
WILL RETURN MONDAY INTO TUESDAY.
&&
.DISCUSSION...STRONG HIGH PRESSURE ALOFT WAS CENTERED OVER EAST
TEXAS AND A LOW AMPLITUDE TROUGH WAS OVER THE WESTERN CONUS EARLY
THIS MORNING. MEANWHILE...HURRICANE DOLORES WITH MAXIMUM SUSTAINED
WINDS OF 130 MPH WAS CENTERED NEAR 18N/110W...OR ABOUT 320 MILES
SOUTH OF CABO SAN LUCAS MEXICO AS PER THE 3 AM MDT NATIONAL
HURRICANE CENTER ADVISORY. MOISTURE PLUME AS PER WATER VAPOR IMAGERY
WILL CONTINUE MAINLY ACROSS CENTRAL/ERN SECTIONS OF THIS FORECAST
AREA INTO THURSDAY AS LITTLE CHANGE IN THE UPPER PATTERN WILL OCCUR.
FOR TODAY...SOME COMPLEXITY HAS BEEN INTRODUCED TO THE EVOLUTION OF
SHOWERS/TSTMS THIS AFTERNOON AND EVENING GIVEN THE COOLING CLOUD
TOPS/INCREASING COVERAGE OF SHOWERS/TSTMS OCCURRING AT THIS TIME
ACROSS ERN SECTIONS. THE SUBSEQUENT DEBRIS CLOUDINESS MAY LIMIT
SHOWER/TSTM CHANCES LATER TODAY...ESPECIALLY NEAR THE NEW MEXICO
BORDER. THE MOST RECENT HRRR SOLUTION FAVORS LOCATIONS SOUTH-TO-
SOUTHWEST OF TUCSON THIS AFTERNOON FOR THE BEST COVERAGE OF PRECIP.
THIS SOLUTION IS A DEVIATION FROM SEVERAL PREVIOUS HRRR SOLUTIONS...
THAT FAVORED A MORE NORTHWARD PROGRESSION OF SHOWERS/TSTMS THAT
WOULD GIVE A GREATER POTENTIAL FOR PRODUCING SOME BLOWING DUST
NORTHWEST OF TUCSON INTO SOUTH CENTRAL ARIZONA LATE THIS AFTERNOON
AND EVENING.
AT ANY RATE...THE OFFICIAL FORECAST DEPICTS SCATTERED SHOWERS/TSTMS
FROM TUCSON EWD TO THE NEW MEXICO BORDER THIS AFTERNOON/EVENING.
ISOLATED SHOWERS/TSTMS EXISTS ACROSS THE TOHONO O`ODHAM NATION AND
SOUTH CENTRAL PINAL COUNTY...WITH PRECIP-FREE CONDITIONS ACROSS WRN
PIMA COUNTY. PER COORD WITH WFO PSR...INTRODUCED PATCHY BLOWING DUST
GENERALLY NORTHWEST OF TUCSON LATE THIS AFTERNOON AND EARLY THIS
EVENING. AGAIN...THIS SCENARIO WILL DEPEND UPON A FARTHER NORTHWARD
PROGRESSION OF SHOWERS/TSTMS THAN DEPICTED BY THE LATEST HRRR
SOLUTION. THERE IS A SLIGHT CHANCE OF SHOWERS/TSTMS LATE TONIGHT AND
THUR MORNING MAINLY EAST TO SOUTH OF TUCSON...THEN ANOTHER ROUND OF
SCATTERED SHOWERS/TSTMS MAINLY FROM TUCSON EWD/SWD THUR AFTERNOON.
15/00Z GFS/ECMWF CONTINUED TO DEPICT INCREASING PRECIP WATER VALUES
TO OCCUR ESPECIALLY ACROSS WRN SECTIONS STARTING THUR NIGHT AND
CONTINUING INTO THIS WEEKEND. THE GFS DEPICTED PWATS BY MIDDAY SAT
TO BE NEAR 1.90 INCHES ACROSS WRN PIMA COUNTY TO AROUND ONE INCH
ACROSS THE WHITE MOUNTAINS. THESE VALUES ARE DOWN NEARLY 0.20 INCH
ACROSS WRN PIMA COUNTY VERSUS THE 14/00Z GFS.
THUS...HAVE OPTED TO MAKE ONLY VERY MINOR ADJUSTMENTS TO THE
INHERITED POPS FOR THIS FORECAST ISSUANCE. EXPECT SCATTERED TO
PERHAPS NUMEROUS SHOWERS/TSTMS FRI-SAT. THE COVERAGE OF SHOWERS/
TSTMS SAT WILL LIKELY FAVOR WRN SECTIONS VERSUS ERN LOCALES. THE
MAIN CONCERN WILL BE FOR MORE WIDESPREAD COVERAGE OF HEAVY RAINFALL
VERSUS THE PAST SEVERAL DAYS. BETTER RAINFALL CHANCES SHOULD
TRANSLATE NORTH OF THIS FORECAST AREA SUN. MOISTURE WILL REMAIN
ADEQUATE FOR CHANCE-CATEGORY POPS AREA-WIDE SUN.
THEREAFTER...THE GFS DEPICTED A SUBSTANTIAL DRYING TREND BY NEXT
TUE...WITH PRECIP WATER VALUES PROGGED TO RANGE FROM 0.50 - 0.75
INCH. BELIEVE THIS DRYING TREND IS TOO AGGRESSIVE...ALTHOUGH A
GRADUAL REDUCTION IN SHOWER/TSTM COVERAGE EARLY NEXT WEEK SHOULD
OCCUR. THUS...HAVE CONTINUED WITH A RETURN OF ISOLATED TO SCATTERED
SHOWERS/TSTMS MAINLY FROM TUCSON EWD/SWD BY TUE.
HIGH TEMPS TODAY AND THURSDAY WILL GENERALLY BE WITHIN A COUPLE OF
DEGS OF NORMAL FOR MUCH OF THE AREA. A COOLING TREND IS ON TAP FRI-
SAT...AND DAYTIME TEMPS SUN ARE FORECAST TO BE ABOUT 5-8 DEGS F
BELOW NORMAL. HIGH TEMPS ARE FORECAST TO RETURN CLOSE TO SEASONAL
NORMALS NEXT TUE.
&&
.AVIATION...VALID THRU 16/12Z.
EXPECT SCATTERED -TSRA/-SHRA FROM KTUS VICINITY EASTWARD AND
SOUTHWARD TO THE NEW MEXICO/INTERNATIONAL BORDERS GENERALLY AFTER
18Z TODAY AND CONTINUING INTO THIS EVENING. ISOLD -TSRA/-SHRA WILL
PREVAIL MAINLY EAST OF KTUS LATE TONIGHT INTO THURSDAY MORNING. THE
STRONGER TSRA WILL PRODUCE WIND GUSTS AROUND 35-45 KTS ESPECIALLY
THIS AFTERNOON AND EARLY THIS EVENING. OTHERWISE...CLOUD DECKS WILL
MOSTLY BE ABOVE 10K FT AGL AND SURFACE WIND WILL BE LESS THAN 10 KTS
INTO THURSDAY MORNING. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS MAINLY
FROM TUCSON EAST AND SOUTH THROUGH THURSDAY. BRIEF GUSTY WINDS AND
LOCALLY HEAVY RAINFALL WILL OCCUR WITH THE STRONGER THUNDERSTORMS.
THE COVERAGE OF SHOWERS AND THUNDERSTORMS WILL THEN EXPAND WESTWARD
FRIDAY THROUGH SUNDAY TO INCLUDE FIRE ZONE 150. A RETURN OF SHOWERS
AND THUNDERSTORMS MAINLY FROM TUCSON EAST AND SOUTH SHOULD OCCUR BY
THE MIDDLE OF NEXT WEEK. OTHERWISE...GENERALLY LIGHT TERRAIN DRIVEN
WINDS WILL PREVAIL WITH AFTERNOON GUSTS DUE TO DAYTIME HEATING.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
DISCUSSION...FRANCIS
AVIATION/FIRE WEATHER...CERNIGLIA
AREA FORECAST DISCUSSION
NWS TUCSON AZ
930 PM MST TUE JUL 14 2015
.SYNOPSIS...ADEQUATE MOISTURE WILL PROVIDE A CHANCE OF SHOWERS AND
THUNDERSTORMS MOSTLY FROM TUCSON EAST AND SOUTH THROUGH FRIDAY.
INCREASED MOISTURE FROM TROPICAL SYSTEM DOLORES SHOULD ENHANCE
RAINFALL CHANCES AREA WIDE THIS WEEKEND. NEAR NORMAL DAYTIME
TEMPERATURES WILL CONTINUE THROUGH THURSDAY FOLLOWED BY RELATIVELY
COOLER TEMPERATURES BY THIS WEEKEND.
&&
.DISCUSSION...ISOLATED STRONG STORMS LATE THIS AFTERNOON INTO THE
EARLY EVENING HOURS. ALSO HAD SOME AREAS WHERE FLOODING ISSUES WERE
ALSO A CONCERN. AS OF THIS WRITING...A FEW LIGHT SHOWERS WERE
OCCURRING ACROSS SRN COCHISE COUNTY WITH ISOLATED STORM NORTH OF
TUCSON. LATEST HRRR RUNS KEEP ISOLATED ACTIVITY DURING THE OVERNIGHT
HOURS. WILL RUN A QUICK UPDATE TO THE FORECAST FOR THE OVERNIGHT
TIME FRAME. ANOTHER ROUND OF STORMS ONCE AGAIN WEDNESDAY AFTERNOON
AND EVENING.
&&
.AVIATION...VALID THRU 16/00Z.
ISOLD -TSRA/-SHRA MAINLY EAST OF KTUS LATE TNGT INTO WED AM. CLOUD
DECKS NR STORMS MAINLY 7-11K FT OTRW DEBRIS CLOUDS WILL BE DCRSG
OVRNGT. SFC WIND OVRNGT INTO WED AM MAINLY LESS THAN 10 KTS. ANOTHER
ROUND OF TSRA/SHRA IS EXPECTED FROM KTUS EWD WED AFTN INTO THE
EVENING HOURS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS MAINLY
EAST OF FIRE WEATHER ZONE 150 THROUGH THURSDAY. BRIEF GUSTY WINDS...
LOCALLY HEAVY RAINFALL...AND FREQUENT LIGHTNING WILL OCCUR WITH THE
STRONGER THUNDERSTORMS. INCREASED MOISTURE FROM TROPICAL SYSTEM
DOLORES WILL ENHANCE RAINFALL CHANCES AREA-WIDE STARTING FRIDAY AND
LASTING THROUGH THE UPCOMING WEEKEND. A REDUCTION IN SHOWER AND
THUNDERSTORM ACTIVITY SHOULD THEN OCCUR EARLY NEXT WEEK. OUTSIDE OF
ANY AREAS OF PRECIPITATION...GENERALLY LIGHT TERRAIN DRIVEN WINDS
WILL PREVAIL WITH OCCASIONAL AFTERNOON GUSTS DUE TO DAYTIME HEATING.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1120 PM MDT TUE JUL 14 2015
.UPDATE...
ISSUED AT 550 PM MDT TUE JUL 14 2015
BUMPED UP POPS OVER FAR EASTERN PLAINS AND MENTIONED HEAVY RAIN IN
THE NDFD. /HODANISH
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 300 PM MDT TUE JUL 14 2015
UPPER LEVEL HIGH PRESSURE REMAINS CENTERED OVER TX THIS
AFTERNOON...KEEPING MOIST SSW MID LEVEL FLOW IN PLACE ACROSS
COLORADO. LOWER LEVELS HAVE CONTINUED TO MOISTEN TODAY...AS SURFACE
DEWPOINTS ARE RUNNING AROUND 10F HIGHER THAN 24 HRS AGO. OVER THE
MOUNTAINS...CAPES ARE IN THE 500-1000 J/KG RANGE...WHILE CAPE OVER
THE PLAINS ALONG THE NM AND KS BORDERS EXCEEDS 1000 J/KG. RELATIVE
MIN IN THE INSTABILITY FIELD LIES OVER EL PASO/PUEBLO/CROWLEY/OTERO
COUNTIES...WHERE DEWPOINTS HAVE DROPPED OFF INTO THE MID TO UPPER
40S...LEADING TO CAPES GENERALLY IN THE 400-800 J/KG RANGE.
CONVECTIVE STRENGTH AND COVERAGE SO FAR TODAY HAS THUS BEEN HIGHER
THAN YESTERDAY MOST AREAS...AND WITH WEAK LEE SURFACE TROUGH OVER
THE PLAINS ENHANCING LOW LEVEL WINDS SLIGHTLY...APPEARS THERE WILL
BE AT LEAST A LOW THREAT OF SEVERE STORMS OVER THE FAR EASTERN
PLAINS...AS 0-6KM SHEAR CLIMBS ABOVE 30 KTS FOR A TIME LATE THIS
AFTERNOON/EARLY THIS EVENING. WHILE WATER VAPOR LOOP SUGGESTS
STRONGEST UPPER WAVE IS FAIRLY FAR TO THE SOUTH OVER SERN
AZ...STREAM OF WEAKER WAVES EMBEDDED IN THE MOIST PLUME WILL
CONTINUE PUSH OVER THE AREA LATE THIS AFTERNOON INTO
TONIGHT...HELPING TO KEEP CONVECTION GOING PAST SUNSET...ESPECIALLY
OVER THE MOUNTAINS AND ACROSS THE FAR EASTERN PLAINS ALONG THE KS
BORDER. MESOSCALE MODELS SUPPORT THIS IDEA...WITH MAIN CLUSTER OF
CONVECTION OVER THE PLAINS THIS EVENING PUSHING INTO KS TOWARD
06Z...WITH HRRR SHOWING A SECONDARY AREA OF MOUNTAIN CONVECTION
MOVING INTO THE I-25 CORRIDOR THIS EVENING. APPEARS MOST STORMS WILL
THEN FADE AWAY BY EARLY WED MORNING...THOUGH CONVECTIVE DEBRIS
CLOUDS MAY LINGER LONG ENOUGH TO KEEP MINS RATHER MILD.
ON WEDNESDAY...MOISTURE LEVELS ACROSS THE MOUNTAINS DON`T CHANGE
VERY MUCH...LEADING TO ANOTHER ROUND OF SCATTERED CONVECTION OVER
MOST HIGH TERRAIN LOCATIONS IN THE AFTERNOON. OVER THE I-25 CORRIDOR
AND EASTERN PLAINS...MODELS SHOW LOW LEVEL WINDS BECOMING WEAKLY
WESTERLY THROUGH THE DAY...SHUNTING THE DEEPER MOISTURE AND
INSTABILITY INTO KS BY LATE AFTERNOON. STILL ENOUGH RESIDUAL
MOISTURE IN PLACE TO PRODUCE ISOLATED TO LOW END SCATTERED
CONVECTION...THOUGH EXPECT BOTH COVERAGE AND INTENSITY TO DECREASE
AS SURFACE LAYER DRIES. MAX TEMPS DRIFT DOWNWARD JUST SLIGHTLY WED
AS MID LEVEL TEMPS COOL...THOUGH READINGS MOST LOCATIONS WILL END UP
WITHIN A COUPLE DEGF OF TUESDAY`S READINGS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 300 PM MDT TUE JUL 14 2015
MODELS CONTINUE TO HAVE ISSUES IN THE EXTENDED PERIOD WITH
DIFFERENCES BETWEEN THE OPERATIONAL SOLUTIONS AND HIGH ENSEMBLE
SPREADS. BOTH THE ECMWF AND GFS ARE IN AGREEMENT THAT SOMETHING
WILL MOVE ACROSS THE AREA...BUT THERE ARE BIG DIFFERENCES IN
TIMING AND TRACK.
WEDNESDAY NIGHT...AN UPPER LEVEL DISTURBANCE WILL BE MOVING ACROSS
THE REGION WEDNESDAY EVENING AND INTO THE CENTRAL PLAINS BY
THURSDAY MORNING. MODELS CONTINUE TO DEVELOP A THUNDERSTORM
COMPLEX ACROSS THE EASTERN PLAINS AND TRACK IT EAST THROUGH THE
OVERNIGHT HOURS. THERE CONTINUE TO BE MODEL DIFFERENCES...WITH
SEVERAL SOLUTIONS ACROSS NORTHEAST COLORADO...AND OTHER OVER
SOUTHEASTERN COLORADO. THUNDERSTORMS THAT DO DEVELOP OVER THE
PLAINS WILL BE CAPABLE OF HEAVY RAINFALL AND AN ELEVATED FLASH
FLOOD RISK...ESPECIALLY WHERE THE STRONG STORMS EXIST. EXPECT
SHOWERS AND THUNDERSTORMS TO SHIFT EAST INTO KANSAS BY THURSDAY
MORNING.
THURSDAY THROUGH SATURDAY...HIGH PRESSURE IS FORECAST TO SIT OVER
TEXAS AND A TROUGH WILL REMAIN OVER THE WEST COAST WITH PERSISTENT
SOUTHWEST FLOW ACROSS COLORADO. SEVERAL EMBEDDED DISTURBANCES IN
THE FLOW WILL LEAD TO NEAR DAILY SHOWERS AND THUNDERSTORMS OVER
THE MOUNTAINS. MODEST STEERING FLOWS ALOFT WILL LIKELY HELP PUSH
THIS ACTIVITY OUT INTO THE I-25 CORRIDOR THROUGH THE EVENING HOURS
BEFORE DISSIPATING AFTER SUNSET. THUNDERSTORMS WILL BE CAPABLE OF
PRODUCING LOCALLY HEAVY RAINFALL AND STRONG THUNDERSTORM WIND
GUSTS. TEMPERATURES WILL REMAIN WARM WITH 90S ACROSS THE LOWER
ELEVATIONS.
SUNDAY THROUGH TUESDAY...MODEL DIFFERENCES BEGIN TO DIVERGE SUNDAY
INTO EARLY NEXT WEEK. BOTH THE ECMWF AND GFS RETROGRADE THE HIGH
PRESSURE FROM TEXAS INTO THE DESERT SOUTHWEST WHILE THE TROUGH
OVER THE WEST COAST EJECT TO THE EAST. THE GFS IS FURTHEST SOUTH
WITH THE UPPER TROUGH...BRINGING IT ACROSS THE AREA SUNDAY INTO
MONDAY WITH WIDESPREAD SHOWERS AND THUNDERSTORMS ACROSS THE
REGION BEFORE DRYING OUT TUESDAY. LOCALLY HEAVY RAINFALL WOULD BE
POSSIBLE WITH A CONTINUED RISK OF FLOODING. THE ECMWF BRINGS THE
UPPER TROUGH ACROSS TO THE NORTH AND SENDS A COLD FRONT ACROSS THE
AREA ON SUNDAY AFTERNOON. IT BRINGS A QUICK SHOT OF WIDESPREAD
SHOWERS AND THUNDERSTORMS TO THE AREA SUNDAY. BY MONDAY THE ECMWF
IS MUCH DRIER WITH WEAK HIGH PRESSURE BUILDING ACROSS THE AREA AND
THE MAIN ENERGY TRACK TO THE SOUTH. GIVEN THE UNCERTAINTY...HAVE
LOW POPS ACROSS THE AREA SUNDAY THROUGH TUESDAY...WITH SUNDAY AND
MONDAY POTENTIALLY BEING WET ACROSS THE AREA. MOZLEY
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1115 PM MDT TUE JUL 14 2015
VFR CONDITIONS ARE ANTICIPATED AT DURING THE NEXT 24H AT ALL 3 TAF
SITES...KPUB...KALS AND KCOS. WINDS WILL BE LIGHT AND DIURNALLY
DRIVEN. ISOLATED TSRA WILL BE POSSIBLE TOMORROW AFTERNOON AT EACH
TAF SITE...BUT PROBABILITY OF OCCURRENCE IS TOO LOW TO MENTION
EXPLICITLY IN TAF PRODUCT.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HODANISH
SHORT TERM...PETERSEN
LONG TERM...MOZLEY
AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS ALBANY NY
511 AM EDT WED JUL 15 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTHEASTWARD ACROSS THE REGION TODAY. WITH
ITS PASSAGE THE HUMID AIRMASS IN PLACE WILL BE REPLACED BY A MUCH
DRIER ONE. HIGH PRESSURE WILL BUILD IN TONIGHT AND MOVE EASTWARD
ACROSS THE REGION THURSDAY...EVENTUALLY SHIFTING OFFSHORE FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A COLD FRONT IS MOVING INTO THE LOCAL AREA FROM THE SAINT
LAWRENCE VALLEY. STORMS ARE EXPECTED TO DEVELOP AHEAD OF THE COLD
FRONT IN THE MOIST AIRMASS ACROSS THE AREA. THE ACTIVITY IS
EXPECTED TO BE MAINLY SOUTH OF THE CAPITAL DISTRICT WHERE THERE
WILL BE SOME INSTABILITY. HAVE NO MENTION OF THUNDER FROM THE
CAPITAL DISTRICT NORTHWARD. PWATS ARE HIGH AROUND 1.5 INCHES SO
ANY STORM WILL BE CAPABLE OF PRODUCING HEAVY DOWNPOURS. ALSO FLOW
ACROSS THE AREA REMAINS WEAK SO THE STORMS WILL BE SLOW MOVERS
WHICH COULD LEAD TO SOME URBAN AND POOR DRAINAGE FLOODING.
WITH THE PASSAGE OF THE BOUNDARY A MUCH DRIER AIRMASS WILL BEGIN
TO FILTER INTO THE REGION ON A NORTHERLY WIND WITH DEW POINTS
DROPPING INTO THE 50S TODAY AND EVEN INTO THE UPPER 40S ACROSS
SOUTHERN ADIRONDACKS BY THIS EVENING. ALSO CLOUDS WILL GIVE WAY TO
INCREASING SUNSHINE ESPECIALLY THIS AFTERNOON.
HIGHS TODAY WILL RANGE FROM A COOL MID/UPPER 60S ACROSS THE
WESTERN ADIRONDACKS TO THE LOWER 80S ACROSS THE MID HUDSON VALLEY
INTO NORTHWESTERN CONNECTICUT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
MUCH COOLER AND DRIER TONIGHT AS HIGH PRESSURE BUILDS IN FROM
CANADA. EXPECTING LOWS TO DROP INTO THE 40S ACROSS MAINLY THE
HIGHER TERRAIN WITH LOWER TO MID 50S ELSEWHERE. WITH LIGHT TO CALM
WIND AND MAINLY CLEAR SKIES SOME PATCHY FOG IS EXPECTED MAINLY IN
VALLEY LOCATIONS.
FAIR WEATHER THROUGH FRIDAY. THE SURFACE HIGH WILL MOVE EASTWARD
PASSING OVER THE REGION THURSDAY NIGHT AND SHIFTING OFFSHORE FRIDAY.
WHILE ALOFT THE FLOW BECOMES ZONAL ACROSS THE NORTHERN CONUS.
THURSDAY WILL BE MOSTLY SUNNY AND DRY WITH HIGHS MAINLY IN THE 70S
ABOUT 5 DEGREES BELOW NORMAL FOR MID JULY. DEW POINTS ARE EXPECTED
TO BE IN THE MID TO UPPER 40S. ANOTHER COOL NIGHT THURSDAY WITH
LOWS SIMILAR TO WEDNESDAY`S NIGHT.
FRIDAY WILL BE WARMER AS A RETURN FLOW SETS UP AS THE SURFACE HIGH
SHIFTS OFFSHORE AND DEW POINTS WILL RISE INTO THE 50S. EXPECTING
SEASONABLE HIGHS IN THE MID 70S TO LOWER 80S.
A SHORT WAVE WILL BE APPROACHING THE REGION IN THE FAST ZONAL FLOW
FRIDAY NIGHT SO CHANCES FOR SHOWERS RETURN TO THE FORECAST.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
ALTHOUGH UNSETTLED WEATHER IS EXPECTED THROUGH MUCH OF THE LONG TERM
PERIOD...PRECIP WILL BE MAINLY SCATTERED IN NATURE AND ANY ONE
PARTICULAR LOCATION WON/T SEE A LONG DURATION WASHOUT THROUGH THE
ENTIRE PERIOD.
AN UPPER LEVEL DISTURBANCE WILL SLIDE BY TO THE NORTH OF THE REGION
FOR SATURDAY INTO SATURDAY NIGHT...AND A SURFACE WARM FRONT WILL BE
SITUATED CLOSE TO THE REGION AS WELL. THE COMBINATION OF THESE TWO
FEATURES COULD ALLOW FOR THE CHANCE OF SOME SHOWERS AND
THUNDERSTORMS...WITH THE BEST CHANCE FOR NORTHERN AREAS...PRIMARILY
DURING THE DIURNALLY FAVORED AFTN AND EARLY EVENING HOURS. STILL TOO
EARLY TO SPECULATE ON JUST HOW STRONG ANY THUNDERSTORM ACTIVITY
COULD BE...AS THERE MAY BE A DECENT AMOUNT OF INSTABILITY PRESENT
THANKS TO SURFACE HEATING...ALTHOUGH 0-6 BULK SHEAR AMOUNTS LOOK
TO BE FAIRLY LIMITED. TEMPS CLOSE TO SEASONAL NORMALS...WITH HIGHS
IN THE UPPER 70S TO MID 80S...AND LOWS IN THE 60S.
HEIGHTS WILL RISE SOMEWHAT FOR SUNDAY INTO MONDAY WITH WARMING TEMPS
ALOFT. STILL...CANNOT RULE OUT A SHOWER OR THUNDERSTORM DURING THESE
DAYS...ESP FOR THE AFTN AND EVENING HOURS...THANKS TO A NEARBY
STALLED SFC FRONTAL BOUNDARY. WITH MID LEVEL LAPSE RATES ONLY AROUND
5.5 TO 6 DEGREES C/KM AND 0-6 BULK SHEAR VALUES MAINLY 25 KTS OR
LESS...IT MAY BE TOUGH FOR ANY STORMS TO GET VERY STRONG ON SUNDAY
INTO MONDAY...BUT WILL CONTINUE TO MONITOR MODEL TRENDS. HIGHS WILL
BE WARMER IN THE MID TO UPPER 80S FOR VALLEY AREAS...AND LOWS IN THE
MID TO UPPER 60S. IT WILL BE MUGGY AS WELL...WITH DEWPOINTS WELL
INTO THE 60S AS WELL.
A STRONGER UPPER LEVEL DISTURBANCE AND FRONTAL BOUNDARY LOOKS TO
CROSS THE REGION FOR MONDAY NIGHT INTO TUESDAY. THIS WILL BRING THE
BEST CHANCE DURING THE LONG TERM PERIOD OF
SHOWERS/THUNDERSTORMS...ALTHOUGH THE EXACT TIMING OF THIS FEATURE IS
STILL SOMEWHAT UNCERTAIN. WITH THE VERY HUMID CONDITIONS AHEAD OF
THIS FEATURE...THERE COULD POTENTIALLY BE SOME HEAVY RAINFALL WITH
ANY THUNDERSTORMS. TEMPS LOOK CLOSE TO SEASONAL NORMALS. DRIER AND
LESS HUMID CONDITIONS LOOK TO OCCUR TOWARDS THE MIDDLE OF THE WEEK
BEHIND THIS FEATURE WITH CONTINUED NEAR NORMAL TEMPS.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
A FRONTAL SYSTEM IS IN THE PROCESS OF MOVING ACROSS THE REGION.
AHEAD OF THIS SYSTEM...A VERY MOIST AIRMASS IS IN PLACE...ALONG
WITH SOME SCATTERED RAIN SHOWERS. ACCORDING TO RADAR TRENDS AND
THE 12KM NAM AND 3KM HRRR GUIDANCE...IT APPEARS SOUTHERN AREAS
WILL HAVE THE BEST CHANCE OF SEEING SHOWERS THROUGH THE REMAINDER
OF THE OVERNIGHT HOURS. BETWEEN CHANCE FOR PRECIP...LOW
STRATUS...AND SOME FOG OVERNIGHT...KPSF IS MOST LIKELY TO SEE AN
EXTENDED PERIOD OF IFR CONDITIONS THROUGH SUNRISE WEDNESDAY. KPOU
WILL LIKELY SEE A PERIOD OF MVFR CIGS...AND POSSIBLY A BRIEF
PERIOD OF IFR CIGS AS WELL. FURTHER NORTH...CANNOT RULE OUT SOME
MVFR CIGS FOR KGFL/KALB...BUT IFR CONDITIONS APPEARS LESS LIKELY.
WINDS WILL BE NEARLY CALM AHEAD OF THE BOUNDARY BUT CHANGE TO THE
N-NW BEHIND THE FRONTAL BOUNDARY ON WEDNESDAY MORNING. THIS WILL
ALSO END THE THREAT FOR RAIN SHOWERS...AND ALLOW CIGS TO GRADUALLY
SCT OUT BY AFTN. VFR CONDITIONS LOOK TO RETURN BEHIND THE
BOUNDARY...AND THIS WILL BE IN PLACE FOR THE REMAINDER OF
WEDNESDAY INTO WEDNESDAY NIGHT.
OUTLOOK...
THU NIGHT-FRI: NO OPERATIONAL IMPACT. NO SIG WX.
FRI NIGHT-SUN: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
SUN NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...TSRA.
MON: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
&&
.FIRE WEATHER...
A COLD FRONT WILL MOVE SOUTHEASTWARD ACROSS THE REGION TODAY. WITH
ITS PASSAGE THE HUMID AIRMASS IN PLACE WILL BE REPLACED BY A MUCH
DRIER ONE. HIGH PRESSURE WILL BUILD IN TONIGHT AND MOVE EASTWARD
ACROSS THE REGION THURSDAY...EVENTUALLY SHIFTING OFFSHORE FRIDAY.
UNSETTLED WEATHER IS EXPECTED OVER THE WEEKEND.&&
.HYDROLOGY...
A COLD FRONT WILL SOUTHEASTWARD ACROSS THE REGION TODAY WITH
STORMS EXPECTED MAINLY SOUTH OF THE CAPITAL DISTRICT. PWATS ARE
HIGH AROUND 1.5 INCHES SO ANY STORM WILL BE CAPABLE OF PRODUCING
HEAVY DOWNPOURS. ALSO FLOW ACROSS THE AREA REMAINS WEAK SO THE
STORMS WILL BE SLOW MOVERS WHICH COULD LEAD TO SOME URBAN AND POOR
DRAINAGE FLOODING.
FAIR WEATHER EXPECTED TONIGHT THROUGH FRIDAY AS HIGH PRESSURE
DOMINATES. UNSETTLED WEATHER EXPECTED OVER THE WEEKEND WITH
PRECIPITATION MAINLY SCATTERED IN NATURE.
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.
&&
.EQUIPMENT...
OUR RADAR /KENX/ IS OUT OF SERVICE WITH PARTS ON EMERGENCY ORDER.
THE RADAR IS EXPECTED TO BE DOWN AT LEAST INTO THIS AFTERNOON.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA
NEAR TERM...IAA
SHORT TERM...IAA
LONG TERM...FRUGIS
AVIATION...FRUGIS
FIRE WEATHER...IAA
HYDROLOGY...IAA
EQUIPMENT...ALY STAFF
AREA FORECAST DISCUSSION
NWS ALBANY NY
148 AM EDT WED JUL 15 2015
.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL PASS TO OUR SOUTH AS A COLD FRONT
MOVES SOUTHEASTWARD ACROSS THE REGION WEDNESDAY. THIS WILL KEEP
THE WEATHER UNSETTLED ACROSS THE AREA WITH BETTER CHANCES FOR
STORMS TO THE SOUTH AND EAST OF THE CAPITAL DISTRICT. CANADIAN
HIGH PRESSURE WILL BRING A RETURN TO DRY WEATHER WEDNESDAY NIGHT
THROUGH FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SHOWERS ARE OCCURRING MAINLY TO THE WEST OF THE HUDSON RIVER VALLEY
ACROSS A PORTION OF THE SOUTHERN ADIRONDACKS AND EASTERN CATSKILLS.
THE MESOSCALE MODELS ARE NOT HANDLING CURRENT CONVECTION WELL
HOWEVER THE OVERALL TREND IS THAT THE CONVECTION WILL WEAKEN AS IT
MOVES EASTWARD. WITH A SURFACE LOW PASSING TO OUR SOUTH AND A COLD
FRONT OVER THE SAINT LAWRENCE RIVER VALLEY AND HEADING SOUTHEASTWARD
HAVE MAINTAINED POPS ACROSS AREA OVERNIGHT.
MUGGY NIGHT WITH OVERNIGHT LOWS MAINLY IN THE 60S WITH DEW POINTS
IN 60S AS WELL.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
BY EARLY WEDNESDAY...THE SURFACE COLD FRONT SHOULD HAVE SLIPPED SOUTH
OF I-90. HOWEVER...THE UPPER LEVEL TROUGH MIGHT LAG A LITTLE
BEHIND...KEEPING THINGS UNSETTLED INITIALLY...EVEN NORTH OF THE
FRONT. THE DAY WILL START WITH PLENTY OF CLOUDS AND CHANCES FOR
SHOWERS FROM ALBANY NORTH...WHILE FURTHER SOUTH SHOWERS WILL BE LIKELY
WITH STILL THE CHANCE FOR THUNDERSTORMS.
BY MIDDAY...CLOUDS SHOULD BEGIN TO CLEAR IN OUR NORTHERN AREAS...REACHING
IN THE CAPITAL REGION DURING THE AFTERNOON. IT MIGHT REMAIN MOSTLY
CLOUDY WITH RESIDUAL SHOWERS AND POSSIBLY ANOTHER THUNDERSTORM IN
OUR SOUTHERN AREAS MUCH OF THE AFTERNOON.
BASED ON UPSTREAM OBS AND LOTS OF CLOUDS TOMORROW...IT WILL TURN
NOTICEABLY COOLER BEHIND THE FRONT WITH A NORTHERLY BREEZE KICKING
IN. WHILE NOT GOING AS LOW AS THE MET GUIDANCE WE ACTUALLY SIDED A
LITTLE MORE WITH IT...THAN THE WARMER MAV NUMBERS. THAT MEANS HIGHS WILL
ONLY REACH AROUND 70 IN OUR NORTHERN ZONES (DESPITE SEEING SOME
CLEARING EARLIER)...MID 70S CAPITAL REGION AND NEAR 80 SOUTH WHERE
THE FRONT AGAIN WILL BE LAST TO CLEAR. DEWPOINTS LOOK TO PLUNGE TO
THE 40S NORTH AND WEST OF ALBANY DURING THE AFTERNOON...50S LOCALLY IN THE
CAPITAL REGION. TO THE SOUTH...DEWPOINTS STARTING OUT NEAR 70...WILL
BE TRIMMED BACK TO THE 60S BY LATE IN THE DAY.
A NORTHERLY BREEZE WILL KICK IN AROUND 10 MPH...BUT COULD GUST OVER
20 MPH AT TIMES.
BY WEDNESDAY NIGHT...A MUCH DRIER AIRMASS WILL WORK IN
EVERYWHERE...CLEARING THE SKY AND MAKING FOR A REFRESHINGLY COOLER
NIGHT. A LIGHT NORTH BREEZE WILL CONTINUE IN MOST AREAS. OVERNIGHT
LOWS LOOK TO DROP INTO THE LOWER TO MID 50S ACROSS MOST AREAS...BUT
DOWN INTO THE MID TO UPPER 40S ACROSS OUR NORTHERN AREAS.
THURSDAY LOOKS LIKE A BEAUTIFUL DAY WITH A FEW CU FORMING. OTHERWISE
IT WILL BE SUNNY WITH RATHER LOW HUMIDITY (DEWPOINTS FROM THE MID
40S TO LOWER 50S) AND HIGH TEMPERATURES 75-80 IN THE VALLEYS...70-75
HIGHER TERRAIN.
THURSDAY NIGHT HIGH PRESSURE WILL CREST OVER THE REGION BRINGING
ANOTHER MAINLY CLEAR AND COOL NIGHT. LOOK FOR LOWS AGAIN LOWER TO
MID 50S ALBANY SOUTH...MID TO UPPER 40S MOST OTHER AREAS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE EXTENDED FORECAST OPENS WITH DRY WEATHER TO CLOSE THE
WORK WEEK...AS A SFC ANTICYCLONE DRIFTS EAST OF NEW ENGLAND BY THE
AFTERNOON. THE CLOSED H500 ANTICYCLONE CONTINUES TO BE CENTERED
NEAR TX...AND THE LOWER MS RIVER VALLEY. THE NRN PERIPHERY OF THE
MID LEVEL RIDGE CONTINUES TO HAVE FLAT RELATIVELY FAST FLOW ALOFT AS
WE ENTER THE WEEKEND. A LOW PRESSURE SYSTEM WILL BE MOVING ACROSS
THE UPPER MIDWEST AND WRN GREAT LAKES REGION FRIDAY AFTERNOON. A
WARM FRONT EXTENDING EAST/SOUTHEAST OF THE WAVE WILL ALLOW MID AND
HIGH CLOUDS TO INCREASE FROM THE WEST LATE IN DAY...AND INTO THE
NIGHT PERIOD. THE GFS/ECMWF/WPC GUIDANCE CONTINUE TO HAVE SOME
ISOLD-SCT SHOWERS AND PERHAPS SOME ISOLD THUNDERSTORM INCREASING
FROM WEST TO EAST OVER THE FCST AREA...ESPECIALLY AFTER MIDNIGHT DUE
TO THE WEAK ISENTROPIC LIFT AHEAD OF THE BOUNDARY. THE BETTER CHC
OF SHOWERS AND ISOLD THUNDERSTORMS LOOKS TO BE NORTH AND WEST OF THE
CAPITAL DISTRICT AND MID HUDSON VALLEY. HIGHS ON FRIDAY WILL BE IN
THE U70S TO L80S IN THE VALLEY AREAS...AND 70S OVER THE MTNS. LOWS
FRI NIGHT WILL RANGE FROM THE MID 50S TO L60S OVER THE FCST AREA.
SAT-SAT NIGHT...THE FIRST WEAK SFC LOW LIFTS NORTH AND EAST OF THE
REGION...AND THE WARM FRONT MAY LIFT NORTH OF MOST OF THE FCST AREA.
IN THE WARM SECTOR...SFC DEWPTS MAY GET WELL INTO THE 60S. MODERATE
AMOUNTS OF SFC BASED INSTABILITY MAY SET UP OVER THE FCST AREA IF
ENOUGH HEATING OCCURS. THE LATEST GFS HAS SBCAPES OF 1000-2000 J/KG
FROM ABOUT THE HUDSON RIVER VALLEY WESTWARD BY 00Z/SUN. SOME STRONG
THUNDERSTORMS WITH HEAVY RAINFALL WILL BE POSSIBLE AS PWATS MAY RISE
A STANDARD DEVIATION OR SO ABOVE NORMAL. CHANCES OF SHOWERS AND
THUNDERSTORMS ARE POSSIBLE ESPECIALLY SATURDAY AFTERNOON INTO THE
EARLY EVENING WITH HIGHS IN THE M70S TO L80S OVER THE FCST AREA.
EXPECTING THE SHOWERS AND THUNDERSTORMS TO DECREASE OVERNIGHT WITH
MUGGY CONDITIONS WITH LOWS IN THE 60S. THE WEAK SYSTEM LIFTS NORTH
AND EAST...AND THE COLD FRONT LOOKS TO WASH OUT NEAR THE FCST AREA.
SUNDAY INTO TUESDAY...THE H500 RIDGE CENTERED OVER THE SRN
PLAINS/SOUTHEAST MAY AMPLIFY A BIT AS WE CLOSE THE WEEKEND. THIS
WILL ALLOW THE OLD COLD FRONT TO MOVE BACK NORTH AND EAST OF UPSTATE
NY AND NEW ENGLAND AS A WARM FRONT. THE ECMWF ACTUALLY SHOWS A
RELATIVELY DRY SUNDAY...WITH THE NEXT DISTURBANCE APPROACHING FROM
THE GREAT LAKES REGION. THE GFS/CMC/ENSEMBLES AND WPC GUIDANCE
INDICATE MORE SHOWERS AND THUNDERSTORMS MAY OCCUR ALONG AND BEHIND
THE WARM FRONT. A CHC OF SHOWERS AND THUNDERSTORM WAS KEPT IN THE
FCST TO CLOSE THE WEEKEND. TEMPS MAY NUDGE A TAD ABOVE NORMAL WITH
MID AND U80S IN THE VALLEYS...AND U70S TO L80S OVER THE HIGHER
PEAKS. SCATTERED SHOWERS PERSIST INTO THE EARLY EVENING...AS
A STICKY AIR MASS CONTINUES OVER THE FCST AREA.
MONDAY MAY FEATURE AIR MASS OR DIFFERENTIAL HEATING ISOLD-SCT
THUNDERSTORMS TIED TO THE PEAK DIURNAL HEATING WELL IN ADVANCE OF
THE NEXT SYSTEM APPROACHING FROM THE GREAT LAKES REGION. IT MAY NOT
BE A COMPLETE WASHOUT. A PROGRESSIVE NRN STREAM TROUGH WILL BE
MOVING OVER THE NRN GREAT LAKES REGION AND S-CNTRL ONTARIO MON NIGHT
INTO TUESDAY. THERE IS A BETTER CHC OF SCT SHOWERS AND
THUNDERSTORMS AHEAD OF THE COLD FRONT AND A PREFRONTAL SFC TROUGH.
SOME HEAVY LOCALLY HEAVY RAINFALL WILL BE POSSIBLE WITH PWATS
POTENTIALLY 1-2 STD DEVS ABOVE NORMAL ON THE GEFS AS WE HEAD INTO
EARLY NEXT WEEK. HIGHS AND LOWS STILL LOOK A LITTLE ABOVE NORMAL AS
WE MOVE INTO EARLY NEXT WEEK.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
A FRONTAL SYSTEM IS IN THE PROCESS OF MOVING ACROSS THE REGION.
AHEAD OF THIS SYSTEM...A VERY MOIST AIRMASS IS IN PLACE...ALONG
WITH SOME SCATTERED RAIN SHOWERS. ACCORDING TO RADAR TRENDS AND
THE 12KM NAM AND 3KM HRRR GUIDANCE...IT APPEARS SOUTHERN AREAS
WILL HAVE THE BEST CHANCE OF SEEING SHOWERS THROUGH THE REMAINDER
OF THE OVERNIGHT HOURS. BETWEEN CHANCE FOR PRECIP...LOW
STRATUS...AND SOME FOG OVERNIGHT...KPSF IS MOST LIKELY TO SEE AN
EXTENDED PERIOD OF IFR CONDITIONS THROUGH SUNRISE WEDNESDAY. KPOU
WILL LIKELY SEE A PERIOD OF MVFR CIGS...AND POSSIBLY A BRIEF
PERIOD OF IFR CIGS AS WELL. FURTHER NORTH...CANNOT RULE OUT SOME
MVFR CIGS FOR KGFL/KALB...BUT IFR CONDITIONS APPEARS LESS LIKELY.
WINDS WILL BE NEARLY CALM AHEAD OF THE BOUNDARY BUT CHANGE TO THE
N-NW BEHIND THE FRONTAL BOUNDARY ON WEDNESDAY MORNING. THIS WILL
ALSO END THE THREAT FOR RAIN SHOWERS...AND ALLOW CIGS TO GRADUALLY
SCT OUT BY AFTN. VFR CONDITIONS LOOK TO RETURN BEHIND THE
BOUNDARY...AND THIS WILL BE IN PLACE FOR THE REMAINDER OF
WEDNESDAY INTO WEDNESDAY NIGHT.
OUTLOOK...
THURSDAY INTO FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF
SHRA...TSRA.
SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA...TSRA.
SATURDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA...TSRA.
SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA...TSRA.
SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA.
MONDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
&&
.FIRE WEATHER...
MOST AREAS SHOULD SEE SOME SHOWERS AND POSSIBLY A
THUNDERSTORM TONIGHT INTO EARLY WEDNESDAY WITH AVERAGE RAINFALL
GENERALLY A QUARTER INCH OR MORE...WHILE SOME AREAS LOCALLY RECEIVING UP TO
AN INCH OR MORE.
A COOLER DRIER CANADIAN AIR MASS WILL BEGIN TO TAKE HOLD LATER
WEDNESDAY AND ESPECIALLY WEDNESDAY NIGHT. DRY WEATHER IS
EXPECTED THURSDAY AND FRIDAY. TEMPERATURES WILL BE A LITTLE LOWER
THAN NORMAL ON THURSDAY...TRENDING TOWARD SEASONAL ON FRIDAY.
THE NEXT CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE SATURDAY.
&&
.HYDROLOGY...
A BROAD AREA OF LOW PRESSURE WILL MOVE SLOWLY EASTWARD ACROSS THE
REGION THROUGH WEDNESDAY. IN THE MEANTIME...A COLD FRONT WILL
APPROACH FROM THE NORTHWEST AND WILL CROSS THE REGION WEDNESDAY.
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL OCCUR AS THESE
FEATURES MOVE ACROSS THE REGION.
AVERAGE BASIN RAINFALL AMOUNTS WILL BE FROM A QUARTER TO THREE
QUARTERS OF AN INCH...BUT THERE WILL BE LOCALIZED AREAS POSSIBLY
EXCEEDING AN INCH.
WITH PWATS MAXING OUT BETWEEN 1.5-2 INCHES...ANY SHOWER OR THUNDERSTORM
COULD PRODUCE ENOUGH RAINFALL TO PRODUCE LOCALIZED PONDING OF
WATER ON ROADWAYS PERHAPS EVEN SOME URBAN FLOODING.
DRIER WEATHER RETURNS LATER WEDNESDAY INTO FRIDAY WITH THE NEXT
CHANCE OF SHOWERS AND THUNDERSTORMS RETURNING ON SATURDAY.
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.
&&
.EQUIPMENT...
OUR RADAR /KENX/ IS DOWN UNTIL WEDNESDAY AFTERNOON...AND
EMERGENCY PARTS ARE ON ORDER. WE APOLOGIZE FOR THE INCONVENIENCE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA/HWJIV/BGM
NEAR TERM...HWJIV/BGM
SHORT TERM...HWJIV
LONG TERM...WASULA
AVIATION...FRUGIS
FIRE WEATHER...HWJIV
HYDROLOGY...IAA/HWJIV
EQUIPMENT...WFO ALY STAFF
AREA FORECAST DISCUSSION
NWS NEW YORK NY
142 AM EDT WED JUL 15 2015
.SYNOPSIS...
A WARM FRONT REMAINS TO THE SOUTH OVERNIGHT...AS LOW PRESSURE
WILL BE APPROACHING LATE TONIGHT AND PASSES TO THE SOUTH
WEDNESDAY. THIS LOW MOVES SOUTHEAST OF LONG ISLAND WEDNESDAY NIGHT
AS A CANADIAN HIGH BUILDS IN FROM THE NORTHWEST. THIS HIGH
CONTINUES TO GRADUALLY BUILD CLOSER TO THE LOCAL REGION THROUGH
FRIDAY. A WARM FRONT WILL MOVE TOWARD THE AREA FRIDAY NIGHT INTO
SATURDAY MORNING AND REMAIN NEAR THE AREA THROUGH SATURDAY NIGHT.
THE WARM FRONT LIFTS WELL NORTH OF THE AREA SUNDAY NIGHT INTO
MONDAY. A COLD FRONT SLOWLY APPROACHES THE AREA FOR THE BEGINNING
OF THE NEW WORK WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
LATEST RADAR TRENDS 00Z NAM ALONG WITH LATEST RUC AND HRRR SUPPORT
EARLY CHANGE TO MAINLY DRY FORECAST FOR THE REMAINDER OF TONIGHT.
IT APPEARS THAT NEGATIVE VORTICITY ADVECTION AT 700-500 HPA WILL
BE THE DOMINATE PLAYER. THUS...HAVE REDUCED POPS LATE TONIGHT TO
20 PERCENT AND SCALED BACK TO ONLY W 1/4 OF CWA (MAINLY W OF
HUDSON). MIGHT SEE SOME SHOWERS MOVE INTO W ORANGE COUNTY
AROUND/JUST AFTER 6Z...HOWEVER CONFIDENCE IN THIS IS NOT HIGH AS
HRRR APPEARS TO HAVE OVERDONE INITIAL STRENGTH/COVERAGE OF THE
CONVECTION IT IS MOVING THERE.
LOWS GENERALLY ON TRACK...WITH MAINLY UPPER 60S N TO LOWER 70S S.
UPDATED WITH BLEND OF 00Z NAM 2-METER TEMPERATURES 18Z MAV
GUIDANCE 1Z LAV AND 12Z MET GUIDANCE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/...
THERE ARE SOME INDICATIONS THAT PRECIPITATION MAY NOT DEVELOP
UNTIL LATER WEDNESDAY MORNING THAN CURRENTLY FORECAST. WILL WAIT
FOR ENTIRE 00Z SUITE TO COME IN BEFORE CHANGING FORECAST.
WEDNESDAY...A VERY ACTIVE DAY IN TERMS OF CONVECTION ESPECIALLY
BY MIDDAY. MORE ELEVATED INSTABILITY EXISTS EARLY WITH THE WARM
AND MOIST AIR ADVECTION WITH THE NOSE OF THE LOW LEVEL JET WITHIN
THE REGION. THE LOW LEVEL JET EXITS BY THE AFTERNOON AND THEN WITH
A LIGHT NE FLOW AT THE SURFACE...THERE WILL BE SOME LINGERING
SHOWERS AND THUNDERSTORMS...BUT WOULD EXPECT THE THUNDERSTORMS TO
BE WIDELY SCATTERED AT THAT POINT.
LAYER PRECIPITABLE WATERS WILL BE LOWERING FROM NW TO SE LATER BY
WEDNESDAY EVENING. SHOWERS WILL TAPER OFF FROM NW TO SE WEDNESDAY
NIGHT.
FOR HIGHS WEDNESDAY...CHOSE RELATIVELY COOLER MET/ECS GUIDANCE AND
LOWS WEDNESDAY NIGHT...CHOSE THIS BLEND AGAIN.
FOR THURSDAY THROUGH FRIDAY...A MORE QUIET AND TRANQUIL WEATHER
PATTERN IS CONVEYED BY THE MORE ZONAL FLOW GETTING ESTABLISHED IN
THE MID LEVELS WITH OVERALL...RIDGING IN MID TO UPPER LEVELS. AT
THE SURFACE...HIGH PRESSURE WILL GRADUALLY BUILD IN FROM THE GREAT
LAKES AND SOUTHEAST CANADA. DEWPOINTS WILL TREND LOWER...MAINLY IN
THE 50S...SO A MUCH LESS HUMID AIRMASS WILL BE ENTERING THE AREA.
FOR TEMPERATURES...USED MOSTLY ECE GUIDANCE WITH SOME BLENDING OF
GMOS FOR THURSDAY NIGHT AND FRIDAY.
THERE IS A MODERATE RISK FOR THE METEOROLOGICAL ENHANCEMENT OF RIP
CURRENT DEVELOPMENT AT ATLANTIC BEACHES WEDNESDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ZONAL FLOW ALOFT FRIDAY NIGHT WILL BE REPLACED BY A WEAK SHORTWAVE
THAT WILL MOVE ACROSS THE NORTHEAST FRIDAY NIGHT INTO SATURDAY
NIGHT. THEREAFTER...AN UPPER LEVEL LONGWAVE TROUGH WILL APPROACH
FROM THE MID-WEST AND GREAT LAKES REGION INTO THE BEGINNING OF THE
NEW WORK WEEK. THERE IS UNCERTAINTY WITH THE AMPLITUDE OF THIS
TROUGH AS THE 12Z ECMWF IS MUCH MORE AMPLIFIED THAN THE 12Z GFS.
THIS WILL FEED INTO THE UNCERTAINTY WITH THE SURFACE FEATURES
THROUGH THIS TIME PERIOD.
AT THE SURFACE...A WARM FRONT WILL LIFT TOWARD THE REGION FRIDAY
NIGHT...AND REMAIN NEAR THE AREA SUNDAY MORNING. THE WARM FRONT
WILL THEN LIFT WELL NORTH OF THE AREA SUNDAY INTO SUNDAY NIGHT.
THEREAFTER...THE ASSOCIATED COLD FRONT WILL APPROACH INTO THE
BEGINNING OF THE NEW WORK WEEK. THE MORE AMPLIFIED UPPER LEVEL
TROUGH IN THE 12Z ECMWF MOVES THE COLD FRONT FASTER THAN THE LESS
AMPLIFIED 12Z GFS. GIVEN THE LARGE UNCERTAINTY...WILL SIDE HEAVILY
ON WPC IN THIS TIME FRAME.
SEASONABLE...BUT WARMING TEMPERATURES THROUGH THE PERIOD AS THE WARM
FRONT INTRODUCES A WARM AND HUMID AIRMASS...WITH THE AREA ALSO BEING
WARM SECTORED FOR SUNDAY AND MONDAY.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
A WARM FRONT IS LOCATED ACROSS THE FORECAST AREA...MAINLY FROM
KEWR...TO KBDR TO JUST SOUTH OF KPVD. THIS FRONT WILL REMAIN
NEARLY STATIONARY TONIGHT AS LOW PRESSURE OVER PENNSYLVANIA TRACKS
SOUTHEAST TO THE SOUTHERN NEW JERSEY COAST BY MORNING. THIS LOW
WILL THEN CONTINUE EASTWARD ON WEDNESDAY.
CIGS AND VSBYS VARY ACROSS THE REGION FROM VFR TO SUB IFR.
THINKING THAT CONDITIONS WILL LOWER A BIT OVERNIGHT TO MVFR OR
LESS THROUGH ABOUT 15Z. ALL 00Z FORECAST GUIDANCE HINTING THAT
MOST TERMINALS BECOME VFR LATE MORNING EARLY AFTERNOON. WITH THE
FRONT NORTH OF LONG ISLAND...THINKING A PERIOD OF VFR MAY BE
LIKELY.
WITH RESPECT TO PRECIPITATION...WILL CONTINUE TO WATCH SHRA/TSTM
ACTIVITY IN CENTRAL PA WHICH IS TRACKING NE. MOST OF THE AREA
SHOULD REMAIN DRY THROUGH 12Z...HOWEVER FAR WESTERN TERMINALS MAY
BE IMPACTED. OTHERWISE...EXPECT MOSTLY DRY CONDITIONS...BUT CAN
NOT RULE OUT A STRAY SHOWER/TSTM WITH THE FRONT IN THE AREA.
PRECIPITATION BECOMES MORE NUMEROUS THIS MORNING AND AFTERNOON.
THUNDERSTORMS WILL BE POSSIBLE...BUT TOO FAR OUT TO INCLUDE IN THE
TAFS AND WOULD LIKE TO GET A BETTER HANDLE ON TIMING OF
PRECIPITATION FIRST.
MODERATE TO HIGH CONFIDENCE IN WINDS.
.OUTLOOK FOR 00Z WED THROUGH SAT...
.WED NIGHT...VFR CONDS RETURNING IN THE EVE.
.THU-FRI...VFR.
.SAT...MVFR OR LOWER POSSIBLE IN SCT SHRA/TSRA.
&&
.MARINE...
MADE MINOR CHANGES THIS UPDATE. THE FORECAST APPEARS ON TRACK.
SUB SCA CONDITIONS ARE EXPECTED TO CONTINUE ACROSS ALL WATERS
WITH A RELATIVELY WEAK PRESSURE GRADIENT IN PLACE THROUGH TONIGHT.
A SE SWELL BUILDING WEDNESDAY WILL EVENTUALLY LEAD TO HIGHER SEAS
IN ADDITION TO THE CONTINUED SOUTHERLY FETCH FOR WEDNESDAY
AFTERNOON...FROM EAST TO WEST. WESTERN OCEAN WILL NOT GET TO SCA
RANGE UNTIL WEDNESDAY EVENING. OVERALL...PRESSURE GRADIENT
INCREASE BEHIND THE LOW WEDNESDAY NIGHT AND NORTHERLY WINDS WILL
INCREASE TO 15-23 KT WITH GUSTS A FEW KT HIGHER. SCA MORE
PROBABLE FOR BOTH WINDS AND SEAS WEDNESDAY NIGHT ACROSS ALL OCEAN.
THESE SCA OCEAN CONDITIONS MAY POTENTIALLY CONTINUE INTO THURSDAY
AND THURSDAY EVENING BUT WITH SOME UNCERTAINTY...DID NOT WANT TO
EXTEND SCA YET. THE SEAS WILL BE MAIN DETERMINANT HERE.
SUB SCA CONDITIONS EXPECTED LATE THURSDAY NIGHT AND FRIDAY WITH A
WEAK PRESSURE GRADIENT WITH HIGH PRESSURE TAKING CONTROL.
NON OCEAN WATERS EXPECTED TO STAY MOSTLY BELOW SCA THROUGH FRIDAY.
WINDS AND WAVES SHOULD REMAIN BELOW SCA CRITERIA FROM FRIDAY NIGHT
THROUGH THE END OF THE LONG TERM.
&&
.HYDROLOGY...
A BASIN AVERAGE OF 1/2-3/4 INCH OF RAINFALL THROUGH WEDNESDAY
NIGHT. DUE TO THE CONVECTIVE NATURE AND RELATIVELY SLOW FORWARD
MOTION OF SHOWERS DURING THIS PERIOD...FAIRLY LARGE DEVIATIONS
FROM THIS AVERAGE WILL PROBABLY OCCUR. PINPOINTING LOCATIONS THAT
WILL RECEIVE THE GREATEST AMOUNTS...AND HOW MUCH ABOVE THE BASIN
AVERAGE THOSE LOCATIONS WOULD RECEIVE IS DIFFICULT WITH THIS
SETUP.
WHAT IS SOMEWHAT MORE CERTAIN IS THAT THE BETTER CHANCES OF
WIDESPREAD RAINFALL ACROSS THE TRI STATE AREA OCCUR LATE TONIGHT
AND WEDNESDAY. THERE WILL PROBABLY BE A FEW AREAS OF MINOR
URBAN/SMALL STREAM/POOR DRAINAGE FLOODING...BUT CONFIDENCE IN A
WIDESPREAD FLASH FLOODING SCENARIO IS TOO LOW TO GO WITH ANY WATCH
AT THIS TIME. WITH THAT SAID...LOCALIZED FLASH FLOODING WILL BE
POSSIBLE AT ANY TIME TODAY THROUGH WEDNESDAY AFTERNOON.
NO HYDROLOGIC PROBLEMS EXPECTED WEDNESDAY NIGHT THROUGH THE END OF
THE WEEK.
SCATTERED SHOWERS AND THUNDERSTORMS ARE IN THE FORECAST FOR THE
WEEKEND AND EARLY NEXT WEEK. A WIDESPREAD RAINFALL IS NOT EXPECTED.
ANY SLOW MOVING SHOWER OR THUNDERSTORM COULD PRODUCE HEAVY RAIN WITH
ISOLATED FLOODING.
&&
.TIDES/COASTAL FLOODING...
SOME TIDAL LOCATIONS ALONG WESTERN LONG ISLAND SOUND AND SOUTH
SHORE BAYS WILL PROBABLY TOUCH MINOR BENCHMARKS WITH THE CONTINUED
SOUTHEAST FETCH DURING HIGH TIDES OVERNIGHT.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 6 AM EDT
THURSDAY FOR ANZ355.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 6 AM EDT
THURSDAY FOR ANZ350-353.
&&
$$
SYNOPSIS...MALOIT/JM/JP
NEAR TERM...MALOIT
SHORT TERM...MALOIT/JM
LONG TERM...JP
AVIATION...BC/24
MARINE...MALOIT/JM/JP
HYDROLOGY...MALOIT/JM/JP
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
957 PM EDT THU JUL 16 2015
.DISCUSSION...
REMOVED PRECIP FROM OVERNIGHT ZONES. REST OF OVERNIGHT FORECAST
REMAINS THE SAME.
.AVIATION...BKN-OVC VFR THROUGH TUE NOON.
.MARINE...NOAA BUOYS RECORDIND SOUTHWEST WIND AROUND 15 KNOTS AND 3
FOOT SEAS. THE CMAN SITES AT PORT CANAVERAL AND SEBASTIAN INLET
RECORDING SOUTH TO SOUTHWEST WIND 5 TO 10 KNOTS. THE NOAA AND
SCRIPPS BUOYS WERE RECORDING 3 FOOT AND 1 TO 2 FEET RESPECTIVELY.
SOUTHWEST WINDS CONTINUE OVERNIGHT.
PREVIOUS AFD
CURRENTLY-TONIGHT...QUITE A BIT OF THE AREA HAS HAD A
SHOWER/STORM/OUTFLOW BOUNDARY. HOWEVER...THE EARLIER ONSET TODAY
WILL ALLOW FOR OUTFLOW BOUNDARIES TO GENERATE ADDITIONAL STORMS
THROUGH EARLY EVENING WHERE POCKETS OF INSTABILITY WILL LINGER.
THE LATEST HRRR SHOWS SOME RAINFALL INTO LATE EVENING...WITH
EMBEDDED THUNDER...FROM BREVARD TO OKEECHOBEE AND THE TREASURE
COAST. MOS POPS ARE AROUND 50 PERCENT THERE...SO WILL KEEP CHANCE
POPS UNTIL LATE EVENING WITH SLIGHT CHANCE ELSEWHERE. NO RAINFALL
IS EXPECTED OVERNIGHT.
FRI-SAT...PERSISTENT WET PATTERN INTO THE WEEKEND AS A DEEP
FRONTAL TROF EXTENDING FROM HUDSON BAY TO THE NORTHEAST GULF OF
MEXICO DRIFTS SEAWARD AND KEEPS THE ATLANTIC RIDGE AXIS SUPPRESSED
OVER SOUTH FLORIDA. WEST/SOUTHWEST FLOW WILL PREVAIL THROUGH THE
1000-700 MB LAYER...PINNING THE EAST COAST SEA BREEZE OVER THE
COASTAL COUNTIES WHERE IT WILL BE THE FOCUS FOR SCATTERED/NUMEROUS
SHOWERS AND STORMS. MEANWHILE...AN 850-300 MB ANTICYCLONE WILL
PUSH ACROSS THE LOWER MISSISSIPPI VALLEY AND NUDGE ITS WAY INTO
THE DEEP SOUTH...INTERACTING WITH THE FRONTAL TROF TO PROVIDE A
NORTH NORTHEAST FLOW ABV 500 MB.
THE MID/UPPER LEVEL WINDS WILL TAP AN AIRMASS OVER THE DEEP SOUTH
WITH RATHER WARM MID LEVEL TEMPS...RESULTING IN 700 MB TEMPS
EXPECTED TO WARM TO AROUND 9C WITH 500 MB TEMPS HOVERING AROUND
-6C. THE RESULTING LAPSE RATES BETWEEN 5.0-6.0C/KM THRU THE LAYER
WILL LIMIT OVERALL STORM POTENTIAL. EVEN SO...PRECIP CHANCES WILL
BE 50-60PCT AREAWIDE AS A PREFRONTAL MOISTURE BAND SETS UP ACROSS
CENTRAL FL AND KEEPS PWATS AT OR ABOVE 2.0". STORMS WILL GENERATE
LOCAL HEAVY RAIN AS THE 850-500 MB STEERING FLOW...ALREADY
WEAKENED BY THE DEEP FRONTAL TROF...REMAINS LARGELY AT OR BELOW 10KTS.
THE WEST/SOUTHWEST FLOW WILL KEEP MAX TEMPS AT OR ABOVE CLIMO WITH
AFTERNOON READINGS IN THE LOWER-MID 90S. SURFACE DEW POINTS IN
THE LOWER-MID 70S WILL KEEP MIN TEMPS ABOUT HALF A CATEGORY
HIGHER (MID-UPPER 70S).
SUN-THU...STAGNANT WEATHER PATTERN INTO THE MIDDLE OF NEXT WEEK
AS A WEAK REFLECTION OF THE FRONTAL TROF PERSISTS OFF THE
SOUTHEAST COAST AND PREVENTS THE ATLANTIC RIDGE AXIS FROM LINKING
UP WITH THE ANTICYCLONE OVER THE DEEP SOUTH. THE RESULTING COL
WILL KEEP MEAN WINDS THROUGH THE COLUMN AT OR BELOW 10 KNOTS...WITH
WEST/SOUTHWEST FLOW PERSISTING THROUGH THE 1000-700 MB LAYER. DEEP
MOISTURE WILL REMAIN TRAPPED BELOW THE COL WHILE THE ATLANTIC
RIDGE AXIS REMAINS SUPPRESSED SOUTH OF THE I-4 CORRIDOR.
THE WEAK ENVIRONMENTAL FLOW WILL ALLOW BOTH EAST AND WEST COAST
SEA BREEZES TO FORM BY MIDDAY AND PUSH WELL INLAND. THE LIGHT
WESTERLY FLOW THROUGH THE 1000-700 MB LAYER WILL ALLOW STORMS TO
CONCENTRATE OVER THE EAST FLORIDA PENINSULA...THOUGH THE WEAK
STEERING WINDS SHOULD KEEP COVERAGE AT OR BELOW 50 PERCENT. TEMPS
NEAR OR SLIGHTLY ABOVE AVERAGE FOR MID SUMMER.
&&
.AVIATION...
THE QUITE EARLY ONSET OF CONVECTION SHOULD LEAD TO A WORKED OVER
ATMOSPHERE BY SUNSET...SO WE ARE EXPECTING STRONG STORMS TO BE OVER
BY THEN. SOME LINGERING STRATIFORM RAIN WITH EMBEDDED LIGHTNING
STRIKES MAY PERSIST A LITTLE AFTER DARK FROM TIX-MLB SOUTHWARD TO
SUA. THEN THE OVERNIGHT PERIOD WILL BE MAINLY VFR.
A VERY MOIST AIR MASS ON FRI WILL LEAD TO EARLY ONSET OF CONVECTION
AGAIN. THE WEST TO EAST STEERING FLOW MAY BE A LITTLE WEAKER...
PUSHING BACK THE ONSET TIME SLIGHTLY OVER THE INTERIOR. A SEA
BREEZE COULD ALSO FORM AND BE PINNED CLOSE TO THE COAST...SO STORM
INTENSITY MAY INCREASE A NOTCH FOR THE COASTAL TERMINALS.
&&
.MARINE...
TONIGHT-FRI...SURFACE RIDGE AXIS WILL STAY SOUTH OF THE WATERS BUT
OVERALL THE PRESSURE GRADIENT SHOULD EASE AS FRONTAL TROUGH TO
THE NORTH WEAKENS. SOUTHWEST FLOW SHOULD BE NEAR 15 KNOTS OFFSHORE
TONIGHT BUT THEN DECREASE TO 10 KNOTS ON FRI. THE MAIN ISSUE FOR
MARINERS WILL CONTINUE TO BE OFFSHORE MOVING STORMS...MAINLY IN
THE AFTERNOON...BUT A FEW COULD AFFECT COASTAL SECTIONS LATE IN
THE MORNING TOO.
WEEKEND-TUE...LITTLE CHANGE IN THE MOIST PATTERN WITH SURFACE
RIDGE AXIS STAYING QUASI STEADY STATE JUST SOUTH OF THE WATERS.
THIS WILL MAINTAIN THE SOUTHWEST WIND FLOW REGIME. SPEEDS WILL BE
MAINLY 10 KNOTS OR LESS THIS WEEKEND...SO THERE SHOULD BE A SEA
BREEZE DEVELOPING. WITH THE MOIST AIR MASS...THIS WILL LIKELY
LEAD TO STRONG BOUNDARY INTERACTIONS IN THE AFTERNOON WITH A
CONTINUATION OF OUR DAILY SPECIAL MARINE WARNINGS FOR STRONG
STORMS. THE PRESSURE GRADIENT IS SHOWN TIGHTENING UP A BIT MON-
TUE WITH SOUTHWEST WINDS CLOSE TO 15 KNOTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 75 91 74 91 / 30 60 30 50
MCO 75 92 75 93 / 20 60 30 60
MLB 74 92 75 91 / 40 60 40 60
VRB 74 92 73 91 / 40 60 40 60
LEE 76 90 77 92 / 20 60 30 50
SFB 76 92 75 92 / 20 60 30 60
ORL 76 92 76 92 / 20 60 30 60
FPR 72 91 73 91 / 40 60 40 60
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
IMPACT WX...SHARP
FORECASTS...WIMMER
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
715 AM EDT WED JUL 15 2015
.Aviation...
[Through 12Z Thursday] Showers and storms are already developing
across the northeast Gulf of Mexico and adjacent coastline. Some
of the storms could affect ECP and TLH this morning prior to 15Z.
Otherwise, scattered to numerous showers and storms are expected
this afternoon with all terminals possibly affected with gusty
winds and brief IFR visibilities. More organized thunderstorms are
possible around DHN and ABY later in the afternoon, so 35 knot
gusts in a TEMPO group were maintained for those terminals. Outside
of thunderstorms, VFR conditions should generally prevail.
&&
.Prev Discussion [424 AM EDT]...
.Near Term [Through Today]...
An earlier convective line that pushed south across the northern
half of Alabama and Georgia diminished earlier tonight. However,
its effects on the boundary layer are still being observed with
a fairly expansive cold pool across the same areas - temperatures
around 70 degrees with dew points in the upper 60s. Meanwhile,
further south over our area, low-level moisture has pooled and
dew points are in the mid-upper 70s, and even into the low 80s in
some spots. Thus, the environment over our forecast area remains
relatively undisturbed and quite unstable. This is expected to set
up an active day with respect to convective activity.
Both hi-res and global models indicate considerable convective
development early this morning (10-15Z) across the far
northeastern Gulf of Mexico and into the Florida Big Bend. The
latest objective RAP analysis at 07Z indicated MLCAPE hovering
around 2500 j/kg with very little CINH over our coastal waters,
and regional radars did show some scattered convection already
developing. Hi-res models forecast thunderstorms to become quite
numerous south of a Mexico Beach to Valdosta line in the early-to-
mid morning, particularly over Taylor, Dixie, and Lafayette
Counties. PoPs were increased to 60-70% in those areas. With
precipitable water values analyzed over 2 inches, the storms could
be efficient rain producers, and hi-res models suggest some
potential for training echoes. Therefore, locally heavy rainfall
and flooding can`t be ruled out and heavy rainfall wording was
inserted into the morning forecast. The hi-res models are also
explicitly forecasting some 35-50 knot gusts, so some of the
storms may produce gusty winds as well.
The focus will then turn to the north for the afternoon and early
evening. Additional showers and storms may develop in the early-
mid afternoon along the sea breeze and/or periphery of the upper
level cloud shield associated with the morning convection.
Additionally, a cold front currently situated over Kentucky is
expected to arrive in central Alabama and central Georgia by
21-00Z. Hi-res and global models are in excellent agreement with
initiating another round of storms along that front, possibly
coalescing into one or more convective clusters/lines and then
propagating to the south into our forecast area. Those organized
linear storms, as well as any scattered early-mid afternoon storms
in areas of stronger heating across our forecast area, would pose
a risk of damaging wind gusts. NAM- and WRF-based models also show
an increase in low-level shear as surface and near-surface winds
back to the southwest and increase with the approach of the front.
Other models are less keen on that scenario, but if it were to
unfold that way there would likely be a greater threat for
organized severe storms.
.Short Term [Tonight Through Friday]...
There is a higher than normal degree of agreement among the
plethora of CAMs we have been looking at this morning that
convection will linger well into the evening hours. The latest
ECAM came in with likely PoPs across most of the region after 00Z.
While the overall severe threat will eventually diurnally ebb, the
atmosphere should remain sufficiently unstable for a threat to
last perhaps as late as midnight. Enhanced wording was maintained
in the weather grids through 04Z. Some graphics are being prepared
that will highlight the severe weather risk for today and tonight.
A surface cold front will settle to a position just north of the
forecast area on Thursday morning and may actually dip into our
northernmost zones. This boundary will couple with residual TS
outflow boundaries and the sea breeze to trigger convection in a
very unstable environment. Marginally severe storms are expected
with wind/hail the primary threat. The current PoP for Thursday is
roughly 40-50%, but the latest ECAM came in with 80-90% PoPs south
of U.S. 84, so we would expect the official forecast to trend
upward in later packages. The remnant front will remain in the
vicinity on Friday with somewhat drier air working into our
northern zones. PoPs will be slightly lower north than south.
Temps will be running a couple of degrees above normal by day and
several degrees above at night.
.Long Term [Friday Night Through Wednesday]...
The eastern upper level trough will lift eastward during this
period which should allow the ridge to edge closer to the
region. This will bring another uptick in daytime temps. There
will be a surface through in the vicinity at least through the
weekend, and of course there will be the typical mesoscale
boundaries around to trigger convection each day. Daytime PoPs
will generally hover in the 35-45% range through the period.
.Marine...
The pressure gradient across the northeastern Gulf of Mexico will
remain tighter than is typical for mid summer. The result will be
a continuation of WSW winds around 15 knots, occasionally
increasing to cautionary levels through Thursday night. Conditions
will be unsettled over the waters during this time with a few
rounds of strong to severe storms possible. By Friday, winds will
finally drop back to seasonal speeds with daily enhancements each
afternoon and evening in the sea breeze.
.Fire Weather...
Hazardous fire weather conditions are not expected over the next
several days.
.Hydrology...
Area rivers remain well below action stage and we do not
anticipate any main stem concerns. That said, some localized
flooding will be possible due to training of thunderstorms over
the next couple of days. While most areas will get lower amounts,
several inches of rain will be possible in localized areas.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 93 77 94 77 96 / 50 30 50 30 40
Panama City 88 80 89 80 90 / 30 30 40 30 40
Dothan 97 76 96 76 98 / 40 50 40 20 30
Albany 96 75 95 75 96 / 60 60 30 20 30
Valdosta 94 75 94 75 96 / 50 40 40 30 40
Cross City 88 76 91 76 93 / 60 40 50 30 40
Apalachicola 89 80 92 80 93 / 70 30 40 30 30
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AL...NONE.
GM...NONE.
&&
$$
NEAR TERM...LAMERS
SHORT TERM...WOOL
LONG TERM...WOOL
AVIATION...LAMERS
MARINE...WOOL
FIRE WEATHER...LAMERS
HYDROLOGY...WOOL
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
424 AM EDT WED JUL 15 2015
...Severe Storms Possible Today...
.Near Term [Through Today]...
An earlier convective line that pushed south across the northern
half of Alabama and Georgia diminished earlier tonight. However,
its effects on the boundary layer are still being observed with
a fairly expansive cold pool across the same areas - temperatures
around 70 degrees with dew points in the upper 60s. Meanwhile,
further south over our area, low-level moisture has pooled and
dew points are in the mid-upper 70s, and even into the low 80s in
some spots. Thus, the environment over our forecast area remains
relatively undisturbed and quite unstable. This is expected to set
up an active day with respect to convective activity.
Both hi-res and global models indicate considerable convective
development early this morning (10-15Z) across the far
northeastern Gulf of Mexico and into the Florida Big Bend. The
latest objective RAP analysis at 07Z indicated MLCAPE hovering
around 2500 j/kg with very little CINH over our coastal waters,
and regional radars did show some scattered convection already
developing. Hi-res models forecast thunderstorms to become quite
numerous south of a Mexico Beach to Valdosta line in the early-to-
mid morning, particularly over Taylor, Dixie, and Lafayette
Counties. PoPs were increased to 60-70% in those areas. With
precipitable water values analyzed over 2 inches, the storms could
be efficient rain producers, and hi-res models suggest some
potential for training echoes. Therefore, locally heavy rainfall
and flooding can`t be ruled out and heavy rainfall wording was
inserted into the morning forecast. The hi-res models are also
explicitly forecasting some 35-50 knot gusts, so some of the
storms may produce gusty winds as well.
The focus will then turn to the north for the afternoon and early
evening. Additional showers and storms may develop in the early-
mid afternoon along the sea breeze and/or periphery of the upper
level cloud shield associated with the morning convection.
Additionally, a cold front currently situated over Kentucky is
expected to arrive in central Alabama and central Georgia by
21-00Z. Hi-res and global models are in excellent agreement with
initiating another round of storms along that front, possibly
coalescing into one or more convective clusters/lines and then
propagating to the south into our forecast area. Those organized
linear storms, as well as any scattered early-mid afternoon storms
in areas of stronger heating across our forecast area, would pose
a risk of damaging wind gusts. NAM- and WRF-based models also show
an increase in low-level shear as surface and near-surface winds
back to the southwest and increase with the approach of the front.
Other models are less keen on that scenario, but if it were to
unfold that way there would likely be a greater threat for
organized severe storms.
.Short Term [Tonight Through Friday]...
There is a higher than normal degree of agreement among the
plethora of CAMs we have been looking at this morning that
convection will linger well into the evening hours. The latest
ECAM came in with likely PoPs across most of the region after 00Z.
While the overall severe threat will eventually diurnally ebb, the
atmosphere should remain sufficiently unstable for a threat to
last perhaps as late as midnight. Enhanced wording was maintained
in the weather grids through 04Z. Some graphics are being prepared
that will highlight the severe weather risk for today and tonight.
A surface cold front will settle to a position just north of the
forecast area on Thursday morning and may actually dip into our
northernmost zones. This boundary will couple with residual TS
outflow boundaries and the sea breeze to trigger convection in a
very unstable environment. Marginally severe storms are expected
with wind/hail the primary threat. The current PoP for Thursday is
roughly 40-50%, but the latest ECAM came in with 80-90% PoPs south
of U.S. 84, so we would expect the official forecast to trend
upward in later packages. The remnant front will remain in the
vicinity on Friday with somewhat drier air working into our
northern zones. PoPs will be slightly lower north than south.
Temps will be running a couple of degrees above normal by day and
several degrees above at night.
.Long Term [Friday Night Through Wednesday]...
The eastern upper level trough will lift eastward during this
period which should allow the ridge to edge closer to the
region. This will bring another uptick in daytime temps. There
will be a surface through in the vicinity at least through the
weekend, and of course there will be the typical mesoscale
boundaries around to trigger convection each day. Daytime PoPs
will generally hover in the 35-45% range through the period.
&&
.Aviation...
[Through 06Z Thursday] Scattered to numerous showers and storms
are expected today, and may arrive in a couple rounds. Early-mid
morning storms are likely to be concentrated further south and
closer to the Gulf of Mexico, so ECP and TLH would be most likely
to be impacted. After that, scattered afternoon storms will be
possible at all terminals. Between 21Z and 03Z, more organized
lines of storms may push across the area from north to south. DHN
and ABY would be most likely to be affected by those more
organized storms, and gusty winds would be a possibility. A TEMPO
group was added at DHN and ABY with gusts up to 35 knots. Outside
of thunderstorms, VFR conditions should generally prevail.
&&
.Marine...
The pressure gradient across the northeastern Gulf of Mexico will
remain tighter than is typical for mid summer. The result will be
a continuation of WSW winds around 15 knots, occasionally
increasing to cautionary levels through Thursday night. Conditions
will be unsettled over the waters during this time with a few
rounds of strong to severe storms possible. By Friday, winds will
finally drop back to seasonal speeds with daily enhancements each
afternoon and evening in the sea breeze.
&&
.Fire Weather...
Hazardous fire weather conditions are not expected over the next
several days.
&&
.Hydrology...
Area rivers remain well below action stage and we do not
anticipate any main stem concerns. That said, some localized
flooding will be possible due to training of thunderstorms over
the next couple of days. While most areas will get lower amounts,
several inches of rain will be possible in localized areas.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 93 77 94 77 96 / 50 30 50 30 40
Panama City 88 80 89 80 90 / 30 30 40 30 40
Dothan 97 76 96 76 98 / 40 50 40 20 30
Albany 96 75 95 75 96 / 60 60 30 20 30
Valdosta 94 75 94 75 96 / 50 40 40 30 40
Cross City 88 76 91 76 93 / 60 40 50 30 40
Apalachicola 89 80 92 80 93 / 70 30 40 30 30
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AL...NONE.
GM...NONE.
&&
$$
NEAR TERM...LAMERS
SHORT TERM...WOOL
LONG TERM...WOOL
AVIATION...LAMERS
MARINE...WOOL
FIRE WEATHER...WOOL
HYDROLOGY...WOOL
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
941 PM EDT THU JUL 16 2015
.SYNOPSIS...
AN INLAND SURFACE TROUGH WILL BECOME ESTABLISHED THIS WEEKEND AND
REMAIN INTO NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
17/01Z MESOANALYSIS SHOWS THE STATIONARY FRONT IS BECOMING
DIFFICULT TO FIND AS THE PACKING OF ISODROSOTHERMS IS BECOMING
LESS DEFINED BY THE HOURS. THERE REMAINS SOMEWHAT OF A BROAD WIND
SHIFT ACROSS NORTHERN PARTS OF DORCHESTER AND BERKELEY COUNTIES
WHICH IS WHERE THE FRONT IS LIKELY POSITIONED AS IT TRAILS BACK
INTO THE CSRA. ONCE CONVECTION OVER LIBERTY AND LONG COUNTIES
DISSIPATES...THERE ARE SIGNALS IN BOTH THE H3R AND RAP THAT
ISOLATED SHOWERS/TSTMS COULD REFIRE OVER PARTS OF THE CHARLESTON
TRI-COUNTY AREA WHERE WEAK LOW-LEVEL SPEED CONVERGENCE LINGERS
NEAR THE DECAYING FRONT. WILL SHOW SLIGHT CHANCE POPS IN THIS AREA
FROM ROUGHLY 11PM-3AM TO COVER THIS POSSIBILITY. OTHERWISE...SLIGHT
CHANCE POPS WILL BE MAINTAINED ACROSS THE FAR SOUTH FOR A FEW MORE
HOURS.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
A WEAK SURFACE INLAND TROF AND THE EASTWARD EDGE OF A STRONG MID
LEVEL RIDGE WILL DOMINATE THE WEATHER THROUGH THE WEEKEND. TEMPS
WILL SLOWLY BE ON THE RISE WITH SOME UPPER 90S POSSIBLE INLAND BY
SUNDAY. THERE IS A CHANCE OF WIDELY SCATTERED AFTERNOON AND EVENING
THUNDERSTORMS EACH DAY...FOCUSED EITHER ALONG THE SEA BREEZE OR THE
CONVERGENCE LINE ASSOCIATED WITH THE INLAND TROF. WARM MID LEVEL
TEMPS AND GENERAL SUBSIDENCE BENEATH THE UPPER RIDGE WILL KEEP THE
THREAT OF ANY SEVERE CONVECTION LOW.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A SLIGHT CHANCE TO CHANCE OF SHOWERS AND THUNDERSTORMS WILL REMAIN
IN THE FORECAST EACH DAY AS A PIEDMONT TROUGH REDEVELOPS INLAND
EARLY NEXT WEEK. GREATER PRECIP CHANCES SHOULD OCCUR BY TUESDAY AS
SOUTHERLY FLOW OCCURS OVER THE AREA WHILE A DEEP LAYERED RIDGE
RETROGRADES WESTWARD IN RESPONSE TO MID LVL TROUGHING OVER THE
EASTERN CONUS. SOME ENHANCEMENT TO SHOWERS/THUNDERSTORMS IS POSSIBLE
WITH A COLD FRONT APPROACHING FROM THE NORTH/NORTHWEST LATER TUESDAY
INTO EARLY WEDNESDAY. LATEST GUIDANCE INDICATES THE FRONT SHOULD
STALL OVER OR NEAR THE AREA...WITH SFC LOW PRESSURE REDEVELOPING
ALONG THE BOUNDARY AND MORE CHANCES OF SHOWERS/THUNDERSTORMS. HIGH
TEMPS SHOULD RANGE IN THE MID 90S ON MONDAY...THEN LOW TO MID 90S ON
TUESDAY AND WEDNESDAY DUE TO GREATER PRECIP COVERAGE. OVERNIGHT LOWS
SHOULD RANGE IN THE MID TO UPPER 70S.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
VFR. COULD SEE A LITTLE FOG/STRATUS IMPACT THE TERMINALS JUST
BEFORE SUNRISE...BUT CONFIDENCE IS TOO LOW TO INCLUDE A MENTION.
WINDS AT KSAV WILL BE ERRATIC FOR THE NEXT 1-2 HOURS AS NUMEROUS
OUTFLOWS FROM CONVECTION TO THE NORTHEAST MOVES ACROSS THE
TERMINALS.
EXTENDED AVIATION OUTLOOK...THERE ARE NO CONCERNS.
&&
.MARINE...
TONIGHT...A WEAK PRESSURE PATTERN WILL MAINTAIN FAIRLY LIGHT
WINDS AND MINIMAL SEAS OVERNIGHT TONIGHT AFTER THE SEA BREEZE DIES
OFF.
FRIDAY THROUGH TUESDAY...WEAK FLOW IS EXPECTED OVER THE WEEKEND
BETWEEN THE BERMUDA HIGH OVER THE ATLANTIC AND THE INLAND HEAT
TROF...WITH THE STRONGEST WINDS LIKELY OCCURRING ALONG THE COAST
WITH THE AFTERNOON SEA BREEZE. WINDS WILL PICK UP SOME OUT OF THE
SOUTHWEST MONDAY AND TUESDAY AS THE INLAND TROF STRENGTHENS A
LITTLE...BUT MAXIMUM WINDS WILL STILL BE NOT MORE THAN 15 KNOTS.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
821 PM EDT THU JUL 16 2015
.SYNOPSIS...
ONLY ISOLATED CONVECTION EXPECTED ON FRIDAY AS SURFACE HIGH
PRESSURE TO OUR NORTHEAST PULLS FURTHER AWAY FROM THE COAST. THE
CHANCE FOR THUNDERSTORMS WILL INCREASE OVER THE WEEKEND AS THE
UPPER RIDGE SHIFTS WEST AND A SURFACE TROUGH SITS SOUTH OF THE
AREA. A FRONTAL SYSTEM MAY MOVE INTO THE AREA TOWARD THE MIDDLE
OF NEXT WEEK. TEMPERATURES ARE FORECAST ABOVE NORMAL THROUGHOUT
THE PERIOD.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THE FORECAST AREA WILL REMAIN ON THE EASTERN EDGE OF AN UPPER
RIDGE OVERNIGHT WHILE AT THE SURFACE...A WEAK BOUNDARY REMAINS TO
OUR SOUTH. ISOLATED DIURNAL CONVECTION WILL DISSIPATE WITH LOSS
OF HEATING AND SKIES WILL BECOME MOSTLY CLEAR FOR THE OVERNIGHT
PERIOD. THE MAIN CONCERN CONTINUES TO BE FOG DEVELOPMENT. MODELS
SHOW POTENTIAL FOR FOG...MAINLY ALONG AND SOUTH OF I-20...WITH
POTENTIAL IN FOG PRONE LOCATIONS TO BECOME DENSE. HAVE INCLUDED
PATCHY FOG BETWEEN 08 AND 13Z. OVERNIGHT LOWS WILL BE IN THE
LOWER TO MIDDLE 70S.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
THE PATTERN WILL CHANGE LITTLE FOR FRIDAY AND FRIDAY NIGHT. THE
MODELS DISPLAY A WEAK SURFACE TROUGH LINGERING JUST SOUTH OF THE
FORECAST AREA WITH UPPER RIDGING EXTENDING INTO THE AREA FROM THE
SOUTHERN PLAINS. THUNDERSTORMS MAINLY ASSOCIATED WITH STRONG
HEATING SHOULD BE ISOLATED WITH SOUTH AND EAST SECTIONS FAVORED
CLOSER TO THE SURFACE TROUGH AND POSSIBLE SEA-BREEZE FRONT
CONVERGENCE. ABOVE NORMAL TEMPERATURES WILL CONTINUE. THE
TEMPERATURE GUIDANCE WAS CONSISTENT.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
THE GFS AND ECMWF DISPLAY THE UPPER RIDGING SHIFTING FARTHER WEST
OVER THE WEEKEND. THE NAM INDICATES MODERATE INSTABILITY ON
SATURDAY...HOWEVER LITTLE UPPER LEVEL FORCING. THERE IS SOME LOW
LEVEL CONVERGENCE ALONG A WEAK SURFACE TROUGH WHICH MAY BE ENOUGH
TO TRIGGER STORMS IN THE AFTERNOON. THE GFS MOVES A WEAK SHORTWAVE
ACROSS THE FORECAST AREA SUNDAY POSSIBLY PRODUCING SHOWERS AND
THUNDERSTORMS.
A FRONT MAY MOVE INTO THE AREA TOWARD THE MIDDLE OF THE WEEK.
STILL...THE H85 AND H5 FLOW SHOULD REMAIN MAINLY WESTERLY LIMITING
MOISTURE. THE GFS...ECMWF...AND EKD MOS PLUS GFS ENSEMBLE MEAN
INDICATE POPS OF MAINLY 10 TO 30 PERCENT THROUGH THE MEDIUM-RANGE
PERIOD. THE MOS HAS CONTINUED ABOVE NORMAL TEMPERATURES.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
HIGH CONFIDENCE FOR VFR THROUGH 05Z.
CLOUD BASES SCT/BKN AT OR ABOVE 7000 FEET IN WEAK LOW LEVEL EASTERLY
FLOW THIS EVENING.
MAIN CONCERN WILL BE FOG/STRATUS DEVELOPING DURING THE EARLY MORNING HOURS.
SHOULD SEE INCREASING LOW LEVEL MOISTURE THIS EVENING BEHIND SEA-BREEZE
FRONT. CONFIDENCE CONTINUES TO INCREASE IN FOG/STRATUS IN THE 07Z-14Z
TIME-FRAME. SEVERAL MODELS INCLUDING THE RAP...NAM AND HRRR NOW INDICATING
RESTRICTIONS. HAVE INCLUDED IFR/MVFR CONDITIONS AT ALL TAF SITES EARLY
FRIDAY MORNING. FOG/STRATUS WHICH DEVELOPS SHOULD LIFT/ERODE 13Z-15Z
WITH THE ONSET OF MIXING. SHOULD SEE VFR AFTER 16Z WITH EASTERLY WINDS
LESS THAN 10 KNOTS.
EXTENDED AVIATION OUTLOOK...BRIEF MVFR/IFR POSSIBLE SATURDAY THROUGH
MONDAY IN DIURNALLY DRIVEN CONVECTION. FOG/STRATUS POSSIBLE EARLY
SATURDAY MORNING.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
123 PM EDT WED JUL 15 2015
.PREV DISCUSSION.../ISSUED 330 AM EDT WED JUL 15 2015/
SHORT TERM /TODAY THROUGH THURSDAY/...
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A WEAKENING COMPLEX WILL
GRAZE NORTHERN GA EARLY THIS MORNING. SATELLITE TRENDS SHOW A
GENERAL WARMING OF TOPS AND A DECREASE IN LIGHTNING. ATMOS FOR THE
NORTHERN HALF OF THE CWFA WAS WORKED OVER PRETTY WELL LAST EVENING
WHEN A STRONGER THUNDERSTORM COMPLEX MOVED ACROSS THE AREA. A FEW
RUMBLES OF THUNDER ARE POSSIBLE THIS MORNING ACROSS THE NORTH...BUT
SEVERE WEATHER IS NOT ANTICIPATED.
A WEAK FRONT/TROUGH WILL MOVE SOUTH ACROSS THE CWFA TODAY. THIS
SURFACE FEATURE IN ADDITION TO A SHORTWAVE TROUGH WILL TEND TO FOCUS
CONVECTION TODAY. IN ADDITION...ANY OUTFLOW BOUNDARY THAT THE
CONVECTION CURRENTLY TO THE NORTH LAYS OUT...MAY PROVIDE ENOUGH
SURFACE CONVERGENCE FOR CONVECTION. HI-RES MODELS...ESPECIALLY THE
WRF...HAVE PERFORMED RATHER DECENTLY OVER THE LAST FEW DAYS. BOTH
THE HRRR AND THE WRF ARE PROGGING THE BULK OF ANY ACTIVITY TODAY
ACROSS THE SOUTHERN THIRD OF THE CWFA.
THE ATMOS DOWN SOUTH HASN`T BEEN WORKED OVER AS MUCH AS FURTHER
NORTH...AND DEEP MOISTURE STILL RESIDES DOWN THERE. SURFACE
INSTABILITY WILL DEFINITELY BE PRESENT. SURFACE CONVERGENCE PROVIDED
BY THE FRONT/TROUGH...OUTFLOW BOUNDARY AND/OR SEABREEZE SHOULD
PROVIDE AMPLE LIFT TO GET THINGS STARTED. IN ADDITION...MID LEVEL
DYNAMICS WILL ALSO BE IN PLAY AS A SHORTWAVE ROUNDS THE BASE OF THE
EASTERN TROUGH. INVERTED V ON THE FORECAST SOUNDINGS SHOW THE
PRIMARY MODE OF SEVERE WEATHER SHOULD BE DAMAGING WIND GUSTS.
HOWEVER...A FEW HAIL REPORTS CANNOT BE RULED OUT AS THE SHORTWAVE
WILL SERVE TO STEEPEN LAPSE RATES.
OLD FRONT/TROUGH WILL REMAIN SITUATED ACROSS SOUTHERN GA THROUGH
TOMORROW. HOWEVER...500MB HIGH PRESSURE WILL BEGIN TO BUILD BACK
EASTWARD. THE UPPER HIGH MAY LIMIT CONVECTIVE DEVELOPMENT...BUT THE
SURFACE FEATURE MAY PROVIDE JUST ENOUGH FOCUS FOR CONVECTIVE
ACTIVITY ACROSS THE SOUTH.
HEAT INDICES ACROSS EAST CENTRAL GEORGIA WILL HAVE THE POTENTIAL TO
REACH NEAR 105 DEGREES AGAIN TODAY. HAVE GONE AHEAD AND ISSUED
ANOTHER HEAT ADVISORY FOR THE REGION.
NLISTEMAA
LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THE UPPER RIDGE HAS NOSED BACK OVER THE AREA TO START THE LONG TERM.
A SURFACE TROUGH OR DISSIPATING STATIONARY FRONT ACROSS CENTRAL GA
WILL CONTINUE SMALL CHANCES FOR SHOWERS AND THUNDERSTORMS THURSDAY
NIGHT.
OTHERWISE THE UPPER RIDGE CONTINUES OVER THE AREA THROUGH SUNDAY
AND BEGINS TO WEAKEN MONDAY AND EVEN MORE SO ON TUESDAY.
THIS WILL ALLOW FOR MAINLY DIURNAL AFTERNOON AND EVENING SHOWERS
AND THUNDERSTORMS FROM THE AFTERNOON HOT TEMPERATURES AND HUMIDITY.
TEMPERATURES FOR THE MOST PART WILL BE A COUPLE TO AS MUCH AS 5-6
DEGREES ABOVE NORMAL DURING THE LONG TERM PERIOD.
BDL
&&
.AVIATION...
18Z UPDATE...
VFR THROUGH THE FORECAST. CU FIELD THIS AFTERNOON OF 3500 TO 5000
FT. THIS WILL DISSIPATE AROUND SUNSET. A FEW015 TOMORROW MORNING
WITH INITIAL LIFTING BUT SHOULD NOT BECOME A CIG. CONVECTION
SHOULD BE CONFINED TO MCN/CSG BUT BY 00Z THU THE CONVECTION WILL
BE SOUTH OF CSG/MCN. WINDS REMAINING WEST TO NORTHWEST WITH A FEW
GUSTS THIS AFTERNOON...BECOMING LIGHT NORTHWEST TONIGHT AND
THURSDAY MORNING.
//ATL CONFIDENCE...18Z UPDATE...
HIGH ON ALL ELEMENTS.
17
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 94 72 92 72 / 20 20 10 10
ATLANTA 91 74 92 74 / 20 20 10 10
BLAIRSVILLE 85 62 85 65 / 20 20 20 10
CARTERSVILLE 91 68 91 69 / 20 20 10 10
COLUMBUS 95 76 95 75 / 40 40 30 20
GAINESVILLE 90 71 89 72 / 20 20 10 10
MACON 96 73 96 73 / 40 40 30 20
ROME 92 69 92 69 / 20 20 10 10
PEACHTREE CITY 92 71 92 71 / 30 30 10 10
VIDALIA 96 75 95 75 / 50 40 40 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR THE FOLLOWING
ZONES: BLECKLEY...DODGE...EMANUEL...JEFFERSON...JOHNSON...
LAURENS...MONTGOMERY...PULASKI...TELFAIR...TOOMBS...TREUTLEN...
TWIGGS...WASHINGTON...WHEELER...WILCOX...WILKINSON.
&&
$$
SHORT TERM...17
LONG TERM....01
AVIATION...17
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
330 AM EDT WED JUL 15 2015
.SHORT TERM /TODAY THROUGH THURSDAY/...
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A WEAKENING COMPLEX WILL
GRAZE NORTHERN GA EARLY THIS MORNING. SATELLITE TRENDS SHOW A
GENERAL WARMING OF TOPS AND A DECREASE IN LIGHTNING. ATMOS FOR THE
NORTHERN HALF OF THE CWFA WAS WORKED OVER PRETTY WELL LAST EVENING
WHEN A STRONGER THUNDERSTORM COMPLEX MOVED ACROSS THE AREA. A FEW
RUMBLES OF THUNDER ARE POSSIBLE THIS MORNING ACROSS THE NORTH...BUT
SEVERE WEATHER IS NOT ANTICIPATED.
A WEAK FRONT/TROUGH WILL MOVE SOUTH ACROSS THE CWFA TODAY. THIS
SURFACE FEATURE IN ADDITION TO A SHORTWAVE TROUGH WILL TEND TO FOCUS
CONVECTION TODAY. IN ADDITION...ANY OUTFLOW BOUNDARY THAT THE
CONVECTION CURRENTLY TO THE NORTH LAYS OUT...MAY PROVIDE ENOUGH
SURFACE CONVERGENCE FOR CONVECTION. HI-RES MODELS...ESPECIALLY THE
WRF...HAVE PERFORMED RATHER DECENTLY OVER THE LAST FEW DAYS. BOTH
THE HRRR AND THE WRF ARE PROGGING THE BULK OF ANY ACTIVITY TODAY
ACROSS THE SOUTHERN THIRD OF THE CWFA.
THE ATMOS DOWN SOUTH HASN`T BEEN WORKED OVER AS MUCH AS FURTHER
NORTH...AND DEEP MOISTURE STILL RESIDES DOWN THERE. SURFACE
INSTABILITY WILL DEFINITELY BE PRESENT. SURFACE CONVERGENCE PROVIDED
BY THE FRONT/TROUGH...OUTFLOW BOUNDARY AND/OR SEABREEZE SHOULD
PROVIDE AMPLE LIFT TO GET THINGS STARTED. IN ADDITION...MID LEVEL
DYNAMICS WILL ALSO BE IN PLAY AS A SHORTWAVE ROUNDS THE BASE OF THE
EASTERN TROUGH. INVERTED V ON THE FORECAST SOUNDINGS SHOW THE
PRIMARY MODE OF SEVERE WEATHER SHOULD BE DAMAGING WIND GUSTS.
HOWEVER...A FEW HAIL REPORTS CANNOT BE RULED OUT AS THE SHORTWAVE
WILL SERVE TO STEEPEN LAPSE RATES.
OLD FRONT/TROUGH WILL REMAIN SITUATED ACROSS SOUTHERN GA THROUGH
TOMORROW. HOWEVER...500MB HIGH PRESSURE WILL BEGIN TO BUILD BACK
EASTWARD. THE UPPER HIGH MAY LIMIT CONVECTIVE DEVELOPMENT...BUT THE
SURFACE FEATURE MAY PROVIDE JUST ENOUGH FOCUS FOR CONVECTIVE
ACTIVITY ACROSS THE SOUTH.
HEAT INDICES ACROSS EAST CENTRAL GEORGIA WILL HAVE THE POTENTIAL TO
REACH NEAR 105 DEGREES AGAIN TODAY. HAVE GONE AHEAD AND ISSUED
ANOTHER HEAT ADVISORY FOR THE REGION.
NLISTEMAA
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THE UPPER RIDGE HAS NOSED BACK OVER THE AREA TO START THE LONG TERM.
A SURFACE TROUGH OR DISSIPATING STATIONARY FRONT ACROSS CENTRAL GA
WILL CONTINUE SMALL CHANCES FOR SHOWERS AND THUNDERSTORMS THURSDAY
NIGHT.
OTHERWISE THE UPPER RIDGE CONTINUES OVER THE AREA THROUGH SUNDAY
AND BEGINS TO WEAKEN MONDAY AND EVEN MORE SO ON TUESDAY.
THIS WILL ALLOW FOR MAINLY DIURNAL AFTERNOON AND EVENING SHOWERS
AND THUNDERSTORMS FROM THE AFTERNOON HOT TEMPERATURES AND HUMIDITY.
TEMPERATURES FOR THE MOST PART WILL BE A COUPLE TO AS MUCH AS 5-6
DEGREES ABOVE NORMAL DURING THE LONG TERM PERIOD.
BDL
&&
.AVIATION...
06Z UPDATE...
HI-RES MODELS CONTINUE TO WEAKEN THE ACTIVITY ACROSS SOUTHERN TN
THIS MORNING AND KEEP IT ACROSS FAR NORTHERN GA. PLENTY OF HIGH
CLOUD DEBRIS AROUND EARLY THIS MORNING. HI-RES WRF AND HRRR KEEP
MOST OF THE PRECIP FOR WEDNESDAY SOUTH OF THE NORTHERN TERMINAL
SITES...NEAR A SURFACE TROUGH. CIGS SHOULD REMAIN VFR. WINDS WILL
REMAIN ON THE WEST SIDE. FREQUENT GUSTS BETWEEN 15 AND 20KT LIKELY
TODAY.
//ATL CONFIDENCE...06Z UPDATE...
HIGH CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 94 72 92 72 / 40 30 10 10
ATLANTA 91 74 92 74 / 40 30 10 10
BLAIRSVILLE 85 62 85 65 / 30 30 10 10
CARTERSVILLE 91 68 91 69 / 30 30 10 10
COLUMBUS 95 76 95 75 / 40 40 30 20
GAINESVILLE 90 71 89 72 / 30 30 10 10
MACON 96 73 96 73 / 40 40 20 20
ROME 92 69 92 69 / 30 30 10 10
PEACHTREE CITY 92 71 92 71 / 40 40 20 10
VIDALIA 96 75 95 75 / 40 40 40 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM EDT THIS EVENING
FOR THE FOLLOWING ZONES: BLECKLEY...DODGE...EMANUEL...
JEFFERSON...JOHNSON...LAURENS...MONTGOMERY...PULASKI...TELFAIR...
TOOMBS...TREUTLEN...TWIGGS...WASHINGTON...WHEELER...WILCOX...
WILKINSON.
&&
$$
SHORT TERM...NLISTEMAA
LONG TERM....BDL
AVIATION...NLISTEMAA
AREA FORECAST DISCUSSION
NWS LINCOLN IL
832 PM CDT THU JUL 16 2015
.UPDATE...
ISSUED AT 832 PM CDT THU JUL 16 2015
A BROKEN LINE OF THUNDERSTORMS THAT DEVELOPED ALONG THE
MISSISSIPPI RIVER LATE THIS AFTERNOON HAS ADVANCED SLOWLY
EASTWARD INTO THE ILLINOIS RIVER VALLEY OVER THE PAST COUPLE OF
HOURS. THE CELLS ON THE SOUTHERN END OF THE LINE HAVE TENDED TO
DIMINISH...WITH THE MAIN FOCUS BEING ON A LARGE CLUSTER OF STRONG
TO SEVERE STORMS OVER KNOX COUNTY. THESE STORMS HAVE HAD A HISTORY
OF ROTATION AS THEY ARE CURRENTLY POSITIONED IMMEDIATELY ALONG A
WARM FRONT. AS THEY PUSH FURTHER EASTWARD AWAY FROM THE FRONT INTO
A MORE STABLE AIRMASS TO THE E/NE...THINK THEY WILL TEND TO WEAKEN
BETWEEN NOW AND 10 PM. HIGH-RES MODELS CONTINUE TO SUGGEST
ADDITIONAL DEVELOPMENT ALONG THE SOUTHERN END OF THIS CLUSTER
LATER THIS EVENING INTO THE OVERNIGHT HOURS AS A 30-40KT 850MB
JET INTERSECTS THE WARM FRONT. WILL CONTINUE TO CARRY LIKELY POPS
ACROSS THE FAR NORTHERN KILX CWA FROM THE PEORIA AREA NORTHWARD
AHEAD OF THE ONGOING STORM COMPLEX...WITH CHANCE POPS FURTHER
SOUTH ACROSS THE CENTER OF THE CWA. FURTHER SOUTH...LITTLE OR NO
PRECIP IS EXPECTED ALONG/SOUTH OF I-70.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 246 PM CDT THU JUL 16 2015
REMNANTS OF EARLIER MCS HAVE EXITED THE FORECAST AREA...AND BREAKS
IN THE CLOUD COVER ARE BECOMING MORE FREQUENT ACROSS MUCH OF THE CWA
THIS AFTERNOON EXCEPT THE FAR NORTHWEST. CAP IS QUICKLY ERODING TO
OUR WEST...AND SPC MESOANALYSIS SHOWING CAPE`S ABOVE 3000 J/KG AS
CLOSE AS THE MISSISSIPPI RIVER. VISIBLE SATELLITE IMAGERY STARTING
SO SHOW SOME AGITATION TO THE CUMULUS CLOUDS ACROSS NORTH CENTRAL
MISSOURI AND SOUTH CENTRAL IOWA...IN AN AREA WHERE THE HRRR HAS BEEN
PERSISTENT IN STARTING UP THE NEXT ROUND OF CONVECTION. ITS SOLUTION
EXPANDS THE CONVECTION NORTHEAST INTO NORTH CENTRAL ILLINOIS THROUGH
VERY LATE AFTERNOON...WITH THE LATEST SOLUTIONS FAVORING AN EASTWARD
SPREAD NORTH OF THE I-72 CORRIDOR THROUGH THE EVENING. OTHER HIGH-
RESOLUTION MODELS SUCH AS THE NMM AND ARW ALSO FAVOR THE NORTHERN
THIRD OF THE STATE...WITH LESSER OF A SOUTHWEST EXTENT. THUS...WILL
FOCUS THE HIGHEST POP`S ACROSS THE NORTHERN THIRD OF THE FORECAST
AREA.
AFTER COLLABORATION WITH WFO CHICAGO...HAVE EXPANDED THE FLASH FLOOD
WATCH A TAD SOUTHWARD AND THEN EAST THROUGH CHAMPAIGN AND VERMILION
COUNTIES. PRECIPITABLE WATER VALUES ANALYZED OVER 2 INCHES ACROSS
NORTHERN MISSOURI...AND THIS WILL BE SHIFTING EAST WITH TIME.
MESOSCALE MODELS FOCUS THE HIGHEST RAIN TOTALS ACROSS THE NORTHWEST
CWA...BUT PARTS OF THE FAR NORTHEAST HAVE ALSO HAD A FEW INCHES OVER
THE LAST SEVERAL DAYS AND ARE A BIT MORE FLOOD PRONE. MOST OF THE
NORTH HALF OF ILLINOIS IS IN A SLIGHT RISK OF FLASH FLOODING PER
GUIDANCE FROM WPC.
.LONG TERM...(FRIDAY THROUGH THURSDAY)
ISSUED AT 246 PM CDT THU JUL 16 2015
SPOTTY SHOWERS/STORMS POSSIBLE FRIDAY ACROSS CENTRAL AND SOUTHEAST
ILLINOIS WITH A WEAK SURFACE BOUNDARY IN THE VICINITY. HOWEVER, THE
PRIMARY THEME AS WE HEAD INTO FRIDAY AFTERNOON (AS WELL AS SATURDAY
AND SUNDAY AFTERNOON) IS THE VERY WARM HEAT INDEX VALUES. THE
SOUTHWESTERLY LOW LEVEL THAT DEVELOPS ACROSS THE AREA TONIGHT WILL
LINGER THROUGH MOST OF THE WEEKEND, TRANSPORTING CONSIDERABLE HEAT
AND HUMIDITY INTO THE AREA. DAYTIME HIGHS AROUND 90S ARE LIKELY
THROUGH SUNDAY, WITH 850 MB TEMPERATURES IN THE LOWER 20S, AND
SURFACE DEW POINTS SHOULD BE WELL INTO THE 70S. THIS HEAT AND
HUMIDITY WILL COMBINE TO PRODUCE HEAT INDEX VALUES FROM 100-105 OR A
LITTLE WARMER DURING PEAK HEATING TIMES. THIS IS CLOSE TO HEAT
ADVISORY LEVELS, AND AN ADVISORY MAY BE NEEDED. HOWEVER, OPTED TO
HOLD OFF UNTIL HEAT INDEX VALUES ARE MORE SOLIDLY 105 OR BETTER.
FORECAST SOUNDINGS SUGGEST THE LOCAL AIRMASS SHOULD BE MOSTLY CAPPED
TO SURFACE BASED CONVECTION INTO SUNDAY (PRONOUNCED WARM LAYER JUST
ABOVE 850 MB). HOWEVER, ELEVATED STORM CHANCES WILL INCREASE
SATURDAY NIGHT AS WARM ADVECTION ALOFT INCREASES AHEAD OF AN
APPROACHING SHORT WAVE. THIS WAVE WILL DRIVE A FRONT THROUGH THE
AREA ON SUNDAY, PRODUCING THE HIGHEST CHANCES FOR SHOWERS/STORMS OF
THE NEXT FEW DAYS (ASIDE FROM TONIGHT). THE STRENGTH OF THIS SYSTEM
ALSO SUPPORTS SOME STRONG TO SEVERE STORMS SUNDAY INTO SUNDAY NIGHT.
SLIGHTLY COOLER AND LESS HUMID CONDITIONS ARE EXPECTED BEHIND
SUNDAY`S SYSTEM FOR THE REMAINDER OF THE FORECAST PERIOD. THE
SOUTHWARD PASSAGE OF THE FRONT WITH SUNDAY`S SYSTEM WILL ALSO HELP
TO SHUNT THE BEST SHOWER/STORM CHANCES TO OUR SOUTH.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 629 PM CDT THU JUL 16 2015
A BROKEN LINE OF CONVECTION HAS DEVELOPED ALONG THE MISSISSIPPI
RIVER NEAR A WARM FRONT AND WELL AHEAD OF AN APPROACHING UPPER
WAVE. INDIVIDUAL CELLS ARE MOVING TO THE NORTHEAST AT 25
MPH...HOWEVER THE ENTIRE LINE IS GRADUALLY SHIFTING TO THE EAST.
BASED ON TIMING TOOLS...HAVE DELAYED THUNDER AT KPIA UNTIL 01Z.
HIGH-RES MODELS GENERALLY SHOW THE STORMS DEVELOPING/SHIFTING
EASTWARD ACROSS MAINLY THE NORTHERN HALF OF THE KILX CWA FROM
MID-EVENING INTO THE OVERNIGHT HOURS. HAVE THEREFORE CARRIED A
TEMPO GROUP FOR THUNDER AND MVFR CEILINGS AT BOTH KPIA AND
KBMI...BUT HAVE ONLY MENTIONED VCTS FURTHER SOUTH AND EAST AT THE
REMAINING TERMINALS. SHOWERS/STORMS WILL COME TO AN END FROM WEST
TO EAST ACROSS THE AREA LATE TONIGHT. WINDS WILL INITIALLY BE FROM
THE S/SE THIS EVENING...THEN WILL SHIFT TO THE SW LATE TONIGHT
INTO FRIDAY.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 1 AM CDT FRIDAY FOR ILZ027>031-036>038-
041>046.
&&
$$
UPDATE...BARNES
SHORT TERM...GEELHART
LONG TERM...BAK
AVIATION...BARNES
AREA FORECAST DISCUSSION
NWS LINCOLN IL
629 PM CDT THU JUL 16 2015
.SHORT TERM...(TONIGHT)
ISSUED AT 246 PM CDT THU JUL 16 2015
REMNANTS OF EARLIER MCS HAVE EXITED THE FORECAST AREA...AND BREAKS
IN THE CLOUD COVER ARE BECOMING MORE FREQUENT ACROSS MUCH OF THE CWA
THIS AFTERNOON EXCEPT THE FAR NORTHWEST. CAP IS QUICKLY ERODING TO
OUR WEST...AND SPC MESOANALYSIS SHOWING CAPE`S ABOVE 3000 J/KG AS
CLOSE AS THE MISSISSIPPI RIVER. VISIBLE SATELLITE IMAGERY STARTING
SO SHOW SOME AGITATION TO THE CUMULUS CLOUDS ACROSS NORTH CENTRAL
MISSOURI AND SOUTH CENTRAL IOWA...IN AN AREA WHERE THE HRRR HAS BEEN
PERSISTENT IN STARTING UP THE NEXT ROUND OF CONVECTION. ITS SOLUTION
EXPANDS THE CONVECTION NORTHEAST INTO NORTH CENTRAL ILLINOIS THROUGH
VERY LATE AFTERNOON...WITH THE LATEST SOLUTIONS FAVORING AN EASTWARD
SPREAD NORTH OF THE I-72 CORRIDOR THROUGH THE EVENING. OTHER HIGH-
RESOLUTION MODELS SUCH AS THE NMM AND ARW ALSO FAVOR THE NORTHERN
THIRD OF THE STATE...WITH LESSER OF A SOUTHWEST EXTENT. THUS...WILL
FOCUS THE HIGHEST POP`S ACROSS THE NORTHERN THIRD OF THE FORECAST
AREA.
AFTER COLLABORATION WITH WFO CHICAGO...HAVE EXPANDED THE FLASH FLOOD
WATCH A TAD SOUTHWARD AND THEN EAST THROUGH CHAMPAIGN AND VERMILION
COUNTIES. PRECIPITABLE WATER VALUES ANALYZED OVER 2 INCHES ACROSS
NORTHERN MISSOURI...AND THIS WILL BE SHIFTING EAST WITH TIME.
MESOSCALE MODELS FOCUS THE HIGHEST RAIN TOTALS ACROSS THE NORTHWEST
CWA...BUT PARTS OF THE FAR NORTHEAST HAVE ALSO HAD A FEW INCHES OVER
THE LAST SEVERAL DAYS AND ARE A BIT MORE FLOOD PRONE. MOST OF THE
NORTH HALF OF ILLINOIS IS IN A SLIGHT RISK OF FLASH FLOODING PER
GUIDANCE FROM WPC.
.LONG TERM...(FRIDAY THROUGH THURSDAY)
ISSUED AT 246 PM CDT THU JUL 16 2015
SPOTTY SHOWERS/STORMS POSSIBLE FRIDAY ACROSS CENTRAL AND SOUTHEAST
ILLINOIS WITH A WEAK SURFACE BOUNDARY IN THE VICINITY. HOWEVER, THE
PRIMARY THEME AS WE HEAD INTO FRIDAY AFTERNOON (AS WELL AS SATURDAY
AND SUNDAY AFTERNOON) IS THE VERY WARM HEAT INDEX VALUES. THE
SOUTHWESTERLY LOW LEVEL THAT DEVELOPS ACROSS THE AREA TONIGHT WILL
LINGER THROUGH MOST OF THE WEEKEND, TRANSPORTING CONSIDERABLE HEAT
AND HUMIDITY INTO THE AREA. DAYTIME HIGHS AROUND 90S ARE LIKELY
THROUGH SUNDAY, WITH 850 MB TEMPERATURES IN THE LOWER 20S, AND
SURFACE DEW POINTS SHOULD BE WELL INTO THE 70S. THIS HEAT AND
HUMIDITY WILL COMBINE TO PRODUCE HEAT INDEX VALUES FROM 100-105 OR A
LITTLE WARMER DURING PEAK HEATING TIMES. THIS IS CLOSE TO HEAT
ADVISORY LEVELS, AND AN ADVISORY MAY BE NEEDED. HOWEVER, OPTED TO
HOLD OFF UNTIL HEAT INDEX VALUES ARE MORE SOLIDLY 105 OR BETTER.
FORECAST SOUNDINGS SUGGEST THE LOCAL AIRMASS SHOULD BE MOSTLY CAPPED
TO SURFACE BASED CONVECTION INTO SUNDAY (PRONOUNCED WARM LAYER JUST
ABOVE 850 MB). HOWEVER, ELEVATED STORM CHANCES WILL INCREASE
SATURDAY NIGHT AS WARM ADVECTION ALOFT INCREASES AHEAD OF AN
APPROACHING SHORT WAVE. THIS WAVE WILL DRIVE A FRONT THROUGH THE
AREA ON SUNDAY, PRODUCING THE HIGHEST CHANCES FOR SHOWERS/STORMS OF
THE NEXT FEW DAYS (ASIDE FROM TONIGHT). THE STRENGTH OF THIS SYSTEM
ALSO SUPPORTS SOME STRONG TO SEVERE STORMS SUNDAY INTO SUNDAY NIGHT.
SLIGHTLY COOLER AND LESS HUMID CONDITIONS ARE EXPECTED BEHIND
SUNDAY`S SYSTEM FOR THE REMAINDER OF THE FORECAST PERIOD. THE
SOUTHWARD PASSAGE OF THE FRONT WITH SUNDAY`S SYSTEM WILL ALSO HELP
TO SHUNT THE BEST SHOWER/STORM CHANCES TO OUR SOUTH.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 629 PM CDT THU JUL 16 2015
A BROKEN LINE OF CONVECTION HAS DEVELOPED ALONG THE MISSISSIPPI
RIVER NEAR A WARM FRONT AND WELL AHEAD OF AN APPROACHING UPPER
WAVE. INDIVIDUAL CELLS ARE MOVING TO THE NORTHEAST AT 25
MPH...HOWEVER THE ENTIRE LINE IS GRADUALLY SHIFTING TO THE EAST.
BASED ON TIMING TOOLS...HAVE DELAYED THUNDER AT KPIA UNTIL 01Z.
HIGH-RES MODELS GENERALLY SHOW THE STORMS DEVELOPING/SHIFTING
EASTWARD ACROSS MAINLY THE NORTHERN HALF OF THE KILX CWA FROM
MID-EVENING INTO THE OVERNIGHT HOURS. HAVE THEREFORE CARRIED A
TEMPO GROUP FOR THUNDER AND MVFR CEILINGS AT BOTH KPIA AND
KBMI...BUT HAVE ONLY MENTIONED VCTS FURTHER SOUTH AND EAST AT THE
REMAINING TERMINALS. SHOWERS/STORMS WILL COME TO AN END FROM WEST
TO EAST ACROSS THE AREA LATE TONIGHT. WINDS WILL INITIALLY BE FROM
THE S/SE THIS EVENING...THEN WILL SHIFT TO THE SW LATE TONIGHT
INTO FRIDAY.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 1 AM CDT FRIDAY FOR ILZ027>031-036>038-
041>046.
&&
$$
SHORT TERM...GEELHART
LONG TERM...BAK
AVIATION...BARNES
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
831 PM EDT THU JUL 16 2015
.SYNOPSIS...
ISSUED AT 342 PM EDT THU JUL 16 2015
WARMER AND MORE HUMID AIR WILL MOVE INTO THE AREA TONIGHT AND
FRIDAY ALONG WITH INCREASED CHANCES FOR MORE SHOWERS AND
THUNDERSTORMS...ESPECIALLY OVERNIGHT. LOWS TONIGHT WILL BE IN THE
MID 60S TO LOWER 70S. HIGH TEMPERATURES ON FRIDAY WILL BE IN THE
MID 80S TO AROUND 90 DEGREES...WITH HEAT INDEX VALUES NEAR 100
DEGREES IN THE AFTERNOON.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 342 PM EDT THU JUL 16 2015
AREA OF RADAR RETURNS CURRENTLY ACROSS THE INTERSTATE 69 CORRIDOR
WILL CONTINUE TO WORK EASTWARD OVER THE NEXT SEVERAL HOURS BEFORE
DISSIPATING. HOWEVER...WITH SFC DEWPOINT DEPRESSIONS FROM 10F TO
15F AND CLOUD BASES AROUND 10KFT...EXPECTING LITTLE MORE THAN
SPRINKLES THROUGH 21Z.
UPSTREAM CONVECTION EXPECTED TO FIRE AS S/W TRACKS ACROSS SE IA INTO
WRN IL BETWEEN 21Z TO 00Z...AS ONGOING SFC DESTABILIZATION SW OF THE
LOCAL AREA CONTINUES W/ SFC FRONT/LOW LVL THETA E GRADIENT PUSHING
NORTHWARD TOWARDS THE AREA. CONTINUED THE TREND FROM PREVIOUS
FCST...W/ POPS PUSHING INTO THE AREA AFTER 00Z. BUMPED UP POPS A BIT
W/ LIKELY MENTION FOR MOST OF THE AREA WEST OF I-69...HOWEVER HI-RES
GUIDANCE SUGGESTING A BIT OF A SPLIT IN CONVECTIVE ACTIVITY AFTER
06Z. LATEST HRRR RUNS SEEM TO FAVOR SOUTHERN CONVECTION RIDING ALONG
APPROACHING WARM FRONT...AND DIVING JUST SOUTHWEST OF THE LOCAL
AREA. HOWEVER EXPECT AT LEAST SCATTERED COVERAGE ACROSS MOST OF THE
AREA THROUGH 06Z. POPS WILL TAPER OFF FROM WEST TO EAST AFTER
06Z...WITH ONLY CHANCE CATEGORY BY 12Z. SEVERE THREAT LOOKS MINIMAL
BY THE TIME CONVECTION WORKS INTO THE AREA W/ LOSS OF INSTABILITY.
HEAVY RAINFALL IS POSSIBLE...HOWEVER CONFIDENCE IS LOW W/ HI RES
MODEL SIGNALS SHOWING HEAVIEST RAIN STAYING SOUTH OF THE AREA.
HOWEVER VERY MOIST ENVIRONMENT EXPECTED TO PUSH NORTHEAST INTO THE
AREA AFTER 06Z...W/ PWAT VALUES IN EXCESS OF 2 INCHES.
INTERESTING SETUP FOR FRIDAY AS SHORTWAVE EXITS EAST OUT OF THE AREA
THROUGH THE MORNING. WITH EXTREMELY WARM/MOIST AIRMASS PUSHING NORTH
THROUGH THE AREA BY MIDDAY...CONTINUED SHOWER/T-STORM CHANCES
THROUGH THE DAY...WITH HIGHEST CHANCES BEING DIURNALLY DRIVEN IN THE
AFTERNOON/EARLY EVENING. TWO CHALLENGES FOR THE FRIDAY FORECAST: MAX
TEMPERATURES/HEAT INDICES AND THUNDERSTORM CHANCES. MADE LITTLE
CHANGE TO TEMPS/DEWPOINTS FROM PREVIOUS FORECAST...WITH HIGHS
TOPPING OUT NEAR 90 IN THE SW WITH MID 80S ACROSS THE NE. WITH
DEWPOINTS IN THE MID 70S...HEAT INDICES ARE EXPECTED TO REACH THE
UPPER 90S ACROSS MOST OF THE FORECAST AREA...WITH SOME AREAS IN THE
SOUTHWEST REACHING AND EXCEEDING 100F. CURRENT THINKING IS THAT
COULD COVER ACROSS THE SW WILL DIMINISH BY THE AFTERNOON...WITH
ENOUGH SUN AND MOISTURE TO CREATE DANGEROUS HEAT INDEX VALUES. AT
THIS POINT...STILL A LOT OF UNCERTAINTY WRT PRECIP POTENTIAL AND
SUBSEQUENT CLOUD COVER...SO WILL HOLD OFF ON HEAT ADVISORY FOR THIS
FORECAST ISSUANCE AND MENTION HEAT INDEX VALUES IN THE HWO.
WITH STRONG TEMP/MOIST ADVECTION THROUGH THE AREA DURING THE
MORNING...ATMOSPHERE WILL BECOME QUITE UNSTABLE THROUGH THE
AFTERNOON. MODEL SOUNDINGS SUGGESTING SBCAPE VALUES EXCEEDING 5000
J/KG LATE AFTERNOON/EARLY EVENING...HOWEVER THIS WILL BE HIGHLY
CONTINGENT ON AMOUNT OF CONVECTIVE DEBRIS FROM THE
OVERNIGHT/MORNING. SHEAR IS WEAK AND FORCING WILL BE MINIMAL OUTSIDE
OF ANY REMNANT OUTFLOW/LAKE BREEZE BOUNDARY...BUT ENVIRONMENT IS
CERTAINLY CAPABLE OF SCATTERED PULSE STORMS...ESPECIALLY W/ DECENT
MID LVL LAPSE RATES THROUGH THE AFTERNOON...ANY STORMS THAT FORM
WILL POSE A MARGINAL WIND RISK. CONCUR W/ MOST RECENT SWODY2 FROM
SPC ADDING A MARGINAL RISK FRIDAY AFTN/EVE FOR MUCH OF THE AREA.
&&
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 342 PM EDT THU JUL 16 2015
UPR TROF OVER THE PAC NW TODAY WILL MOVE INTO THE NRN PLAINS FRI NGT
WITH WK UPR RIDGE AHEAD OF THIS SYSTEM BUILDING INTO THE MIDWEST.
MODELS SUGGEST SHRTWV/CONVECTION THAT MOVED ACROSS THE AREA IN THE
SHORT TERM PERIOD MAY LEAVE A WK SFC BOUNDARY IN OUR CWA FRI EVE AND
WITH AIRMASS REMAINING VERY MOIST/UNSTABLE LEFT A CHC OF TSTMS IN
THE FCST. SFC DWPTS SHOULD BE IN THE L-M70S BY FRIDAY NIGHT WITH
OVERNIGHT LOWS LIKELY IN THE SAME RANGE. THE WK SFC BOUNDARY
EXPECTED TO MOVE SLOWLY NE SATURDAY IN RESPONSE TO GRDLY INCREASING
S-SWLY GRADIENT AHEAD OF SHRTWV/CDFNT MOVG THROUGH THE NRN PLAINS.
GIVEN VERY UNSTABLE AIRMASS IN PLACE... WK FORCING AT BEST... AND
CAPPING AROUND 5-6KFT... FELT GOING SLIGHT CHC OF TSTMS IN THE AFTN
REASONABLE AND MAINTAINED. DWPTS SHOULD REMAIN IN THE L-M70S DURING
THE DAY WITH BOUNDARY LAYER MIXING UP TO H850 WHICH SHOULD RESULT IN
HIGHS IN THE L90S AND HEAT INDICES AOA OUR HEAT ADVISORY CRITERIA OF
100. RECENT MODEL RUNS HAVE TRENDED A LITTLE FASTER WITH EASTWARD
MOVEMENT OF NRN PLAINS UPR TROF WITH 12Z RUNS INDICATING THE
ASSOCIATED CDFNT WILL MOVE ACROSS OUR CWA SUNDAY AFTN/EVE. MODELS
HINT AT ANOTHER WK CONVECTIVELY INDUCED VORT MAX MOVG ACROSS THE
AREA SAT NGT AHEAD OF THE FRONT WHICH WARRANTS KEEPING A LOW CHC POP
IN THE FCST... BUT BETTER CHANCES ARE SUNDAY AFTN AS THE FRONT MOVES
INTO THE AREA. DEEP LAYER SHEAR EXPECTED TO BE WK LIMITING SVR
THREAT DESPITE VERY UNSTABLE AIRMASS. BIGGER PROBLEM MAY BE ANOTHER
ROUND OF HEAVY RAINFALL AS PWATS FCST AROUND 2" ALONG THE FRONT WITH
FAIRLY WK FLOW AND SMALL MBE VECTORS SUGGESTING POTENTIAL FOR
TRAINING/BACKBUILDING CELLS. CONVECTION/FROPA SUNDAY AFTN SHOULD
GENERALLY KEEP TEMPS BLO SATURDAY`S READINGS BUT STILL MAY REACH
HEAT ADVISORY CRITERIA...ESPECIALLY SE HALF OF CWA.
POST-FRONTAL HIGH PRESSURE EXPECTED TO BUILD INTO THE AREA MONDAY
PROVIDING FAIR WX WITH TEMPS COOLING BACK TO AOB NORMAL. ANOTHER
SHRTWV FCST TO MOVE THROUGH THE UPR GRTLKS TUE-TUE NGT. FROPA
ASSOCIATED WITH THIS SYSTEM EXPECTED TO LACK SGFNT FORCING AND
MOISTURE ACROSS OUR AREA SO MAINTAINED A DRY FCST FOR TUE-TUE NGT
FOR NOW. ANOTHER HIGH PRESSURE SYSTEM SHOULD FOLLOW THIS WK FRONT
AND MOVE ACROSS THE GRTLKS WED-THU PROVIDING FAIR WX WITH CONTD
SEASONABLE TO SLIGHTLY BLO NORMAL TEMPS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 823 PM EDT THU JUL 16 2015
LEAD SHORT WAVE TRACKING ACROSS SOUTHERN LOWER MICHIGAN THIS
EVENING WILL CONTINUE TO OVERRUN THE GREATER INSTABILITY ACROSS
THE MID MS RVR VALLEY. AN AREA OF SHOWERS AND ISOLATED
THUNDERSTORMS MAY SURVIVE INTO NORTH CENTRAL INIDIANA THROUGH
02Z- 03Z. GREATER CHANCE OF THUNDERSTORMS SHOULD HOLD OFF UNTIL
THE OVERNIGHT HOURS WHEN LOW LEVEL MOISTURE ADVECTION INCREASES IN
ADVANCE OF STRONGER SHORT WAVE ACROSS THE MID MS RVR VALLEY. FOR
THE 00Z TAFS HAVE TRIED TO CONCENTRATE TEMPO VCTS/SHRA IN THE
PERIOD OF GREATEST CONFIDENCE LATE EVENING/OVERNIGHT...BUT SLOW
MOVING NATURE OF UPPER FORCING AND INCREASING LOW LEVEL MOISTURE
OVERNIGHT MAY NECESSITATE PRECIP MENTION INTO FRIDAY MORNING.
OTHERWISE...SOUTH SOUTHWEST WINDS 10 KNOTS OR LESS WILL VEER
SOUTHWEST ON FRIDAY AS LOW LEVEL WARM FRONT LIFTS NORTHWARD. WILL
KEEP TAFS DRY FOR FRIDAY WITH STRONGER FORCING DEPARTING TO THE
EAST...BUT CANNOT RULE OUT ISOLD THUNDER FRIDAY GIVEN UNSTABLE
CONDITIONS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...NG
SHORT TERM...NG
LONG TERM...JT
AVIATION...MARSILI
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
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AREA FORECAST DISCUSSION
NWS DES MOINES IA
328 PM CDT WED JUL 15 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 327 PM CDT WED JUL 15 2015
CHALLENGING FORECAST FOR THE OVERNIGHT. TWO DISTINCT VORTICITY
MAXIMUM OVER THE REGION THIS AFTERNOON...ONE ASSOCIATED WITH THE
H500 SHORTWAVE IN EASTERN NEBRASKA AND THE OTHER FARTHER SOUTH OVER
NORTHWEST MISSOURI. TO COMPLICATE MATTERS A WEAK SFC LOW AND TROUGH
EXTEND FROM SOUTH CENTRAL NEBRASKA TO NORTHEAST IOWA. SYNOPTIC SCALE
MODELS HAVE BEEN FAIRLY CONSISTENT WITH FORCING INCREASING OVER
WEST CENTRAL TO NORTHEAST IOWA BY 12Z...FOCUSING AN EXPANDING AREA
OF MODERATE TO HEAVY RAINFALL IN THIS LOCATION. OF THESE THE EURO
HAS TRENDED SLIGHTLY FARTHER SOUTH WITH WIDESPREAD COVERAGE OF
RAINFALL. THE HRRR IS CONCENTRATING THE LIONS SHARE OF FORCING
OVER SOUTHERN IOWA TONIGHT...RIGHT ON THE NORTHERN EDGE OF MORE
ROBUST INSTABILITY. WITH BOTH VORT MAXES PLAYING A ROLE IN THE
OVERNIGHT FORECAST...IT LOOKS LIKE AN AREA OF MODERATE TO
POTENTIALLY LOCALLY HEAVY RAINFALL WILL OCCUR FROM WEST CENTRAL
TOWARD NORTHEAST WITH A SECONDARY MAXIMUM OVER THE SOUTHERN
SECTIONS SOUTH OF INTERSTATE 80...EAST TO ABOUT I35 AGAIN THIS
AREA COULD SEE LOCALLY HEAVY RAINFALL. WITH THE MAXIMUM
INSTABILITY SOUTH OF IOWA NOW...THE SOUTHERN AREAS SHOULD FILL IN
LATER THIS EVENING AS THE H850 LOW LEVEL JET OF 30 TO 40KT
INCREASES AFTER 03-04Z. PRECIPITABLE WATER VALUES ARE EXPECTED TO
INCREASE TO NEARLY 2 INCHES BY 06Z OVER MUCH OF THE REGION WITH
WARM CLOUD DEPTHS IN EXCESS OF 13KFT...PROMOTING EFFICIENT
RAINFALL PROCESSES. THE DAY1 CONVECTIVE OUTLOOK HAS BEEN INCREASED
FOR A SLIGHT RISK ACROSS THE SOUTH WITH SOME POTENTIAL FOR SEVERE
STORMS SOUTHWEST/WEST THROUGH THE EVENING HOURS...THOUGH MAIN
CONCERNS REMAIN POTENTIAL FOR LOCALLY HEAVY RAINFALL. WITH FLASH
FLOOD GUIDANCE BETWEEN 2 TO 3 INCHES PER 3 HOURS OVER THE
WEST/SOUTHWEST...WE MAY SEE SOME LOCALIZED FLASH FLOODING OVER
PORTIONS OF WESTERN/SOUTHWEST SECTIONS TONIGHT. FOR NOW HAVE HELD
OFF ON HEADLINES DUE TO SOME UNCERTAINTIES IN THE DEVELOPMENT OF
CONVECTION AND EVENTUAL EVOLUTION. LOWS WILL HOLD IN THE UPPER 60S
TO LOWER 70S WITH UNCOMFORTABLE DEW POINTS NEAR THE SAME VALUES.
WINDS WILL INCREASE A BIT FROM THE SOUTH DURING THE OVERNIGHT
HOURS.
.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
ISSUED AT 327 PM CDT WED JUL 15 2015
THE STORM SYSTEM SET TO AFFECT THE AREA TONIGHT...AS DISCUSSED AT
LENGTH IN THE SHORT TERM SECTION ABOVE...WILL CLEAR OUT TO THE
EAST ON THURSDAY MORNING. LARGE SCALE MODELS ARE A BIT SLOWER WITH
THIS CLEARING...WHILE THE HIGH RESOLUTION MODELS ARE SOMEWHAT
FASTER WHICH IS MORE CONSISTENT WITH CLIMATOLOGY IN THIS SYNOPTIC
SET UP. FURTHERMORE THERE ARE INDICATIONS THAT A WEAK UPPER
IMPULSE MOVING IN BEHIND THE INITIAL WAVE...COMBINED WITH
AFTERNOON DESTABILIZATION AND LINGERING OUTFLOW BOUNDARIES FROM
MORNING CONVECTION...MAY LEAD TO SOME ISOLATED STORM REDEVELOPMENT
LATE IN THE DAY OR THURSDAY EVENING. AS A RESULT OF ALL OF THESE
FACTORS...MAINTAINED A FAIRLY RAPID CLEARING OF HIGHER POPS TO THE
EAST ON THURSDAY MORNING BUT HELD SOME LOWER POPS BACK IN THE
SOUTH AND WEST AT TIMES MAINLY THURSDAY EVENING. ALSO MAINTAINED
SOME FOG MENTION LATE THURSDAY NIGHT/EARLY FRIDAY MORNING GIVEN
THE LIGHT AND VARIABLE WINDS EXPECTED ALONG WITH CLEARING SKIES
AND WET GROUND/HIGH DEWPOINTS.
BY FRIDAY SOUTHERLY SURFACE WINDS WILL RETURN TO THE AREA...WITH
500 MB FLOW TURNING TO WEST SOUTHWEST AND A FRONTAL BOUNDARY
DEVELOPING WELL TO OUR NORTHWEST ACROSS SOUTH DAKOTA AND
MINNESOTA. THIS BOUNDARY WILL LIKELY PROVIDE THE IMPETUS FOR
THUNDERSTORM DEVELOPMENT FRIDAY EVENING AND FRIDAY NIGHT...BUT
THIS SHOULD LARGELY STAY NORTH OF OUR FORECAST AREA. ALSO...THERE
MAY BE SOME PEAK HEATING STORM DEVELOPMENT ACROSS OUR AREA IN THE
WARM SECTOR FRIDAY AFTERNOON AND EVENING...HOWEVER A GENERAL LACK
OF FORCING OR FOCUS MECHANISM PROHIBIT INTRODUCING POPS AT THIS
TIME. FRIDAY WILL ALSO SEE A RETURN OF MORE HEAT AND HUMIDITY...AS
LOW LEVEL WARM AIR AND MOISTURE ADVECTION BENEATH INCREASING
TEMPERATURES ALOFT PROMOTE HIGH TEMPERATURES IN THE LOWER 90S WITH
HEAT INDEX VALUES APPROACHING 100 LATE IN THE DAY. SATURDAY WILL
BE QUITE SIMILAR...WITH HOT AND HUMID CONDITIONS AND A LOW CHANCE
OF WARM SECTOR THUNDERSTORMS THAT WOULD BE ISOLATED IF THEY
DEVELOP.
FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT THE FORECAST WILL BE
DOMINATED BY THE APPROACH AND PASSAGE OF THE AFOREMENTIONED
FRONTAL BOUNDARY FROM NORTHWEST TO SOUTHEAST. A WARM AND VERY
UNSTABLE AIRMASS AHEAD OF THE FRONT WILL PROMOTE VIGOROUS
THUNDERSTORM DEVELOPMENT PARTICULARLY SUNDAY AFTERNOON AND
EVENING...WITH BULK SHEAR FORECASTS CERTAINLY SUPPORTING SOME
SEVERE WEATHER THREAT WITH THE ADVANCING FRONTAL ZONE.
HOWEVER...SIGNIFICANT DIFFERENCES IN THE TIMING OF THIS PASSAGE
REMAIN AMONG THE VARIOUS MODELS. THE ECMWF HAS BEEN STICKING TO
ITS GUNS FOR THE LAST THREE RUNS WITH A MUCH FASTER PASSAGE AND
THE GFS HAS BEEN SLOWLY COMING AROUND IN THAT DIRECTION. IF THIS
OCCURS...IT WOULD RESULT IN SOMEWHAT COOLER HIGHS SUNDAY AND SHIFT
ANY SEVERE WEATHER POTENTIAL MORE ACROSS SOUTHERN AND EASTERN IOWA
RATHER THAN FURTHER NORTHWEST. FOR NOW THE UNCERTAINTY IN THIS
EVOLUTION RESULTS IN SEVERAL PERIODS OF CHANCE POPS WITH NO
LIKELIES INTRODUCED AS OF YET...BUT ONCE THE DETAILS OF TIMING
BECOME CLEARER THEN HIGHER POPS WILL NEED TO BE INTRODUCED IN ONE
OR MORE OF THE PERIODS FROM SATURDAY NIGHT THROUGH SUNDAY
NIGHT...AND SUNDAY HIGH TEMPERATURES MAY NEED TO BE ADJUSTED
FURTHER AS WELL.
AS ROUGHLY ZONAL STEERING FLOW PERSISTS INTO EARLY NEXT WEEK
TEMPERATURES BEHIND THE SUNDAY COOL FRONT WILL SLOWLY MODERATE AND
LOW RAIN CHANCES WILL PERSIST. GIVEN THE DIFFICULTY IN PREDICTING
ANY SUBTLE IMPULSES TYPICALLY MOVING THROUGH SUCH FLOW AT THIS
TIME RANGE...HAVE MAINTAINED ONLY LOW POPS AT TIMES IN THE LATTER
PART OF THE EXTENDED FORECAST PERIOD.
&&
.AVIATION...15/18Z
ISSUED AT 1247 PM CDT WED JUL 15 2015
REMNANT MODERATE SHOWERS MOVING ACROSS THE AREA FROM THE SOUTHWEST
AS MCV CONTINUES TO GENERATE MORE SHOWERS WEST. ACROSS THE EAST
CIGS REMAIN MVFR NEAR KALO AND KOTM...WITH SOME IMPROVEMENT AFT
19Z. MCV EXPECTED TO EXPAND PRECIP SHIELD TONIGHT WITH IFR/MVFR
CIGS AND POTENTIAL FOR +SHRA AND TSRA THROUGH 13Z ACROSS THE
REGION. FAVORED AREAS REMAIN NORTH SITES...HOWEVER MESO MODELS
OFFERING DIFFERING SOLNS EVEN NOW WHICH MAY RESULT IN SOME
SOUTHWARD SHIFT OF HEAVY RAIN/LOWER CONDITIONS AXIS IN THE NEXT
TAF PACKAGE./REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...REV
LONG TERM...LEE
AVIATION...REV
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
250 PM EDT WED JUL 15 2015
.UPDATE...
ISSUED AT 225 PM EDT WED JUL 15 2015
DID A QUICK UPDATE TO FINE TUNE TEMPS AND DEWPOINTS THROUGH THE
REST OF THE AFTERNOON. THESE HAVE BEEN SENT TO THE NDFD AND WEB
SERVERS.
UPDATE ISSUED AT 1025 AM EDT WED JUL 15 2015
14Z SFC ANALYSIS SHOWS HIGH PRESSURE BUILDING INTO EASTERN
KENTUCKY AND PROVIDING A BREATHER FROM THE ACTIVE WEATHER OF THE
PAST SEVERAL DAYS. ACCOMPANYING THE HIGH IS A BAND OF LOWER
STRATUS SINKING SOUTH THROUGH THE CWA. THANKS TO THIS MANY
LOCATIONS IN THE NORTHERN PARTS OF EAST KENTUCKY ARE STILL IN THE
UPPER 60S WHILE SPOTS TO THE SOUTH HAVE CLIMBED INTO THE LOWER AND
MIDDLE 70S. NORTHWEST TO NORTH WINDS OF 5 TO 10 KTS ARE BRINGING
IN DRIER AIR...AS WELL...WITH DEWPOINTS RUNNING ABOUT 10 DEGREES
LOWER THAN THOSE OF YESTERDAY. ON RADAR...THERE HAVE BEEN A FEW
VERY LIGHT RETURNS ACROSS THE FAR EAST OVER THE PAST COUPLE OF
HOURS...BUT IT IS DOUBTFUL THAT ANY MORE THAN A FEW SPRINKLES
MAKING IT TO THE GROUND. THE REST OF THE DAY WILL BE PARTLY CLOUDY
AND DRIER/COOLER THAN YESTERDAY THANKS TO THE CLOUDS AND NORTHERLY
SFC WINDS. THE HRRR AND...TO A CERTAIN DEGREE...THE NAM12 ARE
HINTING THAT SOME VERY LIGHT AND BRIEF SHOWERS WILL BE POSSIBLE
THROUGH THE AREA. AS THIS WILL BE INSIGNIFICANT...FOR NOW...WILL
KEEP THE POPS SUB 14 PERCENT AND ANY PCPN OUT OF THE WX
GRIDS/ZONES. HAVE UPDATED THE FORECAST MAINLY TO REMOVE THE FOG
MENTION AND ALSO TO TWEAK TEMPS/DEWPOINTS PER THE LATEST OBS AND
TRENDS. THE GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS IN
ADDITION TO A FRESHENED SET OF ZONES.
UPDATE ISSUED AT 721 AM EDT WED JUL 15 2015
9Z SURFACE ANALYSIS HAD THE FRONT MOSTLY THROUGH THE ARE AND
SHOULD MAKE IT THE REST OF THE WAY BY AROUND 12Z. A FEW STRATUS
CLOUDS ARE MOVING THROUGH AND ARE STILL EXPECTED TO LIFT OUT BY
THE AFTERNOON. NO MAJOR CHANGES NEEDED THIS UPDATE WITH MINOR
ADJUSTMENTS TO ACCOUNT FOR LATEST OBS AND TRENDS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 327 AM EDT WED JUL 15 2015
WATER VAPOR SHOWS A POTENT UPPER LOW FOR THIS TIME OF YEAR SPINNING
EAST ACROSS THE MID ATLANTIC THIS MORNING. WHILE THERE IS IS BIT
MORE IN THE WAY OF MID/UPPER LEVEL DRYING ACROSS THE OHIO VALLEY.
THEREFORE LOOKING AT REGIONAL RADAR DATA THIS MORNING SHOWS MUCH
OF THE SHOWER AND THUNDERSTORM ACTION SEEN YESTERDAY EVENING HAS
MOVED INTO THE SOUTHERN TENNESSEE VALLEY REGION THIS MORNING. THE
FRONT IS LAGGING BEHIND THIS AND THAT COUPLED WITH SOME DIVERGENCE
ALOFT GENERATED SOME ISOLATED SHOWERS IN THE FAR EAST AND
SOUTHEAST...HOWEVER THIS WILL CONTINUE SOUTHEAST OUT OF THE AREA
THIS MORNING. GIVEN THAT ACTIVITY HAS MOVED OUT OF THE REGION AND
NOT ADDITIONAL RAINFALL IS EXPECTED IN THE SHORT TERM PERIOD WILL
LET THE FLASH FLOOD WATCH EXPIRE WITH PACKAGE ISSUANCE. SOME
STRATUS IS INDICATED BY IR SAT AND UPSTREAM OBS MOVING SOUTH OUT
OF OHIO THIS MORNING AND THIS COULD SWEEP ACROSS THE REGION. ALSO
SHOULD NOTE MODEL SOUNDINGS AND TIME HEIGHTS WANT TO KEEP A BIT OF
LOWER MOISTURE IN PLACE..SO TRY TO REFLECT THIS THROUGH THE MID
MORNING TIME FRAME IN THE GRIDS. OTHERWISE DOES LOOK LIKE OVERALL
CLOUDS WILL BE ON THE DECREASE THROUGH THE DAY. THIS WILL BE A
SIGH OF RELIEF AFTER SUCH A ACTIVE WEATHER PATTERN OVER THE PAST
SEVERAL DAYS.
REST OF THE PERIOD STAYS QUIET AS MODELS STAY IN GOOD AGREEMENT
WITH HEIGHT RISES AS UPPER HIGH MEANDERS AROUND NEAR THE ARKLATEX
REGION. AT THE SURFACE A HIGH PRESSURE TRAVERSES THE GREAT LAKES
INTO SOUTHERN NEW ENGLAND. ALL OF THESE ELEMENTS WILL COMBINE TO
BRING NEAR TO BELOW NORMAL TEMPS AND MOSTLY SUNNY SKIES BY
THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 455 AM EDT WED JUL 15 2015
THE MODELS REMAIN IN GOOD AGREEMENT WITH UPPER LEVEL RIDGING
BUILDING INTO THE LOWER AND MIDDLE MISSISSIPPI VALLEY THROUGH THE
FIRST HALF OF THE WEEKEND...BEFORE ANOTHER TROUGH SHIFTS EAST
ACROSS THE NORTHERN CONUS...SUPPRESSING THE RIDGE TO THE SOUTH AND
SOUTHWEST. THERE ARE MORE MODEL DIFFERENCES WITH REGARDS TO THE
STRENGTH OF THE APPROACHING TROUGH...WITH THE GFS ON THE WEAKER
SIDE...WHILE THE ECMWF IS MORE ROBUST. AS SUCH...FOLLOWED THE
BLEND PRETTY CLOSE.
FOR EASTERN KENTUCKY...PLENTY OF HEAT AND HUMIDITY WILL BE ON TAP
FROM FRIDAY THROUGH MONDAY...WITH HIGHS AROUND 90 AND LOWS AROUND
70. HEAT INDICES WILL GENERALLY PEAK IN THE 95 TO 100 DEGREE RANGE
FROM SATURDAY THROUGH MONDAY. TEMPERATURES WILL THEN COOL OFF A
BIT ON TUESDAY...WITH HIGHS DROPPING BACK INTO THE MID AND UPPER
80S. ALONG WITH THE HEAT AND HUMIDITY...WILL BE THE RETURN OF
SHOWER AND THUNDERSTORM CHANCES...GENERALLY PEAKING DURING THE
AFTERNOON AND EARLY EVENING HOURS. THE BEST POPS WILL ARRIVE EARLY
NEXT WEEK AS A COLD FRONT SHIFTS SOUTHEAST ACROSS THE AREA. STUCK
FAIRLY CLOSE TO BLENDED GUIDANCE...ALTHOUGH DID UNDERCUT POPS A
BIT MORE DURING PERIODS OF WEAKER FORCING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 250 PM EDT WED JUL 15 2015
THE CIGS ARE NOW COMING UP OUT OF THE MVFR REACHING VFR ACROSS
THE AREA. LOOK FOR THE CLOUDS TO BREAKUP AND SCATTER OUT LATER
THIS EVENING. THIS WILL LIKELY LEAD TO THE DEVELOPMENT OF FOG
OVERNIGHT AT ALL SITES. EXPECT THE THICKEST FOG WITH THE WORSE
CONDITIONS...DOWN TO VLIFR...IN THE LOWER TAF SITES OF SME AND
LOZ. THE CONDITIONS WILL THEN IMPROVE DURING THE MORNING THURSDAY
WITH VFR TO FOLLOW. WINDS WILL BE RELATIVELY LIGHT THROUGH THE
PERIOD AT 5 TO 10 KTS OR LESS GENERALLY FROM THE NORTH.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...DJ
LONG TERM...GEOGERIAN
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1025 AM EDT WED JUL 15 2015
.UPDATE...
ISSUED AT 1025 AM EDT WED JUL 15 2015
14Z SFC ANALYSIS SHOWS HIGH PRESSURE BUILDING INTO EASTERN
KENTUCKY AND PROVIDING A BREATHER FROM THE ACTIVE WEATHER OF THE
PAST SEVERAL DAYS. ACCOMPANYING THE HIGH IS A BAND OF LOWER
STRATUS SINKING SOUTH THROUGH THE CWA. THANKS TO THIS MANY
LOCATIONS IN THE NORTHERN PARTS OF EAST KENTUCKY ARE STILL IN THE
UPPER 60S WHILE SPOTS TO THE SOUTH HAVE CLIMBED INTO THE LOWER AND
MIDDLE 70S. NORTHWEST TO NORTH WINDS OF 5 TO 10 KTS ARE BRINGING
IN DRIER AIR...AS WELL...WITH DEWPOINTS RUNNING ABOUT 10 DEGREES
LOWER THAN THOSE OF YESTERDAY. ON RADAR...THERE HAVE BEEN A FEW
VERY LIGHT RETURNS ACROSS THE FAR EAST OVER THE PAST COUPLE OF
HOURS...BUT IT IS DOUBTFUL THAT ANY MORE THAN A FEW SPRINKLES
MAKING IT TO THE GROUND. THE REST OF THE DAY WILL BE PARTLY CLOUDY
AND DRIER/COOLER THAN YESTERDAY THANKS TO THE CLOUDS AND NORTHERLY
SFC WINDS. THE HRRR AND...TO A CERTAIN DEGREE...THE NAM12 ARE
HINTING THAT SOME VERY LIGHT AND BRIEF SHOWERS WILL BE POSSIBLE
THROUGH THE AREA. AS THIS WILL BE INSIGNIFICANT...FOR NOW...WILL
KEEP THE POPS SUB 14 PERCENT AND ANY PCPN OUT OF THE WX
GRIDS/ZONES. HAVE UPDATED THE FORECAST MAINLY TO REMOVE THE FOG
MENTION AND ALSO TO TWEAK TEMPS/DEWPOINTS PER THE LATEST OBS AND
TRENDS. THE GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS IN
ADDITION TO A FRESHENED SET OF ZONES.
UPDATE ISSUED AT 721 AM EDT WED JUL 15 2015
9Z SURFACE ANALYSIS HAD THE FRONT MOSTLY THROUGH THE ARE AND
SHOULD MAKE IT THE REST OF THE WAY BY AROUND 12Z. A FEW STRATUS
CLOUDS ARE MOVING THROUGH AND ARE STILL EXPECTED TO LIFT OUT BY
THE AFTERNOON. NO MAJOR CHANGES NEEDED THIS UPDATE WITH MINOR
ADJUSTMENTS TO ACCOUNT FOR LATEST OBS AND TRENDS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 327 AM EDT WED JUL 15 2015
WATER VAPOR SHOWS A POTENT UPPER LOW FOR THIS TIME OF YEAR SPINNING
EAST ACROSS THE MID ATLANTIC THIS MORNING. WHILE THERE IS IS BIT
MORE IN THE WAY OF MID/UPPER LEVEL DRYING ACROSS THE OHIO VALLEY.
THEREFORE LOOKING AT REGIONAL RADAR DATA THIS MORNING SHOWS MUCH
OF THE SHOWER AND THUNDERSTORM ACTION SEEN YESTERDAY EVENING HAS
MOVED INTO THE SOUTHERN TENNESSEE VALLEY REGION THIS MORNING. THE
FRONT IS LAGGING BEHIND THIS AND THAT COUPLED WITH SOME DIVERGENCE
ALOFT GENERATED SOME ISOLATED SHOWERS IN THE FAR EAST AND
SOUTHEAST...HOWEVER THIS WILL CONTINUE SOUTHEAST OUT OF THE AREA
THIS MORNING. GIVEN THAT ACTIVITY HAS MOVED OUT OF THE REGION AND
NOT ADDITIONAL RAINFALL IS EXPECTED IN THE SHORT TERM PERIOD WILL
LET THE FLASH FLOOD WATCH EXPIRE WITH PACKAGE ISSUANCE. SOME
STRATUS IS INDICATED BY IR SAT AND UPSTREAM OBS MOVING SOUTH OUT
OF OHIO THIS MORNING AND THIS COULD SWEEP ACROSS THE REGION. ALSO
SHOULD NOTE MODEL SOUNDINGS AND TIME HEIGHTS WANT TO KEEP A BIT OF
LOWER MOISTURE IN PLACE..SO TRY TO REFLECT THIS THROUGH THE MID
MORNING TIME FRAME IN THE GRIDS. OTHERWISE DOES LOOK LIKE OVERALL
CLOUDS WILL BE ON THE DECREASE THROUGH THE DAY. THIS WILL BE A
SIGH OF RELIEF AFTER SUCH A ACTIVE WEATHER PATTERN OVER THE PAST
SEVERAL DAYS.
REST OF THE PERIOD STAYS QUIET AS MODELS STAY IN GOOD AGREEMENT
WITH HEIGHT RISES AS UPPER HIGH MEANDERS AROUND NEAR THE ARKLATEX
REGION. AT THE SURFACE A HIGH PRESSURE TRAVERSES THE GREAT LAKES
INTO SOUTHERN NEW ENGLAND. ALL OF THESE ELEMENTS WILL COMBINE TO
BRING NEAR TO BELOW NORMAL TEMPS AND MOSTLY SUNNY SKIES BY
THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 455 AM EDT WED JUL 15 2015
THE MODELS REMAIN IN GOOD AGREEMENT WITH UPPER LEVEL RIDGING
BUILDING INTO THE LOWER AND MIDDLE MISSISSIPPI VALLEY THROUGH THE
FIRST HALF OF THE WEEKEND...BEFORE ANOTHER TROUGH SHIFTS EAST
ACROSS THE NORTHERN CONUS...SUPPRESSING THE RIDGE TO THE SOUTH AND
SOUTHWEST. THERE ARE MORE MODEL DIFFERENCES WITH REGARDS TO THE
STRENGTH OF THE APPROACHING TROUGH...WITH THE GFS ON THE WEAKER
SIDE...WHILE THE ECMWF IS MORE ROBUST. AS SUCH...FOLLOWED THE
BLEND PRETTY CLOSE.
FOR EASTERN KENTUCKY...PLENTY OF HEAT AND HUMIDITY WILL BE ON TAP
FROM FRIDAY THROUGH MONDAY...WITH HIGHS AROUND 90 AND LOWS AROUND
70. HEAT INDICES WILL GENERALLY PEAK IN THE 95 TO 100 DEGREE RANGE
FROM SATURDAY THROUGH MONDAY. TEMPERATURES WILL THEN COOL OFF A
BIT ON TUESDAY...WITH HIGHS DROPPING BACK INTO THE MID AND UPPER
80S. ALONG WITH THE HEAT AND HUMIDITY...WILL BE THE RETURN OF
SHOWER AND THUNDERSTORM CHANCES...GENERALLY PEAKING DURING THE
AFTERNOON AND EARLY EVENING HOURS. THE BEST POPS WILL ARRIVE EARLY
NEXT WEEK AS A COLD FRONT SHIFTS SOUTHEAST ACROSS THE AREA. STUCK
FAIRLY CLOSE TO BLENDED GUIDANCE...ALTHOUGH DID UNDERCUT POPS A
BIT MORE DURING PERIODS OF WEAKER FORCING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 700 AM EDT WED JUL 15 2015
MUCH BETTER PERIOD IS SHAPING UP OVERALL FOR THIS TAF PERIOD
COMPARED TO THE PAST COUPLE OF DAYS. WHILE CONFIDENT A FEW PARTS
OF THE AREA ARE SEEING AT LEAST MVFR VIS...MOST SITES HAVE BEEN
ABLE TO KEEP MOSTLY VFR IN THAT REGARD OVERNIGHT. THIS HAS BEEN
AIDED BY SOME STRATUS THAT DROPPED SOUTHWARD OUT OF OHIO
OVERNIGHT. THIS WILL PLAGUE PORTIONS OF THE REGION THROUGH THE
MORNING HOURS...HOWEVER DOES APPEAR THIS WILL BE MOSTLY MVFR
CEILINGS. OTHERWISE THE NEXT CONCERN WILL BE FOG OR NOT TO FOG
TONIGHT. DID GO AHEAD AND LEAN IN THAT DIRECTION...BUT STILL NOT
CONFIDENT HOW THAT WILL SHAPE UP OVERALL. GIVEN HIGH PRESSURE AND
BUILDING HEIGHTS EXPECTING GENERALLY LIGHT WINDS OVERALL.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...DJ
LONG TERM...GEOGERIAN
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
224 PM CDT WED JUL 15 2015
.UPDATE...TEMPERATURES AND DEW POINTS NOT AS HIGH AS PREVIOUSLY
FCST FOR THIS AFTERNOON. RUC LOOKS TO BE TRACKING TOO HIGH. ZONES
ALREADY UPDATED. GRIDS TO FOLLOW.
SWEENEY
&&
.PREV DISCUSSION... /ISSUED 1236 PM CDT WED JUL 15 2015/
DISCUSSION...
FOR 18Z TAF ISSUANCE.
AVIATION...
NOT MUCH MORE THAN A PERSISTENCE FORECAST THIS AFTERNOON AS
RIDGING ALOFT IS PROGGED TO STAY IN CONTROL AND KEEP MUCH OF THE
ATMOSPHERE DRY THROUGH THE PERIOD. COULD BE SOME MVFR CEILINGS
LATE MAINLY AT KBPT...OTHERWISE VFR WILL BE THE RULE ALONG WITH
MAINLY LIGHT WINDS.
25
PREV DISCUSSION... /ISSUED 1007 AM CDT WED JUL 15 2015/
UPDATE...LATEST RUC CONFIRMING SUBSIDENCE EFFECTS FROM DYNAMIC
HIGH PRESSURE FROM THE UPPER LEVELS. ADJUSTED TEMPS UP FOR
INTERIOR AREAS FROM GUIDANCE. CLOSER TO THE COAST, ONLY A TWEAK
HIGHER. COMBINED WITH UPDATED DEW POINTS, HEAT INDICES APPROACH
BUT DO NOT REACH ADVISORY LEVELS BUT WILL MONITOR THIS. REMAINDER
OF THE FORECAST ON TRACK WITH POSSIBLILITY OF ISOLD SHOWERS FOR
ACADIANA THIS AFTERNOON...NOT ENOUGH TO MENTION IN THE ZONES.
SWEENEY
PREV DISCUSSION... /ISSUED 546 AM CDT WED JUL 15 2015/
AVIATION...STRONG HIGH PRESSURE AT THE SURFACE AND ALOFT WILL
MAINTAIN A DRY WEATHER PATTERN ALONG WITH VFR. WINDS WILL REMAIN
LIGHT AND GENERALLY FROM THE WEST TO SOUTHWEST.
PREV DISCUSSION... /ISSUED 359 AM CDT WED JUL 15 2015/
DISCUSSION...
FAIRLY TYPICAL SUMMER NIGHT ACROSS THE FORECAST AREA WITH
TEMPERATURES IN THE MID 70S...AND A FEW SMALL NOCTURNAL SHOWERS
TRYING TO FORM OFF THE LOWER ACADIANA COAST.
LATEST WATER VAPOR IMAGERY STILL INDICATES AN UPPER LEVEL RIDGE
HANGING IN OVER THE REGION WITH DRY AND SUBSIDENT AIR IN THE MID
AND UPPER LEVELS. THIS IS CONFIRMED BY THE 15/00Z UPPER AIR
SOUNDING FROM KLCH WITH A BELOW NORM PWAT READING OF 1.3 INCHES
AND MEAN RH AROUND 40 PERCENT...WITH THE MID LEVEL RH AT 27
PERCENT. RECENT GPS-MET INTEGRATED PWAT VALUES AROUND THE AREA
SHOW NOT MUCH CHANGE WITH READINGS STILL FROM ROUGHLY 1.25 INCHES
TO 1.4 INCHES.
MOISTURE VALUES ARE PROGGED TO STAY ROUGHLY THE SAME FOR THE NEXT
FEW DAYS AS THE MID/UPPER LEVEL RIDGE CONTINUES TO HOLD IN PLACE.
MID LEVEL MOISTURE LOOKS TO REMAIN ON THE LOW SIDE WITH VALUES IN
THE 30 PERCENT RANGE. THIS SHOULD PRECLUDE ANY SIGNIFICANT SHOWER
ACTIVITY...ALTHOUGH ONE OR TWO ISOLATED CELLS MAY FORM IN THE MAX
DAYTIME HEATING OVER THE COASTAL MARSHES WHERE SEA BREEZE
CONVERGENCE AND ATCHAFALAYA BASIN CONVERGENCE OCCURS...BUT
PROBABILITY LOW ENOUGH (BELOW 15 PERCENT) TO MENTION.
WITH SOUTHERLY SURFACE WINDS...LOW LEVEL MOISTURE WILL BE PLENTY
TO HELP BRING ABOUT SUMMERTIME HOT AND MUGGY CONDITIONS. ENOUGH
MIXING HAS BEEN OCCURRING DURING THE AFTERNOON HOURS TO KEEP HEAT
INDEX READINGS JUST IN CHECK...WITH A MAJORITY OF THE REPORTING
SITES SEEING 100F TO 102F WITH ISOLATED SPOTS FROM 103F TO 106F.
PERSISTENCE LOOKS LIKE THE WAY TO GO HERE...SO VALUES WILL BE JUST
BELOW HEAT ADVISORY CRITERIA. WILL MAKE MENTION IN THE HAZARDOUS
WEATHER OUTLOOK OF THE HEAT INDEX READINGS BETWEEN 102F AND 106F
DURING THE AFTERNOON HOURS.
BY THE WEEKEND...PROGS HINTING AT THE MID/UPPER LEVEL RIDGE
SLIGHTLY WEAKENING...WITH THE GFS MORE INCLINED TO BRING SOME MID
LEVEL MOISTURE BACK INTO THE REGION. WITH THIS...WILL INTRODUCE
ONLY SLIGHT POPS FOR SATURDAY AND SUNDAY FOR EASTERN PORTIONS
(MAINLY LOWER ACADIANA.) WITH CHANCES FOR SHOWERS EXPANDING
WESTWARD TO INCLUDE A MAJORITY OF THE FORECAST AREA EARLY TO MID
PART OF NEXT WEEK. STILL POPS ONLY IN THE 20-30 PERCENT RANGE.
RUA
MARINE...
SURFACE HIGH PRESSURE IS CENTERED OVER THE EASTERN GULF OF MEXICO.
THIS HIGH WILL RIDGE ACROSS THE NORTHERN GULF OF MEXICO FOR THE
NEXT SEVERAL DAYS. THEREFORE...NO REAL CHANGE FOR THE COASTAL
WATERS AS FAR AS WINDS AND SEAS GOES...WITH MAINLY LIGHT SOUTHWEST
TO SOUTH WINDS AND LOW SEAS. A FEW MORE SHOWERS AND THUNDERSTORMS
MAY BEGIN TO DEVELOP OVER THE WEEKEND OFF THE LOWER ACADIANA
WATERS...AS AN UPPER LEVEL HIGH SHOWS SIGNS OF WEAKENING.
RUA
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 99 74 96 74 / 0 0 10 10
LCH 94 77 93 77 / 10 0 10 0
LFT 95 77 93 76 / 10 10 10 10
BPT 94 77 92 79 / 10 0 20 0
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
PUBLIC...11
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1236 PM CDT WED JUL 15 2015
.DISCUSSION...
FOR 18Z TAF ISSUANCE.
&&
.AVIATION...
NOT MUCH MORE THAN A PERSISTENCE FORECAST THIS AFTERNOON AS
RIDGING ALOFT IS PROGGED TO STAY IN CONTROL AND KEEP MUCH OF THE
ATMOSPHERE DRY THROUGH THE PERIOD. COULD BE SOME MVFR CEILINGS
LATE MAINLY AT KBPT...OTHERWISE VFR WILL BE THE RULE ALONG WITH
MAINLY LIGHT WINDS.
25
&&
.PREV DISCUSSION... /ISSUED 1007 AM CDT WED JUL 15 2015/
UPDATE...LATEST RUC CONFIRMING SUBSIDENCE EFFECTS FROM DYNAMIC
HIGH PRESSURE FROM THE UPPER LEVELS. ADJUSTED TEMPS UP FOR
INTERIOR AREAS FROM GUIDANCE. CLOSER TO THE COAST, ONLY A TWEAK
HIGHER. COMBINED WITH UPDATED DEW POINTS, HEAT INDICES APPROACH
BUT DO NOT REACH ADVISORY LEVELS BUT WILL MONITOR THIS. REMAINDER
OF THE FORECAST ON TRACK WITH POSSIBLILITY OF ISOLD SHOWERS FOR
ACADIANA THIS AFTERNOON...NOT ENOUGH TO MENTION IN THE ZONES.
SWEENEY
PREV DISCUSSION... /ISSUED 546 AM CDT WED JUL 15 2015/
AVIATION...STRONG HIGH PRESSURE AT THE SURFACE AND ALOFT WILL
MAINTAIN A DRY WEATHER PATTERN ALONG WITH VFR. WINDS WILL REMAIN
LIGHT AND GENERALLY FROM THE WEST TO SOUTHWEST.
PREV DISCUSSION... /ISSUED 359 AM CDT WED JUL 15 2015/
DISCUSSION...
FAIRLY TYPICAL SUMMER NIGHT ACROSS THE FORECAST AREA WITH
TEMPERATURES IN THE MID 70S...AND A FEW SMALL NOCTURNAL SHOWERS
TRYING TO FORM OFF THE LOWER ACADIANA COAST.
LATEST WATER VAPOR IMAGERY STILL INDICATES AN UPPER LEVEL RIDGE
HANGING IN OVER THE REGION WITH DRY AND SUBSIDENT AIR IN THE MID
AND UPPER LEVELS. THIS IS CONFIRMED BY THE 15/00Z UPPER AIR
SOUNDING FROM KLCH WITH A BELOW NORM PWAT READING OF 1.3 INCHES
AND MEAN RH AROUND 40 PERCENT...WITH THE MID LEVEL RH AT 27
PERCENT. RECENT GPS-MET INTEGRATED PWAT VALUES AROUND THE AREA
SHOW NOT MUCH CHANGE WITH READINGS STILL FROM ROUGHLY 1.25 INCHES
TO 1.4 INCHES.
MOISTURE VALUES ARE PROGGED TO STAY ROUGHLY THE SAME FOR THE NEXT
FEW DAYS AS THE MID/UPPER LEVEL RIDGE CONTINUES TO HOLD IN PLACE.
MID LEVEL MOISTURE LOOKS TO REMAIN ON THE LOW SIDE WITH VALUES IN
THE 30 PERCENT RANGE. THIS SHOULD PRECLUDE ANY SIGNIFICANT SHOWER
ACTIVITY...ALTHOUGH ONE OR TWO ISOLATED CELLS MAY FORM IN THE MAX
DAYTIME HEATING OVER THE COASTAL MARSHES WHERE SEA BREEZE
CONVERGENCE AND ATCHAFALAYA BASIN CONVERGENCE OCCURS...BUT
PROBABILITY LOW ENOUGH (BELOW 15 PERCENT) TO MENTION.
WITH SOUTHERLY SURFACE WINDS...LOW LEVEL MOISTURE WILL BE PLENTY
TO HELP BRING ABOUT SUMMERTIME HOT AND MUGGY CONDITIONS. ENOUGH
MIXING HAS BEEN OCCURRING DURING THE AFTERNOON HOURS TO KEEP HEAT
INDEX READINGS JUST IN CHECK...WITH A MAJORITY OF THE REPORTING
SITES SEEING 100F TO 102F WITH ISOLATED SPOTS FROM 103F TO 106F.
PERSISTENCE LOOKS LIKE THE WAY TO GO HERE...SO VALUES WILL BE JUST
BELOW HEAT ADVISORY CRITERIA. WILL MAKE MENTION IN THE HAZARDOUS
WEATHER OUTLOOK OF THE HEAT INDEX READINGS BETWEEN 102F AND 106F
DURING THE AFTERNOON HOURS.
BY THE WEEKEND...PROGS HINTING AT THE MID/UPPER LEVEL RIDGE
SLIGHTLY WEAKENING...WITH THE GFS MORE INCLINED TO BRING SOME MID
LEVEL MOISTURE BACK INTO THE REGION. WITH THIS...WILL INTRODUCE
ONLY SLIGHT POPS FOR SATURDAY AND SUNDAY FOR EASTERN PORTIONS
(MAINLY LOWER ACADIANA.) WITH CHANCES FOR SHOWERS EXPANDING
WESTWARD TO INCLUDE A MAJORITY OF THE FORECAST AREA EARLY TO MID
PART OF NEXT WEEK. STILL POPS ONLY IN THE 20-30 PERCENT RANGE.
RUA
MARINE...
SURFACE HIGH PRESSURE IS CENTERED OVER THE EASTERN GULF OF MEXICO.
THIS HIGH WILL RIDGE ACROSS THE NORTHERN GULF OF MEXICO FOR THE
NEXT SEVERAL DAYS. THEREFORE...NO REAL CHANGE FOR THE COASTAL
WATERS AS FAR AS WINDS AND SEAS GOES...WITH MAINLY LIGHT SOUTHWEST
TO SOUTH WINDS AND LOW SEAS. A FEW MORE SHOWERS AND THUNDERSTORMS
MAY BEGIN TO DEVELOP OVER THE WEEKEND OFF THE LOWER ACADIANA
WATERS...AS AN UPPER LEVEL HIGH SHOWS SIGNS OF WEAKENING.
RUA
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 99 74 95 75 / 0 0 10 0
LCH 94 77 93 78 / 10 0 10 10
LFT 95 77 94 77 / 10 0 10 0
BPT 94 77 94 77 / 10 0 10 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AVIATION...04
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1007 AM CDT WED JUL 15 2015
.UPDATE...LATEST RUC CONFIRMING SUBSIDENCE EFFECTS FROM DYNAMIC
HIGH PRESSURE FROM THE UPPER LEVELS. ADJUSTED TEMPS UP FOR
INTERIOR AREAS FROM GUIDANCE. CLOSER TO THE COAST, ONLY A TWEAK
HIGHER. COMBINED WITH UPDATED DEW POINTS, HEAT INDICES APPROACH
BUT DO NOT REACH ADVISORY LEVELS BUT WILL MONITOR THIS. REMAINDER
OF THE FORECAST ON TRACK WITH POSSIBLILITY OF ISOLD SHOWERS FOR
ACADIANA THIS AFTERNOON...NOT ENOUGH TO MENTION IN THE ZONES.
SWEENEY
&&
.PREV DISCUSSION... /ISSUED 546 AM CDT WED JUL 15 2015/
AVIATION...STRONG HIGH PRESSURE AT THE SURFACE AND ALOFT WILL
MAINTAIN A DRY WEATHER PATTERN ALONG WITH VFR. WINDS WILL REMAIN
LIGHT AND GENERALLY FROM THE WEST TO SOUTHWEST.
PREV DISCUSSION... /ISSUED 359 AM CDT WED JUL 15 2015/
DISCUSSION...
FAIRLY TYPICAL SUMMER NIGHT ACROSS THE FORECAST AREA WITH
TEMPERATURES IN THE MID 70S...AND A FEW SMALL NOCTURNAL SHOWERS
TRYING TO FORM OFF THE LOWER ACADIANA COAST.
LATEST WATER VAPOR IMAGERY STILL INDICATES AN UPPER LEVEL RIDGE
HANGING IN OVER THE REGION WITH DRY AND SUBSIDENT AIR IN THE MID
AND UPPER LEVELS. THIS IS CONFIRMED BY THE 15/00Z UPPER AIR
SOUNDING FROM KLCH WITH A BELOW NORM PWAT READING OF 1.3 INCHES
AND MEAN RH AROUND 40 PERCENT...WITH THE MID LEVEL RH AT 27
PERCENT. RECENT GPS-MET INTEGRATED PWAT VALUES AROUND THE AREA
SHOW NOT MUCH CHANGE WITH READINGS STILL FROM ROUGHLY 1.25 INCHES
TO 1.4 INCHES.
MOISTURE VALUES ARE PROGGED TO STAY ROUGHLY THE SAME FOR THE NEXT
FEW DAYS AS THE MID/UPPER LEVEL RIDGE CONTINUES TO HOLD IN PLACE.
MID LEVEL MOISTURE LOOKS TO REMAIN ON THE LOW SIDE WITH VALUES IN
THE 30 PERCENT RANGE. THIS SHOULD PRECLUDE ANY SIGNIFICANT SHOWER
ACTIVITY...ALTHOUGH ONE OR TWO ISOLATED CELLS MAY FORM IN THE MAX
DAYTIME HEATING OVER THE COASTAL MARSHES WHERE SEA BREEZE
CONVERGENCE AND ATCHAFALAYA BASIN CONVERGENCE OCCURS...BUT
PROBABILITY LOW ENOUGH (BELOW 15 PERCENT) TO MENTION.
WITH SOUTHERLY SURFACE WINDS...LOW LEVEL MOISTURE WILL BE PLENTY
TO HELP BRING ABOUT SUMMERTIME HOT AND MUGGY CONDITIONS. ENOUGH
MIXING HAS BEEN OCCURRING DURING THE AFTERNOON HOURS TO KEEP HEAT
INDEX READINGS JUST IN CHECK...WITH A MAJORITY OF THE REPORTING
SITES SEEING 100F TO 102F WITH ISOLATED SPOTS FROM 103F TO 106F.
PERSISTENCE LOOKS LIKE THE WAY TO GO HERE...SO VALUES WILL BE JUST
BELOW HEAT ADVISORY CRITERIA. WILL MAKE MENTION IN THE HAZARDOUS
WEATHER OUTLOOK OF THE HEAT INDEX READINGS BETWEEN 102F AND 106F
DURING THE AFTERNOON HOURS.
BY THE WEEKEND...PROGS HINTING AT THE MID/UPPER LEVEL RIDGE
SLIGHTLY WEAKENING...WITH THE GFS MORE INCLINED TO BRING SOME MID
LEVEL MOISTURE BACK INTO THE REGION. WITH THIS...WILL INTRODUCE
ONLY SLIGHT POPS FOR SATURDAY AND SUNDAY FOR EASTERN PORTIONS
(MAINLY LOWER ACADIANA.) WITH CHANCES FOR SHOWERS EXPANDING
WESTWARD TO INCLUDE A MAJORITY OF THE FORECAST AREA EARLY TO MID
PART OF NEXT WEEK. STILL POPS ONLY IN THE 20-30 PERCENT RANGE.
RUA
MARINE...
SURFACE HIGH PRESSURE IS CENTERED OVER THE EASTERN GULF OF MEXICO.
THIS HIGH WILL RIDGE ACROSS THE NORTHERN GULF OF MEXICO FOR THE
NEXT SEVERAL DAYS. THEREFORE...NO REAL CHANGE FOR THE COASTAL
WATERS AS FAR AS WINDS AND SEAS GOES...WITH MAINLY LIGHT SOUTHWEST
TO SOUTH WINDS AND LOW SEAS. A FEW MORE SHOWERS AND THUNDERSTORMS
MAY BEGIN TO DEVELOP OVER THE WEEKEND OFF THE LOWER ACADIANA
WATERS...AS AN UPPER LEVEL HIGH SHOWS SIGNS OF WEAKENING.
RUA
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 99 74 95 75 / 0 0 10 0
LCH 94 77 93 78 / 10 0 10 10
LFT 95 77 94 77 / 10 0 10 0
BPT 94 77 94 77 / 10 0 10 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
PUBLIC...11
AREA FORECAST DISCUSSION
NWS GRAY ME
618 PM EDT WED JUL 15 2015
.SYNOPSIS...
A COLD FRONT WILL PUSH WELL OFF THE COAST THIS EVENING...BRINGING
A MUCH DRIER AIR MASS TO THE REGION. COOLER AIR WILL ALSO FILTER
IN FROM THE NORTH...WITH READINGS FALLING INTO THE 40S AND 50S.
HIGH PRESSURE WILL FOLLOW FOR THURSDAY AND THURSDAY
NIGHT...BRINGING QUIET WEATHER. THE HIGH WILL SHIFT OFFSHORE OVER
THE WEEKEND ALLOWING FOR A WARMER AND MORE MOIST AIRMASS TO MOVE
IN...POSSIBLY ASSOCIATED WITH SHOWERS AND THUNDERSTORMS. THIS
ACTIVITY COULD PERSIST INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
610 PM...MINOR ESTF UPDATE TO REFLECT CURRENT RADAR TRENDS... AND
TO INGEST THE 22Z MESONET INTO FIRST PERIOD GRIDS. SCATTERED
CONVECTION CONTINUES TO FIRE OVER EASTERN ROCKINGHAM COUNTY ALONG
CONVERGENCE ZONE...BUT EXPECT THIS ACTIVITY TO END NEXT 1 TO 2
HOURS WITH LOSS OF HEATING AND PER LATEST HRRR OUTPUT.
PREV DISC...
COLD FRONT CONTINUES ITS MARCH THRU THE FORECAST AREA...AND IS
CLEARING THE WESTERN MAINE COAST AT THIS HOUR. THE ONLY PORTION
OF THE FORECAST AREA REMAINING IN THE WARM SECTOR IS SOUTHEAST
NH...WHICH WILL ONLY BE FOR THE NEXT COUPLE OF HOURS AT MOST.
ANY REMAINING POP WILL CONFINED TO THIS AREA OF NH...WITH RAPID
DRYING FROM THE N.
DEWPOINTS ARE DROPPING INTO THE 50S AS THE DRIER AIR MASS WORKS
INTO THE REGION. AIR MASS IS SEASONABLY COOL...BUT THE CENTER OF
THE COLDEST TEMPERATURES ALOFT WILL DELAY IN ARRIVING UNTIL LATE
THURSDAY INTO FRIDAY. THUS WENT SLIGHTLY WARMER THAN GUIDANCE
TONIGHT...AS COLD ADVECTION WILL KEEP A SOMEWHAT MIXED BOUNDARY
LAYER.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
HIGH PRESSURE SETTLES OVER THE REGION THURSDAY AND THURSDAY NIGHT.
IT WILL BE A SPECTACULAR DAY THURSDAY...AS WARM TEMPERATURES
COMBINE WITH LOW DEWPOINTS FOR A VERY COMFORTABLE SUMMER DAY. NW
BREEZE WILL WEAKEN...ESPECIALLY LATE IN THE DAY...ALLOWING SEA
BREEZE TO PUSH INLAND LATE IN THE AFTERNOON.
WITH SKIES CLEAR AND WINDS LIGHT...TEMPERATURES WILL TUMBLE AFTER
SUNSET THURSDAY. UNDERCUT MODEL GUIDANCE...ESPECIALLY NORTHERN
VALLEYS...AS IDEAL RADIATIONAL COOLING CONDITIONS SET UP. ALSO
EXPECT VALLEY FOG TO BE MORE PREVALENT THURSDAY NIGHT...AS LACK
OF GRADIENT WILL REDUCE ANY POTENTIAL MIXING.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE MOVES EAST ON FRIDAY SETTING UP RETURN SOUTHERLY
LOW LEVEL FLOW OVER THE REGION. THIS WILL BRING IN SLIGHTLY WARMER
AND MORE HUMID AIR FOR FRIDAY THOUGH IT SHOULD REMAIN A DRY DAY.
A SHORTWAVE TROUGH MOVING QUICKLY THROUGH SOUTHERN CANADA WILL
SEND A WEAK SURFACE LOW PRESSURE SYSTEM THROUGH THE NORTHERN GREAT
LAKES AND EASTWARD ALONG THE CANADIAN BORDER INTO MAINE BY
SATURDAY. EXPECT SHOWERS ASSOCIATED WITH THIS SYSTEM TO ARRIVE AS
EARLY AS FRIDAY NIGHT OR EARLY SATURDAY MORNING. THE BEST CHANCE
OF RAIN AND THE HEAVIEST PRECIPITATION WILL BE IN NORTHERN AREAS
WHERE A WARM FRONT MAY BECOME ESTABLISHED. SOUTH OF THIS WARM
FRONT... LOW LEVEL MOISTURE MAY COMBINE WITH DECREASING
TEMPERATURES ALOFT WITHIN THE SHORTWAVE TROUGH TO PRODUCE DIURNAL
INSTABILITY FOR THUNDERSTORMS MAINLY OVER NEW HAMPSHIRE. WIND
SHEAR IS A BIT MARGINAL FOR SEVERE THUNDERSTORMS BUT THEY CANNOT
BE RULED OUT.
SURFACE LOW WILL DROP SOUTHEAST INTO THE GULF OF MAINE BY SUNDAY
MORNING AS UPPER LEVEL RIDGING BUILDS TO THE WEST AND NORTH. COULD
STILL SEE A FEW SHOWERS ON SUNDAY AS THE LOW LINGERS NEARBY
ESPECIALLY OVER COASTAL MAINE. TEMPERATURES REACH THE 70S BUT WILL
RISE INTO THE 80S OVER SOUTHERN NEW HAMPSHIRE FURTHER AWAY FROM
THE MARITIME AIR ASSOCIATED WITH THE OFFSHORE LOW.
AS LOW PRESSURE WEAKENS IT IS ALSO SHOVED FURTHER SOUTHEAST BY A
BUILDING SURFACE HIGH OVER THE CANADIAN MARITIMES. THIS WILL SET
UP AN EASTERLY FLOW OVER MAINE AND EASTERN NEW HAMPSHIRE ON
MONDAY... WITH LOW CLOUDS BECOMING LIKELY ALONG WITH A CHANCE OF
DRIZZLE OR LIGHT SHOWERS. TEMPERATURES ARE CURRENTLY FORECAST TO
REACH THE 70S THOUGH THIS MIGHT BE A LITTLE ON THE HIGH SIDE IF
MOIST EASTERLY FLOW KEEPS THE COOL AIR AND LOW CLOUDS IN MOST OF
THE DAY.
THE NEXT LARGER SCALE FRONTAL SYSTEM MOVES IN FROM THE WEST ON
TUESDAY... WITH ANOTHER ROUND OF SHOWERS EXPECTED AS IT DOES SO.
THERE ARE SOME TIMING DIFFERENCES AMONG THE MODELS WHICH GIVE SOME
UNCERTAINTY. IF THE TIMING LINES UP RIGHT... THERE COULD BE
THUNDERSTORMS FORMING ALONG AND AHEAD OF THE FRONT ON TUESDAY.
HIGH PRESSURE BUILDS IN BEHIND THE FRONT AND COULD LEAD TO A
PERIOD OF DRIER WEATHER.
&&
.AVIATION /22Z WEDNESDAY THROUGH MONDAY/...
SHORT TERM...HIGH PRESSURE BUILDS IN TONIGHT...PROVIDING QUIET
WEATHER THRU THURSDAY NIGHT. ONLY POTENTIAL RESTRICTIONS WILL BE
IN VALLEY FOG. MODEL GUIDANCE SUGGESTS LEB AND HIE WILL DROP TO
IFR OR LOWER TONIGHT. HOWEVER...FEEL THAT AS COOLER AIR MASS
ADVECTS IN THE MODELED COOL TEMPERATURES AND FOG WILL HAVE A
HARDER TIME DEVELOPING. BEST CHANCE FOR VALLEY FOG APPEARS TO BE
THURSDAY NIGHT AND FRIDAY MORNING...AS HIGH PRESSURE SETTLES
OVERHEAD AND WINDS GO CALM.
LONG TERM...SHOULD SEE VFR CONDITIONS THROUGH FRIDAY. SOME SHOWERS
BEGIN ARRIVING LATE FRIDAY NIGHT AND COULD BRING MVFR OR IFR
CONDITIONS AT TIMES THROUGH SATURDAY NIGHT. GRADUALLY IMPROVING
CONDITIONS ON SUNDAY. AN EASTERLY FLOW ON MONDAY MAY BRING IN SOME
LOWER CLOUDS AND FOG OR DRIZZLE TO LOCATIONS EAST OF THE
MOUNTAINS.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA
CRITERIA THROUGH THURSDAY NIGHT...ALTHOUGH SEAS MAY APPROACH 5 FT
ON THE OUTER WATERS TONIGHT...MAINLY DUE TO SWELL.
LONG TERM...A PROLONGED SOUTHERLY FLOW MAY ALLOW WAVE HEIGHTS TO
INCREASE TO 5 FEET OR HIGHER MAINLY OVER THE EASTERN WATERS BY
SATURDAY NIGHT. THIS SHOULD DIMINISH WITH TIME ON SUNDAY AS WEAK
LOW PRESSURE MOVES SOUTHEAST THROUGH THE GULF OF MAINE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
ES
AREA FORECAST DISCUSSION
NWS CARIBOU ME
316 AM EDT WED JUL 15 2015
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO CROSS THE THROUGH THIS AFTERNOON.
HIGH PRESSURE WILL BUILD IN FROM CANADA TONIGHT THROUGH THURSDAY
AND CREST OVER THE REGION ON FRIDAY. LOW PRESSURE FROM THE GREAT
LAKES WILL APPROACH THE REGION ON SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE COLD FRONT LIES POISED ALONG OUR NORTHWESTERN BORDER EARLY
THIS MORNING. THIS BOUNDARY WILL CONTINUE TO SLIDE SOUTHEAST
THROUGH THE DAY TODAY. A BAND OF SHOWERS CAN BE SEEN ON RADAR JUST
AHEAD OF THE BOUNDARY, AND THESE TOO WILL CROSS THE PINE TREE
STATE TODAY. A FEW LIGHTNING STRIKES HAVE BEEN REPORTED IN QUEBEC,
AND THE LATEST MODEL PROGS DO INDICATE THERE WILL BE SOME MAINLY
ELEVATED INSTABILITY OUT AHEAD OF THE FRONT. HAVE THEREFORE KEPT
ISOLATED THUNDER IN THE FORECAST THROUGH EARLY AFTERNOON. PWATS OF
UP TO 1.75 INCHES EXIST AHEAD OF THE FRONT AS WELL, SO HEAVIER
SHOWERS AND ESPECIALLY ANY THUNDERSTORMS WILL BE CAPABLE OF
PRODUCING A QUICK DOWNPOUR. MOST LOCATIONS WILL SEE LESS THAN A
HALF INCH OF RAIN, BUT WOULDN`T BE SURPRISED TO SEE SOME LOCALLY
HIGHER AMOUNTS AROUND THREE-QUARTERS OF AN INCH, ESPECIALLY IN OUR
NORTHWESTERN AREAS. THE LATEST HRRR HAS A GOOD HANDLE ON THE
CURRENT SETUP, AND IT INDICATES THE FRONT WILL BE OFFSHORE BY 4 PM
OR SO. MUCH DRIER AIR WILL OVERSPREAD THE REGION IN THE FRONT`S
WAKE; DEWPOINTS UPSTREAM ARE IN THE 40S, WITH EVEN SOME UPPER 30S.
AS SUCH, EXPECT PRECIPITATION WILL COME TO A QUICK END ONCE THE
FRONT GOES BY AND SKIES WILL RAPIDLY BECOME CLEAR.
FOR TONIGHT...HIGH PRESSURE WILL BEGIN TO BUILD EASTWARD FROM THE
GREAT LAKES. IT WILL BE A MUCH MORE COMFORTABLE NIGHT AS DEWPOINTS
DROP INTO THE 40S. AIRMASS WILL BE DRY ENOUGH TO PRECLUDE ANY FOG
DEVELOPMENT IN SPITE OF CLEAR SKIES AND LIGHT WINDS. LOWS WILL RANGE
FROM THE MID 40S NORTH TO THE LOWER 50S DOWNEAST.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
NO SIG CHGS IN THE FCST WITH REGARD TO THU AND THU NGT...WITH ALL
MODELS SHOWING CAN SFC HI PRES APCHG THE FA TUN AND CRESTING OVRHD
THU NGT. HI TEMPS THU AFTN WILL BE ABOUT 4 TO 8 DEG F BELOW AVG
WITH A LGT NW BREEZE UNDER MSLY SUNNY SKIES WITH SOME PATCHY SC
SPCLY OVR NRN PTNS OF THE FA. WINDS WILL THEN DIMINISH BY SUNSET
THU EVE...ALLOWING FOR CLR SKIES AND GOOD RADIATIONAL COOLING
OVRNGT THU AS THE SFC HI SETTLES OVRHD BY ERLY FRI MORN. WE ADDED
PATCHY LOWING LYING EVAP/CONDENSATIONAL RVR FOG LATE THU NGT AS
SFC TEMPS OVR BROAD VLY FALLS BELOW RVR WATER TEMPS FROM CNTRL
PTNS OF THE FA NWRD.
ANY PATCHY LOW LYING FOG SHOULD LIFT AND DISSIPATE WITHIN AN HR OR
TWO AFT SUNRISE FRI...WITH TEMPS RECOVERING FROM CHILLY ERLY MORN
LOWS TO NEAR SEASONAL NORMS FOR AFTN HI TEMPS WITH LGT SW WINDS.
AFTWRDS...CLDS WILL BEGIN TO INCREASE FRI NGT AS THE SFC HI CONTS
TO MOVE E TOWARD THE OPEN ATLC...AND A S/WV WITH WEAK SFC LOW PRES
FROM THE GREAT LAKES BEGINS TO APCH. THE COMBO OF INCREASING CLD
CVR AND LGT SW WINDS ASSOCIATED WITH LLVL WARM ADVCN WILL KEEP
OVRNGT LOWS FRI NGT SIG MILDER THAN THU NGT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
LONGER RANGE MODELS DIFFER ON THE ONSET SPEED OF RNFL ON SAT FROM
THE GREAT LKS S/WV AS IT APCHS AND CROSSES OUR FA SAT/SAT NGT. THE
00Z DTMNSTC GFS AND NAM ARE IN THE FASTER MODEL CAMP WHILE THE 00Z
ECMWF IS SLOWER. THE 00Z CANGEM AND GFS ESMN AS WELL AS THE 21Z
SREF ARE IN THE MIDDLE...SO WENT WITH THE SUPERBLEND POPS WHICH
REFLECTED COMPROMISED ONSET TMG RESULTING IN SHWRS MOVG INTO THE
FA DURG THE DAY SAT. FOR NOW...GIVEN MODEL TMG AND OVRRNG POTENTIAL
DIFFERENCES...WE KEPT MAX POPS IN THE HI CHC CAT FOR NOW.
OTHERWISE...WITH ADDITIONAL S/WVS AND CONTD SRLY LLVL FLOW ACROSS
THE FA...WE KEPT CHC SHWR POPS GOING THRU SUN AND MON...ALTHOUGH
SIG PTNS OF EACH DAY WILL LIKELY BE RN FREE OVR ANY PARTICULAR
LCTN ACROSS THE FA. A STRONGER S/WV WILL BRING A BETTER CHC OF
SHWRS TUE INTO ERLY WED MORN...WHERE WE GO WITH LOW LIKELY MAX
POPS BY TUE AFTN INTO TUE NGT. ALTHOUGH WE CANNOT RULE OUT TSTMS
DURG THE AFTN/EVE HRS FROM SUN TO TUE...THE FACT THAT HI TEMPS
WILL LIKELY BE HELD DOWN TO AOB SEASONAL NORMS COULD KEEP SFC/ML
CAPES TO LOW...SO FOR NOW WE HELD OFF ANY MENTION OF THUNDER FOR
THESE DAYS ATTM. OVRNGT LOWS WILL BE A LITTLE ABV AVG MSLY DUE TO
POTENTIAL CLD CVR AND SRLY BREEZES.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: WIDESPREAD IFR CONDITIONS IN SHOWERS AND FOG TO
CONTINUE EARLY THIS MORNING, ESPECIALLY AT KBGR AND KBHB. A COLD
FRONT WILL CONTINUE TO SLIDE SOUTHEAST ACROSS THE REGION, WITH
SHOWERS ALONG AND AHEAD OF IT. CONDITIONS WILL QUICKLY IMPROVE
ONCE THE FRONT GOES BY AS DRIER AIR WORKS INTO THE STATE. EXPECT
VFR AT KFVE BY 18Z...AND AT KBHB BY 00Z. HIGH PRESSURE AND VFR
CONDITIONS TO PREVAIL THEREAFTER.
SHORT TERM: VFR XPCTD ALL TAF SITES THU THRU FRI NGT. MVFR CLGS
AND VSBYS POSSIBLE WITH CLGS AND SHWRS/RN SAT...SPCLY SAT AFTN.
MVFR OR IFR CLGS/VSBYS POSSIBLE SAT NGT WITH SHWRS PERHAPS SLOWLY
RECOVERING TO HI MVFR/VFR BY SUN AFTN.
&&
.MARINE...
NEAR TERM: A COLD FRONT WILL APPROACH THE WATERS FROM THE
NORTHWEST THIS MORNING AND MOVE OFFSHORE THIS AFTERNOON. SOUTH-
SOUTHWEST WINDS 5 TO 10 KT WILL BECOME NORTH-NORTHWEST BY THIS
EVENING. SOME INCREASE IN THE WINDS IS EXPECTED OVERNIGHT AS THE
PRESSURE GRADIENT TIGHTENS; IN GENERAL AROUND 10 KT WITH GUSTS TO
20 KT. SEAS WILL BUILD IN RESPONSE, BUT BOTH WAVES AND WINDS WILL
REMAIN BELOW SMALL CRAFT LEVELS. THEREFORE NO HEADLINES ARE
ANTICIPATED.
SHORT TO LONG TERM: THE FCST OPENS IN THE NEAR TERM WITH NEAR SCA
WV HTS MSLY OVR OUR OUTER MZS THU MORN DUE TO LEFT OVR LONG PD
SWELL FROM THE OPEN ATLC...WITH WV HTS GRADUALLY SUBSIDING LATER
THU AFTN AND NGT. WINDS ARE XPCTD TO REMAIN BLO SCA THRU THE SHORT
INTO LONG TERM. WE WENT WITH 90 PERCENT OF CONSRAW DATA FOR
SUSTAINED WIND SPEEDS OVR THE WATERS AND ABOUT 65 PERCENT OF WW3
WV GUIDANCE OVR THE NEAR SHORE UP TO 90 PERCENT OF WW3 WV GUIDANCE
OVR THE OUTER MZ WATERS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS
SHORT TERM...VJN
LONG TERM...VJN
AVIATION...HASTINGS/VJN
MARINE...HASTINGS/VJN
AREA FORECAST DISCUSSION
NWS GRAY ME
122 AM EDT WED JUL 15 2015
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE WEST TONIGHT AND CROSS MAINE
AND NEW HAMPSHIRE DURING THE DAY ON WEDNESDAY...BRINGING SHOWERS
AND THUNDERSTORMS. HIGH PRESSURE THEN MOVES IN FOR WEDNESDAY NIGHT
THROUGH FRIDAY. THE HIGH WILL SHIFT OFFSHORE OVER THE WEEKEND
ALLOWING FOR A WARMER AND MORE MOIST AIRMASS TO MOVE IN...POSSIBLY
ASSOCIATED WITH SHOWERS AND THUNDERSTORMS. THIS ACTIVITY COULD
PERSIST INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
UPDATE...
HAVE UPDATED THE GRIDS BASED ON CURRENT CONDTIONS. THERE IS VERY
LITTLE IN THE WAY OF SCATTERED SHOWERS ACROSS THE FORECAST AREA AS
OF 05Z. SOME PRECIP TO OUR WEST WILL MOVE INTO THE
REGION...HOWEVER LATEST HRRR HAS THIS SHOWER ACTIVITY DISSIPATING
AS IT MOVES TO THE EAST AND INTO NEW HAMPSHIRE.
MINOR ADJUSTMENTS MADE TO DEW POINTS AND TEMPERATURES LATE THIS
EVENING.
PREV DISC...
910 PM UPDATE: OCEAN LOW CLOUDS AND STRATUS HAVE
MOVED WEST ALONG THE ME COAST AND SOME INLAND AREAS OF ME BUT HAVE
NOT REACHED FAR ENOUGH WEST INTO NH. SOME AREAS OF FOG HAD
DEVELOPED BUT IS NOT WIDESPREAD. MADE ADJUSTMENTS ON THE 6 PM
UPDATE TO PUSH BACK FOG DEVELOPMENT AND LOOKS GOOD AT THIS TIME.
FOG MAY BECOME DENSE IN A FEW AREAS BUT GENERALLY NOT EXPECTING
WIDESPREAD DENSE FOG.
ALSO ON EARLIER UPDATE ADJUSTED FORECAST TO REFLECT ONLY SOME
LIGHT SHOWERS FOR THE REST OF THE EVENING AND ELIMINATED ANY
MENTION OF THUNDER. WILL KEEP THIS THINKING IN TACT AND ANY
MENTION OF THUNDER WILL NOT BE UNTIL WELL AFTER MIDNIGHT...RADAR/SATELLITE
CONFIRMS THIS THINKING. MINOR ADJUSTMENTS TO TEMPERATURES BASED ON
LATEST OBSERVATIONS.
PREVIOUS DISCUSSION:
A COLD FRONT WILL GRADUALLY DROP SOUTHEASTWARD INTO MAINE AND NEW
HAMPSHIRE TONIGHT...AND LIKELY BE POSITIONED JUST WEST OF THE
COASTAL PLAIN COME 12Z WEDNESDAY. SCT SHOWERS WILL MOVE FROM S TO
N ACROSS THE REGION THROUGH EARLY THIS EVENING BEFORE STRONGER
FORCING FOR ASCENT ARRIVES LATER IN THE EVENING. THIS SHOULD
RESULT IN AN INCREASE IN SHOWERS ACROSS WESTERN AND NORTHERN ZONES
LATE THIS EVENING AND OVERNIGHT WHILE THE COASTAL PLAIN REMAINS
MAINLY DRY. MAY HAVE TO BE ON THE LOOKOUT FOR LOCALIZED
FLOODING...ESPECIALLY IN COOS COUNTY WHERE THEY RECEIVED HEAVY
RAIN YESTERDAY.
AREAS OF DENSE FOG MAY BECOME AN ISSUE FROM YORK COUNTY NORTHWARD
THROUGH CUMBERLAND COUNTY AND ON NORTHEASTWARD UP I-95 ON EAST.
WILL HOLD OFF ON DENSE FOG ADVISORY AT THIS TIME DUE TO
UNCERTAINTY ON HOW WIDESPREAD 1/4 MILE OR LESS VSBYS WILL BE...BUT
ONE COULD BE NECESSARY LATER ON.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
COLD FRONT TO MOVE OFFSHORE PRIOR TO 18Z WEDNESDAY. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO ACCOMPANY THIS FRONT...ESPECIALLY
ON THE COASTAL PLAIN WHERE SOME EARLY HEATING AND LINEAR FORCING
MAY ALLOW FOR MORE ROBUST AND WIDESPREAD UPDRAFTS. NOT THINKING
SEVERE AT THIS TIME...BUT SOME GUSTY WINDS...FREQUENT
LIGHTNING...AND HEAVY DOWNPOURS WILL BE POSSIBLE PRIOR TO FRONTAL
PASSAGE.
RAPID CLEARING TO TAKE PLACE PRIOR TO SUNSET...WITH COOLER AND
DRIER AIR MOVING IN FOR WEDNESDAY EVENING/NIGHT. LOWS IN THE THE
LOWER TO MID 40S LIKELY IN THE MOUNTAINS AS REFRESHING AIRMASS
MOVES ON IN.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGH PRES BUILDS IN EARLY THU...AND REMAINS IN CONTROL OF THE
REGION THRU FRI. NLY BREEZE WILL FOLLOW THE DEPARTING COLD
FRONT...AS COOLER AND DRIER AIR WORKS IN. RIDGE AXIS SETTLES
OVERHEAD THU NIGHT INTO EARLY FRI. EXPECT A GOOD RADIATIONAL
COOLING NIGHT...AND WENT A FEW DEGREES BELOW GUIDANCE TO ACCOUNT
FOR THIS. ALSO EXPECT AREAS OF VALLEY FOG TO DEVELOP IN THE
FAVORED LOW LYING AREAS AND COOL SPOTS.
WX BECOMES MORE UNSETTLED INTO THE WEEKEND...AS HIGH PRES SLIDES
EWD AND RIDGING ALOFT DEPARTS. A POSSIBLY CONVECTIVELY ENHANCED
S/WV TROF WILL PASS THRU THE GREAT LAKES AND APPROACH WRN ZONES
SAT. CONFIDENCE IS PRETTY LOW ON TIMING AND COVERAGE OF ANY
PRECIP...SO WILL KEEP THINGS CHANCE POP FOR NOW. WEAK S/WV RIDGING
IS EVIDENT IN MODEL GUIDANCE FOR SUN...SO MAYBE POP IS A BIT
OVERDONE IN THIS PERIOD...BUT STRONGER S/WV TROF ARRIVES EARLY
NEXT WEEK AND INCREASES THE CHANCES FOR MORE SHOWERS/TSTMS.
TEMPS LOOK TO AVERAGE NEAR NORMAL FOR HIGHS...AND SLIGHTLY ABOVE
NORMAL FOR LOWS...AS IT WILL TEND TOWARDS RETURN FLOW AND MORE
MOIST AIR MASSES.
&&
.AVIATION /05Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM...MAINLY VFR CONDITIONS ARE EXPECTED THROUGH ABOUT
22-23Z EARLY THIS EVENING BEFORE FOG AND STRATUS IS EXPECTED TO
MOVE IN ON THE COASTAL PLAIN...MAINLY NORTH OF PSM. CIGS/VSBYS
SHOULD DROP TO LIFR FOR KPWM UP THROUGH KRKD AND REMAIN THAT WAY
OVERNIGHT. AUG WILL LIKELY SEE THIS AS WELL. SOME UNCERTAINTY
EXISTS ON SOUTHWARD EXTENT...BUT WE THINK PSM SHOULD STILL SEE
SOME IFR CONDITIONS. FURTHER INLAND...LOW CONDITIONS WILL NOT BE
AS WIDESPREAD...BUT SHOWERS AND POSSIBLE THUNDER ARE LIKELY IN THE
INTERIOR OVERNIGHT. ON WEDNESDAY...LOW CONDITIONS IN THE EARLY
MORNING SHOULD GIVE WAY TO IMPROVEMENT BY 14Z...BUT BE REPLACED BY
SHOWERS AND THUNDERSTORMS BETWEEN 14Z AND 18Z. THEREAFTER...VFR
CONDITIONS ARE EXPECTED THROUGH WED NIGHT.
LONG TERM...VFR GENERALLY EXPECTED TO BEGIN THE PERIOD FOR ALL
TERMINALS. HIGH PRES SETTLING OVERHEAD EARLY FRI MAY LEAD TO AREAS
OF VALLEY FOG...ESPECIALLY AT FAVORED LOCATIONS LIKE HIE AND LEB.
BY THE WEEKEND...WEAK UPPER TROF MOVING THRU THE AREA MAY LEAD TO
SCATTERED SHRA/TSRA...WITH AREAS OF MVFR AND LOCAL IFR CONDITIONS
POSSIBLE.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA
CRITERIA THROUGH WEDNESDAY NIGHT...ALTHOUGH SEAS MAY APPROACH OR
BRIEFLY EXCEED 5 FT ON THE OUTER WATERS WED AFTERNOON AND
EVENING...MAINLY DUE TO SWELL.
LONG TERM...WINDS AND SEAS GENERALLY EXPECTED TO REMAIN BELOW SCA
THRESHOLDS. SOME SEAS NEAR 5 FT POSSIBLE EARLY THU...MAINLY DUE TO
SWELL.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1116 PM EDT THU JUL 16 2015
.UPDATE...
ISSUED AT 1116 PM EDT THU JUL 16 2015
WARM FRONT CONTINUES TO LIFT NE OUT OF THE MID MISSISSIPPI VALLEY
TOWARD THE WRN GREAT LAKES REGION LATE THIS EVENING. LEADING EDGE
OF THE AREA OF WIDESPREAD SHOWERS AHEAD OF THIS FRONT NOW EXTENDS
FROM NEAR TVC TO GOV TO SAGINAW BAY. STRONGER CONVECTION/AREA OF
THUNDERSTORMS IS FURTHER SOUTH OVER SE WISCONSIN AND NRN ILLINOIS
WHERE MUCH BETTER INSTABILITY RESIDES. LACK OF INSTABILITY HAS
PRECLUDED THE DEVELOPMENT OF THUNDER OVER OUR SW CWA....WHERE
ENOUGH LOW LEVEL MOISTENING HAS TAKEN PLACE FOR LIGHT PRECIP TO
ACTUALLY REACH THE GROUND PER AREA SFC OBS. LATEST RAP13 KEEPS
HIGHEST QPF ALONG OUR SRN CWA...MAINLY SOUTH OF A LINE FROM TVC TO
APN. THIS TRAJECTORY MAKES SENSE BASED ON LATEST UPSTREAM RADAR
TRENDS. LATEST RAP STILL DEVELOPS WEAK INSTABILITY OVER OUR CWA
OVERNIGHT...SO WILL KEEP A SLIGHT CHANCE OF THUNDER IN THE
FORECAST. OTHERWISE...CATEGORICAL POPS REMAINS IN ORDER FOR THE
BALANCE OF THE NIGHT.
&&
.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 306 PM EDT THU JUL 16 2015
ON THE LATEST SURFACE WEATHER MAP OF INTEREST...1020 MB HIGH
PRESSURE IS CENTERED ACROSS FAR WESTERN NEW YORK STATE WITH 1005 MB
LOW PRESSURE OVER EASTERN SOUTH DAKOTA. SATELLITE IMAGERY SHOWS
CLOUDS BEGINNING TO INCREASE FROM THE SOUTHWEST. RADAR IMAGERY
SHOWED A LARGE AREA OF SHOWERS EXTENDING FROM CENTRAL AND WESTERN
WISCONSIN SOUTHEAST INTO NORTHERN ILLINOIS AND NORTHERN INDIANA. THE
MAIN NEAR TERM FORECAST CONCERNS REVOLVE AROUND POPS...THUNDER
POTENTIAL AND RAINFALL AMOUNTS FOR TONIGHT.
FAIRLY STRONG WARM/MOIST ADVECTION OVERNIGHT WITH PRECIPITABLE WATER
VALUES INCREASING TO BETWEEN 1.5 AND 2 INCHES. HOWEVER...WITH A
MAINLY CONVECTIVE SCENARIO CONFIDENCE IS SOMEWHAT LOW ESPECIALLY
GIVEN RAINFALL AMOUNTS UPSTREAM ON THE LIGHTER SIDE (THOUGH THERE IS
A BIT OF UPPER FORCING). GIVEN THE STRENGTH OF MOISTURE ADVECTION
WOULD THINK THAT A WIDESPREAD AREA OF SHOWERS WILL OVERSPREAD THE
REGION FROM SOUTHWEST TO NORTHEAST AND LAST FOR AT LEAST A FEW
HOURS. WILL LEAN TOWARD WPC RAINFALL AMOUNTS RANGING FROM ABOUT A
QUARTER OF AN INCH ACROSS EASTERN UPPER TO UPWARDS OF THREE QUARTERS
OF AN INCH CLOSER TO MANISTEE. WITH THE MODELS GENERATING UPWARDS OF
AN INCH OR MORE ACROSS PARTS OF FAR NORTHERN LOWER...THE EVENING
SHIFT WILL HAVE TO MONITOR TENDS FOR POSSIBLE RAISING OF THESE
AMOUNTS. AS FAR AS THUNDER POTENTIAL GOES...LIKE THE SLIGHT CHANCE
WE HAVE GOING DUE TO VERY LIMITED INSTABILITY TO WORK WITH (BUT CAN
NOT RULE OUT A FEW EMBEDDED RUMBLES OF THUNDER). IT WILL BE RATHER
WARM AND INCREASINGLY HUMID OVERNIGHT WITH LOWS IN THE LOWER AND
MIDDLE 60S FOR THE MOST PART.
&&
.SHORT TERM...(FRIDAY THROUGH SUNDAY)
ISSUED AT 306 PM EDT THU JUL 16 2015
HIGH IMPACT WEATHER POTENTIAL...STRONG T-STORMS POSSIBLE SAT NIGHT.
WE WILL START THE WEEKEND WITH BROAD...FLAT RIDGING ALOFT OVER THE
NE QUARTER OF THE COUNTRY. THIS WILL BE DISLODGED BY A TROF THAT
MOVES EAST FROM S CENTRAL CANADA. THE LEAD WAVE FROM THIS TROF WILL
TAKE ON A NEGATIVE TILT AS IT LIFTS ACROSS NORTHERN ONTARIO SAT
NIGHT. A SECONDARY WAVE WILL DIG INTO THE NORTHERN LAKES BY LATE
SUNDAY. THESE WILL COMBINE TO PROPEL A COLD FRONT ACROSS NORTHERN MI
ON SUNDAY. PRECIP TRENDS ARE A PRIMARY CONCERN...WITH LINGERING
ACTIVITY FRIDAY MORNING AND A POSSIBLE INCOMING MCS SAT NIGHT. MAX
TEMPS ARE ANOTHER ISSUE...ESPECIALLY ON SATURDAY.
FRIDAY...PRIMARY PRECIP SHIELD LOOKS TO BE JUST ABOUT EXITING THE
FORECAST AREA AT 12Z. LIKELY POPS AND A CHANCE FOR THUNDER STILL IN
ORDER TO START THE DAY FOR THE ST MARYS VALLEY...AND FOR ROGERS CITY
DOWN TO OSC. HOWEVER...A VERY SLUDGY LOW-LEVEL AIRMASS IS SEEN
BEHIND THE WEAK SURFACE LOW DEPARTING NE LOWER. THAT WILL SUPPORT AT
LEAST A SMALL CHANCE OF -SHRA...SPRINKLES AT THE VERY LEAST...ACROSS
MOST OF NORTHERN MI IN THE MORNING. A TOUCH OF LOW-LEVEL RIDGING
WILL HELP BREAK THAT DOWN BY NOON...AND A LOW CLOUD DECK WILL BREAK
DOWN INTO A BKN CU FIELD. THIS IS A POTENTIALLY TOASTY AIRMASS...
WITH 850MB TEMPS IN THE UPPER TEENS C. BUT INSOLATION WILL BE
SOMEWHAT LIMITED...KEEPING MAX TEMPS IN CHECK. HIGHS WILL RANGE FROM
THE LOWER 70S TO LOWER 80S. HOWEVER...IT WILL BE MARKEDLY MORE
HUMID...WITH DEW POINTS RANGING THRU THE 60S.
FRI NIGHT/SATURDAY...SURFACE RIDGING MORE EMPHATICALLY BUILDS NORTH
INTO MI. WITH LIGHT WINDS...A STICKY AIRMASS...AND AT LEAST PARTIAL
CLEARING...WOULD EXPECT FOG/STRATUS TO FORM IN MANY AREAS.
OTHERWISE...A QUIET BUT WARM NIGHT...WITH LOWS MAINLY IN THE 60S
(SOME UPPER 50S IN EASTERN UPPER). AS LONG AS STRATUS DOES NOT GET
OUT OF HAND...SATURDAY SHOULD BE ONE OF THE TOASTIER DAYS OF THE
SUMMER THUS FAR. 850MB TEMPS REMAIN IN THE UPPER TEENS C...EVEN
AROUND 20C IN SOUTHERN SECTIONS. THAT WILL SUPPORT MAX TEMPS NEAR
90F IN THE SOUTH...LOWERING TO NEAR 80F IN EASTERN UPPER. DEW POINTS
WILL REMAIN IN THE 60S...SO CERTAINLY STICKY AS WELL. WITH 700MB
TEMPS AT 10C...IT WILL BE A CHALLENGE FOR LAKE BREEZES TO LIGHT OFF
CONVECTION IN THE AFTERNOON. CIN LOOKS TO BE PROHIBITIVE. WILL
REMOVE POPS FROM SAT AFTERNOON.
SAT NIGHT/SUNDAY...COLD FRONT MOVING INTO A MOIST/POTENTIALLY
UNSTABLE WOULD SEEM TO SET THE STAGE FOR A TSRA OUTBREAK. BUT...AS
IS USUAL AROUND HERE...THERE ARE REASONS TO PAUSE. MOST NOTABLY IS
THAT FORCING (SURFACE COLD/INITIAL LOWERING OF HEIGHTS) MAXES OUT
LATE SAT NIGHT INTO EARLY SUNDAY...A DIURNALLY UNFAVORED TIME. THE
STRONGEST MID-LEVEL FORCING WILL BE LIFTING INTO FAR NORTHERN
ONTARIO...JUST GIVING US A GLANCING BLOW. AT THIS POINT...AM NOT
QUITE COMFORTABLE WITH A LIKELY POP. A BLANKET 40-50 POP WILL WORK
FOR SAT NIGHT...AND WILL CONTINUE WITH CHANCE POPS IN NORTHERN LOWER
ON SUNDAY. EASTERN UPPER SHOULD DRY OUT BEHIND THE FRONT DURING THE
DAY ON SUNDAY. WEST 500MB WINDS WILL INCREASE TO 40-50KT...
SUGGESTING SOME POTENTIALLY STRONGER STORMS...ESPECIALLY IF
ACTIVITY CAN MOVE IN FROM WI A LITTLE EARLIER ON SAT EVENING. SVR
POTENTIAL DOES NOT LOOK TERRIBLY IMPRESSIVE...BUT IT ISN/T ZERO
EITHER.
MIN TEMPS 60S. MAX TEMPS UPPER 70S TO UPPER 80S.
&&
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 306 PM EDT THU JUL 16 2015
KIND OF ZONAL FLOW WHICH IS MORE LIKE A SHALLOW RIDGE THAT IS
BEING SQUASHED IN THE MIDDLE BY THE 500 MB LOW THAT IS ANCHORED
OVER HUDSON BAY, BUT WITH SHORTWAVE TROUGHS THAT ROTATE AROUND IT,
THAT PRODUCE PERIODIC SHOWER AND DRYNESS. SO THE OVERALL FORECAST
WILL LOOK LIKE THIS...SUNDAY NIGHT, THE LAST OF THE RAIN SHOULD BE
LEAVING THE FORECAST AREA, SO THAT MONDAY AND MONDAY NIGHT WILL BE
DRY. TUESDAY, A WEAK COLD FRONT AND 500 MB TROUGH PUSH THROUGH TO
BRING MORE RAIN. HOWEVER, THAT SHOULD BE GONE FOR TUESDAY NIGHT
AND INTO WEDNESDAY AND THROUGH WEDNESDAY NIGHT. THURSDAY, THE
MODELS DISAGREE ON THE NEXT SYSTEM. ECMWF PUSHES IT THROUGH
MICHIGAN, WHILE THE GFS KEEPS THE REGION DRY AND SHUNTS THE RAIN
NORTH INTO LAKE SUPERIOR. &&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 132 PM EDT THU JUL 16 2015
HIGH PRESSURE WILL CONTINUE TO MOVE OFF TO THE EAST ALLOWING FOR LOW
PRESSURE AND AN ASSOCIATED WARM FRONT TO LIFT ACROSS THE REGION
LATER THIS EVENING INTO EARLY FRIDAY. SHOWERS WILL OVERSPREAD THE
TAF SITES FROM SOUTHWEST TO NORTHEAST LATER THIS EVENING AND
OVERNIGHT...ALONG WITH MVFR CIGS AND PERIODIC LOWERING OF VISIBILITY.
THERE IS ALSO A CHANCE FOR THUNDERSTORMS...ESPECIALLY NEAR
MBL/TVC. LLWS IS EXPECTED THIS EVENING THROUGH THE OVERNIGHT
HOURS. SLOW IMPROVEMENT IN CONDITIONS HEADING INTO THURSDAY
AFTERNOON WITH CIGS EVENTUALLY LIFTING FROM MVFR (POSSIBLY EVEN
IFR OR LOWER IN THE MORNING WITH POSSIBLE FOG AND LOW STRATUS) TO
LOW END VFR TOWARD THE END OF THE TAF PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 132 PM EDT THU JUL 16 2015
HIGH PRESSURE WILL CONTINUE TO MOVE OFF TO THE EAST ALLOWING FOR LOW
PRESSURE AND AN ASSOCIATED WARM FRONT TO LIFT ACROSS THE REGION
LATER THIS EVENING INTO EARLY FRIDAY. SHOWERS WILL OVERSPREAD THE
TAF SITES FROM SOUTHWEST TO NORTHEAST LATER THIS EVENING AND
OVERNIGHT...ALONG WITH MVFR CIGS AND PERIODIC LOWERING OF VISIBILITY.
THERE IS ALSO A CHANCE FOR THUNDERSTORMS...ESPECIALLY NEAR
MBL/TVC. LLWS IS EXPECTED THIS EVENING THROUGH THE OVERNIGHT
HOURS. SLOW IMPROVEMENT IN CONDITIONS HEADING INTO THURSDAY
AFTERNOON WITH CIGS EVENTUALLY LIFTING FROM MVFR (POSSIBLY EVEN
IFR OR LOWER IN THE MORNING WITH POSSIBLE FOG AND LOW STRATUS) TO
LOW END VFR TOWARD THE END OF THE TAF PERIOD.
&&
.MARINE...
ISSUED AT 306 PM EDT THU JUL 16 2015
SOUTHEAST WINDS WILL VEER INTO THE WEST SOUTHWEST FRIDAY. ALTHOUGH
WINDS MAY BE A LITTLE GUSTY AT TIMES...HEADLINES ARE NOT
ANTICIPATED AT THIS JUNCTURE. FAIRLY LIGHT SOUTHWEST WINDS ARE
THEN ANTICIPATED SATURDAY FOLLOWED BY A COLD FRONT MOVING THROUGH
SUNDAY SHIFTING WINDS INTO THE WEST. THERE IS A SLIGHT CHANCE FOR
THUNDERSTORMS LATER THIS EVENING AND OVERNIGHT BUT NO SEVERE
WEATHER IS EXPECTED. SHOWERS AND SOME THUNDERSTORMS ARE POSSIBLE
SATURDAY NIGHT INTO SUNDAY.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...MLR
NEAR TERM...SULLIVAN
SHORT TERM...JAZ
LONG TERM...JSL
AVIATION...MLR
MARINE...SULLIVAN
AREA FORECAST DISCUSSION
NWS JACKSON MS
430 PM CDT WED JUL 15 2015
.DISCUSSION...A LOOSE LOW LEVEL CONVERGENT BOUNDARY LEFT IN THE WAKE
OF ORGANIZED MIDSOUTH STORMS YESTERDAY IS NOW ALIGNED FROM LIT ESE
TO BHM AND TRIGGERING SCATTERED THUNDERSTORMS. THIS BOUNDARY IS ALSO
ESSENTIALLY WORKING TO POOL BOUNDARY LAYER MOISTURE IN MY NORTHERN
ZONES...SPIKING HEAT INDICES ABOVE 110 IN SOME CASES AND DRIVING
SBCAPE VALUES UP TO NEARLY 6000 J/KG. MY LATE MORNING ASSESSMENT DID
NOT QUITE ANTICIPATE SO MUCH CAPE MATERIALIZING ALONG THE BOUNDARY
THIS AFTERNOON...BUT WITH THE NEW INFO IT SEEMS THE HIGH INSTABILITY
COULD INDEED OVERCOME CAPPING AND LACK OF SYNOPTIC FORCING
RESERVATIONS FROM EARLIER. FOR THAT REASON WE INCLUDED A LIMITED
RISK OF SEVERE STORMS IN THE HWO ACROSS BASICALLY NORTHERN AND
CENTRAL ZONES THROUGH THIS EVENING AS LATEST HRRR THINKING OF VERY
LOOSELY ORGANIZED STORM SEGMENTS ADVANCING SOUTHWARD INTO THE
EVENING LOOKS ENTIRELY BELIEVABLE. THE MAIN THREAT WITH THIS
ACTIVITY WILL BE DAMAGING WINDS GUSTS ALTHOUGH TREMENDOUS RAINFALL
RATES MAY BE CAPABLE OF VERY ISOLATED FLOODING ISSUES. ALSO EXPECT
SOME EXTREME LIGHTNING RATES FROM SOME OF THESE STORMS ALONG THE
HIGHWAY 82 CORRIDOR...WHICH IS OF COURSE ALWAYS A HAZARD.
THE HEAT IS THE OTHER BIG...AND CONTINUING...STORY. THE PREVIOUSLY-
MENTIONED EXTREME SPIKE IN HEAT INDEX VALUES UP IN THE ARKLAMISS
DELTA THIS AFTERNOON HAS BRIEFLY EXCEEDED EXCESSIVE HEAT WARNING
CRITERIA AND THERE WAS TALK OF PERHAPS GOING WITH A HEAT WARNING IN
THOSE SPOTS THROUGH TOMORROW. HOWEVER...UPON FURTHER
CONSIDERATION...WE DECIDED TO MAINTAIN THE HEAT ADVISORY STATUS
SINCE THE MOISTURE POOLING NEAR THE CONVERGENCE ZONE SHOULD NOT BE
SUCH AN ISSUE TOMORROW AND THUS PEAK HEAT INDICES UP THERE A LITTLE
TAMER. OVERALL...THE HEAT ADVISORY IN OUR AREA FOR AREAS ALONG AND
NORTH OF ACME LA...TO JACKSON MS...TO MEI LINE THROUGH THURSDAY WAS
EXTENDED THROUGH FRIDAY. SOME LOCATIONS CURRENTLY TO THE SOUTH OF
THE ADVISORY MAY HAVE TO BE ADDED IN BEFORE FRIDAY...BUT THE CURRENT
REGIME IS OFFERING INCREASED MIXING OF DRIER DEWPOINTS ALOFT TO THE
SURFACE ACROSS SOUTHERN ZONES (WHICH IS EFFECTIVELY LIMITING PEAK
HEAT INDEX VALUES TO AROUND THE CENTURY MARK). PAST FRIDAY THERE IS
DEFINITELY DECENT POTENTIAL THAT THE HEAT WILL ACTUALLY WORSEN IN
ALL AREAS THROUGH THE WEEKEND WITH SOME ACTUAL AIR TEMPERATURES IN
SPORADIC SPOTS HITTING 100 DEGREES. IT IS AT THIS POINT THAT A
WIDESPREAD HEAT ADVISORY...AND PERHAPS EVEN SOME HEAT
WARNINGS...WILL HAVE TO BE STRONGLY CONSIDERED.
IN TERMS OF CONVECTIVE TRENDS...AFTER EVENING ACTIVITY DIMINISHES
EXPECT LITTLE POTENTIAL FOR MUCH TO LINGER OVERNIGHT WITH ANY
DIURNALLY-DRIVEN CONVECTION TOMORROW LIKELY CONFINED TO FAR EASTERN
MS (AND THEN INTO SOUTHEAST MS BY FRIDAY AFTERNOON). THE UPPER RIDGE
CENTER MIGRATING MORE FIRMLY OVERHEAD OF THE REGION DURING THIS TIME
FRAME WILL PUSH SEMI-ORGANIZED THUNDERSTORM ACTIVITY WAY NORTH AND
EAST OF OUR REGION. /BB/
&&
.AVIATION...MAINLY VFR CONDITIONS WILL PREVAIL AT MOST SITES THROUGH
THE FORECAST PERIOD. SCATTERED THUNDERSTORMS LOOK TO DEVELOP AND
SINK SOUTH INTO THE AREA THROUGH THIS EVENING. GLH/GWO/GTR MAY BE
IMPACTED WITH BRIEF GUSTY WINDS...MVFR FLIGHT CATS AND COPIOUS
LIGHTNING. TOMORROW ANY AFTERNOON ISOLATED STORMS SHOULD MAINLY BE
CONFINED TO GTR/CBM/NMM/MEI AREA. /7/BB/
&&
.PREV DISCUSSION... /ISSUED 417 AM CDT WED JUL 15 2015/
PREVIOUS LONG TERM...FRIDAY THROUGH TUESDAY...WE`RE BEGINNING TO
SOUND LIKE A BROKEN RECORD BUT...EXCESSIVE HEAT CONTINUES TO BE THE
PRIMARY FORECAST CONCERN THROUGH THE EXTENDED.
THE MID/UPPER RIDGE RESPONSIBLE FOR THE RECENT HOT STREAK WILL BUILD
EASTWARD LATE THIS WEEK AND BECOME CENTERED OVER THE DEEP SOUTH OVER
BY THE WEEKEND, BRINGING POSSIBLY THE WARMEST CONDITIONS SO FAR
DURING THIS HEAT WAVE. AT THE SURFACE HIGH PRESSURE WILL BE CENTERED
OVER THE GULF OF MEXICO, MAINTAINING MAINLY SWLY LOW LEVEL FLOW.
ALONG WITH CONTINUED ABOVE NORMAL SURFACE TEMPS, HIGHER MID LEVEL
TEMPS WILL MAKE FOR STRONGER CAPPING, ESPECIALLY THE FARTHER WEST
YOU ARE IN THE CWA. WHILE POPS (PRIMARILY ISOLATED) WILL REMAIN IN
THE FORECAST OVER SOUTHERN AND EASTERN PORTIONS OF THE AREA EACH
AFTERNOON THROUGH THE WEEKEND, MOST ACTIVITY IS EXPECTED TO BE
RATHER INNOCUOUS. THOUGH SOME MIXING WILL OCCUR DURING THE DAY,
DEWPOINTS ARE EXPECTED TO REMAIN UP IN THE 70S, ESPECIALLY ACROSS
THE ARKLAMISS DELTA. THIS MEANS TRIPLE DIGIT HEAT INDICES WILL
CONTINUE TO BE PERVASIVE DURING THE LATE MORNING AND AFTERNOON HOURS
THROUGH THE WEEKEND.
BY EARLY NEXT WEEK, THERE ARE SOME HINTS THE MID/UPPER RIDGE WILL
BEGIN TO WEAKEN OR AT LEAST THE RIDGE AXIS WILL RETROGRADE BACK
TOWARD THE LOWER PLAINS. THOUGH MODEL AGREEMENT BECOMES WORSE BY
THIS TIME FRAME, INDICATIONS ARE THAT DIURNAL CONVECTION MAY BECOME
MORE PREVALENT BY MONDAY OR TUESDAY. THE EURO EVEN HINTS AT A WEAK
FRONT MAKING A PUSH TOWARD THE AREA BY MIDWEEK. REGARDLESS, THE
PRESENCE OF MORE CLOUDS WOULD SUGGEST MAX TEMPS WILL AT LEAST BEGIN
TRENDING BACK IN THE "RIGHT" DIRECTION. /DL/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 74 95 75 95 / 15 10 4 14
MERIDIAN 72 95 74 96 / 25 21 12 17
VICKSBURG 74 95 73 95 / 11 7 3 10
HATTIESBURG 74 96 75 96 / 11 19 12 21
NATCHEZ 74 94 75 94 / 6 8 5 10
GREENVILLE 75 96 75 96 / 27 7 2 6
GREENWOOD 74 96 74 96 / 30 13 3 9
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...HEAT ADVISORY UNTIL 7 PM CDT FRIDAY FOR MSZ018-019-025>053.
LA...HEAT ADVISORY UNTIL 7 PM CDT FRIDAY FOR LAZ007>009-015-016-
023>025.
AR...HEAT ADVISORY UNTIL 7 PM CDT FRIDAY FOR ARZ074-075.
&&
$$
BB/7/DL
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1051 AM CDT Wed Jul 15 2015
.MESOSCALE DISCUSSION...
Issued at 1050 AM CDT WED JUL 15 2015
Challenging forecast this morning in the short term. Severe
convective cluster that developed yesterday in eastern Colorado
made it to just south of Kansas City before rapidly dissipating
this morning, despite the presence of a very unstable airmass.
Outflow from this cluster is now beginning to enter the central
Missouri portion of the CWA, with some persistent but so far weak
convection noted along it. As mentioned, the airmass ahead of this
feature appears to be very unstable, with dewpoints in the mid to
even upper 70s, and MLCAPE of 3000+ J/KG. In addition, 12Z SGF
RAOB measured low level theta-e differentials of 39K, with SPC
objective analysis suggesting widespread 30-40K values in place.
This should contribute to a somewhat significant downburst wind
threat IF convection can manage to get organized going into the
afternoon. The latest HRRR seems to hint at an uptick in coverage,
but model performance has not been particularly impressive as of
late.
If things can get going, areas from Truman Lake and Lake of the
Ozarks south toward West Plains and Eminence would be most likely
to see convection this afternoon.
The other challenge continues to be heat indices this afternoon,
and just how much cloud cover and convection will affect readings.
Far southwestern Missouri and southeastern Kansas should see the
least impact from cloud cover, with current expectations of seeing
heat index values between 103 and 105. Will hold off on a Heat
Advisory for now, but will watch trends closely going into the
afternoon hours.
&&
.SHORT TERM...(Today and Tonight)
Issued at 340 AM CDT WED JUL 15 2015
Another seasonably hot and muggy day is in store with again the
potential for scattered convection.
A weak boundary augmented by the convective complex on Tuesday
stretched from northwest to southeast north central Kansas into
far southwestern Missouri and will begin a slow retreat to the
northeast today. Meanwhile a weak perturbation will track from
western Kansas and around the northern periphery of the upper
level ridge into northern Missouri this afternoon. The features will
interact with strong destabilization at the surface to support the
potential for convection across much of the area today.
Meanwhile, an ongoing convective complex was pushing across north
central Kansas early today and Corfidi vectors suggest it will
take a southeastward turn later this morning and ride down the
rich theta-e axis into southwestern Missouri.
Mixed layer CAPE will approach 4500 J/KG today along and just
west of the surface boundary across west central and southwestern
Missouri where moisture pooling is expected. Deep layer shear will
be 25 to 30 kts while Theta-E differentials near 40 Celsius.
These factors will support vigorous updrafts and the potential for
strong to severe storms with locally damaging winds the primary
risk. If the convective complex remains intact then the potential
for damaging winds will increase.
High temperatures in the lower 90s coupled with surface dewpoints
in the lower and middle 70s will again yield uncomfortable heat
indicies with values from near 100 to around 105 degrees. The
highest heat indicies will occur within an axis of moisture
pooling just west of the boundary from west central Missouri into
southeastern Kansas and southwestern Missouri.
However the coverage and associated cloud cover could limit
heating at least in localized areas. With the uncertainty of the
coverage of convection including the evolution of the convective
complex, I have held off on issuing a Heat Advisory at this time.
A shorter fuse Heat Advisory may be issued late this morning based
on convective trends.
.LONG TERM...(Thursday through Tuesday)
Issued at 340 AM CDT WED JUL 15 2015
Seasonably hot and humid weather is expected the remainder of the
week and into weekend as the subtropical remains parked over the
lower Mississippi River Valley. Will have to watch for the chance
for isolated convection but widespread rainfall is not expected.
The upper ridge will retrograde to the west early next week
allowing a front to drop southward through the area on Monday.
This will bring an increased coverage of showers and
thunderstorms.
&&
.AVIATION...(For the 12Z TAFS through 12Z Thursday Morning)
Issued at 600 AM CDT WED JUL 15 2015
For the KSGF, KJLN, and KBBG TAFS: A complex of storms is currently
pushing east across northeastern Kansas early this morning. There
are indications that this complex of storms will start to push
southeastward to southward this morning and push into the area
this afternoon. There are still questions on the exact track of
these storms but given the current expectation the better
potential will be at the KSGF and KBBG TAF sites.
Given a very unstable air mass isolated to scattered storms will still
be possible across areas not affected by this complex this
afternoon/early evening, but will not be widespread. The
atmosphere will be supportive of strong gusty winds along with
brief heavy rain reducing the visibility with any storms that
occurs this afternoon into early this evening.
Otherwise outside of convection VFR conditions are expected with
a light southerly breezy today and tonight.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
MESOSCALE...Boxell
SHORT TERM...Foster
LONG TERM...Foster
AVIATION...Wise
AREA FORECAST DISCUSSION...UPDATED
NWS GLASGOW MT
910 PM MDT THU JUL 16 2015
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SATURDAY...
A LOW PRESSURE STORM SYSTEM IN SOUTHERN CANADA WILL SEND A COLD
FRONT THROUGH THE AREA TONIGHT...WHICH WILL PRODUCE SCATTERED RAIN
SHOWERS AND ISOLATED THUNDERSTORMS. A FAIRLY STRONG SURFACE
PRESSURE DIFFERENCE IS PRODUCING GUSTY NORTHWEST WIND OF 20 TO
30KTS THIS EVENING. WINDS WILL DIMINISH AFTER SUNSET. ADJUSTED
WIND BASED ON THE HRRR MODEL AND OBSERVATIONS. ALSO ADJUSTED POPS
BASED ON LATEST GUIDANCE. SCT
PREVIOUS DISCUSSION...
AN UPPER LOW IS CURRENTLY DROPPING SOUTHWARD THROUGH ALBERTA...
TOWARD NORTHEAST MONTANA. THE ASSOCIATED COLD FRONT WILL PUSH
THROUGH THIS EVENING. THE FRONT SHOULD HELP WITH SHOWERS AND
THUNDERSTORM DEVELOPMENT AS IT PUSHES THROUGH. EXPECT A BRIEF
PERIOD OF GUSTY NORTHWEST WINDS WITH THE FRONT. WITH GUSTY WINDS
EXPECTED AGAIN ON FRIDAY...DECIDED TO EXTEND THE CURRENT LAKE WIND
ADVISORY THROUGH FRIDAY EVENING.
FRIDAY THE UPPER LOW DROPS SOUTHWARD INTO SOUTHERN SASKATCHEWAN...
BECOMING VERTICALLY STACKED. GUSTY NORTHWEST WINDS WILL CONTINUE
AS COLD AIR ADVECTION CONTINUES BEHIND THE SURFACE FRONT...ALONG
WITH A TIGHTENED PRESSURE GRADIENT. POTENTIAL FOR SHOWERS WILL BE
THE BEST ALONG THE CANADIAN BORDER NEAR THE CORE OF THE LOW.
FRIDAY NIGHT THE LOW PUSHES EAST INTO NORTH DAKOTA. GUSTY
NORTHWEST WINDS SHOULD TAPER OFF A BIT DURING THE EVENING AS THE
GRADIENT RELAXES. AGAIN THE BEST POTENTIAL FOR SHOWERS AND
THUNDERSTORMS WILL CONTINUE ACROSS THE NORTH...I.E. NORTH OF THE
MISSOURI RIVER.
GILCHRIST
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
SYNOPTIC SET UP... LONG RANGE BEGINS WITH A TROUGH RUNNING FORM
SOUTHERN IDAHO THROUGH EASTERN MONTANA AND UP INTO NORTHERN
MANITOBA. TO THE WEST A RIDGE RUNS DOWN FROM NORTHERN ALBERTA
THROUGH SOUTHERN BRITISH COLUMBIA AND TO CALIFORNIA. MEANWHILE A
LARGE COOL TROUGH LIES FARTHER WEST OVER ALASKA.
SATURDAY THROUGH SUNDAY... COOL TROUGH ACROSS THE AREA WILL BE
PUSHED OUT BY THE RIDGE DIRECTLY TO THE WEST. THIS WILL KEEP POPS
TO A MINIMUM OVERNIGHT INTO SUNDAY.
SUNDAY NIGHT THROUGH MONDAY NIGHT... COLD AIR OVER THE NORTHWEST
TERRITORIES WILL PUSH THE RIDGE OUT AND BRING COOL AIR BACK INTO
THE REGION. A BRIEF SHOT AT SHOWERS IS POSSIBLE WITH THE FRONTS
PASSAGE.
TUESDAY TO WEDNESDAY... HOT INTERMOUNTAIN WEST RIDGE WILL FINALLY
REBUILD AND PUSH UP INTO MONTANA. TEMPERATURES WILL WARM AGAIN
WITH A SMALL CHANCE AT AFTERNOON/EVENING INSTABILITY SHOWERS. COLD
AIR FROM THE TROUGH UP IN ALASKA WILL BREAK APART AND STRADDLE
EITHER SIDE OF THE RIDGE.
WEDNESDAY NIGHT ONWARD... MODEL CONFIDENCE BREAKS DOWN AT THIS
POINT. MODELS ARE UNSURE OF HOW TO HANDLE THE TWO COLD AIR MASSES
AROUND THE RIDGE WITH SOME WANTING TO BE PROGRESSIVE AND MOVE IT
OUT EARLY WHILE OTHERS SHOW IT NOT BEING STRONG ENOUGH TO MOVE
THE RIDGE FROM THE WEST. EVENTUALLY FLOW WILL GAIN MORE OF A
SOUTHWEST COMPONENT IN THIS PATTERN AND LEND ITSELF TOWARD
INCREASED SHOWERS... BUT THIS MAY TAKE LONGER TO SET IN THAN
CURRENTLY ANTICIPATED. GAH
PREVIOUS LONG TERM DISCUSSION...
UPPER TROUGH WILL MOVE TO THE EAST SATURDAY NIGHT WHICH WILL
DIMINISH THE CHANCE OF SHOWERS AND THUNDERSTORMS. SUNDAY LOOKS DRY
WITH A SHORTWAVE RIDGE WITHIN NORTHWEST FLOW ALOFT. THIS RIDGE
WILL ALSO BRING WARMER AIR MASS BACK INTO NORTHEAST MONTANA.
UPPER TROUGH MOVES THROUGH ALBERTA AND SASKATCHEWAN ON MONDAY
WHICH WILL DRAG A COLD FRONT ACROSS THE FORECAST AREA DURING THE
DAY. AT THIS POINT...THE SYSTEM IS LACKING MOISTURE. WILL KEEP
FORECAST DRY.
FLOW ALOFT TURNS TO ZONAL ON TUESDAY AND A WEAK WAVE TUESDAY NIGHT
COULD BRING ENOUGH MOISTURE FOR A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS.
FLOW ALOFT TURNS TO THE SOUTHWEST ON WEDNESDAY AND STAYS THAT WAY
ON THURSDAY WITH SOME MODEL DIFFERENCES IN TIMING WAVES. WILL
BROAD BRUSH A SLIGHT CHANCE OF THUNDERSTORMS. FORRESTER
&&
.AVIATION...
FLIGHT CATEGORY: VFR...OUTSIDE OF THUNDERSTORMS.
THUNDERSTORMS: ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
WILL BE POSSIBLE OFF AND ON THROUGH FRIDAY. AS A RESULT BRIEF
PERIODS OF SUB VFR VSBY AND OR CIGS WILL BE POSSIBLE. GUSTY
ERRATIC WINDS TO 30KTS CAN BE EXPECTED WITH THUNDERSTORMS.
CIGS; SCT-BKN MID LEVEL CLOUDS.
WINDS: WEST 10-20KTS...BECOMING NORTHWEST 15 TO 30KTS THIS
EVENING AS A COLD FRONT PUSHES THROUGH FROM THE NORTHWEST. WINDS
WILL DECREASE BEHIND THE FRONT TO 5 TO 15KTS EARLY FRIDAY
MORNING...BEFORE AGAIN PICKING UP TO 10 TO 25KTS BY NOON FRIDAY.
GILCHRIST/PROTON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 9 PM MDT FRIDAY FOR FORT PECK LAKE FOR
CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN VALLEY...
GARFIELD...MCCONE...PETROLEUM.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION...UPDATED
NWS GLASGOW MT
853 PM MDT THU JUL 16 2015
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SATURDAY...
A LOW PRESSURE STORM SYSTEM IN SOUTHERN CANADA WILL SEND A COLD
FRONT THROUGH THE AREA TONIGHT...WHICH WILL PRODUCE SCATTERED RAIN
SHOWERS AND ISOLATED THUNDERSTORMS. A FAIRLY STRONG SURFACE
PRESSURE DIFFERENCE IS PRODUCING GUSTY NORTHWEST WIND OF 20 TO
30KTS THIS EVENING. WINDS WILL DIMINISH AFTER SUNSET. ADJUSTED
WIND BASED ON THE HRRR MODEL AND OBSERVATIONS. ALSO ADJUSTED POPS
BASED ON LATEST GUIDANCE. SCT
PREVIOUS DISCUSSION...
AN UPPER LOW IS CURRENTLY DROPPING SOUTHWARD THROUGH ALBERTA...
TOWARD NORTHEAST MONTANA. THE ASSOCIATED COLD FRONT WILL PUSH
THROUGH THIS EVENING. THE FRONT SHOULD HELP WITH SHOWERS AND
THUNDERSTORM DEVELOPMENT AS IT PUSHES THROUGH. EXPECT A BRIEF
PERIOD OF GUSTY NORTHWEST WINDS WITH THE FRONT. WITH GUSTY WINDS
EXPECTED AGAIN ON FRIDAY...DECIDED TO EXTEND THE CURRENT LAKE WIND
ADVISORY THROUGH FRIDAY EVENING.
FRIDAY THE UPPER LOW DROPS SOUTHWARD INTO SOUTHERN SASKATCHEWAN...
BECOMING VERTICALLY STACKED. GUSTY NORTHWEST WINDS WILL CONTINUE
AS COLD AIR ADVECTION CONTINUES BEHIND THE SURFACE FRONT...ALONG
WITH A TIGHTENED PRESSURE GRADIENT. POTENTIAL FOR SHOWERS WILL BE
THE BEST ALONG THE CANADIAN BORDER NEAR THE CORE OF THE LOW.
FRIDAY NIGHT THE LOW PUSHES EAST INTO NORTH DAKOTA. GUSTY
NORTHWEST WINDS SHOULD TAPER OFF A BIT DURING THE EVENING AS THE
GRADIENT RELAXES. AGAIN THE BEST POTENTIAL FOR SHOWERS AND
THUNDERSTORMS WILL CONTINUE ACROSS THE NORTH...I.E. NORTH OF THE
MISSOURI RIVER.
GILCHRIST
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
SYNOPTIC SET UP... LONG RANGE BEGINS WITH A TROUGH RUNNING FORM
SOUTHERN IDAHO THROUGH EASTERN MONTANA AND UP INTO NORTHERN
MANITOBA. TO THE WEST A RIDGE RUNS DOWN FROM NORTHERN ALBERTA
THROUGH SOUTHERN BRITISH COLUMBIA AND TO CALIFORNIA. MEANWHILE A
LARGE COOL TROUGH LIES FARTHER WEST OVER ALASKA.
SATURDAY THROUGH SUNDAY... COOL TROUGH ACROSS THE AREA WILL BE
PUSHED OUT BY THE RIDGE DIRECTLY TO THE WEST. THIS WILL KEEP POPS
TO A MINIMUM OVERNIGHT INTO SUNDAY.
SUNDAY NIGHT THROUGH MONDAY NIGHT... COLD AIR OVER THE NORTHWEST
TERRITORIES WILL PUSH THE RIDGE OUT AND BRING COOL AIR BACK INTO
THE REGION. A BRIEF SHOT AT SHOWERS IS POSSIBLE WITH THE FRONTS
PASSAGE.
TUESDAY TO WEDNESDAY... HOT INTERMOUNTAIN WEST RIDGE WILL FINALLY
REBUILD AND PUSH UP INTO MONTANA. TEMPERATURES WILL WARM AGAIN
WITH A SMALL CHANCE AT AFTERNOON/EVENING INSTABILITY SHOWERS. COLD
AIR FROM THE TROUGH UP IN ALASKA WILL BREAK APART AND STRADDLE
EITHER SIDE OF THE RIDGE.
WEDNESDAY NIGHT ONWARD... MODEL CONFIDENCE BREAKS DOWN AT THIS
POINT. MODELS ARE UNSURE OF HOW TO HANDLE THE TWO COLD AIR MASSES
AROUND THE RIDGE WITH SOME WANTING TO BE PROGRESSIVE AND MOVE IT
OUT EARLY WHILE OTHERS SHOW IT NOT BEING STRONG ENOUGH TO MOVE
THE RIDGE FROM THE WEST. EVENTUALLY FLOW WILL GAIN MORE OF A
SOUTHWEST COMPONENT IN THIS PATTERN AND LEND ITSELF TOWARD
INCREASED SHOWERS... BUT THIS MAY TAKE LONGER TO SET IN THAN
CURRENTLY ANTICIPATED. GAH
PREVIOUS LONG TERM DISCUSSION...
UPPER TROUGH WILL MOVE TO THE EAST SATURDAY NIGHT WHICH WILL
DIMINISH THE CHANCE OF SHOWERS AND THUNDERSTORMS. SUNDAY LOOKS DRY
WITH A SHORTWAVE RIDGE WITHIN NORTHWEST FLOW ALOFT. THIS RIDGE
WILL ALSO BRING WARMER AIR MASS BACK INTO NORTHEAST MONTANA.
UPPER TROUGH MOVES THROUGH ALBERTA AND SASKATCHEWAN ON MONDAY
WHICH WILL DRAG A COLD FRONT ACROSS THE FORECAST AREA DURING THE
DAY. AT THIS POINT...THE SYSTEM IS LACKING MOISTURE. WILL KEEP
FORECAST DRY.
FLOW ALOFT TURNS TO ZONAL ON TUESDAY AND A WEAK WAVE TUESDAY NIGHT
COULD BRING ENOUGH MOISTURE FOR A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS.
FLOW ALOFT TURNS TO THE SOUTHWEST ON WEDNESDAY AND STAYS THAT WAY
ON THURSDAY WITH SOME MODEL DIFFERENCES IN TIMING WAVES. WILL
BROAD BRUSH A SLIGHT CHANCE OF THUNDERSTORMS. FORRESTER
&&
.AVIATION...
FLIGHT CATEGORY: VFR...OUTSIDE OF THUNDERSTORMS.
THUNDERSTORMS: ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
WILL BE POSSIBLE OFF AND ON THROUGH FRIDAY. AS A RESULT BRIEF
PERIODS OF SUB VFR VSBY AND OR CIGS WILL BE POSSIBLE. GUSTY
ERRATIC WINDS TO 30KTS CAN BE EXPECTED WITH THUNDERSTORMS.
CIGS; SCT-BKN MID LEVEL CLOUDS.
WINDS: WEST 10-20KTS...BECOMING NORTHWEST 15 TO 30KTS THIS
EVENING AS A COLD FRONT PUSHES THROUGH FROM THE NORTHWEST. WINDS
WILL DECREASE BEHIND THE FRONT TO 5 TO 15KTS EARLY FRIDAY
MORNING...BEFORE AGAIN PICKING UP TO 10 TO 25KTS BY NOON FRIDAY.
GILCHRIST
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 9 PM MDT FRIDAY FOR FORT PECK LAKE FOR
CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN VALLEY...
GARFIELD...MCCONE...PETROLEUM.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1235 PM CDT WED JUL 15 2015
.UPDATE...
ISSUED AT 1019 AM CDT WED JUL 15 2015
UPDATED GRIDS/FORECAST FOR ONGOING TRENDS AND EXPECTED TRENDS THE
NEXT FEW HOURS.
THE FORECAST IS CHALLENGING TODAY. SOME TRENDS SEEM TO BE
EMERGING. THIS STRONG MCV /MESOSCALE CONVECTIVE VORTEX/ WHICH
RESULTED FROM THE LARGE RAIN/STORM AREA LATE NIGHT...IS NOW
WRAPPING THINGS UP IN THE NORTHEAST PART OF THE FORECAST AREA.
DO BELIEVE THAT TREND WILL CONTINUE...WITH MAYBE A BIT OF
REDEVELOPMENT IN THAT REGION EARLY THIS AFTERNOON BUT MAY NOT
BE MORE THAN A FEW SHOWERS.
THE MCV IS STRONG...AND IS PRODUCING A STRONG SUBSIDENT REGION
IN ITS WAKE...WHICH WILL BE A DETERRENT TO AFTERNOON THUNDERSTORM
DEVELOPMENT FOR A LARGE PART OF THE AREA. THE AFTERNOON SEVERE
RISK IS LESS...SIMPLY BECAUSE WE ARE GOING TO HAVE TROUBLE
OVERCOMING THE SUBSIDENT WAKE OF THE MCV...WHICH HAS ALSO BROUGHT
SOME MORE STABLE MID-LEVEL LAPSE RATES THE NEBRASKA COUNTIES. DID
LOWER PRECIPITATION CHANCES MANY AREAS TODAY.
TO THE SOUTH...IN NORTH CENTRAL KANSAS...THIS MAY BE A MORE
ENLIGHTENED AREA FOR THUNDERSTORM DEVELOPMENT LATE THIS AFTERNOON
AND EVENING. THERE IS A WEAK SURFACE TROF ACCESS FROM KHLC TO WEST
OF KGCK...AND THE HRRR HINTS AT DEVELOPMENT IN THAT REGION...AND
THE 4KM NAM FIRES THAT LINE AS WELL TOWARD EVENING. ITS A TOUGH
CALL...BUT ITS SEEMS A MORE FAVORED AREA FOR A STRONG/SEVERE
STORM WOULD BE THE NORTH CENTRAL KANSAS REGION...POSSIBLY UP TO
SUPERIOR AND HEBRON.
IN GENERAL...A MORE WIDESPREAD SEVERE RISK SEEMS TO HAVE
DIMINISHED FOR MUCH OF THE AREA DUE TO THE MCV PASSAGE...
BUT STILL NOT TOTALLY OUT OF THE FORECAST ACROSS THE
SOUTH WHERE MORE FAVORABLE INSTABILITY...SHEAR AND SOME
WEAK CONVERGENCE MAY BE SUFFICIENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 440 AM CDT WED JUL 15 2015
PORTIONS OF THE AREA CONTINUE TO BE AFFECTED BY A COMPLEX OF
SHOWERS/THUNDERSTORMS EARLY THIS MORNING...MAINLY ALONG AND W/SW
OF A LXN TO JEWELL/KS LINE. DRIVEN BY AN UPPER LEVEL SHORTWAVE
DISTURBANCE AND MOISTURE/WARM AIR ADVECTION ASSOCIATED WITH AN
INCREASED LLJ...THIS COMPLEX HASNT EXACTLY BEEN MOVING QUICKLY TO
THE E/NE...THOUGH THE STRONGEST PORTION WHICH SHIFTED ACROSS
ROOKS/OSBORNE/MITCHELL COUNTIES IS WORKING ITS WAY OUT OF THE CWA.
AT THE SFC...A PRETTY WEAK PATTERN IS IN PLACE...WITH AN AREA OF
LOWER PRESSURE OVER THE WRN HALF OF KS...ANY BOUNDARIES THAT HAD
BEEN IN PLACE ARE BEING/WILL BE AFFECTED BY ONGOING ACTIVITY.
THE PRIMARY FORECAST FOR THE SHORT TERM LIES WITH PRECIPITATION
CHANCES AND POTENTIAL FOR SEVERE WEATHER. WANT TO STATE RIGHT OFF
THAT OVERALL CONFIDENCE IN EXACTLY HOW THINGS ARE GOING TO PLAY
OUT OVER THE NEXT 12-18 HOURS IS NOT HIGH. THINKING IS THAT THE
COMPLEX CURRENTLY SHIFTING THROUGH THE REGION WILL CONTINUE TO DO
SO THIS MORNING...AND SHOULD GIVE A CHUNK OF THE CWA AT LEAST
SOMEWHAT OF A BREAK IN THE ACTION TODAY. THERE ARE A FEW
DIFFERENCES BETWEEN MODELS AS WE GET INTO THIS AFTERNOON/EVENING
LOOKING AT QPF OUTPUT...VARYING BETWEEN NOT MUCH TO THE NEXT ROUND
AFFECTING MUCH OF THE CWA.
BROAD UPPER LEVEL SHORTWAVE TROUGHING LOOKS TO REMAIN IN THE
REGION FOR MUCH OF THE PERIOD...WITH MODELS SOWING SFC LOW
PRESSURE DEEPENING SOME OVER WRN PORTIONS OF KS LATER TODAY. STILL
LOOKING AT THE POTENTIAL FOR A SFC TROUGH AXIS/WARM FRONTAL
BOUNDARY TO EXTEND FROM THAT WRN SFC LOW THROUGH PORTIONS OF THE
CWA...BUT CONFIDENCE IN WHERE EXACTLY THAT MAY SET UP IS LOW...AND
WONT BE MORE APPARENT UNTIL THIS ONGOING ACTIVITY SHIFTS OUT AND
CAN SEE HOW OUTFLOW BOUNDARIES AFFECT THINGS. IF THE AREA GETS A
CHANCE TO "RECOVER" THROUGH THE DAY FROM CURRENT
CONDITIONS...MODELS CONTINUE TO SHOW AN AXIS OF STRONG INSTABILITY
DEVELOPING NEAR/NORTH OF THAT BOUNDARY WITH MOISTURE POOLING.
WHILE CURRENT DEEPER LAYER SHEAR IS WEAK...THAT IS EXPECTED TO
IMPROVE SOME WITH TIME...WITH LOW LEVEL SHEAR ALSO PICKING UP THIS
EVENING AS THE LLJ INCREASES. THE CWA SITS IN THE SPC DAY 1 SLIGHT
RISK AREA...WITH ALL MODES OF SEVERE WEATHER STILL A POSSIBILITY.
THOUGH HAIL/WINDS/HEAVY RAIN LOOK TO BE THE PRIMARY HAZARDS...CANT
COMPLETELY RULE OUT THE TORNADO THREAT WITH MORE THAN SUFFICIENT
INSTABILITY/GOOD LOWER LEVEL MOISTURE AND SFC BOUNDARIES IN THE
AREA.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 440 AM CDT WED JUL 15 2015
THE BIGGEST ISSUE REVOLVES AROUND DETERMINING CHANCE OF
PRECIPITATION THROUGHOUT MOST OF THE LONG TERM FORECAST AS WELL AS
STRONG/SEVERE THUNDERSTORM POTENTIAL.
FLOW WILL REMAIN MAINLY ZONAL AS WE REMAIN UNDER CONSIDERABLE
INFLUENCE OF THE SUBTROPICAL HIGH/RIDGE IN THE SOUTH. A SURFACE
TROUGH WILL LIKELY BE DRAPED SOMEWHERE OVER THE CWA...WHICH WILL
PROVIDE A FOCUS FOR NEW THUNDERSTORM DEVELOP BY LATE AFTERNOON AND
INTO THE EVENING AS THE HEAT OF THE DAY WILL INCREASE
INSTABILITY. LEFTOVER OUTFLOW BOUNDARIES WILL BE ANOTHER
POSSIBILITY FOR A FOCUS OF CONVECTION. AT ANY
TIME...ESSENTIALLY...A LOW-AMPLITUDE WAVE WILL BE POSSIBLE WITHIN
ZONAL FLOW WHICH WILL ALSO HELP SPARK CONVECTION. A SIMILAR
SCENARIO EXISTS FOR FRIDAY AFTERNOON/NIGHT. STRONG TO MARGINALLY
SEVERE THUNDERSTORMS WILL BE POSSIBLE FOR THURSDAY THROUGH FRIDAY
NIGHT...BUT THIS WILL BE LARGELY DIURNALLY DRIVEN AS DEEP LAYER
SHEAR WILL BE GENERALLY AROUND 30 KTS...WHICH IS NOT ALL THAT
IMPRESSIVE.
NO HUGE CHANGES TO THE GENERAL PATTERN HERE...EXCEPT FOR A
NORTHERN STREAM SHORTWAVE TROUGH TREKING THROUGH THE
NORTHERN/CENTRAL PLAINS SUNDAY/SUNDAY NIGHT WHICH MAY COOL DOWN
TEMPERATURES TO NEAR NORMAL. I NUDGED UP TEMPERATURES A BIT FOR
THURSDAY/FRIDAY COMPARED TO THE PREVIOUS FORECAST. ITS STILL A BIT
EARLY TO DETERMINE STRONG/SEVERE THUNDERSTORM CHANCES PAST FRIDAY
NIGHT.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1229 PM CDT WED JUL 15 2015
MCV PASSING BY THE REGION WILL HAMPER ADDITIONAL PRECIPITATION
DEVELOPMENT THIS FORECAST PERIOD...AND LIKELY KEEP VFR CONDITIONS
MORE PREVALENT THAN ONCE EXPECTED. SURFACE FLOW IS WEAK SO WINDS
WILL REMAIN BELOW 10KTS THROUGH THE PERIOD...ALTHOUGH THEY MAY
TAKE ON A MORE WEST/NORTHWEST BENT LATE TONIGHT. LOOK FOR MID
HIGH CLOUDS THIS AFTERNOON...WITH POSSIBLY AN MVFR CEILING
FROM TIME TO TIME WAS SUNSHINE INCREASES IN WARM ADVECTION ZONE
BEHIND MCV. INCLUDED THUNDERSTORMS IN THE VICINITY OF THE KGRI
WITH MODELS SUGGESTING NORTH CENTRAL KANSAS LATE THIS EVENING
COULD GRAZE BY THE AREA. CONFIDENCE IS LOW KGRI WOULD ACTUALLY
HAVE A THUNDERSTORM THOUGH TO BE HONEST.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...NOAA/NWS/MORITZ
SHORT TERM...ADP
LONG TERM...HEINLEIN
AVIATION...NOAA/NWS/MORITZ
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1044 AM CDT WED JUL 15 2015
.UPDATE...
ISSUED AT 1019 AM CDT WED JUL 15 2015
UPDATED GRIDS/FORECAST FOR ONGOING TRENDS AND EXPECTED TRENDS THE
NEXT FEW HOURS.
THE FORECAST IS CHALLENGING TODAY. SOME TRENDS SEEM TO BE
EMERGING. THIS STRONG MCV /MESOSCALE CONVECTIVE VORTEX/ WHICH
RESULTED FROM THE LARGE RAIN/STORM AREA LATE NIGHT...IS NOW
WRAPPING THINGS UP IN THE NORTHEAST PART OF THE FORECAST AREA.
DO BELIEVE THAT TREND WILL CONTINUE...WITH MAYBE A BIT OF
REDEVELOPMENT IN THAT REGION EARLY THIS AFTERNOON BUT MAY NOT
BE MORE THAN A FEW SHOWERS.
THE MCV IS STRONG...AND IS PRODUCING A STRONG SUBSIDENT REGION
IN ITS WAKE...WHICH WILL BE A DETERRENT TO AFTERNOON THUNDERSTORM
DEVELOPMENT FOR A LARGE PART OF THE AREA. THE AFTERNOON SEVERE
RISK IS LESS...SIMPLY BECAUSE WE ARE GOING TO HAVE TROUBLE
OVERCOMING THE SUBSIDENT WAKE OF THE MCV...WHICH HAS ALSO BROUGHT
SOME MORE STABLE MID-LEVEL LAPSE RATES THE NEBRASKA COUNTIES. DID
LOWER PRECIPITATION CHANCES MANY AREAS TODAY.
TO THE SOUTH...IN NORTH CENTRAL KANSAS...THIS MAY BE A MORE
ENLIGHTENED AREA FOR THUNDERSTORM DEVELOPMENT LATE THIS AFTERNOON
AND EVENING. THERE IS A WEAK SURFACE TROF ACCESS FROM KHLC TO WEST
OF KGCK...AND THE HRRR HINTS AT DEVELOPMENT IN THAT REGION...AND
THE 4KM NAM FIRES THAT LINE AS WELL TOWARD EVENING. ITS A TOUGH
CALL...BUT ITS SEEMS A MORE FAVORED AREA FOR A STRONG/SEVERE
STORM WOULD BE THE NORTH CENTRAL KANSAS REGION...POSSIBLY UP TO
SUPERIOR AND HEBRON.
IN GENERAL...A MORE WIDESPREAD SEVERE RISK SEEMS TO HAVE
DIMINISHED FOR MUCH OF THE AREA DUE TO THE MCV PASSAGE...
BUT STILL NOT TOTALLY OUT OF THE FORECAST ACROSS THE
SOUTH WHERE MORE FAVORABLE INSTABILITY...SHEAR AND SOME
WEAK CONVERGENCE MAY BE SUFFICIENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 440 AM CDT WED JUL 15 2015
PORTIONS OF THE AREA CONTINUE TO BE AFFECTED BY A COMPLEX OF
SHOWERS/THUNDERSTORMS EARLY THIS MORNING...MAINLY ALONG AND W/SW
OF A LXN TO JEWELL/KS LINE. DRIVEN BY AN UPPER LEVEL SHORTWAVE
DISTURBANCE AND MOISTURE/WARM AIR ADVECTION ASSOCIATED WITH AN
INCREASED LLJ...THIS COMPLEX HASNT EXACTLY BEEN MOVING QUICKLY TO
THE E/NE...THOUGH THE STRONGEST PORTION WHICH SHIFTED ACROSS
ROOKS/OSBORNE/MITCHELL COUNTIES IS WORKING ITS WAY OUT OF THE CWA.
AT THE SFC...A PRETTY WEAK PATTERN IS IN PLACE...WITH AN AREA OF
LOWER PRESSURE OVER THE WRN HALF OF KS...ANY BOUNDARIES THAT HAD
BEEN IN PLACE ARE BEING/WILL BE AFFECTED BY ONGOING ACTIVITY.
THE PRIMARY FORECAST FOR THE SHORT TERM LIES WITH PRECIPITATION
CHANCES AND POTENTIAL FOR SEVERE WEATHER. WANT TO STATE RIGHT OFF
THAT OVERALL CONFIDENCE IN EXACTLY HOW THINGS ARE GOING TO PLAY
OUT OVER THE NEXT 12-18 HOURS IS NOT HIGH. THINKING IS THAT THE
COMPLEX CURRENTLY SHIFTING THROUGH THE REGION WILL CONTINUE TO DO
SO THIS MORNING...AND SHOULD GIVE A CHUNK OF THE CWA AT LEAST
SOMEWHAT OF A BREAK IN THE ACTION TODAY. THERE ARE A FEW
DIFFERENCES BETWEEN MODELS AS WE GET INTO THIS AFTERNOON/EVENING
LOOKING AT QPF OUTPUT...VARYING BETWEEN NOT MUCH TO THE NEXT ROUND
AFFECTING MUCH OF THE CWA.
BROAD UPPER LEVEL SHORTWAVE TROUGHING LOOKS TO REMAIN IN THE
REGION FOR MUCH OF THE PERIOD...WITH MODELS SOWING SFC LOW
PRESSURE DEEPENING SOME OVER WRN PORTIONS OF KS LATER TODAY. STILL
LOOKING AT THE POTENTIAL FOR A SFC TROUGH AXIS/WARM FRONTAL
BOUNDARY TO EXTEND FROM THAT WRN SFC LOW THROUGH PORTIONS OF THE
CWA...BUT CONFIDENCE IN WHERE EXACTLY THAT MAY SET UP IS LOW...AND
WONT BE MORE APPARENT UNTIL THIS ONGOING ACTIVITY SHIFTS OUT AND
CAN SEE HOW OUTFLOW BOUNDARIES AFFECT THINGS. IF THE AREA GETS A
CHANCE TO "RECOVER" THROUGH THE DAY FROM CURRENT
CONDITIONS...MODELS CONTINUE TO SHOW AN AXIS OF STRONG INSTABILITY
DEVELOPING NEAR/NORTH OF THAT BOUNDARY WITH MOISTURE POOLING.
WHILE CURRENT DEEPER LAYER SHEAR IS WEAK...THAT IS EXPECTED TO
IMPROVE SOME WITH TIME...WITH LOW LEVEL SHEAR ALSO PICKING UP THIS
EVENING AS THE LLJ INCREASES. THE CWA SITS IN THE SPC DAY 1 SLIGHT
RISK AREA...WITH ALL MODES OF SEVERE WEATHER STILL A POSSIBILITY.
THOUGH HAIL/WINDS/HEAVY RAIN LOOK TO BE THE PRIMARY HAZARDS...CANT
COMPLETELY RULE OUT THE TORNADO THREAT WITH MORE THAN SUFFICIENT
INSTABILITY/GOOD LOWER LEVEL MOISTURE AND SFC BOUNDARIES IN THE
AREA.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 440 AM CDT WED JUL 15 2015
THE BIGGEST ISSUE REVOLVES AROUND DETERMINING CHANCE OF
PRECIPITATION THROUGHOUT MOST OF THE LONG TERM FORECAST AS WELL AS
STRONG/SEVERE THUNDERSTORM POTENTIAL.
FLOW WILL REMAIN MAINLY ZONAL AS WE REMAIN UNDER CONSIDERABLE
INFLUENCE OF THE SUBTROPICAL HIGH/RIDGE IN THE SOUTH. A SURFACE
TROUGH WILL LIKELY BE DRAPED SOMEWHERE OVER THE CWA...WHICH WILL
PROVIDE A FOCUS FOR NEW THUNDERSTORM DEVELOP BY LATE AFTERNOON AND
INTO THE EVENING AS THE HEAT OF THE DAY WILL INCREASE
INSTABILITY. LEFTOVER OUTFLOW BOUNDARIES WILL BE ANOTHER
POSSIBILITY FOR A FOCUS OF CONVECTION. AT ANY
TIME...ESSENTIALLY...A LOW-AMPLITUDE WAVE WILL BE POSSIBLE WITHIN
ZONAL FLOW WHICH WILL ALSO HELP SPARK CONVECTION. A SIMILAR
SCENARIO EXISTS FOR FRIDAY AFTERNOON/NIGHT. STRONG TO MARGINALLY
SEVERE THUNDERSTORMS WILL BE POSSIBLE FOR THURSDAY THROUGH FRIDAY
NIGHT...BUT THIS WILL BE LARGELY DIURNALLY DRIVEN AS DEEP LAYER
SHEAR WILL BE GENERALLY AROUND 30 KTS...WHICH IS NOT ALL THAT
IMPRESSIVE.
NO HUGE CHANGES TO THE GENERAL PATTERN HERE...EXCEPT FOR A
NORTHERN STREAM SHORTWAVE TROUGH TREKING THROUGH THE
NORTHERN/CENTRAL PLAINS SUNDAY/SUNDAY NIGHT WHICH MAY COOL DOWN
TEMPERATURES TO NEAR NORMAL. I NUDGED UP TEMPERATURES A BIT FOR
THURSDAY/FRIDAY COMPARED TO THE PREVIOUS FORECAST. ITS STILL A BIT
EARLY TO DETERMINE STRONG/SEVERE THUNDERSTORM CHANCES PAST FRIDAY
NIGHT.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 619 AM CDT WED JUL 15 2015
SHIELD OF SHOWERS/THUNDERSTORMS CONTINUES TO SLIDE NE ACROSS THE
AREA THIS MORNING...AND WILL AFFECT BOTH TERMINAL AREAS OVER THE
NEXT COUPLE OF HOURS. UPSTREAM OBS HAVE REMAINED VFR EVEN WITH
THIS PRECIP MOVING THROUGH AND KEPT THAT TREND IN PLACE IN THE
TAF. BY LATE THIS MORNING THIS MAIN AREA IS EXPECTED TO HAVE MOVED
OUT OF THE TERMINAL AREAS...AND SHOULD SEE A BREAK IN ACTIVITY.
LATER THIS AFTERNOON/EVENING...THERE WILL BE ANOTHER CHANCE FOR
THUNDERSTORM ACTIVITY...BUT OF UNCERTAINTIES WITH THE OVERALL
COVERAGE AND TIMING...KEPT MENTION AS VCTS FOR NOW. THE SFC
PATTERN WILL KEEP WINDS FAIRLY LIGHT THROUGH THE PERIOD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...NOAA/NWS/MORITZ
SHORT TERM...ADP
LONG TERM...HEINLEIN
AVIATION...ADP
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1152 PM CDT TUE JUL 14 2015
.SHORT TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 239 PM CDT TUE JUL 14 2015
TWO ROUNDS OF THUNDERSTORMS ARE ANTICIPATED IN THE SHORT TERM WITH
THE FIRST ROUND ADVANCING NORTHEAST INTO THE CWA FROM NORTH
CENTRAL KANSAS/SOUTH CENTRAL NEBRASKA OVERNIGHT INTO THE EARLY
MORNING HOURS WEDNESDAY AND THE SECOND ROUND DEVELOPING WEDNESDAY
AFTERNOON.
LATEST WATER VAPOR IMAGERY AND RAP 500 MB ANALYSIS SHOW AN UPPER
LEVEL RIDGE AXIS EXTENDING FROM THE SOUTH CENTRAL CONUS THROUGH
SOUTH CENTRAL CANADA. MONSOONAL FLOW CONTINUES TO MOVE THROUGH THE
INTERMOUNTAIN WEST WITH TWO DISTINCT SHORTWAVE TROUGHS THAT WILL
SOON IMPACT THE REGION. THE FIRST SHORTWAVE IS CURRENTLY LOCATED
OVER SOUTHEAST COLORADO WITH THE SECOND CURRENTLY OVER
SOUTHWESTERN NEW MEXICO.
AHEAD OF THIS...A FEW ISOLATED THUNDERSTORMS HAVE DEVELOPED NEAR
THE RIDGE AXIS IN CENTRAL NEBRASKA THIS AFTERNOON. A FEW OF THE
CAM`S BRING THIS ACTIVITY INTO OUR FAR WESTERN COUNTIES LATER THIS
EVENING BUT GENERAL FEELING IS THAT THEY WILL WEAKEN AS THEY
CONTINUE EAST AND HAVE LITTLE IMPACT ON THE CWA.
TSTMS ARE EXPECTED TO DEVELOP LATER ACROSS NORTH CENTRAL KANSAS
OVERNIGHT IN ADVANCE OF ABOVE MENTIONED SHORTWAVE IN STRONG WAA
REGIME AIDED BY NOSE OF NOCTURNAL LOW LEVEL JET. THIS ACTIVITY
WILL SPREAD NORTHEAST THROUGH THE MORNING AND LIKELY EXIT THE AREA
BY NOON. SOME OF THESE STORMS COULD BE SEVERE...BUT WILL BE
ELEVATED.
A DEVELOPING SURFACE LOW OVER WESTERN KANSAS AND ASSOCIATED
NORTHEASTWARD EXTENDING WARM FRONT WILL PUSH INTO SOUTHERN
NEBRASKA BY PEAK HEATING WEDNESDAY. IN ADDITION...THE SECOND ABOVE
MENTIONED PIECE OF SHORTWAVE ENERGY WILL MOVE TOWARD CENTRAL
NEBRASKA. DEPENDING ON SPEED OF EXITING MORNING TSTMS...THE
ATMOSPHERE SHOULD BE ABLE TO RECOVER LEADING TO MODERATE TO STRONG
INSTABILITY OVER THE FORECAST AREA BY PEAK HEATING. STRONG BULK
LAYER SHEAR VALUES WOULD INDICATE POTENTIAL FOR SUPERCELLS
INITIALLY...WITH A TORNADIC THREAT ALONG AND AHEAD OF THE WARM
FRONT. IN ADDITION TO SEVERE WEATHER...HEAVY RAIN IS ALSO POSSIBLE
WITH THE MORNING CONVECTION AND THE AFTERNOON/EVENING CONVECTION
WITH PW`S AOA 2.00". MUCH OF THE CWA IS OUTLOOKED IN THE SLIGHT
CATEGORY FOR EXCESSIVE RAINFALL AND FEEL THIS IS QUITE REASONABLE
GIVEN AMOUNT OF AVAILABLE MOISTURE. SOUTHWESTERLY NOCTURNAL LOW
LEVEL JET SHOULD SUSTAIN TSTM ACTIVITY AS IT PROGRESSES NORTHEAST
THROUGH THE CWA...ENDING IT THURSDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 239 PM CDT TUE JUL 14 2015
MODEST WESTERLY/SOUTHWESTERLY FLOW ALOFT WILL PERSIST INTO THE
WEEKEND. VERY HARD TO PIN DOWN EXACT TIMING OF THESE WAVES IN THE
LONG TERM...BUT CANNOT REALLY RULE OUT TSTMS IN ANY PARTICULAR PERIOD
WITH THIS TYPE OF PATTERN. WILL CARRY A LOW CONFIDENCE SMALL POP
THROUGH MUCH OF THE PERIOD. TEMPERATURES OVERALL LOOK SEASONAL.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1143 PM CDT TUE JUL 14 2015
DETERIORATING CONDITIONS A DISTINCT POSSIBILITY WITHIN THE NEXT
COUPLE HOURS AT THE TAF SITES. LATEST MODEL GUIDANCE IS SUGGESTING
A LINE OF CONVECTION INITIATING OVER S-CNTRL SD INTO ERN NEB BTWN
15/08Z-12Z THIS MORNING WITH ACTIVITY POSSIBLY CONTINUING THRU MID
MORNING. HOWEVER HAVE DECIDED TO LIMIT TEMPO GROUPS TO A COUPLE
HOURS DUE TO LOW CONFIDENCE OF AREAL COVERAGE. ANOTHER ROUND OS
TSRA POSSIBLE LATER THIS AFTN ALONG A WARM FRONT LIFTING OUT OF KS
AND INTO NEB. SVR TSTMS APPEAR PROBABLE FROM LATE AFTERNOON UNTIL
EARLY EVENING.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...KERN
LONG TERM...KERN
AVIATION...DEE
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1050 AM PDT WED JUL 15 2015
.SYNOPSIS...DRY CONDITIONS WITH NEAR NORMAL TEMPERATURES WILL
PERSIST THROUGH FRIDAY BEFORE SOME CHANGES BEGIN TO TAKE PLACE FOR
THE WEEKEND. MOISTURE IS EXPECTED TO GET PUSHED NORTH BY HURRICANE
DOLORES LATE FRIDAY INTO SATURDAY AND REMAIN IN PLACE ACROSS THE
AREA THROUGH MONDAY. THIS SHOULD RESULT IN PLENTY OF CLOUDS ALONG
WITH THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS...SOME OF WHICH
COULD PRODUCE LOCALLY HEAVY RAIN.
&&
.UPDATE...RECENT ANALYSES AND 12Z MODELS INDICATE THE AIR MASS OVER
THE FORECAST AREA HAS DRIED IN THE PAST 24 HOURS WITH PW VALUES
LOWERING AROUND A QUARTER INCH AT PW SITES. A MINOR UPDATE WAS MADE
TO REDUCE THE 15 POPS IN NORTHEAST MOHAVE COUNTY NEAR PIPE SPRING
THIS AFTERNOON. ALSO...WINDS WERE UPDATED BASED ON THE LATEST
OBSERVATIONS AND HRRR FORECAST. WILL BE TAKING A CLOSE LOOK AT
MEDIUM RANGE AND ENSEMBLE GUIDANCE FOR THE POTENTIAL MOISTURE INFLUX
THIS WEEKEND. CONFIDENCE IS STILL LOW IN NORTHWARD EXTENT OF THE
MOISTURE DUE TO A TROUGH DROPPING INTO THE NORTHWEST STATES.
&&
.AVIATION...FOR MCCARRAN...LIGHT EAST-SOUTHEAST WIND COMPONONET WILL
GIVE WAY TO A PUSH OF STRONGER SOUTH-SOUTHWEST WINDS AROUND
20Z...GIVE OR TAKE AN HOUR. WIND SPEEDS DURING THE AFTERNOON WILL BE
IN THE 10-15 KT RANGE WITH GUSTS AS HIGH AS 25 KTS.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...DRY AND CLEAR CONDITIONS EXPECTED ACROSS THE AREA WITH
EXCEPTION OF SOME ISOLATED BUILD UPS IN THE SIERRA WEST OF KBIH.
SOUTHERLY WINDS OF 10-15KT WITH GUSTS TO 25KTS EXPECTED DURING THE
AFTERNOON HOURS.
&&
.PREV DISCUSSION...
240 AM PDT WED JUL 15 2015
.SHORT TERM...THROUGH THURSDAY NIGHT.
FAIRLY TRANQUIL CONDITIONS EXPECTED IN THE SHORT TERM THANKS TO A
DRY SOUTHWESTERLY FLOW OVER THE AREA COURTESY OF A WEAK UPPER LEVEL
TROUGH OVER CALIFORNIA. THE ONLY EXCEPTION TO THE DRY CONDITIONS
WILL BE ACROSS THE HIGHEST TERRAIN OF THE SIERRA WHERE AND ISOLATED
SHOWER OR THUNDERSTORM COULD DEVELOP DURING THE AFTERNOON AND
EVENING HOURS. HOWEVER...ANY RAINFALL IS EXPECTED TO BE QUITE LIGHT.
I ALSO ADDED VERY SLIGHT POPS FOR FAR NORTHEAST MOHAVE COUNTY WHICH
SAW SOME ACTIVITY MONDAY AND MAY HAVE JUST ENOUGH INSTABILITY TO
FOSTER A FEW CUMULUS BUILD UPS AND PERHAPS AND ISOLATED SHOWER OR
STORM THIS AFTERNOON.
OTHERWISE...DRY CONDITIONS WILL PERSIST THROUGH THURSDAY WITH NEAR
NORMAL TEMPERATURES. WINDS WILL BE BREEZY AT TIMES DURING THE
AFTERNOON HOURS EACH DAY.
.LONG TERM...FRIDAY THROUGH TUESDAY.
AFTER TWO DAYS OF GOOD MODEL CONTINUITY AND AGREEMENT SOME
DIFFERENCES CREPT INTO THE 00Z CYCLE. THE DIFFERENCES REVOLVE AROUND
THE HANDLING OF A TROUGH DROPPING SOUTH INTO THE NORTHERN
ROCKIES/PAC NW OUT OF WESTERN CANADA IN THE COMING DAYS.
00Z GFS AND ABOUT HALF OF ITS ENSEMBLE MEMBERS PROGRESS THE TROUGH
FURTHER SOUTHEAST INTO THE GREAT BASIN WHICH WOULD KEEP A STRONGER
SOUTHWEST FLOW ACROSS THE GREAT BASIN BASICALLY KEEPING ANY TROPICAL
MOISTURE INTRUSION CONFINED TO THE SOUTHERN FORECAST AREA, CLARK,
MOHAVE AND SAN BERNARDINO COUNTIES. EVEN THOUGH THE TROPICAL
MOISTURE DOES NOT MAKE IT AS FAR AS LINCOLN COUNTY THERE STILL LOOKS
TO BE A CHANCE OF SHOWERS OR THUNDERSTORMS ASSOCIATED WITH THE
TROUGH PASSAGE SUNDAY. THERE WAS LITTLE CHANGE WITH THE 00Z ECMWF
FROM PREVIOUS RUNS.
FOR NOW, NOT JUMPING ON THIS ONE RUN OF THE GFS SO ONLY MADE SOME
MINOR ADJUSTMENTS. HOPING FOR BETTER MODEL CLARITY IN THE COMING
DAYS.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
UPDATE/AVIATION...ADAIR
SHORT TERM...OUTLER
LONG TERM...PIERCE
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS RALEIGH NC
326 AM EDT WED JUL 15 2015
.SYNOPSIS...UPPER TROUGH OVER THE AREA THIS MORNING WILL MOVE OFF
THE MID-ATLANTIC COAST THIS AFTERNOON. THE ATTENDANT SURFACE COLD
FRONT WILL FOLLOW SUITE...WITH HIGH PRESSURE BUILDING INTO THE AREA
TONIGHT THROUGH THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 PM TUESDAY...
..SLIGHT RISK OF SEVERE THUNDERSTORMS REMOVED...
IT APPEARS THAT RAPIDLY DEVELOPING CONVECTIVE INHIBITION WITH
NIGHTFALL WILL LIKELY NOT BE SUPPORTIVE OF REDEVELOPMENT OF THE
CONVECTIVE LINE AS THE REMNANTS MOVE OFF THE BLUE RIDGE OF VA/NC
INTO OUR NW PIEDMONT. THE MORE FAVORABLE CONVECTIVE PARAMETERS FOR
CONVECTION CONTINUE OVER CENTRAL AND NORTHERN VA AND THIS IS WHERE
THE LINE WAS RE-FIRING AND HEADED TOWARD RICHMOND.
WE WILL KEEP LOW CHANCE POP FOR SOME RESIDUAL SHOWERS AND ISOLATED
THUNDER CHANCE FOR A FEW MORE HOURS IN THE NW-NE PIEDMONT AND FAR NE
ZONES OF THE COASTAL PLAIN... OTHERWISE PARTLY CLOUDY OVERNIGHT.
LOWS 68-73.
PREVIOUS DISCUSSION AT 730 PM...
ANOTHER... THE LAST IN THE SERIES OF CONVECTIVE COMPLEXES WAS DIVING
SOUTHEAST INTO WESTERN AND SOUTHWESTERN VIRGINIA AIMED AT NORTHERN
NORTH CAROLINA AT 725 PM. THE HIGHEST INSTABILITY RESIDED OUT AHEAD
OF THE LINE OVER VIRGINIA. THE INSTABILITY AXIS WEAKENED BUT
EXTENDED INTO THE NORTHERN AND EASTERN SECTIONS OF NC. SURFACE DEW
POINTS WERE IN THE 70S NORTH AND EAST... AND 60S IN THE SW PIEDMONT.
DEEP LAYER SHEAR WAS BEST TO OUR NORTH AS WELL... BUT 35-45KT OF
SHEAR EXTENDED OVER THE REGION NEAR THE NC/VA BORDER.
INTERESTINGLY... EVEN AS THE LINE WAS ONLY 2-3 HOURS FROM
POTENTIALLY AFFECTING A PORTION OF OUR REGION... MANY OF THE NEAR
TERM MODELS INCLUDING THE ARW AND HRRR WERE FORECASTING THE CORE OF
THE MCS TO DIVE SOUTH THEN SOUTHWEST TOWARD BOONE/BRISTOL/TRI CITIES
AREA BY LATE EVENING. THE STORM PREDICTION CENTER FELT THAT THE LINE
WOULD CONTINUE MOVING SE AND EITHER MAINTAIN ITSELF OR WEAKEN...
THEN RE-INTENSIFY AS IT HITS A FAVORABLE ENVIRONMENT MENTIONED ABOVE
IN THE VA/FAR NORTHERN NC PIEDMONT. THIS IS WHERE A SEVERE
THUNDERSTORM WATCH WAS PLACED AS FAR SOUTH AS MOUNT AIRY AND
YANCEYVILLE THROUGH 100 AM.
JUST AS IN THE PREVIOUS NW FLOW CONVECTIVE COMPLEXES AND LINES THAT
HAVE AFFECTED OUR REGION - IT WILL LIKELY HAVE TO BE NOWCAST RATHER
THAN FORECAST AS TO THE HOW IT WILL AFFECT OUR REGION. AT THE
CURRENT TIME IT APPEARS LIKELY THAT AT LEAST THE NORTH-NORTHEAST
PIEDMONT FROM THE TRIAD TO ROXBORO TO THE NORTHERN PART OF THE
TRIANGLE WILL HAVE TO DEAL WITH AT LEAST SOME GUSTY WINDS AND
LOCALLY HEAVY RAIN BETWEEN 900 PM AND MIDNIGHT.
WE WILL MAINTAIN THE CURRENT FORECAST WORDING AND THE CURRENT
HAZARDOUS WEATHER OUTLOOK UNTIL THE THREAT FROM THIS SYSTEM
DIMINISHES OR PASSES. IT APPEARS THE THREAT OF SEVERE STORMS IS
LOWEST IN THE SOUTH AND WEST (WHERE THE CONVECTIVE PARAMETERS ARE
MUCH LOWER) - DUE TO SOME NEGATIVE RESIDUAL AFFECTS OF THE SYSTEM
THAT PASSED BY THIS MORNING AND THE CURRENT ONE THAT BRUSHED BY TO
THE WEST OF ASHEVILLE.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 315 PM TUESDAY...
A MID LEVEL TROUGH IS PROGGED TO BE SHIFTING OFF THE MID ATLANTIC
COAST THROUGHOUT THE DAY ON WEDNESDAY. AS THIS DOES SO...A COLD
FRONT WILL GRADUALLY TRACK ACROSS THE REGION...EVENTUALLY SETTLING
SOUTH OF THE AREA BY WEDNESDAY NIGHT. ALL OF THIS WILL LEAD TO A
DECREASE IN CONVECTIVE COVERAGE AS THE BEST FORCING AND MOISTURE
WILL GRADUALLY BE SHIFTING OFF TO THE NORTH AND EAST OF THE AREA.
THEREFORE...WILL SHOW A GRADUAL PROGRESSION OF DECREASING PRECIP
CHANCES FROM WEST TO EAST THROUGHOUT THE DAY...HOWEVER POPS WILL BE
NO HIGHER THAN SLIGHT CHANCE. TEMPS WILL BE SLIGHTLY ABOVE NORMAL
(RANGING FROM NEAR 90 DEGREES TO THE LOWER 90S)...ALTHOUGH HUMIDITY
VALUES WILL BE LOWER THAN PREVIOUS DAYS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 325 AM WEDNESDAY...
A FRONT INITIALLY OVER THE SAVANNAH BASIN WILL RETREAT NORTHEAST
ACROSS NC FRI-SAT...IN ADVANCE OF AN AREA OF LOW PRESSURE FORECAST
TO MIGRATE THROUGH THE GREAT LAKES. PRECEDING HIGH PRESSURE
INITIALLY CENTERED ALONG THE NORTHERN MIDDLE ATLANTIC COAST...AND
ASSOCIATED ENE FLOW ACROSS CENTRAL-EASTERN NC...WILL MAINTAIN
STABILITY OVER MOST OF THE REGION ON FRI. THE EXCEPTION WILL BE NEAR
THE YADKIN RIVER...WHERE THE RETREAT OF THE BOUNDARY AND ASSOCIATED
LOW LEVEL CONFLUENT FLOW AND INCREASING BOUNDARY LAYER MOISTURE MAY
SUPPORT A FEW SHOWERS OR STORMS FRI AFTERNOON.
OTHERWISE...BOTH TEMPERATURES AND HUMIDITY LEVELS WILL INCREASE
THROUGH THE WEEKEND AS THE LOW LEVEL FLOW ASSUMES A MORE SW
DIRECTION...AND SUB-TROPICAL RIDGING ALOFT CENTERED OVER THE LOWER
MS VALLEY AND SOUTHERN PLAINS BUILDS EAST INTO THE SOUTHERN-CENTRAL
APPALACHIANS. NEAR CLIMO PROBABILITY OF PRECIPITATION --WITH A FOCUS
ALONG THE MOUNTAINS; PIEDMONT TROUGH; AND SEA BREEZE-- IS GENERALLY
EXPECTED...WITH PERHAPS A RELATIVE PEAK THIS WEEKEND WHEN THE
ORIENTATION AND LOCATION OF THE SUB-TROPICAL RIDGE WOULD ALLOW FOR
WEAK DISTURBANCES IN NW TO NNW FLOW ALOFT TO DRIFT ACROSS NC.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 200 AM WEDNESDAY...
UPPER LEVEL TROUGH MOVING THROUGH THE AREA THIS MORNING MAY SUPPORT
AN ISOLATED SHOWER OR TWO. OTHERWISE...VFR CONDITIONS ARE EXPECTED
TO PREVAIL THROUGH THE TAF PERIOD. THE EXCEPTION WILL BE ACROSS THE
COASTAL SECTIONS...WHERE ISOLD CONVECTION WILL BE POSSIBLE INVOF THE
EXITING COLD FRONT...THOUGH ACTIVITY SHOULD REMAIN EAST/SOUTH OF THE
FAY TERMINAL.
LOOKING AHEAD: THURSDAY THROUGH SUNDAY WILL BE LESS ACTIVE THAN
PREVIOUS DAYS...WITH MORE IN THE WAY OF TYPICAL DIURNAL CONVECTION
THROUGH THE PERIOD. ASIDE FROM SOME PREDAWN MORNING
FOG/STRATUS...EXPECT PREDOMINATELY VFR CONDITIONS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...PWB
SHORT TERM...KRD
LONG TERM...26
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
326 AM EDT TUE JUL 15 2015
.SYNOPSIS...UPPER TROUGH OVER THE AREA THIS MORNING WILL MOVE OFF
THE MID-ATLANTIC COAST THIS AFTERNOON. THE ATTENDANT SURFACE COLD
FRONT WILL FOLLOW SUITE...WITH HIGH PRESSURE BUILDING INTO THE AREA
TONIGHT THROUGH THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 PM TUESDAY...
..SLIGHT RISK OF SEVERE THUNDERSTORMS REMOVED...
IT APPEARS THAT RAPIDLY DEVELOPING CONVECTIVE INHIBITION WITH
NIGHTFALL WILL LIKELY NOT BE SUPPORTIVE OF REDEVELOPMENT OF THE
CONVECTIVE LINE AS THE REMNANTS MOVE OFF THE BLUE RIDGE OF VA/NC
INTO OUR NW PIEDMONT. THE MORE FAVORABLE CONVECTIVE PARAMETERS FOR
CONVECTION CONTINUE OVER CENTRAL AND NORTHERN VA AND THIS IS WHERE
THE LINE WAS RE-FIRING AND HEADED TOWARD RICHMOND.
WE WILL KEEP LOW CHANCE POP FOR SOME RESIDUAL SHOWERS AND ISOLATED
THUNDER CHANCE FOR A FEW MORE HOURS IN THE NW-NE PIEDMONT AND FAR NE
ZONES OF THE COASTAL PLAIN... OTHERWISE PARTLY CLOUDY OVERNIGHT.
LOWS 68-73.
PREVIOUS DISCUSSION AT 730 PM...
ANOTHER... THE LAST IN THE SERIES OF CONVECTIVE COMPLEXES WAS DIVING
SOUTHEAST INTO WESTERN AND SOUTHWESTERN VIRGINIA AIMED AT NORTHERN
NORTH CAROLINA AT 725 PM. THE HIGHEST INSTABILITY RESIDED OUT AHEAD
OF THE LINE OVER VIRGINIA. THE INSTABILITY AXIS WEAKENED BUT
EXTENDED INTO THE NORTHERN AND EASTERN SECTIONS OF NC. SURFACE DEW
POINTS WERE IN THE 70S NORTH AND EAST... AND 60S IN THE SW PIEDMONT.
DEEP LAYER SHEAR WAS BEST TO OUR NORTH AS WELL... BUT 35-45KT OF
SHEAR EXTENDED OVER THE REGION NEAR THE NC/VA BORDER.
INTERESTINGLY... EVEN AS THE LINE WAS ONLY 2-3 HOURS FROM
POTENTIALLY AFFECTING A PORTION OF OUR REGION... MANY OF THE NEAR
TERM MODELS INCLUDING THE ARW AND HRRR WERE FORECASTING THE CORE OF
THE MCS TO DIVE SOUTH THEN SOUTHWEST TOWARD BOONE/BRISTOL/TRI CITIES
AREA BY LATE EVENING. THE STORM PREDICTION CENTER FELT THAT THE LINE
WOULD CONTINUE MOVING SE AND EITHER MAINTAIN ITSELF OR WEAKEN...
THEN RE-INTENSIFY AS IT HITS A FAVORABLE ENVIRONMENT MENTIONED ABOVE
IN THE VA/FAR NORTHERN NC PIEDMONT. THIS IS WHERE A SEVERE
THUNDERSTORM WATCH WAS PLACED AS FAR SOUTH AS MOUNT AIRY AND
YANCEYVILLE THROUGH 100 AM.
JUST AS IN THE PREVIOUS NW FLOW CONVECTIVE COMPLEXES AND LINES THAT
HAVE AFFECTED OUR REGION - IT WILL LIKELY HAVE TO BE NOWCAST RATHER
THAN FORECAST AS TO THE HOW IT WILL AFFECT OUR REGION. AT THE
CURRENT TIME IT APPEARS LIKELY THAT AT LEAST THE NORTH-NORTHEAST
PIEDMONT FROM THE TRIAD TO ROXBORO TO THE NORTHERN PART OF THE
TRIANGLE WILL HAVE TO DEAL WITH AT LEAST SOME GUSTY WINDS AND
LOCALLY HEAVY RAIN BETWEEN 900 PM AND MIDNIGHT.
WE WILL MAINTAIN THE CURRENT FORECAST WORDING AND THE CURRENT
HAZARDOUS WEATHER OUTLOOK UNTIL THE THREAT FROM THIS SYSTEM
DIMINISHES OR PASSES. IT APPEARS THE THREAT OF SEVERE STORMS IS
LOWEST IN THE SOUTH AND WEST (WHERE THE CONVECTIVE PARAMETERS ARE
MUCH LOWER) - DUE TO SOME NEGATIVE RESIDUAL AFFECTS OF THE SYSTEM
THAT PASSED BY THIS MORNING AND THE CURRENT ONE THAT BRUSHED BY TO
THE WEST OF ASHEVILLE.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 315 PM TUESDAY...
A MID LEVEL TROUGH IS PROGGED TO BE SHIFTING OFF THE MID ATLANTIC
COAST THROUGHOUT THE DAY ON WEDNESDAY. AS THIS DOES SO...A COLD
FRONT WILL GRADUALLY TRACK ACROSS THE REGION...EVENTUALLY SETTLING
SOUTH OF THE AREA BY WEDNESDAY NIGHT. ALL OF THIS WILL LEAD TO A
DECREASE IN CONVECTIVE COVERAGE AS THE BEST FORCING AND MOISTURE
WILL GRADUALLY BE SHIFTING OFF TO THE NORTH AND EAST OF THE AREA.
THEREFORE...WILL SHOW A GRADUAL PROGRESSION OF DECREASING PRECIP
CHANCES FROM WEST TO EAST THROUGHOUT THE DAY...HOWEVER POPS WILL BE
NO HIGHER THAN SLIGHT CHANCE. TEMPS WILL BE SLIGHTLY ABOVE NORMAL
(RANGING FROM NEAR 90 DEGREES TO THE LOWER 90S)...ALTHOUGH HUMIDITY
VALUES WILL BE LOWER THAN PREVIOUS DAYS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 325 AM WEDNESDAY...
A FRONT INITIALLY OVER THE SAVANNAH BASIN WILL RETREAT NORTHEAST
ACROSS NC FRI-SAT...IN ADVANCE OF AN AREA OF LOW PRESSURE FORECAST
TO MIGRATE THROUGH THE GREAT LAKES. PRECEDING HIGH PRESSURE
INITIALLY CENTERED ALONG THE NORTHERN MIDDLE ATLANTIC COAST...AND
ASSOCIATED ENE FLOW ACROSS CENTRAL-EASTERN NC...WILL MAINTAIN
STABILITY OVER MOST OF THE REGION ON FRI. THE EXCEPTION WILL BE NEAR
THE YADKIN RIVER...WHERE THE RETREAT OF THE BOUNDARY AND ASSOCIATED
LOW LEVEL CONFLUENT FLOW AND INCREASING BOUNDARY LAYER MOISTURE MAY
SUPPORT A FEW SHOWERS OR STORMS FRI AFTERNOON.
OTHERWISE...BOTH TEMPERATURES AND HUMIDITY LEVELS WILL INCREASE
THROUGH THE WEEKEND AS THE LOW LEVEL FLOW ASSUMES A MORE SW
DIRECTION...AND SUB-TROPICAL RIDGING ALOFT CENTERED OVER THE LOWER
MS VALLEY AND SOUTHERN PLAINS BUILDS EAST INTO THE SOUTHERN-CENTRAL
APPALACHIANS. NEAR CLIMO PROBABILITY OF PRECIPITATION --WITH A FOCUS
ALONG THE MOUNTAINS; PIEDMONT TROUGH; AND SEA BREEZE-- IS GENERALLY
EXPECTED...WITH PERHAPS A RELATIVE PEAK THIS WEEKEND WHEN THE
ORIENTATION AND LOCATION OF THE SUB-TROPICAL RIDGE WOULD ALLOW FOR
WEAK DISTURBANCES IN NW TO NNW FLOW ALOFT TO DRIFT ACROSS NC.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 200 AM WEDNESDAY...
UPPER LEVEL TROUGH MOVING THROUGH THE AREA THIS MORNING MAY SUPPORT
AN ISOLATED SHOWER OR TWO. OTHERWISE...VFR CONDITIONS ARE EXPECTED
TO PREVAIL THROUGH THE TAF PERIOD. THE EXCEPTION WILL BE ACROSS THE
COASTAL SECTIONS...WHERE ISOLD CONVECTION WILL BE POSSIBLE INVOF THE
EXITING COLD FRONT...THOUGH ACTIVITY SHOULD REMAIN EAST/SOUTH OF THE
FAY TERMINAL.
LOOKING AHEAD: THURSDAY THROUGH SUNDAY WILL BE LESS ACTIVE THAN
PREVIOUS DAYS...WITH MORE IN THE WAY OF TYPICAL DIURNAL CONVECTION
THROUGH THE PERIOD. ASIDE FROM SOME PREDAWN MORNING
FOG/STRATUS...EXPECT PREDOMINATELY VFR CONDITIONS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...PWB
SHORT TERM...KRD
LONG TERM...26
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
200 AM EDT TUE JUL 15 2015
.SYNOPSIS...UPPER TROUGH OVER THE AREA THIS MORNING WILL MOVE OFF
THE MID-ATLANTIC COAST THIS AFTERNOON. THE ATTENDANT SURFACE COLD
FRONT WILL FOLLOW SUITE...WITH HIGH PRESSURE BUILDING INTO THE AREA
TONIGHT THROUGH THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 PM TUESDAY...
..SLIGHT RISK OF SEVERE THUNDERSTORMS REMOVED...
IT APPEARS THAT RAPIDLY DEVELOPING CONVECTIVE INHIBITION WITH
NIGHTFALL WILL LIKELY NOT BE SUPPORTIVE OF REDEVELOPMENT OF THE
CONVECTIVE LINE AS THE REMNANTS MOVE OFF THE BLUE RIDGE OF VA/NC
INTO OUR NW PIEDMONT. THE MORE FAVORABLE CONVECTIVE PARAMETERS FOR
CONVECTION CONTINUE OVER CENTRAL AND NORTHERN VA AND THIS IS WHERE
THE LINE WAS RE-FIRING AND HEADED TOWARD RICHMOND.
WE WILL KEEP LOW CHANCE POP FOR SOME RESIDUAL SHOWERS AND ISOLATED
THUNDER CHANCE FOR A FEW MORE HOURS IN THE NW-NE PIEDMONT AND FAR NE
ZONES OF THE COASTAL PLAIN... OTHERWISE PARTLY CLOUDY OVERNIGHT.
LOWS 68-73.
PREVIOUS DISCUSSION AT 730 PM...
ANOTHER... THE LAST IN THE SERIES OF CONVECTIVE COMPLEXES WAS DIVING
SOUTHEAST INTO WESTERN AND SOUTHWESTERN VIRGINIA AIMED AT NORTHERN
NORTH CAROLINA AT 725 PM. THE HIGHEST INSTABILITY RESIDED OUT AHEAD
OF THE LINE OVER VIRGINIA. THE INSTABILITY AXIS WEAKENED BUT
EXTENDED INTO THE NORTHERN AND EASTERN SECTIONS OF NC. SURFACE DEW
POINTS WERE IN THE 70S NORTH AND EAST... AND 60S IN THE SW PIEDMONT.
DEEP LAYER SHEAR WAS BEST TO OUR NORTH AS WELL... BUT 35-45KT OF
SHEAR EXTENDED OVER THE REGION NEAR THE NC/VA BORDER.
INTERESTINGLY... EVEN AS THE LINE WAS ONLY 2-3 HOURS FROM
POTENTIALLY AFFECTING A PORTION OF OUR REGION... MANY OF THE NEAR
TERM MODELS INCLUDING THE ARW AND HRRR WERE FORECASTING THE CORE OF
THE MCS TO DIVE SOUTH THEN SOUTHWEST TOWARD BOONE/BRISTOL/TRI CITIES
AREA BY LATE EVENING. THE STORM PREDICTION CENTER FELT THAT THE LINE
WOULD CONTINUE MOVING SE AND EITHER MAINTAIN ITSELF OR WEAKEN...
THEN RE-INTENSIFY AS IT HITS A FAVORABLE ENVIRONMENT MENTIONED ABOVE
IN THE VA/FAR NORTHERN NC PIEDMONT. THIS IS WHERE A SEVERE
THUNDERSTORM WATCH WAS PLACED AS FAR SOUTH AS MOUNT AIRY AND
YANCEYVILLE THROUGH 100 AM.
JUST AS IN THE PREVIOUS NW FLOW CONVECTIVE COMPLEXES AND LINES THAT
HAVE AFFECTED OUR REGION - IT WILL LIKELY HAVE TO BE NOWCAST RATHER
THAN FORECAST AS TO THE HOW IT WILL AFFECT OUR REGION. AT THE
CURRENT TIME IT APPEARS LIKELY THAT AT LEAST THE NORTH-NORTHEAST
PIEDMONT FROM THE TRIAD TO ROXBORO TO THE NORTHERN PART OF THE
TRIANGLE WILL HAVE TO DEAL WITH AT LEAST SOME GUSTY WINDS AND
LOCALLY HEAVY RAIN BETWEEN 900 PM AND MIDNIGHT.
WE WILL MAINTAIN THE CURRENT FORECAST WORDING AND THE CURRENT
HAZARDOUS WEATHER OUTLOOK UNTIL THE THREAT FROM THIS SYSTEM
DIMINISHES OR PASSES. IT APPEARS THE THREAT OF SEVERE STORMS IS
LOWEST IN THE SOUTH AND WEST (WHERE THE CONVECTIVE PARAMETERS ARE
MUCH LOWER) - DUE TO SOME NEGATIVE RESIDUAL AFFECTS OF THE SYSTEM
THAT PASSED BY THIS MORNING AND THE CURRENT ONE THAT BRUSHED BY TO
THE WEST OF ASHEVILLE.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 315 PM TUESDAY...
A MID LEVEL TROUGH IS PROGGED TO BE SHIFTING OFF THE MID ATLANTIC
COAST THROUGHOUT THE DAY ON WEDNESDAY. AS THIS DOES SO...A COLD
FRONT WILL GRADUALLY TRACK ACROSS THE REGION...EVENTUALLY SETTLING
SOUTH OF THE AREA BY WEDNESDAY NIGHT. ALL OF THIS WILL LEAD TO A
DECREASE IN CONVECTIVE COVERAGE AS THE BEST FORCING AND MOISTURE
WILL GRADUALLY BE SHIFTING OFF TO THE NORTH AND EAST OF THE AREA.
THEREFORE...WILL SHOW A GRADUAL PROGRESSION OF DECREASING PRECIP
CHANCES FROM WEST TO EAST THROUGHOUT THE DAY...HOWEVER POPS WILL BE
NO HIGHER THAN SLIGHT CHANCE. TEMPS WILL BE SLIGHTLY ABOVE NORMAL
(RANGING FROM NEAR 90 DEGREES TO THE LOWER 90S)...ALTHOUGH HUMIDITY
VALUES WILL BE LOWER THAN PREVIOUS DAYS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 315 PM TUESDAY...
THURSDAY AND FRIDAY...HEIGHTS WILL BEGIN TO RISE OVER THE REGION AS
THE AFOREMENTIONED MID LEVEL TROUGH (SEE SHORT TERM DISCUSSION
ABOVE) PULLS FURTHER OUT TO SEA. AT THE SURFACE...A NEARLY
STATIONARY FRONT WILL REMAIN SOUTH OF THE REGION...ALLOWING HIGH
PRESSURE TO RIDGE DOWN ONTO THE AREA. ALL OF THIS WILL RESULT IN
QUIET WEATHER TO CLOSE OUT THE WORK WEEK...WITH SLIGHTLY ABOVE
NORMAL TEMPS (BUT CONTINUED LOWER RELATIVE HUMIDITIES).
SATURDAY THROUGH TUESDAY...THE SURFACE HIGH PRESSURE WILL SHIFT
OFFSHORE TO BEGIN THE WEEKEND...ALLOWING MOISTURE TO RETURN TO THE
REGION. IN ADDITION...NORTHWESTERLY FLOW ALOFT WILL BECOME RE-
ESTABLISHED OVER THE REGION GIVEN THE MID LEVEL RIDGE OVER THE DEEP
SOUTH. ALL OF THIS WILL LEAD TO INCREASING CHANCES OF PRECIP...
MOSTLY DIURNAL IN NATURE. TEMPS WILL CONTINUE TO BE ABOVE NORMAL.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 200 AM WEDNESDAY...
UPPER LEVEL TROUGH MOVING THROUGH THE AREA THIS MORNING MAY SUPPORT
AN ISOLATED SHOWER OR TWO. OTHERWISE...VFR CONDITIONS ARE EXPECTED
TO PREVAIL THROUGH THE TAF PERIOD. THE EXCEPTION WILL BE ACROSS THE
COASTAL SECTIONS...WHERE ISOLD CONVECTION WILL BE POSSIBLE INVOF THE
EXITING COLD FRONT...THOUGH ACTIVITY SHOULD REMAIN EAST/SOUTH OF THE
FAY TERMINAL.
LOOKING AHEAD: THURSDAY THROUGH SUNDAY WILL BE LESS ACTIVE THAN
PREVIOUS DAYS...WITH MORE IN THE WAY OF TYPICAL DIURNAL CONVECTION
THROUGH THE PERIOD. ASIDE FROM SOME PREDAWN MORNING
FOG/STRATUS...EXPECT PREDOMINATELY VFR CONDITIONS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...PWB
SHORT TERM...KRD
LONG TERM...KRD
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
941 PM CDT THU JUL 16 2015
.UPDATE...
ISSUED AT 941 PM CDT THU JUL 16 2015
CURRENT ACTIVITY IS BEHAVING MUCH AS ANTICIPATED. THERE ARE SURELY
SOME AREAS THAT RECEIVED HEAVIER RAINFALL AMOUNTS WITH MINOR
FLOODING ISSUES...BUT COVERAGE OF THESE LOCATIONS WOULD BE VERY
ISOLATED. NEXT UP WILL BE THUNDER AND SEVERE POTENTIAL FOR FRIDAY.
SPC DAY 2 OUTLOOK STILL REASONABLE...ALTHOUGH 00Z NAM IS FURTHER
NORTH WITH GREATER INSTABILITY (WHICH WILL HINGE ON WHERE CLOUDS
ARE LOCATED WHICH IS DEPENDENT ON THE TRACK OF POSSIBLE WEAK
MORNING SHOWERS). DEEP LAYER SHEAR INCREASES TO NEARLY 50 KNOTS BY
00Z SAT...SO SEVERE POTENTIAL IS DEFINITELY HIGHER TOMORROW
EVENING.
UPDATE ISSUED AT 630 PM CDT THU JUL 16 2015
THE DEEPER LAYER SHEAR/INSTABILITY COMBINATION NOT QUITE ENOUGH
TO PRODUCE SEVERE THUNDERSTORMS THIS AFTERNOON. HOWEVER...WE HAVE
RECEIVED QUITE A FEW FUNNEL CLOUD REPORTS...SO THE LOW LEVEL
SHEAR/INSTABILITY IS SUFFICIENT FOR WEAK ROTATION. THESE
CONDITIONS USUALLY DO NOT PRODUCE TORNADOES...AND EVEN IF ONE DOES
TOUCHDOWN THEY ARE TYPICALLY BRIEF AND VERY WEAK. WILL CONTINUE TO
COVER THIS THREAT WITH THE SPECIAL WEATHER STATEMENT. ANTICIPATE
ACTIVITY TO GREATLY DIMINISH AROUND SUNSET.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 245 PM CDT THU JUL 16 2015
THE MAIN CHALLENGE WILL BE CONVECTIVE/SEVERE CHANCES THROUGH
FRIDAY. THE CAM MODELS ARE IN PRETTY GOOD AGREEMENT...AND THE
CONSISTENT HRRR HAS A GOOD HANDLE ON THINGS THROUGH THIS EVENING.
WILL LEAN ON THE GFS THEREAFTER WITH BETTER SHEAR AROUND FRI
AFTERNOON/EVENING.
FOR LATE THIS AFTERNOON AND TONIGHT...A STRONG SHORTWAVE WILL MOVE
FROM WEST TO EAST. THERE WILL BE MLCAPE AROUND 1500 J/KG IN THE
SOUTH AND 500-1000J/KG NORTH. MID LEVEL LAPSE RATES ARE NOT TOO
STEEP IN THE NORTH...AND A BIT BETTER SOUTH. THERE HAS ALSO BEEN
PLENTY OF CLOUDS/PRECIP THAT HAS HINDERED WARMING WITH CONVECTIVE
TEMPS AROUND 80. THERE COULD BE A WINDOW WHERE AREAS HEAT OUT SOME
THIS AFTERNOON...AND THERE IS STILL A MARGINAL RISK FOR SEVERE
STORMS WITH THE BEST THREAT IN THE SOUTH CLOSER TO SLIGHTLY BETTER
SHEAR/INSTABILITY.
ON FRIDAY...A SPEED MAX WILL APPROACH FROM THE WEST WITH AMPLE
INSTABILITY OVERSPREADING THE AREA. A SFC LOW WILL TRACK NEAR THE
ND/SD BORDER AROUND 00Z...AND THE POTENTIAL FOR SOME MORE SEVERE
WEATHER IS POSSIBLE. SPC HAS A SLIGHT RISK NEAR THE SOUTH FA AND
MARGINAL RISK TO THE NORTH. THERE SHOULD BE MORE HEATING ON FRIDAY
AHEAD OF THE NEXT SHORTWAVE...ALONG WITH MORE SHEAR...SO POTENTIAL
FOR MORE WIDESPREAD SEVERE CLOSE OR INTO THE FA ON FRIDAY
AFTERNOON INTO THE OVERNIGHT POSSIBLE. THERE IS A 45-50KT LLJ
FRIDAY NIGHT INTO THE MN COUNTIES...SO SEVERE THREAT COULD PERSIST
THROUGH MUCH OF THE NIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 245 PM CDT THU JUL 16 2015
ON SATURDAY...MORNING CONVECTION SHOULD QUICKLY MOVE INTO THE
NORTH AND EAST BY AFTERNOON BEHIND A COLD FRONT. MUCH OF THE
REGION WILL BE DRY SAT AFTERNOON WITH COOLER AIR ALOFT AND TEMPS
IN THE MID/UPPER 70S NORTH TO AROUND 80 SOUTH. IT COULD GET A BIT
BREEZY FROM THE W/NW SAT AFTERNOON WITH PWATS FALLING BELOW 1
INCH.
FOR SUNDAY...IT SHOULD BE DRY WITH TEMPS A BIT WARMER THAN SAT.
WESTERLY FLOW SHOULD PERSIST ALONG WITH PLENTY OF SUNSHINE.
FOR SUN THROUGH THU...HIGH PRESSURE WILL GIVE GENERALLY DRY
CONDITIONS SUN NIGHT INTO MONDAY. A WEAK FRONT WILL DROP SOUTH
THROUGH NRN MINNESOTA LATE MONDAY AND MONDAY EVE GIVING A LOW
RISK OF T-STORMS MAINLY EAST OF THE RED RIVER. MAINLY DRY AGAIN
TUESDAY. NEXT SHORT WAVE OF ANY SIGNIFICANCE IS DUE WED WITH BEST
CHANCES FOR T-STORMS AT THAT TIME. TEMPS TO RUN CLOSE TO NORMAL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 630 PM CDT THU JUL 16 2015
THUNDERSTORM AND FOG POTENTIAL WILL BE THE MAIN AVIATION CONCERNS
FOR THIS PERIOD. SCATTERED THUNDERSTORMS WILL GREATLY DIMINISH NEAR
SUNSET...BUT WILL AGAIN BE POSSIBLE FRIDAY AFTERNOON. LIGHT WINDS
TONIGHT COULD LEAD TO FOG FORMATION...ALTHOUGH STILL NOT SURE
ABOUT COVERAGE OR HOW LOW VSBY COULD GET.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...DK
LONG TERM...DK/RIDDLE
AVIATION...TG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
939 PM CDT THU JUL 16 2015
.UPDATE...
ISSUED AT 921 PM CDT THU JUL 16 2015
SURFACE LOW PRESSURE IS SITUATED OVER WEST CENTRAL NORTH DAKOTA
WITH STRONG HIGH PRESSURE BUILDING INTO WESTERN AND CENTRAL
MONTANA. SLIGHTLY UNSTABLE AIRMASS ALOFT OVER WESTERN AND CENTRAL
NORTH DAKOTA TONIGHT. WEAK WAVE MOVING FROM WESTERN INTO CENTRAL
NORTH DAKOTA IS PRODUCING SCATTERED THUNDERSHOWERS ACROSS THE
NORTHWEST INTO NORTH CENTRAL ND...BECOMING ISOLATED AS YOU HEAD
FARTHER SOUTH. DUE TO THE INSTABILITY ALOFT...HAVE EXTENDED THE
SLIGHT CHANCE OF THUNDER FARTHER EAST TONIGHT...COVERING A GOOD
PORTION OF THE FORECAST AREA. LATEST ITERATIONS OF THE RAP AND
HRRR ARE HINTING AT A LINE OF CONVECTION TRACKING ACROSS THE NORTH
CENTRAL LATE THIS EVENING INTO THE EARLY OVERNIGHT HOURS. WILL
NEED TO CONTINUE TO MONITOR CURRENT CONVECTION ACROSS THE
NORTHWEST. THINK THE SEVERE POTENTIAL WOULD BE MINIMAL BUT A FEW
STRONGER STORMS CAN NOT BE RULED OUT. BETTER CHANCE OF SHOWERS AND
THUNDERSTORMS MOVES INTO THE SOUTHWEST LATE THIS EVENING AND
TRACKS INTO CENTRAL NORTH DAKOTA BY MORNING. THIS IS CURRENTLY
COVERED WELL WITH THE CURRENT FORECAST.
UPDATE ISSUED AT 704 PM CDT THU JUL 16 2015
SHOWERS AND THUNDERSTORMS CONTINUE TO TRACK SOUTHEAST ACROSS THE
JAMES RIVER VALLEY. HAVE EXTENDED THE CHANCE FOR THUNDERSTORMS
THROUGH 03Z. LAST SHIFT ADDED A SLIGHT CHANCE OF THUNDERSTORMS TO
THE FAR NORTHWEST EARLY THIS EVENING. A FEW STORMS WERE TRACKING
THROUGH DIVIDE COUNTY. A BETTER CHANCE WILL MOVE INTO THE WEST
LATE THIS EVENING AND TRACK EAST OVERNIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 203 PM CDT THU JUL 16 2015
CURRENT SURFACE ANALYSIS PLACES LOW OVER CENTRAL SASKATCHEWAN WITH
COLD FRONT DROPPING TO THE SOUTH. UPPER LEVEL ANALYSIS PLACES
SHORT WAVE SLIDING THROUGH THE DAKOTAS WITH UPPER LOW OVER WESTERN
ALBERTA. SHOWERS AND THUNDERSTORMS CONTINUE TO DEVELOP OVER THE
JAMES RIVER VALLEY AS AFOREMENTIONED SHORT WAVE CONTINUES ITS
PROGRESSION.
FOR THE REST OF THIS AFTERNOON INTO TONIGHT...SHOWERS AND
THUNDERSTORMS WILL CONTINUE THEIR EASTWARD PROGRESSION...AND
SHOULD PUSH WELL INTO THE EASTERN PART OF THE STATE BY EVENING.
STRONGEST INSTABILITY (~2 KJ/KG) REMAINS OVER THE SOUTHERN JAMES
RIVER VALLEY WITH RATHER WEAK SHEAR. THEREFORE...EXPECT THEIR
COULD BE A SEVERE STORM OR TWO BUT THEY SHOULD BE SHORT LIVED.
WEAK RIDGING PASSES OVER THE AREA BEHIND THE SHORT WAVE TO BRING A
BRIEF QUIET PERIOD. LATE TONIGHT...UPPER LOW WILL PROGRESS
EASTWARD OVER SOUTHERN SASKATCHEWAN. UPPER FLOW SHIFTS
SOUTHWESTERLY WHILE THE AFOREMENTIONED COLD FRONT WORKS INTO
WESTERN PARTS OF THE AREA...BRINGING THE NEXT CHANCES FOR
SHOWERS/THUNDERSTORMS.
ON FRIDAY...UPPER LOW SETTLES SOUTHEAST THROUGH SASKATCHEWAN
BRINGING BROAD CYCLONIC FLOW TO OUR AREA AS COLD FRONT CONTINUES
ITS PROGRESSION. EXPECT SHOWERS AND THUNDERSTORMS TO
CONTINUE...WITH HIGHER COVERAGE TO THE EAST. ONLY AREA WITH
POTENTIAL SEVERE CONCERNS WILL AGAIN BE OVER THE LOWER JAMES RIVER
VALLEY WHERE MODEST INSTABILITY/SHEAR ARE NOTED. TEMPERATURES
WILL BE NOTABLY COOLER...WITH MOST LOCATIONS ONLY PUSHING INTO THE
70S...WITH 80S OVER THE SOUTHERN JAMES RIVER VALLEY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 203 PM CDT THU JUL 16 2015
EXITING MID LEVEL SHORTWAVE SLIDING THROUGH THE JAMES RIVER VALLEY
WILL CONTINUE TO PRODUCE A CHANCE OF SHOWERS/THUNDERSTORMS FRIDAY
EVENING. CHANCES DECREASE TOWARD 06Z SATURDAY AND CONTINUE TO TREND
DOWNWARD QUICKLY THEREAFTER. AS THIS HAPPENS...ATTENTION TURNS TO
THE NORTHWEST. THE NEXT UPPER LOW/ASSOCIATED SHORTWAVE TROUGH AND
SURFACE COLD FRONT WILL SWING ACROSS WESTERN AND CENTRAL NORTH
DAKOTA FRIDAY NIGHT THROUGH SATURDAY AFTERNOON. THE BEST JET
DYNAMICS/LIFT RESIDE ALONG AND NORTH OF THE NORTHERN BORDER. HENCE
CHANCES OF SHOWERS/THUNDERSTORMS ARE HIGHEST ALONG AND NORTH OF
HIGHWAY 2 WITH LITTLE OR NO CHANCE SOUTH OF THIS AREA. A NORTHWEST
FLOW WITH DRIER CONDITIONS TAKE CONTROL SUNDAY. BY MONDAY...A COLD
FRONT WITHIN THE NORTHWEST FLOW WILL MOVE THROUGH. SUPERBLEND GIVES
A SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS SOUTH OF INTERSTATE 94
MONDAY. THEREAFTER...THE UPPER FLOW TRANSITIONS TO WESTERLY BY
MIDWEEK...THEN SOUTHWESTERLY BY LATER IN THE WEEK. APPEARS THERE
WILL BE AN OPPORTUNITY FOR NIGHTTIME CONVECTION ALONG/AHEAD OF AN
ADVANCING WARM FRONT TUESDAY NIGHT INTO WEDNESDAY MORNING AS A LOW
LEVEL JET AND MOISTURE ADVECTION DEVELOP. A MORE ACTIVE PERIOD MAY
BE ON THE INCREASE THURSDAY ONWARD...AS SOUTHWEST FLOW AND EMBEDDED
SHORTWAVES BECOME DOMINANT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 921 PM CDT THU JUL 16 2015
VFR CEILINGS THROUGH THE FORECAST PERIOD EXCEPT IN POSSIBLE
THUNDERSTORMS. ISOLATED THUNDER POSSIBLE AROUND KMOT FROM 03-06Z.
SHOWER AND THUNDERSTORMS CHANCES WILL THEN INCREASE FROM WEST TO
EAST LATE TONIGHT AND INTO FRIDAY. LIGHT SOUTHEAST FLOW THIS
EVENING WILL SHIFT NORTHWEST FROM WEST TO EAST LATE TONIGHT INTO
FRIDAY MORNING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...JJS
LONG TERM...KS
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
630 PM CDT THU JUL 16 2015
.UPDATE...
ISSUED AT 630 PM CDT THU JUL 16 2015
THE DEEPER LAYER SHEAR/INSTABILITY COMBINATION NOT QUITE ENOUGH
TO PRODUCE SEVERE THUNDERSTORMS THIS AFTERNOON. HOWEVER...WE HAVE
RECEIVED QUITE A FEW FUNNEL CLOUD REPORTS...SO THE LOW LEVEL
SHEAR/INSTABILITY IS SUFFICIENT FOR WEAK ROTATION. THESE
CONDITIONS USUALLY DO NOT PRODUCE TORNADOES...AND EVEN IF ONE DOES
TOUCHDOWN THEY ARE TYPICALLY BRIEF AND VERY WEAK. WILL CONTINUE TO
COVER THIS THREAT WITH THE SPECIAL WEATHER STATEMENT. ANTICIPATE
ACTIVITY TO GREATLY DIMINISH AROUND SUNSET.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 245 PM CDT THU JUL 16 2015
THE MAIN CHALLENGE WILL BE CONVECTIVE/SEVERE CHANCES THROUGH
FRIDAY. THE CAM MODELS ARE IN PRETTY GOOD AGREEMENT...AND THE
CONSISTENT HRRR HAS A GOOD HANDLE ON THINGS THROUGH THIS EVENING.
WILL LEAN ON THE GFS THEREAFTER WITH BETTER SHEAR AROUND FRI
AFTERNOON/EVENING.
FOR LATE THIS AFTERNOON AND TONIGHT...A STRONG SHORTWAVE WILL MOVE
FROM WEST TO EAST. THERE WILL BE MLCAPE AROUND 1500 J/KG IN THE
SOUTH AND 500-1000J/KG NORTH. MID LEVEL LAPSE RATES ARE NOT TOO
STEEP IN THE NORTH...AND A BIT BETTER SOUTH. THERE HAS ALSO BEEN
PLENTY OF CLOUDS/PRECIP THAT HAS HINDERED WARMING WITH CONVECTIVE
TEMPS AROUND 80. THERE COULD BE A WINDOW WHERE AREAS HEAT OUT SOME
THIS AFTERNOON...AND THERE IS STILL A MARGINAL RISK FOR SEVERE
STORMS WITH THE BEST THREAT IN THE SOUTH CLOSER TO SLIGHTLY BETTER
SHEAR/INSTABILITY.
ON FRIDAY...A SPEED MAX WILL APPROACH FROM THE WEST WITH AMPLE
INSTABILITY OVERSPREADING THE AREA. A SFC LOW WILL TRACK NEAR THE
ND/SD BORDER AROUND 00Z...AND THE POTENTIAL FOR SOME MORE SEVERE
WEATHER IS POSSIBLE. SPC HAS A SLIGHT RISK NEAR THE SOUTH FA AND
MARGINAL RISK TO THE NORTH. THERE SHOULD BE MORE HEATING ON FRIDAY
AHEAD OF THE NEXT SHORTWAVE...ALONG WITH MORE SHEAR...SO POTENTIAL
FOR MORE WIDESPREAD SEVERE CLOSE OR INTO THE FA ON FRIDAY
AFTERNOON INTO THE OVERNIGHT POSSIBLE. THERE IS A 45-50KT LLJ
FRIDAY NIGHT INTO THE MN COUNTIES...SO SEVERE THREAT COULD PERSIST
THROUGH MUCH OF THE NIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 245 PM CDT THU JUL 16 2015
ON SATURDAY...MORNING CONVECTION SHOULD QUICKLY MOVE INTO THE
NORTH AND EAST BY AFTERNOON BEHIND A COLD FRONT. MUCH OF THE
REGION WILL BE DRY SAT AFTERNOON WITH COOLER AIR ALOFT AND TEMPS
IN THE MID/UPPER 70S NORTH TO AROUND 80 SOUTH. IT COULD GET A BIT
BREEZY FROM THE W/NW SAT AFTERNOON WITH PWATS FALLING BELOW 1
INCH.
FOR SUNDAY...IT SHOULD BE DRY WITH TEMPS A BIT WARMER THAN SAT.
WESTERLY FLOW SHOULD PERSIST ALONG WITH PLENTY OF SUNSHINE.
FOR SUN THROUGH THU...HIGH PRESSURE WILL GIVE GENERALLY DRY
CONDITIONS SUN NIGHT INTO MONDAY. A WEAK FRONT WILL DROP SOUTH
THROUGH NRN MINNESOTA LATE MONDAY AND MONDAY EVE GIVING A LOW
RISK OF T-STORMS MAINLY EAST OF THE RED RIVER. MAINLY DRY AGAIN
TUESDAY. NEXT SHORT WAVE OF ANY SIGNIFICANCE IS DUE WED WITH BEST
CHANCES FOR T-STORMS AT THAT TIME. TEMPS TO RUN CLOSE TO NORMAL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 630 PM CDT THU JUL 16 2015
THUNDERSTORM AND FOG POTENTIAL WILL BE THE MAIN AVIATION CONCERNS
FOR THIS PERIOD. SCATTERED THUNDERSTORMS WILL GREATLY DIMINISH NEAR
SUNSET...BUT WILL AGAIN BE POSSIBLE FRIDAY AFTERNOON. LIGHT WINDS
TONIGHT COULD LEAD TO FOG FORMATION...ALTHOUGH STILL NOT SURE
ABOUT COVERAGE OR HOW LOW VSBY COULD GET.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...DK
LONG TERM...DK/RIDDLE
AVIATION...TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
104 PM CDT WED JUL 15 2015
.UPDATE...
ISSUED AT 1256 PM CDT WED JUL 15 2015
OUTFLOW BOUNDARY FROM EARLIER STORMS THAT WERE NEAR CARRINGTON-
JAMESTOWN HAVE PUSHED SOUTHEAST AND ENTERED A VERY UNSTABLE
AIRMASS WITH ML CAPES OF 2500 AND SFC BASED CAPE VIA SPC MESO PAGE
OF 4000 J/KG FROM NEAR LINTON ND TO LAMOURE ND THEN TOWARD FARGO.
THIS AREA NEEDS TO BE WATCHED FOR ANY SEVERE STORMS AND DID ADD
THIS AREA TO T+ IN THE GRIDS. DOWNFALL IS WEAK BULK SHEAR FOR
SUSTAINED UPDRAFTS/SUPERCELLS SO ANY SEVERE SHOULD BE RATHER BRIEF
AND LIMITED. OTHERWISE UNSURE HOW THE REST OF THE FCST AREA WILL
UNFOLD THIS AFTN/EVE AS A BIT CLOUDIER AND LESS UNSTABLE AIRMASS
IN NE ND/NW MN. MAIN SHORT WAVE DUE TO ARRIVE LATE TONIGHT INTO
THURSDAY AND WOULD EXPECT SOME CLUSTERS OF STORMS LATER TONIGHT
INTO THURSDAY. CHATTED WITH SPC ABOUT DAY 2 AND FOR NOW THEY WILL
KEEP US IN GENERAL.
.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 328 AM CDT WED JUL 15 2015
CONVECTION TIMING AND STRENGTH WILL BE THE MAIN FORECAST ISSUES
FOR THE SHORT TERM.
UPPER RIDGING CONTINUES TO BUILD OVER THE PLAINS...BUT WV LOOP
SHOWS SEVERAL WEAK EMBEDDED SHORTWAVES HEADED INTO THE REGION. SFC
LOW PRESSURE WILL BE DEVELOPING TO OUR WEST...AND SOUTH WINDS WILL
HELP KEEP PLENTY OF MOISTURE IN THE REGION. SOME STORMS HAVE
ALREADY STARTED TO DEVELOP OVER WESTERN ND IN RESPONSE TO ONE OF
THE WEAK SHORTWAVES. 06Z HRRR HAS SOME CONVECTION FIRING IN THAT
AREA...BUT SEEMS TO FIZZLE IT OUT AND DEVELOP STORMS FURTHER SOUTH
NEAR THE SD BORDER. A FEW STORMS HAVE BEEN FIRING OVER NORTHERN
MN...MOSTLY TO OUR EAST BUT SHORT RANGE MODELS PERSIST IN BREAKING
OUT SOME CONVECTION OVER THE FAR EASTERN TIER DURING THE EARLY
MORNING HOURS.
OUT OF THE SHORT RANGE MODELS THE HRRR SEEMS TO HAVE THE BEST
HANDLE ON WHAT IS CURRENTLY GOING ON...AND EVEN THEN IT IS NOT
PERFECT. THINK THAT THE STORMS OVER WESTERN ND WILL MOVE EAST
THROUGH THE MORNING...WITH THE DEVILS LAKE BASIN THE BEST SHOT OF
SEEING SOME CONVECTION THIS MORNING. THINK MORE VIGOROUS
CONVECTION WILL MOVE IN FROM THE WEST LATER THIS AFTERNOON AND
INTO THE EVENING AS A SHORTWAVE CURRENTLY OVER WESTERN WY COMES
OVER THE TOP OF THE RIDGE. MODEL SOUNDINGS HAVE CAPE VALUES OF
1000-1500 J/KG AND SHEAR VALUES AROUND 30 KTS...SO SOME SEVERE
LATER THIS AFTERNOON IS NOT OUT OF THE QUESTION DEPENDING ON HOW
THE MORNING CONVECTION PLAYS OUT. CONVECTION SHOULD MOVE EASTWARD
AND BECOME MORE WIDESPREAD AS THE UPPER SHORTWAVE COMES OUT INTO
THE PLAINS. THE MAIN SFC LOW WILL BE TO OUR SOUTH...ALTHOUGH THE
LATEST 06Z NAM BRINGS IT CLOSER TO OUR SOUTHERN COUNTIES THAN
PREVIOUS RUNS.
THURSDAY...THE MAIN UPPER SHORTWAVE THAT THE MODELS ARE PINGING ON
MOVES OFF INTO MN...BUT THE MODELS HAVE ANOTHER ONE FOLLOWING
SHORTLY FURTHER NORTH OVER OUR NORTHERN COUNTIES. MODELS HAVE A
GOOD AMOUNT OF QPF FOR MUCH OF THE DAY...SO KEPT POPS HIGH AND
TEMPS MAY BE SUPPRESSED A BIT BY ONGOING PRECIP SO HAVE MORE
READINGS IN THE UPPER 70S. DO NOT AT THIS POINT THINK THERE WILL
BE MUCH SEVERE DUE TO WEAK DEEP LAYER BULK SHEAR VALUES.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 328 AM CDT WED JUL 15 2015
THURSDAY NIGHT THROUGH FRIDAY NIGHT...MORE WEAK SHORTWAVE TROUGHS
COMING IN AS SOUTHWESTERLY FLOW ALOFT SETS UP OVER THE REGION.
TIMING OF PRECIP IS DIFFICULT TO TELL AT THIS POINT BUT HAVE A
BIT OF A BREAK LATE THURSDAY NIGHT BEFORE THE NEXT SFC TROUGH AXIS
MOVES IN FRIDAY AND SETS OFF MORE CONVECTION. KEEP POPS FAIRLY
HIGH AND TEMPS SHOULD BE NEAR SEASONAL AVERAGES ALTHOUGH SLIGHTLY
MORE MILD ON LOWS DUE TO CLOUDS AND PRECIP.
SATURDAY THROUGH TUESDAY...MODELS IN GOOD AGREEMENT WITH POSITIONING
OF UPPER LEVEL FEATURES. INDICATIONS ARE FOR A TROF DIGGING OVER
THE INTERMOUNTAIN WEST...KEEPING MORE OF A SW FLOW REGIME OVER THE
AREA. VARIOUS IMPULSES ARE EXPECTED TO PROPAGATE THRU THE
FLOW...BRINGING ENOUGH INSTABILITY TO TRIGGER SHOWERS OR STORMS
ACROSS THE AREA EACH DAY. OTHERWISE...TEMPS WILL REMAIN MAINLY ON
THE WARM SIDE...ALTHOUGH A SLIGHT COOLING MAY OCCUR NEAR THE END
OF THE PERIOD AS A WEAK UPPER TROF CROSSES ALONG THE CANADIAN
BORDER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1256 PM CDT WED JUL 15 2015
THE MAIN CHALLENGE REMAINS CONVECTIVE TRENDS. THE BEST CHANCE FOR
SHOWERS AND STORMS WILL BE IN THE SOUTH THIS AFTERNOON...THEN IN ALL
AREAS AFTER 06Z. FOR NOW WILL NOT MENTION ANY THUNDER
OVERNIGHT...BUT ADD A MENTION TO KFAR AFTER 21Z. WINDS SHOULD REMAIN
SOUTHERLY IN MOST AREAS SHIFTING MORE WESTERLY THURSDAY AFTER 18Z.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...JR
LONG TERM...JR/HOPKINS
AVIATION...DK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1244 PM CDT WED JUL 15 2015
.UPDATE...
ISSUED AT 1237 PM CDT WED JUL 15 2015
SOME THUNDERSTORMS CONTINUE OVER THE AREA...MAINLY OVER THE JAMES
RIVER VALLEY REGION. THESE SHOULD CONTINUE SPREADING EAST...THOUGH
A PAIR OF WAVES UPSTREAM...PARTICULARLY ONE MOVING THROUGH CENTRAL
MONTANA/EASTERN WYOMING...WILL RESULT IN ADDITIONAL CONVECTION
LATER THIS AFTERNOON INTO THIS EVENING. HAVE ADJUSTED POPS TO
REFLECT THIS. PARAMETERS STILL IN PLACE FOR SOME STORMS TO BECOME
SEVERE.
UPDATE ISSUED AT 846 AM CDT WED JUL 15 2015
THUNDERSTORMS CONTINUE OVER CENTRAL NORTH DAKOTA WITH CURRENT WAVE
MOVING THROUGH. UPPER LEVEL ANALYSIS SHOWS ANOTHER PAIR OF WAVES
APPROACHING THE AREA WITH THE FIRST ONE OVER EASTERN MONTANA AND
THE SECOND ONE OVER WESTERN MONTANA/WYOMING INTO EASTERN IDAHO.
THEREFORE...HAVE SPREAD THUNDERSTORM CHANCES ACROSS THE AREA
THROUGH THE REMAINDER OF THE DAY. STORMS HAVE BEEN REMAINING UNDER
SEVERE LIMITS THIS MORNING THOUGH THERE IS STILL SOME POTENTIAL
FOR SEVERE IN THE AFTERNOON/EARLY EVENING AS INSTABILITY INCREASES
AND SHEAR REMAINS MARGINAL.
UPDATE ISSUED AT 646 AM CDT WED JUL 15 2015
INCORPORATED RADAR TRENDS THROUGH 1145 UTC...BLENDED TO A TIME
LAGGED ENSEMBLE OF THE 08-10 UTC HRRR ITERATIONS INTO THE
AFTERNOON AND SUPPORTED BY THE 06 UTC GFS WHICH HAVE HAD THE BEST
DEPICTION OF MORNING CONVECTION THUS FAR.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CDT WED JUL 15 2015
FOCUS IN THE SHORT TERM IS ON CHANCES FOR THUNDERSTORMS WEDNESDAY.
UPPER LEVEL RIDGE REMAINS CENTERED OVER NORTH DAKOTA EARLY THIS
MORNING. THROUGH THE AFTERNOON AND EVENING THE RIDGE WILL PROPAGATE
EAST ALONG WITH A WEAK SURFACE BOUNDARY. AMPLE CAPE AND MARGINAL
BULK SHEAR VALUES WILL MOST LIKELY PRODUCE NUMEROUS THUNDERSTORMS
ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS AFTERNOON AND TONIGHT.
SHORT RANGE MODELS AS OF LATE HAVE BEEN MORE MISS THAN HIT OVER THE
LAST WEEK OR SO...HOWEVER THE PREVIOUS FEW HRRR MODEL RUNS HAVE BEEN
FAIRLY CONSISTENT WITH NUMEROUS STORMS SETTING UP FROM THE TURTLE
MOUNTAINS INTO SOUTHWESTERN NORTH DAKOTA AROUND 18 UTC AND THEN
PROPAGATING EAST. WITH THAT SAID THE HRRR HAS NOT DONE WELL WITH THE
STORMS THAT WILL NOT SEEM TO STOP ACROSS WILLIAMS AND MCKENZIE
COUNTIES EARLY THIS MORNING. THUS HAVE WENT WITH A BLEND BETWEEN THE
HRRR AND LONGER RANGE MODELS FOR TODAY THROUGH TONIGHT.
THE SPC WEDNESDAY OUTLOOK CONTINUES TO SHOW NORTH DAKOTA IN A SLIGHT
RISK FOR SEVERE THUNDERSTORMS...WITH THE MAIN RISK AS LARGE HAIL AND
GUSTY WINDS. AS OF NOW HAVE A MENTION OF SEVERE IN THE GRIDS
STARTING AT 18 UTC AND PERSISTING INTO THE NIGHT. JUDGING BY THE
POTENTIALLY STRONG STORMS ALREADY IN PLACE IN THE NORTHWEST IT IS
CERTAINLY POSSIBLE TO SEE SEVERE THUNDERSTORMS POP UP EARLY THIS
AFTERNOON.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 316 AM CDT WED JUL 15 2015
AN ACTIVE WEATHER PATTERN CONTINUES TO HIGHLIGHT THE EXTENDED
FORECAST.
THE 00 UTC GLOBAL DETERMINISTIC AND ENSEMBLE SUITES ARE IN
AGREEMENT ON QUASI-ZONAL FLOW ALOFT ACROSS THE NORTHERN PLAINS
THURSDAY AND FRIDAY TRANSITIONING TO SOUTHWEST THIS WEEKEND AS A
POSITIVELY TILTED NORTHERN CONUS AND CANADIAN ROCKIES TROUGH
MODESTLY AMPLIFIES BEFORE PROPAGATING DOWNSTREAM OF THE REGION
INTO EARLY NEXT WEEK. AS A RESULT...DAILY CHANCES FOR
THUNDERSTORMS ARE FORECAST TO CONTINUE THURSDAY THROUGH AT LEAST
SATURDAY...BEFORE A POTENTIAL DECREASE IN STORM ACTIVITY NEXT
WEEK. WHILE THE SEVERE THREAT IS NON-ZERO THURSDAY AND MORE SO ON
FRIDAY AHEAD OF THE SURFACE COLD FRONT...UNCERTAINTY IS TOO HIGH
AT THIS TIME TO ADD A SEVERE MENTION TO THE GRIDS. THIS IS IN LINE
WITH THE SPC OUTLOOK SUITE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1237 PM CDT WED JUL 15 2015
SCT TSRA WILL INCREASE IN COVERAGE TONIGHT...BRINGING LCL IFR VIS
IN HEAVIER PRECIP. STORMS WILL CONTINUE OVERNIGHT INTO THURSDAY
MORNING. MODELS ARE HINTING AT SOME FOG POSSIBLY DEVELOPING LATE
TONIGHT OVER PORTIONS OF WESTERN AND CENTRAL NORTH DAKOTA...THOUGH
WILL WAIT TO SEE IF NEXT MODELS RUNS ALSO ADVERTISE THIS BEFORE
MENTIONING IN INDIVIDUAL TERMINAL FORECASTS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...MM
LONG TERM...AYD
AVIATION...JJS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
858 AM CDT WED JUL 15 2015
.UPDATE...
ISSUED AT 846 AM CDT WED JUL 15 2015
THUNDERSTORMS CONTINUE OVER CENTRAL NORTH DAKOTA WITH CURRENT WAVE
MOVING THROUGH. UPPER LEVEL ANALYSIS SHOWS ANOTHER PAIR OF WAVES
APPROACHING THE AREA WITH THE FIRST ONE OVER EASTERN MONTANA AND
THE SECOND ONE OVER WESTERN MONTANA/WYOMING INTO EASTERN IDAHO.
THEREFORE...HAVE SPREAD THUNDERSTORM CHANCES ACROSS THE AREA
THROUGH THE REMAINDER OF THE DAY. STORMS HAVE BEEN REMAINING UNDER
SEVERE LIMITS THIS MORNING THOUGH THERE IS STILL SOME POTENTIAL
FOR SEVERE IN THE AFTERNOON/EARLY EVENING AS INSTABILITY INCREASES
AND SHEAR REMAINS MARGINAL.
UPDATE ISSUED AT 646 AM CDT WED JUL 15 2015
INCORPORATED RADAR TRENDS THROUGH 1145 UTC...BLENDED TO A TIME
LAGGED ENSEMBLE OF THE 08-10 UTC HRRR ITERATIONS INTO THE
AFTERNOON AND SUPPORTED BY THE 06 UTC GFS WHICH HAVE HAD THE BEST
DEPICTION OF MORNING CONVECTION THUS FAR.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CDT WED JUL 15 2015
FOCUS IN THE SHORT TERM IS ON CHANCES FOR THUNDERSTORMS WEDNESDAY.
UPPER LEVEL RIDGE REMAINS CENTERED OVER NORTH DAKOTA EARLY THIS
MORNING. THROUGH THE AFTERNOON AND EVENING THE RIDGE WILL PROPAGATE
EAST ALONG WITH A WEAK SURFACE BOUNDARY. AMPLE CAPE AND MARGINAL
BULK SHEAR VALUES WILL MOST LIKELY PRODUCE NUMEROUS THUNDERSTORMS
ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS AFTERNOON AND TONIGHT.
SHORT RANGE MODELS AS OF LATE HAVE BEEN MORE MISS THAN HIT OVER THE
LAST WEEK OR SO...HOWEVER THE PREVIOUS FEW HRRR MODEL RUNS HAVE BEEN
FAIRLY CONSISTENT WITH NUMEROUS STORMS SETTING UP FROM THE TURTLE
MOUNTAINS INTO SOUTHWESTERN NORTH DAKOTA AROUND 18 UTC AND THEN
PROPAGATING EAST. WITH THAT SAID THE HRRR HAS NOT DONE WELL WITH THE
STORMS THAT WILL NOT SEEM TO STOP ACROSS WILLIAMS AND MCKENZIE
COUNTIES EARLY THIS MORNING. THUS HAVE WENT WITH A BLEND BETWEEN THE
HRRR AND LONGER RANGE MODELS FOR TODAY THROUGH TONIGHT.
THE SPC WEDNESDAY OUTLOOK CONTINUES TO SHOW NORTH DAKOTA IN A SLIGHT
RISK FOR SEVERE THUNDERSTORMS...WITH THE MAIN RISK AS LARGE HAIL AND
GUSTY WINDS. AS OF NOW HAVE A MENTION OF SEVERE IN THE GRIDS
STARTING AT 18 UTC AND PERSISTING INTO THE NIGHT. JUDGING BY THE
POTENTIALLY STRONG STORMS ALREADY IN PLACE IN THE NORTHWEST IT IS
CERTAINLY POSSIBLE TO SEE SEVERE THUNDERSTORMS POP UP EARLY THIS
AFTERNOON.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 316 AM CDT WED JUL 15 2015
AN ACTIVE WEATHER PATTERN CONTINUES TO HIGHLIGHT THE EXTENDED
FORECAST.
THE 00 UTC GLOBAL DETERMINISTIC AND ENSEMBLE SUITES ARE IN
AGREEMENT ON QUASI-ZONAL FLOW ALOFT ACROSS THE NORTHERN PLAINS
THURSDAY AND FRIDAY TRANSITIONING TO SOUTHWEST THIS WEEKEND AS A
POSITIVELY TILTED NORTHERN CONUS AND CANADIAN ROCKIES TROUGH
MODESTLY AMPLIFIES BEFORE PROPAGATING DOWNSTREAM OF THE REGION
INTO EARLY NEXT WEEK. AS A RESULT...DAILY CHANCES FOR
THUNDERSTORMS ARE FORECAST TO CONTINUE THURSDAY THROUGH AT LEAST
SATURDAY...BEFORE A POTENTIAL DECREASE IN STORM ACTIVITY NEXT
WEEK. WHILE THE SEVERE THREAT IS NON-ZERO THURSDAY AND MORE SO ON
FRIDAY AHEAD OF THE SURFACE COLD FRONT...UNCERTAINTY IS TOO HIGH
AT THIS TIME TO ADD A SEVERE MENTION TO THE GRIDS. THIS IS IN LINE
WITH THE SPC OUTLOOK SUITE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 646 AM CDT WED JUL 15 2015
THUNDERSTORMS WILL BE SPREAD ACROSS NORTH DAKOTA THROUGHOUT THE 12Z
TAF PERIOD. AT THIS TIME SITES KDIK...KBIS...AND KMOT HAVE THE
GREATEST CHANCE OF BEING IMPACTED THIS MORNING AND
AFTERNOON...WITH LESSER CHANCES FOR KISN AND KJMS.UNLESS IMPACTED
BY A THUNDERSTORM VFR CONDITIONS ARE EXPECTED FOR THE 12Z TAF
CYCLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...MM
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
654 AM CDT WED JUL 15 2015
.UPDATE...
ISSUED AT 653 AM CDT WED JUL 15 2015
EXPANDED THE PATCHY FOG MENTION A BIT FURTHER ACROSS THE NORTHERN
COUNTIES. IT HAS BEEN DENSE IN SOME SPOTS BUT LOOKING AT WEB CAMS
IT SEEMS THAT THE DENSE STUFF IS RATHER PATCHY SO WILL LEAVE ANY
HEADLINES ALONE FOR NOW. MADE A FEW ADJUSTMENTS TO POPS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 328 AM CDT WED JUL 15 2015
CONVECTION TIMING AND STRENGTH WILL BE THE MAIN FORECAST ISSUES
FOR THE SHORT TERM.
UPPER RIDGING CONTINUES TO BUILD OVER THE PLAINS...BUT WV LOOP
SHOWS SEVERAL WEAK EMBEDDED SHORTWAVES HEADED INTO THE REGION. SFC
LOW PRESSURE WILL BE DEVELOPING TO OUR WEST...AND SOUTH WINDS WILL
HELP KEEP PLENTY OF MOISTURE IN THE REGION. SOME STORMS HAVE
ALREADY STARTED TO DEVELOP OVER WESTERN ND IN RESPONSE TO ONE OF
THE WEAK SHORTWAVES. 06Z HRRR HAS SOME CONVECTION FIRING IN THAT
AREA...BUT SEEMS TO FIZZLE IT OUT AND DEVELOP STORMS FURTHER SOUTH
NEAR THE SD BORDER. A FEW STORMS HAVE BEEN FIRING OVER NORTHERN
MN...MOSTLY TO OUR EAST BUT SHORT RANGE MODELS PERSIST IN BREAKING
OUT SOME CONVECTION OVER THE FAR EASTERN TIER DURING THE EARLY
MORNING HOURS.
OUT OF THE SHORT RANGE MODELS THE HRRR SEEMS TO HAVE THE BEST
HANDLE ON WHAT IS CURRENTLY GOING ON...AND EVEN THEN IT IS NOT
PERFECT. THINK THAT THE STORMS OVER WESTERN ND WILL MOVE EAST
THROUGH THE MORNING...WITH THE DEVILS LAKE BASIN THE BEST SHOT OF
SEEING SOME CONVECTION THIS MORNING. THINK MORE VIGOROUS
CONVECTION WILL MOVE IN FROM THE WEST LATER THIS AFTERNOON AND
INTO THE EVENING AS A SHORTWAVE CURRENTLY OVER WESTERN WY COMES
OVER THE TOP OF THE RIDGE. MODEL SOUNDINGS HAVE CAPE VALUES OF
1000-1500 J/KG AND SHEAR VALUES AROUND 30 KTS...SO SOME SEVERE
LATER THIS AFTERNOON IS NOT OUT OF THE QUESTION DEPENDING ON HOW
THE MORNING CONVECTION PLAYS OUT. CONVECTION SHOULD MOVE EASTWARD
AND BECOME MORE WIDESPREAD AS THE UPPER SHORTWAVE COMES OUT INTO
THE PLAINS. THE MAIN SFC LOW WILL BE TO OUR SOUTH...ALTHOUGH THE
LATEST 06Z NAM BRINGS IT CLOSER TO OUR SOUTHERN COUNTIES THAN
PREVIOUS RUNS.
THURSDAY...THE MAIN UPPER SHORTWAVE THAT THE MODELS ARE PINGING ON
MOVES OFF INTO MN...BUT THE MODELS HAVE ANOTHER ONE FOLLOWING
SHORTLY FURTHER NORTH OVER OUR NORTHERN COUNTIES. MODELS HAVE A
GOOD AMOUNT OF QPF FOR MUCH OF THE DAY...SO KEPT POPS HIGH AND
TEMPS MAY BE SUPPRESSED A BIT BY ONGOING PRECIP SO HAVE MORE
READINGS IN THE UPPER 70S. DO NOT AT THIS POINT THINK THERE WILL
BE MUCH SEVERE DUE TO WEAK DEEP LAYER BULK SHEAR VALUES.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 328 AM CDT WED JUL 15 2015
THURSDAY NIGHT THROUGH FRIDAY NIGHT...MORE WEAK SHORTWAVE TROUGHS
COMING IN AS SOUTHWESTERLY FLOW ALOFT SETS UP OVER THE REGION.
TIMING OF PRECIP IS DIFFICULT TO TELL AT THIS POINT BUT HAVE A
BIT OF A BREAK LATE THURSDAY NIGHT BEFORE THE NEXT SFC TROUGH AXIS
MOVES IN FRIDAY AND SETS OFF MORE CONVECTION. KEEP POPS FAIRLY
HIGH AND TEMPS SHOULD BE NEAR SEASONAL AVERAGES ALTHOUGH SLIGHTLY
MORE MILD ON LOWS DUE TO CLOUDS AND PRECIP.
SATURDAY THROUGH TUESDAY...MODELS IN GOOD AGREEMENT WITH POSITIONING
OF UPPER LEVEL FEATURES. INDICATIONS ARE FOR A TROF DIGGING OVER
THE INTERMOUNTAIN WEST...KEEPING MORE OF A SW FLOW REGIME OVER THE
AREA. VARIOUS IMPULSES ARE EXPECTED TO PROPAGATE THRU THE
FLOW...BRINGING ENOUGH INSTABILITY TO TRIGGER SHOWERS OR STORMS
ACROSS THE AREA EACH DAY. OTHERWISE...TEMPS WILL REMAIN MAINLY ON
THE WARM SIDE...ALTHOUGH A SLIGHT COOLING MAY OCCUR NEAR THE END
OF THE PERIOD AS A WEAK UPPER TROF CROSSES ALONG THE CANADIAN
BORDER.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 653 AM CDT WED JUL 15 2015
MOST OF THE FOG HAS STAYED NORTH OF THE TAF SITES BUT KTVF HAS
BEEN MVFR IN MIST AND KDVL WAS 1SM BUT HAS NOW GONE BACK UP TO
VFR. ANY LINGERING FOG/MIST WILL DISSIPATE IN THE NEXT FEW HOURS
AND WE SHOULD BE VFR THROUGH THE REST OF THE DAY WITH SOME MID AND
HIGH CLOUDS MOVING IN. SHOWERS AND THUNDERSTORMS WILL BEGIN TO
MOVE IN FROM THE WEST LATER THIS AFTERNOON...BUT SO FAR ONLY
INCLUDED VCTS AT KDVL WHICH WILL SEE THE CONVECTION THE SOONEST
AND IS MOST CERTAIN TO BE IMPACTED. THE OTHER TAF SITES ARE LESS
CERTAIN SO WILL LEAVE OUT FOR NOW. HAVE SOME MVFR CIGS AT KBJI
LATE IN THE PERIOD BUT OTHERWISE CIGS EVEN WITH THUNDERSTORMS
SHOULD BE 5000 FT OR MORE. WINDS WILL BE FROM THE SOUTH AT UNDER
10 KTS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...JR
LONG TERM...JR/HOPKINS
AVIATION...JR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
650 AM CDT WED JUL 15 2015
.UPDATE...
ISSUED AT 646 AM CDT WED JUL 15 2015
INCORPORATED RADAR TRENDS THROUGH 1145 UTC...BLENDED TO A TIME
LAGGED ENSEMBLE OF THE 08-10 UTC HRRR ITERATIONS INTO THE
AFTERNOON AND SUPPORTED BY THE 06 UTC GFS WHICH HAVE HAD THE BEST
DEPICTION OF MORNING CONVECTION THUS FAR.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CDT WED JUL 15 2015
FOCUS IN THE SHORT TERM IS ON CHANCES FOR THUNDERSTORMS WEDNESDAY.
UPPER LEVEL RIDGE REMAINS CENTERED OVER NORTH DAKOTA EARLY THIS
MORNING. THROUGH THE AFTERNOON AND EVENING THE RIDGE WILL PROPAGATE
EAST ALONG WITH A WEAK SURFACE BOUNDARY. AMPLE CAPE AND MARGINAL
BULK SHEAR VALUES WILL MOST LIKELY PRODUCE NUMEROUS THUNDERSTORMS
ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS AFTERNOON AND TONIGHT.
SHORT RANGE MODELS AS OF LATE HAVE BEEN MORE MISS THAN HIT OVER THE
LAST WEEK OR SO...HOWEVER THE PREVIOUS FEW HRRR MODEL RUNS HAVE BEEN
FAIRLY CONSISTENT WITH NUMEROUS STORMS SETTING UP FROM THE TURTLE
MOUNTAINS INTO SOUTHWESTERN NORTH DAKOTA AROUND 18 UTC AND THEN
PROPAGATING EAST. WITH THAT SAID THE HRRR HAS NOT DONE WELL WITH THE
STORMS THAT WILL NOT SEEM TO STOP ACROSS WILLIAMS AND MCKENZIE
COUNTIES EARLY THIS MORNING. THUS HAVE WENT WITH A BLEND BETWEEN THE
HRRR AND LONGER RANGE MODELS FOR TODAY THROUGH TONIGHT.
THE SPC WEDNESDAY OUTLOOK CONTINUES TO SHOW NORTH DAKOTA IN A SLIGHT
RISK FOR SEVERE THUNDERSTORMS...WITH THE MAIN RISK AS LARGE HAIL AND
GUSTY WINDS. AS OF NOW HAVE A MENTION OF SEVERE IN THE GRIDS
STARTING AT 18 UTC AND PERSISTING INTO THE NIGHT. JUDGING BY THE
POTENTIALLY STRONG STORMS ALREADY IN PLACE IN THE NORTHWEST IT IS
CERTAINLY POSSIBLE TO SEE SEVERE THUNDERSTORMS POP UP EARLY THIS
AFTERNOON.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 316 AM CDT WED JUL 15 2015
AN ACTIVE WEATHER PATTERN CONTINUES TO HIGHLIGHT THE EXTENDED
FORECAST.
THE 00 UTC GLOBAL DETERMINISTIC AND ENSEMBLE SUITES ARE IN
AGREEMENT ON QUASI-ZONAL FLOW ALOFT ACROSS THE NORTHERN PLAINS
THURSDAY AND FRIDAY TRANSITIONING TO SOUTHWEST THIS WEEKEND AS A
POSITIVELY TILTED NORTHERN CONUS AND CANADIAN ROCKIES TROUGH
MODESTLY AMPLIFIES BEFORE PROPAGATING DOWNSTREAM OF THE REGION
INTO EARLY NEXT WEEK. AS A RESULT...DAILY CHANCES FOR
THUNDERSTORMS ARE FORECAST TO CONTINUE THURSDAY THROUGH AT LEAST
SATURDAY...BEFORE A POTENTIAL DECREASE IN STORM ACTIVITY NEXT
WEEK. WHILE THE SEVERE THREAT IS NON-ZERO THURSDAY AND MORE SO ON
FRIDAY AHEAD OF THE SURFACE COLD FRONT...UNCERTAINTY IS TOO HIGH
AT THIS TIME TO ADD A SEVERE MENTION TO THE GRIDS. THIS IS IN LINE
WITH THE SPC OUTLOOK SUITE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 646 AM CDT WED JUL 15 2015
THUNDERSTORMS WILL BE SPREAD ACROSS NORTH DAKOTA THROUGHOUT THE 12Z
TAF PERIOD. AT THIS TIME SITES KDIK...KBIS...AND KMOT HAVE THE
GREATEST CHANCE OF BEING IMPACTED THIS MORNING AND
AFTERNOON...WITH LESSER CHANCES FOR KISN AND KJMS.UNLESS IMPACTED
BY A THUNDERSTORM VFR CONDITIONS ARE EXPECTED FOR THE 12Z TAF
CYCLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...MM
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
332 AM CDT WED JUL 15 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CDT WED JUL 15 2015
FOCUS IN THE SHORT TERM IS ON CHANCES FOR THUNDERSTORMS WEDNESDAY.
UPPER LEVEL RIDGE REMAINS CENTERED OVER NORTH DAKOTA EARLY THIS
MORNING. THROUGH THE AFTERNOON AND EVENING THE RIDGE WILL PROPAGATE
EAST ALONG WITH A WEAK SURFACE BOUNDARY. AMPLE CAPE AND MARGINAL
BULK SHEAR VALUES WILL MOST LIKELY PRODUCE NUMEROUS THUNDERSTORMS
ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS AFTERNOON AND TONIGHT.
SHORT RANGE MODELS AS OF LATE HAVE BEEN MORE MISS THAN HIT OVER THE
LAST WEEK OR SO...HOWEVER THE PREVIOUS FEW HRRR MODEL RUNS HAVE BEEN
FAIRLY CONSISTENT WITH NUMEROUS STORMS SETTING UP FROM THE TURTLE
MOUNTAINS INTO SOUTHWESTERN NORTH DAKOTA AROUND 18 UTC AND THEN
PROPAGATING EAST. WITH THAT SAID THE HRRR HAS NOT DONE WELL WITH THE
STORMS THAT WILL NOT SEEM TO STOP ACROSS WILLIAMS AND MCKENZIE
COUNTIES EARLY THIS MORNING. THUS HAVE WENT WITH A BLEND BETWEEN THE
HRRR AND LONGER RANGE MODELS FOR TODAY THROUGH TONIGHT.
THE SPC WEDNESDAY OUTLOOK CONTINUES TO SHOW NORTH DAKOTA IN A SLIGHT
RISK FOR SEVERE THUNDERSTORMS...WITH THE MAIN RISK AS LARGE HAIL AND
GUSTY WINDS. AS OF NOW HAVE A MENTION OF SEVERE IN THE GRIDS
STARTING AT 18 UTC AND PERSISTING INTO THE NIGHT. JUDGING BY THE
POTENTIALLY STRONG STORMS ALREADY IN PLACE IN THE NORTHWEST IT IS
CERTAINLY POSSIBLE TO SEE SEVERE THUNDERSTORMS POP UP EARLY THIS
AFTERNOON.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 316 AM CDT WED JUL 15 2015
AN ACTIVE WEATHER PATTERN CONTINUES TO HIGHLIGHT THE EXTENDED
FORECAST.
THE 00 UTC GLOBAL DETERMINISTIC AND ENSEMBLE SUITES ARE IN
AGREEMENT ON QUASI-ZONAL FLOW ALOFT ACROSS THE NORTHERN PLAINS
THURSDAY AND FRIDAY TRANSITIONING TO SOUTHWEST THIS WEEKEND AS A
POSITIVELY TILTED NORTHERN CONUS AND CANADIAN ROCKIES TROUGH
MODESTLY AMPLIFIES BEFORE PROPAGATING DOWNSTREAM OF THE REGION
INTO EARLY NEXT WEEK. AS A RESULT...DAILY CHANCES FOR
THUNDERSTORMS ARE FORECAST TO CONTINUE THURSDAY THROUGH AT LEAST
SATURDAY...BEFORE A POTENTIAL DECREASE IN STORM ACTIVITY NEXT
WEEK. WHILE THE SEVERE THREAT IS NON-ZERO THURSDAY AND MORE SO ON
FRIDAY AHEAD OF THE SURFACE COLD FRONT...UNCERTAINTY IS TOO HIGH
AT THIS TIME TO ADD A SEVERE MENTION TO THE GRIDS. THIS IS IN LINE
WITH THE SPC OUTLOOK SUITE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1224 AM CDT WED JUL 15 2015
VFR CONDITIONS ARE FORECAST THROUGH 06Z TAF PERIOD. HAVE OPTED TO
PUT VCTS IN FOR ALL 5 CENTRAL AND WESTERN NORTH DAKOTA TAF SITES
STARTING BETWEEN 18Z AND 21Z. STORMS WILL PERSIST INTO THE NIGHT
BEYOND 06Z JULY 16.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...MM
LONG TERM...AYD
AVIATION...MM
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
328 AM CDT WED JUL 15 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 328 AM CDT WED JUL 15 2015
CONVECTION TIMING AND STRENGTH WILL BE THE MAIN FORECAST ISSUES
FOR THE SHORT TERM.
UPPER RIDGING CONTINUES TO BUILD OVER THE PLAINS...BUT WV LOOP
SHOWS SEVERAL WEAK EMBEDDED SHORTWAVES HEADED INTO THE REGION. SFC
LOW PRESSURE WILL BE DEVELOPING TO OUR WEST...AND SOUTH WINDS WILL
HELP KEEP PLENTY OF MOISTURE IN THE REGION. SOME STORMS HAVE
ALREADY STARTED TO DEVELOP OVER WESTERN ND IN RESPONSE TO ONE OF
THE WEAK SHORTWAVES. 06Z HRRR HAS SOME CONVECTION FIRING IN THAT
AREA...BUT SEEMS TO FIZZLE IT OUT AND DEVELOP STORMS FURTHER SOUTH
NEAR THE SD BORDER. A FEW STORMS HAVE BEEN FIRING OVER NORTHERN
MN...MOSTLY TO OUR EAST BUT SHORT RANGE MODELS PERSIST IN BREAKING
OUT SOME CONVECTION OVER THE FAR EASTERN TIER DURING THE EARLY
MORNING HOURS.
OUT OF THE SHORT RANGE MODELS THE HRRR SEEMS TO HAVE THE BEST
HANDLE ON WHAT IS CURRENTLY GOING ON...AND EVEN THEN IT IS NOT
PERFECT. THINK THAT THE STORMS OVER WESTERN ND WILL MOVE EAST
THROUGH THE MORNING...WITH THE DEVILS LAKE BASIN THE BEST SHOT OF
SEEING SOME CONVECTION THIS MORNING. THINK MORE VIGOROUS
CONVECTION WILL MOVE IN FROM THE WEST LATER THIS AFTERNOON AND
INTO THE EVENING AS A SHORTWAVE CURRENTLY OVER WESTERN WY COMES
OVER THE TOP OF THE RIDGE. MODEL SOUNDINGS HAVE CAPE VALUES OF
1000-1500 J/KG AND SHEAR VALUES AROUND 30 KTS...SO SOME SEVERE
LATER THIS AFTERNOON IS NOT OUT OF THE QUESTION DEPENDING ON HOW
THE MORNING CONVECTION PLAYS OUT. CONVECTION SHOULD MOVE EASTWARD
AND BECOME MORE WIDESPREAD AS THE UPPER SHORTWAVE COMES OUT INTO
THE PLAINS. THE MAIN SFC LOW WILL BE TO OUR SOUTH...ALTHOUGH THE
LATEST 06Z NAM BRINGS IT CLOSER TO OUR SOUTHERN COUNTIES THAN
PREVIOUS RUNS.
THURSDAY...THE MAIN UPPER SHORTWAVE THAT THE MODELS ARE PINGING ON
MOVES OFF INTO MN...BUT THE MODELS HAVE ANOTHER ONE FOLLOWING
SHORTLY FURTHER NORTH OVER OUR NORTHERN COUNTIES. MODELS HAVE A
GOOD AMOUNT OF QPF FOR MUCH OF THE DAY...SO KEPT POPS HIGH AND
TEMPS MAY BE SUPPRESSED A BIT BY ONGOING PRECIP SO HAVE MORE
READINGS IN THE UPPER 70S. DO NOT AT THIS POINT THINK THERE WILL
BE MUCH SEVERE DUE TO WEAK DEEP LAYER BULK SHEAR VALUES.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 328 AM CDT WED JUL 15 2015
THURSDAY NIGHT THROUGH FRIDAY NIGHT...MORE WEAK SHORTWAVE TROUGHS
COMING IN AS SOUTHWESTERLY FLOW ALOFT SETS UP OVER THE REGION.
TIMING OF PRECIP IS DIFFICULT TO TELL AT THIS POINT BUT HAVE A
BIT OF A BREAK LATE THURSDAY NIGHT BEFORE THE NEXT SFC TROUGH AXIS
MOVES IN FRIDAY AND SETS OFF MORE CONVECTION. KEEP POPS FAIRLY
HIGH AND TEMPS SHOULD BE NEAR SEASONAL AVERAGES ALTHOUGH SLIGHTLY
MORE MILD ON LOWS DUE TO CLOUDS AND PRECIP.
SATURDAY THROUGH TUESDAY...MODELS IN GOOD AGREEMENT WITH POSITIONING
OF UPPER LEVEL FEATURES. INDICATIONS ARE FOR A TROF DIGGING OVER
THE INTERMOUNTAIN WEST...KEEPING MORE OF A SW FLOW REGIME OVER THE
AREA. VARIOUS IMPULSES ARE EXPECTED TO PROPAGATE THRU THE
FLOW...BRINGING ENOUGH INSTABILITY TO TRIGGER SHOWERS OR STORMS
ACROSS THE AREA EACH DAY. OTHERWISE...TEMPS WILL REMAIN MAINLY ON
THE WARM SIDE...ALTHOUGH A SLIGHT COOLING MAY OCCUR NEAR THE END
OF THE PERIOD AS A WEAK UPPER TROF CROSSES ALONG THE CANADIAN
BORDER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1127 PM CDT TUE JUL 14 2015
FOLLOWED SHORT RANGE MODEL GUIDANCE KEEPING FA DRY THROUGH MOST OF
THE FORECAST PERIOD. MAY SEE SOME UPPER LEVEL CONVECTIVE DEBRIS
CLOUD COVER BUT OVERALL A VFR PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...JR
LONG TERM...JR/HOPKINS
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
955 PM EDT THU JUL 16 2015
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFF THE NEW ENGLAND COAST TONIGHT. LOW
PRESSURE OVER NORTHWESTERN IOWA WILL THEN TRACK NORTHEAST INTO
NORTHERN MICHIGAN FRIDAY AND PULL A WEAK FRONTAL BOUNDARY ACROSS THE
AREA FRIDAY AFTERNOON. HIGH PRESSURE WILL BECOME ANCHORED ACROSS THE
SOUTHEASTERN US...DRAWING UP HEAT AND HUMIDITY FROM THE DEEP SOUTH
ACROSS OHIO. SUNDAY NIGHT INTO MONDAY A COLD FRONT WILL CROSS THE
AREA. HIGH PRESSURE RETURNS FOR THE SECOND HALF OF MONDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... OTHER THAN A FEW POSSIBLE
SPRINKLES SOUTH OF MILLERSBURG...FIRST PUSH OF RAIN HAS DISSIPATED
LEAVING BAND OF MID CLOUDS. MCS HAS DEVELOPED OVER NRN IL AND THIS
WILL SPREAD OUT WHILE PUSHING EAST. SHORT TERM HI RES MODELS SEEM
SLOW TO GET THIS PRECIP INTO THE AREA...ESPECIALLY THE RAP WHICH
DOES NOT HAVE ANY MEASURABLE RAIN INTO THE AREA UNTIL AFTER 13Z.
LIKE THE FASTER HRRR MORE. WILL STAY WITH PLAN TO START RAMPING UP
POPS IN THE NW AFTER 06Z TO BE 50 TO 60% FROM 09Z TO 12Z.
OVERNIGHT LOWS WILL BE SLIGHTLY WARMER IN THE WEST WITH ADDITIONAL
CLOUD COVER. LOWS EXPECTED TO RANGE FROM THE MID 60S IN THE WEST TO
UPPER 50S IN THE INLAND EAST.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY NIGHT/...
THE WARMEST TEMPERATURES OF THE SUMMER...SO FAR...ARE LIKELY TO
OCCUR THIS WEEKEND. FRIDAY MORNING/AFTERNOON A WARM FRONT WILL PUSH
THROUGH THE AREA WHILE TRAILING A SURFACE LOW ACROSS NORTHERN
MICHIGAN. THE DEEPEST MOISTURE WILL BE NEARER TO THE LOW PRESSURE
CENTER...AND PRIMARILY NORTH OF LAKE ERIE. HOWEVER...POCKETS OF
DEEPER MOISTURE MAY SNEAK INTO NWRN OHIO. AS THE LOW PULLS INTO
CANADA...SO WILL THE MOISTURE...SO EXPECT RAIN CHANCES TO BE LESS
IN THE EAST...WITH PERHAPS ERIE BEING THE EXCEPTION GIVEN ITS
HIGHER LATITUDE. BEHIND THE WARM FRONT TEMPERATURES WILL INCREASE
INTO THE UPPER 80`S AND DEW POINTS WILL INCREASE INTO THE UPPER
60`S AND LOW 70`S...LENDING ITSELF TO ABUNDANT SURFACE BASED
INSTABILITY...AND IN TURN SCATTERED TO NUMEROUS THUNDERSTORMS.
THESE STORMS WILL BE EFFICIENT RAINMAKERS AND COULD CAUSE AREAS OF
LOCALIZED FLOODING...ESPECIALLY WITH PWAT VALUES PROGGED TO EXCEED
1.90 IN MANY LOCATIONS. SCATTERED SUMMERTIME CONVECTION WILL
CONTINUE INTO SATURDAY BUT WILL LIKELY BE LESS WIDESPREAD THAN
FRIDAY GIVEN THE LACK OF A SIGNIFICANT FORCING MECHANISM. THESE
STORMS WILL BE DIURNALLY DRIVEN FOR THE MOST PART. SUNDAY MORNING
AND AFTERNOON RAIN CHANCES END UP BEING BETTER CARE OF A
SHORTWAVE TROUGH THAT WILL PULSE OUT AHEAD OF A COLD FRONT. THE
COLD FRONT WILL PUSH TROUGH THE AREA SUNDAY NIGHT INTO MONDAY...WITH
ADDITIONAL SHOWERS AND THUNDERSTORMS DEVELOPING. MONDAY AFTERNOON
CONDITIONS DRY OUT BEHIND THE FRONT AS HIGH PRESSURE SPREADS IN
FROM THE NORTH.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
THE MODELS ARE TRENDING FASTER WITH THE COLD FRONT ON
MONDAY...AND MOST HAVE THE FRONT SOUTH OF THE FORECAST AREA MONDAY
MORNING. CUT BACK ON POPS FOR THE DAY BUT STILL KEPT A SMALL CHANCE
GIVEN THE UNCERTAINTY OF A CLEAN FRONTAL PASSAGES THIS TIME OF YEAR
AND THE FACT THAT THE FRONT DOES NOT APPEAR TO PUSH TOO FAR TO THE
SOUTH. WENT A COUPLE OF DEGREES LOWER ON HIGH TEMPERATURES...
GENERALLY FROM THE UPPER 70S NEAR LAKE ERIE TO THE LOWER 80S INLAND.
MOST OF THE MODELS HAVE BEEN HINTING AT A SECONDARY FRONT EARLY
WEDNESDAY. WEAK FRONTS THAT COME THROUGH IN THE EARLY MORNING HOURS
THIS TIME OF YEAR OFTEN END UP BEING DRY. WILL NOT INTRODUCE SHOWERS
BUT WILL INCREASE CLOUDS TUESDAY NIGHT INTO WEDNESDAY MORNING.
A PUSH OF HIGH PRESSURE SHOULD KEEP TEMPERATURES IN CHECK...NEAR TO
SLIGHTLY BELOW NORMAL MID WEEK. THE RETURN SOUTH FLOW AND WARM
ADVECTION COULD BRING A SMALL CHANCE OF SHOWERS AND THUNDERSTORMS BY
NEXT THURSDAY NIGHT OR FRIDAY.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
MID LEVEL CLOUDS SPREADING EAST WITH A FEW SPRINKLES ON REGIONAL
RADAR ACROSS NORTH CENTRAL OHIO. GIVEN VERY DRY LOW LEVEL AIR IN
PLACE...DID NOT INCLUDE ANY PRECIPITATION IN THE TAFS AS THESE
SPRINKLES WILL LIKELY EVAPORATE BEFORE REACHING THE GROUND. A
BETTER PUSH OF MOISTURE ARRIVES AS UPSTREAM SHOWERS AND
THUNDERSTORMS NEAR CHICAGO ARRIVES IN NW OHIO TOWARDS 10Z AND
CONTINUES EAST TOWARDS CLE THROUGH THE MORNING. DESPITE INCREASING
MOISTURE...STILL EXPECTING THESE SHOWERS TO WEAKEN AS THEY SPREAD
EAST WITH BEST CHANCE FOR A THUNDERSTORM AT TOL. OTHERWISE
EXPECTING A BETTER CHANCE OF SCATTERED SHOWERS AND THUNDERSTORMS
DURING THE AFTERNOON. CONDITIONS SHOULD REMAIN VFR THROUGH THE TAF
CYCLE OUTSIDE OF THUNDERSTORMS. SOUTHEASTERLY WINDS OF 6 KNOTS OR
LESS WILL PERSIST FOR MOST OF TONIGHT AT THE TERMINALS...VEERING
TO SOUTH BY 12Z AND SOUTHWESTERLY WITH GUSTS TO AROUND 20 KNOTS BY
16Z.
OUTLOOK...AREAS OF NON VFR IN SHRA AND TSRA FRI THRU MON ALONG
WITH EARLY MORNING FOG SAT THRU MON.
&&
.MARINE...
THE EASTERLY WIND WITH A BIT OF AN ONSHORE COMPONENT WILL KEEP WAVES
RUNNING A FOOT OR TWO THIS EVENING ON LAKE ERIE BUT IN GENERAL...THE
GRADIENT ON LAKE ERIE WILL REMAIN LIGHT. THE MAIN CONCERN THROUGH
THE WEEKEND IS THE RISK FOR THUNDERSTORMS. SHOWERS AND THUNDERSTORMS
WILL LIKELY DEVELOP ALONG A WEAK WARM FRONT LATER TONIGHT AND FRIDAY
AND MARINERS WILL HAVE TO WATCH FOR THUNDERSTORMS. A WEAKENING FRONT
WILL BRUSH THE LAKE EARLY SATURDAY. THE NEXT SIGNIFICANT FRONT WILL
COME SUNDAY NIGHT OR EARLY MONDAY WITH THUNDERSTORMS LIKELY. WINDS
SEEM AS THOUGH THEY WILL REMAIN LIGHT TO MODERATE BEHIND THE FRONT.
HIGH PRESSURE SHOULD BUILD ACROSS THE LAKE EARLY THE FIRST HALF OF
NEXT WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAYERS
NEAR TERM...ADAMS/MAYERS
SHORT TERM...MAYERS
LONG TERM...KOSARIK
AVIATION...KEC
MARINE...KOSARIK
AREA FORECAST DISCUSSION
NWS TULSA OK
837 PM CDT THU JUL 16 2015
.DISCUSSION...
SURFACE TROUGH LIES TO THE NORTH AND WEST OF THE FORECAST AREA
THIS EVENING. A FEW STORMS HAVE DEVELOPED ALONG IT OVER SOUTHWEST
KS. NONE OF THE AVAILABLE GUIDANCE SUGGESTS THAT THIS ACTIVITY
WILL SURVIVE FAR ENOUGH EAST TO AFFECT US GIVEN LOSS OF DAYTIME
HEATING. HOWEVER...BOTH THE NAM AND HRRR DEVELOP ACTIVITY...MOST
LIKELY HIGH BASED...WELL AFTER MIDNIGHT OVER SOUTHEAST KS AND
EVENTUALLY DOWN INTO FAR NORTHEAST OK. THIS AGREES WELL WITH GOING
FORECAST.
LACY
&&
.PREV DISCUSSION... /ISSUED 557 PM CDT THU JUL 16 2015/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
FOR THE 0Z TAFS... VFR CONDITIONS WILL PREVAIL AT ALL SITES
THROUGHOUT THE 24 HOUR FORECAST PERIOD. THERE WILL BE A LOW
CHANCE FOR A SHOWER OR THUNDERSTORM TO AFFECT KBVO EARLY FRIDAY
MORNING. HOWEVER... CHANCES ARE TOO LOW TO WARRANT MENTIONING IN
THE TAF.
PREV DISCUSSION... /ISSUED 236 PM CDT THU JUL 16 2015/
DISCUSSION...
HOT/HUMID CONDITIONS THIS AFTERNOON WITH HEAT INDICES AGAIN IN THE
100-105 DEGREE RANGE. THE HEAT WILL CONTINUE TO BE AN ISSUE IN THE
UPCOMING DAYS AS LARGE UPPER HIGH REMAINS IN CONTROL OF OVERALL
WEATHER PATTERN.
IN THE SHORT TERM...WEAK UPPER WAVE WILL MOVE OUT OF CO/AZ
TONIGHT WITH THE POTENTIAL FOR SCATTERED HIGH BASED SHOWERS ACROSS
NORTHEAST OKLAHOMA LATE TONIGHT INTO FRIDAY MORNING IN NOSE OF
LOW LEVEL JET AXIS. ELEVATED INSTABILITY MAY BE SUFFICIENT FOR A
FEW THUNDERSTORMS HOWEVER OVERALL COVERAGE IS EXPECTED TO BE
FAIRLY ISOLATED.
AS MENTIONED EARLIER...HEAT WILL REMAIN THE MAIN CONCERN ESPECIALLY
INTO THE WEEKEND AS AFTERNOON HEAT INDICES CLIMB INTO THE 105-110
DEGREE RANGE WITH THE HIGHEST READINGS EXPECTED ACROSS NORTHEAST
OKLAHOMA. A HEAT ADVISORY WILL LIKELY BE REQUIRED DURING THIS
TIME.
MODELS IN GENERAL AGREEMENT CONCERNING TIMING OF NEXT COLD FRONT
MONDAY NIGHT/TUESDAY IN ASSOCIATION WITH UPPER DISTURBANCE MOVING
OUT OF THE NORTHERN ROCKIES. SHOWER/THUNDERSTORM CHANCES WILL
INCREASE AS FRONT MOVES INTO THE AREA WITH LINGERING PRECIP
CHANCES THROUGH MID WEEK ALONG STALLED BOUNDARY.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 77 96 78 97 / 20 10 10 0
FSM 75 98 76 98 / 10 10 0 10
MLC 76 95 75 95 / 10 10 0 0
BVO 75 94 73 95 / 30 20 10 0
FYV 71 91 69 92 / 10 10 0 10
BYV 72 93 72 94 / 10 10 0 10
MKO 74 95 74 95 / 10 10 10 0
MIO 74 94 76 94 / 10 20 10 0
F10 75 95 76 94 / 10 10 10 0
HHW 73 95 74 95 / 0 10 0 0
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
LONG TERM....30
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
141 AM EDT WED JUL 15 2015
.SYNOPSIS...
A COMPLEX FRONTAL SYSTEM WILL MOVE THROUGH THE AREA OVERNIGHT.
HIGH PRESSURE BUILDING SOUTHEAST FROM THE GREAT LAKES WILL BRING A
DRIER WEATHER PATTERN DURING THE SECOND HALF OF THE WEEK BEFORE
INCREASING HEAT AND HUMIDITY MAKE A RETURN FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MESO ANAL AS OF 9 PM SHOWS A LOW OVER LAKE ERIE WITH A VERY
COMPLEX FRONTAL SYSTEM IN PLACE OVER THE REGION. LOW PRESSURE IS
BEGINNING TO FORM OVER THE SOUTH-CENTRAL MOUNTAINS ALONG WHAT WAS
THE WARM FRONT...AND IT SEEMS TO BE THE FOCUS MECHANISM FOR
CONVECTION THAT CONTINUES TO FIRE EVEN AT THIS HOUR.
THE HRRR KEEPS US ACTIVE THROUGH AT LEAST MIDNIGHT BEFORE
ACTIVITY BEGINS TO WANE AS THE FRONTAL SYSTEM FINALLY STARTS TO
SETTLE OFF TO THE SOUTH AND EAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
AS THE COLD FRONT COMES THROUGH IT SHOULD BRING DRIER AIR AND MOVE
MOST OF THE STORMS TO THE SOUTHEAST. WILL LINGER HIGH CHC POPS
INTO THE MORNING ON WEDNESDAY FOR THE FAR SERN COS...THOUGH.
THE CURRENT LOW TRACK SOUTHWARD...MOVING THE FRONT THROUGH WEST
VIRGINIA. WIDESPREAD SHOWERS AND THUNDERSTORMS REMAIN POSSIBLE
TONIGHT INTO THE EARLY WEDNESDAY. IN THE WAKE OF THE FRONT EXPECT
DRIER CONDITIONS WHICH COULD LEAD TO PATCHY EARLY MORNING FOG.
IMPROVEMENT IS EXPECTED OVER MOST OF THE AREA LATE WED MORNING AND
THROUGH THE AFTERNOON. HIGHS SHOULD RECOVER CLOSE TO 80F IN THE
S...BUT KEEP AT OR BELOW 70F IN THE FAR NW.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
SHOWERS WILL END OVER SOUTHERN/EASTERN AREAS BY 00Z THURSDAY AS
THE COLD FRONT PUSHES SEWD TOWARD THE MID ATLC COAST. BEHIND THE
FRONT...A LARGE AREA OF BELOW NORMAL PW AIR WILL OVERSPREAD THE
NORTHEAST AND MID ATLANTIC STATES FROM WED NGT THROUGH
THURSDAY...ACCOMPANIED BY AN EXPANSIVE AREA OF HIGH PRESSURE
MIGRATING EWD FROM SERN CANADA INTO THE N. ATLC OCEAN...WHICH
WILL ENSURE DRY WX DURING THIS TIME. MUCH OF FRIDAY ALSO LOOKS DRY
WITH A LOW RISK OF A LATE DAY SHOWER/TSTM ACROSS THE FAR WRN/NWRN
ALLEGHENY MTNS. WED/THU NIGHTS WILL BE REFRESHINGLY COOL WITH LOWS
IN THE MID 40S TO LOW 50S AND VALLEY FOG ACROSS THE NRN TIER.
500MB HEIGHTS SHOULD STEADILY REBOUND THROUGH THE WEEKEND WITH
VERY WARM/HOT AND HUMID CONDITIONS FORECAST INTO EARLY NEXT WEEK.
CENTRAL PA IS CURRENTLY NEAR/AT THE HOTTEST TIME OF THE YEAR
/JULY 11-20/ BASED ON THE MOST RECENT 30-YEAR CLIMATE NORMALS.
HEAT INDEX VALUES MAY APPROACH 100F OVER THE LWR SUSQ VALLEY SUN-
MON WITH GUIDANCE SHOWING HIGHS AROUND 90F.
THE UPSTREAM FLOW ALOFT IS FCST TO TREND FROM QUASI-ZONAL ON THE
NRN PERIPHERY OF SRN PLAINS RIDGE...FROM THE MIDWEST THROUGH THE
GREAT LAKES...EVENTUALLY TOWARD MORE OF A WEST-NORTHWEST FLOW WITH
GENERAL TROUGHING LKLY TO CONTINUE OVER THE EASTERN QUARTER OF
NOAM. NRN STREAM S/WVS MOVING INTO THE AREA FROM THE WNW...ALONG
WITH DIURNAL INSTABILITY...MAY BE A FOCUS FOR SHOWERS/TSTMS SAT-
SUN. A BETTER FOCUS FOR PCPN SHOULD EVOLVE INTO THE MON-TUE TIME
FRAME AS A FRONTAL BOUNDARY PUSHES SEWD FROM THE GREAT LAKES.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
A COLD FRONT MOVING SE ACROSS THE REGION WILL BRING NUMEROUS SHRA
AND TSRA TO THE AREA OVERNIGHT...MAINLY FROM KUNV SOUTH AND
EASTWARD. HEAVIEST ACTIVITY CURRENTLY ALONG AND TO THE EAST OF THE
SUSQUEHANNA RIVER WITH CONVECTION MOVING NORTHEAST FROM EASTERN
MARYLAND TOWARD KLNS.
AS THE COLD FRONT MOVES EAST OF THE AREA...FOCUS LATE TONIGHT
WILL SHIFT TOWARD THE LIKELIHOOD OF LOW CIGS ACROSS THE W MTNS.
RESIDUAL LOW LVL MOISTURE ASCENDING THE ALLEGHENY MTNS WILL LIKELY
RESULT IN IFR CIGS AT KBFD AND KJST LATE TONIGHT. A LIGHT
DOWNSLOPING NW FLOW SHOULD YIELD MORE FAVORABLE CONDS FURTHER
EAST...WITH MVFR CIGS/VSBYS LIKELY LATE TONIGHT ACROSS MOST
CENTRAL PA AIRFIELDS.
LOW CIGS COULD LINGER UNTIL ARND MIDDAY WED ARND KJST. OTHERWISE...EXPECT
IMPROVING FLYING CONDS...AS NORTHERLY FLOW DRAWS DRIER AIR INTO
THE REGION. WIDESPREAD VFR CONDS EXPECTED EVERYWHERE WED AFTN.
OUTLOOK...
THU...NO SIG WX EXPECTED.
FRI...ISOLD PM TSRA IMPACTS POSS W MTNS.
SAT-SUN...SCT PM TSRA IMPACTS POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...DANGELO/CERU
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/TYBURSKI
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
247 PM EDT WED JUL 15 2015
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL DRY OUT THE REGION AS AN UPPER LEVEL
RIDGE BUILDS IN FROM THE WEST...BRINGING WITH IT A RETURN TO ABOVE
NORMAL TEMPERATURES THROUGH LATE THIS WEEK. BETTER COVERAGE OF
AFTERNOON SHOWERS AND THUNDERSTORMS WILL RETURN OVER THE
WEEKEND...WITH ANOTHER FRONT EXPECTED EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
AT 1230 PM...CU FIELD A BIT MORE EXTENSIVE THAN PREVIOUS GRIDS.
ESPECIALLY OVER THE PIEDMONT. HENCE...HAVE INCREASED SKY COVER
WITH THIS UPDATE. THIS ALSO IS SLOWING THE TEMP INCREASE...SO
BACKED OFF ON MAX TEMPS BY A COUPLE DEGREES.
AT 1015 AM EDT...NO BIG CHANGES TO THE GOING FORECAST FOR TODAY.
TROUGH/WEAK FRONT ANALYZED FROM CENTRAL NC THROUGH THE UPSTATE INTO
NE GA AT 14Z. 12Z NAM SETTLES THE BOUNDARY SLOWLY SOUTHWARD INTO THE
SC MIDLANDS BY LATE AFTERNOON. THE NAM AND HRRR SHOW ISOLATED
CONVECTION FIRING OVER THE SOUTHERN UPSTATE EARLY THIS AFTERNOON SO
WILL CONTINUE THE ISOLATED POPS THERE. ALSO...THE MODELS SHOW
ISOLATED UPSLOPE SHOWERS ALONG THE TN LINE SO ISOALTED POPS LOOK
GOOD THERE. UPDATED TEMPS/DEWPOINTS WITH LATEST CONSHORT DATA WHICH
BUMPED MAX TEMPS UPWARD A DEGREE OR SO.
630 AM UPDATE...NO MAJOR CHANGES MADE TO THE GRIDS. POPS WERE
TEMPERED DOWN SRN ZONES AS LAST OF VORT PRECIP PUSHES SOUTH. TEMPS
AND TD/S REQUIRED ONLY MINOR TWEAKS WITH SFC WINDS PROVIDING MODEST
MIXING.
AS OF 255 AM EDT WEDNESDAY...AN UPPER LEVEL TROF WILL CONTINUE TO
SWING EAST THROUGH THE DAY WITH THE AXIS PASSING EAST OF THE CWFA BY
16Z/17Z. HEIGHTS WILL BEGIN TO RISE FAIRLY QUICKLY THROUGH THE
AFTERNOON WITH A STRONG H5 HIGH OVER TX NUDGING EAST. LOW LEVEL
MOISTURE SOURCES WILL BE LIMITED...WITH THE BEST POOLING ACROSS THE
MTN SPINE AIDED BY MECH LIFT AND SOME LINGERING MOISTURE SOUTH ALONG
A WEAKENING THETA/E BNDRY FROM CURRENT PRECIP SHIELD ADVANCING
SOUTH. THERE SHOULD BE ENUF LIFT ACROSS THE FAR WRN MTNS FOR
ISOL/SCT -SHRA AND PERHAPS A COUPLE TSTMS. THE SAME GOES FOR THE SRN
ZONES WHERE H5 VORT ENERGY WILL INTERACT WITH THE BNDRY AND PRODUCE
SHORT-LIVED WEAK CONVECTION BEFORE A SUBS INVERSION LIMITS CLOUDS
TO FAIR WX CU MOST LOCALES. WITH DEEP NW/LY FLOW...GOOD MIXING AND
DOWNSLOPE HEATING WILL LOWER SFC TD/S THROUGH THE AFTERNOON.
THUS...THE DAY WILL FEEL A LITTLE DRIER THAN THE PAST FEW DAYS WITH
LOW END GUSTS DEVELOPING BY MID AFTERNOON. THE OVERNIGHT WILL REMAIN
DRY AS THE MLVL FLOW MAINTAINS A N/LY SUBS PATTERN. AT THE SFC... A
RELATIVELY TIGHT PGRAD WILL SLOWLY WEAKEN AS A TROF AXIS SHIFTS
TOWARD THE COAST. SO...WITH SOME WIND AND WEAK SFC-BASED
INVERSIONS...LOWS WILL BE HELD NEAR SEASONAL LEVELS.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 230 PM EDT WEDNESDAY...THE SHORT TERM FCST PERIOD INITIALIZES
THURSDAY EVENING WITH A BROAD/ELONGATED UPPER ANTICYCLONE BUILDING
OVER THE DEEP SOUTH...WHILE A WEAK UPPER WAVE DIGS ACROSS THE UPPER
MIDWEST. AT THE SURFACE...EXPANSIVE SURFACE RIDING WILL PREVAIL
OVER THE NORTHEAST WITH A SUMMERTIME WEDGE LIKE PATTERN DOMINATES
ACROSS THE SOUTHERN/CENTRAL APPS. MODELS FAVOR EAST/NORTHEAST FLOW
AROUND SAID SURFACE HIGH WHICH COULD POTENTIALLY AID WEAK UPSLOPE
INDUCED SHOWERS ALONG THE NC HIGH TERRAIN...WHICH COULD BE ONGOING
AT FCST INITIALIZATION. FROM THAT POINT THE PATTERN WILL EVOLVE AS
THE SFC RIDGE SLOWLY EJECTS OUT TO SEA AND THE WEAK SUMMERTIME WEDGE
RETREATS INTO FRIDAY MORNING. MEANWHILE...THE UPPER ANTICYCLONE
WILL ADVECT EAST SETTING UP OVER THE MIDSOUTH THROUGH THE REMAINDER
OF THE SHORT TERM ALLOWING FLOW ALOFT TO VEER NORTHWESTERLY AND THUS
LOWERING H5 TEMPS. SOUNDINGS FAVOR SUCH AS MID/UPPER CIN DECREASES
ON FRIDAY...AND FURTHER ON SATURDAY. THE SFC PATTERN ON FRIDAY WILL
FEATURE GRADUALLY VEERING WINDS YIELDING A WEAK WAA REGIME AND THUS
INCREASED DIURNAL SHRA/TSRA CHANCES...ESPECIALLY ALONG THE HIGH
TERRAIN. IN ADDITION...AN OLD FRONTAL AXIS DRAPED ALONG THE GULF
COAST WILL PROVIDE FOCUS FOR A WEAK SFC WAVE TO DEVELOP...WHICH
COULD ENHANCE ANY EASTERLY MOISTURE ADVECTION OFF THE ATLANTIC INTO
NORTHEAST GA AND THE WESTERN CAROLINAS. ALL IN ALL...EXPECTING
CONVECTIVE INITIATION WITH HEATING ALONG THE BLUE RIDGE ON FRIDAY
EVENING LIKELY ENHANCED BY WEAK UPSLOPING. AS FOR THE LOW
TERRAIN...MODELS DO NOT FAVOR ANYTHING MORE THAN ISOLATED
CONVECTION...WHICH IS IN SOME CONTRAST WITH SOUNDING PROFILES WHICH
INDICATE EROSION OF ANY CIN BY MID/LATE AFTERNOON. EXPECTING MUCH
OF THE SAME ON SATURDAY ALBEIT WITH SLIGHT HIGHER PRECIP CONFIDENCE
AS ANY UPPER CIN IS WEAKENED FURTHER...AND LOW LEVEL MOISTURE FLUX
CONTINUES YIELDING DEWPOINTS IN THE MID/UPPER 60S AND THUS ABUNDANT
INSTABILITY.
AS FOR FCST...POPS WILL GRADUALLY INCREASE THROUGH THE PERIOD AS
PROFILES BECOME MORE FAVORABLE FOR CONVECTION EACH DAY.
THUS...CHANCE POPS ARE FEATURED OVER THE NC HIGH TERRAIN ON FRIDAY
AFTERNOON TAPERING TO SLIGHT CHANCE ACROSS THE NC/SC PIEDMONT AND
PORTIONS OF NORTHEAST GA. POPS WILL DECREASE WITH HEATING LOSS INTO
SATURDAY MORNING BEFORE INCREASING DIURNALLY TO SOLID CHANCE LEVELS
REGIONWIDE...WITH THE HIGHEST POPS STILL FOCUSED ALONG THE BLUE
RIDGE. NOT EXPECTING ANY HAZARDOUS WEATHER EITHER DAY...HOWEVER
PROFILES PRESENT THE POSSIBILITY OF MORE ORGANIZED/DEEPER
CONVECTION ON SATURDAY...THUS A FEW STRONGER THUNDERSTORMS CANNOT BE
RULED OUT. TEMPERATURES WILL GRADUALLY MODERATE THROUGH THE PERIOD
WITH NEAR NORMAL LEVELS FCST ON FRIDAY...AND SLIGHTLY ABOVE NORMAL
FOR SATURDAY REGIONWIDE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 230 PM WEDNESDAY...THE MEDIUM RANGE PICKS UP AT 00Z SUNDAY
WITH THE H5 RIDGE OVER THE SOUTHERN CONUS CONTINUING TO RETROGRESS
TOWARDS THE SOUTHERN PLAINS. THOUGH THE FORECAST AREA WILL REMAIN ON
THE PERIPHERY OF THE UPPER HIGH...SLIGHT OVERALL HEIGHT FALLS ARE
EXPECTED THROUGH THE END OF THE WEEKEND AND EARLY NEXT WEEK. NO
PRONOUNCED LARGE SCALE FORCING MECHANISMS APPEAR TO BE PRESENT
THROUGH THE EARLY MEDIUM RANGE...THOUGH A LACK OF SUPPRESSION PLUS
SUFFICIENT MOISTURE WILL ALLOW A NORMAL PATTERN OF DIURNAL SHOWERS
AND THUNDERSTORMS TO DEVELOP. GUIDANCE DIVERGES SIGNIFICANTLY ON
MONDAY...WITH THE ECMWF CARRYING A MUCH FASTER AND DEEPER SHORTWAVE
AND ASSOCIATED COLD FRONT ACROSS THE SOUTHERN APPALACHIANS THAN THE
STUBBORNLY SLOWER GFS. THE SHORTWAVE TROUGH IS ALSO NOT AS AMPLIFIED
IN THE GFS SOLUTION...AND THE GFS BOUNDARY IS ALLOWED TO STALL OUT
ACROSS THE AREA WEDNESDAY AND INTO THURSDAY...WHILE THE ECMWF
FEATURES A CLEAN FRONTAL PASSAGE FOR THE AREA BY TUESDAY NIGHT.
REGARDLESS OF THE TIMING OF THE FRONTAL BOUNDARY...QPF RESPONSE FOR
BOTH MODELS INCREASES MONDAY AFTERNOON AND TUESDAY. WEDNESDAY AND
THURSDAY PRESENT MORE OF A CHALLENGE WITH PRONOUNCED DIFFERENCES IN
LOW LEVEL MOISTURE...AND BECAUSE NO SOLUTION CURRENTLY STANDS
OUT...THE CURRENT FORECAST FEATURING DIURNAL POPS NEAR CLIMO WAS
LEFT INTACT.
MAX TEMPS WILL REMAIN ABOVE AVERAGE...WITH A PEAK ON MONDAY BEFORE
THE FRONT APPROACHES. SOME COOLING IS EXPECTED AFTER THE FRONTAL
PASSAGE ON TUESDAY.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...BKN-SCT CU AROUND 060FT THIS AFTERNOON...THEN SCT
HIGH CLOUDS OVERNIGHT. MORE SCT-BKN CU ON THU. HOWEVER...VFR CONDS
THROUGH THE TAF PERIOD. NW WINDS DIMINISH AND WILL GRADUALLY VEER TO
THE NE OVERNIGHT.
ELSEWHERE...SCT-BKN HIGH BASED CU THIS AFTERNOON...SCATTERING OUT
TONIGHT. VFR THROUGH THE PERIOD. THE EXCEPTION WILL BE AT AVL WHERE
EARLY MORNING FOG MAY REDUCE VSBYS TO MVFR.
OUTLOOK...BUILDING UPPER RIDGE WILL PERSIST THROUGH THE END OF THE
WEEK LEADING TO LOWER PRECIP/RESTRICTION CHANCES OUTSIDE THE
MOUNTAINS. THESE CHANCES WILL INCREASE OVER THE WEEKEND AS THE RIDGE
RETROGRADES LEADING TO INCREASING DIURNAL SHRA/TSRA CHANCES AND THUS
MORNING FOG/STRATUS AS WELL.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 91% HIGH 93%
KHKY HIGH 100% HIGH 100% HIGH 100% MED 79%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.FIRE WEATHER...
RH VALUES ACROSS THE REGION WILL CONTINUE TO HOVER IN THE LOWER/MID
20S WITH A FEW SITES REPORTING IN WITH VALUES IN THE TEENS.
FORTUNATELY...WINDS REMAIN LIGHT WITH NO INCREASES IN FLOW EXPECTED.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...LEV
NEAR TERM...LG
SHORT TERM...CDG
LONG TERM...LEV
AVIATION...LG
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
143 PM EDT WED JUL 15 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA TODAY. FOLLOWING THE
FRONT...SURFACE HIGH PRESSURE WILL DRY OUT THE REGION AS AN UPPER
LEVEL RIDGE BUILDS IN FROM THE WEST...BRINGING WITH IT A RETURN
TO ABOVE NORMAL TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 1230 PM...CU FIELD A BIT MORE EXTENSIVE THAN PREVIOUS GRIDS.
ESPECIALLY OVER THE PIEDMONT. HENCE...HAVE INCREASED SKY COVER
WITH THIS UPDATE. THIS ALSO IS SLOWING THE TEMP INCREASE...SO
BACKED OFF ON MAX TEMPS BY A COUPLE DEGREES.
AT 1015 AM EDT...NO BIG CHANGES TO THE GOING FORECAST FOR TODAY.
TROUGH/WEAK FRONT ANALYZED FROM CENTRAL NC THROUGH THE UPSTATE INTO
NE GA AT 14Z. 12Z NAM SETTLES THE BOUNDARY SLOWLY SOUTHWARD INTO THE
SC MIDLANDS BY LATE AFTERNOON. THE NAM AND HRRR SHOW ISOLATED
CONVECTION FIRING OVER THE SOUTHERN UPSTATE EARLY THIS AFTERNOON SO
WILL CONTINUE THE ISOLATED POPS THERE. ALSO...THE MODELS SHOW
ISOLATED UPSLOPE SHOWERS ALONG THE TN LINE SO ISOALTED POPS LOOK
GOOD THERE. UPDATED TEMPS/DEWPOINTS WITH LATEST CONSHORT DATA WHICH
BUMPED MAX TEMPS UPWARD A DEGREE OR SO.
630 AM UPDATE...NO MAJOR CHANGES MADE TO THE GRIDS. POPS WERE
TEMPERED DOWN SRN ZONES AS LAST OF VORT PRECIP PUSHES SOUTH. TEMPS
AND TD/S REQUIRED ONLY MINOR TWEAKS WITH SFC WINDS PROVIDING MODEST
MIXING.
AS OF 255 AM EDT WEDNESDAY...AN UPPER LEVEL TROF WILL CONTINUE TO
SWING EAST THROUGH THE DAY WITH THE AXIS PASSING EAST OF THE CWFA BY
16Z/17Z. HEIGHTS WILL BEGIN TO RISE FAIRLY QUICKLY THROUGH THE
AFTERNOON WITH A STRONG H5 HIGH OVER TX NUDGING EAST. LOW LEVEL
MOISTURE SOURCES WILL BE LIMITED...WITH THE BEST POOLING ACROSS THE
MTN SPINE AIDED BY MECH LIFT AND SOME LINGERING MOISTURE SOUTH ALONG
A WEAKENING THETA/E BNDRY FROM CURRENT PRECIP SHIELD ADVANCING
SOUTH. THERE SHOULD BE ENUF LIFT ACROSS THE FAR WRN MTNS FOR
ISOL/SCT -SHRA AND PERHAPS A COUPLE TSTMS. THE SAME GOES FOR THE SRN
ZONES WHERE H5 VORT ENERGY WILL INTERACT WITH THE BNDRY AND PRODUCE
SHORT-LIVED WEAK CONVECTION BEFORE A SUBS INVERSION LIMITS CLOUDS
TO FAIR WX CU MOST LOCALES. WITH DEEP NW/LY FLOW...GOOD MIXING AND
DOWNSLOPE HEATING WILL LOWER SFC TD/S THROUGH THE AFTERNOON.
THUS...THE DAY WILL FEEL A LITTLE DRIER THAN THE PAST FEW DAYS WITH
LOW END GUSTS DEVELOPING BY MID AFTERNOON. THE OVERNIGHT WILL REMAIN
DRY AS THE MLVL FLOW MAINTAINS A N/LY SUBS PATTERN. AT THE SFC... A
RELATIVELY TIGHT PGRAD WILL SLOWLY WEAKEN AS A TROF AXIS SHIFTS
TOWARD THE COAST. SO...WITH SOME WIND AND WEAK SFC-BASED
INVERSIONS...LOWS WILL BE HELD NEAR SEASONAL LEVELS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 AM WEDNESDAY...THE 00Z MODEL RUNS SHOW A TREND TOWARD MORE
CONVECTIVE COVERAGE FOR LATE IN THE WEEK...IN SPITE OF THE RETURN OF
THE UPPER RIDGE FROM THE WEST AND THE LACK OF LARGE SCALE FORCING.
THAT BEING SAID...ON THURSDAY AFTERNOON THERE DOES NOT APPEAR TO BE
ANYTHING IN THE MODEL GUIDANCE TO DISCOURAGE DEEP CONVECTION EITHER.
AND...ON A TYPICAL DAY IN THE SUMMERTIME...IT IS DIFFICULT TO KEEP
CONVECTION FROM DEVELOPING ON THE RIDGETOPS GIVEN SUFFICIENT
MOISTURE AND NOTHING THAT ACTS TO PREVENT IT. WILL FOLLOW THE NEW
NAM AND PUT A SMALL PRECIP CHANCE MAINLY OVER THE HIGHEST ELEVATIONS
FOR THE AFTERNOON...AND THEN GET RID OF IT WITH LOSS OF HEATING
THURSDAY EVENING. ON FRIDAY...THE UPPER PATTERN DOES NOT CHANGE
APPRECIABLY WITH THE ANTICYCLONE CENTERED OVER ERN TX/LA...BUT THE
SFC HIGH TO THE NE SEEMS A BIT STRONGER. THE MODELS DEVELOP A WEAK
E/SE FLOW IN THE BOUNDARY LAYER WHICH ADVECTS MOISTURE INTO THE
REGION. THE RESULT IS MORE PRECIP DEVELOPMENT IN THE MODEL. AGAIN...
GIVEN NOTHING TO DISCOURAGE THIS...I EXPECT THERE WILL BE A BIT MORE
COVERAGE THAN PREVIOUSLY EXPECTED...SO PRECIP CHANCES WERE NUDGED
UPWARD A BIT WHICH BRINGS THE PROBABILITY INTO THE CHC RANGE NEAR
THE BLUE RIDGE IN THE AFTERNOON. THE CHANCES FOR ANYTHING BEYOND
GARDEN VARIETY THUNDERSTORMS APPEARS VERY LOW. TEMPS BOTTOM OUT NEAR
NORMAL ON THURSDAY AND THEN BEGIN A CLIMB BACK ABOVE NORMAL STARTING
ON FRIDAY.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 315 AM WEDNESDAY...STILL NO BIG SURPRISES NOTED IN THE LATEST
MEDIUM RANGE GUIDANCE. THE SLOW WESTWARD DRIFT OF THE UPPER
ANTICYCLONE BACK TOWARD THE SRN PLAINS WILL KEEP THE WESTERN
CAROLINAS ON ITS PERIPHERY...AND THUS AWAY FROM ITS SUPPRESSIVE
AFFECTS. THAT SHOULD ALLOW FOR MAINLY DIURNAL SHOWERS AND
THUNDERSTORMS TO DEVELOP EACH DAY GIVEN SUFFICIENT LOW LEVEL
MOISTURE. TEMPS ABOVE NORMAL LOOK LIKE A GOOD BET...BUILDING EACH
DAY TO A PEAK MOST LIKELY ON MONDAY. THE ECMWF SOLUTION SUGGESTS
THAT A SHORT WAVE PASSING TO THE NORTH ON TUESDAY WILL BRING A
WEAKENING COLD FRONT DOWN ACROSS THE AREA THAT WOULD ENHANCE PRECIP
CHANCES AND DROP TEMPS BACK DOWN A BIT. HOWEVER...THE GFS SHOWS THE
UPPER WAVE MUCH FARTHER N AND KEEPS ANY BOUNDARY WELL TO OUR N. WILL
NOT MAKE ANY SIGNIFICANT CHANGES TO THE MEDIUM RANGE AT THIS TIME...
AND THINK EVEN WITHOUT THE FRONT THE COVERAGE OF STORMS WILL
INCREASE A BIT EACH DAY ANYWAY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...BKN-SCT CU AROUND 060FT THIS AFTERNOON...THEN SCT
HIGH CLOUDS OVERNIGHT. MORE SCT-BKN CU ON THU. HOWEVER...VFR CONDS
THROUGH THE TAF PERIOD. NW WINDS DIMINISH AND WILL GRADUALLY VEER TO
THE NE OVERNIGHT.
ELSEWHERE...SCT-BKN HIGH BASED CU THIS AFTERNOON...SCATTERING OUT
TONIGHT. VFR THROUGH THE PERIOD. THE EXCEPTION WILL BE AT AVL WHERE
EARLY MORNING FOG MAY REDUCE VSBYS TO MVFR.
OUTLOOK...BUILDING UPPER RIDGE WILL PERSIST THROUGH THE END OF THE
WEEK LEADING TO LOWER PRECIP/RESTRICTION CHANCES OUTSIDE THE
MOUNTAINS. THESE CHANCES WILL INCREASE OVER THE WEEKEND AS THE RIDGE
RETROGRADES LEADING TO INCREASING DIURNAL SHRA/TSRA CHANCES AND THUS
MORNING FOG/STRATUS AS WELL.
CONFIDENCE TABLE...
17-23Z 23-05Z 05-11Z 11-12Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 91%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...LG
SHORT TERM...PM
LONG TERM...PM
AVIATION...LG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1229 PM EDT WED JUL 15 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA TODAY. FOLLOWING THE
FRONT...SURFACE HIGH PRESSURE WILL DRY OUT THE REGION AS AN UPPER
LEVEL RIDGE BUILDS IN FROM THE WEST...BRINGING WITH IT A RETURN
TO ABOVE NORMAL TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 1230 PM...CU FIELD A BIT MORE EXTENSIVE THAN PREVIOUS GRIDS.
ESPECIALLY OVER THE PIEDMONT. HENCE...HAVE INCREASED SKY COVER
WITH THIS UPDATE. THIS ALSO IS SLOWING THE TEMP INCREASE...SO
BACKED OFF ON MAX TEMPS BY A COUPLE DEGREES.
AT 1015 AM EDT...NO BIG CHANGES TO THE GOING FORECAST FOR TODAY.
TROUGH/WEAK FRONT ANALYZED FROM CENTRAL NC THROUGH THE UPSTATE INTO
NE GA AT 14Z. 12Z NAM SETTLES THE BOUNDARY SLOWLY SOUTHWARD INTO THE
SC MIDLANDS BY LATE AFTERNOON. THE NAM AND HRRR SHOW ISOLATED
CONVECTION FIRING OVER THE SOUTHERN UPSTATE EARLY THIS AFTERNOON SO
WILL CONTINUE THE ISOLATED POPS THERE. ALSO...THE MODELS SHOW
ISOLATED UPSLOPE SHOWERS ALONG THE TN LINE SO ISOALTED POPS LOOK
GOOD THERE. UPDATED TEMPS/DEWPOINTS WITH LATEST CONSHORT DATA WHICH
BUMPED MAX TEMPS UPWARD A DEGREE OR SO.
630 AM UPDATE...NO MAJOR CHANGES MADE TO THE GRIDS. POPS WERE
TEMPERED DOWN SRN ZONES AS LAST OF VORT PRECIP PUSHES SOUTH. TEMPS
AND TD/S REQUIRED ONLY MINOR TWEAKS WITH SFC WINDS PROVIDING MODEST
MIXING.
AS OF 255 AM EDT WEDNESDAY...AN UPPER LEVEL TROF WILL CONTINUE TO
SWING EAST THROUGH THE DAY WITH THE AXIS PASSING EAST OF THE CWFA BY
16Z/17Z. HEIGHTS WILL BEGIN TO RISE FAIRLY QUICKLY THROUGH THE
AFTERNOON WITH A STRONG H5 HIGH OVER TX NUDGING EAST. LOW LEVEL
MOISTURE SOURCES WILL BE LIMITED...WITH THE BEST POOLING ACROSS THE
MTN SPINE AIDED BY MECH LIFT AND SOME LINGERING MOISTURE SOUTH ALONG
A WEAKENING THETA/E BNDRY FROM CURRENT PRECIP SHIELD ADVANCING
SOUTH. THERE SHOULD BE ENUF LIFT ACROSS THE FAR WRN MTNS FOR
ISOL/SCT -SHRA AND PERHAPS A COUPLE TSTMS. THE SAME GOES FOR THE SRN
ZONES WHERE H5 VORT ENERGY WILL INTERACT WITH THE BNDRY AND PRODUCE
SHORT-LIVED WEAK CONVECTION BEFORE A SUBS INVERSION LIMITS CLOUDS
TO FAIR WX CU MOST LOCALES. WITH DEEP NW/LY FLOW...GOOD MIXING AND
DOWNSLOPE HEATING WILL LOWER SFC TD/S THROUGH THE AFTERNOON.
THUS...THE DAY WILL FEEL A LITTLE DRIER THAN THE PAST FEW DAYS WITH
LOW END GUSTS DEVELOPING BY MID AFTERNOON. THE OVERNIGHT WILL REMAIN
DRY AS THE MLVL FLOW MAINTAINS A N/LY SUBS PATTERN. AT THE SFC... A
RELATIVELY TIGHT PGRAD WILL SLOWLY WEAKEN AS A TROF AXIS SHIFTS
TOWARD THE COAST. SO...WITH SOME WIND AND WEAK SFC-BASED
INVERSIONS...LOWS WILL BE HELD NEAR SEASONAL LEVELS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 AM WEDNESDAY...THE 00Z MODEL RUNS SHOW A TREND TOWARD MORE
CONVECTIVE COVERAGE FOR LATE IN THE WEEK...IN SPITE OF THE RETURN OF
THE UPPER RIDGE FROM THE WEST AND THE LACK OF LARGE SCALE FORCING.
THAT BEING SAID...ON THURSDAY AFTERNOON THERE DOES NOT APPEAR TO BE
ANYTHING IN THE MODEL GUIDANCE TO DISCOURAGE DEEP CONVECTION EITHER.
AND...ON A TYPICAL DAY IN THE SUMMERTIME...IT IS DIFFICULT TO KEEP
CONVECTION FROM DEVELOPING ON THE RIDGETOPS GIVEN SUFFICIENT
MOISTURE AND NOTHING THAT ACTS TO PREVENT IT. WILL FOLLOW THE NEW
NAM AND PUT A SMALL PRECIP CHANCE MAINLY OVER THE HIGHEST ELEVATIONS
FOR THE AFTERNOON...AND THEN GET RID OF IT WITH LOSS OF HEATING
THURSDAY EVENING. ON FRIDAY...THE UPPER PATTERN DOES NOT CHANGE
APPRECIABLY WITH THE ANTICYCLONE CENTERED OVER ERN TX/LA...BUT THE
SFC HIGH TO THE NE SEEMS A BIT STRONGER. THE MODELS DEVELOP A WEAK
E/SE FLOW IN THE BOUNDARY LAYER WHICH ADVECTS MOISTURE INTO THE
REGION. THE RESULT IS MORE PRECIP DEVELOPMENT IN THE MODEL. AGAIN...
GIVEN NOTHING TO DISCOURAGE THIS...I EXPECT THERE WILL BE A BIT MORE
COVERAGE THAN PREVIOUSLY EXPECTED...SO PRECIP CHANCES WERE NUDGED
UPWARD A BIT WHICH BRINGS THE PROBABILITY INTO THE CHC RANGE NEAR
THE BLUE RIDGE IN THE AFTERNOON. THE CHANCES FOR ANYTHING BEYOND
GARDEN VARIETY THUNDERSTORMS APPEARS VERY LOW. TEMPS BOTTOM OUT NEAR
NORMAL ON THURSDAY AND THEN BEGIN A CLIMB BACK ABOVE NORMAL STARTING
ON FRIDAY.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 315 AM WEDNESDAY...STILL NO BIG SURPRISES NOTED IN THE LATEST
MEDIUM RANGE GUIDANCE. THE SLOW WESTWARD DRIFT OF THE UPPER
ANTICYCLONE BACK TOWARD THE SRN PLAINS WILL KEEP THE WESTERN
CAROLINAS ON ITS PERIPHERY...AND THUS AWAY FROM ITS SUPPRESSIVE
AFFECTS. THAT SHOULD ALLOW FOR MAINLY DIURNAL SHOWERS AND
THUNDERSTORMS TO DEVELOP EACH DAY GIVEN SUFFICIENT LOW LEVEL
MOISTURE. TEMPS ABOVE NORMAL LOOK LIKE A GOOD BET...BUILDING EACH
DAY TO A PEAK MOST LIKELY ON MONDAY. THE ECMWF SOLUTION SUGGESTS
THAT A SHORT WAVE PASSING TO THE NORTH ON TUESDAY WILL BRING A
WEAKENING COLD FRONT DOWN ACROSS THE AREA THAT WOULD ENHANCE PRECIP
CHANCES AND DROP TEMPS BACK DOWN A BIT. HOWEVER...THE GFS SHOWS THE
UPPER WAVE MUCH FARTHER N AND KEEPS ANY BOUNDARY WELL TO OUR N. WILL
NOT MAKE ANY SIGNIFICANT CHANGES TO THE MEDIUM RANGE AT THIS TIME...
AND THINK EVEN WITHOUT THE FRONT THE COVERAGE OF STORMS WILL
INCREASE A BIT EACH DAY ANYWAY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...VFR CONDS THROUGH THE TAF PERIOD. THE UPPER TROF AXIS WILL
CROSS EAST OF THE TERMINAL AFT 16Z AND SUPPRESSIVE DYNAMICS WILL
ALLOW ONLY FAIR WX CU THROUGH THE AFTERNOON. NO CIG/VSBY CONCERNS
OVERNIGHT AS WINDS REMAIN UP DUE TO A RELATIVELY TIGHT PGRAD. WINDS
WILL BECOME ALIGNED NW/LY WITH LOW END GUSTS ARND NOON AND THEN N/LY
ARND 00Z AS BROAD SFC TROF PUSHES SOUTHEAST.
ELSEWHERE...VERY SIMILAR TAFS TO KCLT WITH KAVL HAVING THE BEST
POTENTIAL FOR LATE PERIOD VSBY CONCERNS. OTHERWISE...FAIR WX CU WILL
DEVELOP THIS AFTERNOON WITH LOW END GUSTS. GENERALLY A NW/LY DIR ALL
SITES WITH WINDS PERSISTING OVERNIGHT IN A RELATIVELY TIGHT PGRAD.
OUTLOOK...BUILDING UPPER RIDGING WILL PERSIST THROUGH WEEKS END
LEADING TO LOWER PRECIP/RESTRICTION CHANCES. THESE CHANCES WILL
INCREASE OVER THE WEEKEND AS SAID RIDGE RETROGRADES LEADING TO
INCREASING DIURNAL SHRA/TSRA CHANCES AND THUS MORNING FOG/STRATUS AS
WELL.
CONFIDENCE TABLE...
16-22Z 22-04Z 04-10Z 10-12Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 81% HIGH 100% HIGH 100% HIGH 86%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...LG
SHORT TERM...PM
LONG TERM...PM
AVIATION...SBK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1021 AM EDT WED JUL 15 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA TODAY. FOLLOWING THE
FRONT...SURFACE HIGH PRESSURE WILL DRY OUT THE REGION AS AN UPPER
LEVEL RIDGE BUILDS IN FROM THE WEST...BRINGING WITH IT A RETURN
TO ABOVE NORMAL TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 1015 AM EDT...NO BIG CHANGES TO THE GOING FORECAST FOR TODAY.
TROUGH/WEAK FRONT ANALYZED FROM CENTRAL NC THROUGH THE UPSTATE INTO
NE GA AT 14Z. 12Z NAM SETTLES THE BOUNDARY SLOWLY SOUTHWARD INTO THE
SC MIDLANDS BY LATE AFTERNOON. THE NAM AND HRRR SHOW ISOLATED
CONVECTION FIRING OVER THE SOUTHERN UPSTATE EARLY THIS AFTERNOON SO
WILL CONTINUE THE ISOLATED POPS THERE. ALSO...THE MODELS SHOW
ISOLATED UPSLOPE SHOWERS ALONG THE TN LINE SO ISOALTED POPS LOOK
GOOD THERE. UPDATED TEMPS/DEWPOINTS WITH LATEST CONSHORT DATA WHICH
BUMPED MAX TEMPS UPWARD A DEGREE OR SO.
630 AM UPDATE...NO MAJOR CHANGES MADE TO THE GRIDS. POPS WERE
TEMPERED DOWN SRN ZONES AS LAST OF VORT PRECIP PUSHES SOUTH. TEMPS
AND TD/S REQUIRED ONLY MINOR TWEAKS WITH SFC WINDS PROVIDING MODEST
MIXING.
AS OF 255 AM EDT WEDNESDAY...AN UPPER LEVEL TROF WILL CONTINUE TO
SWING EAST THROUGH THE DAY WITH THE AXIS PASSING EAST OF THE CWFA BY
16Z/17Z. HEIGHTS WILL BEGIN TO RISE FAIRLY QUICKLY THROUGH THE
AFTERNOON WITH A STRONG H5 HIGH OVER TX NUDGING EAST. LOW LEVEL
MOISTURE SOURCES WILL BE LIMITED...WITH THE BEST POOLING ACROSS THE
MTN SPINE AIDED BY MECH LIFT AND SOME LINGERING MOISTURE SOUTH ALONG
A WEAKENING THETA/E BNDRY FROM CURRENT PRECIP SHIELD ADVANCING
SOUTH. THERE SHOULD BE ENUF LIFT ACROSS THE FAR WRN MTNS FOR
ISOL/SCT -SHRA AND PERHAPS A COUPLE TSTMS. THE SAME GOES FOR THE SRN
ZONES WHERE H5 VORT ENERGY WILL INTERACT WITH THE BNDRY AND PRODUCE
SHORT-LIVED WEAK CONVECTION BEFORE A SUBS INVERSION LIMITS CLOUDS
TO FAIR WX CU MOST LOCALES. WITH DEEP NW/LY FLOW...GOOD MIXING AND
DOWNSLOPE HEATING WILL LOWER SFC TD/S THROUGH THE AFTERNOON.
THUS...THE DAY WILL FEEL A LITTLE DRIER THAN THE PAST FEW DAYS WITH
LOW END GUSTS DEVELOPING BY MID AFTERNOON. THE OVERNIGHT WILL REMAIN
DRY AS THE MLVL FLOW MAINTAINS A N/LY SUBS PATTERN. AT THE SFC... A
RELATIVELY TIGHT PGRAD WILL SLOWLY WEAKEN AS A TROF AXIS SHIFTS
TOWARD THE COAST. SO...WITH SOME WIND AND WEAK SFC-BASED
INVERSIONS...LOWS WILL BE HELD NEAR SEASONAL LEVELS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 AM WEDNESDAY...THE 00Z MODEL RUNS SHOW A TREND TOWARD MORE
CONVECTIVE COVERAGE FOR LATE IN THE WEEK...IN SPITE OF THE RETURN OF
THE UPPER RIDGE FROM THE WEST AND THE LACK OF LARGE SCALE FORCING.
THAT BEING SAID...ON THURSDAY AFTERNOON THERE DOES NOT APPEAR TO BE
ANYTHING IN THE MODEL GUIDANCE TO DISCOURAGE DEEP CONVECTION EITHER.
AND...ON A TYPICAL DAY IN THE SUMMERTIME...IT IS DIFFICULT TO KEEP
CONVECTION FROM DEVELOPING ON THE RIDGETOPS GIVEN SUFFICIENT
MOISTURE AND NOTHING THAT ACTS TO PREVENT IT. WILL FOLLOW THE NEW
NAM AND PUT A SMALL PRECIP CHANCE MAINLY OVER THE HIGHEST ELEVATIONS
FOR THE AFTERNOON...AND THEN GET RID OF IT WITH LOSS OF HEATING
THURSDAY EVENING. ON FRIDAY...THE UPPER PATTERN DOES NOT CHANGE
APPRECIABLY WITH THE ANTICYCLONE CENTERED OVER ERN TX/LA...BUT THE
SFC HIGH TO THE NE SEEMS A BIT STRONGER. THE MODELS DEVELOP A WEAK
E/SE FLOW IN THE BOUNDARY LAYER WHICH ADVECTS MOISTURE INTO THE
REGION. THE RESULT IS MORE PRECIP DEVELOPMENT IN THE MODEL. AGAIN...
GIVEN NOTHING TO DISCOURAGE THIS...I EXPECT THERE WILL BE A BIT MORE
COVERAGE THAN PREVIOUSLY EXPECTED...SO PRECIP CHANCES WERE NUDGED
UPWARD A BIT WHICH BRINGS THE PROBABILITY INTO THE CHC RANGE NEAR
THE BLUE RIDGE IN THE AFTERNOON. THE CHANCES FOR ANYTHING BEYOND
GARDEN VARIETY THUNDERSTORMS APPEARS VERY LOW. TEMPS BOTTOM OUT NEAR
NORMAL ON THURSDAY AND THEN BEGIN A CLIMB BACK ABOVE NORMAL STARTING
ON FRIDAY.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 315 AM WEDNESDAY...STILL NO BIG SURPRISES NOTED IN THE LATEST
MEDIUM RANGE GUIDANCE. THE SLOW WESTWARD DRIFT OF THE UPPER
ANTICYCLONE BACK TOWARD THE SRN PLAINS WILL KEEP THE WESTERN
CAROLINAS ON ITS PERIPHERY...AND THUS AWAY FROM ITS SUPPRESSIVE
AFFECTS. THAT SHOULD ALLOW FOR MAINLY DIURNAL SHOWERS AND
THUNDERSTORMS TO DEVELOP EACH DAY GIVEN SUFFICIENT LOW LEVEL
MOISTURE. TEMPS ABOVE NORMAL LOOK LIKE A GOOD BET...BUILDING EACH
DAY TO A PEAK MOST LIKELY ON MONDAY. THE ECMWF SOLUTION SUGGESTS
THAT A SHORT WAVE PASSING TO THE NORTH ON TUESDAY WILL BRING A
WEAKENING COLD FRONT DOWN ACROSS THE AREA THAT WOULD ENHANCE PRECIP
CHANCES AND DROP TEMPS BACK DOWN A BIT. HOWEVER...THE GFS SHOWS THE
UPPER WAVE MUCH FARTHER N AND KEEPS ANY BOUNDARY WELL TO OUR N. WILL
NOT MAKE ANY SIGNIFICANT CHANGES TO THE MEDIUM RANGE AT THIS TIME...
AND THINK EVEN WITHOUT THE FRONT THE COVERAGE OF STORMS WILL
INCREASE A BIT EACH DAY ANYWAY.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...VFR CONDS THROUGH THE TAF PERIOD. THE UPPER TROF AXIS WILL
CROSS EAST OF THE TERMINAL AFT 16Z AND SUPPRESSIVE DYNAMICS WILL
ALLOW ONLY FAIR WX CU THROUGH THE AFTERNOON. NO CIG/VSBY CONCERNS
OVERNIGHT AS WINDS REMAIN UP DUE TO A RELATIVELY TIGHT PGRAD. WINDS
WILL BECOME ALIGNED NW/LY WITH LOW END GUSTS ARND NOON AND THEN N/LY
ARND 00Z AS BROAD SFC TROF PUSHES SOUTHEAST.
ELSEWHERE...VERY SIMILAR TAFS TO KCLT WITH KAVL HAVING THE BEST
POTENTIAL FOR LATE PERIOD VSBY CONCERNS. OTHERWISE...FAIR WX CU WILL
DEVELOP THIS AFTERNOON WITH LOW END GUSTS. GENERALLY A NW/LY DIR ALL
SITES WITH WINDS PERSISTING OVERNIGHT IN A RELATIVELY TIGHT PGRAD.
OUTLOOK...BUILDING UPPER RIDGING WILL PERSIST THROUGH WEEKS END
LEADING TO LOWER PRECIP/RESTRICTION CHANCES. THESE CHANCES WILL
INCREASE OVER THE WEEKEND AS SAID RIDGE RETROGRADES LEADING TO
INCREASING DIURNAL SHRA/TSRA CHANCES AND THUS MORNING FOG/STRATUS AS
WELL.
CONFIDENCE TABLE...
14-20Z 20-02Z 02-08Z 08-12Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL MED 73% HIGH 100% HIGH 100% HIGH 87%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...LG/SBK
SHORT TERM...PM
LONG TERM...PM
AVIATION...SBK
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1135 PM CDT TUE JUL 14 2015
.DISCUSSION...
UPDATED FOR 06Z AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 758 PM CDT TUE JUL 14 2015/
.UPDATE...
UPDATE TO REMOVE SEVERE THUNDERSTORM AND FLASH FLOOD WATCHES FROM
THE MID SOUTH.
DISCUSSION...
THE POWERFUL MESOSCALE CONVECTIVE COMPLEX (MCS) THAT MOVED ACROSS
THE MID SOUTH RESULTING IN WIDESPREAD WIND DAMAGE HAS FINALLY
EXITED TO THE SOUTHEAST AND INTO CENTRAL ALABAMA. THE RAIN COOLED
AIR HAS STABILIZED THE ATMOSPHERE THIS EVENING AND ANY LINGERING
STORMS SHOULD DIMINISH LATER THIS EVENING. MODELS CONTINUE TO
SUGGEST THAT THE ADDITIONAL SHOWERS AND THUNDERSTORMS MAY DEVELOP
ACROSS NORTHEAST PORTIONS OF THE REGION LATE TONIGHT. IT APPEARS
POSSIBLE AS THE AIRMASS ATTEMPTS TO RECOVER SOME...BUT THINK THAT
COVERAGE SHOULD REMAIN LOW. MAINTAINED SLIGHT CHANCE/LOW END
CHANCE POPS AFTER MIDNIGHT...BUT MAY NEED TO REASSESS LATER THIS
EVENING AS CONFIDENCE IN THIS OCCURRING CONTINUES TO DECREASE.
ALL THREATS FOR SEVERE WEATHER AND FLASH FLOODING ACROSS THE MID
SOUTH HAVE ENDED FOR TONIGHT AND THE LATEST HWO REFLECTS THIS
THINKING. PLEASE PASS ALONG ANY WIND DAMAGE REPORTS FROM EARLIER
STORMS...IT IS GREATLY APPRECIATED.
ADDITIONAL UPDATES WILL BE PROVIDED THROUGH THE EVENING AS
NECESSARY.
JLH
&&
.PREV DISCUSSION... /ISSUED 459 PM CDT TUE JUL 14 2015/
UPDATE...
UPDATE TO INCREASE POPS ACROSS MUCH OF THE REGION AND CLEAN UP
SEVERE THUNDERSTORM WATCH PRODUCTS.
DISCUSSION...
A FORWARD PROPAGATING MESOSCALE CONVECTIVE SYSTEM (MCS) IS
ADVANCING THROUGH SOUTHERN WEST TENNESSEE AND PORTIONS OF NORTH
MISSISSIPPI. THIS SYSTEM HAS HAD A HISTORY OF WIDESPREAD AND
SOMETIMES SIGNIFICANT WIND DAMAGE WITH WIND GUSTS IN EXCESS OF 70
MPH AT TIMES. THERE HAS ALSO BEEN TRAINING THUNDERSTORMS ACROSS
WEST TENNESSEE NEAR THE I-40 CORRIDOR WHERE LOW LEVEL CONVERGENCE
IS BECOMING MAXIMIZED. THIS REGION WILL BE AN AREA WHERE HEAVY
RAINFALL AND FLASH FLOODING WILL BECOME MORE OF AN ISSUE WITH TIME
THROUGH THIS EVENING.
CONVECTION SHOULD CONTINUE TO ADVANCE THROUGH EAST ARKANSAS AND
NORTH MISSISSIPPI THROUGH THE REMAINDER OF THIS EVENING AS THE
CONVECTIVE LINE MOVES INTO A STRONGLY UNSTABLE ENVIRONMENT
CHARACTERIZED BY MLCAPE VALUES IN EXCESS OF 3500 J/KG. ALSO...A
WELL ESTABLISHED COLD POOL WILL SUSTAIN STORM STRUCTURE AND
CONTINUED WIND DAMAGE POTENTIAL IS EXPECTED. STORM COVERAGE AND
INTENSITY SHOULD DIMINISH AREAWIDE AFTER MIDNIGHT.
UPDATED PRODUCTS HAVE BEEN SENT AND WILL BE UPDATED AS NEEDED
THROUGH THE EVENING.
JLH
&&
.PREV DISCUSSION... /ISSUED 344 PM CDT TUE JUL 14 2015/
DISCUSSION...
CURRENTLY... ANOTHER WARM HUMID DAY THROUGHOUT THE MIDSOUTH. HEAT
ADVISORY CRITERIA HAS BEEN MET AT ALL 4 CLIMATE SITES AS
TEMPERATURES CLIMB INTO THE MID TO UPPER 90S. MOISTURE CONTINUES
TO POOL INTO THE MIDSOUTH AHEAD OF A CLUSTER OF THUNDERSTORMS THAT
HAVE ENTERED THE NORTHWESTERN CORNER OF OUR CWA AND WILL CONTINUE
TO MOVE SOUTHEAST TOWARDS THE MISSISSIPPI RIVER. WE ARE ALSO
MONITORING THE NORTHEASTERN PORTIONS OF THE CWA FOR CONVECTION
THAT IS THE RESULT OF WAA ALONG AN OUTFLOW BOUNDARY PRODUCED BY A
DECAYING MCS FURTHER EAST. THE HRRR FORMS A LINE OF THESE TWO
DISTURBANCES AND CARRIES THEM SOUTHWARD INTO NORTH MISSISSIPPI
BEFORE THEY BEGIN TO DIE AS WE LOSE DAYTIME HEATING. AN EXTREMELY
UNSTABLE PRE STORM AIRMASS AIR MASS EXISTS AHEAD OF THESE STORMS
THROUGHOUT THE MIDSOUTH WITH SBCAPE VALUES RANGING FROM 4500-6500
J/KG. SEVERE WIND GUSTS WILL BE THE MAIN THREAT WITH ANY STORMS
TODAY. THE WALNUT RIDGE AWOS STATION HAS ALREADY REPORTED A WIND
GUST OF 66 MPH AT 1935Z. SEVERE HAIL WILL BE A SECONDARY THREAT.
TEMPERATURES TOMORROW WILL BE 1-2 DEGREES COOLER THAN TODAY AS
CLOUD COVER ASSOCIATED WITH A WEAK COLD FRONT PROHIBIT THE TYPE OF
TEMPS THAT WE SAW TODAY. THE HEAT ADVISORY WILL BE RE-EVALUATED
DURING THE MIDNIGHT SHIFT.
TEMPERATURES INCREASE TO THE 90S ON THURSDAY THROUGH THE WEEKEND
AS THE UPPER LEVEL RIDGE SHIFTS EAST AND BECOMES CENTERED OVER
THE LOWER MISSISSIPPI RIVER VALLEY. HEAT INDICES WILL ONCE AGAIN
BECOME OPPRESSIVE FROM THURSDAY THROUGH EARLY NEXT WEEK. TEMPS AT
THE 850 MB LEVEL WILL REMAIN 22-23C. THAT CORRELATES TO
TEMPERATURES IN THE UPPER 90S AT THE SURFACE. DEWPOINTS WILL BE IN
THE LOWER TO MID 70S EACH DAY. CONFIDENT IN THE NEED FOR HEAT
ADVISORIES FOR AT LEAST A FEW IF NOT EVERY DAY THROUGHOUT THE
PERIOD.
LONG TERM MODELS AGREE ON THE UPPER RIDGE BREAKING DOWN AND
RETROGRADING WEST BY NEXT WEDNESDAY. THIS SHOULD RESULT IN COOLER
TEMPS BY MID WEEK.
JPM3
&&
.AVIATION...
WEAK COLD FRONT WILL PUSH THROUGH THE TAF SITES NEXT 24 HOURS.
CONVECTION IS EXPECTED TO REFORM BY MORNING BUT WON`T START
INTENSIFYING UNITL MIDDAY. MEM AND TUP WILL HAVE THE BEST THREAT
FOR T-STORMS IN TH AREA...WITH TEMPO SHRAS. OCCASIONAL MVFR
WEATHER DURING CONVECTION...OTHERWISE PREDOMINATELY VFR THIS
PERIOD. LIGHT WINDS WILL TURN NORTHEAST AT 4-9 KTS BEHIND FRONT.
JAB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR DUNKLIN-PEMISCOT.
MS...HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR ALCORN-BENTON MS-
CALHOUN-CHICKASAW-COAHOMA-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-
MARSHALL-MONROE-PANOLA-PONTOTOC-PRENTISS-QUITMAN-
TALLAHATCHIE-TATE-TIPPAH-TISHOMINGO-TUNICA-UNION-YALOBUSHA.
TN...HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR BENTON TN-CARROLL-
CHESTER-CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-
HARDIN-HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-
MCNAIRY-OBION-SHELBY-TIPTON-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1126 PM EDT THU JUL 16 2015
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL DRIFT EAST FROM THE GREAT LAKES TOWARD
THE CENTRAL NEW ENGLAND COAST THROUGH TONIGHT. WILL SEE A RETURN
OF DEEPER MOISTURE ON FRIDAY AS THE HIGH PASSES OFF THE COAST...
ALLOWING SOUTHERLY WINDFLOW TO TAKE OVER. UPPER LEVEL HIGH
PRESSURE WILL BUILD EAST FROM THE GULF COAST REGION THIS
WEEKEND...RESULTING IN HOTTER AND MORE HUMID WEATHER INTO EARLY
NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 1120 PM EDT THURSDAY...
NOT SEEING ANY OBVIOUS EVIDENCE OF SHOWERS ON RADAR OR IN
OBS...AND THE 18Z/00Z NAM WILL NOT BE USED AS IT HAD CONVECTIVE
FEEDBACK ISSUES PER QPF FIELD BULLSEYES.
WILL SEE THE CLOUD COVER NEAR THE BLUE RIDGE EXPAND OVERNIGHT INTO
PORTIONS OF THE NEW RIVER VALLEY INTO THE VA/NC FOOTHILLS...WITH
LESS CLOUD COVER OVER WRN SLOPES OF SE WV. MSAS SHOWING LOWER
DEWPOINTS STREAMING SWD TOWARD THE LEE OF THE APPALACHIANS...WITH
LYH ALREADY WITH UPPER 50S DEWPOINTS...COMPARED TO MID 60S IN THE
SOUTH. MADE SOME ADJUSTMENTS SLIGHTLY COOLER FOR OVERNIGHT
LOWS...ESPECIALLY OVER THE NRN CWA. WHERE CLOUD COVER WILL BE
GREATEST WILL BE STEADYING OUT OVERNIGHT. ANY SHOWERS APPEAR TO BE
CONFINED TO VERY LIGHT EARLY OVER THE NC MTNS...SO OVERALL KEPT
THE FORECAST DRY OVERNIGHT.
SHOULD SEE PATCHY FOG OVERNIGHT IN THE MTNS AND SOME OF THE WRN
VALLEYS WHERE LESS CLOUD COVER OCCURS. FURTHER EAST HAVE ADDED FOG
AS WELL AS RAP AND GFS SHOWING THAT TEMP/DEWPOINT SPREAD WILL BE
NEAR ZERO...THOUGH CLOUD COVER MAY LIMIT FOG TO CLOSER TO THE BLUE
RIDGE.
PREVIOUS VALID DISCUSSION...
FRIDAY WILL BEGIN A WARMING TREND AS SUBTROPICAL RIDGING OVER THE
GULF COAST REGION BUILDS EASTWARD GOING INTO THE END OF THE WEEK.
FACTOR THAT WITH WINDS SHIFTING SOUTHERLY DURING THE AFTERNOON AND
MOSTLY CLEAR TO PARTLY CLOUDY SKIES TO ALLOW FOR STRONG SURFACE
HEATING...AND WE CAN EXPECT FRIDAY AFTERNOON HIGHS TO RANGE FROM
THE LOW/MID 80S FOR THE MOUNTAINS...TO THE UPPER 80S ACROSS THE
PIEDMONT. WITH TROPICAL MOISTURE BEGINNING ITS RETURN ALONG THE
APPALACHIAN CHAIN...WE CAN ALSO EXPECT A BETTER CHANCE OF POP UP
SHOWERS AND THUNDERSTORMS FOR THE AFTERNOON...MAINLY ACROSS THE
MOUNTAINS...ALTHOUGH A FEW MAY DRIFT EAST ACROSS THE PIEDMONT
DURING THE EVENING.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 255 PM EDT THURSDAY...
SURFACE LOW PRESSURE CROSSES THE GREAT LAKES WITH A WARM FRONT
MOVING NORTHEAST THROUGH THE OHIO VALLEY ON THURSDAY NIGHT AND
FRIDAY. FORECAST AREA WILL BE IN DEEP SOUTHWEST WINDS AND WELL INTO
THE WARM SECTOR BY LATE FRIDAY. MODELS SHOW INCREASE IN 850
TEMPERATURES BY SATURDAY AND SUNDAY WITH VALUES FORECAST AROUND +22
IN SOUTHERN VIRGINIA AND NORTHERN NORTH CAROLINA BY SUNDAY.
EXPECT THERE WILL BE A PRE-FRONTAL/APPALACHIAN LEE TROF ON SUNDAY
AHEAD OF THE COLD FRONT THAT WILL APPROACHING FROM THE NORTHWEST.
THIS TROF WILL CREATE ENOUGH LOW LEVEL CONVERGENCE TO TRIGGER
SHOWERS AND THUNDERSTORMS IN THE AFTERNOON AND EVENING. EXPECT MORE
AREAL COVERAGE OF PRECIPITATION ON SUNDAY THAN ON SATURDAY. FORECAST
AREA WILL BE ON THE EDGE OF THE UPPER RIDGE AND WARMER MID LEVEL
TEMPERATURES...BUT NOT EXPECTING ENOUGH OF A CAP TO LIMIT
THUNDERSTORM DEVELOPMENT.
PRESENCE OF A LEE SIDE TROF WILL MEAN DOWNSLOPING WINDS ON THE EAST
SIDE OF THE APPALACHIANS...FURTHER WARMING THE AIR. MAXIMUM
TEMPERATURES WILL BE ABOVE NORMAL SATURDAY AND SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
.
AS OF 155 PM EDT THURSDAY...
OVERALL PATTERN TUESDAY THROUGH THURSDAY MAINTAINS A BROAD RIDGE IN
THE SOUTH AND ZONAL FLOW IN THE NORTHERN STREAM. TROFFING MAY BE
STARTING TO AMPLIFY IN THE NORTHEAST WITH THE RIDGE RETROGRADING IN
THE SOUTHWEST BY WEDNESDAY AND THURSDAY.
ENSEMBLE GFS AND OTHER GUIDANCE SHOWED FRONTAL PASSAGE ON MONDAY.
EXPECT BEST COVERAGE OF PRECIPITATION ON SUNDAY NIGHT THROUGH MONDAY
NIGHT. FRONT MOVES FAR ENOUGH SOUTH OF THE FORECAST AREA THAT THE
PROBABILITY OF PRECIPITATION LOWERS FOR WEDNESDAY AND THURSDAY.
&&
.AVIATION /04Z FRIDAY THROUGH TUESDAY/...
AS OF 700 PM EDT THURSDAY...
RADAR CLEAR THIS AFTERNOON...ALTHOUGH ISOLATED VERY LIGHT SHOWERS
HAVE POPPED UP FROM TIME TO TIME...ONLY TO FADE AGAIN. ALL AIRPORTS
ARE REPORTING VFR CONDITIONS UNDER A WIDESPREAD SCT CANOPY
WITH BASES RANGING FROM 4KFT TO 6KFT...COVERING MOST OF THE
FORECAST AREA. ALL TAF SITES HAVE REMAINED SHRA FREE THROUGH THIS
TIME PERIOD.
CENTER OF HIGH PRESSURE WILL CONTINUE TO SLIDE TO THE CENTRAL NEW
ENGLAND COAST BY SUNRISE FRIDAY. DURING THIS TIME...WINDFLOW ACROSS
THE MID ATLANTIC WILL SHIFT INCREASINGLY SOUTHEASTERLY TO SOUTHERLY
OVER.
SHOWER FORMATION AND ACTIVITY WILL SLOWLY WIND DOWN AS SUNSET
APPROACHES...BEFORE FADING ALL TOGETHER BY 02Z THIS EVENING.
OVERNIGHT...EXPECT SPOTTY REDEVELOPMENT OF MVFR CEILINGS IN THE
VICINITY OF THE BLUE RIDGE. WILL ALSO SEE SPOTTY FG
FORMATION...MAINLY AFFECTING DEEPER MOUNTAIN VALLEYS TO INCLUDE
KLWB. LEFT BR IN THE FCST FOR KBLF/KDAN/KBCB/KLYH. CONFIDENCE IS
HIGHER THAT KBCB/KBLF WILL DROP AT LEAST TO IFR CONDITIONS BEFORE
DAYBREAK. BR FORMATION IN THE PIEDMONT IS LESS
UNCERTAIN...ESPECIALLY WITH EXPECTED LOW LVL CLOUD ADVECTION FROM
THE SE BY 08Z.
FOG WILL LIFT QUICKLY AFTER 13Z FRIDAY...WITH CEILINGS GRADUALLY
LIFTING THROUGH THE REMAINDER OF THE MORNING.
WITH WINDS SHIFTING INCREASINGLY SOUTHERLY FRIDAY AFTERNOON...
WILL SEE GREATER RETURN OF MOISTURE ACROSS THE MOUNTAINS...AND
SLIGHTLY BETTER CHANCES OF POP UP SHOWER/THUNDERSTORM ACTIVITY
ACROSS THE MOUNTAINS. MOST CONVECTION WILL NOT DEVELOP UNTIL MID
AFTERNOON/EVENING TIME FRAME. POP VALUES ARE SO LOW...LEFT OUT ANY
TS/RA IN THE TAFS. THAT MAY NEED AMENDING AS WE ENTER INTO THE
12Z/18Z TAF FCST PERIOD TOMORROW BASED ON SHORT-RANGE MODEL +
RADAR/SATELLITE TRENDS.
EXTENDED AVIATION DISCUSSION...
WITH OPPORTUNITY FOR CLEARING TO TAKE PLACE FRIDAY NIGHT...WILL
HAVE SOME MORNING FOG/LOW CLOUDS ISSUES IN THE MOUNTAIN
VALLEYS...AND GROUND FOG FOR THE LOW LYING AREAS OF THE FOOTHILLS
AND PIEDMONT. OVERALL CONDITIONS HOWEVER SHOULD BE MAINLY VFR.
WIDELY SCATTERED MORE DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS
RETURN TO THE REGION ON SATURDAY AND SUNDAY WITH POSSIBLY MORE
WIDESPREAD COVERAGE ON MONDAY AHEAD OF THE NEXT COLD FRONT. MVFR
TO IFR CONDITIONS ARE POSSIBLE WITH ANY OF THE STORMS. OTHERWISE
VFR CEILINGS AND VISIBILITIES ARE EXPECTED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...NF
NEAR TERM...NF/WP
SHORT TERM...AMS
LONG TERM...AMS
AVIATION...JM/NF/WP
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1053 PM CDT THU JUL 16 2015
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 254 PM CDT THU JUL 16 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW THE UPPER
FLOW BACKING THIS AFTERNOON AS A SHORTWAVE TROUGH LIFTS NORTHEAST
INTO WISCONSIN. THIS SHORTWAVE IN COMBO WITH A LLJ IS PRODUCING A
BAND OF SHOWERS THAT IS MOVING INTO CENTRAL WISCONSIN. THE BACKING
FLOW ALOFT IS ALSO PUSHING A SURFACE WARM FRONT NORTHEAST ACROSS THE
CENTRAL PLAINS. PLENTY OF LOW CEILINGS NORTH OF THE WARM FRONT AND
BEHIND THE BAND OF SHOWERS. FORECAST CONCERNS INCLUDE PRECIP TRENDS
TONIGHT AND MAX TEMPS ON FRIDAY.
TONIGHT...THE SHORTWAVE TROUGH WILL MOVE NORTHEAST ACROSS NORTHEAST
WISCONSIN THIS EVENING. THE LATEST SHORT RANGE MODELS ARE QUITE
AMBITIOUS CRANKING OUT RAINFALL OVER EAST-CENTRAL WISCONSIN...BUT
THE AIRMASS IS QUITE STABLE OVER THE REGION AT THE MOMENT. THOUGH
MOISTURE IS PLENTIFUL...IT WILL BE TOUGH TO GET HEAVY RAINFALL
WITHOUT INSTABILITY OR STRONG FORCING...AND BOTH APPEAR TO BE
ABSENT. BUT WILL STILL GO WITH PRECIP CHANCES IN THE 60-80% RANGE
THIS EVENING WITH AROUND A QUARTER INCH OF RAINFALL. AS THE RAIN
EXITS LATE IN THE EVENING OR EARLY OVERNIGHT...CLOUDS SHOULD LOWER
AND CREATE A WIDESPREAD OVERCAST DECK WITH SOME LOWER VSBYS IN MIST.
LOWS WILL BE MORE MILD AS A RESULT...AND WENT WITH MINS IN THE UPPER
50S TO LOWER 60S.
FRIDAY...THE WARM FRONT WILL STALL OVER CENTRAL WISCONSIN BUT
SHORTWAVE RIDGING WILL BE MOVING OVERHEAD WHICH WILL INCREASE
SUBSIDENCE ALOFT. AS A RESULT...THINK THE DAY WILL BE A DRY ONE
THOUGH WILL START OFF RATHER CLOUDY. THESE CLOUDS SHOULD LIFT BY
MID TO LATE MORNING. THEN CONDITIONS TURN WARM AND MUGGY WITH HIGHS
IN THE LOW TO MID 80S.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 254 PM CDT THU JUL 16 2015
ZONAL FLOW WITH FAIRLY STRONG WINDS ALOFT FOR MID SUMMER IS EXPECTED
MOST OF THE TIME DURING THIS PERIOD...WITH A FEW SHORTWAVES MOVING
THROUGH EVERY TWO OR THREE DAYS.
THE FIRST ONE COMES THROUGH SATURDAY AFTERNOON AND EVENING WITH
ASSOCIATED SURFACE FRONT. SOUTHERLY FLOW WILL BRING WARM AND HUMID
AIR UP INTO WISCONSIN WITH MODELS FORECASTING HIGH TEMPERATURES IN
THE UPPER 80S TO LOW 90S WITH DEWPOINTS AROUND 70F. THE MODELS
HAVE BEEN A BIT TOO WARM SO FAR THIS SEASON SO NOT SURE IF 90F IS
LIKELY OR NOT. IF IT DOES GET THAT WARM WITH 70F DEWPOINTS HEAT INDICES
WILL BE CLOSE TO ADVISORY CRITERIA OF 100F. FORECAST CAPE OF 3000
J/KG SATURDAY AFTERNOON WILL PRESENT A SEVERE THUNDERSTORM THREAT.
SLIGHTLY COOLER AND DRIER AIR WILL ARRIVE SUNDAY AND MONDAY WITH
TEMPERATURES JUST A COUPLE DEGREES ABOVE NORMAL. ANOTHER SHORTWAVE
TROUGH COMES BY MONDAY NIGHT OR TUESDAY WITH ANOTHER CHANCE OF
SHOWERS AND THUNDERSTORMS FOLLOWED BY DRY WEATHER WEDNESDAY AND
THURSDAY.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1052 PM CDT THU JUL 16 2015
ISOLATED SHOWERS WILL CONTINUE TO MOVE THROUGH THE CWA
OVERNIGHT...WITH LOWER CIGS PROGRESSIVELY WORKING THEIR WAY
THROUGH THE STATE. MOST OF THE AREAS HAVE LOWERED TO IFR/LIFR
CIGS...WITH THE REST EXPECTED TO FOLLOW SHORTLY AS A WARM FRONT
TRACKS EAST. CLOUDS ARE EXPECTED TO MIX OUT BY MID TO LATE MORNING
FRIDAY...WITH VFR CIGS EXPECTED FOR THE REST OF FRIDAY BEHIND THE
WARM FRONT.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......KURIMSKI
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
622 PM CDT THU JUL 16 2015
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 254 PM CDT THU JUL 16 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW THE UPPER
FLOW BACKING THIS AFTERNOON AS A SHORTWAVE TROUGH LIFTS NORTHEAST
INTO WISCONSIN. THIS SHORTWAVE IN COMBO WITH A LLJ IS PRODUCING A
BAND OF SHOWERS THAT IS MOVING INTO CENTRAL WISCONSIN. THE BACKING
FLOW ALOFT IS ALSO PUSHING A SURFACE WARM FRONT NORTHEAST ACROSS THE
CENTRAL PLAINS. PLENTY OF LOW CEILINGS NORTH OF THE WARM FRONT AND
BEHIND THE BAND OF SHOWERS. FORECAST CONCERNS INCLUDE PRECIP TRENDS
TONIGHT AND MAX TEMPS ON FRIDAY.
TONIGHT...THE SHORTWAVE TROUGH WILL MOVE NORTHEAST ACROSS NORTHEAST
WISCONSIN THIS EVENING. THE LATEST SHORT RANGE MODELS ARE QUITE
AMBITIOUS CRANKING OUT RAINFALL OVER EAST-CENTRAL WISCONSIN...BUT
THE AIRMASS IS QUITE STABLE OVER THE REGION AT THE MOMENT. THOUGH
MOISTURE IS PLENTIFUL...IT WILL BE TOUGH TO GET HEAVY RAINFALL
WITHOUT INSTABILITY OR STRONG FORCING...AND BOTH APPEAR TO BE
ABSENT. BUT WILL STILL GO WITH PRECIP CHANCES IN THE 60-80% RANGE
THIS EVENING WITH AROUND A QUARTER INCH OF RAINFALL. AS THE RAIN
EXITS LATE IN THE EVENING OR EARLY OVERNIGHT...CLOUDS SHOULD LOWER
AND CREATE A WIDESPREAD OVERCAST DECK WITH SOME LOWER VSBYS IN MIST.
LOWS WILL BE MORE MILD AS A RESULT...AND WENT WITH MINS IN THE UPPER
50S TO LOWER 60S.
FRIDAY...THE WARM FRONT WILL STALL OVER CENTRAL WISCONSIN BUT
SHORTWAVE RIDGING WILL BE MOVING OVERHEAD WHICH WILL INCREASE
SUBSIDENCE ALOFT. AS A RESULT...THINK THE DAY WILL BE A DRY ONE
THOUGH WILL START OFF RATHER CLOUDY. THESE CLOUDS SHOULD LIFT BY
MID TO LATE MORNING. THEN CONDITIONS TURN WARM AND MUGGY WITH HIGHS
IN THE LOW TO MID 80S.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 254 PM CDT THU JUL 16 2015
ZONAL FLOW WITH FAIRLY STRONG WINDS ALOFT FOR MID SUMMER IS EXPECTED
MOST OF THE TIME DURING THIS PERIOD...WITH A FEW SHORTWAVES MOVING
THROUGH EVERY TWO OR THREE DAYS.
THE FIRST ONE COMES THROUGH SATURDAY AFTERNOON AND EVENING WITH
ASSOCIATED SURFACE FRONT. SOUTHERLY FLOW WILL BRING WARM AND HUMID
AIR UP INTO WISCONSIN WITH MODELS FORECASTING HIGH TEMPERATURES IN
THE UPPER 80S TO LOW 90S WITH DEWPOINTS AROUND 70F. THE MODELS
HAVE BEEN A BIT TOO WARM SO FAR THIS SEASON SO NOT SURE IF 90F IS
LIKELY OR NOT. IF IT DOES GET THAT WARM WITH 70F DEWPOINTS HEAT INDICES
WILL BE CLOSE TO ADVISORY CRITERIA OF 100F. FORECAST CAPE OF 3000
J/KG SATURDAY AFTERNOON WILL PRESENT A SEVERE THUNDERSTORM THREAT.
SLIGHTLY COOLER AND DRIER AIR WILL ARRIVE SUNDAY AND MONDAY WITH
TEMPERATURES JUST A COUPLE DEGREES ABOVE NORMAL. ANOTHER SHORTWAVE
TROUGH COMES BY MONDAY NIGHT OR TUESDAY WITH ANOTHER CHANCE OF
SHOWERS AND THUNDERSTORMS FOLLOWED BY DRY WEATHER WEDNESDAY AND
THURSDAY.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 622 PM CDT THU JUL 16 2015
SHOWERS CONTINUE TO MOVE THROUGH THE CWA DURING THE EARLY EVENING
HOURS. HOWEVER ALL OF THE LIGHTNING ACTIVITY HAS BEEN WELL TO THE
SOUTH AND NORTH...WITH LITTLE THREAT OF IT HITTING THE TAF SITES.
CIGS WILL CONTINUE TO LOWER THROUGH TONIGHT WITH WIDESPREAD
IFR/LIFR CIGS POSSIBLE OVERNIGHT ALONG THE WARM FRONT UNTIL THE
CLOUDS MIX OUT BY MID TO LATE MORNING ON FRIDAY. VFR CIGS ARE
EXPECTED FOR THE REST OF FRIDAY BEHIND THE WARM FRONT.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......KURIMSKI
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
338 PM CDT WED JUL 15 2015
.SHORT TERM...
.TONIGHT - CONFIDENCE...MEDIUM
INFLUENCE OF DRY AND STABLE HIGH PRESSURE RIDGE WILL LINGER WELL
INTO THE EVENING HOURS WITH ONLY SOME CIRRUS SPILLING ACROSS SRN WI.
LATER IN THE NIGHT PRONOUNCED 850 SOUTHERLY LLJ APPROACHES SW WI
THOUGH AXIS AND BEST MOISTURE PROGGD TO STAY LARGELY WEST OF THE
CWA...HOWEVER INCREASE IN MID LEVEL MOISTURE AND SOME ELEVATED THOUGH
LIMITED INSTABILITY IN PROXIMITY TO THE LLJ SUGGESTS SOME POP PRIOR
TO 12Z SEEMS PRUDENT IN PARTS OF THE WESTERN CWA LATER IN THE NIGHT.
.THURSDAY - CONFIDENCE...MEDIUM
850 LLJ PROGGD TO TRANSLATE EASTWARD INTO SRN WI AND FAVOR A PATTERN
OF SIGNIFICANT MOIST/THERMAL ADVECTION. ISODROSOTHERM ANALYSIS SHOWS
MOIST AXIS NOT FAR AWAY IN MN AND IA. IN ADDITION THE MID LEVELS
SHOW SHORTWAVE ACTIVITY AIDING FURTHER ON ALREADY FAVORABLE VERTICAL
MOTION FIELD PROVIDED BY LLJ. THE GFS IS SUGGESTING AN INITIAL SURGE
IN THE MORNING WITH SECONDARY DEVELOPMENT IN THE AFTERNOON...WHILE
THE NAM/ECMWF IMPLY SHOW ONE MAIN QPF AREA. SHOULD ANY CLEARING TAKE
PLACE WITH A NORTHWARD ADVANCING WARM FRONT INTO SRN WI...THEN SOME
STRONGER CONVECTION IS POSSIBLE PER SWODY2 MARGINAL RISK. HOWEVER
MORNING SOUNDINGS FROM THE GFS/NAM DURING ANY OF THE CONVECTION IN
THAT TIMEFRAME SHOW MINIMAL MID LEVEL LAPSE RATES/ELEVATED CAPE. 925
TEMPS RAMP UP INTO THE LOW TO MID 20S CELSIUS IN THE FAR SOUTH SO IF
THAT WARM SECTOR CAN MAKE GROUND INTO THE CWA WITH SOME
CLEARING...WILL NEED TO BOOST TEMPS A BIT MORE SOUTH OF THE BOUNDARY.
THURSDAY NIGHT AND FRIDAY ...FORECAST CONFIDENCE MEDIUM
KEEPING LIKELY POPS IN THE EVENING WITH MODELS TAKING MOST OF THE
FORCING WITH INITIAL WARM-AIR ADVECTION SURGE WITH THE 500 MB SHORT
WAVE AND SURFACE WAVE TO THE NORTHEAST OF THE AREA BY 06Z FRIDAY.
NAM AND GFS SHOW SOME PCPN WITH LINGERING LOW-LAYER FRONTOGENESIS
ALONG THE SURFACE BAROCLINIC ZONE...WITH THE NAM LAYING THE SURFACE
BAROCLINIC ZONE ACROSS THE NRN FORECAST AREA AND THE GFS A BIT
FARTHER SOUTH. MODELS EITHER KEEP THIS BOUNDARY ACROSS AREA OR LIFT
IT BACK ACROSS SRN WI DURING THE AFTERNOON. THIS WILL KEEP SLIGHT
CHANCE/LOW CHANCE POPS IN MAINLY EASTERN AREAS THROUGH THE DAY.
925 MB TEMPS RISE TO 27-28C...WITH THE 00Z ECMWF AROUND 25C BY 00Z
SATURDAY. THOUGH SOME CHANCE FOR LOWER VALUES IF THERE IS MORE
EXTENSIVE CLOUD COVER IN THE AFTERNOON THAN FORECAST...BLENDED
VALUES AND MOS GUIDANCE IN LINE WITH UPPER 80S TO AROUND 90 WITH SW
WINDS ASSURING EVEN EASTERN AREAS WILL GET INTO THE WARM AIR. HEAT
INDEX VALUES WILL REACH THE 90 TO 95 RANGE.
FRIDAY NIGHT AND SATURDAY...FORECAST CONFIDENCE MEDIUM
DRY INITIALLY WITH SHORT WAVE RIDGING FRIDAY NIGHT...WITH NAM A BIT
FASTER AND STRONGER WITH AN MCV/COMPACT SHORT WAVE APPROACHING THE
AREA FRIDAY NIGHT AND MOVING ACROSS FORECAST AREA SATURDAY. MODEL
VARIANCE WITH LOCATION OF WARM FRONT AND 850 MB BAROCLINIC ZONE
LEADS TO DIFFERING LOCATIONS AND TRACKS OF EXPECTED MCS. WILL HOLD
POPS TO WESTERN AREAS FRIDAY NIGHT AND THEN SPREAD CHANCE POPS
ACROSS FORECAST AREA WITH TROUGH PASSAGE SATURDAY.
925 MB TEMPS IN THE SAME NEIGHBORHOOD AS FRIDAY AND WILL ONLY DROP
HIGHS A DEGREE OR TWO AS RAIN WILL NOT BE AN ALL DAY AFFAIR...THOUGH
TIMING OF CLOUDS AND PCPN COULD KEEP HIGHS EVEN COOLER THAN
FORECAST. HEAT INDEX VALUES AGAIN CLIMB INTO THE MID 90S AWAY FROM
LAKE MICHIGAN...WITH SOME UPPER 90S POSSIBLE.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY...FORECAST
CONFIDENCE MEDIUM.
AREA WILL SEE SHORT WAVE ENERGY LIFTING UP THE LEADING FLANK OF A
POSITIVELY TILTED TROUGH CROSSING THE NORTHERN PLAINS SATURDAY
NIGHT/SUNDAY...REACHING THE WESTERN GREAT LAKES BY MONDAY MORNING.
WARM...MOIST UNSTABLE AIR FLOWING NORTHWARD AHEAD OF THE TROUGH WILL
IMPINGE ON SLOW MOVING SURFACE TROUGH...WITH DIFFERING TIMING...
PLACEMENT AND STRENGTH OF SHORT WAVES LEADING TO VARYING MOVEMENT
AND LOCATION OF THE TROUGH. CONSENSUS SOLUTION BRINGS LIKELY POPS
ACROSS MAINLY THE NORTHERN CWA SATURDAY NIGHT...THEN CHANCE POPS
THROUGH SUNDAY NIGHT AS SURFACE TROUGH SLOWLY TRACKS ACROSS THE
AREA...WITH A SLIGHT CHANCE LINGERING INTO MONDAY MORNING.
TEMPERATURES WILL BE A BIT COOLER SUNDAY BUT STILL HUMID WITH HEAT
INDICES OF UPPER 80S TO LOW 90S.
ECMWF TRIES TO BRUSH SRN CWA WITH PRECIPITATION FROM A THUNDERSTORM
COMPLEX PASSING TO THE SOUTH OVER IL MONDAY NIGHT...BUT WILL KEEP
AREA DRY THROUGH TUESDAY WITH HIGH PRESSURE BUILDING IN AND
TEMPERATURES DROPPING BACK TO NORMAL LEVELS FOR THIS TIME OF YEAR
AND DEW POINTS IN THE LOWER 60S. MOST MODELS TRENDING DRIER TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT SO LATER SHIFTS MAY BE ABLE TO DROP
SLIGHT CHANCE/LOW CHANCE POPS.
&&
.AVIATION/00Z TAFS/...VFR CONDITIONS INTO MUCH OF THE NIGHT WITH
DRY/STABLE INFLUENCE OF SURFACE HIGH. EXPECT AN INCREASE IN MID
LEVEL CLOUDS AS THE NIGHT WEARS ON WITH LATEST RAP SOUNDINGS SHOW
LOW LEVELS REMAINING QUITE DRY. IMPRESSIVE LLJ TAKES AIM AT SRN WI
FOR THURSDAY WITH DECENT THERMAL/MOIST ADVECTION EXPECTED. SO HIGH
POPS LOOK GOOD. SREF MVFR CIG PROBS SHOW GREATEST LIKELIHOOD OF
MVFR/IFR CONDITIONS ACRS NRN WI ON THURSDAY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TONIGHT/THURSDAY AND AVIATION/MARINE...COLLAR
THURSDAY NIGHT THROUGH WEDNESDAY...REM
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1021 AM CDT WED JUL 15 2015
.AVIATION/18Z TAFS/...VFR CONDITIONS TODAY INTO MUCH OF THE NIGHT
WITH DRY/STABLE INFLUENCE OF SURFACE HIGH. EXPECT AN INCREASE IN
MID LEVEL CLOUDS AS THE NIGHT WEARS ON WITH LATEST RAP SOUNDINGS
SHOW LOW LEVELS REMAINING QUITE DRY. IMPRESSIVE LLJ TAKES AIM AT
SRN WI FOR THURSDAY WITH DECENT THERMAL/MOIST ADVECTION EXPECTED.
SO HIGH POPS LOOK GOOD. SREF MVFR CIG PROBS SHOW GREATEST
LIKELIHOOD OF MVFR/IFR CONDITIONS ACRS NRN WI ON THURSDAY.
PC
&&
.PREV DISCUSSION... /ISSUED 359 AM CDT WED JUL 15 2015/
TODAY...FORECAST CONFIDENCE IS HIGH.
KEEPING EYE ON LOW CLOUDS MOVING WWD ACROSS LAKE FROM LOWER MI.
APPEARS DECREASING TREND SHOWING UP ON LATEST IR IMAGERY. LOW
CLOUDS NOT INDUCED BY LAKE EFFECT DUE TO MINIMAL DELTA T
DIFFERENCE. CLOUDS ALSO RUNNING INTO DRIER AIR AND SUBSIDENCE OVER
SRN WI. AFTER PATCHY EARLY MORNING CLOUDS IN THE SOUTHEAST...STILL
EXPECTING A VERY PLEASANT DAY UNDER LOTS OF SUNSHINE WITH SOME
PASSING MID TO HIGH CLOUDS LATER THIS MRNG AND AFTN.
NORTHEAST BREEZES WL CONTRIBUTE TO TEMPERATURES REMAINING BELOW
NORMAL TODAY. WARMEST TEMPS IN FAR WEST WHERE KLNR WL MOST LIKELY
CRACK 80.
TONIGHT...FORECAST CONFIDENCE IS HIGH.
A QUIET NIGHT IS EXPECTED MOST AREAS AS SHORT WAVE RIDGING SLIDES
OFF TO THE EAST. DRY AIR AND LIGHT WINDS WILL ALLOW TEMPERATURES
TO FALL RAPIDLY DURING THE EVENING. HOWEVER EXPECT INCREASING MID
TO HIGH CLOUDS LATER IN THE EVENING AND OVERNIGHT AS UPSTREAM LOW
LEVEL JET FOCUSES ON IA/MN. SOUTHWEST WI GETS CLIPPED BY
INCREASING MID LEVEL MOISTURE AND SURGE OF 700MB WARM AIR
ADVECTION. MAY BE JUST ENOUGH MID LEVEL INSTABILITY FOR ISOLD
-SHRA/-TSRA TO DEVELOP LATE TNGT ACROSS FAR WRN CWA WITH BULK OF
PRECIPITATION OCCURRING ON THURSDAY.
SHORT TERM...THURSDAY THROUGH FRIDAY NIGHT...FORECAST CONFIDENCE
IS MEDIUM.
MODELS ARE STILL SHOWING SOME VARIATION IN TIMING AND PLACEMENT OF
FEATURES FOR THURSDAY INTO THURSDAY NIGHT. THE NAM AND CANADIAN
MODELS CONTINUE TO BRING WEAK LOW PRESSURE AND A WARM FRONT
NORTHEASTWARD TOWARD AND ACROSS CENTRAL/NORTHEAST WISCONSIN
DURING THIS PERIOD. THE GFS HAS TRENDED FURTHER NORTHWARD WITH
THESE FEATURES...SIMILAR TO THE NAM/CANADIAN. THE ECMWF CONTINUES
TO BE THE FURTHEST SOUTH WITH THESE FEATURES...NORTHEASTWARD INTO
AND ACROSS SOUTHERN WISCONSIN.
ALL MODELS SHOW A GOOD AMOUNT OF FOCUSED WARM AIR ADVECTION ACROSS
THE AREA THURSDAY INTO THURSDAY NIGHT. THE BEST FRONTOGENESIS
RESPONSE FIELDS REMAIN NORTH/NORTHWEST OF THE AREA...ALONG WITH
THE NOSE OF THE SOUTH SOUTHWESTERLY LOW LEVEL JET. THE MAIN 500 MB
VORTICITY MAXIMUM MOVES THROUGH THE REGION ON THURSDAY...FOCUSING
ON NORTHERN WISCONSIN...EXCEPT THE ECMWF WHICH BRINGS IT THROUGH
SOUTHERN WISCONSIN.
CONTINUED TREND OF BRINGING LIKELY POPS EASTWARD INTO THE AREA
THURSDAY...LINGERING THURSDAY NIGHT. SPC EXPANDED THE MARGINAL
RISK FOR SEVERE STORMS INTO SOUTH CENTRAL WISCONSIN. THERE IS
ENOUGH ELEVATED CAPE LATER THURSDAY INTO THURSDAY NIGHT WITH
MARGINAL DEEP LAYER SHEAR THAT WOULD SUPPORT ISOLATED SEVERE
HAIL. ECMWF HAS MUCH LOWER CAPE VALUES THAN NAM/GFS...SO WENT
BETWEEN THESE FOR CAPE ESTIMATES. HIGH PRECIPITABLE WATER VALUES
AS WELL...SO SOME HEAVY RAINFALL COULD OCCUR.
KEPT CHANCE POPS FOR SHOWERS AND STORMS FRIDAY AND FRIDAY NIGHT
ACROSS THE AREA...AS SURFACE TROUGH/STATIONARY FRONT LINGERS WEST
TO EAST. NAM/ECMWF SHOWING A POSSIBLE MCS TRYING TO MOVE ALONG IT
TOWARD THE AREA FRIDAY NIGHT. THE OTHER MODELS HINT AT QPF ALONG
THE BOUNDARY AT VARIOUS TIMES DURING THIS PERIOD.
AGAIN...WENT BETWEEN HIGH CAPES ON NAM/GFS AND LOWER VALUES ON
ECMWF DURING THIS TIME. DEEP LAYER SHEAR IS MODEST AT BEST...WITH
DECENT PRECIPITABLE WATER VALUES. BEST SHOT AT ANY SEVERE WEATHER
WOULD BE WITH MCS MOVING TOWARD THE AREA LATER FRIDAY NIGHT.
VERY WARM AND HUMID DAY IS EXPECTED FRIDAY...WITH SOUTHWEST WINDS
BRINGING MID TO UPPER 80S ACROSS THE AREA. DEW POINTS SHOULD RISE
INTO THE UPPER 60S TO LOWER 70S AS WELL.
LONG TERM...SATURDAY THROUGH TUESDAY...FORECAST CONFIDENCE IS
MEDIUM.
GFS/ECMWF CONTINUE TO SHOW SOME DIFFERENCES WITH TIMING AND
PLACEMENT OF FEATURES DURING THIS PERIOD. ECMWF TRIES TO BRING
POSSIBLE WEAKENING MCS THROUGH THE AREA SATURDAY MORNING...KEEPING
BOUNDARY NEARBY IN THE AFTERNOON. IT BRINGS A COLD FRONT SOUTHEAST
THROUGH THE AREA SUNDAY WITH DECENT QPF VALUES.
THE GFS HAS THE BOUNDARY FURTHER NORTH...WITH THE COLD FRONT
SLIDING THROUGH MAINLY SUNDAY NIGHT WITH GOOD QPF VALUES.
CONTINUED POPS FOR SHOWERS AND THUNDERSTORMS SATURDAY INTO SUNDAY
NIGHT. MODIFIED CAPES AND MODEST AT BEST DEEP LAYER SHEAR SUGGEST
RELATIVELY LOW SEVERE RISK AT THIS TIME.
VERY WARM AND HUMID CONDITIONS CONTINUE SATURDAY AND SUNDAY...THOUGH
LAKE BREEZE SATURDAY SHOULD COOL THINGS DOWN NEAR THE LAKE. HEAT
INDEX VALUES MAY REACH THE MID 90S DURING THIS TIME INLAND.
THERE MAY BE A LULL IN ANY PRECIPITATION ACTIVITY MONDAY INTO
TUESDAY...WITH COOLER AND DRIER AIR WORKING INTO THE REGION. KEPT
CONSENSUS BLEND OF POPS AND TEMPERATURES FOR THIS PERIOD...BUT MAY
HAVE TO GO DRIER IN LATER FORECASTS IF THIS TREND PERSISTS.
AVIATION/12Z TAFS/...
WEAK LOW LEVEL CONVERGENCE OVER SRN LOWER MI AND LAKE MI CARRYING
SOME STRATUS INTO PORTIONS OF THE WI LAKESHORE EARLY THIS MORNING.
UNFORTUNATELY...PATCHY HIGH CLOUDS CURRENTLY OBSCURING TRENDS OVER
PAST HOUR OR SO...BUT SLIGHT DECREASING TREND NOTED IN LAST
SEVERAL 11-3.9 MICRON IMAGES.
STILL...LATEST IMAGE SHOWS LOW CLOUDS KNOCKING ON DOORSTEP OF
KMKE AND KENW SO INTRODUCED IN LATEST UPDATE. WOULD EXPECT THESE
LOW CLOUDS WOULD THIN RAPIDLY EARLY THIS MORNING AS DRIER AIR AND
BUILDING SUBSIDENCE ERODE LOW CLOUDS. OTRW A VFR PERIOD WITH
THICKENING CLOUDS LATER TONIGHT DUE TO UPSTREAM SURGE OF LOW LEVEL
MOISTURE AND WARM AIR.
MARINE...
WINDS REMAINING GUSTY ACROSS SOUTHERN MARINE ZONES EARLY THIS
MORNING. STATIONARY VESSEL IN RACINE HARBOR REPORTING SUSTAINED NE
WINDS OF 13KTS WHILE FARTHER SOUTH...NE WINDS STILL GUSTING TO
26KTS AT KNSW3. FARTHER NORTH...WEAKENING PRESSURE GRADIENT AND
SURGE OF COLD AIR HAS ALLOWED WINDS TO SUBSIDE TO MOSTLY 10 TO
18KTS.
THIS DIMINISHING TREND WI AFFECT SOUTHERN LAKE MI ZONES EARLY
THIS MORNING...BUT EXPECT WINDS TO REMAIN GUSTY ACROSS SRN LAKE MI
ZONE THROUGH 12Z OR SO. HENCE WL EXTEND SMALL CRAFT ADVY IN LMZ646
BUT CANCEL ELSEWHERE.
BEACHES...
WILL LET BEACH HAZARD STATEMENT EXPIRE AT 09Z. WINDS HAVE
DECREASED TO BELOW 15 KNOTS NORTH OF WIND POINT LIGHT OVERNIGHT
DUE TO WEAKENING PRESSURE GRADIENT AND WEAKENING PUSH OF LOW LEVEL
COLD AIR. WINDS REMAIN GUSTY SOUTH OF WIND POINT ACROSS RACINE AND
KENOSHA BEACHES AS WAVE HEIGHTS STILL IN THE 3 TO 5 FT RANGE.
HOWEVER EXPECT WINDS AND WAVES TO SUBSIDE THROUGH 8 AM SO DO NOT
SEE THE NEED TO EXTEND BEACH HAZARD STATEMENT AT THIS TIME. MOST
SWIMMERS WOULD BE HEADING TO THE BEACH LATER THIS MORNING AND AFTN
WHEN WINDS AND WAVES WILL BE SIGNIFICANTLY LOWER.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...MBK
THURSDAY THROUGH TUESDAY...WOOD
FORECAST DISCUSSION...THE RIGHT ENTRANCE REGION OF THE ULJ WILL
REMAIN OVER THE AREA THROUGH ABOUT MONDAY SO LIFT WILL BE ENHANCED
DURING THIS TIME.
OVER THE NEXT WEEK AND THE REMNANTS OF DOLORES...THERE WILL BE
MULTIPLE IMPULSES OF ENERGY TO KEEP A STORMY PERIOD IN PLACE. NO
DRY SPELL IS EXPECTED OVER THE FORECAST PERIOD. TEMPERATURES WILL
REMAIN BELOW NORMAL FOR THIS TIME OF YEAR DUE TO CLOUD COVER AND
PRECIPITATION COVERAGE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1122 PM MDT THU JUL 16 2015
ISOLATED SHOWERS WILL LINGER NORTH OF INTERSTATE 70 UNTIL AROUND
10Z THIS MORNING...OTHERWISE DRY CONDITIONS ARE EXPECTED
OVERNIGHT. ANOTHER ROUND OF ISOLATED THUNDERSTORMS DEVELOPS AFTER
18Z AND LINGER THROUGH 06Z FRIDAY NIGHT. CONVECTION IS EXPECTED TO
FAVOR THE HIGHER TERRAIN...WITH A FEW STORMS MOVING INTO THE VCNTY
OF KTEX. ALL OTHER SITES ARE EXPECTED TO REMAIN VFR THROUGH THE
PERIOD. GUSTY WEST TO SOUTHWEST WINDS WILL ALSO DEVELOP AFTER
18Z AND PERSIST UNTIL SUNSET FRIDAY EVENING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...RED FLAG WARNING FROM NOON TODAY TO 8 PM MDT THIS EVENING FOR
COZ200-202.
UT...NONE.
&&
$$
UPDATE...JDC
SHORT TERM...CC/JAM
LONG TERM...JAM
AVIATION...JDC
AREA FORECAST DISCUSSION
NWS LINCOLN IL
348 AM CDT FRI JUL 17 2015
.SHORT TERM...(TODAY)
ISSUED AT 347 AM CDT FRI JUL 17 2015
WARM FRONT HAS LIFTED NE OF CENTRAL IL EARLY THIS MORNING
LEAVING CWA IN A TROPICAL AIRMASS. WILL ISSUE A SPECIAL WEATHER
STATEMENT (SPS) TO ADDRESS THE HEAT WAVE FROM THIS AFTERNOON THROUGH
THIS WEEKEND. HEAT INDICES SHOULD PEAK FROM 100-105F THIS AFTERNOON
WITH HIGHEST READINGS IN WESTERN COUNTIES WHICH MAY COME CLOSE TO
HEAT ADVISORY CRITERIA AROUND 105F ESPECIALLY FROM JACKSONVILLE
WEST. HIGHS OF 89-93F THIS AFTERNOON WITH VERY MUGGY DEWPOINTS IN
THE MID TO UPPER 70S. A FEW SHOWERS AND THUNDERSTORMS LINGER ALONG
OUTFLOW BOUNDARY FROM MCS IN CENTRAL IL NORTH OF I-72 INTO FAR SE
IA. HRRR IS HANDLING THIS ISOLATED CONVECTION WELL AND USED THIS
MODEL FOR FORECAST TODAY WHICH SHIFTS THE ISOLATED CONVECTION
FURTHER SE DURING THE MORNING. UNSTABLE AIRMASS THIS AFTERNOON WITH
CAPES OF 2-3K J/KG WILL SUPPORT MORE ISOLATED SHOWERS AND
THUNDERSTORMS THIS AFTERNOON AND EARLY EVENING. SPC HAS MARGINAL
RISK OF SEVERE STORMS IN PARTS OF CENTRAL AND EASTERN IL DURING THAT
TIME WITH 5% RISK OF DAMAGING WIND GUSTS EAST OF PEORIA AND
SPRINGFIELD. BULK SHEAR IS WEAK TODAY (10-20 KTS) SO STORMS WILL NOT
BE TOO ORGANIZED.
&&
.LONG TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 347 AM CDT FRI JUL 17 2015
EVEN HOTTER HEAT INDICES EXPECTED SATURDAY AFTERNOON PEAKING FROM
104-109F AND HEAT ADVISORY WILL LIKELY BE NEEDED THEN AND POSSIBLY
IN SOUTHEAST IL ON SUNDAY AFTERNOON WHERE HEAT INDICES NEAR 105F.
SAT APPEARS TO BE THE HOTTEST DAY WITH HIGHS IN THE LOW TO MID 90S
WHILE SUNDAY HIGHS RANGE FROM MID 80S NW OF IL RIVER TO 90-95F IN
SOUTH OF I-72. DEWPOINTS IN THE MID TO UPPER 70S TO COMBINE WITH
THESE HOT TEMPS FOR THE HEAT INDICES TOPPING 105F. HEAT INDICES
SUNDAY AFTERNOON RANGE FROM MID 90S OVER IL RIVER VALLEY TO 104-108F
IN SOUTHEAST IL.
ISOLATED SHOWERS AND THUNDERSTORMS POSSIBLE SAT AFTERNOON OVER
MAINLY NORTHERN AREAS. THEN INCREASING CHANCES OF SHOWERS AND
THUNDERSTORMS OVER AREAS NORTH OF I-72 OVERNIGHT SAT NIGHT WITH
APPROACHING COLD FRONT FROM THE UPPER MIDWEST. SPC HAS MARGINAL RISK
OF SEVERE STORMS NW OF LINCOLN SAT NIGHT FOR GUSTY WINDS WHILE
SLIGHT RISK IS NW OF KNOX AND STARK COUNTIES. 00Z FORECAST MODELS
TRACK COLD FRONT SE ACROSS CENTRAL IL ON SUNDAY AND INTO SOUTHEAST
IL SUNDAY EVENING. THIS TO LIKELY BRING A ROUND OF SHOWERS AND
THUNDERSTORMS. SPC HAS ALL BUT FAR SOUTHEAST IL IN SLIGHT RISK OF
SEVERE STORMS SUNDAY AFTERNOON/EVENING FOR MAINLY DAMAGING WIND
GUSTS.
UPPER LEVEL SUBTROPICAL HIGH PRESSURE RIDGE EXPECTED TO RETROGRADE
BACK INTO THE HIGH PLAINS EARLY NEXT WEEK. THIS WILL BRING A
NORTHWEST FLOW OVER IL WITH TEMPS COOLING CLOSER TO NORMAL ON MONDAY
BEHIND THE COLD FRONT WITH HIGHS OF 82-87F. DEWPOINTS SLIPPING INTO
THE MID TO UPPER 60S OVER CENTRAL AND NW CWA AND LOWER 70S IN
SOUTHEAST IL ON MONDAY. HAVE TRENDED POPS LOWER ON MONDAY INTO
MONDAY NIGHT WITH FRONT GETTING FURTHER SOUTH OF CENTRAL IL INTO THE
TN VALLEY WITH CHANCE POPS IN SOUTHEAST IL, SLIGHT CHANCES CENTRAL
PARTS AND DRY FROM I-74 NORTH.
UPPER LEVEL RIDGE TO EXPAND EAST INTO THE MID MS AND OHIO VALLEYS BY
MIDDLE OF NEXT WEEK WITH 850MB TEMPS CLIMB BACK UP TO LOWER 20SC
WED/THU. HIGH TEMPS IN THE LOW TO MID 80S TUE SHOULD ELEVATE INTO
THE MID TO UPPER 80S WED AND 85-90F THU, AND UPPER 80S/LOWER 90S
NEXT FRI. DEWPOINTS TO CLIMB BACK INTO THE 70S LATER NEXT WORK WEEK.
ECMWF AND GEM MODELS ARE STILL DRIER DURING MIDDLE OF NEXT WEEK
WHILE GFS MODEL BRINGS QPF BACK INTO CENTRAL IL ON TUE. GFS MODEL IS
AN OUTLIER AND JUST KEPT SLIGHT CHANCES OF CONVECTION ON TUE AND
AREAS FROM I-72 NORTH ON WED NIGHT AND THU.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1202 AM CDT FRI JUL 17 2015
MAIN FORECAST CONCERN WILL BE COVERAGE OF CONVECTION ACROSS THE
NORTHERN TAF SITES OVER THE NEXT SEVERAL HOURS AND THEIR AFFECT
ON CIGS AND VSBYS. KPIA RIGHT ON THE EDGE OF THE STRONGER
CONVECTION WITH KBMI RECEIVING THE MOST SIGNIFICANT RAINS DURING
THIS PAST HOUR. FURTHER SOUTH...VFR CONDITIONS WERE REPORTED WITH
THE LATEST SHORT TERM FORECAST MODELS SUGGESTING THIS TREND WILL
CONTINUE. DUE TO THE STEADIER RAINFALL AT KBMI...IT APPEARS THERE
WILL BE AT LEAST SOME TEMPORARY MVFR TO IFR CIGS WITH THE RAIN
AND THUNDER FOR THE NEXT FEW HOURS.
MOST OF THE SHORT TERM MODELS TAKE THE BULK OF THE PRECIP TO THE
EAST IN THE 07Z-09Z TIME FRAME. ONCE THE RAIN CLEARS THE NORTHERN
TAF SITES...AND IF CIGS CAN LIFT...WE MAY HAVE TO INCLUDE SOME
FOG FOR A FEW HOURS AT BOTH PIA AND BMI WHO HAVE RECEIVED THE
RAINFALL OVER THE PAST 6 HOURS. AT THIS POINT WILL INCLUDE A
MVFR VSBY IN FOG FOR A FEW HOURS AROUND SUNRISE. FORECAST
SOUNDINGS SUGGEST SCT-BKN CUMULUS POSSIBLE FRIDAY AFTERNOON...ESP
AT KBMI AND KCMI WITH BASES OF 3500-4500 FEET. WINDS SHOULD BE
VARIABLE IN DIRECTION AT 5 TO 10 KTS TONIGHT BUT BE RATHER GUSTY
IN AN NEAR THE THUNDERSTORMS ACROSS THE NORTH. SOUTH TO SOUTHWEST
WINDS ARE EXPECTED AT 10 TO 15 KTS ON FRIDAY.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...07
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1202 AM CDT FRI JUL 17 2015
.UPDATE...
ISSUED AT 832 PM CDT THU JUL 16 2015
A BROKEN LINE OF THUNDERSTORMS THAT DEVELOPED ALONG THE
MISSISSIPPI RIVER LATE THIS AFTERNOON HAS ADVANCED SLOWLY
EASTWARD INTO THE ILLINOIS RIVER VALLEY OVER THE PAST COUPLE OF
HOURS. THE CELLS ON THE SOUTHERN END OF THE LINE HAVE TENDED TO
DIMINISH...WITH THE MAIN FOCUS BEING ON A LARGE CLUSTER OF STRONG
TO SEVERE STORMS OVER KNOX COUNTY. THESE STORMS HAVE HAD A HISTORY
OF ROTATION AS THEY ARE CURRENTLY POSITIONED IMMEDIATELY ALONG A
WARM FRONT. AS THEY PUSH FURTHER EASTWARD AWAY FROM THE FRONT INTO
A MORE STABLE AIRMASS TO THE E/NE...THINK THEY WILL TEND TO WEAKEN
BETWEEN NOW AND 10 PM. HIGH-RES MODELS CONTINUE TO SUGGEST
ADDITIONAL DEVELOPMENT ALONG THE SOUTHERN END OF THIS CLUSTER
LATER THIS EVENING INTO THE OVERNIGHT HOURS AS A 30-40KT 850MB
JET INTERSECTS THE WARM FRONT. WILL CONTINUE TO CARRY LIKELY POPS
ACROSS THE FAR NORTHERN KILX CWA FROM THE PEORIA AREA NORTHWARD
AHEAD OF THE ONGOING STORM COMPLEX...WITH CHANCE POPS FURTHER
SOUTH ACROSS THE CENTER OF THE CWA. FURTHER SOUTH...LITTLE OR NO
PRECIP IS EXPECTED ALONG/SOUTH OF I-70.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 246 PM CDT THU JUL 16 2015
REMNANTS OF EARLIER MCS HAVE EXITED THE FORECAST AREA...AND BREAKS
IN THE CLOUD COVER ARE BECOMING MORE FREQUENT ACROSS MUCH OF THE CWA
THIS AFTERNOON EXCEPT THE FAR NORTHWEST. CAP IS QUICKLY ERODING TO
OUR WEST...AND SPC MESOANALYSIS SHOWING CAPE`S ABOVE 3000 J/KG AS
CLOSE AS THE MISSISSIPPI RIVER. VISIBLE SATELLITE IMAGERY STARTING
SO SHOW SOME AGITATION TO THE CUMULUS CLOUDS ACROSS NORTH CENTRAL
MISSOURI AND SOUTH CENTRAL IOWA...IN AN AREA WHERE THE HRRR HAS BEEN
PERSISTENT IN STARTING UP THE NEXT ROUND OF CONVECTION. ITS SOLUTION
EXPANDS THE CONVECTION NORTHEAST INTO NORTH CENTRAL ILLINOIS THROUGH
VERY LATE AFTERNOON...WITH THE LATEST SOLUTIONS FAVORING AN EASTWARD
SPREAD NORTH OF THE I-72 CORRIDOR THROUGH THE EVENING. OTHER HIGH-
RESOLUTION MODELS SUCH AS THE NMM AND ARW ALSO FAVOR THE NORTHERN
THIRD OF THE STATE...WITH LESSER OF A SOUTHWEST EXTENT. THUS...WILL
FOCUS THE HIGHEST POP`S ACROSS THE NORTHERN THIRD OF THE FORECAST
AREA.
AFTER COLLABORATION WITH WFO CHICAGO...HAVE EXPANDED THE FLASH FLOOD
WATCH A TAD SOUTHWARD AND THEN EAST THROUGH CHAMPAIGN AND VERMILION
COUNTIES. PRECIPITABLE WATER VALUES ANALYZED OVER 2 INCHES ACROSS
NORTHERN MISSOURI...AND THIS WILL BE SHIFTING EAST WITH TIME.
MESOSCALE MODELS FOCUS THE HIGHEST RAIN TOTALS ACROSS THE NORTHWEST
CWA...BUT PARTS OF THE FAR NORTHEAST HAVE ALSO HAD A FEW INCHES OVER
THE LAST SEVERAL DAYS AND ARE A BIT MORE FLOOD PRONE. MOST OF THE
NORTH HALF OF ILLINOIS IS IN A SLIGHT RISK OF FLASH FLOODING PER
GUIDANCE FROM WPC.
.LONG TERM...(FRIDAY THROUGH THURSDAY)
ISSUED AT 246 PM CDT THU JUL 16 2015
SPOTTY SHOWERS/STORMS POSSIBLE FRIDAY ACROSS CENTRAL AND SOUTHEAST
ILLINOIS WITH A WEAK SURFACE BOUNDARY IN THE VICINITY. HOWEVER, THE
PRIMARY THEME AS WE HEAD INTO FRIDAY AFTERNOON (AS WELL AS SATURDAY
AND SUNDAY AFTERNOON) IS THE VERY WARM HEAT INDEX VALUES. THE
SOUTHWESTERLY LOW LEVEL THAT DEVELOPS ACROSS THE AREA TONIGHT WILL
LINGER THROUGH MOST OF THE WEEKEND, TRANSPORTING CONSIDERABLE HEAT
AND HUMIDITY INTO THE AREA. DAYTIME HIGHS AROUND 90S ARE LIKELY
THROUGH SUNDAY, WITH 850 MB TEMPERATURES IN THE LOWER 20S, AND
SURFACE DEW POINTS SHOULD BE WELL INTO THE 70S. THIS HEAT AND
HUMIDITY WILL COMBINE TO PRODUCE HEAT INDEX VALUES FROM 100-105 OR A
LITTLE WARMER DURING PEAK HEATING TIMES. THIS IS CLOSE TO HEAT
ADVISORY LEVELS, AND AN ADVISORY MAY BE NEEDED. HOWEVER, OPTED TO
HOLD OFF UNTIL HEAT INDEX VALUES ARE MORE SOLIDLY 105 OR BETTER.
FORECAST SOUNDINGS SUGGEST THE LOCAL AIRMASS SHOULD BE MOSTLY CAPPED
TO SURFACE BASED CONVECTION INTO SUNDAY (PRONOUNCED WARM LAYER JUST
ABOVE 850 MB). HOWEVER, ELEVATED STORM CHANCES WILL INCREASE
SATURDAY NIGHT AS WARM ADVECTION ALOFT INCREASES AHEAD OF AN
APPROACHING SHORT WAVE. THIS WAVE WILL DRIVE A FRONT THROUGH THE
AREA ON SUNDAY, PRODUCING THE HIGHEST CHANCES FOR SHOWERS/STORMS OF
THE NEXT FEW DAYS (ASIDE FROM TONIGHT). THE STRENGTH OF THIS SYSTEM
ALSO SUPPORTS SOME STRONG TO SEVERE STORMS SUNDAY INTO SUNDAY NIGHT.
SLIGHTLY COOLER AND LESS HUMID CONDITIONS ARE EXPECTED BEHIND
SUNDAY`S SYSTEM FOR THE REMAINDER OF THE FORECAST PERIOD. THE
SOUTHWARD PASSAGE OF THE FRONT WITH SUNDAY`S SYSTEM WILL ALSO HELP
TO SHUNT THE BEST SHOWER/STORM CHANCES TO OUR SOUTH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1202 AM CDT FRI JUL 17 2015
MAIN FORECAST CONCERN WILL BE COVERAGE OF CONVECTION ACROSS THE
NORTHERN TAF SITES OVER THE NEXT SEVERAL HOURS AND THEIR AFFECT
ON CIGS AND VSBYS. KPIA RIGHT ON THE EDGE OF THE STRONGER
CONVECTION WITH KBMI RECEIVING THE MOST SIGNIFICANT RAINS DURING
THIS PAST HOUR. FURTHER SOUTH...VFR CONDITIONS WERE REPORTED WITH
THE LATEST SHORT TERM FORECAST MODELS SUGGESTING THIS TREND WILL
CONTINUE. DUE TO THE STEADIER RAINFALL AT KBMI...IT APPEARS THERE
WILL BE AT LEAST SOME TEMPORARY MVFR TO IFR CIGS WITH THE RAIN
AND THUNDER FOR THE NEXT FEW HOURS.
MOST OF THE SHORT TERM MODELS TAKE THE BULK OF THE PRECIP TO THE
EAST IN THE 07Z-09Z TIME FRAME. ONCE THE RAIN CLEARS THE NORTHERN
TAF SITES...AND IF CIGS CAN LIFT...WE MAY HAVE TO INCLUDE SOME
FOG FOR A FEW HOURS AT BOTH PIA AND BMI WHO HAVE RECEIVED THE
RAINFALL OVER THE PAST 6 HOURS. AT THIS POINT WILL INCLUDE A
MVFR VSBY IN FOG FOR A FEW HOURS AROUND SUNRISE. FORECAST
SOUNDINGS SUGGEST SCT-BKN CUMULUS POSSIBLE FRIDAY AFTERNOON...ESP
AT KBMI AND KCMI WITH BASES OF 3500-4500 FEET. WINDS SHOULD BE
VARIABLE IN DIRECTION AT 5 TO 10 KTS TONIGHT BUT BE RATHER GUSTY
IN AN NEAR THE THUNDERSTORMS ACROSS THE NORTH. SOUTH TO SOUTHWEST
WINDS ARE EXPECTED AT 10 TO 15 KTS ON FRIDAY.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 1 AM CDT EARLY THIS MORNING FOR
ILZ027>031-036>038-041>046.
&&
$$
UPDATE...BARNES
SHORT TERM...GEELHART
LONG TERM...BAK
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
143 AM EDT FRI JUL 17 2015
.SYNOPSIS...
ISSUED AT 140 AM EDT FRI JUL 17 2015
SHOWERS AND A FEW THUNDERSTORMS WILL BE ACROSS THE AREA EARLY THIS
MORNING. THE RAIN WILL DIMINISH TOWARD SUNRISE AND IT WILL BE MUCH
WARMER AND HUMID TODAY AND TONIGHT. THERE WILL STILL BE A SMALL
CHANCE FOR THUNDERSTORMS TODAY AND THIS EVENING WITH THE HEAT AND
HUMIDITY. HIGH TEMPERATURES TODAY WILL RANGE FROM THE MID 80S TO
AROUND 90. HEAT INDEX VALUES WILL BE BETWEEN 90 AND 100 THIS
AFTERNOON. LOWS TONIGHT WILL ONLY DROP INTO THE LOWER 70S.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 342 PM EDT THU JUL 16 2015
AREA OF RADAR RETURNS CURRENTLY ACROSS THE INTERSTATE 69 CORRIDOR
WILL CONTINUE TO WORK EASTWARD OVER THE NEXT SEVERAL HOURS BEFORE
DISSIPATING. HOWEVER...WITH SFC DEWPOINT DEPRESSIONS FROM 10F TO
15F AND CLOUD BASES AROUND 10KFT...EXPECTING LITTLE MORE THAN
SPRINKLES THROUGH 21Z.
UPSTREAM CONVECTION EXPECTED TO FIRE AS S/W TRACKS ACROSS SE IA INTO
WRN IL BETWEEN 21Z TO 00Z...AS ONGOING SFC DESTABILIZATION SW OF THE
LOCAL AREA CONTINUES W/ SFC FRONT/LOW LVL THETA E GRADIENT PUSHING
NORTHWARD TOWARDS THE AREA. CONTINUED THE TREND FROM PREVIOUS
FCST...W/ POPS PUSHING INTO THE AREA AFTER 00Z. BUMPED UP POPS A BIT
W/ LIKELY MENTION FOR MOST OF THE AREA WEST OF I-69...HOWEVER HI-RES
GUIDANCE SUGGESTING A BIT OF A SPLIT IN CONVECTIVE ACTIVITY AFTER
06Z. LATEST HRRR RUNS SEEM TO FAVOR SOUTHERN CONVECTION RIDING ALONG
APPROACHING WARM FRONT...AND DIVING JUST SOUTHWEST OF THE LOCAL
AREA. HOWEVER EXPECT AT LEAST SCATTERED COVERAGE ACROSS MOST OF THE
AREA THROUGH 06Z. POPS WILL TAPER OFF FROM WEST TO EAST AFTER
06Z...WITH ONLY CHANCE CATEGORY BY 12Z. SEVERE THREAT LOOKS MINIMAL
BY THE TIME CONVECTION WORKS INTO THE AREA W/ LOSS OF INSTABILITY.
HEAVY RAINFALL IS POSSIBLE...HOWEVER CONFIDENCE IS LOW W/ HI RES
MODEL SIGNALS SHOWING HEAVIEST RAIN STAYING SOUTH OF THE AREA.
HOWEVER VERY MOIST ENVIRONMENT EXPECTED TO PUSH NORTHEAST INTO THE
AREA AFTER 06Z...W/ PWAT VALUES IN EXCESS OF 2 INCHES.
INTERESTING SETUP FOR FRIDAY AS SHORTWAVE EXITS EAST OUT OF THE AREA
THROUGH THE MORNING. WITH EXTREMELY WARM/MOIST AIRMASS PUSHING NORTH
THROUGH THE AREA BY MIDDAY...CONTINUED SHOWER/T-STORM CHANCES
THROUGH THE DAY...WITH HIGHEST CHANCES BEING DIURNALLY DRIVEN IN THE
AFTERNOON/EARLY EVENING. TWO CHALLENGES FOR THE FRIDAY FORECAST: MAX
TEMPERATURES/HEAT INDICES AND THUNDERSTORM CHANCES. MADE LITTLE
CHANGE TO TEMPS/DEWPOINTS FROM PREVIOUS FORECAST...WITH HIGHS
TOPPING OUT NEAR 90 IN THE SW WITH MID 80S ACROSS THE NE. WITH
DEWPOINTS IN THE MID 70S...HEAT INDICES ARE EXPECTED TO REACH THE
UPPER 90S ACROSS MOST OF THE FORECAST AREA...WITH SOME AREAS IN THE
SOUTHWEST REACHING AND EXCEEDING 100F. CURRENT THINKING IS THAT
COULD COVER ACROSS THE SW WILL DIMINISH BY THE AFTERNOON...WITH
ENOUGH SUN AND MOISTURE TO CREATE DANGEROUS HEAT INDEX VALUES. AT
THIS POINT...STILL A LOT OF UNCERTAINTY WRT PRECIP POTENTIAL AND
SUBSEQUENT CLOUD COVER...SO WILL HOLD OFF ON HEAT ADVISORY FOR THIS
FORECAST ISSUANCE AND MENTION HEAT INDEX VALUES IN THE HWO.
WITH STRONG TEMP/MOIST ADVECTION THROUGH THE AREA DURING THE
MORNING...ATMOSPHERE WILL BECOME QUITE UNSTABLE THROUGH THE
AFTERNOON. MODEL SOUNDINGS SUGGESTING SBCAPE VALUES EXCEEDING 5000
J/KG LATE AFTERNOON/EARLY EVENING...HOWEVER THIS WILL BE HIGHLY
CONTINGENT ON AMOUNT OF CONVECTIVE DEBRIS FROM THE
OVERNIGHT/MORNING. SHEAR IS WEAK AND FORCING WILL BE MINIMAL OUTSIDE
OF ANY REMNANT OUTFLOW/LAKE BREEZE BOUNDARY...BUT ENVIRONMENT IS
CERTAINLY CAPABLE OF SCATTERED PULSE STORMS...ESPECIALLY W/ DECENT
MID LVL LAPSE RATES THROUGH THE AFTERNOON...ANY STORMS THAT FORM
WILL POSE A MARGINAL WIND RISK. CONCUR W/ MOST RECENT SWODY2 FROM
SPC ADDING A MARGINAL RISK FRIDAY AFTN/EVE FOR MUCH OF THE AREA.
&&
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 342 PM EDT THU JUL 16 2015
UPR TROF OVER THE PAC NW TODAY WILL MOVE INTO THE NRN PLAINS FRI NGT
WITH WK UPR RIDGE AHEAD OF THIS SYSTEM BUILDING INTO THE MIDWEST.
MODELS SUGGEST SHRTWV/CONVECTION THAT MOVED ACROSS THE AREA IN THE
SHORT TERM PERIOD MAY LEAVE A WK SFC BOUNDARY IN OUR CWA FRI EVE AND
WITH AIRMASS REMAINING VERY MOIST/UNSTABLE LEFT A CHC OF TSTMS IN
THE FCST. SFC DWPTS SHOULD BE IN THE L-M70S BY FRIDAY NIGHT WITH
OVERNIGHT LOWS LIKELY IN THE SAME RANGE. THE WK SFC BOUNDARY
EXPECTED TO MOVE SLOWLY NE SATURDAY IN RESPONSE TO GRDLY INCREASING
S-SWLY GRADIENT AHEAD OF SHRTWV/CDFNT MOVG THROUGH THE NRN PLAINS.
GIVEN VERY UNSTABLE AIRMASS IN PLACE... WK FORCING AT BEST... AND
CAPPING AROUND 5-6KFT... FELT GOING SLIGHT CHC OF TSTMS IN THE AFTN
REASONABLE AND MAINTAINED. DWPTS SHOULD REMAIN IN THE L-M70S DURING
THE DAY WITH BOUNDARY LAYER MIXING UP TO H850 WHICH SHOULD RESULT IN
HIGHS IN THE L90S AND HEAT INDICES AOA OUR HEAT ADVISORY CRITERIA OF
100. RECENT MODEL RUNS HAVE TRENDED A LITTLE FASTER WITH EASTWARD
MOVEMENT OF NRN PLAINS UPR TROF WITH 12Z RUNS INDICATING THE
ASSOCIATED CDFNT WILL MOVE ACROSS OUR CWA SUNDAY AFTN/EVE. MODELS
HINT AT ANOTHER WK CONVECTIVELY INDUCED VORT MAX MOVG ACROSS THE
AREA SAT NGT AHEAD OF THE FRONT WHICH WARRANTS KEEPING A LOW CHC POP
IN THE FCST... BUT BETTER CHANCES ARE SUNDAY AFTN AS THE FRONT MOVES
INTO THE AREA. DEEP LAYER SHEAR EXPECTED TO BE WK LIMITING SVR
THREAT DESPITE VERY UNSTABLE AIRMASS. BIGGER PROBLEM MAY BE ANOTHER
ROUND OF HEAVY RAINFALL AS PWATS FCST AROUND 2" ALONG THE FRONT WITH
FAIRLY WK FLOW AND SMALL MBE VECTORS SUGGESTING POTENTIAL FOR
TRAINING/BACKBUILDING CELLS. CONVECTION/FROPA SUNDAY AFTN SHOULD
GENERALLY KEEP TEMPS BLO SATURDAY`S READINGS BUT STILL MAY REACH
HEAT ADVISORY CRITERIA...ESPECIALLY SE HALF OF CWA.
POST-FRONTAL HIGH PRESSURE EXPECTED TO BUILD INTO THE AREA MONDAY
PROVIDING FAIR WX WITH TEMPS COOLING BACK TO AOB NORMAL. ANOTHER
SHRTWV FCST TO MOVE THROUGH THE UPR GRTLKS TUE-TUE NGT. FROPA
ASSOCIATED WITH THIS SYSTEM EXPECTED TO LACK SGFNT FORCING AND
MOISTURE ACROSS OUR AREA SO MAINTAINED A DRY FCST FOR TUE-TUE NGT
FOR NOW. ANOTHER HIGH PRESSURE SYSTEM SHOULD FOLLOW THIS WK FRONT
AND MOVE ACROSS THE GRTLKS WED-THU PROVIDING FAIR WX WITH CONTD
SEASONABLE TO SLIGHTLY BLO NORMAL TEMPS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 135 AM EDT FRI JUL 17 2015
SHOWERS AND A FEW TSRA WERE MOVING THROUGH KSBN AREA AT ISSUANCE.
RADAR SHOWS A LULL BEHIND THIS LINE SO ONLY INCLUDED A TEMPO TSRA
FOR AN HOUR. PCPN HEADING TOWARD KFWA STRUGGLING TO HOLD TOGETHER
AS IT ENCOUNTERS DRIER AND MORE STABLE AIR. EXPECT AT LEAST SOME
LIGHT SHRA THERE SO KEPT THIS IN A TEMPO GROUP. WILL HAVE TO
MONITOR UPSTREAM DEVELOPMENT FOR ANY ADDITIONAL INCLUSION AT TAF
SITES LATER THIS MORNING. ATMOSPHERE BECOMES VERY UNSTABLE THIS
AFTERNOON BUT LITTLE IN WAY OF TRIGGER SEEN IN MODELS. THIS KEEPS
CHANCES FOR TSRA AT TERMINALS SMALL ENOUGH TO NOT INCLUDE IN POINT
FORECAST AT THIS TIME BUT ISOLATED DEVELOPMENT IS POSSIBLE.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...NG
LONG TERM...JT
AVIATION...LASHLEY
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AREA FORECAST DISCUSSION
NWS HASTINGS NE
356 AM CDT FRI JUL 17 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 353 AM CDT FRI JUL 17 2015
SATELLITE AND OBSERVATIONS SHOW CLEAR SKIES FOR MOST OF THE FORECAST
AREA EARLY THIS MORNING. WINDS ARE LIGHT AND VARIABLE DUE TO A WEAK
HIGH PRESSURE SYSTEM ACROSS THE AREA.
A SURFACE LOW IS EXPECTED TO DEVELOP ACROSS WESTERN SOUTH DAKOTA
TODAY. THIS SURFACE LOW AND A WEAK COLD FRONT IS EXPECTED TO MOVE
INTO THE AREA DURING THE DAY AND INTO TONIGHT. AN UPPER LEVEL WAVE
WILL MOVE INTO THE AREA TODAY AND TONIGHT. MODELS HAVE A FEW
DIFFERENCES IN THE TIMING OF THE SURFACE LOW AND FRONT. THE NAM AND
THE RAP ARE A LITTLE SLOWER THAN THE GFS. THUNDERSTORMS ARE EXPECTED
TO DEVELOP DURING THE AFTERNOON IN THE VICINITY OF THE FRONT. HAVE
KEPT SOME LOW POPS IN THE WEST AND NORTH LATE THIS AFTERNOON...BUT
EXPECT THAT CHANCES WILL BE A LITTLE BIT BETTER DURING THE EVENING
HOURS AND ACROSS MORE OF THE AREA. DURING THE EVENING HOURS THE
FRONT IS EXPECTED TO PUSH INTO THE AREA AND THIS WILL SPREAD
THUNDERSTORM CHANCES ACROSS THE ENTIRE AREA.
THIS AFTERNOON TEMPERATURES WILL REACH INTO THE MID 90S TO AROUND 100
DEGREES. WITH DEW POINTS IN THE MID 60S TO AROUND 70 DEGREES...THE
HEAT INDEX VALUES WILL REACH INTO THE 95 TO 103 DEGREE RANGE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 353 AM CDT FRI JUL 17 2015
PRIMARY FORECAST CONCERNS THROUGH THE LONG TERM PERIOD LIE WITH
PERIODIC THUNDERSTORM CHANCES...AND HEAT INDEX VALUES ON SATURDAY
AFTERNOON.
THE START OF THE LONG TERM PERIOD SHOWS MODELS IN GOOD AGREEMENT
LOOKING AT THE OVERALL UPPER LEVEL PATTERN. THE CWA SITS UNDER
SOUTHWESTERLY FLOW...HIGH PRESSURE REMAINS IN PLACE OVER THE SRN
PLAINS/GULF COAST REGIONS...WHILE LOW PRESSURE IS SHIFTING EAST NEAR
THE CAN/ND BORDER WITH A TROUGH AXIS EXTENDING SW INTO THE CENTRAL
WRN COAST AREA. THROUGH THE DAYTIME HOURS ON SATURDAY...THAT NRN LOW
WILL CONTINUE SLIDING EAST...AND WILL PUSH A SURFACE COLD FRONT
SOUTH THROUGH THE NRN/CENTRAL PLAINS. AT THE START OF THE DAY
SATURDAY...MODELS ARE IN PRETTY GOOD AGREEMENT SHOWING THE FRONT
THROUGH THE NWRN CORNER OF THE CWA...AND BY LATE AFTERNOON IS
EXPECTED TO BE OVER THE FAR SERN CORNER. EVEN WITH THE FRONT PASSING
THROUGH...KEPT THE FORECAST DRY DURING THE DAY...WITH MODELS SHOWING
MID LEVEL TEMPS IN THE 14-16 DEGREE C RANGE...AND SHOULD KEEP THINGS
CAPPED. CONFIDENCE IN THE HIGH TEMPERATURES FOR SATURDAY IS ON THE
LOW SIDE WITH A DAYTIME FRONTAL PASSAGE...CURRENT THINKING IS THAT
NRN AREAS WILL PEAK IN THE UPPER 80S /MAYBE MID 80S?/...WHILE FAR
SRN AREAS WHICH WILL BE AHEAD OF THE FRONT LONGER INTO THE AFTERNOON
MAY REACH UP TOWARD THE 100 DEGREE MARK. STILL LOOKING AT THOSE SRN
AREAS TO HAVE THE POTENTIAL TO HAVE HEAT INDEX VALUES CLIMB INTO THE
100 TO 105 DEGREE RANGE.
SAT EVENING/NIGHT...THUNDERSTORMS MAKE A RETURN TO THE FORECAST...AS
THE BROAD MID/UPPER LEVEL TROUGH AXIS STARTS TO PUSH INTO THE AREA.
THINKING THAT THE BETTER CHANCES WOULD BE ACROSS THE SRN HALF OF THE
CWA...CLOSER TO THE SFC FRONT AND AREA OF CONVERGENCE ALONG AN
INCREASED LLJ...BUT THUNDERSTORMS CANT BE COMPLETELY RULED OUT
ANYWHERE IN THE CWA. MODELS SHOW A MODEST AXIS OF INSTABILITY ACROSS
THE AREA...AND WHILE DEEP LAYER SHEAR NEAR/AHEAD OF THE FRONT ISNT
OVERLY STRONG...COULD SEE SOME STRONG/MARGINALLY SEVERE
THUNDERSTORMS DEVELOP. THE CWA SITS IN THE SPC DAY 2 OUTLOOK
MARGINAL RISK AREA.
AS WE GET INTO SUNDAY...THE TRAILING EDGE OF THAT MID/UPPER LEVEL
SHORTWAVE TROUGH CONTINUES TO SLIDE THROUGH THE REGION...AND KEPT
POPS IN THE FORECAST. AGAIN THIS LOOKS TO PRIMARILY AFFECT THE SRN
HALF OF THE CWA...AND MAY BE MAINLY A FIRST HALF OF THE DAY
ISSUE...THOUGH THERE IS SOME HINT IT COULD LINGER INTO THE
AFTERNOON. A SLIGHTLY COOLER /ROUGHLY 5 DEGREES COOLER AT 850MB/
AIRMASS IS EXPECTED TO RESULT IN HIGH TEMPS SUNDAY AFTERNOON
GENERALLY IN THE MID 80S. E/NE WINDS ARE EXPECTED THROUGH THE DAY.
SUNDAY NIGHT...POPS ARE GOING TO BE DEPENDENT ON WHERE THAT SFC
FRONT IS LOCATED...WITH THE POTENTIAL FOR IT TO NOT BE TOO FAR SOUTH
OF THE CWA. POPS ARE CONFINED TO THE SRN HALF OF THE CWA...BUT THERE
IS THE POSSIBILITY THAT ALL ACTIVITY WOULD REMAIN SOUTH OF THE CWA.
WILL HAVE TO SEE HOW MODELS TREND.
LOOKING AHEAD TO THE MON-THURSDAY TIME FRAME...THERE IS THE
POTENTIAL FOR AN UNSETTLED WEATHER PATTERN...AS THE CWA SITS WITH
GENERALLY ZONAL FLOW ALOFT ON THE NRN EDGE OF ELONGATED HIGH
PRESSURE ACROSS THE SRN CONUS. PERIODIC SHORTWAVE DISTURBANCES WILL
CONTINUE TO BRING CHANCES FOR THUNDERSTORMS TO THE CWA...BUT OVERALL
CONFIDENCE IN THE TIMING/LOCATIONS OF THESE DISTURBANCES AND
ASSOCIATED POPS IS DEFINITELY ON THE LOW SIDE. HIGHS THROUGH THIS
TIME FRAME RANGE FROM THE MID 80S/NEAR 90 NORTH TO LOWER/MID 90S IN
THE SOUTH.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1220 AM CDT FRI JUL 17 2015
CLEAR SKIES AND LIGHT WINDS ARE EXPECTED THROUGH THE NIGHT WITH
INCREASING MID LEVEL CLOUDS DURING THE MORNING. THE MAIN QUESTION
IS WHETHER THERE WILL BE THUNDERSTORMS LATE IN THE PERIOD. THERE
IS AN OUTSIDE CHANCE...BUT WILL LEAVE IT OUT FOR NOW.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...ADP
AVIATION...JCB
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1231 AM CDT FRI JUL 17 2015
.UPDATE...
ISSUED AT 1225 AM CDT FRI JUL 17 2015
NO MAJOR CHANGES WERE NEEDED FOR THIS UPDATE. TWEAKED
PRECIPITATION CHANCES BASED ON CURRENT RADAR TRENDS AND THE LAST
FEW RUNS OF THE HRRR AND RAP. SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS WILL CONTINUE TO MOVE EAST INTO NORTH DAKOTA FROM
MONTANA THROUGH THE MORNING.
UPDATE ISSUED AT 921 PM CDT THU JUL 16 2015
SURFACE LOW PRESSURE IS SITUATED OVER WEST CENTRAL NORTH DAKOTA
WITH STRONG HIGH PRESSURE BUILDING INTO WESTERN AND CENTRAL
MONTANA. SLIGHTLY UNSTABLE AIRMASS ALOFT OVER WESTERN AND CENTRAL
NORTH DAKOTA TONIGHT. WEAK WAVE MOVING FROM WESTERN INTO CENTRAL
NORTH DAKOTA IS PRODUCING SCATTERED THUNDERSHOWERS ACROSS THE
NORTHWEST INTO NORTH CENTRAL ND...BECOMING ISOLATED AS YOU HEAD
FARTHER SOUTH. DUE TO THE INSTABILITY ALOFT...HAVE EXTENDED THE
SLIGHT CHANCE OF THUNDER FARTHER EAST TONIGHT...COVERING A GOOD
PORTION OF THE FORECAST AREA. LATEST ITERATIONS OF THE RAP AND
HRRR ARE HINTING AT A LINE OF CONVECTION TRACKING ACROSS THE NORTH
CENTRAL LATE THIS EVENING INTO THE EARLY OVERNIGHT HOURS. WILL
NEED TO CONTINUE TO MONITOR CURRENT CONVECTION ACROSS THE
NORTHWEST. THINK THE SEVERE POTENTIAL WOULD BE MINIMAL BUT A FEW
STRONGER STORMS CAN NOT BE RULED OUT. BETTER CHANCE OF SHOWERS AND
THUNDERSTORMS MOVES INTO THE SOUTHWEST LATE THIS EVENING AND
TRACKS INTO CENTRAL NORTH DAKOTA BY MORNING. THIS IS CURRENTLY
COVERED WELL WITH THE CURRENT FORECAST.
UPDATE ISSUED AT 704 PM CDT THU JUL 16 2015
SHOWERS AND THUNDERSTORMS CONTINUE TO TRACK SOUTHEAST ACROSS THE
JAMES RIVER VALLEY. HAVE EXTENDED THE CHANCE FOR THUNDERSTORMS
THROUGH 03Z. LAST SHIFT ADDED A SLIGHT CHANCE OF THUNDERSTORMS TO
THE FAR NORTHWEST EARLY THIS EVENING. A FEW STORMS WERE TRACKING
THROUGH DIVIDE COUNTY. A BETTER CHANCE WILL MOVE INTO THE WEST
LATE THIS EVENING AND TRACK EAST OVERNIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 203 PM CDT THU JUL 16 2015
CURRENT SURFACE ANALYSIS PLACES LOW OVER CENTRAL SASKATCHEWAN WITH
COLD FRONT DROPPING TO THE SOUTH. UPPER LEVEL ANALYSIS PLACES
SHORT WAVE SLIDING THROUGH THE DAKOTAS WITH UPPER LOW OVER WESTERN
ALBERTA. SHOWERS AND THUNDERSTORMS CONTINUE TO DEVELOP OVER THE
JAMES RIVER VALLEY AS AFOREMENTIONED SHORT WAVE CONTINUES ITS
PROGRESSION.
FOR THE REST OF THIS AFTERNOON INTO TONIGHT...SHOWERS AND
THUNDERSTORMS WILL CONTINUE THEIR EASTWARD PROGRESSION...AND
SHOULD PUSH WELL INTO THE EASTERN PART OF THE STATE BY EVENING.
STRONGEST INSTABILITY (~2 KJ/KG) REMAINS OVER THE SOUTHERN JAMES
RIVER VALLEY WITH RATHER WEAK SHEAR. THEREFORE...EXPECT THEIR
COULD BE A SEVERE STORM OR TWO BUT THEY SHOULD BE SHORT LIVED.
WEAK RIDGING PASSES OVER THE AREA BEHIND THE SHORT WAVE TO BRING A
BRIEF QUIET PERIOD. LATE TONIGHT...UPPER LOW WILL PROGRESS
EASTWARD OVER SOUTHERN SASKATCHEWAN. UPPER FLOW SHIFTS
SOUTHWESTERLY WHILE THE AFOREMENTIONED COLD FRONT WORKS INTO
WESTERN PARTS OF THE AREA...BRINGING THE NEXT CHANCES FOR
SHOWERS/THUNDERSTORMS.
ON FRIDAY...UPPER LOW SETTLES SOUTHEAST THROUGH SASKATCHEWAN
BRINGING BROAD CYCLONIC FLOW TO OUR AREA AS COLD FRONT CONTINUES
ITS PROGRESSION. EXPECT SHOWERS AND THUNDERSTORMS TO
CONTINUE...WITH HIGHER COVERAGE TO THE EAST. ONLY AREA WITH
POTENTIAL SEVERE CONCERNS WILL AGAIN BE OVER THE LOWER JAMES RIVER
VALLEY WHERE MODEST INSTABILITY/SHEAR ARE NOTED. TEMPERATURES
WILL BE NOTABLY COOLER...WITH MOST LOCATIONS ONLY PUSHING INTO THE
70S...WITH 80S OVER THE SOUTHERN JAMES RIVER VALLEY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 203 PM CDT THU JUL 16 2015
EXITING MID LEVEL SHORTWAVE SLIDING THROUGH THE JAMES RIVER VALLEY
WILL CONTINUE TO PRODUCE A CHANCE OF SHOWERS/THUNDERSTORMS FRIDAY
EVENING. CHANCES DECREASE TOWARD 06Z SATURDAY AND CONTINUE TO TREND
DOWNWARD QUICKLY THEREAFTER. AS THIS HAPPENS...ATTENTION TURNS TO
THE NORTHWEST. THE NEXT UPPER LOW/ASSOCIATED SHORTWAVE TROUGH AND
SURFACE COLD FRONT WILL SWING ACROSS WESTERN AND CENTRAL NORTH
DAKOTA FRIDAY NIGHT THROUGH SATURDAY AFTERNOON. THE BEST JET
DYNAMICS/LIFT RESIDE ALONG AND NORTH OF THE NORTHERN BORDER. HENCE
CHANCES OF SHOWERS/THUNDERSTORMS ARE HIGHEST ALONG AND NORTH OF
HIGHWAY 2 WITH LITTLE OR NO CHANCE SOUTH OF THIS AREA. A NORTHWEST
FLOW WITH DRIER CONDITIONS TAKE CONTROL SUNDAY. BY MONDAY...A COLD
FRONT WITHIN THE NORTHWEST FLOW WILL MOVE THROUGH. SUPERBLEND GIVES
A SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS SOUTH OF INTERSTATE 94
MONDAY. THEREAFTER...THE UPPER FLOW TRANSITIONS TO WESTERLY BY
MIDWEEK...THEN SOUTHWESTERLY BY LATER IN THE WEEK. APPEARS THERE
WILL BE AN OPPORTUNITY FOR NIGHTTIME CONVECTION ALONG/AHEAD OF AN
ADVANCING WARM FRONT TUESDAY NIGHT INTO WEDNESDAY MORNING AS A LOW
LEVEL JET AND MOISTURE ADVECTION DEVELOP. A MORE ACTIVE PERIOD MAY
BE ON THE INCREASE THURSDAY ONWARD...AS SOUTHWEST FLOW AND EMBEDDED
SHORTWAVES BECOME DOMINANT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1225 AM CDT FRI JUL 17 2015
A COLD FRONT WAS APPROACHING NORTH DAKOTA FROM EASTERN
MONTANA...TRIGGERING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS.
THIS PRECIPITATION WILL CONTINUE TO MOVE EAST INTO WESTERN AND
CENTRAL NORTH DAKOTA THROUGH THE MORNING. VFR CEILINGS AND
VISIBILITIES ARE EXPECTED AT ALL SITES THROUGHOUT THE FORECAST
PERIOD...HOWEVER THUNDERSTORM CHANCES WILL INCREASE FROM WEST TO
EAST AFTER 08Z. EXPECT A SECOND ROUND OF SHOWERS AND STORMS TO
PROPAGATE ACROSS THE STATE FRIDAY AFTERNOON. THUNDERSTORM CHANCES
WILL GREATLY DIMINISH BY SUNSET FRIDAY EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ZH
SHORT TERM...JJS
LONG TERM...KS
AVIATION...ZH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1134 PM CDT THU JUL 16 2015
.UPDATE...
ISSUED AT 1134 PM CDT THU JUL 16 2015
PATCHY FOG DEVELOPING DUE TO LIGHT WINDS AND LOW LEVEL MOISTURE
(PLUS MANY AREAS WITH AMPLE RAINFALL). HRRR INDICATES MOST
LOCATIONS MAY DEVELOP FOG...LIKELY DENSE AT TIMES. NOT SURE HOW
WIDESPREAD THE DENSE FOG WILL BE...BUT AN ADVISORY MAY BE NEEDED
IF CONDITIONS UNFOLD AS THE HRRR SUGGESTS. FOR NOW...ADDED PATCHY
DENSE FOG TO THE FORECAST.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 245 PM CDT THU JUL 16 2015
THE MAIN CHALLENGE WILL BE CONVECTIVE/SEVERE CHANCES THROUGH
FRIDAY. THE CAM MODELS ARE IN PRETTY GOOD AGREEMENT...AND THE
CONSISTENT HRRR HAS A GOOD HANDLE ON THINGS THROUGH THIS EVENING.
WILL LEAN ON THE GFS THEREAFTER WITH BETTER SHEAR AROUND FRI
AFTERNOON/EVENING.
FOR LATE THIS AFTERNOON AND TONIGHT...A STRONG SHORTWAVE WILL MOVE
FROM WEST TO EAST. THERE WILL BE MLCAPE AROUND 1500 J/KG IN THE
SOUTH AND 500-1000J/KG NORTH. MID LEVEL LAPSE RATES ARE NOT TOO
STEEP IN THE NORTH...AND A BIT BETTER SOUTH. THERE HAS ALSO BEEN
PLENTY OF CLOUDS/PRECIP THAT HAS HINDERED WARMING WITH CONVECTIVE
TEMPS AROUND 80. THERE COULD BE A WINDOW WHERE AREAS HEAT OUT SOME
THIS AFTERNOON...AND THERE IS STILL A MARGINAL RISK FOR SEVERE
STORMS WITH THE BEST THREAT IN THE SOUTH CLOSER TO SLIGHTLY BETTER
SHEAR/INSTABILITY.
ON FRIDAY...A SPEED MAX WILL APPROACH FROM THE WEST WITH AMPLE
INSTABILITY OVERSPREADING THE AREA. A SFC LOW WILL TRACK NEAR THE
ND/SD BORDER AROUND 00Z...AND THE POTENTIAL FOR SOME MORE SEVERE
WEATHER IS POSSIBLE. SPC HAS A SLIGHT RISK NEAR THE SOUTH FA AND
MARGINAL RISK TO THE NORTH. THERE SHOULD BE MORE HEATING ON FRIDAY
AHEAD OF THE NEXT SHORTWAVE...ALONG WITH MORE SHEAR...SO POTENTIAL
FOR MORE WIDESPREAD SEVERE CLOSE OR INTO THE FA ON FRIDAY
AFTERNOON INTO THE OVERNIGHT POSSIBLE. THERE IS A 45-50KT LLJ
FRIDAY NIGHT INTO THE MN COUNTIES...SO SEVERE THREAT COULD PERSIST
THROUGH MUCH OF THE NIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 245 PM CDT THU JUL 16 2015
ON SATURDAY...MORNING CONVECTION SHOULD QUICKLY MOVE INTO THE
NORTH AND EAST BY AFTERNOON BEHIND A COLD FRONT. MUCH OF THE
REGION WILL BE DRY SAT AFTERNOON WITH COOLER AIR ALOFT AND TEMPS
IN THE MID/UPPER 70S NORTH TO AROUND 80 SOUTH. IT COULD GET A BIT
BREEZY FROM THE W/NW SAT AFTERNOON WITH PWATS FALLING BELOW 1
INCH.
FOR SUNDAY...IT SHOULD BE DRY WITH TEMPS A BIT WARMER THAN SAT.
WESTERLY FLOW SHOULD PERSIST ALONG WITH PLENTY OF SUNSHINE.
FOR SUN THROUGH THU...HIGH PRESSURE WILL GIVE GENERALLY DRY
CONDITIONS SUN NIGHT INTO MONDAY. A WEAK FRONT WILL DROP SOUTH
THROUGH NRN MINNESOTA LATE MONDAY AND MONDAY EVE GIVING A LOW
RISK OF T-STORMS MAINLY EAST OF THE RED RIVER. MAINLY DRY AGAIN
TUESDAY. NEXT SHORT WAVE OF ANY SIGNIFICANCE IS DUE WED WITH BEST
CHANCES FOR T-STORMS AT THAT TIME. TEMPS TO RUN CLOSE TO NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1134 PM CDT THU JUL 16 2015
LIGHT WINDS AND AMPLE LOW LEVEL MOISTURE WILL LEAD TO SOME AREAS
OF FOG THROUGH THE OVERNIGHT HOURS. KTVF ALREADY DOWN TO
1/2SM...WHICH IS POSSIBLE AT OTHER SITES (MOST LIKELY ALONG AND
EAST OF THE VALLEY WHERE WINDS WILL BE LIGHTEST). FOR
KGFK...KFAR...KBJI...DID NOT GO TOO LOW WITH VSBY AS COVERAGE OF
DENSE FOG IS UNCERTAIN...BUT WILL MONITOR AND AMEND IF NEEDED.
THUNDERSTORM CHANCES INCREASE FRIDAY AFTERNOON.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...DK
LONG TERM...DK/RIDDLE
AVIATION...TG
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
122 AM EDT FRI JUL 17 2015
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFF THE NEW ENGLAND COAST TONIGHT. LOW
PRESSURE OVER NORTHWESTERN IOWA WILL THEN TRACK NORTHEAST INTO
NORTHERN MICHIGAN FRIDAY AND PULL A WEAK FRONTAL BOUNDARY ACROSS THE
AREA FRIDAY AFTERNOON. HIGH PRESSURE WILL BECOME ANCHORED ACROSS THE
SOUTHEASTERN US...DRAWING UP HEAT AND HUMIDITY FROM THE DEEP SOUTH
ACROSS OHIO. SUNDAY NIGHT INTO MONDAY A COLD FRONT WILL CROSS THE
AREA. HIGH PRESSURE RETURNS FOR THE SECOND HALF OF MONDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
OTHER THAN A FEW POSSIBLE
SPRINKLES SOUTH OF MILLERSBURG...FIRST PUSH OF RAIN HAS DISSIPATED
LEAVING BAND OF MID CLOUDS. MCS HAS DEVELOPED OVER NRN IL AND THIS
WILL SPREAD OUT WHILE PUSHING EAST. SHORT TERM HI RES MODELS SEEM
SLOW TO GET THIS PRECIP INTO THE AREA...ESPECIALLY THE RAP WHICH
DOES NOT HAVE ANY MEASURABLE RAIN INTO THE AREA UNTIL AFTER 13Z.
LIKE THE FASTER HRRR MORE. WILL STAY WITH PLAN TO START RAMPING UP
POPS IN THE NW AFTER 06Z TO BE 50 TO 60% FROM 09Z TO 12Z.
OVERNIGHT LOWS WILL BE SLIGHTLY WARMER IN THE WEST WITH ADDITIONAL
CLOUD COVER. LOWS EXPECTED TO RANGE FROM THE MID 60S IN THE WEST TO
UPPER 50S IN THE INLAND EAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
THE WARMEST TEMPERATURES OF THE SUMMER...SO FAR...ARE LIKELY TO
OCCUR THIS WEEKEND. FRIDAY MORNING/AFTERNOON A WARM FRONT WILL PUSH
THROUGH THE AREA WHILE TRAILING A SURFACE LOW ACROSS NORTHERN
MICHIGAN. THE DEEPEST MOISTURE WILL BE NEARER TO THE LOW PRESSURE
CENTER...AND PRIMARILY NORTH OF LAKE ERIE. HOWEVER...POCKETS OF
DEEPER MOISTURE MAY SNEAK INTO NWRN OHIO. AS THE LOW PULLS INTO
CANADA...SO WILL THE MOISTURE...SO EXPECT RAIN CHANCES TO BE LESS
IN THE EAST...WITH PERHAPS ERIE BEING THE EXCEPTION GIVEN ITS
HIGHER LATITUDE. BEHIND THE WARM FRONT TEMPERATURES WILL INCREASE
INTO THE UPPER 80`S AND DEW POINTS WILL INCREASE INTO THE UPPER
60`S AND LOW 70`S...LENDING ITSELF TO ABUNDANT SURFACE BASED
INSTABILITY...AND IN TURN SCATTERED TO NUMEROUS THUNDERSTORMS.
THESE STORMS WILL BE EFFICIENT RAINMAKERS AND COULD CAUSE AREAS OF
LOCALIZED FLOODING...ESPECIALLY WITH PWAT VALUES PROGGED TO EXCEED
1.90 IN MANY LOCATIONS. SCATTERED SUMMERTIME CONVECTION WILL
CONTINUE INTO SATURDAY BUT WILL LIKELY BE LESS WIDESPREAD THAN
FRIDAY GIVEN THE LACK OF A SIGNIFICANT FORCING MECHANISM. THESE
STORMS WILL BE DIURNALLY DRIVEN FOR THE MOST PART. SUNDAY MORNING
AND AFTERNOON RAIN CHANCES END UP BEING BETTER CARE OF A
SHORTWAVE TROUGH THAT WILL PULSE OUT AHEAD OF A COLD FRONT. THE
COLD FRONT WILL PUSH TROUGH THE AREA SUNDAY NIGHT INTO MONDAY...WITH
ADDITIONAL SHOWERS AND THUNDERSTORMS DEVELOPING. MONDAY AFTERNOON
CONDITIONS DRY OUT BEHIND THE FRONT AS HIGH PRESSURE SPREADS IN
FROM THE NORTH.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
THE MODELS ARE TRENDING FASTER WITH THE COLD FRONT ON
MONDAY...AND MOST HAVE THE FRONT SOUTH OF THE FORECAST AREA MONDAY
MORNING. CUT BACK ON POPS FOR THE DAY BUT STILL KEPT A SMALL CHANCE
GIVEN THE UNCERTAINTY OF A CLEAN FRONTAL PASSAGES THIS TIME OF YEAR
AND THE FACT THAT THE FRONT DOES NOT APPEAR TO PUSH TOO FAR TO THE
SOUTH. WENT A COUPLE OF DEGREES LOWER ON HIGH TEMPERATURES...
GENERALLY FROM THE UPPER 70S NEAR LAKE ERIE TO THE LOWER 80S INLAND.
MOST OF THE MODELS HAVE BEEN HINTING AT A SECONDARY FRONT EARLY
WEDNESDAY. WEAK FRONTS THAT COME THROUGH IN THE EARLY MORNING HOURS
THIS TIME OF YEAR OFTEN END UP BEING DRY. WILL NOT INTRODUCE SHOWERS
BUT WILL INCREASE CLOUDS TUESDAY NIGHT INTO WEDNESDAY MORNING.
A PUSH OF HIGH PRESSURE SHOULD KEEP TEMPERATURES IN CHECK...NEAR TO
SLIGHTLY BELOW NORMAL MID WEEK. THE RETURN SOUTH FLOW AND WARM
ADVECTION COULD BRING A SMALL CHANCE OF SHOWERS AND THUNDERSTORMS BY
NEXT THURSDAY NIGHT OR FRIDAY.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
MID LEVEL CLOUDS CONTINUE TO OVERSPREAD THE AREA. RADAR SHOWING
RETURNS OVER NW OHIO. A LOT OF THIS IS PROBABLY VIRGA GIVEN HOW
DRY IT IS IN LOW LEVELS. WILL PROBABLY HAVE TO WAIT FOR THE
RETURNS OVER NE INDIANA TO REACH THE AREA BEFORE THERE IS A
LEGITIMATE CHANCE OF PRECIP REACHING THE GROUND. WILL GIVE THE
WESTERN SITES A FEW HOURS OF LIGHT RAIN LATER TONIGHT. NO THUNDER
FOR NOW. THE NEXT CHALLENGE IS PRECIP CHANCES LATER IN THE DAY.
IT APPEARS THUNDER WILL BE POSSIBLE JUST ABOUT ANYWHERE THIS
AFTERNOON. A LOT OF THIS DEPENDS ON HOW MUCH CLOUDINESS THERE IS
TODAY SO CONFIDENCE ON TIMING AND AERIAL EXTENT IS LOW. WILL GIVE
ALL SITES EITHER A TEMPO OR PROB MENTION LATER IN THE AFTERNOON.
BEST CHANCES WILL BE IN THE SOUTH AND SOUTHWEST WHERE LOW LEVEL
MOISTURE WILL INCREASE THE FASTEST. LIGHT SE FLOW WILL BECOME S TO
SW THIS MORNING WITH GUSTS TO 25 KNOTS LIKELY IN THE AFTERNOON.
OUTLOOK...AREAS OF NON VFR IN SHRA AND TSRA FRI THRU MON ALONG
WITH EARLY MORNING FOG SAT THRU MON.
&&
.MARINE...
THE EASTERLY WIND WITH A BIT OF AN ONSHORE COMPONENT WILL KEEP WAVES
RUNNING A FOOT OR TWO THIS EVENING ON LAKE ERIE BUT IN GENERAL...THE
GRADIENT ON LAKE ERIE WILL REMAIN LIGHT. THE MAIN CONCERN THROUGH
THE WEEKEND IS THE RISK FOR THUNDERSTORMS. SHOWERS AND THUNDERSTORMS
WILL LIKELY DEVELOP ALONG A WEAK WARM FRONT LATER TONIGHT AND FRIDAY
AND MARINERS WILL HAVE TO WATCH FOR THUNDERSTORMS. A WEAKENING FRONT
WILL BRUSH THE LAKE EARLY SATURDAY. THE NEXT SIGNIFICANT FRONT WILL
COME SUNDAY NIGHT OR EARLY MONDAY WITH THUNDERSTORMS LIKELY. WINDS
SEEM AS THOUGH THEY WILL REMAIN LIGHT TO MODERATE BEHIND THE FRONT.
HIGH PRESSURE SHOULD BUILD ACROSS THE LAKE EARLY THE FIRST HALF OF
NEXT WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAYERS
NEAR TERM...ADAMS/MAYERS
SHORT TERM...MAYERS
LONG TERM...KOSARIK
AVIATION...KUBINA
MARINE...KOSARIK
AREA FORECAST DISCUSSION
NWS TULSA OK
1156 PM CDT THU JUL 16 2015
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
FOR THE 6Z TAFS... VFR CONDITIONS WILL PREVAIL AT ALL SITES
THROUGHOUT THE 24 HOUR FORECAST PERIOD. THERE WILL BE A LOW
CHANCE FOR A SHOWER OR THUNDERSTORM TO AFFECT KBVO EARLY FRIDAY
MORNING. HOWEVER... CHANCES ARE TOO LOW TO WARRANT MENTIONING IN
THE TAF. SOUTHWEST WINDS WILL INCREASE DURING THE DAY FRIDAY.
&&
.PREV DISCUSSION... /ISSUED 837 PM CDT THU JUL 16 2015/
DISCUSSION...
SURFACE TROUGH LIES TO THE NORTH AND WEST OF THE FORECAST AREA
THIS EVENING. A FEW STORMS HAVE DEVELOPED ALONG IT OVER SOUTHWEST
KS. NONE OF THE AVAILABLE GUIDANCE SUGGESTS THAT THIS ACTIVITY
WILL SURVIVE FAR ENOUGH EAST TO AFFECT US GIVEN LOSS OF DAYTIME
HEATING. HOWEVER...BOTH THE NAM AND HRRR DEVELOP ACTIVITY...MOST
LIKELY HIGH BASED...WELL AFTER MIDNIGHT OVER SOUTHEAST KS AND
EVENTUALLY DOWN INTO FAR NORTHEAST OK. THIS AGREES WELL WITH GOING
FORECAST.
LACY
PREV DISCUSSION... /ISSUED 557 PM CDT THU JUL 16 2015/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
FOR THE 0Z TAFS... VFR CONDITIONS WILL PREVAIL AT ALL SITES
THROUGHOUT THE 24 HOUR FORECAST PERIOD. THERE WILL BE A LOW
CHANCE FOR A SHOWER OR THUNDERSTORM TO AFFECT KBVO EARLY FRIDAY
MORNING. HOWEVER... CHANCES ARE TOO LOW TO WARRANT MENTIONING IN
THE TAF.
PREV DISCUSSION... /ISSUED 236 PM CDT THU JUL 16 2015/
DISCUSSION...
HOT/HUMID CONDITIONS THIS AFTERNOON WITH HEAT INDICES AGAIN IN THE
100-105 DEGREE RANGE. THE HEAT WILL CONTINUE TO BE AN ISSUE IN THE
UPCOMING DAYS AS LARGE UPPER HIGH REMAINS IN CONTROL OF OVERALL
WEATHER PATTERN.
IN THE SHORT TERM...WEAK UPPER WAVE WILL MOVE OUT OF CO/AZ
TONIGHT WITH THE POTENTIAL FOR SCATTERED HIGH BASED SHOWERS ACROSS
NORTHEAST OKLAHOMA LATE TONIGHT INTO FRIDAY MORNING IN NOSE OF
LOW LEVEL JET AXIS. ELEVATED INSTABILITY MAY BE SUFFICIENT FOR A
FEW THUNDERSTORMS HOWEVER OVERALL COVERAGE IS EXPECTED TO BE
FAIRLY ISOLATED.
AS MENTIONED EARLIER...HEAT WILL REMAIN THE MAIN CONCERN ESPECIALLY
INTO THE WEEKEND AS AFTERNOON HEAT INDICES CLIMB INTO THE 105-110
DEGREE RANGE WITH THE HIGHEST READINGS EXPECTED ACROSS NORTHEAST
OKLAHOMA. A HEAT ADVISORY WILL LIKELY BE REQUIRED DURING THIS
TIME.
MODELS IN GENERAL AGREEMENT CONCERNING TIMING OF NEXT COLD FRONT
MONDAY NIGHT/TUESDAY IN ASSOCIATION WITH UPPER DISTURBANCE MOVING
OUT OF THE NORTHERN ROCKIES. SHOWER/THUNDERSTORM CHANCES WILL
INCREASE AS FRONT MOVES INTO THE AREA WITH LINGERING PRECIP
CHANCES THROUGH MID WEEK ALONG STALLED BOUNDARY.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...06
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
306 AM EDT FRI JUL 17 2015
.SYNOPSIS...
SURFACE HIGH PRESSURE ALONG THE MID ATLANTIC COAST WILL CONTINUE
TO EXTEND SOUTHWEST ALONG THE EASTERN SLOPES OF THE MOUNTAINS
TODAY. RETURN SOUTHERLY FLOW AROUND THE HIGH BRING A RETURN OF
DEEPER MOISTURE LATER TODAY AS WELL AS WIDELY SCATTERED SHOWERS
AND STORMS INTO TONIGHT. UPPER LEVEL HIGH PRESSURE WILL BUILD
EAST FROM THE GULF COAST REGION THIS WEEKEND...RESULTING IN HOTTER
AND MORE HUMID WEATHER INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 235 AM EDT FRIDAY...
WEAK RESIDUAL WEDGE ACROSS THE REGION WILL GRADUALLY BREAK DOWN FOR A
WHILE TODAY AS HIGH PRESSURE SLIDES OFFSHORE ALLOWING THE FLOW TO TURN
MORE SOUTH/SW THIS AFTERNOON. THIS SHOULD ALSO PROVIDE A SLOW INCREASE
IN MOISTURE AS THE WEAK WARM FRONT TO THE SW EDGES SLOWLY NE TOWARD THE
SW MOUNTAINS LATE IN THE DAY. SIMILAR TO THURSDAY...WILL AGAIN INIT
WITH A MIX OF LOWER CLOUDS ESPCLY ALONG/EAST OF THE BLUE RIDGE WITH
THESE GIVING WAY TO AT LEAST PERIODS OF SUN WITH HEATING DURING THE
AFTERNOON. CONVECTIVE CHANCES AGAIN LOOK TO BE TIED TO OROGRAPHICS
LATER THIS AFTERNOON WITH MOISTURE DEPTH AND INSTABILITY LIKELY A BIT
BETTER. HOWEVER DESPITE LINGERING HIGH 85H THETA-E OVER THE WEST...MODELS
REMAIN RATHER ISOLATED WITH SHRA/TSRA AGAIN TODAY GIVEN LACK OF MUCH
FORCING UNDER WEAK FLOW AND LINGERING CAPPED DRY AIR ALOFT. FOR
NOW WILL KEEP 20/30 POPS GOING MAINLY BLUE RIDGE WEST THIS AFTERNOON
FOR POP UP SHALLOW CONVECTION WITH LITTLE POP ACROSS THE FAR EAST
OVERALL PER LATEST HRRR TRENDS. WITH CONTINUED WARMING ALOFT AND
MORE SOUTH/SW FLOW EXPECT TEMPS TO GET A LITTLE MORE OF A BOOST BUT
MAY TAKE A WHILE FOR READINGS TO JUMP PENDING EARLY CLOUDS. WITH
MOS LOCKED IN ON UNIFORM MID/UPPER 80S WONT ADJUST MUCH FROM THE
PREVIOUS FORECAST VALUES FOR NOW.
MOISTURE DEPTH ALONG WITH BETTER FOCUS AND CONVERGENCE MAY ACTUALLY
INCREASE OVERNIGHT AS A WEAK IMPULSE THAT IS CURRENTLY WORKING THROUGH
THE SOUTHERN LAKES DIPS SE WHILE THE FAINT WARM FRONT SLIDES NORTH.
THIS COULD PROVIDE A CORRIDOR FOR UPSTREAM CONVECTION TO SLIDE SE INTO
WEST VA LATE THIS EVENING WITH SOME LATE NIGHT REDEVELOPMENT POSSIBLE
UNDER WEAK WESTERLY FLOW CONVERGENCE ALONG THE NW SLOPES. FORECAST
INSTABILITY ALSO LINGERS OVERNIGHT UNDER WEAK DIFFLUENCE SO
BUMPED UP POPS TO HIGHER CHANCE NW THIRD MAINLY AFTER MIDNIGHT
WHILE SPILLING SOME COVERAGE OUT INTO THE NE SECTIONS ALONG THE
PASSING WARM FRONT LATE. SHOULD STAY DRY ACROSS THE FAR SOUTH/SW
WHERE WILL HAVE ONLY ISOLATED POPS AT BEST. OTRW PARTLY TO MOSTLY
CLOUDY AND A BIT MORE MUGGY UNDER MOISTENING DEWPOINTS...AND LOWS
THAT LOOK TO BE IN THE WARM UPPER 60S TO LOW 70S OVERALL.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 235 AM EDT FRIDAY...
ANY LINGER INFLUENCES OF A WEAK WEDGE OVER THE REGION WILL DISSIPATE
QUICKLY SATURDAY MORNING. BY THE AFTERNOON...A LEE TROUGH WILL
DEVELOP OVER THE COASTAL PIEDMONT AND REMAIN THERE THROUGH THE
WEEKEND. WITH AN UPPER LEVEL RIDGE OVER THE SOUTHERN MISSISSIPPI
VALLEY...WESTERLY WINDS WILL BRING AN INCREASE IN MOISTURE INTO THE
AREA OVER THE WEEKEND. THE COMBINATION OF OROGRAPHIC LIFT OVER THE
MOUNTAINS AND CONVERGENCE NEAR THE LEE TROUGH...WILL BRING SCATTERED
SHOWERS AND THUNDERSTORMS TO THE REGION OVER THE WEEKEND. EXPECTING
TYPICAL DIURNAL CONVECTION TO FADE WITH LOSE OF HEATING EACH
EVENING. HOWEVER...LINGERING INSTABILITIES AND HEAT COULD KEEP
ISOLATED SHOWERS ONGOING INTO THE EARLY MORNING HOURS. TEMPERATURES
WILL RUN WARMER THAN NORMAL THIS WEEKEND WITH MID TO UPPER 80S WEST
TO LOWER TO MID 90S EAST.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
.
AS OF 155 PM EDT THURSDAY...
OVERALL PATTERN TUESDAY THROUGH THURSDAY MAINTAINS A BROAD RIDGE IN
THE SOUTH AND ZONAL FLOW IN THE NORTHERN STREAM. TROFFING MAY BE
STARTING TO AMPLIFY IN THE NORTHEAST WITH THE RIDGE RETROGRADING IN
THE SOUTHWEST BY WEDNESDAY AND THURSDAY.
ENSEMBLE GFS AND OTHER GUIDANCE SHOWED FRONTAL PASSAGE ON MONDAY.
EXPECT BEST COVERAGE OF PRECIPITATION ON SUNDAY NIGHT THROUGH MONDAY
NIGHT. FRONT MOVES FAR ENOUGH SOUTH OF THE FORECAST AREA THAT THE
PROBABILITY OF PRECIPITATION LOWERS FOR WEDNESDAY AND THURSDAY.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
AS OF 1252 AM EDT FRIDAY...
SEEING STRATO-CU ONCE AGAIN FILL IN ALONG THE BLUE RIDGE TONIGHT
AS WEAK SOUTH/SE FLOW IS LIFTED OVER THE WEAK WEDGE AND UNDER THE
INVERSION ALOFT. THIS WILL ALLOW FOR AREAS OF MVFR CIGS THROUGH
DAYBREAK AS BASES LOWER AND THE CANOPY SPILLS BACK EAST LATE WITH
THE FLOW TURNING A BIT MORE SW TOWARD DAWN. HOWEVER THINK OVERALL
WILL SEE CIGS STAY AT LOW END VFR LEVELS FOR A FEW MORE HOURS
ESPCLY EAST WHERE DRIER AIR CONTINUES TO ADVECT IN FROM THE NORTH.
FOG FORMATION REMAINS IFFY GIVEN EXPANSIVE CLOUD COVER OVERNIGHT
AND SE FLOW. APPEARS FOG MAY DEVELOP DUE TO STRATUS PER LOWER CIGS
ACROSS THE WEST WHILE IF ANY CLEARING DOES DEVELOP THEN MAY SEE
KLWB/KBCB TREND DOWN INTO MVFR/IFR VSBYS BUT LOW CONFIDENCE AT
THIS POINT SO EDGED FORECAST VSBYS UP A NOTCH. ELSW SOME PATCHY
FOG POSSIBLE OVER THE EAST BEFORE CLOUDS FILL IN BUT THINK MIXING
AND LACK OF UPSLOPE AT KBLF SHOULD ALLOW LESS FOG THERE THAN SEEN
IN PAST OVERNIGHTS.
TRAPPED LOWER CIGS INCLUDING SOME FOG WILL LIKELY LINGER INTO
FRIDAY MORNING AND MAY TAKE UNTIL EARLY AFTERNOON TO MIX OUT LOW
CLOUDS ALONG THE SOUTHERN BLUE RIDGE AND POINTS EAST. APPEARS MOST
SITES SHOULD RETURN TO VFR FRIDAY AFTERNOON BUT GIVEN
MOISTURE/HEATING STILL EXPECTING A 4-6K FT SCTD-BKN LAYER THIS
AFTERNOON.
WITH WINDS SHIFTING SOUTHERLY FRIDAY AFTERNOON...WILL SEE GREATER
RETURN OF MOISTURE ACROSS THE MOUNTAINS...AND SLIGHTLY BETTER
CHANCES OF POP UP SHOWER/THUNDERSTORM ACTIVITY ACROSS THE
MOUNTAINS. MOST CONVECTION WILL NOT DEVELOP UNTIL MID
AFTERNOON/EVENING TIME FRAME. POP VALUES ARE SO LOW...LEFT OUT ANY
CONVECTIVE MENTION IN THE TAFS. THAT MAY NEED AMENDING AS WE
ENTER INTO THE 12Z/18Z TAF FCST PERIOD TOMORROW BASED ON SHORT-
RANGE MODEL + RADAR/SATELLITE TRENDS.
EXTENDED AVIATION DISCUSSION...
WITH OPPORTUNITY FOR CLEARING TO TAKE PLACE FRIDAY NIGHT...WILL
HAVE SOME MORNING FOG/LOW CLOUDS ISSUES IN THE MOUNTAIN
VALLEYS...AND GROUND FOG FOR THE LOW LYING AREAS OF THE FOOTHILLS
AND PIEDMONT. OVERALL CONDITIONS HOWEVER SHOULD BE MAINLY VFR.
WIDELY SCATTERED MORE DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS
RETURN TO THE REGION ON SATURDAY AND SUNDAY WITH PERHAPS MORE
WIDESPREAD COVERAGE ON MONDAY AHEAD OF THE NEXT COLD FRONT. THE
BOUNDARY MAY STALL OUT NEAR THE REGION TUESDAY WITH ISOLATED
CONVECTION POSSIBLE MAINLY OVER SOUTHERN/WESTERN SECTIONS TUESDAY
AFTERNOON/EVENING. MVFR TO IFR CONDITIONS ARE POSSIBLE WITH ANY OF
THE STORMS. OTHERWISE VFR CEILINGS AND VISIBILITIES ARE EXPECTED
OUTSIDE OF ANY OF THE CONVECTION.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/NF
NEAR TERM...JH
SHORT TERM...RCS
LONG TERM...AMS
AVIATION...JH/JM/NF/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
109 AM EDT FRI JUL 17 2015
.SYNOPSIS...
SURFACE HIGH PRESSURE ALONG THE MID ATLANTIC COAST WILL CONTINUE
TO EXTEND SOUTHWEST ALONG THE EASTERN SLOPES OF THE MOUNTAINS
INTO FRIDAY. RETURN SOUTHERLY FLOW AROUND THE HIGH BRING A RETURN
OF DEEPER MOISTURE LATER FRIDAY AS WELL AS WIDELY SCATTERED
SHOWERS AND STORMS INTO FRIDAY NIGHT. UPPER LEVEL HIGH PRESSURE
WILL BUILD EAST FROM THE GULF COAST REGION THIS WEEKEND...RESULTING
IN HOTTER AND MORE HUMID WEATHER INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1120 PM EDT THURSDAY...
NOT SEEING ANY OBVIOUS EVIDENCE OF SHOWERS ON RADAR OR IN
OBS...AND THE 18Z/00Z NAM WILL NOT BE USED AS IT HAD CONVECTIVE
FEEDBACK ISSUES PER QPF FIELD BULLSEYES.
WILL SEE THE CLOUD COVER NEAR THE BLUE RIDGE EXPAND OVERNIGHT INTO
PORTIONS OF THE NEW RIVER VALLEY INTO THE VA/NC FOOTHILLS...WITH
LESS CLOUD COVER OVER WRN SLOPES OF SE WV. MSAS SHOWING LOWER
DEWPOINTS STREAMING SWD TOWARD THE LEE OF THE APPALACHIANS...WITH
LYH ALREADY WITH UPPER 50S DEWPOINTS...COMPARED TO MID 60S IN THE
SOUTH. MADE SOME ADJUSTMENTS SLIGHTLY COOLER FOR OVERNIGHT
LOWS...ESPECIALLY OVER THE NRN CWA. WHERE CLOUD COVER WILL BE
GREATEST WILL BE STEADYING OUT OVERNIGHT. ANY SHOWERS APPEAR TO BE
CONFINED TO VERY LIGHT EARLY OVER THE NC MTNS...SO OVERALL KEPT
THE FORECAST DRY OVERNIGHT.
SHOULD SEE PATCHY FOG OVERNIGHT IN THE MTNS AND SOME OF THE WRN
VALLEYS WHERE LESS CLOUD COVER OCCURS. FURTHER EAST HAVE ADDED FOG
AS WELL AS RAP AND GFS SHOWING THAT TEMP/DEWPOINT SPREAD WILL BE
NEAR ZERO...THOUGH CLOUD COVER MAY LIMIT FOG TO CLOSER TO THE BLUE
RIDGE.
PREVIOUS VALID DISCUSSION...
FRIDAY WILL BEGIN A WARMING TREND AS SUBTROPICAL RIDGING OVER THE
GULF COAST REGION BUILDS EASTWARD GOING INTO THE END OF THE WEEK.
FACTOR THAT WITH WINDS SHIFTING SOUTHERLY DURING THE AFTERNOON AND
MOSTLY CLEAR TO PARTLY CLOUDY SKIES TO ALLOW FOR STRONG SURFACE
HEATING...AND WE CAN EXPECT FRIDAY AFTERNOON HIGHS TO RANGE FROM
THE LOW/MID 80S FOR THE MOUNTAINS...TO THE UPPER 80S ACROSS THE
PIEDMONT. WITH TROPICAL MOISTURE BEGINNING ITS RETURN ALONG THE
APPALACHIAN CHAIN...WE CAN ALSO EXPECT A BETTER CHANCE OF POP UP
SHOWERS AND THUNDERSTORMS FOR THE AFTERNOON...MAINLY ACROSS THE
MOUNTAINS...ALTHOUGH A FEW MAY DRIFT EAST ACROSS THE PIEDMONT
DURING THE EVENING.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
AS OF 255 PM EDT THURSDAY...
SURFACE LOW PRESSURE CROSSES THE GREAT LAKES WITH A WARM FRONT
MOVING NORTHEAST THROUGH THE OHIO VALLEY ON THURSDAY NIGHT AND
FRIDAY. FORECAST AREA WILL BE IN DEEP SOUTHWEST WINDS AND WELL INTO
THE WARM SECTOR BY LATE FRIDAY. MODELS SHOW INCREASE IN 850
TEMPERATURES BY SATURDAY AND SUNDAY WITH VALUES FORECAST AROUND +22
IN SOUTHERN VIRGINIA AND NORTHERN NORTH CAROLINA BY SUNDAY.
EXPECT THERE WILL BE A PRE-FRONTAL/APPALACHIAN LEE TROF ON SUNDAY
AHEAD OF THE COLD FRONT THAT WILL APPROACHING FROM THE NORTHWEST.
THIS TROF WILL CREATE ENOUGH LOW LEVEL CONVERGENCE TO TRIGGER
SHOWERS AND THUNDERSTORMS IN THE AFTERNOON AND EVENING. EXPECT MORE
AREAL COVERAGE OF PRECIPITATION ON SUNDAY THAN ON SATURDAY. FORECAST
AREA WILL BE ON THE EDGE OF THE UPPER RIDGE AND WARMER MID LEVEL
TEMPERATURES...BUT NOT EXPECTING ENOUGH OF A CAP TO LIMIT
THUNDERSTORM DEVELOPMENT.
PRESENCE OF A LEE SIDE TROF WILL MEAN DOWNSLOPING WINDS ON THE EAST
SIDE OF THE APPALACHIANS...FURTHER WARMING THE AIR. MAXIMUM
TEMPERATURES WILL BE ABOVE NORMAL SATURDAY AND SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
.
AS OF 155 PM EDT THURSDAY...
OVERALL PATTERN TUESDAY THROUGH THURSDAY MAINTAINS A BROAD RIDGE IN
THE SOUTH AND ZONAL FLOW IN THE NORTHERN STREAM. TROFFING MAY BE
STARTING TO AMPLIFY IN THE NORTHEAST WITH THE RIDGE RETROGRADING IN
THE SOUTHWEST BY WEDNESDAY AND THURSDAY.
ENSEMBLE GFS AND OTHER GUIDANCE SHOWED FRONTAL PASSAGE ON MONDAY.
EXPECT BEST COVERAGE OF PRECIPITATION ON SUNDAY NIGHT THROUGH MONDAY
NIGHT. FRONT MOVES FAR ENOUGH SOUTH OF THE FORECAST AREA THAT THE
PROBABILITY OF PRECIPITATION LOWERS FOR WEDNESDAY AND THURSDAY.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 1252 AM EDT FRIDAY...
SEEING STRATO-CU ONCE AGAIN FILL IN ALONG THE BLUE RIDGE TONIGHT
AS WEAK SOUTH/SE FLOW IS LIFTED OVER THE WEAK WEDGE AND UNDER THE
INVERSION ALOFT. THIS WILL ALLOW FOR AREAS OF MVFR CIGS THROUGH
DAYBREAK AS BASES LOWER AND THE CANOPY SPILLS BACK EAST LATE WITH
THE FLOW TURNING A BIT MORE SW TOWARD DAWN. HOWEVER THINK OVERALL
WILL SEE CIGS STAY AT LOW END VFR LEVELS FOR A FEW MORE HOURS
ESPCLY EAST WHERE DRIER AIR CONTINUES TO ADVECT IN FROM THE NORTH.
FOG FORMATION REMAINS IFFY GIVEN EXPANSIVE CLOUD COVER OVERNIGHT
AND SE FLOW. APPEARS FOG MAY DEVELOP DUE TO STRATUS PER LOWER CIGS
ACROSS THE WEST WHILE IF ANY CLEARING DOES DEVELOP THEN MAY SEE
KLWB/KBCB TREND DOWN INTO MVFR/IFR VSBYS BUT LOW CONFIDENCE AT
THIS POINT SO EDGED FORECAST VSBYS UP A NOTCH. ELSW SOME PATCHY
FOG POSSIBLE OVER THE EAST BEFORE CLOUDS FILL IN BUT THINK MIXING
AND LACK OF UPSLOPE AT KBLF SHOULD ALLOW LESS FOG THERE THAN SEEN
IN PAST OVERNIGHTS.
TRAPPED LOWER CIGS INCLUDING SOME FOG WILL LIKELY LINGER INTO
FRIDAY MORNING AND MAY TAKE UNTIL EARLY AFTERNOON TO MIX OUT LOW
CLOUDS ALONG THE SOUTHERN BLUE RIDGE AND POINTS EAST. APPEARS MOST
SITES SHOULD RETURN TO VFR FRIDAY AFTERNOON BUT GIVEN
MOISTURE/HEATING STILL EXPECTING A 4-6K FT SCTD-BKN LAYER THIS
AFTERNOON.
WITH WINDS SHIFTING SOUTHERLY FRIDAY AFTERNOON...WILL SEE GREATER
RETURN OF MOISTURE ACROSS THE MOUNTAINS...AND SLIGHTLY BETTER
CHANCES OF POP UP SHOWER/THUNDERSTORM ACTIVITY ACROSS THE
MOUNTAINS. MOST CONVECTION WILL NOT DEVELOP UNTIL MID
AFTERNOON/EVENING TIME FRAME. POP VALUES ARE SO LOW...LEFT OUT ANY
CONVECTIVE MENTION IN THE TAFS. THAT MAY NEED AMENDING AS WE
ENTER INTO THE 12Z/18Z TAF FCST PERIOD TOMORROW BASED ON SHORT-
RANGE MODEL + RADAR/SATELLITE TRENDS.
EXTENDED AVIATION DISCUSSION...
WITH OPPORTUNITY FOR CLEARING TO TAKE PLACE FRIDAY NIGHT...WILL
HAVE SOME MORNING FOG/LOW CLOUDS ISSUES IN THE MOUNTAIN
VALLEYS...AND GROUND FOG FOR THE LOW LYING AREAS OF THE FOOTHILLS
AND PIEDMONT. OVERALL CONDITIONS HOWEVER SHOULD BE MAINLY VFR.
WIDELY SCATTERED MORE DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS
RETURN TO THE REGION ON SATURDAY AND SUNDAY WITH PERHAPS MORE
WIDESPREAD COVERAGE ON MONDAY AHEAD OF THE NEXT COLD FRONT. THE
BOUNDARY MAY STALL OUT NEAR THE REGION TUESDAY WITH ISOLATED
CONVECTION POSSIBLE MAINLY OVER SOUTHERN/WESTERN SECTIONS TUESDAY
AFTERNOON/EVENING. MVFR TO IFR CONDITIONS ARE POSSIBLE WITH ANY OF
THE STORMS. OTHERWISE VFR CEILINGS AND VISIBILITIES ARE EXPECTED
OUTSIDE OF ANY OF THE CONVECTION.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/NF
NEAR TERM...NF/WP
SHORT TERM...AMS
LONG TERM...AMS
AVIATION...JH/JM/NF/WP
AREA FORECAST DISCUSSION
NWS MIAMI FL
1125 AM EDT FRI JUL 17 2015
.UPDATE...
LATEST SURFACE ANALYSIS SHOWS WEAK FRONTAL BOUNDARY WITH LOW LEVEL
CONVERGENCE BOUNDARY FURTHER SOUTH ACROSS EAST CENTRAL GULF UNDERNEATH
AREA OF UPPER LEVEL DIFLUENCE AND HIGHER PRECIPITABLE WATER VALUES
FUELING CONVECTION ACROSS THAT REGION AT THIS TIME. 12Z SNDG PARAMETERS
REVEAL MID LEVELS SLIGHTLY WARMER THAN NORMAL ACROSS SOUTH FLORIDA,
WITH 700-500MB LAPSE RATES OF AROUND 6.2 C/KM WITH A VERY UNIMPRESSIVE
THERMAL PROFILE BELOW 650 MB OR SO. MICROBURST INDICES INDICATE
ONLY MARGINAL POTENTIAL FOR TODAY WITH EVEN LESS FOR HAIL. PWAT
VALUES HAVE FALLEN SINCE YESTERDAY TO NEAR NORMAL LEVELS PER
BLENDED AMSU/SSMI/GPSMET SATELLITE PRODUCT WITH SLIGHTLY DRIER AIR
COLUMN. ON THE OTHER HAND, PLENTY OF HEATING TODAY VERSUS
YESTERDAY YET BECAUSE OF UNIMPRESSIVE THERMAL PROFILES MODIFIED
SOUNDING STILL YIELDED 2700 J/KG CAPE. ALL IN ALL THIS MEANS
MOSTLY GARDEN VARIETY STORMS TODAY WITH MAIN CONCERNS BEING
FREQUENT LIGHTNING WITH THE STRONGEST STORMS AND MAY BE WIND GUSTS
IN EXCESS OF 40 MPH.
ENSEMBLE OF HIGH RESOLUTION MODELS BETWEEN HRRR AND TWO OTHER LOCAL
CONFIGURATIONS STILL INDICATE AREA MOST FAVORED FOR CONVECTION TODAY
WILL BE INTERIOR AND EASTERN HALF OF SOUTH FLORIDA WITH BEST CHANCES
UP THE EAST COAST TOWARDS WEST PALM BEACH. THERE IS STILL A LESSER
CHANCE FOR THE WEST COAST FROM ACTIVITY TO THE NORTH/NORTHWEST
PROPAGATING SOUTH AND/OR DIURNAL CONVECTION ACROSS THE INTERIOR
IMPACTING NAPLES AREA ON ITS WESTERN PERIPHERY.
FORECAST GRIDS ARE BEING AMENDED ACCORDINGLY ALONG WITH HWO.
&&
.PREV DISCUSSION... /ISSUED 819 AM EDT FRI JUL 17 2015/
AVIATION...
A LIGHT SOUTHWESTERLY FLOW PREVAILS ACROSS THE REGION WITH NO
CONVECTION EXPECTED AND MAINLY VFR CONDITIONS EXPECTED DURING THE
MORNING HOURS. A BROAD AND WEAK SURFACE LOW WILL DEVELOP ACROSS
NORTH FLORIDA LATER TODAY WITH LIGHT SOUTHWESTERLY WINDS PREVAILING
ACROSS SOUTH FLORIDA. BUT AROUND THE 16-17Z TIME FRAME THE EAST
SEA BREEZE SHOULD FORM AND WITH DEEP TROPICAL MOISTURE ACROSS THE
REGION ACTIVE CONVECTION IS EXPECTED ACROSS THE EASTERN PENINSULA
TODAY WITH ALL EAST COAST TERMINALS ASSIGNED VCTS OR EVEN
TEMPO/PROB30 AFTER 16Z...WITH BRIEF PERIODS OF MVFR TO NEAR IFR
CONDITIONS POSSIBLE WITH STRONGER SHOWERS/THUNDERSTORMS. FOR
TERMINAL KAPF ...ON-SET OF SEA BREEZE COULD BE AROUND 15-17Z BUT
ON-SET OF CONVECTION COULD BE ANYTIME AFTER 15Z PARTICULARLY FROM
ACTIVITY TO THE NORTH NORTHWEST PROPAGATING SOUTH OR FROM DIURNAL
CONVECTION INLAND IMPACTING THE SITE ON ITS WESTERN PERIPHERY.
CONVECTION SHOULD ALSO WIND DOWN BY THE EVENING. STRONGER
CONVECTION TODAY FAVORS THE EAST COAST SITES.
PREV DISCUSSION... /ISSUED 354 AM EDT FRI JUL 17 2015/
DISCUSSION...
A BROAD TROUGH WITH AXIS OVER NORTH FLORIDA ALONG WITH THE
ATLANTIC SURFACE RIDGE SHUNTED SOUTH ACROSS THE FLORIDA STRAITS IS
RESULTING IN A PREVAILING SOUTHWEST WIND FLOW ACROSS SOUTH
FLORIDA. MOISTURE IS AT OR SLIGHTLY ABOVE THE MEAN FOR MID
JULY...WITH PW IN THE 1.75-2.00 RANGE. BROAD SCALE CONVERGENCE
WILL OCCUR ACROSS SOUTH FL TODAY ALONG WITH MESOSCALE SEA BREEZE
CONVERGENCE...AND WITH HEALTHY MOISTURE AND INSTABILITY IN PLACE,
AM EXPECTING THE TRANQUIL MORNING TO TURN TO A STORMY AFTERNOON
FOR MANY LOCALES. A FEW TSTORMS COULD EVEN DEVELOP BY LATE
MORNING.
HIGH RES MODEL CONSENSUS SHOWS CONVECTION DEVELOPING ALONG BOTH
THE GULF AND ATLANTIC SEA BREEZE WITH THE HIGHER COVERAGE AND
INTENSITY ALONG THE ATLANTIC SEA BREEZE...WHICH MAKES SENSE GIVEN
THE FLOW PATTERN.
HRRR SHOWS ISOLATED RAINFALL AMOUNTS OF 2-3" ACROSS THE EAST
COAST METRO AND INTO THE INTERIOR WITH IMPACTS BEING ISOLATED
STREET FLOODING IN TYPICAL (ALTHOUGH NOT THIS YEAR) SOUTH FL
RAINY SEASON STYLE. GUSTY WINDS OF 40-50 MPH WILL BE POSSIBLE AS
WELL.
THE ATLANTIC RIDGE SLOWLY BUILDS NORTH ACROSS SOUTH FL THIS
WEEKEND. THIS WILL LEAD TO A MORE SE SURFACE WIND WHICH WILL FOCUS
TSTORMS FURTHER INLAND. DRIER AIR MOVES IN FROM THE SOUTHEAST.
THE NAVY MODEL SHOWS THIS TO BE A WEAK SAHARAN AIR LAYER
(SAL)...MOVING IN SATURDAY THEN DEPARTING THE AREA BY SUNDAY
EVENING. THIS LOOKS TO REDUCE TSTORM COVERAGE A TAD...BUT WILL
HAVE TO WATCH FOR THE POSSIBILITY OF A FEW STRONGER CELLS
DEVELOPING DUE TO INCREASED INSTABILITY/STEEPER LAPSE RATES OF
THE SAL.
MODEL CONSENSUS SHOWS THE ATLANTIC RIDGE BUILDING INTO THE LAKE
REGION AND POSSIBLY CENTRAL FL EARLY-MID NEXT WEEK BEFORE MOVING
SOUTH AGAIN LATE WEEK. A TYPICAL DIURNAL CONVECTIVE PATTERN WILL
PREVAIL WITH STEERING WINDS FAVORING A FOCUS OF TSTORM
DEVELOPMENT OVER THE INTERIOR EACH DAY.
/GREGORIA
AVIATION...
A LIGHT SOUTHWESTERLY FLOW PREVAILS ACROSS THE REGION WITH NO
CONVECTION EXPECTED AND MAINLY VFR CONDITIONS EXPECTED DURING THE
EARLY MORNING HOURS. A BROAD AND WEAK SURFACE LOW WILL DEVELOP
ACROSS NORTH FLORIDA LATER TODAY WITH LIGHT SOUTHWESTERLY WINDS
PREVAILING ACROSS SOUTH FLORIDA. BUT AROUND THE 16-17Z TIME FRAME
THE EAST SEA BREEZE SHOULD FORM AND WITH DEEP TROPICAL MOISTURE
ACROSS THE REGION ACTIVE CONVECTION IS EXPECTED ACROSS THE EASTERN
PENINSULA TODAY WITH ALL EAST COAST TERMINALS ASSIGNED VCTS AT
16Z...WITH BRIEF PERIODS OF MVFR TO NEAR IFR CONDITIONS POSSIBLE
WITH STRONGER SHOWERS/THUNDERSTORMS. FOR TERMINAL KAPF...ONSET OF
SEA BREEZE COULD BE AROUND 14-16Z BUT ONSET OF CONVECTION STARTING
LATER AROUND 20Z WITH BRIEF PERIODS OF MVFR TO NEAR IFR CONDITIONS
POSSIBLE WITH STRONGER SHOWERS/THUNDERSTORMS. /BD
MARINE...
A PREVAILING WIND FLOW OF AROUND 10 KT OR LESS WILL PREVAIL
THROUGH THE FORECAST PERIOD WITH CORRESPONDINGLY LOW SEAS.
PREVAILING SOUTH-SOUTHWEST WINDS WILL BECOME SOUTH TO SOUTHEAST
THIS WEEKEND AS THE ATLANTIC SURFACE RIDGE BUILDS SLIGHTLY
NORTHWARD.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 91 77 91 77 / 60 30 50 40
FORT LAUDERDALE 90 78 90 79 / 50 40 50 20
MIAMI 91 78 91 79 / 50 30 50 10
NAPLES 89 77 90 77 / 50 30 50 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...52/PS
LONG TERM....52/PS
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1035 AM CDT FRI JUL 17 2015
.UPDATE...
ISSUED AT 1028 AM CDT FRI JUL 17 2015
UPDATED FORECAST PRIMARILY TO ISSUE A HEAT ADVISORY ACROSS THE
NORTHWEST HALF OF THE FORECAST AREA (BLOOMINGTON-TAYLORVILLE
WESTWARD) BEGINNING AROUND NOON TODAY...AND ACROSS THE SOUTHEAST
HALF FOR SATURDAY. PLENTY OF SUNSHINE THIS MORNING HAS ALREADY
RESULTED IN TEMPERATURES REACHING THE MID-UPPER 80S ACROSS THE
WESTERN CWA...AND MOST OF THESE AREAS SHOULD SEE HEAT INDEX OF 105
OR MORE AS EARLY AS THIS AFTERNOON. THE EAST IS SEEING MORE CLOUD
COVER AND ISOLATED STORMS...WHICH MAY KEEP THINGS A BIT LOWER FOR
THE HEAT INDEX TODAY.
IN TERMS OF THE STORMS...CLUSTERS OF STORMS WERE OCCURRING LATE
THIS MORNING AROUND THE NORTHERN PART OF THE ST LOUIS METRO AND
ALSO NORTH OF INDIANAPOLIS. LATEST VISIBLE SATELLITE IMAGERY
SHOWING SOME CUMULUS GROWING NORTHEAST ALONG THIS LINE TOWARD
VANDALIA. HRRR TRYING TO FILL SOME OF THIS IN LATER THIS AFTERNOON
ALONG A WEAK BOUNDARY...PERHAPS A REMNANT OF THE OUTFLOW FROM LAST
NIGHT`S STORMS. HAVE MAINLY KEPT ISOLATED STORMS GOING IN THE
SOUTHEAST HALF OF THE FORECAST AREA...WITH SOME AREAS UP TO ABOUT
A 30% CHANCE.
&&
.SHORT TERM...(TODAY)
ISSUED AT 347 AM CDT FRI JUL 17 2015
WARM FRONT HAS LIFTED NE OF CENTRAL IL EARLY THIS MORNING
LEAVING CWA IN A TROPICAL AIRMASS. WILL ISSUE A SPECIAL WEATHER
STATEMENT (SPS) TO ADDRESS THE HEAT WAVE FROM THIS AFTERNOON THROUGH
THIS WEEKEND. HEAT INDICES SHOULD PEAK FROM 100-105F THIS AFTERNOON
WITH HIGHEST READINGS IN WESTERN COUNTIES WHICH MAY COME CLOSE TO
HEAT ADVISORY CRITERIA AROUND 105F ESPECIALLY FROM JACKSONVILLE
WEST. HIGHS OF 89-93F THIS AFTERNOON WITH VERY MUGGY DEWPOINTS IN
THE MID TO UPPER 70S. A FEW SHOWERS AND THUNDERSTORMS LINGER ALONG
OUTFLOW BOUNDARY FROM MCS IN CENTRAL IL NORTH OF I-72 INTO FAR SE
IA. HRRR IS HANDLING THIS ISOLATED CONVECTION WELL AND USED THIS
MODEL FOR FORECAST TODAY WHICH SHIFTS THE ISOLATED CONVECTION
FURTHER SE DURING THE MORNING. UNSTABLE AIRMASS THIS AFTERNOON WITH
CAPES OF 2-3K J/KG WILL SUPPORT MORE ISOLATED SHOWERS AND
THUNDERSTORMS THIS AFTERNOON AND EARLY EVENING. SPC HAS MARGINAL
RISK OF SEVERE STORMS IN PARTS OF CENTRAL AND EASTERN IL DURING THAT
TIME WITH 5% RISK OF DAMAGING WIND GUSTS EAST OF PEORIA AND
SPRINGFIELD. BULK SHEAR IS WEAK TODAY (10-20 KTS) SO STORMS WILL NOT
BE TOO ORGANIZED.
.LONG TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 347 AM CDT FRI JUL 17 2015
EVEN HOTTER HEAT INDICES EXPECTED SATURDAY AFTERNOON PEAKING FROM
104-109F AND HEAT ADVISORY WILL LIKELY BE NEEDED THEN AND POSSIBLY
IN SOUTHEAST IL ON SUNDAY AFTERNOON WHERE HEAT INDICES NEAR 105F.
SAT APPEARS TO BE THE HOTTEST DAY WITH HIGHS IN THE LOW TO MID 90S
WHILE SUNDAY HIGHS RANGE FROM MID 80S NW OF IL RIVER TO 90-95F IN
SOUTH OF I-72. DEWPOINTS IN THE MID TO UPPER 70S TO COMBINE WITH
THESE HOT TEMPS FOR THE HEAT INDICES TOPPING 105F. HEAT INDICES
SUNDAY AFTERNOON RANGE FROM MID 90S OVER IL RIVER VALLEY TO 104-108F
IN SOUTHEAST IL.
ISOLATED SHOWERS AND THUNDERSTORMS POSSIBLE SAT AFTERNOON OVER
MAINLY NORTHERN AREAS. THEN INCREASING CHANCES OF SHOWERS AND
THUNDERSTORMS OVER AREAS NORTH OF I-72 OVERNIGHT SAT NIGHT WITH
APPROACHING COLD FRONT FROM THE UPPER MIDWEST. SPC HAS MARGINAL RISK
OF SEVERE STORMS NW OF LINCOLN SAT NIGHT FOR GUSTY WINDS WHILE
SLIGHT RISK IS NW OF KNOX AND STARK COUNTIES. 00Z FORECAST MODELS
TRACK COLD FRONT SE ACROSS CENTRAL IL ON SUNDAY AND INTO SOUTHEAST
IL SUNDAY EVENING. THIS TO LIKELY BRING A ROUND OF SHOWERS AND
THUNDERSTORMS. SPC HAS ALL BUT FAR SOUTHEAST IL IN SLIGHT RISK OF
SEVERE STORMS SUNDAY AFTERNOON/EVENING FOR MAINLY DAMAGING WIND
GUSTS.
UPPER LEVEL SUBTROPICAL HIGH PRESSURE RIDGE EXPECTED TO RETROGRADE
BACK INTO THE HIGH PLAINS EARLY NEXT WEEK. THIS WILL BRING A
NORTHWEST FLOW OVER IL WITH TEMPS COOLING CLOSER TO NORMAL ON MONDAY
BEHIND THE COLD FRONT WITH HIGHS OF 82-87F. DEWPOINTS SLIPPING INTO
THE MID TO UPPER 60S OVER CENTRAL AND NW CWA AND LOWER 70S IN
SOUTHEAST IL ON MONDAY. HAVE TRENDED POPS LOWER ON MONDAY INTO
MONDAY NIGHT WITH FRONT GETTING FURTHER SOUTH OF CENTRAL IL INTO THE
TN VALLEY WITH CHANCE POPS IN SOUTHEAST IL, SLIGHT CHANCES CENTRAL
PARTS AND DRY FROM I-74 NORTH.
UPPER LEVEL RIDGE TO EXPAND EAST INTO THE MID MS AND OHIO VALLEYS BY
MIDDLE OF NEXT WEEK WITH 850MB TEMPS CLIMB BACK UP TO LOWER 20SC
WED/THU. HIGH TEMPS IN THE LOW TO MID 80S TUE SHOULD ELEVATE INTO
THE MID TO UPPER 80S WED AND 85-90F THU, AND UPPER 80S/LOWER 90S
NEXT FRI. DEWPOINTS TO CLIMB BACK INTO THE 70S LATER NEXT WORK WEEK.
ECMWF AND GEM MODELS ARE STILL DRIER DURING MIDDLE OF NEXT WEEK
WHILE GFS MODEL BRINGS QPF BACK INTO CENTRAL IL ON TUE. GFS MODEL IS
AN OUTLIER AND JUST KEPT SLIGHT CHANCES OF CONVECTION ON TUE AND
AREAS FROM I-72 NORTH ON WED NIGHT AND THU.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 620 AM CDT FRI JUL 17 2015
OTHER THAN AN HOUR OR TWO OF MVFR VSBYS IN FOG...VFR CONDITIONS
ARE EXPECTED THRU THIS FORECAST PERIOD. FORECAST SOUNDINGS
INDICATE ONLY SCATTERED CUMULUS THIS AFTERNOON WITH BASES AROUND
4000 FEET. SURFACE WINDS WILL BE FROM THE SOUTHWEST AT 10 TO 15
KTS WITH A FEW GUSTS AROUND 20 KTS DURING THE AFTERNOON. A LIGHT
SOUTHWEST WIND IS EXPECTED TONIGHT WITH SPEEDS OF 3 TO 8 KTS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TO 7 PM CDT SATURDAY FOR ILZ044>046-
054>057-061>063-066>068-071>073.
HEAT ADVISORY UNTIL 7 PM CDT SATURDAY FOR ILZ027>031-036>038-
040>043-047>053.
&&
$$
UPDATE...GEELHART
SHORT TERM...07
LONG TERM...07
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
628 AM CDT FRI JUL 17 2015
.SHORT TERM...(TODAY)
ISSUED AT 347 AM CDT FRI JUL 17 2015
WARM FRONT HAS LIFTED NE OF CENTRAL IL EARLY THIS MORNING
LEAVING CWA IN A TROPICAL AIRMASS. WILL ISSUE A SPECIAL WEATHER
STATEMENT (SPS) TO ADDRESS THE HEAT WAVE FROM THIS AFTERNOON THROUGH
THIS WEEKEND. HEAT INDICES SHOULD PEAK FROM 100-105F THIS AFTERNOON
WITH HIGHEST READINGS IN WESTERN COUNTIES WHICH MAY COME CLOSE TO
HEAT ADVISORY CRITERIA AROUND 105F ESPECIALLY FROM JACKSONVILLE
WEST. HIGHS OF 89-93F THIS AFTERNOON WITH VERY MUGGY DEWPOINTS IN
THE MID TO UPPER 70S. A FEW SHOWERS AND THUNDERSTORMS LINGER ALONG
OUTFLOW BOUNDARY FROM MCS IN CENTRAL IL NORTH OF I-72 INTO FAR SE
IA. HRRR IS HANDLING THIS ISOLATED CONVECTION WELL AND USED THIS
MODEL FOR FORECAST TODAY WHICH SHIFTS THE ISOLATED CONVECTION
FURTHER SE DURING THE MORNING. UNSTABLE AIRMASS THIS AFTERNOON WITH
CAPES OF 2-3K J/KG WILL SUPPORT MORE ISOLATED SHOWERS AND
THUNDERSTORMS THIS AFTERNOON AND EARLY EVENING. SPC HAS MARGINAL
RISK OF SEVERE STORMS IN PARTS OF CENTRAL AND EASTERN IL DURING THAT
TIME WITH 5% RISK OF DAMAGING WIND GUSTS EAST OF PEORIA AND
SPRINGFIELD. BULK SHEAR IS WEAK TODAY (10-20 KTS) SO STORMS WILL NOT
BE TOO ORGANIZED.
.LONG TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 347 AM CDT FRI JUL 17 2015
EVEN HOTTER HEAT INDICES EXPECTED SATURDAY AFTERNOON PEAKING FROM
104-109F AND HEAT ADVISORY WILL LIKELY BE NEEDED THEN AND POSSIBLY
IN SOUTHEAST IL ON SUNDAY AFTERNOON WHERE HEAT INDICES NEAR 105F.
SAT APPEARS TO BE THE HOTTEST DAY WITH HIGHS IN THE LOW TO MID 90S
WHILE SUNDAY HIGHS RANGE FROM MID 80S NW OF IL RIVER TO 90-95F IN
SOUTH OF I-72. DEWPOINTS IN THE MID TO UPPER 70S TO COMBINE WITH
THESE HOT TEMPS FOR THE HEAT INDICES TOPPING 105F. HEAT INDICES
SUNDAY AFTERNOON RANGE FROM MID 90S OVER IL RIVER VALLEY TO 104-108F
IN SOUTHEAST IL.
ISOLATED SHOWERS AND THUNDERSTORMS POSSIBLE SAT AFTERNOON OVER
MAINLY NORTHERN AREAS. THEN INCREASING CHANCES OF SHOWERS AND
THUNDERSTORMS OVER AREAS NORTH OF I-72 OVERNIGHT SAT NIGHT WITH
APPROACHING COLD FRONT FROM THE UPPER MIDWEST. SPC HAS MARGINAL RISK
OF SEVERE STORMS NW OF LINCOLN SAT NIGHT FOR GUSTY WINDS WHILE
SLIGHT RISK IS NW OF KNOX AND STARK COUNTIES. 00Z FORECAST MODELS
TRACK COLD FRONT SE ACROSS CENTRAL IL ON SUNDAY AND INTO SOUTHEAST
IL SUNDAY EVENING. THIS TO LIKELY BRING A ROUND OF SHOWERS AND
THUNDERSTORMS. SPC HAS ALL BUT FAR SOUTHEAST IL IN SLIGHT RISK OF
SEVERE STORMS SUNDAY AFTERNOON/EVENING FOR MAINLY DAMAGING WIND
GUSTS.
UPPER LEVEL SUBTROPICAL HIGH PRESSURE RIDGE EXPECTED TO RETROGRADE
BACK INTO THE HIGH PLAINS EARLY NEXT WEEK. THIS WILL BRING A
NORTHWEST FLOW OVER IL WITH TEMPS COOLING CLOSER TO NORMAL ON MONDAY
BEHIND THE COLD FRONT WITH HIGHS OF 82-87F. DEWPOINTS SLIPPING INTO
THE MID TO UPPER 60S OVER CENTRAL AND NW CWA AND LOWER 70S IN
SOUTHEAST IL ON MONDAY. HAVE TRENDED POPS LOWER ON MONDAY INTO
MONDAY NIGHT WITH FRONT GETTING FURTHER SOUTH OF CENTRAL IL INTO THE
TN VALLEY WITH CHANCE POPS IN SOUTHEAST IL, SLIGHT CHANCES CENTRAL
PARTS AND DRY FROM I-74 NORTH.
UPPER LEVEL RIDGE TO EXPAND EAST INTO THE MID MS AND OHIO VALLEYS BY
MIDDLE OF NEXT WEEK WITH 850MB TEMPS CLIMB BACK UP TO LOWER 20SC
WED/THU. HIGH TEMPS IN THE LOW TO MID 80S TUE SHOULD ELEVATE INTO
THE MID TO UPPER 80S WED AND 85-90F THU, AND UPPER 80S/LOWER 90S
NEXT FRI. DEWPOINTS TO CLIMB BACK INTO THE 70S LATER NEXT WORK WEEK.
ECMWF AND GEM MODELS ARE STILL DRIER DURING MIDDLE OF NEXT WEEK
WHILE GFS MODEL BRINGS QPF BACK INTO CENTRAL IL ON TUE. GFS MODEL IS
AN OUTLIER AND JUST KEPT SLIGHT CHANCES OF CONVECTION ON TUE AND
AREAS FROM I-72 NORTH ON WED NIGHT AND THU.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 620 AM CDT FRI JUL 17 2015
OTHER THAN AN HOUR OR TWO OF MVFR VSBYS IN FOG...VFR CONDITIONS
ARE EXPECTED THRU THIS FORECAST PERIOD. FORECAST SOUNDINGS
INDICATE ONLY SCATTERED CUMULUS THIS AFTERNOON WITH BASES AROUND
4000 FEET. SURFACE WINDS WILL BE FROM THE SOUTHWEST AT 10 TO 15
KTS WITH A FEW GUSTS AROUND 20 KTS DURING THE AFTERNOON. A LIGHT
SOUTHWEST WIND IS EXPECTED TONIGHT WITH SPEEDS OF 3 TO 8 KTS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...07
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
614 AM CDT Fri Jul 17 2015
.SHORT TERM...(Today through Saturday night)
Issued at 317 AM CDT FRI JUL 17 2015
High pressure centered over the Southern Plains is keeping a hot and
humid air mass firmly in place over the region. A series of short
waves moving along the northern periphery of the upper level ridge
has set off scattered convection across the mid Mississippi into the
Texas panhandle overnight. However...the convection seems to be
falling apart as it makes its way across Kansas. But with lots of
unstable air across the region...will keep slight chance PoPs in
for the morning hours.
High temperatures and heat index values will once again be the main
concerns into the weekend. Highs for today and Saturday are
expected to be in the low to mid 90s with afternoon heat index values
ranging from 99 to 104 today and 100 to 105 on Saturday. With these
conditions having occurred over several days now in our northern
tier of counties...a heat advisory is in effect for this area for
today and will be in effect for the entire area on Saturday.
.LONG TERM...(Sunday through Thursday)
Issued at 317 AM CDT FRI JUL 17 2015
Conditions are expected to remain hot and humid through the weekend as
the upper level ridge remains in place over the area. The heat
advisory will be in effect through the early evening on Sunday.
Heat index values on Sunday will range from 102 to 109 across the
entire region.
An upper level shortwave trough is forecast to move across the
Northern Plains on Sunday which will suppress the upper ridge and
allow a surface cold front to move into the area. This will bring
a period of unsettled weather to the region through the remainder
of the forecast period.
This next chance of rain is expected to begin during the day on
Sunday. The front stalls out over Arkansas on Monday which will
keep rain chances in the forecast as upper level short waves
periodically traverse the northern periphery of the upper level
ridge. Scattered showers and thunderstorms will be in the forecast
through Thursday.
Highs will also begin to moderate early in the week. Temperatures are
expected to be in the upper 80s to lower 90s on Monday and in the
80s for Tuesday and Wednesday. As the upper level ridge begins to
reassert itself late in the week...expect a return to the hot and
humid conditions.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday Morning)
Issued at 608 AM CDT FRI JUL 17 2015
Some scattered showers were developing in south central Kansas
early this morning and HRRR brings this activity eastward into the
forecast area this morning. Not a high confidence in specific TAF
sites getting showers/thunderstorms today and for now will leave
out and keep in VFR conditions. Should this activity affect any of
the TAF sites, a brief drop to MVFR conditions would be
possible...generally from the mid morning into the early afternoon.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...HEAT ADVISORY from 1 PM Saturday to 8 PM CDT Sunday FOR MOZ057-
058-068>071-077-079>083-088>098-101>106.
HEAT ADVISORY from 1 PM this afternoon to 8 PM CDT Sunday FOR
MOZ055-056-066-067-078.
KS...HEAT ADVISORY from 1 PM Saturday to 8 PM CDT Sunday FOR KSZ097-
101.
HEAT ADVISORY from 1 PM this afternoon to 8 PM CDT Sunday FOR
KSZ073.
&&
$$
SHORT TERM...Gaede
LONG TERM...Gaede
AVIATION...Lindenberg
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1120 AM EDT FRI JUL 17 2015
.SYNOPSIS...
A FRONT WILL REMAIN STALLED ACROSS SOUTHERN SOUTH CAROLINA
TODAY...WITH DRY HIGH PRESSURE CREATING SEASONABLE TEMPERATURES.
AN UPPER RIDGE WILL COMBINE WITH BERMUDA HIGH PRESSURE TO BRING
INCREASING HEAT AND HUMIDITY TO THE AREA BEGINNING SATURDAY. A
COLD FRONT WILL APPROACH ON THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1100 AM FRIDAY...STRONG CAP AT 700 MB AND DEEP...DRY AND
SUBSIDENT NW FLOW SHOULD MAKE IT VERY DIFFICULT FOR ANY SHOWERS TO
DEVELOP TODAY AND HAVE KEPT POPS BELOW THRESHOLD. HOWEVER...ALONG
THE SEABREEZE A STRAY SHOWER OR BRIEF THUNDERSTORM IS POSSIBLE
DURING PEAK HEATING.
CONSENSUS OF GUIDANCE SHOW THAT A STALLED FRONTAL BOUNDARY JUST
TO OUR SOUTH AND EAST TODAY WILL LIFT BACK NORTH ACROSS THE
EASTERN CAROLINAS WHILE DISSIPATING THIS EVENING AND OVERNIGHT.
MEANWHILE...AN UPPER RIDGE WILL EXTEND EASTWARDS ACROSS THE AREA
THROUGH THE PERIOD.
TEMPERATURES WILL RUN NEAR CLIMO...WITH UPPER 80S AT THE COAST
AND LOWER 90S INLAND. OVERNIGHT LOWS WILL BE SIMILARLY SEASONAL OR
ABOVE...RUNNING IN LOWER TO MID 70S.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...BUILDING HEAT AND HUMIDITY FOR THE WKND AS
UPPER RIDGE STRENGTHENS ACROSS THE ARKLATEX AND EXPANDS NORTHEAST.
INITIALLY THIS CREATES HOT BUT DRY WEATHER SATURDAY AS THE MID-
LEVELS REMAIN DRY BENEATH SUBSIDENT FLOW...BUT WITH THE RIDGE AXIS
DISPLACED WELL WEST OF THE AREA...A SHORTWAVE TROUGH WILL DIG
TOWARDS THE AREA ON NW FLOW...AND DRIVE A WEAK COLD FRONT ACROSS THE
REGION LATE SATURDAY. ALTHOUGH TEMPERATURE ADVECTION BEHIND THIS
FEATURE IS BASICALLY NIL (IN FACT SUNDAY MAY BE A BIT HOTTER THAN
SATURDAY) CONVECTION CHANCES WILL RAMP UP LATE SATURDAY INTO
SATURDAY NIGHT THANKS TO THIS FEATURE COMBINING WITH...OR
ENHANCING...THE PIEDMONT TROUGH. WE WILL BE LOSING INSTABILITY AND
HEATING BY THAT TIME...BUT WILL BUMP POP TO MDT/HIGH CHC ESPECIALLY
ACROSS WESTERN ZONES EARLY SATURDAY NIGHT. THEREAFTER...DRY MID-
LEVEL FLOW AND SUBSIDENCE RETURNS...SO ONLY ISOLATED DIURNAL TSTMS
EXPECTED SUNDAY.
850 MB TEMPS CLIMB FROM ABOUT 19C SATURDAY...UP TO 21C ON
SUNDAY...WHICH COMBINED WITH DOWNSLOPE COMPRESSIONAL WARMING WILL
ALLOW THE ENTIRE CWA TO RISE INTO THE 90S...EVEN AT THE BEACHES.
SOME UPR 90S ARE POSSIBLE INLAND ON SUNDAY. LOWS BOTH NIGHTS WILL BE
WELL ABOVE NORMAL FOR MID-JULY...72-75 SATURDAY NIGHT...AND 74-78
SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 AM FRIDAY...BIG HEAT EXPECTED FOR THE FIRST HALF OF THE
UPCOMING WEEK...WITH DANGEROUS HEAT INDICES ONCE AGAIN POSSIBLE.
MASSIVE UPPER RIDGE BUILDS ACROSS 2/3 OF THE NATION MONDAY AND
TUESDAY AND INTO WEDNESDAY. THE CENTER OF THIS RIDGE WILL REMAIN
OVER THE CENTER OF THE NATION...SO MID-LEVEL FLOW LOCALLY WILL BE
W/NW. THE AIRMASS COMING INTO THE CAROLINAS EARLY NEXT WEEK
ORIGINATES ACROSS THE MEXICAN MOUNTAINS AND THEN ADVECTS AROUND THE
RIDGE AND INTO THE MID-ATLANTIC. THIS DRIVES TREMENDOUSLY WARM 850MB
AIR INTO THE AREA...WITH THE GFS SHOWING 24C...ALTHOUGH THE COOLER
ECMWF KEEPING TEMPS TO 22C AT THAT LEVEL. THE GFS HAS PERFORMED
BETTER WITH THE BIG HEAT THIS SUMMER HOWEVER...AND IS PREFERRED.
THIS WILL DRIVE HIGHS WELL INTO THE 90S EVEN AT THE COAST...WITH 100
DEGREE READINGS POSSIBLY RETURNING TO INLAND ZONES. LOWS AT NIGHT
WILL STRUGGLE TO DROP MUCH BELOW 80. FORCING DURING THIS TIME IS
LIMITED AS WELL...BUT WITH A POTENTIAL MEXICAN EML AND VERY
HOT/UNSTABLE AIR IN PLACE...SCT CONVECTION WILL BE POSSIBLE EACH
DAY. LATE WEDNESDAY INTO THURSDAY...GUIDANCE TRIES TO PUSH A FRONT
DOWN INTO THE AREA WITH HEIGHTS LOWERING ALOFT. AS THE RIDGE STAYS
TO THE WEST...IT IS POSSIBLE THAT A BOUNDARY WILL DRAG THIS FAR
SOUTH...ALTHOUGH THIS IS CLIMATOLOGICALLY WELL OUT OF SEASON. FOR
NOW WILL SHOW SLIGHTLY COOLER TEMPS AT THE END OF THE PERIOD ALONG
WITH SLIGHTLY HIGHER POP.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 12Z...THE MORNING STARTS WITH IFR CEILINGS AT KFLO AND KMYR
WITH STRATUS AT 600 TO 700 FEET. THIS WILL LIFT BETWEEN 13 AND 14
UTC AND VFR CONDITIONS WILL THEN PREVAIL AT ALL TAF SITES THROUGH
MUCH OF THE PERIOD. THE 10 UTC HRRR MODEL ONLY SHOWS WEAK ISOLATED
SHOWERS DEVELOPING IN AND AROUND THE TAF SITES AFTER 19 UTC BUT
SINCE THE HRRR HAS SHOWN A BIAS FOR OVERDEVELOPING CONVECTION WILL
NOT INCLUDE VCSH AT THIS TIME.
WITH LOW LEVEL MOISTURE RETURNING LATER TODAY THERE IS
POSSIBILITY OF MVFR/IFR RESTRICTIONS TO VISION MAINLY AT THE
INLAND TAF SITES AFTER 08 UTC.
EXTENDED OUTLOOK...BRIEF MVFR POSSIBLE OVER THE WEEKEND DUE TO
DIURNALLY DRIVEN CONVECTION. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH 6 AM FRIDAY/...
AS OF 1100 AM FRIDAY...NE TO E WINDS WILL BECOME SE TONIGHT AS A
WEAK FRONTAL BOUNDARY PUSHES BACK NORTH ACROSS THE WATERS. WINDS
WILL RANGE FROM 10 TO 15 KT THROUGH THE PERIOD...WITH SEAS OF
2 TO 3 FT.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...A BRIEF PERIOD OF NE WINDS WILL START THE
PERIOD...BUT THESE QUICKLY RETURN TO THE SW SATURDAY AFTN AS BERMUDA
HIGH PRESSURE RE-ASSERTS ITSELF ACROSS THE AREA. THESE WINDS WILL BE
LIGHT ON SATURDAY...LESS THAN 10 KT...BUT THEN INCREASE SUNDAY AS
A COLD FRONT APPROACHES FROM THE NW. THIS FRONT LIKELY WILL STALL
WEST OF THE WATERS SO NOW FURTHER WIND SHIFT IS EXPECTED...BUT THE
TIGHTENING OF THE GRADIENT WILL DRIVE WIND SPEEDS UP TO 15 KT LATE
SUNDAY BEFORE THEY EASE AGAIN AT THE END OF THE PERIOD. SEAS WILL
BE ONLY AROUND 2 FT SATURDAY ON THE LIGHT AND VARYING
WINDS...RISING TO 3 FT SUNDAY THANKS TO AN INCREASING 5 SEC SW
WIND WAVE.
LONG TERM /MONDAY THROUGH TUESDAY/
AS OF 300 AM FRIDAY...PERSISTENT BERMUDA HIGH PRESSURE WILL DRIVE SW
FLOW THROUGH THE PERIOD...AND SPEEDS WILL BE AROUND 15 KT WITH
LITTLE FLUCTUATION. ALTHOUGH WINDS WILL BE NEARLY CONSTANT...SEAS
WILL SLOWLY BUILD MONDAY INTO TUESDAY...THANKS TO THE DURATION OF
THIS CONSTANT SW FETCH. SEAS OF AROUND 3 FT MONDAY WILL RISE TO 4
FT TUESDAY...WITH THE 5 SEC SW WIND CHOP DOMINATING THE SPECTRUM.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RJD
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...DRH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
738 AM EDT FRI JUL 17 2015
.SYNOPSIS...
A FRONT WILL REMAIN STALLED ACROSS SOUTHERN SOUTH CAROLINA
TODAY...WITH DRY HIGH PRESSURE CREATING SEASONABLE TEMPS LOCALLY.
AN UPPER RIDGE WILL COMBINE WITH BERMUDA HIGH PRESSURE TO BRING
INCREASING HEAT AND HUMIDITY TO THE AREA BEGINNING SATURDAY. HEAT
ADVISORY CRITERIA MAY BE REACHED SEVERAL DAYS NEXT WEEK. A COLD
FRONT WILL APPROACH ON THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM FRIDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:
A CONSENSUS OF GUIDANCE SHOW THAT A STALLED FRONTAL BOUNDARY JUST
TO OUR SOUTH AND EAST TODAY WILL LIFT BACK NORTH ACROSS THE
EASTERN CAROLINAS WHILE DISSIPATING THIS EVENING AND OVERNIGHT.
MEANWHILE...AN UPPER RIDGE WILL EXTEND EASTWARDS ACROSS THE AREA
THROUGH THE PERIOD.
CONVECTION LOOKS LIKE LESS OF A POSSIBILITY THAN YESTERDAY DESPITE
THE REMNANTS OF THE FRONT MOVING NORTH ACROSS THE AREA THIS EVENING
AND THE DEVELOPMENT OF A RESULTANT SEA BREEZE FRONT THIS AFTERNOON.
A DEEPLY DRY NORTHWESTERLY FLOW WILL DOMINATE ALOFT AND A GENERALLY
SUBSIDENT REGIME WILL SUPPRESS ANY CONVECTION THAT TRIES TO INITIATE
THIS AFTERNOON. MODEL SOUNDINGS SHOW MARGINALLY UNSTABLE CONDITIONS
AT BEST DEVELOPING THIS AFTERNOON. BEST CHANCE FOR PRECIPITATION
WILL BE ALONG THE IMMEDIATE COAST THIS AFTERNOON AND EVENING WITH
THE SLIGHT CHANCE FOR SHOWERS MOVING ASHORE IN ADVANCE OF THE
NORTHWARD-MOVING FRONTAL BOUNDARY OR POSSIBLY SOME SPOT SHOWERS
ALONG THE SEA BREEZE FRONT.
TEMPERATURES WILL RUN NEAR OR JUST ABOVE CLIMO...WITH UPPER 80S AT
THE COAST AND LOWER 90S INLAND. OVERNIGHT LOWS WILL BE SIMILARLY
SEASONAL OR ABOVE...RUNNING IN LOWER TO MID 70S.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...BUILDING HEAT AND HUMIDITY FOR THE WKND AS
UPPER RIDGE STRENGTHENS ACROSS THE ARKLATEX AND EXPANDS NORTHEAST.
INITIALLY THIS CREATES HOT BUT DRY WEATHER SATURDAY AS THE MID-
LEVELS REMAIN DRY BENEATH SUBSIDENT FLOW...BUT WITH THE RIDGE AXIS
DISPLACED WELL WEST OF THE AREA...A SHORTWAVE TROUGH WILL DIG
TOWARDS THE AREA ON NW FLOW...AND DRIVE A WEAK COLD FRONT ACROSS THE
REGION LATE SATURDAY. ALTHOUGH TEMPERATURE ADVECTION BEHIND THIS
FEATURE IS BASICALLY NIL (IN FACT SUNDAY MAY BE A BIT HOTTER THAN
SATURDAY) CONVECTION CHANCES WILL RAMP UP LATE SATURDAY INTO
SATURDAY NIGHT THANKS TO THIS FEATURE COMBINING WITH...OR
ENHANCING...THE PIEDMONT TROUGH. WE WILL BE LOSING INSTABILITY AND
HEATING BY THAT TIME...BUT WILL BUMP POP TO MDT/HIGH CHC ESPECIALLY
ACROSS WESTERN ZONES EARLY SATURDAY NIGHT. THEREAFTER...DRY MID-
LEVEL FLOW AND SUBSIDENCE RETURNS...SO ONLY ISOLATED DIURNAL TSTMS
EXPECTED SUNDAY.
850 MB TEMPS CLIMB FROM ABOUT 19C SATURDAY...UP TO 21C ON
SUNDAY...WHICH COMBINED WITH DOWNSLOPE COMPRESSIONAL WARMING WILL
ALLOW THE ENTIRE CWA TO RISE INTO THE 90S...EVEN AT THE BEACHES.
SOME UPR 90S ARE POSSIBLE INLAND ON SUNDAY. LOWS BOTH NIGHTS WILL BE
WELL ABOVE NORMAL FOR MID-JULY...72-75 SATURDAY NIGHT...AND 74-78
SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 AM FRIDAY...BIG HEAT EXPECTED FOR THE FIRST HALF OF THE
UPCOMING WEEK...WITH DANGEROUS HEAT INDICES ONCE AGAIN POSSIBLE.
MASSIVE UPPER RIDGE BUILDS ACROSS 2/3 OF THE NATION MONDAY AND
TUESDAY AND INTO WEDNESDAY. THE CENTER OF THIS RIDGE WILL REMAIN
OVER THE CENTER OF THE NATION...SO MID-LEVEL FLOW LOCALLY WILL BE
W/NW. THE AIRMASS COMING INTO THE CAROLINAS EARLY NEXT WEEK
ORIGINATES ACROSS THE MEXICAN MOUNTAINS AND THEN ADVECTS AROUND THE
RIDGE AND INTO THE MID-ATLANTIC. THIS DRIVES TREMENDOUSLY WARM 850MB
AIR INTO THE AREA...WITH THE GFS SHOWING 24C...ALTHOUGH THE COOLER
ECMWF KEEPING TEMPS TO 22C AT THAT LEVEL. THE GFS HAS PERFORMED
BETTER WITH THE BIG HEAT THIS SUMMER HOWEVER...AND IS PREFERRED.
THIS WILL DRIVE HIGHS WELL INTO THE 90S EVEN AT THE COAST...WITH 100
DEGREE READINGS POSSIBLY RETURNING TO INLAND ZONES. LOWS AT NIGHT
WILL STRUGGLE TO DROP MUCH BELOW 80. FORCING DURING THIS TIME IS
LIMITED AS WELL...BUT WITH A POTENTIAL MEXICAN EML AND VERY
HOT/UNSTABLE AIR IN PLACE...SCT CONVECTION WILL BE POSSIBLE EACH
DAY. LATE WEDNESDAY INTO THURSDAY...GUIDANCE TRIES TO PUSH A FRONT
DOWN INTO THE AREA WITH HEIGHTS LOWERING ALOFT. AS THE RIDGE STAYS
TO THE WEST...IT IS POSSIBLE THAT A BOUNDARY WILL DRAG THIS FAR
SOUTH...ALTHOUGH THIS IS CLIMATOLOGICALLY WELL OUT OF SEASON. FOR
NOW WILL SHOW SLIGHTLY COOLER TEMPS AT THE END OF THE PERIOD ALONG
WITH SLIGHTLY HIGHER POP.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 12Z...THE MORNING STARTS WITH IFR CEILINGS AT KFLO AND
KMYR WITH STRATUS AT 600 TO 700 FEET. THIS WILL LIFT BETWEEN 13
AND 14 UTC AND VFR CONDTIONS WILL THEN PREVAIL AT ALL TAF SITES
THROUGH MUCH OF THE PERIOD. THE 10 UTC HRRR MODEL ONLY SHOWS WEAK
ISOLATED SHOWERS DEVELOPING IN AND AROUND THE TAF SITES AFTER 19
UTC BUT SINCE THE HRRR HAS SHOWN A BIAS FOR OVERDEVELOPING
CONVECTION WILL NOT INCLUDE VCSH AT THIS TIME.
WITH LOW LEVEL MOISTURE RETURNING LATER TODAY THERE IS
POSSIBILITY OF MVFR/IFR RESTRICTIONS TO VISION MAINLY AT THE
INLAND TAF SITES AFTER 08 UTC.
EXTENDED OUTLOOK...BRIEF MVFR POSSIBLE OVER THE WEEKEND DUE TO
DIURNALLY DRIVEN CONVECTION. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH 6 AM FRIDAY/...
AS OF 630 AM FRIDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:
GENERALLY NE TO EASTERLY WINDS TODAY WILL BECOME SOUTHEASTERLY
TONIGHT AS A WEAK FRONTAL BOUNDARY PUSHES BACK NORTH ACROSS THE
WATERS. WINDS WILL RANGE FROM 10 TO 15 KTS THROUGH THE
PERIOD...WITH SEAS STAYING IN THE 2 TO 3 FT RANGE.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...A BRIEF PERIOD OF NE WINDS WILL START THE
PERIOD...BUT THESE QUICKLY RETURN TO THE SW SATURDAY AFTN AS BERMUDA
HIGH PRESSURE RE-ASSERTS ITSELF ACROSS THE AREA. THESE WINDS WILL BE
LIGHT ON SATURDAY...LESS THAN 10 KTS...BUT THEN INCREASE SUNDAY AS A
COLD FRONT APPROACHES FROM THE NW. THIS FRONT LIKELY WILL STALL WEST
OF THE WATERS SO NOW FURTHER WIND SHIFT IS EXPECTED...BUT THE
TIGHTENING OF THE GRADIENT WILL DRIVE WIND SPEEDS UP TO 15 KTS LATE
SUNDAY BEFORE THEY EASE AGAIN AT THE END OF THE PERIOD. SEAS WILL BE
ONLY AROUND 2 FT SATURDAY ON THE LIGHT AND VARYING WINDS...RISING TO
3 FT SUNDAY THANKS TO AN INCREASING 5 SEC SW WIND WAVE.
LONG TERM /MONDAY THROUGH TUESDAY/
AS OF 300 AM FRIDAY...PERSISTENT BERMUDA HIGH PRESSURE WILL DRIVE SW
FLOW THROUGH THE PERIOD...AND SPEEDS WILL BE AROUND 15 KTS WITH
LITTLE FLUCTUATION. ALTHOUGH WINDS WILL BE NEARLY CONSTANT...SEAS
WILL SLOWLY BUILD MONDAY INTO TUESDAY...THANKS TO THE DURATION OF
THIS CONSTANT SW FETCH. SEAS OF AROUND 3 FT MONDAY WILL RISE TO 4 FT
TUESDAY...WITH THE 5 SEC SW WIND CHOP DOMINATING THE SPECTRUM.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...REK/CRM
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...HAWKINS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1004 AM CDT FRI JUL 17 2015
.UPDATE...
ISSUED AT 1004 AM CDT FRI JUL 17 2015
FORECAST ON TRACK FOR THIS MORNING. LEAD EMBEDDED S/WV ALONG WITH
A SFC TROUGH GENERATING AN AREA OF MODERATE SHOWERS AND SCATTERED
THUNDERSTORMS FROM SOUTH CENTRAL NORTH DAKOTA NORTH-NORTHEAST INTO
THE DEVILS LAKE BASIN AREA...PUSHING EAST. MORE ISOLATED ACTIVITY
WEST WITH LITTLE IF ANY INSTABILITY SO WILL LEAVE THUNDER OUT
THERE. REDEVELOPMENT OVER OUR SOUTHEAST THIS AFTERNOON WITH ROBUST
UPDRAFTS POSSIBLE SUGGESTING A STRONG TO SEVERE CONVECTION THREAT.
UPDATE ISSUED AT 636 AM CDT FRI JUL 17 2015
NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE. UTILIZED A TIME
LAGGED ENSEMBLE OF THE 08-10 UTC HRRR ITERATIONS FOR THE REMAINDER
OF THE DAY WHICH HAS A GOOD DEPICTION OF THE ONGOING
PRECIPITATION TRENDS THROUGH 1130 UTC. THE SEVERE CONVECTION
POTENTIAL REMAINS ON TRACK ACROSS THE SOUTHERN PORTIONS OF THE
JAMES RIVER VALLEY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 252 AM CDT FRI JUL 17 2015
EARLY MORNING SHOWERS AND THUNDERSTORMS AND SEVERE THUNDERSTORM
POTENTIAL IN THE SOUTHEAST FRIDAY AFTERNOON ARE THE MAIN CONCERNS
FOR THE SHORT TERM FORECAST PERIOD.
A CLOSED UPPER LEVEL LOW AND AMPLIFYING SHORTWAVE TROUGH
STRETCHED OVER SASKATCHEWAN AND EASTERN MONTANA EARLY THIS
MORNING. AT THE SURFACE...LOW PRESSURE WAS DEVELOPING OVER EASTERN
SASKATCHEWAN. A COLD FRONT EXTENDED SOUTH FROM THIS LOW INTO
WESTERN NORTH DAKOTA...TRIGGERING WIDELY SCATTERED SHOWERS AND A
FEW ISOLATED THUNDERSTORMS. HIGH RESOLUTION MODELS SUGGEST THAT
THIS PRECIPITATION SHOULD HOLD TOGETHER AS THE COLD FRONT MOVES
EAST ACROSS THE STATE THROUGH THE EARLY MORNING HOURS. GUSTY WINDS
AND SMALL HAIL WILL BE THE MAIN THREATS WITH ANY STRONGER
STORMS...BUT SEVERE WEATHER IS NOT EXPECTED WITH THE MORNING
CONVECTION.
FRIDAY AFTERNOON...THE COLD FRONT WILL BE DRAPED OVER OUR EASTERN
ZONES AND THUNDERSTORMS WILL BEGIN TO REDEVELOP AS EARLY AS 18Z.
AHEAD OF THE COLD FRONT...DEWPOINTS SHOULD RISE INTO THE MID 60S
WITH TEMPERATURES IN THE MID 80S. THIS...IN CONJUNCTION WITH STEEP
MID-LEVEL LAPSE RATES...WILL LEAD TO A MODERATELY UNSTABLE
ATMOSPHERE IN OUR SOUTH CENTRAL AND SOUTHEAST ZONES. 00Z NAM
FORECAST SOUNDINGS SUGGEST MLCAPE VALUES AS HIGH AS 1500-2000 J/KG
OVER DICKEY AND LAMOURE COUNTIES BY 21Z. THIS INSTABILITY WILL BE
COUPLED WITH 45-50 KNOTS OF 0-6 KM BULK SHEAR...SUGGESTING A
SUPERCELLULAR STORM MODE. STORMS SHOULD BE ABLE TO REMAIN DISCRETE
EARLY WITH NEARLY PERPENDICULAR CROSSOVER VECTORS FROM 850-500 MB.
LARGE HAIL AND STRONG WINDS WILL BE THE GREATEST THREATS...BUT
THERE MAY BE A CONDITIONAL TORNADO THREAT INTO THE EXTREME
SOUTHEAST...AS 0-1 KM SHEAR INCREASES TO 15-20 KTS BY 00Z
SATURDAY. HOWEVER...IT IS ENTIRELY POSSIBLE THAT THE COLD FRONT
WILL ALREADY BE OUT OF OUR FORECAST AREA BY THE TIME THE LOW LEVEL
JET KICKS IN. THE OTHER CONCERN FOR SEVERE POTENTIAL WILL BE
WHETHER EARLY MORNING CONVECTION AND CLOUD COVER CAN LIMIT
INSTABILITY.
AS THE SEVERE THREAT BEGINS TO CLEAR OUT OF THE AREA BY LATE
FRIDAY EVENING...EXPECT A FEW SCATTERED SHOWERS BEHIND THE FRONT
WITH SOME CLEARING LIKELY FROM WEST TO EAST.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 252 AM CDT FRI JUL 17 2015
A BREEZY SATURDAY FOLLOWED BY A GENERALLY LESS ACTIVE WEATHER
PERIOD INTO NEXT WEEK HIGHLIGHTS THE EXTENDED FORECAST.
AN ANOMALOUS DEEP UPPER LEVEL LOW ACROSS SOUTHERN SASKATCHEWAN
AND MANITOBA ON SATURDAY IS FORECAST BY THE 00 UTC DETERMINISTIC
AND ENSEMBLE CONSENSUS. A DRY SLOT ASSOCIATED WITH THIS FEATURE IS
FORECAST ACROSS MOST OF WESTERN AND CENTRAL NORTH DAKOTA...WITH
WRAP AROUND MOISTURE IMPINGING ON THE US HIGHWAY 2 CORRIDOR TO
SUPPORT AN ISOLATED TO SCATTERED SHOWER AND THUNDERSTORM THREAT
FOR THESE AREAS. GIVEN GOOD POST COLD FRONTAL MIXING AND A TIGHT
PRESSURE GRADIENT...BREEZY NORTHWEST WIND GUSTS OF 25-30 KTS ARE
FORECAST AREA WIDE FOR SATURDAY. THEREAFTER...NORTHWEST FLOW ALOFT
IS FORECAST SUNDAY INTO EARLY NEXT WEEK...BEFORE A POSSIBLE
TRANSITION TO ZONAL BY WEDNESDAY. OVERALL...THIS WOULD SUPPORT
NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES...AND SPORADIC
PRECIPITATION CHANCES ASSOCIATED WITH IMPULSES WITH LOW
PREDICTABILITY AT THESE TIME RANGES EMBEDDED IN THE FAST UPPER
LEVEL FLOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 1004 AM CDT FRI JUL 17 2015
A COLD FRONT CONTINUES TO PUSH EAST THROUGH NORTH DAKOTA THIS
MORNING...TRIGGERING SHOWERS AND A FEW THUNDERSTORMS FROM THE
SOUTH CENTRAL PART OF THE STATE INTO THE NORTHEAST. SCATTERED
THUNDERSTORMS WILL REDEVELOP ACROSS THE STATE FRIDAY AFTERNOON
NEAR THE FRONT SOUTHEAST BEFORE TAPERING OFF IN THE EVENING
BEHIND THE FRONT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
SHORT TERM...ZH
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
947 AM CDT FRI JUL 17 2015
.UPDATE...
ISSUED AT 945 AM CDT FRI JUL 17 2015
NO MAJOR CHANGES NEEDED THIS MORNING. A BAND OF SHOWERS AND STORMS
CONTINUES TO PUSH EAST INTO THE DEVILS LAKE BASIN. EXPECT THE MAIN
SEVERE THREAT TO BEGIN AFTER 19Z AFTER HEATING HAS WARMED THE
BOUNDARY LAYER SUFFICIENTLY...AND WE WILL LIKELY HAVE SOME SEVERE
STORMS THIS AFTERNOON/EVENING. THE HRRR INDICATED THE BEST THREAT
IN THE SOUTH WHERE INSTABILITY/SHEAR COMBINATION WILL OVERLAP THE
MOST.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 355 AM CDT FRI JUL 17 2015
LULL IN ACTIVITY ACROSS THE FA THIS MORNING. FAIR SKIES AND LIGHT
AND VARIABLE WINDS HAVE ALLOWED FOR PATCHY DENSE FOG FORMATION
ACROSS MANY RECENTLY WETTED AREAS...ESPECIALLY ALONG AND EAST OF
THE RRV. THIS SHOULD BURN OFF QUICKLY AFTER SUNRISE.
A DEEPENING CLOSED H5 LOW PRESSURE SYSTEM OVER SOUTHERN SASK
SHOULD MAKE FOR SOME ACTIVE CONVECTIVE WEATHER ACROSS THE REGION
LATER TODAY. ONE UPPER LEVEL DISTURBANCE IS PRESENTLY MOVING FROM
THE BASE OF THE LOW PRESSURE TROF...IN EASTERN MT...AND IS PRESSING
INTO WESTERN ND. THAT DISTURBANCE SHOULD CONTINUE ACROSS EASTERN
ND THROUGH LATE AFTERNOON AND NORTHERN MN THROUGH THE EARLY
EVENING.
WITH THAT...WIDESPREAD CLOUD COVER...RAIN SHOWERS AND SCATTERED
THUNDERSTORMS...WITH ISOLATED STRONG TO SEVERE STORMS...ARE
EXPECTED TO DEVELOP INTO EASTERN ND MIDDAY AND ACROSS NORTHWEST MN
THROUGH THE AFTERNOON...ESPECIALLY ALONG AND NORTH OF HIGHWAY
200. MEANWHILE...SOUTHEASTERN ND AND ADJACENT PORTIONS OF
NORTHWEST AND WEST CENTRAL MN...ESPECIALLY SOUTH OF HWY 200...CAN
EXPECT A BIT MORE SUNSHINE AND DAYTIME HEATING TO OCCUR. THIS
SHOULD INTENSIFY A SFC LOW PRESSURE TROF DEVELOPING ACROSS THAT
AREA AND PROVIDE A FOCUS FOR MORE WIDESPREAD STRONG TO SEVERE
THUNDERSTORMS FROM MIDAFTERNOON INTO EARLY EVENING. INCREASING
DEEP LAYER SHEAR LATE SATURDAY AFTERNOON SHOULD BECOME FAVORABLE
TO LARGE HAIL AND DAMAGING WINDS AS A MAIN THREAT...WHILE ISOLATED
TORNADOES ARE ALSO CONSIDERED POSSIBLE.
FRIDAY NIGHT AND SATURDAY...RESIDUAL THUNDERSTORM ACTIVITY SHOULD
PUSH OFF ACROSS NORTHERN MN DURING THE LATE NIGHT PERIOD AND
ALLOW FOR MORE SETTLED WEATHER INTO SATURDAY. THE UPPER LEVEL LOW
PRESSURE SYSTEM IS EXPECTED TO TRACK ACROSS SOUTHERN MANITOBA ON
SATURDAY... SO ITS PROXIMITY SHOULD PRODUCE SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS ALONG NORTHERN TIER COUNTIES THROUGH
SATURDAY AFTERNOON.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 355 AM CDT FRI JUL 17 2015
SATURDAY NIGHT AND SUNDAY...LOOKS MAINLY DRY AND MILD...WITH
TEMPERATURES RUNNING VERY NEAR SEASONAL NORMALS. CONSENSUS MODELS
HAVE H5 TROF SHIFTED EAST OF THE FA WITH A WEAK H5 SHORTWAVE RIDGE
ACROSS THE AREA EARLY ON SUNDAY ...WITH UPR FLOW PATTERN OUT OF
WEST NORTHWEST. NAM HAS A SHORTWAVE TROF KICKING ACROSS CENTRAL
AND SOUTHERN MANITOBA LATE ON SUNDAY...BUT FOR NOW HAS KEPT THE
RED RIVE BASIN DRY.
MONDAY-THURSDAY...THIS PERIOD SHOULD START OUT ON A RATHER QUIET
NOTE UNDER WEST NORTHWEST FLOW ALOFT. A SFC FRONT IS FORECAST TO
DROP SOUTH MONDAY WITH AN UPPER WAVE PASSING TO THE NORTH. A FEW
THUNDERSTORMS COULD ACCOMPANY THE FRONT...DEPENDING ON TIMING.
HIGH PRESSURE AND SEASONABLE TEMPS ARE THEN EXPECTED FOR TUESDAY.
MODELS INDICATE A TRANSITION BACK TO A MORE ACTIVE ZONAL FLOW
PATTERN BY THE MID AND LATTER PORTION OF THE NEXT WEEK...WITH
CHANCES FOR CONVECTION EXPECTED TO INCREASE BY SOMETIME AROUND
WED/THUR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 655 AM CDT FRI JUL 17 2015
PATCHY FOG EXPECTED TO AFFECT PORTIONS OF THE FA THROUGH
13Z...WITH FOG DISSIPATING RAPIDLY THEREAFTER. INCREASING MID
AND LOWER LEVEL MOISTURE EXPECTED THROUGH THE LATE FORENOON INTO
THE DEVILS LAKE BASIN... WITH SCT THUNDERSTORMS EXPECTED THERE
MIDDAY. STRING TO SEVERE TSTM ACTIVITY WILL OVERSPREAD EASTERN ND
THROUGH EARLY AFTERNOON AND LEAN INTO NORTHWEST AND WEST CENTRAL
MN BY LATE AFTERNOON. ACTIVITY WILL DECREASE FROM THE WEST FROM
EARLY INTO LATE EVENING.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...DK
SHORT TERM...GUST
LONG TERM...GUST/MAKOWSKI
AVIATION...GUST
AREA FORECAST DISCUSSION
NWS BISMARCK ND
641 AM CDT FRI JUL 17 2015
.UPDATE...
ISSUED AT 636 AM CDT FRI JUL 17 2015
NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE. UTILIZED A TIME
LAGGED ENSEMBLE OF THE 08-10 UTC HRRR ITERATIONS FOR THE REMAINDER
OF THE DAY WHICH HAS A GOOD DEPICTION OF THE ONGOING
PRECIPITATION TRENDS THROUGH 1130 UTC. THE SEVERE CONVECTION
POTENTIAL REMAINS ON TRACK ACROSS THE SOUTHERN PORTIONS OF THE
JAMES RIVER VALLEY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 252 AM CDT FRI JUL 17 2015
EARLY MORNING SHOWERS AND THUNDERSTORMS AND SEVERE THUNDERSTORM
POTENTIAL IN THE SOUTHEAST FRIDAY AFTERNOON ARE THE MAIN CONCERNS
FOR THE SHORT TERM FORECAST PERIOD.
A CLOSED UPPER LEVEL LOW AND AMPLIFYING SHORTWAVE TROUGH
STRETCHED OVER SASKATCHEWAN AND EASTERN MONTANA EARLY THIS
MORNING. AT THE SURFACE...LOW PRESSURE WAS DEVELOPING OVER EASTERN
SASKATCHEWAN. A COLD FRONT EXTENDED SOUTH FROM THIS LOW INTO
WESTERN NORTH DAKOTA...TRIGGERING WIDELY SCATTERED SHOWERS AND A
FEW ISOLATED THUNDERSTORMS. HIGH RESOLUTION MODELS SUGGEST THAT
THIS PRECIPITATION SHOULD HOLD TOGETHER AS THE COLD FRONT MOVES
EAST ACROSS THE STATE THROUGH THE EARLY MORNING HOURS. GUSTY WINDS
AND SMALL HAIL WILL BE THE MAIN THREATS WITH ANY STRONGER
STORMS...BUT SEVERE WEATHER IS NOT EXPECTED WITH THE MORNING
CONVECTION.
FRIDAY AFTERNOON...THE COLD FRONT WILL BE DRAPED OVER OUR EASTERN
ZONES AND THUNDERSTORMS WILL BEGIN TO REDEVELOP AS EARLY AS 18Z.
AHEAD OF THE COLD FRONT...DEWPOINTS SHOULD RISE INTO THE MID 60S
WITH TEMPERATURES IN THE MID 80S. THIS...IN CONJUNCTION WITH STEEP
MID-LEVEL LAPSE RATES...WILL LEAD TO A MODERATELY UNSTABLE
ATMOSPHERE IN OUR SOUTH CENTRAL AND SOUTHEAST ZONES. 00Z NAM
FORECAST SOUNDINGS SUGGEST MLCAPE VALUES AS HIGH AS 1500-2000 J/KG
OVER DICKEY AND LAMOURE COUNTIES BY 21Z. THIS INSTABILITY WILL BE
COUPLED WITH 45-50 KNOTS OF 0-6 KM BULK SHEAR...SUGGESTING A
SUPERCELLULAR STORM MODE. STORMS SHOULD BE ABLE TO REMAIN DISCRETE
EARLY WITH NEARLY PERPENDICULAR CROSSOVER VECTORS FROM 850-500 MB.
LARGE HAIL AND STRONG WINDS WILL BE THE GREATEST THREATS...BUT
THERE MAY BE A CONDITIONAL TORNADO THREAT INTO THE EXTREME
SOUTHEAST...AS 0-1 KM SHEAR INCREASES TO 15-20 KTS BY 00Z
SATURDAY. HOWEVER...IT IS ENTIRELY POSSIBLE THAT THE COLD FRONT
WILL ALREADY BE OUT OF OUR FORECAST AREA BY THE TIME THE LOW LEVEL
JET KICKS IN. THE OTHER CONCERN FOR SEVERE POTENTIAL WILL BE
WHETHER EARLY MORNING CONVECTION AND CLOUD COVER CAN LIMIT
INSTABILITY.
AS THE SEVERE THREAT BEGINS TO CLEAR OUT OF THE AREA BY LATE
FRIDAY EVENING...EXPECT A FEW SCATTERED SHOWERS BEHIND THE FRONT
WITH SOME CLEARING LIKELY FROM WEST TO EAST.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 252 AM CDT FRI JUL 17 2015
A BREEZY SATURDAY FOLLOWED BY A GENERALLY LESS ACTIVE WEATHER
PERIOD INTO NEXT WEEK HIGHLIGHTS THE EXTENDED FORECAST.
AN ANOMALOUS DEEP UPPER LEVEL LOW ACROSS SOUTHERN SASKATCHEWAN
AND MANITOBA ON SATURDAY IS FORECAST BY THE 00 UTC DETERMINISTIC
AND ENSEMBLE CONSENSUS. A DRY SLOT ASSOCIATED WITH THIS FEATURE IS
FORECAST ACROSS MOST OF WESTERN AND CENTRAL NORTH DAKOTA...WITH
WRAP AROUND MOISTURE IMPINGING ON THE US HIGHWAY 2 CORRIDOR TO
SUPPORT AN ISOLATED TO SCATTERED SHOWER AND THUNDERSTORM THREAT
FOR THESE AREAS. GIVEN GOOD POST COLD FRONTAL MIXING AND A TIGHT
PRESSURE GRADIENT...BREEZY NORTHWEST WIND GUSTS OF 25-30 KTS ARE
FORECAST AREA WIDE FOR SATURDAY. THEREAFTER...NORTHWEST FLOW ALOFT
IS FORECAST SUNDAY INTO EARLY NEXT WEEK...BEFORE A POSSIBLE
TRANSITION TO ZONAL BY WEDNESDAY. OVERALL...THIS WOULD SUPPORT
NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES...AND SPORADIC
PRECIPITATION CHANCES ASSOCIATED WITH IMPULSES WITH LOW
PREDICTABILITY AT THESE TIME RANGES EMBEDDED IN THE FAST UPPER
LEVEL FLOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 636 AM CDT FRI JUL 17 2015
A COLD FRONT CONTINUES TO PUSH EAST THROUGH NORTH DAKOTA THIS
MORNING...TRIGGERING SCATTERED SHOWERS AND A FEW THUNDERSTORMS FROM
THE NORTH CENTRAL PART OF THE STATE INTO THE SOUTHWEST. SOME PATCHY
DENSE FOG WILL CONTINUE TO BRING PERIODS OF IFR/LIFR VSBYS TO KJMS
FOR THE NEXT COUPLE OF HOURS...WHILE VFR CONDITIONS ARE EXPECTED
AT ALL OTHER SITES THROUGH THE 12Z FORECAST PERIOD. SCATTERED
THUNDERSTORMS WILL REDEVELOP ACROSS THE STATE FRIDAY AFTERNOON
NEAR THE FRONT BEFORE TAPERING OFF IN THE EVENING BEHIND THE
FRONT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...ZH
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1116 AM EDT FRI JUL 17 2015
.SYNOPSIS...
SOUTHERLY WINDS WILL BRING INCREASING HEAT AND HUMIDITY INTO THE
REGION HEADING INTO THE WEEKEND. A COLD FRONT WILL SLIDE SOUTH
INTO THE AREA LATE SUNDAY INTO SUNDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EMBEDDED S/WV ASSOC WITH A SFC WARM FRONT WILL CONTINUE TO EXIT TO
THE EAST THROUGH EARLY AFTERNOON. MAIN CONVECTION WITH THESE
FEATURES WILL MOVE EAST AS WELL. HOWEVER...LATEST RADAR MOSAIC
INDICATES THAT SOME CONVERGENCE IS STILL OCCUR ACRS OUR NW ZONES
AND EXTENDING INTO INDIANA...MOST LIKELY DUE TO A LOW LEVEL JET.
CONVECTION HERE SHOULD BECOME SURFACE BASED BY AFTERNOON AND MORE
SCATTERED IN NATURE. ELSEWHERE...LATEST HRRR INDICATES THAT
PERHAPS A POP UP SHOWER/STORM MAY DEVELOP IN THE HEAT OF THE DAY.
THUS...WILL HAVE HIGHEST POPS ACRS THE NW AND THE LEAST IN THE SE.
WITH INCREASING HEAT AND HUMIDITY...HIGHS WILL RISE INTO THE UPPER
80S NORTH AND EAST...TO THE LOWER 90S SOUTHWEST WITH DEWPOINTS IN
THE LOWER 70S. OUR SW CWFA...INCLUDING THE DAYTON AND CINCINNATI
METRO AREAS...HAVE THE GREATEST POTENTIAL OF SEEING HEAT INDEX
VALUES IN THE 95-100 DEGREE RANGE. GIVEN THAT WE HAVE NOT HAD
REALLY HOT AND HUMID WEATHER THIS SUMMER...THOUGHT IT PRUDENT TO
ISSUE A SPECIAL WEATHER STATEMENT FOR THESE AREAS FOR THE
AFTERNOON HOURS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
LATEST HRRR RUN SUGGESTS THAT EVENING CONVECTION SHOULD WANE IN
COVERAGE BUT SHOW A PROGRESSION TO THE EAST AND SOUTHEAST AS WELL.
STORMS SHOULD MOVE EAST/SOUTHEAST AND DIMINISH IN INTENSITY AND
COVERAGE AFTER MIDNIGHT.
THE CHANCE OF RAIN WILL BE QUITE LIMITED ON SATURDAY WITH LITTLE
FORCING TO BREAK WEAK CAPPING AND TAP SUBSTANTIAL INSTABILITY.
UPPER RIDGE CENTERED OVER THE LOWER MISSISSIPPI VALLEY WILL MAKE
ITS FURTHEST NORTHWARD ENCROACHMENT ON SATURDAY. THIS WILL RESULT
IN THE WARMEST TEMPERATURES IN OVER A MONTH. IN ADDITION...DEW
POINTS WILL INCREASE WHICH WILL RESULT IN HEAT INDICES AT OR ABOVE
100 FOR MOST OF THE FORECAST AREA.
UPPER RIDGE WILL START TO GET SUPPRESSED ON SUNDAY AS A SHORT
WAVE TRACKS ACROSS THE NORTHERN TIER. THIS WILL PUSH A COLD FRONT
TOWARDS THE REGION LATER SUNDAY WITH SLOWER MODEL SOLUTIONS
PREFERRED. CHANCE OF STORMS WILL INCREASE ON SUNDAY. TEMPERATURES
MAY BE JUST A BIT LOWER IN NORTHERN COUNTIES BUT EXPECT SOUTHERN
SECTIONS TO BE JUST AS WARM AS SATURDAY. HEAT INDICES ARE FORECAST
TO BE AT OR ABOVE 100 AGAIN NEAR AND SOUTH OF THE OHIO RIVER.
SPECIAL HEAT CRITERIA FOR HAMILTON COUNTY NECESSITATES A HEAT
WATCH/WARNING IF THE HEAT INDEX IS 100 OR GREATER FOR AT LEAST TWO
CONSECUTIVE DAYS. IF FORECAST CONTINUES AS IS THEN THE REST OF THE
REGION WILL LIKELY NEED A HEAT ADVISORY FOR SATURDAY AND IN THE
SOUTH AGAIN ON SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
COLD FRONT WILL MOVE THOROUGH THE AREA ON SUNDAY NIGHT. IT WILL
STALL SOUTH OF THE AREA. 00Z GUIDANCE CONTINUES TO SHOW
DIFFERENCES IN HANDLING THIS BOUNDARY DURING THE WEEK. THE GFS
KEEPS THE FRONT FURTHER NORTH BUT SEEMS TO OVERDEVELOP A WAVE THAT
TRACKS ALONG THE FRONT. MEANWHILE THE ECMWF DRIVES THE BOUNDARY
MUCH FURTHER SOUTH ALTHOUGH THIS SEEMS AMBITIOUS. HAVE OPTED TO
ONLY TWEAK PREVIOUS FORECAST AND KEEP CHANCE POPS PRIMARILY IN THE
SOUTH TUESDAY AND TUESDAY NIGHT. FORECAST BECOMES MORE UNCERTAIN
LATER IN THE PERIOD WITH INCREASING SPREAD IN SOLUTIONS ALTHOUGH
THERE IS SOME SIGNAL THAT HIGH PRESSURE WILL INFLUENCE THE REGION
LATER IN THE WEEK.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
MAINLY MID/HIGH CLOUDS CONTINUE TO STREAM EASTWARD ACROSS THE TAF
SITES EARLY THIS MORNING. AM EXPECTING SHRA TO GENERALLY REMAIN
NORTH OF THE TERMINALS THIS MORNING...ALTHOUGH COULD BE CLOSE TO
KCMH/KLCK.
BY THIS AFTERNOON...WITH MOISTURE/INSTABILITY BACK EXPECT SOME
THUNDERSTORMS TO DEVELOP. NORTHERN TAF SITES LOOK TO HAVE THE
BETTER CHANCES...AND WILL INTRODUCE VCTS FOR ALL SITES BUT
KCVG/KLUK FOR THE MID AFTERNOON TO EARLY EVENING PERIOD.
THUNDERSTORMS CAN PRODUCE BRIEF IFR VIS RESTRICTIONS AND GUSTY
WINDS. OUTSIDE OF THUNDERSTORMS...TIGHTENING PRESSURE GRADIENT
WILL PROMOTE AFTERNOON WIND GUSTS AROUND 20 KT. WINDS DIMINISH
THIS EVENING...MVFR VIS POSSIBLE LATE TONIGHT AT KLUK.
OUTLOOK...THUNDERSTORMS POSSIBLE SATURDAY THROUGH MONDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...EXCESSIVE HEAT WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY
EVENING FOR OHZ077.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...
AVIATION...BPP
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1104 AM EDT FRI JUL 17 2015
.SYNOPSIS...
MUCH WARMER AND MORE HUMID CONDITIONS WILL PREVAIL LATER TODAY AND
THROUGH THIS WEEKEND AS AN UPPER LEVEL RIDGE BUILDS OVER THE
NORTHEAST CONUS THIS WEEKEND. A SHORTWAVE PASSING TO THE NORTH
WILL PUSH A COLD FRONT THROUGH PENNSYLVANIA ON MONDAY. HIGH
PRESSURE IS LIKELY TO BUILD SOUTHEAST INTO PENNSYLVANIA WEDNESDAY
OR THURSDAY OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NICE MCV TRAVERSING ONTARIO ALONG THE NORTHERN LAKE ERIE SHORELINE
LATE THIS MORNING...MAINTAINING SHOWERS AS IT TRACKS TOWARDS THE
FINGERLAKES REGION. FRACTURED LINE OF SHOWERS EXTENDS FROM IT SSWD
ALONG UPPER SHEAR AXIS INTO A MUCH WARMER AND MORE TROPICAL
MOISTURE ENVIRONMENT OVER CENTRAL AND SOUTHERN OHIO...WHERE A
SECOND CONVECTIVE CLUSTER IS PROPOGATING. SLOWLY WARMING CLOUD
TOPS ARE EVIDENT ACROSS ONTARIO ACTIVITY...WHILE CONVECTION
OVER NORTH CENTRAL OHIO IS MAINTAINING ITS INTENSITY.
MID LEVEL DEBRIS FROM THE UPSTREAM CONVECTION IS FILTERING INTO
WESTERN AND CENTRAL PA...WITH SCT TO BKN COVERAGE. EXPECT A FAIR
AMOUNT OF CONVECTIVE DEBRIS TO CONTINUE SPREADING EASTWARD THROUGH
THIS AFTERNOON...WHILE THE OVERALL AREA OF SHRA/TSRA ASSOCIATED
WITH THE MCS PUSHES EASTWARD WHILE MAINTAINING CURRENT INTENSITY.
HI RES HRRR DEPICTS A NARROW CLUSTER OF SHOWERS AND LIKELY SOME
EMBEDDED THUNDER CROSSING WESTERN AND CENTRAL PORTIONS OF CENTRAL
PA EARLY TO MID AFTERNOON TIMEFRAME. ALL BUT THE ALLEGHENY FRONT
COUNTIES OF MY CWA ARE IN GENERAL THUNDER OUTLOOK...WITH THE
ALLEGHENY PLATEAU IN MARGINAL AREA ALONG THE TRACK OF THE SLOWLY
WEAKENING MCS. ACROSS THE SUSQ VALLEY...PROXIMITY TO RETREATING
HIGH PRESSURE ALONG THE EAST COAST AND MUCH LOWER DEEP LAYER
MOISTURE SHOULD RESULT IN A DRY FRIDAY DESPITE INCREASING HIGH
CLOUDS THIS AFTERNOON.
LITTLE CHANGE TO GOING FORECAST NEEDED EARLY TODAY. PARTLY SUNNY
SKIES...COMBINED WITH RETURN SOUTHERLY FLOW IN WAKE OF DEPARTING
HIGH PRESSURE WILL PUSH TEMPS TO NEAR SEASONAL LEVELS BY THIS
AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
SCT SHRA/TSRA OVR THE W MTNS THIS EVENING WILL LIKELY SHIFT TO
THE SUSQ VALLEY BY EARLY SAT AM...AS LL JET/PLUME OF ANOMALOUS
PWATS MARCHES EAST ACROSS THE STATE. CURRENT ENSEMBLE DATA
SUPPORTS CHC POPS ACROSS MOST OF CENTRAL PA TONIGHT. APPROACH OF
SFC WARM FRONT WILL BRING A NOTICEABLE INCREASE IN HUMIDITY AND A
MUCH WARMER NIGHT THAN THOSE RECENTLY...WITH MIN TEMPS MOSTLY IN
THE M/U60S.
WARM FRONT WILL PUSH NE OF THE REGION ON SATURDAY. HEATING OF VERY
WARM/UNSTABLE AIR MASS S OF THE FRONT SHOULD YIELD MODERATE CAPES
BY AFTN. FOCUS OF PM CONVECTION SHOULD BE IN VICINITY OF LEE
TROUGH OVR THE SUSQ VALLEY. MODERATE CAPES AND RELATIVELY WEAK
SHEAR IN MDL DATA IMPLIES A THREAT OF ISOLD PULSE-TYPE SVR STORMS.
BASED ON GEFS/SREF OUTPUT...WILL RAISE POPS TO LIKELY ACROSS THE
EASTERN COUNTIES AND MAINTAIN JUST A CHC OF A PASSING TSRA FURTHER
WEST ACROSS THE ALLEGHENIES/CENTRAL MTNS. ENS MEAN 8H TEMPS
SUPPORT MAX TEMPS BTWN 85-90F...COMBINED WITH VERY HIGH HUMIDITY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
500MB HEIGHTS WILL STEADILY REBOUND THROUGH THE WEEKEND WITH
LIKELY THE HOTTEST DAY YET OF THE SUMMER COMING SUNDAY. CENTRAL
PA IS CURRENTLY NEAR/AT THE HOTTEST TIME OF THE YEAR /JULY 11-20/
BASED ON THE MOST RECENT 30-YEAR CLIMATE NORMALS. MAX TEMPS IN THE
L/M90S...COMBINED WITH OPPRESSIVE HUMIDITY...WILL LIKELY PUSH
HEAT INDEX VALUES TO ARND OR JUST OVER 100F ACROSS THE LWR SUSQ
VALLEY FOR A FEW HOURS SUNDAY. WILL CONTINUE TO MENTION HEAT RISK
IN THE HWO. UPPER LVL RIDGE AXIS AND ASSOC WARM MID LVL TEMPS
SHOULD HELP SUPPRESS CONVECTION SUNDAY. HOWEVER...APPROACH OF
SHORTWAVE/COLD FRONT OVR THE GRT LKS COULD BRING THE CHC OF LATE
DAY TSRA...MAINLY OVR THE W MTNS.
TWO NRN STREAM FRONTS SHOULD BE A FOCUS FOR PCPN NEXT WEEK. THE
FIRST WILL BE ON MONDAY...WITH A LOWER RISK ON WEDNESDAY. EXPECT
TEMPS TO REMAIN NEAR OR SLIGHTLY ABOVE MID/LATE JULY CLIMATE
NORMALS.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
VFR CONDS ARE EXPECTED AT MOST TAF SIGHTS TODAY AS HIGH PRESSURE
SLIDES EAST OF THE REGION...BRINGING GENERALLY CLEAR SKIES AND
LIGHT WINDS.
CU FIELD WILL BLOSSOM THIS AFTERNOON...BENEATH PERIODS OF BKN
ALTO CU ACRS WRN PENN...AS INCREASING WARMTH AND DEEP-LAYER
MOISTURE PUSHES EAST FROM THE OHIO VALLEY. CONDITIONS SHOULD STILL
STAY VFR...THOUGH SOME ISOLATED AND BRIEF MVFR MAY ACCOMPANY A FEW
TSRA LATER FRIDAY AFTERNOON AND EVENING.
OUTLOOK...
FRI...ISOLD LATE PM AND NIGHTTIME TSRA IMPACTS POSS W MTNS.
SAT-SUN...SCT...MAINLY PM TSRA IMPACTS POSSIBLE.
MON...MORE NUMEROUS SHOWERS/TSRA LIKELY AS A COLD FRONT PUSHES
EAST ACROSS THE REGION.
TUE...IMPROVING CONDS AS HIGH PRESSURE DOMINATING.
&&
.EQUIPMENT...
THE KBFD OBSERVATIONS ARE NOT AVAILABLE LONG-LINE DUE TO AN FAA COMMS
PROBLEM.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/STEINBUGL
AVIATION...GARTNER/TYBURSKI
EQUIPMENT...CTP
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
826 AM EDT FRI JUL 17 2015
.SYNOPSIS...
AN UPPER LEVEL RIDGE WILL BUILD OVER THE NORTHEAST CONUS OVER THIS
WEEKEND. A SHORTWAVE PASSING TO THE NORTH WILL PUSH A COLD FRONT
THROUGH PENNSYLVANIA ON MONDAY. HIGH PRESSURE IS LIKELY TO BUILD
SOUTHEAST INTO PENNSYLVANIA WEDNESDAY OR THURSDAY OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MCS TRAVERSING MIDWEST AND CENTRAL GLAKS EARLY THIS MORNING.
WARMING CLOUD TOPS ARE EVIDENT ACROSS LAKE SUPERIOR AND ONTARIO
PROVINCE...WHILE CONVECTION ENTERING NORTHWEST OHIO IS FOR THE
TIME BEING MAINTAINING ITS INTENSITY.
MID LEVEL DEBRIS FROM THE UPSTREAM CONVECTION IS FILTERING INTO
WESTERN AND CENTRAL PA...WITH SCT TO BKN COVERAGE. EXPECT A FAIR
AMOUNT OF CONVECTIVE DEBRIS TO CONTINUE SPREADING EASTWARD THIS
MORNING...WHILE THE OVERALL AREA OF SHRA/TSRA ASSOCIATED WITH THE
MCS DECREASES AND SLOWLY DISSIPATES. HI RES HRRR DEPICTS A NARROW
LINE OF SHOWERS CROSSING WESTERN AND CENTRAL PORTIONS OF CENTRAL
PA EARLY TO MID AFTERNOON TIMEFRAME. ALL BUT THE ALLEGHENY FRONT
COUNTIES OF MY CWA ARE IN GENERAL THUNDER OUTLOOK...WITH THE
ALLEGHENY PLATEAU IN MARGINAL AREA ALONG THE TRACK OF THE SLOWLY
WEAKENING MCS. ACROSS THE SUSQ VALLEY...PROXIMITY TO RETREATING
HIGH PRESSURE ALONG THE EAST COAST AND MUCH LOWER DEEP LAYER
MOISTURE SHOULD RESULT IN A DRY FRIDAY DESPITE INCREASING HIGH
CLOUDS THIS AFTERNOON.
LITTLE CHANGE TO GOING FORECAST NEEDED EARLY TODAY. PARTLY SUNNY
SKIES...COMBINED WITH RETURN SOUTHERLY FLOW IN WAKE OF DEPARTING
HIGH PRESSURE WILL PUSH TEMPS TO NEAR SEASONAL LEVELS BY THIS
AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
SCT SHRA/TSRA OVR THE W MTNS THIS EVENING WILL LIKELY SHIFT TO
THE SUSQ VALLEY BY EARLY SAT AM...AS LL JET/PLUME OF ANOMALOUS
PWATS MARCHES EAST ACROSS THE STATE. CURRENT ENSEMBLE DATA
SUPPORTS CHC POPS ACROSS MOST OF CENTRAL PA TONIGHT. APPROACH OF
SFC WARM FRONT WILL BRING A NOTICEABLE INCREASE IN HUMIDITY AND A
MUCH WARMER NIGHT THAN THOSE RECENTLY...WITH MIN TEMPS MOSTLY IN
THE M/U60S.
WARM FRONT WILL PUSH NE OF THE REGION ON SATURDAY. HEATING OF VERY
WARM/UNSTABLE AIR MASS S OF THE FRONT SHOULD YIELD MODERATE CAPES
BY AFTN. FOCUS OF PM CONVECTION SHOULD BE IN VICINITY OF LEE
TROUGH OVR THE SUSQ VALLEY. MODERATE CAPES AND RELATIVELY WEAK
SHEAR IN MDL DATA IMPLIES A THREAT OF ISOLD PULSE-TYPE SVR STORMS.
BASED ON GEFS/SREF OUTPUT...WILL RAISE POPS TO LIKELY ACROSS THE
EASTERN COUNTIES AND MAINTAIN JUST A CHC OF A PASSING TSRA FURTHER
WEST ACROSS THE ALLEGHENIES/CENTRAL MTNS. ENS MEAN 8H TEMPS
SUPPORT MAX TEMPS BTWN 85-90F...COMBINED WITH VERY HIGH HUMIDITY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
500MB HEIGHTS WILL STEADILY REBOUND THROUGH THE WEEKEND WITH
LIKELY THE HOTTEST DAY YET OF THE SUMMER COMING SUNDAY. CENTRAL
PA IS CURRENTLY NEAR/AT THE HOTTEST TIME OF THE YEAR /JULY 11-20/
BASED ON THE MOST RECENT 30-YEAR CLIMATE NORMALS. MAX TEMPS IN THE
L/M90S...COMBINED WITH OPPRESSIVE HUMIDITY...WILL LIKELY PUSH
HEAT INDEX VALUES TO ARND OR JUST OVER 100F ACROSS THE LWR SUSQ
VALLEY FOR A FEW HOURS SUNDAY. WILL CONTINUE TO MENTION HEAT RISK
IN THE HWO. UPPER LVL RIDGE AXIS AND ASSOC WARM MID LVL TEMPS
SHOULD HELP SUPPRESS CONVECTION SUNDAY. HOWEVER...APPROACH OF
SHORTWAVE/COLD FRONT OVR THE GRT LKS COULD BRING THE CHC OF LATE
DAY TSRA...MAINLY OVR THE W MTNS.
TWO NRN STREAM FRONTS SHOULD BE A FOCUS FOR PCPN NEXT WEEK. THE
FIRST WILL BE ON MONDAY...WITH A LOWER RISK ON WEDNESDAY. EXPECT
TEMPS TO REMAIN NEAR OR SLIGHTLY ABOVE MID/LATE JULY CLIMATE
NORMALS.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
VFR CONDS ARE EXPECTED AT MOST TAF SIGHTS TODAY AS HIGH PRESSURE
SLIDES EAST OF THE REGION...BRINGING GENERALLY CLEAR SKIES AND
LIGHT WINDS.
LOW CLOUDS AND FOG AT KLNS SHOULD IMPROVE QUICKLY OVER THE NEXT 2
TO 3 HOURS. AREA OF SHOWERS OVER OHIO ARE DISSIPATING BUT MY BRING
A LIGHT SHOWER TO KBFD THIS MORNING.
CU FIELD WILL BLOSSOM THIS AFTERNOON...BENEATH PERIODS OF BKN
ALTO CU ACRS WRN PENN...AS INCREASING WARMTH AND DEEP-LAYER
MOISTURE PUSHES EAST FROM THE OHIO VALLEY. CONDITIONS SHOULD STILL
STAY VFR...THOUGH SOME ISOLATED AND BRIEF MVFR MAY ACCOMPANY A FEW
TSRA LATER FRIDAY AFTERNOON AND EVENING.
OUTLOOK...
FRI...ISOLD LATE PM AND NIGHTTIME TSRA IMPACTS POSS W MTNS.
SAT-SUN...SCT...MAINLY PM TSRA IMPACTS POSSIBLE.
MON...MORE NUMEROUS SHOWERS/TSRA LIKELY AS A COLD FRONT PUSHES
EAST ACROSS THE REGION.
TUE...IMPROVING CONDS AS HIGH PRESSURE DOMINATING.
&&
.EQUIPMENT...
THE KBFD OBSERVATIONS ARE NOT AVAILABLE LONG-LINE DUE TO AN FAA COMMS
PROBLEM.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/STEINBUGL
AVIATION...GARTNER/TYBURSKI
EQUIPMENT...CTP
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
1017 AM EDT FRI JUL 17 2015
.DISCUSSION...
THE 12Z OHX SOUNDING SHOWS THAT THE CAPPING INVERSION THAT HAS BEEN
IN PLACE THE PAST FEW DAYS HAS SHRUNK CONSIDERABLY...AND LOW LEVEL
MOISTURE CONTENT IS HIGHER...SO THERE MAY BE A BETTER CHANCE OF
SEEING CONVECTION DEVELOP THIS AFTERNOON. STILL...THERE IS LITTLE
IN THE WAY OF FORCING TO GET LIFT OTHER THAN SURFACE HEATING...SO
CHANCES WILL BE MAINLY NEAR THE HIGHER TERRAIN AND NO HIGHER THAN A
SLIGHT CHANCE. WILL ADD A SLIGHT CHANCE MENTION IN THE PLATEAU
COUNTIES BASED ON THE LATEST HRRR AND RAP DEPICTIONS OF SHOWERS IN
THAT AREA BETWEEN 20-00Z.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
708 AM EDT FRI JUL 17 2015
.SYNOPSIS...
SURFACE HIGH PRESSURE ALONG THE MID ATLANTIC COAST WILL CONTINUE
TO EXTEND SOUTHWEST ALONG THE EASTERN SLOPES OF THE MOUNTAINS
TODAY. RETURN SOUTHERLY FLOW AROUND THE HIGH BRING A RETURN OF
DEEPER MOISTURE LATER TODAY AS WELL AS WIDELY SCATTERED SHOWERS
AND STORMS INTO TONIGHT. UPPER LEVEL HIGH PRESSURE WILL BUILD
EAST FROM THE GULF COAST REGION THIS WEEKEND...RESULTING IN HOTTER
AND MORE HUMID WEATHER INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 235 AM EDT FRIDAY...
WEAK RESIDUAL WEDGE ACROSS THE REGION WILL GRADUALLY BREAK DOWN FOR A
WHILE TODAY AS HIGH PRESSURE SLIDES OFFSHORE ALLOWING THE FLOW TO TURN
MORE SOUTH/SW THIS AFTERNOON. THIS SHOULD ALSO PROVIDE A SLOW INCREASE
IN MOISTURE AS THE WEAK WARM FRONT TO THE SW EDGES SLOWLY NE TOWARD THE
SW MOUNTAINS LATE IN THE DAY. SIMILAR TO THURSDAY...WILL AGAIN INIT
WITH A MIX OF LOWER CLOUDS ESPCLY ALONG/EAST OF THE BLUE RIDGE WITH
THESE GIVING WAY TO AT LEAST PERIODS OF SUN WITH HEATING DURING THE
AFTERNOON. CONVECTIVE CHANCES AGAIN LOOK TO BE TIED TO OROGRAPHICS
LATER THIS AFTERNOON WITH MOISTURE DEPTH AND INSTABILITY LIKELY A BIT
BETTER. HOWEVER DESPITE LINGERING HIGH 85H THETA-E OVER THE WEST...MODELS
REMAIN RATHER ISOLATED WITH SHRA/TSRA AGAIN TODAY GIVEN LACK OF MUCH
FORCING UNDER WEAK FLOW AND LINGERING CAPPED DRY AIR ALOFT. FOR
NOW WILL KEEP 20/30 POPS GOING MAINLY BLUE RIDGE WEST THIS AFTERNOON
FOR POP UP SHALLOW CONVECTION WITH LITTLE POP ACROSS THE FAR EAST
OVERALL PER LATEST HRRR TRENDS. WITH CONTINUED WARMING ALOFT AND
MORE SOUTH/SW FLOW EXPECT TEMPS TO GET A LITTLE MORE OF A BOOST BUT
MAY TAKE A WHILE FOR READINGS TO JUMP PENDING EARLY CLOUDS. WITH
MOS LOCKED IN ON UNIFORM MID/UPPER 80S WONT ADJUST MUCH FROM THE
PREVIOUS FORECAST VALUES FOR NOW.
MOISTURE DEPTH ALONG WITH BETTER FOCUS AND CONVERGENCE MAY ACTUALLY
INCREASE OVERNIGHT AS A WEAK IMPULSE THAT IS CURRENTLY WORKING THROUGH
THE SOUTHERN LAKES DIPS SE WHILE THE FAINT WARM FRONT SLIDES NORTH.
THIS COULD PROVIDE A CORRIDOR FOR UPSTREAM CONVECTION TO SLIDE SE INTO
WEST VA LATE THIS EVENING WITH SOME LATE NIGHT REDEVELOPMENT POSSIBLE
UNDER WEAK WESTERLY FLOW CONVERGENCE ALONG THE NW SLOPES. FORECAST
INSTABILITY ALSO LINGERS OVERNIGHT UNDER WEAK DIFFLUENCE SO
BUMPED UP POPS TO HIGHER CHANCE NW THIRD MAINLY AFTER MIDNIGHT
WHILE SPILLING SOME COVERAGE OUT INTO THE NE SECTIONS ALONG THE
PASSING WARM FRONT LATE. SHOULD STAY DRY ACROSS THE FAR SOUTH/SW
WHERE WILL HAVE ONLY ISOLATED POPS AT BEST. OTRW PARTLY TO MOSTLY
CLOUDY AND A BIT MORE MUGGY UNDER MOISTENING DEWPOINTS...AND LOWS
THAT LOOK TO BE IN THE WARM UPPER 60S TO LOW 70S OVERALL.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 235 AM EDT FRIDAY...
ANY LINGER INFLUENCES OF A WEAK WEDGE OVER THE REGION WILL DISSIPATE
QUICKLY SATURDAY MORNING. BY THE AFTERNOON...A LEE TROUGH WILL
DEVELOP OVER THE COASTAL PIEDMONT AND REMAIN THERE THROUGH THE
WEEKEND. WITH AN UPPER LEVEL RIDGE OVER THE SOUTHERN MISSISSIPPI
VALLEY...WESTERLY WINDS WILL BRING AN INCREASE IN MOISTURE INTO THE
AREA OVER THE WEEKEND. THE COMBINATION OF OROGRAPHIC LIFT OVER THE
MOUNTAINS AND CONVERGENCE NEAR THE LEE TROUGH...WILL BRING SCATTERED
SHOWERS AND THUNDERSTORMS TO THE REGION OVER THE WEEKEND. EXPECTING
TYPICAL DIURNAL CONVECTION TO FADE WITH LOSE OF HEATING EACH
EVENING. HOWEVER...LINGERING INSTABILITIES AND HEAT COULD KEEP
ISOLATED SHOWERS ONGOING INTO THE EARLY MORNING HOURS. TEMPERATURES
WILL RUN WARMER THAN NORMAL THIS WEEKEND WITH MID TO UPPER 80S WEST
TO LOWER TO MID 90S EAST.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
.
AS OF 155 PM EDT THURSDAY...
OVERALL PATTERN TUESDAY THROUGH THURSDAY MAINTAINS A BROAD RIDGE IN
THE SOUTH AND ZONAL FLOW IN THE NORTHERN STREAM. TROFFING MAY BE
STARTING TO AMPLIFY IN THE NORTHEAST WITH THE RIDGE RETROGRADING IN
THE SOUTHWEST BY WEDNESDAY AND THURSDAY.
ENSEMBLE GFS AND OTHER GUIDANCE SHOWED FRONTAL PASSAGE ON MONDAY.
EXPECT BEST COVERAGE OF PRECIPITATION ON SUNDAY NIGHT THROUGH MONDAY
NIGHT. FRONT MOVES FAR ENOUGH SOUTH OF THE FORECAST AREA THAT THE
PROBABILITY OF PRECIPITATION LOWERS FOR WEDNESDAY AND THURSDAY.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 645 AM EDT FRIDAY...
BANDS OF MVFR STRATO-CU CONTINUE ALONG THE BLUE RIDGE AND POINTS
EAST EARLY THIS MORNING WITH IFR UNDER PATCHY STRATUS AND FOG IN
SPOTS LIKE KLYH/KDAN THAT SAW EARLIER CLEAR SKIES.
THIS TRAPPED LOWER LEVEL MOISTURE INCLUDING SOME FOG WILL LIKELY
LINGER INTO MID/LATE MORNING AND MAY TAKE UNTIL EARLY AFTERNOON
TO MIX OUT LOW CLOUDS ALONG THE SOUTHERN BLUE RIDGE AND POINTS
EAST. APPEARS MOST SITES SHOULD RETURN TO VFR THIS AFTERNOON BUT
GIVEN MOISTURE/HEATING STILL EXPECTING A 4-6K FT SCTD-BKN LAYER
THIS AFTERNOON.
WITH WINDS SHIFTING SOUTHERLY THIS AFTERNOON...WILL SEE GREATER
RETURN OF MOISTURE ACROSS THE MOUNTAINS...AND SLIGHTLY BETTER
CHANCES OF POP UP SHOWER/THUNDERSTORM ACTIVITY ACROSS THE
MOUNTAINS. MOST CONVECTION WILL NOT DEVELOP UNTIL MID
AFTERNOON/EVENING TIME FRAME. POP VALUES ARE LOW...SO LEFT OUT
ANY CONVECTIVE MENTION IN THE TAFS FOR NOW. THAT MAY NEED
AMENDING AS WE ENTER INTO THE 12Z/18Z TAF FCST PERIOD TOMORROW
BASED ON SHORT- RANGE MODEL + RADAR/SATELLITE TRENDS.
EXTENDED AVIATION DISCUSSION...
WITH OPPORTUNITY FOR CLEARING TO TAKE PLACE TONIGHT...WILL HAVE
SOME MORNING FOG/LOW CLOUDS ISSUES IN THE MOUNTAIN VALLEYS...AND
GROUND FOG FOR THE LOW LYING AREAS OF THE FOOTHILLS AND PIEDMONT.
OVERALL CONDITIONS HOWEVER SHOULD BE MAINLY VFR.
WIDELY SCATTERED MORE DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS
RETURN TO THE REGION ON SATURDAY AND SUNDAY WITH PERHAPS MORE
WIDESPREAD COVERAGE ON MONDAY AHEAD OF THE NEXT COLD FRONT. THE
BOUNDARY MAY STALL OUT NEAR THE REGION TUESDAY WITH ISOLATED
CONVECTION POSSIBLE MAINLY OVER SOUTHERN/WESTERN SECTIONS TUESDAY
AFTERNOON/EVENING. MVFR TO IFR CONDITIONS ARE POSSIBLE WITH ANY OF
THE STORMS. OTHERWISE VFR CEILINGS AND VISIBILITIES ARE EXPECTED
OUTSIDE OF ANY OF THE CONVECTION.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/NF
NEAR TERM...JH
SHORT TERM...RCS
LONG TERM...AMS
AVIATION...JH/JM/NF/WP
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
531 AM MDT FRI JUL 17 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 350 AM MDT FRI JUL 17 2015
CURRENT KCYS RADAR LOOP SHOWS SOME RAIN SHOWERS MOVING INTO THE
CARBON AND ALBANY COUNTIES EARLY THIS MORNING. THIS ACTIVITY IS IN
RESPONSE TO THE SURFACE COOL FRONT SLOWLY MOVING SOUTH ACROSS
WYOMING AT THIS HOUR. THIS FRONT WILL GRADUALLY PUSH INTO
SOUTHEAST WYOMING AND PARALLEL I80 BY THIS AFTERNOON. SHOWERS ARE
EXPECTED TO CONTINUE THIS MORNING WITH TSTORMS EVENTUALLY
DEVELOPING BY THIS AFTERNOON. THE 06Z HRRR SHOWS SOME CONVECTION
DEVELOPING FURTHER SOUTH BY THE MIDDLE OF THE AFTERNOON...WITH
SOME STRONGER CELLS BY 20Z. MODELS SHOW THIS COLD FRONT MOVING
INTO COLORADO BY THIS EVENING...WITH COOLER TEMPERATURES EXPECTED
OVER THE AREA LATE THIS EVENING. THERE IS A RISK FOR STRONG TO
SEVERE TSTORMS ACROSS THE HIGH PLAINS EAST OF THE LARAMIE RANGE AS
WELL DUE TO 0-6KM SHEAR BETWEEN 40 TO 50 KNOTS. THE BEST CHANCE
FOR SEVERE TSTORMS APPEARS TO BE EAST OF A LINE EXTENDING FROM
CASPER WYOMING TO SIDNEY NEBRASKA...HOWEVER...WILL HAVE TO MONITOR
THIS THROUGH THE DAY AS RECENT MODEL RUNS ARE SHOWING A GREATER
COVERAGE MAINLY DUE TO THE POSITION OF THE FRONT AND CONSIDERABLE
UPPER LEVEL DIFFLUENCE ASSOCIATED WITH THE UPPER LEVEL JET.
STRONG GUSTY WINDS AND HAIL APPEAR TO BE THE PRIMARY THREATS WITH
ANY TSTORMS THAT DO DEVELOP. IN CONTRAST...THERE IS SOME DRIER AIR
MOVING ACROSS SOUTHEAST WYOMING AHEAD OF THE COOL FRONT...WHICH
MAY LIMIT CONVECTION INITIALLY. THE TIMING AND LOCATIONS OF THE
COOL FRONT WILL BE KEY IN TSTORMS DEVELOPMENT THIS AFTERNOON AS
WELL AS THE POTENTIAL FOR STRONG TO SEVERE TSTORMS. PATCHY FOG AND
LOW STRATUS ARE STILL POSSIBLE EAST OF THE LARAMIE RANGE LATE
TONIGHT AND EARLY SATURDAY MORNING DUE TO SOME RAINFALL AND LIGHT
UPSLOPE WINDS.
FOR THE WEEKEND...A PERIOD OF UNSETTLED WEATHER IS POSSIBLE FOR
THIS WEEKEND AS MODELS SHOW THE FRONT STALLING ACROSS THE
MOUNTAINS. THERE MAY EVEN BE SOME STRONGER TSTORMS ON SATURDAY
NEAR THE COLORADO BORDER AS WELL. SHOULD SEE A HIGHER COVERAGE OF
SHOWERS AND TSTORMS ALONG THE I80 CORRIDOR DUE TO DYNAMIC FORCING
IN ADDITION TO BL INSTABILITY. INCREASED POP BETWEEN 40 TO 50
PERCENT ACROSS THE MOUNTAINS AND HIGH PLAINS FOR A DECENT CHANCE
OF WIDESPREAD RAINFALL. COOLER TEMPERATURES ARE EXPECTED ON
SATURDAY WITH HIGHS IN THE 70S TO LOW 80S. SIMILAR CONDITIONS ARE
EXPECTED ON SUNDAY AS A SHORTWAVE DISTURBANCE ALOFT MOVES ACROSS
THE AREA. SURFACE TEMPERATURES MAY BE COOL ENOUGH TO LIMIT DEEP
CONVECTION AND TSTORM ACTIVITY SO KEPT POP BETWEEN 25 TO 35
PERCENT ACROSS THE HIGH PLAINS. HIGH TEMPERATURES WILL BE BELOW
NORMAL FOR THIS TIME OF THE YEAR WITH READINGS IN THE 70S TO NEAR
80. CURRENT FORECAST MAY BE A LITTLE TOO WARM ON SUNDAY DUE TO
RECENT MODEL GUIDANCE SUGGESTING HIGHS MAINLY IN THE LOW TO MID
70S AND CLOUDY SKIES.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
CONSIDERABLE MODEL DIFFERENCES STILL EXIST AMONG MEDIUM RANGE MODELS
CONCERNING THE TIMING/STRENGTH OF A MID LEVEL SHORTWAVE DISTURBANCE
PROGGED TO MOVE ACROSS THE CENTRAL ROCKIES EARLY IN THE PERIOD. THE
GFS IS THE SLOWEST...BUT HAS BEEN CONSISTENT WITH A FAIRLY VIGOROUS
PIECE OF ENERGY TRACKING ACROSS SOUTHERN WY/NORTHERN CO DURING THE
AFTN HOURS ON MON. ECMWF/GEM ARE MUCH MORE PROGRESSIVE AND TEND TO
MOVE THIS FEATURE WELL INTO NEBRASKA BY MONDAY AFTERNOON...RESULTING
IN RIDGING OVER THE CWA. TEND TO FAVOR THE MORE PROGRESSIVE THINKING
AS THE GFS SHOWS THIS WAVE TOTALLY OUT OF PHASE WITH A RATHER ACTIVE
NORTHERN STREAM. PLUS...BELIEVE THE UPSTREAM VORT MAX OVER THE PAC
NW WOULD SERVE AS A KICKER. RESTRICTED POPS TO THE MOUNTAINS THROUGH
AT LEAST MIDDAY TUESDAY. BY THEN...TROUGHING OVER THE WESTERN CONUS
SHOULD GIVE WAY TO SOUTHWEST FLOW ALOFT OVER THE ROCKIES. IT DOES
NOT APPEAR TO BE A PARTICULARLY MOIST PATTERN BY ANY MEANS...BUT WE
SHOULD SEE PERIODIC SHOTS OF MID AND HIGH LEVEL MOISTURE WITH WEAK
DISTURBANCES EMBEDDED WITHIN THE FLOW. AS SUCH...FAIRLY TYPICAL JULY
WEATHER CAN BE EXPECTED FOR TUE-THU WITH ISOLATED/WIDELY SCATTERED
AFTERNOON CONVECTION. TEMPS THROUGH THE PERIOD SHOULD BE NEAR NORMS
FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 525 AM MDT FRI JUL 17 2015
VFR CONDITIONS WILL PERSIST OUTSIDE OF THUNDERSTORMS. THERE IS A
GOOD CHANCE FOR CONVECTION ACROSS MUCH OF SOUTHEAST WYOMING AND
THE WESTERN NEBRASKA PANHANDLE AFTER 18Z. BRIEF MVFR VISIBILITIES
AND GUSTY/ERRATIC SURFACE WINDS CAN BE EXPECTED WITH SOME OF THIS
ACTIVITY...ALONG WITH SMALL HAIL. GENERAL WINDS WILL GUST AS HIGH
AS 30 KTS OVER WYOMING TERMINALS BETWEEN 15-02Z.
&&
.FIRE WEATHER...
ISSUED AT 252 AM MDT FRI JUL 17 2015
NO FIRE WEATHER CONCERNS THROUGH THIS WEEKEND AND INTO EARLY NEXT
WEEK. IT WILL BE DRY TODAY ACROSS SOUTHERN WYOMING FROM RAWLINS TO
CHEYENNE AS GUSTY WEST TO SOUTHWEST WINDS DEVELOP. DAYTIME
RELATIVE HUMIDITIES WILL LOWER TO 15 TO 20 PERCENT THIS AFTERNOON.
HOWEVER...FUELS REMAIN NON CRITICAL DUE TO RECENT RAINFALL. IN
ADDITION...A COOL FRONT WILL PUSH SOUTHEAST ACROSS THE AREA WITH
HUMIDITIES TRENDING HIGHER FOR THIS WEEKEND.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...TJT
LONG TERM...CLH
AVIATION...CLH
FIRE WEATHER...TJT
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
418 AM MDT FRI JUL 17 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 350 AM MDT FRI JUL 17 2015
CURRENT KCYS RADAR LOOP SHOWS SOME RAIN SHOWERS MOVING INTO THE
CARBON AND ALBANY COUNTIES EARLY THIS MORNING. THIS ACTIVITY IS IN
RESPONSE TO THE SURFACE COOL FRONT SLOWLY MOVING SOUTH ACROSS
WYOMING AT THIS HOUR. THIS FRONT WILL GRADUALLY PUSH INTO
SOUTHEAST WYOMING AND PARALLEL I80 BY THIS AFTERNOON. SHOWERS ARE
EXPECTED TO CONTINUE THIS MORNING WITH TSTORMS EVENTUALLY
DEVELOPING BY THIS AFTERNOON. THE 06Z HRRR SHOWS SOME CONVECTION
DEVELOPING FURTHER SOUTH BY THE MIDDLE OF THE AFTERNOON...WITH
SOME STRONGER CELLS BY 20Z. MODELS SHOW THIS COLD FRONT MOVING
INTO COLORADO BY THIS EVENING...WITH COOLER TEMPERATURES EXPECTED
OVER THE AREA LATE THIS EVENING. THERE IS A RISK FOR STRONG TO
SEVERE TSTORMS ACROSS THE HIGH PLAINS EAST OF THE LARAMIE RANGE AS
WELL DUE TO 0-6KM SHEAR BETWEEN 40 TO 50 KNOTS. THE BEST CHANCE
FOR SEVERE TSTORMS APPEARS TO BE EAST OF A LINE EXTENDING FROM
CASPER WYOMING TO SIDNEY NEBRASKA...HOWEVER...WILL HAVE TO MONITOR
THIS THROUGH THE DAY AS RECENT MODEL RUNS ARE SHOWING A GREATER
COVERAGE MAINLY DUE TO THE POSITION OF THE FRONT AND CONSIDERABLE
UPPER LEVEL DIFFLUENCE ASSOCIATED WITH THE UPPER LEVEL JET.
STRONG GUSTY WINDS AND HAIL APPEAR TO BE THE PRIMARY THREATS WITH
ANY TSTORMS THAT DO DEVELOP. IN CONTRAST...THERE IS SOME DRIER AIR
MOVING ACROSS SOUTHEAST WYOMING AHEAD OF THE COOL FRONT...WHICH
MAY LIMIT CONVECTION INITIALLY. THE TIMING AND LOCATIONS OF THE
COOL FRONT WILL BE KEY IN TSTORMS DEVELOPMENT THIS AFTERNOON AS
WELL AS THE POTENTIAL FOR STRONG TO SEVERE TSTORMS. PATCHY FOG AND
LOW STRATUS ARE STILL POSSIBLE EAST OF THE LARAMIE RANGE LATE
TONIGHT AND EARLY SATURDAY MORNING DUE TO SOME RAINFALL AND LIGHT
UPSLOPE WINDS.
FOR THE WEEKEND...A PERIOD OF UNSETTLED WEATHER IS POSSIBLE FOR
THIS WEEKEND AS MODELS SHOW THE FRONT STALLING ACROSS THE
MOUNTAINS. THERE MAY EVEN BE SOME STRONGER TSTORMS ON SATURDAY
NEAR THE COLORADO BORDER AS WELL. SHOULD SEE A HIGHER COVERAGE OF
SHOWERS AND TSTORMS ALONG THE I80 CORRIDOR DUE TO DYNAMIC FORCING
IN ADDITION TO BL INSTABILITY. INCREASED POP BETWEEN 40 TO 50
PERCENT ACROSS THE MOUNTAINS AND HIGH PLAINS FOR A DECENT CHANCE
OF WIDESPREAD RAINFALL. COOLER TEMPERATURES ARE EXPECTED ON
SATURDAY WITH HIGHS IN THE 70S TO LOW 80S. SIMILAR CONDITIONS ARE
EXPECTED ON SUNDAY AS A SHORTWAVE DISTURBANCE ALOFT MOVES ACROSS
THE AREA. SURFACE TEMPERATURES MAY BE COOL ENOUGH TO LIMIT DEEP
CONVECTION AND TSTORM ACTIVITY SO KEPT POP BETWEEN 25 TO 35
PERCENT ACROSS THE HIGH PLAINS. HIGH TEMPERATURES WILL BE BELOW
NORMAL FOR THIS TIME OF THE YEAR WITH READINGS IN THE 70S TO NEAR
80. CURRENT FORECAST MAY BE A LITTLE TOO WARM ON SUNDAY DUE TO
RECENT MODEL GUIDANCE SUGGESTING HIGHS MAINLY IN THE LOW TO MID
70S AND CLOUDY SKIES.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
CONSIDERABLE MODEL DIFFERENCES STILL EXIST AMONG MEDIUM RANGE MODELS
CONCERNING THE TIMING/STRENGTH OF A MID LEVEL SHORTWAVE DISTURBANCE
PROGGED TO MOVE ACROSS THE CENTRAL ROCKIES EARLY IN THE PERIOD. THE
GFS IS THE SLOWEST...BUT HAS BEEN CONSISTENT WITH A FAIRLY VIGOROUS
PIECE OF ENERGY TRACKING ACROSS SOUTHERN WY/NORTHERN CO DURING THE
AFTN HOURS ON MON. ECMWF/GEM ARE MUCH MORE PROGRESSIVE AND TEND TO
MOVE THIS FEATURE WELL INTO NEBRASKA BY MONDAY AFTERNOON...RESULTING
IN RIDGING OVER THE CWA. TEND TO FAVOR THE MORE PROGRESSIVE THINKING
AS THE GFS SHOWS THIS WAVE TOTALLY OUT OF PHASE WITH A RATHER ACTIVE
NORTHERN STREAM. PLUS...BELIEVE THE UPSTREAM VORT MAX OVER THE PAC
NW WOULD SERVE AS A KICKER. RESTRICTED POPS TO THE MOUNTAINS THROUGH
AT LEAST MIDDAY TUESDAY. BY THEN...TROUGHING OVER THE WESTERN CONUS
SHOULD GIVE WAY TO SOUTHWEST FLOW ALOFT OVER THE ROCKIES. IT DOES
NOT APPEAR TO BE A PARTICULARLY MOIST PATTERN BY ANY MEANS...BUT WE
SHOULD SEE PERIODIC SHOTS OF MID AND HIGH LEVEL MOISTURE WITH WEAK
DISTURBANCES EMBEDDED WITHIN THE FLOW. AS SUCH...FAIRLY TYPICAL JULY
WEATHER CAN BE EXPECTED FOR TUE-THU WITH ISOLATED/WIDELY SCATTERED
AFTERNOON CONVECTION. TEMPS THROUGH THE PERIOD SHOULD BE NEAR NORMS
FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1129 PM MDT THU JUL 16 2015
VFR. A MORE WIDESPREAD THREAT FOR SHOWERS AND THUNDERSTORMS WILL
ARRIVE BY LATE FRIDAY AFTERNOON THROUGH SATURDAY.
&&
.FIRE WEATHER...
ISSUED AT 252 AM MDT FRI JUL 17 2015
NO FIRE WEATHER CONCERNS THROUGH THIS WEEKEND AND INTO EARLY NEXT
WEEK. IT WILL BE DRY TODAY ACROSS SOUTHERN WYOMING FROM RAWLINS TO
CHEYENNE AS GUSTY WEST TO SOUTHWEST WINDS DEVELOP. DAYTIME
RELATIVE HUMIDITIES WILL LOWER TO 15 TO 20 PERCENT THIS AFTERNOON.
HOWEVER...FUELS REMAIN NON CRITICAL DUE TO RECENT RAINFALL. IN
ADDITION...A COOL FRONT WILL PUSH SOUTHEAST ACROSS THE AREA WITH
HUMIDITIES TRENDING HIGHER FOR THIS WEEKEND.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...TJT
LONG TERM...CLH
AVIATION...CLH
FIRE WEATHER...TJT
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
127 PM PDT FRI JUL 17 2015
.SYNOPSIS...
HIGH PRESSURE BUILDING ALOFT WILL BRING SLIGHT WARMING TODAY WITH
MOSTLY SUNNY SKIES. TROPICAL MOISTURE FROM TROPICAL CYCLONE DOLORES
WILL BRING CLOUDS...WARM AND MUGGY CONDITIONS...AND ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS THIS WEEKEND. SOME REMNANT
MOISTURE WILL BRING THE CHANCE FOR AFTERNOON AND EARLY EVENING
THUNDERSTORMS AND SHOWERS FOR THE MOUNTAINS AND DESERTS MONDAY.
GRADUALLY DRIER FOR TUESDAY THROUGH FRIDAY OF NEXT WEEK ALONG WITH A
RETURN OF THE NIGHT AND MORNING COASTAL AND WESTERN VALLEY LOW
CLOUDS AND PATCHY FOG.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
MARINE LAYER STRATUS WAS A BIT SHALLOWER THIS MORNING...AS EARLIER
VISIBLE SATELLITE SHOWED LOW CLOUDS COVERING THE COAST AND WESTERN
VALLEYS...BUT NOT QUITE INTO THE INLAND EMPIRE. THE 12Z MIRAMAR
SOUNDING SHOWED AN 8 DEG C INVERSION AT AROUND 2300 FEET MSL...WITH
SOUTHWEST FLOW ALOFT. STRATUS HAS CLEARED OUT NICELY ACCORDING TO
THE LATEST VISIBLE IMAGES. WITH A RIDGE BUILDING IN
ALOFT...TEMPERATURES CURRENTLY ARE A 3-7 DEGREES HIGHER THAN AT THIS
TIME YESTERDAY.
DOLORES IS NOW A TROPICAL STORM AND LOCATED 420 MILES WEST OF CABO
SAN LUCAS AS IT CONTINUES TO MOVE TO THE WEST-NORTHWEST. AS THE
RIDGE TO THE EAST CONTINUES TO EXPAND WESTWARD INTO SOUTHERN
CALIFORNIA AND BAJA...IT WILL STEER DOLORES TO MORE OF A NORTHWEST
MOVEMENT THROUGH THIS WEEKEND...EVENTUALLY REACHING A POINT 200-300
MILES WEST OF NORTHERN BAJA BY LATE SUNDAY NIGHT AS IT BECOMES A
REMNANT LOW OR TROPICAL DEPRESSION. INCREASING MOISTURE...SOME FROM
DOLORES AND SOME FROM NORTHWEST MEXICO...WILL ADVECT INTO THE REGION
STARTING TONIGHT AND CONTINUING THROUGH SUNDAY...RESULTING IN
PLENTIFUL CLOUDS...INCREASINGLY HUMID AND MUGGY CONDITIONS...AND
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS FROM THE COASTAL
WATERS TO THE DESERTS. GFS...NAM AND WRF SHOW PRECIPITABLE WATER
INCREASING TO 1.7-1.9 INCHES BY LATE SATURDAY AFTERNOON...AND
CONTINUING NEAR THOSE VALUES THROUGH SUNDAY. STARTING TONIGHT AND
CONTINUING THROUGH SUNDAY...THE BUFKIT FORECAST SOUNDINGS FROM THE
NAM AND GFS SHOW ELEVATED CAPE...WHICH INDICATES THAT THERE IS
ELEVATED INSTABILITY AND THE POTENTIAL FOR THUNDERSTORMS.
THERE WILL BE SMALL INCREASES IN MOISTURE THIS AFTERNOON UNDER
SOUTHWEST FLOW ALOFT...RESULTING IN SOME CUMULUS OVER THE MOUNTAINS
AND HIGH DESERTS. THE 19Z HRRR SHOWS SOME CONVECTION SPARKING OFF
THIS AFTERNOON OVER IMPERIAL COUNTY...WITH POSSIBLY SOME SPILLING
INTO OUR LOWER DESERTS...BUT CONFIDENCE IS LOW...ESPECIALLY WITH HOW
POOR THE 19Z HRRR INITIALIZED. MOISTURE CONTINUES TO INCREASE LATE
TONIGHT INTO SATURDAY MORNING...BUT NOT QUITE AS MUCH AS FOR THAT
TIME-PERIOD AS MODELS HAVE SHOWN PREVIOUSLY. NONE OF THE HIGH-RES
MODELS SHOW MUCH OF ANY ACCUMULATIONS DURING THAT TIME.
THUS...SHOWER/THUNDERSTORM CHANCES FOR OVERNIGHT TONIGHT ARE NOT
GREAT...BUT WILL KEEP IT IN THE FORECAST FOR NOW. IT MAY START OUT
AS MOSTLY VIRGA OR SPRINKLES. THEN...WE START TO SEE THE GOOD SURGE
OF MOISTURE COMING IN DURING SATURDAY AFTERNOON...WITH THE MAJORITY
OF MOISTURE LOCATED IN THE 700-300 MB LAYER...AND SOME ENHANCED
MOISTURE REACHING DOWN TO 850 MB. AT THAT TIME...A WEAK WAVE MAY
MOVE OVER THE AREA TO HELP TRIGGER SOME ELEVATED CONVECTION.
ALSO...IF THERE IS ENOUGH CLEARING OVER THE MOUNTAINS TO ALLOW FOR
DAY-TIME HEATING INDUCED INSTABILITY...THAT WOULD ALSO HELP
THUNDERSTORMS/SHOWERS TO SPARK OVER THE MOUNTAINS AND DESERTS. WRF
SHOWS THE WINDS ALOFT BEING SOMEWHAT WEAK...WHICH MEANS THE
POSSIBILITY OF SLOW MOVING STORMS AND AN INCREASED FLASH FLOOD
THREAT FOR SATURDAY...BUT THE GFS INDICATES STRONGER WINDS ALOFT AND
FASTER MOVING STORMS. FOR SATURDAY NIGHT INTO SUNDAY MORNING...THE
NAM...WRF AND CANSAC WRF SHOW SCATTERED TO WIDESPREAD PRECIPITATION
OVER THE AREA WITH AN UPPER LEVEL WAVE MOVING OVER THE AREA FROM THE
SOUTH. THE MOISTURE ALSO REACHES THE SURFACE BY THIS TIME ACCORDING
TO MODEL CROSS-SECTIONS. GOING TO SUNDAY AFTERNOON...LOOKS LIKE SOME
OF THE UPPER LEVEL MOISTURE CLEARS OUT...WHICH COULD RESULT IN
BETTER CLEARING OF CLOUDS AND MORE SUNSHINE. THIS WOULD HELP ENHANCE
CHANCES FOR THUNDERSTORMS AND SHOWERS FOR THE MOUNTAINS AND DESERTS
THAT AFTERNOON AND EARLY EVENING...WITH SOUTHWESTERLY FLOW ALOFT
CONTINUING. WINDS ALOFT OF 15-20 KT SHOULD KEEP STORMS MOVING
QUICKLY ENOUGH FOR THERE NOT TO BE A BIG FLASH FLOOD THREAT...WITH
THE FRESH MOUNTAIN BURN SCARS BEING OF BIGGEST CONCERN. FOR
MONDAY...THERE WILL STILL BE ENOUGH MOISTURE AROUND TO PRODUCE A
CHANCE FOR THUNDERSTORMS AND SHOWERS OVER THE MOUNTAINS AND DESERTS
DURING THE AFTERNOON AND EARLY EVENING HOURS.
FOR SUNDAY AND MONDAY...THE CLOSENESS OF THE REMNANT LOW OF DOLORES
COULD CREATE AN OFFSHORE FLOW SCENARIO WHICH COULD HELP TO HEAT UP
THE AREAS WEST OF THE MOUNTAINS. THIS...IN ADDITION TO SURFACE
DEWPOINTS POSSIBLY RISING INTO THE THE UPPER 60S/LOW 70S FOR THE
COAST AND VALLEYS...WILL RESULT IN HOT AND MUGGY CONDITIONS
SUNDAY...AND MONDAY AS WELL. FINALLY...ALL THE MOISTURE IN THE MID-
TO-HIGH LEVELS MAY INHIBIT NIGHT AND MORNING MARINE LAYER LOW
STRATUS/FOG FORMATION...WITH PATCHY LOW CLOUDS AT BEST.
DRY CONDITIONS LOOK TO PREVAIL NEXT TUESDAY THROUGH FRIDAY UNDER
SOUTHWEST FLOW ALOFT AS THE RIDGE GETS NUDGED EAST BY A TROUGH ALONG
THE WEST COAST...WITH DAY-TIME HIGHS SEVERAL DEGREES BELOW NORMAL.
EXPECT THE NIGHT AND MORNING MARINE LAYER CLOUDS TO RETURN FOR THE
COAST AND PORTIONS OF THE VALLEYS.
&&
.AVIATION...
172030Z...COAST/VALLEYS...VFR CONDITIONS THROUGH THIS EVENING.
PATCHY STRATUS...WITH BASES FROM 1500-1800 FT MSL AND TOPS TO 2500
FT MSL...WILL DEVELOP ALONG THE COAST/VALLEYS TONIGHT. HIGH/MID
CLOUDS MOVING INTO THE REGION TONIGHT THROUGH SATURDAY WILL HELP
MAKE THE LOW CLOUDS MORE PATCHY. SHRA/TSRA WILL BEGIN TO DEVELOP
ACROSS THE AREA LATE TOMORROW MORNING AND CONTINUE THROUGH THE END
OF THE WEEKEND. FORECASTER CONFIDENCE IN CLOUD FORECAST IS MODERATE
TO HIGH.
MTNS/DESERTS...MOSTLY CLEAR WITH UNRESTRICTED VIS THROUGH THIS
EVENING. INCREASING MID/HIGH CLOUDS LATE THIS EVENING THROUGH
SATURDAY MORNING. OCCASIONAL WESTERLY WIND GUSTS TO 40 KT WILL
CREATE MOSTLY MDT UDDFS AND LLWS OVER AND EAST OF THE MTNS...MAINLY
THIS AFTN AND EVENING. CHANCE OF SHRA/TSRA SATURDAY LATE MORNING
THROUGH THE END OF THE WEEKEND.
&&
.MARINE...
130 PM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH THIS
EVENING. CHANCE OF THUNDERSTORMS SATURDAY THROUGH SUNDAY OVER THE
COASTAL WATERS. GUSTY AND ERRATIC WINDS...CLOUD-TO-WATER LIGHTNING
AND ROUGH SEAS MAY ACCOMPANY ANY THUNDERSTORMS. CONDITIONS WILL
IMPROVE BY SUNDAY NIGHT.
&&
.BEACHES...
130 PM...A 5 FT/11 SEC SOUTHERLY SWELL FROM TROPICAL CYCLONE DOLORES
WILL REACH PARTS OF ORANGE COUNTY AND NORTHERN SAN DIEGO COUNTY
SATURDAY INTO SUNDAY. ELEVATED SURF OF 5 TO 7 FT...WITH ISOLATED
SETS TO 8 FT...WILL BE LIKELY ALONG SOUTH FACING BEACHES OF ORANGE
COUNTY AND NORTHERN SAN DIEGO COUNTY. STRONG RIP CURRENTS ARE
EXPECTED THROUGH THE WEEKEND.
ISOLATED TO SCATTERED THUNDERSTORMS ARE POSSIBLE SATURDAY THROUGH
SUNDAY AT THE BEACHES. LIGHTNING...GUSTY AND ERRATIC WINDS...AND
HEAVY DOWNPOURS ARE POSSIBLE WHERE STORMS DEVELOP. A BEACH HAZARDS
STATEMENT IS IN EFFECT THROUGH THE PERIOD.
&&
.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...BEACH HAZARDS STATEMENT FROM LATE TONIGHT THROUGH MONDAY EVENING
FOR ORANGE COUNTY COASTAL AREAS-SAN DIEGO COUNTY COASTAL
AREAS.
PZ...NONE.
&&
$$
PUBLIC...HARRISON
AVIATION/MARINE/BEACHES...JJT
AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
922 AM PDT FRI JUL 17 2015
.UPDATE...
QUICK UPDATE TO ADJUST PRECIP CHANCES THIS AFTERNOON BASED ON
LATEST MODELS AND OBS. EAST FLOW IS MUCH WEAKER ON THE SIERRA
CREST AND SLIDE MTN THIS MORNING COMPARED TO 24 HRS AGO. WITH WEST
FLOW INCREASING AHEAD OF THE INSIDE SLIDER WE SHOULD SEE WEST
WINDS EARLIER TODAY. AS A RESULT, IT IS DOUBTFUL CONVECTION WILL
FORM ALONG THE SIERRA CREST UNLESS IT IS BY 1 PM. HAVE PUSHED THE
THREAT FURTHER EAST FROM THE CARSON RANGE INTO THE SIERRA FRONT
AND FURTHER SOUTH ALONG THE 395 CORRIDOR TO LEE VINING. HRRR SHOWS
THIS IDEA AND BASED ON PAST EXPERIENCE THIS MAKES THE MOST SENSE.
NO ADJUSTMENTS TO THIS EVENING OR TONIGHT AS THEY APPEAR ON TRACK
AT THIS TIME. WALLMANN
&&
.SYNOPSIS...
LOW PRESSURE FROM THE PACIFIC NORTHWEST WILL GRADUALLY INCREASE THE
THUNDERSTORM THREAT INTO TONIGHT WITH NEAR NORMAL TEMPERATURES.
AFTER A BRIEF BREAK THERE IS THE POTENTIAL FOR A COOLER AND WETTER
WEATHER PATTERN FOR THE START OF NEXT WEEK.
&&
.PREVIOUS DISCUSSION... /ISSUED 250 AM PDT FRI JUL 17 2015/
SYNOPSIS...
LOW PRESSURE FROM THE PACIFIC NORTHWEST WILL GRADUALLY INCREASE THE
THUNDERSTORM THREAT INTO TONIGHT WITH NEAR NORMAL TEMPERATURES.
AFTER A BRIEF BREAK THERE IS THE POTENTIAL FOR A COOLER AND WETTER
WEATHER PATTERN FOR THE START OF NEXT WEEK.
SHORT TERM...
THERE WERE A FEW SLIGHT ADJUSTMENTS TO THE EXISTING FORECAST
CONCERNING THUNDERSTORMS THE NEXT FEW DAYS. ADDED SOME ISOLATED
THUNDERSTORMS EARLY THIS AFTERNOON ALONG THE SIERRA MAINLY AROUND
THE CREST FROM THE TAHOE BASIN SOUTH THROUGH MONO COUNTY. NAM AND
HRRR HIGHLIGHT THIS POTENTIAL BEFORE WESTERLIES KICK CONVERGENCE
INTO THE SIERRA FRONT. OTHERWISE, ADJUSTMENTS TO THUNDERSTORM
PLACEMENT WERE ONLY SMALL NUDGES BASED ON UPDATED GUIDANCE.
LOW PRESSURE WILL DROP OUT OF THE PACIFIC NORTHWEST THIS EVENING
INCREASING THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS ESPECIALLY
NORTH OF INTERSTATE 80. GFS AND NAM ARE BEGINNING TO RESOLVE
EMBEDDED IMPULSES AND CONVECTION ALONG THE FRONTAL BOUNDARY
ITSELF. THE FRONT IS EXPECTED TO MOVE THROUGH THE REGION EARLY
SATURDAY. TROUGHING LINGERS INTO SUNDAY WITH CONTINUED ISOLATED
CHANCES OF SHOWERS AND THUNDERSTORMS.
ASIDE FROM THUNDERSTORMS, WINDS WILL INCREASE AHEAD OF THIS
BOUNDARY THIS AFTERNOON. EXPECT WIND GUSTS UP TO 30 MPH AT TIMES.
THIS WILL CREATE CHOPPY CONDITIONS ON AREA LAKES INCLUDING LAKE
TAHOE AND PYRAMID LAKE. SOME BRIEF AND VERY ISOLATED CRITICAL FIRE
WEATHER CONDITIONS MAY ALSO BE MET ALONG THE SIERRA FRONT.
HOWEVER, WILL BE MORE OPTIMISTIC SINCE FUELS ARE NOT EXTREMELY DRY
FOR NOW AND THE WINDOW FOR THESE CONDITIONS IS VERY SMALL. EXPECT
TEMPERATURES AROUND 90 TODAY IN WESTERN NEVADA AND AROUND 80 FOR
THE SIERRA. TEMPERATURES DIP A LITTLE OVER THE WEEKEND WITH
RELATIVELY COOLER NORTHERLY FLOW; BACK INTO THE MID/UPPER 80S AND
MID/UPPER 70S RESPECTIVELY. BOYD
LONG TERM...MONDAY THROUGH THURSDAY...
THE NATIONAL HURRICANE CENTER FORECAST CALLS FOR DOLORES TO BECOME A
TROPICAL DEPRESSION LOCATED SOUTHWEST OF SAN DIEGO BY MONDAY. THE
OPERATIONAL GLOBAL MODELS CAPTURE THIS TRACK FAIRLY WELL BUT THEY
CONTINUE TO DIFFER ON WHEN AND HOW FAR NORTH MOISTURE FROM DOLORES
WILL REACH ACROSS THE SIERRA AND WESTERN NEVADA. FOR MONDAY THEY
ALSO DIFFER ON WHETHER A LOW FROM THE NORTHERN STREAM WILL DROP OVER
THE GREAT BASIN, OR INSTEAD A LOW FROM THE SOUTH COULD DEVELOP AND
TRACK NORTHEASTWARD ACROSS THE SOUTHERN SIERRA INTO WESTERN NV.
WHILE THE EXACT EVOLUTION OF THE PATTERN HASN`T COME INTO FOCUS YET,
THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS IS SOUTH OF I-80
SUNDAY THROUGH MONDAY, WITH LOWER CHANCES FOR THUNDERSTORMS NORTH OF
I-80.
FOR TUESDAY-THURSDAY, A NEW TROUGH IS EXPECTED TO MOVE OVER THE WEST
U.S. THE CURRENT MODEL ENSEMBLES SHOW GOOD AGREEMENT THE TROUGH
AXIS WILL BE WEST OF THE SIERRA THROUGH AT LEAST WEDNESDAY.
DEPENDING ON HOW LONG MOISTURE LINGERS, THIS PATTERN WILL CONTINUE
TO PROVIDE A THREAT FOR AFTERNOON/EVENING THUNDERSTORMS THROUGH AT
LEAST WEDNESDAY. JCM
AVIATION...
AS A LOW APPROACHES FROM THE NORTH TODAY, WESTERLY SURFACE WINDS
WILL GUST TO UP TO 30 KTS THIS AFTERNOON. AS THE LOW DROPS SOUTH,
BREEZY WEST OR NORTHWEST WINDS MAY PERSIST UNTIL AROUND MIDNIGHT.
ISOLATED THUNDERSTORMS COULD DEVELOP NEAR THE SIERRA CREST THIS
AFTERNOON. THE BETTER CHANCE IS NORTH OF SUSANVILLE AND GERLACH AND
STARTING LATE IN THE AFTERNOON FOR ZEPHYR WINDS TO BE A FOCUS FOR
THUNDERSTORMS EAST OF HIGHWAY 395. EXPECT TURBULENCE AND GUSTY AND
ERRATIC WINDS NEAR ANY THUNDERSTORMS. JCM
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1031 AM MDT FRI JUL 17 2015
.UPDATE...
ISSUED AT 1027 AM MDT FRI JUL 17 2015
ONLY SOME MINOR TWEAKING HERE AND THERE TO THE GRIDS BASED ON
CURRENT CONDITIONS AND LATEST NWP. LATEST HRRR RUN IS A BIT MORE
GENEROUS WITH THE CONVECTION COMPARED TO EARLIER RUNS BUT NOTHING
SIGNIFICANT.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 255 AM MDT FRI JUL 17 2015
THE FLOW ALOFT WILL BECOME MORE WSW TODAY AS AN UPPER LEVEL TROUGH
IS OVER THE NRN ROCKIES. OVERALL PRECIPITABLE WATER VALUES WILL
STAY ON THE LOW SIDE HOWEVER THERE IS STILL ENOUGH MOISTURE TO ALLOW
FOR THE DEVELOPMENT OF ISOLD-WDLY SCT HIGH BASED STORMS THIS AFTN
INTO THE EARLY EVENING HOURS. SOUNDINGS ARE INVERTED-V TYPE WHICH
WILL BE CONDUCIVE TO GUSTY WINDS FM ANY SHOWER/TSTM. OVER THE FAR
NERN CORNER A WK CONVERGENCE ZN MAY DVLP BY EARLY AFTN WHICH
COMBINED WITH HIGHER CAPE VALUES COULD LEAD TO AN ISOLD SVR STORM.
AS FOR HIGHS 850-700 MB TEMPS CONTINUE TO RISE A FEW MORE DEGREES SO
READINGS ACROSS NERN CO WILL BE IN THE 90S THIS AFTN.
FOR TONIGHT A WK FNTL BNDRY WILL WILL MOVE ACROSS THE PLAINS AFTER
MIDNIGHT WHICH MAY BE FOLLOWED BY SOME STRATUS DEVELOPMENT TOWARDS
SUNRISE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 255 AM MDT FRI JUL 17 2015
INCREASING STORM COVERAGE BY THE TAIL END OF THE WEEK INTO NEXT WEEK
AS SUBTROPICAL MOISTURE RETURNS TO THE REGION WITH AVERAGE TO
SLIGHTLY BELOW AVERAGE TEMPERATURES.
THE WEEKEND WILL START WITH SLIGHTLY COOLER TEMPERATURES THEN THE
PREVIOUS WEEK WITH HIGHS IN THE UPPER 80S DIPPING INTO THE LOWER 80S
BY SUNDAY. THE REASON IS A FEW DISTURBANCES MOVING INTO NE COLORADO
IN THE FORM OF A WEAK COLD FRONT FRIDAY NIGHT THEN A BACK DOOR COLD
FRONT SATURDAY NIGHT INTO SUNDAY MORNING. THE LOW PRESSURE SYSTEM
ENTRENCHED OVER THE NORTHERN PORTIONS OF THE CONUS COMBINED WITH THE
STRONG HIGH PRESSURE OVER THE SOUTHERN CONUS WILL KEEP MODERATE WSW
FLOW ALOFT. THIS WILL SLOWLY RE-ENERGIZE THE FLOW OF SUBTROPICAL
MOISTURE INTO COLORADO THAT WILL HELP TO INCREASE PW VALUES AND
CONVECTION. SATURDAY WILL SEE AFTERNOON SCATTERED STORMS OVER THE
MOUNTAINS WITH ISOLATED ON THE PLAINS. MAIN THREATS WILL BE BRIEF
HEAVY RAIN WITH GUSTY WINDS. FOR SUNDAY THE COLD FRONT WILL DROP
TEMPERATURES EVEN MORE AND INTRODUCE INCREASED MOISTURE IN THE
FORM OF CLOUD COVER. THIS MAY INHIBIT CONVECTION IN THE AFTERNOON
DUE TO INCREASED MID LEVEL STABILITY. HOWEVER...IF CONVECTION TEMP
CAN BE REACHED CAPE VALUES ARE ABOVE 1000 J/KG WITH MODERATE SHEAR
VALUES IN THE 40S. THIS COMBINED WITH THE INCREASED PW VALUES
ABOVE 1 INCH COULD LEAD TO A FEW STRONG TO SEVERE STORMS OVER THE
PLAINS.
FOR THE NEXT WEEK PW VALUES WILL REMAIN HIGH AS THE RIDGE CONTINUES
TO BE OVER THE SOUTHERN PORTIONS OF THE CONUS CREATING WSW FLOW.
THIS WILL HELP TO KEEP ISOLATED TO SCATTERED POPS IN THE FORECAST
FOR AFTERNOON AND EVENING CONVECTION THROUGH FRIDAY. HIGH
TEMPERATURES WILL SLOWLY INCREASE DURING THE WEEK WITH UPPER 80S TO
LOWER 90S POSSIBLE BY FRIDAY.
&&
.AVIATION...(FOR THE TAFS THROUGH 18Z SATURDAY MORNING)
ISSUED AT 1027 AM MDT FRI JUL 17 2015
18Z TAFS WON`T DIFFER MUCH FROM 12Z ONES. WITH LACK OF SUBSIDENCE
TODAY AREA TERMINALS STAND A BIT BETTER CHANCE OF SEEING VCTS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...ET
SHORT TERM...RPK
LONG TERM...BOWEN
AVIATION...ET
AREA FORECAST DISCUSSION
NWS MIAMI FL
152 PM EDT FRI JUL 17 2015
.AVIATION...
MOSTLY VFR CONDITIONS FORECAST FOR THE NEXT 24 HOURS OUTSIDE
BRIEF PERIODS OF MVFR TO NEAR IFR CONDITIONS POSSIBLE WITH ANY
SHOWERS OR THUNDERSTORMS MOVING ACROSS A GIVEN SITE PARTICULARLY
THIS AFTERNOON/EVENING. POTENTIAL FOR STRONGER STORMS MOVING
ACROSS A SITE THIS AFTERNOON OR EARLY EVENING FAVORS THE EAST
COAST SITES. CONDITIONS SHOULD ABATE THIS EVENING WITH LIGHT AND
VARIABLE WINDS OVERNIGHT PICKING UP FROM THE SE ALONG EAST COAST
SITES BY MID TO LATE MORNING TOMORROW WITH A SWLY C-BRZ AT APF BY
LATE MORNING.
&&
.PREV DISCUSSION... /ISSUED 1125 AM EDT FRI JUL 17 2015/
UPDATE...
LATEST SURFACE ANALYSIS SHOWS WEAK FRONTAL BOUNDARY WITH LOW LEVEL
CONVERGENCE BOUNDARY FURTHER SOUTH ACROSS EAST CENTRAL GULF UNDERNEATH
AREA OF UPPER LEVEL DIFLUENCE AND HIGHER PRECIPITABLE WATER VALUES
FUELING CONVECTION ACROSS THAT REGION AT THIS TIME. 12Z SNDG PARAMETERS
REVEAL MID LEVELS SLIGHTLY WARMER THAN NORMAL ACROSS SOUTH FLORIDA,
WITH 700-500MB LAPSE RATES OF AROUND 6.2 C/KM WITH A VERY UNIMPRESSIVE
THERMAL PROFILE BELOW 650 MB OR SO. MICROBURST INDICES INDICATE
ONLY MARGINAL POTENTIAL FOR TODAY WITH EVEN LESS FOR HAIL. PWAT
VALUES HAVE FALLEN SINCE YESTERDAY TO NEAR NORMAL LEVELS PER
BLENDED AMSU/SSMI/GPSMET SATELLITE PRODUCT WITH SLIGHTLY DRIER AIR
COLUMN. ON THE OTHER HAND, PLENTY OF HEATING TODAY VERSUS
YESTERDAY YET BECAUSE OF UNIMPRESSIVE THERMAL PROFILES MODIFIED
SOUNDING STILL YIELDED 2700 J/KG CAPE. ALL IN ALL THIS MEANS
MOSTLY GARDEN VARIETY STORMS TODAY WITH MAIN CONCERNS BEING
FREQUENT LIGHTNING WITH THE STRONGEST STORMS AND MAY BE WIND GUSTS
IN EXCESS OF 40 MPH.
ENSEMBLE OF HIGH RESOLUTION MODELS BETWEEN HRRR AND TWO OTHER LOCAL
CONFIGURATIONS STILL INDICATE AREA MOST FAVORED FOR CONVECTION TODAY
WILL BE INTERIOR AND EASTERN HALF OF SOUTH FLORIDA WITH BEST CHANCES
UP THE EAST COAST TOWARDS WEST PALM BEACH. THERE IS STILL A LESSER
CHANCE FOR THE WEST COAST FROM ACTIVITY TO THE NORTH/NORTHWEST
PROPAGATING SOUTH AND/OR DIURNAL CONVECTION ACROSS THE INTERIOR
IMPACTING NAPLES AREA ON ITS WESTERN PERIPHERY.
FORECAST GRIDS ARE BEING AMENDED ACCORDINGLY ALONG WITH HWO.
PREV DISCUSSION... /ISSUED 819 AM EDT FRI JUL 17 2015/
AVIATION...
A LIGHT SOUTHWESTERLY FLOW PREVAILS ACROSS THE REGION WITH NO
CONVECTION EXPECTED AND MAINLY VFR CONDITIONS EXPECTED DURING THE
MORNING HOURS. A BROAD AND WEAK SURFACE LOW WILL DEVELOP ACROSS
NORTH FLORIDA LATER TODAY WITH LIGHT SOUTHWESTERLY WINDS PREVAILING
ACROSS SOUTH FLORIDA. BUT AROUND THE 16-17Z TIME FRAME THE EAST
SEA BREEZE SHOULD FORM AND WITH DEEP TROPICAL MOISTURE ACROSS THE
REGION ACTIVE CONVECTION IS EXPECTED ACROSS THE EASTERN PENINSULA
TODAY WITH ALL EAST COAST TERMINALS ASSIGNED VCTS OR EVEN
TEMPO/PROB30 AFTER 16Z...WITH BRIEF PERIODS OF MVFR TO NEAR IFR
CONDITIONS POSSIBLE WITH STRONGER SHOWERS/THUNDERSTORMS. FOR
TERMINAL KAPF ...ON-SET OF SEA BREEZE COULD BE AROUND 15-17Z BUT
ON-SET OF CONVECTION COULD BE ANYTIME AFTER 15Z PARTICULARLY FROM
ACTIVITY TO THE NORTH NORTHWEST PROPAGATING SOUTH OR FROM DIURNAL
CONVECTION INLAND IMPACTING THE SITE ON ITS WESTERN PERIPHERY.
CONVECTION SHOULD ALSO WIND DOWN BY THE EVENING. STRONGER
CONVECTION TODAY FAVORS THE EAST COAST SITES.
PREV DISCUSSION... /ISSUED 354 AM EDT FRI JUL 17 2015/
DISCUSSION...
A BROAD TROUGH WITH AXIS OVER NORTH FLORIDA ALONG WITH THE
ATLANTIC SURFACE RIDGE SHUNTED SOUTH ACROSS THE FLORIDA STRAITS IS
RESULTING IN A PREVAILING SOUTHWEST WIND FLOW ACROSS SOUTH
FLORIDA. MOISTURE IS AT OR SLIGHTLY ABOVE THE MEAN FOR MID
JULY...WITH PW IN THE 1.75-2.00 RANGE. BROAD SCALE CONVERGENCE
WILL OCCUR ACROSS SOUTH FL TODAY ALONG WITH MESOSCALE SEA BREEZE
CONVERGENCE...AND WITH HEALTHY MOISTURE AND INSTABILITY IN PLACE,
AM EXPECTING THE TRANQUIL MORNING TO TURN TO A STORMY AFTERNOON
FOR MANY LOCALES. A FEW TSTORMS COULD EVEN DEVELOP BY LATE
MORNING.
HIGH RES MODEL CONSENSUS SHOWS CONVECTION DEVELOPING ALONG BOTH
THE GULF AND ATLANTIC SEA BREEZE WITH THE HIGHER COVERAGE AND
INTENSITY ALONG THE ATLANTIC SEA BREEZE...WHICH MAKES SENSE GIVEN
THE FLOW PATTERN.
HRRR SHOWS ISOLATED RAINFALL AMOUNTS OF 2-3" ACROSS THE EAST
COAST METRO AND INTO THE INTERIOR WITH IMPACTS BEING ISOLATED
STREET FLOODING IN TYPICAL (ALTHOUGH NOT THIS YEAR) SOUTH FL
RAINY SEASON STYLE. GUSTY WINDS OF 40-50 MPH WILL BE POSSIBLE AS
WELL.
THE ATLANTIC RIDGE SLOWLY BUILDS NORTH ACROSS SOUTH FL THIS
WEEKEND. THIS WILL LEAD TO A MORE SE SURFACE WIND WHICH WILL FOCUS
TSTORMS FURTHER INLAND. DRIER AIR MOVES IN FROM THE SOUTHEAST.
THE NAVY MODEL SHOWS THIS TO BE A WEAK SAHARAN AIR LAYER
(SAL)...MOVING IN SATURDAY THEN DEPARTING THE AREA BY SUNDAY
EVENING. THIS LOOKS TO REDUCE TSTORM COVERAGE A TAD...BUT WILL
HAVE TO WATCH FOR THE POSSIBILITY OF A FEW STRONGER CELLS
DEVELOPING DUE TO INCREASED INSTABILITY/STEEPER LAPSE RATES OF
THE SAL.
MODEL CONSENSUS SHOWS THE ATLANTIC RIDGE BUILDING INTO THE LAKE
REGION AND POSSIBLY CENTRAL FL EARLY-MID NEXT WEEK BEFORE MOVING
SOUTH AGAIN LATE WEEK. A TYPICAL DIURNAL CONVECTIVE PATTERN WILL
PREVAIL WITH STEERING WINDS FAVORING A FOCUS OF TSTORM
DEVELOPMENT OVER THE INTERIOR EACH DAY.
/GREGORIA
AVIATION...
A LIGHT SOUTHWESTERLY FLOW PREVAILS ACROSS THE REGION WITH NO
CONVECTION EXPECTED AND MAINLY VFR CONDITIONS EXPECTED DURING THE
EARLY MORNING HOURS. A BROAD AND WEAK SURFACE LOW WILL DEVELOP
ACROSS NORTH FLORIDA LATER TODAY WITH LIGHT SOUTHWESTERLY WINDS
PREVAILING ACROSS SOUTH FLORIDA. BUT AROUND THE 16-17Z TIME FRAME
THE EAST SEA BREEZE SHOULD FORM AND WITH DEEP TROPICAL MOISTURE
ACROSS THE REGION ACTIVE CONVECTION IS EXPECTED ACROSS THE EASTERN
PENINSULA TODAY WITH ALL EAST COAST TERMINALS ASSIGNED VCTS AT
16Z...WITH BRIEF PERIODS OF MVFR TO NEAR IFR CONDITIONS POSSIBLE
WITH STRONGER SHOWERS/THUNDERSTORMS. FOR TERMINAL KAPF...ONSET OF
SEA BREEZE COULD BE AROUND 14-16Z BUT ONSET OF CONVECTION STARTING
LATER AROUND 20Z WITH BRIEF PERIODS OF MVFR TO NEAR IFR CONDITIONS
POSSIBLE WITH STRONGER SHOWERS/THUNDERSTORMS. /BD
MARINE...
A PREVAILING WIND FLOW OF AROUND 10 KT OR LESS WILL PREVAIL
THROUGH THE FORECAST PERIOD WITH CORRESPONDINGLY LOW SEAS.
PREVAILING SOUTH-SOUTHWEST WINDS WILL BECOME SOUTH TO SOUTHEAST
THIS WEEKEND AS THE ATLANTIC SURFACE RIDGE BUILDS SLIGHTLY
NORTHWARD.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 91 77 91 77 / 60 30 50 40
FORT LAUDERDALE 90 78 90 79 / 50 40 50 20
MIAMI 91 78 91 79 / 50 30 50 10
NAPLES 89 77 90 77 / 40 30 50 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...52/PS
LONG TERM....21/KM
AVIATION...52/PS
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1224 PM CDT FRI JUL 17 2015
.UPDATE...
ISSUED AT 1028 AM CDT FRI JUL 17 2015
UPDATED FORECAST PRIMARILY TO ISSUE A HEAT ADVISORY ACROSS THE
NORTHWEST HALF OF THE FORECAST AREA (BLOOMINGTON-TAYLORVILLE
WESTWARD) BEGINNING AROUND NOON TODAY...AND ACROSS THE SOUTHEAST
HALF FOR SATURDAY. PLENTY OF SUNSHINE THIS MORNING HAS ALREADY
RESULTED IN TEMPERATURES REACHING THE MID-UPPER 80S ACROSS THE
WESTERN CWA...AND MOST OF THESE AREAS SHOULD SEE HEAT INDEX OF 105
OR MORE AS EARLY AS THIS AFTERNOON. THE EAST IS SEEING MORE CLOUD
COVER AND ISOLATED STORMS...WHICH MAY KEEP THINGS A BIT LOWER FOR
THE HEAT INDEX TODAY.
IN TERMS OF THE STORMS...CLUSTERS OF STORMS WERE OCCURRING LATE
THIS MORNING AROUND THE NORTHERN PART OF THE ST LOUIS METRO AND
ALSO NORTH OF INDIANAPOLIS. LATEST VISIBLE SATELLITE IMAGERY
SHOWING SOME CUMULUS GROWING NORTHEAST ALONG THIS LINE TOWARD
VANDALIA. HRRR TRYING TO FILL SOME OF THIS IN LATER THIS AFTERNOON
ALONG A WEAK BOUNDARY...PERHAPS A REMNANT OF THE OUTFLOW FROM LAST
NIGHT`S STORMS. HAVE MAINLY KEPT ISOLATED STORMS GOING IN THE
SOUTHEAST HALF OF THE FORECAST AREA...WITH SOME AREAS UP TO ABOUT
A 30% CHANCE.
&&
.SHORT TERM...(TODAY)
ISSUED AT 347 AM CDT FRI JUL 17 2015
WARM FRONT HAS LIFTED NE OF CENTRAL IL EARLY THIS MORNING
LEAVING CWA IN A TROPICAL AIRMASS. WILL ISSUE A SPECIAL WEATHER
STATEMENT (SPS) TO ADDRESS THE HEAT WAVE FROM THIS AFTERNOON THROUGH
THIS WEEKEND. HEAT INDICES SHOULD PEAK FROM 100-105F THIS AFTERNOON
WITH HIGHEST READINGS IN WESTERN COUNTIES WHICH MAY COME CLOSE TO
HEAT ADVISORY CRITERIA AROUND 105F ESPECIALLY FROM JACKSONVILLE
WEST. HIGHS OF 89-93F THIS AFTERNOON WITH VERY MUGGY DEWPOINTS IN
THE MID TO UPPER 70S. A FEW SHOWERS AND THUNDERSTORMS LINGER ALONG
OUTFLOW BOUNDARY FROM MCS IN CENTRAL IL NORTH OF I-72 INTO FAR SE
IA. HRRR IS HANDLING THIS ISOLATED CONVECTION WELL AND USED THIS
MODEL FOR FORECAST TODAY WHICH SHIFTS THE ISOLATED CONVECTION
FURTHER SE DURING THE MORNING. UNSTABLE AIRMASS THIS AFTERNOON WITH
CAPES OF 2-3K J/KG WILL SUPPORT MORE ISOLATED SHOWERS AND
THUNDERSTORMS THIS AFTERNOON AND EARLY EVENING. SPC HAS MARGINAL
RISK OF SEVERE STORMS IN PARTS OF CENTRAL AND EASTERN IL DURING THAT
TIME WITH 5% RISK OF DAMAGING WIND GUSTS EAST OF PEORIA AND
SPRINGFIELD. BULK SHEAR IS WEAK TODAY (10-20 KTS) SO STORMS WILL NOT
BE TOO ORGANIZED.
.LONG TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 347 AM CDT FRI JUL 17 2015
EVEN HOTTER HEAT INDICES EXPECTED SATURDAY AFTERNOON PEAKING FROM
104-109F AND HEAT ADVISORY WILL LIKELY BE NEEDED THEN AND POSSIBLY
IN SOUTHEAST IL ON SUNDAY AFTERNOON WHERE HEAT INDICES NEAR 105F.
SAT APPEARS TO BE THE HOTTEST DAY WITH HIGHS IN THE LOW TO MID 90S
WHILE SUNDAY HIGHS RANGE FROM MID 80S NW OF IL RIVER TO 90-95F IN
SOUTH OF I-72. DEWPOINTS IN THE MID TO UPPER 70S TO COMBINE WITH
THESE HOT TEMPS FOR THE HEAT INDICES TOPPING 105F. HEAT INDICES
SUNDAY AFTERNOON RANGE FROM MID 90S OVER IL RIVER VALLEY TO 104-108F
IN SOUTHEAST IL.
ISOLATED SHOWERS AND THUNDERSTORMS POSSIBLE SAT AFTERNOON OVER
MAINLY NORTHERN AREAS. THEN INCREASING CHANCES OF SHOWERS AND
THUNDERSTORMS OVER AREAS NORTH OF I-72 OVERNIGHT SAT NIGHT WITH
APPROACHING COLD FRONT FROM THE UPPER MIDWEST. SPC HAS MARGINAL RISK
OF SEVERE STORMS NW OF LINCOLN SAT NIGHT FOR GUSTY WINDS WHILE
SLIGHT RISK IS NW OF KNOX AND STARK COUNTIES. 00Z FORECAST MODELS
TRACK COLD FRONT SE ACROSS CENTRAL IL ON SUNDAY AND INTO SOUTHEAST
IL SUNDAY EVENING. THIS TO LIKELY BRING A ROUND OF SHOWERS AND
THUNDERSTORMS. SPC HAS ALL BUT FAR SOUTHEAST IL IN SLIGHT RISK OF
SEVERE STORMS SUNDAY AFTERNOON/EVENING FOR MAINLY DAMAGING WIND
GUSTS.
UPPER LEVEL SUBTROPICAL HIGH PRESSURE RIDGE EXPECTED TO RETROGRADE
BACK INTO THE HIGH PLAINS EARLY NEXT WEEK. THIS WILL BRING A
NORTHWEST FLOW OVER IL WITH TEMPS COOLING CLOSER TO NORMAL ON MONDAY
BEHIND THE COLD FRONT WITH HIGHS OF 82-87F. DEWPOINTS SLIPPING INTO
THE MID TO UPPER 60S OVER CENTRAL AND NW CWA AND LOWER 70S IN
SOUTHEAST IL ON MONDAY. HAVE TRENDED POPS LOWER ON MONDAY INTO
MONDAY NIGHT WITH FRONT GETTING FURTHER SOUTH OF CENTRAL IL INTO THE
TN VALLEY WITH CHANCE POPS IN SOUTHEAST IL, SLIGHT CHANCES CENTRAL
PARTS AND DRY FROM I-74 NORTH.
UPPER LEVEL RIDGE TO EXPAND EAST INTO THE MID MS AND OHIO VALLEYS BY
MIDDLE OF NEXT WEEK WITH 850MB TEMPS CLIMB BACK UP TO LOWER 20SC
WED/THU. HIGH TEMPS IN THE LOW TO MID 80S TUE SHOULD ELEVATE INTO
THE MID TO UPPER 80S WED AND 85-90F THU, AND UPPER 80S/LOWER 90S
NEXT FRI. DEWPOINTS TO CLIMB BACK INTO THE 70S LATER NEXT WORK WEEK.
ECMWF AND GEM MODELS ARE STILL DRIER DURING MIDDLE OF NEXT WEEK
WHILE GFS MODEL BRINGS QPF BACK INTO CENTRAL IL ON TUE. GFS MODEL IS
AN OUTLIER AND JUST KEPT SLIGHT CHANCES OF CONVECTION ON TUE AND
AREAS FROM I-72 NORTH ON WED NIGHT AND THU.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1224 PM CDT FRI JUL 17 2015
DIURNAL CUMULUS STARTING TO INCREASE...AND THERE WILL LIKELY BE AN
HOUR OR TWO WHERE MVFR CEILINGS OCCUR BEFORE CLOUD LEVELS START TO
LIFT. LOCATIONS FROM KPIA-KCMI ARE MOST PRONE FOR THIS OCCURRENCE.
HAVE MENTIONED SOME VCTS FOR KCMI FOR THIS AFTERNOON AS THEY ARE
NEAR A WEAK BOUNDARY LEFT OVER FROM LAST NIGHT. SOUTHWEST WINDS TO
PREVAIL THROUGH THE PERIOD...GENERALLY NEAR 10 KNOTS DURING THE
DAY AND LESS THAN 5 KNOTS AT NIGHT.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TO 7 PM CDT SATURDAY FOR ILZ044>046-
054>057-061>063-066>068-071>073.
HEAT ADVISORY UNTIL 7 PM CDT SATURDAY FOR ILZ027>031-036>038-
040>043-047>053.
&&
$$
UPDATE...GEELHART
SHORT TERM...07
LONG TERM...07
AVIATION...GEELHART
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
330 PM EDT FRI JUL 17 2015
LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/HYDRO/MARINE
.SYNOPSIS...
ISSUED AT 330 PM EDT FRI JUL 17 2015
A FEW SHOWERS AND STORMS WILL BE POSSIBLE LATE THIS AFTERNOON SOUTH
AND EAST OF INTERSTATE 69. THESE WILL MOVE OUT QUICKLY BY EARLY
EVENING.
HEAT AND HUMIDITY WILL BUILD IN ACROSS THE AREA THROUGH THE DAY ON
SATURDAY. TEMPERATURES ARE EXPECTED TO WARM INTO THE LOWER 90S SOUTH
WHILE HEAT INDICES WILL BE AROUND 100 DEGREES. THERE IS A SLIGHT
CHANCE OF A SHOWER OR STORM SATURDAY. A BETTER CHANCE OF STORMS WILL
COME IN LATER SATURDAY NIGHT AND SUNDAY AS A COLD FRONT PUSHES
THROUGH THE AREA. COOLER AND SOMEWHAT DRIER AIR WILL FILTER IN FOR
THE BEGINNING OF THE WORK WEEK NEXT WEEK.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 330 PM EDT FRI JUL 17 2015
OUR BIGGEST CONCERNS IN THE FCST THROUGH SUN NIGHT ARE THE STORM
CHCS THROUGH THE PERIOD...ALONG WITH THE HEAT POTENTIAL FOR SAT. A
HEAT ADVISORY WILL BE ISSUED WITH THIS FCST PACKAGE FOR THE SRN HALF
OF THE CWFA.
WE HAVE A FEW SHOWERS/STORMS THAT WILL REMAIN POSSIBLE LATE THIS
AFTERNOON MAINLY SOUTH AND EAST OF INTERSTATE 69. WE ARE WATCHING AN
ENHANCED CU FIELD THAT STRETCHES ROUGHLY FROM MIDLAND COUNTY TO EAST
OF SOUTH HAVEN. THIS IS AHEAD OF A WEAK TROUGH DROPPING SOUTHEAST
THROUGH THE AREA ALONG WITH SOME ENHANCEMENT OCCURRING DUE TO THE
WRLY FLOW OFF OF COOLER LAKE MICHIGAN. SOUTH OF THIS LINE...MU CAPES
ARE AROUND 3000 J/KG. DEEP LAYER SHEAR STILL LOOKS TO BE LACKING A
BIT...BUT WE COULD SEE SOME STRONGER PULSE TYPE STORMS POSSIBLE
BEFORE THEY MOVE OUT EARLY THIS EVENING.
THE NEXT LOW CHC OF SOME SHOWERS AND MAYBE A STORM WOULD COME ON SAT
MORNING...ESPECIALLY ACROSS THE WRN HALF OF THE CWFA. A COMPLEX OF
STORMS IS FCST TO DEVELOP/EXPAND ACROSS MN THIS EVENING AHEAD OF A
DEVELOPING LLJ/MOISTURE TRANSPORT THERE. THERE ARE SOME MODELS LIKE
THE HRRR AND NSSL WRF THAT BRING THIS E/SE AFTER DAYBREAK SAT
MORNING. THIS SEEMS PLAUSIBLE WITH DEEP LAYER THICKNESSES EXPECTED
TO BE ORIENTED THIS WAY AND A DEEP LAYER INSTABILITY GRADIENT VERY
SIMILAR. THE LLJ WEAKENS BY THE TIME IT GETS HERE...SO WE EXPECT IT
WOULD BE IN THE DECAYING STAGES IF IT MAKES IT HERE.
ONCE THE DECAYING LINE OF SHOWERS/STORMS IS OUT OF THE PICTURE...THE
HEAT WILL BE THE STORY. ASSUMING THERE IS NOT A PROBLEM WITH
CLEARING CLOUDS OUT SAT MORNING AND SOME POSSIBLE FOG...WE SHOULD
WARM UP QUICKLY AND DEW POINTS WILL REMAIN GENERALLY IN THE LOWER
70S. WE ARE LOOKING AT HEAT INDICES AROUND 100F ROUGHLY OVER THE SRN
HALF OF THE CWFA AWAY FROM THE IMMEDIATE LAKESHORE. WE CAN NOT RULE
OUT A POP UP STORM SAT AFTERNOON WITH A POSSIBLE OUTFLOW BOUNDARY
FLOATING AROUND AND POSSIBLE MU CAPES OF 5000 J/KG. WE LOOK VERY
CAPPED...SO THE CHCS OF A STORM ARE LIMITED TO ABOUT 10-20 PCT.
ANYTHING THAT POPS WOULD HAVE THE POTENTIAL TO BECOME SEVERE WITH
THE EXTREME INSTABILITY AVAILABLE...EVEN WITH WEAK SHEAR VALUES
AROUND 20 KNOTS.
THE BETTER CHC FOR STORMS WILL ROLL IN SAT NIGHT AND THEN MOVE OUT
LATER ON SUN. THE BEST MOISTURE TRANSPORT AND LLJ AHEAD OF THE FRONT
WILL DRIFT IN FROM THE NW SAT NIGHT. THIS WILL BRING SOME HIGHER
CHCS ACROSS THE NW PORTION OF THE AREA. THIS WILL BE ON THE EDGE OF
THE CAP AND WILL FOLLOW THE EDGE OF STRONG INSTABILITY. LARGE HAIL
WILL BE POSSIBLE...AND IT WILL HAVE THE POTENTIAL TO HAVE SOME
DAMAGING WINDS AND BE BETTER ORGANIZED AS A BETTER WIND FIELD ALOFT
MOVES IN. ADDITIONAL STORMS FIRING ALONG THE FRONT WILL HAVE THAT
POTENTIAL THEN ON SUN IF THE FRONT IS STILL IN THE AREA. IF THE
FRONT CLEARS THE CWFA SOONER RATHER THAN LATER ON SUN...THE SEVERE
THREAT WILL BE LOWER.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 330 PM EDT FRI JUL 17 2015
IN GENERAL NEXT WEEK LOOKS VERY SUMMER LIKE WITH HIGHS MAINLY IN THE
LOWER TO MID 80S AND LOWS IN THE MID 50S TO MID 60S. CHANCES FOR
SHOWERS AND THUNDERSTORMS LOOK RELATIVELY LOW.
CONFIDENCE IS HIGH THAT MONDAY WILL BE SUNNY AND LESS HUMID. A WEAK
COLD FRONT IS SHOWN TO DROP SOUTH THROUGH THE STATE ON TUESDAY
ALTHOUGH SOME TIMING DIFFERENCE EXISTS WITH THE ECMWF MUCH QUICKER
THAN THE GFS. EITHER WAY THE COVERAGE OF CONVECTION IS EXPECTED TO
BE LIMITED IN SW LWR MI WITH BETTER POPS IN ERN LWR MI WHERE BETTER
CONVERGENCE IS PROGGED.
HIGH PRESSURE IS EXPECTED TO DOMINATE ON WEDNESDAY AND POSSIBLY INTO
THURSDAY AS WELL. THE ECMWF IS A BIT MORE BULLISH THAN THE GFS WITH
THE RETURN OF WAA RELATED PRECIP...AIDED BY A SHORTWAVE ALOFT...
ALREADY SHOWING QPF ON THURSDAY. THE GFS MEANWHILE WANTS TO HOLD THE
SFC RIDGE AND DRY AIR THROUGH THE END OF THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 200 PM EDT FRI JUL 17 2015
MVFR CIGS OF 1500-2500 FT AT 18Z WILL GRADUALLY LIFT TO VFR LEVELS
OF 3000 FT OR GREATER OVER THE NEXT FEW HOURS OR MIX OUT
COMPLETELY. VFR WEATHER WILL PREVAIL THIS EVENING BUT LOOK FOR FOG
TO DEVELOP AFTER MIDNIGHT AND WITH VSBYS PROBABLY TRENDING TO IFR
CATEGORY OF 1-3 MILES OR POSSIBLY LOWER...ESPECIALLY 09Z-13Z. THE
FOG WILL LIFT/MIX OUT TOWARD MID MORNING SATURDAY FOLLOWED BY VFR.
AN ISOLATED SHOWER OR TSTM CANNOT BE RULED OUT AROUND JXN AND BTL
FOR A FEW HOURS BETWEEN ROUGHLY 20Z AND 00Z TODAY. FELT THIS
POSSIBILITY WAS TOO LOW TO HAVE IN THE TAFS BUT WILL MONITOR.
BELIEVE ANY LATE DAY CONVECTION WILL FIRE JUST SOUTH/SOUTHEAST OF
THESE TERMINALS.
&&
.MARINE...
ISSUED AT 330 PM EDT FRI JUL 17 2015
WE HAVE EXPANDED THE MARINE DENSE FOG ADVISORY THROUGH SAT NIGHT FOR
THE TIME BEING. VISIBLE SATELLITE IMAGERY THIS AFTERNOON COMBINED
WITH WEB CAMS ALONG THE SHORE SHOW FAIRLY DENSE FOG AT MOST
LOCATIONS. CONDITIONS ARE NOT QUITE AS BAD AT SOUTH HAVEN...BUT IT
HAS EXPANDED SOUTH THIS AFTERNOON AS WINDS HAVE GONE WRLY. EVEN
HIGHER DEW POINTS MOVING IN WITH DIMINISHING WINDS WILL KEEP THE
POTENTIAL HIGH THROUGH AT LEAST SAT NIGHT.
WINDS DO NOT LOOK TO BE A PROBLEM UNTIL AT LEAST SATURDAY NIGHT IF
NOT SUNDAY. A CORE OF WINDS ALOFT AHEAD OF THE INCOMING COLD FRONT
COULD RAMP WINDS UP SAT NIGHT...HOWEVER THIS IS ALWAYS TRICKY WITH
WARMER AIR OVER THE COOLER WATERS.
&&
.HYDROLOGY...
ISSUED AT 330 PM EDT FRI JUL 17 2015
STREAMFLOWS AT MOST OF OUR RIVER GAUGES ARE RUNNING WELL ABOVE
NORMAL FOR THIS TIME OF YEAR. THUNDERSTORMS THIS WEEKEND MAY PRODUCE
LOCALLY HEAVY RAINFALL... WHICH WOULD LEAD TO SHORT DURATION URBAN
AND LOW LYING AREA FLOODING. A FEW RIVERS COULD RISE OUT OF THEIR
BANKS IF HEAVY RAIN FALLS WITHIN CERTAIN DRAINAGE BASINS. THE MOST
SUSCEPTIBLE RIVERS TO FLOODING WILL BE THE ONES THAT WERE AFFECTED
BY HEAVY RAIN LAST MONTH... GENERALLY THE UPPER PORTION OF THE GRAND
RIVER BASIN (IONIA-LANSING-JACKSON AREAS) AND THE KALAMAZOO BASIN.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...MI...HEAT ADVISORY FROM NOON TO
9 PM EDT SATURDAY FOR MIZ056>059-064>067-071>074.
LM...DENSE FOG ADVISORY UNTIL 8 AM EDT SUNDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...CAS
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS DULUTH MN
314 PM CDT FRI JUL 17 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 248 PM CDT FRI JUL 17 2015
FORECAST FOCUS IN THE SHORT TERM WILL BE ON STORM
CHANCES...STRENGTH...AND POTENTIAL FOR HEAVY RAIN.
AS OF 3 PM SHOWERS AND STORMS WERE MOVING NORTHEAST THROUGH
NORTHWEST MINNESOTA TOWARD KOOCHICHING COUNTY. THE STORMS HAVE
WEAKENED AS THEY HAVE MOVED OUT OF NORTHWEST MINNESOTA AND MOST
OF THE CAMS HAVE SHOWN THIS TREND...ALTHOUGH THE PRECIP IS FURTHER
EAST THAN MOST HAD IT AT THIS TIME. A FRONTAL BOUNDARY STRETCHED
FROM SOUTHERN MANITOBA THROUGH THE RED RIVER VALLEY INTO SOUTH
DAKOTA AS OF LATE AFTERNOON AND WILL MOVE EAST OVERNIGHT MOVING
INTO CENTRAL MINNESOTA BY 12Z SATURDAY...THEN JUST CLEARING OUR
EASTERN CWA BY 00Z SUN. WATER VAPOR IMAGERY SHOWED AN UPPER LOW
OVER SOUTHERN SK...AND THIS IS FORECAST TO TRACK ALONG AND JUST
NORTH OF THE INTERNATIONAL BORDER...LAGGING THE FRONT.
SHOWERS/STORMS WILL CONTINUE TO DEVELOP ALONG THE FRONT THIS
AFTERNOON INTO TONIGHT MOVING INTO THE NORTHLAND. THE MODELS WERE
OFFERING VARIOUS SOLUTIONS AS TO HOW FAR EAST THE RAIN WILL MAKE
IT TONIGHT...AND WE BLENDED THE HRRR WITH THE GFS/NAM/ECMWF.
MLCAPE VALUES HAVE BEEN CLIMBING THIS AFTERNOON AND WERE FROM
500 OVER THE ARROWHEAD TO 1500 J/KG ACROSS OUR SOUTHERN ZONES AS
OF THE 19Z SPC MESOANALYSIS. THE HIGHEST CAPE AND NOSE OF THE LLJ
WILL REMAIN SOUTH OF OUR CWA TONIGHT AND THE HRRR SEEMS TO HAVE A
GOOD HANDLE ON DEVELOPING STRONG TO SEVERE STORMS NEAR OR JUST
SOUTH OF OUR CWA THIS EVENING. A STRONG TO SEVERE STORM WILL
REMAIN POSSIBLE OVERNIGHT OVER OUR AREA...BUT CHANCES WILL BE
HIGHEST SOUTH. WE HAVE BEEN QUITE CONCERNED ABOUT ANOTHER ROUND OF
HEAVY RAIN TONIGHT IN AREAS THAT RECEIVED HEAVY RAIN FRIDAY/FRIDAY
EVENING...MAINLY FROM NORTHERN CASS COUNTY NNE TO NORTHERN SAINT
LOUIS COUNTY. PWAT VALUES RISE TO 1.5 TO 1.7 INCHES AGAIN
TONIGHT. WE THOUGHT ABOUT ISSUING A FLASH FLOOD WATCH...BUT IT
DOES NOT APPEAR THAT TRAINING THUNDERSTORMS WILL BE AS BIG A
THREAT AS LAST NIGHT. THE HRRR/NMM/ARW HIGH RES SOLUTIONS SUPPORT
A MORE PROGRESSIVE NATURE TO THE STORMS WITH THE STRONGEST STORMS
SOUTH. WE WILL HAVE TO MONITOR CLOSELY AS 2 TO 4 INCHES OF RAIN
FELL FROM NORTHERN CASS TO KOOCHICHING COUNTIES YESTERDAY INTO THE
EVENING. THE EVENING SHIFT WILL HAVE TO MONITOR STORM
MODE/STRENGTH AND MAY HAVE TO ISSUE HEADLINES IF NEEDED.
SHOWERS/STORMS SHOULD BE ONGOING IN SPOTS SATURDAY MORNING...THEN
MAY WEAKEN OR MOVE OFF LATE MORNING. ADDITIONAL STORMS WILL
DEVELOP ALONG THE FRONT SATURDAY AFTERNOON AND THEY COULD BE
SEVERE...MAINLY OVER PORTIONS OF NORTHWEST WISCONSIN WHERE A MOIST
UNSTABLE AIRMASS WILL BE IN PLACE. DEWPOINTS AHEAD OF THE FRONT
WILL BE FROM 65 TO AROUND 70...THEN DROP BEHIND IT. MOST AREAS
SHOULD RISE INTO THE UPPER 70S TO MID 80S ON SATURDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 248 PM CDT FRI JUL 17 2015
SATURDAY NIGHT...A COLD FRONT WILL FINISH MOVING THROUGH THE
NORTHLAND IN THE LATE EVENING...WHILE AN UPPER LEVEL TROUGH OVER
MANITOBA/ONTARIO LIFTS THROUGH THE REGION. THERE COULD BE LINGERING
SHOWERS AND STORMS IN NW WISCONSIN AND FAR NORTHERN MINNESOTA BEFORE
MIDNIGHT.
SUNDAY...WARMER AIR WILL BEGIN TO FILTER BACK INTO THE NORTHLAND
WITH THE WESTERLY FLOW. THE NAM12 SOUNDINGS INDICATE BREEZY
CONDITIONS DURING THE AFTERNOON AND EARLY EVENING. MOST OF THE
MODELS ARE DRY...BUT THE SREF IS INDICATING LOW PCPN CHANCES...SO
ADDED THE SREF TO THE MODEL BLEND TO GIVE LOW CHANCES OF SHOWERS AND
STORMS OVER NORTHERN MINNESOTA.
MONDAY...THE MODELS ARE NOT IN GOOD AGREEMENT...BUT GENERALLY
INDICATE ANOTHER COLD FRONT WILL MOVE FROM NW TO SE THROUGH THE
FORECAST AREA. THE ECMWF IS ABOUT 12 TO 18 HOURS FASTER THAN THE GFS
AND GEM. THE TIMING OF THE FRONT HAS IMPLICATIONS ON TEMPERATURES
AND PCPN CHANCES. SINCE THE ECMWF FRONT PASSAGE IS DURING THE WEE
HOURS OF MONDAY MORNING...IT DOES NOT HAVE THE INSTABILITY AND PCPN
THAT THE GFS AND GEM ARE INDICATING WITH THE AFTERNOON/EVENING
PASSAGE TIMEFRAME. THE GFS HAS MUCH HOTTER TEMPERATURES FOR
MONDAY...PARTLY SINCE ITS COLD FRONT PASSAGE IS NOT UNTIL MONDAY
NIGHT. USED A BLEND OF THE GFS/GEM/ECMWF/SREF.
TUESDAY...HIGH PRESSURE WILL LIKELY KEEP THE NORTHLAND DRY AND A BIT
COOLER FOR THIS DAY. TEMPERATURES WILL LIKELY BE SEASONAL NORMALS
WITH HIGHS IN THE UPPER 70S.
WEDNESDAY AND THURSDAY...THE MODELS ARE IN POOR AGREEMENT...BUT
GENERALLY SUGGEST A WARM AND HUMID SOUTHERLY LOW LEVEL FLOW PATTERN
SETTING UP DURING THIS TIME. THIS COULD BEGIN TO BRING WARMER AND
UNSTABLE AIR INTO THE REGION. SHOWERS AND THUNDERSTORMS ARE
POSSIBLE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1240 PM CDT FRI JUL 17 2015
THERE MAY BE LINGERING MVFR CEILING ACROSS NW WISCONSIN AND NE
MINNESOTA EARLY THIS AFTERNOON. OTHERWISE...VFR CONDITIONS ARE
EXPECTED FOR THE REST OF TODAY AND THIS EVENING WITH WESTERLY
WINDS AROUND 5 TO 10 KNOTS.
RAIN SHOWERS WILL LIKELY AFFECT NE MINNESOTA AND NW
WISCONSIN...GENERALLY FROM WEST TO EAST...LATE TONIGHT AND
SATURDAY MORNING IN ADVANCE OF AN APPROACHING COLD FRONT.
THUNDERSTORMS ARE POSSIBLE...BUT NOT CONFIDENT ENOUGH ON TIMING TO
PLACE IN THE FORECASTS YET. THERE IS ALSO A LOW PROBABILITY OF
MVFR CEILINGS/VISIBILITY LATE TONIGHT AND EARLY SATURDAY MORNING.
THE COLD FRONT WILL MOVE THROUGH THE NORTHLAND LATE SATURDAY
MORNING AND EARLY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 65 82 60 81 / 40 50 10 10
INL 61 79 57 78 / 70 50 10 20
BRD 66 83 59 84 / 60 20 0 10
HYR 65 85 60 81 / 40 50 0 10
ASX 63 85 61 81 / 30 50 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
SHORT TERM...MELDE
LONG TERM...GROCHOCINSKI
AVIATION...GROCHOCINSKI
AREA FORECAST DISCUSSION
NWS JACKSON MS
400 PM CDT FRI JUL 17 2015
...HEAT BUILDS...
.DISCUSSION...THERE IS CURRENTLY A BIT MORE CONVECTION ADVANCING
GRADUALLY WESTWARD ALONG THE AL GULF COAST THAN WAS GENERALLY
ANTICIPATED. SOME OF THESE SHOWERS AND STORMS ON THE PERIPHERY OF
THE MAIN ACTIVITY SHOULD AFFECT PORTIONS OF SOUTHEASTERN MS THROUGH
EARLY EVENING WITH THE LATEST HRRR MODEL SHOWING SOME POTENTIAL OF A
SMALL THUNDERSTORM CLUSTER ADVANCING WSW DOWN THE COASTLINE THROUGH
EARLY EVENING. ANY SUCH ACTIVITY COULD HAVE SOME GUSTY WINDS...BUT
IT IS LIKELY THE BULK OF THE MOST POTENT CONVECTION SHOULD REMAIN
SOUTH OF THE SOUTHEAST BORDER OF MY CWA. REGARDLESS...WE WILL OF
COURSE BE WATCHING IT CLOSELY.
THIS CONVECTIVE TRENDS OF SHOWERS AND THUNDERSTORMS BREAKING OUT IN
THE MID TO LATE AFTERNOON HOURS ON THE EAST AND SOUTHWARD EDGE OF
THE RIDGE AXIS SHOULD CONTINUE TO THE NEXT SEVERAL DAYS...PROVIDING
MAINLY SOUTHERN ZONES WITH SOME HOPE OF A COOLING LATE-DAY SHOWER.
BUT DO NOT GET YOUR HOPES UP TOO HIGH BECAUSE POPS ARE GENERALLY
ONLY IN THE 10 TO 30 PERCENT RANGE. EXAMINING MODEL DETAILS...IT
APPEARS AN ENHANCED LOW LEVEL CONVERGENCE AXIS ACROSS SOUTHWEST AL
IS REALLY HELPING DRIVE SEMI-ORGANIZED ACTIVITY PRESENTLY OCCURRING
BUT THIS SIGNATURE SHOULD BECOME MUCH MORE SUBTLE THE NEXT FEW DAYS.
THE LATTER IS AN ARGUMENT TO SUGGEST WE ARE NOT BIASING POPS TOO LOW
IN THE SHORT TERM.
OTHERWISE...ANTICIPATE THE TREND OF GRADUALLY BUILDING HEAT TO
CONTINUE FOR MOST OF THE REGION THROUGH THE WEEKEND AS SOILS
CONTINUE TO DRY AND HEAT UP. INCREASED BOUNDARY LAYER MIXING WILL
LIKELY WORK TO DROP DEWPOINTS A LITTLE MORE IN THE AFTERNOON...BUT
HIGHER ACTUAL AIR TEMPS MIGHT ALLOW FOR ZERO NET IMPROVEMENT IN HEAT
INDICES. THE MAJORITY OF THE REGION THIS AFTERNOON IS SEEING HEAT
INDEX VALUES PEAK BETWEEN 103 AND 109 DEGREES AND THIS SHOULD
CONTINUE TO BE THE CASE AT LEAST THROUGH THE WEEKEND. CONSIDERING
THIS OUTLOOK WE EXTENDED WITH HEAT ADVISORY FOR ALL AREAS THROUGH
SUNDAY EVENING.
IN ALL ACTUALITY...THE PEAK IN HEAT MIGHT WAIT UNTIL MONDAY AND
TUESDAY AS THE EASTERN EXTENT OF THE RIDGE OVER US STARTS BREAKING
DOWN A BIT AND COMPRESSIONAL HEATING IS MAXIMIZED SOUTH OF A COLD
FRONT SLOWLY APPROACHING FROM THE MIDSOUTH AND TN VALLEY. AT SOME
POINT IN THE NOT-TOO-DISTANT FUTURE ANTICIPATE AT LEAST HEAT
ADVISORIES BEING EXTENDED IN TIME FOR MOST (IF NOT ALL ALL AREAS)
FOR THE BEGINNING OF THE NEXT WORK WEEK. /BB/
&&
.AVIATION...ALL SITES ARE VFR THIS AFTERNOON AND THESE CONDITIONS
WILL CONTINUE THROUGH THE PERIOD FOR MOST SITES. SHOWERS AND
THUNDERSTORMS MAY BRING BRIEF MVFR POSSIBLY IFR CONDITIONS TO HBG
THIS AFTERNOON BEFORE THE THUNDERSTORMS DISSIPATE BY EARLY EVENING.
THE WINDS WILL REMAIN GENERALLY LIGHT OUT OF THE WEST THROUGH THE
PERIOD./15/
&&
.PREV DISCUSSION... /ISSUED 344 AM CDT FRI JUL 17 2015/
PORTIONS OF THE PREVIOUS LONG TERM DISCUSSION... AS THE MID LEVEL
RIDGE WEAKENS MONDAY INTO TUESDAY A WEAKENING COLD FRONT WILL TRY
AND DROP INTO OUR AREA. MODEL CONSENSUS STALLS THE FRONT WELL NORTH
OF OUR AREA BUT SOME CLOUD COVER AND RAIN MAY TRACK OVER OUR
NORTHEAST ZONES AS A RESULT ON TUESDAY. A WEAKENED MID LEVEL RIDGE
WILL LINGER OVER OUR REGION THROUGH THE END OF THE WEEK ALLOWING FOR
SLIGHTLY GREATER DIURNALLY DRIVEN CONVECTION BUT MODEL RUN
ACCUMULATIONS STILL SHOW VERY LITTLE QPF OVER OUR CWA THROUGH THE
LONG TERM. IN FACT...MODELS STILL SHOW NO RAINFALL OVER OUR
NORTHEAST LOUISIANA PARISHES AND PORTIONS OF THE DELTA. GREATEST
RAIN CHANCES TUESDAY THROUGH THURSDAY WILL BE ACROSS OUR NORTHEAST
AND SOUTHEAST MOST ZONES. LOWER AFTERNOON HIGHS WILL RESULT IN LOWER
MAXIMUM HEAT INDEX VALUES BUT WITH CONTINUED HIGH HUMIDITY...HEAT
ADVISORIES MAY STILL BE NEEDED FOR PORTIONS OF THE AREA TUESDAY
THROUGH THURSDAY. /22/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 76 97 77 97 / 5 15 5 12
MERIDIAN 75 96 76 97 / 8 16 8 16
VICKSBURG 76 96 76 97 / 4 8 3 7
HATTIESBURG 76 97 76 98 / 15 36 12 25
NATCHEZ 75 94 76 96 / 5 11 5 14
GREENVILLE 77 97 77 98 / 3 4 2 4
GREENWOOD 76 97 77 97 / 3 7 2 5
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...HEAT ADVISORY UNTIL 7 PM CDT SUNDAY FOR MSZ018-019-025>066-
072>074.
LA...HEAT ADVISORY UNTIL 7 PM CDT SUNDAY FOR LAZ007>009-015-016-
023>026.
AR...HEAT ADVISORY UNTIL 7 PM CDT SUNDAY FOR ARZ074-075.
&&
$$
BB/15/22
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
321 PM EDT FRI JUL 17 2015
.SYNOPSIS...
HIGH PRESSURE SLIDES EASTWARD TODAY. SEVERAL ROUNDS OF SHOWERS
AND THUNDERSTORMS ARE EXPECTED BETWEEN TONIGHT AND MONDAY. SOME OF
THESE STORMS MAY BE STRONG AND PRODUCE LOCALLY HEAVY RAIN. IN
ADDITION, SUNDAY IS EXPECTED TO BE HOT AND HUMID WITH TEMPERATURES
APPROACHING 90 DEGREES.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 134 PM EDT FRIDAY...FOR 0130 PM UPDATE SOME SMALL
ADJUSTMENTS TO THE TEMPS AS A FEW AREAS ARE WARMING SLIGHTLY
FASTER THAN NORMAL. KTYX RADAR SHOWS SOME PRECIP ON THE NORTH SIDE
OF LAKE ONTARIO AT 16Z...SO BASED ON CURRENT FORECAST I WENT AHEAD
AND BROUGHT IN HIGHER RAIN CHANCES IN SOONER BY A COUPLE OF HOURS
TO MATCH RADAR TRENDS AND HIGHER RESOLUTION GUIDANCE FROM THE HRRR
AND RAP MODELS OVER THE ST LAWRENCE VALLEY AFTER 21Z. PREVIOUS
DISCUSSION FOLLOWS.
SURFACE HIGH PRESSURE WILL BEGIN TO SLIDE EASTWARD TODAY...WARM
AIR ADVECTION INCREASES DURING THE AFTERNOON HOURS AHEAD OF NEXT
APPROACHING LOW PRESSURE SYSTEM AND ASSOCIATED FRONTS. WHILE MUCH
OF THE DAY WILL BE DRY...THERE IS A CHANCE FOR SHOWERS DURING THE
LATE AFTERNOON MOVING INTO THE AREA FROM WEST TO EAST. CLOUDS
WILL ALSO INCREASE FROM WEST TO EAST ACROSS THE AREA. MAX TEMPS
WILL BE VERY NEAR TO SEASONAL NORMALS. SOUTHERLY FLOW PICKS UP
DURING THE AFTERNOON.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH SUNDAY NIGHT/...
AS OF 430 AM EDT FRIDAY...WARM AIR ADVECTION WILL INCREASE
OVERNIGHT AS A WARM FRONT LIFTS ACROSS OUR FORECAST AREA. CLOUDS
AND PRECIPITATION INCREASE ACROSS THE AREA AND WITH SOME ELEVATED
INSTABILITY IN PLACE HAVE MENTIONED THUNDER ALONG WITH LIKELY
POPS. SHOWALTERS GO NEGATIVE AND PWATS SURGE TO AROUND 1.75".
WINDS WILL PICK UP OUT OF THE SOUTH WITH INCREASED PRESSURE
GRADIENT AND LOW LEVEL JET PASSING OVER THE AREA. MODELS HAVE COME
INTO BETTER AGREEMENT FOR POSSIBILITY OF SHOWERS AND THUNDERSTORMS
DEVELOPING ON SATURDAY. HAVE ADDED IN ENHANCED WORDING AS NAM
CONTINUES TO INDICATED HIGH CAPE ACROSS THE AREA IN EXCESS OF
2500. STILL A QUESTION OF HOW MUCH CLEARING THAT WE WILL SEE. SOME
SHOWERS WILL BE LINGERING EARLY SATURDAY MORNING FROM WARM FRONTAL
PASSAGE OVERNIGHT. LATEST MODEL RUNS HAVE BROUGHT THE WARM FRONT
THROUGH A BIT QUICKER...WHICH SHOULD ALLOW FOR SOME MORE CLEARING
AND RESULTING INCREASED INSTABILITY. SATURDAY AFTERNOON A STRONG
UPPER LEVEL SHORT WAVE PASSES JUST NORTHEAST OF THE
CWA...THEREFORE BEST CHANCE FOR THUNDERSTORMS APPEARS TO BE ACROSS
NORTHERN VERMONT. AMPLE MOISTURE WITH HIGH DEWPOINTS AND PWATS
NEARING 2 INCHES WILL BE PLENTY REASON TO EXPECT SOME HEAVY RAIN
WITH ANY THUNDERSTORMS THAT DEVELOP. THERE WILL ALSO BE DECENT LOW
LEVEL SHEAR WITH LOW LEVEL JET NEARBY. SHOWERS AND THUNDERSTORMS
WILL WIND DOWN OVERNIGHT. ANOTHER WEAKER SHORTWAVE WILL MOVE
ACROSS OUR AREA ON SUNDAY...AND EXPECT ANOTHER CHANCE FOR SOME
AFTERNOON SHOWERS AND THUNDERSTORMS AFTER A BRIEF BREAK IN THE
WEATHER SUNDAY MORNING. SUNDAY WILL BE THE WARMEST DAY OF THE
PERIOD...NEARING 90 DEGREES AND HUMID. DECENT LAPSE RATES ON
SUNDAY...AND POTENTIALLY HIGH CAPES ONCE AGAIN MAY BE A SECOND
BUSY DAY FOR US.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 320 PM EDT FRIDAY...SURFACE COLD FRONT SHIFTING THROUGH THE
FORECAST AREA MONDAY MORNING WITH PRECIPITATION EXITING FROM WEST
TO EAST THROUGH THE DAY. MAX TEMPS WILL BE TRICKY WITH UNCERTAINTY
IN THE EXACT FROPA TIMING, BUT GIVEN THE WARM OVERNIGHT TEMPERATURES
ANY CLEARING IN THE AFTERNOON SHOULD ALLOW TEMPS TO REBOUND INTO
THE LOWER 80S.
DRIER CONDITIONS RETURN FOR MONDAY NIGHT THROUGH TUESDAY NIGHT AS A
WEAK RIDGE OF HIGH PRESSURE MOVES ACROSS THE AREA. A FEW WEAK
DISTURBANCES IN FLOW ALOFT COMBINED WITH SOME AFTERNOON INSTABILITY
MAY BE ENOUGH TO PRODUCE SOME SHOWERS OVER THE HIGHER TERRAIN
TUESDAY/WEDNESDAY, BUT OTHERWISE DRY WEATHER IS EXPECTED THROUGH THE
END OF THE WORK WEEK. TEMPS WILL RUN RIGHT AROUND NORMAL, MAYBE JUST
A FEW DEGREES ABOVE WITH HIGHS GENERALLY IN THE UPPER 70S TO MID 80S
AND LOWS IN THE MID 50S TO LOW 60S.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
THROUGH 18Z SATURDAY...VFR CONDITIONS WILL PREVAIL ACROSS THE REGION
THROUGH THE DAYLIGHT HOURS WITH MID-HIGH CLOUDS CONTINUING TO
INCREASE AND SLOWLY LOWER FROM WEST TO EAST AHEAD OF A WARM FRONT.
ASSOCIATED PRECIP/SHOWERS DEVELOP BETWEEN 00Z AND 03Z SATURDAY, WITH
CIGS LOWERING TO MVFR AREA-WIDE AND LOCALLY IFR FOR A BRIEF
PERIOD AT KSLK/KMPV. PRECIP SHIFTS OUT OF THE REGION AFTER 09-12Z
WITH MVFR CIGS TRENDING TO VFR BY 18Z. SOUTHERLY WINDS SLIGHTLY
GUSTY THIS AFTERNOON, LIGHTER 5-10KTS AFTER 00Z.
OUTLOOK 18Z SATURDAY THROUGH WEDNESDAY...
18Z SAT - 06Z SUN...VFR/MVFR. SCATTERED SHOWERS AND THUNDERSTORMS, MAINLY
ACROSS VT.
06Z SUN - 18Z SUN...MAINLY VFR. EARLY MORNING IFR FOG POSSIBLE AT KMPV/KSLK.
18Z SUN - 18Z MON...VFR/MVFR IN PERIODS OF SHOWERS AND THUNDERSTORMS.
18Z MON - 12Z WED...MAINLY VFR. EARLY MORNING IFR FOG POSSIBLE AT KMPV/KSLK.
12Z WED - 00Z THU...MAINLY VFR. CHANCE AFTERNOON -SHRA.
&&
.MARINE...
AS OF 252 PM EDT FRIDAY...A LAKE WIND ADVISORY IS CURRENTLY IN
EFFECT. STRONG SOUTHERLY WINDS 25-30 KNOTS ARE EXPECTED OVER LAKE
CHAMPLAIN AFTER 8PM LASTING THROUGH THE OVERNIGHT HOURS. WIND
WAVES ARE EXPECTED TO REACH 2-4 FEET DURING THIS EVENT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...DEAL/MV
SHORT TERM...NEILES
LONG TERM...LAHIFF
AVIATION...LAHIFF
MARINE...MV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
252 PM EDT FRI JUL 17 2015
.SYNOPSIS...
HIGH PRESSURE SLIDES EASTWARD TODAY. SEVERAL ROUNDS OF SHOWERS
AND THUNDERSTORMS ARE EXPECTED BETWEEN TONIGHT AND MONDAY. SOME OF
THESE STORMS MAY BE STRONG AND PRODUCE LOCALLY HEAVY RAIN. IN
ADDITION, SUNDAY IS EXPECTED TO BE HOT AND HUMID WITH TEMPERATURES
APPROACHING 90 DEGREES.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 134 PM EDT FRIDAY...FOR 0130 PM UPDATE SOME SMALL
ADJUSTMENTS TO THE TEMPS AS A FEW AREAS ARE WARMING SLIGHTLY
FASTER THAN NORMAL. KTYX RADAR SHOWS SOME PRECIP ON THE NORTH SIDE
OF LAKE ONTARIO AT 16Z...SO BASED ON CURRENT FORECAST I WENT AHEAD
AND BROUGHT IN HIGHER RAIN CHANCES IN SOONER BY A COUPLE OF HOURS
TO MATCH RADAR TRENDS AND HIGHER RESOLUTION GUIDANCE FROM THE HRRR
AND RAP MODELS OVER THE ST LAWRENCE VALLEY AFTER 21Z. PREVIOUS
DISCUSSION FOLLOWS.
SURFACE HIGH PRESSURE WILL BEGIN TO SLIDE EASTWARD TODAY...WARM
AIR ADVECTION INCREASES DURING THE AFTERNOON HOURS AHEAD OF NEXT
APPROACHING LOW PRESSURE SYSTEM AND ASSOCIATED FRONTS. WHILE MUCH
OF THE DAY WILL BE DRY...THERE IS A CHANCE FOR SHOWERS DURING THE
LATE AFTERNOON MOVING INTO THE AREA FROM WEST TO EAST. CLOUDS
WILL ALSO INCREASE FROM WEST TO EAST ACROSS THE AREA. MAX TEMPS
WILL BE VERY NEAR TO SEASONAL NORMALS. SOUTHERLY FLOW PICKS UP
DURING THE AFTERNOON.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH SUNDAY/...
AS OF 430 AM EDT FRIDAY...WARM AIR ADVECTION WILL INCREASE
OVERNIGHT AS A WARM FRONT LIFTS ACROSS OUR FORECAST AREA. CLOUDS
AND PRECIPITATION INCREASE ACROSS THE AREA AND WITH SOME ELEVATED
INSTABILITY IN PLACE HAVE MENTIONED THUNDER ALONG WITH LIKELY
POPS. SHOWALTERS GO NEGATIVE AND PWATS SURGE TO AROUND 1.75".
WINDS WILL PICK UP OUT OF THE SOUTH WITH INCREASED PRESSURE
GRADIENT AND LOW LEVEL JET PASSING OVER THE AREA. MODELS HAVE COME
INTO BETTER AGREEMENT FOR POSSIBILITY OF SHOWERS AND THUNDERSTORMS
DEVELOPING ON SATURDAY. HAVE ADDED IN ENHANCED WORDING AS NAM
CONTINUES TO INDICATED HIGH CAPE ACROSS THE AREA IN EXCESS OF
2500. STILL A QUESTION OF HOW MUCH CLEARING THAT WE WILL SEE. SOME
SHOWERS WILL BE LINGERING EARLY SATURDAY MORNING FROM WARM FRONTAL
PASSAGE OVERNIGHT. LATEST MODEL RUNS HAVE BROUGHT THE WARM FRONT
THROUGH A BIT QUICKER...WHICH SHOULD ALLOW FOR SOME MORE CLEARING
AND RESULTING INCREASED INSTABILITY. SATURDAY AFTERNOON A STRONG
UPPER LEVEL SHORT WAVE PASSES JUST NORTHEAST OF THE
CWA...THEREFORE BEST CHANCE FOR THUNDERSTORMS APPEARS TO BE ACROSS
NORTHERN VERMONT. AMPLE MOISTURE WITH HIGH DEWPOINTS AND PWATS
NEARING 2 INCHES WILL BE PLENTY REASON TO EXPECT SOME HEAVY RAIN
WITH ANY THUNDERSTORMS THAT DEVELOP. THERE WILL ALSO BE DECENT LOW
LEVEL SHEAR WITH LOW LEVEL JET NEARBY. SHOWERS AND THUNDERSTORMS
WILL WIND DOWN OVERNIGHT. ANOTHER WEAKER SHORTWAVE WILL MOVE
ACROSS OUR AREA ON SUNDAY...AND EXPECT ANOTHER CHANCE FOR SOME
AFTERNOON SHOWERS AND THUNDERSTORMS AFTER A BRIEF BREAK IN THE
WEATHER SUNDAY MORNING. SUNDAY WILL BE THE WARMEST DAY OF THE
PERIOD...NEARING 90 DEGREES AND HUMID. DECENT LAPSE RATES ON
SUNDAY...AND POTENTIALLY HIGH CAPES ONCE AGAIN MAY BE A SECOND
BUSY DAY FOR US.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 424 AM EDT FRIDAY...CHANCES FOR SHOWERS AND PERHAPS SOME
THUNDERSTORMS RAMP UP PRETTY QUICKLY SUNDAY NIGHT AND CONTINUE
INTO MONDAY AS A POTENT SHORTWAVE AND ASSOCIATED COLD FRONT MOVE
EAST FROM THE GREAT LAKES AND ACROSS THE NORTHEAST. AHEAD OF THE
FRONT...PRECIPITABLE WATER VALUES INCREASE TO 1.5 TO 2 INCHES. IN
ADDITION...A MODEST EML LAYER SHIFTS THROUGH SUNDAY NIGHT INTO
MONDAY AHEAD OF THE BOUNDARY. GIVEN THE HIGH PRECIPITABLE WATER
VALUES AND MID-LEVEL INSTABILITY THE THREAT FOR HEAVY RAIN AND
PERHAPS A FEW STRONG STORMS EXISTS. PRECIPITATION SUNDAY
NIGHT/MONDAY WHEN COMBINED WITH ANY HEAVY RAINFALL FROM STORMS ON
SATURDAY COULD RAISE SOME FLASH FLOOD CONCERNS. MILD AND VERY
MUGGY CONDITIONS SUNDAY NIGHT WITH LOWS RANGING FROM THE MID 60S
TO THE LOWER 70S. MAX TEMPS ON MONDAY TRICKY...BECAUSE ALTHOUGH
THE DAY WILL START OUT WITH SHOWERS...SOME CLEARING IS POSSIBLE
IN THE AFTERNOON. THIS SHOULD ALLOW TEMPS TO REBOUND INTO THE
LOWER 80S BEHIND THE FRONT.
DRIER CONDITIONS RETURN FOR MONDAY NIGHT THROUGH TUESDAY NIGHT AS A
WEAK RIDGE OF HIGH PRESSURE MOVES ACROSS THE AREA. DISTURBANCE IN
FLOW ALOFT COMBINED WITH SOME AFTERNOON INSTABILITY MAY BE ENOUGH
TO PRODUCE A SHOWER OVER THE HIGHER TERRAIN...BUT OTHERWISE DRY
WEATHER DURING THIS PERIOD. FLOW TURNS MORE WEST TO NORTHWEST
ALOFT WEDNESDAY WHILE SHORTWAVE TROUGH AND WEAK SURFACE BOUNDARY
MOVE THROUGH THE NORTH COUNTRY. THIS WILL RESULT IN CHANCE FOR A FEW
SHOWERS OR THUNDERSTORMS. DRIER WEATHER THEN FOLLOWS FOR THURSDAY.
TEMPS WILL AVERAGE A BIT ABOVE NORMAL TUESDAY THROUGH THURSDAY
WITH VALLEY HIGHS MOSTLY IN THE LOWER TO MID 80S.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
THROUGH 18Z SATURDAY...VFR CONDITIONS WILL PREVAIL ACROSS THE REGION
THROUGH THE DAYLIGHT HOURS WITH MID-HIGH CLOUDS CONTINUING TO
INCREASE AND SLOWLY LOWER FROM WEST TO EAST AHEAD OF A WARM FRONT.
ASSOCIATED PRECIP/SHOWERS DEVELOP BETWEEN 00Z AND 03Z SATURDAY, WITH
CIGS LOWERING TO MVFR AREA-WIDE AND LOCALLY IFR FOR A BRIEF
PERIOD AT KSLK/KMPV. PRECIP SHIFTS OUT OF THE REGION AFTER 09-12Z
WITH MVFR CIGS TRENDING TO VFR BY 18Z. SOUTHERLY WINDS SLIGHTLY
GUSTY THIS AFTERNOON, LIGHTER 5-10KTS AFTER 00Z.
OUTLOOK 18Z SATURDAY THROUGH WEDNESDAY...
18Z SAT - 06Z SUN...VFR/MVFR. SCATTERED SHOWERS AND THUNDERSTORMS, MAINLY
ACROSS VT.
06Z SUN - 18Z SUN...MAINLY VFR. EARLY MORNING IFR FOG POSSIBLE AT KMPV/KSLK.
18Z SUN - 18Z MON...VFR/MVFR IN PERIODS OF SHOWERS AND THUNDERSTORMS.
18Z MON - 12Z WED...MAINLY VFR. EARLY MORNING IFR FOG POSSIBLE AT KMPV/KSLK.
12Z WED - 00Z THU...MAINLY VFR. CHANCE AFTERNOON -SHRA.
&&
.MARINE...
A LAKE WIND ADVISORY IS CURRENTLY IN EFFECT. STRONG SOUTHERLY
WINDS 25-30 KNOTS ARE EXPECTED OVER LAKE CHAMPLAIN AFTER 8PM
LASTING THROUGH THE OVERNIGHT HOURS. WIND WAVES ARE EXPECTED TO
REACH 2-4 FEET DURING THIS EVENT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...DEAL/MV
SHORT TERM...NEILES
LONG TERM...RJS
AVIATION...MV
MARINE...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
151 PM EDT FRI JUL 17 2015
.SYNOPSIS...
HIGH PRESSURE SLIDES EASTWARD TODAY. SEVERAL ROUNDS OF SHOWERS
AND THUNDERSTORMS ARE EXPECTED BETWEEN TONIGHT AND MONDAY. SOME OF
THESE STORMS MAY BE STRONG AND PRODUCE LOCALLY HEAVY RAIN. IN
ADDITION, SUNDAY IS EXPECTED TO BE HOT AND HUMID WITH TEMPERATURES
APPROACHING 90 DEGREES.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 134 PM EDT FRIDAY...FOR 0130 PM UPDATE SOME SMALL
ADJUSTMENTS TO THE TEMPS AS A FEW AREAS ARE WARMING SLIGHTLY
FASTER THAN NORMAL. KTYX RADAR SHOWS SOME PRECIP ON THE NORTH SIDE
OF LAKE ONTARIO AT 16Z...SO BASED ON CURRENT FORECAST I WENT AHEAD
AND BROUGHT IN HIGHER RAIN CHANCES IN SOONER BY A COUPLE OF HOURS
TO MATCH RADAR TRENDS AND HIGHER RESOLUTION GUIDANCE FROM THE HRRR
AND RAP MODELS OVER THE ST LAWRENCE VALLEY AFTER 21Z. PREVIOUS
DISCUSSION FOLLOWS.
SURFACE HIGH PRESSURE WILL BEGIN TO SLIDE EASTWARD TODAY...WARM
AIR ADVECTION INCREASES DURING THE AFTERNOON HOURS AHEAD OF NEXT
APPROACHING LOW PRESSURE SYSTEM AND ASSOCIATED FRONTS. WHILE MUCH
OF THE DAY WILL BE DRY...THERE IS A CHANCE FOR SHOWERS DURING THE
LATE AFTERNOON MOVING INTO THE AREA FROM WEST TO EAST. CLOUDS
WILL ALSO INCREASE FROM WEST TO EAST ACROSS THE AREA. MAX TEMPS
WILL BE VERY NEAR TO SEASONAL NORMALS. SOUTHERLY FLOW PICKS UP
DURING THE AFTERNOON.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH SUNDAY/...
AS OF 430 AM EDT FRIDAY...WARM AIR ADVECTION WILL INCREASE
OVERNIGHT AS A WARM FRONT LIFTS ACROSS OUR FORECAST AREA. CLOUDS
AND PRECIPITATION INCREASE ACROSS THE AREA AND WITH SOME ELEVATED
INSTABILITY IN PLACE HAVE MENTIONED THUNDER ALONG WITH LIKELY
POPS. SHOWALTERS GO NEGATIVE AND PWATS SURGE TO AROUND 1.75".
WINDS WILL PICK UP OUT OF THE SOUTH WITH INCREASED PRESSURE
GRADIENT AND LOW LEVEL JET PASSING OVER THE AREA. MODELS HAVE COME
INTO BETTER AGREEMENT FOR POSSIBILITY OF SHOWERS AND THUNDERSTORMS
DEVELOPING ON SATURDAY. HAVE ADDED IN ENHANCED WORDING AS NAM
CONTINUES TO INDICATED HIGH CAPE ACROSS THE AREA IN EXCESS OF
2500. STILL A QUESTION OF HOW MUCH CLEARING THAT WE WILL SEE. SOME
SHOWERS WILL BE LINGERING EARLY SATURDAY MORNING FROM WARM FRONTAL
PASSAGE OVERNIGHT. LATEST MODEL RUNS HAVE BROUGHT THE WARM FRONT
THROUGH A BIT QUICKER...WHICH SHOULD ALLOW FOR SOME MORE CLEARING
AND RESULTING INCREASED INSTABILITY. SATURDAY AFTERNOON A STRONG
UPPER LEVEL SHORT WAVE PASSES JUST NORTHEAST OF THE
CWA...THEREFORE BEST CHANCE FOR THUNDERSTORMS APPEARS TO BE ACROSS
NORTHERN VERMONT. AMPLE MOISTURE WITH HIGH DEWPOINTS AND PWATS
NEARING 2 INCHES WILL BE PLENTY REASON TO EXPECT SOME HEAVY RAIN
WITH ANY THUNDERSTORMS THAT DEVELOP. THERE WILL ALSO BE DECENT LOW
LEVEL SHEAR WITH LOW LEVEL JET NEARBY. SHOWERS AND THUNDERSTORMS
WILL WIND DOWN OVERNIGHT. ANOTHER WEAKER SHORTWAVE WILL MOVE
ACROSS OUR AREA ON SUNDAY...AND EXPECT ANOTHER CHANCE FOR SOME
AFTERNOON SHOWERS AND THUNDERSTORMS AFTER A BRIEF BREAK IN THE
WEATHER SUNDAY MORNING. SUNDAY WILL BE THE WARMEST DAY OF THE
PERIOD...NEARING 90 DEGREES AND HUMID. DECENT LAPSE RATES ON
SUNDAY...AND POTENTIALLY HIGH CAPES ONCE AGAIN MAY BE A SECOND
BUSY DAY FOR US.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 424 AM EDT FRIDAY...CHANCES FOR SHOWERS AND PERHAPS SOME
THUNDERSTORMS RAMP UP PRETTY QUICKLY SUNDAY NIGHT AND CONTINUE
INTO MONDAY AS A POTENT SHORTWAVE AND ASSOCIATED COLD FRONT MOVE
EAST FROM THE GREAT LAKES AND ACROSS THE NORTHEAST. AHEAD OF THE
FRONT...PRECIPITABLE WATER VALUES INCREASE TO 1.5 TO 2 INCHES. IN
ADDITION...A MODEST EML LAYER SHIFTS THROUGH SUNDAY NIGHT INTO
MONDAY AHEAD OF THE BOUNDARY. GIVEN THE HIGH PRECIPITABLE WATER
VALUES AND MID-LEVEL INSTABILITY THE THREAT FOR HEAVY RAIN AND
PERHAPS A FEW STRONG STORMS EXISTS. PRECIPITATION SUNDAY
NIGHT/MONDAY WHEN COMBINED WITH ANY HEAVY RAINFALL FROM STORMS ON
SATURDAY COULD RAISE SOME FLASH FLOOD CONCERNS. MILD AND VERY
MUGGY CONDITIONS SUNDAY NIGHT WITH LOWS RANGING FROM THE MID 60S
TO THE LOWER 70S. MAX TEMPS ON MONDAY TRICKY...BECAUSE ALTHOUGH
THE DAY WILL START OUT WITH SHOWERS...SOME CLEARING IS POSSIBLE
IN THE AFTERNOON. THIS SHOULD ALLOW TEMPS TO REBOUND INTO THE
LOWER 80S BEHIND THE FRONT.
DRIER CONDITIONS RETURN FOR MONDAY NIGHT THROUGH TUESDAY NIGHT AS A
WEAK RIDGE OF HIGH PRESSURE MOVES ACROSS THE AREA. DISTURBANCE IN
FLOW ALOFT COMBINED WITH SOME AFTERNOON INSTABILITY MAY BE ENOUGH
TO PRODUCE A SHOWER OVER THE HIGHER TERRAIN...BUT OTHERWISE DRY
WEATHER DURING THIS PERIOD. FLOW TURNS MORE WEST TO NORTHWEST
ALOFT WEDNESDAY WHILE SHORTWAVE TROUGH AND WEAK SURFACE BOUNDARY
MOVE THROUGH THE NORTH COUNTRY. THIS WILL RESULT IN CHANCE FOR A FEW
SHOWERS OR THUNDERSTORMS. DRIER WEATHER THEN FOLLOWS FOR THURSDAY.
TEMPS WILL AVERAGE A BIT ABOVE NORMAL TUESDAY THROUGH THURSDAY
WITH VALLEY HIGHS MOSTLY IN THE LOWER TO MID 80S.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
THROUGH 18Z SATURDAY...VFR CONDITIONS WILL PREVAIL ACROSS THE REGION
THROUGH THE DAYLIGHT HOURS WITH MID-HIGH CLOUDS CONTINUING TO
INCREASE AND SLOWLY LOWER FROM WEST TO EAST AHEAD OF A WARM FRONT.
ASSOCIATED PRECIP/SHOWERS DEVELOP BETWEEN 00Z AND 03Z SATURDAY, WITH
CIGS LOWERING TO MVFR AREA-WIDE AND LOCALLY IFR FOR A BRIEF
PERIOD AT KSLK/KMPV. PRECIP SHIFTS OUT OF THE REGION AFTER 09-12Z
WITH MVFR CIGS TRENDING TO VFR BY 18Z. SOUTHERLY WINDS SLIGHTLY
GUSTY THIS AFTERNOON, LIGHTER 5-10KTS AFTER 00Z.
OUTLOOK 18Z SATURDAY THROUGH WEDNESDAY...
18Z SAT - 06Z SUN...VFR/MVFR. SCATTERED SHOWERS AND THUNDERSTORMS, MAINLY
ACROSS VT.
06Z SUN - 18Z SUN...MAINLY VFR. EARLY MORNING IFR FOG POSSIBLE AT KMPV/KSLK.
18Z SUN - 18Z MON...VFR/MVFR IN PERIODS OF SHOWERS AND THUNDERSTORMS.
18Z MON - 12Z WED...MAINLY VFR. EARLY MORNING IFR FOG POSSIBLE AT KMPV/KSLK.
12Z WED - 00Z THU...MAINLY VFR. CHANCE AFTERNOON -SHRA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...DEAL/MV
SHORT TERM...NEILES
LONG TERM...RJS
AVIATION...LAHIFF
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
139 PM EDT FRI JUL 17 2015
.SYNOPSIS...
HIGH PRESSURE SLIDES EASTWARD TODAY. SEVERAL ROUNDS OF SHOWERS
AND THUNDERSTORMS ARE EXPECTED BETWEEN TONIGHT AND MONDAY. SOME OF
THESE STORMS MAY BE STRONG AND PRODUCE LOCALLY HEAVY RAIN. IN
ADDITION, SUNDAY IS EXPECTED TO BE HOT AND HUMID WITH TEMPERATURES
APPROACHING 90 DEGREES.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 134 PM EDT FRIDAY...FOR 0130 PM UPDATE SOME SMALL
ADJUSTMENTS TO THE TEMPS AS A FEW AREAS ARE WARMING SLIGHTLY
FASTER THAN NORMAL. KTYX RADAR SHOWS SOME PRECIP ON THE NORTH SIDE
OF LAKE ONTARIO AT 16Z...SO BASED ON CURRENT FORECAST I WENT AHEAD
AND BROUGHT IN HIGHER RAIN CHANCES IN SOONER BY A COUPLE OF HOURS
TO MATCH RADAR TRENDS AND HIGHER RESOLUTION GUIDANCE FROM THE HRRR
AND RAP MODELS OVER THE ST LAWRENCE VALLEY AFTER 21Z. PREVIOUS
DISCUSSION FOLLOWS.
SURFACE HIGH PRESSURE WILL BEGIN TO SLIDE EASTWARD TODAY...WARM
AIR ADVECTION INCREASES DURING THE AFTERNOON HOURS AHEAD OF NEXT
APPROACHING LOW PRESSURE SYSTEM AND ASSOCIATED FRONTS. WHILE MUCH
OF THE DAY WILL BE DRY...THERE IS A CHANCE FOR SHOWERS DURING THE
LATE AFTERNOON MOVING INTO THE AREA FROM WEST TO EAST. CLOUDS
WILL ALSO INCREASE FROM WEST TO EAST ACROSS THE AREA. MAX TEMPS
WILL BE VERY NEAR TO SEASONAL NORMALS. SOUTHERLY FLOW PICKS UP
DURING THE AFTERNOON.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH SUNDAY/...
AS OF 430 AM EDT FRIDAY...WARM AIR ADVECTION WILL INCREASE
OVERNIGHT AS A WARM FRONT LIFTS ACROSS OUR FORECAST AREA. CLOUDS
AND PRECIPITATION INCREASE ACROSS THE AREA AND WITH SOME ELEVATED
INSTABILITY IN PLACE HAVE MENTIONED THUNDER ALONG WITH LIKELY
POPS. SHOWALTERS GO NEGATIVE AND PWATS SURGE TO AROUND 1.75".
WINDS WILL PICK UP OUT OF THE SOUTH WITH INCREASED PRESSURE
GRADIENT AND LOW LEVEL JET PASSING OVER THE AREA. MODELS HAVE COME
INTO BETTER AGREEMENT FOR POSSIBILITY OF SHOWERS AND THUNDERSTORMS
DEVELOPING ON SATURDAY. HAVE ADDED IN ENHANCED WORDING AS NAM
CONTINUES TO INDICATED HIGH CAPE ACROSS THE AREA IN EXCESS OF
2500. STILL A QUESTION OF HOW MUCH CLEARING THAT WE WILL SEE. SOME
SHOWERS WILL BE LINGERING EARLY SATURDAY MORNING FROM WARM FRONTAL
PASSAGE OVERNIGHT. LATEST MODEL RUNS HAVE BROUGHT THE WARM FRONT
THROUGH A BIT QUICKER...WHICH SHOULD ALLOW FOR SOME MORE CLEARING
AND RESULTING INCREASED INSTABILITY. SATURDAY AFTERNOON A STRONG
UPPER LEVEL SHORT WAVE PASSES JUST NORTHEAST OF THE
CWA...THEREFORE BEST CHANCE FOR THUNDERSTORMS APPEARS TO BE ACROSS
NORTHERN VERMONT. AMPLE MOISTURE WITH HIGH DEWPOINTS AND PWATS
NEARING 2 INCHES WILL BE PLENTY REASON TO EXPECT SOME HEAVY RAIN
WITH ANY THUNDERSTORMS THAT DEVELOP. THERE WILL ALSO BE DECENT LOW
LEVEL SHEAR WITH LOW LEVEL JET NEARBY. SHOWERS AND THUNDERSTORMS
WILL WIND DOWN OVERNIGHT. ANOTHER WEAKER SHORTWAVE WILL MOVE
ACROSS OUR AREA ON SUNDAY...AND EXPECT ANOTHER CHANCE FOR SOME
AFTERNOON SHOWERS AND THUNDERSTORMS AFTER A BRIEF BREAK IN THE
WEATHER SUNDAY MORNING. SUNDAY WILL BE THE WARMEST DAY OF THE
PERIOD...NEARING 90 DEGREES AND HUMID. DECENT LAPSE RATES ON
SUNDAY...AND POTENTIALLY HIGH CAPES ONCE AGAIN MAY BE A SECOND
BUSY DAY FOR US.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 424 AM EDT FRIDAY...CHANCES FOR SHOWERS AND PERHAPS SOME
THUNDERSTORMS RAMP UP PRETTY QUICKLY SUNDAY NIGHT AND CONTINUE
INTO MONDAY AS A POTENT SHORTWAVE AND ASSOCIATED COLD FRONT MOVE
EAST FROM THE GREAT LAKES AND ACROSS THE NORTHEAST. AHEAD OF THE
FRONT...PRECIPITABLE WATER VALUES INCREASE TO 1.5 TO 2 INCHES. IN
ADDITION...A MODEST EML LAYER SHIFTS THROUGH SUNDAY NIGHT INTO
MONDAY AHEAD OF THE BOUNDARY. GIVEN THE HIGH PRECIPITABLE WATER
VALUES AND MID-LEVEL INSTABILITY THE THREAT FOR HEAVY RAIN AND
PERHAPS A FEW STRONG STORMS EXISTS. PRECIPITATION SUNDAY
NIGHT/MONDAY WHEN COMBINED WITH ANY HEAVY RAINFALL FROM STORMS ON
SATURDAY COULD RAISE SOME FLASH FLOOD CONCERNS. MILD AND VERY
MUGGY CONDITIONS SUNDAY NIGHT WITH LOWS RANGING FROM THE MID 60S
TO THE LOWER 70S. MAX TEMPS ON MONDAY TRICKY...BECAUSE ALTHOUGH
THE DAY WILL START OUT WITH SHOWERS...SOME CLEARING IS POSSIBLE
IN THE AFTERNOON. THIS SHOULD ALLOW TEMPS TO REBOUND INTO THE
LOWER 80S BEHIND THE FRONT.
DRIER CONDITIONS RETURN FOR MONDAY NIGHT THROUGH TUESDAY NIGHT AS A
WEAK RIDGE OF HIGH PRESSURE MOVES ACROSS THE AREA. DISTURBANCE IN
FLOW ALOFT COMBINED WITH SOME AFTERNOON INSTABILITY MAY BE ENOUGH
TO PRODUCE A SHOWER OVER THE HIGHER TERRAIN...BUT OTHERWISE DRY
WEATHER DURING THIS PERIOD. FLOW TURNS MORE WEST TO NORTHWEST
ALOFT WEDNESDAY WHILE SHORTWAVE TROUGH AND WEAK SURFACE BOUNDARY
MOVE THROUGH THE NORTH COUNTRY. THIS WILL RESULT IN CHANCE FOR A FEW
SHOWERS OR THUNDERSTORMS. DRIER WEATHER THEN FOLLOWS FOR THURSDAY.
TEMPS WILL AVERAGE A BIT ABOVE NORMAL TUESDAY THROUGH THURSDAY
WITH VALLEY HIGHS MOSTLY IN THE LOWER TO MID 80S.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
THROUGH 12Z SATURDAY. MAINLY VFR FOR MUCH OF THE PERIOD. FOG AND
LOW CLOUDS AT MPV WILL DISSIPATE BY 13Z. OTHERWISE...EXPECT SUNSHINE
TO GIVE WAY TO INCREASING CLOUDS WITH LOWERING VFR CEILINGS THIS
AFTERNOON/EVENING IN ADVANCE OF A WARM FRONT. SHOWERS EXPECTED TO
DEVELOP FROM WEST TO EAST BETWEEN 00Z AND 06Z SATURDAY...WITH CIGS
LOWERING TO MVFR BETWEEN 04Z AND 08Z SATURDAY. LIGHT AND VARIABLE
WINDS WILL BECOME SOUTHERLY AROUND 10 KNOTS TODAY.
OUTLOOK 12Z SATURDAY THROUGH TUESDAY...
12Z SAT - 00Z SUN...VFR/MVFR IN PERIODS OF SHOWERS AND
THUNDERSTORMS.
00Z SUN - 00Z MON...MAINLY VFR. EARLY MORNING IFR FOG POSSIBLE AT
KMPV/KSLK.
00Z MON - 00Z TUE...VFR/MVFR IN PERIODS OF SHOWERS AND THUNDERSTORMS.
00Z TUE - 00Z WED...MAINLY VFR. EARLY MORNING IFR FOG POSSIBLE AT
KMPV/KSLK.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...DEAL/MV
SHORT TERM...NEILES
LONG TERM...RJS
AVIATION...RJS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1206 PM CDT FRI JUL 17 2015
.UPDATE...
ISSUED AT 1206 PM CDT FRI JUL 17 2015
NO CHANGES FROM PREVIOUS DISCUSSION. CLEARING ACROSS THE SOUTHEAST
LEADING TO INCREASING MUCAPE. STRONG TO SEVERE STORMS STILL VERY
POSSIBLE ACROSS THE SOUTHERN JAMES RIVER VALLEY AND IMMEDIATE
AREAS ADJACENT.
UPDATE
ISSUED AT 1004 AM CDT FRI JUL 17 2015
FORECAST ON TRACK FOR THIS MORNING. LEAD EMBEDDED S/WV ALONG WITH
A SFC TROUGH GENERATING AN AREA OF MODERATE SHOWERS AND SCATTERED
THUNDERSTORMS FROM SOUTH CENTRAL NORTH DAKOTA NORTH-NORTHEAST INTO
THE DEVILS LAKE BASIN AREA...PUSHING EAST. MORE ISOLATED ACTIVITY
WEST WITH LITTLE IF ANY INSTABILITY SO WILL LEAVE THUNDER OUT
THERE. REDEVELOPMENT OVER OUR SOUTHEAST THIS AFTERNOON WITH ROBUST
UPDRAFTS POSSIBLE SUGGESTING A STRONG TO SEVERE CONVECTION THREAT.
UPDATE ISSUED AT 636 AM CDT FRI JUL 17 2015
NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE. UTILIZED A TIME
LAGGED ENSEMBLE OF THE 08-10 UTC HRRR ITERATIONS FOR THE REMAINDER
OF THE DAY WHICH HAS A GOOD DEPICTION OF THE ONGOING
PRECIPITATION TRENDS THROUGH 1130 UTC. THE SEVERE CONVECTION
POTENTIAL REMAINS ON TRACK ACROSS THE SOUTHERN PORTIONS OF THE
JAMES RIVER VALLEY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 252 AM CDT FRI JUL 17 2015
EARLY MORNING SHOWERS AND THUNDERSTORMS AND SEVERE THUNDERSTORM
POTENTIAL IN THE SOUTHEAST FRIDAY AFTERNOON ARE THE MAIN CONCERNS
FOR THE SHORT TERM FORECAST PERIOD.
A CLOSED UPPER LEVEL LOW AND AMPLIFYING SHORTWAVE TROUGH
STRETCHED OVER SASKATCHEWAN AND EASTERN MONTANA EARLY THIS
MORNING. AT THE SURFACE...LOW PRESSURE WAS DEVELOPING OVER EASTERN
SASKATCHEWAN. A COLD FRONT EXTENDED SOUTH FROM THIS LOW INTO
WESTERN NORTH DAKOTA...TRIGGERING WIDELY SCATTERED SHOWERS AND A
FEW ISOLATED THUNDERSTORMS. HIGH RESOLUTION MODELS SUGGEST THAT
THIS PRECIPITATION SHOULD HOLD TOGETHER AS THE COLD FRONT MOVES
EAST ACROSS THE STATE THROUGH THE EARLY MORNING HOURS. GUSTY WINDS
AND SMALL HAIL WILL BE THE MAIN THREATS WITH ANY STRONGER
STORMS...BUT SEVERE WEATHER IS NOT EXPECTED WITH THE MORNING
CONVECTION.
FRIDAY AFTERNOON...THE COLD FRONT WILL BE DRAPED OVER OUR EASTERN
ZONES AND THUNDERSTORMS WILL BEGIN TO REDEVELOP AS EARLY AS 18Z.
AHEAD OF THE COLD FRONT...DEWPOINTS SHOULD RISE INTO THE MID 60S
WITH TEMPERATURES IN THE MID 80S. THIS...IN CONJUNCTION WITH STEEP
MID-LEVEL LAPSE RATES...WILL LEAD TO A MODERATELY UNSTABLE
ATMOSPHERE IN OUR SOUTH CENTRAL AND SOUTHEAST ZONES. 00Z NAM
FORECAST SOUNDINGS SUGGEST MLCAPE VALUES AS HIGH AS 1500-2000 J/KG
OVER DICKEY AND LAMOURE COUNTIES BY 21Z. THIS INSTABILITY WILL BE
COUPLED WITH 45-50 KNOTS OF 0-6 KM BULK SHEAR...SUGGESTING A
SUPERCELLULAR STORM MODE. STORMS SHOULD BE ABLE TO REMAIN DISCRETE
EARLY WITH NEARLY PERPENDICULAR CROSSOVER VECTORS FROM 850-500 MB.
LARGE HAIL AND STRONG WINDS WILL BE THE GREATEST THREATS...BUT
THERE MAY BE A CONDITIONAL TORNADO THREAT INTO THE EXTREME
SOUTHEAST...AS 0-1 KM SHEAR INCREASES TO 15-20 KTS BY 00Z
SATURDAY. HOWEVER...IT IS ENTIRELY POSSIBLE THAT THE COLD FRONT
WILL ALREADY BE OUT OF OUR FORECAST AREA BY THE TIME THE LOW LEVEL
JET KICKS IN. THE OTHER CONCERN FOR SEVERE POTENTIAL WILL BE
WHETHER EARLY MORNING CONVECTION AND CLOUD COVER CAN LIMIT
INSTABILITY.
AS THE SEVERE THREAT BEGINS TO CLEAR OUT OF THE AREA BY LATE
FRIDAY EVENING...EXPECT A FEW SCATTERED SHOWERS BEHIND THE FRONT
WITH SOME CLEARING LIKELY FROM WEST TO EAST.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 252 AM CDT FRI JUL 17 2015
A BREEZY SATURDAY FOLLOWED BY A GENERALLY LESS ACTIVE WEATHER
PERIOD INTO NEXT WEEK HIGHLIGHTS THE EXTENDED FORECAST.
AN ANOMALOUS DEEP UPPER LEVEL LOW ACROSS SOUTHERN SASKATCHEWAN
AND MANITOBA ON SATURDAY IS FORECAST BY THE 00 UTC DETERMINISTIC
AND ENSEMBLE CONSENSUS. A DRY SLOT ASSOCIATED WITH THIS FEATURE IS
FORECAST ACROSS MOST OF WESTERN AND CENTRAL NORTH DAKOTA...WITH
WRAP AROUND MOISTURE IMPINGING ON THE US HIGHWAY 2 CORRIDOR TO
SUPPORT AN ISOLATED TO SCATTERED SHOWER AND THUNDERSTORM THREAT
FOR THESE AREAS. GIVEN GOOD POST COLD FRONTAL MIXING AND A TIGHT
PRESSURE GRADIENT...BREEZY NORTHWEST WIND GUSTS OF 25-30 KTS ARE
FORECAST AREA WIDE FOR SATURDAY. THEREAFTER...NORTHWEST FLOW ALOFT
IS FORECAST SUNDAY INTO EARLY NEXT WEEK...BEFORE A POSSIBLE
TRANSITION TO ZONAL BY WEDNESDAY. OVERALL...THIS WOULD SUPPORT
NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES...AND SPORADIC
PRECIPITATION CHANCES ASSOCIATED WITH IMPULSES WITH LOW
PREDICTABILITY AT THESE TIME RANGES EMBEDDED IN THE FAST UPPER
LEVEL FLOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1206 PM CDT FRI JUL 17 2015
A COLD FRONT CONTINUES TO PUSH EAST THROUGH NORTH DAKOTA THIS
MORNING...TRIGGERING SHOWERS AND A FEW THUNDERSTORMS FROM THE
SOUTH CENTRAL PART OF THE STATE INTO THE NORTHEAST. SCATTERED
THUNDERSTORMS WILL REDEVELOP ACROSS THE STATE FRIDAY AFTERNOON
NEAR THE FRONT SOUTHEAST BEFORE TAPERING OFF IN THE EVENING
BEHIND THE FRONT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
SHORT TERM...ZH
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
207 PM EDT FRI JUL 17 2015
.SYNOPSIS...
SOUTHERLY WINDS WILL BRING INCREASING HEAT AND HUMIDITY INTO THE
REGION HEADING INTO THE WEEKEND. A COLD FRONT WILL SLIDE SOUTH
INTO THE AREA LATE SUNDAY INTO SUNDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EMBEDDED S/WV ASSOC WITH A SFC WARM FRONT WILL CONTINUE TO EXIT TO
THE EAST THROUGH EARLY AFTERNOON. MAIN CONVECTION WITH THESE
FEATURES WILL MOVE EAST AS WELL. HOWEVER...LATEST RADAR MOSAIC
INDICATES THAT SOME CONVERGENCE IS STILL OCCUR ACRS OUR NW ZONES
AND EXTENDING INTO INDIANA...MOST LIKELY DUE TO A LOW LEVEL JET.
CONVECTION HERE SHOULD BECOME SURFACE BASED BY AFTERNOON AND MORE
SCATTERED IN NATURE. ELSEWHERE...LATEST HRRR INDICATES THAT
PERHAPS A POP UP SHOWER/STORM MAY DEVELOP IN THE HEAT OF THE DAY.
THUS...WILL HAVE HIGHEST POPS ACRS THE NW AND THE LEAST IN THE SE.
WITH INCREASING HEAT AND HUMIDITY...HIGHS WILL RISE INTO THE UPPER
80S NORTH AND EAST...TO THE LOWER 90S SOUTHWEST WITH DEWPOINTS IN
THE LOWER 70S. OUR SW CWFA...INCLUDING THE DAYTON AND CINCINNATI
METRO AREAS...HAVE THE GREATEST POTENTIAL OF SEEING HEAT INDEX
VALUES IN THE 95-100 DEGREE RANGE. GIVEN THAT WE HAVE NOT HAD
REALLY HOT AND HUMID WEATHER THIS SUMMER...THOUGHT IT PRUDENT TO
ISSUE A SPECIAL WEATHER STATEMENT FOR THESE AREAS FOR THE
AFTERNOON HOURS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
LATEST HRRR RUN SUGGESTS THAT EVENING CONVECTION SHOULD WANE IN
COVERAGE BUT SHOW A PROGRESSION TO THE EAST AND SOUTHEAST AS WELL.
STORMS SHOULD MOVE EAST/SOUTHEAST AND DIMINISH IN INTENSITY AND
COVERAGE AFTER MIDNIGHT.
THE CHANCE OF RAIN WILL BE QUITE LIMITED ON SATURDAY WITH LITTLE
FORCING TO BREAK WEAK CAPPING AND TAP SUBSTANTIAL INSTABILITY.
UPPER RIDGE CENTERED OVER THE LOWER MISSISSIPPI VALLEY WILL MAKE
ITS FURTHEST NORTHWARD ENCROACHMENT ON SATURDAY. THIS WILL RESULT
IN THE WARMEST TEMPERATURES IN OVER A MONTH. IN ADDITION...DEW
POINTS WILL INCREASE WHICH WILL RESULT IN HEAT INDICES AT OR ABOVE
100 FOR MOST OF THE FORECAST AREA.
UPPER RIDGE WILL START TO GET SUPPRESSED ON SUNDAY AS A SHORT
WAVE TRACKS ACROSS THE NORTHERN TIER. THIS WILL PUSH A COLD FRONT
TOWARDS THE REGION LATER SUNDAY WITH SLOWER MODEL SOLUTIONS
PREFERRED. CHANCE OF STORMS WILL INCREASE ON SUNDAY. TEMPERATURES
MAY BE JUST A BIT LOWER IN NORTHERN COUNTIES BUT EXPECT SOUTHERN
SECTIONS TO BE JUST AS WARM AS SATURDAY. HEAT INDICES ARE FORECAST
TO BE AT OR ABOVE 100 AGAIN NEAR AND SOUTH OF THE OHIO RIVER.
SPECIAL HEAT CRITERIA FOR HAMILTON COUNTY NECESSITATES A HEAT
WATCH/WARNING IF THE HEAT INDEX IS 100 OR GREATER FOR AT LEAST TWO
CONSECUTIVE DAYS. IF FORECAST CONTINUES AS IS THEN THE REST OF THE
REGION WILL LIKELY NEED A HEAT ADVISORY FOR SATURDAY AND IN THE
SOUTH AGAIN ON SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
COLD FRONT WILL MOVE THOROUGH THE AREA ON SUNDAY NIGHT. IT WILL
STALL SOUTH OF THE AREA. 00Z GUIDANCE CONTINUES TO SHOW
DIFFERENCES IN HANDLING THIS BOUNDARY DURING THE WEEK. THE GFS
KEEPS THE FRONT FURTHER NORTH BUT SEEMS TO OVERDEVELOP A WAVE THAT
TRACKS ALONG THE FRONT. MEANWHILE THE ECMWF DRIVES THE BOUNDARY
MUCH FURTHER SOUTH ALTHOUGH THIS SEEMS AMBITIOUS. HAVE OPTED TO
ONLY TWEAK PREVIOUS FORECAST AND KEEP CHANCE POPS PRIMARILY IN THE
SOUTH TUESDAY AND TUESDAY NIGHT. FORECAST BECOMES MORE UNCERTAIN
LATER IN THE PERIOD WITH INCREASING SPREAD IN SOLUTIONS ALTHOUGH
THERE IS SOME SIGNAL THAT HIGH PRESSURE WILL INFLUENCE THE REGION
LATER IN THE WEEK.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
A WARM FRONT WAS TRYING TO PIVOT NORTHEAST THROUGH THE REMAINDER
OF THE REGION THIS AFTERNOON. SCATTERED SHOWERS AND STORMS ARE
STILL OCCURRING IN ITS VICINITY NEAR THE KCMH/KLCK TAF SITES.
FOR THE REMAINDER OF THIS AFTERNOON INTO THIS EVENING...MODELS ARE
STRUGGLING ON HOW CONVECTION WILL EVOLVE AND PROPAGATE. SATELLITE
AND RADAR INDICATE THAT CONVECTION IS TRYING TO DEVELOP IN THE
WARM SECTOR ACROSS INDIANA ALONG OLD OUTFLOW BOUNDARIES. IF THESE
CAN GET GOING IN A MARGINAL SHEAR DEEP SHEAR ENVIRONMENT BUT
FAIRLY HIGH INSTABILITY ENVIRONMENT...THEN THE THREAT FOR
SCATTERED STORMS WILL CONTINUE AT THE TAF SITES AT LEAST THROUGH
SUNSET. EXCEPT FOR CURRENT STORMS AT KCMH AT THIS ISSUANCE...STILL
DO NOT HAVE CONFIDENCE TO PUT TEMPO GROUPS WITH TSRA AT THE
REMAINING TAF SITES. WILL STICK WITH VCTS/CB FOR NOW AND MONITOR
DEVELOPMENT.
FOR TONIGHT...SURFACE WIND FLOW WILL RELAX AND DECOUPLE. SCATTERED
CONVECTION WILL WANE OVERNIGHT WITH THE LOSS OF HEATING. WE WILL
LIKELY SEE POCKETS OF MVFR MIST AT SOME TERMINALS WITH IFR
VISIBILITIES POSSIBLE AT KLUK.
ON SATURDAY...MID LEVEL RIDGE AXIS WILL POKE NORTHEAST INTO THE
OHIO VALLEY. AM NOT SEEING ANY REAL TRIGGERING MECHANISMS TO
INITIATE THUNDERSTORMS IN THE HOT AND HUMID AIRMASS. THUS...FEEL
ANY CONVECTION WILL BE DIURNALLY DRIVEN...DISORGANIZED...AND
AROUND THE 20 PERCENT PROBABILITY. THIS IS TOO SMALL TO PLACE IN
THE TAFS AT THIS TIME.
OUTLOOK...THUNDERSTORMS POSSIBLE SUNDAY THROUGH TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...EXCESSIVE HEAT WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY
EVENING FOR OHZ077.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...
LONG TERM...
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
600 PM EDT FRI JUL 17 2015
.SYNOPSIS...
WARMER AND MUCH MORE HUMID CONDITIONS WILL PREVAIL TONIGHT
THROUGH THIS WEEKEND AS AN UPPER LEVEL RIDGE BUILDS OVER THE
NORTHEAST CONUS THIS WEEKEND. A SHORTWAVE PASSING TO THE NORTH
WILL PUSH A COLD FRONT THROUGH PENNSYLVANIA ON MONDAY. HIGH
PRESSURE IS LIKELY TO BUILD SOUTHEAST INTO PENNSYLVANIA WEDNESDAY
OR THURSDAY OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
6 PM UPDATE...
ALL CONVECTION OVERHEAD AND INTO WESTERN OHIO HAS DISSIPATED. NEXT
FORCING DOES NOT COME ALONG FOR 3-5 MORE HOURS WHEN A SHORT WAVE
TROUGH MOVES INTO PA FROM THE WEST. CURRENT RADAR OVER NW OHIO
DEPICTS A SMALL CLUSTER OF STORMS WHERE THE FORCING MAY BE
GREATEST AT THIS TIME. MORE STORMS ARE FORMING BACK IN FAR LWR MI.
DEWPOINTS ARE IN THE M70S IN C OH...AND ARE CLIMBING INTO THE U60S
HERE. HAVE DIPPED POPS INITIALLY THIS EVENING...THEN BROUGHT THEM
BACK TO THE GOING FCST FOR AFTER MIDNIGHT AND INTO THE MORNING -
GENERALLY ISOLD/SCT POPS. THE MAIN FOCUS WILL BE ON THAT AREA OF
SHRA/TSRA MOVING IN FROM THE W/NW. WILL TRY SOME ROUGH TIMING TO
CAPTURE THAT FEATURE.
PREV...
MOISTURE FLOWING RAPIDLY BACK INTO THE REGION THIS AFTERNOON...WITH
NOTICEABLE STICKINESS RETURNING AS DEWPOINTS RISE THROUGH THE 60S
THROUGHOUT. BROAD MCV LIFTING ACROSS THE FINGERLAKES REGION AND
LAKE ONTARIO IS MAINTAINING WIDESPREAD SHOWERS NORTH OF THE PA/NY
BORDER THIS AFTERNOON...WITH A TRAILING LINE OF SHOWERS ALONG AN
UPPER SHEAR AXIS THAT EXTENDS INTO WEST CENTRAL PA. SHOWERS ALONG
THIS SOUTHERN FLANK HAVE BEEN WEAKENING FOR THE LAST SEVERAL
HOURS...MUCH AS THE HRRR DEPICTED. STILL... EXPECT ISOLD TO SCT
SHRA TO CROSS THE NORTHWEST AND WEST CENTRAL MOUNTAINS THROUGH MID
AFTERNOON AND THEN ISOLATED ACTIVITY TO PUSH INTO THE CENTRAL
MOUNTAINS AND LAUREL HIGHLANDS WITH JUST A SLIGHT CHANCE OF A
THUNDERSTORM IN SOME SPOTS.
OTHERWISE...LOTS OF MID LEVEL DEBRIS FROM THE UPSTREAM CONVECTION
OVER OHIO IS KEEPING MY FAR NORTHWEST NEARLY OVERCAST...WHILE
PARTLY TO MOSTLY CLOUDY SKIES ARE DISTRIBUTED OVER THE REMAINDER
OF CENTRAL PA. AS THE SHEAR AXIS CROSSES CENTRAL PA AND EXITS TO
THE EAST BY 04Z...WE SHOULD SEE PARTIAL CLEARING THROUGHOUT. SOME
AREAS OF VALLEY FOG ARE POSSIBLE.
ANOTHER ROUND OF SHOWERS IS POSSIBLE AFT 04Z AS ANOTHER UPSTREAM
SHORTWAVE LIFTS INTO ONTARIO FROM THE EASTERN GLAKS. NOTICEABLE
INCREASE IN HUMIDITY TONIGHT WITH A MUCH WARMER NIGHT THAN THOSE
RECENTLY...WITH MIN TEMPS MOSTLY IN THE M/U60S.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
BOUNDARY LAYER MOISTURE CONTINUES TO INCREASE ON SATURDAY...WITH
RIDGING ALOFT COUNTERACTING THE POTENTIAL DESTABILIZATION OF
INCREASING SFC DEWPOINTS AND HEAT. STILL SHOULD SEE ISOLD TO LCLLY
SCT AFTERNOON CONVECTION FIRING OVER THE HIGHER TERRAIN...BUT WITH
NO SHEAR TO ORGANIZE...NOT EXPECTING ANY SIGNIFICANT IMPACTS. JUST
ANOTHER NON-DRY DAY TO ADD TO THE PILE WE`VE ACCUMULATED THIS
SUMMER. HEATING OF VERY WARM/UNSTABLE AIR MASS IN THE WARM SECTOR
SHIELD MODERATE CAPES BY AFTN...BUT AGAIN TRIGGER WILL BE THE
LIMITING FACTOR. MODEL OUTPUT INDICATES A DECENT LIKELIHOOD OF LEE
TROF OVER SOUTHEAST PA...WHICH APPEARS TO BE THE MAIN FOCUS FOR
INITIATION OTHER THAN ELEVATED HEAT SOURCES. IF INSTABILITY CAN
BE RELEASED...MODERATE CAPES AND RELATIVELY WEAK SHEAR IN MDL DATA
DOES YIELD A LOW END THREAT OF ISOLD PULSE TYPE SVR STORMS.
HIGHEST POPS WILL BE INDICATED OVER THE SOUTHEAST IN VICINITY OF
THE LEE TROF. SPC HAS US IN GENERAL THUNDER AREA FOR DAY 2.
WESTERN AREAS WILL ONLY SEE A SLIGHT CHC TO LOW CHC OF A PASSING
SHOWER OR THUNDERSTORM IN THE AFTERNOON OR EVENING.
BOUNDARY LAYER WARMING SUPPORTS WIDESPREAD HIGHS OF 85 TO 90. THIS
COMBINED WITH SFC DEWPOINTS RISING TO AROUND 70 OR THE LOWER 70S
WILL CREATE HEAT INDICES IN THE MID TO UPPER 90S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
THE RETURN TO MORE SUMMERLIKE WEATHER WILL CONTINUE ON
SUNDAY...AS 850HPA TEMPS RISE TO +2SD BY SUNDAY AFTN. AS TEMPS
CONTINUE TO WARM AND HUMIDITY CONTINUES TO CLIMB...HEAT INDICES
WILL APPROACH 100F /BORDERLINE HEAT ADVISORY CRITERIA/ IN THE
LOWER SUSQUEHANNA VALLEY SUNDAY AFTN.
A COLD FRONT WILL CROSS CENTRAL PA SUN NIGHT/EARLY
MONDAY...ACCOMPANIED BY A CHC FOR SHRA/TSRA. THE TIMING OF THE
FRONT EARLY IN THE DAY MAY BE A LIMITING FACTOR FOR SEVERE WX.
BEHIND THE FRONT...TEMPS WILL BE /SLIGHTLY/ COOLER AND THERE WILL
BE A RESPITE FROM THE MUGGINESS.
HIGH PRESSURE WILL ATTEMPT TO BUILD OVERHEAD LATE NEXT
WEEK...BEHIND ANOTHER WEAK COLD FRONT THAT IS FORECAST TO SETTLE
ACROSS CENTRAL PA NEXT WEDNESDAY.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
VFR CONDS ARE EXPECTED AT MOST TAF SIGHTS TODAY AS HIGH PRESSURE
SLIDES EAST OF THE REGION...BRINGING GENERALLY CLEAR SKIES AND
LIGHT WINDS.
CU FIELD WILL BLOSSOM THIS AFTERNOON...BENEATH PERIODS OF BKN
ALTO CU ACRS WRN PENN...AS INCREASING WARMTH AND DEEP-LAYER
MOISTURE PUSHES EAST FROM THE OHIO VALLEY. CONDITIONS SHOULD STILL
STAY VFR...THOUGH SOME ISOLATED AND BRIEF MVFR MAY ACCOMPANY A FEW
TSRA LATER FRIDAY AFTERNOON AND EVENING.
OUTLOOK...
FRI...ISOLD LATE PM AND NIGHTTIME TSRA IMPACTS POSS W MTNS.
SAT-SUN...SCT...MAINLY PM TSRA IMPACTS POSSIBLE.
MON...MORE NUMEROUS SHOWERS/TSRA LIKELY AS A COLD FRONT PUSHES
EAST ACROSS THE REGION.
TUE...IMPROVING CONDS AS HIGH PRESSURE DOMINATING.
&&
.EQUIPMENT...
THE KBFD OBSERVATIONS ARE NOT AVAILABLE LONG-LINE DUE TO AN FAA COMMS
PROBLEM.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DEVOIR
LONG TERM...EVANEGO
AVIATION...DEVOIR/GARTNER/TYBURSKI
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
332 PM EDT FRI JUL 17 2015
.SYNOPSIS...
WARMER AND MUCH MORE HUMID CONDITIONS WILL PREVAIL TONIGHT
THROUGH THIS WEEKEND AS AN UPPER LEVEL RIDGE BUILDS OVER THE
NORTHEAST CONUS THIS WEEKEND. A SHORTWAVE PASSING TO THE NORTH
WILL PUSH A COLD FRONT THROUGH PENNSYLVANIA ON MONDAY. HIGH
PRESSURE IS LIKELY TO BUILD SOUTHEAST INTO PENNSYLVANIA WEDNESDAY
OR THURSDAY OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
MOISTURE FLOWING RAPIDLY BACK INTO THE REGION THIS
AFTERNOON...WITH NOTICEABLE STICKINESS RETURNING AS DEWPOINTS RISE
THROUGH THE 60S THROUGHOUT. BROAD MCV LIFTING ACROSS THE
FINGERLAKES REGION AND LAKE ONTARIO IS MAINTAINING WIDESPREAD
SHOWERS NORTH OF THE PA/NY BORDER THIS AFTERNOON...WITH A TRAILING
LINE OF SHOWERS ALONG AN UPPER SHEAR AXIS THAT EXTENDS INTO WEST
CENTRAL PA. SHOWERS ALONG THIS SOUTHERN FLANK HAVE BEEN WEAKENING
FOR THE LAST SEVERAL HOURS...MUCH AS THE HRRR DEPICTED. STILL...
EXPECT ISOLD TO SCT SHRA TO CROSS THE NORTHWEST AND WEST CENTRAL
MOUNTAINS THROUGH MID AFTERNOON AND THEN ISOLATED ACTIVITY TO PUSH
INTO THE CENTRAL MOUNTAINS AND LAUREL HIGHLANDS WITH JUST A SLIGHT
CHANCE OF A THUNDERSTORM IN SOME SPOTS.
OTHERWISE...LOTS OF MID LEVEL DEBRIS FROM THE UPSTREAM CONVECTION
OVER OHIO IS KEEPING MY FAR NORTHWEST NEARLY OVERCAST...WHILE
PARTLY TO MOSTLY CLOUDY SKIES ARE DISTRIBUTED OVER THE REMAINDER
OF CENTRAL PA. AS THE SHEAR AXIS CROSSES CENTRAL PA AND EXITS TO
THE EAST BY 04Z...WE SHOULD SEE PARTIAL CLEARING THROUGHOUT. SOME
AREAS OF VALLEY FOG ARE POSSIBLE.
ANOTHER ROUND OF SHOWERS IS POSSIBLE AFT 04Z AS ANOTHER UPSTREAM
SHORTWAVE LIFTS INTO ONTARIO FROM THE EASTERN GLAKS. NOTICEABLE
INCREASE IN HUMIDITY TONIGHT WITH A MUCH WARMER NIGHT THAN THOSE
RECENTLY...WITH MIN TEMPS MOSTLY IN THE M/U60S.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
BOUNDARY LAYER MOISTURE CONTINUES TO INCREASE ON SATURDAY...WITH
RIDGING ALOFT COUNTERACTING THE POTENTIAL DESTABILIZATION OF
INCREASING SFC DEWPOINTS AND HEAT. STILL SHOULD SEE ISOLD TO LCLLY
SCT AFTERNOON CONVECTION FIRING OVER THE HIGHER TERRAIN...BUT WITH
NO SHEAR TO ORGANIZE...NOT EXPECTING ANY SIGNIFICANT IMPACTS. JUST
ANOTHER NON-DRY DAY TO ADD TO THE PILE WE`VE ACCUMULATED THIS
SUMMER. HEATING OF VERY WARM/UNSTABLE AIR MASS IN THE WARM SECTOR
SHIELD MODERATE CAPES BY AFTN...BUT AGAIN TRIGGER WILL BE THE
LIMITING FACTOR. MODEL OUTPUT INDICATES A DECENT LIKELIHOOD OF LEE
TROF OVER SOUTHEAST PA...WHICH APPEARS TO BE THE MAIN FOCUS FOR
INITIATION OTHER THAN ELEVATED HEAT SOURCES. IF INSTABILITY CAN
BE RELEASED...MODERATE CAPES AND RELATIVELY WEAK SHEAR IN MDL DATA
DOES YIELD A LOW END THREAT OF ISOLD PULSE TYPE SVR STORMS.
HIGHEST POPS WILL BE INDICATED OVER THE SOUTHEAST IN VICINITY OF
THE LEE TROF. SPC HAS US IN GENERAL THUNDER AREA FOR DAY 2.
WESTERN AREAS WILL ONLY SEE A SLIGHT CHC TO LOW CHC OF A PASSING
SHOWER OR THUNDERSTORM IN THE AFTERNOON OR EVENING.
BOUNDARY LAYER WARMING SUPPORTS WIDESPREAD HIGHS OF 85 TO 90. THIS
COMBINED WITH SFC DEWPOINTS RISING TO AROUND 70 OR THE LOWER 70S
WILL CREATE HEAT INDICES IN THE MID TO UPPER 90S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
THE RETURN TO MORE SUMMERLIKE WEATHER WILL CONTINUE ON
SUNDAY...AS 850HPA TEMPS RISE TO +2SD BY SUNDAY AFTN. AS TEMPS
CONTINUE TO WARM AND HUMIDITY CONTINUES TO CLIMB...HEAT INDICES
WILL APPROACH 100F /BORDERLINE HEAT ADVISORY CRITERIA/ IN THE
LOWER SUSQUEHANNA VALLEY SUNDAY AFTN.
A COLD FRONT WILL CROSS CENTRAL PA SUN NIGHT/EARLY
MONDAY...ACCOMPANIED BY A CHC FOR SHRA/TSRA. THE TIMING OF THE
FRONT EARLY IN THE DAY MAY BE A LIMITING FACTOR FOR SEVERE WX.
BEHIND THE FRONT...TEMPS WILL BE /SLIGHTLY/ COOLER AND THERE WILL
BE A RESPITE FROM THE MUGGINESS.
HIGH PRESSURE WILL ATTEMPT TO BUILD OVERHEAD LATE NEXT
WEEK...BEHIND ANOTHER WEAK COLD FRONT THAT IS FORECAST TO SETTLE
ACROSS CENTRAL PA NEXT WEDNESDAY.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
VFR CONDS ARE EXPECTED AT MOST TAF SIGHTS TODAY AS HIGH PRESSURE
SLIDES EAST OF THE REGION...BRINGING GENERALLY CLEAR SKIES AND
LIGHT WINDS.
CU FIELD WILL BLOSSOM THIS AFTERNOON...BENEATH PERIODS OF BKN
ALTO CU ACRS WRN PENN...AS INCREASING WARMTH AND DEEP-LAYER
MOISTURE PUSHES EAST FROM THE OHIO VALLEY. CONDITIONS SHOULD STILL
STAY VFR...THOUGH SOME ISOLATED AND BRIEF MVFR MAY ACCOMPANY A FEW
TSRA LATER FRIDAY AFTERNOON AND EVENING.
OUTLOOK...
FRI...ISOLD LATE PM AND NIGHTTIME TSRA IMPACTS POSS W MTNS.
SAT-SUN...SCT...MAINLY PM TSRA IMPACTS POSSIBLE.
MON...MORE NUMEROUS SHOWERS/TSRA LIKELY AS A COLD FRONT PUSHES
EAST ACROSS THE REGION.
TUE...IMPROVING CONDS AS HIGH PRESSURE DOMINATING.
&&
.EQUIPMENT...
THE KBFD OBSERVATIONS ARE NOT AVAILABLE LONG-LINE DUE TO AN FAA COMMS
PROBLEM.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...EVANEGO
AVIATION...DEVOIR/GARTNER/TYBURSKI
EQUIPMENT...CTP
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
248 PM EDT FRI JUL 17 2015
.SYNOPSIS...
WARMER AND MUCH MORE HUMID CONDITIONS WILL PREVAIL TONIGHT
THROUGH THIS WEEKEND AS AN UPPER LEVEL RIDGE BUILDS OVER THE
NORTHEAST CONUS THIS WEEKEND. A SHORTWAVE PASSING TO THE NORTH
WILL PUSH A COLD FRONT THROUGH PENNSYLVANIA ON MONDAY. HIGH
PRESSURE IS LIKELY TO BUILD SOUTHEAST INTO PENNSYLVANIA WEDNESDAY
OR THURSDAY OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
MOISTURE FLOWING RAPIDLY BACK INTO THE REGION THIS
AFTERNOON...WITH NOTICEABLE STICKINESS RETURNING AS DEWPOINTS RISE
THROUGH THE 60S THROUGHOUT. BROAD MCV LIFTING ACROSS THE
FINGERLAKES REGION AND LAKE ONTARIO IS MAINTAINING WIDESPREAD
SHOWERS NORTH OF THE PA/NY BORDER THIS AFTERNOON...WITH A TRAILING
LINE OF SHOWERS ALONG AN UPPER SHEAR AXIS THAT EXTENDS INTO WEST
CENTRAL PA. SHOWERS ALONG THIS SOUTHERN FLANK HAVE BEEN WEAKENING
FOR THE LAST SEVERAL HOURS...MUCH AS THE HRRR DEPICTED. STILL...
EXPECT ISOLD TO SCT SHRA TO CROSS THE NORTHWEST AND WEST CENTRAL
MOUNTAINS THROUGH MID AFTERNOON AND THEN ISOLATED ACTIVITY TO PUSH
INTO THE CENTRAL MOUNTAINS AND LAUREL HIGHLANDS WITH JUST A SLIGHT
CHANCE OF A THUNDERSTORM IN SOME SPOTS.
OTHERWISE...LOTS OF MID LEVEL DEBRIS FROM THE UPSTREAM CONVECTION
OVER OHIO IS KEEPING MY FAR NORTHWEST NEARLY OVERCAST...WHILE
PARTLY TO MOSTLY CLOUDY SKIES ARE DISTRIBUTED OVER THE REMAINDER
OF CENTRAL PA. AS THE SHEAR AXIS CROSSES CENTRAL PA AND EXITS TO
THE EAST BY 04Z...WE SHOULD SEE PARTIAL CLEARING THROUGHOUT. SOME
AREAS OF VALLEY FOG ARE POSSIBLE.
ANOTHER ROUND OF SHOWERS IS POSSIBLE AFT 04Z AS ANOTHER UPSTREAM
SHORTWAVE LIFTS INTO ONTARIO FROM THE EASTERN GLAKS. NOTICEABLE
INCREASE IN HUMIDITY TONIGHT WITH A MUCH WARMER NIGHT THAN THOSE
RECENTLY...WITH MIN TEMPS MOSTLY IN THE M/U60S.
&&
.SHORT TERM /SATURDAY/...
BOUNDARY LAYER MOISTURE CONTINUES TO INCREASE ON SATURDAY...WITH
RIDGING ALOFT COUNTERACTING THE POTENTIAL DESTABLIZATION OF
INCREASING SFC DEWPOINTS AND HEAT. STILL SHOULD SEE ISOLD TO LCLLY
SCT AFTERNOON CONVECTION FIRING OVER THE HIGHER TERRAIN...BUT WITH
NO SHEAR TO ORGANIZE...NOT EXPECTING ANY SIGNIFICANT IMPACTS. JUST
ANOTHER NON-DRY DAY TO ADD TO THE PILE WE`VE ACCUMULATED THIS
SUMMER. HEATING OF VERY WARM/UNSTABLE AIR MASS IN THE WARM SECTOR
SHIELD MODERATE CAPES BY AFTN...BUT AGAIN TRIGGER WILL BE THE
LIMITING FACTOR. MODEL OUTPUT INDICATES A DECENT LIKELIHOOD OF LEE
TROF OVER SOUTHEAST PA...WHICH APPEARS TO BE THE MAIN FOCUS FOR
INITIATION OTHER THAN ELEVATED HEAT SOURCES. IF INSABILITY CAN BE
RELEASED...MODERATE CAPES AND RELATIVELY WEAK SHEAR IN MDL DATA
DOES YIELD A LOW END THREAT OF ISOLD PULSE TYPE SVR STORMS.
HIGHEST POPS WILL BE INDICATED OVER THE SOUTHEAST IN VICINITY OF
THE LEE TROF. SPC HAS US IN GENERAL THUNDER AREA FOR DAY 2.
WESTERN AREAS WILL ONLY SEE A SLIGHT CHC TO LOW CHC OF A PASSING
SHOWER OR THUNDERSTORM IN THE AFTERNOON OR EVENING.
BOUNDARY LAYER WARMING SUPPORTS WIDESPREAD HIGHS OF 85 TO 90. THIS
COMBINED WITH SFC DEWPOINTS RISING TO AROUND 70 OR THE LOWER 70S
WILL CREATE HEAT INDICES IN THE MID TO UPPER 90S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
500MB HEIGHTS WILL STEADILY REBOUND THROUGH THE WEEKEND WITH
LIKELY THE HOTTEST DAY YET OF THE SUMMER COMING SUNDAY. CENTRAL
PA IS CURRENTLY NEAR/AT THE HOTTEST TIME OF THE YEAR /JULY 11-20/
BASED ON THE MOST RECENT 30-YEAR CLIMATE NORMALS. MAX TEMPS IN THE
L/M90S...COMBINED WITH OPPRESSIVE HUMIDITY...WILL LIKELY PUSH
HEAT INDEX VALUES TO ARND OR JUST OVER 100F ACROSS THE LWR SUSQ
VALLEY FOR A FEW HOURS SUNDAY. WILL CONTINUE TO MENTION HEAT RISK
IN THE HWO. UPPER LVL RIDGE AXIS AND ASSOC WARM MID LVL TEMPS
SHOULD HELP SUPPRESS CONVECTION SUNDAY. HOWEVER...APPROACH OF
SHORTWAVE/COLD FRONT OVR THE GRT LKS COULD BRING THE CHC OF LATE
DAY TSRA...MAINLY OVR THE W MTNS.
TWO NRN STREAM FRONTS SHOULD BE A FOCUS FOR PCPN NEXT WEEK. THE
FIRST WILL BE ON MONDAY...WITH A LOWER RISK ON WEDNESDAY. EXPECT
TEMPS TO REMAIN NEAR OR SLIGHTLY ABOVE MID/LATE JULY CLIMATE
NORMALS.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
VFR CONDS ARE EXPECTED AT MOST TAF SIGHTS TODAY AS HIGH PRESSURE
SLIDES EAST OF THE REGION...BRINGING GENERALLY CLEAR SKIES AND
LIGHT WINDS.
CU FIELD WILL BLOSSOM THIS AFTERNOON...BENEATH PERIODS OF BKN
ALTO CU ACRS WRN PENN...AS INCREASING WARMTH AND DEEP-LAYER
MOISTURE PUSHES EAST FROM THE OHIO VALLEY. CONDITIONS SHOULD STILL
STAY VFR...THOUGH SOME ISOLATED AND BRIEF MVFR MAY ACCOMPANY A FEW
TSRA LATER FRIDAY AFTERNOON AND EVENING.
OUTLOOK...
FRI...ISOLD LATE PM AND NIGHTTIME TSRA IMPACTS POSS W MTNS.
SAT-SUN...SCT...MAINLY PM TSRA IMPACTS POSSIBLE.
MON...MORE NUMEROUS SHOWERS/TSRA LIKELY AS A COLD FRONT PUSHES
EAST ACROSS THE REGION.
TUE...IMPROVING CONDS AS HIGH PRESSURE DOMINATING.
&&
.EQUIPMENT...
THE KBFD OBSERVATIONS ARE NOT AVAILABLE LONG-LINE DUE TO AN FAA COMMS
PROBLEM.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...FITZGERALD/STEINBUGL
AVIATION...DEVOIR/GARTNER/TYBURSKI
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
357 PM EDT FRI JUL 17 2015
.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE THROUGH THE REGION FROM THE NORTHWEST
SATURDAY. SCATTERED SHOWERS AND THUNDERSTORMS WILL ACCOMPANY THE
FRONT. WEAK HIGH PRESSURE WILL BUILD IN FOR SUNDAY. ANOTHER WEAK
FRONT WILL DRIFT INTO THE REGION FROM THE NORTHWEST BY
MONDAY...THEN STALL ACROSS THE REGION AS WEAK WAVES OF LOW
PRESSURE RIDE ALONG THE FRONT THROUGH THE FIRST HALF OF NEXT WEEK.
WARM...HUMID CONDITIONS WILL PREVAIL THROUGH THE PERIOD.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 330 PM EDT FRIDAY...
MAIN FOCUS THROUGH THIS PERIOD WILL BE ON A SHORT WAVE...CURRENTLY
MOVING THROUGH THE GREAT LAKES. THE MAIN DYNAMICS FROM THIS SYSTEM
WILL TRACK TO OUR NORTHEAST AS A BROAD UPPER RIDGE REMAINS ACROSS
THE ENTIRE SOUTHERN U.S. HOWEVER...THUNDERSTORMS DEVELOPING ACROSS
IN/OH THIS AFTERNOON HAVE THE POTENTIAL TO DRIFT SOUTHEAST
OVERNIGHT...AS INDICATED BY SEVERAL OF THE SYNOPTIC-SCALE MODELS.
THE MESO-SCALE MODELS ARE IN LESS AGREEMENT ABOUT THIS...HINGING
MORE ON DIURNAL DEVELOPMENT ACROSS THE MOUNTAINS...WHICH AS OF
THIS WRITING HAS FAILED TO MATERIALIZE. THE SOLUTION PRESENTED BY
THE GFS...AND SEVERAL OF THE SYNOPTIC MODELS...SEEMS PLAUSIBLE
GIVEN THE PATTERN AND RECENT TREND OF THIS IN RECENT WEEKS.
THEREFORE...CURRENT THINKING IS THAT A REMNANT MCS/CONVECTIVE
COMPLEX WILL DRIFT INTO THE WV MOUNTAINS AFTER MIDNIGHT...THEN
DIMINISH AS IT ATTEMPTS TO CROSS THE MOUNTAINS. NOT REALLY
EXPECTING MUCH MORE THAN A FEW LIGHT SHOWERS TO MAKE IT EAST OF
THE MOUNTAINS AND MOST LIGHTNING/THUNDER SHOULD BE GONE BY THE
11Z-12Z TIME FRAME.
SATURDAYS FORECAST DEPENDS LARGELY ON THE ABOVE SCENARIO UNFOLDING
AS EXPECTED. CONSIDERABLE CONVECTIVE CLOUD DEBRIS AND EVEN LIGHT
SHOWERS SHOULD BE LINGERING AT DAYBREAK AND SHORTLY THEREAFTER
ACROSS THE WESTERN PART OF THE CWA...WEST OF THE BLUE RIDGE. THIS
CLOUD COVER...COMBINED WITH THE BETTER UPPER-LEVEL DYNAMICS
SHIFTING INTO THE PIEDMONT/NC AREA BY AFTERNOON...SHOULD LEAVE THE
NORTHWEST HALF OF THE CWA CLOUDY AND MAINLY CONVECTIVE FREE
THROUGH MUCH OF THE DAY UNTIL PERHAPS ISOLATED DIURNAL ACTIVITY
DEVELOPS ACROSS THE MOUNTAINS LATER IN THE DAY. HOWEVER...EAST AND
SOUTH OF THE BLUE RIDGE...WOULD EXPECT MORE WIDESPREAD CONVECTION
TO DEVELOP FROM DIFFERENTIAL HEATING ON THE EDGE OF MORNING CLOUD
DEBRIS...AND IN AN AREA OF BETTER HEATING AND INSTABILITY. THERE
COULD POSSIBLE EVEN BE A FEW STRONG TO SEVERE THUNDERSTORMS IN
THIS AREA DURING THE AFTERNOON...BUT CONFIDENCE IS LOW IN THIS AND
SPC DOES NOT CURRENTLY HAVE ANY AREA HIGHLIGHTED FOR SUCH. ONLY
SLIGHTLY BETTER THAN A PULSE-TYPE THUNDERSTORM ENVIRONMENT. ANY
CONVECTION WILL DRIFT SOUTH OF THE CWA SHORTLY AFTER SUNSET.
TEMPERATURES WILL BE MOSTLY ABOVE NORMAL THROUGH THE PERIOD.
CONSIDERABLE CLOUD COVER TONIGHT WILL LIMIT COOLING WEST AND
LIKELY RADIATIONAL FOG AS WELL. WESTERN AREAS MAY REMAIN A TAD
COOLER SATURDAY THAN TODAY BECAUSE OF CLOUD COVER...BUT LATE
AFTERNOON BREAKS COULD ALLOW TEMPERATURES TO RECOVER FAIRLY
QUICKLY. 850MB TEMPS HOVER NEAR +20C...OF SLIGHTLY HIGHER
PIEDMONT...SO THERE IS LITTLE COOLING TO BE HAD OTHER THAN CLOUDS
AND PRECIPITATION.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 300 PM EDT FRIDAY...
SUBTROPICAL RIDGING OVER THE WESTERN GULF COAST REGION WILL BUILD
EAST THROUGH THE PERIOD...WHILE SOUTHWESTERLY WINDFLOW IN THE LOW
LEVELS WILL CONTINUE TO DRAW WARM HUMID AIR UP THE APPALACHIAN
CHAIN. AS SUCH...WE CAN EXPECT TEMPERATURES FOR SUNDAY AND MONDAY TO
BE SOME OF THE WARMEST OUR AREA HAS EXPERIENCED THIS SUMMER AS
AFTERNOON HIGHS RANGE FROM THE MID/UPPER 80S ACROSS THE MOUNTAINS...
TO THE LOW/MID 90S ACROSS THE PIEDMONT...PERHAPS A FEW UPPER 90S
ACROSS THE SOUTHSIDE. THESE TEMPERATURES WILL PUSH HEAT INDICES INTO
THE 100F TO 105F RANGE BOTH DAY EAST OF A DANVILLE TO LYNCHBURG
LINE...AND WE MAY BE ISSUING OUR FIRST HEAT ADVISORIES OF THE
YEAR. OVERNIGHTS WILL BE ON THE WARM AND MUGGY SIDE...WITH LOWS
RANGING FROM THE MID 60S TO THE LOW 70S AREAWIDE.
NOT MUCH SUPPORT FOR MORE THAN SPOTTY SHOWER AND THUNDERSTORM
ACTIVITY FOR SUNDAY...MAINLY ACROSS THE MOUNTAINS DURING THE
AFTERNOON AND EARLY EVENING...BUT PERHAPS WITH A FEW STORMS DRIFTING
ACROSS THE PIEDMONT BEFORE SUNSET. INSTABILITY WILL REMAIN
MARGINAL...WITH CAPES RISING TO AROUND ~1500 J/KG...WHICH WILL
SUPPORT A FEW STRONG STORMS.
EXPECT MORE WIDESPREAD CONVECTION ON MONDAY HOWEVER DUE TO STRONGER
SURFACE CONVERGENCE AS A COLD FRONT SINKS SOUTH TOWARD OUR AREA.
UPPER LEVEL WINDS REMAIN WEAK...BUT WITH DEEPER MOISTURE POOLING
ACROSS OUR AREA AHEAD OF THE FRONT PUSHING PRECIPITABLE WATER VALUES
TO THE 1.5 TO 1.8 INCH RANGE FOR OUR AREA...LOOKING AT BETTER
CHANCES FOR PRECIPITATION LOADING TO ENHANCE THUNDERSTORMS
DOWNDRAFTS. COMBINE THAT WITH CAPES EXCEEDING 2000 J/KG...AND ITS
LOOKING LIKE A DECENT CHANCE FOR SOME STORMS TO BECOME SEVERE. THE
COLD FRONT WILL CONTINUE TO SINK SOUTH INTO THE EVENING...EVENTUALLY
SETTLING SOMEWHERE OVER OR AROUND OUR AREA BY DAWN TUESDAY.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
EXPECT TO START TUESDAY MORNING WITH THE FRONT DRAPED AROUND OUR
AREA. LOW PRESSURE ARRIVING FROM THE WEST DURING THE AFTERNOON AND
EVENING WILL TRIGGER MORE SCATTERED SHOWER AND THUNDERSTORM ACTIVITY
FOR THE AFTERNOON AND EVENING. PASSAGE OF THE LOW ACROSS OUR AREA
WILL HELP PUSH THE FRONT INTO THE CAROLINAS TUESDAY NIGHT.
UPPER LEVEL WINDFLOW WILL TRANSITION TO A WEAK WEST TO EAST PATTERN
FOR THE MIDDLE OF NEXT WEEK...BRINGING A SERIES OF SUBTLE
DISTURBANCES ACROSS THE MID ATLANTIC. AS SUCH...EXPECT A CHANCE OF
SHOWERS AND THUNDERSTORMS EACH DAY...MAINLY THOSE WHICH DEVELOP WITH
DAYTIME HEATING. TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
AS OF 130 PM EDT FRIDAY...
MVFR STRATO-CU PRIMARILY EAST OF THE BLUE RIDGE APPEARS TO BE
HANGING ON LATER INTO THE DAY THAN EXPECTED. HOWEVER WITH
SOUTHWEST WINDS IN PLACE NOW...THIS IS EXPECTED TO BREAK OUT
SOON.
AS HIGH PRESSURE BEGINS TO MOVE OFF EAST WINDS WILL BECOME MORE
SOUTH TO SOUTHWEST. UNDER THIS FLOW...MOISTURE WILL ADVECT INTO
THE REGION FROM THE GULF. GIVEN MOISTURE AND DAYTIME HEATING
STILL CAN EXPECT A SCT-BKN LAYER.
POPS ARE VERY LOW AND WERE LEFT OUT OF TAFS FOR HOWEVER BASED ON
LATEST HRRR BEST POSSIBILITIES ARE JUST WEST OF THE BLUE RIDGE. OF
GREATER CONCERN IS FOR A POTENTIAL REMNANT MCS TO DRIFT SOUTHEAST
INTO THE REGION AFTER MIDNIGHT...IN A GREATLY DIMINISHED
FASHION...BUT PERHAPS ENOUGH TO SUPPORT LIGHT SHOWERS WEST OF THE
ALLEGHANY FRONT...NAMELY BLF/LWB. MVFR CEILINGS ARE POSSIBLE IN
AREAS OF PRECIPITATION...BUT VFR CEILINGS SHOULD PREVAIL
ELSEWHERE.
FOG DEVELOPMENT OVERNIGHT QUESTIONABLE. EXTENSIVE CLOUDS FROM
UPSTREAM MCS AND/OR DEBRIS SHOULD LIMIT FOG DEVELOPMENT. THIS
WOULD BE LESS OF AN EFFECT EAST OF THE BLUE RIDGE...BUT T/TD
SPREAD FROM A HOT AFTERNOON SHOULD FURTHER LIMIT FOG DEVELOPMENT
IN THESE AREAS. FOR NOW...HAVE JUST ADVERTISED MVFR AT LWB...BUT
BCB/LYH COULD SEE MVFR BR AS WELL.
LIGHT SW WINDS THROUGH MUCH OF THE TAF VALID PERIOD...FOR THE MOST
PART 5KTS OR LESS.
MEDIUM CONFIDENCE IN CIGS THROUGH THE TAF VALID PERIOD.
MEDIUM TO HIGH CONFIDENCE IN VSBYS THROUGH THE TAF VALID PERIOD.
MEDIUM CONFIDENCE IN WIND DIR THROUGH THE TAF VALID PERIOD...HIGH
CONFIDENCE IN WIND SPD THROUGH THE TAF VALID PERIOD.
LOW TO MEDIUM CONFIDENCE IN OVERNIGHT TSRA POTENTIAL.
EXTENDED AVIATION DISCUSSION...
REMNANT MCS OR ASSOCIATED DEBRIS LIKELY LINGERING ACROSS AT LEAST
THE NORTHERN HALF OF THE CWA SATURDAY MORNING. THUS...EXTENSIVE
MID/HIGH CLOUDS AT A MINIMUM LIKELY TO BEGIN THE DAY. THIS WILL
BECOME IMPORTANT DURING THE AFTERNOON WITH POSSIBLE REGENERATION
OF CONVECTIONON THE PERIPHERAL BOUNDARY AND/OR IN AREAS OF
DIFFERENTIAL HEATING. MODELS HINT THAT THIS IS MOST LIKELY TO
OCCUR ALONG OR EAST OF THE BLUE RIDGE AND IN NC...THEN DRIFT SOUTH
DURING THE EVENING. SUN APPEARS TO BRING A MINIMUM IN CONVECTION
WITH SHORT WAVE RIDGING. MON SHOULD SEE AN INCREASE IN CONVECTION
AGAIN...POTENTIALLY LINGERING INTO TUESDAY WITH WAVES OF LOW
PRESSURE RIDING THROUGH THE REGION IN A WEST TO WEST- NORTHWEST
FLOW. OUTSIDE SHRA/TSRA AND EARLY MORNING FOG/LOW
CLOUDS...GENERALLY VFR CONDITIONS EXPECTED THROUGH MUCH OF THE
PERIOD.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...RAB
NEAR TERM...RAB
SHORT TERM...NF
LONG TERM...AMS/NF
AVIATION...JH/JR/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
134 PM EDT FRI JUL 17 2015
.SYNOPSIS...
SURFACE HIGH PRESSURE ALONG THE MID ATLANTIC COAST WILL CONTINUE
TO EXTEND SOUTHWEST ALONG THE EASTERN SLOPES OF THE MOUNTAINS
TODAY. RETURN SOUTHERLY FLOW AROUND THE HIGH BRING A RETURN OF
DEEPER MOISTURE LATER TODAY AS WELL AS WIDELY SCATTERED SHOWERS
AND STORMS INTO TONIGHT. UPPER LEVEL HIGH PRESSURE WILL BUILD
EAST FROM THE GULF COAST REGION THIS WEEKEND...RESULTING IN HOTTER
AND MORE HUMID WEATHER INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 235 AM EDT FRIDAY...
WEAK RESIDUAL WEDGE ACROSS THE REGION WILL GRADUALLY BREAK DOWN FOR A
WHILE TODAY AS HIGH PRESSURE SLIDES OFFSHORE ALLOWING THE FLOW TO TURN
MORE SOUTH/SW THIS AFTERNOON. THIS SHOULD ALSO PROVIDE A SLOW INCREASE
IN MOISTURE AS THE WEAK WARM FRONT TO THE SW EDGES SLOWLY NE TOWARD THE
SW MOUNTAINS LATE IN THE DAY. SIMILAR TO THURSDAY...WILL AGAIN INIT
WITH A MIX OF LOWER CLOUDS ESPCLY ALONG/EAST OF THE BLUE RIDGE WITH
THESE GIVING WAY TO AT LEAST PERIODS OF SUN WITH HEATING DURING THE
AFTERNOON. CONVECTIVE CHANCES AGAIN LOOK TO BE TIED TO OROGRAPHICS
LATER THIS AFTERNOON WITH MOISTURE DEPTH AND INSTABILITY LIKELY A BIT
BETTER. HOWEVER DESPITE LINGERING HIGH 85H THETA-E OVER THE WEST...MODELS
REMAIN RATHER ISOLATED WITH SHRA/TSRA AGAIN TODAY GIVEN LACK OF MUCH
FORCING UNDER WEAK FLOW AND LINGERING CAPPED DRY AIR ALOFT. FOR
NOW WILL KEEP 20/30 POPS GOING MAINLY BLUE RIDGE WEST THIS AFTERNOON
FOR POP UP SHALLOW CONVECTION WITH LITTLE POP ACROSS THE FAR EAST
OVERALL PER LATEST HRRR TRENDS. WITH CONTINUED WARMING ALOFT AND
MORE SOUTH/SW FLOW EXPECT TEMPS TO GET A LITTLE MORE OF A BOOST BUT
MAY TAKE A WHILE FOR READINGS TO JUMP PENDING EARLY CLOUDS. WITH
MOS LOCKED IN ON UNIFORM MID/UPPER 80S WONT ADJUST MUCH FROM THE
PREVIOUS FORECAST VALUES FOR NOW.
MOISTURE DEPTH ALONG WITH BETTER FOCUS AND CONVERGENCE MAY ACTUALLY
INCREASE OVERNIGHT AS A WEAK IMPULSE THAT IS CURRENTLY WORKING THROUGH
THE SOUTHERN LAKES DIPS SE WHILE THE FAINT WARM FRONT SLIDES NORTH.
THIS COULD PROVIDE A CORRIDOR FOR UPSTREAM CONVECTION TO SLIDE SE INTO
WEST VA LATE THIS EVENING WITH SOME LATE NIGHT REDEVELOPMENT POSSIBLE
UNDER WEAK WESTERLY FLOW CONVERGENCE ALONG THE NW SLOPES. FORECAST
INSTABILITY ALSO LINGERS OVERNIGHT UNDER WEAK DIFFLUENCE SO
BUMPED UP POPS TO HIGHER CHANCE NW THIRD MAINLY AFTER MIDNIGHT
WHILE SPILLING SOME COVERAGE OUT INTO THE NE SECTIONS ALONG THE
PASSING WARM FRONT LATE. SHOULD STAY DRY ACROSS THE FAR SOUTH/SW
WHERE WILL HAVE ONLY ISOLATED POPS AT BEST. OTRW PARTLY TO MOSTLY
CLOUDY AND A BIT MORE MUGGY UNDER MOISTENING DEWPOINTS...AND LOWS
THAT LOOK TO BE IN THE WARM UPPER 60S TO LOW 70S OVERALL.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 235 AM EDT FRIDAY...
ANY LINGER INFLUENCES OF A WEAK WEDGE OVER THE REGION WILL DISSIPATE
QUICKLY SATURDAY MORNING. BY THE AFTERNOON...A LEE TROUGH WILL
DEVELOP OVER THE COASTAL PIEDMONT AND REMAIN THERE THROUGH THE
WEEKEND. WITH AN UPPER LEVEL RIDGE OVER THE SOUTHERN MISSISSIPPI
VALLEY...WESTERLY WINDS WILL BRING AN INCREASE IN MOISTURE INTO THE
AREA OVER THE WEEKEND. THE COMBINATION OF OROGRAPHIC LIFT OVER THE
MOUNTAINS AND CONVERGENCE NEAR THE LEE TROUGH...WILL BRING SCATTERED
SHOWERS AND THUNDERSTORMS TO THE REGION OVER THE WEEKEND. EXPECTING
TYPICAL DIURNAL CONVECTION TO FADE WITH LOSE OF HEATING EACH
EVENING. HOWEVER...LINGERING INSTABILITIES AND HEAT COULD KEEP
ISOLATED SHOWERS ONGOING INTO THE EARLY MORNING HOURS. TEMPERATURES
WILL RUN WARMER THAN NORMAL THIS WEEKEND WITH MID TO UPPER 80S WEST
TO LOWER TO MID 90S EAST.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
.
AS OF 155 PM EDT THURSDAY...
OVERALL PATTERN TUESDAY THROUGH THURSDAY MAINTAINS A BROAD RIDGE IN
THE SOUTH AND ZONAL FLOW IN THE NORTHERN STREAM. TROFFING MAY BE
STARTING TO AMPLIFY IN THE NORTHEAST WITH THE RIDGE RETROGRADING IN
THE SOUTHWEST BY WEDNESDAY AND THURSDAY.
ENSEMBLE GFS AND OTHER GUIDANCE SHOWED FRONTAL PASSAGE ON MONDAY.
EXPECT BEST COVERAGE OF PRECIPITATION ON SUNDAY NIGHT THROUGH MONDAY
NIGHT. FRONT MOVES FAR ENOUGH SOUTH OF THE FORECAST AREA THAT THE
PROBABILITY OF PRECIPITATION LOWERS FOR WEDNESDAY AND THURSDAY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 130 PM EDT FRIDAY...
MVFR STRATO-CU PRIMARILY EAST OF THE BLUE RIDGE APPEARS TO BE
HANGING ON LATER INTO THE DAY THAN EXPECTED. HOWEVER WITH
SOUTHWEST WINDS IN PLACE NOW...THIS IS EXPECTED TO BREAK OUT
SOON.
AS HIGH PRESSURE BEGINS TO MOVE OFF EAST WINDS WILL BECOME MORE
SOUTH TO SOUTHWEST. UNDER THIS FLOW...MOISTURE WILL ADVECT INTO
THE REGION FROM THE GULF. GIVEN MOISTURE AND DAYTIME HEATING
STILL CAN EXPECT A SCT-BKN LAYER.
POPS ARE VERY LOW AND WERE LEFT OUT OF TAFS FOR HOWEVER BASED ON
LATEST HRRR BEST POSSIBILITIES ARE JUST WEST OF THE BLUE RIDGE. OF
GREATER CONCERN IS FOR A POTENTIAL REMNANT MCS TO DRIFT SOUTHEAST
INTO THE REGION AFTER MIDNIGHT...IN A GREATLY DIMINISHED
FASHION...BUT PERHAPS ENOUGH TO SUPPORT LIGHT SHOWERS WEST OF THE
ALLEGHANY FRONT...NAMELY BLF/LWB. MVFR CEILINGS ARE POSSIBLE IN
AREAS OF PRECIPITATION...BUT VFR CEILINGS SHOULD PREVAIL
ELSEWHERE.
FOG DEVELOPMENT OVERNIGHT QUESTIONABLE. EXTENSIVE CLOUDS FROM
UPSTREAM MCS AND/OR DEBRIS SHOULD LIMIT FOG DEVELOPMENT. THIS
WOULD BE LESS OF AN EFFECT EAST OF THE BLUE RIDGE...BUT T/TD
SPREAD FROM A HOT AFTERNOON SHOULD FURTHER LIMIT FOG DEVELOPMENT
IN THESE AREAS. FOR NOW...HAVE JUST ADVERTISED MVFR AT LWB...BUT
BCB/LYH COULD SEE MVFR BR AS WELL.
LIGHT SW WINDS THROUGH MUCH OF THE TAF VALID PERIOD...FOR THE MOST
PART 5KTS OR LESS.
MEDIUM CONFIDENCE IN CIGS THROUGH THE TAF VALID PERIOD.
MEDIUM TO HIGH CONFIDENCE IN VSBYS THROUGH THE TAF VALID PERIOD.
MEDIUM CONFIDENCE IN WIND DIR THROUGH THE TAF VALID PERIOD...HIGH
CONFIDENCE IN WIND SPD THROUGH THE TAF VALID PERIOD.
LOW TO MEDIUM CONFIDENCE IN OVERNIGHT TSRA POTENTIAL.
EXTENDED AVIATION DISCUSSION...
REMNANT MCS OR ASSOCIATED DEBRIS LIKELY LINGERING ACROSS AT LEAST
THE NORTHERN HALF OF THE CWA SATURDAY MORNING. THUS...EXTENSIVE
MID/HIGH CLOUDS AT A MINIMUM LIKELY TO BEGIN THE DAY. THIS WILL
BECOME IMPORTANT DURING THE AFTERNOON WITH POSSIBLE REGENERATIONCONVECTION
ON THE PERIPHERAL BOUNDARY AND/OR IN AREAS OF DIFFERENTIAL
HEATING. MODELS HINT THAT THIS IS MOST LIKELY TO OCCUR ALONG OR
EAST OF THE BLUE RIDGE AND IN NC...THEN DRIFT SOUTH DURING THE
EVENING. SUN APPEARS TO BRING A MINIMUM IN CONVECTION WITH SHORT
WAVE RIDGING. MON SHOULD SEE AN INCREASE IN CONVECTION
AGAIN...POTENTIALLY LINGERING INTO TUESDAY WITH WAVES OF LOW
PRESSUR RIDING THROUGH THE REGION IN A WEST TO WEST- NORTHWEST
FLOW. OUTSIDE SHRA/TSRA AND EARLY MORNING FOG/LOW
CLOUDS...GENERALLY VFR CONDITIONS EXPECTED THROUGH MUCH OF THE
PERIOD.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/NF
NEAR TERM...JH
SHORT TERM...RCS
LONG TERM...AMS
AVIATION...JH/JR/RAB
AREA FORECAST DISCUSSION...CORRECTED AVIATION
NWS CHEYENNE WY
1117 AM MDT FRI JUL 17 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 350 AM MDT FRI JUL 17 2015
CURRENT KCYS RADAR LOOP SHOWS SOME RAIN SHOWERS MOVING INTO THE
CARBON AND ALBANY COUNTIES EARLY THIS MORNING. THIS ACTIVITY IS IN
RESPONSE TO THE SURFACE COOL FRONT SLOWLY MOVING SOUTH ACROSS
WYOMING AT THIS HOUR. THIS FRONT WILL GRADUALLY PUSH INTO
SOUTHEAST WYOMING AND PARALLEL I80 BY THIS AFTERNOON. SHOWERS ARE
EXPECTED TO CONTINUE THIS MORNING WITH TSTORMS EVENTUALLY
DEVELOPING BY THIS AFTERNOON. THE 06Z HRRR SHOWS SOME CONVECTION
DEVELOPING FURTHER SOUTH BY THE MIDDLE OF THE AFTERNOON...WITH
SOME STRONGER CELLS BY 20Z. MODELS SHOW THIS COLD FRONT MOVING
INTO COLORADO BY THIS EVENING...WITH COOLER TEMPERATURES EXPECTED
OVER THE AREA LATE THIS EVENING. THERE IS A RISK FOR STRONG TO
SEVERE TSTORMS ACROSS THE HIGH PLAINS EAST OF THE LARAMIE RANGE AS
WELL DUE TO 0-6KM SHEAR BETWEEN 40 TO 50 KNOTS. THE BEST CHANCE
FOR SEVERE TSTORMS APPEARS TO BE EAST OF A LINE EXTENDING FROM
CASPER WYOMING TO SIDNEY NEBRASKA...HOWEVER...WILL HAVE TO MONITOR
THIS THROUGH THE DAY AS RECENT MODEL RUNS ARE SHOWING A GREATER
COVERAGE MAINLY DUE TO THE POSITION OF THE FRONT AND CONSIDERABLE
UPPER LEVEL DIFFLUENCE ASSOCIATED WITH THE UPPER LEVEL JET.
STRONG GUSTY WINDS AND HAIL APPEAR TO BE THE PRIMARY THREATS WITH
ANY TSTORMS THAT DO DEVELOP. IN CONTRAST...THERE IS SOME DRIER AIR
MOVING ACROSS SOUTHEAST WYOMING AHEAD OF THE COOL FRONT...WHICH
MAY LIMIT CONVECTION INITIALLY. THE TIMING AND LOCATIONS OF THE
COOL FRONT WILL BE KEY IN TSTORMS DEVELOPMENT THIS AFTERNOON AS
WELL AS THE POTENTIAL FOR STRONG TO SEVERE TSTORMS. PATCHY FOG AND
LOW STRATUS ARE STILL POSSIBLE EAST OF THE LARAMIE RANGE LATE
TONIGHT AND EARLY SATURDAY MORNING DUE TO SOME RAINFALL AND LIGHT
UPSLOPE WINDS.
FOR THE WEEKEND...A PERIOD OF UNSETTLED WEATHER IS POSSIBLE FOR
THIS WEEKEND AS MODELS SHOW THE FRONT STALLING ACROSS THE
MOUNTAINS. THERE MAY EVEN BE SOME STRONGER TSTORMS ON SATURDAY
NEAR THE COLORADO BORDER AS WELL. SHOULD SEE A HIGHER COVERAGE OF
SHOWERS AND TSTORMS ALONG THE I80 CORRIDOR DUE TO DYNAMIC FORCING
IN ADDITION TO BL INSTABILITY. INCREASED POP BETWEEN 40 TO 50
PERCENT ACROSS THE MOUNTAINS AND HIGH PLAINS FOR A DECENT CHANCE
OF WIDESPREAD RAINFALL. COOLER TEMPERATURES ARE EXPECTED ON
SATURDAY WITH HIGHS IN THE 70S TO LOW 80S. SIMILAR CONDITIONS ARE
EXPECTED ON SUNDAY AS A SHORTWAVE DISTURBANCE ALOFT MOVES ACROSS
THE AREA. SURFACE TEMPERATURES MAY BE COOL ENOUGH TO LIMIT DEEP
CONVECTION AND TSTORM ACTIVITY SO KEPT POP BETWEEN 25 TO 35
PERCENT ACROSS THE HIGH PLAINS. HIGH TEMPERATURES WILL BE BELOW
NORMAL FOR THIS TIME OF THE YEAR WITH READINGS IN THE 70S TO NEAR
80. CURRENT FORECAST MAY BE A LITTLE TOO WARM ON SUNDAY DUE TO
RECENT MODEL GUIDANCE SUGGESTING HIGHS MAINLY IN THE LOW TO MID
70S AND CLOUDY SKIES.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
CONSIDERABLE MODEL DIFFERENCES STILL EXIST AMONG MEDIUM RANGE MODELS
CONCERNING THE TIMING/STRENGTH OF A MID LEVEL SHORTWAVE DISTURBANCE
PROGGED TO MOVE ACROSS THE CENTRAL ROCKIES EARLY IN THE PERIOD. THE
GFS IS THE SLOWEST...BUT HAS BEEN CONSISTENT WITH A FAIRLY VIGOROUS
PIECE OF ENERGY TRACKING ACROSS SOUTHERN WY/NORTHERN CO DURING THE
AFTN HOURS ON MON. ECMWF/GEM ARE MUCH MORE PROGRESSIVE AND TEND TO
MOVE THIS FEATURE WELL INTO NEBRASKA BY MONDAY AFTERNOON...RESULTING
IN RIDGING OVER THE CWA. TEND TO FAVOR THE MORE PROGRESSIVE THINKING
AS THE GFS SHOWS THIS WAVE TOTALLY OUT OF PHASE WITH A RATHER ACTIVE
NORTHERN STREAM. PLUS...BELIEVE THE UPSTREAM VORT MAX OVER THE PAC
NW WOULD SERVE AS A KICKER. RESTRICTED POPS TO THE MOUNTAINS THROUGH
AT LEAST MIDDAY TUESDAY. BY THEN...TROUGHING OVER THE WESTERN CONUS
SHOULD GIVE WAY TO SOUTHWEST FLOW ALOFT OVER THE ROCKIES. IT DOES
NOT APPEAR TO BE A PARTICULARLY MOIST PATTERN BY ANY MEANS...BUT WE
SHOULD SEE PERIODIC SHOTS OF MID AND HIGH LEVEL MOISTURE WITH WEAK
DISTURBANCES EMBEDDED WITHIN THE FLOW. AS SUCH...FAIRLY TYPICAL JULY
WEATHER CAN BE EXPECTED FOR TUE-THU WITH ISOLATED/WIDELY SCATTERED
AFTERNOON CONVECTION. TEMPS THROUGH THE PERIOD SHOULD BE NEAR NORMS
FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1111 AM MDT FRI JUL 17 2015
A WEAK FRONT ALONG A CASPER-ALLIANCE LINE WILL SLOWLY DRIFT SOUTH
ACROSS SOUTHEAST WY AND WESTERN NE THIS AFTERNOON AND EARLY EVENING.
ISOLATED TO SCATTERED TSTORMS WILL DEVELOP EARLY THIS AFTERNOON AND
LINGER INTO THE LATE EVENING OVER WESTERN NE. BRIEF PERIODS OF MVFR
VSBY WILL OCCUR WITH TSTORMS...ALONG WITH GUSTY/ERRATIC
WINDS...SMALL HAIL AND LIGHTNING. AHEAD OF THE FRONT...SOUTHWEST
WINDS WILL GUST BETWEEN 25 AND 35 KT ALONG AND WEST OF THE LARAMIE
RANGE THIS AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 252 AM MDT FRI JUL 17 2015
NO FIRE WEATHER CONCERNS THROUGH THIS WEEKEND AND INTO EARLY NEXT
WEEK. IT WILL BE DRY TODAY ACROSS SOUTHERN WYOMING FROM RAWLINS TO
CHEYENNE AS GUSTY WEST TO SOUTHWEST WINDS DEVELOP. DAYTIME
RELATIVE HUMIDITIES WILL LOWER TO 15 TO 20 PERCENT THIS AFTERNOON.
HOWEVER...FUELS REMAIN NON CRITICAL DUE TO RECENT RAINFALL. IN
ADDITION...A COOL FRONT WILL PUSH SOUTHEAST ACROSS THE AREA WITH
HUMIDITIES TRENDING HIGHER FOR THIS WEEKEND.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...TJT
LONG TERM...CLH
AVIATION...MAJ
FIRE WEATHER...TJT