Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/19/14
AREA FORECAST DISCUSSION
NWS TUCSON AZ
935 AM MST SUN AUG 17 2014
.SYNOPSIS...AMPLE MOISTURE WILL PROVIDE SCATTERED THUNDERSTORMS
THIS WEEK. SOME STORMS WILL PRODUCE GUSTY WINDS AS WELL AS HEAVY
RAIN THAT MAY LEAD TO FLASH FLOODING.
&&
.DISCUSSION...ISOLATED SHOWERS WERE OCCURRING IN AN ARC FROM ORACLE
TO PICACHO PEAK TO JUST WEST OF SELLS. THE REST OF SE AZ WAS
PRECIP-FREE AT THIS TIME. IR/VISIBLE SATELLITE IMAGERY INDICATED
MOSTLY SUNNY SKIES ACROSS FAR ERN SECTIONS...AND PARTLY CLOUDY TO
MOSTLY CLOUDY SKIES ELSEWHERE. DEWPOINTS AT LOWER ELEVATIONS VALID
16Z RANGED FROM THE UPPER 50S-MID 60S F...AND THESE TEMPS WERE
GENERALLY 2-5 DEGS F LOWER VERSUS 24 HOURS AGO. SURFACE TEMPS FROM
TUCSON WWD VALID 16Z WERE ABOUT 3-8 DEGS F COOLER VERSUS 24 HOURS
AGO. SURFACE TEMPS ELSEWHERE WERE NEARLY IDENTICAL TO THIS TIME SAT.
1501Z BLENDED TOTAL PRECIP WATER PRODUCT YIELDED VALUES RANGING FROM
AROUND 0.75 INCHES ACROSS THE WHITE MOUNTAINS TO NEARLY 1.40 INCHES
ACROSS WRN PIMA COUNTY. 17/12Z UPPER AIR PLOTS DEPICTED BROAD RIDGE
OVER THE SWRN CONUS WITH 594 DM HIGH PRESSURE CENTERED OVER NERN AZ.
LIGHT GENERALLY ELY MID-LEVEL STEERING FLOW PREVAILED OVER SE AZ.
THE ISOLATED SHOWERS ACROSS WRN SECTIONS ARE EXPECTED TO MOVE WWD
AND WEAKEN DURING THE NEXT 1-2 HOURS AS PER THE 17/14Z RUC HRRR AND
17/12Z NAM SOLUTIONS. SCATTERED SHOWERS/TSTMS SHOULD DEVELOP BY
EARLY THIS AFTERNOON ACROSS THE HIGHER TERRAIN OF GREENLEE/GRAHAM/
COCHISE COUNTIES. THESE SHOWERS/TSTMS WILL THEN MOVE WWD THIS
AFTERNOON AND INTO THIS EVENING. THERE ARE SOME DIFFERENCES BETWEEN
THE NAM...RUC HRRR...AND UNIV OF AZ WRF-NAM REGARDING THE WWD EXTENT
OF CELL MIGRATION INTO THIS EVENING.
HOWEVER...THESE SOLUTIONS ARE SIMILAR WITH LIMITING ANY RAINFALL OF
SIGNIFICANCE MOSTLY TO AREAS EAST OF TUCSON THIS AFTERNOON. APPEARS
THAT SHOWERS/TSTMS THAT OCCURRED LAST NIGHT ACROSS ERN PIMA COUNTY
WERE SUFFICIENT TO INHIBIT CONVECTIVE DEVELOPMENT THIS AFTERNOON.
THUS...FORECAST CONFIDENCE IS SUFFICIENTLY HIGH AT THIS TIME TO
LOWER POPS FOR THE TUCSON METRO AREA AND ADJACENT LOWER ELEVATION
LOCALES THIS AFTERNOON.
THE OFFICIAL FORECAST WILL BE UPDATED TO REFLECT THIS SCENARIO. WILL
ALSO FAVOR THE DRIER RUC HRRR SOLUTION TO REDUCE POPS ACROSS WRN
SECTIONS THIS AFTERNOON. OTHERWISE...SCATTERED SHOWERS/TSTMS WILL
OCCUR THIS AFTERNOON ACROSS ERN SECTIONS. THE MAIN IMPACTS WILL BE
LOCALLY HEAVY RAINFALL AND BRIEF STRONG WIND GUSTS.
PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.
&&
.AVIATION...VALID THRU 18/18Z.
SCATTERED -TSRA/-SHRA WILL DEVELOP ACROSS THE HIGHER TERRAIN EAST OF
KTUS BY EARLY THIS AFTERNOON. THESE SHOWERS/THUNDERSTORMS WILL THEN
MOVE WWD ACROSS SE AZ THRU THIS EVENING AND LATER TONIGHT. THE BULK
OF ANY -TSRA/-SHRA IS THEN EXPECTED TO BE WEST OF KTUS MONDAY
MORNING. MVFR VISIBILITIES AND BRIEF WIND GUSTS TO NEAR 50 KTS WILL
OCCUR WITH THE STRONGER TSRA. OTHERWISE...CLOUD DECKS WILL MAINLY BE
AT 6-12K FT AGL AND SURFACE WIND WILL GENERALLY BE LESS THAN 10 KTS
THRU MONDAY MORNING. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...SCATTERED THUNDERSTORMS WILL OCCUR THIS WEEK AS
AMPLE MOISTURE REMAINS ACROSS SOUTHEAST ARIZONA. THE STRONGER
THUNDERSTORMS WILL PRODUCE STRONG...GUSTY AND ERRATIC WINDS.
OTHERWISE...AFTERNOON MINIMUM RELATIVE HUMIDITIES ARE FORECAST TO BE
MOSTLY IN THE 25-40 PERCENT RANGE AT LOWER ELEVATIONS FOLLOWED BY
GOOD TO EXCELLENT OVERNIGHT RECOVERIES. 20-FOOT WINDS WILL EXHIBIT
NORMAL DIURNAL TRENDS AND BE MOSTLY LESS THAN 15 MPH.
&&
.PREV DISCUSSION...MONDAY...E-SE FLOW ALOFT WITH UPPER HIGH OVER NRN
NM. PRECIPITABLE WATER VALUES ARE FORECAST TO BE A TICK WETTER THAN
TODAY. LOOKING AT ANOTHER ROUND OF SCATTERED STORMS WITH A FEW
LINGERING INTO THE OVERNIGHT HOURS. FURTHER UPSTREAM ON MONDAY AN
UPPER LEVEL TROF WHICH IS OVER THE PACIFIC NW TODAY...WILL DROP INTO
NRN CA AND DEVELOP INTO A CLOSED LOW OFF NRN CA CST. THIS FEATURE
WILL BE A PLAYER IN OUR FORECAST LATER IN THE WEEK.
TUESDAY...SOUTHERLY FLOW INCREASES AS THE ABOVE MENTIONED NRN CA
UPPER LOW DROPS S ALONG THE CA CST AND BE OFF LA BASIN LATE IN THE
AFTERNOON. PRECIPITABLE WATER VALUES ARE FORECAST TO BE IN THE
1.50"-1.80" RANGE.
CHAOS REIGNS FOR THE REMAINDER OF THE WEEK WITH RESPECT TO WHERE
THE ABOVE MENTIONED CUT-OFF LOW WILL MOVE AND HOW MUCH THE TROPICS
START TO BE PLAYER. AT THIS TIME...AND WITH THE MEDIUM RANGE MODELS
ALONG WITH THE ENSEMBLES HAVE MANY SOLUTIONS...HAVE DECIDED TO GO
WITH CLIMO POPS ACROSS THE AREA STARTING WEDNESDAY THROUGH SATURDAY.
SURE LOOKS LIKE IT WILL BE A WET WEEK ACROSS SE ARIZONA.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
FRANCIS
PREVIOUS DISCUSSION...GLUECK
AREA FORECAST DISCUSSION
NWS PUEBLO CO
823 PM MDT MON AUG 18 2014
.UPDATE...
ISSUED AT 820 PM MDT MON AUG 18 2014
UPDATED MOST POP FORECASTS, REMOVING POPS OVER THE PLAINS AND
EASTERN MOUNTAINS, WHILE ADDING/EXTENDING PRECIP CHANCES OVER THE
SOUTHWEST MOUNTAINS AND SAN LUIS VALLEY...AS AREA OF TSRA OVER THE
SAN JUANS WILL MOVE EAST ACROSS LOWER ELEVATIONS BEFORE ENDING.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 259 PM MDT MON AUG 18 2014
THE UPR RIDGE IS STILL CENTERED NR THE FOUR CORNERS AREA TODAY
AND PRECIPITABLE WATER VALUES ARE SIMILAR TO WHAT THEY WERE
YESTERDAY. ISOLATED SHOWERS AND TSTMS HAVE DEVELOPED OVR SOME OF
THE MOUNTAIN AREAS AS OF 1930Z. SHOULD SEE COVERAGE OVR THE MTNS
INCREASE THIS AFTERNOON. HRRR AND RAP SHOW PCPN DEVELOPING/MOVING
OVR THE SERN PLAINS AND PORTIONS OF THE SAN LUIS VALLEY LATER THIS
AFTERNOON AND THIS EVENING. THE HRRR AND RAP HAVE PCPN ENDING IN
MOST LOCATIONS BY LATE EVENING...BUT SHOW THE POTENTIAL FOR SOME
CONTINUING OVR THE SAN JUAN MTNS INTO THE LATE NIGHT HOURS.
AS AN UPR TROF DIGS INTO SRN CA TONIGHT AND TUESDAY...THE UPR RIDGE
OVR OUR AREA SHIFTS EASTWARD. THIS PUSHES A LITTLE BETTER MSTR INTO
WRN CO FOR TUE...WITH PRECIPITABLE WATER VALUES INCREASING SLIGHTLY
OVR THE CONTDVD. AS A RESULT THERE SHOULD BE MORE WIDESPREAD SHOWER
AND TSTM ACTIVITY ALONG THE CONTDVD TOMORROW. THE ERN MTNS WL
LIKELY SEE SCT PCPN DEVELOPING IN THE AFTERNOON HOURS...WHILE THE
SERN PLAINS SHOULD JUST SEE A FEW SHOWERS OR STORMS DEVELOP. HIGH
TEMPS ON TUE SHOULD BE 5-8 DEGREES ABOVE AVERAGE OVR THE SERN
PLAINS...AND AROUND NORMAL IN THE SAN LUIS VALLEY AND UPR ARKANSAS
RIVER VALLEY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 259 PM MDT MON AUG 18 2014
...ACTIVE WEATHER FOR AT LEAST THE NEXT WEEK...
MODELS ARE NOW IN REASONABLE AGREEMENT THAT THE CUTOFF LOW
OFF THE CA COAST WILL PHASE WITH THE TROUGH MOVING INTO THE
PACNW...AND THIS WILL LEAD TO AN ENHANCED MONSOONAL PATTERN
FOR THE LATTER PART OF THIS WEEK AND BEYOND. A COUPLE OF
ADDITIONAL SHORTWAVES WILL MOVE THROUGH THE LONGWAVE TROUGH
PATTERN THAT IS OVER WRN CANADA...BRINGING THE THREAT FOR PERIODS
OF HEAVY RAIN TO OUR AREA.
TUE NIGHT...EXPECT ISOLD STORMS TO PERSIST OVER THE CONTDVD
AS THE PLUME BEGINS TO MOVE OVR WRN CO. BY LATE WED THE TROUGH
AND ABSORBED CUTOFF WILL MOVE INTO NW AZ/SW UT...AND THE THREAT
OF HEAVY BANDS OF CONVECTION WILL CONTINUE FOR THE SW MTS AND
CONTDVD. DEPENDING ON WHAT HAS ALREADY FALLEN OVR THE MTS
WE COULD SEE THE THREAT OF MORE FLASH FLOODING AND RISK OF
SLIDES FOR THE MT AREAS. TIMING FOR OUR CWA`S STAGES IN THE
PRO CYCLING CHALLENGE DOES NOT LOOK FAVORABLE AS THE STRONGEST
DYNAMICS FROM THIS SYSTEM MOVE THROUGH ON THURSDAY. THAT IS WHEN
THE CORE OF A 100 KT JET STREAK MOVES THROUGH CO. THIS IS PRETTY
ROBUST FOR AN AUGUST SYSTEM. WITH H6 TEMPS AT MINUS 2C OR LOWER IN
THE CORE OF THE LOW...COULD EASILY SEE SOME SNOW FOR ELEVS ABOVE
12K FEET BY FRI MORNING. THE GFS BRINGS US A BIT OF A BREAK IN THE
ACTION ON SATURDAY BEFORE ANOTHER FRONT COMES THROUGH SAT
NIGHT...FOLLOWED BY A THIRD SYSTEM SUN OR MON. THE ECMWF HAS SOME
OF THE HEAVIEST QPF ON FRI AND CONTINUES THE ONSLAUGHT THROUGH THE
WEEKEND. A BIT HARD TO SAY WHEN THE HEAVIEST RAIN WILL FALL...BUT
THE THREAT OF HEAVY PRECIP WILL CERTAINLY BE WITH US SO LONG AS
THIS PARADE OF SHORTWAVES CONTINUE...AT LEAST THROUGH THE FIRST
DAYS OF NEXT WEEK. ENSEMBLE POPS LOOKED MUCH TOO LOW SO HAVE
RAISED POPS BY AT LEAST 10 PERCENT OVER THIS TIME FRAME FOR BOTH
THE PLAINS AND MTS...WHILE THE MTS WILL SEE THE BEST SHOT AT HEAVY
PRECIP. TEMPS WILL TREND DOWNWARD THROUGH THE PERIOD...STARTING IN
THE NR 90 RANGE FOR TUE-THU...AND THEN FALLING INTO THE 80S AND
POSSIBLY LOWER FOR THE PLAINS NEXT WEEKEND. LOOKS LIKE THE
FORECAST WILL REMAIN CHALLENGING FOR THE REST OF THIS MONTH. ROSE
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 259 PM MDT MON AUG 18 2014
VFR CONDITIONS ARE EXPECTED AT KCOS...KPUB AND KALS TONIGHT THROUGH
TUESDAY AFTERNOON. TSTMS COULD MOVE INTO THE VCNTY OF THE TERMINAL
SITES THIS EVENING...WITH KCOS SEEING THE BEST CHANCE OF THIS
OCCURRING. SHOWERS AND TSTMS WL AGAIN DEVELOP OVR THE MOUNTAINS AND
THEN SPREAD OVR SOME OF THE LOWER ELEVATIONS...POSSIBLY MOVING IN
THE VCNTY OF THE TERMINAL SITE.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...PETERSEN
SHORT TERM...28
LONG TERM...ROSE
AVIATION...28
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
523 PM MDT MON AUG 18 2014
.SHORT TERM...(TONIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 333 PM MDT MON AUG 18 2014
BIG CHANGES WILL OCCUR OVER THE NEXT 24 HOURS AS AN UNSEASONABLY
STRONG AND NEARLY VERTICALLY STACKED TROUGH...CURRENTLY OVER
CALIFORNIA...MOVES EAST INTO THE GREAT BASIN. THIS BRINGS EASTERN
UTAH AND WESTERN COLORADO INTO IDEAL POSITION FOR DEEP
SUBTROPICAL MOISTURE TO ADVECT INTO THE REGION. PRECIPITABLE
WATER VALUES OF 1 TO 1.3 INCH ARE EXPECTED TO COVER EASTERN UTAH
AND EVEN EXTREME WESTERN COLORADO BY LATE TUESDAY AFTERNOON. THIS
IS ALMOST 2 STANDARD DEVIATIONS ABOVE NORMAL FOR THIS TIME OF
YEAR.
MODELS ARE FORECASTING MULTIPLE VORT MAXES TO REACH THE UT/CO
BORDER THROUGHOUT THE DAY FROM NOON TO MIDNIGHT. THERE IS SOME
UNCERTAINTY ON THE TIMING OF H3 JET SUPPORT OF 60KTS REACHING THE
AREA...WHICH WILL HELP TO PROVIDE ASCENT IN THE UNIMPRESSIVE CAPE
AND SHEAR ENVIRONMENT. EXPECTING CLOUD COVER TO HINDER INSTABILITY
DURING THE DAY...HOWEVER THIS SCENARIO COULD CHANGE IF SUFFICIENT
CLEAR AIR IS ABOUND BY LATE MORNING. THE RAP SHOWS JET SUPPORT
INCHING INTO EASTERN UTAH AND SOUTHWEST COLORADO DURING THE
MORNING ON TUESDAY...HOWEVER THE NAM AND GFS SHOW THE BEST JET
SUPPORT ON TUESDAY NIGHT AND WEDNESDAY MORNING. STORM MOTION WILL
BE DECENT FOR TUESDAY - ABOUT 20 TO 30 KTS...SO COULD NOT JUSTIFY
A FLASH FLOOD WATCH AT THIS TIME. IT WILL RAIN IN MANY LOCATIONS
BY TUESDAY NIGHT...BUT ONLY EXPECTING MODERATE TO HEAVY RAIN
MULTICELLULAR STORMS CAUSING NUISANCE/SMALL STREAM FLOODING AT
THIS TIME. SEE HYDRO SECTION FOR MORE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 333 PM MDT MON AUG 18 2014
THE FORECAST AREA REMAINS UNDER SW FLOW WED-THU WITH THE JET AXIS
OVERHEAD. MONSOONAL MOISTURE PLUME WEAKENS WITH PRECIPITABLE WATER
VALUES DROPPING UNDER 1 INCH. NAM/GFS SHOW A WEAK 300 MB JET MAX
ARRIVING ON WED FOR POTENTIAL SUPPORT AND INCREASED VERTICAL
SHEAR....AND SHOULD IT ENTRAIN SOME DRIER MIDLEVEL AIR OVER HIGHER
MOISTURE NEAR THE SURFACE...IT COULD LEAD TO SOME STRONGER STORMS
WED AFTERNOON.
MODELS STILL HAVING TROUBLE HANDLING THE UPPER LOW THAT IS
CURRENTLY DROPPING SOUTH ALONG THE NRN CA COAST...WHICH LOWERS
FORECAST CONFIDENCE AFTER MIDWEEK. BUT AT LEAST THE GFS AND ECWMF
NOW BOTH BRING THE 500 MB LOW INLAND...JUST TIMING AND TRACK ARE
DIFFERENT. THE 12Z GFS SWINGS THE LOW INLAND ACROSS SRN CA WED AND
THEN LIFTS IT NE ACROSS UT AS AN OPEN WAVE ON THU. THIS COULD ADD
SOME DYNAMIC PUNCH TO STORM DEVELOPMENT ON THU. THE 12Z ECMWF IS
SLOWER BRINGING IT INLAND AND TRACKS IT FARTHER SOUTH ACROSS AZ
AND NWRN NM. THE 12Z CANADIAN HAS IT SHEARING OUT ALONG THE SRN CA
COAST THU-FRI. MODELS ALSO SHOW ENERGY DROPPING OUT OF THE GULF OF
AK LATE IN THE WEEK THAT SHOULD MAINTAIN TROUGHING OVER THE PAC
NW/NRN ROCKIES.
FOR NOW...WITH FOLLOW THE CONSENSUS MODEL TREND...WHICH SHOWS A
LESSENING OF STORM COVERAGE THE LAST HALF OF THE WEEK BUT NOT A
COMPLETE CESSATION. LOWER LEVEL MOISTURE LIKELY TO LINGER WITH SOME
SMALLER EMBEDDED WAVES IN THE FLOW THAT COULD TRIGGER ISOLATED-
SCATTERED ACTIVITY ABOUT EACH DAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 519 PM MDT MON AUG 18 2014
MOST CONVECTION IS EXPECTED TO DIE DOWN OVERNIGHT THOUGH SOME
LINGERING SHOWERS...MAYBE A QUICK RUMBLE OF THUNDER...IS POSSIBLE
THROUGH 09Z. FLYING CONDITIONS WILL DETERIORATE TOMORROW AS A
DISTURBANCE MOVES OVERHEAD WITH MID LEVEL BKN TO OCCNL OVC CIGS
EXPECTED FROM 18Z ONWARDS. MANY AREAS WILL SEE VCSH BECOMING VCTS
AS THE AFTERNOON PROGRESSES. THE STRONGER CELLS WILL PRODUCE MVFR
TO POSSIBLY IFR VIS AT TIMES DUE TO LOWERED VISIBILITIES. GUSTY
OUTFLOW WINDS ARE ALSO POSSIBLE REACHING 40+ MPH IN THE AFTERNOON
AND EVENING HOURS. MTN TOPS WILL LIKELY BE OBSCURED FOR MOST OF
THE FORECAST AREA. CONVECTION IS EXPECTED TO CONTINUE OVERNIGHT
THOUGH COVERAGE WILL LESS THAN SEEN DURING THE DAY.
&&
.HYDROLOGY...
ISSUED AT 333 PM MDT MON AUG 18 2014
MONSOONAL MOISTURE WILL RETURN TOMORROW AS AN UPPER LEVEL LOW OVER
CALIFORNIA PULLS DEEP SUBTROPICAL MOISTURE INTO THE REGION.
SHOWERS AND THUNDERSTORMS WILL INCREASE IN COVERAGE FROM WEST TO
EAST THROUGHOUT THE AFTERNOON AND PEAK DURING THE LATE HOURS OF
THE DAY AND OVERNIGHT INTO WEDNESDAY MORNING. EXPECTING TO HAVE
SMALL STREAM AND ARROYO FLOOD ISSUES BY WEDNESDAY MORNING IN THE
USUAL PROBLEM AREAS...BUT AT THIS NOT EXPECTING HIGH COVERAGE OF
TORRENTIAL DOWNPOURS DUE TO THUNDERSTORMS. THEREFORE...NO WATCHES
HAVE BEEN ISSUED AT THIS TIME.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...JAM
LONG TERM...JAD
AVIATION...TGR
HYDROLOGY...JAM
AREA FORECAST DISCUSSION
NWS PUEBLO CO
316 PM MDT SUN AUG 17 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 252 PM MDT SUN AUG 17 2014
AN UPR RIDGE WL REMAIN CENTERED NR THE FOUR CORNERS THRU
TONIGHT...SHIFTING A LITTLE EASTWARD ON MON. THIS AFTERNOON A WEAK
DISTURBANCE IS MOVING ACRS NRN CO. SOME ISOLD THUNDERSTORMS HAVE
DEVELOPED OVR SOME OF THE MTN AREAS AND OVER THE EAST CENTRAL
PLAINS. EXPECTING MORE DEVELOPMENT OVR THE MTNS THE REST OF THIS
AFTERNOON...WITH SOME ISOLD DEVELOPMENT OVR PORTIONS OF THE SERN
PLAINS. BOTH THE RAP AND HRRR CONTINUE TO SHOW AN AREA OF TSTMS
DEVELOPING THIS AFTERNOON...ASSOCIATED WITH THE WX DISTURBANCE...
OVER THE PIKES PEAK REGION AND THEN MOVING SOUTHEASTWARD ACRS THE
SERN PLAINS THRU THE EVENING HOURS...AND DISSIPATING OR EXITING
THE SERN CORNER OF THE STATE BY ABOUT 1 OR 2 AM.
ON MONDAY AN UPR TROF MOVES INTO WRN NV AND SHIFT THE UPR RIDGE
CENTER A LITTLE EASTWARD OVR CO. PRECIPITABLE WATER VALUES ACRS THE
FORECAST AREA ARE EXPECTED TO BE SIMILAR TO TODAY. EXPECTING SOME
SHOWERS/TSTM DEVELOPMENT OVR SOME OF THE MTN AREAS IN THE LATE
MORNING HOURS AGAIN. THEN INCREASING IN COVERAGE IN THE AFTERNOON
HOURS OVER THE MTNS AND HIGH VALLEYS...WITH SOME ISOLD STORMS
DEVELOPING OVR MOVING OVR THE SOUTHEAST PLAINS. HIGH TEMPS ON MON
WL AGAIN BE ABOVE AVERAGE BY AROUND 5 DEGREES.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 252 PM MDT SUN AUG 17 2014
...MORE MONSOON NEXT WEEK...
EXTENDED FORECAST CONTINUES TO BE A BIT SHAKY AS THE GLOBAL
MODEL RUNS STRUGGLE WITH FAIRLY COMPLEX INTERACTIONS INVOLVING
THE POLAR JET TO THE NORTH AND A SUBTROPICAL INFLUENCE TO THE
SOUTH. THE EC AND GFS ARE IN REASONABLE AGREEMENT THROUGH ABOUT
TUESDAY...THEN THE CONSISTENCY STARTS TO UNRAVEL.
A PACIFIC TROUGH WILL AMPLIFY ON TUESDAY AND BEGIN MOVING INTO
THE PACNW...AS A CUTOFF LOW DRIFTS OFF THE CA COAST. INCREASED
S-SW FLOW ALOFT WILL BRING MOISTURE UP FROM MEXICO AND THE DESERT
SW INTO WRN CO. THE ECMWF SEEMS TO BE OVERDOING QPF E OF THE
MTS...WHILE THE GFS AND NAM ARE MORE REALISTIC IN DEPICTING
MOSTLY DRY CONDITIONS FOR THE PLAINS BUT PLENTY OF MOISTURE
FOR THE MTN AREAS. TEMPS WILL START TO MODERATE FOR MOST OF OUR
CWA AND SHOULD BE CLOSE TO AVERAGE.
THE LATEST GFS HAS A STRONGER OR MORE AMPLIFIED NRN TROUGH...AND
ALSO SHOWS BETTER PHASING WITH THE CA CUT-OFF LOW. IT ALSO HINTS
AT AT LEAST A POTENTIAL MOISTURE TAP FROM A TROPICAL SYSTEM THAT
WILL BE MOVING NWD...WELL OFF OF THE BAJA PENINSULA. THE EC HAS A
WEAKER NRN SYSTEM AND RETROGRADES THE UPPER LOW AND TROPICAL
SYSTEM OFF THE CA COAST...WITH LESS OF A MOISTURE FLUX INTO CO.
BASED ON THE PATTERN AND ENSEMBLE TRENDS...IT APPEARS LIKELY THAT
AN AMPLIFIED PACIFIC SYSTEM WILL MOVE INTO THE NRN ROCKIES FOR THE
LATTER PART OF NEXT WEEK INTO NEXT WEEKEND. HAVE BOOSTED POPS FROM
WED ONWARD BY 5-10 PERCENT TO ACCOUNT FOR THAT LIKELIHOOD...AND
LATER SHIFTS MAY HAVE TO CONTINUE THAT TREND IF THE DEEPER SYSTEM
ENDS UP LOOKING MORE LIKELY. WILL HAVE TO KEEP A CLOSE EYE ON
TRENDS...SINCE THE LONG RANGE GFS HINTS AT SIGNIFICANT RAINFALL
POSSIBLE ON THE BACKSIDE OF THIS NRN BRANCH SYSTEM...BY THE LAST
WEEK IN AUGUST. ROSE
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 252 PM MDT SUN AUG 17 2014
EXPECTING VFR CONDITIONS AT KCOS...KPUB AND KALS TONIGHT THROUGH
MONDAY AFTERNOON. SOME TSTMS MAY MOVE INTO THE VCNTY OF THE
TERMINAL SITES THIS EVENING WITH GUSTY WINDS BEING THE MAIN THREAT.
ON MONDAY...GENERALLY AFTER 20Z THERE MAY AGAIN BE SOME TSTMS IN THE
VCNTY OF THE TERMINAL SITES.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...28
LONG TERM...ROSE
AVIATION...28
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1122 PM MDT SAT AUG 16 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 236 PM MDT SAT AUG 16 2014
AN UPR RIDGE WL REMAIN CENTERED OVR NORTHERN AZ TONIGHT AND
SUNDAY. THIS AFTERNOON...WV SATELLITE IMAGERY SHOWING DRIER AIR
PUSHING EASTWARD ACRS THE STATE. HOWEVER THERE IS STILL ENOUGH
MSTR OUT THERE...THAT WITH THE AFTERNOON INSTABILITY...ISOLATED
SHOWERS/TSTMS HAVE DEVELOPED OVR THE SERN PLAINS WHERE THE MSTR IS
A LITTLE BETTER...AND ISOLATED TO SCATTERED CONVECTION HAS
DEVELOPED OVR THE MTNS. WILL KEEP ISOLD TO SCT SHOWERS/TSTMS IN
THE FORECAST ACRS THE AREA THRU THE EVENING HOURS...THEN SHOULD
SEE DECREASING PCPN CHANCES AFTER SUNSET. THE RAP AND HRRR SHOW
ALL PCPN ENDING BY MIDNIGHT. THE NAM KEEPS SOME PCPN GOING ACRS
MAINLY THE SEN PLAINS INTO THE LATE NIGHT. FOR NOW HAVE DECIDED TO
GO WITH RAP AND HRRR AND END ALL PCPN BY MIDNIGHT IN THE FORECAST.
THE NAM SHOWS SLIGHTLY LOWER PRECIPITABLE WATER VALUES ACRS THE
FORECAST AREA ON SUN...BUT THERE WL STILL BE ENOUGH MSTR AND
INSTABILITY FOR SHOWERS AND TSTMS TO DEVELOP. IT SHOULD START OVR
THE MTNS IN THE LATE MORNING/EARLY AFTERNOON HOURS WITH ISOLD TO SCT
COVERAGE IN THE AFTERNOON AND EVENING HOURS. SOME ISOLATED
SHOWERS/STORMS SHOULD DEVELOP OVR THE SERN PLAINS IN THE AFTERNOON
AS WELL. HIGH TEMPS ON SUN WL AGAIN BE A LITTLE ABOVE AVERAGE.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 236 PM MDT SAT AUG 16 2014
...MONSOON CONTINUES THROUGH NEXT WEEK...
THE TYPICAL SUMMER MONSOON WE HAVE BEEN DEALING WITH LOOKS
TO CONTINUE THROUGH NEXT WEEK. THE UPPER HIGH TO OUR SW WILL
SHIFT INTO ERN OK/TX AS A TROUGH OVER THE PACNW ADVANCES
EWD...AND THIS WILL KEEP A STEADY STREAM OF SUBTROPICAL
MOISTURE OVER OUR AREA.
SUN NIGHT...MODELS HAVE BEEN VERY CONSISTENT IN DEVELOPING
A LINE/CLUSTER OF STORMS OVER E-CENTRAL CO BY EARLY EVENING
IN A WEAK BAROCLINIC ZONE. THIS MCS WILL SHIFT SLOWLY SWD
DURING THE EVENING. EXPECT THE HEAVIEST QPF TO BE OVER ERN
AL PASO AND KIOWA COUNTIES. SHOULD CLEAR OUT AFTER MIDNIGHT.
MONDAY...WEAK UPSLOPE WILL PROVIDE AN EXTRA TRIGGER FOR MORE
PM STORMS...PROBABLY A BIT MORE COVERAGE OVER THE PLAINS THAN ON
PRECEDING DAYS. IT WILL BE ANOTHER VERY WARM DAY WITH SOME
MID 90S OVER THE HOT SPOTS ON THE PLAINS.
BY TUESDAY...WILL START TO SEE INCREASING MOISTURE MOVE NWD OVER
WRN CO AS A CUTTOFF DROPS ACROSS THE SRN CA COAST AND THE PACNW
TROUGH BEGINS MOVING INLAND. STILL SOME UNCERTAINTY ON HOW WELL
THE CUTOFF WILL PHASE WITH THE NRN JET BRANCH...AND THIS WILL
AFFECT HOW MUCH RAIN TO EXPECT OVER OUR AREA NEXT WEEK INTO NEXT
WEEKEND. HOWEVER...IT APPEARS LIKELY THAT THERE WILL BE
INCREASING SRLY FLOW AHEAD OF THE PACNW TROUGH...WHICH WILL LEAD
TO INCREASING HEAVY RAIN CONCERNS FOR THE CENTRAL MTS/CONTDVD TUE-
WED...AND THEN THE ERN RANGES AND POSSIBLY PLAINS BY LATE IN THE
WEEK. IF THE CUTOFF GETS PICKED UP SOONER BY THE ADVANCING
TROUGH...WE COULD SEE ENHANCED PRECIP OVER OUR WHOLE CWA. THE
LATEST 12Z ECMWF IS MUCH MORE AGGRESSIVE WITH PHASING THE LOW AND
PACNW TROUGH...AND WOULD BRING SIGNIFICANT PRECIP TO OUR AREA FOR
THE LATTER PART OF THE WEEK. FOR NOW...WILL STAY THE COURSE WITH
CONSERVATIVE LOW POPS FOR THE PLAINS AND TYPICAL SCT/CHANCE POPS
FOR THE MTS. WILL HAVE TO SEE HOW THINGS GO OVER THE NEXT COUPLE
OF DAYS...BUT IT BEARS WATCHING FOR THE POTENTIAL OF MORE
FLOODING...PARTICULARLY FOR THE MTS. ROSE
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1116 PM MDT SAT AUG 16 2014
VFR CONDITIONS ALL TAF SITES TONIGHT AND THROUGH THE DAY SUNDAY.
ISOLATED TSRA WILL DEVELOP OVER THE MOUNTAINS BUT DOUBTFUL THEY
WILL SURVIVE LONG ENOUGH TO REACH KPUB OR KALS. MAY SEE A FEW TSRA
ALONG THE PALMER DIVIDE AND EASTWARD TOWARD KLIC SUN
AFTERNOON...AND WHILE NO VCTS MENTION IN THE KCOS TAF YET...STORMS
MAY BE JUST NORTH OF KCOS FOR A BRIEF TIME AROUND 00Z.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...28
LONG TERM...ROSE
AVIATION...PETERSEN
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
936 PM EDT MON AUG 18 2014
.UPDATE...
HAVE MADE SEVERAL CHANGES TO POPS THROUGH THE EVENING TO ACCOUNT
FOR TRENDS. MOST CONVECTION IS DYING OFF NOW...WITH ONLY LIGHT
RAIN REMAINING...BUT THE LEFTOVER MISSISSIPPI VALLEY MCV IS
WORKING ITS WAY ACROSS NORTHERN ALABAMA AT AFD TIME AND SHOULD
PUSH INTO NORTH GEORGIA IN THE NEXT FEW HOURS. AGAIN HAVE TRIED TO
ADJUST POPS TO ACCOUNT FOR THIS. AIRMASS IS PRETTY STABLE BEHIND
CONVECTION THIS EVENING SO THINK SEVERE POTENTIAL WITH ANY MCV
CONVECTION WOULD BE PRETTY LOW...HEAVY RAIN WOULD BE THE MORE
SIGNIFICANT THREAT.
UPDATED PRODUCTS OUT SHORTLY.
TDP
&&
.PREV DISCUSSION... /ISSUED 750 PM EDT MON AUG 18 2014/
PREV DISCUSSION... /ISSUED 320 PM EDT MON AUG 18 2014/
SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
STALLED FRONTAL BOUNDARY STRETCHES FROM THE TN VALLEY TO THE
SOUTHERN MID ATLANTIC STATES. A HIGH PRESSURE RIDGE IS SITUATED
ACROSS NORTHERN FL. 500MB ANALYSIS AND WV LOOP SHOWS A POTENT
SHORTWAVE MOVING EAST ACROSS NORTHERN MS. THIS FEATURE WILL BE THE
FOCUS FOR LATE AFTERNOON AND EVENING CONVECTION ACROSS THE CWFA.
THE 16Z HRRR HAS THE BEST HANDLE ON THE ONGOING CONVECTION THIS
AFTERNOON. HAVE TRIED TO ORIENT THE POPS ACCORDING TO CURRENT RADAR
TRENDS AND CLOSE TO THE HRRR SOLUTION. GOOD INSTABILITY DOES EXIST
AT THE SURFACE...BUT LAPSE RATES REMAIN POOR UNTIL THE COLD POOL
ALOFT MOVES OVERHEAD. BY THE TIME THE SHORTWAVE NEARS THE
CWFA...INSTABILITY HAS DECREASED WITH THE LOSS OF HEATING.
HOWEVER...WITH UNIDIRECTIONAL FLOW...STORMS MAY MOVE REPEATEDLY OVER
THE SAME AREAS...WITH LOCALLY HEAVY RAINFALL POSSIBLE. AREAS TO THE
NORTH RECEIVED ONE TO TWO INCHES OF RAINFALL OVERNIGHT/EARLY THIS
MORNING...SO ANY TRAINING STORMS OR HEAVY RAINFALL MAY CAUSE SOME
LOCALIZED FLOODING.
BY EARLY TUESDAY...THE POTENT EVENING/OVERNIGHT SHORTWAVE WILL HAVE
MOVED OFF TO THE EAST. MODELS ARE PROGGING ANOTHER...WEAKER...
SHORTWAVE TO MOVE EAST IN THE FLOW TOMORROW. CONFIDENCE IS LOW ON
EXACTLY WHERE CONVECTION WILL DEVELOP TOMORROW.
NLISTEMAA
LONG TERM /WEDNESDAY THROUGH MONDAY/...
LONG TERM FORECAST IS ON TRACK AND HAVE NOT MADE SIGNIFICANT
ADJUSTMENTS. ONE ADDITIONAL POINT TO NOTE IS THAT HEAT INDEX VALUES
ARE CREEPING ABOVE 100 DEGREES SOUTH OF AN ATLANTA TO ATHENS
LINE...WITH PORTIONS OF CENTRAL GEORGIA APPROACHING 105 DEGREES
DURING THE SECOND HALF OF THE WEEK. IF THIS TREND CONTINUES...MAY
NEED A HEAT ADVISORY FOR THESE 105-108 DEGREE VALUES ACROSS THE
SOUTHEAST PART OF THE CWA.
11/ATWELL
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
00Z GFS AND ECMWF ARE IN UNCOMMONLY GOOD AGREEMENT THROUGH THE
EXTENDED FORECAST PERIOD AND CONTINUE THE RECENT TREND OF BUILDING
UPPER-LEVEL HIGH PRESSURE INTO THE CENTRAL GULF COAST REGION AND
LOWER MISSISSIPPI VALLEY FROM MID-WEEK THROUGH NEXT WEEKEND. BY THE
WEEKEND THE UPPER RIDGE IS QUITE STRONG...BUT GEORGIA REMAINS ON THE
EASTERN PERIPHERY. THIS SHOULD ALLOW VERY WARM TEMPERATURES AND
INHIBIT DIURNAL CONVECTION SOMEWHAT...BUT I DO NOT BELIEVE THE
FORECAST AREA IS CLOSE ENOUGH TO THE CENTER OF THE RIDGE TO
ELIMINATE POPS ALTOGETHER.
20
AVIATION...
00Z UPDATE...
AREA OF TSRA AFFECTING MOST TAF SITES THIS EVENING...THOUGH SHOULD
SEE A DIMINISHING TREND OVER THE NEXT FEW HOURS. EXPECT TO SEE
MVFR CIGS DEVELOP OVERNIGHT AND CANNOT RULE OUT BRIEF IFR CIGS.
CLEARING TOMORROW MORNING BUT HAVE INCLUDED PROB30 DURING THE
AFTERNOON TO COVER CHANCE OF CONVECTION. WINDS W THROUGH THE
PERIOD GENERALLY BETWEEN 5-10KT THOUGH VRB AND GUSTY IN TSRA THIS
EVENING...AND LOW END GUSTS TUESDAY.
//ATL CONFIDENCE...00Z UPDATE...
HIGH ON CONVECTION TONIGHT...MEDIUM ON TIMING OF CLEARING.
MEDIUM ON EARLY MORNING CIGS...LOW ON POTENTIAL IFR DEVELOPMENT.
HIGH ON ALL OTHER ELEMENTS.
TDP
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 71 91 72 97 / 60 40 30 10
ATLANTA 72 88 73 94 / 60 40 30 10
BLAIRSVILLE 66 84 67 90 / 60 40 30 20
CARTERSVILLE 70 89 71 94 / 60 40 30 10
COLUMBUS 72 92 73 96 / 60 40 30 10
GAINESVILLE 70 89 71 94 / 60 40 30 10
MACON 72 92 72 97 / 60 40 30 10
ROME 70 89 71 95 / 60 40 30 20
PEACHTREE CITY 71 89 71 94 / 60 40 30 10
VIDALIA 74 95 74 97 / 40 40 30 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
750 PM EDT MON AUG 18 2014
.PREV DISCUSSION... /ISSUED 320 PM EDT MON AUG 18 2014/
SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
STALLED FRONTAL BOUNDARY STRETCHES FROM THE TN VALLEY TO THE
SOUTHERN MID ATLANTIC STATES. A HIGH PRESSURE RIDGE IS SITUATED
ACROSS NORTHERN FL. 500MB ANALYSIS AND WV LOOP SHOWS A POTENT
SHORTWAVE MOVING EAST ACROSS NORTHERN MS. THIS FEATURE WILL BE THE
FOCUS FOR LATE AFTERNOON AND EVENING CONVECTION ACROSS THE CWFA.
THE 16Z HRRR HAS THE BEST HANDLE ON THE ONGOING CONVECTION THIS
AFTERNOON. HAVE TRIED TO ORIENT THE POPS ACCORDING TO CURRENT RADAR
TRENDS AND CLOSE TO THE HRRR SOLUTION. GOOD INSTABILITY DOES EXIST
AT THE SURFACE...BUT LAPSE RATES REMAIN POOR UNTIL THE COLD POOL
ALOFT MOVES OVERHEAD. BY THE TIME THE SHORTWAVE NEARS THE
CWFA...INSTABILITY HAS DECREASED WITH THE LOSS OF HEATING.
HOWEVER...WITH UNIDIRECTIONAL FLOW...STORMS MAY MOVE REPEATEDLY OVER
THE SAME AREAS...WITH LOCALLY HEAVY RAINFALL POSSIBLE. AREAS TO THE
NORTH RECEIVED ONE TO TWO INCHES OF RAINFALL OVERNIGHT/EARLY THIS
MORNING...SO ANY TRAINING STORMS OR HEAVY RAINFALL MAY CAUSE SOME
LOCALIZED FLOODING.
BY EARLY TUESDAY...THE POTENT EVENING/OVERNIGHT SHORTWAVE WILL HAVE
MOVED OFF TO THE EAST. MODELS ARE PROGGING ANOTHER...WEAKER...
SHORTWAVE TO MOVE EAST IN THE FLOW TOMORROW. CONFIDENCE IS LOW ON
EXACTLY WHERE CONVECTION WILL DEVELOP TOMORROW.
NLISTEMAA
LONG TERM /WEDNESDAY THROUGH MONDAY/...
LONG TERM FORECAST IS ON TRACK AND HAVE NOT MADE SIGNIFICANT
ADJUSTMENTS. ONE ADDITIONAL POINT TO NOTE IS THAT HEAT INDEX VALUES
ARE CREEPING ABOVE 100 DEGREES SOUTH OF AN ATLANTA TO ATHENS
LINE...WITH PORTIONS OF CENTRAL GEORGIA APPROACHING 105 DEGREES
DURING THE SECOND HALF OF THE WEEK. IF THIS TREND CONTINUES...MAY
NEED A HEAT ADVISORY FOR THESE 105-108 DEGREE VALUES ACROSS THE
SOUTHEAST PART OF THE CWA.
11/ATWELL
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
00Z GFS AND ECMWF ARE IN UNCOMMONLY GOOD AGREEMENT THROUGH THE
EXTENDED FORECAST PERIOD AND CONTINUE THE RECENT TREND OF BUILDING
UPPER-LEVEL HIGH PRESSURE INTO THE CENTRAL GULF COAST REGION AND
LOWER MISSISSIPPI VALLEY FROM MID-WEEK THROUGH NEXT WEEKEND. BY THE
WEEKEND THE UPPER RIDGE IS QUITE STRONG...BUT GEORGIA REMAINS ON THE
EASTERN PERIPHERY. THIS SHOULD ALLOW VERY WARM TEMPERATURES AND
INHIBIT DIURNAL CONVECTION SOMEWHAT...BUT I DO NOT BELIEVE THE
FORECAST AREA IS CLOSE ENOUGH TO THE CENTER OF THE RIDGE TO
ELIMINATE POPS ALTOGETHER.
20
&&
.AVIATION...
00Z UPDATE...
AREA OF TSRA AFFECTING MOST TAF SITES THIS EVENING...THOUGH SHOULD
SEE A DIMINISHING TREND OVER THE NEXT FEW HOURS. EXPECT TO SEE
MVFR CIGS DEVELOP OVERNIGHT AND CANNOT RULE OUT BRIEF IFR CIGS.
CLEARING TOMORROW MORNING BUT HAVE INCLUDED PROB30 DURING THE
AFTERNOON TO COVER CHANCE OF CONVECTION. WINDS W THROUGH THE
PERIOD GENERALLY BETWEEN 5-10KT THOUGH VRB AND GUSTY IN TSRA THIS
EVENING...AND LOW END GUSTS TUESDAY.
//ATL CONFIDENCE...00Z UPDATE...
HIGH ON CONVECTION TONIGHT...MEDIUM ON TIMING OF CLEARING.
MEDIUM ON EARLY MORNING CIGS...LOW ON POTENTIAL IFR DEVELOPMENT.
HIGH ON ALL OTHER ELEMENTS.
TDP
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 71 91 72 97 / 50 40 30 10
ATLANTA 72 88 73 94 / 60 40 30 10
BLAIRSVILLE 67 84 67 90 / 60 40 30 20
CARTERSVILLE 70 89 71 94 / 60 40 30 10
COLUMBUS 74 92 73 96 / 60 40 30 10
GAINESVILLE 71 89 71 94 / 60 40 30 10
MACON 73 92 72 97 / 60 40 30 10
ROME 71 89 71 95 / 60 40 30 20
PEACHTREE CITY 71 89 71 94 / 60 40 30 10
VIDALIA 75 95 74 97 / 40 40 30 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
353 AM EDT SUN AUG 17 2014
.SYNOPSIS...
HIGH PRESSURE EXTENDING FROM THE ATLANTIC WESTWARD ALONG THE GULF
COAST WILL DOMINATE INTO MONDAY. THIS WILL RESULT DRY CONDITIONS WITH
SEASONABLE TEMPERATURES TODAY. A PASSING UPPER DISTURBANCE AND
INCREASING MOISTURE WILL BRING THE CHANCE FOR SHOWERS AND
THUNDERSTORMS ON MONDAY...FOLLOWED BY WARMING TEMPERATURES THROUGH
MID WEEK AS AN UPPER RIDGE BUILDS OVER THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
ZONAL WESTERLY MID LEVEL FLOW IS EXPECTED TO PERSIST TODAY ACROSS
THE CAROLINAS WHILE AN UPPER TROUGH SLIDES ACROSS NEW ENGLAND AND
OFF THE NORTHEAST COAST BY TONIGHT. AT THE SURFACE...WEAK HIGH
PRESSURE CONTINUES TO RIDGE INTO THE SOUTHEASTERN STATES FROM THE
WESTERN ATLANTIC. SOUTHWESTERLY SURFACE WINDS WILL ENSURE
WEAK MOIST WARM ADVECTION. FORECAST SOUNDINGS INDICATE LOWERING
PRECIPITABLE WATER VALUES TO BELOW 1.5 INCHES (BELOW 1.25 INCHES
ON THE NAM) AND SHOW A CAPPING INVERSION JUST BELOW 700MB...WHICH
SHOULD PREVENT DIURNAL CONVECTION THIS AFTERNOON AND EVENING.
HIGH TEMPERATURES TODAY WILL BE SLIGHTLY WARMER THAN YESTERDAY IN
THE MID 90S WITH HEAT INDICES AROUND 100 DEGREES UNDER MOSTLY
SUNNY SKIES. OVERNIGHT LOWS TONIGHT WILL FALL INTO THE LOWER 70S
UNDER AVERAGE RADIATIONAL COOLING CONDITIONS AS SOME MID LEVEL
CLOUDS MAY MOVE INTO THE ARE FROM THE WEST.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
CHANCES OF RAIN RETURN TO THE FORECAST AREA ON MONDAY AS
SHORTWAVE ENERGY MOVES ACROSS THE CENTRAL APPALACHIANS AND PVA
COINCIDES WITH MODERATE DIURNAL INSTABILITY WITH INCREASING
ATMOSPHERIC MOISTURE AS PWAT VALUES RISE TO OVER 1.75 INCHES.
INCREASED POPS TO HIGHER CHANCE ACROSS THE NORTHERN MIDLANDS
CLOSER TO THE UPPER SUPPORT WHILE MAINTAINING CHANCE POPS
ELSEWHERE MONDAY AFTERNOON INTO EARLY EVENING. TEMPERATURES WILL
AGAIN BE WARM BUT MAY BE TEMPERED A BIT BY INCREASED CLOUDINESS
WITH HIGHS IN THE LOWER TO MID 90S. ANY LINGERING CONVECTION
SHOULD DIMINISH BY MIDNIGHT TO 2AM AS SHORTWAVE ENERGY SHIFTS EAST
OF THE FORECAST AREA. OVERNIGHT LOWS MONDAY NIGHT WILL BE IMPACTED
BY LINGERING CLOUD COVER AND TEMPERATURES EXPECTED TO BE IN THE
LOWER TO MID 70S.
GENERALLY ZONAL WEST-NORTHWESTERLY MID LEVEL FLOW AGAIN SETS UP
ACROSS THE CAROLINAS FOR TUESDAY PROVIDING A WEAK DOWNSLOPING
COMPONENT TO THE LOW LEVEL FLOW. EXPECT MAINLY DIURNAL CONVECTION
WITH THE BEST CHANCES IN THE EASTERN MIDLANDS WHERE LINGERING
MOISTURE WILL BE BETTER AND THERE IS THE POSSIBILITY OF SEA BREEZE
INTERACTION. TEMPERATURES WILL REMAIN NEAR TO SLIGHTLY ABOVE
NORMAL IN THE LOWER TO MID 90S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
SOME UNCERTAINTY IN THE EXTENDED PERIODS...ESPECIALLY BY NEXT
WEEKEND.
GENERALLY ZONAL WESTERLY FLOW WILL BECOME MORE AMPLIFIED LATE IN
THE WEEK WITH DEEP TROUGHING IN THE WESTERN UNITED STATES
RESULTING IN DOWNSTREAM RIDGING OVER THE MISSISSIPPI AND TENNESSEE
VALLEY...WHILE ANOTHER TROUGH DIVES SOUTH ACROSS NEW ENGLAND INTO
THE MID-ATLANTIC. WILL MAINTAIN THE DIURNAL POPS FOR CONVECTION
WHILE TEMPERATURES ARE EXPECTED TO WARM BACK ABOVE NORMAL DURING
THIS PERIOD. MEDIUM RANGE MODELS TRENDING TOWARDS A BACK DOOR
FRONT NEXT SATURDAY BUT THE GFS IS MUCH MORE AMPLIFIED AND
AGGRESSIVE WITH THE BACKDOOR FRONT COMPARED TO THE ECMWF...AND
THEREFORE LOW CONFIDENCE AT THIS TIME.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
EXPECT MAINLY VFR CONDITIONS THROUGH MUCH OF THE TAF PERIOD...ONLY
EXCEPTION WILL BE OVERNIGHT INTO THE EARLY MORNING HOURS. ALREADY
HAVE SOME FOG THAT HAS DEVELOPED AT AGS AND EXPECT CONDITIONS THERE
TO DETERIORATE FROM TIME TO TIME. EXPECT MAINLY IFR/LIFR THROUGH
13Z...THEN IMPROVING CONDITIONS. THERE IS A VERY WEAK PRESSURE
GRADIENT ACROSS THE AREA AND WINDS OVERNIGHT WILL BE CALM/LIGHT AND
VARIABLE. NOCTURNAL COOLING AND LINGERING LOW-LEVEL MOISTURE MAY
SUPPORT STRATUS AND FOG AGAIN EARLY SUNDAY MORNING. SOME DRYING WILL
OCCUR IN THE WEST-SOUTHWEST LOW-LEVEL FLOW. HRRR INDICATES SOME FOG
AND ESPECIALLY STRATUS DEVELOPING THROUGH THE EARLY MORNING HOURS
ALONG THE SAVANNAH RIVER VALLEY. HAVE ALSO INCLUDED A TEMPO GROUP
FOR SOME MVFR CONDITIONS AT OGB/CAE/CUB BUT NOT DNL THROUGH 13Z.
DURING THE DAY...EXPECT VFR CONDITIONS WITH WINDS BECOMING SW TO W
THROUGH THE AFTERNOON AND RANGING FROM 5 TO 8 KNOTS. THE ATMOSPHERE
LOOKS TO BE CAPPED AND IF ANY CONVECTION DEVELOPS EXPECT IT TO BE
ISOLATED.
EXTENDED AVIATION OUTLOOK...MVFR OR IFR CONDITIONS POSSIBLE IN LATE
NIGHT AND EARLY MORNING FOG THROUGH THE PERIOD. A SLIGHTLY BETTER
CHANCE OF SCATTERED AFTERNOON AND EVENING THUNDERSTORMS MAY ALSO
BRING RESTRICTIONS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
142 AM EDT SUN AUG 17 2014
.SYNOPSIS...
HIGH PRESSURE EXTENDING FROM THE ATLANTIC WESTWARD ALONG THE GULF
COAST WILL DOMINATE THROUGH MONDAY. THIS FEATURE WILL KEEP THE
FORECAST AREA MAINLY DRY WITH SEASONABLE TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
THE SURFACE RIDGE TO OUR SOUTH WILL CONTINUE TO DOMINATE. THE
TEMPERATURE GUIDANCE WAS CONSISTENT. LINGERING LOW- LEVEL MOISTURE
UNDER THE NOCTURNAL INVERSION MAY SUPPORT FOG. THE MODELS INDICATE
DRYING WITH THE WESTERLY COMPONENT TO THE LOW- LEVEL FLOW SO FOG
WILL LIKELY NOT BE AS EXTENSIVE AS WHAT OCCURRED LAST NIGHT.
EXPECT PATCHY FOG.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
A DRY FORECAST IS ON TAP THROUGH SUNDAY AND SUNDAY NIGHT WITH
TEMPERATURES SUNDAY AFTERNOON A LITTLE ABOVE NORMAL IN THE MID
90S.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
ZONAL UPPER LEVEL FLOW ON MONDAY SLOWLY EVOLVES INTO NW FLOW ALOFT
BY THE END OF THE WEEK AS A RIDGE OF HIGH PRESSURE BUILDS JUST TO
OUR WEST. LOW LEVEL MOISTURE FLUX IS FROM THE WEST TO NORTHWEST
THROUGH THE PERIOD SO NOT A LOT OF MOISTURE TO SUPPORT
PRECIPITATION. MODELS INDICATE AN UPPER WAVE MOVING EAST OVER THE
AREA MONDAY AFTERNOON INTO TUESDAY WHICH MAY BE A FORCING
MECHANISM FOR CONVECTION. POPS ARE GENERALLY 10 TO 20 PERCENT AT
NIGHT AND 20 TO 30 PERCENT DURING THE DAY. TEMPS ABOVE NORMAL WITH
BUILDING RIDGE AND INSTABILITY MAY SUPPORT WIDELY SCATTERED MAINLY
DIURNAL CONVECTION. GFS SHOWS BACK DOOR FRONT NEXT SATURDAY BUT
THAT IS STILL A WAYS OFF.
&&
.AVIATION /06Z SUNDAY THROUGH FRIDAY/...
EXPECT MAINLY VFR CONDITIONS THROUGH MUCH OF THE TAF PERIOD...ONLY
EXCEPTION WILL BE OVERNIGHT INTO THE EARLY MORNING HOURS. ALREADY
HAVE SOME FOG THAT HAS DEVELOPED AT AGS AND EXPECT CONDITIONS THERE
TO DETERIORATE FROM TIME TO TIME. EXPECT MAINLY IFR/LIFR THROUGH
13Z...THEN IMPROVING CONDITIONS. THERE IS A VERY WEAK PRESSURE
GRADIENT ACROSS THE AREA AND WINDS OVERNIGHT WILL BE CALM/LIGHT AND
VARIABLE. NOCTURNAL COOLING AND LINGERING LOW-LEVEL MOISTURE MAY
SUPPORT STRATUS AND FOG AGAIN EARLY SUNDAY MORNING. SOME DRYING WILL
OCCUR IN THE WEST-SOUTHWEST LOW-LEVEL FLOW. HRRR INDICATES SOME FOG
AND ESPECIALLY STRATUS DEVELOPING THROUGH THE EARLY MORNING HOURS
ALONG THE SAVANNAH RIVER VALLEY. HAVE ALSO INCLUDED A TEMPO GROUP
FOR SOME MVFR CONDITIONS AT OGB/CAE/CUB BUT NOT DNL THROUGH 13Z.
DURING THE DAY...EXPECT VFR CONDITIONS WITH WINDS BECOMING SW TO W
THROUGH THE AFTERNOON AND RANGING FROM 5 TO 8 KNOTS. THE ATMOSPHERE
LOOKS TO BE CAPPED AND IF ANY CONVECTION DEVELOPS EXPECT IT TO BE
ISOLATED.
EXTENDED AVIATION OUTLOOK...MVFR OR IFR CONDITIONS POSSIBLE IN LATE
NIGHT AND EARLY MORNING FOG THROUGH THE PERIOD. A SLIGHTLY BETTER
CHANCE OF SCATTERED AFTERNOON AND EVENING THUNDERSTORMS MAY ALSO
BRING RESTRICTIONS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS POCATELLO ID
542 PM MDT MON AUG 18 2014
.UPDATE...
UPDATED EVENING FORECAST TO MENTION ISOLATED TO SCATTERED
THUNDERSTORMS ACROSS THE UPPER SNAKE PLAIN BASED UPON RADAR
TRENDS. MUCH OF THE ACTIVITY SHOULD DIMINISH AFTER SUNSET.
VALLE
&&
.PREV DISCUSSION... /ISSUED 144 PM MDT MON AUG 18 2014/
DISCUSSION...CENTER OF UPPER LOW OVER NORTHERN CALIFORNIA PER WV
IMAGERY. MOISTURE PULLING NORTH THROUGH NEVADA AND NORTHERN
ARIZONA THROUGH GREAT BASIN TOWARD EASTERN IDAHO. PAIR OF WEAK
SHORTWAVES MOVING THROUGH EAST IDAHO...ONE ALONG DIVIDE AND
ANOTHER ALONG SOUTHERN BORDER. SOME MOISTURE IN PLACE ALREADY AND
CONVECTION HAS BEGUN TO REDEVELOP ALREADY EARLY THIS AFTERNOON
ALONG/AHEAD OF SHORTWAVES. NAM/RAP SEEMS TO HAVE BEST HANDLE ON
CONVECTIVE THREAT THIS AFTERNOON AND EVENING WHILE HRRR STRUGGLING
TO CATCH UP. BOTH NAM/GFS CONTINUE CONVECTION OVERNIGHT INTO EARLY
TUESDAY BUT CONVECTION BLOOMS DURING THE AFTERNOON AS MID LEVEL
MONSOON FLOW REACHES EAST IDAHO. HAVE NUDGED POPS UPWARD TUESDAY
ALL AREAS. SOME DIFFERENCES IN MODELS AS NAM STRONGER WITH
SHORTWAVE EJECTING OUT OF EAST IDAHO TUESDAY NIGHT. DIFFERENCES
AMPLIFY THROUGH THURSDAY WITH NAM A BIT FURTHER SOUTH WITH BASE OF
TROUGH. GFS HOLDS EAST IDAHO IN NEUTRAL FLOW ALOFT WITH SOUTHERN
CUT OFF LOW FURTHER NORTH THAN THE NAM. BOTH MODELS REMAIN
UNSETTLED WITH PLENTY OF MOISTURE IN PLACE TO CONTINUE THREAT OF
SCATTERED THUNDERSTORMS ACROSS THE REGION. SHORTWAVE ROUNDS TROUGH
WEDNESDAY NIGHT INTO THURSDAY FOR ANOTHER WET DAY MOST AREAS WITH
EASTERN IDAHO JUST AHEAD OF MAIN TROUGH AXIS. BOTH MODELS
PRODUCING MORE WIDESPREAD CONVECTIVE COVERAGE SO NUDGED POPS
UPWARD AGAIN FOR THURSDAY AFTERNOON/EVENING.
ECMWF AND GFS AGAIN DIFFERING IN DETAILS FOR REMAINDER OF FORECAST.
ECMWF LOOKING AGAIN TO DROP CLOSED SHORTWAVE INTO BASE OF BROAD
PACNW TROUGH THURSDAY NIGHT INTO FRIDAY BUT THEN OPENS IT UP AGAIN
FRIDAY NIGHT. PLACEMENT/DEPTH OF TROUGH SIMILAR WITH HINTS OF DRY
SLOT WORKING IN FROM OREGON FRIDAY INTO SATURDAY. BOTH MODELS
TREAT NORTHERN PACIFIC ENERGY A LITTLE DIFFERENTLY. EAST IDAHO
UNDER SOME INFLUENCE OF BASE OF TROUGH...BUT FLOW RANGES FROM
WEST/DRY IN THE GFS TO NORTHWEST/MOIST IN THE ECMWF. OVERALL OPTED
TO MAKE NO CHANGES TO CURRENT EXTENDED RANGE WITH ISOLATED POPS
CLOSE TO CLIMO AND TEMPS NEAR GUIDANCE BLEND. DMH
AVIATION...SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH TOMORROW
ACROSS EASTERN IDAHO. COVERAGE WILL BE ISOLATED TODAY BECOMING
CLOSER TO SCATTERED IN SOME AREAS ON TUESDAY. GUSTY WINDS OVER 30KTS
ARE POSSIBLE WITH STORMS...WITH AN INCREASING THREAT OF HEAVY
DOWNPOURS TONIGHT AND TUESDAY. EITHER COULD BRING REDUCED
VISIBILITY. WE WILL BE CARRYING AT LEAST VCTS OR VCSH FOR ALL SITES.
KEYES
FIRE WEATHER...SHOWERS AND STORMS WILL CONTINUE TO INCREASE ACROSS
EASTERN IDAHO THROUGH THE NEXT 24 HOURS. THUNDERSTORM COVERAGE WILL
BE ISOLATED TODAY AND WIDELY SCATTERED TOMORROW. THE SOUTHEAST
CORNER WILL BE INTERESTING TO WATCH AS THEY MAY BE TOO STABLE TO SEE
ANY THUNDER AT ALL IF CLOUDS AND TIMING MATCH UP. STORMS WILL BE
CAPABLE OF PRODUCING WIND GUSTS OVER 35 MPH AND LOCALLY HEAVY
DOWNPOURS. WE ARE NOT EXPECTING ANY ISSUES WITH SLIDES OR FLOODING
THIS TIME AROUND. ISOLATED TO WIDELY SCATTERED THUNDERSTORMS WILL
CONTINUE THROUGH THE END OF THE WEEK AS THE LOW OUT OF CANADA SAGS
SOUTH INTO THE NORTHERN STATES. THE BETTER CHANCES WEDNESDAY-FRIDAY
WILL BE ACROSS THE NORTH AND ALONG THE WYOMING BORDER. DRIER
CONDITIONS WILL FILTER INTO PORTIONS OF THE SNAKE PLAIN AND
SOUTH-CENTRAL HIGHLANDS...HELPING TO REDUCE SHOWERS/STORMS. WE WILL
ALSO SEE THE WIND PICKING UP...BUT INCREASED HUMIDITY SHOULD NEGATE
THIS AND PREVENT ANY ISSUES WITH CRITICAL FIRE CONDITIONS. THE
MODELS CONTINUE TO SHOW WIDELY VARYING FORECASTS EACH DAY IN THE
EXTENDED...BUT ONE TREND IS EMERGING DESPITE ALL OF THIS. IT DOES
APPEAR FOR THE WEEKEND AND EARLY NEXT WEEK...WE SHOULD BR PRETTY DRY
BUT BREEZY ACROSS THE SOUTH AND SNAKE PLAIN. WE SLOWLY TRENDED THAT
DIRECTION WITH THE FORECAST WHERE IT WAS NEEDED...BUT NOT COMPLETELY
TO THAT END OF THE SPECTRUM. KEYES
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
959 PM CDT MON AUG 18 2014
.DISCUSSION...
650 PM...EARLY EVENING UPDATE...CONVECTION FIRING ACROSS CENTRAL
WI WILL CONTINUE THIS EVENING WITH ADDITIONAL THUNDERSTORMS
RAPIDLY DEVELOPING OVER FAR NORTHERN IA AND SOUTHERN MN. THIS
ACTIVITY WILL SLOWLY SAG SOUTH BUT PROBABLY NOT REACH NORTHERN IL
UNTIL AFTER 04Z-05Z. ACTIVITY WILL THEN SPREAD SOUTHEAST ACROSS
MAINLY THE NORTHERN TWO THIRDS OF THE CWA OVERNIGHT. SHORT TERM/
HI RES GUIDANCE IS IN FAIR AGREEMENT WITH MUCH OF THE AREA NOW
STAYING DRY THROUGH MIDNIGHT. HAVE UPDATED GRIDS/ZFP FOR THESE
TRENDS ALONG WITH MOSTLY CLEAR SKIES OVER MUCH OF THE AREA AS CU
FIELD DISSIPATES...THOUGH HIGH CLOUDS WILL LIKELY QUICKLY SPREAD
ACROSS THE AREA LATER THIS EVENING AS STORMS APPROACH. NO CHANGES
TO LIKELY POPS OVERNIGHT THOUGH POPS MAY NEED TO BE LOWERED ACROSS
THE FAR SOUTH AS TRENDS EMERGE. CMS
//PREV DISCUSSION...
239 PM CDT
SYNOPSIS...A WARMER AND NOTICEABLY MORE HUMID PATTERN WILL BE
DEVELOPING THROUGH MID WEEK. IN ADDITION TO THE WARMTH AN EVOLVING
UPPER AIR PATTERN WILL BRING PERIODIC CHANCES FOR SHOWERS AND
THUNDERSTORMS THROUGH THE WEEKEND. HIGH TEMPERATURES LATER IN THE
WEEK MAY BE DICTATED BY THE CONVECTION.
TONIGHT...
A LOW PRESSURE TROUGH IS OVER MINNESOTA AND IT WILL BECOME A CLOSED
LOW OVER WISCONSIN AND LAKE SUPERIOR TUESDAY EVENING. AT THE
SURFACE THERE IS A LOW PRESSURE TROUGH OVER MINNESOTA THAT WILL
BECOME A CLOSED LOW OVER WISCONSIN TOMORROW MORNING. THE LOW WILL
PUSH EAST OF THE LAKE WEDNESDAY.
EXPECTING THE FIRST ROUND OF STORMS TO MOVE INTO THE RFD AREA THIS
EVENING WITH THE MAJORITY OF CONVECTIVE ACTIVITY REMAINING OVER
WISCONSIN CLOSER TO THE LOW. THE FIRST WAVE WILL WEAKEN AS IT
PUSHES EAST. A SECOND WAVE FORMS AHEAD OF A VORT STREAMER OVERNIGHT
AND THINKING THIS WILL BE THE MAIN SHOW TONIGHT. EXPECTING ACTIVITY
TO REMAIN NORTH OF I-80 MOST OF THE NIGHT. ACTIVITY WILL THEN SPREAD
SOUTH AND EAST COVERING AREAS EAST OF I-39 EARLY TUESDAY MORNING.
THIS ACTIVITY WILL WEAKEN THROUGH THE MORNING AND CONTINUE SOUTHEAST
OUT OF THE WARNING AREA.
THE FIRST CONCERN OVERNIGHT IS HEAVY RAIN AS PWAT VALUES WILL BE
BETWEEN 1.5 AND 1.75 INCHES. CAPE VALUES WILL BE AROUND 1000 J/KG
THIS EVENING AND THEN DIMINISH OVERNIGHT. SHEAR VALUES ARE 20-30 KT
SO SEVERE WEATHER IS NOT EXPECTED...BUT SMALL HAIL MAY OCCUR WITH
THE STRONGEST STORMS. STEERING LEVEL FLOW IS ALSO WEAK SO STORMS
WILL BE SLOW MOVING WHICH COULD ENHANCE RAINFALL TOTALS.
THE OTHER CONCERN IS FOG TONIGHT. IF WE CLEAR OUT AT ALL EXPECTING
AREAS OF DENSE FOG TO DEVELOP. HAVE MEDIUM CONFIDENCE IN SKY COVER
SO ONLY HAVE PATCHY FOG IN THE FORECAST TONIGHT AFTER MIDNIGHT.
TUESDAY AND TUESDAY NIGHT...
MORE STORMS ARE EXPECTED AS THE LOW SHIFTS EAST OVER WISCONSIN.
EXPECTING FOG/LOW STRATUS/GENERAL CLOUD COVER TO THIN TUESDAY
MORNING. HEATING WILL RESULT IN DECENT CAPE VALUES. THE MOISTURE
RICH NAM FEATURES THE HIGHEST CAPE VALUES AROUND 3000 J/KG BUT THE
MORE CONSERVATIVE GFS ONLY SHOWS LESS THAN 1000 J/KG. SHEAR VALUES
STILL LOOK MARGINAL AROUND 35 KT. BUT PWAT VALUES WILL BE A BIT
LOWER AT 1.3 TO 1.5 INCHES. HEAVY RAIN IS STILL POSSIBLE BUT STORMS
SHOULD BE MOVING AT A BETTER PACE WITH STRONGER STEERING LEVEL
FLOW. THE FORCING WILL BE A COMBO OF THE LOWS FRONT THAT MOVES
THROUGH IN THE LATE AFTN/EVENING AND VORTICITY STREAMERS THAT ROTATE
AROUND THE LOW. HAVE MEDIUM CONFIDENCE IN WIDESPREAD TS
COVERAGE...BUT KEPT POPS IN THE CHANCE RANGE DUE TO LOW CONFIDENCE
IN WHEN AND WHERE STORMS WILL DEVELOP. HAIL AND STRONG WINDS ARE
POSSIBLE IN ADDITION TO THE HEAVY DOWNPOURS.
TEMPS REMAIN A CHALLENGE AS WE COULD BE WARMER IF SKY COVER IS ON
THE WEAKER SIDE. HOWEVER...HAVE MEDIUM CONFIDENCE IN WIDESPREAD TS
COVERAGE SO KEPT HIGH TEMPS IN THE LOW TO MID 80S.
JEE
WEDNESDAY THROUGH SUNDAY...
THE UPPER LOW OVER THE UPPER GREAT LAKES WILL START TO MOVE MORE
QUICKLY TO THE NORTHEAST WEDNESDAY MORNING AS NORTHERN PACIFIC
TROUGHING PUSHES INLAND OVER WESTERN CANADA. THIS HELPS TO PUSH
CUTOFF LOW PRESSURE ONTO THE CALIFORNIA COAST WITH BOTH OF THESE
FEATURES HELPING TO DRIVE UPPER RIDGE DEVELOPMENT OVER THE HIGH
PLAINS. THE LOCAL AREA WILL BE BETWEEN THE DEPARTING UPPER LOW AND
THE APPROACHING RIDGE WEDNESDAY MORNING WITH WEAK LOW LEVEL FLOW
IN PLACE AS WELL. THIS SHOULD RESULT IN DRY WEATHER FOR MUCH OF
WEDNESDAY BEFORE MID LEVEL BAROCLINICITY INCREASES LATE IN THE DAY
AND MORE SO IN THE EVENING AS THE RIDGE APPROACHES. PRECIPITABLE
WATER VALUES WILL INCREASE MARKEDLY WITH THE ARRIVAL OF THE MID
LEVEL WARM ADVECTION LEADING TO MOIST ASCENT WEDNESDAY EVENING AND
WEDNESDAY NIGHT. THIS LIFT ALONE MAY BE ENOUGH TO PRODUCE SHOWERS
AND THUNDERSTORMS AND MAY BE AIDED BY THE PASSAGE OF AN UPPER WAVE
WHICH GUIDANCE HAS BEEN HINTING AT. THIS IS CERTAINLY PLAUSIBLE
GIVEN THE PRESENCE OF THE DEEP TROUGH TO THE WEST AND THE TENDENCY
FOR WAVES TO EMANATE FROM IT. WILL CARRY HIGHEST POPS LATE
WEDNESDAY EVENING THROUGH THURSDAY MORNING. THE RIDGE AXIS WILL
SHIFT EASTWARD ACROSS THE AREA THROUGH FRIDAY. THE AMPLITUDE OF
THE RIDGE AND THEREFORE THE POSITIONING OF THE TRACK OF
SHORTWAVES/THUNDERSTORMS ALONG ITS NORTHERN PERIPHERY WILL BE
DRIVEN BY THE SPEED WITH WHICH THE LARGE WESTERN UPPER TROUGH
EVOLVES EASTWARD. THE GFS CONTINUES TO BE MORE PROGRESSIVE WITH
THE TROUGH AND THEREFORE SHARPER WITH THE RIDGE SUGGESTING THAT
THE MAIN STORM TRACK WILL BE NORTH OF THE LOCAL AREA FRIDAY
WHEREAS THE SLOWER AND LOWER AMPLITUDE ECMWF KEEPS THE FAVORED
TRACK ACROSS THE AREA INTO THE WEEKEND. THE UPPER TROUGH WILL
EVOLVE EASTWARD PUSHING THE RIDGE TO THE EAST AND BRINGING A COOL
FRONT INTO THE REGION LATE IN THE WEEKEND. THE BIGGEST UNCERTAINTY
IS THE TIMING. WITH PRECIPITABLE WATER VALUES OVER 2 INCHES FROM
THURSDAY ONWARD HEAVY RAINFALL WILL BE A CONCERN WITH ANY
STORMS...ESPECIALLY IF MULTIPLE ROUNDS ARE ABLE TO AFFECT THE AREA
THROUGH THE WEEKEND. HOWEVER A SHARPER RIDGE WOULD RESULT IN A
SHIFT IN THE TRACK TO THE NORTH AND STRONGER CAPPING LOCALLY.
TEMPERATURES WILL BE WARMING INTO THE MID 80S WEDNESDAY AND MOSTLY
MID AND UPPER 80S FROM THURSDAY INTO THE WEEKEND. LAKESHORE AREAS
WILL LIKELY BE COOLER MOST DAYS WITH LAKE INFLUENCES EXPECTED DUE TO
A RATHER LIGHT LOW LEVEL FLOW. THUNDERSTORMS AND ANY REMNANT
INFLUENCES MAY NEGATIVELY AFFECT HIGHS DEPENDING ON THEIR TIMING.
CANNOT RULE OUT SOME 90 DEGREE READINGS IN THE WEST AND SOUTH LATE
IN THE WEEK...ESPECIALLY IF THUNDERSTORM ACTIVITY KEEPS AT A
MINIMUM.
MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* A PERIOD OF SHRA/TSRA LIKELY SOMETIME BETWEEN 08Z-11Z.
* POTENTIAL FOR LOWER CIGS LATE TONIGHT INTO TUE MORNING.
* CHANCE FOR SCATTERED SHRA/TSRA MUCH OF TUE WITH A SLIGHTLY MORE
FAVORED TIME DURING THE AFTERNOON.
//DISCUSSION...UPDATED 00Z...
A QUIET EVENING IS EXPECTED OVER LOCAL AIRPORTS BEFORE TSRA
CHANCES INCREASE OVERNIGHT. MUCH OF THE CUMULUS IS EXPECTED TO
FADE WITH SOUTH TO SOUTHWEST WINDS. REGENERATING STORMS ACROSS
CENTRAL WISCONSIN WILL LIKELY EVOLVE SLOWLY SOUTHEAST...HOWEVER
THESE ARE NOT ANTICIPATED TO REACH ALL THE WAY DOWN INTO NORTHERN
IL. EVEN IF THEY WERE TO BY LATE THIS EVENING...THEY SHOULD SLOWLY
FADE IN INTENSITY.
AN UPPER LEVEL DISTURBANCE OVER MN WILL ROTATE ITS WAY EAST-
SOUTHEAST WITH THE SOUTHERN AREA OF FORCING MOVING OVER NORTHERN
IL AND NORTHWEST IN LATE TONIGHT. COMPLIMENTING THIS WILL BE A
MOIST LOW-LEVEL AIR MASS THAT WILL FURTHER BE MOISTENING OVERNIGHT
AND COULD BLOSSOM MVFR CIGS OVERNIGHT. STORMS ARE EXPECTED TO BE
SCATTERED TO NUMEROUS IN COVERAGE AS THEY PROGRESS EASTWARD OVER
THE AREA. BY DAYBREAK WHAT IS LEFT OF THESE SHOULD BE MAINLY EAST
OF THE TERMINALS...HOWEVER REDEVELOPING SHOWERS AND POSSIBILITY A
FEW STORMS COULD OCCUR TUESDAY MORNING. AS THE SYSTEM COLD FRONT
MOVES THROUGH DURING THE AFTERNOON...SCATTERED REDEVELOPMENT OF
STORMS IS PROBABLE...BUT PLACEMENT OF THAT IS DIFFICULT TO TELL AT
THIS POINT. SOUTHWEST WINDS WILL TURN WESTERLY WITH THIS FRONTAL
PASSAGE WITH SOME GUSTS POSSIBLE BOTH AHEAD AND BEHIND THE FRONT.
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* MEDIUM IN SHRA AND/OR TSRA OCCURRING LATE TONIGHT BUT LOW IN
SPECIFIC DURATION.
* HIGH IN WIND DIRECTION AND MEDIUM IN WIND SPEED THROUGH MUCH OF
THE TAF. THE EXCEPTION WOULD BE DURING AND IMMEDIATELY AFTER ANY
STORMS...BUT ANY SHIFT FROM SOUTH-SOUTHWEST SHOULD BE
TEMPORARY.
* LOW IN MVFR CIGS OCCURRING LATE TONIGHT INTO TUE MORNING.
* LOW IN WHETHER TSRA OCCURS TUESDAY AND IN SPECIFIC TIMING.
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...CHANCE OF TSRA AND LOWER CIGS DURING THE NIGHT.
THURSDAY-SATURDAY...PERIODS OF TSRA POSSIBLE.
SUNDAY...SLIGHT CHANCE OF TSRA.
MTF
&&
.MARINE...
239 PM CDT
LOW PRESSURE OVER MINNESOTA WILL MOVE OVER WISCONSIN TOMORROW AND
THEN OVER THE LAKE TOMORROW EVENING AND NIGHT. WINDS WILL BECOME
SOUTH ACROSS THE LAKE AND INCREASE TO 15 TO 25 KT OVERNIGHT. AS THE
LOW MOVES OVER THE LAKE TOMORROW...WINDS WILL DIMINISH SLOWLY OVER
THE SOUTH HALF AND BECOME SW. ON THE NORTH HALF...WINDS WILL ALSO
DIMINISH AND BECOME SE TO E AHEAD OF THE LOW. THE LOW SHIFTS EAST
OF THE LAKE TUESDAY NIGHT AND WINDS BECOME NW 10-15 KT.
THE LOW SHIFTING TO THE EAST WILL LEAVE A WEAK PRESSURE GRADIENT
IN ITS WAKE. THIS WILL RESULT IN LIGHT ONSHORE OR VARIABLE WINDS
WEDNESDAY WITH BEFORE A SOMEWHAT BETTER ORGANIZED PRESSURE
GRADIENT SPREADS IN WITH LOW PRESSURE FROM THE CENTRAL HIGH PLAINS
TO NORTHERN MANITOBA. THIS WILL BRING MAINLY SOUTH TO SOUTHEAST
WINDS ACROSS THE LAKE THURSDAY...WITH OCCASIONAL EAST WINDS OVER
THE FAR NORTH...BUT EVEN THEN THE FLOW MAY BE WEAK ENOUGH TO
SUPPORT A SHIFT TO ONSHORE WINDS THURSDAY AFTERNOON. SOUTH TO
SOUTHEAST WINDS ARE FAVORED THROUGH THE WEEKEND BUT THERE MAY BE
QUITE A BIT OF VARIABILITY IF THE LOW PRESSURE TO THE WEST EVOLVES
MORE SLOWLY AS SOME FORECAST GUIDANCE INDICATES. THE UPPER FLOW
PATTERN DOES LOOK TO SHIFT SUNDAY OR MONDAY BRINGING A COOL FRONT
ACROSS THE LAKE WITH A SHIFT TO NORTHERLY WINDS WHICH MAY BE
RATHER BREEZY.
JEE/MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
902 PM CDT Mon Aug 18 2014
.UPDATE...
ISSUED AT 900 PM CDT MON AUG 18 2014
Skies have become mostly clear across central and SE Illinois this
evening as diurnal heating ends. Although a few pockets of light
fog are possible early tonight, the next main forecast feature
will be the chance for thunderstorms overnight as an upper level
shortwave and cold front move into central IL. Have trimmed back
POPs before midnight as current radar and satellite indicate
storms are still several hours away. HRRR model simulated
reflectivity has been depicting movement of the system well in
northern IA, southern MN, southwest WI this evening and has been
used as a guide for timing through the first few hours of Tuesday.
Currently the system is associated with a slight risk (15% +) of
severe winds and hail to our northwest, but as it approaches
central IL, CAPE of 3000 J/kg should be diminishing to around 1500
or less with marginal 0-6 km bulk shear around 25-30 kts. This is
enough for only a 5% severe risk from the Illinois River
northwest. To the south, risk of severe storms is negligible, but
at least a slight chance for storms will reach as far as SE
Illinois by early morning. Have sent updates for
POP/Temp/Humidity/Wind trends this evening/early tonight.
&&
.SHORT TERM...(This evening through Tuesday)
ISSUED AT 311 PM CDT MON AUG 18 2014
Earlier stratus has given way to diurnal type clouds over central
and southeast Illinois early this afternoon, underneath a weak high
pressure axis. Leading edge of shortwave currently seen on water
vapor imagery pushing through Minnesota and northern Iowa, with a
more potent vorticity maximum moving out of North Dakota.
Convection ahead of the shortwave expected to begin over the next
couple hours over northern Iowa, where skies have been sunny and
CAPE`s are over 3000 J/kg per SPC mesoanalysis. High-resolution
models pushing the first wave of storms into Wisconsin with another
line forming in southern Minnesota/northern Iowa later this evening.
The second line is more of a concern for us as it will have a
southeast trajectory. However, most of the models show some fading
of the line with more of the energy staying to our north, and a
separate convective cluster developing over northwest Missouri
overnight. Have adjusted the PoP`s in our area to be primarily after
midnight, and largely eliminated them south of I-70.
Associated surface boundary expected to push into central Illinois
Tuesday afternoon as the upper wave arrives. Some concerns with
severe weather potential across east central and southeast Illinois,
as development takes place early afternoon and bulk shear increases
during the peak heating time. Latest Day2 SPC convective outlook
indicates a severe threat southeast of a Danville to Effingham line,
with NAM indicating a 2 pm to 7 pm time frame being the most
concern.
&&
.LONG TERM...(Tuesday night through Monday)
ISSUED AT 311 PM CDT MON AUG 18 2014
Tuesday evening will see decreasing storm chances from north to
south as a shortwave in the upper level trough over the Great Lakes
advances east of IL. We are in the day 2 slight risk in our
southeast counties, so we can`t rule out some lingering strong
storms into early evening, but the main threat should advance
southeast of IL by mid evening.
Additional storm chances re-develop across our far S-SW counties late
Tue night as a 300mb 75kt jet max in the back side of the trough
generates some lift in the left exit region. Minor rain/storm
chances will continue on Wednesday as the jet max progresses
eastward over Illinois, but only slight chances are expected.
Wednesday night, a warm front developing across our northern
counties oriented from NW to SE will become a focus for a round of
storms, with chances increasing to likely after midnight along and
north of I-74. Storms should progress northward with the warm front
on Thursday. However, storms chances are expected to linger north of
a line from Peoria to Paris Thursday and Thursday night.
Height rises and mid-level warming on Friday and Saturday should
help to keep provide a capping layer, and reduce storm chances
across central IL. The may be an isolated late afternoon or early
evening flare-up of a storm, but most areas should stay dry.
Rain-free conditions are forecast to continue into Sunday by the
ECMWF and GFS. They both show a cold front arriving later Sunday
night and wash-out as it passes across IL on Monday. The weakening
front is not expected to trigger much in the way of storms at this
point, but confidence is low on that scenario staying dry.
Heat and humidity will definitely dominate the last half of this
week, as highs climb into the upper 80s and lower 90s, with heat
index readings in the mid to upper 90s. Some relief will come on
Monday behind the cold front, with low to mid 80s for highs and
lowering dewpoints into the 60s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
ISSUED AT 659 PM CDT MON AUG 18 2014
Mainly VFR conditions across central/SE IL this evening as
ceilings have lifted and scattered out. VFR conditions to continue
until around 07-09Z when a line of thunderstorms moves into the
region from the northwest. This line expected to weaken as it
approaches and mainly affect TAF sites from KPIA and KBMI
northward. Have included a PROB30 group at KPIA and KBMI to
address potential MVFR visibilities with the storms moving through
northern Illinois, but currently feel potential further south is
still too uncertain to go more than the existing VCTS. A break in
shower/thunderstorm activity likely in the morning then an upper
level shortwave and daytime heating should produce a
re-intensification of storms along the cold frontal boundary
lingering over central Illinois and have brought VCTS and ceilings
near MVFR thresholds for the remainder of the afternoon.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ONTON
SHORT TERM...GEELHART
LONG TERM...SHIMON
AVIATION...ONTON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
303 PM CDT SUN AUG 17 2014
.DISCUSSION...
301 PM CDT
A WARMER...MORE HUMID...AND POTENTIALLY MORE UNSETTLED PATTERN IS ON
THE WAY FOR MUCH OF THE UPCOMING WEEK. MOISTURE CHANNEL IMAGERY
SHOWS THE UPPER LOW WHICH PROVIDED SOME SHOWER ACTIVITY YESTERDAY
MOVING MORE STEADILY ACROSS THE OHIO VALLEY. TO THE NORTH...A WAVE
IS MEANDERING EASTWARD ACROSS CENTRAL MINNESOTA WHILE A CLOSED UPPER
LOW SPINS OVER SOUTHERN MANITOBA. THIS TROUGH WILL DETERMINE THUNDER
CHANCES MONDAY NIGHT. ALSO OF NOTE IS A SERIES OF UPPER LOWS OVER
THE NORTHERN PACIFIC NEAR ALASKA. ENERGY FROM THESE SYSTEMS WILL
TRANSLATE INTO WESTERN/CENTRAL CANADA AND HELP FORCE UPPER RIDGING
OVER THE U.S. MIDWEST BRINGING THE AFOREMENTIONED WARM UP. AT THE
SURFACE...WEAK LOW PRESSURE IS OVER THE LOWER OHIO VALLEY IN
CONJUNCTION WITH THE UPPER LOW. ANOTHER WEAK LOW IS STRETCHED ACROSS
WESTERN MINNESOTA WHILE HIGH PRESSURE IS CENTERED OVER CENTRAL
ONTARIO. ANOTHER LOW IS OVER SOUTHERN MANITOBA IN CONJUNCTION WITH
THE BETTER ORGANIZED UPPER LOW IN THAT VICINITY.
TONIGHT...THE MAIN CONCERN TONIGHT WILL BE FOG/STRATUS AS RESIDUAL
LOW LEVEL MOISTURE LINGERS IN THE MIDST OF WEAK LOW LEVEL FLOW AND A
WEAK RIDGE AXIS. THE RIDGE AXIS WILL STRETCH ACROSS NORTHWEST AND
NORTH CENTRAL ILLINOIS BY MONDAY MORNING. WESTERN AREAS APPEAR TO BE
FAVORED FOR FOG DEVELOPMENT WHILE EASTERN AREAS MAY SEE MORE IN THE
WAY OF STRATUS...ESPECIALLY IF SOME EXISTING STRATUS IS UNABLE TO
ERODE INTO THE EVENING...ESPECIALLY NEAR THE LAKE. WILL INCLUDE FOG
MENTION IN THE FORECAST FOR MOST AREAS BUT THERE IS DECENT POTENTIAL
FOR DENSE FOG SO WILL NEED TO MONITOR THIS. WESTERN AREAS LOOK TO
HAVE THE BEST CHANCE FOR THIS AS THEY MAY CLEAR OUT THIS EVENING AND
BE IN CLOSEST PROXIMITY TO THE RIDGE AXIS.
MONDAY AND TUESDAY...THE UPPER WAVE OVER MINNESOTA WILL TRACK EAST
WITH ITS EFFECTS LARGELY STAYING TO THE NORTH OF THE AREA INTO
MONDAY MORNING...EXCEPT FOR SOME INCREASED MID AND HIGH LEVEL CLOUD
COVER. HOWEVER THE MANITOBA LOW WILL BE TRACKING EAST-SOUTHEAST
ACROSS THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER VALLEY MONDAY
BEFORE SLOWING OVER THE WESTERN GREAT LAKES MONDAY NIGHT. THIS WILL
PUSH ASCENT INTO THE AREA AS EARLY AS LATE MONDAY AFTERNOON IN THE
NORTHWEST BUT MORE LIKELY MONDAY EVENING INTO MONDAY NIGHT. A MORE
FOCUSED SURFACE TROUGH AXIS IS FORECAST TO CROSS THE AREA SOME TIME
EARLY TUESDAY BRINGING THE MOST FOCUSED CHANCE FOR SHOWERS AND
THUNDERSTORMS ESPECIALLY ACROSS CENTRAL AND NORTHERN AREAS. LATEST
FORECAST GUIDANCE SHOWS QUITE A BIT OF SPREAD IN TERMS OF TIMING OF
THE BEST FOCUS FOR PRECIP. WILL CARRY HIGHEST POPS MONDAY EVENING
AND OVERNIGHT WITH LOWER POPS LATER TUESDAY AS FOCUS IS LOST BUT
UPPER CYCLONIC FLOW CONTINUES AROUND THE STALLED UPPER LOW TO THE
NORTH FOR THE MORNING. SOME MODEST WARMING WILL OCCUR ALOFT MONDAY
BUT PERIODIC BOUTS OF MID CLOUD MAY HELP LIMIT TEMPS SOMEWHAT...NOT
TO MENTION IMPACT OF ANY MORNING STRATUS/FOG. FLOW WILL CONTINUE OFF
THE LAKE KEEPING LAKESHORE AREAS COOLEST. WILL CARRY HIGHS IN THE
LOW TO MID 70S LAKESIDE AND AROUND 80 INLAND MONDAY WITH SOUTH TO
SOUTHWEST WINDS TUESDAY ALLOWING TEMPS TO REACH THE LOWER 80S FOR
MOST PLACES UNLESS PRECIP TIMING SLOWS AND LINGERS THROUGH MORE OF
THE DAY.
WEDNESDAY INTO THE WEEKEND...A LARGER UPPER TROUGH WILL AMPLIFY OVER
WESTERN CANADA INTO WEDNESDAY AS ANOTHER UPPER LOW DROPS SOUTHWARD
DOWN THE CALIFORNIA COAST AND CUTS OFF. THIS WILL LEAD TO
AMPLIFICATION OF AN UPPER RIDGE ACROSS THE HIGH PLAINS TUESDAY WHICH
WILL QUICKLY SHIFT EAST INTO THE CENTRAL U.S. WEDNESDAY. THIS WILL
BRING A PUSH OF WARM ADVECTION ACROSS THE AREA WEDNESDAY WHICH MAY
BE ENOUGH TO KICK OFF SOME SHOWERS AND STORMS. WITH THE COMPLEX
TROUGH PATTERN TO THE WEST THERE WILL BE THE TENDENCY FOR SHORTWAVES
TO TRAVERSE THE RIDGE WITH SOME POTENTIAL FOR THIS TO BEGIN
WEDNESDAY BUT IT APPEARS MORE LIKELY TO BEGIN WEDNESDAY NIGHT. THE
RIDGE WILL PARK ITSELF OVER THE MIDWEST/WESTERN LAKES INTO FRIDAY
KEEPING THE LIKELIHOOD OF SHORTWAVES TRACKING THROUGH THE FLOW RATHER
HIGH. THE TRACK OF THESE WILL DEPEND ON HOW AMPLIFIED THE RIDGE
BECOMES BUT LATEST GUIDANCE CONTINUES TO KEEP THE LOCAL AREA IN A
FAVORED ZONE FOR THESE WAVES. THE AIRMASS WILL BECOME VERY MOIST BY
THURSDAY WITH PRECIPITABLE WATER VALUES PUSHING/TOPPING 2 INCHES.
BETWEEN THE POTENTIAL WAVES AND THE VERY MOIST AIRMASS SEVERAL
ROUNDS OF THUNDERSTORMS MAY AFFECT THE FORECAST AREA FROM LATER
WEDNESDAY THROUGH FRIDAY. IF THE AIRMASS BECOMES AS MOIST AS
EXPECTED THEN ANY STORM WILL HAVE A GOOD CHANCE TO BRING HEAVY
RAINFALL. RAINFALL POTENTIAL WILL NEED TO BE WATCHED CLOSELY OVER
THE NEXT SEVERAL DAYS ESPECIALLY IF MULTIPLE ROUNDS LOOK MORE
LIKELY. THIS RIDGE LOOKS TO AMPLIFY NORTHWARD SATURDAY PUSHING THE
FAVORED STORM TRACK TO THE NORTH. EVOLUTION BEYOND SATURDAY IS MORE
UNCERTAIN AND WILL BE DRIVEN BY THE MOVEMENT OF THE LARGE UPPER
TROUGH OVER NORTHERN U.S. AND CANADIAN ROCKIES. GUIDANCE IS IN
DISAGREEMENT ON HOW QUICKLY THIS OCCURS. OTHERWISE...HIGHS WILL WARM
FROM MIDWEEK INTO THE WEEKEND AS WILL HUMIDITY LEVELS. THE WILD CARD
WILL BE THUNDERSTORMS WITH THEIR TIMING AND LINGERING EFFECTS SUCH
AS CLOUD COVER PLAYING A KEY ROLE IN HOW WARM THINGS GET. MINIMAL
THUNDER IMPACT WOULD RESULT IN HIGHS IN THE MID AN UPPER 80S BY
THURSDAY WITH 90 POSSIBLE...ESPECIALLY IF THE RIDGE AMPLIFIES MORE
THAN CURRENTLY THOUGHT.
MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* CIGS AROUND 1,000 FEET LIKELY BECOMING IFR AGAIN THIS EVENING.
* NELY WINDS TO ARND 10KT.
KJB
//DISCUSSION...UPDATED 19Z...
BASED ON VISIBLE SATELLITE TRENDS EARLY THIS AFTERNOON...IT
APPEARS LESS LIKELY THAT KORD...KMDW AND KGYY WILL SEE MUCH OF ANY
ADDITIONAL IMPROVEMENT LATE THIS AFTERNOON AS PREVIOUSLY THOUGHT. THE
NORTHEASTERLY FLOW CONTINUES TO PULL LOWER CLOUDS INTO
NORTHEASTERN ILLINOIS AND THIS WILL LIKELY CONTINUE TO BE THE
TREND TONIGHT. THEREFORE...CIGS LOOK TO LOWER BACK INTO THE IFR
RANGE DURING THE EVENING AND LOSS OF DAYTIME HEATING. AREAS OF FOG
COULD ALSO DEVELOP THIS EVENING...LEADING TO BOTH VERY LOW CIGS
AND VISIBILITIES.
//DISCUSSION...UPDATED 18Z...
IFR CLOUDS CONTINUE TO STREAM IN OFF LAKE MICHIGAN THIS AFTERNOON
UNDER NORTHEASTERLY FLOW. HOWEVER...AS TEMPERATURES SLOWLY
WARM...CLOUD HEIGHTS ARE VERY SLOWLY LIFTING AT THE MAIN TERMINALS.
IT APPEARS OVER THE NEXT FEW HOURS CLOUDS WILL HANG TOUGH ACROSS
KORD AND KMDW...BUT WILL LIKELY INCREASE TO AROUND OR JUST ABOVE 1500
FEET BY MID AFTERNOON. HOWEVER...FARTHER INLAND AWAY FROM LAKE
MICHIGAN...CONDITIONS WILL LIKELY IMPROVE QUICKER...WITH CLOUD COVER
SCATTERING OUT IN SOME AREAS.
LOOKING AHEAD TO TONIGHT...IT APPEARS THAT FOG COULD BECOME AN
ISSUE...ESPECIALLY AFTER MIDNIGHT TONIGHT. WINDS ARE EXPECTED TO
BECOME VERY LIGHT...AND WITH THE ABUNDANCE OF LOW LEVEL MOISTURE
LOW VISIBILITIES IN FOG APPEAR TO BE A DECENT BET...ESPECIALLY AT
KRFD AND KDPA. LOW CLOUDS AND VISIBILITIES ARE ALSO LIKELY AT THE
EASTERN TERMINALS TONIGHT. CONDITIONS COULD AGAIN BE SLOW TO
IMPROVE MONDAY MORNING...BUT CIGS SHOULD GRADUALLY BECOME VFR BY
AFTERNOON.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM WITH CIG TRENDS INTO THIS EVENING.
* MEDIUM TO HIGH WITH WIND TRENDS.
* MEDIUM TO HIGH WITH IFR CONDITIONS TONIGHT INTO MONDAY MORNING.
KJB
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT THROUGH FRIDAY NIGHT...PERIODIC CHANCES FOR
SHRA/TSRA. OCNL MVFR CIGS/VIS POSSIBLE.
SATURDAY...VFR. WX NIL.
KREIN
&&
.MARINE...
150 PM CDT
A COLD FRONT HAS CLEARED THE SOUTHERN TIP OF THE LAKE...AND NORTH TO
NORTHEAST WINDS HAVE OVERSPREAD LAKE MICHIGAN WITH HIGH
PRESSURE OVER SOUTHERN ONTARIO AND LOW PRESSURE IN FAR SOUTHERN
ILLINOIS. EXPECT WAVES TO BUILD GENERALLY INTO THE 2 TO 4 FT
RANGE OVER THE SOUTHERN HALF OF THE LAKE BEFORE EASING SOME LATE
TONIGHT. BOTH THE CANADIAN HIGH AND THE LOW IN SOUTHERN ILLINOIS
WILL WORK THEIR WAY EASTWARD TONIGHT INTO MONDAY WHICH WILL
SLACKEN THE WINDS AND VEER THEM TO MORE OF AN EASTERLY DIRECTION
TONIGHT THAN SOUTH TO SOUTHEASTERLY ON MONDAY. ANOTHER WEAK LOW
PASSING THROUGH THE CANADIAN PRAIRIES WILL WORK ITS WAY SE TOWARD
THE NORTHERN HALF OF THE LAKE ON TUESDAY AND SLOWLY DRIFT EAST ON
WEDNESDAY. AFTER A PERIOD OF HIGH PRESSURE...A SERIES OF WEAK LOWS
WILL MIGRATE EASTWARD OUT OF THE PLAINS TOWARD THE LAKE FOR THE
LATTER HALF OF THE WEEK. KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
300 PM CDT Sun Aug 17 2014
.SHORT TERM...(This evening through Monday)
ISSUED AT 259 PM CDT SUN AUG 17 2014
Surface low has dropped into far southern Illinois early this
afternoon with remnant MCV still evident on radar imagery over the
far southeast CWA. This is where most of the lingering showers are
continuing, with a few as far north as Taylorville and Tuscola. Some
thinning of the low clouds has been developing but skies still
mainly cloudy.
Main concern for this part of the forecast is with fog potential
tonight. Cloudiness across far northern Illinois and southeast Iowa
is more cellular in nature and should diminish with loss of daytime
heating. Latest RAP guidance showing the northern CWA becoming
partly cloudy this evening. With northeast flow continuing, not a
lot of drying will take place in the lower levels with dew points
upstream still in the mid 60s in many areas. This should allow
visibilities to start dropping by late evening across the north.
Model guidance showing a fair range as to how extensive or thick the
fog gets, so for now will only mention patchy or areas of fog in the
grids for late tonight and early Monday. Skies expected to become
partly to mostly sunny by midday as forecast soundings are rather
dry.
In terms of the lingering showers, most of what`s left in our area
is along a weak trough axis dropping into southern Illinois, aided
by the upper low which is currently located in far southwest
Indiana. Am expecting the showers to fade early this evening as the
low pulls away. On Monday, have maintained some isolated showers/
storms across the eastern CWA during the afternoon as a weak wave
passes through the area.
&&
.LONG TERM...(Monday night through Sunday)
ISSUED AT 259 PM CDT SUN AUG 17 2014
Monday night will feature an upper trough and weak surface low
tracking from the upper midwest into the western Great Lakes, with a
cold front extending south into northern Illinois. Rain chances will
return to areas NW of the I-55 later Monday evening, with chances
expanding to Indiana along and north of I-72 by 12z/7am Tuesday.
Better forcing from the 500mb vort max should remain in northern IL,
but moisture convergence along the front and a weak 300mb jet max
overhead could provide just enough lift for a few storms with the
front. No severe weather is expected, especially with limited
instability overnight.
Tuesday should see a decreasing trend in rain/storm chances in the
afternoon as the bulk of the mid and upper level energy departs to
the east. The break in the rain should continue Tues night for all
but the far southwest KILX CWA, from Jacksonville to Effingham,
where a warm front will quickly approach the area. Rain/storm
chances will remain mainly southwest of Havana to Lincoln to
Shelbyville on Wednesday as the front slowly pushes into IL.
That warm front is expected to usher in a progressively warmer
airmass the remainder of the week and into the weekend. Wednesday
night, an MCV is projected to move from N Iowa across N Illinois,
with enough support from strong mid level warm air advection and a
low level jet across central IL to trigger showers/storms across most
of our forecast area.
Low surface pressure and a stalled frontal boundary are still
expected across northern Illinois for Thursday, keeping rain chances
going into Thursday night. The front is expected wash out Thursday
night as warming continues through a deep layer of the atmosphere.
The warming at mid levels will eventually work to cap the atmosphere
and limit storm potential, despite ample low level moisture. A
shortwave is forecast by the ECMWF to move from Nebraska across N
Illinois Saturday, which could affect our northern counties with a
few storms, depending on the extent of elevated CAPE above the
capping inversion.
The ECMWF is also showing a cold frontal passage following the
shortwave on Saturday night, bringing a period of storms and
slightly cooler air for Sunday. The GFS keeps the upper level ridge
entrenched over IL, limiting much storm potential by keeping
shortwave tracks north of central IL. It also has much warmer
conditions continuing into Sunday. Confidence remains low on the
scenario for next weekend due to the differences.
Heat and humidity levels will climb the last half of the week, as
highs reach into the lower 90s south of Lincoln to Mattoon Thurs
through Saturday. Dewpoints in the low to mid 70s will help push
heat index readings into the upper 90s to around 100 in at least the
south half of the KILX CWA.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
ISSUED AT 1235 PM CDT SUN AUG 17 2014
Still have some IFR conditions lingering at midday from KUIN east
to near KCMI and north to KBMI, just north of a weak surface trough.
Areas from about KPIA northward have seen some increase in
ceilings with MVFR conditions lingering. Will continue to see some
increase there, but think that MVFR conditions will be most
prominent later this afternoon across central Illinois with an
upper low in the southeast part of the state.
Outlook for tonight will be tricky. Currently thinking that
KPIA/KBMI may scatter out long enough to allow for rapid fog
development toward 06Z and subsequent IFR conditions. Further
south, have brought conditions down to around 2SM in visibility
overnight, but am not as sure about widespread dense fog, since no
substantial clearing is expected ahead of time. Low ceilings
should start to lift mid to late Monday morning.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GEELHART
LONG TERM...SHIMON
AVIATION...GEELHART
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
300 PM CDT SUN AUG 17 2014
.DISCUSSION...
1103 AM CDT
CLOUD TRENDS REMAIN THE MAIN CHALLENGE THROUGH THE AFTERNOON
FOLLOWED BY THEIR IMPACT ON TEMPS. LATEST SATELLITE IMAGES SHOWS
SOME EROSION OF THE MOST WIDESPREAD STRATUS...ESPECIALLY INLAND OF
THE LAKE. HOWEVER...STRATOCU IS BEGINNING TO DEVELOP IN THE LOWER
COVERAGE AREAS AND MAY STRATIFY SOMEWHAT FOR A FEW HOURS THROUGH
EARLY AFTERNOON BUT LIFT WITH TIME THEN ERODE LATER THIS AFTERNOON.
FAR SOUTHERN AREAS WILL CONTINUE TO SEE CLOUD COVER FROM THE
UPPER LOW TO THE SOUTH AND EAST AS WELL AS SOME LOW SHOWER
POTENTIAL. STRATUS IS QUITE EXTENSIVE ACROSS LAKE MICHIGAN WITH
TRAJECTORIES FEEDING THIS INTO WESTERN AND SOUTHERN SHORELINE
AREAS. THIS WILL LIKELY RESULT IN AREAS NEAR THE LAKE REMAINING
UNDER THE MORE WIDESPREAD CLOUD COVER LONGER AND IT IS TOUGH TO
SAY HOW MUCH IMPROVEMENT MAY OCCUR THROUGH THE AFTERNOON. HAVE
ADJUSTED TEMPS BASED ON LATEST TRENDS WITH MINOR DOWNWARD
ADJUSTMENTS CLOSE TO THE LAKE.
MDB
//PREV DISCUSSION...
315 AM CDT
SHORT TERM...THROUGH SUNDAY NIGHT...
FOR THE REMAINDER OF THE NIGHT AND INTO SUNDAY MORNING...FORECAST
CONCERNS WILL FOCUS ON THE COLD FRONT MOVING INTO NERN IL WHILE A
SLOW MOVING SHORTWAVE MOVES OVER SRN IL. AS OF 08Z...THE BACK DOOR
COLD FRONT HAS PUSHED THROUGH FAR NERN IL AND IS STEADILY PUSHING TO
THE SOUTHWEST. THIS CLIMATOLOGICALLY UNUSUAL TYPE OF FRONTAL PASSAGE
WILL TURN WINDS TO NELY OFF OF LAKE MICHIGAN AND USHER IN A LOWERING
STRATUS DECK AND LOWER TEMPERATURES...ESPECIALLY FOR THE LAKEFRONT.
LATEST RADAR IMAGERY INDICATES THAT THE BULK OF THE PCPN ASSOCIATED
WITH THIS SYSTEM IS MOVING TO THE SOUTHEAST UNDER MODEST NWLY FLOW
ALOFT...SO DO NOT ANTICIPATE MUCH PCPN TO FOLLOW THE FROPA...THOUGH
A FEW ISOLD SPRINKLES ARE NOT OUT OF THE QUESTION. THE OTHER
FEATURE OF CONCERN...THE SHORTWAVE PASSING OVER SRN IL IS STILL
MOVING VERY SLOWLY THROUGH AN AREA OF WEAK FLOW ALOFT. THE BULK OF
THE PCPN ASSOCIATED WITH THIS SYSTEM WILL REMAIN UNDER THE MAIN
CIRCULATION CENTER...WELL TO THE SOUTH OF THE CWA...BUT THERE ARE
STILL BANDS OF SHRA MOVING NWD ON THE NERN PERIPHERY OF THE SYSTEM.
THESE SHOWERS SHOULD MOSTLY IMPACT LOCATIONS SOUTH OF THE I-80
CORRIDOR. THE AIRMASS IS STILL QUITE MOIST THROUGH A DEEP LAYER
WITH THE 00Z ILX SOUNDING INDICATING PWAT OF 1.79 INCHES.
AGAIN...THE HEAVIEST RAIN WILL REMAIN WELL SOUTH OF THE CWA...BUT
GIVEN THE MOIST ENVIRONMENT IN PLACE...WITH WEAK FLOW ALOFT OVER
THAT AREA...SOME OF THE HEAVIER SHOWERS OR A FEW THUNDERSTORMS COULD
STILL PRODUCE SOME LOCALLY HEAVY RAINFALL TODAY.
THE SHORTWAVE OVER SRN IL SHOULD CONTINUE TO TRACK SLOWLY TO THE
EAST INTO THE OHIO VALLEY THIS EVENING...BRINGING AN END TO THE PCPN
POTENTIAL FOR THE SRN PORTIONS OF THE CWA LATE SUNDAY NIGHT. AS FOR
THE BACK DOOR COLD FRONT...THE INITIAL SURGE OF COOLER AIR WITH THE
LOW STRATUS SHOULD PERSIST THROUGH THE MORNING. SINCE IT IS
TECHNICALLY STILL SUMMER...DIURNAL HEATING SHOULD ALLOW THE STRATUS
AND ANY RESIDUAL PATCHY FOG TO BURN OFF THROUGH THE LATE MORNING AND
INTO THE EARLY AFTERNOON. UPPER LEVEL SHORT WAVE RIDGING SHOULD
BUILD OVER THE AREA TODAY FOLLOWING THE PASSAGE OF THE SHORT WAVE
INTO THE OHIO VALLEY...SO THERE WILL STILL BE OPPORTUNITY FOR INLAND
TEMPERATURES TO REACH AROUND 80F. LOCATIONS INVOF LAKE MICHIGAN
WILL REMAIN COOLER...WITH TEMPERATURES ALONG THE LAKEFRONT ONLY
REACHING THE LOWER 70S AND INLAND LOCATIONS WITHIN 30 MILES OR SO OF
THE LAKE ONLY REACHING THE MIDDLE 70S.
OVERNIGHT TONIGHT...HIGH PRESSURE WITH BUILD ACROSS THE UPPER GREAT
LAKES WITH A SFC RIDGE AXIS EXTENDING INTO NRN IL. A NORTHERN
STREAM SHORTWAVE MOVING OVER MINNESOTA WILL SLOWLY EWD ACROSS
WISCONSIN. THIS SYSTEM WILL BRING SHOWERS AND THUNDERSTORMS...BUT
ANY ASSOCIATED PCPN SHOULD REMAIN WELL NORTH OF THE WISCONSIN BORDER
AND WILL LIKELY ONLY BRING INCREASING CLOUD COVER TO NRN IL/NWRN IN.
KREIN
MONDAY THROUGH TUESDAY...
MAIN CONCERN IN THE MEDIUM TERM WILL BE ON THE DISSIPATING SHORTWAVE
ACROSS THE OHIO VALLEY...WITH A SLIGHTLY MORE ROBUST AREA OF
VORTICITY/TROUGH PIVOTING EAST ACROSS THE UPPER MIDWEST/WESTERN
GREAT LAKES.
IN THE WAKE OF THE OHIO VALLEY WAVE...IT APPEARS MUCH OF MON COULD
END UP BEING RATHER QUIET/DRY WITH A WEAK BUMP IN THE SFC
HEIGHTS/MID-LVL DIFFLUENCE. LAYERED RH STILL SUPPORTS CLOUDS AND
THIS COUPLED WITH A LIGHT MAINLY EASTERLY FLOW AT THE SFC...AND
TEMPS WILL LIKELY HOLD IN THE MID/UPR 70S WITH NEAR 80 FOR THE FAR
WEST/SOUTH PORTIONS OF THE FORECAST AREA MON.
BY MON EVE THE TROUGH AXIS OVER THE UPPER MIDWEST WILL BE NEARING
THE CWFA. HEIGHTS LOWER WITH A STEADY MOISTENING IN THE COLUMN AND
INSTABILITY CREEPING BACK INTO THE REGION. LOCAL ARW8KM SOLUTION
HOLDS PRECIP OFF UNTIL AFT 6Z TUE IN THE WESTERN CWFA THEN SLOWLY
SLIDES EAST BY DAYBREAK TUE. COULD SEE THIS SOLUTION VERIFYING IF
THE WEAK BUMP IN HEIGHTS MON AFTN LINGERS OR IS SLIGHTLY STRONGER.
FOR NOW WILL HEDGE SLIGHTLY TOWARDS THIS OUTCOME...AND HOLD ONTO SLT
CHC/CHC POPS MON NGT. WITH STEADILY INCREASING LLVL MOISTURE AND
CLOUDS MON NGT WILL LIKELY REMAIN MILD...WITH LOWS IN THE MID/UPR
60S.
FOR TUE THE TROUGH WILL BE OVER THE WESTERN LAKES...WITH GUIDANCE
BRINGING A BETTER DEFINED SFC FEATURE INTO THE UPPER PENINSULA TUE
MORNING. THE BEST FORCING WILL BE CONFINED WELL NORTH OF THE
CWFA...HOWEVER SOUNDINGS STILL SUPPORT ROUGHLY 1000J/KG IN A NARROW
COLUMN ACROSS THE AREA. PWAT VALUES SHUD HOVER ARND 1.2-1.7"...SO
NOT EXPECTING ANY HEAVY RAIN TO OCCUR TUE.
TUE HIGHS SHUD BE A LITTLE WARMER WITH 850MB TEMPS PUSHING TO ARND
16-18 DEG C IN THE AFTN. SO EXPECT GENERALLY ARND 80 TO THE LOW 80S
ACROSS THE FORECAST AREA. LLVL FLOW SHUD GENERALLY BE FROM THE S/SW
AND KEEP ANY LAKE BREEZE CONFINED ALONG THE SHORELINE.
WEDNESDAY THROUGH SATURDAY...
FOR THE EXTENDED PERIODS THE FOCUS OF LATE HAS BEEN ON A PATTERN
CHANGE FROM TROUGHING ACROSS THE GREAT LAKES REGION...BEING REPLACED
WITH A MID-LVL RIDGE WITH MUCH WARMER TEMPS. ALTHOUGH THE CHALLENGE
WILL BE HOW WARM GIVEN WHAT APPEARS TO BE A SOMEWHAT ACTIVE
STRETCH...WHICH COULD FEATURE RIDGE-ROLLERS OR CONVECTIVE COMPLEXES
THAT TRAVERSE THE TOP OF THE RIDGE.
ENSEMBLES SOLUTIONS HAVE THE NORTH ATLANTIC RIDGE WEAKENING SLIGHTLY
THEN RETROGRADING ACROSS NORTHERN QUEBEC AND EXPANDING SOUTHWEST
WITH TIME. MEANWHILE RIDGING ACROSS THE EASTERN PACIFIC
CONTINUES...ALLOWING TROUGHING TO BE DISPLACED FURTHER WEST ACROSS
THE ROCKIES/SOUTHWEST CONUS LATER IN THE WEEK. THIS WILL SET THE
STAGE FOR BROAD RIDING TO DEVELOP IN THE CENTRAL CONUS AND LIKELY
ALLOW TEMPS TO STEADILY WARM. THE PLACEMENT OF THE MID-LVL RIDGE
WILL STEER THE PLACEMENT OF CONVECTION/PRECIP. SOME CONSISTENCY
REMAINS THAT THE ACTIVE WEATHER WILL LIKELY FALL ACROSS THE
CWFA...WHICH COULD KEEP TEMPS FROM GETTING TOO WARM. ALTHOUGH IF THE
RIDGE IS SLIGHTLY STRONGER AND CENTERED FURTHER NORTH...THIS COULD
PUSH THE ACTIVE ZONE NORTH INTO WISC AND ALLOW OUR TEMPS TO BE MUCH
WARMER IN THE UPR 80S TO PERHAPS A FEW 90 DEG READINGS LATE IN THE
WEEK.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* CIGS AROUND 1,000 FEET LIKELY BECOMING IFR AGAIN THIS EVENING.
* NELY WINDS TO ARND 10KT.
KJB
//DISCUSSION...UPDATED 19Z...
BASED ON VISIBLE SATELLITE TRENDS EARLY THIS AFTERNOON...IT
APPEARS LESS LIKELY THAT KORD...KMDW AND KGYY WILL SEE MUCH OF ANY
ADDITIONAL IMPROVEMENT LATE THIS AFTERNOON AS PREVIOUSLY THOUGHT. THE
NORTHEASTERLY FLOW CONTINUES TO PULL LOWER CLOUDS INTO
NORTHEASTERN ILLINOIS AND THIS WILL LIKELY CONTINUE TO BE THE
TREND TONIGHT. THEREFORE...CIGS LOOK TO LOWER BACK INTO THE IFR
RANGE DURING THE EVENING AND LOSS OF DAYTIME HEATING. AREAS OF FOG
COULD ALSO DEVELOP THIS EVENING...LEADING TO BOTH VERY LOW CIGS
AND VISIBILITIES.
//DISCUSSION...UPDATED 18Z...
IFR CLOUDS CONTINUE TO STREAM IN OFF LAKE MICHIGAN THIS AFTERNOON
UNDER NORTHEASTERLY FLOW. HOWEVER...AS TEMPERATURES SLOWLY
WARM...CLOUD HEIGHTS ARE VERY SLOWLY LIFTING AT THE MAIN TERMINALS.
IT APPEARS OVER THE NEXT FEW HOURS CLOUDS WILL HANG TOUGH ACROSS
KORD AND KMDW...BUT WILL LIKELY INCREASE TO AROUND OR JUST ABOVE 1500
FEET BY MID AFTERNOON. HOWEVER...FARTHER INLAND AWAY FROM LAKE
MICHIGAN...CONDITIONS WILL LIKELY IMPROVE QUICKER...WITH CLOUD COVER
SCATTERING OUT IN SOME AREAS.
LOOKING AHEAD TO TONIGHT...IT APPEARS THAT FOG COULD BECOME AN
ISSUE...ESPECIALLY AFTER MIDNIGHT TONIGHT. WINDS ARE EXPECTED TO
BECOME VERY LIGHT...AND WITH THE ABUNDANCE OF LOW LEVEL MOISTURE
LOW VISIBILITIES IN FOG APPEAR TO BE A DECENT BET...ESPECIALLY AT
KRFD AND KDPA. LOW CLOUDS AND VISIBILITIES ARE ALSO LIKELY AT THE
EASTERN TERMINALS TONIGHT. CONDITIONS COULD AGAIN BE SLOW TO
IMPROVE MONDAY MORNING...BUT CIGS SHOULD GRADUALLY BECOME VFR BY
AFTERNOON.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM WITH CIG TRENDS INTO THIS EVENING.
* MEDIUM TO HIGH WITH WIND TRENDS.
* MEDIUM TO HIGH WITH IFR CONDITIONS TONIGHT INTO MONDAY MORNING.
KJB
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT THROUGH FRIDAY NIGHT...PERIODIC CHANCES FOR
SHRA/TSRA. OCNL MVFR CIGS/VIS POSSIBLE.
SATURDAY...VFR. WX NIL.
KREIN
&&
.MARINE...
150 PM CDT
A COLD FRONT HAS CLEARED THE SOUTHERN TIP OF THE LAKE...AND NORTH TO
NORTHEAST WINDS HAVE OVERSPREAD LAKE MICHIGAN WITH HIGH
PRESSURE OVER SOUTHERN ONTARIO AND LOW PRESSURE IN FAR SOUTHERN
ILLINOIS. EXPECT WAVES TO BUILD GENERALLY INTO THE 2 TO 4 FT
RANGE OVER THE SOUTHERN HALF OF THE LAKE BEFORE EASING SOME LATE
TONIGHT. BOTH THE CANADIAN HIGH AND THE LOW IN SOUTHERN ILLINOIS
WILL WORK THEIR WAY EASTWARD TONIGHT INTO MONDAY WHICH WILL
SLACKEN THE WINDS AND VEER THEM TO MORE OF AN EASTERLY DIRECTION
TONIGHT THAN SOUTH TO SOUTHEASTERLY ON MONDAY. ANOTHER WEAK LOW
PASSING THROUGH THE CANADIAN PRAIRIES WILL WORK ITS WAY SE TOWARD
THE NORTHERN HALF OF THE LAKE ON TUESDAY AND SLOWLY DRIFT EAST ON
WEDNESDAY. AFTER A PERIOD OF HIGH PREESURE...A SERIES OF WEAK LOWS
WILL MIGRATE EASTWARD OUT OF THE PLAINS TOWARD THE LAKE FOR THE
LATTER HALF OF THE WEEK. KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
300 PM CDT Sun Aug 17 2014
.SHORT TERM...(This evening through Monday)
ISSUED AT 259 PM CDT SUN AUG 17 2014
Surface low has dropped into far southern Illinois early this
afternoon with remnant MCV still evident on radar imagery over the
far southeast CWA. This is where most of the lingering showers are
continuing, with a few as far north as Taylorville and Tuscola. Some
thinning of the low clouds has been developing but skies still
mainly cloudy.
Main concern for this part of the forecast is with fog potential
tonight. Cloudiness across far northern Illinois and southeast Iowa
is more cellular in nature and should diminish with loss of daytime
heating. Latest RAP guidance showing the northern CWA becoming
partly cloudy this evening. With northeast flow continuing, not a
lot of drying will take place in the lower levels with dew points
upstream still in the mid 60s in many areas. This should allow
visibilities to start dropping by late evening across the north.
Model guidance showing a fair range as to how extensive or thick the
fog gets, so for now will only mention patchy or areas of fog in the
grids for late tonight and early Monday. Skies expected to become
partly to mostly sunny by midday as forecast soundings are rather
dry.
In terms of the lingering showers, most of what`s left in our area
is along a weak trough axis dropping into southern Illinois, aided
by the upper low which is currently located in far southwest
Indiana. Am expecting the showers to fade early this evening as the
low pulls away. On Monday, have maintained some isolated showers/
storms across the eastern CWA during the afternoon as a weak wave
passes through the area.
&&
.LONG TERM...(Monday night through Sunday)
ISSUED AT 259 PM CDT SUN AUG 17 2014
Monday night will feature an upper trough and weak surface low
tracking from the upper midwest into the western Great Lakes, with a
cold front extending south into northern Illinois. Rain chances will
return to areas NW of the I-55 later Monday evening, with chances
expanding to Indiana along and north of I-72 by 12z/7am Tuesday.
Better forcing from the 500mb vort max should remain in northern IL,
but moisture convergence along the front and a weak 300mb jet max
overhead could provide just enough lift for a few storms with the
front. No severe weather is expected, especially with limited
instability overnight.
Tuesday should see a decreasing trend in rain/storm chances in the
afternoon as the bulk of the mid and upper level energy departs to
the east. The break in the rain should continue Tues night for all
but the far southwest KILX CWA, from Jacksonville to Effingham,
where a warm front will quickly approach the area. Rain/storm
chances will remain mainly southwest of Havana to Lincoln to
Shelbyville on Wednesday as the front slowly pushes into IL.
That warm front is expected to usher in a progressively warmer
airmass the remainder of the week and into the weekend. Wednesday
night, an MCV is projected to move from N Iowa across N Illinois,
with enough support from strong mid level warm air advection and a
low level jet across central IL to trigger showers/storms across most
of our forecast area.
Low surface pressure and a stalled frontal boundary are still
expected across northern Illinois for Thursday, keeping rain chances
going into Thursday night. The front is expected wash out Thursday
night as warming continues through a deep layer of the atmosphere.
The warming at mid levels will eventually work to cap the atmosphere
and limit storm potential, despite ample low level moisture. A
shortwave is forecast by the ECMWF to move from Nebraska across N
Illinois Saturday, which could affect our northern counties with a
few storms, depending on the extent of elevated CAPE above the
capping inversion.
The ECMWF is also showing a cold frontal passage following the
shortwave on Saturday night, bringing a period of storms and
slightly cooler air for Sunday. The GFS keeps the upper level ridge
entrenched over IL, limiting much storm potential by keeping
shortwave tracks north of central IL. It also has much warmer
conditions continuing into Sunday. Confidence remains low on the
scenario for next weekend due to the differences.
Heat and humidity levels will climb the last half of the week, as
highs reach into the lower 90s south of Lincoln to Mattoon Thurs
through Saturday. Dewpoints in the low to mid 70s will help push
heat index readings into the upper 90s to around 100 in at least the
south half of the KILX CWA.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
ISSUED AT 1235 PM CDT SUN AUG 17 2014
Still have some IFR conditions lingering at midday from KUIN east
to near KCMI and north to KBMI, just north of a weak surface trough.
Areas from about KPIA northward have seen some increase in
ceilings with MVFR conditions lingering. Will continue to see some
increase there, but think that MVFR conditions will be most
prominent later this afternoon across central Illinois with an
upper low in the southeast part of the state.
Outlook for tonight will be tricky. Currently thinking that
KPIA/KBMI may scatter out long enough to allow for rapid fog
development toward 06Z and subsequent IFR conditions. Further
south, have brought conditions down to around 2SM in visibility
overnight, but am not as sure about widespread dense fog, since no
substantial clearing is expected ahead of time. Low ceilings
should start to lift mid to late Monday morning.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GEELHART
LONG TERM...SHIMON
AVIATION...GEELHART
AREA FORECAST DISCUSSION
NWS TOPEKA KS
644 PM CDT Mon Aug 18 2014
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Tuesday)
Issued at 352 PM CDT MON AUG 18 2014
The center of an upper level trough was located across eastern ND
late this afternoon with an upper level trough axis extending
southwest across central SD. The numerical models show this upper
level trough digging southeast across southern MN and eastern NE
into northern MO. The southwest section of the upper trough will
move southeast across northeast KS between 6Z and 12Z. The NAM,
GFS and ECMWF forecast QPF across northeast and east central KS
later Tonight, with the ECMWF and NAM showing most of the CWA with
QPF. The NAM model shows weak isentropic lift at the 310K level
with LFCs around 700mb. The most intense isentropic lift at the
310K level will be across northern MO and IA.
The mesoscale models, consisting of the ARW, NMM and HRRR do not
forecast any QPF across the CWA tonight. I will probably keep slight
chance to chance pops across much of the CWA, since the ascent ahead
of the H5 trough combined with isentropic lift should allow elevated
thunderstorms to develop across the northeast counties of the CWA
around midnight, then building southwest across the central and
southwest counties of the CWA through the early morning hours before
spreading southeast across much of east central KS by 12Z TUE.
Any lingering elevated thunderstorms, if they do develop, will shift
southeast of the CWA during the mid morning hours. Skies should
clear through the late morning and early afternoon hours and
temperatures will warm into the lower to mid 90s. If there is a
leftover outflow boundary across the northeast counties, then
temperatures along the NE border may only reach into the upper 80s.
I placed in 14 pops in case there is enough surface convergence for
an isolated thunderstorm during the afternoon hours.
.LONG TERM...(Tuesday Night through Monday)
Issued at 352 PM CDT MON AUG 18 2014
Models are in agreement that heights rises and resulting warm air
advection will be situated across the northeast corner of the county
warning area Tuesday evening providing another chance for
thunderstorms. As this area focuses further northward through the
night...have removed pops this area after midnight. Will keep lows
mild in the low to middle 70s. This will then set the stage for
mostly sunny very warm...breezy day on Wednesday. Highs will
generally be 95 to 100 degrees with the warmest in the Abilene area
and the coolest near Hiawatha.
As the upper ridge builds across the southern plains...expect dry
weather across the cwa Wednesday night through Thursday. However...
with south winds continuing...highs Thursday will again be in the
middle to upper 90s.
As the cutoff upper trough in the desert southwest gets picked up by
Thursday and heads into the central and northern high plains into
the weekend...there will be better chances for thunderstorms across
the area...although the northern/northwest 1/2 of the cwa will be
the more likely areas to see rain. Do not expect a frontal passage
until during the day Sunday...so may not see highs temps below 90
degrees until Monday when readings in the middle to upper 80s should
be the rule.
&&
.AVIATION...(For the 00Z TAFs through 00Z Tuesday Evening)
Issued at 626 PM CDT MON AUG 18 2014
VFR conditions prevail at sites as new guidance is increasing
confidence for VCTS mention for scattered TSRA to form along and
north of a frontal boundary near the terminals. Best timing for
convection in vicinity of terminals is from 06Z to 13Z. Isolated
strong wind gusts are possible. VRB winds persist near the boundary
axis shifting towards the southeast during the afternoon.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Gargan
LONG TERM...63
AVIATION...Bowen
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
610 PM CDT Mon Aug 18 2014
...Updated aviation discussion...
.SHORT TERM...(This evening through Tuesday)
ISSUED AT 1202 PM CDT MON AUG 18 2014
There is a high pressure ridge over Colorado south into New Mexico
late this afternoon. A lee side trough is near the Kansas and
Colorado border, and a warm front has been pushing northeast
through western Kansas this morning. The forecast is on track for
today, with highs just over 100F degrees likely somewhere across
southern and western Kansas, and upper 90s in our northern zones.
There could be a few and far between showers and isolated
thunderstorms just about anywhere late today. The HRRR model shows
a few thunderstorms across our south and southeast zones after
21z, but the NAM and NAMNG5 models are showing storms first over
our west and then moving across the northern CWA. Mid and high
clouds will be on the increase late this afternoon and evening.
So, the low Pops in the 17-20 percent range blanketing our
forecast area seem reasonable. Time will tell on which model is
more correct.
The same HRRR, NAM, and NAMNG5 models decrease the measurable
precip after 04Z, and then the clouds will slowly dissipate after
09Z or so. I plan to reduce 20 percent Pops rapidly between 06Z and
12Z. Not much precipitation will fall either, as any convection
will be high based. I used the QPF_from_PoP application, and it
only shows 0.01 to spotty 0.03 inches of rain overnight. With
clouds breaking late and perhaps a little rain, minimum temperatures
should end up in the middle 60s in Syracuse, Scott City, and
Wakeeney, while settling only to around 70F degrees in the Meade,
Coldwater and Medicine Lodge areas. Winds will continue to hover
at less than 10 MPH tonight.
On Tuesday, the surface low will advect into central Kansas, and the
front will sag south across part of our CWA. Thus, Max temps should
dip just a little north of the front, while south along the Oklahoma
border near Medicine Lodge, it should warm up to around 100F. Winds
on Tuesday will be breezy from the south in the 15 to 25 mph and
gusty range. I do not think there will any precipitation on
Tuesday, as the lower max temps will result in less instability than
today.
.LONG TERM...(Tuesday night through Monday)
ISSUED AT 225 PM CDT MON AUG 18 2014
Medium range models indicate an upper level ridge of high pressure
transitioning eastward out of the Western High Plains into the
Central Plains to begin the period Tuesday night. Combined with
a weak flow aloft, drier conditions are likely to prevail through
late Wednesday afternoon. Meanwhile, an upper level trough will dig
southeast across southern California Wednesday setting up a strong
southwest flow aloft across the Central and Southern Rockies,
including a +90kt jet core projected to lift northeast out of the
Desert Southwest into the Colorado Rockies. With a prevailing lee
side trough providing increased convergence in the lower levels,
thunderstorm development is likely across portions of eastern
Colorado Wednesday afternoon with a few storms potentially
drifting into western Kansas later in the evening through early
Thursday. However, the weaker flow aloft across western Kansas
will limit the strength and coverage of any storms. The upper
level shortwave will then lift northeast going into the weekend
while a large scale upper level high remains locked in across the
Deep South. Although precip chances will remain present virtually
each day into the weekend, the weaker flow aloft will limit storm
development, strength, and coverage.
Temperatures will remain above normal Wednesday as the
aforementioned upper level ridge shifts east across the Central
Plains. A prevailing southerly flow across western Kansas will
reinforce the warmer air mass already in place across the region
with H85 temperatures ranging from the upper 20s(C) in central
Kansas to around 30C closer to the Colorado border. As lower level
lapse rates steepen into the afternoon, look for highs well up
into the 90s(F) to near 100F Wednesday. Similar temperatures are
then expected each day through Saturday as the low level southerly
flow persists into the early part of the weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
ISSUED AT 607 PM CDT MON AUG 18 2014
VFR conditions are expected overnight and Tuesday based on the
moisture profiles from the 18z NAM BUFR soundings. Ongoing
diurnally driven convection near GCK and DDC will dissipate by or
shortly after sunset. There will be another chance for convection
after 03z as an upper level disturbance crosses western Kansas. At
this time given the latest NAM, RAP, and HRRR the probability for
convection after 03z at GCK, DDC, or HYS still appears small so will
not include mention of a prevailing group of convection in the 00z
tafs. Will place VCTS in the HYS tafs for several hours, mainly
between 04z and 08z. Prevailing winds will be south/southwest at
around 10 knots.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 69 97 71 99 / 30 10 0 10
GCK 67 96 70 98 / 30 10 0 10
EHA 66 95 68 98 / 30 10 0 20
LBL 66 96 71 98 / 30 10 0 10
HYS 68 98 71 99 / 20 10 0 10
P28 70 98 74 99 / 50 10 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Burke
LONG TERM...JJohnson
AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS GOODLAND KS
227 PM MDT SUN AUG 17 2014
.SHORT TERM...(THIS AFTERNOON THROUGH MONDAY)
ISSUED AT 121 PM MDT SUN AUG 17 2014
EARLY AFTERNOON WV IMAGERY AND RAP ANALYSIS CONTINUE TO SHOW
PERSISTENT RIDGE IN PLACE ACROSS THE SW US. A SHORTWAVE TROUGH IS
EVIDENT OVER NORTHERN COLORADO...WITH H7 TROUGH ON LATEST RAP JUST
OVER THE CENTRAL ROCKIES. RADAR AND VIS SATELLITE SHOW ISOLATED TO
WIDELY SCATTERED THUNDERSTORMS ALREADY DEVELOPING ALONG SURFACE
TROUGH AXIS AHEAD OF UPPER TROUGH OVER OUR SW CWA.
HRRR HAS A REASONABLE HANDLE ON CURRENT COVERAGE AND INDICATED
ACTIVITY MAINLY REMAINING ALONG AND EAST OF A TRIBUNE TO FLAGLER
LINE. MODERATE INSTABILITY IS IN PLACE WITH ML CAPE IN THE 1500-
3000 J/KG RANGE. CIN IS STILL HIGH ACROSS THE EASTERN HALF OF THE
CWA...HOWEVER AS SHORTWAVE TROUGH MOVES EAST LATER THIS AFTERNOON
AND EVENING ML CINH SHOULD WEAKEN ALLOWING FOR ACTIVITY TO SPREAD
EASTWARD. COVERAGE IS STILL A QUESTION WITH DRY INVERTED V TYPE
MOISTURE PROFILES...HOWEVER WITH LARGE SCALE FORCING INCREASE AND
GOOD BL MOISTURE IN PLACE WE SHOULD BE ABLE TO SEE SCATTERED
ACTIVITY DEVELOP. THERE IS AT LEAST AN ELEVATED SEVERE THREAT
CONSIDERING THE FAVORABLE CAPE AND EXPECTATION OF EFFECTIVE SHEER
INCREASING LATER THIS AFTERNOON/EVENING AS TROUGH MOVES INTO THE
REGION. PROFILES WOULD ALSO SUPPORT POTENTIAL FOR MICROBURST
POTENTIAL...WHICH IS ALSO SUPPORTED BY DCAPE VALUES AROUND 1800
J/KG. AS SHORTWAVE TROUGH SHIFTS EAST A WEAK FRONTAL PASSAGE WILL
SLIGHTLY COOL TEMPS ALOFT TONIGHT AND PRECIP SHOULD COME TO AN END
ACROSS THE EAST AFTER MIDNIGHT.
MONDAY...WITH ELEVATED FRONT ACROSS THE NORTH...AND WASHED OUT
FRONT/SURFACE BAROCLINIC ZONE IN THE SOUTH THUNDERSTORM
REDEVELOPMENT WILL BE POSSIBLE ACROSS THE CWA MONDAY AFTERNOON.
ANOTHER WEAK VORTICITY MAX WILL ROTATE JUST NORTH OF THE CWA
MONDAY AFTERNOON/EVENING...WHICH COULD ALSO HELP WITH THUNDERSTORM
INITIATION. PRECIP SIGNAL IS STRONGEST ACROSS THE SOUTHERN CWA
THROUGH MONDAY AFTERNOON ALONG BAROCLINIC ZONE AS IS LIFTS
NORTH...WITH BETTER COVERAGE TOWARDS LATE AFTERNOON IN THE SOUTH.
HIGH TEMPS MONDAY SHOULD BE SLIGHTLY COOLER THAN TODAY...THOUGH
THEY WILL REMAIN ABOVE NORMAL WITH MOST LOCATIONS IN THE LOW-MID
90S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 227 PM MDT SUN AUG 17 2014
SHOWER/THUNDERSTORM ACTIVITY SHOULD CONTINUE ACROSS THE REGION
MONDAY EVENING BEFORE COMING TO AN END EARLY TUESDAY MORNING. AT
FIRST...MAIN ACTIVITY SHOULD MOVE IN FROM NORTH CENTRAL COLORADO
UNDER WEST-NORTHWEST FLOW. GFS CONDENSATION PRESSURE DEFICITS AND
WINDS AT 320K INDICATE THAT ADDITIONAL ELEVATED STORM DEVELOPMENT IS
POSSIBLE BY MIDNIGHT AS MAIN SHORTWAVE TROUGH PASSES THROUGH.
DECIDED TO KEEP CHANCE POPS GOING THROUGH MOST OF THE NIGHT BEFORE
WANING EARLY TUESDAY MORNING...BETWEEN 3-6 AM MDT. SOME OF THESE
STORMS COULD BECOME SEVERE WITH LARGE HAIL AND DAMAGING WINDS AS THE
MAIN THREAT...TRANSITIONING TO PRIMARILY A LARGE HAIL THREAT WITH
THE OVERNIGHT ELEVATED THUNDERSTORM ACTIVITY.
THROUGH THE REST OF THE EXTENDED FORECAST PERIOD...A PERSISTENT
UPPER LEVEL PATTERN IS THE MAIN STORY BEFORE A PACIFIC NORTHWEST
TROUGH BREAKS THE RIDGE DOWN TOWARDS NEXT WEEKEND. FOR EACH DAY...
SHOWERS AND STORMS ARE POSSIBLE AS WEAK UPPER LEVEL DISTURBANCES
PASS OVER THE NORTHERN PERIPHERY OF THE SOUTHWESTERN U.S. RIDGE.
STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE TUESDAY WITH CAPE OF
2000-2500J/KG ALONG AND NORTH OF INTERSTATE 70...850-500 MB LAPSE
RATES AROUND 8 C/KM AND 0-6 KM BULK SHEAR AROUND 30-35 KTS. SOME
DRIER BOUNDARY LAYER AIR MOVES INTO THE REGION FROM THE WEST FOR
WEDNESDAY AND THURSDAY...LIMITING SEVERE CHANCES SOME BY DECREASING
AVAILABLE MOISTURE AND ATMOSPHERIC INSTABILITY.
AS FOR TEMPERATURES...HOT WEATHER IS EXPECTED TO PERSIST UNTIL THE
RIDGE BEGINS TO BREAK DOWN NEXT WEEKEND. DID LOWER MIN TEMPERATURES
A TOUCH BELOW MODEL GUIDANCE BASED ON RECENT TRENDS OBSERVED AND
COOL THUNDERSTORM OUTFLOWS LIKELY EACH EVENING. MODEL GUIDANCE...
ESPECIALLY THE EUROPEAN...SUGGESTS THAT A COLD FRONT PASSAGE IS
POSSIBLE BY THE END OF THE WEEK. MODEL AGREEMENT IS FAIRLY POOR WITH
THE GFS SUGGESTING THE HOT WEATHER WILL REMAIN. THEREFORE...DID NOT
MAKE ANY LARGE CHANGES TO THE EXTENDED FORECAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1139 AM MDT SUN AUG 17 2014
VFR CONDITIONS SHOULD PREVAIL THROUGH THE TAF PERIOD AT BOTH KGLD
AND KMCK TERMINALS. MAIN CONCERN IS THUNDERSTORMS EXPECTED TO
DEVELOP ALONG KS/CO STATE LINE AND WITHIN VICINITY OF
KGLD...EVENTUALLY INCREASING IN COVERAGE AS DISTURBANCE MOVES
NORTH. SHORT RANGE GUIDANCE FAVORS KGLD FOR NOW...WITH LESS
CONFIDENCE AT KMCK...SO I LIMITED TEMPO -TSRA TEMPO TO KGLD.
GUSTY WINDS AROUND 15-20KT WILL CONTINUE THIS AFTERNOON ON EASTERN
EDGE OF SURFACE TROUGH AT KMCK WITH LIGHTER WINDS GENERALLY AROUND
6KT AT KMCK. WILL WILL DIMINISH AT KMCK THIS EVENING WITH LOSS OF
DAYTIME HEATING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...RRH
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
122 PM MDT SUN AUG 17 2014
.SHORT TERM...(THIS AFTERNOON THROUGH MONDAY)
ISSUED AT 121 PM MDT SUN AUG 17 2014
EARLY AFTERNOON WV IMAGERY AND RAP ANALYSIS CONTINUE TO SHOW
PERSISTENT RIDGE IN PLACE ACROSS THE SW US. A SHORTWAVE TROUGH IS
EVIDENT OVER NORTHERN COLORADO...WITH H7 TROUGH ON LATEST RAP JUST
OVER THE CENTRAL ROCKIES. RADAR AND VIS SATELLITE SHOW ISOLATED TO
WIDELY SCATTERED THUNDERSTORMS ALREADY DEVELOPING ALONG SURFACE
TROUGH AXIS AHEAD OF UPPER TROUGH OVER OUR SW CWA.
HRRR HAS A REASONABLE HANDLE ON CURRENT COVERAGE AND INDICATED
ACTIVITY MAINLY REMAINING ALONG AND EAST OF A TRIBUNE TO FLAGLER
LINE. MODERATE INSTABILITY IS IN PLACE WITH ML CAPE IN THE 1500-
3000 J/KG RANGE. CIN IS STILL HIGH ACROSS THE EASTERN HALF OF THE
CWA...HOWEVER AS SHORTWAVE TROUGH MOVES EAST LATER THIS AFTERNOON
AND EVENING ML CINH SHOULD WEAKEN ALLOWING FOR ACTIVITY TO SPREAD
EASTWARD. COVERAGE IS STILL A QUESTION WITH DRY INVERTED V TYPE
MOISTURE PROFILES...HOWEVER WITH LARGE SCALE FORCING INCREASE AND
GOOD BL MOISTURE IN PLACE WE SHOULD BE ABLE TO SEE SCATTERED
ACTIVITY DEVELOP. THERE IS AT LEAST AN ELEVATED SEVERE THREAT
CONSIDERING THE FAVORABLE CAPE AND EXPECTATION OF EFFECTIVE SHEER
INCREASING LATER THIS AFTERNOON/EVENING AS TROUGH MOVES INTO THE
REGION. PROFILES WOULD ALSO SUPPORT POTENTIAL FOR MICROBURST
POTENTIAL...WHICH IS ALSO SUPPORTED BY DCAPE VALUES AROUND 1800
J/KG. AS SHORTWAVE TROUGH SHIFTS EAST A WEAK FRONTAL PASSAGE WILL
SLIGHTLY COOL TEMPS ALOFT TONIGHT AND PRECIP SHOULD COME TO AN END
ACROSS THE EAST AFTER MIDNIGHT.
MONDAY...WITH ELEVATED FRONT ACROSS THE NORTH...AND WASHED OUT
FRONT/SURFACE BAROCLINIC ZONE IN THE SOUTH THUNDERSTORM
REDEVELOPMENT WILL BE POSSIBLE ACROSS THE CWA MONDAY AFTERNOON.
ANOTHER WEAK VORTICITY MAX WILL ROTATE JUST NORTH OF THE CWA
MONDAY AFTERNOON/EVENING...WHICH COULD ALSO HELP WITH THUNDERSTORM
INITIATION. PRECIP SIGNAL IS STRONGEST ACROSS THE SOUTHERN CWA
THROUGH MONDAY AFTERNOON ALONG BAROCLINIC ZONE AS IS LIFTS
NORTH...WITH BETTER COVERAGE TOWARDS LATE AFTERNOON IN THE SOUTH.
HIGH TEMPS MONDAY SHOULD BE SLIGHTLY COOLER THAN TODAY...THOUGH
THEY WILL REMAIN ABOVE NORMAL WITH MOST LOCATIONS IN THE LOW-MID
90S.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 125 AM MDT SUN AUG 17 2014
THERE ARE STILL DIFFERENCES IN THE DETERMINISTIC AND ENSEMBLE
OUTPUT BUT THEY ARE MUCH LESS THAN YESTERDAY. IN GENERAL THE
MODELS DO AGREE ON THE OVERALL PATTERN OF HAVING A MEAN WESTERN
TROUGH AND A STRONG RIDGE OVER THE SOUTHEAST PORTION OF THE
COUNTRY. THIS DOES MAKE SENSE CONSIDERING THE CURRENT
AMPLIFIED/BLOCKY PATTERN WE ARE NOW IN.
THERE ARE TIMING DIFFERENCES...WITH THE ECMWF AND GFS IN MORE
AGREEMENT...WITH THE TIMING/AMPLITUDE OF THE INDIVIDUAL WAVES. THE
GFS IS FASTER AND LESS AMPLIFIED THAN THE ECMWF. NO MATTER WHAT
THOUGH THIS PATTERN LEAVES THE AREA OPEN TO SHORTWAVES ROTATING
THROUGH WITH SUBTROPICAL MOISTURE NEAR OR OVER THE AREA. THE ECMWF
IS A LITTLE WETTER THAN THE GFS.
SO DO LIKE WHAT THE CRH_INIT GAVE ME WITH THUNDERSTORM CHANCES
EVERY DAY UNTIL SATURDAY WHEN IT LOOKS LIKE WE MAY DRY OUT.
HOWEVER COULD SEE SATURDAY HAVING SOME LOW CHANCE OF THUNDERSTORMS.
WILL LEAVE SATURDAY DRY FOR NOW SINCE IT IS A WEEK OUT PLUS THE
MODELS ARE SHOWING ENOUGH DRYING TO SUPPORT THE DRY FORECAST. ALSO
THIS PATTERN SUPPORTS THE CONTINUED HOT AND ABOVE NORMAL
TEMPERATURES GIVEN TO ME BY THE INIT. THERE MAY BE A LITTLE COOL
DOWN TOWARD THE END THOUGH. SO OVERALL PLAN ON LITTLE IF ANY
CHANGES TO THE INIT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1139 AM MDT SUN AUG 17 2014
VFR CONDITIONS SHOULD PREVAIL THROUGH THE TAF PERIOD AT BOTH KGLD
AND KMCK TERMINALS. MAIN CONCERN IS THUNDERSTORMS EXPECTED TO
DEVELOP ALONG KS/CO STATE LINE AND WITHIN VICINITY OF
KGLD...EVENTUALLY INCREASING IN COVERAGE AS DISTURBANCE MOVES
NORTH. SHORT RANGE GUIDANCE FAVORS KGLD FOR NOW...WITH LESS
CONFIDENCE AT KMCK...SO I LIMITED TEMPO -TSRA TEMPO TO KGLD.
GUSTY WINDS AROUND 15-20KT WILL CONTINUE THIS AFTERNOON ON EASTERN
EDGE OF SURFACE TROUGH AT KMCK WITH LIGHTER WINDS GENERALLY AROUND
6KT AT KMCK. WILL WILL DIMINISH AT KMCK THIS EVENING WITH LOSS OF
DAYTIME HEATING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
138 AM MDT SUN AUG 17 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 230 PM MDT SAT AUG 16 2014
EARLY AFTERNOON WV IMAGERY AND RAP ANALYSIS SHOWS 595 DM RIDGE
CENTERED OVER SW US...WITH DIFFLUENT FLOW OVER THE NORTHERN PLAINS
AHEAD OF A CLOSED LOW OVER THE SOUTHERN CANADIAN ROCKIES. AT THE
SURFACE A COLD FRONT THAT MOVED INTO THE CWA LAST NIGHT ANS SHIFTED
EAST WITH WEAK CONVERGENCE ALONG A TROUGH AXIS EXTENDING ACROSS
EASTERN COLORADO.
MODERATE INSTABILITY IS IN PLACE ACROSS THE EASTERN HALF OF THE CWA
WITH ML CAPE VALUES IN THE 1000-2000 J/KG RANGE. LOWER VALUES AROUND
500 J/KG ARE IN PLACE ALONG THE TROUGH AXIS WHERE BETTER FOCUS FOR
THUNDERSTORM INITIATION IS EXPECTED. HIGHER CINH WAS EXPECTED TO
LIMIT INITIATION IN THE EAST...HOWEVER EXTENSIVE CU FIELD NOW IN
PLACE WITH BETTER VERTICAL EXTENT THAT WOULD BE EXPECTED IF AIR
MASS WAS COMPLETELY INHIBITED. WHERE THUNDERSTORMS HAVE DEVELOPED
IN THE WEST WILL REMAIN MOST LIKELY AREA FOR CONVECTION ALONG WEAK
CONVERGENCE ZONE...HOWEVER I COULDNT RULE OUT ISOLATED
THUNDERSTORM ACTIVITY FURTHER EAST WERE CAP TO WEAKEN...ESPECIALLY
WITH WESTERN EDGE OF FRONT NEAR OUR EASTERN CWA BORDER. HAVE
EXTENDED AREA OF SLIGHT CHANCE POPS AND BUMPED UP COVERAGE IN THE
SW. SEVERE THREAT REMAINS VERY LOW WITH WEAK SHEER...HOWEVER IF A
BETTER UPDRAFT WERE TO DEVELOP IN THE EAST WHERE BETTER CAPE
PROFILES EXIST THEN SEVERE HAIL/WIND COULD BE THREATS.
BETTER THUNDERSTORM COVERAGE IS EXPECTED BY MID-LATE AFTERNOON
SUNDAY AS A WEAK SHORTWAVE MOVES JUST NORTH OF THE CWA. MODELS HAVE
A DECENT PRECIP SIGNAL OVER OUR CWA...DESPITE DRY SOUNDINGS...SO
CHANCE POPS WERE RETAINED. THUNDERSTORMS WILL TEND TO BE
ELEVATED..HOWEVER EFFECTIVE SHEER AROUND 35KT AND MODERATE MU CAPE
IN THE 2000-2600 J/KG WOULD BE SUPPORTIVE OF A ELEVATED SEVERE
WIND/HAIL THREAT WITH STORMS THAT DEVELOP. WIND MAY ACTUALLY BE THE
GREATER THREAT CONSIDERING THE INVERTED V PROFILES IN PLACE.
SOUTHERLY FLOW SHOULD BRING GOOD WAA BACK TO THE CWA...AND TEMPS
SHOULD BE AS WARM IF NOT WARMER AS TODAY WITH VALUES IN THE MID-
UPPER 90S.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 125 AM MDT SUN AUG 17 2014
THERE ARE STILL DIFFERENCES IN THE DETERMINISTIC AND ENSEMBLE
OUTPUT BUT THEY ARE MUCH LESS THAN YESTERDAY. IN GENERAL THE
MODELS DO AGREE ON THE OVERALL PATTERN OF HAVING A MEAN WESTERN
TROUGH AND A STRONG RIDGE OVER THE SOUTHEAST PORTION OF THE
COUNTRY. THIS DOES MAKE SENSE CONSIDERING THE CURRENT
AMPLIFIED/BLOCKY PATTERN WE ARE NOW IN.
THERE ARE TIMING DIFFERENCES...WITH THE ECMWF AND GFS IN MORE
AGREEMENT...WITH THE TIMING/AMPLITUDE OF THE INDIVIDUAL WAVES. THE
GFS IS FASTER AND LESS AMPLIFIED THAN THE ECMWF. NO MATTER WHAT
THOUGH THIS PATTERN LEAVES THE AREA OPEN TO SHORTWAVES ROTATING
THROUGH WITH SUBTROPICAL MOISTURE NEAR OR OVER THE AREA. THE ECMWF
IS A LITTLE WETTER THAN THE GFS.
SO DO LIKE WHAT THE CRH_INIT GAVE ME WITH THUNDERSTORM CHANCES
EVERY DAY UNTIL SATURDAY WHEN IT LOOKS LIKE WE MAY DRY OUT.
HOWEVER COULD SEE SATURDAY HAVING SOME LOW CHANCE OF THUNDERSTORMS.
WILL LEAVE SATURDAY DRY FOR NOW SINCE IT IS A WEEK OUT PLUS THE
MODELS ARE SHOWING ENOUGH DRYING TO SUPPORT THE DRY FORECAST. ALSO
THIS PATTERN SUPPORTS THE CONTINUED HOT AND ABOVE NORMAL TEMPERATURES
GIVEN TO ME BY THE INIT. THERE MAY BE A LITTLE COOL DOWN TOWARD
THE END THOUGH. SO OVERALL PLAN ON LITTLE IF ANY CHANGES TO THE
INIT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1107 PM MDT SAT AUG 16 2014
VFR CONDITIONS ARE EXPECTED OVERNIGHT AND SUNDAY AT KGLD AND KMCK.
A DISTURBANCE MOVING INTO THE REGION WILL FIRE THUNDERSTORMS
SUNDAY AFTERNOON WHICH MAY MOVE INTO THE KGLD AND KMCK AREAS WITH
POSSIBLE BRIEF MVFR CONDITIONS. FORECAST SOUNDINGS INDICATE
DECREASING CLOUDS BY LATE EVENING. NO VISIBILITY OR CIG REDUCTIONS
FROM STRATUS/FOG ARE EXPECTED.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1113 PM MDT SAT AUG 16 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 230 PM MDT SAT AUG 16 2014
EARLY AFTERNOON WV IMAGERY AND RAP ANALYSIS SHOWS 595 DM RIDGE
CENTERED OVER SW US...WITH DIFFLUENT FLOW OVER THE NORTHERN PLAINS
AHEAD OF A CLOSED LOW OVER THE SOUTHERN CANADIAN ROCKIES. AT THE
SURFACE A COLD FRONT THAT MOVED INTO THE CWA LAST NIGHT ANS SHIFTED
EAST WITH WEAK CONVERGENCE ALONG A TROUGH AXIS EXTENDING ACROSS
EASTERN COLORADO.
MODERATE INSTABILITY IS IN PLACE ACROSS THE EASTERN HALF OF THE CWA
WITH ML CAPE VALUES IN THE 1000-2000 J/KG RANGE. LOWER VALUES AROUND
500 J/KG ARE IN PLACE ALONG THE TROUGH AXIS WHERE BETTER FOCUS FOR
THUNDERSTORM INITIATION IS EXPECTED. HIGHER CINH WAS EXPECTED TO
LIMIT INITIATION IN THE EAST...HOWEVER EXTENSIVE CU FIELD NOW IN
PLACE WITH BETTER VERTICAL EXTENT THAT WOULD BE EXPECTED IF AIR
MASS WAS COMPLETELY INHIBITED. WHERE THUNDERSTORMS HAVE DEVELOPED
IN THE WEST WILL REMAIN MOST LIKELY AREA FOR CONVECTION ALONG WEAK
CONVERGENCE ZONE...HOWEVER I COULDNT RULE OUT ISOLATED
THUNDERSTORM ACTIVITY FURTHER EAST WERE CAP TO WEAKEN...ESPECIALLY
WITH WESTERN EDGE OF FRONT NEAR OUR EASTERN CWA BORDER. HAVE
EXTENDED AREA OF SLIGHT CHANCE POPS AND BUMPED UP COVERAGE IN THE
SW. SEVERE THREAT REMAINS VERY LOW WITH WEAK SHEER...HOWEVER IF A
BETTER UPDRAFT WERE TO DEVELOP IN THE EAST WHERE BETTER CAPE
PROFILES EXIST THEN SEVERE HAIL/WIND COULD BE THREATS.
BETTER THUNDERSTORM COVERAGE IS EXPECTED BY MID-LATE AFTERNOON
SUNDAY AS A WEAK SHORTWAVE MOVES JUST NORTH OF THE CWA. MODELS HAVE
A DECENT PRECIP SIGNAL OVER OUR CWA...DESPITE DRY SOUNDINGS...SO
CHANCE POPS WERE RETAINED. THUNDERSTORMS WILL TEND TO BE
ELEVATED..HOWEVER EFFECTIVE SHEER AROUND 35KT AND MODERATE MU CAPE
IN THE 2000-2600 J/KG WOULD BE SUPPORTIVE OF A ELEVATED SEVERE
WIND/HAIL THREAT WITH STORMS THAT DEVELOP. WIND MAY ACTUALLY BE THE
GREATER THREAT CONSIDERING THE INVERTED V PROFILES IN PLACE.
SOUTHERLY FLOW SHOULD BRING GOOD WAA BACK TO THE CWA...AND TEMPS
SHOULD BE AS WARM IF NOT WARMER AS TODAY WITH VALUES IN THE MID-
UPPER 90S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 230 PM MDT SAT AUG 16 2014
A PERSISTENT UPPER LEVEL PATTERN WILL REMAIN DRAPED ACROSS THE
FORECAST AREA THROUGHOUT THE EXTENDED FORECAST PERIOD. THIS MEANS A
CONTINUATION OF THE ABOVE NORMAL TEMPERATURES AND THUNDERSTORM
CHANCES EACH AFTERNOON.
FOR SUNDAY NIGHT...A STRONG SHORTWAVE WILL PROGRESS ACROSS THE
NORTHERN GREAT PLAINS. SOME ENERGY SHOULD PASS OVER THE TRI-STATE
REGION...LEADING SCATTERED THUNDERSTORMS. WITH THIS DISTURBANCE AND
ASSOCIATED STRONGER WINDS MOVING THROUGH...THERE IS AN INCREASE IN
WIND SHEAR. WITH ATMOSPHERE INSTABILITY/CAPE UP TO 2000-2500
J/KG...THERE COULD BE A MORE ORGANIZED THREAT FOR SEVERE
WEATHER...ESPECIALLY EAST OF THE COLORADO BORDER. LARGE HAIL AND
DAMAGING WINDS WOULD BE THE MAIN THREATS AS BOUNDARY LAYER MOISTURE
IS NOT SUPPORTIVE OF A TORNADIC ENVIRONMENT. MOST OF THE
THUNDERSTORM ACTIVITY SHOULD LEAVE THE AREA BY MIDNIGHT AS THIS WILL
BE A FAST MOVING SHORTWAVE.
FOR MONDAY AFTERNOON/EVENING AND TUESDAY AFTERNOON/EVENING...
ADDITIONAL UPPER DISTURBANCES LEAD TO CONTINUED CHANCES FOR
STRONG/SEVERE THUNDERSTORMS. TUESDAY APPEARS HAVE A SLIGHTLY BETTER
CHANCE OF CONVECTIVE ACTIVITY AS THERE ARE SOME QUESTIONS ABOUT
ATMOSPHERE INSTABILITY MONDAY AND THE EFFECT THAT SUNDAY NIGHTS
CONVECTION WOULD HAVE ON THE ENVIRONMENT. LARGE HAIL AND DAMAGING
WINDS ARE ONCE AGAIN THE PRIMARY THREATS.
FOR WEDNESDAY AND BEYOND...DISAGREEMENT WITHIN THE MODEL GUIDANCE
LEADS TO LOWER CONFIDENCE IN THE TIMING AND LOCATIONS FOR BEST
THUNDERSTORM CHANCES. THERE COULD BE STORMS EACH DAY WITH THE
STAGNANT PATTERN AND CONTINUED UPPER LEVEL DISTURBANCE PASSAGES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1107 PM MDT SAT AUG 16 2014
VFR CONDITIONS ARE EXPECTED OVERNIGHT AND SUNDAY AT KGLD AND KMCK.
A DISTURBANCE MOVING INTO THE REGION WILL FIRE THUNDERSTORMS
SUNDAY AFTERNOON WHICH MAY MOVE INTO THE KGLD AND KMCK AREAS WITH
POSSIBLE BRIEF MVFR CONDITIONS. FORECAST SOUNDINGS INDICATE
DECREASING CLOUDS BY LATE EVENING. NO VISIBILITY OR CIG REDUCTIONS
FROM STRATUS/FOG ARE EXPECTED.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...RRH
AVIATION...FS
AREA FORECAST DISCUSSION
NWS JACKSON KY
1130 PM EDT MON AUG 18 2014
.UPDATE...
ISSUED AT 1130 PM EDT MON AUG 18 2014
UPDATED THE FORECAST TO ISSUE A DENSE FOG ADVISORY FOR EASTERN
KENTUCKY. HAD REPORTS OF DENSE FOG MOST OF THE WAY FROM CLAY CITY TO
JACKSON. AT SIGNS POINT TO A WIDESPREAD FOG EVENT TONIGHT THAT IS
WORSE THAN THE NORMAL AUGUST VALLEY FOG.
UPDATE ISSUED AT 702 PM EDT MON AUG 18 2014
UPDATED THE FORECAST TO BETTER REFLECT CURRENT CONDITIONS AND MODEL
TRENDS. THE PRECIPITATION HAS BEEN TAPERING OFF AS THE SHORT WAVE
MOVES OFF TO THE EAST. LOWERED THE PROBABILITY OF PRECIPITATION
BASED ON CURRENT RADAR AND THE LATEST HRRR OUTPUT. ALSO TOOK OUT THE
CHANCE OF THUNDER OUT AS NONE HAS DEVELOPED ALL DAY AND THE MODELS
ARE NOT SUPPORTING THEIR DEVELOPMENT IN THE NEAR TERM. THE ONLY
THUNDER IS CURRENTLY OVER CENTRAL TENNESSEE. A WEAK FRONT IS STILL
QUASI STATIONARY OVER THE AREA. EXPECT TO SEE SOME FAIRLY DENSE FOG
TONIGHT...ESPECIALLY IN THE VALLEYS.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 255 PM EDT MON AUG 18 2014
THE LOW PRESSURE SYSTEM THAT BROUGHT THE WIDESPREAD RAIN LAST NIGHT
INTO THIS MORNING HAS MOVED INTO WV...TAKING THE DEEPER MOISTURE AND
BETTER LIFT WITH IT. A WEST EAST ORIENTED QUASI STATIONARY FRONT
REMAINS ACROSS KENTUCKY...AND SCATTERED LIGHT SHOWERS CONTINUE TO
MOVE FROM WEST TO EAST ACROSS THE AREA. ANOTHER WAVE OF LOW PRESSURE
EVIDENT ON SATELLITE AND RADAR IMAGERY WAS MOVING EAST ALONG THE TN MS
BORDER. THIS FEATURE...ALONG WITH THE BOUNDARY ACROSS KY WILL
NECESSITATE CONTINUING WITH A CHANCE OF RAIN OVERNIGHT. HOWEVER THE
BEST RAIN AND THUNDER CHANCES SHOULD BE SOUTH OF KY TONIGHT.
WITH VERY MOIST BOUNDARY LAYER AND SOME BREAKS EXPECTED IN THE CLOUDS
THIS EVENING...FOG AND LOW CLOUDS ARE EXPECTED TO DEVELOP DURING THE
NIGHT AND LINGER INTO THE MORNING ON TUESDAY. WILL INCLUDE FOG IN THE
FORECAST FOR TONIGHT. ON TUESDAY THE NEXT SHORT WAVE IN THIS VERY
ACTIVE PATTERN WILL BE PUSHING INTO THE WESTERN GREAT LAKES REGION. AT
THE SURFACE A VERY MOIST AND WARM AIR MASS WILL REMAIN IN PLACE
ACROSS EASTERN KY ON TUESDAY...WHILE A COLD FRONT DROPS SOUTHEAST ACROSS IL
AND INDIANA. THUNDERSTORMS ARE EXPECTED TO DEVELOP AHEAD OF THIS
FRONT TUESDAY AFTERNOON. CURRENT THINKING IS THAT SHOWERS AND
THUNDERSTORMS THAT DEVELOP TO OUR NORTHWEST ON TUESDAY WILL MOVE INTO
OUR AREA TUESDAY NIGHT. WITH THIS THOUGHT IN MIND WILL INTRODUCE
LIKELY PROBABILITIES FOR SHOWERS AND THUNDERSTORMS IN THE NORTHERN
PART OF OUR FORECAST AREA TUESDAY NIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 255 PM EDT MON AUG 18 2014
MODELS CONTINUE TO DISPLAY GOOD AGREEMENT THROUGH THE EXTENDED.
UPPER/MID LEVEL GREAT LAKES LOW WILL MAKE A BEE LINE TO THE MID
ATLANTIC COAST BY FRIDAY. MEANWHILE BURGEONING RIDGE TO OUR WEST
WILL EXERT ITS INFLUENCE FROM THE SOUTHERN PLAINS/MISSISSIPPI RIVER
DELTA NORTHWARD INTO THE UPPER MIDWEST. GREAT LAKES LOW WILL PASS TO
OUR NORTHEAST DURING ITS MARCH TO THE COAST AND DRAG A SURFACE
FRONTAL BOUNDARY ACROSS THE CENTER OF THE OHIO VALLEY REGION.
SHARPENING UPPER LEVEL RIDGE AXIS WILL SHIFT SOUTHEASTWARD OVER OUR
AREA TOWARDS THE END OF THE EXTENDED AS ENERGY ROUNDS ITS TOP ACROSS
THE NORTHERN TIER. DESPITE THE BUILDING RIDGE ALOFT...THE BY THEN
QUASI-STATIONARY SFC FRONTAL BOUNDARY WILL REMAIN IN OUR VICINITY AS
IT BECOMES ORIENTED PARALLEL TO THE UPPER LEVEL FLOW PATTERN. THUS
WITH LITTLE TO NO FORCING AT THE MID AND UPPER LEVELS...THIS
BOUNDARY WILL REMAIN CLOSE ENOUGH TO OUR AREA TO SERVE AS A FOCUS
FOR ADDITIONAL SHOWER AND THUNDERSTORM ACTIVITY THROUGH THE LATTER
HALF OF THE EXTENDED PERIOD. THE MAINLY DIURNAL SHOWER AND
THUNDERSTORM ACTIVITY MAY BE AUGMENTED BY ONE OR TWO ORGANIZED
THUNDERSTORM COMPLEXES DROPPING DOWN FROM THE NORTHWEST ON THE EAST
SIDE OF THE UPPER RIDGE.
FOR SENSIBLE WEATHER...WE WILL SEE THE RETURN OF TRUE SUMMER LIKE
WEATHER AS RIDGING TO OUR SOUTHWEST WILL BE STRONG ENOUGH TO SEND
TEMPERATURES INTO AND ABOVE SEASONABLE NORMS DESPITE THE INCREASED
HUMIDITY. THIS WILL ALSO HELP TO ENHANCE THE DIURNALLY DRIVEN
INSTABILITY ACROSS THE AREA RESULTING IN THE BEST CHANCES OF STORMS
EACH AFTERNOON AND EVENING. THE THREAT OF RAIN DECREASES BY NEXT
WEEKEND AS THE UPPER RIDGE AMPLIFIES AND SHIFTS EASTWARD A BIT...BUT
THE POTENTIAL CAN NOT BE TOTALLY REMOVED. IN ADDITION...SHOULD THE
RIDGE EXERT A STRONGER INFLUENCE BY SHIFTING JUST A BIT MORE EAST WE
MAY BE IN FOR EVEN HOTTER WEATHER BY NEXT WEEKEND. WITH THE 0Z ECMWF
ADVERTISING H850 TEMPS UP AROUND 22C TO 24C...THE POSSIBLY EXISTS
THAT WE MIGHT SEE SOME OF OUR HOTTEST WEATHER OF THE SUMMER THUS
FAR.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 702 PM EDT MON AUG 18 2014
A WIDE VARIETY OF CONDITIONS CAN BE EXPECTED ACROSS EASTERN KENTUCKY
FOR THE REMAINDER OF THE EARLY EVENING. AS THERE IS SOME CLEARING
THIS EVENING...EXPECT TO SEE SOME DENSE FOG FORMING IN THE VALLEYS
AS WELL AS THE TAF STATIONS WITH VLIFR AND IFR CONDITIONS
PREDOMINATING. THE FOG WILL MOST LIKELY TAKE UNTIL 14-15Z TO FINALLY
BURN OFF. EXPECTING SOME SCATTERED SHOWERS AND THUNDERSTORMS TOMORROW
ACROSS THE AREA. EXPECT THE ACTIVITY TO PICK UP IN THE LATE AFTERNOON
AND EVENING. WILL MOST LIKELY NOT SEE MUCH VFR TOMORROW UNTIL THE
AFTERNOON.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM EDT TUESDAY FOR KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...JJ
SHORT TERM...SBH
LONG TERM...RAY
AVIATION...JJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
147 PM EDT SUN AUG 17 2014
.UPDATE...
ISSUED AT 146 PM EDT SUN AUG 17 2014
LINE OF SHOWERS AND A FEW THUNDERSTORMS NOW OVER THE WESTERN PART OF
THE FORECAST AREA CONTINUES TO MOVE EAST AND WEAKEN WITH TIME. THIS
LINE WILL CONTINUE TO WEAKEN AS IT MOVES EAST THROUGH THE REMAINDER
OF THE AFTERNOON. MAIN HEAVY RAIN THREAT STILL APPEARS TO BE LATER
TONIGHT INTO EARLY MONDAY MORNING AS THE UPPER LEVEL LOW AND TROUGH
PROGRESS EAST AND 8H LOW LEVEL JET RAMPS UP AND LIFT INCREASES. BASED
ON 12Z SOUNDINGS AND SOME GOES SOUNDER DATA AVAILABLE BEFORE THE
WIDESPREAD CLOUDS MOVED IN...PWS AROUND 2 INCHES SEEM REASONABLE AS
FORECAST BY THE MAJORITY OF THE MODEL DATA FOR LATER TONIGHT.
UPDATE ISSUED AT 939 AM EDT SUN AUG 17 2014
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE ACROSS THE
AREA THIS MORNING...BUT ARE DIMINISHING. TOTAL LIGHTNING DATA IS
SHOWING SOME IN CLOUD LIGHTNING WITH STORM OVER MENIFEE COUNTY. THIS
HAS BEEN THE ONLY LIGHTNING NOTED IN OUR AREA THIS MORNING.
FOCUS IS ON LARGE CONVECTIVE COMPLEX OVER WESTERN KY ASSOCIATED WITH
THE MCV CENTERED OVER S IL/W KY. SATELLITE AND RADAR TRENDS HAVE SHOWN
SOME OVERALL WEAKENING...HOWEVER NEW CONVECTION IS NOW DEVELOPING ON
THE LEADING EDGE OF THIS SYSTEM...AND IT MAY SUSTAIN ITSELF INTO THE
EARLY AFTERNOON. CURRENT MOVEMENT AND PROJECTED DEVELOPMENT ON THE
LEADING EDGE WOULD BRING SHOWERS AND THUNDERSTORMS INTO THE WESTERN
PART OF THE FORECAST AREA BETWEEN 11 AM AND NOON. ENVIRONMENT LOOKS
LESS FAVORABLE FOR THIS CONVECTION TO MAINTAIN STRENGTH AS IT WILL
MOVE EAST QUICKER THAN THE SUPPORTING UPPER TROUGH. THE LATEST HRRR
DOES SHOW THE REMNANTS OF THE WESTERN KY CONVECTION MOVING ACROSS OUR
AREA THIS AFTERNOON...BUT WEAKENING AS IT DOES SO.
A QUICK LOOK AT THE 12Z SOUNDINGS SHOWS PW OF 1.32 AT ILN AND 1.83 AT
OHX. BASED ON GOES SOUNDER DATA IT APPEARS THE OHX SOUNDING IS MORE
REPRESENTATIVE OF THE AIR MASS OVER THE MAJORITY OF OUR AREA. AS THE
TROUGH AXIS NOW OVER IL INTO SE MO MOVES EAST 8H WINDS OVER EASTERN
KY WILL INCREASE THIS EVENING AND INTO THE NIGHT. THIS...COMBINED
WITH HIGH PWS POINT TOWARDS THE BEST CHANCE FOR HEAVY RAIN FROM THIS
EVENING INTO THE OVERNIGHT PERIOD.
WILL UPDATE NDFD AND ASSOCIATED PRODUCTS SHORTLY AFTER 10 AM EDT TO
ACCOUNT FOR LATEST OBSERVATIONAL TRENDS.
UPDATE ISSUED AT 705 AM EDT SUN AUG 17 2014
CONDITIONS THIS MORNING ACROSS THE AREA FEATURE SOME SHOWERS NOW
MOVING THROUGH THE AREA WITH A WEAKENED MCV UPSTREAM IN WESTERN
KENTUCKY MAKING ITS WAY INTO CENTRAL KENTUCKY. THIS FEATURE WILL POSE
A CONCERN FOR THE AREA TODAY AS IT SLOWLY TRACKS INTO EASTERN
KENTUCKY BY THE AFTERNOON. THE ONE FORECAST CHALLENGE TODAY IS HOW
FAVORABLE THE ENVIRONMENT WILL BE TO THIS FEATURE. MODEL
SOUNDINGS...AS WELL AS THE HRRR DO NOT FAVOR INTENSIFYING THIS
SYSTEM. SURFACE INSTABILITY WITH THE GFS IS RATHER LACKING AND THE
HRRR SHOWS NO REAL INCREASE IN THE ECHOS. NONETHELESS...THE HEAVY
RAIN THREAT MAY BEGIN SLIGHTLY EARLIER TODAY AS THE CURRENT SITUATION
SEEMS TO JIVE WITH THE EXCESSIVE RAINFALL FORECAST. AS WELL...THE
POSSIBILITY OF A STRONG STORM POSSESSING GUSTY WIND CAPABILITY INTO
THIS AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 330 AM EDT SUN AUG 17 2014
CURRENT CONDITIONS ACROSS THE AREA AS OF 07Z FEATURE SOME SHOWERS
MOVING THROUGH EASTERN KENTUCKY FORMED BY SOME OVERRUNNING MOISTURE
OVER A WEAK SURFACE WARM FRONT DEVELOPING AS A LOW PRESSURE CENTER
OUT WEST CONTINUES TO DEVELOP AND SLOWLY MOVE EAST. A DRY LAYER AT
THE SURFACE OVER MUCH OF THE AREA HAS HINDERED MEASURABLE PRECIP.
HOWEVER...THIS BOUNDARY LAYER HAS AND WILL CONTINUE TO MOISTENED UP
QUITE A BIT THROUGH THE PERIOD OF THE MORNING HOURS AS SOUTHERLY FLOW
INCREASES AND RAINFALL FALLS OVER THESE AREAS. THIS RAINFALL ALONG
WITH THE SURFACE BOUNDARY WILL WEAKEN AND LIFT OFF TO THE NORTHEAST
AS THE LOW OUT WEST MOVES EAST. THIS WILL RESULT IN A BETTER CHANCE
FOR SHOWERS AND THUNDERSTORMS AS THE BETTER FORCING AND MOISTURE
MOVES EAST THIS AFTERNOON AND INTO THE EVENING.
HEADING INTO THIS EVENING AND TONIGHT...THE SURFACE LOW BEGINS TO
ENTER CENTRAL KY AND EVENTUALLY EASTERN KENTUCKY INTO MONDAY.
MENTIONING THE FACT THAT THE MODELS HAVE NOT HANDLED THIS FEATURE
WELL...ESPECIALLY THE NAM. MODEL SOUNDINGS FOR THE GFS AND NAM HAVE
HAD SOLUTION PRETTY FAR APART WITH CONCERN WITH AVAILABLE MOISTURE
WITH PWATS FOR THE NAM BEING WELL OVER 2.10 INCHES AND THE GFS BEING
AROUND 1.70 INCHES. A SLIGHT RISK OF EXCESSIVE RAIN WAS ISSUED FOR
THE AREA MAINLY ALONG THE I-75 CORRIDOR AND WEST FOR TONIGHT THROUGH
MONDAY. THE FACT THAT THERE IS SO MUCH INCONSISTENCY IN THE
MODELS...STORM MOTION IS ABOVE 10 KNOTS...AND FINALLY THE ADVERTISED
WAVE LOOKS MUCH LESS POTENT THAN ADVERTISED...IT APPEARS THE RISK OF
FLASH FLOODING WILL BE QUITE LOCALIZED AND ONLY CENTERED AROUND AREAS
THAT ARE STILL DRYING OUT FROM LAST WEEK RAINS. ALSO AREAS WHERE
STORMS MOVE REPEATEDLY OVER THE SAME AREA. AS SUCH...WILL ONLY CONTINUE
MENTIONING THIS RISK IN THE HWO BASED UPON REASONING AS WELL AS
COLLABORATION WITH SURROUNDING OFFICES. HOWEVER...THE WAVE AS WELL AS
THE SURFACE FEATURE IS MOVING THROUGH QUITE SLOW SO THE CHANCE FOR
STORMS TO MOVE OVER REPEATEDLY IS CERTAINLY A GOOD POSSIBILITY. THE
CHALLENGING PORTION OF THE FORECAST WILL BE TONIGHT AND INTO MONDAY
AND IDENTIFYING WHICH AREAS WILL RECEIVE HEAVY RAIN AND ALSO MONDAY
AFTERNOON AS BASED UPON MODEL SOUNDINGS...A DRY LAYER DOES SHOW UP IN
THE GFS IN CONJUNCTION WITH SOME GOOD INSTABILITY AND SHEAR. A
MARGINAL SEVERE THREAT MAY ARISE. A CHALLENGING AND MURKY SHORT TERM
FORECAST LOOKS TO BE THE CASE WITH A FEW CONCERNS.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 500 AM EDT SUN AUG 17 2014
MODELS CONTINUE TO DISPLAY GOOD AGREEMENT THROUGH THE EXTENDED...
INTERESTINGLY WITH THE GFS SHOWING A BIT MORE CONTINUITY THAN THE
ECMWF THIS CYCLE. MID AND UPPER PATTERN WILL BE QUASI ZONAL AS A
PROGRESSIVE BUT SLOW LOW AMPLITUDE WAVE MOVES ACROSS THE GREAT LAKES
REGION. PATTERN AMPLIFIES A BIT TOWARDS THE END OF THE EXTENDED
WINDOW WITH OUR FORECAST AREA ON THE EASTERN PERIPHERY OF RIDGE THAT
EXTENDS FROM THE SOUTHERN PLAINS/MISSISSIPPI RIVER DELTA TO THE UPPER
MIDWEST. AT THE SURFACE...LOW PRESSURE WILL BE EXITING TO OUR EAST
JUST AS A SECOND LOW PRESSURE SYSTEM ROLLS THROUGH THE GREAT LAKES
REGION BY MID WEEK. THE GREAT LAKES LOW WILL PULL A SURFACE COLD
FRONTAL BOUNDARY ACROSS THE OHIO VALLEY. THIS FRONTAL BOUNDARY WILL
BECOME ORIENTED IN A NORTHWEST TO SOUTHEAST DIRECTION...PARALLEL TO
THE UPPER FLOW PATTERN ON THE EASTERN SIDE OF THE AFOREMENTIONED
RIDGE. THUS WITH LITTLE TO NO FORCING AT THE MID AND UPPER LEVELS...
THIS BOUNDARY WILL ESTABLISH A STATIONARY BAROCLINIC ZONE ACROSS THE
REGION WHICH APPEARS TO SET UP JUST TO OUR NORTH AND EAST. IT APPEARS
THIS ZONE WILL BECOME THE FOCUS OF ADDITIONAL SHOWER AND THUNDERSTORM
ACTIVITY...AND SHOULD BE CLOSE ENOUGH THAT THE THREAT OF RAIN WILL
CONTINUE TO EXIST FOR OUR AREA THROUGH THE REMAINDER OF THE FORECAST.
MODELS EVEN HINT AT THE POSSIBILITY OF A SERIES OF MCS TYPE SYSTEMS
DEVELOPING AND MOVING ALONG THIS ZONE...POSSIBLY AFFECTING PORTIONS
OF OUR AREA.
FOR SENSIBLE WEATHER...THE MOST SIGNIFICANT AND NOTABLE DIFFERENCE
IN OUR WEATHER WILL BE THE RETURN OF TRUE SUMMER LIKE CONDITIONS WITH
SEASONABLY WARM AND HUMID AFTERNOONS AND MUGGY NIGHTS. TWEAKED TEMPS
TOWARDS LATEST MODEL BLENDS WHICH RESULTED IN ONLY MINOR CHANGES TO
PREVIOUS FORECASTS. THE DAILY THREAT OF SOME TYPE OF SHOWER AND
THUNDERSTORM ACTIVITY WILL ENSURE AN OVERALL UNSETTLED WEATHER
PATTERN...ESPECIALLY IF CONDITIONS BECOME FAVORABLE FOR THE
OCCASIONAL MCS SYSTEM TO MATERIALIZE AND MOVE THROUGH THE REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 146 PM EDT SUN AUG 17 2014
A BAND OF SHOWERS AND A FEW THUNDERSTORMS WILL WEAKEN AS IT MOVES
EAST ACROSS THE FORECAST AREA THROUGH THE REMAINDER OF THE
AFTERNOON. IN THE PRECIPITATION AREA MVFR TO IFR CONDITIONS CAN BE
EXPECTED...WITH VFR PREVAILING OUTSIDE OF THE RAIN AREA. LOW PRESSURE
OVER SOUTHERN INDIANA AND WESTERN KY WILL MOVE EAST TONIGHT BRINGING
WIDESPREAD RAIN ALONG WITH SOME THUNDERSTORMS TO THE AREA. CONDITIONS
WILL DETERIORATE AFTER 03Z WITH WIDESPREAD MVFR TO IFR CONDITIONS
EXPECTED FOR LATE TONIGHT INTO MONDAY MORNING. CONDITIONS WILL BE
SLOW TO IMPROVE ON MONDAY. THE RAIN AND THUNDERSTORMS WILL END FROM
WEST TO EAST DURING THE MORNING BUT LOW CLOUD AND FOG WILL LINGER
AFTER THE RAIN ENDS. VFR CONDITIONS ARE EXPECTED TO RETURN MONDAY
AFTERNOON. WINDS WILL REMAIN LIGHT THROUGH THE FORECAST PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SBH
SHORT TERM...SHALLENBERGER
LONG TERM...RAY
AVIATION...RAY
AREA FORECAST DISCUSSION
NWS JACKSON KY
939 AM EDT SUN AUG 17 2014
.UPDATE...
ISSUED AT 939 AM EDT SUN AUG 17 2014
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE ACROSS THE
AREA THIS MORNING...BUT ARE DIMINISHING. TOTAL LIGHTNING DATA IS
SHOWING SOME IN CLOUD LIGHTNING WITH STORM OVER MENIFEE COUNTY. THIS
HAS BEEN THE ONLY LIGHTNING NOTED IN OUR AREA THIS MORNING.
FOCUS IS ON LARGE CONVECTIVE COMPLEX OVER WESTERN KY ASSOCIATED WITH
THE MCV CENTERED OVER S IL/W KY. SATELLITE AND RADAR TRENDS HAVE SHOWN
SOME OVERALL WEAKENING...HOWEVER NEW CONVECTION IS NOW DEVELOPING ON
THE LEADING EDGE OF THIS SYSTEM...AND IT MAY SUSTAIN ITSELF INTO THE
EARLY AFTERNOON. CURRENT MOVEMENT AND PROJECTED DEVELOPMENT ON THE
LEADING EDGE WOULD BRING SHOWERS AND THUNDERSTORMS INTO THE WESTERN
PART OF THE FORECAST AREA BETWEEN 11 AM AND NOON. ENVIRONMENT LOOKS
LESS FAVORABLE FOR THIS CONVECTION TO MAINTAIN STRENGTH AS IT WILL
MOVE EAST QUICKER THAN THE SUPPORTING UPPER TROUGH. THE LATEST HRRR
DOES SHOW THE REMNANTS OF THE WESTERN KY CONVECTION MOVING ACROSS OUR
AREA THIS AFTERNOON...BUT WEAKENING AS IT DOES SO.
A QUICK LOOK AT THE 12Z SOUNDINGS SHOWS PW OF 1.32 AT ILN AND 1.83 AT
OHX. BASED ON GOES SOUNDER DATA IT APPEARS THE OHX SOUNDING IS MORE
REPRESENTATIVE OF THE AIR MASS OVER THE MAJORITY OF OUR AREA. AS THE
TROUGH AXIS NOW OVER IL INTO SE MO MOVES EAST 8H WINDS OVER EASTERN
KY WILL INCREASE THIS EVENING AND INTO THE NIGHT. THIS...COMBINED
WITH HIGH PWS POINT TOWARDS THE BEST CHANCE FOR HEAVY RAIN FROM THIS
EVENING INTO THE OVERNIGHT PERIOD.
WILL UPDATE NDFD AND ASSOCIATED PRODUCTS SHORTLY AFTER 10 AM EDT TO
ACCOUNT FOR LATEST OBSERVATIONAL TRENDS.
UPDATE ISSUED AT 705 AM EDT SUN AUG 17 2014
CONDITIONS THIS MORNING ACROSS THE AREA FEATURE SOME SHOWERS NOW
MOVING THROUGH THE AREA WITH A WEAKENED MCV UPSTREAM IN WESTERN
KENTUCKY MAKING ITS WAY INTO CENTRAL KENTUCKY. THIS FEATURE WILL POSE
A CONCERN FOR THE AREA TODAY AS IT SLOWLY TRACKS INTO EASTERN
KENTUCKY BY THE AFTERNOON. THE ONE FORECAST CHALLENGE TODAY IS HOW
FAVORABLE THE ENVIRONMENT WILL BE TO THIS FEATURE. MODEL
SOUNDINGS...AS WELL AS THE HRRR DO NOT FAVOR INTENSIFYING THIS
SYSTEM. SURFACE INSTABILITY WITH THE GFS IS RATHER LACKING AND THE
HRRR SHOWS NO REAL INCREASE IN THE ECHOS. NONETHELESS...THE HEAVY
RAIN THREAT MAY BEGIN SLIGHTLY EARLIER TODAY AS THE CURRENT SITUATION
SEEMS TO JIVE WITH THE EXCESSIVE RAINFALL FORECAST. AS WELL...THE
POSSIBILITY OF A STRONG STORM POSSESSING GUSTY WIND CAPABILITY INTO
THIS AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 330 AM EDT SUN AUG 17 2014
CURRENT CONDITIONS ACROSS THE AREA AS OF 07Z FEATURE SOME SHOWERS
MOVING THROUGH EASTERN KENTUCKY FORMED BY SOME OVERRUNNING MOISTURE
OVER A WEAK SURFACE WARM FRONT DEVELOPING AS A LOW PRESSURE CENTER
OUT WEST CONTINUES TO DEVELOP AND SLOWLY MOVE EAST. A DRY LAYER AT
THE SURFACE OVER MUCH OF THE AREA HAS HINDERED MEASURABLE PRECIP.
HOWEVER...THIS BOUNDARY LAYER HAS AND WILL CONTINUE TO MOISTENED UP
QUITE A BIT THROUGH THE PERIOD OF THE MORNING HOURS AS SOUTHERLY FLOW
INCREASES AND RAINFALL FALLS OVER THESE AREAS. THIS RAINFALL ALONG
WITH THE SURFACE BOUNDARY WILL WEAKEN AND LIFT OFF TO THE NORTHEAST
AS THE LOW OUT WEST MOVES EAST. THIS WILL RESULT IN A BETTER CHANCE
FOR SHOWERS AND THUNDERSTORMS AS THE BETTER FORCING AND MOISTURE
MOVES EAST THIS AFTERNOON AND INTO THE EVENING.
HEADING INTO THIS EVENING AND TONIGHT...THE SURFACE LOW BEGINS TO
ENTER CENTRAL KY AND EVENTUALLY EASTERN KENTUCKY INTO MONDAY.
MENTIONING THE FACT THAT THE MODELS HAVE NOT HANDLED THIS FEATURE
WELL...ESPECIALLY THE NAM. MODEL SOUNDINGS FOR THE GFS AND NAM HAVE
HAD SOLUTION PRETTY FAR APART WITH CONCERN WITH AVAILABLE MOISTURE
WITH PWATS FOR THE NAM BEING WELL OVER 2.10 INCHES AND THE GFS BEING
AROUND 1.70 INCHES. A SLIGHT RISK OF EXCESSIVE RAIN WAS ISSUED FOR
THE AREA MAINLY ALONG THE I-75 CORRIDOR AND WEST FOR TONIGHT THROUGH
MONDAY. THE FACT THAT THERE IS SO MUCH INCONSISTENCY IN THE
MODELS...STORM MOTION IS ABOVE 10 KNOTS...AND FINALLY THE ADVERTISED
WAVE LOOKS MUCH LESS POTENT THAN ADVERTISED...IT APPEARS THE RISK OF
FLASH FLOODING WILL BE QUITE LOCALIZED AND ONLY CENTERED AROUND AREAS
THAT ARE STILL DRYING OUT FROM LAST WEEK RAINS. ALSO AREAS WHERE
STORMS MOVE REPEATEDLY OVER THE SAME AREA. AS SUCH...WILL ONLY CONTINUE
MENTIONING THIS RISK IN THE HWO BASED UPON REASONING AS WELL AS
COLLABORATION WITH SURROUNDING OFFICES. HOWEVER...THE WAVE AS WELL AS
THE SURFACE FEATURE IS MOVING THROUGH QUITE SLOW SO THE CHANCE FOR
STORMS TO MOVE OVER REPEATEDLY IS CERTAINLY A GOOD POSSIBILITY. THE
CHALLENGING PORTION OF THE FORECAST WILL BE TONIGHT AND INTO MONDAY
AND IDENTIFYING WHICH AREAS WILL RECEIVE HEAVY RAIN AND ALSO MONDAY
AFTERNOON AS BASED UPON MODEL SOUNDINGS...A DRY LAYER DOES SHOW UP IN
THE GFS IN CONJUNCTION WITH SOME GOOD INSTABILITY AND SHEAR. A
MARGINAL SEVERE THREAT MAY ARISE. A CHALLENGING AND MURKY SHORT TERM
FORECAST LOOKS TO BE THE CASE WITH A FEW CONCERNS.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 500 AM EDT SUN AUG 17 2014
MODELS CONTINUE TO DISPLAY GOOD AGREEMENT THROUGH THE EXTENDED...
INTERESTINGLY WITH THE GFS SHOWING A BIT MORE CONTINUITY THAN THE
ECMWF THIS CYCLE. MID AND UPPER PATTERN WILL BE QUASI ZONAL AS A
PROGRESSIVE BUT SLOW LOW AMPLITUDE WAVE MOVES ACROSS THE GREAT LAKES
REGION. PATTERN AMPLIFIES A BIT TOWARDS THE END OF THE EXTENDED
WINDOW WITH OUR FORECAST AREA ON THE EASTERN PERIPHERY OF RIDGE THAT
EXTENDS FROM THE SOUTHERN PLAINS/MISSISSIPPI RIVER DELTA TO THE UPPER
MIDWEST. AT THE SURFACE...LOW PRESSURE WILL BE EXITING TO OUR EAST
JUST AS A SECOND LOW PRESSURE SYSTEM ROLLS THROUGH THE GREAT LAKES
REGION BY MID WEEK. THE GREAT LAKES LOW WILL PULL A SURFACE COLD
FRONTAL BOUNDARY ACROSS THE OHIO VALLEY. THIS FRONTAL BOUNDARY WILL
BECOME ORIENTED IN A NORTHWEST TO SOUTHEAST DIRECTION...PARALLEL TO
THE UPPER FLOW PATTERN ON THE EASTERN SIDE OF THE AFOREMENTIONED
RIDGE. THUS WITH LITTLE TO NO FORCING AT THE MID AND UPPER LEVELS...
THIS BOUNDARY WILL ESTABLISH A STATIONARY BAROCLINIC ZONE ACROSS THE
REGION WHICH APPEARS TO SET UP JUST TO OUR NORTH AND EAST. IT APPEARS
THIS ZONE WILL BECOME THE FOCUS OF ADDITIONAL SHOWER AND THUNDERSTORM
ACTIVITY...AND SHOULD BE CLOSE ENOUGH THAT THE THREAT OF RAIN WILL
CONTINUE TO EXIST FOR OUR AREA THROUGH THE REMAINDER OF THE FORECAST.
MODELS EVEN HINT AT THE POSSIBILITY OF A SERIES OF MCS TYPE SYSTEMS
DEVELOPING AND MOVING ALONG THIS ZONE...POSSIBLY AFFECTING PORTIONS
OF OUR AREA.
FOR SENSIBLE WEATHER...THE MOST SIGNIFICANT AND NOTABLE DIFFERENCE
IN OUR WEATHER WILL BE THE RETURN OF TRUE SUMMER LIKE CONDITIONS WITH
SEASONABLY WARM AND HUMID AFTERNOONS AND MUGGY NIGHTS. TWEAKED TEMPS
TOWARDS LATEST MODEL BLENDS WHICH RESULTED IN ONLY MINOR CHANGES TO
PREVIOUS FORECASTS. THE DAILY THREAT OF SOME TYPE OF SHOWER AND
THUNDERSTORM ACTIVITY WILL ENSURE AN OVERALL UNSETTLED WEATHER
PATTERN...ESPECIALLY IF CONDITIONS BECOME FAVORABLE FOR THE
OCCASIONAL MCS SYSTEM TO MATERIALIZE AND MOVE THROUGH THE REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 735 AM EDT SUN AUG 17 2014
A BAND OF LIGHT RAIN SHOWERS ACROSS THE HEART OF THE FORECAST AREA
ALONG WITH A SMALL AREA OF RAIN IN THE SOUTH APPEAR TO BE WEAKENING
WITH TIME. HOWEVER...UPSTREAM STORM SYSTEM IS POISED TO MAKE A RUN AT
OUR AREA LATER TODAY. FOLLOWED VERY NEAR TERM...HIGHER RESOLUTION
MODELS CLOSELY WITH RESPECT TO TIMING SHOWER AND THUNDERSTORM
ACTIVITY INTO AND OUT OF THE AREA...BUT CONFIDENCE IS LOW. THAT BEING
SAID CURRENT ACTIVITY SHOULD CONTINUE TO WEAKEN OVER THE NEXT COUPLE
OF HOURS. THEN EXPECT AN EARLY TO MID MORNING LULL BEFORE ACTIVITY
PICKS BACK UP TOWARDS NOON AND CONTINUES THROUGH THE REMAINDER OF THE
FORECAST. THREAT OF THUNDERSTORMS WILL INCREASE WITH TIME AS WELL. IN
GENERAL WENT WITH VRF CONDITIONS UNTIL THIS EVENING/TONIGHT AS VSBYS
AND CIGS EVENTUALLY RESPOND TO THE RAINFALL AND AN INCREASINGLY
SATURATED BOUNDARY LAYER. WINDS WILL BE LIGHT AND ROUGHLY SOUTHERLY
AT ABOUT 5 KTS OR LESS THROUGH THE ENTIRE FORECAST PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SBH
SHORT TERM...SHALLENBERGER
LONG TERM...RAY
AVIATION...RAY
AREA FORECAST DISCUSSION
NWS JACKSON KY
735 AM EDT SUN AUG 17 2014
.UPDATE...
ISSUED AT 705 AM EDT SUN AUG 17 2014
CONDITIONS THIS MORNING ACROSS THE AREA FEATURE SOME SHOWERS NOW
MOVING THROUGH THE AREA WITH A WEAKENED MCV UPSTREAM IN WESTERN
KENTUCKY MAKING ITS WAY INTO CENTRAL KENTUCKY. THIS FEATURE WILL POSE
A CONCERN FOR THE AREA TODAY AS IT SLOWLY TRACKS INTO EASTERN
KENTUCKY BY THE AFTERNOON. THE ONE FORECAST CHALLENGE TODAY IS HOW
FAVORABLE THE ENVIRONMENT WILL BE TO THIS FEATURE. MODEL
SOUNDINGS...AS WELL AS THE HRRR DO NOT FAVOR INTENSIFYING THIS
SYSTEM. SURFACE INSTABILITY WITH THE GFS IS RATHER LACKING AND THE
HRRR SHOWS NO REAL INCREASE IN THE ECHOS. NONETHELESS...THE HEAVY
RAIN THREAT MAY BEGIN SLIGHTLY EARLIER TODAY AS THE CURRENT SITUATION
SEEMS TO JIVE WITH THE EXCESSIVE RAINFALL FORECAST. AS WELL...THE
POSSIBILITY OF A STRONG STORM POSSESSING GUSTY WIND CAPABILITY INTO
THIS AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 330 AM EDT SUN AUG 17 2014
CURRENT CONDITIONS ACROSS THE AREA AS OF 07Z FEATURE SOME SHOWERS
MOVING THROUGH EASTERN KENTUCKY FORMED BY SOME OVERRUNNING MOISTURE
OVER A WEAK SURFACE WARM FRONT DEVELOPING AS A LOW PRESSURE CENTER
OUT WEST CONTINUES TO DEVELOP AND SLOWLY MOVE EAST. A DRY LAYER AT
THE SURFACE OVER MUCH OF THE AREA HAS HINDERED MEASURABLE PRECIP.
HOWEVER...THIS BOUNDARY LAYER HAS AND WILL CONTINUE TO MOISTENED UP
QUITE A BIT THROUGH THE PERIOD OF THE MORNING HOURS AS SOUTHERLY FLOW
INCREASES AND RAINFALL FALLS OVER THESE AREAS. THIS RAINFALL ALONG
WITH THE SURFACE BOUNDARY WILL WEAKEN AND LIFT OFF TO THE NORTHEAST
AS THE LOW OUT WEST MOVES EAST. THIS WILL RESULT IN A BETTER CHANCE
FOR SHOWERS AND THUNDERSTORMS AS THE BETTER FORCING AND MOISTURE
MOVES EAST THIS AFTERNOON AND INTO THE EVENING.
HEADING INTO THIS EVENING AND TONIGHT...THE SURFACE LOW BEGINS TO
ENTER CENTRAL KY AND EVENTUALLY EASTERN KENTUCKY INTO MONDAY.
MENTIONING THE FACT THAT THE MODELS HAVE NOT HANDLED THIS FEATURE
WELL...ESPECIALLY THE NAM. MODEL SOUNDINGS FOR THE GFS AND NAM HAVE
HAD SOLUTION PRETTY FAR APART WITH CONCERN WITH AVAILABLE MOISTURE
WITH PWATS FOR THE NAM BEING WELL OVER 2.10 INCHES AND THE GFS BEING
AROUND 1.70 INCHES. A SLIGHT RISK OF EXCESSIVE RAIN WAS ISSUED FOR
THE AREA MAINLY ALONG THE I-75 CORRIDOR AND WEST FOR TONIGHT THROUGH
MONDAY. THE FACT THAT THERE IS SO MUCH INCONSISTENCY IN THE
MODELS...STORM MOTION IS ABOVE 10 KNOTS...AND FINALLY THE ADVERTISED
WAVE LOOKS MUCH LESS POTENT THAN ADVERTISED...IT APPEARS THE RISK OF
FLASH FLOODING WILL BE QUITE LOCALIZED AND ONLY CENTERED AROUND AREAS
THAT ARE STILL DRYING OUT FROM LAST WEEK RAINS. ALSO AREAS WHERE
STORMS MOVE REPEATEDLY OVER THE SAME AREA. AS SUCH...WILL ONLY CONTINUE
MENTIONING THIS RISK IN THE HWO BASED UPON REASONING AS WELL AS
COLLABORATION WITH SURROUNDING OFFICES. HOWEVER...THE WAVE AS WELL AS
THE SURFACE FEATURE IS MOVING THROUGH QUITE SLOW SO THE CHANCE FOR
STORMS TO MOVE OVER REPEATEDLY IS CERTAINLY A GOOD POSSIBILITY. THE
CHALLENGING PORTION OF THE FORECAST WILL BE TONIGHT AND INTO MONDAY
AND IDENTIFYING WHICH AREAS WILL RECEIVE HEAVY RAIN AND ALSO MONDAY
AFTERNOON AS BASED UPON MODEL SOUNDINGS...A DRY LAYER DOES SHOW UP IN
THE GFS IN CONJUNCTION WITH SOME GOOD INSTABILITY AND SHEAR. A
MARGINAL SEVERE THREAT MAY ARISE. A CHALLENGING AND MURKY SHORT TERM
FORECAST LOOKS TO BE THE CASE WITH A FEW CONCERNS.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 500 AM EDT SUN AUG 17 2014
MODELS CONTINUE TO DISPLAY GOOD AGREEMENT THROUGH THE EXTENDED...
INTERESTINGLY WITH THE GFS SHOWING A BIT MORE CONTINUITY THAN THE
ECMWF THIS CYCLE. MID AND UPPER PATTERN WILL BE QUASI ZONAL AS A
PROGRESSIVE BUT SLOW LOW AMPLITUDE WAVE MOVES ACROSS THE GREAT LAKES
REGION. PATTERN AMPLIFIES A BIT TOWARDS THE END OF THE EXTENDED
WINDOW WITH OUR FORECAST AREA ON THE EASTERN PERIPHERY OF RIDGE THAT
EXTENDS FROM THE SOUTHERN PLAINS/MISSISSIPPI RIVER DELTA TO THE UPPER
MIDWEST. AT THE SURFACE...LOW PRESSURE WILL BE EXITING TO OUR EAST
JUST AS A SECOND LOW PRESSURE SYSTEM ROLLS THROUGH THE GREAT LAKES
REGION BY MID WEEK. THE GREAT LAKES LOW WILL PULL A SURFACE COLD
FRONTAL BOUNDARY ACROSS THE OHIO VALLEY. THIS FRONTAL BOUNDARY WILL
BECOME ORIENTED IN A NORTHWEST TO SOUTHEAST DIRECTION...PARALLEL TO
THE UPPER FLOW PATTERN ON THE EASTERN SIDE OF THE AFOREMENTIONED
RIDGE. THUS WITH LITTLE TO NO FORCING AT THE MID AND UPPER LEVELS...
THIS BOUNDARY WILL ESTABLISH A STATIONARY BAROCLINIC ZONE ACROSS THE
REGION WHICH APPEARS TO SET UP JUST TO OUR NORTH AND EAST. IT APPEARS
THIS ZONE WILL BECOME THE FOCUS OF ADDITIONAL SHOWER AND THUNDERSTORM
ACTIVITY...AND SHOULD BE CLOSE ENOUGH THAT THE THREAT OF RAIN WILL
CONTINUE TO EXIST FOR OUR AREA THROUGH THE REMAINDER OF THE FORECAST.
MODELS EVEN HINT AT THE POSSIBILITY OF A SERIES OF MCS TYPE SYSTEMS
DEVELOPING AND MOVING ALONG THIS ZONE...POSSIBLY AFFECTING PORTIONS
OF OUR AREA.
FOR SENSIBLE WEATHER...THE MOST SIGNIFICANT AND NOTABLE DIFFERENCE
IN OUR WEATHER WILL BE THE RETURN OF TRUE SUMMER LIKE CONDITIONS WITH
SEASONABLY WARM AND HUMID AFTERNOONS AND MUGGY NIGHTS. TWEAKED TEMPS
TOWARDS LATEST MODEL BLENDS WHICH RESULTED IN ONLY MINOR CHANGES TO
PREVIOUS FORECASTS. THE DAILY THREAT OF SOME TYPE OF SHOWER AND
THUNDERSTORM ACTIVITY WILL ENSURE AN OVERALL UNSETTLED WEATHER
PATTERN...ESPECIALLY IF CONDITIONS BECOME FAVORABLE FOR THE
OCCASIONAL MCS SYSTEM TO MATERIALIZE AND MOVE THROUGH THE REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 735 AM EDT SUN AUG 17 2014
A BAND OF LIGHT RAIN SHOWERS ACROSS THE HEART OF THE FORECAST AREA
ALONG WITH A SMALL AREA OF RAIN IN THE SOUTH APPEAR TO BE WEAKENING
WITH TIME. HOWEVER...UPSTREAM STORM SYSTEM IS POISED TO MAKE A RUN AT
OUR AREA LATER TODAY. FOLLOWED VERY NEAR TERM...HIGHER RESOLUTION
MODELS CLOSELY WITH RESPECT TO TIMING SHOWER AND THUNDERSTORM
ACTIVITY INTO AND OUT OF THE AREA...BUT CONFIDENCE IS LOW. THAT BEING
SAID CURRENT ACTIVITY SHOULD CONTINUE TO WEAKEN OVER THE NEXT COUPLE
OF HOURS. THEN EXPECT AN EARLY TO MID MORNING LULL BEFORE ACTIVITY
PICKS BACK UP TOWARDS NOON AND CONTINUES THROUGH THE REMAINDER OF THE
FORECAST. THREAT OF THUNDERSTORMS WILL INCREASE WITH TIME AS WELL. IN
GENERAL WENT WITH VRF CONDITIONS UNTIL THIS EVENING/TONIGHT AS VSBYS
AND CIGS EVENTUALLY RESPOND TO THE RAINFALL AND AN INCREASINGLY
SATURATED BOUNDARY LAYER. WINDS WILL BE LIGHT AND ROUGHLY SOUTHERLY
AT ABOUT 5 KTS OR LESS THROUGH THE ENTIRE FORECAST PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...SHALLENBERGER
LONG TERM...RAY
AVIATION...RAY
AREA FORECAST DISCUSSION
NWS JACKSON KY
705 AM EDT SUN AUG 17 2014
.UPDATE...
ISSUED AT 705 AM EDT SUN AUG 17 2014
CONDITIONS THIS MORNING ACROSS THE AREA FEATURE SOME SHOWERS NOW
MOVING THROUGH THE AREA WITH A WEAKENED MCV UPSTREAM IN WESTERN
KENTUCKY MAKING ITS WAY INTO CENTRAL KENTUCKY. THIS FEATURE WILL POSE
A CONCERN FOR THE AREA TODAY AS IT SLOWLY TRACKS INTO EASTERN
KENTUCKY BY THE AFTERNOON. THE ONE FORECAST CHALLENGE TODAY IS HOW
FAVORABLE THE ENVIRONMENT WILL BE TO THIS FEATURE. MODEL
SOUNDINGS...AS WELL AS THE HRRR DO NOT FAVOR INTENSIFYING THIS
SYSTEM. SURFACE INSTABILITY WITH THE GFS IS RATHER LACKING AND THE
HRRR SHOWS NO REAL INCREASE IN THE ECHOS. NONETHELESS...THE HEAVY
RAIN THREAT MAY BEGIN SLIGHTLY EARLIER TODAY AS THE CURRENT SITUATION
SEEMS TO JIVE WITH THE EXCESSIVE RAINFALL FORECAST. AS WELL...THE
POSSIBILITY OF A STRONG STORM POSSESSING GUSTY WIND CAPABILITY INTO
THIS AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 330 AM EDT SUN AUG 17 2014
CURRENT CONDITIONS ACROSS THE AREA AS OF 07Z FEATURE SOME SHOWERS
MOVING THROUGH EASTERN KENTUCKY FORMED BY SOME OVERRUNNING MOISTURE
OVER A WEAK SURFACE WARM FRONT DEVELOPING AS A LOW PRESSURE CENTER
OUT WEST CONTINUES TO DEVELOP AND SLOWLY MOVE EAST. A DRY LAYER AT
THE SURFACE OVER MUCH OF THE AREA HAS HINDERED MEASURABLE PRECIP.
HOWEVER...THIS BOUNDARY LAYER HAS AND WILL CONTINUE TO MOISTENED UP
QUITE A BIT THROUGH THE PERIOD OF THE MORNING HOURS AS SOUTHERLY FLOW
INCREASES AND RAINFALL FALLS OVER THESE AREAS. THIS RAINFALL ALONG
WITH THE SURFACE BOUNDARY WILL WEAKEN AND LIFT OFF TO THE NORTHEAST
AS THE LOW OUT WEST MOVES EAST. THIS WILL RESULT IN A BETTER CHANCE
FOR SHOWERS AND THUNDERSTORMS AS THE BETTER FORCING AND MOISTURE
MOVES EAST THIS AFTERNOON AND INTO THE EVENING.
HEADING INTO THIS EVENING AND TONIGHT...THE SURFACE LOW BEGINS TO
ENTER CENTRAL KY AND EVENTUALLY EASTERN KENTUCKY INTO MONDAY.
MENTIONING THE FACT THAT THE MODELS HAVE NOT HANDLED THIS FEATURE
WELL...ESPECIALLY THE NAM. MODEL SOUNDINGS FOR THE GFS AND NAM HAVE
HAD SOLUTION PRETTY FAR APART WITH CONCERN WITH AVAILABLE MOISTURE
WITH PWATS FOR THE NAM BEING WELL OVER 2.10 INCHES AND THE GFS BEING
AROUND 1.70 INCHES. A SLIGHT RISK OF EXCESSIVE RAIN WAS ISSUED FOR
THE AREA MAINLY ALONG THE I-75 CORRIDOR AND WEST FOR TONIGHT THROUGH
MONDAY. THE FACT THAT THERE IS SO MUCH INCONSISTENCY IN THE
MODELS...STORM MOTION IS ABOVE 10 KNOTS...AND FINALLY THE ADVERTISED
WAVE LOOKS MUCH LESS POTENT THAN ADVERTISED...IT APPEARS THE RISK OF
FLASH FLOODING WILL BE QUITE LOCALIZED AND ONLY CENTERED AROUND AREAS
THAT ARE STILL DRYING OUT FROM LAST WEEK RAINS. ALSO AREAS WHERE
STORMS MOVE REPEATEDLY OVER THE SAME AREA. AS SUCH...WILL ONLY CONTINUE
MENTIONING THIS RISK IN THE HWO BASED UPON REASONING AS WELL AS
COLLABORATION WITH SURROUNDING OFFICES. HOWEVER...THE WAVE AS WELL AS
THE SURFACE FEATURE IS MOVING THROUGH QUITE SLOW SO THE CHANCE FOR
STORMS TO MOVE OVER REPEATEDLY IS CERTAINLY A GOOD POSSIBILITY. THE
CHALLENGING PORTION OF THE FORECAST WILL BE TONIGHT AND INTO MONDAY
AND IDENTIFYING WHICH AREAS WILL RECEIVE HEAVY RAIN AND ALSO MONDAY
AFTERNOON AS BASED UPON MODEL SOUNDINGS...A DRY LAYER DOES SHOW UP IN
THE GFS IN CONJUNCTION WITH SOME GOOD INSTABILITY AND SHEAR. A
MARGINAL SEVERE THREAT MAY ARISE. A CHALLENGING AND MURKY SHORT TERM
FORECAST LOOKS TO BE THE CASE WITH A FEW CONCERNS.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 500 AM EDT SUN AUG 17 2014
MODELS CONTINUE TO DISPLAY GOOD AGREEMENT THROUGH THE EXTENDED...
INTERESTINGLY WITH THE GFS SHOWING A BIT MORE CONTINUITY THAN THE
ECMWF THIS CYCLE. MID AND UPPER PATTERN WILL BE QUASI ZONAL AS A
PROGRESSIVE BUT SLOW LOW AMPLITUDE WAVE MOVES ACROSS THE GREAT LAKES
REGION. PATTERN AMPLIFIES A BIT TOWARDS THE END OF THE EXTENDED
WINDOW WITH OUR FORECAST AREA ON THE EASTERN PERIPHERY OF RIDGE THAT
EXTENDS FROM THE SOUTHERN PLAINS/MISSISSIPPI RIVER DELTA TO THE UPPER
MIDWEST. AT THE SURFACE...LOW PRESSURE WILL BE EXITING TO OUR EAST
JUST AS A SECOND LOW PRESSURE SYSTEM ROLLS THROUGH THE GREAT LAKES
REGION BY MID WEEK. THE GREAT LAKES LOW WILL PULL A SURFACE COLD
FRONTAL BOUNDARY ACROSS THE OHIO VALLEY. THIS FRONTAL BOUNDARY WILL
BECOME ORIENTED IN A NORTHWEST TO SOUTHEAST DIRECTION...PARALLEL TO
THE UPPER FLOW PATTERN ON THE EASTERN SIDE OF THE AFOREMENTIONED
RIDGE. THUS WITH LITTLE TO NO FORCING AT THE MID AND UPPER LEVELS...
THIS BOUNDARY WILL ESTABLISH A STATIONARY BAROCLINIC ZONE ACROSS THE
REGION WHICH APPEARS TO SET UP JUST TO OUR NORTH AND EAST. IT APPEARS
THIS ZONE WILL BECOME THE FOCUS OF ADDITIONAL SHOWER AND THUNDERSTORM
ACTIVITY...AND SHOULD BE CLOSE ENOUGH THAT THE THREAT OF RAIN WILL
CONTINUE TO EXIST FOR OUR AREA THROUGH THE REMAINDER OF THE FORECAST.
MODELS EVEN HINT AT THE POSSIBILITY OF A SERIES OF MCS TYPE SYSTEMS
DEVELOPING AND MOVING ALONG THIS ZONE...POSSIBLY AFFECTING PORTIONS
OF OUR AREA.
FOR SENSIBLE WEATHER...THE MOST SIGNIFICANT AND NOTABLE DIFFERENCE
IN OUR WEATHER WILL BE THE RETURN OF TRUE SUMMER LIKE CONDITIONS WITH
SEASONABLY WARM AND HUMID AFTERNOONS AND MUGGY NIGHTS. TWEAKED TEMPS
TOWARDS LATEST MODEL BLENDS WHICH RESULTED IN ONLY MINOR CHANGES TO
PREVIOUS FORECASTS. THE DAILY THREAT OF SOME TYPE OF SHOWER AND
THUNDERSTORM ACTIVITY WILL ENSURE AN OVERALL UNSETTLED WEATHER
PATTERN...ESPECIALLY IF CONDITIONS BECOME FAVORABLE FOR THE
OCCASIONAL MCS SYSTEM TO MATERIALIZE AND MOVE THROUGH THE REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 134 AM EDT SUN AUG 17 2014
EXPECT SOME MID LEVEL CLOUDS TO REMAIN OVER THE AREA AS SOME SHOWERS
AND EXTENSIVE CLOUD COVER AHEAD OF AN APPROACHING WARM FRONT MOVING
INTO THE AREA. THOUGH FOR NOW...LOW CEILINGS OR LOW VISIBILITY SHOULD
NOT BE AN ISSUE WITH THE EXCEPTION OF A FEW OF THE DEEPER VALLEYS
ACROSS EASTERN KENTUCKY. AS THE APPROACHING SYSTEM DEVELOPS...SHOWERS
WILL BECOME MORE NUMEROUS ALONG WITH SCATTERED THUNDERSTORMS BY THIS
AFTERNOON AND INTO THE EVENING. MOST SITES WILL BEGIN TO GO DOWN WITH
LOW CEILINGS AND LOW VISIBILITY BY 00Z. WINDS WILL REMAIN LIGHT AND
VARIABLE THROUGH THE PERIOD WITH THE EXCEPTION OF A THUNDERSTORM
MOVING OVER A STATION.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...SHALLENBERGER
LONG TERM...RAY
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
101 PM CDT SUN AUG 17 2014
.AVIATION...
FOR THE 17/18Z TAFS...A MIX OF MVFR/LOW END VFR CONDITIONS WILL
LIKELY PREVAIL FOR MUCH OF THE PERIOD AT LOCATIONS THAT ARE NOT
EXPERIENCING RAIN. LARGE AREA OF RAIN ASSOCIATED WITH A SLOW
MOVING MID LVL TROUGH HAS MADE VERY LITTLE PROGRESS EWD OVER THE
LAST FEW HRS WHILE ALSO SHOWING A DECREASE IN INTENSITY PER LATEST
RADAR LOOPS. THIS UPPER TROUGH SHOULD EVENTUALLY MOVE FARTHER
EAST INTO THE AREA. CONVECTION SHOULD REDEVELOP/RE-INTENSIFY DURING
THE LATE AFTERNOON AND INTO THE EVENING HRS. SCT SHWRS/TSTMS
LIKELY TO PERSIST THROUGH THE NIGHT AND INTO EARLY MONDAY MORNING
AS THE SYSTEM CONTINUES TO SLOWLY MOVE EWD.
FARTHER SOUTH...SEA BREEZE CONVECTION HAS STARTED TO EXPAND IN
COVERAGE BUT WILL MAINLY BE CONFINED SOUTH OF I-20. HAVE INCLUDED
VCTS AT KLFK TO ACCOUNT FOR THIS ACTIVITY BUT MOST OF THESE TSTMS
SHOULD BE FARTHER E ACROSS THE TOLEDO BEND COUNTRY AND INTO CNTRL
LA. /09/
&&
.PREV DISCUSSION... /ISSUED 1159 AM CDT SUN AUG 17 2014/
DISCUSSION...
MADE A FEW CHANGES TO THE CURRENT FORECAST. BUMPED UP THE DAYTIME
HIGHS FOR THE EAST TEXAS...SOUTHWEST ARKANSAS...AND NORTHWEST AND
NORTH CENTRAL LOUISIANA ZONES GIVEN THAT MORE SUN HAS BEEN PEEKING
THROUGH WITH LESS CLOUD COVER AND SPARSE COVERAGE OF ANY RAINFALL.
THE AREA OF SHOWERS AND THUNDERSTORMS TO THE WEST HAS NOT MADE MUCH
PROGRESS INTO THE FORECAST AREA EVEN WITH A DISTURBANCE/SHEAR AXIS
OVERHEAD. A TIGHT PRESSURE GRADIENT OVER PARTS OF THE AREA HAS
REQUIRED THE WINDS TO BE INCREASED SLIGHTLY. /06/
PREV DISCUSSION... /ISSUED 450 AM CDT SUN AUG 17 2014/
DISCUSSION...
SCT CONVECTION HAS REDEVELOPED THIS MORNING N OF THE I-30 CORRIDOR
OF NE TX/SW AR EARLY THIS MORNING...WHICH IS OCCURRING NEAR AND
NORTH OF AN OLD OUTFLOW BNDRY FROM SATURDAY EVENING/S
CONVECTION. THE CONVECTION APPEARS TO BE AIDED BY WEAK FORCING
ASSOCIATED WITH A 25KT SWRLY LLJ ATOP THE COOL/STABLE AIR AND WEAK
PVA AHEAD OF A SHEAR AXIS NOW EXTENDING FROM NCNTRL AR SW INTO SE
OK/EXTREME NE TX AND INTO CNTRL TX. MOSAIC RADAR LOOP ACTUALLY
REVEALS A MCV EMBEDDED WITHIN THE SHEAR AXIS ITSELF OVER JUST N OF
DTO NEAR THE RED RIVER...WHERE ELEVATED THUNDER HAS RECENTLY
DEVELOPED. THE SHORT TERM PROGS HAVE INITIALIZED POORLY THIS
MORNING WITH THE ONGOING CONVECTION...WITH THE HRRR SEVERAL HOURS
TOO SLOW WITH THE CURRENT ELEVATED -SHRA OVER EXTREME NE TX/SE
OK/SW AR. WITH THIS IN MIND...CONFIDENCE IS LOW WITH THE
TIMING/EXACT PLACEMENT OF CONVECTION TODAY...BUT HAVE TRENDED THE
FORECAST CLOSER TO THE WRF SOLUTION WHICH SHOWS MUCH LESS FEEDBACK
THAN THE GFS...AND HAS BEEN MORE CONSISTENT IN THE SLOWER MOVEMENT
OF THE SHEAR AXIS AS IT DRIFTS SE INTO SW AR/EXTREME SE OK/NE TX
THIS AFTERNOON. EXTENSIVE ELEVATED CONVECTIVE DEBRIS AND
CONVECTIVE REDEVELOPMENT SHOULD HELP HOLD MAX TEMPS DOWN SEVERAL
DEGREES COOLER THAN WHAT WAS OBSERVED SATURDAY OVER THE NW
ZONES...WITH THE HOTTEST TEMPS FARTHER SSE OVER DEEP E TX/NCNTRL
LA. SHOULD AGAIN SEE A WEAK SEABREEZE AFFECTING THE SRN ZONES THIS
AFTERNOON WHICH SHOULD DIMINISH DURING THE EARLY EVENING...WITH
THE SHEAR AXIS SETTLING TO NEAR THE I-20 CORRIDOR OF E TX INTO
EXTREME NW LA/SW AR. HAVE MAINTAINED MID CHANCE POPS TODAY/TONIGHT
ALONG THE AXIS ITSELF...BEFORE IT DRIFTS FARTHER ESE TO NEAR THE
I-20 CORRIDOR OF N LA MONDAY.
THE PROGS HAVE CONTINUED THE TREND WITH A MORE SWD PLACEMENT OF
THIS FEATURE FOR THE LAST FEW DAYS...BUT DON/T THINK IT SHOULD
ADVANCE MUCH FARTHER S AS THE PARENT SHORTWAVE ENERGY ACROSS THE
MID-SOUTH AND LOWER MS VALLEY BEGINS TO SHIFT E AWAY FROM THE
AREA. ELEVATED CONVECTIVE DEBRIS AND WIDELY SCT CONVECTION SHOULD
AGAIN HELP RETARD HEATING SLIGHTLY MONDAY...BEFORE THE SHEAR AXIS
BEGINS TO WEAKEN BY TUESDAY AS UPPER RIDGING SHIFTS E INTO THE SRN
PLAINS FROM THE SRN ROCKIES...AND THE WRN ATLANTIC/ERN GULF OF MX
RIDGE BEGINS TO EXPAND W ACROSS THE REMAINDER OF THE GULF.
THUS...CONVECTION SHOULD BECOME MORE ISOLATED AND CONFINED MAINLY
TO PORTIONS OF E TX/N LA TUESDAY AFTERNOON. SHOULD START TO SEE
HOTTER TEMPS RETURN BY THIS TIME...WITH THE HEAT BUILDING EVEN
MORE WEDNESDAY THROUGH THE REMAINDER OF THE EXTENDED AFTER THE
SHEAR AXIS FILLS...AND RIDGING ALOFT EXPANDS FARTHER W ACROSS THE
GULF STATES. STILL APPEARS ISOLATED CONVECTION WILL BE POSSIBLE
WEDNESDAY AND THURSDAY AFTERNOONS IN RESPONSE TO A WEAK
SEABREEZE...BUT THE REMAINDER OF THE EXTENDED WILL REMAIN VERY HOT
AND DRY GIVEN THE INCREASED SUBSIDENCE BENEATH THE RIDGE. IN
FACT...CAN/T RULE OUT NEAR TRIPLE DIGIT HEAT RETURNING TO PORTIONS
OF THE REGION NEXT WEEKEND/EARLY NEXT WEEK AS AVAILABLE SOIL
MOISTURE CONTINUES TO DRY...AND SOIL TEMPS QUICKLY HEAT UP.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 95 75 93 76 96 / 20 40 30 20 20
MLU 95 74 93 75 95 / 20 30 30 20 20
DEQ 92 72 94 72 94 / 40 20 20 10 10
TXK 93 75 94 74 95 / 40 40 20 10 10
ELD 93 74 93 74 95 / 20 40 30 10 10
TYR 94 75 94 75 96 / 30 40 30 10 10
GGG 94 75 93 75 96 / 30 40 30 10 10
LFK 96 76 94 76 96 / 30 30 20 10 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
09
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1159 AM CDT SUN AUG 17 2014
.DISCUSSION...
MADE A FEW CHANGES TO THE CURRENT FORECAST. BUMPED UP THE DAYTIME
HIGHS FOR THE EAST TEXAS...SOUTHWEST ARKANSAS...AND NORTHWEST AND
NORTH CENTRAL LOUISIANA ZONES GIVEN THAT MORE SUN HAS BEEN PEEKING
THROUGH WITH LESS CLOUD COVER AND SPARSE COVERAGE OF ANY RAINFALL.
THE AREA OF SHOWERS AND THUNDERSTORMS TO THE WEST HAS NOT MADE MUCH
PROGRESS INTO THE FORECAST AREA EVEN WITH A DISTURBANCE/SHEAR AXIS
OVERHEAD. A TIGHT PRESSURE GRADIENT OVER PARTS OF THE AREA HAS
REQUIRED THE WINDS TO BE INCREASED SLIGHTLY. /06/
&&
.PREV DISCUSSION... /ISSUED 535 AM CDT SUN AUG 17 2014/
AVIATION...
MOSTLY VFR CONDITIONS ACROSS AREA THIS MORNING....EXCEPT FOR NE TX..WHERE
LOW MVFR CIGS SPREADING EASTARD. FURTHER NORTH...SCATTERED LGT
RW...MOSTLY FROM MID LVL CLOUD BASES...WILL LIKELY INTENSIFY WITH
DAYTIME HEATING. A FEW TSTMS POSSIBLE THIS AFTN...MAINLY AT
KTXK...KTYR...AND KGGG TERMINALS. REMAINING TERMINALS LIKELY NOT
SEE TSTMS UNTIL AFTER 08/00Z. SW WINDS TO INCREASE TO AROUND 10
KTS BY MIDDAY...STGR GUSTS POSSIBLE NEAR STORMS GIVEN STEEP LOW
LVL LAPSE RATES./VII/.
PREV DISCUSSION... /ISSUED 450 AM CDT SUN AUG 17 2014/
DISCUSSION...
SCT CONVECTION HAS REDEVELOPED THIS MORNING N OF THE I-30 CORRIDOR
OF NE TX/SW AR EARLY THIS MORNING...WHICH IS OCCURRING NEAR AND
NORTH OF AN OLD OUTFLOW BNDRY FROM SATURDAY EVENING/S
CONVECTION. THE CONVECTION APPEARS TO BE AIDED BY WEAK FORCING
ASSOCIATED WITH A 25KT SWRLY LLJ ATOP THE COOL/STABLE AIR AND WEAK
PVA AHEAD OF A SHEAR AXIS NOW EXTENDING FROM NCNTRL AR SW INTO SE
OK/EXTREME NE TX AND INTO CNTRL TX. MOSAIC RADAR LOOP ACTUALLY
REVEALS A MCV EMBEDDED WITHIN THE SHEAR AXIS ITSELF OVER JUST N OF
DTO NEAR THE RED RIVER...WHERE ELEVATED THUNDER HAS RECENTLY
DEVELOPED. THE SHORT TERM PROGS HAVE INITIALIZED POORLY THIS
MORNING WITH THE ONGOING CONVECTION...WITH THE HRRR SEVERAL HOURS
TOO SLOW WITH THE CURRENT ELEVATED -SHRA OVER EXTREME NE TX/SE
OK/SW AR. WITH THIS IN MIND...CONFIDENCE IS LOW WITH THE
TIMING/EXACT PLACEMENT OF CONVECTION TODAY...BUT HAVE TRENDED THE
FORECAST CLOSER TO THE WRF SOLUTION WHICH SHOWS MUCH LESS FEEDBACK
THAN THE GFS...AND HAS BEEN MORE CONSISTENT IN THE SLOWER MOVEMENT
OF THE SHEAR AXIS AS IT DRIFTS SE INTO SW AR/EXTREME SE OK/NE TX
THIS AFTERNOON. EXTENSIVE ELEVATED CONVECTIVE DEBRIS AND
CONVECTIVE REDEVELOPMENT SHOULD HELP HOLD MAX TEMPS DOWN SEVERAL
DEGREES COOLER THAN WHAT WAS OBSERVED SATURDAY OVER THE NW
ZONES...WITH THE HOTTEST TEMPS FARTHER SSE OVER DEEP E TX/NCNTRL
LA. SHOULD AGAIN SEE A WEAK SEABREEZE AFFECTING THE SRN ZONES THIS
AFTERNOON WHICH SHOULD DIMINISH DURING THE EARLY EVENING...WITH
THE SHEAR AXIS SETTLING TO NEAR THE I-20 CORRIDOR OF E TX INTO
EXTREME NW LA/SW AR. HAVE MAINTAINED MID CHANCE POPS TODAY/TONIGHT
ALONG THE AXIS ITSELF...BEFORE IT DRIFTS FARTHER ESE TO NEAR THE
I-20 CORRIDOR OF N LA MONDAY.
THE PROGS HAVE CONTINUED THE TREND WITH A MORE SWD PLACEMENT OF
THIS FEATURE FOR THE LAST FEW DAYS...BUT DON/T THINK IT SHOULD
ADVANCE MUCH FARTHER S AS THE PARENT SHORTWAVE ENERGY ACROSS THE
MID-SOUTH AND LOWER MS VALLEY BEGINS TO SHIFT E AWAY FROM THE
AREA. ELEVATED CONVECTIVE DEBRIS AND WIDELY SCT CONVECTION SHOULD
AGAIN HELP RETARD HEATING SLIGHTLY MONDAY...BEFORE THE SHEAR AXIS
BEGINS TO WEAKEN BY TUESDAY AS UPPER RIDGING SHIFTS E INTO THE SRN
PLAINS FROM THE SRN ROCKIES...AND THE WRN ATLANTIC/ERN GULF OF MX
RIDGE BEGINS TO EXPAND W ACROSS THE REMAINDER OF THE GULF.
THUS...CONVECTION SHOULD BECOME MORE ISOLATED AND CONFINED MAINLY
TO PORTIONS OF E TX/N LA TUESDAY AFTERNOON. SHOULD START TO SEE
HOTTER TEMPS RETURN BY THIS TIME...WITH THE HEAT BUILDING EVEN
MORE WEDNESDAY THROUGH THE REMAINDER OF THE EXTENDED AFTER THE
SHEAR AXIS FILLS...AND RIDGING ALOFT EXPANDS FARTHER W ACROSS THE
GULF STATES. STILL APPEARS ISOLATED CONVECTION WILL BE POSSIBLE
WEDNESDAY AND THURSDAY AFTERNOONS IN RESPONSE TO A WEAK
SEABREEZE...BUT THE REMAINDER OF THE EXTENDED WILL REMAIN VERY HOT
AND DRY GIVEN THE INCREASED SUBSIDENCE BENEATH THE RIDGE. IN
FACT...CAN/T RULE OUT NEAR TRIPLE DIGIT HEAT RETURNING TO PORTIONS
OF THE REGION NEXT WEEKEND/EARLY NEXT WEEK AS AVAILABLE SOIL
MOISTURE CONTINUES TO DRY...AND SOIL TEMPS QUICKLY HEAT UP.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 95 75 93 76 96 / 20 40 30 20 20
MLU 95 74 93 75 95 / 20 30 30 20 20
DEQ 92 72 94 72 94 / 40 20 20 10 10
TXK 93 75 94 74 95 / 40 40 20 10 10
ELD 93 74 93 74 95 / 20 40 30 10 10
TYR 94 75 94 75 96 / 30 40 30 10 10
GGG 94 75 93 75 96 / 30 40 30 10 10
LFK 96 76 94 76 96 / 30 30 20 10 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
06
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
535 AM CDT SUN AUG 17 2014
.AVIATION...
MOSTLY VFR CONDITIONS ACROSS AREA THIS MORNING....EXCEPT FOR NE TX..WHERE
LOW MVFR CIGS SPREADING EASTARD. FURTHER NORTH...SCATTERED LGT
RW...MOSTLY FROM MID LVL CLOUD BASES...WILL LIKELY INTENSIFY WITH
DAYTIME HEATING. A FEW TSTMS POSSIBLE THIS AFTN...MAINLY AT
KTXK...KTYR...AND KGGG TERMINALS. REMAINING TERMINALS LIKELY NOT
SEE TSTMS UNTIL AFTER 08/00Z. SW WINDS TO INCREASE TO AROUND 10
KTS BY MIDDAY...STGR GUSTS POSSIBLE NEAR STORMS GIVEN STEEP LOW
LVL LAPSE RATES./VII/.
&&
.PREV DISCUSSION... /ISSUED 450 AM CDT SUN AUG 17 2014/
DISCUSSION...
SCT CONVECTION HAS REDEVELOPED THIS MORNING N OF THE I-30 CORRIDOR
OF NE TX/SW AR EARLY THIS MORNING...WHICH IS OCCURRING NEAR AND
NORTH OF AN OLD OUTFLOW BNDRY FROM SATURDAY EVENING/S
CONVECTION. THE CONVECTION APPEARS TO BE AIDED BY WEAK FORCING
ASSOCIATED WITH A 25KT SWRLY LLJ ATOP THE COOL/STABLE AIR AND WEAK
PVA AHEAD OF A SHEAR AXIS NOW EXTENDING FROM NCNTRL AR SW INTO SE
OK/EXTREME NE TX AND INTO CNTRL TX. MOSAIC RADAR LOOP ACTUALLY
REVEALS A MCV EMBEDDED WITHIN THE SHEAR AXIS ITSELF OVER JUST N OF
DTO NEAR THE RED RIVER...WHERE ELEVATED THUNDER HAS RECENTLY
DEVELOPED. THE SHORT TERM PROGS HAVE INITIALIZED POORLY THIS
MORNING WITH THE ONGOING CONVECTION...WITH THE HRRR SEVERAL HOURS
TOO SLOW WITH THE CURRENT ELEVATED -SHRA OVER EXTREME NE TX/SE
OK/SW AR. WITH THIS IN MIND...CONFIDENCE IS LOW WITH THE
TIMING/EXACT PLACEMENT OF CONVECTION TODAY...BUT HAVE TRENDED THE
FORECAST CLOSER TO THE WRF SOLUTION WHICH SHOWS MUCH LESS FEEDBACK
THAN THE GFS...AND HAS BEEN MORE CONSISTENT IN THE SLOWER MOVEMENT
OF THE SHEAR AXIS AS IT DRIFTS SE INTO SW AR/EXTREME SE OK/NE TX
THIS AFTERNOON. EXTENSIVE ELEVATED CONVECTIVE DEBRIS AND
CONVECTIVE REDEVELOPMENT SHOULD HELP HOLD MAX TEMPS DOWN SEVERAL
DEGREES COOLER THAN WHAT WAS OBSERVED SATURDAY OVER THE NW
ZONES...WITH THE HOTTEST TEMPS FARTHER SSE OVER DEEP E TX/NCNTRL
LA. SHOULD AGAIN SEE A WEAK SEABREEZE AFFECTING THE SRN ZONES THIS
AFTERNOON WHICH SHOULD DIMINISH DURING THE EARLY EVENING...WITH
THE SHEAR AXIS SETTLING TO NEAR THE I-20 CORRIDOR OF E TX INTO
EXTREME NW LA/SW AR. HAVE MAINTAINED MID CHANCE POPS TODAY/TONIGHT
ALONG THE AXIS ITSELF...BEFORE IT DRIFTS FARTHER ESE TO NEAR THE
I-20 CORRIDOR OF N LA MONDAY.
THE PROGS HAVE CONTINUED THE TREND WITH A MORE SWD PLACEMENT OF
THIS FEATURE FOR THE LAST FEW DAYS...BUT DON/T THINK IT SHOULD
ADVANCE MUCH FARTHER S AS THE PARENT SHORTWAVE ENERGY ACROSS THE
MID-SOUTH AND LOWER MS VALLEY BEGINS TO SHIFT E AWAY FROM THE
AREA. ELEVATED CONVECTIVE DEBRIS AND WIDELY SCT CONVECTION SHOULD
AGAIN HELP RETARD HEATING SLIGHTLY MONDAY...BEFORE THE SHEAR AXIS
BEGINS TO WEAKEN BY TUESDAY AS UPPER RIDGING SHIFTS E INTO THE SRN
PLAINS FROM THE SRN ROCKIES...AND THE WRN ATLANTIC/ERN GULF OF MX
RIDGE BEGINS TO EXPAND W ACROSS THE REMAINDER OF THE GULF.
THUS...CONVECTION SHOULD BECOME MORE ISOLATED AND CONFINED MAINLY
TO PORTIONS OF E TX/N LA TUESDAY AFTERNOON. SHOULD START TO SEE
HOTTER TEMPS RETURN BY THIS TIME...WITH THE HEAT BUILDING EVEN
MORE WEDNESDAY THROUGH THE REMAINDER OF THE EXTENDED AFTER THE
SHEAR AXIS FILLS...AND RIDGING ALOFT EXPANDS FARTHER W ACROSS THE
GULF STATES. STILL APPEARS ISOLATED CONVECTION WILL BE POSSIBLE
WEDNESDAY AND THURSDAY AFTERNOONS IN RESPONSE TO A WEAK
SEABREEZE...BUT THE REMAINDER OF THE EXTENDED WILL REMAIN VERY HOT
AND DRY GIVEN THE INCREASED SUBSIDENCE BENEATH THE RIDGE. IN
FACT...CAN/T RULE OUT NEAR TRIPLE DIGIT HEAT RETURNING TO PORTIONS
OF THE REGION NEXT WEEKEND/EARLY NEXT WEEK AS AVAILABLE SOIL
MOISTURE CONTINUES TO DRY...AND SOIL TEMPS QUICKLY HEAT UP.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 94 75 93 76 96 / 20 40 30 20 20
MLU 94 74 93 75 95 / 20 30 30 20 20
DEQ 91 72 94 72 94 / 40 20 20 10 10
TXK 91 75 94 74 95 / 40 40 20 10 10
ELD 93 74 93 74 95 / 20 40 30 10 10
TYR 92 75 94 75 96 / 40 40 30 10 10
GGG 93 75 93 75 96 / 30 40 30 10 10
LFK 95 76 94 76 96 / 30 30 20 10 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
450 AM CDT SUN AUG 17 2014
.DISCUSSION...
SCT CONVECTION HAS REDEVELOPED THIS MORNING N OF THE I-30 CORRIDOR
OF NE TX/SW AR EARLY THIS MORNING...WHICH IS OCCURRING NEAR AND
NORTH OF AN OLD OUTFLOW BNDRY FROM SATURDAY EVENING/S
CONVECTION. THE CONVECTION APPEARS TO BE AIDED BY WEAK FORCING
ASSOCIATED WITH A 25KT SWRLY LLJ ATOP THE COOL/STABLE AIR AND WEAK
PVA AHEAD OF A SHEAR AXIS NOW EXTENDING FROM NCNTRL AR SW INTO SE
OK/EXTREME NE TX AND INTO CNTRL TX. MOSAIC RADAR LOOP ACTUALLY
REVEALS A MCV EMBEDDED WITHIN THE SHEAR AXIS ITSELF OVER JUST N OF
DTO NEAR THE RED RIVER...WHERE ELEVATED THUNDER HAS RECENTLY
DEVELOPED. THE SHORT TERM PROGS HAVE INITIALIZED POORLY THIS
MORNING WITH THE ONGOING CONVECTION...WITH THE HRRR SEVERAL HOURS
TOO SLOW WITH THE CURRENT ELEVATED -SHRA OVER EXTREME NE TX/SE
OK/SW AR. WITH THIS IN MIND...CONFIDENCE IS LOW WITH THE
TIMING/EXACT PLACEMENT OF CONVECTION TODAY...BUT HAVE TRENDED THE
FORECAST CLOSER TO THE WRF SOLUTION WHICH SHOWS MUCH LESS FEEDBACK
THAN THE GFS...AND HAS BEEN MORE CONSISTENT IN THE SLOWER MOVEMENT
OF THE SHEAR AXIS AS IT DRIFTS SE INTO SW AR/EXTREME SE OK/NE TX
THIS AFTERNOON. EXTENSIVE ELEVATED CONVECTIVE DEBRIS AND
CONVECTIVE REDEVELOPMENT SHOULD HELP HOLD MAX TEMPS DOWN SEVERAL
DEGREES COOLER THAN WHAT WAS OBSERVED SATURDAY OVER THE NW
ZONES...WITH THE HOTTEST TEMPS FARTHER SSE OVER DEEP E TX/NCNTRL
LA. SHOULD AGAIN SEE A WEAK SEABREEZE AFFECTING THE SRN ZONES THIS
AFTERNOON WHICH SHOULD DIMINISH DURING THE EARLY EVENING...WITH
THE SHEAR AXIS SETTLING TO NEAR THE I-20 CORRIDOR OF E TX INTO
EXTREME NW LA/SW AR. HAVE MAINTAINED MID CHANCE POPS TODAY/TONIGHT
ALONG THE AXIS ITSELF...BEFORE IT DRIFTS FARTHER ESE TO NEAR THE
I-20 CORRIDOR OF N LA MONDAY.
THE PROGS HAVE CONTINUED THE TREND WITH A MORE SWD PLACEMENT OF
THIS FEATURE FOR THE LAST FEW DAYS...BUT DON/T THINK IT SHOULD
ADVANCE MUCH FARTHER S AS THE PARENT SHORTWAVE ENERGY ACROSS THE
MID-SOUTH AND LOWER MS VALLEY BEGINS TO SHIFT E AWAY FROM THE
AREA. ELEVATED CONVECTIVE DEBRIS AND WIDELY SCT CONVECTION SHOULD
AGAIN HELP RETARD HEATING SLIGHTLY MONDAY...BEFORE THE SHEAR AXIS
BEGINS TO WEAKEN BY TUESDAY AS UPPER RIDGING SHIFTS E INTO THE SRN
PLAINS FROM THE SRN ROCKIES...AND THE WRN ATLANTIC/ERN GULF OF MX
RIDGE BEGINS TO EXPAND W ACROSS THE REMAINDER OF THE GULF.
THUS...CONVECTION SHOULD BECOME MORE ISOLATED AND CONFINED MAINLY
TO PORTIONS OF E TX/N LA TUESDAY AFTERNOON. SHOULD START TO SEE
HOTTER TEMPS RETURN BY THIS TIME...WITH THE HEAT BUILDING EVEN
MORE WEDNESDAY THROUGH THE REMAINDER OF THE EXTENDED AFTER THE
SHEAR AXIS FILLS...AND RIDGING ALOFT EXPANDS FARTHER W ACROSS THE
GULF STATES. STILL APPEARS ISOLATED CONVECTION WILL BE POSSIBLE
WEDNESDAY AND THURSDAY AFTERNOONS IN RESPONSE TO A WEAK
SEABREEZE...BUT THE REMAINDER OF THE EXTENDED WILL REMAIN VERY HOT
AND DRY GIVEN THE INCREASED SUBSIDENCE BENEATH THE RIDGE. IN
FACT...CAN/T RULE OUT NEAR TRIPLE DIGIT HEAT RETURNING TO PORTIONS
OF THE REGION NEXT WEEKEND/EARLY NEXT WEEK AS AVAILABLE SOIL
MOISTURE CONTINUES TO DRY...AND SOIL TEMPS QUICKLY HEAT UP.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 94 75 93 76 96 / 20 40 30 20 20
MLU 94 74 93 75 95 / 20 30 30 20 20
DEQ 91 72 94 72 94 / 40 20 20 10 10
TXK 91 75 94 74 95 / 40 40 20 10 10
ELD 93 74 93 74 95 / 20 40 30 10 10
TYR 92 75 94 75 96 / 40 40 30 10 10
GGG 93 75 93 75 96 / 30 40 30 10 10
LFK 95 76 94 76 96 / 30 30 20 10 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
15
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1158 PM CDT SAT AUG 16 2014
.AVIATION...
TSTMS HAVE DIMINISHED ACROSS THE ARKLATEX FOR THE TIME BEING.
HOWEVER...MORE HAVE DEVELOPED OVER N TX...AND IT IS POSSIBLE THAT
SOME OF THESE COULD WORK THEIR WAY INTO THE REGION DURING THE
OVERNIGHT HOURS. ADDITIONALY...MVFR/PATCHY IFR CIGS/VSBYS WILL BE
POSSIBLE AROUND SUNRISE...AS LL MOISTURE CONTINUES TO INCREASE.
VFR CONDITIONS ARE EXPECTED TO RETURN BY MID MORNING...WITH CONVECTION
POSSIBLE AGAIN SUNDAY PRIMARILY DURING PEAK HEATING. COVERAGE IS
EXPECTED TO BE TOO ISOLD/UNCERTAIN TO WARRANT MENTION IN THE TAFS
OUTSIDE OF VCTS ATTM. /12/
&&
.PREV DISCUSSION... /ISSUED 944 PM CDT SAT AUG 16 2014/
DISCUSSION...
CONVECTION DEVELOPED RIGHT AS PLANNED ALONG AND NORTHWEST OF THE
I-30 CORRIDOR OF NE TX THIS EVENING. WEAK COLD POOL FORMED AND HAS
SINCE MOVED WELL SOUTHEAST OF WHAT CONVECTION WE HAVE LEFT OVER
ACROSS NE TX/SE OK AND SW AR.
LOTS OF THINGS TO CONSIDER FOR AN UPDATE THIS EVENING THROUGH
TOMORROW. ONE OF WHICH WILL BE A PERSISTENT ELEVATED THETA-E
BOUNDARY ACROSS OUR NW ZONES...RELATIVELY HIGH PWAT VALUES
REMAINING IN PLACE...NOT TO MENTION A WEAK SHEAR AXIS THAT WILL
REMAIN ANCHORED ACROSS THE REGION AS WELL. AFTER HAVING
COORDINATED WITH THE FWD OFFICE...WE WILL CONTINUE TO HOLD ON TO
CHANCE POPS ALONG AND NORTHWEST OF A LINE FROM TYR AND GGG TO NEAR
TXK FOR THE REMAINDER OF THE NIGHT. HRRR OUTPUT DOES NOT SUPPORT
REDEVELOPMENT ACROSS OUR NW ZONES AND THE NEW 00Z NAM OUTPUT DOES
NOT SUPPORT MUCH EITHER AND WHILE THE 18Z GFS OUTPUT IS OBVIOUSLY
SHOWING CONVECTIVE FEEDBACK PROBLEMS...CANNOT RULE OUT THE
POSSIBILITY OF REDEVELOPMENT EVEN THOUGH I WOULD LIKE TO SEE MORE
THAN 15KTS WORTH OF A LOW LEVEL SOUTHWEST JET OVERNIGHT.
FOR THE TEMPERATURE FORECAST...24HR TEMPERATURE CHANGES COMPARED
TO THIS TIME LAST NIGHT ARE SHOWING AN AVERAGE OF 4 TO 7 DEGREES
WARMER THAN THIS TIME LAST NIGHT WITH A SLIGHTLY LOWER AVERAGE FOR
DEWPOINTS AS WELL. FOR THIS REASON...HAVE RAISED OVERNIGHT MIN
TEMPERATURES ACROSS THE BOARD AS WELL.
OTHER THAN ADDITIONAL CHANGES TO DEWPOINT/RH GRIDS...ALL OTHER GRIDS
ARE IN GOOD SHAPE AND NO OTHER CHANGES WERE NECESSARY ATTM. /13/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 76 93 73 94 74 / 10 30 20 20 10
MLU 74 92 73 94 73 / 10 30 20 30 20
DEQ 73 91 71 93 73 / 30 40 20 20 20
TXK 76 92 73 94 74 / 30 40 20 20 10
ELD 74 92 73 93 73 / 10 30 20 30 20
TYR 78 94 75 95 76 / 30 40 20 20 10
GGG 76 93 75 95 75 / 30 40 20 20 10
LFK 78 94 75 94 74 / 10 30 20 20 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
12
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
935 PM EDT MON AUG 18 2014
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL DEVELOP OVER VIRGINIA TONIGHT BEFORE
MOVING OFF THE COAST TUESDAY. WEAK HIGH PRESSURE RETURNS ON
WEDNESDAY BEFORE ANOTHER SYSTEM OVER THE GREAT LAKES MOVES INTO
THE MID ATLANTIC STATES FOR THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
BANDS OF SHOWERS WILL CONTINUE TO MOVE ACROSS THE AREA OVER THE NEXT
SEVERAL HOURS AND OVERNIGHT. THE HRRR AND RAP RE BOTH DOING A GOOD
JOB HANDLING THE SURFACE LOW OVER CENTRAL NE LIFTING IT NORTH INTO
VA AND MERGING IT WITH THE BROAD LOW JUST TO THE WEST.
PRECIP COVERAGE WILL BE GREATEST ACROSS SOUTH CENTRAL
VA...TIDEWATER...HAMPTON ROADS AND NORTHEAST NC. ALSO EXPECT THE
LINGERING SHOWER TO PERSIST NORTH OF RIC FROM LOUISA AND ESPECIALLY
INTO CAROLINE. OVERNIGHT ACTIVITY SHOULD REMAIN MOSTLY SHOWERS
WITH LITTLE TO NO THUNDER.
A FEW LOCATIONS COULD SEE 0.50 OR MORE OF RAIN OVERNIGHT AS PWATS
CONTINUE TO RUN A LITTLE OVER 2 INCHES IN A VERY MOIST ATMOSPHERE.
OVERNIGHT LOWS WILL HOVER IN THE LOW TO MID 70S DUE TO THE MORE
HUMID AIRMASS.
FOR TUESDAY...THE LOW SLOWLY SLIDES OFF THE VA COAST AND HAS SOME
WRAP AROUND MOISTURE SO HAVE HELD ON TO THE PCPN A LITTLE LONGER
ACROSS THE DELMARVA AS THE 12Z NAM IS SLOWER THAN THE 12Z GFS IN
PULLING THE LOW OUT. LATER IN THE AFTERNOON...WILL GET THE SFC
BOUNDARY SLIDING DOWN INTO THE TIDEWATER AND NE NC SO MORE SHOWERS
ARE POSSIBLE THERE. FOR TEMPERATURES HAVE LEAN A LITTLE LOW
ESPECIALLY TOWARD THE NORTH THINKING THAT CLOUDS WILL LINGER AND
LIMIT THE DAY TIME HEATING.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
FROM TUESDAY NIGHT THROUGH THURSDAY...THE MODELS ARE SHOWING LOTS
OF VARIABLIITY WITH THE MOVEMENT OF SHORTWAVE ENERGY IN THE
NORTHWEST FLOW AS THE UPPER RIDGE OVER THE MS VALLEY BUILDS AND
THE UPPER LOW OVER THE GREAT LAKES IS SLOW TO MOVE EAST. WEDNESDAY
LOOKS TO BE THE DRIER OF THE TWO DAY AS THE EXITING LOW OFF THE
COAST ALLOWS FOR WEAK HIGH PRESSURE OVER THE NE TO NOSE SOUTHWARD
INTO THE MID ATLANTIC STATES AND THE MOISTURE LESSENS. BUT BY
THURSDAY...THE NW FLOW IS MORE ESTABLISHED AND WITH CONVECTION TO
THE NORTHWEST AND THE REGION IN A GOOD POSITION ON THE EDGE OF THE
RIDGE...COULD EASILY SEE CONVECTION DROP SE INTO THE REGION. SO
HAVE VERY LITTLE PCPN ON WEDNESDAY WITH HIGHER CHANCE POPS ON
THURSDAY. BUT CONFIDENCE IN THE OVER PATTERN IS LOW DUE TO THE
MODEL UNCERTAINTY FROM RUN TO RUN.
FOR TEMPERATURES...HAVE ALLOWED FOR SOME ADDITIONAL HEATING ON WED
AND THU DUE TO MORE SUNSHINE AND ALSO DUE TO THE WEST/NW FLOW
ALOFT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
UNSETTLED WEATHER PATTERN CONTINUES INTO THE EXTENDED PERIOD AS NWLY
FLOW ALOFT DEVELOPS. TEMPS WILL BE NEAR TO SLIGHTLY BELOW
SEASONABLE...LATE SUMMER NORMS.
WHILE MEDIUM RANGE GUIDANCE CONTINUES TO STRUGGLE HANDLING THE
SPLIT/BLOCKY FLOW OVER THE HIGHER LATITUDES...MODELS HAVE BECOME
MORE STABLE WITH RESOLVING SRN STREAM ENERGY OVER THE OH VALLEY AND
MID-ATLANTIC REGION. THIS THANKS TO UPPER/SFC HIGH PRESSURE FROM THE
SE STATES EWD OFF THE COAST. WITH THAT SAID...FLOW AMPLIFIES OVER
THE ERN CONUS AS MID LEVEL HIGH PRESSURE BUILDS OVER THE CNTRL US
AND LOW PRESSURE REMAINS OVER THE NE US. THIS WILL PLACE THE
MID-ATLANTIC STATES IN NWLY FLOW ALOFT...OPENING THE DOOR FOR
SHORTWAVE ENERGY IN THE UPPER FLOW. QUASI-STATIONARY BOUNDARY WILL
LOCATE OVER THE REGION...JUST TO THE SOUTH. MOISTURE WILL NOT BE A
LIMITATION WITH PWATS PROGGED AROUND 2 INCHES (+1 STD DEV) AND
DEWPOINTS IN THE MID-UPPER 60S. ANTICIPATE A DIURNAL TREND WITH
SHOWERS/THUNDERSTORMS...BUT UPSTREAM MCS DEVELOPMENT MAY SPILL INTO
THE REGION DURING THE OVERNIGHT HOURS THRU THE WEEKEND. HIGHER POPS
MAY BE WARRANTED...BUT BASED ON THE DEGREE OF UNCERTAINTY AND
TIMING...WILL STICK MORE TO CLIMO WITH CHANCE POPS DURING THE
AFTERNOON AND EVENING. COULD BEGIN TO SEE A DRYING TREND BY LATE IN
THE WEEKEND INTO EARLY NEXT WEEK AS THE UPPER HIGH BUILDS
EWD...SHUNTING THE BEST MOISTURE OFFSHORE.
WITH THE LATEST MODEL RUNS PLACING THE FRONT SOUTH OF THE LOCAL
AREA...NLY FLOW AND FALLING THICKNESSES WILL LIKELY YIELD TEMPS IN
THE LOW-MID 80S. LOW-MID 80S TO CONTINUE THRU THE WEEKEND...WARMING
BACK INTO THE MID 80S BY EARLY NEXT WEEK.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
A COMPLEX AREA OF LOW PRESSURE AND FRONTAL SYSTEMS COVERED THE MID
ATLANTIC STATES MONDAY EVENING. LOW PRESSURE MOVES OFF THE COAST
TUESDAY MORNING WITH WEAK HIGH PRESSURE BUILDING FROM THE NORTH
THROUGH WEDNESDAY. UNSETTLED WEATHER RETURNS LATE IN THE WEEK.
THE LINE OF TSTMS THAT AFFECTED SOUTHEAST VIRGINIA MOVED OFF THE
COAST JUST PRIOR TO THE 00Z TAF ISSUANCE MORE SHOWERS WERE
DEVELOPING BUT NO SIGNIFICANT TSTMS ARE EXPECTED OVERNIGHT. WITH
MOIST CONDITIONS... MVFR WITH AREAS OF IFR CAN BE EXPECTED IN THE
LATE EVENING AND OVERNIGHT.
MVFR SHOULD END BY LATE MORNING. WIDELY SCT SHOWERS AND TSTMS WILL
BE PSBL TUESDAY BUT NOT NEARLY AS WIDESPREAD AS THEY WERE MONDAY.
OUTLOOK...SCT AFTN/EVENING TSTMS RETURN TO THE FCST THURSDAY
THROUGH SATURDAY. THERE WILL BE THE POSSIBILITY OF MVFR/IFR CONDS
WITHIN A FEW HOURS OF SUNRISE EACH MORNING.
&&
.MARINE...
UNSETTLED WEATHER PATTERN WILL PREVAIL OVER THE WATERS THRU THE
FORECAST PERIOD...BUT SCA CONDITIONS ARE NOT ANTICIPATED.
AREA OF LOW PRESSURE HAS LOCATED OVER WV WITH A FRONTAL BOUNDARY
EXTENDING EWD OVER SRN VA AND THE LOWER BAY. MEANWHILE...HIGH
PRESSURE BUILDS OVER THE NE STATES. THE RESULT IS GENERALLY ONSHORE
AROUND 10 KT. WAVES/SEAS AVG 1-2 FT. SFC LOW WEAKENS OVER THE CNTRL
APPALACHIANS AS AN ADDITIONAL AREA OF LOW PRESSURE DEVELOPS OVER THE
WATERS. WITH THE SFC LOW OVER THE WATERS...FLOW OVER THE COASTAL
WATERS (ON THE ERN PERIPHERY OF THE LOW) WILL BE SW OVER THE SRN
WATERS...VEERING TO E OVER THE NRN WATERS...AVG 10-15 KT. SCA
CONDITIONS ARE NOT ANTICIPATED. SEAS WILL BUILD ONLY TO 2-3 FT WITH
WAVES AVG 1-2 FT. SFC LOW SLOWLY PUSHES OFFSHORE LATE TUES-TUES
NIGHT AS HIGH PRESSURE OFF THE NE COAST RIDGES SWD OVER THE NRN
WATERS. FLOW REMAINS GENERALLY ONSHORE...AOB 15 KT. LOW PRESSURE
LINGERS OFF THE MID-ATLANTIC COAST THRU THE END OF THE WORK WEEK AND
INTO THE WEEKEND AS A FRONTAL BOUNDARY REMAINS SOUTH OF THE WATERS.
THE RESULT WILL BE ONGOING ONSHORE/NELY FLOW. GRADIENT WILL REMAIN
WEAK (AOB 15 KT)...BUT PERSISTENT NE FETCH MAY PUSH SEAS UPWARDS OF
5 FT IN THE NRN COASTAL WATERS FRIDAY NIGHT THRU THE WEEKEND.
UNDERCUT WAVEWATCH AS GFS IS NOT THE PREFERRED MEDIUM RANGE MODEL.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...ESS
NEAR TERM...ESS/JAO
SHORT TERM...ESS
LONG TERM...SAM
AVIATION...LSA
MARINE...SAM
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
850 PM EDT MON AUG 18 2014
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL DEVELOP OVER VIRGINIA TONIGHT BEFORE
MOVING OFF THE COAST TUESDAY. WEAK HIGH PRESSURE RETURNS ON
WEDNESDAY BEFORE ANOTHER SYSTEM OVER THE GREAT LAKES MOVES INTO
THE MID ATLANTIC STATES FOR THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
UPDATE THIS EVENING TO DROP THE WATCH AND TWEAK THE POPS SOME
OVERNIGHT. AS SECONDARY LOW DEVELOPING OVER CENTRAL NC SHOULD
BECOME THE DOMINANT LOW OVERNIGHT LIFTING NORTHEAST INTO NORTHEAST
NC AND SOUTHEAST VA AND LOWER BAY. TRENDING TOWARDS THE HRRR POP
TRENDS WITH THE MOST WIDESPREAD SHOWERS AND STORMS ACROSS THE
SOUTHERN TWO THIRDS OF THE FORECAST AREA. EXPECT SCATTERED SHOWERS
AND STORMS WELL NORTH AND NORTHWEST OF RIC.
ONCE THE LOW BEGINS TO DEVELOP THIS EVENING...EXPECT TO SEE MORE
SHOWERS AND AREAS OF RAIN FORM ALONG AN NORTH OF THE FRONT WITH
MORE CONVECTIVE PRECIPITATION TO THE SOUTH OF IT. SOME AREAS COULD SEE
0.50 - 1 INCH OF RAIN AS PW CONTINUE TO RUN A LITTLE OVER 2 INCHES
IN A VERY MOIST ATMOSPHERE. HAVE ALSO BUMPED UP OVERNIGHT LOWS DUE
TO THE MORE HUMID AIRMASS.
FOR TUESDAY...THE LOW SLOWLY SLIDES OFF THE VA COAST AND HAS SOME
WRAP AROUND MOISTURE SO HAVE HELD ON TO THE PCPN A LITTLE LONGER
ACROSS THE DELMARVA AS THE 12Z NAM IS SLOWER THAN THE 12Z GFS IN
PULLING THE LOW OUT. LATER IN THE AFTERNOON...WILL GET THE SFC
BOUNDARY SLIDING DOWN INTO THE TIDEWATER AND NE NC SO MORE SHOWERS
ARE POSSIBLE THERE. FOR TEMPERATURES HAVE LEAN A LITTLE LOW
ESPECIALLY TOWARD THE NORTH THINKING THAT CLOUDS WILL LINGER AND
LIMIT THE DAY TIME HEATING.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
FROM TUESDAY NIGHT THROUGH THURSDAY...THE MODELS ARE SHOWING LOTS
OF VARIABLIITY WITH THE MOVEMENT OF SHORTWAVE ENERGY IN THE
NORTHWEST FLOW AS THE UPPER RIDGE OVER THE MS VALLEY BUILDS AND
THE UPPER LOW OVER THE GREAT LAKES IS SLOW TO MOVE EAST. WEDNESDAY
LOOKS TO BE THE DRIER OF THE TWO DAY AS THE EXITING LOW OFF THE
COAST ALLOWS FOR WEAK HIGH PRESSURE OVER THE NE TO NOSE SOUTHWARD
INTO THE MID ATLANTIC STATES AND THE MOISTURE LESSENS. BUT BY
THURSDAY...THE NW FLOW IS MORE ESTABLISHED AND WITH CONVECTION TO
THE NORTHWEST AND THE REGION IN A GOOD POSITION ON THE EDGE OF THE
RIDGE...COULD EASILY SEE CONVECTION DROP SE INTO THE REGION. SO
HAVE VERY LITTLE PCPN ON WEDNESDAY WITH HIGHER CHANCE POPS ON
THURSDAY. BUT CONFIDENCE IN THE OVER PATTERN IS LOW DUE TO THE
MODEL UNCERTAINTY FROM RUN TO RUN.
FOR TEMPERATURES...HAVE ALLOWED FOR SOME ADDITIONAL HEATING ON WED
AND THU DUE TO MORE SUNSHINE AND ALSO DUE TO THE WEST/NW FLOW
ALOFT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
UNSETTLED WEATHER PATTERN CONTINUES INTO THE EXTENDED PERIOD AS NWLY
FLOW ALOFT DEVELOPS. TEMPS WILL BE NEAR TO SLIGHTLY BELOW
SEASONABLE...LATE SUMMER NORMS.
WHILE MEDIUM RANGE GUIDANCE CONTINUES TO STRUGGLE HANDLING THE
SPLIT/BLOCKY FLOW OVER THE HIGHER LATITUDES...MODELS HAVE BECOME
MORE STABLE WITH RESOLVING SRN STREAM ENERGY OVER THE OH VALLEY AND
MID-ATLANTIC REGION. THIS THANKS TO UPPER/SFC HIGH PRESSURE FROM THE
SE STATES EWD OFF THE COAST. WITH THAT SAID...FLOW AMPLIFIES OVER
THE ERN CONUS AS MID LEVEL HIGH PRESSURE BUILDS OVER THE CNTRL US
AND LOW PRESSURE REMAINS OVER THE NE US. THIS WILL PLACE THE
MID-ATLANTIC STATES IN NWLY FLOW ALOFT...OPENING THE DOOR FOR
SHORTWAVE ENERGY IN THE UPPER FLOW. QUASI-STATIONARY BOUNDARY WILL
LOCATE OVER THE REGION...JUST TO THE SOUTH. MOISTURE WILL NOT BE A
LIMITATION WITH PWATS PROGGED AROUND 2 INCHES (+1 STD DEV) AND
DEWPOINTS IN THE MID-UPPER 60S. ANTICIPATE A DIURNAL TREND WITH
SHOWERS/THUNDERSTORMS...BUT UPSTREAM MCS DEVELOPMENT MAY SPILL INTO
THE REGION DURING THE OVERNIGHT HOURS THRU THE WEEKEND. HIGHER POPS
MAY BE WARRANTED...BUT BASED ON THE DEGREE OF UNCERTAINTY AND
TIMING...WILL STICK MORE TO CLIMO WITH CHANCE POPS DURING THE
AFTERNOON AND EVENING. COULD BEGIN TO SEE A DRYING TREND BY LATE IN
THE WEEKEND INTO EARLY NEXT WEEK AS THE UPPER HIGH BUILDS
EWD...SHUNTING THE BEST MOISTURE OFFSHORE.
WITH THE LATEST MODEL RUNS PLACING THE FRONT SOUTH OF THE LOCAL
AREA...NLY FLOW AND FALLING THICKNESSES WILL LIKELY YIELD TEMPS IN
THE LOW-MID 80S. LOW-MID 80S TO CONTINUE THRU THE WEEKEND...WARMING
BACK INTO THE MID 80S BY EARLY NEXT WEEK.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
A COMPLEX AREA OF LOW PRESSURE AND FRONTAL SYSTEMS COVERED THE MID
ATLANTIC STATES MONDAY EVENING. LOW PRESSURE MOVES OFF THE COAST
TUESDAY MORNING WITH WEAK HIGH PRESSURE BUILDING FROM THE NORTH
THROUGH WEDNESDAY. UNSETTLED WEATHER RETURNS LATE IN THE WEEK.
THE LINE OF TSTMS THAT AFFECTED SOUTHEAST VIRGINIA MOVED OFF THE
COAST JUST PRIOR TO THE 00Z TAF ISSUANCE MORE SHOWERS WERE
DEVELOPING BUT NO SIGNIFICANT TSTMS ARE EXPECTED OVERNIGHT. WITH
MOIST CONDITIONS... MVFR WITH AREAS OF IFR CAN BE EXPECTED IN THE
LATE EVENING AND OVERNIGHT.
MVFR SHOULD END BY LATE MORNING. WIDELY SCT SHOWERS AND TSTMS WILL
BE PSBL TUESDAY BUT NOT NEARLY AS WIDESPREAD AS THEY WERE MONDAY.
OUTLOOK...SCT AFTN/EVENING TSTMS RETURN TO THE FCST THURSDAY
THROUGH SATURDAY. THERE WILL BE THE POSSIBILITY OF MVFR/IFR CONDS
WITHIN A FEW HOURS OF SUNRISE EACH MORNING.
&&
.MARINE...
UNSETTLED WEATHER PATTERN WILL PREVAIL OVER THE WATERS THRU THE
FORECAST PERIOD...BUT SCA CONDITIONS ARE NOT ANTICIPATED.
AREA OF LOW PRESSURE HAS LOCATED OVER WV WITH A FRONTAL BOUNDARY
EXTENDING EWD OVER SRN VA AND THE LOWER BAY. MEANWHILE...HIGH
PRESSURE BUILDS OVER THE NE STATES. THE RESULT IS GENERALLY ONSHORE
AROUND 10 KT. WAVES/SEAS AVG 1-2 FT. SFC LOW WEAKENS OVER THE CNTRL
APPALACHIANS AS AN ADDITIONAL AREA OF LOW PRESSURE DEVELOPS OVER THE
WATERS. WITH THE SFC LOW OVER THE WATERS...FLOW OVER THE COASTAL
WATERS (ON THE ERN PERIPHERY OF THE LOW) WILL BE SW OVER THE SRN
WATERS...VEERING TO E OVER THE NRN WATERS...AVG 10-15 KT. SCA
CONDITIONS ARE NOT ANTICIPATED. SEAS WILL BUILD ONLY TO 2-3 FT WITH
WAVES AVG 1-2 FT. SFC LOW SLOWLY PUSHES OFFSHORE LATE TUES-TUES
NIGHT AS HIGH PRESSURE OFF THE NE COAST RIDGES SWD OVER THE NRN
WATERS. FLOW REMAINS GENERALLY ONSHORE...AOB 15 KT. LOW PRESSURE
LINGERS OFF THE MID-ATLANTIC COAST THRU THE END OF THE WORK WEEK AND
INTO THE WEEKEND AS A FRONTAL BOUNDARY REMAINS SOUTH OF THE WATERS.
THE RESULT WILL BE ONGOING ONSHORE/NELY FLOW. GRADIENT WILL REMAIN
WEAK (AOB 15 KT)...BUT PERSISTENT NE FETCH MAY PUSH SEAS UPWARDS OF
5 FT IN THE NRN COASTAL WATERS FRIDAY NIGHT THRU THE WEEKEND.
UNDERCUT WAVEWATCH AS GFS IS NOT THE PREFERRED MEDIUM RANGE MODEL.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...ESS
NEAR TERM...ESS/JAO
SHORT TERM...ESS
LONG TERM...SAM
AVIATION...LSA
MARINE...SAM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1141 PM EDT MON AUG 18 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 345 PM EDT MON AUG 18 2014
THE REGION IS HEADING INTO A WETTER PATTERN THE NEXT WEEK WITH THE
FIRST CHANCES FOR RAINFALL COMING UP TONIGHT INTO TUESDAY. ANOTHER
TIME FRAME OF PERIODS OF SHOWERS AND STORMS WILL COME FROM THURSDAY
THROUGH SUNDAY WITH A FRONTAL BOUNDARY NEAR THE AREA. SHOWERS AND
STORMS WILL BECOME MORE NUMEROUS LATE TONIGHT AND ESPECIALLY ON
TUESDAY AS AN AREA OF LOW PRESSURE MOVES INTO THE GREAT LAKES. A
GRADUAL WARMING TREND WILL BE SEEN THROUGH THE WEEK AND INTO NEXT
WEEKEND. HIGHS AROUND 80 AT THE START OF THE WEEK WILL WARM TO THE
MIDDLE 80S BY NEXT WEEKEND.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 345 PM EDT MON AUG 18 2014
MAIN FOCUS IN THE SHORT TERM IS ON THE CHANCES FOR SHOWERS/STORMS
TONIGHT INTO TUESDAY. PRECIPITATION WILL BE DRIVEN BY AN TROUGH
DIGGING INTO THE GREAT LAKES REGION FROM THE NORTHERN PLAINS.
MOISTURE SURGES INTO REGION THIS EVENING WITH THE HRRR TRYING TO
FLOAT CONVECTION FROM WISCONSIN OVER LAKE MICHIGAN IN THE 00Z-06Z
TIME FRAME. THINKING OUR BEST CHANCES FOR PRECIP THOUGH WILL BE
OVERNIGHT INTO TUESDAY WHEN ALL OF THE SHORT TERM MODELS FOCUS A LLJ
ON THE AREA. NOT EXPECTING SEVERE WEATHER GIVEN THE TIMING OF THE
PRECIP AND THE FACT THAT INSTABILITY WILL LIKELY BE LIMITED SOMEWHAT
BY OVERNIGHT PRECIP. 0-6KM SHEAR IS SUB 30 KNOTS BOTH TONIGHT AND
TUESDAY FOR THE MOST PART AS WELL. SOME LOCALLY HEAVY RAIN IS
POSSIBLE.
SHOWERS AND STORMS WILL BECOME MORE SCATTERED TUESDAY NIGHT THROUGH
WEDNESDAY AS THE SYSTEM FILLS OVERHEAD. PLENTY OF MOISTURE LINGERS
HOWEVER SO SCATTERED SHOWERS AND A FEW STORMS WILL REMAIN POSSIBLE
BOTH PERIODS. WEDNESDAY NIGHT KEPT THE DRY FORECAST GOING AS SURFACE
RIDGING BEGINS TO TAKE OVER AND THE UPPER LOW SLIDES SLIGHTLY OFF TO
THE EAST.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 345 PM EDT MON AUG 18 2014
IT LOOKS TO BE A RATHER ACTIVE EXTENDED PERIOD. THE MAIN FOCUS WILL
BE ON OPPORTUNITIES FOR SHOWERS AND STORMS THURSDAY THROUGH SUNDAY
NIGHT. BY 12Z THURSDAY...A ULJ CORE WILL BE MOVING ACROSS THE LOWER
PENINSULA AS UPPER LEVEL RIDGING BUILDINGS IN. IN CONCERT WITH THIS
WILL BE A FAIRLY STRONG H850 TEMP GRADIENT (6-8C) MOVING INTO SW
LOWER MICHIGAN AND INCREASING MID LEVEL MOISTURE. LIGHT EASTERLY
WIND CONV AT THE SFC (AS SHOWN BY THE ECMWF) MAY HELP ENHANCE
CONVECTIVE DEVELOPMENT PARTICULARLY ACROSS THE LAKESHORE REGION AND
GENERALLY ALONG AND WEST OF US 131 FOR THURSDAY EVENING INTO FRIDAY.
WHILE MODEL QPF IS NOT HIGH...INCREASING PW VALUES TO 2" OR SO ON
FRIDAY IS A CAUSE FOR CONCERN WITH ANY STORMS THAT DO DEVELOP.
LOCALLY HEAVY DOWNPOURS WOULD BE A POSSIBILITY THURSDAY NIGHT AND
FRIDAY ON THE WING OF WARM AIR ADVECTION. IF H500 HEIGHTS CONTINUE
TO BUILD STRONG ENOUGH BY SATURDAY (LIKE THE ECMWF SHOWS) THEN
PERHAPS WE WILL BE STABLE ENOUGH TO MITIGATE ANY SIGNIFICANT
CONVECTION. ON SATURDAY...GFS BUFKIT SOUNDINGS INDICATE SIGNIFICANT
SFC BASED CAPE UPWARDS OF 2000 J/KG AND LI VALUES OF -4 TO -6 BUT
WEAK SHEAR AND WEAK MID LEVEL LAPSE RATES. ECMWF WOULD SUGGEST A
LACK OF TRIGGER AND MORE STABLE CONDITIONS. OUR POP GRIDS ARE
CURRENTLY MIDDLE OF THE ROAD CHC CATEGORY FOR SATURDAY...REFLECTING
A LACK OF MODEL BULLISHNESS ON PRECIP.
UPPER LEVEL RIDGING MAY FLATTEN LATER SUNDAY AND AN ASSOCIATED
COLD FRONT COULD ARRIVE BY SUNDAY NIGHT. THE TIMING OF THIS IS
ACTUALLY AGREED UPON BY THE GFS AND ECMWF (00Z-06Z MON)...WHEREAS
THE GEM CLEARS THE FRONT 24 HOURS EARLIER. CURRENTLY AM PREFERRING A
SLOWER BREAKDOWN OF THE H500 RIDGE AND THUS A SLOWER FROPA AS SHOWN
BY THE GFS AND ECMWF. THERE WILL LIKELY BE SUFFICIENT DEEP LAYER
SHEAR BY THAT TIME TO PROVIDE A MORE CONDUCIVE ENVIRONMENT TO
STRONGER STORMS.
IN TERMS OF TEMPS AND HUMIDITY...BOTH WILL BE GOING UP BY THE
WEEKEND. DEW POINTS SHOULD CLIMB TO AROUND 70 AND HIGHS IN THE MID
80S MAY BE CONSERVATIVE FOR SATURDAY AND SUNDAY DEPENDING ON MUCH
CLOUD COVER HANGS AROUND. WOULDN`T BE SURPRISED IF HIGHS NOTCH UP
SEVERAL DEGREES WARMER WITH H850 TEMPS OF 20C KNOCKING ON THE DOOR
SATURDAY EVENING. COOLER WEATHER MOVES IN FOR EARLY NEXT WEEK BEHIND
THE FRONT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1137 PM EDT MON AUG 18 2014
AREA OF THUNDERSTORMS WILL BE CROSSING PARTS OF SOUTHWEST LOWER MI
TO START THE PERIOD. THERE COULD BE LOCAL IFR WITHIN THIS AREA OF
RAIN. THUNDERSTORMS WILL REDEVELOP ON TUESDAY...ESPECIALLY INLAND.
INCREASING MOISTURE WILL ALSO LEAD TO HAZY CONDITIONS. MVFR LIKELY
FOR MANY LOCATIONS...BUT ANY THUNDERSTORM WILL BE CAPABLE OF LOCAL
IFR OR LOWER.
&&
.MARINE...
ISSUED AT 345 PM EDT MON AUG 18 2014
MAIN IMPACT WEATHER FOR WINDS/WAVES WILL COME ON TUESDAY. SOUTH
WINDS WILL INCREASE TONIGHT INTO TUESDAY WITH WAVES BECOMING
BORDERLINE FOR BEACH HAZARDS FROM HOLLAND NORTHWARD UP THE SHORE.
EXPECTING WAVES TO PUSH INTO THE 2 TO 4 FOOT RANGE ON TUESDAY NORTH
OF HOLLAND OR SO. THE WINDS SLACKEN OFF AS WE HEAD INTO WEDNESDAY AS
THE GRADIENT BECOMES BAGGY...SO THE WAVES WILL SUBSIDE FOR MID WEEK.
&&
.HYDROLOGY...
ISSUED AT 139 PM EDT MON AUG 18 2014
RIVERS ARE RUNNING A LITTLE ABOVE NORMAL... BUT ARE STILL FAR BELOW
BANK FULL. PRECIPITATION THIS EVENING THROUGH WEDNESDAY IS EXPECTED
TO TOTAL AROUND HALF AN INCH. THIS SHOULD LEAD TO SLOW RISES ON AREA
RIVERS WITH PEAK LEVELS WELL BELOW FLOOD STAGE OCCURRING BY THE END
OF THE WEEK. LOCALLY HEAVY RAINFALL IS POSSIBLE AND COULD LEAD TO
BRIEFLY HIGHER FLOWS.
LOOKING AHEAD...IT APPEARS TO BE A RATHER ACTIVE SECOND HALF OF
AUGUST WHICH MAY HELP BRING MANY RIVERS TO ABOVE NORMAL FLOWS.
WITH AN UPPER LEVEL RIDGE DEVELOPING TO THE SOUTH OF THE GREAT
LAKES OVER THE NEXT WEEK OR SO...IT WILL PLACE MICHIGAN IN AN
ACTIVE WEATHER PATTERN WITH NUMEROUS OPPORTUNITIES FOR RAIN.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...DUKE
SHORT TERM...DUKE
LONG TERM...HOVING
AVIATION...MJS
HYDROLOGY...63
MARINE...DUKE
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
806 PM EDT MON AUG 18 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 345 PM EDT MON AUG 18 2014
THE REGION IS HEADING INTO A WETTER PATTERN THE NEXT WEEK WITH THE
FIRST CHANCES FOR RAINFALL COMING UP TONIGHT INTO TUESDAY. ANOTHER
TIME FRAME OF PERIODS OF SHOWERS AND STORMS WILL COME FROM THURSDAY
THROUGH SUNDAY WITH A FRONTAL BOUNDARY NEAR THE AREA. SHOWERS AND
STORMS WILL BECOME MORE NUMEROUS LATE TONIGHT AND ESPECIALLY ON
TUESDAY AS AN AREA OF LOW PRESSURE MOVES INTO THE GREAT LAKES. A
GRADUAL WARMING TREND WILL BE SEEN THROUGH THE WEEK AND INTO NEXT
WEEKEND. HIGHS AROUND 80 AT THE START OF THE WEEK WILL WARM TO THE
MIDDLE 80S BY NEXT WEEKEND.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 345 PM EDT MON AUG 18 2014
MAIN FOCUS IN THE SHORT TERM IS ON THE CHANCES FOR SHOWERS/STORMS
TONIGHT INTO TUESDAY. PRECIPITATION WILL BE DRIVEN BY AN TROUGH
DIGGING INTO THE GREAT LAKES REGION FROM THE NORTHERN PLAINS.
MOISTURE SURGES INTO REGION THIS EVENING WITH THE HRRR TRYING TO
FLOAT CONVECTION FROM WISCONSIN OVER LAKE MICHIGAN IN THE 00Z-06Z
TIME FRAME. THINKING OUR BEST CHANCES FOR PRECIP THOUGH WILL BE
OVERNIGHT INTO TUESDAY WHEN ALL OF THE SHORT TERM MODELS FOCUS A LLJ
ON THE AREA. NOT EXPECTING SEVERE WEATHER GIVEN THE TIMING OF THE
PRECIP AND THE FACT THAT INSTABILITY WILL LIKELY BE LIMITED SOMEWHAT
BY OVERNIGHT PRECIP. 0-6KM SHEAR IS SUB 30 KNOTS BOTH TONIGHT AND
TUESDAY FOR THE MOST PART AS WELL. SOME LOCALLY HEAVY RAIN IS
POSSIBLE.
SHOWERS AND STORMS WILL BECOME MORE SCATTERED TUESDAY NIGHT THROUGH
WEDNESDAY AS THE SYSTEM FILLS OVERHEAD. PLENTY OF MOISTURE LINGERS
HOWEVER SO SCATTERED SHOWERS AND A FEW STORMS WILL REMAIN POSSIBLE
BOTH PERIODS. WEDNESDAY NIGHT KEPT THE DRY FORECAST GOING AS SURFACE
RIDGING BEGINS TO TAKE OVER AND THE UPPER LOW SLIDES SLIGHTLY OFF TO
THE EAST.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 345 PM EDT MON AUG 18 2014
IT LOOKS TO BE A RATHER ACTIVE EXTENDED PERIOD. THE MAIN FOCUS WILL
BE ON OPPORTUNITIES FOR SHOWERS AND STORMS THURSDAY THROUGH SUNDAY
NIGHT. BY 12Z THURSDAY...A ULJ CORE WILL BE MOVING ACROSS THE LOWER
PENINSULA AS UPPER LEVEL RIDGING BUILDINGS IN. IN CONCERT WITH THIS
WILL BE A FAIRLY STRONG H850 TEMP GRADIENT (6-8C) MOVING INTO SW
LOWER MICHIGAN AND INCREASING MID LEVEL MOISTURE. LIGHT EASTERLY
WIND CONV AT THE SFC (AS SHOWN BY THE ECMWF) MAY HELP ENHANCE
CONVECTIVE DEVELOPMENT PARTICULARLY ACROSS THE LAKESHORE REGION AND
GENERALLY ALONG AND WEST OF US 131 FOR THURSDAY EVENING INTO FRIDAY.
WHILE MODEL QPF IS NOT HIGH...INCREASING PW VALUES TO 2" OR SO ON
FRIDAY IS A CAUSE FOR CONCERN WITH ANY STORMS THAT DO DEVELOP.
LOCALLY HEAVY DOWNPOURS WOULD BE A POSSIBILITY THURSDAY NIGHT AND
FRIDAY ON THE WING OF WARM AIR ADVECTION. IF H500 HEIGHTS CONTINUE
TO BUILD STRONG ENOUGH BY SATURDAY (LIKE THE ECMWF SHOWS) THEN
PERHAPS WE WILL BE STABLE ENOUGH TO MITIGATE ANY SIGNIFICANT
CONVECTION. ON SATURDAY...GFS BUFKIT SOUNDINGS INDICATE SIGNIFICANT
SFC BASED CAPE UPWARDS OF 2000 J/KG AND LI VALUES OF -4 TO -6 BUT
WEAK SHEAR AND WEAK MID LEVEL LAPSE RATES. ECMWF WOULD SUGGEST A
LACK OF TRIGGER AND MORE STABLE CONDITIONS. OUR POP GRIDS ARE
CURRENTLY MIDDLE OF THE ROAD CHC CATEGORY FOR SATURDAY...REFLECTING
A LACK OF MODEL BULLISHNESS ON PRECIP.
UPPER LEVEL RIDGING MAY FLATTEN LATER SUNDAY AND AN ASSOCIATED
COLD FRONT COULD ARRIVE BY SUNDAY NIGHT. THE TIMING OF THIS IS
ACTUALLY AGREED UPON BY THE GFS AND ECMWF (00Z-06Z MON)...WHEREAS
THE GEM CLEARS THE FRONT 24 HOURS EARLIER. CURRENTLY AM PREFERRING A
SLOWER BREAKDOWN OF THE H500 RIDGE AND THUS A SLOWER FROPA AS SHOWN
BY THE GFS AND ECMWF. THERE WILL LIKELY BE SUFFICIENT DEEP LAYER
SHEAR BY THAT TIME TO PROVIDE A MORE CONDUCIVE ENVIRONMENT TO
STRONGER STORMS.
IN TERMS OF TEMPS AND HUMIDITY...BOTH WILL BE GOING UP BY THE
WEEKEND. DEW POINTS SHOULD CLIMB TO AROUND 70 AND HIGHS IN THE MID
80S MAY BE CONSERVATIVE FOR SATURDAY AND SUNDAY DEPENDING ON MUCH
CLOUD COVER HANGS AROUND. WOULDN`T BE SURPRISED IF HIGHS NOTCH UP
SEVERAL DEGREES WARMER WITH H850 TEMPS OF 20C KNOCKING ON THE DOOR
SATURDAY EVENING. COOLER WEATHER MOVES IN FOR EARLY NEXT WEEK BEHIND
THE FRONT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 805 PM EDT MON AUG 18 2014
VFR CONDITIONS ARE EXPECTED TO DETERIORATE TO MVFR AROUND 05Z OR
SO. AS OF THIS WRITING...THE LEADING EDGE OF A LINE SHOWERS AND
WEAKENING THUNDERSTORMS OVER CENTRAL WISCONSIN IS MAKING ITS WAY
ACROSS NORTHERN LAKE MICHIGAN. THESE STORMS ARE EXPECTED TO
CONTINUE TO COLLAPSE AS THEY MOVE ESE TOWARD KLDM.
HIGHER IMPACTS ARE EXPECTED AFTER ROUGHLY 10Z AND CONTINUING
THROUGH THE MORNING FOR ALL TAF SITES. MORE WIDESPREAD SHOWERS AND
STORMS WILL MOVE IN AND WINDS WILL INCREASE TO AROUND 10-12 KTS
OUT OF THE SOUTH. SCATTERED IFR CERTAINLY A POSSIBILITY UNDER
HEAVIER PRECIPITATION. CONFIDENCE IN IFR IS AVERAGE AND FUTURE
AMENDMENTS AND ISSUANCES MAY LOWER VSBYS/CIGS. CONDITIONS WILL
GRADUALLY IMPROVE AFTER 18Z TUESDAY.
&&
.MARINE...
ISSUED AT 345 PM EDT MON AUG 18 2014
MAIN IMPACT WEATHER FOR WINDS/WAVES WILL COME ON TUESDAY. SOUTH
WINDS WILL INCREASE TONIGHT INTO TUESDAY WITH WAVES BECOMING
BORDERLINE FOR BEACH HAZARDS FROM HOLLAND NORTHWARD UP THE SHORE.
EXPECTING WAVES TO PUSH INTO THE 2 TO 4 FOOT RANGE ON TUESDAY NORTH
OF HOLLAND OR SO. THE WINDS SLACKEN OFF AS WE HEAD INTO WEDNESDAY AS
THE GRADIENT BECOMES BAGGY...SO THE WAVES WILL SUBSIDE FOR MID WEEK.
&&
.HYDROLOGY...
ISSUED AT 139 PM EDT MON AUG 18 2014
RIVERS ARE RUNNING A LITTLE ABOVE NORMAL... BUT ARE STILL FAR BELOW
BANK FULL. PRECIPITATION THIS EVENING THROUGH WEDNESDAY IS EXPECTED
TO TOTAL AROUND HALF AN INCH. THIS SHOULD LEAD TO SLOW RISES ON AREA
RIVERS WITH PEAK LEVELS WELL BELOW FLOOD STAGE OCCURRING BY THE END
OF THE WEEK. LOCALLY HEAVY RAINFALL IS POSSIBLE AND COULD LEAD TO
BRIEFLY HIGHER FLOWS.
LOOKING AHEAD...IT APPEARS TO BE A RATHER ACTIVE SECOND HALF OF
AUGUST WHICH MAY HELP BRING MANY RIVERS TO ABOVE NORMAL FLOWS.
WITH AN UPPER LEVEL RIDGE DEVELOPING TO THE SOUTH OF THE GREAT
LAKES OVER THE NEXT WEEK OR SO...IT WILL PLACE MICHIGAN IN AN
ACTIVE WEATHER PATTERN WITH NUMEROUS OPPORTUNITIES FOR RAIN.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...DUKE
SHORT TERM...DUKE
LONG TERM...HOVING
AVIATION...EBW
HYDROLOGY...63
MARINE...DUKE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
743 PM EDT MON AUG 18 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 322 PM EDT MON AUG 18 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A FAIRLY STRONG
SHRTWV OVER THE NRN PLAINS DRIFTING TO THE ESE INTO NW MN DOWNSTREAM
OF A RDG OVER WRN CANADA AND TOWARD A SHRTWV RDG STRETCHING FM
HUDSON BAY TOWARD THE SE GREAT LKS ON THE WRN FLANK OF A DEEP TROF
OVER THE CNDN MARITIMES. THERE IS ALSO A WEAKER SHRTWV MOVING E THRU
THE UPR LKS AHEAD OF THE MAIN DISTURBANCE APRCHG MN...AND THIS
FEATURE ALONG WITH ACCOMPANING AXIS OF GREATER H85 THETA E ADVCTN/A
FAIRLY MOIST 12Z GRB RAOB /KINX 36C AND PWAT 1.64 INCH OR ALMOST 175
PERCENT OF NORMAL/ HAS BEEN THE FOCUS FOR SOME SCT-NMRS SHOWERS
MAINLY OVER CENTRAL CWA TODAY. BUT QUITE A CONTRAST JUST TO THE E
WITH THE 12Z APX RAOB DISPLAYING A MUCH DRIER PROFILE...KINX -12C
AND PWAT 0.66 INCH OR ONLY 75 PERCENT OF NORMAL. THIS DRIER/STABLE
AIRMASS HAS SLOWED THE PROGRESS OF THE SHOWERS INTO THE AREA ARND
NEWBERRY SO FAR. THERE ARE MORE NMRS SHOWERS/A FEW TS MOVING INTO
WRN LK SUP CLOSER TO THE TRAILING SHRTWV. OTRW...QUITE A BIT OF CLD
COVER HAS LIMITED THE DIURNAL RISE OF TEMP AND DESTABILIZATION IN
THE ABSENCE OF STEEP LAPSE RATES SHOWN ON EVEN THE MOISTER 12Z GRB
RAOB...SO TS HAVE BEEN FEW AND FAR BTWN. BUT SOME HEAVY RAINS HAVE
FALLEN UNDER THE STRONGER SHOWERS WITH THE HIER PWAT/DEEPER MSTR.
MAIN FCST CONCERNS IN THE SHORT TERM ARE POPS RELATED TO THE TWO
DISTURBANCES THAT ARE MOVING THRU MN/THE UPR LKS.
LATE TODAY/TNGT...AS TROF OVER QUEBEC SLOWLY EXITS TO THE E...LEAD
SHRTWV MOVING THRU THE UPR LKS/ACCOMPANYING AXIS OF H85 THETA E
ADVCTN WL DRIFT TO THE E AND BRING SOME SHOWERS TO THE FAR ERN CWA
BY 00Z. ALTHOUGH THERE MAY BE ONLY SOME ISOLD/SCT SHOWERS OVER WRN
UPR MI WITH SOME H7-5 DRYING MOST OF TODAY...MORE NMRS SHOWERS/SOME
TS ASSOCIATED WITH THE STRONGER SHRTWV MOVING INTO MN WL ARRIVE OVER
THE FAR W ARND 00Z TOWARD AREA WHERE THE 12Z NAM/REGIONAL CNDN MODEL
SHOW HIER MUCAPE UP TO ABOUT 750 J/KG NEAR IWD. BUT SINCE THE MN
SHRTWV WL BE TENDING TO DIG ESEWD THRU THE NGT...THE 12Z NAM/
REGIONAL CNDN MODEL INDICATE THE MORE NMRS SHOWERS WL IMPACT WI
CLOSER TO MORE VIGOROUS H85-7 MSTR CNVGC/HIER MUCAPE IN THE 500-
1000J/KG THAT WL BE CONFINED TO WI. SO WL MAINTAIN THE HIEST LIKELY
POPS TOWARD THE WI BORDER... ALONG WITH THE TS CHANCES PER ABSENCE
OF FCST MUCAPE AOA 200 J/KG FARTHER N. BUT DEEP LYR QVECTOR CNVGC/
DEEP SATURATION ON FCST SDNGS ON THE CYC SIDE OF SHRTWV TRACK
JUSTIFIES AT LEAST 50-60 POPS OVER THE ENTIRE CWA EVEN IF THE BETTER
FORCING/INSTABILITY HOLD TO THE SW. EXPECT LTL DIURNAL TEMP DROP
WITH LOTS OF CLDS/LINGERING HIER PWAT IN THE 1.50-1.75 RANGE. ADDED
SOME PATCHY FOG...ESPECIALLY IN AREAS OVER THE CENTRAL THAT WL
EXPERIENCE UPSLOPE SE FLOW.
TUE...EXPECT CONTINUED SCT-NMRS SHOWERS AND A FEW TS AS THE SHRTWV/
SFC LO REFLECTION SLIDE ESEWD THRU NRN WI AND MAINTAINS DEEP MSTR...
CYC FLOW AND DEEP LYR QVECTOR CNVGC OVER UPR MI. FCST WL SHOW
DIMINISHING POPS IN THE AFTN OVER THE W WITH PASSAGE OF SHRTWV TO
THE E AND ARRIVAL OF SOME DNVA/DEEP LYR QVECTOR DVGC AFT 18Z. FOG IN
THE MRNG OVER MAINLY THE CENTRAL ZNS WL DSPT SLOWLY WITH DIURNAL
HEATING LIMITED BY EXTENSIVE CLD COVER.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 431 PM EDT MON AUG 18 2014
THE 500MB LOW CENTERED OVER UPPER MI AND LAKE SUPERIOR AT 00Z
WEDNESDAY WILL SHIFT ACROSS LAKE HURON WEDNESDAY NIGHT/THURSDAY
MORNING WITH A BRIEF RIDGE BUILDING ACROSS UPPER MI THURSDAY. THE
APEX OF THE RIDGE WILL SHIFT JUST TO OUR E THURSDAY NIGHT. A SIZABLE
TROUGH SET UP FROM FROM W AND CENTRAL CANADA THROUGH THE ENTIRE W
U.S. WEDNESDAY WILL SLOWLY SHIFT THE N CENTRAL U.S. FOR THE
WEEKEND...AND UPPER GREAT LAKES SUNDAY NIGHT/MONDAY.
AS FOR THE SFC FEATURES AND WX...THE EXITING SFC LOW OVER N LAKE MI
AT 00Z WEDNESDAY WILL LINGER THROUGH THE NIGHT BEFORE SHIFTING TO
LOWER MI THROUGH THE DAY WEDNESDAY. WITH WRAP AROUND/UPSLOPE
MOISTURE ACROSS THE AREA...EXPECT LIGHT SHOWERS TO LINGER THROUGH
MID DAY AT LEAST. THE BEST CHANCE OF THUNDERSTORMS WILL SINK SE WITH
THE SFC LOW.
IT LOOKS LIKE THE ONLY PERIOD OF MAINLY DRY WEATHER WILL BE LATE
WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING...DESPITE THE 500MB
RIDGE OVERHEAD THURSDAY THROUGH FRIDAY. THE LARGE HIGH PRESSURE OVER
QUEBEC...WITH A RIDGE EXTENDING OVER THE UPPER GREAT LAKES WILL EXIT
E ON FRIDAY. THERE STILL LOOKS TO BE PLENTY OF INCONSISTENCIES FOR
FRIDAY AFTERNOON ON. WILL CONTINUE TO RUN WITH A GENERAL CONSENSUS
FOR THIS PERIOD...WITH HAS AN ELONGATED SFC LOW FROM HUDSON BAY
THROUGH MN AND THE CENTRAL PLAINS AT 00Z SUNDAY. THE LOW WILL SLOWLY
SHIFT TO ONTARIO/FAR W LAKE SUPERIOR SATURDAY. THIS WOULD BRING WAA
TO THE AREA WITH HIGH TEMPS RETURNING TO NEAR NORMAL READINGS FRIDAY
AND SATURDAY. THE SFC TROUGH SHOULD BE OVER THE CWA SATURDAY
NIGHT/SUNDAY MORNING. HAVE SLOWLY DIMINISHING POPS FOR SUNDAY AND
MONDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 742 PM EDT MON AUG 18 2014
ALTHOUGH THE SPECIFICS ARE UNCERTAIN...LIFR TO POSSIBLY VLIFR
CONDITIONS WILL LIKELY PREVAIL AT KCMX/KSAW THRU AT LEAST TUE
MORNING UNDER LIGHT UPSLOPE FLOW/DEEP MOISTURE AND SCT TO AT TIMES
NMRS SHRA ASSOCIATED WITH DISTURBANCE MOVING SLOWLY ESEWD THRU MN.
AT KIWD...LOW-LEVEL MOISTURE HAS MIXED OUT TEMPORARILY...AND THIS
SHOULD ALLOW VFR CONDITIONS FOR THE NEXT FEW HRS...THOUGH
OCCASIONALLY MVFR AS SCT SHRA IN NW WI SPREAD E AND NE. EXPECT A
RETURN TO IFR LATE EVENING AND THEN TO LIFR LATE TONIGHT AS WINDS
BECOME LIGHT UPSLOPE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 322 PM EDT MON AUG 18 2014
ADDED SOME FOG TO THE FORECAST THRU MUCH OF TUE OVER MAINLY THE
CENTRAL LAKE GIVEN ARRIVAL OF DEEPER MOISTURE AND EXPECTED AREA OF
LOWER TEMPERATURES NEAR THE LINGERING COOLEST DEEPER WATER.
OTHERWISE... EXPECT WINDS UNDER 20 KTS OVER THE NEXT WEEK AS A
RELATIVELY WEAK PRESSURE GRADIENT DOMINATES THE UPPER GREAT LAKES
ABOVE THE CHILLY WATERS OF LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
334 PM EDT SUN AUG 17 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 332 PM EDT SUN AUG 17 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALF BTWN
A SLOWLY RETREATING...DEEP UPR TROF IN QUEBEC AND AN UPR RDG IN THE
PLAINS/UPR MS RIVER VALLEY. SFC HI PRES UNDER THIS RDG AXIS IS
LOCATED JUST NNW OF LK SUP. THE LLVL NE FLOW ON THE SRN FLANK OF
THIS HI IS FUNNELING SOME COOL...MOIST AIR INTO THE UPR LKS BLO
SHARP SUBSIDENCE INVRN ARND H85 AS SHOWN ON THE LOCAL 12Z RAOBS. THE
RESULT HAS BEEN A GOOD DEAL OF LO CLD COVER. THERE WAS EVEN SOME
DRIZZLE INTO THE EARLY AFTN OVER THE HIER TERRAIN OF THE NCENTRAL...
WHERE THE NE WIND PRESENTS A SHARPER UPSLOPE COMPONENT. BUT WITH
DAYTIME HEATING UNDER THE MID LVL DRY AIR AND SOME DRY H95-9
ADVECTION FM THE NE...THE LO CLDS ARE SHOWING SIGNS OF BREAKING
UP...ESPECIALLY IN AREAS THAT EXPERIENCE DOWNSLOPE FLOW. LOOKING TO
THE W...A VIGOROUS SHRTWV IN SRN SASKATCHEWAN IS MOVING EWD JUST N
OF THE CNDN BORDER AND TENDING TO SUPPRESS THE UPR RDG IN THE
PLAINS. THERE IS ANOTHER WEAKER SHRTWV AHEAD OF THIS FEATURE MOVING
THRU MN. CLDS ALONG WITH SHOWERS/A FEW TS ASSOCIATED WITH THIS
DISTURBANCE/OVERALL H85 THETA E ADVCTN IN THE LARGER SCALE SW FLOW
AHEAD OF THE STRONGER SASKATCHEWAN SHRTWV ARE APRCHG DULUTH EARLY
THIS AFTN.
MAIN FCST CONCERNS INTO THIS EVNG ARE FOCUSED ON LO CLD TRENDS.
TIMING/COVERAGE OF SHOWERS ASSOCIATED WITH PAIR OF UPSTREAM SHRTWVS
ARE THE CONCERNS FOR LATER TNGT AND MON.
LATE TODAY/TNGT...ALTHOUGH THE COMBINATION OF SOME LLVL DRY ADVCTN
AND DAYTIME HEATING MAY BREAK UP THE LO CLDS NOW IMPACTING THE CWA
THRU THIS AFTN...FAIRLY HI INVRN BASE OBSVD ON THE 12Z RAOBS WL
PROBABLY MAINTAIN BKN LO CLDS AT MANY LOCATIONS NOT IMPACTED BY
DOWNSLOPING FLOW AS THE SLOWLY RISING LCL WL REMAIN UNDER THE HIER
INVRN BASE. BUT THE LATEST TRENDS INDICATE THESE CLDS SHOULD BE
ALMOST COMPLETELY GONE BY 00Z. AFTER THIS EVNG...CLD COVER/SCT
SHOWERS NOW APRCHG DLH ARE LIKELY TO SPREAD INTO THE WRN CWA IN
ADVANCE OF LEAD SHRTWV AND WHERE STRONGER H85 THETA E ADVCTN WL
DVLP. EXPECT THE LOWEST MIN TEMPS OVER THE INTERIOR E WHERE THERE IS
LIKELY TO BE A LONGER PERIOD OF MOCLR SKIES/LGT WINDS CLOSER TO SFC
HI MOVING FM ERN LK SUP INTO ADJOINING ONTARIO. ADDED SOME PATCHY
FOG TO THE FCST IN THIS AREA WHERE TEMPS ARE EXPECTED TO FALL BLO
THE CROSS OVER DEWPTS OBSVD THIS AFTN.
MON...MAIN SHRTWV NOW MOVING THRU SRN SASKATCHEWAN IS FCST TO MOVE
INTO MN DURING THE AFTN. ALTHOUGH SOME SCT SHOWERS ASSOCIATED WITH
THE LEAD DISTURBANCE/AREA OF H85 THETA E ADVCTN MAY SPREAD INTO THE
CENTRAL AND ERN CWA...THESE ARE MORE LIKELY TO WEAKEN WITH TIME AS
THE CLUSTER MOVES TOWARD THE SHRTWV RDG AXIS/DRIER MID LVL AIR ON
THE WRN FLANK OF THE SLOW MOVING QUEBEC TROF. MORE NMRS SHOWERS ARE
LIKELY TO MOVE INTO THE W HALF OF THE CWA IN THE AFTN UPON THE
ARRIVAL OF DEEPER MSTR/MORE VIGOROUS DYANMIC SUPPORT ASSOCIATED WITH
THE MORE VIGOROUS TRAILING SHRTWV IN THE PRESENCE OF DAYTIME
HEATING. WITH FCST MUCAPES NO HIER THAN 100-200 J/KG ASSOCIATED WITH
A GOOD DEAL OF CLD COVER/EXPECTED DAYTIME HI TEMPS MAINLY IN THE
60S...WL LEAVE OUT A MENTION OF TS EXCEPT OVER THE FAR W...WHERE THE
MORE UNSTABLE GFS HINTS MUCAPES MAY REACH 500 J/KG CLOSER TO THE
INCOMING DISTURBANCE/COLDER AIR ALF.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 332 PM EDT SUN AUG 17 2014
AT 00Z TUESDAY THE NEXT 500MB WAVE WILL BE SET UP ACROSS MN THROUGH
W ONTARIO. MID/LONG TERM MODELS INDICATE THAT THIS FEATURE WILL
DEVELOP INTO A LOW 12-18Z TUESDAY OVER E MN AND THE W HALF OF THE
MQT CWA. AT THAT POINT...LITTLE MOVEMENT WILL BE EXPECTED AT 500MB
UNTIL AFTER DAYBREAK WEDNESDAY...AS THE 500MB SITS AND SPINS ACROSS
UPPER MI AND LAKE SUPERIOR. THE SFC LOW SHOULD TRACK FROM N AND
CENTRAL MN AT 00Z TUESDAY NEAR THE WI/UPPER MI BORDER ON
TUESDAY...BEFORE EXITING ACROSS LAKE MI TUESDAY NIGHT...AND LOWER MI
ON WEDNESDAY. WITH UPPER MI STAYING ON THE N SIDE OF THE SFC LOW
EXPECT A PERIOD OF CLOUDY CONDITIONS...WITH AFTERNOON TEMPS ON
TUESDAY AVERAGING AROUND 5F BELOW THE SEASONAL NORMAL VALUES. THE
BEST CHANCE FOR PRECIP IS DIFFICULT TO PIN DOWN AT THIS POINT...AS
FCST MODELS VARY SIGNIFICANTLY WITH THE SMALLER SCALE FEATURES WITH
THIS DEVELOPING SYSTEM. WILL CONTINUE TO GO RELATIVELY GENERAL WITH
THE POPS AT THIS POINT. WILL KEEP TS POTENTIAL TO A MINIMUM...GIVEN
THE TRACK OF THE SFC LOW MAINLY TO OUR S...AND MU CAPE VALUES OVER
THE FAR W AOB 100J/KG FAR W TUESDAY MORNING. TUESDAY DURING THE DAY
DOESN/T LOOK MUCH MORE IMPRESSIVE...TOPPING OUT ALONG THE WI BORDER
GENERALLY AROUND 200 J/KG OR LESS /RESTRICTED TS MENTION TO CENTRAL
U.P./.
THE 500MB RIDGE WILL BRIEFLY BUILD OVERHEAD LATER WEDNESDAY INTO
EARLY THURSDAY. OUT OF THE WORK WEEK FROM TUESDAY ON...THIS SHOULD
BE THE DRIEST PERIOD. WILL TRY TO SHOW A BIT MORE IN OUR
FCST...DESPITE THE PW VALUES REMAINING 80-140 PERCENT OF NORMAL
/LOWEST E/.
THE CHANCE OF SHOWERS RETURN LATE THURSDAY INTO FRIDAY AS A
SHORTWAVE/TROUGH GLANCES THE AREA. TS MAY RETURN ON FRIDAY. EXPECT
WAA FRIDAY TO PUSH 850MB TEMPS UP TO 15-19C. IF CLOUDS AND PRECIP
CAN STAY TO A MINIMUM...SFC SHOULD SHIFT TO ABOVE NORMAL READINGS.
AS FOR THE OPEN HOUSE AT THE MQT NWS ON SATURDAY 10AM-2PM
EDT...THERE IS ENOUGH DISCREPANCIES AT THIS POINT IN THE FCST MODEL
DATA TO KEEP A GENERAL BLEND OR CONSENSUS GOING. BOTH THE GFS AND
ECMWF SHOW A 500MB LOW TO THE W OF UPPER MI AT 12Z.
HOWEVER...LOCATIONS VARY FROM N MANITOBA TO THE DAKOTAS...WITH A SFC
LOW OR TROUGH EITHER JUST TO OUR W OR OVER W UPPER MI. IF THE 17/00Z
AND 06Z GFS RUNS ARE CORRECT...WINDS NEAR 20KTS WILL BE POSSIBLE.
THE 12Z RUN DID DIMINISH THESE STRONG WINDS...DOWN TO AROUND 10KTS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 123 PM EDT SUN AUG 17 2014
WITH DAYTIME HEATING/DRY AIR SLOWLY ENCROACHING FM THE NE TO THE S
OF HI PRES MOVING INTO NRN LK SUP...EXPECT LO CLDS/MVFR CIGS
IMPACTING THE TAF SITES TO GIVE WAY TO CLRG/VFR CONSITIONS THRU THE
AFTN. MORE CLDS AND EVEN A FEW -SHRA IN ADVANCE OF DISTURBANCE
SPREADING E FM MN WL ARRIVE OVER THE W OVERNGT. PER UPSTREAM OBS IN
MN...FCST MVFR CIGS TO ARRIVE AT IWD AND THEN CMX ON MON MRNG AS
DEEPER MSTR ASSOCIATED WITH AN APRCHG DISTURBANCE OVERSPREADS THESE
SITES. ALTHOUGH THIS DEEPER MSTR IS LIKELY TO REMAIN W OF SAW THRU
THIS TAF PERIOD...SOME FOG MAY DVLP AT THAT SITE OVERNGT. DID NOT
FCST A LOWER CONDITION ATTM WITH EXPECTATION THAT HI CLDS PUSHING E
OF THE APRCHG DISTURBANCE MAY LIMIT DIURNAL COOLING SUFFICIENTLY TO
PREVENT FOG.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 332 PM EDT SUN AUG 17 2014
EXCEPT FOR A BRIEF PERIOD OVER EASTERN LAKE SUPERIOR LATE MON NIGHT
INTO TUE WHEN WINDS MAY REACH 20-25 KTS UNDER A SHARPER PRES
GRADIENT BETWEEN HI PRES IN QUEBEC AND A LO TRACKING THRU THE UPPER
MIDWEST...EXPECT WINDS UNDER 20 KTS OVER THE NEXT WEEK AS A
RELATIVELY WEAK PRES GRADIENT DOMINATES THE UPPER GREAT LAKES ABOVE
THE CHILLY WATERS OF LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
100 AM EDT SUN AUG 17 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 407 PM EDT SAT AUG 16 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW OVER
QUEBEC WITH NW FLOW IN ITS WAKE THROUGH THE NRN GREAT LAKES.
AT THE SFC...THE COLD FRONT HAS DROPPED SOUTH OF UPPER MI AS HIGH
PRES OVER NRN MANITOBA INTO NW ONTARIO BUILDS SOUTHWARD. ALTHOUGH
STRONG MID LEVEL DRYING HAD TAKEN OVER IN THE WAKE OF THE SHRTWV
THAT MOVED THROUGH EARLY TODAY...ABUNDANT LOW LEVEL MOISTURE AND
NRLY FLOW SUSTAINED OVC SKIES OVER MOST OF NRN UPPER MI. DOWNSLOPE
FLOW AND DAYTIME MIXING HAS BROUGHT MORE CLEARING TO SRN UPPER MI.
TONIGHT...HIGH PRES WILL BUILD FROM NRN ONTARIO THROUGH THE NRN
GREAT LAKES. CLOUDS SHOULD CONTINUE TO DIMINISH THIS EVENING BUT
WILL BE BE DELAYED WHERE ONSHORE/UPSLOPE NE WINDS PREVAIL...PER
UPSTREAM/SATELLITE TRENDS AND NAM/RUC 925-900 MB RH FCST. WITH
ENOUGH CLEARING MIN READINGS WILL FALL INTO THE MID 40S INLAND BUT
WHERE THICKER CLOUDS PERSIST...LOWS WILL ONLY DROP INTO THE LOWER
50S.
SUNDAY...AS THE RIDGE BUILDS OVER THE AREA...EXPECT THAT THE
COMBINATION OF DRY ADVECTION AND MIXING BY AFTERNOON WILL FINALLY
SCOUR OUT THE REMAINING OVERCAST WITH MAINLY JUST SCT/BKN CU INLAND.
TEMPS WILL CLIMB BACK INTO EH UPPER 50S AND LOWER 70S BUT REMAIN IN
THE LOWER 60S WHERE ENE ONSHORE FLOW PREVAILS NEAR LAKE SUPERIOR.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 335 PM EDT SAT AUG 16 2014
MAIN FCST CONCERNS IN THE LONGER TERM WL FOCUS ON HOW QUICKLY SHRTWV
NOW TRACKING THRU THE NRN ROCKIES AND ACCOMPANYING DEEPER MSTR WL
ARRIVE AND IMPACT POPS INTO MID WEEK UNDER BLDG UPR RDG.
SUN NGT/MON...SFC HI PRES JUST S OF JAMES BAY UNDER RDG AXIS ACRS NW
ONTARIO AT 12Z MON WL DOMINATE AND BRING DRY WX THRU AT LEAST MOST
OF SUN NGT. BUT A GOOD NUMBER OF THE MORE RECENT MODELS HAVE TRENDED
FASTER ON SHIFTING THE REMNANT OF THE CLOSED LO TRACKING THRU THE
NRN ROCKIES/ASSOCIATED MSTR UNDER WAD IN ADVANCE OF THIS DISTURBANCE
TO THE E AND TOWARD THE UPR LKS ON MON. SO HAVE INCREASED CLD COVER
AND BROUGHT POPS TO THE E FASTER THAN SHOWN ON THE PREVIOUS FCST...
WITH CHC POPS OVER THE W BY 12Z MON AND ACROSS ALL BUT THE E ON MON
AFTN AS PWAT IS FCST TO INCRS TO 1.50 TO 1.75 INCHES UNDER FALLING
HGTS/DIFFLUENT UPR FLOW/DPVA/DEEP LYR QVECTOR CNVGC TO THE E OF THE
APRCHG SHRTWV. CONSIDERING THE FASTER ARRIVAL OF THE MSTR/STRONGER
SLY FLOW FM THE W...BUMPED UP FCST MIN TEMPS OVER THE W ON SUN NGT.
BUT LOWERED FCST TEMPS OVER THE INTERIOR E CLOSER TO THE DEPARTING
SFC HI/DRIER AIR WITH PWAT UNDER 0.75 INCH/LIGHTER WINDS. WITH AN
EARLIER ARRIVAL OF MORE CLDS ON MON...OPTED TO LOWER FCST HI TEMPS A
BIT DESPITE FCST H85 TEMPS UP TO 14-15C OVER THE W.
MON NGT INTO WED...WHILE MEAN UPR RDG IS FCST TO BUILD ACROSS ERN
NAMERICA DOWNSTREAM OF DEEPENING TROF OVER THE W...SHRTWV APRCHG FM
THE W WL DRIFT SLOWLY THRU THE GREAT LKS. UNDER POCKET OF COOLER H5
TEMPS/HIER PWAT UP TO 1.50-1.75 INCHES...THERE WL BE AT LEAST SOME
SCT SHOWERS/A FEW TS ARND DURING THIS PERIOD. THE PROBABILITY OF
THESE SHOWERS WL BE GREATEST DURING DAYTIME HEATING ON TUE AFTN/
EVNG. A GOOD DEAL OF CLD COVER WL RESTRICT THE DIURNAL TEMP
RANGE...WITH HI TEMPS NOT FAR FM 70 RUNNING BLO NORMAL BUT MRNG LO
TEMPS MAINLY 55 TO 60 ABV AVG. IF THE UPR LO EXITS FASTER ON WED...
MORE AFTN SUNSHINE MIGHT ALLOW FOR WARMER TEMPS THEN.
END OF THE WEEK...AS THE SHRTWV MOVING THRU THE LKS SHIFTS AWAY
LATER WED AND HGTS RISE...EXPECT A DRYING TREND FOR WED NGT INTO
THU. SOME OF THE LONGER RANGE GUIDANCE HINTS ANOTHER SHRTWV RIDING
ENEWD THRU THE UPR MS RIVER VALLEY AND TOWARD NW ONTARIO/THE UPR LKS
MAY BRING MORE SHOWERS/A FEW TS TO THE AREA LATER ON THU INTO FRI.
VARIOUS MODELS INDICATE THIS SHRTWV WL BE SLOWER AND NOT IMPACT THE
AREA UNTIL SAT. CONSIDERING THE UNCERTAINTY ON SPECIFICS THIS FAR
OUT IN THE FCST PERIOD...WL RELY ON EXTENDED MODEL CONSENSUS FOR
FCST GENERATION. OVERALL TEMPS SHOULD RUN AOA NORMAL IN THE PRESENCE
OF MEAN UPR RDG TO THE E OF LARGER SCALE WRN TROF.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1259 AM EDT SUN AUG 17 2014
LOW CLOUDS WILL BE THE MAIN CONCERN THRU THIS MORNING...MAINLY AT
KCMX/KSAW. WITH A GENERAL DOWNSLOPE EASTERLY FLOW AT KIWD...NOTHING
MORE THAN SCT LOW CLOUDS ARE EXPECTED. SO...VFR CONDITIONS SHOULD
PREVAIL. SATELLITE IMAGERY CONTINUES TO SHOW LOW CLOUDS
MOVING/DEVELOPING S AND AFFECTING KCMX/KSAW. THESE MVFR CIGS SHOULD
PERSIST THRU THE NIGHT. EXACTLY WHEN THE CLOUDS WILL CLEAR OUT IS
UNCERTAIN...BUT IMPROVEMENT TO VFR SHOULD OCCUR AT KCMX/KSAW NO
LATER THAN LATE MORNING/EARLY AFTN AS FLOW BECOMES INCREASINGLY
ANTICYCLONIC AND MOISTURE MIXES OUT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 335 PM EDT SAT AUG 16 2014
EXPECT WINDS UNDER 20 KTS OVER THE NEXT WEEK AS A RELATIVELY WEAK
PRESSURE GRADIENT DOMINATES THE UPPER GREAT LAKES ABOVE THE CHILLY
WATERS OF LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
329 PM CDT Sun Aug 17 2014
.SHORT TERM: (Through Late Tonight)
Issued at 323 PM CDT Sun Aug 17 2014
Surface low/MCV continues to make very slow progress to the east
southeast away from forecast area. Will still see some lingering
light showers/sprinkles for far eastern and southeastern portions
of forecast area this evening. Then begin to dry out with clouds
scattering out a bit. Lows will be in the mid 60s to low 70s.
Another issue tonight could be fog development. Will add mention
of patchy fog after potential issue tonight could be fog...as
boundary layer will remain very moist. Due to uncertainty in cloud
cover overnight tonight...elected not add fog to forecast for now.
Byrd
.LONG TERM: (Monday through Next Sunday)
Issued at 323 PM CDT Sun Aug 17 2014
Monday will remain dry but will see plenty of cu developing so
temperatures will warm up but not as much as previously thought.
Lowered highs a degree or two. Highs will be in the mid upper 80s.
Next shortwave/cold front to move through region beginning Monday
night. So kept chance pops going through Tuesday. Then system to
stall out over southern portions of forecast area before returning
north as a warm front beginning Tuesday night. Will see rain chances
across most of area Tuesday night, then lift northward out of area
by Thursday, though kept low chance pops going for northern portions
of forecast area through Friday night. During this period, will see
a warming trend, but did lower highs a tad on Tuesday due to warm
front position as well as clouds and precipitation, in the mid 80s
to low 90s. Then temps warm up into the 90s everywhere for the last
half of the work week and into the first part of the weekend. With
frontal boundary lingering just north of forecast area for the
weekend, could see some activity in the northern portions of
forecast area, but hard to pin down at this time.
Byrd
&&
.AVIATION: (For the 18z TAFs through 18z Monday Afternoon)
Issued at 1119 AM CDT Sun Aug 17 2014
Good new is the upper level system that has plagued the area is
forecast to pick up speed and is forecast to be over eastern Ohio
by 18z Monday. The bad news is ample low level moisture remains to
keep MVFR/IFR ceilings and visibilities in place overnight into
Monday. Area of light rain moving over east central MO and
southwest IL may be the end of the precipitation as it has a back
edge. HRRR model wants to produce scattered showers this afternoon
but the other short range models trend to dry so will go with the
concensus. Any improvement in cloud conditions this evening will
lead to quick fog development, so in essence: pick your poison.
Expect most terminals to be MVFR to VFR at the end of the forecast
period.
Specifics for KSTL: Not much improvement expected overall until
18z Monday. Extensive area of MVRR/IFR ceilings and fog expected
to remain in place overnight with the surface to boundary layer
relative humidity staying very high. Some light rain moving
through now looks like it will end in an hour or so via radar
trends. If system moves as it is forecast the goal will be to see
VFR by 18z Monday.
JPK
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1138 AM CDT Sun Aug 17 2014
.SHORT TERM: (Today)
Issued at 343 AM CDT Sun Aug 17 2014
Vorticity maxima/MCV will slowly move to the southeast to around KSLO by
mid morning. Precipitation shield overnight as largely been tied to
forcing via aforementioned vort max as well as WSW LLJ. Convection
on nose of LLJ has already moved off to the south and east of forecast
area so primary focus will be on track of closed low/MCV. Since it will
be exiting the CWA around late morning...believe highest PoPs this morning
will be across portions of southwest Illinois or far eastern sections of
the CWFA. With subsidence setting in behind this feature...believe
measurable showers/storms will be tough to come by. Weak convergence along
trailing sfc inverted trough may yield areas of drizzle beneath low
ceilings however. Similar to previous forecaster...leaned cool for high
temperatures today yielding upper 70s to low 80s or 5-10 degrees below
average. This is due to weak cold advection and low clouds hanging around
through the daylight hours.
Gosselin
.LONG TERM: (Tonight through Saturday)
Issued at 343 AM CDT Sun Aug 17 2014
(Tonight - Wednesday night)
Slowly decreasing clouds should be the rule tonight with mild temperatures.
Lows should be near or slightly above average in the mid 60s to low 70s.
A potential issue tonight could be fog...as boundary layer will remain
very moist. Due to uncertainty in cloud cover overnight tonight...elected
not add fog to forecast for now.
Monday should also be dry with warmer conditions returning. By Monday
night...a shortwave trough transverses northern sections of the area
with a trailing cold front swinging in from the northwest. Raised PoPs into
the high chance category over portions of central and northeastern Missouri
where combination of strongest moist/warm advection and upper-air
dynamics interact.
Weak Pacific "cold" front will wash out and stall across southern sections
of the area on Tuesday as upper-level heights begin to climb. Raised
highs across portions of the region on Tuesday due to favorable WSW
downslope sfc flow and partly cloudy skies expected. Chances of showers
and thunderstorms will continue and move northward through the region
Tuesday night through Wednesday night invof retreating warm frontal
boundary as upper-level heights climb.
(Thursday - Saturday)
Warm front is expected to move northward of the CWA by Thursday as
upper ridge continues to build into mid-Mississippi Valley. Some concern
that antecedent convection may prevent or retard northward progression of
warm front or effective baroclinic zone. Also some uncertainty as to
how far north upper ridge will build in...as models tonight have
backed off the strength of 500-hPa anticyclone. This could result
in increased cloudiness/PoPs and consequently lower temperatures
for Thursday and maybe Friday as parts of the forecast area...
especially far northern sections...may be on northern edge of
upper ridge or in the so-called "ring of fire". Current forecast
package still reflects the scenario where upper ridge does indeed
build in late in the work week brining potentially our hottest
stretch of weather all summer...but again due to the possibilities
above...that is not a given at this juncture.
Gosselin
&&
.AVIATION: (For the 18z TAFs through 18z Monday Afternoon)
Issued at 1119 AM CDT Sun Aug 17 2014
Good new is the upper level system that has plagued the area is
forecast to pick up speed and is forecast to be over eastern Ohio
by 18z Monday. The bad news is ample low level moisture remains to
keep MVFR/IFR ceilings and visibilities in place overnight into
Monday. Area of light rain moving over east central MO and
southwest IL may be the end of the precipitation as it has a back
edge. HRRR model wants to produce scattered showers this afternoon
but the other short range models trend to dry so will go with the
concensus. Any improvement in cloud conditions this evening will
lead to quick fog development, so in essence: pick your poison.
Expect most terminals to be MVFR to VFR at the end of the forecast
period.
Specifics for KSTL: Not much improvement expected overall until
18z Monday. Extensive area of MVRR/IFR ceilings and fog expected
to remain in place overnight with the surface to boundary layer
relative humidity staying very high. Some light rain moving
through now looks like it will end in an hour or so via radar
trends. If system moves as it is forecast the goal will be to see
VFR by 18z Monday.
JPK
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1136 PM CDT Sat Aug 16 2014
.UPDATE:
Issued at 942 PM CDT Sat Aug 16 2014
The latest water vapor and VWP data suggest the mid level
low/vort max is located near KUIN. The associated surface low is just
east of Mexico with a warm front trailing southeast through the
St. Louis metro area and cold front extending to just east of the
Lake of the Ozarks. The air mass along and ahead of these features
is very moist with PWs average around 1.80 inches and warm cloud
depths are running 3.5-4.0 km. While this speaks to the efficiency
of rainfall production, thus far there has been a lack of overall
mesoscale organization and convection has been moving, resulting
in spotty rainfall totals of just over 2 inches since this
afternoon.
Short term guidance from the RAP and HRRR move the vort max to
just southeast of St. Louis by 12z with a nearly vertically
stacked surface low. The southwesterly LLJ is forecast to increase
some to around 30 kts ahead of the system while the current CAPE
stream of 1000-1500 J/KG will gradually wane. Present indications
given these trends suggest 2 zones with the highest probability of
locally heavy rain - 1) south of St. Louis across the eastern
Ozarks into southern Illinois more coincident with the LLJ axis
and 2) north of St. Louis from roughly Pike County IL to Fayette
County IL more associated with mesoscale forcing with the MCV. The
current mention of locally heavy rain has this covered well and if
a greater threat materializes will update accordingly.
Glass
&&
.SHORT TERM: (Through Late Tonight)
Issued at 347 PM CDT Sat Aug 16 2014
We have entered a quiet period of weather early this afternoon as
the atmosphere re-organizes itself. Just entering extreme northeast
MO was a powerful 50-something MCV, and with the very moist
atmospheric column in place where PWs were in excess of two inches,
it is having no problem in perpetually generating rain around it.
Extending to the southwest of this important upper level feature was
a surface cold front: from just W of Moberly to just N of Sedalia.
This front was intersecting a very moist atmosphere as well, where
surface dewpoints were in the low 70s and PWs near two inches, and
an unstable atmosphere as well, with MLCAPES up to 3000 J/kg. This
front was just beginning to ignite some TSRA along it. Further
downstream into eastern MO and southern IL, temps were just
beginning to recover into the upper 70s and low 80s where clouds and
rain had previously dominated.
The atmosphere is essentially primed and merely needs a trigger to
get the next round of rain going. Moisture convergence should be at
sufficient levels for TSRA to get going along the front, but have
also noted that convergence was also beginning to increase over STL
metro and southeast MO where a window of opportunity for additional
development will present itself between now and early this evening.
Otherwise, primary foci will be surface front and MCV as they both
very slowly progress southeastward thru our region tonight and
continue on Sunday morning...finally expected to leave and pull away
Sunday afternoon. As stated earlier, PWs will be in excess of two
inches, which is greater than two standard deviations from the mean
for mid-August, and models are also forecasting rather deep warm
cloud layers over 4km. Greatest threat for excessive rainfall will
be an area sandwiched between the MCV, the broadscale lift from the
mid level shortwave, and the trailing surface front. This all seems
to point to an area from east-central MO and throughout southwest
IL, including STL metro. The problem is that 6hr FFG values are
mainly above 3 inches, with a small area just north of STL metro
where it is as low as 2.5 inches. Given this, will pass these
concerns on to evening shift and let them see how convection
develops before issuance of any Flood Watch.
Categorical PoPs were forecasted thru this system`s conclusion on
Sunday with a warm and muggy night ahead tonight and a cool day on
Sunday with substantial lo clouds in the system`s wake expected.
TES
.LONG TERM: (Sunday through Next Saturday)
Issued at 347 PM CDT Sat Aug 16 2014
A somewhat drier atmosphere is in place for Monday and with a lack
of upper level support and a decent lo level cap in place, should
see one day of dry wx.
A weak cold front drops down on late Monday night and lingers thru
late Wednesday and will result in a threat for thunderstorms.
Depending on where the front settles, it will separate seasonable
warmth to the north from summertime heat in the south. This
summertime heat will be coupled with humidity that may result in 100
heat index values for parts of the area Tuesday and Wednesday
afternoons.
By late next week, there trend will be for drier and hotter wx as an
upper ridge builds overhead and may result in the summer we nearly
missed. Looks like a period of a few more days of max temps in the
90s with heat index values between 100-105. May need a heat
headline at some point for quite a few areas for next week as a
result.
TES
&&
.AVIATION: (For the 06z TAFs through 06z Sunday Night)
Issued at 1114 PM CDT Sat Aug 16 2014
A slow-moving low pressure system will continue to bring scattered
SH/TS to the terminals over the next few hours. Coverage will
probably be greater at St. Louis metro area TAF sites due to their
proximity to the low. Once the precipitation moves out, ceilings
should drop to IFR and remain there for the rest of the night and
into tomorrow. There will probably also be transient MVFR to IFR
visibilities in fog overnight because of the highly saturated air
mass, but models are forecasting winds to stay high enough
overnight that it looks more like a low stratus situation rather
than widespread dense fog. Ceilings should slowly improve during
the afternoon as the low pressure system moves away from the area.
Prevailing winds will eventually turn around to the north behind a
cold front and on the back side of the departing surface low.
Kanofsky
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
657 PM CDT MON AUG 18 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 341 PM CDT MON AUG 18 2014
THE MAIN FORECAST ISSUE WILL BE THE POSSIBILITY OF SOME
THUNDERSTORM ACTIVITY IN THE FAR SOUTHERN CWA OVERNIGHT.
WEST NORTHWEST FLOW ALOFT IS FAIRLY WEAK AND A NEARLY STALLED
BOUNDARY ACROSS THE CWA CONTINUES TO DRIFT SOUTH TODAY. LITTLE IF
ANY DEVELOPMENT SHOULD DEVELOP ALONG THIS BOUNDARY TODAY INTO THIS
EVENING AS A FAIRLY HEALTHY CAP KEEPS THINGS QUIET...DESPITE
MODERATE INSTABILITY IN THE 1500 TO 2000 J/KG RANGE FOR CONVECTIVE
AVAILABLE POTENTIAL ENERGY. SOME SMALL POP-UPS ARE SHOWING UP JUST
NORTH OF THE CWA...BUT THERE SHOULD BE ENOUGH OF A CAP TO TAMP
MUCH FURTHER DEVELOPMENT IN THE NORTH.
LATER ON TONIGHT...A HEALTHY 40 TO 45 KT JET WILL DEVELOP OVER
KANSAS AND WILL CURVE EAST...MOSTLY LIKELY OVER NORTH CENTRAL
KANSAS. THIS WILL SET THE STAGE FOR SOME POTENTIAL LOW-LEVEL
CONVERGENCE ACROSS OUR SOUTHERN CWA IN NORTH CENTRAL KANSAS AND
FAR SOUTHERN NEBRASKA NEAR THE AFOREMENTIONED SURFACE BOUNDARY.
THIS COULD BE JUST ENOUGH SUPPORT FOR SOME SMALL HAIL AND GUSTY
WIND IN OUR FAR SOUTH AS WELL. THE HRRR IS TRENDING STRONGER WITH
SOME DEVELOPMENT OVER THE HIGH PLAINS THIS AFTERNOON...SUPPORTED
BY ANOTHER LOW-AMPLITUDE SHORTWAVE TROUGH. THIS COULD BE ENHANCED
BY THE DEVELOPING LOW-LEVEL JET IN KANSAS AS THIS POTENTIAL
CONVECTION HEADS SOUTH. THE NAM HAS BEEN ADVERTISING SOME ACTIVITY
IN THIS VICINITY FOR THE PAST COUPLE OF DAYS. THE PRUDENT ACTION
WOULD BE TO PUT A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS BACK
INTO THE FORECAST IN OUR SOUTH. OUR CHANCES OF RAIN ARE LARGELY
DEPENDENT ON INITIAL CONVECTION IN THE HIGH PLAINS WITHIN THE
STRONGLY UNSTABLE...YET STILL CAPPED ENVIRONMENT TO THE WEST AS
THE AFOREMENTIONED TROUGH ENTERS THE CENTRAL PLAINS. THE SREF
SOLUTIONS ARE ALSO COMING IN WITH STRONGER SIGNALS TOWARD
CONVECTION IN OUR SOUTH AS WELL.
FOR TUESDAY...KEEPING IT QUIET WITH THE THINKING THAT THERE
SHOULD BE ENOUGH OF A CAP FROM PRECLUDING DEVELOPMENT UNTIL THE
EVENING HOURS. HIGH PLAINS CONVECTION COULD DEVELOP DURING THE
DAY...BUT SHOULD HOLD OFF MAKING IT HERE UNTIL EVENING...WHEN A
LOW-LEVEL JET AXIS DEVELOPS JUST TO THE WEST OF THE CWA.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 341 PM CDT MON AUG 18 2014
GUIDANCE SUGGESTS UPPER TROPOSPHERIC RIDGING WILL EXIST OVER THE
CENTRAL CONUS TO START THE LONG TERM FORECAST PERIOD. THE RIDGE
AXIS IS EXPECTED TO SHIFT EAST SOMEWHAT BY THURSDAY OR FRIDAY
HOWEVER...ALLOWING FOR MORE OF A SOUTHWESTERLY UPPER TROPOSPHERIC
FLOW OVER OUR AREA LATE THIS WEEK INTO EARLY NEXT WEEK.
THE AXIS OF A 35-40KT LOWER TROPOSPHERIC JET STREAK...JUST ABOVE
THE BOUNDARY LAYER...IS EXPECTED DEVELOP FROM WESTERN KANSAS INTO
SOUTH CENTRAL NEBRASKA TUESDAY NIGHT INTO EARLY WEDNESDAY MORNING.
THERMAL ADVECTION ALONG THIS AXIS APPEARS AS THOUGH IT WILL BE
SUFFICIENT FOR PRECIPITATION PRODUCTION ACROSS NORTHEASTERN
PORTIONS OF OUR CWA...A SOLUTION SUPPORTED BY QPF FIELDS FROM THE
NAM...OPERATIONAL GFS AND EC. WENT AHEAD WITH 20-30% POPS ACROSS
OUR NORTHEAST TUESDAY NIGHT INTO EARLY WEDNESDAY MORNING AS A
RESULT.
ON OVERALL LACK IN OMEGA SHOULD THEN PROVIDE DRY CONDITIONS TO
OUR AREA THROUGH MUCH OF THE DAY WEDNESDAY. BY LATE WEDNESDAY
AFTERNOON HOWEVER...THE NAM AND OPERATIONAL GFS BOTH SUGGEST
CONVECTION WILL INITIATE OVER THE CENTRAL HIGH PLAINS...AND THEN
MOVE EAST INTO OUR AREA WEDNESDAY EVENING AND OVERNIGHT. GIVEN
THIS...WENT AHEAD WITH 20-30% POPS ACROSS MUCH OF THE CWA
WEDNESDAY EVENING AND NIGHT.
ALTHOUGH OMEGA IS EXPECTED TO REMAIN WEAK THROUGH THE DAY
THURSDAY AS WELL...FORECAST PROXIMITY SOUNDINGS FROM ACROSS THE
CWA...PER THE NAM AND OPERATIONAL GFS...SUGGEST A NEARLY DRY
ADIABATIC TEMPERATURE PROFILE WILL BE REALIZED FROM THE SURFACE TO
JUST ABOVE 700MB ACROSS MUCH OF THE CWA...THUS ALLOWING CONVECTIVE
TEMPERATURE READINGS TO BE REACH AND PROVIDING FOR ISOLATED
THUNDERSTORM DEVELOPMENT. THIS IS A SOLUTION ALSO SUPPORTED BY QPF
FIELDS FROM THE NAM...OPERATIONAL GFS AND EC. GIVEN ALL
THIS...WENT AHEAD WITH ~20% POPS ACROSS MUCH OF THE CWA THURSDAY
AFTERNOON AND EVENING.
HEADING INTO THURSDAY NIGHT AND BEYOND...GUIDANCE SUGGESTS
MULTIPLE UPPER TROPOSPHERIC PERTURBATIONS COULD MOVE OVER THE
CENTRAL PLAINS AS THE SOUTHWESTERLY UPPER TROPOSPHERIC FLOW
INTENSIFIES. ALLBLEND RESPONDED BY PROVIDING 20-50% POPS TO MANY
AREAS ACROSS THE CWA THURSDAY NIGHT THROUGH MONDAY...AND THESE
POPS WERE LEFT UNCHANGED FOR THE MOST PART.
FORECAST PROXIMITY SOUNDINGS FROM THE NORTHEASTERN CWA...PER THE
NAM AND OPERATIONAL GFS...SUGGEST STORM-ACCESSIBLE POTENTIAL
ENERGY WILL NOT EXCEED 200-300J/KG TUESDAY NIGHT INTO EARLY
WEDNESDAY MORNING AND THUS...WILL HOLD OFF FROM ANY MENTION OF
SEVERE WEATHER TUESDAY NIGHT INTO EARLY WEDNESDAY MORNING.
CONVECTION ALONG THE CENTRAL HIGH PLAINS WEDNESDAY AFTERNOON AND
EVENING WILL LIKELY HAVE THE CAPABILITY TO BE STRONG...BUT THERE
IS CONSIDERABLE UNCERTAINTY AS TO HOW LONG THIS CONVECTION WILL BE
ABLE TO MAINTAIN ITS INTENSITY AS IT MOVES EAST INTO OUR AREA.
GIVEN THIS UNCERTAINTY...WILL HOLD OFF FROM ANY MENTION OF SEVERE
WEATHER ACROSS OUR AREA WEDNESDAY EVENING AND LET FUTURE SHIFTS
REEVALUATE. BEYOND WEDNESDAY EVENING...AT THIS TIME THERE ARE NO
OVERWHELMING SIGNALS OF A SIGNIFICANT SEVERE WEATHER OUTBREAK.
ALTHOUGH A FEW HIT AND MISS STRONG TO SEVERE STORMS PROBABLY
CANNOT BE RULED OUT...DUE TO THE UNCERTAINTY WILL LEAVE OUT ANY
MENTION OF SEVERE WEATHER WEDNESDAY NIGHT AND BEYOND.
LITTLE CHANGE IN THE LOWER TROPOSPHERIC AIR MASS SHOULD PROMOTE
SIMILAR TEMPERATURE READINGS FROM DAY TO DAY WEDNESDAY THROUGH
SATURDAY...WITH AFTERNOON HIGHS IN THE UPPER 80S AND 90S AND
OVERNIGHT LOWS IN THE 60S AND LOWER 70S EXPECTED FOR THE MOST
PART. BEYOND SATURDAY...GUIDANCE DOES SUGGEST A LOWER TROPOSPHERIC
BAROCLINIC ZONE WILL MOVE ACROSS THE AREA...THUS ALLOWING A COOLER
LOWER TROPOSPHERIC AIR MASS INTO THE REGION. AFTERNOON HIGHS IN
THE UPPER 70S TO MID 80S AND LOWS GENERALLY IN THE 60S ARE
CURRENTLY EXPECTED TO FINISH THE LONG TERM FORECAST PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 652 PM CDT MON AUG 18 2014
VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH THE TAF VALID
PERIOD. THUNDERSTORMS TO THE WEST THIS EVENING ARE EXPECTED TO
REMAIN WEST OF BOTH KEAR AND KGRI. THE WIND WILL BE LIGHT AND
VARIABLE THROUGH TUESDAY MORNING...POSSIBLY BECOMING MORE
PREDOMINATELY OUT OF THE SOUTHEAST BY TOMORROW AFTERNOON...BUT
WILL REMAIN LIGHT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...HEINLEIN
LONG TERM...BRYANT
AVIATION...WESELY
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
313 PM CDT SUN AUG 17 2014
.SHORT TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 305 PM CDT SUN AUG 17 2014
...OUR PATTERN REMAINS UNSETTLED...AND WARMER THIS WEEK...
FORECAST CHALLENGES FOR THE SHORT TERM WILL BE THUNDERSTORM
CHANCES AND SEVERE POTENTIAL TONIGHT THROUGH MONDAY EARLY
AFTERNOON.
IT LOOKED FAIRLY QUIET WEATHER TO BEGIN THIS EVENING...HOWEVER IT
SEEMS LIKE THE SHORT RANGE MODELS ARE A BIT UNDERDONE WITH THE
CONVECTION OVER CENTRAL SOUTH DAKOTA BASES ON THE LATEST RADAR.
THE HRRR HAS A SHORTWAVE AND CONVECTION THAT DROPS SOUTHEAST
ACROSS THE FORECAST AREA. THIS EVENING...WHILE THE OTHER MODELS
ARE SLOWER AND LESS AGGRESSIVE UNTIL LATER TONIGHT. EVEN THE 18Z
NAM IS STILL DRY THIS EVENING. NOT SURE HOW HIGH TO GO EARLY...BUT
WILL INCLUDE ISOLATED THUNDERSTORMS FOR PARTS OF NORTHEAST
NEBRASKA EARLY THIS EVENING. THE STORM PREDICTION CENTER DOES HAVE
A SEVERE THUNDERSTORM WATCH OUT FOR COUNTIES JUST TO THE WEST OF
OUR FORECAST AREA THIS EVENING AND THE SLIGHT RISK FOR SEVERE
WEATHER DOES CLIP OUR WESTERN FORECAST AREA COUNTIES.
THE 12Z UPPER AIR MAPS SHOWED A RIDGE OVER THE SOUTHWEST U.S. WITH A
CLOSED LOW OVER SASKATCHEWAN AND LEADING SHORTWAVE TROF ENERGY OVER
MINNESOTA. THE STRONGER HEIGHT FALLS AT H5 WERE NOTED OVER
CANADA...ASSOCIATED WITH THIS NORTHERN SYSTEM. THERE WERE RIBBONS
OF POOLED H7 MOISTURE OVER THE PLAINS WITH THE H7 THERMAL RIDGE OVER
WESTERN NEBRASKA AND COLORADO. SIMILAR PATTERNS WERE NOTED AT H85.
THE OAX SOUNDING HAD A PWAT OF 1.44 INCHES WHICH WAS 134% OF NORMAL.
A MAX OF 185% OF NORMAL WAS CENTERED OVER KMPX.
AS THE EVENING PROGRESSES...A LOW LEVEL JET INCREASES TO 35-40KTS
OVER CENTRAL NEBRASKA...MEANWHILE THE SHORTWAVE TROF ENERGY OVER
CANADA EXTENDS SOUTHWARD INTO THE PLAINS. UPPER LEVEL JET
SUPPORT...OMEGA... FRONTOGENESIS AND THETA-E ADVECTION ALL
INCREASE. AS A RESULT...THE DETERMINISTIC MODELS INCREASE
CONVECTION OVER THE DAKOTAS AND THIS CONVECTION EXTENDS SOUTHWARD
INTO EASTERN NEBRASKA AND IOWA TONIGHT AND MONDAY. THERE IS A
GOOD H7 WARM AIR ADVECTION SIGNAL AND GOOD 7-8 DEG C H7 DEWPOINTS.
EXPECTED TRENDS LATER TONIGHT ARE WELL HANDLED BY THE CURRENT
FORECAST WITH INCREASING POPS INTO THE LIKELY CATEGORY AND WILL
TREND FARTHER SOUTH TO COVER POTENTIAL FOR INCREASED CONVERGENCE
CLOSER TO THE SURFACE LOW.
DEEP LAYER SHEAR IS FROM 30- 40KTS TONIGHT...HOWEVER DROPS CLOSER
TO 30KTS MONDAY. THE SURFACE AND H85 FRONT ARE STILL IN EASTERN
NEBRASKA MONDAY MORNING...AND GRADUALLY PUSH OUT OF THE FORECAST
AREA BY 00Z MONDAY. INSTABILITY IS 500-2000J/KG TONIGHT...BUT
INCREASES TO 3000+ MONDAY. FORECAST SOUNDINGS LOOK TO FAVOR
ELEVATED STORMS TONIGHT...HOWEVER THEY ARE MORE SURFACE BASED FOR
MONDAY. ALTHOUGH FREEZING LEVELS ARE HIGHER AND INSTABILITY IS
O.K. STRONGER SHEAR...PLUME OF STEEPER LAPSE RATES AND BETTER LOW
AND MID LEVEL FORCING MAY SUPPORT SOME SEVERE STORMS. SEVERE
WEATHER CHANCES CONTINUE INTO MONDAY AS THUNDERSTORMS WILL BE
ONGOING WITH INCREASED INSTABILITY...ALTHOUGH FORCING AND SHEAR
APPEAR TO BE NOT AS HIGH. TREND WITH HIGHER POPS IN THE
AM...DECREASING FROM WEST TO EAST IN THE AFTERNOON. STORM MOTION
IS AROUND 20KTS...BUT WITH HIGH PWATS/H7 DEWPOINTS AND POTENTIAL
FOR STORMS MOVING OVER THE SAME AREA COULD PRODUCE HEAVY RAIN.
MAINLY DRY FOR MONDAY NIGHT INTO TUESDAY WITH A WARM FRONT
SITUATED OVER NORTHERN KANSAS. THERE IS LIFT OVER THE FRONT AND
THE FRONT LIFTS NORTH TUESDAY NIGHT AND WEDNESDAY...SO HAVE
SCATTERED THUNDERSTORMS MENTIONED. WARMER HIGHS IN THE 90S CAN BE
EXPECTED SOUTH OF THE FRONT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 305 PM CDT SUN AUG 17 2014
STILL QUITE A FEW MODEL DIFFERENCES WEDNESDAY NIGHT THROUGH
SUNDAY. IT LOOKS LIKE A FRONT WILL BE IN THE AREA WEDNESDAY NIGHT
THROUGH FRIDAY...WITH A MID LEVEL RIDGE TO OUR SOUTH AND A
FLATTER...TROF INFLUENCE TO OUR NORTH. WARM H85 TEMPS FROM 20-24
DEG C PERSIST THROUGH FRIDAY NIGHT...HOWEVER THE EC BRINGS COOLER
WEATHER IN FOR SATURDAY...WHILE THE GFS HOLDS OFF UNTIL SUNDAY
NIGHT.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 219 PM CDT SUN AUG 17 2014
HAVE ADJUSTED TIMING OF THUNDERSTORMS AT TAF LOCATIONS BASED ON
MOST RECENT HI RESOLUTION HRRR AND NAM ARW MODEL DATA. STORM
DEVELOPMENT ACROSS NORTH CENTRAL NEBRASKA COULD REACH THE KOFK BY
03Z WHERE WE WENT WITH A TEMPORARY GROUP WITH VARIABLE WINDS 15 TO
25 KNOTS. STILL KEPT A PROB30 GROUP FOR KLNK BY 04Z AND KOMA BY 06Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
219 PM CDT SUN AUG 17 2014
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 340 AM CDT SUN AUG 17 2014
SIMILAR TO LAST NIGHT...THE PRIMARY NEAR-TERM CONCERN IS DENSE
FOG...THIS TIME OVER SOUTHWEST IOWA. METARS FOR SDA/ICL/RDK/AIO
HAVE BEEN BOUNCING AROUND 1/4 TO 1/2 MILE VISIBILITIES. MUCH OF
THIS DENSE FOG IS TIED TO LAST NIGHTS RAINFALL AND GIVEN THE LIGHT
WIND REGIME IN PLACE SHOULD HAVE NO TROUBLE STICKING AROUND UNTIL
AFTER DAYBREAK.
FOR TODAY EXPECT DRY WEATHER...AT LEAST UNTIL EARLY EVENING...AS
THE AREA IS IN BETWEEN SHORTWAVES. BY TONIGHT THE NEXT FEATURE
ENTERS FROM THE NORTHWEST ACCOMPANIED BY MODEST HEIGHT FALLS
AVERAGING AROUND 4-6 DM. THERE IS A SLIGHT RISK FOR SEVERE WEATHER
ACROSS NORTH CENTRAL NEBRASKA...FOR OUR AREA CONDITIONS JUST
AREN/T IN PLACE FOR MUCH OF A SEVERE WEATHER CONCERN. INTO THE
OVERNIGHT HOURS...INSTABILITY WANES AND DEEP LAYER SHEAR VALUES
ARE MARGINAL ALONG WITH A LOW-LEVEL JET DISPLACED WELL TO OUR
WEST. AN ISOLATED SEVERE THUNDERSTORM ACROSS OUR FAR WESTERN
COUNTY WARNING AREA CANNOT BE RULED OUT AS STRONG STORMS PROPAGATE
EAST...BUT THE PRIMARY THREAT FOR US WILL BE HEAVY RAIN.
MONDAY AND TUESDAY...ANY LEFTOVER SHOWERS AND THUNDERSTORMS WILL
BE MOVING EAST BY LATE MONDAY MORNING...LEAVING A DRY FORECAST FOR
MUCH OF MONDAY AFTN/EVENING AND THROUGH TUESDAY.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 340 AM CDT SUN AUG 17 2014
BY TUESDAY NIGHT THE NEXT SHORTWAVE WILL MOVE INTO CENTRAL AND
EASTERN NEBRASKA. ITS HARD TO SAY THIS WILL BE A GOOD CHANCE AT
MEASURABLE RAIN GIVEN HOW HIT AND MISS PRECIPITATION HAS BEEN
RECENTLY. FOR NOW WILL GO WITH A HIGH CHANCE FOR SHOWERS AND
THUNDERSTORMS AND EXPECT TIMING/PLACEMENT TO WORK ITSELF OUT IN
FORTHCOMING MODEL RUNS. THEREAFTER THE FORECAST PICTURE IS QUITE
UNCLEAR WITH A SIMILAR STORY OF SHORTWAVES MOVING THROUGH THE
REGION. LATEST LONG TERM GUIDANCE HINTS AT A STRONG COLD FRONT
MOVING THROUGH LATE NEXT WEEKEND...BRINGING A DOSE OF COOLER AIR
AND VERY UNSETTLED WEATHER.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 219 PM CDT SUN AUG 17 2014
HAVE ADJUSTED TIMING OF THUNDERSTORMS AT TAF LOCATIONS BASED ON
MOST RECENT HI RESOLUTION HRRR AND NAM ARW MODEL DATA. STORM
DEVELOPMENT ACROSS NORTH CENTRAL NEBRASKA COULD REACH THE KOFK BY
03Z WHERE WE WENT WITH A TEMPORARY GROUP WITH VARIABLE WINDS 15 TO
25 KNOTS. STILL KEPT A PROB30 GROUP FOR KLNK BY 04Z AND KOMA BY 06Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...PEARSON
LONG TERM...PEARSON
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1145 PM CDT SAT AUG 16 2014
.SHORT TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 248 PM CDT SAT AUG 16 2014
THE AREA REMAINS IN BETWEEN TWO UPPER SYSTEMS WITH ONE WELL TO OUR
NORTH AND ANOTHER TO OUR EAST. CONVECTION COULD STILL DEVELOP IN
NORTHEAST NEBRASKA ON THE FAR SOUTHERN EXTENT OF THE NORTHERN
SYSTEM...WITHIN A SLIGHTLY AGITATED CU FIELD BETWEEN KBVN...KONL
AND KYKN...AS SUGGESTED BY THE HRRR MODEL. ANY ANYTHING INDEED
DEVELOPS EARLY THIS EVENING...IT WOULD PROBABLY DIMINISH/END BY
MIDNIGHT...ALTHOUGH THE NAM WOULD HOLD IT TOGETHER ACROSS EASTERN
NEBRASKA THROUGH THE WEE HOURS.
FOCUS THEN SHIFTS TO FOG REDEVELOPMENT OVERNIGHT AS AMPLE LOW
LEVEL MOISTURE REMAINS WITH SURFACE DEWPOINTS IN THE UPPER 60S TO
LOWER 70S. WINDS WILL LIKELY GO CALM IN MANY PLACES OVERNIGHT.
MET/MAV/LAV GUIDANCE ALL INDICATES FOG WILL REDEVELOP BY 06Z...AND
COULD BECOME LOCALLY DENSE BY 09-11Z...THEN LIFTING/BURNING OFF BY
14-15Z. HAVE ADDED PATCHY DENSE FOG INTO THE GRIDS...AND MAY HAVE
TO EVENTUALLY ISSUE A DENSE FOG ADVISORY FOR PARTS OF THE REGION
TONIGHT AS CONDITIONS MATERIALIZE. AREAS MOST SUSCEPTIBLE INCLUDE
ALL OF WESTERN IOWA...THE THE PLATTE AND MISSOURI RIVER VALLEYS.
CONVECTIVE DEVELOPMENT SUNDAY IS ALSO QUESTIONABLE...BUT THE
LINGERING VERY SUBTLE TROUGH WITH ASSOCIATED ACTIVITY THIS
EVENING COULD BE ALONG THE MISSOURI RIVER SUNDAY AFTERNOON...THUS
WILL MAINTAIN JUST 20 PERCENT CHANCE OF STORMS ALONG/EAST OF THE
MISSOURI RIVER THROUGH PEAK HEATING TOMORROW.
SHOULD BE ANOTHER DRY PERIOD SUNDAY EVENING...BUT CONVECTION
CHANCES INCREASE AGAIN BY DAYBREAK MONDAY AS THE NEXT IMPULSE
BEGINS TO MOVE INTO THE AREA FROM THE HIGH PLAINS. RAIN CHANCES
CONTINUE MONDAY...AND MAY LINGER FOR SOUTHEAST NEBRASKA MONDAY
NIGHT...BUT SHOULD BE DRY AGAIN FOR TUESDAY.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 248 PM CDT SAT AUG 16 2014
ANOTHER SLOW MOVING WAVE MOVES INTO THE REGION TUESDAY NIGHT
THROUGH WEDNESDAY NIGHT BRINGING ONE MORE CHANCE OF STORMS TO THE
AREA. RIDGING THEN BUILDS BACK ACROSS THE PLAINS FOR THE END OF
THE WEEK WITH DRY WEATHER...AND TEMPS WARMING INTO THE LOWER 90S
AGAIN. COULD SEE A NOCTURNAL CHANCE OF STORMS UNDERNEATH THE RIDGE
FRIDAY NIGHT.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1145 PM CDT SAT AUG 16 2014
WE ARE STILL LOOKING FOR DETERIORATING CONDITIONS OVERNIGHT WITH
FOG DEVELOPING. ISOLD TSRA CONTINUE TO DRIFT EASTWARD TO THE EAST
AND NORTHEAST OF KOFK. THERE ARE HINTS THAT SOME OF THIS ACTIVITY
COULD AFFECT KOMA LATE TONIGHT...BUT CHANCES SEEMED LOW ENOUGH TO
LEAVE IT OUT OF THE TAF FOR NOW. LIGHT SOUTHEAST WINDS OVERNIGHT
AND PLENTY OF LOW LEVEL MOISTURE IN PLACE STILL SUGGEST FOG WILL
DEVELOP. THERE WAS ALREADY SOME FOG IN SOUTHWEST IOWA. THE FOG
AND LOW CLOUDS SHOULD GRADUALLY LIFT/BREAK UP BY MID TO LATE
MORNING WITH VFR CONDITIONS FOR THE AFTERNOON.
THE CHANCE FOR TSRA SHOULD INCREASE SUNDAY NIGHT...MAINLY AFTER
ABOUT 06Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...DEWALD
LONG TERM...DEWALD
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS RALEIGH NC
320 PM EDT SUN AUG 17 2014
.SYNOPSIS...A SERIES OF UPPER LEVEL DISTURBANCES IN WEST-NORTHWESTERLY
FLOW WILL CROSS THE REGION THIS WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM SUNDAY...
DIURNAL DESTABILIZATION WILL YIELD MODERATE INSTABILITY IN MOST
AREAS THIS AFTERNOON. HOWEVER...FORCING FOR ASCENT WILL BE LIMITED
(AT BEST) TO TRANSIENT SMALL AMPLITUDE DISTURBANCES IN WNW FLOW
ALOFT...FEATURES WHICH ARE EITHER ABSENT OR DIFFICULT TO RESOLVE PER
LATEST WV IMAGERY AND RAP DATA. WILL CONTINUE TO INDICATE A DRY
FORECAST...WITH HIGH IN THE UPPER 80S TO LOWER/MID 90S. A MORE
DETAILED DISCUSSION WILL BE FORTHCOMING. -VINCENT
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 330 AM SUNDAY...
THE MCV CURRENTLY IN THE VICINITY OF KSTL...WHICH IS RATHER STRONG
BASED ON SATELLITE PRESENTATION...IS FORECAST TO CROSS THE
APPALACHIANS BY MIDDAY MONDAY....WITH A SHARPENING PIEDMONT TROUGH.
GFS FORECAST SOUNDINGS GIVE 1000-2000 J/KG OF MLCAPE... HIGHER IN
THE EAST WHERE HEATING WILL BE FAVORED AND LAPSE RATES STEEPEN THE
MOST. PW INCREASES TO OVER 2 INCHES BY MONDAY AFTERNOON...AND
COMBINED WITH THE FORCING AND INSTABILITY SHOULD SUPPORT SCATTERED
STORMS. THE LARGER SCALE SHEAR IS EXPECTED TO BE RELATIVELY
WEAK...20-25KT...THOUGH THE DISTURBANCE MAY AUGMENT SHEAR LOCALLY AS
IT CROSSES THE AREA. HOWEVER...HIGH PW AND STEEP LOW-LEVEL LAPSE
RATES MAY STILL CREATE THE POTENTIAL FOR A FEW STRONG WIND GUSTS.
HIGHS 88-93.
SHOULD SEE SOME CLEARING BEHIND THE UPPER DISTURBANCE ON MONDAY
NIGHT AND THE POTENTIAL FOR SOME PATCHY FOG DEPENDING ON WHERE
STORMS OCCUR. LOWS UPPER 60S TO LOWER 70S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 320 PM SUNDAY...
THE UPPER AIR PATTERN AT THE BEGINNING OF THE LONG TERM PERIOD
INCLUDES A GENERAL WESTERLY FLOW WITH A WEAK SHEAR AXIS EXTENDING
FROM NORTH TO SOUTH ACROSS THE MID ATLANTIC. DURING THE REMAINDER OF
THE LONG TERM PERIOD THE PATTERN EVOLVES AS BOTH THE GFS AND THE
ECMWF DEVELOP A LARGE RIDGE ACROSS THE LOWER MISSISSIPPI VALLY ON
THURSDAY WITH 5950M HEIGHTS THAT PERSISTS INTO EARLY SATURDAY.
GUIDANCE DIVERGES A BIT AT THAT TIME AS THE RIDGE IN THE ECMWF
WEAKENS AND A BROAD TROUGH SWEEPS ACROSS THE NORTHERN ROCKIES AND
NORTHERN PLAINS ON SUNDAY WHILE THE GFS HOLDS ONTO A STRONGER RIDGE.
REGARDLESS... CENTRAL NC WILL BE IN A NORTHWEST FLOW ALOFT FOR MUCH
OF THE PERIOD WITH A THREAT OF SCATTERED MAINLY AFTERNOON AND
EVENING THUNDERSTORMS EACH DAY. NEAR TO ABOVE AVERAGE HIGH
TEMPERATURES WILL COOL DOWN TO NEAR TO BELOW AVERAGE AS A COLD
FRONT PUSHES SOUTH THROUGH THE REGION.
ONE SHORTWAVE TROUGH AND AN ASSOCIATED SURFACE LOW WILL MOVE
OFFSHORE TUESDAY MORNING BEFORE ANOTHER DISTURBANCE ALOFT MOVES INTO
THE REGION FROM THE WEST LATE TUESDAY. CONVECTIVE COVERAGE SHOULD BE
MUCH LESS ON TUESDAY THAN ON MONDAY WITH THE GREATEST COVERAGE IN
THE EAST AHEAD OF THE BEST FORCING AND IN THE REGION OF DEEPEST
MOISTURE. NOT TOO EXCITED ABOUT SIGNIFICANT SEVERE WEATHER
WITH THE SREF SUGGESTING A WEAK TO MODERATELY UNSTABLE AIR MASS WITH
BULK SHEAR VALUES PEAKING AROUND 20-25KTS. BUT THE FLOW HIGHS SHOULD
RANGE IN THE UPPER 80S TO LOWER 90S.
GUIDANCE DEPICTS A SIMILAR PATTERN ACROSS THE CAROLINAS FOR THE MID
TO END OF THE LONG TERM PERIOD AS A NORTHWEST FLOW ALOFT DRIVES
MULTIPLE IMPULSES ACROSS THE REGION. DEEP LAYER MOISTURE IS MORE
LIMITED ON WEDNESDAY AND THURSDAY BUT INCREASES MARKEDLY ON FRIDAY
INTO THE WEEKEND WITH PRECIPITABLE WATER VALUES ON SAT AND
SUN RANGING FROM NEAR 2.1 ACROSS THE COASTAL PLAIN TO 1.8 ACROSS THE
WESTERN PIEDMONT. A WEAK COLD FRONT IS PROGGED TO MOVE SOUTH ACROSS
THE REGION ON FRIDAY AND SATURDAY AND LIKELY LINGER IN A WEST TO
EAST ORIENTATION ACROSS GA/SC AND SOUTHERN NC PROVIDING A FOCUS FOR
CONVECTION. ITS DIFFICULT TO PLACE MUCH SPECIFICITY IN THE FORECAST
BUT WEDNESDAY AND THURSDAY WOULD APPEAR TO HAVE LESS CONVECTIVE
COVERAGE WITH INCREASING CHANCES OF CONVECTION ON FRIDAY INTO THE
WEEKEND. HIGH TEMPERATURES IN THE LOWER 90S ON WEDNESDAY AND
THURSDAY WILL COOL DOWN A BIT ON FRIDAY AND SHOULD BE NOTICEABLY
COOLER FOR SATURDAY AND SUNDAY WITH HIGHS IN THE LOWER TO MID 80S.
MORNING LOWS WILL COOL SLIGHTLY FROM THE UPPER 60S TO LOWER 70S
AROUND MID WEEK TO THE UPPER 60S TO AROUND 70 BY THE WEEKEND. -BLAES
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 730 AM SUNDAY...
WINDS WILL BE LIGHT THROUGH THE PERIOD...GENERALLY OUR OF THE WEST-
SOUTHWEST. MID CLOUDS WILL TO STREAM IN FROM THE
NORTHWEST...ESPECIALLY ACROSS THE NORTHERN PORTIONS OF NC AS A
DISTURBANCE CROSSES THE AREA. IFR/LIFR VSBYS DEVELOP FROM KFAY TO
KRWI THIS MORNING BUT ARE ALREADY BEGINNING TO IMPROVE. VFR
CONDITIONS SHOULD THUS RETURN BY 14Z AND CONTINUE THROUGH THE
REMAINDER OF THE TAF PERIOD.
OUTLOOK... BETTER CHANCES FOR SHOWERS AND STORMS LATE MONDAY WITH
ANOTHER DISTURBANCE CROSSING THE REGION. THEN THE NEXT PERIOD O
UNSETTLED WEATHER LOOKS TO COME LATE IN THE WEEK. SUB-VFR FOG
AND/OR CEILINGS WILL BE POSSIBLE DURING THE EARLY MORNING HOURS EACH
DAY...ESPECIALLY IN LOCATIONS RECENTLY AFFECTED BY CONVECTION.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...VINCENT
SHORT TERM...BLS
LONG TERM...BLAES
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1233 PM EDT SUN AUG 17 2014
.SYNOPSIS...A SERIES OF UPPER LEVEL DISTURBANCES IN WEST-NORTHWESTERLY
FLOW WILL CROSS THE REGION THIS WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM SUNDAY...
DIURNAL DESTABILIZATION WILL YIELD MODERATE INSTABILITY IN MOST
AREAS THIS AFTERNOON. HOWEVER...FORCING FOR ASCENT WILL BE LIMITED
(AT BEST) TO TRANSIENT SMALL AMPLITUDE DISTURBANCES IN WNW FLOW
ALOFT...FEATURES WHICH ARE EITHER ABSENT OR DIFFICULT TO RESOLVE PER
LATEST WV IMAGERY AND RAP DATA. WILL CONTINUE TO INDICATE A DRY
FORECAST...WITH HIGH IN THE UPPER 80S TO LOWER/MID 90S. A MORE
DETAILED DISCUSSION WILL BE FORTHCOMING. -VINCENT
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 330 AM SUNDAY...
THE MCV CURRENTLY IN THE VICINITY OF KSTL...WHICH IS RATHER STRONG
BASED ON SATELLITE PRESENTATION...IS FORECAST TO CROSS THE
APPALACHIANS BY MIDDAY MONDAY....WITH A SHARPENING PIEDMONT TROUGH.
GFS FORECAST SOUNDINGS GIVE 1000-2000 J/KG OF MLCAPE... HIGHER IN
THE EAST WHERE HEATING WILL BE FAVORED AND LAPSE RATES STEEPEN THE
MOST. PW INCREASES TO OVER 2 INCHES BY MONDAY AFTERNOON...AND
COMBINED WITH THE FORCING AND INSTABILITY SHOULD SUPPORT SCATTERED
STORMS. THE LARGER SCALE SHEAR IS EXPECTED TO BE RELATIVELY
WEAK...20-25KT...THOUGH THE DISTURBANCE MAY AUGMENT SHEAR LOCALLY AS
IT CROSSES THE AREA. HOWEVER...HIGH PW AND STEEP LOW-LEVEL LAPSE
RATES MAY STILL CREATE THE POTENTIAL FOR A FEW STRONG WIND GUSTS.
HIGHS 88-93.
SHOULD SEE SOME CLEARING BEHIND THE UPPER DISTURBANCE ON MONDAY
NIGHT AND THE POTENTIAL FOR SOME PATCHY FOG DEPENDING ON WHERE
STORMS OCCUR. LOWS UPPER 60S TO LOWER 70S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 235 AM SUNDAY...
TUESDAY AND TUESDAY NIGHT: TUESDAY WILL SEE A SHORTWAVE AND
ASSOCIATED MESO-LOW MOVE THROUGH THE NORTHERN HALF OF THE
CWA...ENDING UP NORTHEAST OF THE AREA BY TUESDAY AFTERNOON. THE
ASSOCIATED DPVA MAXIMUM IS NOW TRACKING A LITTLE FURTHER SOUTH THAN
PREVIOUS RUNS...ENDING UP BETWEEN KFAY AND KRWI BY 18Z TUESDAY. THIS
IS CAUSING A VERY SMALL AMPLITUDE SHORTWAVE TROUGH AT 500MB THAT
COULD CAUSE CONVECTION TO EXTEND FURTHER SOUTH ALONG THE I-95
CORRIDOR THAN ORIGINALLY THOUGHT ON TUESDAY AFTERNOON/EVENING. WILL
RAISE POPS ACCORDINGLY...CLOSER TO 40 PERCENT IN THE EAST...WHILE
MAINTAINING SLIGHT CHANCE IN THE WEST. MODEL FORECAST SOUNDINGS
DURING THIS TIME INDICATE ABOUT 1000 J/KG OF CAPE AND BULK SHEAR
NEAR 20 KTS. VERY STRONG LOW LEVEL LAPSE RATES HELPING TO CREATE
INVERTED V SIGNATURES ON THE SOUNDINGS. CANT RULE OUT A SEVERE STORM
OR TWO WITH DAMAGING WINDS THE MOST LIKELY SCENARIO BUT SOME SMALL
HAIL ALSO POSSIBLE WITH GOOD CAPE IN THE HAIL GROWTH ZONE. WHILE
HODOGRAPHS AT KRWI DO SHOW SOME CURVATURE IN THE LOWEST 3 KM...THE
SHEAR MAGNITUDE IS VERY LOW AT LESS THAN 10 KTS AND THUS KEEPING
HELICITY VALUES DOWN. THIS COUPLED WITH VERY HIGH LCL VALUES MAKES
ANY TORNADIC THREAT UNLIKELY. SPC HAS THE AREA IN A GENERIC SEE TEXT
FOR THE DAY 3 CONVECTIVE OUTLOOK AT THIS TIME. DUE TO AN INCREASE IN
EXPECTED CLOUD COVER/PRECIPIATION COVERAGE...WILL LOWER MAX TEMPS IN
THE EASTERN HALF OF THE CWA...UPPER 80S TO NEAR 90 AND MAINTAIN
UPPER 80S TO LOW 90S IN THE WEST. EXPECT PRECIPIATION TO WIND DOWN
OVERNIGHT TUESDAY AS LOW PULLS OFF TO THE NORTHEAST. LOWS IN THE
UPPER 60S TO LOWER 70S.
WEDNESDAY THROUGH SATURDAY: THE CONFIDENCE IN THE FORECAST BEGINS TO
DEGRADE SIGNIFICANTLY AS THE FORECAST PERIOD GOES ON AS MODELS BEGIN
TO AMPLIFY A LONGWAVE TROUGH OVER THE EASTERN CONUS WITH STRONG HIGH
PRESSURE OVER THE DEEP SOUTH AND INTO THE TEXARKANA REGION AND AN
ASSOCIATED RIDGE EXTENDING UP INTO THE CENTRAL PLAINS. WHILE
DETERMINISTIC MODELS AMPLIFY THE PATTERN STRONGLY...ENSEMBLE MEANS
HAVE BEEN MORE CONSISTENT WITH A MORE MUTED SCENARIO. A SERIES OF
SHORTWAVES WILL MARCH THROUGH THE UPPER TROUGH THROUGH SATURDAY
MAKING PRECIPITATION POSSIBLE EACH DAY. TOTAL MOISTURE DROPS OFF
WEDNESDAY AND THURSDAY MAKING THESE DAYS MORE LIKELY TO REMAIN DRY
OR FOR CONVECTION TO BE MORE SCATTERED IN NATURE. A STRONGER SURGE
OF MOISTURE RETURNS FOR FRIDAY AND SATURDAY. WILL MAINTAIN SLIGHT
CHANCE POPS WEDNESDAY AND THURSDAY AFTERNOONS AND RAMP UP TO CHANCE
FOR FRIDAY AND SATURDAY. HIGHS WEDNESDAY AND THURSDAY IN THE LOW 90S
AND THEN DROPPING BACK TO THE UPPER 80S FOR FRIDAY AND SATURDAY WITH
INCREASED CLOUD AND PRECIP COVERAGE. LOWS GENERALLY IN THE UPPER 60S
TO LOWER 70S.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 730 AM SUNDAY...
WINDS WILL BE LIGHT THROUGH THE PERIOD...GENERALLY OUR OF THE WEST-
SOUTHWEST. MID CLOUDS WILL TO STREAM IN FROM THE
NORTHWEST...ESPECIALLY ACROSS THE NORTHERN PORTIONS OF NC AS A
DISTURBANCE CROSSES THE AREA. IFR/LIFR VSBYS DEVELOP FROM KFAY TO
KRWI THIS MORNING BUT ARE ALREADY BEGINNING TO IMPROVE. VFR
CONDITIONS SHOULD THUS RETURN BY 14Z AND CONTINUE THROUGH THE
REMAINDER OF THE TAF PERIOD.
OUTLOOK... BETTER CHANCES FOR SHOWERS AND STORMS LATE MONDAY WITH
ANOTHER DISTURBANCE CROSSING THE REGION. THEN THE NEXT PERIOD O
UNSETTLED WEATHER LOOKS TO COME LATE IN THE WEEK. SUB-VFR FOG
AND/OR CEILINGS WILL BE POSSIBLE DURING THE EARLY MORNING HOURS EACH
DAY...ESPECIALLY IN LOCATIONS RECENTLY AFFECTED BY CONVECTION.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...VINCENT
SHORT TERM...BLS
LONG TERM...ELLIS
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
330 AM EDT SUN AUG 17 2014
.SYNOPSIS...A SERIES OF UPPER LEVEL DISTURBANCES IN WEST-NORTHWESTERLY
FLOW WILL CROSS THE REGION THIS WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM SUNDAY...
WATER VAPOR AND RAP SHOW A WEAK DISTURBANCE MOVING FROM KENTUCKY
INTO SOUTHWESTERN VIRGINIA..CAUSING SOME SOME RADAR ECHOES TO START
SHOWING UP AS FAR SOUTH AS BOONE. RAP FORECAST SOUNDINGS SHOW
ALMOST NO MUCAPE OVER CENTRAL NC AND RATHER DRY AIR BELOW 15K FT.
MOST OF THE PRECIP WONT REACH THE GROUND...THROUGH A FEW SPRINKLES
ARE POSSIBLE AS THE DISTURBANCE MOVES ACROSS THE AREA THIS
MORNING....MAINLY NORTH OF HWY 64. OTHERWISE IT APPEARS THE CHANCES
OF ANY SHOWERS OR STORMS THIS AFTERNOON WILL BE FAIRLY LIMITED DUE
TO A PERIOD OF SUBSIDENCE THAT IS LIKELY BEHIND THE AFOREMENTIONED
DISTURBANCE AND VERY WEAK INSTABILITY. BASED ON SATELLITE IMAGERY
UPSTREAM...MID/HIGH CLOUDS WILL BE FAIRLY OPAQUE THIS MORNING...AND
IF A BREAK DOESNT DEVELOP THIS AFTERNOON BEHIND THE UPPER
DISTURBANCE...THEN FORECAST HIGHS MAY STILL BE TOO WARM. HAVE
TRIMMED HIGHS BACK INTO HE UPPER 80S ACROSS THE NORTHERN
PIEDMONT...WITH LOW/MID 90S TO THE SOUTH IN ACCORDANCE WITH MOS CONSENSUS.
SHOULD CONTINUE TO SEE MID AND HIGH CLOUDS STREAMING IN FROM THE
NORTHWEST AHEAD OF THE MCV CURRENTLY OVER THE STL AREA. LOWS WILL
BE IN THE UPPER 60S AND LOWER 70S.
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 330 AM SUNDAY...
THE MCV CURRENTLY IN THE VICINITY OF KSTL...WHICH IS RATHER STRONG
BASED ON SATELLITE PRESENTATION...IS FORECAST TO CROSS THE
APPALACHIANS BY MIDDAY MONDAY....WITH A SHARPENING PIEDMONT TROUGH.
GFS FORECAST SOUNDINGS GIVE 1000-2000 J/KG OF MLCAPE... HIGHER IN
THE EAST WHERE HEATING WILL BE FAVORED AND LAPSE RATES STEEPEN THE
MOST. PW INCREASES TO OVER 2 INCHES BY MONDAY AFTERNOON...AND
COMBINED WITH THE FORCING AND INSTABILITY SHOULD SUPPORT SCATTERED
STORMS. THE LARGER SCALE SHEAR IS EXPECTED TO BE RELATIVELY
WEAK...20-25KT...THOUGH THE DISTURBANCE MAY AUGMENT SHEAR LOCALLY AS
IT CROSSES THE AREA. HOWEVER...HIGH PW AND STEEP LOW-LEVEL LAPSE
RATES MAY STILL CREATE THE POTENTIAL FOR A FEW STRONG WIND GUSTS.
HIGHS 88-93.
SHOULD SEE SOME CLEARING BEHIND THE UPPER DISTURBANCE ON MONDAY
NIGHT AND THE POTENTIAL FOR SOME PATCHY FOG DEPENDING ON WHERE
STORMS OCCUR. LOWS UPPER 60S TO LOWER 70S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 235 AM SUNDAY...
TUESDAY AND TUESDAY NIGHT: TUESDAY WILL SEE A SHORTWAVE AND
ASSOCIATED MESO-LOW MOVE THROUGH THE NORTHERN HALF OF THE
CWA...ENDING UP NORTHEAST OF THE AREA BY TUESDAY AFTERNOON. THE
ASSOCIATED DPVA MAXIMUM IS NOW TRACKING A LITTLE FURTHER SOUTH THAN
PREVIOUS RUNS...ENDING UP BETWEEN KFAY AND KRWI BY 18Z TUESDAY. THIS
IS CAUSING A VERY SMALL AMPLITUDE SHORTWAVE TROUGH AT 500MB THAT
COULD CAUSE CONVECTION TO EXTEND FURTHER SOUTH ALONG THE I-95
CORRIDOR THAN ORIGINALLY THOUGHT ON TUESDAY AFTERNOON/EVENING. WILL
RAISE POPS ACCORDINGLY...CLOSER TO 40 PERCENT IN THE EAST...WHILE
MAINTAINING SLIGHT CHANCE IN THE WEST. MODEL FORECAST SOUNDINGS
DURING THIS TIME INDICATE ABOUT 1000 J/KG OF CAPE AND BULK SHEAR
NEAR 20 KTS. VERY STRONG LOW LEVEL LAPSE RATES HELPING TO CREATE
INVERTED V SIGNATURES ON THE SOUNDINGS. CANT RULE OUT A SEVERE STORM
OR TWO WITH DAMAGING WINDS THE MOST LIKELY SCENARIO BUT SOME SMALL
HAIL ALSO POSSIBLE WITH GOOD CAPE IN THE HAIL GROWTH ZONE. WHILE
HODOGRAPHS AT KRWI DO SHOW SOME CURVATURE IN THE LOWEST 3 KM...THE
SHEAR MAGNITUDE IS VERY LOW AT LESS THAN 10 KTS AND THUS KEEPING
HELICITY VALUES DOWN. THIS COUPLED WITH VERY HIGH LCL VALUES MAKES
ANY TORNADIC THREAT UNLIKELY. SPC HAS THE AREA IN A GENERIC SEE TEXT
FOR THE DAY 3 CONVECTIVE OUTLOOK AT THIS TIME. DUE TO AN INCREASE IN
EXPECTED CLOUD COVER/PRECIPIATION COVERAGE...WILL LOWER MAX TEMPS IN
THE EASTERN HALF OF THE CWA...UPPER 80S TO NEAR 90 AND MAINTAIN
UPPER 80S TO LOW 90S IN THE WEST. EXPECT PRECIPIATION TO WIND DOWN
OVERNIGHT TUESDAY AS LOW PULLS OFF TO THE NORTHEAST. LOWS IN THE
UPPER 60S TO LOWER 70S.
WEDNESDAY THROUGH SATURDAY: THE CONFIDENCE IN THE FORECAST BEGINS TO
DEGRADE SIGNIFICANTLY AS THE FORECAST PERIOD GOES ON AS MODELS BEGIN
TO AMPLIFY A LONGWAVE TROUGH OVER THE EASTERN CONUS WITH STRONG HIGH
PRESSURE OVER THE DEEP SOUTH AND INTO THE TEXARKANA REGION AND AN
ASSOCIATED RIDGE EXTENDING UP INTO THE CENTRAL PLAINS. WHILE
DETERMINISTIC MODELS AMPLIFY THE PATTERN STRONGLY...ENSEMBLE MEANS
HAVE BEEN MORE CONSISTENT WITH A MORE MUTED SCENARIO. A SERIES OF
SHORTWAVES WILL MARCH THROUGH THE UPPER TROUGH THROUGH SATURDAY
MAKING PRECIPITATION POSSIBLE EACH DAY. TOTAL MOISTURE DROPS OFF
WEDNESDAY AND THURSDAY MAKING THESE DAYS MORE LIKELY TO REMAIN DRY
OR FOR CONVECTION TO BE MORE SCATTERED IN NATURE. A STRONGER SURGE
OF MOISTURE RETURNS FOR FRIDAY AND SATURDAY. WILL MAINTAIN SLIGHT
CHANCE POPS WEDNESDAY AND THURSDAY AFTERNOONS AND RAMP UP TO CHANCE
FOR FRIDAY AND SATURDAY. HIGHS WEDNESDAY AND THURSDAY IN THE LOW 90S
AND THEN DROPPING BACK TO THE UPPER 80S FOR FRIDAY AND SATURDAY WITH
INCREASED CLOUD AND PRECIP COVERAGE. LOWS GENERALLY IN THE UPPER 60S
TO LOWER 70S.
&&
.AVIATION /06 SUNDAY THROUGH THURSDAY/...
AS OF 130 AM SUNDAY...
WINDS WILL BE LIGHT THROUGH THE PERIOD...GENERALLY OUR OF THE WEST-
SOUTHWEST. MID CLOUDS WILL INCREASE...ESPECIALLY ACROSS THE
NORTHERN PORTIONS OF NC AS A DISTURBANCE CROSSES THE AREA...BUT THE
CHANCES OF MORE THAN SPRINKLE SEEM LOW. PATCHY FOG SHOULD CONTINUE
TO DEVELOP THIS MORNING..WITH A GOOD POSSIBILITY OF MVFR/IFR VSBYS
ARE KFAY OR KRWI PRIOR TO 13Z.. OTHERWISE...VFR EXPECTED AT OTHER
TAF SITES.
OUTLOOK... BETTER CHANCES FOR SHOWERS AND STORMS LATE MONDAY WITH
ANOTHER DISTURBANCE CROSSING THE REGION. THEN THE NEXT PERIOD O
UNSETTLED WEATHER LOOKS TO COME LATE IN THE WEEK. SUB-VFR FOG
AND/OR CEILINGS WILL BE POSSIBLE DURING THE EARLY MORNING HOURS EACH
DAY...ESPECIALLY IN LOCATIONS RECENTLY AFFECTED BY CONVECTION.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...BLS
SHORT TERM...BLS
LONG TERM...ELLIS
AVIATION...BLS/CBL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
300 AM EDT SUN AUG 17 2014
.SYNOPSIS...A CLIMATOLOGICAL SUMMER PATTERN WILL PREVAIL ACROSS THE
REGION THROUGH THE REMAINDER OF THE WEEKEND. A SERIES OF UPPER LEVEL
DISTURBANCES WILL TRACK ACROSS THE CAROLINAS AND MID ATLANTIC EARLY
TO MID WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM SUNDAY...
WATER VAPOR AND RAP SHOW A WEAK DISTURBANCE MOVING FROM KENTUCKY
INTO SOUTHWESTERN VIRGINIA..CAUSING SOME SOME RADAR ECHOES TO START
SHOWING UP AS FAR SOUTH AS BOONE. RAP FORECAST SOUNDINGS SHOW
ALMOST NO MUCAPE OVER CENTRAL NC AND RATHER DRY AIR BELOW 15K FT.
MOST OF THE PRECIP WONT REACH THE GROUND...THROUGH A FEW SPRINKLES
ARE POSSIBLE AS THE DISTURBANCE MOVES ACROSS THE AREA THIS
MORNING....MAINLY NORTH OF HWY 64. OTHERWISE IT APPEARS THE CHANCES
OF ANY SHOWERS OR STORMS THIS AFTERNOON WILL BE FAIRLY LIMITED DUE
TO A PERIOD OF SUBSIDENCE THAT IS LIKELY BEHIND THE AFOREMENTIONED
DISTURBANCE AND VERY WEAK INSTABILITY. BASED ON SATELLITE IMAGERY
UPSTREAM...MID/HIGH CLOUDS WILL BE FAIRLY OPAQUE THIS MORNING...AND
IF A BREAK DOESNT DEVELOP THIS AFTERNOON BEHIND THE UPPER
DISTURBANCE...THEN FORECAST HIGHS MAY STILL BE TOO WARM. HAVE
TRIMMED HIGHS BACK INTO HE UPPER 80S ACROSS THE NORTHERN
PIEDMONT...WITH LOW/MID 90S TO THE SOUTH IN ACCORDANCE WITH MOS CONSENSUS.
SHOULD CONTINUE TO SEE MID AND HIGH CLOUDS STREAMING IN FROM THE
NORTHWEST AHEAD OF THE MCV CURRENTLY OVER THE STL AREA. LOWS WILL
BE IN THE UPPER 60S AND LOWER 70S.
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 330 PM SATURDAY...
TO BE UPDATED SHORTLY...
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 235 AM SUNDAY...
TUESDAY AND TUESDAY NIGHT: TUESDAY WILL SEE A SHORTWAVE AND
ASSOCIATED MESO-LOW MOVE THROUGH THE NORTHERN HALF OF THE
CWA...ENDING UP NORTHEAST OF THE AREA BY TUESDAY AFTERNOON. THE
ASSOCIATED DPVA MAXIMUM IS NOW TRACKING A LITTLE FURTHER SOUTH THAN
PREVIOUS RUNS...ENDING UP BETWEEN KFAY AND KRWI BY 18Z TUESDAY. THIS
IS CAUSING A VERY SMALL AMPLITUDE SHORTWAVE TROUGH AT 500MB THAT
COULD CAUSE CONVECTION TO EXTEND FURTHER SOUTH ALONG THE I-95
CORRIDOR THAN ORIGINALLY THOUGHT ON TUESDAY AFTERNOON/EVENING. WILL
RAISE POPS ACCORDINGLY...CLOSER TO 40 PERCENT IN THE EAST...WHILE
MAINTAINING SLIGHT CHANCE IN THE WEST. MODEL FORECAST SOUNDINGS
DURING THIS TIME INDICATE ABOUT 1000 J/KG OF CAPE AND BULK SHEAR
NEAR 20 KTS. VERY STRONG LOW LEVEL LAPSE RATES HELPING TO CREATE
INVERTED V SIGNATURES ON THE SOUNDINGS. CANT RULE OUT A SEVERE STORM
OR TWO WITH DAMAGING WINDS THE MOST LIKELY SCENARIO BUT SOME SMALL
HAIL ALSO POSSIBLE WITH GOOD CAPE IN THE HAIL GROWTH ZONE. WHILE
HODOGRAPHS AT KRWI DO SHOW SOME CURVATURE IN THE LOWEST 3 KM...THE
SHEAR MAGNITUDE IS VERY LOW AT LESS THAN 10 KTS AND THUS KEEPING
HELICITY VALUES DOWN. THIS COUPLED WITH VERY HIGH LCL VALUES MAKES
ANY TORNADIC THREAT UNLIKELY. SPC HAS THE AREA IN A GENERIC SEE TEXT
FOR THE DAY 3 CONVECTIVE OUTLOOK AT THIS TIME. DUE TO AN INCREASE IN
EXPECTED CLOUD COVER/PRECIPIATION COVERAGE...WILL LOWER MAX TEMPS IN
THE EASTERN HALF OF THE CWA...UPPER 80S TO NEAR 90 AND MAINTAIN
UPPER 80S TO LOW 90S IN THE WEST. EXPECT PRECIPIATION TO WIND DOWN
OVERNIGHT TUESDAY AS LOW PULLS OFF TO THE NORTHEAST. LOWS IN THE
UPPER 60S TO LOWER 70S.
WEDNESDAY THROUGH SATURDAY: THE CONFIDENCE IN THE FORECAST BEGINS TO
DEGRADE SIGNIFICANTLY AS THE FORECAST PERIOD GOES ON AS MODELS BEGIN
TO AMPLIFY A LONGWAVE TROUGH OVER THE EASTERN CONUS WITH STRONG HIGH
PRESSURE OVER THE DEEP SOUTH AND INTO THE TEXARKANA REGION AND AN
ASSOCIATED RIDGE EXTENDING UP INTO THE CENTRAL PLAINS. WHILE
DETERMINISTIC MODELS AMPLIFY THE PATTERN STRONGLY...ENSEMBLE MEANS
HAVE BEEN MORE CONSISTENT WITH A MORE MUTED SCENARIO. A SERIES OF
SHORTWAVES WILL MARCH THROUGH THE UPPER TROUGH THROUGH SATURDAY
MAKING PRECIPITATION POSSIBLE EACH DAY. TOTAL MOISTURE DROPS OFF
WEDNESDAY AND THURSDAY MAKING THESE DAYS MORE LIKELY TO REMAIN DRY
OR FOR CONVECTION TO BE MORE SCATTERED IN NATURE. A STRONGER SURGE
OF MOISTURE RETURNS FOR FRIDAY AND SATURDAY. WILL MAINTAIN SLIGHT
CHANCE POPS WEDNESDAY AND THURSDAY AFTERNOONS AND RAMP UP TO CHANCE
FOR FRIDAY AND SATURDAY. HIGHS WEDNESDAY AND THURSDAY IN THE LOW 90S
AND THEN DROPPING BACK TO THE UPPER 80S FOR FRIDAY AND SATURDAY WITH
INCREASED CLOUD AND PRECIP COVERAGE. LOWS GENERALLY IN THE UPPER 60S
TO LOWER 70S.
&&
.AVIATION /06 SUNDAY THROUGH THURSDAY/...
AS OF 130 AM SUNDAY...
WINDS WILL BE LIGHT THROUGH THE PERIOD...GENERALLY OUR OF THE WEST-
SOUTHWEST. MID CLOUDS WILL INCREASE...ESPECIALLY ACROSS THE
NORTHERN PORTIONS OF NC AS A DISTURBANCE CROSSES THE AREA...BUT THE
CHANCES OF MORE THAN SPRINKLE SEEM LOW. PATCHY FOG SHOULD CONTINUE
TO DEVELOP THIS MORNING..WITH A GOOD POSSIBILITY OF MVFR/IFR VSBYS
ARE KFAY OR KRWI PRIOR TO 13Z.. OTHERWISE...VFR EXPECTED AT OTHER
TAF SITES.
OUTLOOK... BETTER CHANCES FOR SHOWERS AND STORMS LATE MONDAY WITH
ANOTHER DISTURBANCE CROSSING THE REGION. THEN THE NEXT PERIOD O
UNSETTLED WEATHER LOOKS TO COME LATE IN THE WEEK. SUB-VFR FOG
AND/OR CEILINGS WILL BE POSSIBLE DURING THE EARLY MORNING HOURS EACH
DAY...ESPECIALLY IN LOCATIONS RECENTLY AFFECTED BY CONVECTION.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...BLS
SHORT TERM...VINCENT
LONG TERM...ELLIS
AVIATION...BLS/CBL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
235 AM EDT SUN AUG 17 2014
.SYNOPSIS...A CLIMATOLOGICAL SUMMER PATTERN WILL PREVAIL ACROSS THE
REGION THROUGH THE REMAINDER OF THE WEEKEND. A SERIES OF UPPER LEVEL
DISTURBANCES WILL TRACK ACROSS THE CAROLINAS AND MID ATLANTIC EARLY
TO MID WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10 PM SATURDAY...
ISOLATED TO SCATTERED CONVECTION ACROSS THE SOUTHERN/SOUTHEASTERN
HALF OF THE AREA HAS DISSIPATED WITH THE LOSS OF DAYTIME HEATING
THIS EVENING AND WEAK S/W ENERGY ALOFT PUSHING TO THE EAST/SOUTH OF
THE AREA. ONLY ADDITIONAL WEAK PERTURBATIONS ARE EXPECTED TO TRACK
ACROSS CENTRAL NC OVERNIGHT IN THE WNW FLOW ALOFT... WITH MODELS
GENERALLY INDICATING DRY CONDITIONS OVERNIGHT. HOWEVER... THE LATEST
RUC AND HRRR ARE SHOWING THE POTENTIAL FOR INCREASING MID AND HIGH
LEVEL CLOUD COVER IN ADVANCE OF MORE PRONOUNCED S/W ENERGY CURRENTLY
OVER MO/IL/IN/KY... AN PERHAPS EVEN GENERATING SOME SPRINKLES ACROSS
THE NORTHWEST PIEDMONT BY AROUND DAYBREAK. IN ADDITION... DEPENDING
ON THE AMOUNT OF MID AND HIGH LEVEL CLOUD COVER WE COULD SEE SOME
PATCHY FOG OVERNIGHT THANKS TO THE SPOTTY HEAVY RAIN EARLIER TODAY
ACROSS SOUTHERN PORTIONS OF THE AREA (AND WHERE THE HIGHEST SURFACE
DEWPOINTS RESIDE). OVERNIGHT LOWS ARE EXPECTED TO RANGE FROM THE MID
TO UPPER 60S NORTH/NORTHWEST TO THE LOWER 70S SOUTH.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 330 PM SATURDAY...
WNW FLOW ALOFT WILL PERSIST OVER THE CAROLINAS THROUGH SUNDAY NIGHT.
A COMPACT UPPER LOW CENTERED IN NORTHERN MO/SOUTHERN IA THIS
AFTERNOON WILL TRACK THROUGH SOUTHERN IL/IN TONIGHT...INTO THE TN
VALLEY ON SUNDAY...AND THE WINDWARD SLOPES OF THE SOUTHERN
APPALACHIANS SUNDAY NIGHT. 12Z MODEL GUIDANCE IS IN GOOD AGREEMENT
ON THE EVOLUTION (I.E. TIMING/LOCATION) OF THIS FEATURE...SUGGESTING
THAT IT SHOULD HAVE LITTLE INFLUENCE ON FORCING FOR ASCENT IN
CENTRAL NC PRIOR TO EARLY MONDAY MORNING. HOWEVER...TRANSIENT DPVA
IS EXPECTED IN ASSOC/W PROGRESSIVE SMALL AMPLITUDE DISTURBANCES
TRACKING ACROSS THE REGION IN WNW FLOW ALOFT SUN/SUN NIGHT...
POSSIBLY INCLUDING MID-LEVEL VORTICITY MAXIMA SPAWNED BY UPSTREAM
MCS ACTIVITY. STRONG INSOLATION WILL YIELD HIGHS IN THE LOWER TO MID
90S OR 90-95F SUNDAY...PERHAPS A DEGREE OR TWO LOWER IF BROKEN MID-
LEVEL CLOUD COVER IS PRESENT. MODEL GUIDANCE VARIES W/REGARD TO
DEGREE OF DESTABILIZATION SUN AFTERNOON...THOUGH AGREES ON THE
GENERAL TREND OF LOWER INSTABILITY W/NW AND HIGHER E/SE. GIVEN A
WEAK MSLP PATTERN...THE LACK OF A LOW-LEVEL FOCUS (OUTSIDE OF THE
SEABREEZE)...DIFFICULTY IN ASSESSING THE PRECISE EVOLUTION OF
PROGRESSIVE SMALL AMPLITUDE DISTURBANCES ALOFT...AND UNCERTAINTY IN
THE DEGREE OF DESTABILIZATION...HAVE OPTED TO LEAVE CHANCES FOR
CONVECTION AT 20%. LOWS SUN NIGHT WILL BE SLIGHTLY WARMER THAN
TONIGHT...IN THE UPPER 60S TO LOWER 70S. -VINCENT
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 235 AM SUNDAY...
TUESDAY AND TUESDAY NIGHT: TUESDAY WILL SEE A SHORTWAVE AND
ASSOCIATED MESO-LOW MOVE THROUGH THE NORTHERN HALF OF THE
CWA...ENDING UP NORTHEAST OF THE AREA BY TUESDAY AFTERNOON. THE
ASSOCIATED DPVA MAXIMUM IS NOW TRACKING A LITTLE FURTHER SOUTH THAN
PREVIOUS RUNS...ENDING UP BETWEEN KFAY AND KRWI BY 18Z TUESDAY. THIS
IS CAUSING A VERY SMALL AMPLITUDE SHORTWAVE TROUGH AT 500MB THAT
COULD CAUSE CONVECTION TO EXTEND FURTHER SOUTH ALONG THE I-95
CORRIDOR THAN ORIGINALLY THOUGHT ON TUESDAY AFTERNOON/EVENING. WILL
RAISE POPS ACCORDINGLY...CLOSER TO 40 PERCENT IN THE EAST...WHILE
MAINTAINING SLIGHT CHANCE IN THE WEST. MODEL FORECAST SOUNDINGS
DURING THIS TIME INDICATE ABOUT 1000 J/KG OF CAPE AND BULK SHEAR
NEAR 20 KTS. VERY STRONG LOW LEVEL LAPSE RATES HELPING TO CREATE
INVERTED V SIGNATURES ON THE SOUNDINGS. CANT RULE OUT A SEVERE STORM
OR TWO WITH DAMAGING WINDS THE MOST LIKELY SCENARIO BUT SOME SMALL
HAIL ALSO POSSIBLE WITH GOOD CAPE IN THE HAIL GROWTH ZONE. WHILE
HODOGRAPHS AT KRWI DO SHOW SOME CURVATURE IN THE LOWEST 3 KM...THE
SHEAR MAGNITUDE IS VERY LOW AT LESS THAN 10 KTS AND THUS KEEPING
HELICITY VALUES DOWN. THIS COUPLED WITH VERY HIGH LCL VALUES MAKES
ANY TORNADIC THREAT UNLIKELY. SPC HAS THE AREA IN A GENERIC SEE TEXT
FOR THE DAY 3 CONVECTIVE OUTLOOK AT THIS TIME. DUE TO AN INCREASE IN
EXPECTED CLOUD COVER/PRECIPIATION COVERAGE...WILL LOWER MAX TEMPS IN
THE EASTERN HALF OF THE CWA...UPPER 80S TO NEAR 90 AND MAINTAIN
UPPER 80S TO LOW 90S IN THE WEST. EXPECT PRECIPIATION TO WIND DOWN
OVERNIGHT TUESDAY AS LOW PULLS OFF TO THE NORTHEAST. LOWS IN THE
UPPER 60S TO LOWER 70S.
WEDNESDAY THROUGH SATURDAY: THE CONFIDENCE IN THE FORECAST BEGINS TO
DEGRADE SIGNIFICANTLY AS THE FORECAST PERIOD GOES ON AS MODELS BEGIN
TO AMPLIFY A LONGWAVE TROUGH OVER THE EASTERN CONUS WITH STRONG HIGH
PRESSURE OVER THE DEEP SOUTH AND INTO THE TEXARKANA REGION AND AN
ASSOCIATED RIDGE EXTENDING UP INTO THE CENTRAL PLAINS. WHILE
DETERMINISTIC MODELS AMPLIFY THE PATTERN STRONGLY...ENSEMBLE MEANS
HAVE BEEN MORE CONSISTENT WITH A MORE MUTED SCENARIO. A SERIES OF
SHORTWAVES WILL MARCH THROUGH THE UPPER TROUGH THROUGH SATURDAY
MAKING PRECIPITATION POSSIBLE EACH DAY. TOTAL MOISTURE DROPS OFF
WEDNESDAY AND THURSDAY MAKING THESE DAYS MORE LIKELY TO REMAIN DRY
OR FOR CONVECTION TO BE MORE SCATTERED IN NATURE. A STRONGER SURGE
OF MOISTURE RETURNS FOR FRIDAY AND SATURDAY. WILL MAINTAIN SLIGHT
CHANCE POPS WEDNESDAY AND THURSDAY AFTERNOONS AND RAMP UP TO CHANCE
FOR FRIDAY AND SATURDAY. HIGHS WEDNESDAY AND THURSDAY IN THE LOW 90S
AND THEN DROPPING BACK TO THE UPPER 80S FOR FRIDAY AND SATURDAY WITH
INCREASED CLOUD AND PRECIP COVERAGE. LOWS GENERALLY IN THE UPPER 60S
TO LOWER 70S.
&&
.AVIATION /06 SUNDAY THROUGH THURSDAY/...
AS OF 130 AM SUNDAY...
WINDS WILL BE LIGHT THROUGH THE PERIOD...GENERALLY OUR OF THE WEST-
SOUTHWEST. MID CLOUDS WILL INCREASE...ESPECIALLY ACROSS THE
NORTHERN PORTIONS OF NC AS A DISTURBANCE CROSSES THE AREA...BUT THE
CHANCES OF MORE THAN SPRINKLE SEEM LOW. PATCHY FOG SHOULD CONTINUE
TO DEVELOP THIS MORNING..WITH A GOOD POSSIBILITY OF MVFR/IFR VSBYS
ARE KFAY OR KRWI PRIOR TO 13Z.. OTHERWISE...VFR EXPECTED AT OTHER
TAF SITES.
OUTLOOK... BETTER CHANCES FOR SHOWERS AND STORMS LATE MONDAY WITH
ANOTHER DISTURBANCE CROSSING THE REGION. THEN THE NEXT PERIOD O
UNSETTLED WEATHER LOOKS TO COME LATE IN THE WEEK. SUB-VFR FOG
AND/OR CEILINGS WILL BE POSSIBLE DURING THE EARLY MORNING HOURS EACH
DAY...ESPECIALLY IN LOCATIONS RECENTLY AFFECTED BY CONVECTION.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...BSD
SHORT TERM...VINCENT
LONG TERM...ELLIS
AVIATION...BLS/CBL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
935 PM CDT MON AUG 18 2014
.UPDATE...
ISSUED AT 935 PM CDT MON AUG 18 2014
NO SIGNIFICANT UPDATES THIS EVENING. PRECIPITATION HAS ALL BUT
ENDED OVER EASTERN NORTH DAKOTA...THUS CLEAR TO PARTLY CLOUDY
SKIES EXPECTED TONIGHT WITH PATCHY FOG POSSIBLE AFTER MIDNIGHT.
CURRENT FORECAST LOWS IN THE 50S LOOK REASONABLE.
UPDATE ISSUED AT 638 PM CDT MON AUG 18 2014
ISOLATED THUNDERSHOWERS CONTINUE TO DISSIPATE ACROSS EASTERN
PORTIONS OF CENTRAL NORTH DAKOTA. HAVE REMOVED ALL EVENING POPS
EXCEPT FOR JUST A SLIGHT CHANCE FAR EAST THROUGH 9 PM. OTHERWISE
MOSTLY CLEAR SKIES TONIGHT WITH LIGHT WINDS. PREVIOUS FORECAST HAD
A MENTION OF PATCHY FOG AFTER MIDNIGHT...WHICH LOOKS GOOD.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 318 PM CDT MON AUG 18 2014
DIURNAL CONVECTION THROUGH SUNSET THIS EVENING AND FOG TONIGHT
HIGHLIGHT THE SHORT TERM.
DIURNAL SCATTERED CONVECTION IS EXPECTED TO REMAIN FOCUSED ACROSS
THE SOUTH CENTRAL AND JAMES RIVER VALLEY GIVEN RADAR AND SATELLITE
TRENDS THROUGH 1930 UTC...AND THE 16-17 UTC HRRR ITERATIONS.
MODEST INSTABILITY AND WEAK SHEAR ARE EXPECTED TO KEEP STORMS
BELOW SEVERE LIMITS. HOWEVER...THE NON SUPERCELL TORNADO OR
LANDSPOUT PARAMETER HAS A LOCAL MAXIMA ACROSS THE JAMES RIVER
VALLEY INTO THE SOUTHERN RED RIVER VALLEY WITH STEEP LOW LEVEL
LAPSE RATES AND ENVIRONMENTAL VORTICITY. THUS...WOULD NOT BE
SURPRISED BY A FUNNEL CLOUD REPORT.
FOR TONIGHT...WITH WEAK SURFACE HIGH PRESSURE IN PLACE...CLEAR
SKIES...LIGHT WINDS AND PLENTIFUL MOISTURE FROM WEEKEND RAINS...AREAS
OF FOG ARE POSSIBLE ACROSS MUCH OF THE AREA TONIGHT.
TUESDAY WILL BE THE ONLY DRY DAY IN THE FORECAST UNDER SHORTWAVE
RIDGING BEFORE A RETURN TO AN ACTIVE WEATHER PATTERN THROUGH THE
EXTENDED.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 318 PM CDT MON AUG 18 2014
A SLOW MOVING TROUGH EXTENDING FROM THE NORTHWEST TERRITORIES WILL
PRODUCE CHANCES FOR WIDESPREAD SHOWERS/THUNDERSTORMS FROM WEDNESDAY
INTO THE WEEKEND. CHANCES FOR PRECIPITATION WILL CONTINUE THROUGH
THE EXTENDED...AS UNSETTLED SOUTHWESTERLY FLOW REMAINS OVER THE
AREA.
HEAVY RAINFALL IS EXPECTED OVER WESTERN AND CENTRAL PORTIONS OF THE
STATE WEDNESDAY INTO THURSDAY...WITH ADDITIONAL RAINFALL THROUGH THE
WEEKEND. WESTERN AND CENTRAL AREAS HAVE ALREADY BEEN SATURATED WITH
ABUNDANT RAINFALL...FLOODING ISSUES REMAIN A CONCERN.
TEMPERATURES WILL NEAR AVERAGE FOR WEDNESDAY AND THURSDAY. A
COOLER AIRMASS BEGINS MOVING INTO THE AREA BY FRIDAY MORNING...HIGHS
WILL RANGE BETWEEN 10 AND 15 DEGREES BELOW AVERAGE THROUGH THE REST
OF THE PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 935 PM CDT MON AUG 18 2014
FOR THE MOST PART...EXPECT VFR CONDITIONS AT ALL TAF SITES THROUGH
THE 00 UTC TAF PERIOD. COULD SEE SOME PATCHY FOG EARLY TUESDAY
MORNING GIVEN THE LIGHT WINDS AND CLEAR SKIES...AND THE RECENT
RAINS. HOWEVER...NOT CONFIDENT ENOUGH TO MENTION AT AERODROMES
EXCEPT FOR A VCFG FROM 09-13 UTC AT KJMS WHERE DEWPOINT
DEPRESSIONS ARE EXPECTED TO BE LOWEST. NORTHWEST WINDS WILL
DIMINISH QUICKLY THIS EVENING WITH LIGHT WINDS OVERNIGHT. SURFACE
FLOW WILL SHIFT SOUTHERLY FROM WEST TO EAST ON TUESDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...AYD
LONG TERM...AC
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
638 PM CDT MON AUG 18 2014
.UPDATE...
ISSUED AT 638 PM CDT MON AUG 18 2014
ISOLATED THUNDERSHOWERS CONTINUE TO DISSIPATE ACROSS EASTERN
PORTIONS OF CENTRAL NORTH DAKOTA. HAVE REMOVED ALL EVENING POPS
EXCEPT FOR JUST A SLIGHT CHANCE FAR EAST THROUGH 9 PM. OTHERWISE
MOSTLY CLEAR SKIES TONIGHT WITH LIGHT WINDS. PREVIOUS FORECAST HAD
A MENTION OF PATCHY FOG AFTER MIDNIGHT...WHICH LOOKS GOOD.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 318 PM CDT MON AUG 18 2014
DIURNAL CONVECTION THROUGH SUNSET THIS EVENING AND FOG TONIGHT
HIGHLIGHT THE SHORT TERM.
DIURNAL SCATTERED CONVECTION IS EXPECTED TO REMAIN FOCUSED ACROSS
THE SOUTH CENTRAL AND JAMES RIVER VALLEY GIVEN RADAR AND SATELLITE
TRENDS THROUGH 1930 UTC...AND THE 16-17 UTC HRRR ITERATIONS.
MODEST INSTABILITY AND WEAK SHEAR ARE EXPECTED TO KEEP STORMS
BELOW SEVERE LIMITS. HOWEVER...THE NON SUPERCELL TORNADO OR
LANDSPOUT PARAMETER HAS A LOCAL MAXIMA ACROSS THE JAMES RIVER
VALLEY INTO THE SOUTHERN RED RIVER VALLEY WITH STEEP LOW LEVEL
LAPSE RATES AND ENVIRONMENTAL VORTICITY. THUS...WOULD NOT BE
SURPRISED BY A FUNNEL CLOUD REPORT.
FOR TONIGHT...WITH WEAK SURFACE HIGH PRESSURE IN PLACE...CLEAR
SKIES...LIGHT WINDS AND PLENTIFUL MOISTURE FROM WEEKEND RAINS...AREAS
OF FOG ARE POSSIBLE ACROSS MUCH OF THE AREA TONIGHT.
TUESDAY WILL BE THE ONLY DRY DAY IN THE FORECAST UNDER SHORTWAVE
RIDGING BEFORE A RETURN TO AN ACTIVE WEATHER PATTERN THROUGH THE
EXTENDED.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 318 PM CDT MON AUG 18 2014
A SLOW MOVING TROUGH EXTENDING FROM THE NORTHWEST TERRITORIES WILL
PRODUCE CHANCES FOR WIDESPREAD SHOWERS/THUNDERSTORMS FROM WEDNESDAY
INTO THE WEEKEND. CHANCES FOR PRECIPITATION WILL CONTINUE THROUGH
THE EXTENDED...AS UNSETTLED SOUTHWESTERLY FLOW REMAINS OVER THE
AREA.
HEAVY RAINFALL IS EXPECTED OVER WESTERN AND CENTRAL PORTIONS OF THE
STATE WEDNESDAY INTO THURSDAY...WITH ADDITIONAL RAINFALL THROUGH THE
WEEKEND. WESTERN AND CENTRAL AREAS HAVE ALREADY BEEN SATURATED WITH
ABUNDANT RAINFALL...FLOODING ISSUES REMAIN A CONCERN.
TEMPERATURES WILL NEAR AVERAGE FOR WEDNESDAY AND THURSDAY. A
COOLER AIRMASS BEGINS MOVING INTO THE AREA BY FRIDAY MORNING...HIGHS
WILL RANGE BETWEEN 10 AND 15 DEGREES BELOW AVERAGE THROUGH THE REST
OF THE PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 638 PM CDT MON AUG 18 2014
FOR THE MOST PART...EXPECT VFR CONDITIONS AT ALL TAF SITES THROUGH
THE 00 UTC TAF PERIOD. COULD SEE SOME PATCHY FOG EARLY TUESDAY
MORNING GIVEN THE LIGHT WINDS AND CLEAR SKIES...AND THE RECENT
RAINS. HOWEVER...NOT CONFIDENT ENOUGH TO MENTION AT AERODROMES
EXCEPT FOR A VCFG FROM 09-13 UTC AT KJMS WHERE DEWPOINT
DEPRESSIONS ARE EXPECTED TO BE LOWEST. NORTHWEST WINDS WILL
DIMINISH QUICKLY THIS EVENING WITH LIGHT WINDS OVERNIGHT. SURFACE
FLOW WILL SHIFT SOUTHERLY FROM WEST TO EAST ON TUESDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...AYD
LONG TERM...AC
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1259 PM CDT SUN AUG 17 2014
.UPDATE...
ISSUED AT 1256 PM CDT SUN AUG 17 2014
THE NEWEST HIGH RESOLUTION MODELING...NAMELY THE 12 UTC WRF-ARW
AND NMM AND THE 15 AND 16 UTC HRRR INITIATE CONVECTION A BIT
FURTHER EAST THEN THEIR PREVIOUS ITERATIONS AND ADJUSTED POPS
ACCORDINGLY. SEE SPC DAY ONE OUTLOOK FOR OVERALL DETAILS.
UPDATE ISSUED AT 1011 AM CDT SUN AUG 17 2014
NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE. THE 12 UTC NAM
AND 10-11 UTC HRRR ITERATIONS CONTINUE THE TREND OF THE 00 UTC
WRF-ARW AND NMM OF INITIATING POSSIBLY SEVERE CONVECTION ALONG A
SURFACE TROUGH ACROSS WESTERN NORTH DAKOTA JUST EAST OF HIGHWAY 85
AROUND 20 UTC...PROPAGATING EAST INTO THE LATE AFTERNOON AND
EVENING. THE 14 UTC RAP FORECASTS A MESOSCALE ENVIRONMENT
CHARACTERIZED BY DEEP LAYER SHEAR OF 25-30KTS AND ML CAPE OF
1500-2000 J/KG...SUPPORTIVE OF POSSIBLE SUPERCELLS WITH LARGE HAIL
BEING THE PRIMARY THREAT. RATHER WEAK LOW LEVEL SHEAR DOES
DIMINISH THE TORNADIC THREAT. WILL HAVE TO CLOSELY MONITOR
RAINFALL...ESPECIALLY FOR THOSE LOCATIONS HEAVILY IMPACTED ON
SATURDAY.
UPDATE ISSUED AT 625 AM CDT SUN AUG 17 2014
PRECIPITATION OVER FAR SOUTHWESTERN NORTH DAKOTA CONTINUES TO
DISSIPATE AS IT MOVES EAST...WHICH IS REFLECTED WELL IN ONGOING
POPS. SOME PATCHY FOG CONTINUES TO LOITER AROUND THE CWA...AND
WILL CONTINUE THRU THE EARLY MORNING. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 420 AM CDT SUN AUG 17 2014
HYDROLOGY AND THE RISK FOR SEVERE THUNDERSTORMS RULE THE SHORT TERM.
ADVISORIES FOR FLOODING HAVE ALL BEEN ALLOWED TO EXPIRE BASED ON
REPORTS FROM LAW ENFORCEMENT AND THE LACK OF RAIN OVER THE PAST
EIGHT HOURS OR SO IN THOSE ADVISORY AREAS.
HYDROLOGIC OUTLOOKS HAVE BEEN ISSUED FOR THE APPLE CREEK IN
BURLEIGH COUNTY...AND THE KNIFE RIVER BASIN...MAINLY THROUGH
MERCER COUNTY. APPLE CREEK WAS PERFORMING WELL BELOW EXPECTATIONS
WHILE THE KNIFE LOOKS LIKE IT WILL APPROACH MINOR FLOOD STAGE BUT
MAY NOT MAKE IT TO THAT DEFINED FLOOD LEVEL.
WILL BE REMOVING A FEW WESTERN COUNTIES FROM THE FLOOD WARNING IN
THE CENTRAL PART OF WESTERN NORTH DAKOTA...AND LIKELY EXTENDING
IN TIME THROUGH SUNDAY THE EASTERN PART OF THAT WARNING.
HIGH RESOLUTION MODELS DEVELOP THUNDERSTORMS IN EASTERN MONTANA
AND BRING THEM THROUGH WESTERN AND CENTRAL NORTH DAKOTA THIS
AFTERNOON IN RESPONSE TO A MID LEVEL SHORT WAVE APPROACHING...AND
THE CUT OFF MID LEVEL COOL POOL OVER SOUTHERN SASKATCHEWAN
INCREASING DEEP LAYER SHEAR. INSTABILITY AND CAPE BECOME
SUPPORTIVE OF SEVERE WEATHER ESPECIALLY BETWEEN 2 PM CDT AND 7 PM
CDT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 420 AM CDT SUN AUG 17 2014
LOW/TROF CONTINUES ITS EASTWARD PROGRESSION INTO MONDAY WITH PRECIP
CONTINUING TO TAPER FROM WEST TO EAST IN THE MORNING. IN THE
AFTERNOON...SOME RE-DEVELOPMENT MAY OCCUR AS THE AREA REMAINS UNDER
CYCLONIC FLOW...THOUGH MOST LOCATIONS SHOULD DRY OUT BY EVENING. A SHORT
LIVED DRY PERIOD IS EXPECTED THROUGH THE DAY ON TUESDAY AS A FAST
MOVING SHORT WAVE RIDGE MOVES THROUGH THE AREA. UPPER FLOW STARTS TO
SHIFT SOUTHWESTERLY TUESDAY EVENING AS RIDGE PUSHES EAST AND TROF
OVER THE WESTERN CONUS DEEPENS. CHANCES FOR PRECIPITATION THEN
STEADILY INCREASE THROUGH MID-WEEK AS A VARIETY OF WAVES MOVE
THROUGH THE FLOW...WITH THE GREATEST CHANCES COMING LATE WEDNESDAY
AS A SFC LOW/BOUNDARY SHIFTS THROUGH THE AREA. MODELS THEN HAVING
TROUBLE WITH THE TIMING OF INDIVIDUAL SYSTEMS FOR THE END OF THE
WEEK...BUT GENERAL CONSENSUS IS AN ACTIVE PATTERN SO WILL KEEP POPS
IN THE FORECAST. NEAR AVERAGE TEMPS EXPECTED THROUGH MID-WEEK WITH
MODELS ADVERTISING A COOLING TREND FOR THE END OF THE WEEK/WEEKEND.
WILL HAVE TO KEEP AN EYE ON THIS TO SEE HOW SIGNIFICANT OF A COOL
DOWN THIS WILL BE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1256 PM CDT SUN AUG 17 2014
A LINE OF POSSIBLY
SEVERE THUNDERSTORMS IS FORECAST TO DEVELOP ACROSS WESTERN NORTH
DAKOTA AROUND 20 UTC...AND MOVE EAST THROUGH THE EVENING. SEE TAFS
FOR EXPECTED TIMING AND IMPACTS TO EACH TERMINAL.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...JPM
LONG TERM...JJS
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1225 PM CDT SUN AUG 17 2014
.UPDATE...
ISSUED AT 1225 PM CDT SUN AUG 17 2014
MADE SOME ADDITIONAL ADJUSTMENTS TO POPS...AS MOST OF THE CURRENT
PRECIP HAS MOVED EAST OF THE CWA EXCEPT FOR SMALL AREAS IN THE
NORTHERN RED RIVER VALLEY AND THE FAR SOUTH. WILL KEEP THE
DOWNWARD TREND FOR THE REST OF THE DAY FOR THE PRECIP IN THE
EAST...BUT RAMP UP POPS IN THE WEST THIS AFTERNOON AS THE SFC
TROUGH AXIS MOVES INTO THE REGION.
UPDATE ISSUED AT 1006 AM CDT SUN AUG 17 2014
SHOWERS CONTINUE TO DEVELOP OVER THE RED RIVER VALLEY AS THE WEAK
UPPER LOW CONTINUES ON ONLY SLOWLY PULL EASTWARD. THESE SHOWERS
SHOULD CONTINUE INTO OUR MN COUNTIES FOR THE REST OF THE MORNING
AND SHOULD BE OUT OF THE CWA BY LATER IN THE AFTERNOON. THE MAIN
UPPER TROUGH CONTINUES TO MOVE SLOWLY THROUGH THE NORTHERN
ROCKIES...AND MODELS CONTINUE TO BE PRETTY BULLISH ON BREAKING OUT
PRECIP AS THE TROUGH COMES THROUGH. THERE HAS BEEN A FASTER
TREND...WITH THE RAP BRINGING THE PRECIP INTO THE RED RIVER VALLEY
BY THIS EVENING AND LEAVING THE WESTERN COUNTIES DRY. THE WRF AND
NAM ARE NOT QUITE AS FAST...AND GIVEN THE FAIRLY SLOW PROGRESSION
OF THE TROUGH AND THE FACT THAT CONVECTION HAS NOT DEVELOPED
YET...WILL LEAN TOWARDS THE NAM. SPED UP POPS A BIT THROUGH THIS
AFTERNOON AND TONIGHT...BUT CONTINUED THE TREND OF KEEPING US
FAIRLY WET THROUGH THE NIGHT.
UPDATE ISSUED AT 710 AM CDT SUN AUG 17 2014
WATER VAPOR SHOWS THE 500 MB LOW/VORT HAS INCHED EAST AND WAS IN
THE WHEATON MN AREA. GOT CLUSTERS OF SHOWERS AND A FEW STORMS
NORTH AND EAST-SOUTHEAST OF SYSTEM OVER WEST CENTRAL-CENTRAL MN
THEN BACK INTO SOUTHEASTERN ND. EXPECT ONLY SLOW MOVEMENT OF
ENTIRE SYSTEM EAST TODAY. DID UPDATE WESTERN EDGE OF POPS TO
INCREASE A BIT IN FARGO-LISBON AREA. ISOLATED SHOWERS IN THE NRN
RRV. OTHERWISE 06Z MODEL RUNS SHOW MAIN ACTION MID AFTN IN WRN-
CNTRL ND AS A BROKEN LINE OF STORMS FORMS ESTEVAN SK TO WEST OF
BISMARCK AND STARTS TO MOVE EAST.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 350 AM CDT SUN AUG 17 2014
UPPER LEVEL LOW/VORT SEEN VERY SLOWLY DRIFTING EAST-NORTHEAST
ALONG THE SD/ND BORDER NORTHEAST OF ABERDEEN EARLY THIS MORNING.
CONVECTION WTIH THIS FEATURE WANED A BIT SINCE MIDNIGHT AS CLOUD
TOPS WARMED WITH SOME NEW CONVECTION FIRING A BIT SOUTH BUT RADAR
HAS SHOWN SOME NEW CONVECTION LAST 30 MIN IN FORMAN ND AREA.
OVERALL EXPECT THIS SYSTEM TO SLOWLY MOVE EAST-NORTHEAST TODAY
WITH MAIN POPS HOLDING IN REGION FROM BEMIDJI-ADA-FARGO-LISBON
AREA SOUTHWARD. DID HOWEVER SPREAD SOME LOWER POPS NORTH AS A FEW
VERY LIGHT SHOWERS HAVE BEEN ON RADAR DRIFTING EAST BTWN GFK-DVL
UP TOWARD WEST OF LANGDON. SHORT RANGE MODELS NOT DOING TOO WELL
WITH PRECIP CURRENTLY THRU TODAY. MOST DRIFT MAIN RAIN A BIT TOO
FAR NORTH TODAY I BELIEVE. PWATS ARE HIGHEST EARLY ON TODAY BUT DO
SLOWLY DECREASE A LITTLE AS DAY PROGRESSES AND SYSTEM SLOWLY MOVES
EAST. OUTSIDE OF THIS SYSTEM LOOKS QUIET OVER WRN FCST BALANCE OF
TODAY. NEXT SHORT WAVE TROUGH ENTERING WRN ND THIS AFTN AND TSTMS
WILL FORM AND SPC HAS A SLIGHT RISK OF SVR WEST OF FCST AREA WITH
MU CAPES IN THE 2-3K J/KG RANGE. SHORT WAVE TROUGH DOES MOVE EAST
AND INTO THE RRV TOWARD 12Z MON AND THEN EAST THRU NW MINNESOTA
MONDAY. KEPT IDEA OF LIKELY POPS SPREADING INTO ERN ND MOSTLY MID
EVENIGN SPREADING INTO MN FCST AREA MONDAY. HPC QPF VALUES HAVE
DROPPED WITH HPC FCSTS OF A GENERAL HALF INCH TO THREE QUARTERS OF
AN INCH.
FOR TEMPS...WITH CLOUDS HOLDING IN MOST AREAS TODAY NOT EXPECTING
A HUGE RISE WITH MOSTLY 70S THOUGH IF ENOUGH SUN AROUND 80 PSBL IN
THE WEST. 70S AGAIN MONDAY WITH CLOUDS. WITH CLOUDS HOLDING...FOG
LOOKS A BIT LESS CERTAIN AND THUS SCALED BACK A BIT. NARROW
CLEARING ZONE MORE IN ERN WFO BIS FCST AREA.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 350 AM CDT SUN AUG 17 2014
500 MB TROUGH WILL EXIT ERN MN MONDAY NIGHT WITH SHOWER THREAT
ENDING. THEN HIGH PRESSURE BUILDS IN TUESDAY. TEMPS HOLDING NR
NORMAL.
WEDNESDAY-SATURDAY...DURING THIS TIME PERIOD THE SYNOPTIC FLOW
PATTERN WILL BE IN TRANSITION TO A WESTERN US TROUGH AND DOWNSTREAM
RIDGE...ALTHOUGH VARIOUS MODEL RUNS HAVE SHOWN DIFFERENCES IN THE
ORIENTATION OF THIS PATTERN. EITHER WAY...INITIALLY QUIET WEATHER IS
EXPECTED TO TREND MORE UNSETTLED LATER IN THE WEEK AS THE UPPER FLOW
BECOMES MORE WESTERLY OR SOUTHWESTERLY OVER THE AREA. THERE IS STILL
RATHER LOW CONFIDENCE ON THE TIMING OF INDIVIDUAL DISTURBANCES...AND
THUS WHEN RAIN CHANCES WILL BE GREATEST. TEMPS WILL CONTINUE TO RUN
WITHIN SEVERAL DEGREES OF AVERAGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1225 PM CDT SUN AUG 17 2014
MVFR/IFR CIGS WILL ADVECT EASTWARD THROUGH THE AFTERNOON HOURS...AND
THERE SHOULD BE A PERIOD OF MOSTLY CLEAR SKY THIS EVENING. USED THE
LATEST HRRR/RAP FOR TIMING GUIDANCE. THE NEXT CONCERN WILL BE
THUNDERSTORM CHANCES MOVING THROUGH THE REGION LATER THIS EVENING
AND OVERNIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...RIDDLE
LONG TERM...MAKOWSKI/RIDDLE
AVIATION...TG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1013 AM CDT SUN AUG 17 2014
.UPDATE...
ISSUED AT 1011 AM CDT SUN AUG 17 2014
NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE. THE 12 UTC NAM
AND 10-11 UTC HRRR ITERATIONS CONTINUE THE TREND OF THE 00 UTC
WRF-ARW AND NMM OF INITIATING POSSIBLY SEVERE CONVECTION ALONG A
SURFACE TROUGH ACROSS WESTERN NORTH DAKOTA JUST EAST OF HIGHWAY 85
AROUND 20 UTC...PROPAGATING EAST INTO THE LATE AFTERNOON AND
EVENING. THE 14 UTC RAP FORECASTS A MESOSCALE ENVIRONMENT
CHARACTERIZED BY DEEP LAYER SHEAR OF 25-30KTS AND ML CAPE OF
1500-2000 J/KG...SUPPORTIVE OF POSSIBLE SUPERCELLS WITH LARGE HAIL
BEING THE PRIMARY THREAT. RATHER WEAK LOW LEVEL SHEAR DOES
DIMINISH THE TORNADIC THREAT. WILL HAVE TO CLOSELY MONITOR
RAINFALL...ESPECIALLY FOR THOSE LOCATIONS HEAVILY IMPACTED ON
SATURDAY.
UPDATE ISSUED AT 625 AM CDT SUN AUG 17 2014
PRECIPITATION OVER FAR SOUTHWESTERN NORTH DAKOTA CONTINUES TO
DISSIPATE AS IT MOVES EAST...WHICH IS REFLECTED WELL IN ONGOING
POPS. SOME PATCHY FOG CONTINUES TO LOITER AROUND THE CWA...AND
WILL CONTINUE THRU THE EARLY MORNING. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 420 AM CDT SUN AUG 17 2014
HYDROLOGY AND THE RISK FOR SEVERE THUNDERSTORMS RULE THE SHORT TERM.
ADVISORIES FOR FLOODING HAVE ALL BEEN ALLOWED TO EXPIRE BASED ON
REPORTS FROM LAW ENFORCEMENT AND THE LACK OF RAIN OVER THE PAST
EIGHT HOURS OR SO IN THOSE ADVISORY AREAS.
HYDROLOGIC OUTLOOKS HAVE BEEN ISSUED FOR THE APPLE CREEK IN
BURLEIGH COUNTY...AND THE KNIFE RIVER BASIN...MAINLY THROUGH
MERCER COUNTY. APPLE CREEK WAS PERFORMING WELL BELOW EXPECTATIONS
WHILE THE KNIFE LOOKS LIKE IT WILL APPROACH MINOR FLOOD STAGE BUT
MAY NOT MAKE IT TO THAT DEFINED FLOOD LEVEL.
WILL BE REMOVING A FEW WESTERN COUNTIES FROM THE FLOOD WARNING IN
THE CENTRAL PART OF WESTERN NORTH DAKOTA...AND LIKELY EXTENDING
IN TIME THROUGH SUNDAY THE EASTERN PART OF THAT WARNING.
HIGH RESOLUTION MODELS DEVELOP THUNDERSTORMS IN EASTERN MONTANA
AND BRING THEM THROUGH WESTERN AND CENTRAL NORTH DAKOTA THIS
AFTERNOON IN RESPONSE TO A MID LEVEL SHORT WAVE APPROACHING...AND
THE CUT OFF MID LEVEL COOL POOL OVER SOUTHERN SASKATCHEWAN
INCREASING DEEP LAYER SHEAR. INSTABILITY AND CAPE BECOME
SUPPORTIVE OF SEVERE WEATHER ESPECIALLY BETWEEN 2 PM CDT AND 7 PM
CDT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 420 AM CDT SUN AUG 17 2014
LOW/TROF CONTINUES ITS EASTWARD PROGRESSION INTO MONDAY WITH PRECIP
CONTINUING TO TAPER FROM WEST TO EAST IN THE MORNING. IN THE
AFTERNOON...SOME RE-DEVELOPMENT MAY OCCUR AS THE AREA REMAINS UNDER
CYCLONIC FLOW...THOUGH MOST LOCATIONS SHOULD DRY OUT BY EVENING. A SHORT
LIVED DRY PERIOD IS EXPECTED THROUGH THE DAY ON TUESDAY AS A FAST
MOVING SHORT WAVE RIDGE MOVES THROUGH THE AREA. UPPER FLOW STARTS TO
SHIFT SOUTHWESTERLY TUESDAY EVENING AS RIDGE PUSHES EAST AND TROF
OVER THE WESTERN CONUS DEEPENS. CHANCES FOR PRECIPITATION THEN
STEADILY INCREASE THROUGH MID-WEEK AS A VARIETY OF WAVES MOVE
THROUGH THE FLOW...WITH THE GREATEST CHANCES COMING LATE WEDNESDAY
AS A SFC LOW/BOUNDARY SHIFTS THROUGH THE AREA. MODELS THEN HAVING
TROUBLE WITH THE TIMING OF INDIVIDUAL SYSTEMS FOR THE END OF THE
WEEK...BUT GENERAL CONSENSUS IS AN ACTIVE PATTERN SO WILL KEEP POPS
IN THE FORECAST. NEAR AVERAGE TEMPS EXPECTED THROUGH MID-WEEK WITH
MODELS ADVERTISING A COOLING TREND FOR THE END OF THE WEEK/WEEKEND.
WILL HAVE TO KEEP AN EYE ON THIS TO SEE HOW SIGNIFICANT OF A COOL
DOWN THIS WILL BE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 1012 AM CDT SUN AUG 17 2014
MORNING FOG AND STRATUS WILL CONTINUE TO BURN OFF AND LIFT ACROSS
WESTERN AND CENTRAL NORTH DAKOTA. THEREAFTER...A LINE OF POSSIBLY
SEVERE THUNDERSTORMS IS FORECAST TO DEVELOP ACROSS WESTERN NORTH
DAKOTA AROUND 20 UTC...AND MOVE EAST THROUGH THE EVENING. SEE TAFS
FOR EXPECTED TIMING AND IMPACTS TO EACH TERMINAL.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...JPM
LONG TERM...JJS
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1006 AM CDT SUN AUG 17 2014
.UPDATE...
ISSUED AT 1006 AM CDT SUN AUG 17 2014
SHOWERS CONTINUE TO DEVELOP OVER THE RED RIVER VALLEY AS THE WEAK
UPPER LOW CONTINUES ON ONLY SLOWLY PULL EASTWARD. THESE SHOWERS
SHOULD CONTINUE INTO OUR MN COUNTIES FOR THE REST OF THE MORNING
AND SHOULD BE OUT OF THE CWA BY LATER IN THE AFTERNOON. THE MAIN
UPPER TROUGH CONTINUES TO MOVE SLOWLY THROUGH THE NORTHERN
ROCKIES...AND MODELS CONTINUE TO BE PRETTY BULLISH ON BREAKING OUT
PRECIP AS THE TROUGH COMES THROUGH. THERE HAS BEEN A FASTER
TREND...WITH THE RAP BRINGING THE PRECIP INTO THE RED RIVER VALLEY
BY THIS EVENING AND LEAVING THE WESTERN COUNTIES DRY. THE WRF AND
NAM ARE NOT QUITE AS FAST...AND GIVEN THE FAIRLY SLOW PROGRESSION
OF THE TROUGH AND THE FACT THAT CONVECTION HAS NOT DEVELOPED
YET...WILL LEAN TOWARDS THE NAM. SPED UP POPS A BIT THROUGH THIS
AFTERNOON AND TONIGHT...BUT CONTINUED THE TREND OF KEEPING US
FAIRLY WET THROUGH THE NIGHT.
UPDATE ISSUED AT 710 AM CDT SUN AUG 17 2014
WATER VAPOR SHOWS THE 500 MB LOW/VORT HAS INCHED EAST AND WAS IN
THE WHEATON MN AREA. GOT CLUSTERS OF SHOWERS AND A FEW STORMS
NORTH AND EAST-SOUTHEAST OF SYSTEM OVER WEST CENTRAL-CENTRAL MN
THEN BACK INTO SOUTHEASTERN ND. EXPECT ONLY SLOW MOVEMENT OF
ENTIRE SYSTEM EAST TODAY. DID UPDATE WESTERN EDGE OF POPS TO
INCREASE A BIT IN FARGO-LISBON AREA. ISOLATED SHOWERS IN THE NRN
RRV. OTHERWISE 06Z MODEL RUNS SHOW MAIN ACTION MID AFTN IN WRN-
CNTRL ND AS A BROKEN LINE OF STORMS FORMS ESTEVAN SK TO WEST OF
BISMARCK AND STARTS TO MOVE EAST.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 350 AM CDT SUN AUG 17 2014
UPPER LEVEL LOW/VORT SEEN VERY SLOWLY DRIFTING EAST-NORTHEAST
ALONG THE SD/ND BORDER NORTHEAST OF ABERDEEN EARLY THIS MORNING.
CONVECTION WTIH THIS FEATURE WANED A BIT SINCE MIDNIGHT AS CLOUD
TOPS WARMED WITH SOME NEW CONVECTION FIRING A BIT SOUTH BUT RADAR
HAS SHOWN SOME NEW CONVECTION LAST 30 MIN IN FORMAN ND AREA.
OVERALL EXPECT THIS SYSTEM TO SLOWLY MOVE EAST-NORTHEAST TODAY
WITH MAIN POPS HOLDING IN REGION FROM BEMIDJI-ADA-FARGO-LISBON
AREA SOUTHWARD. DID HOWEVER SPREAD SOME LOWER POPS NORTH AS A FEW
VERY LIGHT SHOWERS HAVE BEEN ON RADAR DRIFTING EAST BTWN GFK-DVL
UP TOWARD WEST OF LANGDON. SHORT RANGE MODELS NOT DOING TOO WELL
WITH PRECIP CURRENTLY THRU TODAY. MOST DRIFT MAIN RAIN A BIT TOO
FAR NORTH TODAY I BELIEVE. PWATS ARE HIGHEST EARLY ON TODAY BUT DO
SLOWLY DECREASE A LITTLE AS DAY PROGRESSES AND SYSTEM SLOWLY MOVES
EAST. OUTSIDE OF THIS SYSTEM LOOKS QUIET OVER WRN FCST BALANCE OF
TODAY. NEXT SHORT WAVE TROUGH ENTERING WRN ND THIS AFTN AND TSTMS
WILL FORM AND SPC HAS A SLIGHT RISK OF SVR WEST OF FCST AREA WITH
MU CAPES IN THE 2-3K J/KG RANGE. SHORT WAVE TROUGH DOES MOVE EAST
AND INTO THE RRV TOWARD 12Z MON AND THEN EAST THRU NW MINNESOTA
MONDAY. KEPT IDEA OF LIKELY POPS SPREADING INTO ERN ND MOSTLY MID
EVENIGN SPREADING INTO MN FCST AREA MONDAY. HPC QPF VALUES HAVE
DROPPED WITH HPC FCSTS OF A GENERAL HALF INCH TO THREE QUARTERS OF
AN INCH.
FOR TEMPS...WITH CLOUDS HOLDING IN MOST AREAS TODAY NOT EXPECTING
A HUGE RISE WITH MOSTLY 70S THOUGH IF ENOUGH SUN AROUND 80 PSBL IN
THE WEST. 70S AGAIN MONDAY WITH CLOUDS. WITH CLOUDS HOLDING...FOG
LOOKS A BIT LESS CERTAIN AND THUS SCALED BACK A BIT. NARROW
CLEARING ZONE MORE IN ERN WFO BIS FCST AREA.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 350 AM CDT SUN AUG 17 2014
500 MB TROUGH WILL EXIT ERN MN MONDAY NIGHT WITH SHOWER THREAT
ENDING. THEN HIGH PRESSURE BUILDS IN TUESDAY. TEMPS HOLDING NR
NORMAL.
WEDNESDAY-SATURDAY...DURING THIS TIME PERIOD THE SYNOPTIC FLOW
PATTERN WILL BE IN TRANSITION TO A WESTERN US TROUGH AND DOWNSTREAM
RIDGE...ALTHOUGH VARIOUS MODEL RUNS HAVE SHOWN DIFFERENCES IN THE
ORIENTATION OF THIS PATTERN. EITHER WAY...INITIALLY QUIET WEATHER IS
EXPECTED TO TREND MORE UNSETTLED LATER IN THE WEEK AS THE UPPER FLOW
BECOMES MORE WESTERLY OR SOUTHWESTERLY OVER THE AREA. THERE IS STILL
RATHER LOW CONFIDENCE ON THE TIMING OF INDIVIDUAL DISTURBANCES...AND
THUS WHEN RAIN CHANCES WILL BE GREATEST. TEMPS WILL CONTINUE TO RUN
WITHIN SEVERAL DEGREES OF AVERAGE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 710 AM CDT SUN AUG 17 2014
TRUE TO FORM RIGHT BEFORE 12Z CIGS CRASHED IN MANY SPOTS TO LOW
END MVFR LEVELS AT FAR-BJI-GFK AREA. A BIT HIGHER CIGS DVL-TVF.
OVERALL EXPECT MVFR CIGS PREDOMINATE THIS MORNING...TRYING TO LIFT
INTO A LOW END VFR CIG THIS AFTN. SHOWERS AND A FEW STORMS THIS
MORNING FAR-BJI REGION. TIMING OF NEXT WAVE OF STORMS TONIGHT IS
A CHALLENGE...BUT MOST MODELS INDICATE BY 01Z DVL AND BY 05Z GFK-
FAR AND A BIT LATER TOWARD BJI. COVERAGE AND INTENSITY OF RAINFALL
AND CIGS HIGHLY QUESTIONABLE AT THIS TIME. A LIGHT SOUTHEAST WIND
IN GENERAL TODAY/TONIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...RIDDLE
LONG TERM...MAKOWSKI/RIDDLE
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
912 PM EDT MON AUG 18 2014
.SYNOPSIS...
LOW PRESSURE OVER SOUTHERN OHIO WILL MOVE EAST TO THE VIRGINIA
COAST BY TUESDAY MORNING. A STATIONARY FRONT ACROSS CENTRAL OHIO
WILL BE DRAWN SOUTH IN THE WAKE OF THE LOW. ANOTHER LOW WILL MOVE
INTO THE WESTERN GREAT LAKES OVERNIGHT AND EXPAND ACROSS THE
CENTRAL LAKES TUESDAY BRINGING THE FRONT BACK NORTH INTO THE AREA
AS A WARM FRONT. THE LOW WILL REMAIN IN THE AREA THROUGH MID WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
OVERNIGHT WE ARE EXPECTING DRY CONDITIONS. NOT SURE WHY HRRR KEEPS
ON AND OFF LIGHT SHRA/SPRINKLES OVER THE EAST THRUT THE NIGHT. THIS
AREA IS WHERE THE MODELS HAVE THE DRIEST AIR SO IT DOES NOT SEEM TO
MAKE SENSE...UNLESS ITS TRYING TO INDICATE MID LEVEL ATTEMPTS AT
PRECIP/VIRGA.
MORE CLOUDS ON THE WAY FROM THE WEST OVERNIGHT ASSOCIATED WITH THE
LOW MOVING INTO THE WESTERN LAKES. EXPECTING THOSE AFTER MIDNIGHT IN
THE WEST ALONG WITH A SLIGHT CHANCE OF SHOWERS OR A THUNDERSTORM
TOWARD DAYBREAK. LOWS SHOULD BE IN THE LOWER 60S WITH A FEW UPPER
50S EAST.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
THE SOUTHERN OHIO LOW WILL HAVE REACHED THE VIRGINIA COAST BY
MORNING WITH THE NEXT LOW MOVING INTO/ THROUGH THE WESTERN LAKES.
THIS LOW WILL DOMINATE THE SHORT TERM PERIOD AS IT ROTATES THROUGH
THE GREAT LAKES REGION THROUGH MID WEEK. ALSO THE FRONT TO OUR
SOUTH WILL BEGIN MOVING NORTHEAST AS A WARM FRONT AS THE LOW
APPROACHES AND BY MORNING IT SHOULD EXTEND FROM NEAR CHICAGO TO
CINCINNATI. FOLLOWED THE SREF FOR PRECIP TIMING TUESDAY WHICH
BRINGS CHANCE POPS INTO THE WEST DURING THE MORNING...INCREASING
TO LIKELY BY MID DAY AS THE REST OF THE AREA INCREASES TO CHANCE
POPS. BY EARLY EVENING SPREAD THE LIKELY POPS FURTHER EAST ACROSS
THE CENTRAL COUNTIES...EVENTUALLY EXPANDING ACROSS THE REMAINDER
OF THE EAST LATE EVENING TO OVERNIGHT. WEDNESDAY MORNING THE UPPER
LOW WILL REMAIN STUCK OVER NRN MI WITH CONTINUED DIVERGENCE ACROSS
NRN OHIO/NWRN PA. AXIS OF DEEPEST MOISTURE WILL BE NEGATIVELY
TILTED FROM THE WESTERN LAKES TO PA AND NY. WILL KEEP HIGHEST POPS
ACROSS NERN OHIO AND NWRN PA WITH DECREASING CHANCES WEST. THE LOW
WILL WEAKEN AND MOVE TO PA/NY THURSDAY AS AN UPPER RIDGE AXIS
BUILDS INTO THE UPPER MIDWEST. STILL WILL LIKELY SEE SHOWERS AND
THUNDERSTORMS DURING THE DAY GIVEN THE CONTINUED MOISTURE AND
DAYTIME HEATING SO WILL CONTINUE WITH CHANCE POPS. TEMPS NEAR
NORMAL.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
UPPER LEVEL LOW MOVES OFF THE EAST COAST ON FRIDAY WITH THE UPPER
LEVEL RIDGE OVER THE MISSISSIPPI VALLEY SLOWLY EXPANDING EASTWARD
OVER THE WEEKEND. FRIDAY LOOKS LIKE A TRANSITION DAY AND COULD BE
ACTIVE WITH SHOWERS AND THUNDERSTORMS AS ENERGY RIDES AROUND THE
BUILDING RIDGE. BOTH THE ECMWF AND GFS TRY TO BUILD A STRONG RIDGE
OVER THE GREAT LAKES THIS WEEKEND AND EXTENDING NORTHEAST INTO
QUEBEC. THIS SHOULD LEAD TO DECREASING CHANCES OF SHOWERS AND
THUNDERSTORMS BOTH SATURDAY AND SUNDAY AS MID LEVELS WARM AND WARM
FRONT SHIFTS NORTH OF THE AREA. MODELS DO INDICATE SOME LINGERING
MOISTURE AND SOMEWHAT OF A BOUNDARY IN PLACE THOUGH SO WILL HOLD
ONTO LOW CHANCES OF SHOWERS AND THUNDERSTORMS IN ALL BUT THE EAST
WHERE A DRIER EASTERLY FLOW ON THE PERIPHERY OF HIGH PRESSURE TO THE
EAST SHOULD LIKELY MAINTAIN DRY CONDITIONS. STILL EXPECT A WARMING
TREND OVER THE WEEKEND BUT HAVE BACKED OFF A FEW DEGREES FOR NOW
WITH UNCERTAINTY IN CLOUD COVER.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
THE EVENING HOURS WILL BE QUIET WITH JUST SOME MID LEVEL CLOUDS.
STILL EXPECTING MVFR FOG TO DEVELOP AFTER MIDNIGHT WITH IFR
CONDITIONS DEVELOPING AT THE INLAND TAF SITES. CIGS WILL GRADUALLY
LOWER ON TUESDAY AS A WARM FRONT LIFTS ACROSS THE REGION. THE NEW
GUIDANCE COMING IN IS SLOWER BRINGING PRECIP IN. BEST GUESS RIGHT NOW
IS THAT IT WILL BE LATE AFTERNOON BEFORE SCATTERED STORMS BEGIN TO
DEVELOP ACROSS THE AREA. GREATEST COVERAGE SHOULD BE OVER NW
OHIO...AT LEAST INITIALLY. THE FLOW WILL BECOME LIGHT AND VARIABLE
AFTER DARK AND THEN SOUTHERLY ON TUESDAY AS THE FRONT LIFTS.
OUTLOOK...NON VFR POSSIBLE IN SHOWERS/THUNDERSTORMS TUESDAY NIGHT
THROUGH FRIDAY.
&&
.MARINE...
LAKE ERIE IS LOCATED BETWEEN HIGH PRESSURE TO THE NORTH AND A WEAK
AREA OF LOW PRESSURE OVER THE OHIO VALLEY. NORTHEAST TO EAST WINDS
HAVE INCREASED TO AROUND 15 KNOTS OR SO ALONG MUCH OF THE SOUTH
SHORE OF THE LAKE...WITH WAVES OF 1 TO 3 FEET. THE HIGH WILL BUILD
TO THE EAST OVERNIGHT AND WINDS WILL DECREASE AS THE GRADIENT
RELAXES...SHIFTING TO EASTERLY AND THEN SOUTHEAST LATE.
AN AREA OF LOW PRESSURE WILL MOVE INTO THE WESTERN GREAT LAKES ON
TUESDAY THEN MOVE ACROSS LAKE ERIE ON WEDNESDAY BRINGING UNSETTLED
WEATHER. WINDS WILL GENERALLY REMAIN 15 KNOTS OR LESS AS THEY SHIFT
AROUND TO THE WEST BEHIND THIS SYSTEM. HIGH PRESSURE WILL RETURN ON
THURSDAY FOLLOWED BY A SLOW MOVING WARM FRONT THAT WILL LIFT NORTH
ACROSS THE LAKE OVER THE WEEKEND.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK/ADAMS
SHORT TERM...TK
LONG TERM...KEC
AVIATION...KUBINA
MARINE...KEC
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
414 PM EDT SUN AUG 17 2014
.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM OVER SOUTHERN INDIANA WILL BEGIN TO
ACCELERATE A LITTLE AS IT CONTINUES TO WEAKEN FURTHER WHILE MOVING
ALONG AND JUST SOUTH OF THE OHIO RIVER. SHOWERS AND THUNDERSTORMS
WILL GENERALLY STAY FOCUSED SOUTH OF THE OHIO RIVER TONIGHT AND
MONDAY NEAR THE PATH OF THE LOW...THOUGH SCATTERED SHOWERS AND
STORMS WILL BE POSSIBLE OVER CENTRAL AND SOUTHERN OHIO AND INDIANA
AS WELL IN THE VERY HUMID AND MODERATELY UNSTABLE AIRMASS. A BRIEF
PERIOD DRY WEATHER IS EXPECTED MONDAY NIGHT INTO EARLY TUESDAY
BEFORE THE NEXT WEAK COLD FRONT APPROACHES THE REGION WITH A
THREAT FOR SHOWERS AND THUNDERSTORMS. THIS FRONT WILL WASH OUT AND
STALL OVER THE AREA...WITH A WARM AND VERY HUMID AIRMASS TAKING
HOLD FOR THE LAST HALF OF THE WEEK INTO EARLY NEXT WEEKEND...WITH
HIGHS WELL INTO THE 80S AND MILD NIGHTS IN THE 60S AND LOWER 70S.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
THIS AFTERNOON OBJECTIVE RAP ANALYSIS AND OBSERVATIONAL DATA SETS
/SATELLITE AND RADAR LOOPS/ CONFIRM THE WEAKENING MID LEVEL CLOSED
LOW NEARLY STATIONARY OVER SOUTHWESTERN INDIANA. A WEAK COLD FRONT
HAD ALSO STALLED ACROSS NORTHERN OHIO. RADAR TRENDS OVER THE LAST
FEW HOURS SHOW THAT THE BULK OF STRONG FORCING/DEEPER MOISTURE
RESIDED ON THE SRN/SERN FLANK OF THE UPPER LOW...WITH WIDESPREAD
SHOWERS AND THUNDERSTORMS OVER KY/TN. THE NERN FLANK OF A SHIELD
OF LGT/MOD SHOWERS/RAIN HAS STUBBORNLY BEEN ERODED AS IT MAKES
INROADS INTO THE WFO ILN FORECAST AREA. SCT SHRA/TSRA WERE SLOWLY
DEVELOPING ALONG THE STALLED FRONT OVER NORTHERN OHIO.
MESOANALYSIS LATE THIS AFTERNOON INDICATED A PLUME OF HIGH PWAT
REMAINED ATTENDANT TO THE UPPER LOW...WITH PWAT ABOUT 160% OF
NORMAL OVER SRN IND/NRN KY NEAR AND JUST EAST OF THE CENTER OF
CIRCULATION. A LARGE RESERVOIR OF MID 60S TO MID 70S SURFACE
DEWPOINTS EXISTED NEAR THE CIRCULATION AND ESPECIALLY TO THE
SOUTH/WEST. INSTBY WAS RATHER MEAGER OWING TO MOIST LAPSE RATES
AND AMPLE/WIDESPREAD CLOUDS OVER MUCH OF THE AREA...KEEPING
TEMPERATURES IN THE 70S FOR THE MOST PART. ALSO OF IMPORTANCE TO
THE SHORT TERM FORECAST IS A STRONG SHORTWAVE TROUGH ACROSS SASK
MOVING EAST.
TONIGHT...THERE IS STRONG AGREEMENT AMONG 17.12Z DATA THAT THE
WEAKENING CLOSED LOW WILL CONTINUE TO SLOWLY WEAKEN AND BECOME A
LITTLE MORE PROGRESSIVE AS IT OPENS UP AND SHEARS DOWNSTREAM A
BIT. THIS IS OWING TO THE KICKER ENERGY MOVING QUICKLY ACROSS SASK
ATOP THE SUBTROPICAL SWRN CONUS RIDGING. SPECIFICALLY...THE 700MB
CLOSED LOW WILL PLOD SLOWLY ALONG AND JUST SOUTH OF THE OHIO RIVER
THROUGH NORTHERN KENTUCKY REACHING THE CVG AREA BY SUNRISE MONDAY
MORNING. GIVEN THE BULK OF THE FLOW/FORCING WILL BE ON THE
SOUTH/SOUTHEAST SIDE OF THE CIRCULATION...EXPECT THE MOST
WIDESPREAD/HEAVIEST RAIN JUST SOUTH OF THE LOCAL FORECAST AREA.
HOWEVER...WILL NEED TO WATCH ANY ACTIVITY THAT FORMS ACROSS NRN KY
AS MID LVL STEERING FLOW WILL BE LIGHT NEAR THE PATH OF THE MID
LEVEL SYSTEM AND IF A DEFORMATION TYPE RAIN BAND FORMS ACRS OUR
NRN KY COUNTIES THE PWAT/WARM RAIN PROCESSES COULD LEAD TO NARROW
BAND OF HEAVIER RAIN...BUT RIGHT NOW IT SEEMS THE WEAKENING NATURE
OF THE OPENING WAVE AND THE IDEA IT BECOMES MORE PROGRESSIVE WITH
TIME SHOULD MITIGATE THIS POTENTIAL A GREAT DEGREE. MAINTAINED THE
LIKELY RAIN CHANCES ACROSS OUR FAR SOUTH NEAR THE NOSE OF MODEST
NORTHEAST-ORIENTED LOW LEVEL JET THAT POINTS INTO OUR AREA THIS
EVENING INTO THE FIRST PART OF THE OVERNIGHT...ALTHOUGH RECENT
EXPERIMENTAL /ESRL/ AND PARALLEL /NCEP/ HRRR RUNS ARE NOT VERY
BULLISH ON RAIN COVERAGE ACRS NRN KY TONIGHT. ELSEWHERE...AS THERE
HAS BEEN DURING THE DAY...SCT SHRA ON THE PERIPHERY OF THE UPPER
LOW WILL CON/T TO BE POSSIBLE...WITH ACTIVITY REMAINING LIGHT AND
LIKELY NOT CONTAINING THUNDER.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
THROUGH THE DAY MONDAY THE UPPER LEVEL WAVE REALLY OPENS
UP/SHEARS OUT/WEAKENS AS DEEPER LAYER NWLY FLOW DRIVING THE KICKER
ENERGY TO OUR NW SPREADS ACROSS THE GREAT LAKES. A SURFACE
TROUGH/INVERTED TROUGH HANGS BACK OVER THE FORECAST AREA IN THE
WAKE OF THE WEAKENING SURFACE LOW...AS DOES THE WEAK/WASHING OUT
STATIONARY FRONT OVER NORTHERN OHIO. A VERY MOIST AND UNCAPPED
AIRMASS REMAINS DURING PEAK HEATING WITH WIDESPREAD CUMULUS
EVENTUALLY CONVECTING DURING DAYTIME HEATING WITH THE SUBTLE
SURFACE FORCING MECHANISMS...AND MLCAPE PER 17.12Z FORECAST
SOUNDINGS /GFS AND NAM/ OF 1000-1500 J/KG. FLOW IS WEAK SO JUST
SOME SLOW MOVING HEAVY RAINERS ALL THAT IS EXPECTED DURING THE
AFTERNOON/EARLY EVENING. GIVEN THE AMPLE MOISTURE...AND NOTING
THIS REGION WEST OF THE UPPER LOW FAILED TO WARM MUCH TODAY...AM
KEEPING HIGHS MOSTLY IN THE 70S TO AROUND 80 ON MONDAY...ON THE
COOLER SIDE OF 17.12Z MOS.
ON TUESDAY...THE AFOREMENTIONED SHORTWAVE OVER SASK WILL BE
ARRIVING WITH A COLD FRONT AT PEAK HEATING WILL ACTUALLY ENCOUNTER
A SOMEWHAT FAVORABLE AIRMASS FOR ROBUST CONVECTION. BOUNDARY LAYER
FLOW WILL HAVE TURNED TO THE SOUTHWEST WHILE MID LEVEL WNWLY FLOW
WILL BE INCREASING AS RIDGING BEGINS TO BUILD A MODEST HEIGHT
GRADIENT TO OUR WEST/SOUTH. 17.12Z NAM/GFS FORECAST BUFR SOUNDINGS
FOR ILN/CVG/DAY/CMH ALL EXHIBIT MLCAPE FROM 1500 TO 2000 J/KG WITH
A STEEPER MID LEVEL LAPSE RATE WITH BOUNDARY LAYER DWPTS STILL IN
THE 60S. 0-6KM BULK SHEAR VALUES AROUND 30-35KTS COULD PROMOTE A
LITTLE MORE ORGANIZATION TO THE STORMS COMPARED TO MONDAY.
UPCOMING SHIFTS MAY NEED TO MOVE TO HIGHER RAIN CHANCES IF CURRENT
SIGNALS PERSIST..ESPECIALLY LATER IN THE DAY TUES INTO TUESDAY EVENING.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
UPPER LEVEL RIDGE OVER THE GULF COAST REGION WILL BUILD SLOWLY NORTH
INTO THE MID MISSISSIPPI VALLEY THROUGH THE END OF THE WEEK. THIS
WILL RESULT IN A NORTHWEST FLOW PATTERN ALOFT THROUGH AT LEAST
FRIDAY. BOTH THE 12Z GFS AND 12Z ECMWF CONTINUE TO INDICATE THE
POSSIBILITY OF SEVERAL SHORT WAVES RIDING DOWN THROUGH THE AREA IN
THIS PATTERN. WITH DEWPOINTS PUSHING UP INTO THE UPPER 60S TO LOWER
70S...THERE SHOULD BE SUFFICIENT INSTABILITY TO CREATE THE POTENTIAL
FOR A RATHER ACTIVE PATTERN THROUGH THE END OF THE WEEK. TIMING
REMAINS DIFFICULT THOUGH SO WILL KEEP POPS IN THE CHANCE CATEGORY.
TEMPERATURES ALSO REMAIN SOMEWHAT PROBLEMATIC AS WE WILL REMAIN IN
THE TRANSITION ZONE BETWEEN WARMER TEMPERATURES TO OUR
SOUTHWEST/COOLER TO THE NORTHEAST. WILL CONTINUE WITH FAIRLY
SEASONABLE HIGHS...BUT OVERNIGHT LOWS MAY REMAIN A LITTLE ON THE
WARM SIDE...UPPER 60S TO NEAR 70...GIVEN THE HIGHER DEWPOINTS.
SOME UNCERTAINTY EXIST BETWEEN THE 12Z GFS AND 12Z ECMWF OVER THE
WEEKEND AS THE GFS IS TRYING TO BUILD THE UPPER LEVEL RIDGE MORE
EAST TOWARD OUR AREA...WHILE THE ECMWF BEGINS TO FLATTEN OUT THE
RIDGE AS SHORT WAVE ENERGY MOVES ACROSS THE UPPER GREAT LAKES. HAVE
TRENDED MORE TOWARD THE GFS...DECREASING POPS THROUGH THE WEEKEND
AND ALLOWING FOR A CONTINUED SLOW WARMUP IN TEMPS THROUGH SUNDAY.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
LOW PRESSURE TRAVELING THROUGH KENTUCKY WILL HAVE VARYING EFFECTS
ON TAF SITES. SOUTHERN SITES CVG AND LUK WILL HAVE SHOWERS IN THE
VICINITY THROUGH MUCH OF THE PERIOD AS THE LOW SPINS NEARBY TO THE
SOUTH. CEILINGS BELOW 2000 FT WILL BE POSSIBLE THERE LATE TONIGHT
IN A MOIST BOUNDARY LAYER...AND BR AND HZ WILL REDUCE VISIBILITIES
TONIGHT INTO MONDAY. CONDITIONS COULD IMPROVE MONDAY AFTERNOON AS
THE LOW MOVES EAST.
FARTHER NORTH AT ILN DAY CMH AND LCK...THE SYSTEM IS FORECAST TO
PRODUCE MUCH LESS PRECIPITATION. WENT WITH VCSH THIS AFTERNOON
INTO THIS EVENING...WITH NO PRECIP IN THE FORECAST THEREAFTER.
CEILINGS MAY FALL INTO THE MVFR RANGE AT DAY AND ILN WHILE
REMAINING VFR AT CMH AND LCK. BR WILL BE POSSIBLE AT DAY ILN AND
LCK...WITH THE TYPICALLY WARMER CMH REMAINING FREE FROM SURFACE
OBSCURATION.
WIND DIRECTION WILL VARY WITH RESPECT TO THE POSITION OF THE LOW
AND A WEAK FRONT THAT IS WASHING OUT OVER CENTRAL OHIO. WIND
SPEEDS ARE EXPECTED TO REMAIN BELOW 10 KNOTS.
OUTLOOK...THUNDERSTORMS POSSIBLE TUESDAY THROUGH THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...BINAU
NEAR TERM...BINAU
SHORT TERM...BINAU
LONG TERM...JGL
AVIATION...CONIGLIO
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
125 PM EDT SUN AUG 17 2014
.SYNOPSIS...
A COLD FRONT OVER LAKE ERIE WILL SLOWLY MOVE SOUTH ACROSS THE AREA
TODAY. THE WILL STALL IN CENTRAL OHIO TONIGHT. LOW PRESSURE WILL
MOVE ALONG THE STALLED FRONT ON MONDAY. ANOTHER WEAK LOW PRESSURE
AREA WILL MOVE FORM THE UPPER MIDWEST ACROSS THE AREA LATE TUESDAY
INTO WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED...CLOUD COVER ASSOCIATED WITH THE FRONT ACROSS THE AREA IS
NOT GOING ANYWHERE FAST ALTHOUGH DURING THE AFTERNOON WE SHOULD
LIKELY GET SOME BREAKUP AND SPORADIC THINNING. HRRR CONTINUES TO
SUPPORT NO BIG INCREASE IN PRECIP ACROSS THE AREA THROUGH THE
AFTERNOON SO WILL CONTINUE WITH THE LOW CHANCE POPS CENTRAL AND
SOUTH AND HAVE ALSO TRIMMED NORTHERN EXTENT OF THUNDER. TRIMMED
TEMPS AGAIN ESP NORTHWEST.
ORIGINAL...
THE WEAK COLD FRONT WILL SLIDE ACROSS THE NORTHERN COUNTIES NEAR
LAKE ERIE THIS MORNING. THERE IS STILL SOME QUESTION AS TO HOW FAR
AND HOW FAST THE COLD FRONT WILL MOVE SOUTH TODAY. I SUSPECT IT MAY
NOT MATTER MUCH SINCE THE FRONT IS SHALLOW AND LOW AND MID LEVEL
INSTABILITY MAY LINGER NORTH OF THE FRONT SO SHOWERS MAY CONTINUE TO
DEVELOP. WILL KEEP A CHANCE OF SHOWERS OR A THUNDERSTORMS EVERYWHERE
EXCEPT NORTH OF THE TURNPIKE BY THIS AFTERNOON. SOME CLEARING IS
LIKELY ACROSS NORTHEAST OH AND NORTHWEST PA.
COOLER AIR WILL BEGIN TO SPILL ACROSS LAKE ERIE AND IT MAY NOT MAKE
IT ABOVE THE LOWER 70S ALONG THE LAKESHORE ESPECIALLY AROUND
ASHTABULA AND ERIE. GENERALLY 75 TO 80 ELSEWHERE...LOWER 80S IN THE
FAR SOUTH FROM FINDLAY TO MARION AND MOUNT VERNON WHERE IT WILL ALSO
BE RELATIVELY HUMID WITH DEWPOINTS HOLDING IN THE MID TO UPPER 60S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
THE FRONT SHOULD PUSH SOUTH OF THE AREA TONIGHT. CANNOT RULE OUT A
SHOWER ACROSS THE SOUTHERN COUNTIES SOUTH OF ROUTE 30 OTHERWISE DRY.
WITH LOWERING DEWPOINTS AND THE WIND BECOMING LIGHT...THE COOL SPOTS
OF EXTREME NE OH/NW PA COULD DROP TO THE LOWER 50S OR PERHAPS
UPPER 40S TONIGHT OTHERWISE LOWS MOSTLY IN THE UPPER 50S TO LOWER
60S.
THE SURFACE LOW SHOULD MOVE EAST ALONG THE STALLED FRONT ON MONDAY.
THE MAJORITY OF RAIN SHOULD STAY SOUTH OF THE FORECAST AREA. WITH
THE STALLED FRONT JUST TO OUR SOUTH THOUGH...SOME OVER RUNNING
SHOWERS AND PERHAPS A RUMBLE OF THUNDER IS PROBABLE....AGAIN MAINLY
FROM AROUND THE TURNPIKE SOUTH. HIGHS MOSTLY IN THE MID AND UPPER
70S.
THE NEXT SHORT WAVE AND WEAK COLD FRONT WILL APPROACH ON TUESDAY.
THE SHOWERS MAY SPREAD IN QUICKLY BUT I PREFER THE SLOWER SOLUTIONS
BASED ON THE RELATIVELY SLOW MOVEMENT PROGGED OF THE SHORT WAVE.
THIS SHOULD ALLOW FOR A LITTLE SUNSHINE AND THE CHANCE TO BUBBLE UP
SOME DECENT SHOWERS AND THUNDERSTORMS. HIGHS GENERALLY NEAR 80 OR
THE LOWER 80S WITH DEWPOINTS IN THE MID AND UPPER 60S... ALMOST
LIKE SUMMER TIME.
SHOWERS WILL PROBABLY REDEVELOP ON WEDNESDAY...ESPECIALLY ACROSS NE
OH/NW PA...AS THE SLOW MOVING SHORT WAVE CROSSES THE AREA. HIGHS
SHOULD GET INTO THE 80S EXCEPT WHERE THERE ARE MORE NUMEROUS
SHOWERS.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
THE LONG TERM STARTS
OFF WITH A CLOSED LOW OVER THE LOWER GREAT LAKES. H850 FLOW SHOULD
BRING HIGH PWATS AND MOIST IN WITH THE GFS SHOWING ANOMALOUS PWATS
THU INTO FRI. THE LARGER SCALE MODELS SHOW THE BEST MOISTURE
CORRESPONDS TO WEAK JET DYNAMICS AND MODERATE INSTABILITIES.
THEREFORE HAVE KEPT POPS AROUND 30-40 PRIMARILY DURING PEAK
HEATING...THOUGH ELEVATED CONVECTION POSSIBLE UNTIL THE UPPER LOW
SKIRTS TO OUR EAST AND CUTS OFF THE BEST MOISTURE ON SATURDAY. FOR
NEXT WEEKEND THE ECMWF/GFS DIFFER NOTABLY ON THE BREAK DOWN (OR
NOT) OF THE UPPER LOW OVER THE GREAT LAKES. THE ECMWF MOVES THE
LOW OVER NEW ENGLAND WITH A SFC LOW DEVELOPING OFF THE MID
ATLANTIC. THE GFS HOWEVER SHOWS THE LOW MOVING OFF THE ATLANTIC
COAST RESULTING IN A LESS AMPLIFIED FLOW ALOFT OVER THE GREAT
LAKES. THIS CAUSES UNCERTAINLY LATE IN THE FCST WHERE TEMPERATURES
COULD BE IN THE UPPER 70S OR THE UPPER 80S DEPENDING ON WHICH
SCENARIO PLAYS OUT. BOTH SCENARIOS DO SUGGEST A CUT OFF OF
MOISTURE WHICH WOULD REDUCE RAIN CHANCES. WILL CONTINUE WITH
FORECAST TREND OF LOW 80S AND A NON-GFS SOLUTION FOLLOWING HPC`S
LEAD.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
RESIDUAL BOUNDARY POSITIONED FROM NEAR KTOL TO NEAR KMFD AND IS
EXPECTED TO MOVE LITTLE DURING THE PERIOD. FRONT DIVIDES UPPER 60S
DEWPOINTS FROM UPPER 50 DEWPOINTS. HIGH PRESSURE TO THE NORTH
DRAWING IN DRIER AIR INTO FAR NE OH/NW PA...WHICH HAS ERODED MOST
OF THE NON-VFR CEILINGS FROM EARLIER TODAY. FRONT MAY SPARK A FEW
SHOWERS DURING PEAK HEATING...BUT LOW COVERAGE. WITH ALL OF THE
LINGERING LOW LEVEL MOISTURE EXPECTING RESTRICTIONS TO VISIBILITY
OVERNIGHT/EARLY MONDAY MORNING...ESPECIALLY FOR FDY/MFD WHERE SOME
IFR VSBY/CIGS COULD DEVELOP. IMPROVING CONDITIONS MONDAY.
OUTLOOK...NON VFR POSSIBLE IN SHOWERS/THUNDERSTORMS TUESDAY
THROUGH FRIDAY.
&&
.MARINE...
WITH A COLD FRONT MOVING SOUTH ACROSS THE LAKE THIS MORNING WINDS
WILL SWITCH TO THE NORTH AND NORTHEAST. HIGH PRESSURE WILL BUILD IN
FROM THE NORTH THROUGH EARLY NEXT WEEK KEEPING WINDS 15KT OR LESS.
THE NE FLOW THROUGH TUESDAY WILL KEEP A CHOP ESPECIALLY ALONG THE
WESTERN BASIN...WITH WAVE HEIGHTS 3 FT OR LESS. A WARM FRONT WILL
LIFT NORTH TUESDAY NIGHT AND A WEAK DISTURBANCE WILL MOVE ACROSS THE
LAKES. WINDS AND WAVES EXPECTED TO REMAIN BELOW SCA THROUGHOUT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KOSARIK
NEAR TERM...TK/KOSARIK
SHORT TERM...KOSARIK
LONG TERM...JAMISON
AVIATION...JAMISON
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1140 AM EDT SUN AUG 17 2014
.SYNOPSIS...
A COLD FRONT OVER LAKE ERIE WILL SLOWLY MOVE SOUTH ACROSS THE AREA
TODAY. THE WILL STALL IN CENTRAL OHIO TONIGHT. LOW PRESSURE WILL
MOVE ALONG THE STALLED FRONT ON MONDAY. ANOTHER WEAK LOW PRESSURE
AREA WILL MOVE FORM THE UPPER MIDWEST ACROSS THE AREA LATE TUESDAY
INTO WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED...CLOUD COVER ASSOCIATED WITH THE FRONT ACROSS THE AREA IS
NOT GOING ANYWHERE FAST ALTHOUGH DURING THE AFTERNOON WE SHOULD
LIKELY GET SOME BREAKUP AND SPORADIC THINNING. HRRR CONTINUES TO
SUPPORT NO BIG INCREASE IN PRECIP ACROSS THE AREA THROUGH THE
AFTERNOON SO WILL CONTINUE WITH THE LOW CHANCE POPS CENTRAL AND
SOUTH AND HAVE ALSO TRIMMED NORTHERN EXTENT OF THUNDER. TRIMMED
TEMPS AGAIN ESP NORTHWEST.
ORIGINAL...
THE WEAK COLD FRONT WILL SLIDE ACROSS THE NORTHERN COUNTIES NEAR
LAKE ERIE THIS MORNING. THERE IS STILL SOME QUESTION AS TO HOW FAR
AND HOW FAST THE COLD FRONT WILL MOVE SOUTH TODAY. I SUSPECT IT MAY
NOT MATTER MUCH SINCE THE FRONT IS SHALLOW AND LOW AND MID LEVEL
INSTABILITY MAY LINGER NORTH OF THE FRONT SO SHOWERS MAY CONTINUE TO
DEVELOP. WILL KEEP A CHANCE OF SHOWERS OR A THUNDERSTORMS EVERYWHERE
EXCEPT NORTH OF THE TURNPIKE BY THIS AFTERNOON. SOME CLEARING IS
LIKELY ACROSS NORTHEAST OH AND NORTHWEST PA.
COOLER AIR WILL BEGIN TO SPILL ACROSS LAKE ERIE AND IT MAY NOT MAKE
IT ABOVE THE LOWER 70S ALONG THE LAKESHORE ESPECIALLY AROUND
ASHTABULA AND ERIE. GENERALLY 75 TO 80 ELSEWHERE...LOWER 80S IN THE
FAR SOUTH FROM FINDLAY TO MARION AND MOUNT VERNON WHERE IT WILL ALSO
BE RELATIVELY HUMID WITH DEWPOINTS HOLDING IN THE MID TO UPPER 60S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
THE FRONT SHOULD PUSH SOUTH OF THE AREA TONIGHT. CANNOT RULE OUT A
SHOWER ACROSS THE SOUTHERN COUNTIES SOUTH OF ROUTE 30 OTHERWISE DRY.
WITH LOWERING DEWPOINTS AND THE WIND BECOMING LIGHT...THE COOL SPOTS
OF EXTREME NE OH/NW PA COULD DROP TO THE LOWER 50S OR PERHAPS
UPPER 40S TONIGHT OTHERWISE LOWS MOSTLY IN THE UPPER 50S TO LOWER
60S.
THE SURFACE LOW SHOULD MOVE EAST ALONG THE STALLED FRONT ON MONDAY.
THE MAJORITY OF RAIN SHOULD STAY SOUTH OF THE FORECAST AREA. WITH
THE STALLED FRONT JUST TO OUR SOUTH THOUGH...SOME OVER RUNNING
SHOWERS AND PERHAPS A RUMBLE OF THUNDER IS PROBABLE....AGAIN MAINLY
FROM AROUND THE TURNPIKE SOUTH. HIGHS MOSTLY IN THE MID AND UPPER
70S.
THE NEXT SHORT WAVE AND WEAK COLD FRONT WILL APPROACH ON TUESDAY.
THE SHOWERS MAY SPREAD IN QUICKLY BUT I PREFER THE SLOWER SOLUTIONS
BASED ON THE RELATIVELY SLOW MOVEMENT PROGGED OF THE SHORT WAVE.
THIS SHOULD ALLOW FOR A LITTLE SUNSHINE AND THE CHANCE TO BUBBLE UP
SOME DECENT SHOWERS AND THUNDERSTORMS. HIGHS GENERALLY NEAR 80 OR
THE LOWER 80S WITH DEWPOINTS IN THE MID AND UPPER 60S... ALMOST
LIKE SUMMER TIME.
SHOWERS WILL PROBABLY REDEVELOP ON WEDNESDAY...ESPECIALLY ACROSS NE
OH/NW PA...AS THE SLOW MOVING SHORT WAVE CROSSES THE AREA. HIGHS
SHOULD GET INTO THE 80S EXCEPT WHERE THERE ARE MORE NUMEROUS
SHOWERS.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
THE LONG TERM STARTS
OFF WITH A CLOSED LOW OVER THE LOWER GREAT LAKES. H850 FLOW SHOULD
BRING HIGH PWATS AND MOIST IN WITH THE GFS SHOWING ANOMALOUS PWATS
THU INTO FRI. THE LARGER SCALE MODELS SHOW THE BEST MOISTURE
CORRESPONDS TO WEAK JET DYNAMICS AND MODERATE INSTABILITIES.
THEREFORE HAVE KEPT POPS AROUND 30-40 PRIMARILY DURING PEAK
HEATING...THOUGH ELEVATED CONVECTION POSSIBLE UNTIL THE UPPER LOW
SKIRTS TO OUR EAST AND CUTS OFF THE BEST MOISTURE ON SATURDAY. FOR
NEXT WEEKEND THE ECMWF/GFS DIFFER NOTABLY ON THE BREAK DOWN (OR
NOT) OF THE UPPER LOW OVER THE GREAT LAKES. THE ECMWF MOVES THE
LOW OVER NEW ENGLAND WITH A SFC LOW DEVELOPING OFF THE MID
ATLANTIC. THE GFS HOWEVER SHOWS THE LOW MOVING OFF THE ATLANTIC
COAST RESULTING IN A LESS AMPLIFIED FLOW ALOFT OVER THE GREAT
LAKES. THIS CAUSES UNCERTAINLY LATE IN THE FCST WHERE TEMPERATURES
COULD BE IN THE UPPER 70S OR THE UPPER 80S DEPENDING ON WHICH
SCENARIO PLAYS OUT. BOTH SCENARIOS DO SUGGEST A CUT OFF OF
MOISTURE WHICH WOULD REDUCE RAIN CHANCES. WILL CONTINUE WITH
FORECAST TREND OF LOW 80S AND A NON-GFS SOLUTION FOLLOWING HPC`S
LEAD.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
A COLD FRONT IS CURRENTLY PUSHING SOUTH THROUGH THE REGION
BRINGING IFR CEILINGS IN IT`S WAKE. AT THE TIME OF THIS ISSUANCE
THE FRONT WAS ALLIGNED FROM TOLEDO TO YOUNGSTOWN AND MOVING SOUTH.
DRIER AIR WILL MOVE IN AND ERODE THE CLOUDS STARTING IN ERI AND
THEN CLE BY MIDDAY. RAIN CHANCES WILL CONTINUE ALONG THE FRONT
THROUGH EARLY AFTERNOON. THE FRONT WILL WASH OUT AND KEEP THE LOW
LEVELS MOIST FOR MFD TO FDY SO IFR CONDITIONS WILL BE POSSIBLE
EARLY MONDAY.
OUTLOOK...NON VFR POSSIBLE OVERNIGHT AND THEN IN
SHOWERS/THUNDERSTORMS THROUGH THURSDAY.
&&
.MARINE...
WITH A COLD FRONT MOVING SOUTH ACROSS THE LAKE THIS MORNING WINDS
WILL SWITCH TO THE NORTH AND NORTHEAST. HIGH PRESSURE WILL BUILD IN
FROM THE NORTH THROUGH EARLY NEXT WEEK KEEPING WINDS 15KT OR LESS.
THE NE FLOW THROUGH TUESDAY WILL KEEP A CHOP ESPECIALLY ALONG THE
WESTERN BASIN...WITH WAVE HEIGHTS 3 FT OR LESS. A WARM FRONT WILL
LIFT NORTH TUESDAY NIGHT AND A WEAK DISTURBANCE WILL MOVE ACROSS THE
LAKES. WINDS AND WAVES EXPECTED TO REMAIN BELOW SCA THROUGHOUT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KOSARIK
NEAR TERM...TK/KOSARIK
SHORT TERM...KOSARIK
LONG TERM...JAMISON
AVIATION...JAMISON
MARINE...JAMISON
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
621 AM EDT SUN AUG 17 2014
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL TRAVERSE THE OHIO VALLEY REGION
TODAY INTO TONIGHT. THIS FEATURE WILL MOVE TO THE EAST ON MONDAY
WHILE A LINGERING WEAK FRONTAL BOUNDARY REMAINS ACROSS THE REGION.
IN A NORTHWEST FLOW ALOFT...A SERIES OF UPPER LEVEL DISTURBANCES
WILL THEN ROTATE SOUTHEAST ACROSS THE GREAT LAKES AND OHIO VALLEY
THROUGH THE REMAINDER OF THE WEEK...KEEPING THE THREAT OF PRECIPITATION
IN THE FORECAST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A WEAK COLD FRONT WILL DROP SOUTH INTO THE NRN CWFA TODAY WHILE A
COMPACT UPR LVL DISTURBANCE AND WEAK SFC LOW ROTATE SLOWLY
EAST/SOUTHEAST TOWARD THE MIDDLE OHIO VALLEY. FOCUS FOR TODAY WILL
BE ON THE PROSPECTS FOR SHOWERS AND THUNDERSTORMS. ALTHOUGH PWATS
WILL REMAIN HIGH...1.75 TO NEAR 2 INCHES...THERE WILL BE A LACK OF
STRONG FORCING OVER MUCH OF THE REGION. THE EXCEPTION WILL BE THE
TRI-STATE REGION WHERE THE APPROACH OF AFOREMENTIONED COMPACT
DISTURBANCE MAY PUSH A WEAK LOW LEVEL JET TOWARD THIS AREA BY THE
AFTERNOON HOURS. HAVE ADJUSTED THE FORECAST TO BRING IN HIGHER
POPS TO THIS AREA BASED ON THE LATEST HRRR AND RUC. THE QUESTION
WILL STILL BE HOW FAR EAST/NORTHEAST THE LIKELY POPS WILL GET
BETWEEN THE AFTERNOON AND EVENING HOURS...AND THAT WILL BE THE
AREA TO WATCH FOR ANY ADDITIONAL UPDATES. ELSEWHERE...WEAK FORCING
SHOULD KEEP CHANCES FOR SHOWERS/STORMS AROUND 30 TO 40 PERCENT.
SKIES WILL BE MOSTLY CLOUDY TO CLOUDY WHICH SHOULD HOLD
TEMPERATURES DOWN IN THE UPPER 70S TO THE LOWER 80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THE 00Z ECMWF AND 00Z GFS HAVE BEEN USED FOR THE SHORT TERM
FORECAST. THE 00Z NAM CONTINUES TO SUFFER WITH CONVECTIVE FEEDBACK
ISSUES IN WHICH IT GENERATES SMALL BUT YET SUBSTANTIAL LOW LEVEL
JETLETS WHICH SEEM UNREALISTIC GIVEN SUCH A WEAK AND SHEARING OUT
SYSTEM. AFOREMENTIONED COMPACT UPR LVL DISTURBANCE WILL BEGIN TO
SHEAR TONIGHT AS IT TRAVELS MORE EAST NEAR OUR SRN CWFA. BEST LOW
LEVEL FORCING AND DYNAMICS WILL REMAIN ALONG AND SOUTH OF THE OHIO
RIVER AND THAT IS WHERE LIKELY POPS HAVE BEEN PLACED. CHANCES FOR
PCPN WILL DROP OFF CONSIDERABLY HEADING NORTH DUE TO THE LOSS OF
INSTABILITY AND FAIRLY WEAK FORCING WITH A NEARLY STATIONARY
FRONTAL BOUNDARY. PWATS WILL REMAIN HIGH...ESPECIALLY ALONG AND
SOUTH OF THE OHIO RIVER...AND THERE COULD STILL BE SOME LOCALIZED
FLOODING WHERE THE HEAVIER SHOWERS/STORMS OCCUR. WILL CONTINUE TO
MENTION THIS IN THE HWO. LOWS TONIGHT WILL RANGE FROM THE MID TO
THE UPPER 60S.
ON MONDAY...DISTURBANCE WILL EXIT OFF TO OUR EAST DURING THE
MORNING. AS IT DOES...LIKELY POPS WILL SHIFT OFF TO THE EAST AS
WELL. BY THE AFTERNOON...THE WEAK FRONTAL BOUNDARY WILL REMAIN
OVER THE REGION. THIS BOUNDARY...ALONG WITH DAYTIME HEATING...WILL
PRODUCE SOME SCATTERED CONVECTION...WITH POPS IN THE 30 TO 40
PERCENT RANGE. CLOUDS WILL HOLD TEMPERATURES DOWN ONCE AGAIN WITH
UPPER 70S TO LOWER 80S FORECAST.
BY MONDAY NIGHT...THE LOSS OF DAYTIME HEATING WILL MEAN A DOWNWARD
TREND IN INSTABILITY. AND WITH NO SIGNIFICANT SYSTEMS
EXPECTED...WE SHOULD EVENTUALLY DRY OUT WITH THE PCPN THREAT
COMING TO AN END DURING THE EVENING OR AROUND MIDNIGHT. LOWS WILL
ONCE AGAIN WILL RANGE FROM THE MID TO THE UPPER 60S.
FOR TUESDAY INTO TUESDAY NIGHT...UNDER A NORTHWEST FLOW
ALOFT...ANOTHER S/WV IS FORECAST TO ROTATE EAST/SOUTHEAST ACROSS
THE GREAT LAKES. THE COMBINATION OF THIS FEATURE AND A WEAK
REFLECTED SFC TROF AXIS WILL BRING AN INCREASE CHANCE OF SHOWERS
AND THUNDERSTORMS...WITH THE BEST CHANCE FROM LATE AFTERNOON INTO
THE EVENING HOURS. WE SHOULD BE ABLE TO SEE SOME SUN EARLY ON AND
THIS WILL ALLOW TEMPERATURES TO WARM BACK INTO THE LOWER AND MID
80S. LOWS TUESDAY NIGHT WILL FALL BACK INTO THE MID AND UPPER 60S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
UPPER LEVEL RIDGING WILL BUILD FROM THE GULF COAST UP INTO THE
CENTRAL PLAINS THROUGH THE END OF THE WEEK. THIS WILL KEEP THE MID
OHIO VALLEY IN NORTHWEST FLOW ALOFT THROUGH MID TO LATE WEEK BEFORE
POSSIBLY TRANSITIONING TO MORE OF A NORTHERLY FLOW PATTERN ALOFT
HEADING INTO NEXT WEEKEND. A SERIES OF MID LEVEL SHORTWAVES ARE
FORECAST TO DROP DOWN THROUGH THE REGION THROUGH MUCH OF THE LONG
TERM PERIOD. THIS WILL RESULT IN A CONTINUED CHANCE OF
SHOWERS/THUNDERSTORMS THROUGH THE WEEK. HOWEVER...THE MODELS TEND TO
STRUGGLE WITH THE TIMING/PLACEMENT OF SHORT WAVES IN THIS KIND OF A
PATTERN. WILL THEREFORE GENERALLY JUST KEEP POPS IN THE CHANCE
CATEGORY WITH A BIT OF A DIURNAL ENHANCEMENT TO THEM. GIVEN THE
NORTHWEST FLOW PATTERN...EXPECT SOMEWHAT OF A NORTHEAST TO SOUTHWEST
TEMPERATURE GRADIENT ACROSS THE AREA THROUGH THE WEEK BUT OVERALL
TEMPERATURES SHOULD BE FAIRLY SEASONABLE.
&&
.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
AREA OF RAIN WITH SCATTERED EMBEDDED MODERATE SHOWERS LOCATED OVER
SOUTH CENTRAL INDIANA AND EXTENDING SOUTHEASTWARD INTO NORTHERN
KENTUCKY IS ASSOCIATED WITH ISENTROPIC LIFT. THIS PRECIPITATION IS
SLIDING TO THE EAST SOUTHEAST AND IS EXPECTED TO BEGIN WEAKENING
AFTER 09Z. HAVE INTRODUCED VCSH INTO THE FIRST PERIOD OF THE KCVG
TAF TO REPRESENT THIS FEATURE SINCE THE BULK OF THE PRECIPITATION
WILL BE WEST AND SOUTH OF KCVG. CONDITIONS WILL BE SOMEWHAT
FAVORABLE FOR THE FORMATION OF MAINLY MVFR FOG TO LOCALLY IFR IN
THE FOG PRONE AREAS. THE REASON FOR THE FOG FORMATION IS MAINLY
DUE TO THE RESIDUAL MOISTURE FROM EARLIER PRECIPITATION. WINDS
TONIGHT WILL BE CALM TO LIGHT SOUTHWESTERLY.
AS THE LOW FROM THE WEST APPROACHES THE AREA THE BEST CHANCE FOR
PRECIPITATION WILL BE KCVG AND KLUK. THUS VCSH IN THE MORNING
BECOMING VCTS IN THE AFTERNOON BECOMING TEMPO TS IN THE EVENING.
AS THE FRONT APPROACHES FROM THE NORTH HAVE ADDED VCSH TO THE
CENTRAL OHIO TAFS FOR LATE AFTERNOON AND EVENING. IN THE KDAY AND
KILN TAFS HAVE REDUCED VCTS TO VCSH AS THEY WILL BE LOCATED
BETWEEN THE TWO WEATHER PRODUCING SYSTEMS.
WINDS WILL BE OUT OF THE SOUTH AT LESS THAN 10 KTS ON SUNDAY.
OUTLOOK...THUNDERSTORMS POSSIBLE SUNDAY THROUGH THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...HICKMAN
AVIATION...HAYDU
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
152 AM EDT SUN AUG 17 2014
.SYNOPSIS...
A SLOW MOVING LOW PRESSURE SYSTEM OVER THE MID MISSISSIPPI VALLEY
WILL CONTINUE TO CREEP SLOWLY EASTWARD AS IT SLOWLY WEAKENS. A
PLUME OF UNSEASONABLY DEEP MOISTURE AHEAD OF THE SYSTEM WILL
CONTINUE TO SPREAD INTO AND THROUGH THE OHIO VALLEY TONIGHT AND
SUNDAY...AND THIS MOISTURE AND COMBINED WITH SUBTLE DISTURBANCES
AHEAD OF THE LOW WILL CONTINUE TO ALLOW SHOWERS TO DEVELOP AT
TIMES TONIGHT THROUGH SUNDAY IN SCATTERED FASHION. THE SLOW MOVING
LOW WILL MOVE INTO THE TRI STATE ON SUNDAY NIGHT AND
MONDAY...SHIFTING EAST OF THE AREA MONDAY NIGHT. THIS WILL BRING
SHOWERS AND A FEW THUNDERSTORMS...PRIMARILY TO AREAS ALONG AND
SOUTH OF THE OHIO RIVER...BUT ALL AREAS WILL SEE AT LEAST SOME
THREAT OF RAIN WITH THIS SYSTEM. IT WILL BE HUMID AND MILD DESPITE
AMPLE CLOUDS SUNDAY AND MONDAY. IN THE WAKE OF THIS SYSTEM ON
TUESDAY...AND CONTINUING THROUGH THE REST OF THE WORK WEEK...WILL
BE A WARM AND MUGGY AIRMASS WITH DAILY THREATS FOR SHOWERS AND
THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
LATEST RAP MODEL SHOWS EMBEDDED MID LEVEL S/W TRACKING EAST THRU
NRN KY. THIS FEATURE...ALONG WITH ISENTROPIC LIFT LEAD TO ISOLD
TO SCATTERED SHOWERS LATE THIS AFTN INTO THIS EVENING. WITH THE
PASSAGE OF THIS FEATURE...EXPECT A GENERAL LULL IN PRECIPITATION
OVERNIGHT. HAVE TRENDED POPS A SLIGHTLY LOWER TONIGHT DUE TO WEAK
FORCING WITH A SLIGHT INCREASE (STILL IN CHANCE CATEGORY) INTO THE
SW LATE...CLOSER TO MODEST LOW LEVEL JET POINTING INTO SRN IND.
GIVEN INCREASE IN MOISTURE...LOWS TONIGHT WILL BE CONSIDERABLY WARMER
THAN YDA...WITH LOWS IN THE MID AND UPPER 60S.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/...
THE WEAK CLOSED LOW DRIFTING SOUTHEAST THROUGH THE MID MISSISSIPPI
VALLEY WILL BEGIN TO WEAKEN FURTHER AND SHEAR EASTWARD MORE
QUICKLY BEGINNING SUNDAY INTO SUNDAY NIGHT. THIS PROCESS STILL
KEEPS THE BULK OF THE FORCING WEST /ESPECIALLY SOUTHWEST/ OF THE
ILN FORECAST AREA ON SUNDAY...WHILE A COLD FRONT THAT HAS DROPPED
INTO NRN OHIO ATTENDANT TO ENERGY DIVING THROUGH SERN CANADA COMES
TO A HALT. BUT TROPOSPHERIC MOISTURE WILL CONTINUE TO BUILD WITH
PWATS EXCEEDING 1.75" ACROSS THE SOUTHERN FORECAST AREA. AREAS OF
SHOWERS WILL STILL BE POSSIBLE ACROSS THE AREA IN THE WEAKLY
FORCED REGION DOWNSTREAM OF THE WEAK CLOSED LOW...BUT DON/T SEE
MORE ORGANIZED ACTIVITY PUSHING INTO THE SOUTHERN/WESTERN AREAS
UNTIL EARLY SUNDAY EVENING OR INTO SUNDAY NIGHT. FLOW IS PRETTY
WEAK OVERALL SO NOT EXPECTING ANY THREAT OF SEVERE...BUT
INDIVIDUAL CORES WILL BE SLOW MOVING AND WITH THE AMPLE MOISTURE
THERE COULD BE SOME LOCALIZED HEAVY RAIN LATER SUNDAY NIGHT INTO
MONDAY IN OUR SOUTH. THINK OVERALL THIS THREAT IS LOWER THAN WHAT
PREVIOUS GUIDANCE HAD INDICATED...AS MODELS HAVE TRENDED
FASTER/WEAKER/MORE SHEARED WITH THE CLOSE LOW AS IT SHIFTS ACROSS
KENTUCKY AND OPENS UP AND BECOMES MORE PROGRESSIVE. NOTICED WPC
STILL KEEPS FAR SOUTHERN AREAS IN SLGT RISK FOR FLASH FLOOD
EXCEEDING RAINS...SO WILL KEEP THIS IN THE HAZ WX OUTLOOK BUT
REFINE THE THREAT AREA TO CLOSER TO THE TRACK OF MID LEVEL
CIRCULATION WHERE POTENTIAL FOR REGENERATION ALONG THE MAJOR AXIS
OF SHOWER/STORM POTENTIAL IS GREATEST. AMPLE CLOUDS AGAIN EXPECTED
SUNDAY INTO MONDAY SHOULD KEEP HIGHS IN CHECK FOR THE MOST
PART...70S TO LOWER 80S...IN WHAT WILL BE QUITE A HUMID AIRMASS.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
UPPER LEVEL RIDGING WILL BUILD FROM THE GULF COAST UP INTO THE
CENTRAL PLAINS THROUGH THE END OF THE WEEK. THIS WILL KEEP THE MID
OHIO VALLEY IN NORTHWEST FLOW ALOFT THROUGH MID TO LATE WEEK BEFORE
POSSIBLY TRANSITIONING TO MORE OF A NORTHERLY FLOW PATTERN ALOFT
HEADING INTO NEXT WEEKEND. A SERIES OF MID LEVEL SHORTWAVES ARE
FORECAST TO DROP DOWN THROUGH THE REGION THROUGH MUCH OF THE LONG
TERM PERIOD. THIS WILL RESULT IN A CONTINUED CHANCE OF
SHOWERS/THUNDERSTORMS THROUGH THE WEEK. HOWEVER...THE MODELS TEND TO
STRUGGLE WITH THE TIMING/PLACEMENT OF SHORT WAVES IN THIS KIND OF A
PATTERN. WILL THEREFORE GENERALLY JUST KEEP POPS IN THE CHANCE
CATEGORY WITH A BIT OF A DIURNAL ENHANCEMENT TO THEM. GIVEN THE
NORTHWEST FLOW PATTERN...EXPECT SOMEWHAT OF A NORTHEAST TO SOUTHWEST
TEMPERATURE GRADIENT ACROSS THE AREA THROUGH THE WEEK BUT OVERALL
TEMPERATURES SHOULD BE FAIRLY SEASONABLE.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AREA OF RAIN WITH SCATTERED EMBEDDED MODERATE SHOWERS LOCATED OVER
SOUTH CENTRAL INDIANA AND EXTENDING SOUTHEASTWARD INTO NORTHERN
KENTUCKY IS ASSOCIATED WITH ISENTROPIC LIFT. THIS PRECIPITATION IS
SLIDING TO THE EAST SOUTHEAST AND IS EXPECTED TO BEGIN WEAKENING
AFTER 09Z. HAVE INTRODUCED VCSH INTO THE FIRST PERIOD OF THE KCVG
TAF TO REPRESENT THIS FEATURE SINCE THE BULK OF THE PRECIPITATION
WILL BE WEST AND SOUTH OF KCVG. CONDITIONS WILL BE SOMEWHAT
FAVORABLE FOR THE FORMATION OF MAINLY MVFR FOG TO LOCALLY IFR IN
THE FOG PRONE AREAS. THE REASON FOR THE FOG FORMATION IS MAINLY
DUE TO THE RESIDUAL MOISTURE FROM EARLIER PRECIPITATION. WINDS
TONIGHT WILL BE CALM TO LIGHT SOUTHWESTERLY.
AS THE LOW FROM THE WEST APPROACHES THE AREA THE BEST CHANCE FOR
PRECIPITATION WILL BE KCVG AND KLUK. THUS VCSH IN THE MORNING
BECOMING VCTS IN THE AFTERNOON BECOMING TEMPO TS IN THE EVENING.
AS THE FRONT APPROACHES FROM THE NORTH HAVE ADDED VCSH TO THE
CENTRAL OHIO TAFS FOR LATE AFTERNOON AND EVENING. IN THE KDAY AND
KILN TAFS HAVE REDUCED VCTS TO VCSH AS THEY WILL BE LOCATED
BETWEEN THE TWO WEATHER PRODUCING SYSTEMS.
WINDS WILL BE OUT OF THE SOUTH AT LESS THAN 10 KTS ON SUNDAY.
OUTLOOK...THUNDERSTORMS POSSIBLE SUNDAY THROUGH THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...BINAU
NEAR TERM...AR
SHORT TERM...BINAU
LONG TERM...JGL
AVIATION...HAYDU
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
131 AM EDT SUN AUG 17 2014
.SYNOPSIS...
A COLD FRONT OVER THE NORTHERN GREAT LAKES WILL DROP SOUTH ACROSS
THE AREA LATE TONIGHT AND SUNDAY. THE FRONT WILL STALL IN CENTRAL
OHIO BY SUNDAY NIGHT. LOW PRESSURE WILL MOVE ALONG THE STALLED
FRONT ON MONDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SHOWERS CONTINUE TO DEVELOP ALONG THE FRONT OVER LOWER MICHIGAN.
LATEST HRRR HAS THIS ACTIVITY SPREADING SOUTH ACROSS THE LOCAL
AREA OVERNIGHT. DO NOT THINK THERE WILL BE MUCH IF ANY THUNDER SO
WILL OMIT FROM THE FORECAST. WILL HOWEVER...CARRY AT LEAST CHANCE
POPS ALL AREAS OVERNIGHT. BEST CHANCES THROUGH MIDNIGHT WILL BE
OVER FAR NE AND NW PA AND WILL CONTINUE WITH SCATTERED WORDING
THERE. GIVEN CURRENT DEWPOINTS AND EXPECTED CLOUD COVER HAVE NUDGE
TEMPS UP SLIGHTLY FOR LOWS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/...
THE COLD FRONT SHOULD EXTEND EAST/WEST ACROSS NRN OHIO SUNDAY
MORNING AND WILL CONTINUE SOUTH OF THE AREA DURING THE DAY. ALONG
AND SOUTH OF THE FRONT EXPECT SHOWERS AND THUNDERSTORMS TO FLARE
UP DURING THE DAY. BROUGHT A FEW HOURS OF LIKELY POPS INTO THE FAR
SOUTH DURING MID DAY WITH POPS TAPERING OFF TO THE NORTH DOWN TO A
SLIGHT CHANCE ROUGHLY ALONG A KCLE-KYNG LINE. MODELS SHOW DRY AIR
GETTING INTO THE FAR NORTHEAST AND WILL GO DRY THERE. NO BIG
CHANCE FOR SUNDAY NIGHT...DRY NORTHEAST AND CHANCE POPS ACROSS THE
SOUTHERN 2/3RDS. MONDAY LOW PRESSURE WILL TRACK ACROSS
SOUTHERN/CENTRAL OHIO ALONG THE STATIONARY FRONT. MODELS AGREE THAT
THE BULK OF THE PRECIP WILL REMAIN SOUTH OF THE AREA HOWEVER DO
EXPECT SHOWERS AND THUNDERSTORMS TO REACH NORTH INTO THE AREA DURING
THE DAY. WILL HAVE CHANCE POPS ACROSS MUCH OF THE AREA WITH LIKELY
FAR SOUTH AND SLIGHT CHANCE FAR NORTH. ANY CHANGE IN THE TRACK WILL
OF COURSE CHANGE THE FORECAST SIGNIFICANTLY. TUESDAY MOISTURE FROM
THE LOW WILL BE MOVING EAST HOWEVER THE GFS SHOWS ANOTHER UPPER TROF
CHURNING IN THE WESTERN LAKES WITH DIVERGENCE ALOFT ACROSS THE AREA
SO WILL NEED TO CONTINUE WITH CHANCE POPS THROUGH THE DAY AND INTO
TUESDAY NIGHT. TEMPS NEAR TO A FEW DEGREES BELOW NORMAL.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
GENERAL IDEA FOR THE THE LONG TERM WILL BE A FEW ROUNDS OF SHOWERS
AND THUNDERSTORMS...POSSIBLY DRYING OUT BY THE WEEKEND. UPPER LOW
OPENS UP BETWEEN WEDNESDAY AND THURSDAY AS IT PASSES ACROSS THE
GREAT LAKES AND SOUTH OF A BLOCKING RIDGE ACROSS CANADA. THIS WILL
TAKE A WEAK LOW ACROSS SOUTHERN ONTARIO. THIS WILL BE ENOUGH TO GIVE
US ELEVATED PRECIPITATION CHANCES. WITH TIMING DIFFICULTIES...DID
NOT GO ANY HIGHER THAN 30 OR 40 PERCENT. NORTHWEST UPPER FLOW IN ITS
WAKE COULD STILL GIVE US INCREASED THUNDERSTORM CHANCES FOR
FRIDAY...BUT GENERAL TREND IS FOR INCREASING HEIGHTS/A RIDGE TO
BUILD INTO THE REGION FOR THE WEEKEND. WITH THAT HAVE TEMPERATURES
THAT ARE CLOSE TO NORMAL...COMING UP A COUPLE OF DEGREES TOWARD THE
WEEKEND. CLOUD COVER AND ANY MID-DAY PRECIP COULD ALTER THAT.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
A COLD FRONT SINKING SOUTH ACROSS THE LAKE WILL CLIP ERI/CLE/YNG
EARLY THIS MORNING WITH SHOWERS AND ISOLATED THUNDERSTORMS.
INCREASED LOW LEVEL MOISTURE WILL SUPPORT IFR CONDITIONS ACROSS
THE REGION DURING THE EARLY MORNING HOURS. ERI WILL BE THE FIRST
TO IMPROVE AS DRIER AIR BEHIND THE FRONT ERODES THE LOW CLOUDS.
CLE WILL BEGIN TO BREAK UP MID DAY. THE FRONT WILL STALL AND IT`S
LOCATION WILL BE THE FOCUS FOR AFTERNOON CONVECTION. THE BEST
INDICATIONS SHOW IT SAGGING JUST SOUTH OF A LINE FROM FDY TO YNG.
CAN`T RULE OUT VICINITY SHRA FOR THOSE TAF SITES FOR THE BETTER
PART OF THE DAY. CANNOT RULE OUT THUNDER BUT ODDS TOO LOW TO
MENTION. CEILINGS WILL LIKELY DROP BACK TO MVFR OVERNIGHT.
OUTLOOK...NON VFR POSSIBLE OVERNIGHT AND THEN IN
SHOWERS/THUNDERSTORMS THROUGH THURSDAY.
&&
.MARINE...
STIFF SOUTHWEST FLOW WILL DECREASE OVERNIGHT AND SHIFT TO THE NNW AS
A COLD FRONT COMES SOUTH...STRETCHING OUT ACROSS NORTHERN OHIO EARLY
SUNDAY. SMALL CRAFT ADVISORY WILL CONTINUE FOR OFF OF ERIE THROUGH
THIS EVENING AND INTO THE EARLY OVERNIGHT. HIGH PRESSURE WILL BE
BUILDING NORTH OF THE LAKE FOR SUNDAY WITH A LIGHTER NORTHEAST FLOW
FOR THE LAKE. THE HIGH WILL BE IN PLACE MONDAY WHILE THE NEXT SYSTEM
TAKES A SOUTHERN TRACK ACROSS THE OHIO VALLEY. THE NORTHEAST FLOW
MAY MAKE THE ISLAND A LITTLE CHOPPY...BUT AT THIS POINT WINDS DO NOT
APPEAR STRONG ENOUGH FOR A SMALL CRAFT ADV. BEYOND MONDAY THE
WEATHER PATTERN IS A BIT MORE UNSETTLED WITH A SLOW MOVING SYSTEM
MAKING ITS WAY ACROSS THE GREAT LAKES THROUGH THURSDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT EARLY THIS MORNING FOR
LEZ149.
&&
$$
SYNOPSIS...TK
NEAR TERM...KUBINA
SHORT TERM...TK
LONG TERM...OUDEMAN
AVIATION...JAMISON
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS NORMAN OK
1026 AM CDT SUN AUG 17 2014
.UPDATE...
THE ONLY CHANGE THE FORECAST THIS MORNING WAS TO ADJUST POPS TO
REFLECT RECENT RADAR TRENDS. THIS REQUIRED INCREASING POPS TO
LIKELY ACROSS FAR SOUTHEASTERN PORTIONS OF THE AREA...MAINLY BRYAN
COUNTY. MAX TEMPS WERE ALSO NUDGED DOWNWARD IN AREAS OF CLOUD
COVER. OTHERWISE...THE FORECAST LOOKS TO BE ON TRACK.
&&
.PREV DISCUSSION... /ISSUED 621 AM CDT SUN AUG 17 2014/
DISCUSSION...
AVIATION DISCUSSION FOR THE 12Z TAFS IS BELOW.
AVIATION...
VFR CONDITIONS AND LIGHT WINDS ARE EXPECTED TO CONTINUE.
BRIEF MVFR VISIBILITIES IN BR MAY OCCUR AT KPNC THROUGH 14Z...
BUT DID NOT MENTION DUE TO LOW CONFIDENCE OF OCCURRENCE.
ISO TSRA ARE EXPECTED ACROSS THE AREA 18-02Z...MAINLY WEST AND
SOUTH OF A KAVK-KOUN-KSNL LINE...BUT CHANCES OF OCCURRENCE AT
ANY TAF SITE REMAINS TOO LOW TO MENTION.
MBS
PREV DISCUSSION... /ISSUED 358 AM CDT SUN AUG 17 2014/
DISCUSSION...
THE MAIN CONCERN IS DEALING WITH HOT WEATHER...PERHAPS THE
HOTTEST SO FAR THIS SUMMER...DURING THE NEXT SEVEN DAYS. ANY
RAINFALL WILL REMAIN SPARSE AND LOCALIZED THROUGH NEXT SATURDAY.
DID NOT ISSUE A HEAT ADVISORY AS CONFIDENCE OF HEAT INDICES
EXCEEDING 105 DEGREES REMAINS RATHER LOW. SOME UNCERTAINTY
REMAINS WITH FORECAST SURFACE DEWPOINTS OVER THE NEXT SEVEN
DAYS...WHICH MAY DECREASE SIGNIFICANTLY AS THE GROUND DRIES OUT.
TODAY WILL BE ANOTHER HOT DAY. MORE SUN WILL ALLOW FOR HOTTER
READINGS ACROSS CENTRAL AND SOUTHERN OKLAHOMA AS WELL AS PARTS OF
WESTERN NORTH TEXAS. USED A BLEND OF GUIDANCE HIGHS MAINLY IN THE
95 TO 103 DEGREE RANGE.
THIS MORNING...A FEW LIGHT SHOWERS AND PERHAPS A RUMBLE OF
THUNDER WILL CONTINUE ACROSS PARTS OF SOUTHERN AND SOUTHEASTERN
OKLAHOMA. KEPT 20 TO 30 PERCENT CHANCES MAINLY SOUTH OF A WAURIKA
TO ADA TO HOLDENVILLE LINE. ANY RAINFALL IS EXPECTED TO REMAIN ON
THE LIGHT SIDE.
THIS AFTERNOON INTO EVENING...THINK A FEW THUNDERSTORMS WILL
DEVELOP DURING THE HEAT OF THE DAY IN A WEAKLY CAPPED ENVIRONMENT.
LATEST HRRR HINTS AT FIRST DEVELOPMENT 1 TO 3 PM ACROSS WESTERN
AND SOUTHERN OKLAHOMA...SOMEWHERE NEAR A GAGE TO HOBART TO ATOKA
LINE. WENT WITH 10 TO 20 PERCENT ISOLATED MENTION WEST AND SOUTH
OF AN ALVA TO CHICKASHA TO SEMINOLE LINE. ANY STORM WOULD MOVE
VERY SLOWLY WITH LOCALIZED STRONG WINDS AND HEAVY RAINFALL AS THE
MAIN HAZARDS...THEN DISSIPATE WITH THE LOSS OF DAYTIME HEATING.
STORM COVERAGE WILL REMAIN LIMITED DUE TO VERY WEAK MID/UPPER
LEVEL FORCING.
MONDAY THROUGH SATURDAY...HOT AND MAINLY DRY WEATHER WILL
CONTINUE WITH MID/UPPER LEVEL RIDGING. REMOVED RAIN CHANCES
MONDAY THROUGH WEDNESDAY AS STORM COVERAGE WILL LIKELY REMAIN
BELOW 15 PERCENT...THOUGH THERE MAY A FEW MAINLY AFTERNOON AND
EVENING STORMS DURING THIS TIME FRAME. WENT FAIRLY CONSERVATIVE
WITH TEMPERATURES. WIDESPREAD TRIPLE DIGIT HEAT MAY OCCUR.
SURFACE WINDS WILL INCREASE BY THE MIDDLE OF THE WEEK.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 96 73 101 74 / 10 10 10 10
HOBART OK 99 73 103 74 / 10 10 10 10
WICHITA FALLS TX 99 75 103 77 / 10 10 10 10
GAGE OK 100 70 102 71 / 10 10 10 10
PONCA CITY OK 93 71 100 73 / 10 10 10 10
DURANT OK 91 74 99 76 / 60 20 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
84/30
AREA FORECAST DISCUSSION
NWS NORMAN OK
621 AM CDT SUN AUG 17 2014
.DISCUSSION...
AVIATION DISCUSSION FOR THE 12Z TAFS IS BELOW.
&&
.AVIATION...
VFR CONDITIONS AND LIGHT WINDS ARE EXPECTED TO CONTINUE.
BRIEF MVFR VISIBILITIES IN BR MAY OCCUR AT KPNC THROUGH 14Z...
BUT DID NOT MENTION DUE TO LOW CONFIDENCE OF OCCURRENCE.
ISO TSRA ARE EXPECTED ACROSS THE AREA 18-02Z...MAINLY WEST AND
SOUTH OF A KAVK-KOUN-KSNL LINE...BUT CHANCES OF OCCURRENCE AT
ANY TAF SITE REMAINS TOO LOW TO MENTION.
MBS
&&
.PREV DISCUSSION... /ISSUED 358 AM CDT SUN AUG 17 2014/
DISCUSSION...
THE MAIN CONCERN IS DEALING WITH HOT WEATHER...PERHAPS THE
HOTTEST SO FAR THIS SUMMER...DURING THE NEXT SEVEN DAYS. ANY
RAINFALL WILL REMAIN SPARSE AND LOCALIZED THROUGH NEXT SATURDAY.
DID NOT ISSUE A HEAT ADVISORY AS CONFIDENCE OF HEAT INDICES
EXCEEDING 105 DEGREES REMAINS RATHER LOW. SOME UNCERTAINTY
REMAINS WITH FORECAST SURFACE DEWPOINTS OVER THE NEXT SEVEN
DAYS...WHICH MAY DECREASE SIGNIFICANTLY AS THE GROUND DRIES OUT.
TODAY WILL BE ANOTHER HOT DAY. MORE SUN WILL ALLOW FOR HOTTER
READINGS ACROSS CENTRAL AND SOUTHERN OKLAHOMA AS WELL AS PARTS OF
WESTERN NORTH TEXAS. USED A BLEND OF GUIDANCE HIGHS MAINLY IN THE
95 TO 103 DEGREE RANGE.
THIS MORNING...A FEW LIGHT SHOWERS AND PERHAPS A RUMBLE OF
THUNDER WILL CONTINUE ACROSS PARTS OF SOUTHERN AND SOUTHEASTERN
OKLAHOMA. KEPT 20 TO 30 PERCENT CHANCES MAINLY SOUTH OF A WAURIKA
TO ADA TO HOLDENVILLE LINE. ANY RAINFALL IS EXPECTED TO REMAIN ON
THE LIGHT SIDE.
THIS AFTERNOON INTO EVENING...THINK A FEW THUNDERSTORMS WILL
DEVELOP DURING THE HEAT OF THE DAY IN A WEAKLY CAPPED ENVIRONMENT.
LATEST HRRR HINTS AT FIRST DEVELOPMENT 1 TO 3 PM ACROSS WESTERN
AND SOUTHERN OKLAHOMA...SOMEWHERE NEAR A GAGE TO HOBART TO ATOKA
LINE. WENT WITH 10 TO 20 PERCENT ISOLATED MENTION WEST AND SOUTH
OF AN ALVA TO CHICKASHA TO SEMINOLE LINE. ANY STORM WOULD MOVE
VERY SLOWLY WITH LOCALIZED STRONG WINDS AND HEAVY RAINFALL AS THE
MAIN HAZARDS...THEN DISSIPATE WITH THE LOSS OF DAYTIME HEATING.
STORM COVERAGE WILL REMAIN LIMITED DUE TO VERY WEAK MID/UPPER
LEVEL FORCING.
MONDAY THROUGH SATURDAY...HOT AND MAINLY DRY WEATHER WILL
CONTINUE WITH MID/UPPER LEVEL RIDGING. REMOVED RAIN CHANCES
MONDAY THROUGH WEDNESDAY AS STORM COVERAGE WILL LIKELY REMAIN
BELOW 15 PERCENT...THOUGH THERE MAY A FEW MAINLY AFTERNOON AND
EVENING STORMS DURING THIS TIME FRAME. WENT FAIRLY CONSERVATIVE
WITH TEMPERATURES. WIDESPREAD TRIPLE DIGIT HEAT MAY OCCUR.
SURFACE WINDS WILL INCREASE BY THE MIDDLE OF THE WEEK.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 98 73 101 74 / 10 10 10 10
HOBART OK 101 73 103 74 / 10 10 10 10
WICHITA FALLS TX 100 75 103 77 / 10 10 10 10
GAGE OK 100 70 102 71 / 10 10 10 10
PONCA CITY OK 96 71 100 73 / 10 10 10 10
DURANT OK 96 74 99 76 / 30 20 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
25/17/17
AREA FORECAST DISCUSSION
NWS NORMAN OK
358 AM CDT SUN AUG 17 2014
.DISCUSSION...
THE MAIN CONCERN IS DEALING WITH HOT WEATHER...PERHAPS THE
HOTTEST SO FAR THIS SUMMER...DURING THE NEXT SEVEN DAYS. ANY
RAINFALL WILL REMAIN SPARSE AND LOCALIZED THROUGH NEXT SATURDAY.
DID NOT ISSUE A HEAT ADVISORY AS CONFIDENCE OF HEAT INDICES
EXCEEDING 105 DEGREES REMAINS RATHER LOW. SOME UNCERTAINTY
REMAINS WITH FORECAST SURFACE DEWPOINTS OVER THE NEXT SEVEN
DAYS...WHICH MAY DECREASE SIGNIFICANTLY AS THE GROUND DRIES OUT.
TODAY WILL BE ANOTHER HOT DAY. MORE SUN WILL ALLOW FOR HOTTER
READINGS ACROSS CENTRAL AND SOUTHERN OKLAHOMA AS WELL AS PARTS OF
WESTERN NORTH TEXAS. USED A BLEND OF GUIDANCE HIGHS MAINLY IN THE
95 TO 103 DEGREE RANGE.
THIS MORNING...A FEW LIGHT SHOWERS AND PERHAPS A RUMBLE OF
THUNDER WILL CONTINUE ACROSS PARTS OF SOUTHERN AND SOUTHEASTERN
OKLAHOMA. KEPT 20 TO 30 PERCENT CHANCES MAINLY SOUTH OF A WAURIKA
TO ADA TO HOLDENVILLE LINE. ANY RAINFALL IS EXPECTED TO REMAIN ON
THE LIGHT SIDE.
THIS AFTERNOON INTO EVENING...THINK A FEW THUNDERSTORMS WILL
DEVELOP DURING THE HEAT OF THE DAY IN A WEAKLY CAPPED ENVIRONMENT.
LATEST HRRR HINTS AT FIRST DEVELOPMENT 1 TO 3 PM ACROSS WESTERN
AND SOUTHERN OKLAHOMA...SOMEWHERE NEAR A GAGE TO HOBART TO ATOKA
LINE. WENT WITH 10 TO 20 PERCENT ISOLATED MENTION WEST AND SOUTH
OF AN ALVA TO CHICKASHA TO SEMINOLE LINE. ANY STORM WOULD MOVE
VERY SLOWLY WITH LOCALIZED STRONG WINDS AND HEAVY RAINFALL AS THE
MAIN HAZARDS...THEN DISSIPATE WITH THE LOSS OF DAYTIME HEATING.
STORM COVERAGE WILL REMAIN LIMITED DUE TO VERY WEAK MID/UPPER
LEVEL FORCING.
MONDAY THROUGH SATURDAY...HOT AND MAINLY DRY WEATHER WILL
CONTINUE WITH MID/UPPER LEVEL RIDGING. REMOVED RAIN CHANCES
MONDAY THROUGH WEDNESDAY AS STORM COVERAGE WILL LIKELY REMAIN
BELOW 15 PERCENT...THOUGH THERE MAY A FEW MAINLY AFTERNOON AND
EVENING STORMS DURING THIS TIME FRAME. WENT FAIRLY CONSERVATIVE
WITH TEMPERATURES. WIDESPREAD TRIPLE DIGIT HEAT MAY OCCUR.
SURFACE WINDS WILL INCREASE BY THE MIDDLE OF THE WEEK.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 98 73 101 74 / 10 10 10 10
HOBART OK 101 73 103 74 / 10 10 10 10
WICHITA FALLS TX 100 75 103 77 / 10 10 10 10
GAGE OK 100 70 102 71 / 10 10 10 10
PONCA CITY OK 96 71 100 73 / 10 10 10 10
DURANT OK 96 74 99 76 / 30 20 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
25/17
AREA FORECAST DISCUSSION
NWS PENDLETON OR
1050 AM PDT SUN AUG 17 2014
UPDATED THE AVIATION DISCUSSION
.UPDATE...TODAY AND TONIGHT...AN UPPER LEVEL LOW PRESENTLY MOVING
SOUTH ALONG THE WASHINGTON COASTLINE WILL CONTINUE TO MOVE SOUTH
DURING THE PERIOD. THE BEST DYNAMICS ASSOCIATED WITH THIS UPPER
LOW REMAINS ON THE WEST SIDE OF THE SYSTEM...WHICH IS OFFSHORE AND
AWAY FROM OUR AREA. HOWEVER...THE HEATING OF THE DAY WILL COMBINE WITH
THE LIFT PROVIDED BY THE LOW TO CAUSE SOME ISOLATED TO SCATTERED
THUNDERSTORMS OVER THE EAST SLOPES OF THE CASCADES...CENTRAL
OREGON...THE JOHN DAY HIGHLANDS AND THE SOUTHERN BLUE MOUNTAINS.
HAVE OPTED TO INDICATE THE BEST CHANCES OF THUNDERSTORMS TO BE
LATE THIS AFTERNOON INTO EARLY EVENING GIVEN HRRR AND LATEST MODEL
GUIDANCE. HAVE ALSO ADJUSTED THE SKY GRIDS TO ACCOUNT FOR THE
EXPECTED CLOUD COVER WITH THESE THUNDERSTORMS. OTHERWISE...OUTSIDE
OF MINOR TWEAKS TO TEMPERATURE GRIDS...THE FORECAST REMAINS ON
TRACK. BIEDA
.AVIATION...MOSTLY VFR CONDITIONS WILL PERSIST FOR THE NEXT 24 HOURS
EXCEPT FOR TAF SITES KRDM AND KBDN WHICH COULD APPROACH LCL MVFR
CEILINGS IN AND NEAR TSRA BETWEEN 20Z AND 04Z.
&&
.PREV DISC... /ISSUED 249 AM PDT SUN AUG 17 2014/
SHORT TERM...TODAY THROUGH MONDAY NIGHT...A WEAK UPPER LOW OVER
VANCOUVER ISLAND EARLY THIS MORNING WILL SLIDE SOUTH TODAY, CUTTING
OFF NEAR ASTORIA BY LATE AFTERNOON. THIS LOW WILL SLIDE SOUTH ALONG
THE COAST THROUGH THE REMAINDER OF THE PERIOD REACHING TO NEAR CAPE
BLANCO MONDAY MORNING THEN SOUTHWEST OF THE SAN FRANCISCO BAY AREA
BY EARLY TUESDAY MORNING. THE BEST DYNAMIC ENERGY WITH THIS SYSTEM
WILL REMAIN ON THE WEST SIDE OF THE LOW AND OVER THE COASTAL WATERS.
THIS WILL LIMIT THE CONTRIBUTION DYNAMIC ENERGY WILL ADD TO THE
POTENTIAL FOR THUNDERSTORM DEVELOPMENT THROUGH THIS PERIOD. ALSO
SHEAR ACROSS THE REGION WILL BE WEAK, LESS THAN 25 KTS. MOISTURE
WILL ALSO BE SOMEWHAT LIMITED, ESPECIALLY ACROSS SOUTHEAST
WASHINGTON AND EXTREME NORTHEAST OREGON ON MONDAY WHERE DRY WESTERLY
FLOW WILL RETURN. MEANWHILE DAYTIME HIGH TEMPS WILL RUN FROM THE LOW
80S TO LOW 90S, THUS HEATING WILL BE SUFFICIENT TO WORK ON THE
MOISTURE THAT IS AVAILABLE AND CAUSE SOME CONVECTIVE DEVELOPMENT.
OVERALL, WILL CONTINUE TO INDICATE A SLIGHT CHANCE OF AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS FROM CENTRAL OREGON EAST TO GRANT
COUNTY AND THE SOUTHERN BLUES TODAY AND MONDAY. THESE AREAS WILL SEE
SOME DIFFLUENCE ALOFT AND WILL HAVE THE DEEPEST MOISTURE. WILL ALSO
CONTINUE A SLIGHT CHANCE OVER THE WALLOWA MOUNTAINS EACH DAY DUE TO
CONVERGENT UPSLOPE/UP VALLEY WINDS. WILL ALSO ADD A SLIGHT CHANCE OF
STORMS TO THE CENTRAL WASHINGTON CASCADE EAST SLOPES TODAY DUE TO
THE LOW PASSING BY TO THE WEST AND SOME LOW LEVEL UPSLOPE FLOW THIS
AFTERNOON. 90
LONG TERM...TUESDAY THROUGH SATURDAY...TUESDAY A TROUGH WILL
DEVELOP OVER THE PACIFIC NORTHWEST WITH A PACIFIC COLD FRONT MOVING
THROUGH THE AREA DURING THE AFTERNOON. CONDITIONS WILL BECOME BREEZY
BEHIND THE FRONT...ESPECIALLY IN THE COLUMBIA BASIN AND CASCADE
GAPS. THE MAIN LIFT FROM THE TROUGH WILL REMAIN IN CANADA SO
PRECIPITATION WILL BE LIMITED TO OROGRAPHICALLY ENHANCED SHOWERS
OVER THE EAST SLOPES OF THE CASCADES AND THE BLUE MOUNTAINS. A BROAD
TROUGH WILL REMAIN OVER THE PACIFIC NORTHWEST WEDNESDAY THROUGH
FRIDAY. EMBEDDED IMPULSES WITHIN THE FLOW MAY TRIGGER SOME SHOWERS
AND THUNDERSTORMS THROUGH THE PERIOD...BUT MODELS ARE INCONSISTENT
ON TIMING AND LOCATION OF THESE IMPULSES. WITH LIMITED CONFIDENCE
DID NOT CHANGE EXISTING FORECAST OF SLIGHT CHANCE OF DIURNALLY AND
OROGRAPHICALLY ENHANCED SHOWERS AND THUNDERSTORMS OVER THE
MOUNTAINS. COONFIELD
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 89 62 92 62 / 0 10 10 10
ALW 90 67 93 67 / 0 10 10 10
PSC 92 64 95 64 / 0 10 0 0
YKM 89 62 92 62 / 0 10 0 0
HRI 92 63 94 62 / 0 10 0 0
ELN 91 66 94 61 / 10 10 0 0
RDM 88 53 90 54 / 20 20 20 20
LGD 87 53 90 54 / 10 10 10 10
GCD 89 59 92 58 / 20 20 20 10
DLS 92 65 95 66 / 0 10 10 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
98/97
AREA FORECAST DISCUSSION
NWS PENDLETON OR
835 AM PDT SUN AUG 17 2014
.UPDATE...TODAY AND TONIGHT...AN UPPER LEVEL LOW PRESENTLY MOVING
SOUTH ALONG THE WASHINGTON COASTLINE WILL CONTINUE TO MOVE SOUTH
DURING THE PERIOD. THE BEST DYNAMICS ASSOCIATED WITH THIS UPPER
LOW REMAINS ON THE WEST SIDE OF THE SYSTEM...WHICH IS OFFSHORE AND
AWAY FROM OUR AREA. HOWEVER...THE HEATING OF THE DAY WILL COMBINE WITH
THE LIFT PROVIDED BY THE LOW TO CAUSE SOME ISOLATED TO SCATTERED
THUNDERSTORMS OVER THE EAST SLOPES OF THE CASCADES...CENTRAL
OREGON...THE JOHN DAY HIGHLANDS AND THE SOUTHERN BLUE MOUNTAINS.
HAVE OPTED TO INDICATE THE BEST CHANCES OF THUNDERSTORMS TO BE
LATE THIS AFTERNOON INTO EARLY EVENING GIVEN HRRR AND LATEST MODEL
GUIDANCE. HAVE ALSO ADJUSTED THE SKY GRIDS TO ACCOUNT FOR THE
EXPECTED CLOUD COVER WITH THESE THUNDERSTORMS. OTHERWISE...OUTSIDE
OF MINOR TWEAKS TO TEMPERATURE GRIDS...THE FORECAST REMAINS ON
TRACK. BIEDA
&&
.PREV DISC... /ISSUED 249 AM PDT SUN AUG 17 2014/
SHORT TERM...TODAY THROUGH MONDAY NIGHT...A WEAK UPPER LOW OVER
VANCOUVER ISLAND EARLY THIS MORNING WILL SLIDE SOUTH TODAY, CUTTING
OFF NEAR ASTORIA BY LATE AFTERNOON. THIS LOW WILL SLIDE SOUTH ALONG
THE COAST THROUGH THE REMAINDER OF THE PERIOD REACHING TO NEAR CAPE
BLANCO MONDAY MORNING THEN SOUTHWEST OF THE SAN FRANCISCO BAY AREA
BY EARLY TUESDAY MORNING. THE BEST DYNAMIC ENERGY WITH THIS SYSTEM
WILL REMAIN ON THE WEST SIDE OF THE LOW AND OVER THE COASTAL WATERS.
THIS WILL LIMIT THE CONTRIBUTION DYNAMIC ENERGY WILL ADD TO THE
POTENTIAL FOR THUNDERSTORM DEVELOPMENT THROUGH THIS PERIOD. ALSO
SHEAR ACROSS THE REGION WILL BE WEAK, LESS THAN 25 KTS. MOISTURE
WILL ALSO BE SOMEWHAT LIMITED, ESPECIALLY ACROSS SOUTHEAST
WASHINGTON AND EXTREME NORTHEAST OREGON ON MONDAY WHERE DRY WESTERLY
FLOW WILL RETURN. MEANWHILE DAYTIME HIGH TEMPS WILL RUN FROM THE LOW
80S TO LOW 90S, THUS HEATING WILL BE SUFFICIENT TO WORK ON THE
MOISTURE THAT IS AVAILABLE AND CAUSE SOME CONVECTIVE DEVELOPMENT.
OVERALL, WILL CONTINUE TO INDICATE A SLIGHT CHANCE OF AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS FROM CENTRAL OREGON EAST TO GRANT
COUNTY AND THE SOUTHERN BLUES TODAY AND MONDAY. THESE AREAS WILL SEE
SOME DIFFLUENCE ALOFT AND WILL HAVE THE DEEPEST MOISTURE. WILL ALSO
CONTINUE A SLIGHT CHANCE OVER THE WALLOWA MOUNTAINS EACH DAY DUE TO
CONVERGENT UPSLOPE/UP VALLEY WINDS. WILL ALSO ADD A SLIGHT CHANCE OF
STORMS TO THE CENTRAL WASHINGTON CASCADE EAST SLOPES TODAY DUE TO
THE LOW PASSING BY TO THE WEST AND SOME LOW LEVEL UPSLOPE FLOW THIS
AFTERNOON. 90
LONG TERM...TUESDAY THROUGH SATURDAY...TUESDAY A TROUGH WILL
DEVELOP OVER THE PACIFIC NORTHWEST WITH A PACIFIC COLD FRONT MOVING
THROUGH THE AREA DURING THE AFTERNOON. CONDITIONS WILL BECOME BREEZY
BEHIND THE FRONT...ESPECIALLY IN THE COLUMBIA BASIN AND CASCADE
GAPS. THE MAIN LIFT FROM THE TROUGH WILL REMAIN IN CANADA SO
PRECIPITATION WILL BE LIMITED TO OROGRAPHICALLY ENHANCED SHOWERS
OVER THE EAST SLOPES OF THE CASCADES AND THE BLUE MOUNTAINS. A BROAD
TROUGH WILL REMAIN OVER THE PACIFIC NORTHWEST WEDNESDAY THROUGH
FRIDAY. EMBEDDED IMPULSES WITHIN THE FLOW MAY TRIGGER SOME SHOWERS
AND THUNDERSTORMS THROUGH THE PERIOD...BUT MODELS ARE INCONSISTENT
ON TIMING AND LOCATION OF THESE IMPULSES. WITH LIMITED CONFIDENCE
DID NOT CHANGE EXISTING FORECAST OF SLIGHT CHANCE OF DIURNALLY AND
OROGRAPHICALLY ENHANCED SHOWERS AND THUNDERSTORMS OVER THE
MOUNTAINS. COONFIELD
AVIATION...12Z TAFS...VFR CONDITIONS WILL PREVAIL FOR THE NEXT 24
HOURS AT MOST TAF LOCATIONS. MOISTURE AND INSTABILITY COMBINED WITH
AFTERNOON HEATING MAY TRIGGER A FEW THUNDERSTORMS NEAR KRDM AND KBDN
BETWEEN 21Z AND 04Z. WINDS WILL INCREASE TO 10 TO 15 KTS WITH HIGHER
GUSTS DURING THE AFTERNOON IN ALL AREAS...ESPECIALLY AT KRDM...KBDN
AND KDLS. 76
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 89 62 92 62 / 0 10 10 10
ALW 90 67 93 67 / 0 10 10 10
PSC 92 64 95 64 / 0 10 0 0
YKM 89 62 92 62 / 0 10 0 0
HRI 92 63 94 62 / 0 10 0 0
ELN 91 66 94 61 / 10 10 0 0
RDM 88 53 90 54 / 20 20 20 20
LGD 87 53 90 54 / 10 10 10 10
GCD 89 59 92 58 / 20 20 20 10
DLS 92 65 95 66 / 0 10 10 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
98/76/76
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1129 AM EDT SUN AUG 17 2014
.SYNOPSIS...
A WEAK FRONTAL BOUNDARY WILL PUSH TO OUR SOUTH TODAY. ANOTHER WAVE
IN THE UPPER- LEVEL NORTHWESTERLY FLOW WILL PULL THIS BOUNDARY
BACK INTO OUR REGION MONDAY INTO TUESDAY INCREASING THE CHANCE OF
RAIN. THE NORTHWESTERLY FLOW WILL WEAKEN BUT REMAIN OVER THE
REGION...TRAPPED BENEATH A HIGH LATITUDE BLOCK. MOISTURE AND A
FRONTAL BOUNDARY JUST TO OUR SOUTH WILL LIKELY PRODUCE PERIODS OF
UNSETTLED WEATHER UNTIL THE HIGH LATITUDE BLOCK WEAKENS.
&&
.NEAR TERM /THROUGH TONIGHT/...
USING HRRR AND RADAR PUT HIGH POPS AND RAIN IN SE MAXIMIZED OVER
LANCASTER FOR NEXT 1-2 HOURS THEN DROPPED POPS. TRIED TO SHOW
BASED ON RADAR...THE RAIN MOVING ACROSS SOUTHWEST MOUNTAINS IN
NEXT 1-2 HOURS. VERY LIGHT RAIN IN SW.
AFTER THAT POPS WITH CHANCE AND SLIGHT CHANCE FOCUSED NEAR MD
BORDER. MAINLY PARTLY TO MOSTLY CLOUDY CENTRAL AND NORTHERN AREAS.
CONVECTIVE ALLOWING MODELS SEEM TO SUGGEST ALL ORGANIZED RAIN OUT
OF OUR AREA BY ABOUT NOON. THEN ONLY MINOR BUMPINESS IMPLYING WEAK
CONVECTION...LESS IN EACH RUN AND MAINLY SOUTH AND EAST OF OUR
AREA.
SHOULD BE A PRETTY GOOD AFTERNOON ACROSS THE REGION WITH ANY
ISOLATED RESIDUAL SHOWERS IN AFTERNOON IN SOUTHERN AREAS.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
QUIET OVERNIGHT IN A RELATIVE SENSE AND NO WEATHER TO MENTION.
PATCHY FOG WITH MOISTURE FROM LIGHT RAINS THAT AFFECTED THE
REGION TODAY.
THE SREF AND GEFS AND A BLEND SUGGEST RAIN MOVES INTO SOUTHWEST PA
MONDAY. SREF PDF IMPLIES RAIN IN OUR SOUTHWEST COUNTIES AT SLIGHT CHANCE
LEVEL BY LATE MORNING THEN CHANCE BY EARLY AFTERNOON. THIS SPREADS
SLOWLY TO THE NORTHEAST. THE WESTERN THIRD OF OUR REGION SHOULD BE
IN CHANCE SHOWERS/RAIN BY EVENING MONDAY. THE EASTERN AREAS SHOULD
STAY DRY UNTIL THE OVERNIGHT PERIOD. IF ONE BELIEVES THE 3-HOUR
INCREMENTS IN THE SREF AND 6-HOUR INCREMENTS IN THE GEFS.
RAIN IS LIKELY IN EXTREME SOUTHEAST BY MID-LATE AFTERNOON.
GENERALLY SLOW EVOLUTION OF PRECIPITATION SHIELD.
KEY POINT: NICE OVERNIGHT PARTIAL CLEARING. MOSTLY SUNNY WEST AND
NORTH WITH CLOUDS RAIN COMING INTO SOUTHWEST. MOST EAST AND
NORTHEAST AREAS SHOULD HAVE A PRETTY GOOD DAY. SOMERSET COUNTY
SHOULD BE THE WETTEST.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE PERIOD STARTS OFF WITH A WEAK SFC LOW AND ASSOCD FRONTAL
SYSTEM TRACKING EWD THRU THE GRT LKS WED-FRI. THIS WILL KEEP THE
PATTERN UNSETTLED AND POTENTIALLY WET DURING THE SECOND HALF OF
THE WORK WEEK. FOR NOW IT APPEARS A DRYING TREND WILL START THE
WEEKEND WITH HIGH PRESSURE TAKING UP RESIDENCE IN NRN NEW ENGLAND.
BLOCKING OVER ATLANTIC CANADA AND GREENLAND SHOULD ALLOW FOR THE
BERMUDA HIGH AND SOUTHEAST RIDGE TO BUILD WWD INTO THE TN AND LWR
MS VLYS...WHILE EASTERLY COMPNT TO THE LLVL FLOW TEMPERS HIGHS
DESPITE RISING HGTS ALOFT. A CONSENSUS BLEND OF WPC WITH GFS AND
ECMWF MOS BASED PRODUCTS FAVORS NEAR OR JUST BLW CLIMO NUMBERS FOR
MID-LATE AUGUST.
&&
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
RESIDUAL SHOWERS MOVING OUT OF LANCASTER COUNTY TO POINTS EAST AND
ISOLATED SHOWERS IN SOUTHWEST MOUNTAINS WEAKENING. EXPECT ALL
AREAS TO CLIMB TO VFR IN THE NEXT HOUR OR SO.
VFR SHOULD DOMINATE THE REGION THIS AFTERNOON AND EVENING.
PATCHY FOG OVERNIGHT WILL BRING REGIONS OF IFR/MVFR. BETTER
RADIATIONAL COOLING LOCATIONS WHERE IT RAINED WILL LIKELY GENERATE
ISOLATED AREAS OF LIFR AFTER MIDNIGHT AND A FEW HOURS AFTER
SUNRISE MONDAY.
MOSTLY VFR MONDAY...EXCEPT MVFR MOVING INTO SOUTHWEST AS NEXT
FRONTAL SYSTEM SPREADS RAIN SOUTHWEST TO NORTHEAST ACROSS THE
STATE MONDAY IN THE AFTERNOON AND INTO THE EVENING.
CONDITIONS IMPROVE AGAIN TUESDAY INTO WEDNESDAY EXCEPT FOR
OVERNIGHT PATCHY FOG ISSUES.
OUTLOOK...
MON...AM FOG POSS N MTNS. SLIGHT CHC OF PM TSRA IMPACTS
KJST/KAOO.
TUE...RAIN/LOW CIGS POSSIBLE...MAINLY SOUTHERN PA FIRST HALF DAY.
WED-THU...AM FOG POSS. SCT PM TSRA IMPACTS POSS W MTNS...ESP W
MTNS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GRUMM
NEAR TERM...GRUMM
SHORT TERM...GRUMM
LONG TERM...STEINBUGL
AVIATION...GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1116 AM EDT SUN AUG 17 2014
.SYNOPSIS...
A WEAK FRONTAL BOUNDARY WILL PUSH TO OUR SOUTH TODAY. ANOTHER WAVE
IN THE UPPER- LEVEL NORTHWESTERLY FLOW WILL PULL THIS BOUNDARY
BACK INTO OUR REGION MONDAY INTO TUESDAY INCREASING THE CHANCE OF
RAIN. THE NORTHWESTERLY FLOW WILL WEAKEN BUT REMAIN OVER THE
REGION...TRAPPED BENEATH A HIGH LATITUDE BLOCK. MOISTURE AND A
FRONTAL BOUNDARY JUST TO OUR SOUTH WILL LIKELY PRODUCE PERIODS OF
UNSETTLED WEATHER UNTIL THE HIGH LATITUDE BLOCK WEAKENS.
&&
.NEAR TERM /THROUGH TONIGHT/...
USING HRRR AND RADAR PUT HIGH POPS AND RAIN IN SE MAXIMIZED OVER
LANCASTER FOR NEXT 1-2 HOURS THEN DROPPED POPS. TRIED TO SHOW
BASED ON RADAR...THE RAIN MOVING ACROSS SOUTHWEST MOUNTAINS IN
NEXT 1-2 HOURS. VERY LIGHT RAIN IN SW.
AFTER THAT POPS WITH CHANCE AND SLIGHT CHANCE FOCUSED NEAR MD
BORDER. MAINLY PARTLY TO MOSTLY CLOUDY CENTRAL AND NORTHERN AREAS.
CONVECTIVE ALLOWING MODELS SEEM TO SUGGEST ALL ORGANIZED RAIN OUT
OF OUR AREA BY ABOUT NOON. THEN ONLY MINOR BUMPINESS IMPLYING WEAK
CONVECTION...LESS IN EACH RUN AND MAINLY SOUTH AND EAST OF OUR
AREA.
SHOULD BE A PRETTY GOOD AFTERNOON ACROSS THE REGION WITH ANY
ISOLATED RESIDUAL SHOWERS IN AFTERNOON IN SOUTHERN AREAS.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
QUIET OVERNIGHT IN A RELATIVE SENSE AND NO WEATHER TO MENTION.
PATCHY FOG WITH MOISTURE FROM LIGHT RAINS THAT AFFECTED THE
REGION TODAY.
THE SREF AND GEFS AND A BLEND SUGGEST RAIN MOVES INTO SOUTHWEST PA
MONDAY. SREF PDF IMPLIES RAIN IN OUR SOUTHWEST COUNTIES AT SLIGHT CHANCE
LEVEL BY LATE MORNING THEN CHANCE BY EARLY AFTERNOON. THIS SPREADS
SLOWLY TO THE NORTHEAST. THE WESTERN THIRD OF OUR REGION SHOULD BE
IN CHANCE SHOWERS/RAIN BY EVENING MONDAY. THE EASTERN AREAS SHOULD
STAY DRY UNTIL THE OVERNIGHT PERIOD. IF ONE BELIEVES THE 3-HOUR
INCREMENTS IN THE SREF AND 6-HOUR INCREMENTS IN THE GEFS.
RAIN IS LIKELY IN EXTREME SOUTHEAST BY MID-LATE AFTERNOON.
GENERALLY SLOW EVOLUTION OF PRECIPITATION SHIELD.
KEY POINT: NICE OVERNIGHT PARTIAL CLEARING. MOSTLY SUNNY WEST AND
NORTH WITH CLOUDS RAIN COMING INTO SOUTHWEST. MOST EAST AND
NORTHEAST AREAS SHOULD HAVE A PRETTY GOOD DAY. SOMERSET COUNTY
SHOULD BE THE WETTEST.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE PERIOD STARTS OFF WITH A WEAK SFC LOW AND ASSOCD FRONTAL
SYSTEM TRACKING EWD THRU THE GRT LKS WED-FRI. THIS WILL KEEP THE
PATTERN UNSETTLED AND POTENTIALLY WET DURING THE SECOND HALF OF
THE WORK WEEK. FOR NOW IT APPEARS A DRYING TREND WILL START THE
WEEKEND WITH HIGH PRESSURE TAKING UP RESIDENCE IN NRN NEW ENGLAND.
BLOCKING OVER ATLANTIC CANADA AND GREENLAND SHOULD ALLOW FOR THE
BERMUDA HIGH AND SOUTHEAST RIDGE TO BUILD WWD INTO THE TN AND LWR
MS VLYS...WHILE EASTERLY COMPNT TO THE LLVL FLOW TEMPERS HIGHS
DESPITE RISING HGTS ALOFT. A CONSENSUS BLEND OF WPC WITH GFS AND
ECMWF MOS BASED PRODUCTS FAVORS NEAR OR JUST BLW CLIMO NUMBERS FOR
MID-LATE AUGUST.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
A WEAKENING COLD FRONT WILL PUSH SE ACROSS THE AREA OVERNIGHT...
ACCOMPANIED BY SCT -SHRA. HOWEVER...THE MAIN AVIATION CONCERN
WILL BE THE POTENTIAL OF PRE-DAWN LOW CIGS AT KBFD...CAUSED BY
POST-FRONTAL LOW LVL MOISTURE ASCENDING THE HIGH TERRAIN OF NW PA
AND MOISTENING CAUSED BY SHOWERS NOW OCCURRING. THE THREAT OF LOW
CIGS WILL PUSH SOUTHWARD ALONG THE SPINE OF THE ALLEGHENIES TO
KJST IN THE 10Z- 14Z TIME FRAME. FARTHER EAST...A DRYING/DOWNSLOPING
FLOW WILL MAKE ANY SIGNIFICANT RESTRICTIONS MUCH LESS LIKELY.
THE COLD FRONT WILL SETTLE SOUTH OF THE AREA DURING THE DAY
TODAY. ANY LOW CIGS ARND KJST SHOULD GIVE WAY TO WIDESPREAD VFR
CONDS ACROSS CENTRAL PA...AS DRIER NW FLOW OVERSPREADS THE REGION.
OUTLOOK...
MON...AM FOG POSS N MTNS. SLIGHT CHC OF PM TSRA IMPACTS
KJST/KAOO.
TUE...RAIN/LOW CIGS POSSIBLE...MAINLY SOUTHERN PA.
WED-THU...AM FOG POSS. SCT PM TSRA IMPACTS POSS W MTNS...ESP W
MTNS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GRUMM
NEAR TERM...GRUMM
SHORT TERM...GRUMM
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1049 AM EDT SUN AUG 17 2014
.SYNOPSIS...
A COLD FRONT MOVING SOUTHEAST FROM LAKE ERIE WILL CONTINUE TO PUSH
THROUGH CENTRAL PENNSYLVANIA BY TONIGHT BEFORE BECOMING NEARLY
STATIONARY SOUTH OF THE MASON DIXON LINE. WAVES OF LOW PRESSURE
MOVING EAST FROM THE OHIO VALLEY ALONG THE FRONTAL ZONE WILL
BRING PERIODS OF RAIN TO THE AREA THROUGH MUCH OF THE UPCOMING
WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
USING HRRR AND RADAR PUT HIGH POPS AND RAIN IN SE MAXIMIZED OVER
LANCASTER FOR NEXT 1-2 HOURS THEN DROPPED POPS. TRIED TO SHOW
BASED ON RADAR...THE RAIN MOVING ACROSS SOUTHWEST MOUNTAINS IN
NEXT 1-2 HOURS. VERY LIGHT RAIN IN SW.
AFTER THAT POPS WITH CHANCE AND SLIGHT CHANCE FOCUSED NEAR MD
BORDER. MAINLY PARTLY TO MOSTLY CLOUDY CENTRAL AND NORTHERN AREAS.
CONVECTIVE ALLOWING MODELS SEEM TO SUGGEST ALL ORGANIZED RAIN OUT
OF OUR AREA BY ABOUT NOON. THEN ONLY MINOR BUMPINESS IMPLYING WEAK
CONVECTION...LESS IN EACH RUN AND MAINLY SOUTH AND EAST OF OUR
AREA.
SHOULD BE A PRETTY GOOD AFTERNOON ACROSS THE REGION WITH ANY
ISOLATED RESIDUAL SHOWERS IN AFTERNOON IN SOUTHERN AREAS.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
QUIET OVERNIGHT IN A RELATIVE SENSE AND NO WEATHER TO MENTION.
PATCHY FOG WITH MOISTURE FROM LIGHT RAINS THAT AFFECTED THE
REGION TODAY.
THE SREF AND GEFS AND A BLEND SUGGEST RAIN MOVES INTO SOUTHWEST PA
MONDAY. SREF PDF IMPLIES RAIN IN OUR SOUTHWEST COUNTIES AT SLIGHT CHANCE
LEVEL BY LATE MORNING THEN CHANCE BY EARLY AFTERNOON. THIS SPREADS
SLOWLY TO THE NORTHEAST. THE WESTERN THIRD OF OUR REGION SHOULD BE
IN CHANCE SHOWERS/RAIN BY EVENING MONDAY. THE EASTERN AREAS SHOULD
STAY DRY UNTIL THE OVERNIGHT PERIOD. IF ONE BELIEVES THE 3-HOUR
INCREMENTS IN THE SREF AND 6-HOUR INCREMENTS IN THE GEFS.
RAIN IS LIKELY IN EXTREME SOUTHEAST BY MID-LATE AFTERNOON.
GENERALLY SLOW EVOLUTION OF PRECIPITATION SHIELD.
KEY POINT: NICE OVERNIGHT PARTIAL CLEARING. MOSTLY SUNNY WEST AND
NORTH WITH CLOUDS RAIN COMING INTO SOUTHWEST. MOST EAST AND
NORTHEAST AREAS SHOULD HAVE A PRETTY GOOD DAY. SOMERSET COUNTY
SHOULD BE THE WETTEST.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE PERIOD STARTS OFF WITH A WEAK SFC LOW AND ASSOCD FRONTAL
SYSTEM TRACKING EWD THRU THE GRT LKS WED-FRI. THIS WILL KEEP THE
PATTERN UNSETTLED AND POTENTIALLY WET DURING THE SECOND HALF OF
THE WORK WEEK. FOR NOW IT APPEARS A DRYING TREND WILL START THE
WEEKEND WITH HIGH PRESSURE TAKING UP RESIDENCE IN NRN NEW ENGLAND.
BLOCKING OVER ATLANTIC CANADA AND GREENLAND SHOULD ALLOW FOR THE
BERMUDA HIGH AND SOUTHEAST RIDGE TO BUILD WWD INTO THE TN AND LWR
MS VLYS...WHILE EASTERLY COMPNT TO THE LLVL FLOW TEMPERS HIGHS
DESPITE RISING HGTS ALOFT. A CONSENSUS BLEND OF WPC WITH GFS AND
ECMWF MOS BASED PRODUCTS FAVORS NEAR OR JUST BLW CLIMO NUMBERS FOR
MID-LATE AUGUST.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
A WEAKENING COLD FRONT WILL PUSH SE ACROSS THE AREA OVERNIGHT...
ACCOMPANIED BY SCT -SHRA. HOWEVER...THE MAIN AVIATION CONCERN
WILL BE THE POTENTIAL OF PRE-DAWN LOW CIGS AT KBFD...CAUSED BY
POST-FRONTAL LOW LVL MOISTURE ASCENDING THE HIGH TERRAIN OF NW PA
AND MOISTENING CAUSED BY SHOWERS NOW OCCURRING. THE THREAT OF LOW
CIGS WILL PUSH SOUTHWARD ALONG THE SPINE OF THE ALLEGHENIES TO
KJST IN THE 10Z- 14Z TIME FRAME. FARTHER EAST...A DRYING/DOWNSLOPING
FLOW WILL MAKE ANY SIGNIFICANT RESTRICTIONS MUCH LESS LIKELY.
THE COLD FRONT WILL SETTLE SOUTH OF THE AREA DURING THE DAY
TODAY. ANY LOW CIGS ARND KJST SHOULD GIVE WAY TO WIDESPREAD VFR
CONDS ACROSS CENTRAL PA...AS DRIER NW FLOW OVERSPREADS THE REGION.
OUTLOOK...
MON...AM FOG POSS N MTNS. SLIGHT CHC OF PM TSRA IMPACTS
KJST/KAOO.
TUE...RAIN/LOW CIGS POSSIBLE...MAINLY SOUTHERN PA.
WED-THU...AM FOG POSS. SCT PM TSRA IMPACTS POSS W MTNS...ESP W
MTNS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...GRUMM
SHORT TERM...GRUMM
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
759 AM EDT SUN AUG 17 2014
.SYNOPSIS...
A COLD FRONT MOVING SOUTHEAST FROM LAKE ERIE WILL CONTINUE TO PUSH
THROUGH CENTRAL PENNSYLVANIA BY TONIGHT BEFORE BECOMING NEARLY
STATIONARY SOUTH OF THE MASON DIXON LINE. WAVES OF LOW PRESSURE
MOVING EAST FROM THE OHIO VALLEY ALONG THE FRONTAL ZONE WILL
BRING PERIODS OF RAIN TO THE AREA THROUGH MUCH OF THE UPCOMING
WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
A BAND OF RAIN OVER CENTRAL PA TO NEARLY THE MARYLAND BORDER IS
SAGGING SLOWLY TO THE SOUTH AND EAST. IT WILL BE A RELATIVELY WET
FIRST HALF OF THE MORNING IN MOST OF CENTRAL PA AS CORES OF
SHOWERS MOVE EAST ALONG THE SAGGING BOUNDARY. MOST RAIN SHOULD END
AROUND NOON. EARLIER NORTH LATER SOUTH.
THE VISUAL SATELLITE IMAGERY SHOWS A BREAK IN THE CLOUDS OVER THE
NORTHEASTERN TIER OF THE STATE IT TOO IS SAGGING SOUTH...BUT SOME
MORE LOW CLOUDS IN NEW YORK ARE LINED UP TO REPLACE THEM. THE
CLEAR AREA WILL PROVIDE SOME PEAKS OF SUN AS IT MOVES SOUTH.
THE LATEST 3KM HRRR IS AGGRESSIVE GETTING ALL THE RAIN TO OUR
EAST BY NOON (16Z). THIS IS CLOSE TO LINEAR EXTRAPOLATION SHOULD
NO NEW SHOWERS EVOLVE.
CONDITIONS SHOULD IMPROVE NORTHWEST TO SOUTHEAST TODAY. LESS
ACTIVITY BUT WITH SOME PEAKS OF SUN...SHOWERS COULD HAVE ISOLATED
THUNDERSTORMS POSSIBLE NORTH OF THE BOUNDARY. THE HRRR SHOWS
ISOLATED SHOWERS AND THUNDER LOOK TO IT SOUTHERN PA AND MD SO KEPT
LOW POPS IN SOUTHERN AREAS INTO EVENING.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
UPDATED FORECAST A BIT WITH ONLY MINOR CHANGES TO TEMPS AND POPS.
BUT THE RAIN POTENTIAL WILL SLOWLY INCREASE MONDAY INTO MONDAY
NIGHT FROM SOUTHWEST. THE GEFS/SREF WOULD IMPLY CHANCE RAIN MOST
OF SOUTHERN PA BY MONDAY AFTERNOON.
PREVIOUS:
A WAVE OF LOW PRESSURE WILL TRACK EWD FROM THE OH VLY
ALONG THE Q-STNRY FRONTAL BOUNDARY DRAPED ACRS THE CNTRL APPLCHNS
ON D2 AND SHOULD REACH THE VA/DELMARVA COAST AROUND 12Z TUE. A N-S
GRADIENT OF PWS WILL EXIST OVER THE AREA WITH THE BEST MSTR /1.5+
INCH PWATS/ POOLING FROM SRN PA SWD INTO THE SRN MID ATLANTIC AND
SOUTHEAST STATES. WAA/ISENT LIFT ALONG WITH INCR ESELY LLVL INFLOW
SHOULD BRING RAIN INTO AT LEAST THE SRN PARTS OF THE REGION WITH
GLOBAL MODELS AND ENSEMBLE DATA DEPICTING THE HIGHEST QPF AMTS
OVER NRN VA BLUE RIDGE/WV PNHDL/XTRME S-CNTRL PA. THERE IS A LARGE
SPREAD IN THE GUIDANCE CONCERNING THE EVOLUTION OF THE LOW AS IT
MOVES OFFSHORE BY 12Z WED. MEANWHILE...THE NEXT H5 S/WV TROUGH
STARTS TO CROSS THE GRT LKS REGION WITH AN ACCOMPANYING SFC LOW OF
ITS OWN REACHING LK MI VCNTY BY THE END OF THE PERIOD. THIS
FRONTAL SYSTEM SHOULD BRING RAIN INTO THE AREA THRU MID-WEEK.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE PERIOD STARTS OFF WITH A WEAK SFC LOW AND ASSOCD FRONTAL
SYSTEM TRACKING EWD THRU THE GRT LKS WED-FRI. THIS WILL KEEP THE
PATTERN UNSETTLED AND POTENTIALLY WET DURING THE SECOND HALF OF
THE WORK WEEK. FOR NOW IT APPEARS A DRYING TREND WILL START THE
WEEKEND WITH HIGH PRESSURE TAKING UP RESIDENCE IN NRN NEW ENGLAND.
BLOCKING OVER ATLANTIC CANADA AND GREENLAND SHOULD ALLOW FOR THE
BERMUDA HIGH AND SOUTHEAST RIDGE TO BUILD WWD INTO THE TN AND LWR
MS VLYS...WHILE EASTERLY COMPNT TO THE LLVL FLOW TEMPERS HIGHS
DESPITE RISING HGTS ALOFT. A CONSENSUS BLEND OF WPC WITH GFS AND
ECMWF MOS BASED PRODUCTS FAVORS NEAR OR JUST BLW CLIMO NUMBERS FOR
MID-LATE AUGUST.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
A WEAKENING COLD FRONT WILL PUSH SE ACROSS THE AREA OVERNIGHT...
ACCOMPANIED BY SCT -SHRA. HOWEVER...THE MAIN AVIATION CONCERN
WILL BE THE POTENTIAL OF PRE-DAWN LOW CIGS AT KBFD...CAUSED BY
POST-FRONTAL LOW LVL MOISTURE ASCENDING THE HIGH TERRAIN OF NW PA
AND MOISTENING CAUSED BY SHOWERS NOW OCCURRING. THE THREAT OF LOW
CIGS WILL PUSH SOUTHWARD ALONG THE SPINE OF THE ALLEGHENIES TO
KJST IN THE 10Z- 14Z TIME FRAME. FARTHER EAST...A DRYING/DOWNSLOPING
FLOW WILL MAKE ANY SIGNIFICANT RESTRICTIONS MUCH LESS LIKELY.
THE COLD FRONT WILL SETTLE SOUTH OF THE AREA DURING THE DAY
TODAY. ANY LOW CIGS ARND KJST SHOULD GIVE WAY TO WIDESPREAD VFR
CONDS ACROSS CENTRAL PA...AS DRIER NW FLOW OVERSPREADS THE REGION.
OUTLOOK...
MON...AM FOG POSS N MTNS. SLIGHT CHC OF PM TSRA IMPACTS
KJST/KAOO.
TUE...RAIN/LOW CIGS POSSIBLE...MAINLY SOUTHERN PA.
WED-THU...AM FOG POSS. SCT PM TSRA IMPACTS POSS W MTNS...ESP W
MTNS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...GRUMM/STEINBUGL
SHORT TERM...GRUMM/STEINBUGL
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
527 AM EDT SUN AUG 17 2014
.SYNOPSIS...
A COLD FRONT MOVING SOUTHEAST FROM LAKE ERIE WILL CONTINUE TO PUSH
THROUGH CENTRAL PENNSYLVANIA BY TONIGHT BEFORE BECOMING NEARLY
STATIONARY SOUTH OF THE MASON DIXON LINE. WAVES OF LOW PRESSURE
MOVING EAST FROM THE OHIO VALLEY ALONG THE FRONTAL ZONE WILL
BRING PERIODS OF RAIN TO THE AREA THROUGH MUCH OF THE UPCOMING
WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
A NARROW BAND OF FRONTAL SHOWERS CURRENTLY LOCATED JUST SOUTH OF
THE I-80 CORRIDOR WILL CONTINUE TO DROP SEWD ACROSS S-CENTRAL PA
EARLY THIS MORNING. THE LATEST HRRR SHOWS THE BAND REACHING THE PA
TURNPIKE AROUND 12-13Z WITH DEC CVRG OVER THE SRN ZONES THRU THE
MORNING HOURS. IR STLT LOOP SHOWS A POST-FRONTAL LOW STRATUS
CLOUD DECK WORKING INTO NRN PA IN THE WAKE OF THE COLD FRONT.
STILL EXPECT DRY WX TO PREVAIL OVER THIS AREA TODAY BUT WILL NEED
TO INCREASE SKY COVER THIS MORNING.
A LOW RISK FOR SCT SHOWERS AND ISOLD TSTMS /20-30 PCT AT BEST/
WILL REMAIN THRU THE AFTN HOURS IN THE SRN TIER ZONES INVOF THE
BOUNDARY. MAX TEMPS WILL BE SLIGHTLY BELOW NORMAL FOR MID-AUG IN
THE LOW 70S NORTH TO AROUND 80F IN THE LOWER SUSQ. VLY.
THE FRONT BECOMES Q-STNRY SOUTH OF THE MASON DIXON LINE TONIGHT.
CLEARING/LGT WINDS IN THE NORTH ALONG WITH LOW PWS SHOULD ALLOW
TEMPS TO DROP TO AROUND 50F WITH WARMER READINGS AROUND 60F OVER
SRN PA WHERE CLOUD COVER SHOULD MORE EXPANSIVE.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
A WAVE OF LOW PRESSURE WILL TRACK EWD FROM THE OH VLY ALONG THE
Q-STNRY FRONTAL BOUNDARY DRAPED ACRS THE CNTRL APPLCHNS ON D2 AND
SHOULD REACH THE VA/DELMARVA COAST AROUND 12Z TUE. A N-S GRADIENT
OF PWS WILL EXIST OVER THE AREA WITH THE BEST MSTR /1.5+ INCH
PWATS/ POOLING FROM SRN PA SWD INTO THE SRN MID ATLANTIC AND
SOUTHEAST STATES. WAA/ISENT LIFT ALONG WITH INCR ESELY LLVL INFLOW
SHOULD BRING RAIN INTO AT LEAST THE SRN PARTS OF THE REGION WITH
GLOBAL MODELS AND ENSEMBLE DATA DEPICTING THE HIGHEST QPF AMTS
OVER NRN VA BLUE RIDGE/WV PNHDL/XTRME S-CNTRL PA. THERE IS A LARGE
SPREAD IN THE GUIDANCE CONCERNING THE EVOLUTION OF THE LOW AS IT
MOVES OFFSHORE BY 12Z WED. MEANWHILE...THE NEXT H5 S/WV TROUGH
STARTS TO CROSS THE GRT LKS REGION WITH AN ACCOMPANYING SFC LOW OF
ITS OWN REACHING LK MI VCNTY BY THE END OF THE PERIOD. THIS
FRONTAL SYSTEM SHOULD BRING RAIN INTO THE AREA THRU MID-WEEK.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE PERIOD STARTS OFF WITH A WEAK SFC LOW AND ASSOCD FRONTAL
SYSTEM TRACKING EWD THRU THE GRT LKS WED-FRI. THIS WILL KEEP THE
PATTERN UNSETTLED AND POTENTIALLY WET DURING THE SECOND HALF OF
THE WORK WEEK. FOR NOW IT APPEARS A DRYING TREND WILL START THE
WEEKEND WITH HIGH PRESSURE TAKING UP RESIDENCE IN NRN NEW ENGLAND.
BLOCKING OVER ATLANTIC CANADA AND GREENLAND SHOULD ALLOW FOR THE
BERMUDA HIGH AND SOUTHEAST RIDGE TO BUILD WWD INTO THE TN AND LWR
MS VLYS...WHILE EASTERLY COMPNT TO THE LLVL FLOW TEMPERS HIGHS
DESPITE RISING HGTS ALOFT. A CONSENSUS BLEND OF WPC WITH GFS AND
ECMWF MOS BASED PRODUCTS FAVORS NEAR OR JUST BLW CLIMO NUMBERS FOR
MID-LATE AUGUST.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
A WEAKENING COLD FRONT WILL PUSH SE ACROSS THE AREA OVERNIGHT...
ACCOMPANIED BY SCT -SHRA. HOWEVER...THE MAIN AVIATION CONCERN
WILL BE THE POTENTIAL OF PRE-DAWN LOW CIGS AT KBFD...CAUSED BY
POST-FRONTAL LOW LVL MOISTURE ASCENDING THE HIGH TERRAIN OF NW PA
AND MOISTENING CAUSED BY SHOWERS NOW OCCURRING. THE THREAT OF LOW
CIGS WILL PUSH SOUTHWARD ALONG THE SPINE OF THE ALLEGHENIES TO
KJST IN THE 10Z- 14Z TIME FRAME. FARTHER EAST...A DRYING/DOWNSLOPING
FLOW WILL MAKE ANY SIGNIFICANT RESTRICTIONS MUCH LESS LIKELY.
THE COLD FRONT WILL SETTLE SOUTH OF THE AREA DURING THE DAY
TODAY. ANY LOW CIGS ARND KJST SHOULD GIVE WAY TO WIDESPREAD VFR
CONDS ACROSS CENTRAL PA...AS DRIER NW FLOW OVERSPREADS THE REGION.
OUTLOOK...
MON...AM FOG POSS N MTNS. SLIGHT CHC OF PM TSRA IMPACTS
KJST/KAOO.
TUE...RAIN/LOW CIGS POSSIBLE...MAINLY SOUTHERN PA.
WED-THU...AM FOG POSS. SCT PM TSRA IMPACTS POSS W MTNS...ESP W
MTNS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/GARTNER
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
808 PM MDT MON AUG 18 2014
.UPDATE...
ISSUED AT 806 PM MDT MON AUG 18 2014
00Z KUNR SOUNDING SHOWED A BIT OF MUCAPE. COUPLE OF WEAK
SHORTWAVES OVER SOUTH CENTRAL MT/NORTHWEST WY WILL MOVE EAST
THROUGH THE SOUTHWEST THIRD OF THE CWA OVERNIGHT BRINGING WITH IT
ISOLATED TSRA. LATEST HRRR SEEMS TO PICK UP ON THIS AS WELL AS
CURRENT RADAR TRENDS TO OUR WEST. WILL SPREAD POPS FROM CURRENT
RADAR RETURNS THROUGH SOUTHWEST THIRD OF CWA TO ACCOUNT WITH UPDATE.
&&
.SHORT TERM...THIS EVENING THROUGH TUESDAY NIGHT
ISSUED AT 300 PM MDT MON AUG 18 2014
CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE OVER FAR NORTHERN MN
WITH HIGH PRESSURE OVER CENTRAL MT. UPPER LEVEL ANALYSIS SHOWS
TROF OVER SOUTH CENTRAL CANADA...WITH NORTHWESTERLY FLOW OVER MOST
OF THE NORTHERN HIGH PLAINS. DRIER AIR IS IN PLACE ACROSS THE AREA
FOR TODAY...WITH DEWPOINTS MOSTLY IN THE UPPER 40S AND 50S.
SHOWERS AND STORMS THIS AFTERNOON HAVE STAYED TO THE NORTH AND
SOUTH OF THE CWA...WITH A FEW STRONG STORMS OVER THE NEB PANHANDLE
RIGHT NOW. TEMPS ARE IN THE UPPER 79S TO UPPER 80S WITH BRISK
NORTHWESTERLY WINDS ACROSS MUCH OF THE PLAINS. THESE WINDS WILL
BEGIN TO DIMINISH BY EARLY EVENING.
UNSETTLED WEATHER WILL RETURN LATER ON TUESDAY AND PERSIST AT TIMES
THROUGH THE END OF THE WEEK AS HIGH PRESSURE ALOFT MOVES INTO THE
SOUTHEASTERN CONUS AND A BROAD TROF DEVELOPS OVER THE WESTERN
STATES. DAILY CHANCES FOR SHOWERS AND STORMS CAN BE EXPECTED...
ESPECIALLY DURING THE AFTERNOON AND EVENING HOURS.
FOR TONIGHT...SKIES WILL BE CLEAR TO PARTLY CLOUDY. A WEAK
DISTURBANCE IN NORTHWEST FLOW COULD PRODUCE A FEW SHOWERS AND
POSSIBLY A STORM LATE TONIGHT INTO EARLY TUESDAY OVER THE BLACK
HILLS AREA. WINDS WILL BECOME LIGHT THIS EVENING AND THEN SWITCH TO
THE SOUTHEAST OVERNIGHT INTO TUESDAY MORNING AS HIGH PRESSURE PASSES
OVER AND EVENTUALLY EAST OF THE AREA.
WARMER AIR WILL RETURN ON TUESDAY AS SOUTH-SOUTHEAST WINDS INCREASE.
HIGHS WILL BE IN THE MID 80S TO AROUND 90 DEGREES ACROSS THE
PLAINS...MOSTLY 80S OVER THE BLACK HILLS. A MORE WIDESPREAD CHANCE
FOR STORMS WILL RETURN LATE TUESDAY AND ESPECIALLY TUESDAY NIGHT AS
FLOW ALOFT TURNS SOUTHWESTERLY OVER THE HIGH PLAINS. THE
SOUTH-SOUTHEAST WINDS WILL ALSO BRING LOW LEVEL MOISTURE BACK INTO
THE AREA...WITH INCREASING INSTABILITY INTO TUESDAY NIGHT. WILL
GENERALLY KEEP POPS AS IS LATE TUESDAY INTO TUESDAY NIGHT. THE
THREAT FOR SEVERE STORMS STILL LOOKS RELATIVELY LOW. HOWEVER...WITH
SUFFICIENT INSTABILITY AROUND...ISOLATED STRONG TO MARGINALLY SEVERE
STORMS WITH HAIL AND GUSTY WINDS ARE CERTAINLY POSSIBLE LATE IN THE
AFTERNOON INTO THE EVENING.
&&
.LONG TERM...WEDNESDAY THROUGH MONDAY
ISSUED AT 300 PM MDT MON AUG 18 2014
MEAN WESTERN NOAM TROUGHING WILL PERSIST IN THE PERIOD...WITH
MASSIVE EASTERN NOAM RIDGING ENSUING TOWARD THE END OF THE WEEK.
THIS WILL SUPPORT A LOCAL PATTERN CHANGE AS LOWER HEIGHTS AND MUCH
COOLER TEMPS SPREAD OVER THE NORTHERN PLAINS BY THIS WEEKEND...PER
THE WESTERN CONUS TROUGH PHASING WITH A LONG WAVE NORTHERN STREAM
TROUGH. ACTIVE SW FLOW CAN BE EXPECTED TO SUPPORT NEAR DAILY
CHANCES FOR PRECIP THROUGH THE PERIOD...WITH THE WESTERN CONUS
TROUGH SHIFTING EAST OVER THE NORTHERN PLAINS BY LATE THIS
WEEKEND.
HAVE RETAINED DAILY CHANCES FOR SHRA/TS WITH A WAVERING FRONTAL ZONE
OVER THE REGION THROUGH THUR. COLD FRONT WILL SHIFT SE TROUGH THE
REGION FRIDAY...WITH CAA SPREADING ACROSS THE REGION VIA GUSTY NW
WINDS. CYCLONIC DISTURBED SW FLOW WILL PERSIST THROUGH THE WEEKEND.
HOWEVER...GIVEN SIGNALS FOR THE BEST LSA BEING NW OF THE FA...WITH
MORE DIURNALLY DRIVEN CHANCES FOR CONVECTION...HAVE BIASED POPS MORE
TOWARD CLIMO NUMBERS THIS WEEKEND..ESP GIVEN CONVECTIVE NATURE TO
PRECIP.
AS FOR TEMPS...SEASONAL NUMBERS WILL PERSIST THROUGH THURS...WITH
COOLING CONDITIONS FRI-SUN. TEMPERATURES ARE PROGGED TO BE 5 TO 15
DEGREES BELOW SEASONAL NORMS BY SUNDAY AND MONDAY...ESP HIGH
TEMPERATURES. HAVE CONTINUED TO ADD A NEGATIVE BIAS PER HIGHS
SAT-MONDAY...WITH MANY PLACES LIKELY STRUGGLING TO REACH 70 ACROSS
THE NORTHERN HALF SUNDAY AND MONDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 518 PM MDT MON AUG 18 2014
VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD. A WARM
FRONT WILL SHIFT NORTH TONIGHT AND POSSIBLY SUPPORT AN ISOLATED
TSRA LATE TONIGHT. ADDITIONAL ACTIVITY IS POSSIBLE LATER TUESDAY
AFTERNOON.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...HELGESON
SHORT TERM...26
LONG TERM...JC
AVIATION...HELGESON
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1208 PM CDT SUN AUG 17 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 332 AM CDT SUN AUG 17 2014
A MAJORITY OF THE PRECIPITATION THIS MORNING HAS REMAINED NORTH OF
THE CWA CLOSER TO THE MID LEVEL VORTICITY MAXIMUM. ALL THE HI RES
MODELS ARE OVERDOING PRECIPITATION OVER OUR AREA...POSSIBLY DUE TO
DRY AIR ABOVE 600 MB AS SEEN ON RAP SOUNDINGS. DO THINK THEY HAVE
THE GENERAL IDEA OF WHERE THE THUNDERSTORM THREAT IS THOUGH...AHEAD
OF THE EASTWARD MOVING SURFACE AND UPPER TROUGH AXIS. BASED ON WHAT
HAPPENED YESTERDAY AND SO FAR TONIGHT...WILL LEAN TOWARDS JUST AN
ISOLATED TO WIDELY SCATTERED SHOWER AND THUNDERSTORM THREAT
TODAY...MAINLY ACROSS SOUTHWEST MINNESOTA AND ADJACENT AREAS OF
NORTHWEST IOWA. THE REST OF US WILL BE IN A SUBSIDENT REGIME ALOFT
BEHIND THE WAVE...WHICH SHOULD SUPPRESS CONVECTIVE DEVELOPMENT.
PATCHY AREAS OF DENSE FOG THIS MORNING NEAR THE SURFACE TROUGH
SHOULD DISSIPATE AFTER SUNRISE. MAY SEE SOME STRATOCU DEVELOPMENT
THIS MORNING GIVEN THE MOIST LOW LEVELS...HOWEVER THIS SHOULD
SCATTER OUT BY LATER THIS MORNING AS WE BEGIN MIXING. GIVEN
YESTERDAYS HIGH TEMPERATURES....AND THE FACT THAT TODAY SHOULD SEE
JUST AS MUCH IF NOT MORE SUN AND WARMER TEMPERATURES ALOFT...WENT
AHEAD AND BUMPED HIGHS UP A COUPLE DEGREES...MAINLY INTO THE LOW TO
MID 80S. WITH DEWPOINTS RUNNING IN THE UPPER 60S TO LOW 70S AND
LIGHT WINDS IT WILL FEEL QUITE WARM AND HUMID OUTSIDE.
OTHER FORECAST CONCERN IS CONVECTION CHANCES LATER TODAY INTO
TONIGHT AS ANOTHER WAVE MOVES ACROSS THE PLAINS. CONVECTION WILL
LIKELY FORM THIS AFTERNOON IN THE WESTERN PLAINS AND MOVE TOWARDS
OUR AREA THIS EVENING. STILL DECENT UNCERTAINTY ON HOW EXACTLY THE
EVOLUTION OF THINGS WILL PLAY OUT...BUT SEEMS LIKE A GOOD CHANCE FOR
PRECIPITATION OVER MOST OF OUR AREA. GIVEN THE LOSS OF DAYTIME
HEATING STORMS WILL PROBABLY BE IN A WEAKENING STATE AS THEY
APPROACH THE WESTERN EDGE OF OUR CWA AFTER 0Z. HOWEVER THE LOW LEVEL
JET WILL INCREASE ACROSS NEBRASKA AFTER SUNSET...PUTTING OUR CWA IN
A GOOD AREA OF LOW LEVEL CONVERGENCE ON THE NOSE OF THE JET. WOULD
SEEM LIKE THIS COMBINED WITH THE UPPER SUPPORT FROM THE VORT MAX
MOVING ACROSS THE CWA SHOULD BE ENOUGH TO EITHER SUSTAIN THE
STORMS...OR ALLOW REDEVELOPMENT OVERHEAD THROUGH THE NIGHT. THIS IS
SUPPORTED BY A MAJORITY OF THE GLOBAL MODELS. HOWEVER THE HI RES
MODELS ARE LESS AGGRESSIVE AS THEY HAVE MORE CONVECTION DIVING
SOUTHEAST INTO NEBRASKA THIS AFTERNOON AND EVENING...POSSIBLY
IMPACTING THE MOISTURE FLOW INTO OUR AREA. SO WHILE THE FORCING
SEEMS TO SUGGEST A GOOD THUNDERSTORM THREAT TONIGHT...NOTHING IS A
SURE BET WITH CONVECTION...SO WILL NEED TO MONITOR TRENDS. EITHER
WAY LOW END LIKELY POPS SEEM WARRANTED. A SEVERE THREAT MAY EXIST IN
OUR FAR WEST THIS EVENING WITH THE OUTFLOW DOMINANT CONVECTION
MOVING IN FROM THE WEST POSSIBLY POSING A WIND RISK. HOWEVER...WOULD
EXPECT THIS THREAT TO WANE OVERNIGHT AS CONVECTION PUSHES EAST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 332 AM CDT SUN AUG 17 2014
SCATTERED CONVECTION WILL LIKELY BE ONGOING BY DAYBREAK MONDAY AS
SHORTWAVE ENERGY AT THE BASE OF A DEEPENING TROUGH MOVES THROUGH THE
REGION. THIS CONVECTION WILL MOVE EAST OF THE AREA BY MID-
MORNING...WITH A BRIEF LULL BEFORE AXIS OF LARGER SYNOPTIC TROUGH
PIVOTS THROUGH THE REGION LATER IN THE DAY. FRONTAL BOUNDARY BRINGING
SLIGHTLY DRIER AIR SOUTHWARD WILL RACE THROUGH THE CWA EARLY MONDAY
AFTERNOON...AND IT`S POSSIBLE TO HAVE REDEVELOPMENT ALONG THIS
BOUNDARY AS SUGGESTED BY SEVERAL HIGH-RES MODEL SOLUTIONS. QUESTIONS
LINGER ON THE AMOUNT OF DESTABILIZATION AFTER MORNING CONVECTION.
ADDITIONALLY SHEAR REMAINS FAIRLY UNIDIRECTIONAL WITH SPEEDS
INCREASING AFTER THE FRONT PASSES. THAT SAID...IF THINGS LINE UP JUST
RIGHT...COULD SEE A VERY BRIEF WINDOW FOR A FEW STRONGER STORMS OVER
THE SERN THIRD OF THE CWA MONDAY AFTN.
SLIGHTLY DRIER AIR WILL FILTER INTO THE AREA FOR MONDAY NIGHT AND
TUESDAY...BUT MORE HUMID AIR WON`T BE FAR TO THE SOUTH. MODELS
CONVERGING ONTO A SOLN THAT SUGGEST A MORE FLATTENED MID-LEVEL RIDGE
THROUGH MIDWEEK...BEFORE THE LONGWAVE PATTERN AMPLIFIES BY NEXT
WEEKEND. SEVERAL SHORTWAVES WILL LIFT NE THROUGH THE MID-LVL
FLOW...LIKELY BRINGING A CHANCE FOR CONVECTION SOUTH OF THE CWA
WEDNESDAY...WITH MUCH MORE UNCERTAINTY ON RAIN CHANCES LIFTING
NORTHWARD ON THURSDAY.
THE PATTERN INTO NEXT WEEKEND WOULD FAVOR TWO THINGS...ABOVE NORMAL
TEMPERATURES AND INCREASED PRECIPITATION CHANCES...ESPECIALLY FRIDAY
INTO SATURDAY AS SOUTHWEST FLOW INCREASES AND AN UPPER LVL JET NOSES
INTO THE PLAINS. QUESTIONS REMAIN HOWEVER ON JUST HOW THE UPPER
TROUGH OVER THE PACIFIC NW WILL EVOLVE...AND WHERE ENERGY OFF THE
CALIFORNIA COAST WILL END UP. NEVERTHELESS...A FORECAST PERIOD TO
KEEP AN EYE ON.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1203 PM CDT SUN AUG 17 2014
STRATUS ACROSS PORTIONS OF THE AREA WILL CONTINUE TO BREAK UP
THROUGH THE AFTERNOON. OTHERWISE...THUNDERSTORMS ARE EXPECTED TO
DEVELOP OVER CENTRAL SOUTH DAKOTA THIS AFTERNOON AND PUSH
EASTWARD DURING THE OVERNIGHT HOURS...EFFECTING AREAS TO THE WEST
OF INTERSTATE 29 GENERALLY PRIOR TO 06Z...THEN AREAS TO THE EAST
LATER IN THE NIGHT.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHENARD
LONG TERM...DUX
AVIATION...JM
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
652 AM CDT SUN AUG 17 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 332 AM CDT SUN AUG 17 2014
A MAJORITY OF THE PRECIPITATION THIS MORNING HAS REMAINED NORTH OF
THE CWA CLOSER TO THE MID LEVEL VORTICITY MAXIMUM. ALL THE HI RES
MODELS ARE OVERDOING PRECIPITATION OVER OUR AREA...POSSIBLY DUE TO
DRY AIR ABOVE 600 MB AS SEEN ON RAP SOUNDINGS. DO THINK THEY HAVE
THE GENERAL IDEA OF WHERE THE THUNDERSTORM THREAT IS THOUGH...AHEAD
OF THE EASTWARD MOVING SURFACE AND UPPER TROUGH AXIS. BASED ON WHAT
HAPPENED YESTERDAY AND SO FAR TONIGHT...WILL LEAN TOWARDS JUST AN
ISOLATED TO WIDELY SCATTERED SHOWER AND THUNDERSTORM THREAT
TODAY...MAINLY ACROSS SOUTHWEST MINNESOTA AND ADJACENT AREAS OF
NORTHWEST IOWA. THE REST OF US WILL BE IN A SUBSIDENT REGIME ALOFT
BEHIND THE WAVE...WHICH SHOULD SUPPRESS CONVECTIVE DEVELOPMENT.
PATCHY AREAS OF DENSE FOG THIS MORNING NEAR THE SURFACE TROUGH
SHOULD DISSIPATE AFTER SUNRISE. MAY SEE SOME STRATOCU DEVELOPMENT
THIS MORNING GIVEN THE MOIST LOW LEVELS...HOWEVER THIS SHOULD
SCATTER OUT BY LATER THIS MORNING AS WE BEGIN MIXING. GIVEN
YESTERDAYS HIGH TEMPERATURES....AND THE FACT THAT TODAY SHOULD SEE
JUST AS MUCH IF NOT MORE SUN AND WARMER TEMPERATURES ALOFT...WENT
AHEAD AND BUMPED HIGHS UP A COUPLE DEGREES...MAINLY INTO THE LOW TO
MID 80S. WITH DEWPOINTS RUNNING IN THE UPPER 60S TO LOW 70S AND
LIGHT WINDS IT WILL FEEL QUITE WARM AND HUMID OUTSIDE.
OTHER FORECAST CONCERN IS CONVECTION CHANCES LATER TODAY INTO
TONIGHT AS ANOTHER WAVE MOVES ACROSS THE PLAINS. CONVECTION WILL
LIKELY FORM THIS AFTERNOON IN THE WESTERN PLAINS AND MOVE TOWARDS
OUR AREA THIS EVENING. STILL DECENT UNCERTAINTY ON HOW EXACTLY THE
EVOLUTION OF THINGS WILL PLAY OUT...BUT SEEMS LIKE A GOOD CHANCE FOR
PRECIPITATION OVER MOST OF OUR AREA. GIVEN THE LOSS OF DAYTIME
HEATING STORMS WILL PROBABLY BE IN A WEAKENING STATE AS THEY
APPROACH THE WESTERN EDGE OF OUR CWA AFTER 0Z. HOWEVER THE LOW LEVEL
JET WILL INCREASE ACROSS NEBRASKA AFTER SUNSET...PUTTING OUR CWA IN
A GOOD AREA OF LOW LEVEL CONVERGENCE ON THE NOSE OF THE JET. WOULD
SEEM LIKE THIS COMBINED WITH THE UPPER SUPPORT FROM THE VORT MAX
MOVING ACROSS THE CWA SHOULD BE ENOUGH TO EITHER SUSTAIN THE
STORMS...OR ALLOW REDEVELOPMENT OVERHEAD THROUGH THE NIGHT. THIS IS
SUPPORTED BY A MAJORITY OF THE GLOBAL MODELS. HOWEVER THE HI RES
MODELS ARE LESS AGGRESSIVE AS THEY HAVE MORE CONVECTION DIVING
SOUTHEAST INTO NEBRASKA THIS AFTERNOON AND EVENING...POSSIBLY
IMPACTING THE MOISTURE FLOW INTO OUR AREA. SO WHILE THE FORCING
SEEMS TO SUGGEST A GOOD THUNDERSTORM THREAT TONIGHT...NOTHING IS A
SURE BET WITH CONVECTION...SO WILL NEED TO MONITOR TRENDS. EITHER
WAY LOW END LIKELY POPS SEEM WARRANTED. A SEVERE THREAT MAY EXIST IN
OUR FAR WEST THIS EVENING WITH THE OUTFLOW DOMINANT CONVECTION
MOVING IN FROM THE WEST POSSIBLY POSING A WIND RISK. HOWEVER...WOULD
EXPECT THIS THREAT TO WANE OVERNIGHT AS CONVECTION PUSHES EAST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 332 AM CDT SUN AUG 17 2014
SCATTERED CONVECTION WILL LIKELY BE ONGOING BY DAYBREAK MONDAY AS
SHORTWAVE ENERGY AT THE BASE OF A DEEPENING TROUGH MOVES THROUGH THE
REGION. THIS CONVECTION WILL MOVE EAST OF THE AREA BY MID-
MORNING...WITH A BRIEF LULL BEFORE AXIS OF LARGER SYNOPTIC TROUGH
PIVOTS THROUGH THE REGION LATER IN THE DAY. FRONTAL BOUNDARY BRINGING
SLIGHTLY DRIER AIR SOUTHWARD WILL RACE THROUGH THE CWA EARLY MONDAY
AFTERNOON...AND IT`S POSSIBLE TO HAVE REDEVELOPMENT ALONG THIS
BOUNDARY AS SUGGESTED BY SEVERAL HIGH-RES MODEL SOLUTIONS. QUESTIONS
LINGER ON THE AMOUNT OF DESTABILIZATION AFTER MORNING CONVECTION.
ADDITIONALLY SHEAR REMAINS FAIRLY UNIDIRECTIONAL WITH SPEEDS
INCREASING AFTER THE FRONT PASSES. THAT SAID...IF THINGS LINE UP JUST
RIGHT...COULD SEE A VERY BRIEF WINDOW FOR A FEW STRONGER STORMS OVER
THE SERN THIRD OF THE CWA MONDAY AFTN.
SLIGHTLY DRIER AIR WILL FILTER INTO THE AREA FOR MONDAY NIGHT AND
TUESDAY...BUT MORE HUMID AIR WON`T BE FAR TO THE SOUTH. MODELS
CONVERGING ONTO A SOLN THAT SUGGEST A MORE FLATTENED MID-LEVEL RIDGE
THROUGH MIDWEEK...BEFORE THE LONGWAVE PATTERN AMPLIFIES BY NEXT
WEEKEND. SEVERAL SHORTWAVES WILL LIFT NE THROUGH THE MID-LVL
FLOW...LIKELY BRINGING A CHANCE FOR CONVECTION SOUTH OF THE CWA
WEDNESDAY...WITH MUCH MORE UNCERTAINTY ON RAIN CHANCES LIFTING
NORTHWARD ON THURSDAY.
THE PATTERN INTO NEXT WEEKEND WOULD FAVOR TWO THINGS...ABOVE NORMAL
TEMPERATURES AND INCREASED PRECIPITATION CHANCES...ESPECIALLY FRIDAY
INTO SATURDAY AS SOUTHWEST FLOW INCREASES AND AN UPPER LVL JET NOSES
INTO THE PLAINS. QUESTIONS REMAIN HOWEVER ON JUST HOW THE UPPER
TROUGH OVER THE PACIFIC NW WILL EVOLVE...AND WHERE ENERGY OFF THE
CALIFORNIA COAST WILL END UP. NEVERTHELESS...A FORECAST PERIOD TO
KEEP AN EYE ON.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 646 AM CDT SUN AUG 17 2014
SURFACE TROUGH ALMOST TO INTERSTATE 29 THIS MORNING. AREA OF IFR TO
LIFR STRATUS HAS DEVELOPED ALONG AND BEHIND THIS TROUGH. WITH DAYTIME
HEATING...SHOULD SEE STRATOCU FIELD INCREASE GIVEN THE MOIST LOW
LEVELS. THIS STRATOCU WILL SLOWLY LIFT AND SCATTER OUT AS WE HEAD
THROUGH THE MORNING INTO THE AFTERNOON. EXACT TIMING OF THIS RETURN TO
VFR REMAINS UNCERTAIN. SHOWER AND THUNDERSTORM THREAT WILL INCREASE
FROM WEST TO EAST ACROSS THE AREA TONIGHT. HOWEVER STILL TOO FAR OUT
TO NARROW DOWN TIMING...SO WILL LEAVE OUT OF THE TAFS FOR NOW.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHENARD
LONG TERM...DUX
AVIATION...CHENARD
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
405 AM CDT SUN AUG 17 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 332 AM CDT SUN AUG 17 2014
A MAJORITY OF THE PRECIPITATION THIS MORNING HAS REMAINED NORTH OF
THE CWA CLOSER TO THE MID LEVEL VORTICITY MAXIMUM. ALL THE HI RES
MODELS ARE OVERDOING PRECIPITATION OVER OUR AREA...POSSIBLY DUE TO
DRY AIR ABOVE 600 MB AS SEEN ON RAP SOUNDINGS. DO THINK THEY HAVE
THE GENERAL IDEA OF WHERE THE THUNDERSTORM THREAT IS THOUGH...AHEAD
OF THE EASTWARD MOVING SURFACE AND UPPER TROUGH AXIS. BASED ON WHAT
HAPPENED YESTERDAY AND SO FAR TONIGHT...WILL LEAN TOWARDS JUST AN
ISOLATED TO WIDELY SCATTERED SHOWER AND THUNDERSTORM THREAT
TODAY...MAINLY ACROSS SOUTHWEST MINNESOTA AND ADJACENT AREAS OF
NORTHWEST IOWA. THE REST OF US WILL BE IN A SUBSIDENT REGIME ALOFT
BEHIND THE WAVE...WHICH SHOULD SUPPRESS CONVECTIVE DEVELOPMENT.
PATCHY AREAS OF DENSE FOG THIS MORNING NEAR THE SURFACE TROUGH
SHOULD DISSIPATE AFTER SUNRISE. MAY SEE SOME STRATOCU DEVELOPMENT
THIS MORNING GIVEN THE MOIST LOW LEVELS...HOWEVER THIS SHOULD
SCATTER OUT BY LATER THIS MORNING AS WE BEGIN MIXING. GIVEN
YESTERDAYS HIGH TEMPERATURES....AND THE FACT THAT TODAY SHOULD SEE
JUST AS MUCH IF NOT MORE SUN AND WARMER TEMPERATURES ALOFT...WENT
AHEAD AND BUMPED HIGHS UP A COUPLE DEGREES...MAINLY INTO THE LOW TO
MID 80S. WITH DEWPOINTS RUNNING IN THE UPPER 60S TO LOW 70S AND
LIGHT WINDS IT WILL FEEL QUITE WARM AND HUMID OUTSIDE.
OTHER FORECAST CONCERN IS CONVECTION CHANCES LATER TODAY INTO
TONIGHT AS ANOTHER WAVE MOVES ACROSS THE PLAINS. CONVECTION WILL
LIKELY FORM THIS AFTERNOON IN THE WESTERN PLAINS AND MOVE TOWARDS
OUR AREA THIS EVENING. STILL DECENT UNCERTAINTY ON HOW EXACTLY THE
EVOLUTION OF THINGS WILL PLAY OUT...BUT SEEMS LIKE A GOOD CHANCE FOR
PRECIPITATION OVER MOST OF OUR AREA. GIVEN THE LOSS OF DAYTIME
HEATING STORMS WILL PROBABLY BE IN A WEAKENING STATE AS THEY
APPROACH THE WESTERN EDGE OF OUR CWA AFTER 0Z. HOWEVER THE LOW LEVEL
JET WILL INCREASE ACROSS NEBRASKA AFTER SUNSET...PUTTING OUR CWA IN
A GOOD AREA OF LOW LEVEL CONVERGENCE ON THE NOSE OF THE JET. WOULD
SEEM LIKE THIS COMBINED WITH THE UPPER SUPPORT FROM THE VORT MAX
MOVING ACROSS THE CWA SHOULD BE ENOUGH TO EITHER SUSTAIN THE
STORMS...OR ALLOW REDEVELOPMENT OVERHEAD THROUGH THE NIGHT. THIS IS
SUPPORTED BY A MAJORITY OF THE GLOBAL MODELS. HOWEVER THE HI RES
MODELS ARE LESS AGGRESSIVE AS THEY HAVE MORE CONVECTION DIVING
SOUTHEAST INTO NEBRASKA THIS AFTERNOON AND EVENING...POSSIBLY
IMPACTING THE MOISTURE FLOW INTO OUR AREA. SO WHILE THE FORCING
SEEMS TO SUGGEST A GOOD THUNDERSTORM THREAT TONIGHT...NOTHING IS A
SURE BET WITH CONVECTION...SO WILL NEED TO MONITOR TRENDS. EITHER
WAY LOW END LIKELY POPS SEEM WARRANTED. A SEVERE THREAT MAY EXIST IN
OUR FAR WEST THIS EVENING WITH THE OUTFLOW DOMINANT CONVECTION
MOVING IN FROM THE WEST POSSIBLY POSING A WIND RISK. HOWEVER...WOULD
EXPECT THIS THREAT TO WANE OVERNIGHT AS CONVECTION PUSHES EAST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 332 AM CDT SUN AUG 17 2014
SCATTERED CONVECTION WILL LIKELY BE ONGOING BY DAYBREAK MONDAY AS
SHORTWAVE ENERGY AT THE BASE OF A DEEPENING TROUGH MOVES THROUGH THE
REGION. THIS CONVECTION WILL MOVE EAST OF THE AREA BY MID-
MORNING...WITH A BRIEF LULL BEFORE AXIS OF LARGER SYNOPTIC TROUGH
PIVOTS THROUGH THE REGION LATER IN THE DAY. FRONTAL BOUNDARY BRINGING
SLIGHTLY DRIER AIR SOUTHWARD WILL RACE THROUGH THE CWA EARLY MONDAY
AFTERNOON...AND IT`S POSSIBLE TO HAVE REDEVELOPMENT ALONG THIS
BOUNDARY AS SUGGESTED BY SEVERAL HIGH-RES MODEL SOLUTIONS. QUESTIONS
LINGER ON THE AMOUNT OF DESTABILIZATION AFTER MORNING CONVECTION.
ADDITIONALLY SHEAR REMAINS FAIRLY UNIDIRECTIONAL WITH SPEEDS
INCREASING AFTER THE FRONT PASSES. THAT SAID...IF THINGS LINE UP JUST
RIGHT...COULD SEE A VERY BRIEF WINDOW FOR A FEW STRONGER STORMS OVER
THE SERN THIRD OF THE CWA MONDAY AFTN.
SLIGHTLY DRIER AIR WILL FILTER INTO THE AREA FOR MONDAY NIGHT AND
TUESDAY...BUT MORE HUMID AIR WON`T BE FAR TO THE SOUTH. MODELS
CONVERGING ONTO A SOLN THAT SUGGEST A MORE FLATTENED MID-LEVEL RIDGE
THROUGH MIDWEEK...BEFORE THE LONGWAVE PATTERN AMPLIFIES BY NEXT
WEEKEND. SEVERAL SHORTWAVES WILL LIFT NE THROUGH THE MID-LVL
FLOW...LIKELY BRINGING A CHANCE FOR CONVECTION SOUTH OF THE CWA
WEDNESDAY...WITH MUCH MORE UNCERTAINTY ON RAIN CHANCES LIFTING
NORTHWARD ON THURSDAY.
THE PATTERN INTO NEXT WEEKEND WOULD FAVOR TWO THINGS...ABOVE NORMAL
TEMPERATURES AND INCREASED PRECIPITATION CHANCES...ESPECIALLY FRIDAY
INTO SATURDAY AS SOUTHWEST FLOW INCREASES AND AN UPPER LVL JET NOSES
INTO THE PLAINS. QUESTIONS REMAIN HOWEVER ON JUST HOW THE UPPER
TROUGH OVER THE PACIFIC NW WILL EVOLVE...AND WHERE ENERGY OFF THE
CALIFORNIA COAST WILL END UP. NEVERTHELESS...A FORECAST PERIOD TO
KEEP AN EYE ON.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1038 PM CDT SAT AUG 16 2014
HI RES MODELS CONTINUE TO DEVELOP FOG OVERNIGHT...LIKELY A RESULT
OF THE CONVECTION THAT THE MODEL IS DEVELOPING THAT IS NOT THERE. WITH
DECENT MIXING TODAY..HAVE CONTINUED TO CUT BACK ON FOG MENTION FOR
SUNDAY MORNING. OTHERWISE...MAINLY VFR CONDITION WITH WEAK BOUNDARY
IN THE JAMES VALLEY POTENTIALLY BECOMING THE FOCUS FOR ADDITIONAL
SHOWER AND THUNDERSTORM DEVELOPMENT SUNDAY AFTERNOON. TIMING IS
LOW...SO HAVE LEFT MENTION OUT OF TAFS FOR NOW.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHENARD
LONG TERM...DUX
AVIATION...
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
921 PM CDT MON AUG 18 2014
.UPDATE...
A CLUSTER OF SHOWERS AND THUNDERSTORMS ARE SKIRTING PHILLIPS
COUNTY ARKANSAS AND COAHOMA COUNTY MISSISSIPPI AT THIS TIME.
LATEST HRRR SHOWS THAT THE AREA FROM COAHOMA COUNTY TO MONROE
COUNTY MISSISSIPPI COULD CONTINUE SEE THIS ACTIVITY INTO THE
OVERNIGHT HOURS. OTHERWISE...EXPECT MAINLY DRY CONDITIONS. WILL
ADJUST POPS OTHERWISE REST OF THE FORECAST LOOKS GOOD.
KRM
&&
.DISCUSSION... /ISSUED 253 PM CDT MON AUG 18 2014/
SKIES ARE PARTLY CLOUDY OVER MUCH OF THE FORECAST AREA THIS
AFTERNOON WITH TEMPERATURES RANGING FROM THE LOWER 70S TO MID 80S.
SHOWERS AND A FEW THUNDERSTORMS CONTINUE TO MOVE ACROSS PORTIONS
OF THE FORECAST AREA. EARLIER THIS AFTERNOON WE HAD SOME HEAVY
RAINFALL OVER PORTIONS OF WEST TENNESSEE WITH 3 TO 5 INCHES OF
RAIN FALLING IN A FEW LOCATIONS. THE UPPER LEVEL DISTURBANCE WHICH
HELPED PRODUCE ALL THE THUNDERSTORM ACTIVITY WAS MOVING ACROSS
NORTH MISSISSIPPI THIS AFTERNOON. AS THIS DISTURBANCE CONTINUES TO
MOVE EAST INTO NORTH ALABAMA...THUNDERSTORMS WILL DECREASE IN
COVERAGE TONIGHT.
MEANWHILE...A WEAK FRONTAL BOUNDARY WAS LOCATED JUST NORTH OF THE
FORECAST AREA. AS IT BEGIN TO MOVE NORTH TONIGHT...SOME ADDITIONAL
THUNDERSTORMS MAY MOVE INTO NORTHWEST SECTIONS OF THE FORECAST
AREA OVERNIGHT. AS THE FRONT MOVES NORTH TUESDAY...THE CHANCE OF
THUNDERSTORMS WILL BE CONFINED TO MAINLY NORTHERN AND EASTERN
SECTIONS OF THE FORECAST AREA. TEMPERATURES WILL START TO BECOME
QUITE WARM ON TUESDAY WITH HIGHS IN THE LOW TO MID 90S.
BY WEDNESDAY...AN UPPER LEVEL RIDGE WILL START TO BUILD INTO THE
SOUTHEAST AND SOUTH CENTRAL U.S. THIS WILL BRING AN EXTENDED
PERIOD OF DRY WEATHER TO THE FORECAST AREA WITH NO RAIN EXPECTED
FROM WEDNESDAY THROUGH NEXT MONDAY. IN ADDITIONAL...TEMPERATURES
WILL BE AS HOT IF NOT HOTTER THAN WE HAVE SEEN THIS SUMMER WITH
HIGH TEMPERATURES IN THE MID TO UPPER 90S FROM WEDNESDAY THROUGH
NEXT MONDAY. HEAT INDEX VALUES MAY EXCEED 105 AT TIMES DURING THIS
PERIOD SO THERE MAY BE A NEED FOR A HEAT ADVISORY LATER THIS WEEK.
ARS
&&
.AVIATION...
SHOULD BE A QUIETER NIGHT ACROSS THE MIDSOUTH AS THE UPPER LEVEL
DISTURBANCE MOVES EAST OF THE REGION. VFR CONDS EXPECTED THROUGH
THE EVENING WITH PATCHY FOG DEVELOPING LATER TONIGHT. LOW CLOUDS
ARE POSSIBLE AT KMKL AND KTUP THOUGH CONFIDENCE IS TOO LOW FOR A
BKN DECK ATTM. UPPER RIDGE WILL START BUILDING IN ON TUESDAY AND
AREAL COVERAGE OF SHRAS/TSRAS WILL BE TOO LOW TO MENTION VCTS.
WINDS WILL BE LIGHT OVERNIGHT AND WSW 7-10 KTS ON TUESDAY.
&&
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
615 PM CDT MON AUG 18 2014
.AVIATION...
/00Z TAFS/
As of 6 pm, there is an area of widespread rainfall with embedded
thunderstorms south of KABI and KSJT and affecting only the southern
terminals. VFR conditions are expected to continue through the next
24 hours at all terminals. Isolated to scattered thunderstorms are
possible through mid-evening over the southern terminal. Any
thunderstorms that occur will be capable of producing variable and
gusty winds. Thunderstorms are expected to occur again Tuesday
morning, mainly over the southern terminals.
&&
.PREV DISCUSSION... /ISSUED 350 PM CDT MON AUG 18 2014/
.SHORT TERM...
(Tonight and Tuesday)
Low confidence forecast across West Central Texas for the next 24
hours. Remnant Mesoscale Convective Vortex (MCV) continues to
remain nearly stationary across Sterling County early this
afternoon, and buried within a larger scale mid level shear axis
stretching across much of the area. Much like we saw on Sunday, as
the main morning area of showers and storms slowly winds down from
Abilene to Brownwood, more scattered convection is developing
along the periphery of the MCV where better heating is taking
place.
Biggest question in the forecast concerns tonight and Tuesday
rain chances. As the low level jet intensifies towards midnight,
expect to see another round of showers and storms form near the
center of the MCV and along its eastern flank. MCV is definitely
weaker today than it was yesterday, and should continue to slowly
wind down. How strong it remains tonight, where it ends up, and
what kind of storm coverage it can actually generate is highly
uncertain though. Models not a lot of help, with even the TTU WRF
and the HRRR models struggling in this highly mesoscale situation.
At this point, will bump pops to chance for most of the area,
knowing that some areas may miss out and others may see some
decent rainfall. Some of this area has seen rainfall totals in the
1 to 3 inch range, so if the rain can train over these areas, than
a flood threat becomes more pronounced. This will need to be
monitored through tonight.
07
.LONG TERM...
(Tuesday night through next Monday)
A mainly dry forecast expected for the extended period.
By Tuesday evening...the 500mb ridge that is currently centered
near Florida will expand farther west into Texas, pushing the
shear axis over the top of our CWA farther west as well. In
addition, by Tuesday night, 250mph ridging will move in over the
top of the region out of the southwest. These two factors point to
decreasing chances of precipitation overall for the area by
Tuesday night. However, we have left an area of slight chance PoPs
in for Tuesday evening. The combination of the previously
mentioned upper level shear axis and MCV is expected to result in
additional thunderstorm activity tomorrow afternoon. And although
these features are expected to be drifting to the west, there
could still be lingering activity for areas mainly south and west
of a Sterling City to San Angelo to Sonora line.
By Wednesday, upper level ridging will be in place across our
forecast area, effectively ending rain chances through the end of
the forecast period, and allowing temperatures to remain warm in
the mid to upper 90s for highs, and generally lower to mid 70s for
lows.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 72 94 71 97 74 / 30 30 5 5 5
San Angelo 71 93 72 95 74 / 30 30 10 5 5
Junction 73 92 73 93 73 / 30 30 10 5 5
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
610 PM CDT MON AUG 18 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 315 PM CDT MON AUG 18 2014
FORECAST FOCUS IS ON RAIN TONIGHT AS UPPER SHORT WAVE PASSES
THROUGH THE REGION WITH A WARM AND HUMID AIRMASS IN PLACE. A
CLOSED LOW CUTS OFF OVER THE GREAT LAKES AS THIS WAVE ROUNDS THE
BASE OF THE LONG WAVE TROUGH. WITH WEAKER IMPULSES CIRCULATING
AROUND THE LOW...RAIN CHANCES LINGER INTO TUESDAY AS WELL.
19Z MESOANALYSIS SHOWS UPPER WAVE SPINNING INTO NORTHWEST MN...
HEADING SOUTHEAST. PLUME OF 70+ LOW LEVEL DEWPOINTS FROM EASTERN
IA UP INTO WESTERN WI AHEAD OF THE APPROACHING WAVE. ACTIVE
CONVECTION ONGOING FROM WEST CENTRAL INTO NORTHEAST WI...AND NEW
ACTIVITY GOING UP OVER NORTHEAST IA AND SOUTHEAST MN. ANTICIPATE
SCATTERED SHOWERS AND THUNDERSTORMS TONIGHT...WITH PERHAPS A BREAK
FOR A TIME EARLY THIS EVENING AFTER THIS FIRST INITIAL BAND.
PRECIPITABLE WATER SOMEWHAT ELEVATED AND WARM CLOUD DEPTH 3500+
METERS. ANY STORMS WILL BE PRODUCING HEAVY DOWNPOURS. DCAPE
SUGGESTS WIND POTENTIAL AS WELL.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 315 PM CDT MON AUG 18 2014
UPPER LEVEL LOW OVER THE GREAT LAKES SHIFTS EAST ON WEDNESDAY AS
UPPER RIDGING BUILDS INTO THE UPPER MIDWEST. A PATTERN SHIFT TO
MORE SOUTHWEST FLOW TAKES PLACE MID-WEEK WITH A LONG WAVE TROUGH
ESTABLISHING ITSELF OVER THE WESTERN CONUS. EVENTUAL RAIN CHANCES
LATER THIS WEEK...AND THE DEGREE OF WARMING...ARE TIED TO HOW THE
SHORT WAVE TROUGH ENERGY EJECTS NORTHEAST TOWARD OUR REGION.
MEDIUM RANGE MODELS DO SHOW SOME DIFFERENCES IN TIMING OF THESE
IMPULSES...SO CONFIDENCE NOT HIGH. BUT IT DOES APPEAR THE OVERALL
TREND OF WARM AND HUMID CONDITIONS WILL COME TO FRUITION. IT HAS
BEEN DRY LATELY...BUT THESE STORMS ONCE AGAIN LOOK TO HAVE
INGREDIENTS FOR HEAVY RAIN POTENTIAL. THIS WILL HAVE TO BE
MONITORED AS WE START TO ACCUMULATE SOME RAINFALL ON OUR RECENTLY
DRY SOILS...WILL A FLOOD WATCH EVENTUALLY BE NECESSARY?
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 610 PM CDT MON AUG 18 2014
FIRST ROUND OF AFTERNOON CONVECTION EXPECTED TO PAST BOTH TAF
SITES BY 00Z. HOWEVER...THE NEXT ROUND ALREADY TAKING SHAPE ACROSS
SOUTH CENTRAL MINNESOTA AHEAD OF THE NEXT SHORT WAVE TROUGH. THE
18.21Z HRRR SEEMS TO HAVE A GOOD HANDLE ON BOTH OF THESE ROUNDS OF
CONVECTION BRINGING THE NEXT ROUND THROUGH BOTH TAF SITES THIS
EVENING. WILL INCLUDE A TWO HOUR TEMPO GROUP FOR THUNDER WITH MVFR
CONDITIONS. ONCE THIS GOES THROUGH...IT APPEARS THE WIND
SHIFT/COLD FRONT SHOULD COME THROUGH SHORTLY AFTER SWINGING THE
WINDS AROUND TO THE WEST. THE 18.18Z NAM SUGGESTS THAT THERE WILL
BE A DECENT WEST TO NORTHWEST WIND BETWEEN 5 AND 10 KNOTS WITH
WINDS OF 15 TO 20 KNOTS JUST ABOVE THE SURFACE. WHILE THE NAM
WANTS TO SATURATE THE SURFACE AND PRODUCE SOME FOG AND LOW
CEILINGS...CONCERNED THAT THIS MAY BE TOO MUCH WIND FOR THE FOG TO
FORM AND POSSIBLY THE CEILINGS AS WELL. FOR NOW WILL MAINTAIN SOME
CONTINUITY WITH PREVIOUS FORECASTS AND SHOW PREVAILING MVFR
CONDITIONS WITH THE POSSIBILITY OF IFR. ANY FOG AND LOW CEILINGS
THAT DO FORM SHOULD DISSIPATE BY MID MORNING TUESDAY AS THE
SURFACE WINDS INCREASE TO AROUND 10 KNOTS WITH SCATTERED TO SOME
BROKEN VFR CLOUDS EXPECTED FOR THE REMAINDER OF THE DAY.
&&
.HYDROLOGY...
ISSUED AT 315 PM CDT MON AUG 18 2014
SO FAR IN AUGUST...OVERALL IT HAS BEEN QUITE DRY WITH MUCH OF THE
AREA ADDED TO THE ABNORMALLY DRY CATEGORY PER THE DROUGHT MONITOR.
BUT AS WE SAW LAST NIGHT...SLOW MOVING STORMS PRODUCING TORRENTIAL
DOWNPOURS CAN RESULT IN SOME LOCALIZED FLOODING ISSUES. ONCE AGAIN
TONIGHT...WARM CLOUD DEPTH AND ELEVATED PRECIPITABLE WATER
AMOUNTS POINT TO HEAVY RAINFALL POTENTIAL. THIS TREND LOOKS TO
CONTINUE THROUGH MUCH OF THE WEEK AS WELL. DRY CONDITIONS
INITIALLY WILL ALLOW FOR MUCH OF THIS WATER TO BE UTILIZED BY THE
SOIL AND REPLENISHING STORAGE AREAS. BUT WE WILL HAVE TO MONITOR
THE RAINFALL OVER THE COMING DAYS AND PERHAPS CONSIDER THE NEED
FOR A FLOOD WATCH FOR AREAS THAT SEE REPEATED RAINFALL.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...MW
LONG TERM...MW
AVIATION...04
HYDROLOGY...MW
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1246 PM CDT SUN AUG 17 2014
.UPDATE...
ISSUED AT 1147 AM CDT SUN AUG 17 2014
SHOWERS HAVE DEVELOPED ALONG A DIFFERENTIAL HEATING BOUNDARY LATE
THIS MORNING ACROSS DODGE AND MOWER COUNTIES IN SOUTHEAST
MINNESOTA...AND FLOYD AND MITCHELL COUNTIES IN NORTHEAST IOWA.
WHILE THE MESO MODELS ARE NOT INDICATING ANY PRECIPITATION IN THIS
AREA...THE RAP DOES SHOW MODERATE TO STRONG 900 TO 800 MB
FORNTOGENESIS AND THE SPC MESO PAGE HAS AROUND 1000 J/KG SURFACE
BASED CAPE. THESE PARAMETERS STAY PRETTY CONSISTENT AND OVER THE
SAME GENERAL AREAS THIS AFTERNOON. DUE TO THIS...THE PRECIPITATION
CHANCES WERE DRAMATICALLY INCREASED THIS AFTERNOON.
UPDATE ISSUED AT 911 AM CDT SUN AUG 17 2014
LAW ENFORCEMENT REPORT...OBSERVATIONS...AND WEB CAMS ARE SHOWING
THAT MUCH OF THE DENSE FOG HAS LIFTED ACROSS MUCH OF NORTHEAST
IOWA. DUE TO THIS...THE DENSE FOG WAS ALLOWED TO EXPIRE. WHILE
CONDITIONS ARE IMPROVING...DRIVERS STILL SHOULD BE ALERT FOR AREAS
OF LOW VISIBILITIES THROUGH 10 AM THIS MORNING.
UPDATE ISSUED AT 437 AM CDT SUN AUG 17 2014
FOG IS BECOMING A BIGGER PROBLEM OVER NORTHEAST IOWA WITH MANY
SITES DROPPING TO OR BELOW 1/4 MILE VISIBILITY. MUCH OF THIS IS A
RESULT OF SKIES STILL CLEAR BECAUSE THE COOL FRONT HAS YET TO
MOVE INTO THE AREA. BEHIND THE FRONT ACROSS WISCONSIN...STRATUS
HAS HELPED KEEP THE FOG AT BAY. THERE HAS BEEN SOME SCATTERED
CLOUDS ACROSS SOUTHEAST MN AS WELL AHEAD OF THE FRONT KEEPING FOG
AT A MINIMUM THERE. SHOULD THESE CLOUDS CLEAR...THEN ITS POSSIBLE
THE THICKER FOG IN NORTHEAST IOWA COULD EXPAND INTO SOUTHEAST MN.
HAVE WENT AHEAD...ALONG WITH DMX AND DVN...AND ISSUED A DENSE FOG
ADVISORY FOR NORTHEAST IA. EXPIRATION TIME IS SET AT 9 AM...WHEN
THE WIDESPREAD NATURE OF THE DENSE FOG SHOULD BEGIN TO IMPROVE. IT
MAY NOT FULLY BE IMPROVED UNTIL 10 AM...THOUGH...PER 17.07Z HRRR
VISIBILITY PROGS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 310 AM CDT SUN AUG 17 2014
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED AN UPPER LOW AND TROUGH TRAVERSING SOUTHERN SASKATCHEWAN AND
NORTHEAST MONTANA...A SHORTWAVE NEAR FARGO...AND RIDGING OVER
EASTERN MN. SUBSIDENCE UNDER THIS UPPER RIDGING HAS RESULTED IN
MAINLY DRY CONDITIONS OVERNIGHT IN THE FORECAST AREA. THERE WERE
SHOWERS LAST EVENING AROUND I-94 FROM CENTRAL MN INTO SOUTHEAST
WI...ASSOCIATED WITH LINGERING DAYTIME INSTABILITY AND CONVERGENCE
ALONG A BACKDOOR COLD FRONT. THOSE HAVE SINCE MOSTLY DISSIPATED DUE
TO LOSS OF DAYTIME HEATING. THAT COLD FRONT NOW STRETCHES FROM
SOUTHERN WI INTO SOUTHWEST MN AND TO A LOW IN SOUTHEAST NORTH
DAKOTA. AROUND THIS SURFACE LOW AND THE ASSOCIATED SHORTWAVE
ALOFT...MORE SHOWERS AND STORMS EXIST. GOES PRECIPITABLE WATER
IMAGERY DEPICTS PLENTIFUL MOISTURE POOLED ALONG THE FRONT...WITH
VALUES RANGING FROM 1.5-2 INCHES...HIGHEST IN THE CONVECTION NEAR
FARGO. THE MOISTURE HAS BEEN FELT AT THE SURFACE AS WELL WITH
DEWPOINTS IN THE MID TO UPPER 60S AROUND THE FRONT. THESE HIGH
DEWPOINTS HAVE LED TO SOME FOG AND STRATUS FORMATION THIS MORNING.
BEHIND THE FRONT OVER NORTH CENTRAL WISCONSIN THROUGH UPPER
MICHIGAN...DRIER AND COOLER AIR IS FILTERING IN AHEAD OF HIGH
PRESSURE OVER NORTHERN ONTARIO.
MUCH OF THE SHORT TERM PERIOD FOCUS IS ON THE SHORTWAVE NEAR FARGO
AS WELL AS THE COLD FRONT THAT HAS LAYED UP OVER THE SOUTHWESTERN
PORTION OF THE FORECAST AREA. REGARDING THE SHORTWAVE...MODELS
GENERALLY SUGGEST THE CORE NEAR FARGO ENDS UP TRACKING TO THE EAST
OVER THE NEXT 24 HOURS...REACHING CENTRAL UPPER MI BY 12Z MON.
HOWEVER...THE TAIL OF THE SHORTWAVE WILL END UP CROSSING THE
FORECAST AREA TONIGHT. DPVA FROM THE TAIL OF THE SHORTWAVE...DAYTIME
HEATING/INSTABILITY THAT DEVELOPS TO INTERACT WITH CONVERGENCE ALONG
THE COLD FRONT...AND INCREASING 850MB MOISTURE TRANSPORT TONIGHT
OVER THE FORECAST AREA ALL SUGGEST POTENTIAL FOR SHOWERS AND STORMS
OVER THE NEXT 24 HOURS. GIVEN THE TRACK OF THE SHORTWAVE TAIL AND
MOISTURE TRANSPORT SIGNAL...THE NORTHWEST HALF OF THE FORECAST AREA
STANDS TO HAVE THE BEST SHOT FOR PRECIPITATION. HIGH RESOLUTION
MODEL GUIDANCE SUGGEST MUCH OF THE ACTIVITY THIS AFTERNOON AND
EVENING SHOULD BE ISOLATED TO SCATTERED AT BEST. THE INCREASE IN
850MB MOISTURE TRANSPORT AFTER MIDNIGHT COULD ALLOW CONVECTION TO
INCREASE A BIT MORE IN COVERAGE...THUS HIGHEST CHANCES ARE 06-12Z
MONDAY.
REGARDING CONVECTIVE HAZARDS. 0-6KM AND 0-3KM SHEAR IS ALL BELOW 20
KT THROUGH TONIGHT...LIMITING SEVERE POTENTIAL. HOWEVER...
PRECIPITABLE WATER IS PROGGED IN THE 1.5-1.8 INCH RANGE WHICH WOULD
ALLOW THE STORMS TO PRODUCE BRIEF HEAVY RAIN.
TEMPERATURES TODAY SHOULD VARY QUITE A BIT ACROSS THE FORECAST AREA.
ACROSS THE SOUTHWEST END OF THE FORECAST AREA WHERE THE FRONT HAS
STALLED OUT...925MB TEMPS ARE SIMILAR TO YESTERDAY IN THE 21-22C
RANGE...SUPPORTING HIGHS INTO THE LOW 80S OR SO. MEANWHILE...IN
NORTH CENTRAL WI WHERE 925MB TEMPS ONLY TOP OUT AT 18C...HIGHS MAY
ONLY REACH THE MID 70S. SOUTHERLY FLOW ACROSS THE FORECAST AREA
TONIGHT SHOULD HELP KEEP BOTH TEMPERATURES AND DEWPOINTS UP...WITH
ONLY PRECIPITATION COOLING LOWS. THEREFORE...EXPECT ANOTHER MILD
AND SOMEWHAT HUMID NIGHT FOR MID AUGUST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 310 AM CDT SUN AUG 17 2014
FOCUS FOR MONDAY THROUGH TUESDAY REMAINS ON THE UPPER LOW AND TROUGH
CURRENTLY OVER SOUTHERN SASKATCHEWAN AND EASTERN MONTANA. MODELS
CONTINUE TO BE IN GOOD AGREEMENT DROPPING THIS TROUGH INTO MN ON
MONDAY...INTO THE FORECAST AREA BY 12Z TUE...AND OVER EASTERN WI BY
00Z WED. THE TRACK OF THE TROUGH SUGGESTS THE BEST DYNAMICAL
FORCING FOR THE FORECAST AREA OCCURS FROM 18Z MONDAY TO 18Z
TUESDAY...MAXIMIZED DURING MONDAY EVENING. THERE SHOULD BE PLENTY OF
MOISTURE FOR THE TROUGH TO WORK ON TOO...WITH 1.5-1.75 INCHES OF
PRECIPITABLE WATER ALREADY IN PLACE AND IS PROGGED TO REMAIN STEADY
THROUGH THE TROUGH PASSAGE. GIVEN THE GOOD CONSISTENCY ON THIS
SIGNAL FOR THE TROUGH...FEEL FAIRLY CONFIDENT MUCH OF THE AREA WILL
SEE SHOWERS AND STORMS. DAYTIME HEATING INCREASING INSTABILITY FOR
MONDAY AND TUESDAY AFTERNOONS SHOULD ONLY HELP MATTERS. THEREFORE...
HAVE INCREASED PRECIPITATION CHANCES EVEN MORE. IT DOES APPEAR
LOCATIONS WEST OF THE MS RIVER SHOULD SEE PRECIPITATION DIMINISH FOR
A TIME FROM 03-12Z TUESDAY OVER THE WEST HALF OF THE FORECAST
AREA...THOUGH. 925MB TEMPS ON MONDAY IN THE 20-22C RANGE SHOULD
SUPPORT HIGHS IN THE UPPER 70S/LOW 80S...HELD DOWN BY
PRECIPITATION. IT WILL LIKELY FEEL A BIT HUMID TOO. 925MB TEMPS ONLY
TOP OUT FROM 18-20C ON TUESDAY...AND WITH THE POTENTIAL FOR
PRECIPITATION...HIGHS GET KNOCKED DOWN A FEW DEGREES.
ALL INDICATIONS ARE THAT THE UPPER LOW AND TROUGH WILL MOVE AWAY
FROM THE REGION TUESDAY NIGHT...ALLOWING ANY CONVECTION TO
DIMINISH/END TUESDAY EVENING WITH THE LOSS OF DAYTIME HEATING. WITH
THE AREA PROGGED TO LIE IN AN INFLECTION POINT BETWEEN THE DEPARTING
TROUGH AND UPPER RIDGING BUILDING UP ALONG I-29...SUBSIDENCE SHOULD
BE IN PLACE TO ALLOW FOR A DRY OVERNIGHT. CLEARING OF THE SKIES
COMBINED WITH RECENT RAINS AND DIMINISHING WINDS SHOULD PROMOTE
FOG DEVELOPMENT AND THUS ADDED AREAS OF FOG TO THE FORECAST. THE
DRY CONDITIONS COULD PERSIST THROUGH WEDNESDAY AS THAT UPPER RIDGE
SHIFTS EAST TO I-35. HOWEVER...THERE ARE SIGNS FOR SHOWER AND
THUNDERSTORM ACTIVITY TO DEVELOP ACROSS IOWA...NORTH OF A WARM
FRONTAL BOUNDARY PROGGED TO SET UP ALONG THE MO/IA BORDER. HAVE KEPT
SOME LOW CHANCES IN ACROSS THE FAR SOUTHERN PORTION OF THE FORECAST
AREA JUST IN CASE.
FOR WEDNESDAY NIGHT AND INTO NEXT WEEKEND...THERE IS GOOD MODEL
AGREEMENT AMONGST 17.00Z GUIDANCE AS WELL AS PREVIOUS MODELS FOR
TROUGHING TO DIG INTO THE PACIFIC NORTHWEST. IN RESPONSE...RIDGING
BUILDS DOWNSTREAM TOWARDS THE FORECAST AREA...RESULTING IN A
WARM/MOIST AIR ADVECTION PATTERN. THIS WILL LEAD TO MORE CHANCES OF
SHOWERS AND THUNDERSTORMS. ITS APPEARING LIKE LATE WEDNESDAY NIGHT
INTO THURSDAY MORNING COULD BE AN ENHANCED CHANCE BASED ON ECMWF/GFS
MODEL TRENDS. THIS IS ASSOCIATED WITH THE WARM FRONTAL BOUNDARY
ALONG THE MO/IA BORDER ON WEDNESDAY LIFTING INTO THE AREA. 1-6 KM
SHEAR IS 25 KT OR LESS...SO THINKING HEAVY RAIN SHOULD BE THE MAIN
CONCERN. WE MAY BE ABLE TO SQUEEZE IN A DRY DAY ON FRIDAY...AS A
SURFACE COOL FRONT PASSES...BUT HARD TO SAY AT THIS TIME. THEN
HEADING INTO THE WEEKEND...THERE ARE SOME UNCERTAINTIES WITH THE
PACIFIC NORTHWEST TROUGH. THE 17.00Z ECMWF NOW WANTS TO PUSH THE
TROUGH EASTWARD WHICH RESULTS IN A RELATIVELY STRONG STORM SYSTEM
LIFTING THROUGH THE REGION SATURDAY. THE RESULT COULD BE SOME SEVERE
WEATHER. THE GFS HAS A SIMILAR STORM SYSTEM BUT FARTHER OFF TO THE
WEST SINCE IT IS SLOWER TO MOVE THE UPPER TROUGH. EITHER SCENARIO
WOULD PULL WARMER AND MORE HUMID AIR INTO THE REGION. VERY HARD TO
SAY WHAT SUNDAY IS GOING TO LOOK LIKE WITH THE UNCERTAINTY ON UPPER
TROUGH PROGRESSION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1246 PM CDT SUN AUG 17 2014
MODERATE TO STRONG 900 TO 800 MB FRONTOGENESIS WILL PRODUCE SHOWERS
AND SCATTERED THUNDRESTORMS MAINLY WEST OF KRST THIS AFTERNOON. AS
A SHORT WAVE APPROACHES THE AREA THIS AFTERNOON...THESE SHOWERS
WILL MOVE INTO KRST AROUND 17.23Z AND INTO KLSE AROUND 18.08Z. AS
THE LOW LEVELS MOISTEN OVERNIGHT...EXPECT AN LIFR TO IFR DECK AND
IFR TO MVFR FOG TO AFFECT BOTH TAF SITES AFTER 18.08Z. THIS WILL
THEN PERSIST THROUGH THE REMAINDER OF MONDAY MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...BOYNE
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1151 AM CDT SUN AUG 17 2014
.UPDATE...
ISSUED AT 1147 AM CDT SUN AUG 17 2014
SHOWERS HAVE DEVELOPED ALONG A DIFFERENTIAL HEATING BOUNDARY LATE
THIS MORNING ACROSS DODGE AND MOWER COUNTIES IN SOUTHEAST
MINNESOTA...AND FLOYD AND MITCHELL COUNTIES IN NORTHEAST IOWA.
WHILE THE MESO MODELS ARE NOT INDICATING ANY PRECIPITATION IN THIS
AREA...THE RAP DOES SHOW MODERATE TO STRONG 900 TO 800 MB
FORNTOGENESIS AND THE SPC MESO PAGE HAS AROUND 1000 J/KG SURFACE
BASED CAPE. THESE PARAMETERS STAY PRETTY CONSISTENT AND OVER THE
SAME GENERAL AREAS THIS AFTERNOON. DUE TO THIS...THE PRECIPITATION
CHANCES WERE DRAMATICALLY INCREASED THIS AFTERNOON.
UPDATE ISSUED AT 911 AM CDT SUN AUG 17 2014
LAW ENFORCEMENT REPORT...OBSERVATIONS...AND WEB CAMS ARE SHOWING
THAT MUCH OF THE DENSE FOG HAS LIFTED ACROSS MUCH OF NORTHEAST
IOWA. DUE TO THIS...THE DENSE FOG WAS ALLOWED TO EXPIRE. WHILE
CONDITIONS ARE IMPROVING...DRIVERS STILL SHOULD BE ALERT FOR AREAS
OF LOW VISIBILITIES THROUGH 10 AM THIS MORNING.
UPDATE ISSUED AT 437 AM CDT SUN AUG 17 2014
FOG IS BECOMING A BIGGER PROBLEM OVER NORTHEAST IOWA WITH MANY
SITES DROPPING TO OR BELOW 1/4 MILE VISIBILITY. MUCH OF THIS IS A
RESULT OF SKIES STILL CLEAR BECAUSE THE COOL FRONT HAS YET TO
MOVE INTO THE AREA. BEHIND THE FRONT ACROSS WISCONSIN...STRATUS
HAS HELPED KEEP THE FOG AT BAY. THERE HAS BEEN SOME SCATTERED
CLOUDS ACROSS SOUTHEAST MN AS WELL AHEAD OF THE FRONT KEEPING FOG
AT A MINIMUM THERE. SHOULD THESE CLOUDS CLEAR...THEN ITS POSSIBLE
THE THICKER FOG IN NORTHEAST IOWA COULD EXPAND INTO SOUTHEAST MN.
HAVE WENT AHEAD...ALONG WITH DMX AND DVN...AND ISSUED A DENSE FOG
ADVISORY FOR NORTHEAST IA. EXPIRATION TIME IS SET AT 9 AM...WHEN
THE WIDESPREAD NATURE OF THE DENSE FOG SHOULD BEGIN TO IMPROVE. IT
MAY NOT FULLY BE IMPROVED UNTIL 10 AM...THOUGH...PER 17.07Z HRRR
VISIBILITY PROGS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 310 AM CDT SUN AUG 17 2014
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED AN UPPER LOW AND TROUGH TRAVERSING SOUTHERN SASKATCHEWAN AND
NORTHEAST MONTANA...A SHORTWAVE NEAR FARGO...AND RIDGING OVER
EASTERN MN. SUBSIDENCE UNDER THIS UPPER RIDGING HAS RESULTED IN
MAINLY DRY CONDITIONS OVERNIGHT IN THE FORECAST AREA. THERE WERE
SHOWERS LAST EVENING AROUND I-94 FROM CENTRAL MN INTO SOUTHEAST
WI...ASSOCIATED WITH LINGERING DAYTIME INSTABILITY AND CONVERGENCE
ALONG A BACKDOOR COLD FRONT. THOSE HAVE SINCE MOSTLY DISSIPATED DUE
TO LOSS OF DAYTIME HEATING. THAT COLD FRONT NOW STRETCHES FROM
SOUTHERN WI INTO SOUTHWEST MN AND TO A LOW IN SOUTHEAST NORTH
DAKOTA. AROUND THIS SURFACE LOW AND THE ASSOCIATED SHORTWAVE
ALOFT...MORE SHOWERS AND STORMS EXIST. GOES PRECIPITABLE WATER
IMAGERY DEPICTS PLENTIFUL MOISTURE POOLED ALONG THE FRONT...WITH
VALUES RANGING FROM 1.5-2 INCHES...HIGHEST IN THE CONVECTION NEAR
FARGO. THE MOISTURE HAS BEEN FELT AT THE SURFACE AS WELL WITH
DEWPOINTS IN THE MID TO UPPER 60S AROUND THE FRONT. THESE HIGH
DEWPOINTS HAVE LED TO SOME FOG AND STRATUS FORMATION THIS MORNING.
BEHIND THE FRONT OVER NORTH CENTRAL WISCONSIN THROUGH UPPER
MICHIGAN...DRIER AND COOLER AIR IS FILTERING IN AHEAD OF HIGH
PRESSURE OVER NORTHERN ONTARIO.
MUCH OF THE SHORT TERM PERIOD FOCUS IS ON THE SHORTWAVE NEAR FARGO
AS WELL AS THE COLD FRONT THAT HAS LAYED UP OVER THE SOUTHWESTERN
PORTION OF THE FORECAST AREA. REGARDING THE SHORTWAVE...MODELS
GENERALLY SUGGEST THE CORE NEAR FARGO ENDS UP TRACKING TO THE EAST
OVER THE NEXT 24 HOURS...REACHING CENTRAL UPPER MI BY 12Z MON.
HOWEVER...THE TAIL OF THE SHORTWAVE WILL END UP CROSSING THE
FORECAST AREA TONIGHT. DPVA FROM THE TAIL OF THE SHORTWAVE...DAYTIME
HEATING/INSTABILITY THAT DEVELOPS TO INTERACT WITH CONVERGENCE ALONG
THE COLD FRONT...AND INCREASING 850MB MOISTURE TRANSPORT TONIGHT
OVER THE FORECAST AREA ALL SUGGEST POTENTIAL FOR SHOWERS AND STORMS
OVER THE NEXT 24 HOURS. GIVEN THE TRACK OF THE SHORTWAVE TAIL AND
MOISTURE TRANSPORT SIGNAL...THE NORTHWEST HALF OF THE FORECAST AREA
STANDS TO HAVE THE BEST SHOT FOR PRECIPITATION. HIGH RESOLUTION
MODEL GUIDANCE SUGGEST MUCH OF THE ACTIVITY THIS AFTERNOON AND
EVENING SHOULD BE ISOLATED TO SCATTERED AT BEST. THE INCREASE IN
850MB MOISTURE TRANSPORT AFTER MIDNIGHT COULD ALLOW CONVECTION TO
INCREASE A BIT MORE IN COVERAGE...THUS HIGHEST CHANCES ARE 06-12Z
MONDAY.
REGARDING CONVECTIVE HAZARDS. 0-6KM AND 0-3KM SHEAR IS ALL BELOW 20
KT THROUGH TONIGHT...LIMITING SEVERE POTENTIAL. HOWEVER...
PRECIPITABLE WATER IS PROGGED IN THE 1.5-1.8 INCH RANGE WHICH WOULD
ALLOW THE STORMS TO PRODUCE BRIEF HEAVY RAIN.
TEMPERATURES TODAY SHOULD VARY QUITE A BIT ACROSS THE FORECAST AREA.
ACROSS THE SOUTHWEST END OF THE FORECAST AREA WHERE THE FRONT HAS
STALLED OUT...925MB TEMPS ARE SIMILAR TO YESTERDAY IN THE 21-22C
RANGE...SUPPORTING HIGHS INTO THE LOW 80S OR SO. MEANWHILE...IN
NORTH CENTRAL WI WHERE 925MB TEMPS ONLY TOP OUT AT 18C...HIGHS MAY
ONLY REACH THE MID 70S. SOUTHERLY FLOW ACROSS THE FORECAST AREA
TONIGHT SHOULD HELP KEEP BOTH TEMPERATURES AND DEWPOINTS UP...WITH
ONLY PRECIPITATION COOLING LOWS. THEREFORE...EXPECT ANOTHER MILD
AND SOMEWHAT HUMID NIGHT FOR MID AUGUST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 310 AM CDT SUN AUG 17 2014
FOCUS FOR MONDAY THROUGH TUESDAY REMAINS ON THE UPPER LOW AND TROUGH
CURRENTLY OVER SOUTHERN SASKATCHEWAN AND EASTERN MONTANA. MODELS
CONTINUE TO BE IN GOOD AGREEMENT DROPPING THIS TROUGH INTO MN ON
MONDAY...INTO THE FORECAST AREA BY 12Z TUE...AND OVER EASTERN WI BY
00Z WED. THE TRACK OF THE TROUGH SUGGESTS THE BEST DYNAMICAL
FORCING FOR THE FORECAST AREA OCCURS FROM 18Z MONDAY TO 18Z
TUESDAY...MAXIMIZED DURING MONDAY EVENING. THERE SHOULD BE PLENTY OF
MOISTURE FOR THE TROUGH TO WORK ON TOO...WITH 1.5-1.75 INCHES OF
PRECIPITABLE WATER ALREADY IN PLACE AND IS PROGGED TO REMAIN STEADY
THROUGH THE TROUGH PASSAGE. GIVEN THE GOOD CONSISTENCY ON THIS
SIGNAL FOR THE TROUGH...FEEL FAIRLY CONFIDENT MUCH OF THE AREA WILL
SEE SHOWERS AND STORMS. DAYTIME HEATING INCREASING INSTABILITY FOR
MONDAY AND TUESDAY AFTERNOONS SHOULD ONLY HELP MATTERS. THEREFORE...
HAVE INCREASED PRECIPITATION CHANCES EVEN MORE. IT DOES APPEAR
LOCATIONS WEST OF THE MS RIVER SHOULD SEE PRECIPITATION DIMINISH FOR
A TIME FROM 03-12Z TUESDAY OVER THE WEST HALF OF THE FORECAST
AREA...THOUGH. 925MB TEMPS ON MONDAY IN THE 20-22C RANGE SHOULD
SUPPORT HIGHS IN THE UPPER 70S/LOW 80S...HELD DOWN BY
PRECIPITATION. IT WILL LIKELY FEEL A BIT HUMID TOO. 925MB TEMPS ONLY
TOP OUT FROM 18-20C ON TUESDAY...AND WITH THE POTENTIAL FOR
PRECIPITATION...HIGHS GET KNOCKED DOWN A FEW DEGREES.
ALL INDICATIONS ARE THAT THE UPPER LOW AND TROUGH WILL MOVE AWAY
FROM THE REGION TUESDAY NIGHT...ALLOWING ANY CONVECTION TO
DIMINISH/END TUESDAY EVENING WITH THE LOSS OF DAYTIME HEATING. WITH
THE AREA PROGGED TO LIE IN AN INFLECTION POINT BETWEEN THE DEPARTING
TROUGH AND UPPER RIDGING BUILDING UP ALONG I-29...SUBSIDENCE SHOULD
BE IN PLACE TO ALLOW FOR A DRY OVERNIGHT. CLEARING OF THE SKIES
COMBINED WITH RECENT RAINS AND DIMINISHING WINDS SHOULD PROMOTE
FOG DEVELOPMENT AND THUS ADDED AREAS OF FOG TO THE FORECAST. THE
DRY CONDITIONS COULD PERSIST THROUGH WEDNESDAY AS THAT UPPER RIDGE
SHIFTS EAST TO I-35. HOWEVER...THERE ARE SIGNS FOR SHOWER AND
THUNDERSTORM ACTIVITY TO DEVELOP ACROSS IOWA...NORTH OF A WARM
FRONTAL BOUNDARY PROGGED TO SET UP ALONG THE MO/IA BORDER. HAVE KEPT
SOME LOW CHANCES IN ACROSS THE FAR SOUTHERN PORTION OF THE FORECAST
AREA JUST IN CASE.
FOR WEDNESDAY NIGHT AND INTO NEXT WEEKEND...THERE IS GOOD MODEL
AGREEMENT AMONGST 17.00Z GUIDANCE AS WELL AS PREVIOUS MODELS FOR
TROUGHING TO DIG INTO THE PACIFIC NORTHWEST. IN RESPONSE...RIDGING
BUILDS DOWNSTREAM TOWARDS THE FORECAST AREA...RESULTING IN A
WARM/MOIST AIR ADVECTION PATTERN. THIS WILL LEAD TO MORE CHANCES OF
SHOWERS AND THUNDERSTORMS. ITS APPEARING LIKE LATE WEDNESDAY NIGHT
INTO THURSDAY MORNING COULD BE AN ENHANCED CHANCE BASED ON ECMWF/GFS
MODEL TRENDS. THIS IS ASSOCIATED WITH THE WARM FRONTAL BOUNDARY
ALONG THE MO/IA BORDER ON WEDNESDAY LIFTING INTO THE AREA. 1-6 KM
SHEAR IS 25 KT OR LESS...SO THINKING HEAVY RAIN SHOULD BE THE MAIN
CONCERN. WE MAY BE ABLE TO SQUEEZE IN A DRY DAY ON FRIDAY...AS A
SURFACE COOL FRONT PASSES...BUT HARD TO SAY AT THIS TIME. THEN
HEADING INTO THE WEEKEND...THERE ARE SOME UNCERTAINTIES WITH THE
PACIFIC NORTHWEST TROUGH. THE 17.00Z ECMWF NOW WANTS TO PUSH THE
TROUGH EASTWARD WHICH RESULTS IN A RELATIVELY STRONG STORM SYSTEM
LIFTING THROUGH THE REGION SATURDAY. THE RESULT COULD BE SOME SEVERE
WEATHER. THE GFS HAS A SIMILAR STORM SYSTEM BUT FARTHER OFF TO THE
WEST SINCE IT IS SLOWER TO MOVE THE UPPER TROUGH. EITHER SCENARIO
WOULD PULL WARMER AND MORE HUMID AIR INTO THE REGION. VERY HARD TO
SAY WHAT SUNDAY IS GOING TO LOOK LIKE WITH THE UNCERTAINTY ON UPPER
TROUGH PROGRESSION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 656 AM CDT SUN AUG 17 2014
LOW STRATUS WILL PRODUCE IFR CONDITIONS AT THE TAF SITES THIS
MORNING WITH CEILING RANGING FROM 900 FT AT KLSE TO 200 FT AT
KRST. ALSO...AS THE STRATUS ADVECTS WESTWARD INTO KRST...IT IS
LIKELY THAT KRST WILL DROP TO VLIFR IN FOG. MIXING WILL INCREASE
LATER THIS MORNING AND WE SHOULD SEE CONDITIONS IMPROVE TO MVFR BY
LATE MORNING AND EVENTUALLY TO VFR THIS AFTERNOON. LOW PRESSURE
APPROACHES FROM THE NORTHERN PLAINS TONIGHT AND WITH THE MOIST
AIRMASS OVER THE REGION WE WILL ONCE AGAIN SEE STRATUS OVER THE
TAF SITES. THE PRESSURE GRADIENT TIGHTENS TONIGHT WITH SOUTH WINDS
INCREASING INTO THE 6 TO 12 KT RANGE. THIS SHOULD PROMOTE MIXING
AND KEEP THE VISIBILITY FROM FALLING BELOW 3SM. THE LOW STRATUS
WILL BE THE MAIN CONCERN WHERE CEILINGS WILL LIKELY FALL INTO THE
MVFR TO IFR CATEGORY AFTER MIDNIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...BOYNE
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
913 AM CDT SUN AUG 17 2014
.UPDATE...
ISSUED AT 911 AM CDT SUN AUG 17 2014
LAW ENFORCEMENT REPORT...OBSERVATIONS...AND WEB CAMS ARE SHOWING
THAT MUCH OF THE DENSE FOG HAS LIFTED ACROSS MUCH OF NORTHEAST
IOWA. DUE TO THIS...THE DENSE FOG WAS ALLOWED TO EXPIRE. WHILE
CONDITIONS ARE IMPROVING...DRIVERS STILL SHOULD BE ALERT FOR AREAS
OF LOW VISIBILITIES THROUGH 10 AM THIS MORNING.
UPDATE ISSUED AT 437 AM CDT SUN AUG 17 2014
FOG IS BECOMING A BIGGER PROBLEM OVER NORTHEAST IOWA WITH MANY
SITES DROPPING TO OR BELOW 1/4 MILE VISIBILITY. MUCH OF THIS IS A
RESULT OF SKIES STILL CLEAR BECAUSE THE COOL FRONT HAS YET TO
MOVE INTO THE AREA. BEHIND THE FRONT ACROSS WISCONSIN...STRATUS
HAS HELPED KEEP THE FOG AT BAY. THERE HAS BEEN SOME SCATTERED
CLOUDS ACROSS SOUTHEAST MN AS WELL AHEAD OF THE FRONT KEEPING FOG
AT A MINIMUM THERE. SHOULD THESE CLOUDS CLEAR...THEN ITS POSSIBLE
THE THICKER FOG IN NORTHEAST IOWA COULD EXPAND INTO SOUTHEAST MN.
HAVE WENT AHEAD...ALONG WITH DMX AND DVN...AND ISSUED A DENSE FOG
ADVISORY FOR NORTHEAST IA. EXPIRATION TIME IS SET AT 9 AM...WHEN
THE WIDESPREAD NATURE OF THE DENSE FOG SHOULD BEGIN TO IMPROVE. IT
MAY NOT FULLY BE IMPROVED UNTIL 10 AM...THOUGH...PER 17.07Z HRRR
VISIBILITY PROGS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 310 AM CDT SUN AUG 17 2014
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED AN UPPER LOW AND TROUGH TRAVERSING SOUTHERN SASKATCHEWAN AND
NORTHEAST MONTANA...A SHORTWAVE NEAR FARGO...AND RIDGING OVER
EASTERN MN. SUBSIDENCE UNDER THIS UPPER RIDGING HAS RESULTED IN
MAINLY DRY CONDITIONS OVERNIGHT IN THE FORECAST AREA. THERE WERE
SHOWERS LAST EVENING AROUND I-94 FROM CENTRAL MN INTO SOUTHEAST
WI...ASSOCIATED WITH LINGERING DAYTIME INSTABILITY AND CONVERGENCE
ALONG A BACKDOOR COLD FRONT. THOSE HAVE SINCE MOSTLY DISSIPATED DUE
TO LOSS OF DAYTIME HEATING. THAT COLD FRONT NOW STRETCHES FROM
SOUTHERN WI INTO SOUTHWEST MN AND TO A LOW IN SOUTHEAST NORTH
DAKOTA. AROUND THIS SURFACE LOW AND THE ASSOCIATED SHORTWAVE
ALOFT...MORE SHOWERS AND STORMS EXIST. GOES PRECIPITABLE WATER
IMAGERY DEPICTS PLENTIFUL MOISTURE POOLED ALONG THE FRONT...WITH
VALUES RANGING FROM 1.5-2 INCHES...HIGHEST IN THE CONVECTION NEAR
FARGO. THE MOISTURE HAS BEEN FELT AT THE SURFACE AS WELL WITH
DEWPOINTS IN THE MID TO UPPER 60S AROUND THE FRONT. THESE HIGH
DEWPOINTS HAVE LED TO SOME FOG AND STRATUS FORMATION THIS MORNING.
BEHIND THE FRONT OVER NORTH CENTRAL WISCONSIN THROUGH UPPER
MICHIGAN...DRIER AND COOLER AIR IS FILTERING IN AHEAD OF HIGH
PRESSURE OVER NORTHERN ONTARIO.
MUCH OF THE SHORT TERM PERIOD FOCUS IS ON THE SHORTWAVE NEAR FARGO
AS WELL AS THE COLD FRONT THAT HAS LAYED UP OVER THE SOUTHWESTERN
PORTION OF THE FORECAST AREA. REGARDING THE SHORTWAVE...MODELS
GENERALLY SUGGEST THE CORE NEAR FARGO ENDS UP TRACKING TO THE EAST
OVER THE NEXT 24 HOURS...REACHING CENTRAL UPPER MI BY 12Z MON.
HOWEVER...THE TAIL OF THE SHORTWAVE WILL END UP CROSSING THE
FORECAST AREA TONIGHT. DPVA FROM THE TAIL OF THE SHORTWAVE...DAYTIME
HEATING/INSTABILITY THAT DEVELOPS TO INTERACT WITH CONVERGENCE ALONG
THE COLD FRONT...AND INCREASING 850MB MOISTURE TRANSPORT TONIGHT
OVER THE FORECAST AREA ALL SUGGEST POTENTIAL FOR SHOWERS AND STORMS
OVER THE NEXT 24 HOURS. GIVEN THE TRACK OF THE SHORTWAVE TAIL AND
MOISTURE TRANSPORT SIGNAL...THE NORTHWEST HALF OF THE FORECAST AREA
STANDS TO HAVE THE BEST SHOT FOR PRECIPITATION. HIGH RESOLUTION
MODEL GUIDANCE SUGGEST MUCH OF THE ACTIVITY THIS AFTERNOON AND
EVENING SHOULD BE ISOLATED TO SCATTERED AT BEST. THE INCREASE IN
850MB MOISTURE TRANSPORT AFTER MIDNIGHT COULD ALLOW CONVECTION TO
INCREASE A BIT MORE IN COVERAGE...THUS HIGHEST CHANCES ARE 06-12Z
MONDAY.
REGARDING CONVECTIVE HAZARDS. 0-6KM AND 0-3KM SHEAR IS ALL BELOW 20
KT THROUGH TONIGHT...LIMITING SEVERE POTENTIAL. HOWEVER...
PRECIPITABLE WATER IS PROGGED IN THE 1.5-1.8 INCH RANGE WHICH WOULD
ALLOW THE STORMS TO PRODUCE BRIEF HEAVY RAIN.
TEMPERATURES TODAY SHOULD VARY QUITE A BIT ACROSS THE FORECAST AREA.
ACROSS THE SOUTHWEST END OF THE FORECAST AREA WHERE THE FRONT HAS
STALLED OUT...925MB TEMPS ARE SIMILAR TO YESTERDAY IN THE 21-22C
RANGE...SUPPORTING HIGHS INTO THE LOW 80S OR SO. MEANWHILE...IN
NORTH CENTRAL WI WHERE 925MB TEMPS ONLY TOP OUT AT 18C...HIGHS MAY
ONLY REACH THE MID 70S. SOUTHERLY FLOW ACROSS THE FORECAST AREA
TONIGHT SHOULD HELP KEEP BOTH TEMPERATURES AND DEWPOINTS UP...WITH
ONLY PRECIPITATION COOLING LOWS. THEREFORE...EXPECT ANOTHER MILD
AND SOMEWHAT HUMID NIGHT FOR MID AUGUST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 310 AM CDT SUN AUG 17 2014
FOCUS FOR MONDAY THROUGH TUESDAY REMAINS ON THE UPPER LOW AND TROUGH
CURRENTLY OVER SOUTHERN SASKATCHEWAN AND EASTERN MONTANA. MODELS
CONTINUE TO BE IN GOOD AGREEMENT DROPPING THIS TROUGH INTO MN ON
MONDAY...INTO THE FORECAST AREA BY 12Z TUE...AND OVER EASTERN WI BY
00Z WED. THE TRACK OF THE TROUGH SUGGESTS THE BEST DYNAMICAL
FORCING FOR THE FORECAST AREA OCCURS FROM 18Z MONDAY TO 18Z
TUESDAY...MAXIMIZED DURING MONDAY EVENING. THERE SHOULD BE PLENTY OF
MOISTURE FOR THE TROUGH TO WORK ON TOO...WITH 1.5-1.75 INCHES OF
PRECIPITABLE WATER ALREADY IN PLACE AND IS PROGGED TO REMAIN STEADY
THROUGH THE TROUGH PASSAGE. GIVEN THE GOOD CONSISTENCY ON THIS
SIGNAL FOR THE TROUGH...FEEL FAIRLY CONFIDENT MUCH OF THE AREA WILL
SEE SHOWERS AND STORMS. DAYTIME HEATING INCREASING INSTABILITY FOR
MONDAY AND TUESDAY AFTERNOONS SHOULD ONLY HELP MATTERS. THEREFORE...
HAVE INCREASED PRECIPITATION CHANCES EVEN MORE. IT DOES APPEAR
LOCATIONS WEST OF THE MS RIVER SHOULD SEE PRECIPITATION DIMINISH FOR
A TIME FROM 03-12Z TUESDAY OVER THE WEST HALF OF THE FORECAST
AREA...THOUGH. 925MB TEMPS ON MONDAY IN THE 20-22C RANGE SHOULD
SUPPORT HIGHS IN THE UPPER 70S/LOW 80S...HELD DOWN BY
PRECIPITATION. IT WILL LIKELY FEEL A BIT HUMID TOO. 925MB TEMPS ONLY
TOP OUT FROM 18-20C ON TUESDAY...AND WITH THE POTENTIAL FOR
PRECIPITATION...HIGHS GET KNOCKED DOWN A FEW DEGREES.
ALL INDICATIONS ARE THAT THE UPPER LOW AND TROUGH WILL MOVE AWAY
FROM THE REGION TUESDAY NIGHT...ALLOWING ANY CONVECTION TO
DIMINISH/END TUESDAY EVENING WITH THE LOSS OF DAYTIME HEATING. WITH
THE AREA PROGGED TO LIE IN AN INFLECTION POINT BETWEEN THE DEPARTING
TROUGH AND UPPER RIDGING BUILDING UP ALONG I-29...SUBSIDENCE SHOULD
BE IN PLACE TO ALLOW FOR A DRY OVERNIGHT. CLEARING OF THE SKIES
COMBINED WITH RECENT RAINS AND DIMINISHING WINDS SHOULD PROMOTE
FOG DEVELOPMENT AND THUS ADDED AREAS OF FOG TO THE FORECAST. THE
DRY CONDITIONS COULD PERSIST THROUGH WEDNESDAY AS THAT UPPER RIDGE
SHIFTS EAST TO I-35. HOWEVER...THERE ARE SIGNS FOR SHOWER AND
THUNDERSTORM ACTIVITY TO DEVELOP ACROSS IOWA...NORTH OF A WARM
FRONTAL BOUNDARY PROGGED TO SET UP ALONG THE MO/IA BORDER. HAVE KEPT
SOME LOW CHANCES IN ACROSS THE FAR SOUTHERN PORTION OF THE FORECAST
AREA JUST IN CASE.
FOR WEDNESDAY NIGHT AND INTO NEXT WEEKEND...THERE IS GOOD MODEL
AGREEMENT AMONGST 17.00Z GUIDANCE AS WELL AS PREVIOUS MODELS FOR
TROUGHING TO DIG INTO THE PACIFIC NORTHWEST. IN RESPONSE...RIDGING
BUILDS DOWNSTREAM TOWARDS THE FORECAST AREA...RESULTING IN A
WARM/MOIST AIR ADVECTION PATTERN. THIS WILL LEAD TO MORE CHANCES OF
SHOWERS AND THUNDERSTORMS. ITS APPEARING LIKE LATE WEDNESDAY NIGHT
INTO THURSDAY MORNING COULD BE AN ENHANCED CHANCE BASED ON ECMWF/GFS
MODEL TRENDS. THIS IS ASSOCIATED WITH THE WARM FRONTAL BOUNDARY
ALONG THE MO/IA BORDER ON WEDNESDAY LIFTING INTO THE AREA. 1-6 KM
SHEAR IS 25 KT OR LESS...SO THINKING HEAVY RAIN SHOULD BE THE MAIN
CONCERN. WE MAY BE ABLE TO SQUEEZE IN A DRY DAY ON FRIDAY...AS A
SURFACE COOL FRONT PASSES...BUT HARD TO SAY AT THIS TIME. THEN
HEADING INTO THE WEEKEND...THERE ARE SOME UNCERTAINTIES WITH THE
PACIFIC NORTHWEST TROUGH. THE 17.00Z ECMWF NOW WANTS TO PUSH THE
TROUGH EASTWARD WHICH RESULTS IN A RELATIVELY STRONG STORM SYSTEM
LIFTING THROUGH THE REGION SATURDAY. THE RESULT COULD BE SOME SEVERE
WEATHER. THE GFS HAS A SIMILAR STORM SYSTEM BUT FARTHER OFF TO THE
WEST SINCE IT IS SLOWER TO MOVE THE UPPER TROUGH. EITHER SCENARIO
WOULD PULL WARMER AND MORE HUMID AIR INTO THE REGION. VERY HARD TO
SAY WHAT SUNDAY IS GOING TO LOOK LIKE WITH THE UNCERTAINTY ON UPPER
TROUGH PROGRESSION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 656 AM CDT SUN AUG 17 2014
LOW STRATUS WILL PRODUCE IFR CONDITIONS AT THE TAF SITES THIS
MORNING WITH CEILING RANGING FROM 900 FT AT KLSE TO 200 FT AT
KRST. ALSO...AS THE STRATUS ADVECTS WESTWARD INTO KRST...IT IS
LIKELY THAT KRST WILL DROP TO VLIFR IN FOG. MIXING WILL INCREASE
LATER THIS MORNING AND WE SHOULD SEE CONDITIONS IMPROVE TO MVFR BY
LATE MORNING AND EVENTUALLY TO VFR THIS AFTERNOON. LOW PRESSURE
APPROACHES FROM THE NORTHERN PLAINS TONIGHT AND WITH THE MOIST
AIRMASS OVER THE REGION WE WILL ONCE AGAIN SEE STRATUS OVER THE
TAF SITES. THE PRESSURE GRADIENT TIGHTENS TONIGHT WITH SOUTH WINDS
INCREASING INTO THE 6 TO 12 KT RANGE. THIS SHOULD PROMOTE MIXING
AND KEEP THE VISIBILITY FROM FALLING BELOW 3SM. THE LOW STRATUS
WILL BE THE MAIN CONCERN WHERE CEILINGS WILL LIKELY FALL INTO THE
MVFR TO IFR CATEGORY AFTER MIDNIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...BOYNE
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
656 AM CDT SUN AUG 17 2014
.UPDATE...
ISSUED AT 437 AM CDT SUN AUG 17 2014
FOG IS BECOMING A BIGGER PROBLEM OVER NORTHEAST IOWA WITH MANY
SITES DROPPING TO OR BELOW 1/4 MILE VISIBILITY. MUCH OF THIS IS A
RESULT OF SKIES STILL CLEAR BECAUSE THE COOL FRONT HAS YET TO
MOVE INTO THE AREA. BEHIND THE FRONT ACROSS WISCONSIN...STRATUS
HAS HELPED KEEP THE FOG AT BAY. THERE HAS BEEN SOME SCATTERED
CLOUDS ACROSS SOUTHEAST MN AS WELL AHEAD OF THE FRONT KEEPING FOG
AT A MINIMUM THERE. SHOULD THESE CLOUDS CLEAR...THEN ITS POSSIBLE
THE THICKER FOG IN NORTHEAST IOWA COULD EXPAND INTO SOUTHEAST MN.
HAVE WENT AHEAD...ALONG WITH DMX AND DVN...AND ISSUED A DENSE FOG
ADVISORY FOR NORTHEAST IA. EXPIRATION TIME IS SET AT 9 AM...WHEN
THE WIDESPREAD NATURE OF THE DENSE FOG SHOULD BEGIN TO IMPROVE. IT
MAY NOT FULLY BE IMPROVED UNTIL 10 AM...THOUGH...PER 17.07Z HRRR
VISIBILITY PROGS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 310 AM CDT SUN AUG 17 2014
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED AN UPPER LOW AND TROUGH TRAVERSING SOUTHERN SASKATCHEWAN AND
NORTHEAST MONTANA...A SHORTWAVE NEAR FARGO...AND RIDGING OVER
EASTERN MN. SUBSIDENCE UNDER THIS UPPER RIDGING HAS RESULTED IN
MAINLY DRY CONDITIONS OVERNIGHT IN THE FORECAST AREA. THERE WERE
SHOWERS LAST EVENING AROUND I-94 FROM CENTRAL MN INTO SOUTHEAST
WI...ASSOCIATED WITH LINGERING DAYTIME INSTABILITY AND CONVERGENCE
ALONG A BACKDOOR COLD FRONT. THOSE HAVE SINCE MOSTLY DISSIPATED DUE
TO LOSS OF DAYTIME HEATING. THAT COLD FRONT NOW STRETCHES FROM
SOUTHERN WI INTO SOUTHWEST MN AND TO A LOW IN SOUTHEAST NORTH
DAKOTA. AROUND THIS SURFACE LOW AND THE ASSOCIATED SHORTWAVE
ALOFT...MORE SHOWERS AND STORMS EXIST. GOES PRECIPITABLE WATER
IMAGERY DEPICTS PLENTIFUL MOISTURE POOLED ALONG THE FRONT...WITH
VALUES RANGING FROM 1.5-2 INCHES...HIGHEST IN THE CONVECTION NEAR
FARGO. THE MOISTURE HAS BEEN FELT AT THE SURFACE AS WELL WITH
DEWPOINTS IN THE MID TO UPPER 60S AROUND THE FRONT. THESE HIGH
DEWPOINTS HAVE LED TO SOME FOG AND STRATUS FORMATION THIS MORNING.
BEHIND THE FRONT OVER NORTH CENTRAL WISCONSIN THROUGH UPPER
MICHIGAN...DRIER AND COOLER AIR IS FILTERING IN AHEAD OF HIGH
PRESSURE OVER NORTHERN ONTARIO.
MUCH OF THE SHORT TERM PERIOD FOCUS IS ON THE SHORTWAVE NEAR FARGO
AS WELL AS THE COLD FRONT THAT HAS LAYED UP OVER THE SOUTHWESTERN
PORTION OF THE FORECAST AREA. REGARDING THE SHORTWAVE...MODELS
GENERALLY SUGGEST THE CORE NEAR FARGO ENDS UP TRACKING TO THE EAST
OVER THE NEXT 24 HOURS...REACHING CENTRAL UPPER MI BY 12Z MON.
HOWEVER...THE TAIL OF THE SHORTWAVE WILL END UP CROSSING THE
FORECAST AREA TONIGHT. DPVA FROM THE TAIL OF THE SHORTWAVE...DAYTIME
HEATING/INSTABILITY THAT DEVELOPS TO INTERACT WITH CONVERGENCE ALONG
THE COLD FRONT...AND INCREASING 850MB MOISTURE TRANSPORT TONIGHT
OVER THE FORECAST AREA ALL SUGGEST POTENTIAL FOR SHOWERS AND STORMS
OVER THE NEXT 24 HOURS. GIVEN THE TRACK OF THE SHORTWAVE TAIL AND
MOISTURE TRANSPORT SIGNAL...THE NORTHWEST HALF OF THE FORECAST AREA
STANDS TO HAVE THE BEST SHOT FOR PRECIPITATION. HIGH RESOLUTION
MODEL GUIDANCE SUGGEST MUCH OF THE ACTIVITY THIS AFTERNOON AND
EVENING SHOULD BE ISOLATED TO SCATTERED AT BEST. THE INCREASE IN
850MB MOISTURE TRANSPORT AFTER MIDNIGHT COULD ALLOW CONVECTION TO
INCREASE A BIT MORE IN COVERAGE...THUS HIGHEST CHANCES ARE 06-12Z
MONDAY.
REGARDING CONVECTIVE HAZARDS. 0-6KM AND 0-3KM SHEAR IS ALL BELOW 20
KT THROUGH TONIGHT...LIMITING SEVERE POTENTIAL. HOWEVER...
PRECIPITABLE WATER IS PROGGED IN THE 1.5-1.8 INCH RANGE WHICH WOULD
ALLOW THE STORMS TO PRODUCE BRIEF HEAVY RAIN.
TEMPERATURES TODAY SHOULD VARY QUITE A BIT ACROSS THE FORECAST AREA.
ACROSS THE SOUTHWEST END OF THE FORECAST AREA WHERE THE FRONT HAS
STALLED OUT...925MB TEMPS ARE SIMILAR TO YESTERDAY IN THE 21-22C
RANGE...SUPPORTING HIGHS INTO THE LOW 80S OR SO. MEANWHILE...IN
NORTH CENTRAL WI WHERE 925MB TEMPS ONLY TOP OUT AT 18C...HIGHS MAY
ONLY REACH THE MID 70S. SOUTHERLY FLOW ACROSS THE FORECAST AREA
TONIGHT SHOULD HELP KEEP BOTH TEMPERATURES AND DEWPOINTS UP...WITH
ONLY PRECIPITATION COOLING LOWS. THEREFORE...EXPECT ANOTHER MILD
AND SOMEWHAT HUMID NIGHT FOR MID AUGUST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 310 AM CDT SUN AUG 17 2014
FOCUS FOR MONDAY THROUGH TUESDAY REMAINS ON THE UPPER LOW AND TROUGH
CURRENTLY OVER SOUTHERN SASKATCHEWAN AND EASTERN MONTANA. MODELS
CONTINUE TO BE IN GOOD AGREEMENT DROPPING THIS TROUGH INTO MN ON
MONDAY...INTO THE FORECAST AREA BY 12Z TUE...AND OVER EASTERN WI BY
00Z WED. THE TRACK OF THE TROUGH SUGGESTS THE BEST DYNAMICAL
FORCING FOR THE FORECAST AREA OCCURS FROM 18Z MONDAY TO 18Z
TUESDAY...MAXIMIZED DURING MONDAY EVENING. THERE SHOULD BE PLENTY OF
MOISTURE FOR THE TROUGH TO WORK ON TOO...WITH 1.5-1.75 INCHES OF
PRECIPITABLE WATER ALREADY IN PLACE AND IS PROGGED TO REMAIN STEADY
THROUGH THE TROUGH PASSAGE. GIVEN THE GOOD CONSISTENCY ON THIS
SIGNAL FOR THE TROUGH...FEEL FAIRLY CONFIDENT MUCH OF THE AREA WILL
SEE SHOWERS AND STORMS. DAYTIME HEATING INCREASING INSTABILITY FOR
MONDAY AND TUESDAY AFTERNOONS SHOULD ONLY HELP MATTERS. THEREFORE...
HAVE INCREASED PRECIPITATION CHANCES EVEN MORE. IT DOES APPEAR
LOCATIONS WEST OF THE MS RIVER SHOULD SEE PRECIPITATION DIMINISH FOR
A TIME FROM 03-12Z TUESDAY OVER THE WEST HALF OF THE FORECAST
AREA...THOUGH. 925MB TEMPS ON MONDAY IN THE 20-22C RANGE SHOULD
SUPPORT HIGHS IN THE UPPER 70S/LOW 80S...HELD DOWN BY
PRECIPITATION. IT WILL LIKELY FEEL A BIT HUMID TOO. 925MB TEMPS ONLY
TOP OUT FROM 18-20C ON TUESDAY...AND WITH THE POTENTIAL FOR
PRECIPITATION...HIGHS GET KNOCKED DOWN A FEW DEGREES.
ALL INDICATIONS ARE THAT THE UPPER LOW AND TROUGH WILL MOVE AWAY
FROM THE REGION TUESDAY NIGHT...ALLOWING ANY CONVECTION TO
DIMINISH/END TUESDAY EVENING WITH THE LOSS OF DAYTIME HEATING. WITH
THE AREA PROGGED TO LIE IN AN INFLECTION POINT BETWEEN THE DEPARTING
TROUGH AND UPPER RIDGING BUILDING UP ALONG I-29...SUBSIDENCE SHOULD
BE IN PLACE TO ALLOW FOR A DRY OVERNIGHT. CLEARING OF THE SKIES
COMBINED WITH RECENT RAINS AND DIMINISHING WINDS SHOULD PROMOTE
FOG DEVELOPMENT AND THUS ADDED AREAS OF FOG TO THE FORECAST. THE
DRY CONDITIONS COULD PERSIST THROUGH WEDNESDAY AS THAT UPPER RIDGE
SHIFTS EAST TO I-35. HOWEVER...THERE ARE SIGNS FOR SHOWER AND
THUNDERSTORM ACTIVITY TO DEVELOP ACROSS IOWA...NORTH OF A WARM
FRONTAL BOUNDARY PROGGED TO SET UP ALONG THE MO/IA BORDER. HAVE KEPT
SOME LOW CHANCES IN ACROSS THE FAR SOUTHERN PORTION OF THE FORECAST
AREA JUST IN CASE.
FOR WEDNESDAY NIGHT AND INTO NEXT WEEKEND...THERE IS GOOD MODEL
AGREEMENT AMONGST 17.00Z GUIDANCE AS WELL AS PREVIOUS MODELS FOR
TROUGHING TO DIG INTO THE PACIFIC NORTHWEST. IN RESPONSE...RIDGING
BUILDS DOWNSTREAM TOWARDS THE FORECAST AREA...RESULTING IN A
WARM/MOIST AIR ADVECTION PATTERN. THIS WILL LEAD TO MORE CHANCES OF
SHOWERS AND THUNDERSTORMS. ITS APPEARING LIKE LATE WEDNESDAY NIGHT
INTO THURSDAY MORNING COULD BE AN ENHANCED CHANCE BASED ON ECMWF/GFS
MODEL TRENDS. THIS IS ASSOCIATED WITH THE WARM FRONTAL BOUNDARY
ALONG THE MO/IA BORDER ON WEDNESDAY LIFTING INTO THE AREA. 1-6 KM
SHEAR IS 25 KT OR LESS...SO THINKING HEAVY RAIN SHOULD BE THE MAIN
CONCERN. WE MAY BE ABLE TO SQUEEZE IN A DRY DAY ON FRIDAY...AS A
SURFACE COOL FRONT PASSES...BUT HARD TO SAY AT THIS TIME. THEN
HEADING INTO THE WEEKEND...THERE ARE SOME UNCERTAINTIES WITH THE
PACIFIC NORTHWEST TROUGH. THE 17.00Z ECMWF NOW WANTS TO PUSH THE
TROUGH EASTWARD WHICH RESULTS IN A RELATIVELY STRONG STORM SYSTEM
LIFTING THROUGH THE REGION SATURDAY. THE RESULT COULD BE SOME SEVERE
WEATHER. THE GFS HAS A SIMILAR STORM SYSTEM BUT FARTHER OFF TO THE
WEST SINCE IT IS SLOWER TO MOVE THE UPPER TROUGH. EITHER SCENARIO
WOULD PULL WARMER AND MORE HUMID AIR INTO THE REGION. VERY HARD TO
SAY WHAT SUNDAY IS GOING TO LOOK LIKE WITH THE UNCERTAINTY ON UPPER
TROUGH PROGRESSION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 656 AM CDT SUN AUG 17 2014
LOW STRATUS WILL PRODUCE IFR CONDITIONS AT THE TAF SITES THIS
MORNING WITH CEILING RANGING FROM 900 FT AT KLSE TO 200 FT AT
KRST. ALSO...AS THE STRATUS ADVECTS WESTWARD INTO KRST...IT IS
LIKELY THAT KRST WILL DROP TO VLIFR IN FOG. MIXING WILL INCREASE
LATER THIS MORNING AND WE SHOULD SEE CONDITIONS IMPROVE TO MVFR BY
LATE MORNING AND EVENTUALLY TO VFR THIS AFTERNOON. LOW PRESSURE
APPROACHES FROM THE NORTHERN PLAINS TONIGHT AND WITH THE MOIST
AIRMASS OVER THE REGION WE WILL ONCE AGAIN SEE STRATUS OVER THE
TAF SITES. THE PRESSURE GRADIENT TIGHTENS TONIGHT WITH SOUTH WINDS
INCREASING INTO THE 6 TO 12 KT RANGE. THIS SHOULD PROMOTE MIXING
AND KEEP THE VISIBILITY FROM FALLING BELOW 3SM. THE LOW STRATUS
WILL BE THE MAIN CONCERN WHERE CEILINGS WILL LIKELY FALL INTO THE
MVFR TO IFR CATEGORY AFTER MIDNIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR IAZ008>011-
018-019-029-030.
&&
$$
UPDATE...AJ
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
437 AM CDT SUN AUG 17 2014
.UPDATE...
ISSUED AT 437 AM CDT SUN AUG 17 2014
FOG IS BECOMING A BIGGER PROBLEM OVER NORTHEAST IOWA WITH MANY
SITES DROPPING TO OR BELOW 1/4 MILE VISIBILITY. MUCH OF THIS IS A
RESULT OF SKIES STILL CLEAR BECAUSE THE COOL FRONT HAS YET TO
MOVE INTO THE AREA. BEHIND THE FRONT ACROSS WISCONSIN...STRATUS
HAS HELPED KEEP THE FOG AT BAY. THERE HAS BEEN SOME SCATTERED
CLOUDS ACROSS SOUTHEAST MN AS WELL AHEAD OF THE FRONT KEEPING FOG
AT A MINIMUM THERE. SHOULD THESE CLOUDS CLEAR...THEN ITS POSSIBLE
THE THICKER FOG IN NORTHEAST IOWA COULD EXPAND INTO SOUTHEAST MN.
HAVE WENT AHEAD...ALONG WITH DMX AND DVN...AND ISSUED A DENSE FOG
ADVISORY FOR NORTHEAST IA. EXPIRATION TIME IS SET AT 9 AM...WHEN
THE WIDESPREAD NATURE OF THE DENSE FOG SHOULD BEGIN TO IMPROVE. IT
MAY NOT FULLY BE IMPROVED UNTIL 10 AM...THOUGH...PER 17.07Z HRRR
VISIBILITY PROGS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 310 AM CDT SUN AUG 17 2014
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED AN UPPER LOW AND TROUGH TRAVERSING SOUTHERN SASKATCHEWAN AND
NORTHEAST MONTANA...A SHORTWAVE NEAR FARGO...AND RIDGING OVER
EASTERN MN. SUBSIDENCE UNDER THIS UPPER RIDGING HAS RESULTED IN
MAINLY DRY CONDITIONS OVERNIGHT IN THE FORECAST AREA. THERE WERE
SHOWERS LAST EVENING AROUND I-94 FROM CENTRAL MN INTO SOUTHEAST
WI...ASSOCIATED WITH LINGERING DAYTIME INSTABILITY AND CONVERGENCE
ALONG A BACKDOOR COLD FRONT. THOSE HAVE SINCE MOSTLY DISSIPATED DUE
TO LOSS OF DAYTIME HEATING. THAT COLD FRONT NOW STRETCHES FROM
SOUTHERN WI INTO SOUTHWEST MN AND TO A LOW IN SOUTHEAST NORTH
DAKOTA. AROUND THIS SURFACE LOW AND THE ASSOCIATED SHORTWAVE
ALOFT...MORE SHOWERS AND STORMS EXIST. GOES PRECIPITABLE WATER
IMAGERY DEPICTS PLENTIFUL MOISTURE POOLED ALONG THE FRONT...WITH
VALUES RANGING FROM 1.5-2 INCHES...HIGHEST IN THE CONVECTION NEAR
FARGO. THE MOISTURE HAS BEEN FELT AT THE SURFACE AS WELL WITH
DEWPOINTS IN THE MID TO UPPER 60S AROUND THE FRONT. THESE HIGH
DEWPOINTS HAVE LED TO SOME FOG AND STRATUS FORMATION THIS MORNING.
BEHIND THE FRONT OVER NORTH CENTRAL WISCONSIN THROUGH UPPER
MICHIGAN...DRIER AND COOLER AIR IS FILTERING IN AHEAD OF HIGH
PRESSURE OVER NORTHERN ONTARIO.
MUCH OF THE SHORT TERM PERIOD FOCUS IS ON THE SHORTWAVE NEAR FARGO
AS WELL AS THE COLD FRONT THAT HAS LAYED UP OVER THE SOUTHWESTERN
PORTION OF THE FORECAST AREA. REGARDING THE SHORTWAVE...MODELS
GENERALLY SUGGEST THE CORE NEAR FARGO ENDS UP TRACKING TO THE EAST
OVER THE NEXT 24 HOURS...REACHING CENTRAL UPPER MI BY 12Z MON.
HOWEVER...THE TAIL OF THE SHORTWAVE WILL END UP CROSSING THE
FORECAST AREA TONIGHT. DPVA FROM THE TAIL OF THE SHORTWAVE...DAYTIME
HEATING/INSTABILITY THAT DEVELOPS TO INTERACT WITH CONVERGENCE ALONG
THE COLD FRONT...AND INCREASING 850MB MOISTURE TRANSPORT TONIGHT
OVER THE FORECAST AREA ALL SUGGEST POTENTIAL FOR SHOWERS AND STORMS
OVER THE NEXT 24 HOURS. GIVEN THE TRACK OF THE SHORTWAVE TAIL AND
MOISTURE TRANSPORT SIGNAL...THE NORTHWEST HALF OF THE FORECAST AREA
STANDS TO HAVE THE BEST SHOT FOR PRECIPITATION. HIGH RESOLUTION
MODEL GUIDANCE SUGGEST MUCH OF THE ACTIVITY THIS AFTERNOON AND
EVENING SHOULD BE ISOLATED TO SCATTERED AT BEST. THE INCREASE IN
850MB MOISTURE TRANSPORT AFTER MIDNIGHT COULD ALLOW CONVECTION TO
INCREASE A BIT MORE IN COVERAGE...THUS HIGHEST CHANCES ARE 06-12Z
MONDAY.
REGARDING CONVECTIVE HAZARDS. 0-6KM AND 0-3KM SHEAR IS ALL BELOW 20
KT THROUGH TONIGHT...LIMITING SEVERE POTENTIAL. HOWEVER...
PRECIPITABLE WATER IS PROGGED IN THE 1.5-1.8 INCH RANGE WHICH WOULD
ALLOW THE STORMS TO PRODUCE BRIEF HEAVY RAIN.
TEMPERATURES TODAY SHOULD VARY QUITE A BIT ACROSS THE FORECAST AREA.
ACROSS THE SOUTHWEST END OF THE FORECAST AREA WHERE THE FRONT HAS
STALLED OUT...925MB TEMPS ARE SIMILAR TO YESTERDAY IN THE 21-22C
RANGE...SUPPORTING HIGHS INTO THE LOW 80S OR SO. MEANWHILE...IN
NORTH CENTRAL WI WHERE 925MB TEMPS ONLY TOP OUT AT 18C...HIGHS MAY
ONLY REACH THE MID 70S. SOUTHERLY FLOW ACROSS THE FORECAST AREA
TONIGHT SHOULD HELP KEEP BOTH TEMPERATURES AND DEWPOINTS UP...WITH
ONLY PRECIPITATION COOLING LOWS. THEREFORE...EXPECT ANOTHER MILD
AND SOMEWHAT HUMID NIGHT FOR MID AUGUST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 310 AM CDT SUN AUG 17 2014
FOCUS FOR MONDAY THROUGH TUESDAY REMAINS ON THE UPPER LOW AND TROUGH
CURRENTLY OVER SOUTHERN SASKATCHEWAN AND EASTERN MONTANA. MODELS
CONTINUE TO BE IN GOOD AGREEMENT DROPPING THIS TROUGH INTO MN ON
MONDAY...INTO THE FORECAST AREA BY 12Z TUE...AND OVER EASTERN WI BY
00Z WED. THE TRACK OF THE TROUGH SUGGESTS THE BEST DYNAMICAL
FORCING FOR THE FORECAST AREA OCCURS FROM 18Z MONDAY TO 18Z
TUESDAY...MAXIMIZED DURING MONDAY EVENING. THERE SHOULD BE PLENTY OF
MOISTURE FOR THE TROUGH TO WORK ON TOO...WITH 1.5-1.75 INCHES OF
PRECIPITABLE WATER ALREADY IN PLACE AND IS PROGGED TO REMAIN STEADY
THROUGH THE TROUGH PASSAGE. GIVEN THE GOOD CONSISTENCY ON THIS
SIGNAL FOR THE TROUGH...FEEL FAIRLY CONFIDENT MUCH OF THE AREA WILL
SEE SHOWERS AND STORMS. DAYTIME HEATING INCREASING INSTABILITY FOR
MONDAY AND TUESDAY AFTERNOONS SHOULD ONLY HELP MATTERS. THEREFORE...
HAVE INCREASED PRECIPITATION CHANCES EVEN MORE. IT DOES APPEAR
LOCATIONS WEST OF THE MS RIVER SHOULD SEE PRECIPITATION DIMINISH FOR
A TIME FROM 03-12Z TUESDAY OVER THE WEST HALF OF THE FORECAST
AREA...THOUGH. 925MB TEMPS ON MONDAY IN THE 20-22C RANGE SHOULD
SUPPORT HIGHS IN THE UPPER 70S/LOW 80S...HELD DOWN BY
PRECIPITATION. IT WILL LIKELY FEEL A BIT HUMID TOO. 925MB TEMPS ONLY
TOP OUT FROM 18-20C ON TUESDAY...AND WITH THE POTENTIAL FOR
PRECIPITATION...HIGHS GET KNOCKED DOWN A FEW DEGREES.
ALL INDICATIONS ARE THAT THE UPPER LOW AND TROUGH WILL MOVE AWAY
FROM THE REGION TUESDAY NIGHT...ALLOWING ANY CONVECTION TO
DIMINISH/END TUESDAY EVENING WITH THE LOSS OF DAYTIME HEATING. WITH
THE AREA PROGGED TO LIE IN AN INFLECTION POINT BETWEEN THE DEPARTING
TROUGH AND UPPER RIDGING BUILDING UP ALONG I-29...SUBSIDENCE SHOULD
BE IN PLACE TO ALLOW FOR A DRY OVERNIGHT. CLEARING OF THE SKIES
COMBINED WITH RECENT RAINS AND DIMINISHING WINDS SHOULD PROMOTE
FOG DEVELOPMENT AND THUS ADDED AREAS OF FOG TO THE FORECAST. THE
DRY CONDITIONS COULD PERSIST THROUGH WEDNESDAY AS THAT UPPER RIDGE
SHIFTS EAST TO I-35. HOWEVER...THERE ARE SIGNS FOR SHOWER AND
THUNDERSTORM ACTIVITY TO DEVELOP ACROSS IOWA...NORTH OF A WARM
FRONTAL BOUNDARY PROGGED TO SET UP ALONG THE MO/IA BORDER. HAVE KEPT
SOME LOW CHANCES IN ACROSS THE FAR SOUTHERN PORTION OF THE FORECAST
AREA JUST IN CASE.
FOR WEDNESDAY NIGHT AND INTO NEXT WEEKEND...THERE IS GOOD MODEL
AGREEMENT AMONGST 17.00Z GUIDANCE AS WELL AS PREVIOUS MODELS FOR
TROUGHING TO DIG INTO THE PACIFIC NORTHWEST. IN RESPONSE...RIDGING
BUILDS DOWNSTREAM TOWARDS THE FORECAST AREA...RESULTING IN A
WARM/MOIST AIR ADVECTION PATTERN. THIS WILL LEAD TO MORE CHANCES OF
SHOWERS AND THUNDERSTORMS. ITS APPEARING LIKE LATE WEDNESDAY NIGHT
INTO THURSDAY MORNING COULD BE AN ENHANCED CHANCE BASED ON ECMWF/GFS
MODEL TRENDS. THIS IS ASSOCIATED WITH THE WARM FRONTAL BOUNDARY
ALONG THE MO/IA BORDER ON WEDNESDAY LIFTING INTO THE AREA. 1-6 KM
SHEAR IS 25 KT OR LESS...SO THINKING HEAVY RAIN SHOULD BE THE MAIN
CONCERN. WE MAY BE ABLE TO SQUEEZE IN A DRY DAY ON FRIDAY...AS A
SURFACE COOL FRONT PASSES...BUT HARD TO SAY AT THIS TIME. THEN
HEADING INTO THE WEEKEND...THERE ARE SOME UNCERTAINTIES WITH THE
PACIFIC NORTHWEST TROUGH. THE 17.00Z ECMWF NOW WANTS TO PUSH THE
TROUGH EASTWARD WHICH RESULTS IN A RELATIVELY STRONG STORM SYSTEM
LIFTING THROUGH THE REGION SATURDAY. THE RESULT COULD BE SOME SEVERE
WEATHER. THE GFS HAS A SIMILAR STORM SYSTEM BUT FARTHER OFF TO THE
WEST SINCE IT IS SLOWER TO MOVE THE UPPER TROUGH. EITHER SCENARIO
WOULD PULL WARMER AND MORE HUMID AIR INTO THE REGION. VERY HARD TO
SAY WHAT SUNDAY IS GOING TO LOOK LIKE WITH THE UNCERTAINTY ON UPPER
TROUGH PROGRESSION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1142 PM CDT SAT AUG 16 2014
LOOKS LIKE ANOTHER GOOD NIGHT FOR THE FORMATION OF FOG AND LOW
STRATUS ACROSS THE AREA. THE WEAK COLD FRONT CONTINUES TO MAKE
SLOW SOUTHWARD PROGRESS AND SHOULD EVENTUALLY PASS THROUGH BOTH
SITES. HOWEVER...THE WIND FIELD AHEAD OF THE FRONT IS SO LIGHT
WITH ONLY A MINOR INCREASE IN SPEEDS BEHIND THE FRONT...THAT IT
WILL NOT MAKE MUCH OF AN IMPACT. SOME CLOUDS CURRENTLY WITH THE
FRONT...BUT GENERALLY MOSTLY CLEAR AHEAD OF IT. EXPECT TO SEE SOME
FOG AND STRATUS DEVELOP BEFORE THE PASSAGE OF THE FRONT AND LOCAL
WEB CAM ALREADY SHOWING SIGNS OF THIS OVER THE MISSISSIPPI RIVER
CHANNEL. ONCE THE FRONT GOES THROUGH...THE 17.00Z NAM AND 17.03Z
RAP BOTH SHOW SOME INCREASE IN THE LOW LEVEL WINDS OUT OF THE EAST
TO THE POINT THAT SURFACE DEW POINTS MAY START TO DRY OUT SOME AT
KLSE SO THAT THE VISIBILITY MAY NOT GET TOO LOW. A VISIBILITY
BELOW A MILE STILL POSSIBLE AT KRST THOUGH. CONDITIONS EXPECTED TO
SLOWLY IMPROVE SUNDAY MORNING WITH A RETURN TO VFR CONDITIONS BY
EARLY AFTERNOON. THE NAM SUGGESTS THE POSSIBILITY OF SOME SHOWERS
AND STORMS IN THE AFTERNOON AS A SHORT WAVE TROUGH COMES OUT OF
THE DAKOTAS AND ACROSS MINNESOTA. HOWEVER...ITS FORECAST SOUNDINGS
SHOW VERY LITTLE VERTICAL MOTION AND OPTED TO STAY WITH A DRY
FORECAST. BETTER CHANCES FOR RAIN MAY COME AFTER 06Z MONDAY AS A
STRONGER SHORT WAVE TROUGH APPROACHES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR IAZ008>011-
018-019-029-030.
&&
$$
UPDATE...AJ
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
310 AM CDT SUN AUG 17 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 310 AM CDT SUN AUG 17 2014
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED AN UPPER LOW AND TROUGH TRAVERSING SOUTHERN SASKATCHEWAN AND
NORTHEAST MONTANA...A SHORTWAVE NEAR FARGO...AND RIDGING OVER
EASTERN MN. SUBSIDENCE UNDER THIS UPPER RIDGING HAS RESULTED IN
MAINLY DRY CONDITIONS OVERNIGHT IN THE FORECAST AREA. THERE WERE
SHOWERS LAST EVENING AROUND I-94 FROM CENTRAL MN INTO SOUTHEAST
WI...ASSOCIATED WITH LINGERING DAYTIME INSTABILITY AND CONVERGENCE
ALONG A BACKDOOR COLD FRONT. THOSE HAVE SINCE MOSTLY DISSIPATED DUE
TO LOSS OF DAYTIME HEATING. THAT COLD FRONT NOW STRETCHES FROM
SOUTHERN WI INTO SOUTHWEST MN AND TO A LOW IN SOUTHEAST NORTH
DAKOTA. AROUND THIS SURFACE LOW AND THE ASSOCIATED SHORTWAVE
ALOFT...MORE SHOWERS AND STORMS EXIST. GOES PRECIPITABLE WATER
IMAGERY DEPICTS PLENTIFUL MOISTURE POOLED ALONG THE FRONT...WITH
VALUES RANGING FROM 1.5-2 INCHES...HIGHEST IN THE CONVECTION NEAR
FARGO. THE MOISTURE HAS BEEN FELT AT THE SURFACE AS WELL WITH
DEWPOINTS IN THE MID TO UPPER 60S AROUND THE FRONT. THESE HIGH
DEWPOINTS HAVE LED TO SOME FOG AND STRATUS FORMATION THIS MORNING.
BEHIND THE FRONT OVER NORTH CENTRAL WISCONSIN THROUGH UPPER
MICHIGAN...DRIER AND COOLER AIR IS FILTERING IN AHEAD OF HIGH
PRESSURE OVER NORTHERN ONTARIO.
MUCH OF THE SHORT TERM PERIOD FOCUS IS ON THE SHORTWAVE NEAR FARGO
AS WELL AS THE COLD FRONT THAT HAS LAYED UP OVER THE SOUTHWESTERN
PORTION OF THE FORECAST AREA. REGARDING THE SHORTWAVE...MODELS
GENERALLY SUGGEST THE CORE NEAR FARGO ENDS UP TRACKING TO THE EAST
OVER THE NEXT 24 HOURS...REACHING CENTRAL UPPER MI BY 12Z MON.
HOWEVER...THE TAIL OF THE SHORTWAVE WILL END UP CROSSING THE
FORECAST AREA TONIGHT. DPVA FROM THE TAIL OF THE SHORTWAVE...DAYTIME
HEATING/INSTABILITY THAT DEVELOPS TO INTERACT WITH CONVERGENCE ALONG
THE COLD FRONT...AND INCREASING 850MB MOISTURE TRANSPORT TONIGHT
OVER THE FORECAST AREA ALL SUGGEST POTENTIAL FOR SHOWERS AND STORMS
OVER THE NEXT 24 HOURS. GIVEN THE TRACK OF THE SHORTWAVE TAIL AND
MOISTURE TRANSPORT SIGNAL...THE NORTHWEST HALF OF THE FORECAST AREA
STANDS TO HAVE THE BEST SHOT FOR PRECIPITATION. HIGH RESOLUTION
MODEL GUIDANCE SUGGEST MUCH OF THE ACTIVITY THIS AFTERNOON AND
EVENING SHOULD BE ISOLATED TO SCATTERED AT BEST. THE INCREASE IN
850MB MOISTURE TRANSPORT AFTER MIDNIGHT COULD ALLOW CONVECTION TO
INCREASE A BIT MORE IN COVERAGE...THUS HIGHEST CHANCES ARE 06-12Z
MONDAY.
REGARDING CONVECTIVE HAZARDS. 0-6KM AND 0-3KM SHEAR IS ALL BELOW 20
KT THROUGH TONIGHT...LIMITING SEVERE POTENTIAL. HOWEVER...
PRECIPITABLE WATER IS PROGGED IN THE 1.5-1.8 INCH RANGE WHICH WOULD
ALLOW THE STORMS TO PRODUCE BRIEF HEAVY RAIN.
TEMPERATURES TODAY SHOULD VARY QUITE A BIT ACROSS THE FORECAST AREA.
ACROSS THE SOUTHWEST END OF THE FORECAST AREA WHERE THE FRONT HAS
STALLED OUT...925MB TEMPS ARE SIMILAR TO YESTERDAY IN THE 21-22C
RANGE...SUPPORTING HIGHS INTO THE LOW 80S OR SO. MEANWHILE...IN
NORTH CENTRAL WI WHERE 925MB TEMPS ONLY TOP OUT AT 18C...HIGHS MAY
ONLY REACH THE MID 70S. SOUTHERLY FLOW ACROSS THE FORECAST AREA
TONIGHT SHOULD HELP KEEP BOTH TEMPERATURES AND DEWPOINTS UP...WITH
ONLY PRECIPITATION COOLING LOWS. THEREFORE...EXPECT ANOTHER MILD
AND SOMEWHAT HUMID NIGHT FOR MID AUGUST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 310 AM CDT SUN AUG 17 2014
FOCUS FOR MONDAY THROUGH TUESDAY REMAINS ON THE UPPER LOW AND TROUGH
CURRENTLY OVER SOUTHERN SASKATCHEWAN AND EASTERN MONTANA. MODELS
CONTINUE TO BE IN GOOD AGREEMENT DROPPING THIS TROUGH INTO MN ON
MONDAY...INTO THE FORECAST AREA BY 12Z TUE...AND OVER EASTERN WI BY
00Z WED. THE TRACK OF THE TROUGH SUGGESTS THE BEST DYNAMICAL
FORCING FOR THE FORECAST AREA OCCURS FROM 18Z MONDAY TO 18Z
TUESDAY...MAXIMIZED DURING MONDAY EVENING. THERE SHOULD BE PLENTY OF
MOISTURE FOR THE TROUGH TO WORK ON TOO...WITH 1.5-1.75 INCHES OF
PRECIPITABLE WATER ALREADY IN PLACE AND IS PROGGED TO REMAIN STEADY
THROUGH THE TROUGH PASSAGE. GIVEN THE GOOD CONSISTENCY ON THIS
SIGNAL FOR THE TROUGH...FEEL FAIRLY CONFIDENT MUCH OF THE AREA WILL
SEE SHOWERS AND STORMS. DAYTIME HEATING INCREASING INSTABILITY FOR
MONDAY AND TUESDAY AFTERNOONS SHOULD ONLY HELP MATTERS. THEREFORE...
HAVE INCREASED PRECIPITATION CHANCES EVEN MORE. IT DOES APPEAR
LOCATIONS WEST OF THE MS RIVER SHOULD SEE PRECIPITATION DIMINISH FOR
A TIME FROM 03-12Z TUESDAY OVER THE WEST HALF OF THE FORECAST
AREA...THOUGH. 925MB TEMPS ON MONDAY IN THE 20-22C RANGE SHOULD
SUPPORT HIGHS IN THE UPPER 70S/LOW 80S...HELD DOWN BY
PRECIPITATION. IT WILL LIKELY FEEL A BIT HUMID TOO. 925MB TEMPS ONLY
TOP OUT FROM 18-20C ON TUESDAY...AND WITH THE POTENTIAL FOR
PRECIPITATION...HIGHS GET KNOCKED DOWN A FEW DEGREES.
ALL INDICATIONS ARE THAT THE UPPER LOW AND TROUGH WILL MOVE AWAY
FROM THE REGION TUESDAY NIGHT...ALLOWING ANY CONVECTION TO
DIMINISH/END TUESDAY EVENING WITH THE LOSS OF DAYTIME HEATING. WITH
THE AREA PROGGED TO LIE IN AN INFLECTION POINT BETWEEN THE DEPARTING
TROUGH AND UPPER RIDGING BUILDING UP ALONG I-29...SUBSIDENCE SHOULD
BE IN PLACE TO ALLOW FOR A DRY OVERNIGHT. CLEARING OF THE SKIES
COMBINED WITH RECENT RAINS AND DIMINISHING WINDS SHOULD PROMOTE
FOG DEVELOPMENT AND THUS ADDED AREAS OF FOG TO THE FORECAST. THE
DRY CONDITIONS COULD PERSIST THROUGH WEDNESDAY AS THAT UPPER RIDGE
SHIFTS EAST TO I-35. HOWEVER...THERE ARE SIGNS FOR SHOWER AND
THUNDERSTORM ACTIVITY TO DEVELOP ACROSS IOWA...NORTH OF A WARM
FRONTAL BOUNDARY PROGGED TO SET UP ALONG THE MO/IA BORDER. HAVE KEPT
SOME LOW CHANCES IN ACROSS THE FAR SOUTHERN PORTION OF THE FORECAST
AREA JUST IN CASE.
FOR WEDNESDAY NIGHT AND INTO NEXT WEEKEND...THERE IS GOOD MODEL
AGREEMENT AMONGST 17.00Z GUIDANCE AS WELL AS PREVIOUS MODELS FOR
TROUGHING TO DIG INTO THE PACIFIC NORTHWEST. IN RESPONSE...RIDGING
BUILDS DOWNSTREAM TOWARDS THE FORECAST AREA...RESULTING IN A
WARM/MOIST AIR ADVECTION PATTERN. THIS WILL LEAD TO MORE CHANCES OF
SHOWERS AND THUNDERSTORMS. ITS APPEARING LIKE LATE WEDNESDAY NIGHT
INTO THURSDAY MORNING COULD BE AN ENHANCED CHANCE BASED ON ECMWF/GFS
MODEL TRENDS. THIS IS ASSOCIATED WITH THE WARM FRONTAL BOUNDARY
ALONG THE MO/IA BORDER ON WEDNESDAY LIFTING INTO THE AREA. 1-6 KM
SHEAR IS 25 KT OR LESS...SO THINKING HEAVY RAIN SHOULD BE THE MAIN
CONCERN. WE MAY BE ABLE TO SQUEEZE IN A DRY DAY ON FRIDAY...AS A
SURFACE COOL FRONT PASSES...BUT HARD TO SAY AT THIS TIME. THEN
HEADING INTO THE WEEKEND...THERE ARE SOME UNCERTAINTIES WITH THE
PACIFIC NORTHWEST TROUGH. THE 17.00Z ECMWF NOW WANTS TO PUSH THE
TROUGH EASTWARD WHICH RESULTS IN A RELATIVELY STRONG STORM SYSTEM
LIFTING THROUGH THE REGION SATURDAY. THE RESULT COULD BE SOME SEVERE
WEATHER. THE GFS HAS A SIMILAR STORM SYSTEM BUT FARTHER OFF TO THE
WEST SINCE IT IS SLOWER TO MOVE THE UPPER TROUGH. EITHER SCENARIO
WOULD PULL WARMER AND MORE HUMID AIR INTO THE REGION. VERY HARD TO
SAY WHAT SUNDAY IS GOING TO LOOK LIKE WITH THE UNCERTAINTY ON UPPER
TROUGH PROGRESSION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1142 PM CDT SAT AUG 16 2014
LOOKS LIKE ANOTHER GOOD NIGHT FOR THE FORMATION OF FOG AND LOW
STRATUS ACROSS THE AREA. THE WEAK COLD FRONT CONTINUES TO MAKE
SLOW SOUTHWARD PROGRESS AND SHOULD EVENTUALLY PASS THROUGH BOTH
SITES. HOWEVER...THE WIND FIELD AHEAD OF THE FRONT IS SO LIGHT
WITH ONLY A MINOR INCREASE IN SPEEDS BEHIND THE FRONT...THAT IT
WILL NOT MAKE MUCH OF AN IMPACT. SOME CLOUDS CURRENTLY WITH THE
FRONT...BUT GENERALLY MOSTLY CLEAR AHEAD OF IT. EXPECT TO SEE SOME
FOG AND STRATUS DEVELOP BEFORE THE PASSAGE OF THE FRONT AND LOCAL
WEB CAM ALREADY SHOWING SIGNS OF THIS OVER THE MISSISSIPPI RIVER
CHANNEL. ONCE THE FRONT GOES THROUGH...THE 17.00Z NAM AND 17.03Z
RAP BOTH SHOW SOME INCREASE IN THE LOW LEVEL WINDS OUT OF THE EAST
TO THE POINT THAT SURFACE DEW POINTS MAY START TO DRY OUT SOME AT
KLSE SO THAT THE VISIBILITY MAY NOT GET TOO LOW. A VISIBILITY
BELOW A MILE STILL POSSIBLE AT KRST THOUGH. CONDITIONS EXPECTED TO
SLOWLY IMPROVE SUNDAY MORNING WITH A RETURN TO VFR CONDITIONS BY
EARLY AFTERNOON. THE NAM SUGGESTS THE POSSIBILITY OF SOME SHOWERS
AND STORMS IN THE AFTERNOON AS A SHORT WAVE TROUGH COMES OUT OF
THE DAKOTAS AND ACROSS MINNESOTA. HOWEVER...ITS FORECAST SOUNDINGS
SHOW VERY LITTLE VERTICAL MOTION AND OPTED TO STAY WITH A DRY
FORECAST. BETTER CHANCES FOR RAIN MAY COME AFTER 06Z MONDAY AS A
STRONGER SHORT WAVE TROUGH APPROACHES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
335 PM MDT SUN AUG 17 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 330 PM MDT SUN AUG 17 2014
AFTERNOON WATER VAPOR LOOP REVEALED A CLOSED UPPER LOW NORTH OF THE
NORTH DAKOTA BORDER WITH A TROUGH AXIS INTO THE WESTERN DAKOTAS.
CLUSTERS OF INTENSE CONVECTION WERE DEVELOPING AHEAD OF THIS FEATURE.
CYS/RIW RADARS SHOWED A FEW SHOWERS DEVELOPING ALONG A WEAK CONVERGENCE
ZONE FROM SOUTHERN NATRONA TO SOUTHERN CONVERSE COUNTY. THE HRRR MODEL
COMPOSITE REFLECTIVITY LOOP SHOWED THIS ACTIVITY MOVING ACROSS EAST
CENTRAL WYOMING THROUGH LATE AFTERNOON THEN DISSIPATING. WITH VERY DRY
SUB-CLOUD LAYER...CAN EXPECT GUSTY WINDS AND LITTLE IF ANY MEASURABLE
RAINFALL WITH THESE SHOWERS. MAIN CONCERN CONTINUES TO BE FIRE WEATHER
IMPACTS FROM THE GUSTY WINDS AND LOW HUMIDITY FOR ELEVATIONS BELOW
8000 FT. RED FLAG WARNING REMAINS IN EFFECT FOR ALL BUT THE SIERRA
MADRE/SNOWY RANGE ZONES THROUGH 7 PM. GETTING CLOSE TO RED FLAG
CRITERIA OVER THE NEBRASKA PANHANDLE ZONES BORDERING WYOMING.
CONDITIONS WILL IMPROVE THIS EVENING AS WINDS DECREASE AND HUMIDITIES
INCREASE.
A BLEND OF THE 12Z SHORT RANGE MODEL GUIDANCE HANDLES THE LARGE SCALE
PATTERN PRETTY WELL. THE UPPER TROUGH ADVANCES EAST SOUTHEAST ACROSS
THE DAKOTAS AND MIDWEST DURING THE NEXT 24 HOURS. MEANWHILE...A UPPER
RIDGE EXPANDS NORTHWEST FROM THE FOUR CORNERS REGION WITH A HEALTHY
SURGE OF SUBTROPICAL MOISTURE MOVING INTO THE CENTRAL ROCKIES TUESDAY.
PRECIP WATER VALUES MONDAY WILL RANGE FROM A HALF INCH WEST OF THE
LARAMIE RANGE TO AROUND AN INCH FOR THE HIGH PLAINS. TUESDAY...PRECIP
WATER INCREASE TO AROUND 1.25 INCHES EAST OF THE LARAMIE AND 0.75-1.0
INCH TO THE WEST. DIURNAL CONVECTIVE COVERAGE MONDAY WILL BE ISOLATED
AND CONFINED TO THE MOUNTAINS. THE AIRMASS OVER THE PLAINS WILL REMAIN
CAPPED PRECLUDING SHOWER DEVELOPMENT. SHOWER/TSTORM COVERAGE INCREASES
TO SCATTERED TUESDAY AFTERNOON/EVENING AS A POTENT SHORTWAVE RIDES
NORTHEAST ACROSS WYOMING AND COLORADO. DOWNSLOPING WESTERLY WINDS WILL
LIMIT QPF OVER THE EASTERN WYOMING PLAINS...WITH AT LEAST O.25 INCH
AMOUNTS POSSIBLE OVER THE HIGHER TERRAIN AND WESTERN NEBRASKA PANHANDLE.
ABOVE NORMAL WARMTH WILL CONTINUE MONDAY LOWER ELEVATIONS MONDAY AND
EAST OF THE LARAMIE RANGE TUESDAY WITH HIGHS IN THE 80S TO LOWER 90S.
TEMPERATURES WILL TREND SLIGHTLY COOLER WEST OF THE LARAMIE RANGE
TUESDAY DUE TO GREATER CLOUD AND SHOWER COVERAGE.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 300 PM MDT SUN AUG 17 2014
WARM AND MAINLY DRY WEATHER EXPECTED ACROSS THE CWA WEDNESDAY AND
THURSDAY THOUGH A FEW SHOWERS/TSTRMS POSSIBLE OVER THE HIGHER SRN
MTNS BOTH AFTERNOONS/EARLY EVENINGS. CHANGES LOOK TO BE IN THE
OFFING BEGINNING FRIDAY AND CONTINUING INTO THE WEEKEND AS AN
UPPER TROF SETTLES OVER THE NW PART OF THE COUNTRY AND A PUSH OF
COOLER CANADIAN AIR DROPS DOWN THE HIGH PLAINS SATURDAY AND
SATURDAY NIGHT WITH THE EC CONTINUING TO BE MUCH MORE BULLISH IN
PUSHING THIS COOL AIR ACROSS THE CWA BY LATE SATURDAY...SETTING UP
A MILD DAY FOR SUNDAY. EC HAS BEEN CONSISTENT WITH THIS. SHOULD
ALSO SEE A BIT OF AN UPTICK IN CONVECTION FRIDAY AND SATURDAY AS
THE UPPER TROF NEARS WITH ANY ASSOCIATED IMPULSES ROUNDING THE
BASE OF IT PASSING ACROSS THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY MORNING)
ISSUED AT 1120 AM MDT SUN AUG 17 2014
VFR CONDITIONS THROUGH MONDAY WITH A RATHER DRY AIR MASS OVER THE
AREA. A WEAK SFC COOL FRONT WILL MOVE SOUTH ACROSS WY AND WRN
NEBRASKA TONIGHT SWITCHING WINDS TO LIGHT NORTHERLY OVER THE PLAINS.
&&
.FIRE WEATHER...
ISSUED AT 220 PM MDT SUN AUG 17 2014
NORTHWEST WINDS GUSTS OF 25 TO 35 MPH COMBINED WITH RELATIVE HUMDITIES
OF 10 TO 15 PERCENT WILL CREATE CONDITIONS CONDUCIVE TO RAPID FIRE
GROWTH FOR AREAS BELOW 8000 FEET IN SOUTHEAST WYOMING THROUGH EARLY
EVENING. GUSTS APPROACHING 25 MPH AND 10 TO 15 PERCENT HUMIDITIES
OVER THE FAR WESTERN NEBRASKA PANHANDLE WILL ENHANCE THE FIRE WEATHER
THREAT THIS AFTERNOON. FIRE WEATHER CONCERNS WILL BECOME MINIMAL
MONDAY AND TUESDAY AS AN INFLUX OF MONSOON MOISTURE FROM THE SOUTHWEST
INCREASES CHANCES FOR WETTING RAINS EARLY THIS WEEK. WINDS WILL BE
LIGHTER AS WELL. DRIER CONDITIONS RETURN MID WEEK FOLLOWED BY A SLIGHT
INCREASE IN MOISTURE LATE IN THE WEEK. ABOVE AVERAGE TEMPERATURES THIS
WEEK WILL GRADUALLY COOL NEXT WEEKEND.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...RED FLAG WARNING UNTIL 7 PM MDT THIS EVENING FOR WYZ301>304-306-
308>310.
NE...NONE.
&&
$$
SHORT TERM...JAMSKI
LONG TERM...RE
AVIATION...RE
FIRE WEATHER...JAMSKI
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1120 AM MDT SUN AUG 17 2014
.UPDATE...
ISSUED AT 1050 AM MDT SUN AUG 17 2014
LATE MORNING WATER VAPOR LOOP SHOWED A CLOSED UPPER LOW DRIFTING
EAST ACROSS SOUTHERN SASKATCHEWAN PROVINCE WITH A TROUGH EXTENDING
INTO MT/NORTHERN WY. UPPER HIGH WAS SITUATED OVER THE DESERT
SOUTHWEST WITH ZONAL FLOW ALOFT OVER SOUTHEAST WY/WESTERN NE. 12Z
RIW/DEN SOUNDINGS INDICATED A VERY DRY LOW/MID LAYER WITH PRECIP
WATER VALUES OF .42/.52 INCH RESPECTIVELY. THE RIW SOUNDING DEPICTED
35 TO 45 KT WESTERLY WINDS JUST ABOVE 600MB. AS TEMPERATURES RISE TO
AROUND 90 THIS AFTERNOON...EFFICIENT MIXING OF MID LEVEL WINDS TO
THE SURFACE WILL RESULT IN GUSTS TO AROUND 30 KT FOR MUCH OF
SOUTHEAST WY. HUMIDITIES WILL DROP TO 10 TO 15 PERCENT BELOW 8000
FT. CURRENT RED FLAG WARNING FOR ALL WY ZONES EXCEPT THE SIERRA
MADRE AND SNOWY RANGES ON TRACK. WILL NEED TO CLOSELY MONITOR THE
WESTERN NE PANHANDLE FOR POTENTIAL CRITICAL FIRE WEATHER CONDITIONS
WITH WIND GUSTS OF 15 TO 20 MPH AND HUMIDITIES DROPPING TO AROUND 15
PERCENT...ESPECIALLY THOSE COUNTIES BORDERING WY.
LATEST HRRR MODEL KEEPS THE CWA DRY THIS AFTERNOON AND EARLY EVENING
AS SHOWER/TSTORM ACTIVITY WILL BE CONFINED TO CENTRAL/EASTERN CO
AND BLACK HILLS TO NORTHERN NE EASTWARD. THEREFORE...REMOVED SMALL
POPS FOR THE MOUNTAINS. RAISED MAX TEMPERATURES A FEW DEGREES FOR
THE PLAINS.
&&
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 500 AM MDT SUN AUG 17 2014
MAIN CONCERN FOR TODAY WILL ONCE AGAIN BE FIRE WEATHER AS CRITICAL
CONDITIONS ARE ANTICIPATED FOR MUCH OF SOUTHEAST WYOMING. AN
UPPER LEVEL SHORTWAVE CURRENTLY OVER IDAHO PER WATER VAPOR IMAGERY
WILL MOVE ACROSS NORTHERN WYOMING TODAY AND WILL SYNC UP WITH A
STRONGER UPPER TROUGH MOVING ALONG THE US/CANADIAN BORDER. THE
COMBINATION OF FEATURES WILL DEEPEN THE LEE SIDE SFC PRESSURE
TROUGH THROUGH THE DAY WITH BREEZY NORTHWEST WINDS DEVELOPING
ACROSS SOUTHEAST WYOMING AS THE SFC PRESSURE GRADIENT STRENGTHENS.
GUSTS OF 25 TO 35 MPH LOOK COMMON OVER THIS AREA THRU THE
AFTERNOON AS FORECAST SOUNDINGS SUGGEST THE TOP OF THE MIXING
LEVEL WILL BE UP BETWEEN 500 AND 600 MB WHERE WINDS WILL BE 30 TO
35 KT. THE ALREADY DRY BOUNDARY LAYER AIRMASS COMBINED WITH DRY
AND WARM DOWNSLOPE WINDS WILL TANK HUMIDITIES FAIRLY QUICKLY LATE
THIS MORNING OVER SOUTHEAST WYOMING...WITH HUMIDITIES EXPECTED TO
REMAIN IN THE LOW TEENS FOR MUCH OF THE AFTERNOON. THE COMBINATION
OF LOW RHS AND GUSTY WINDS WILL CREATE CRITICAL FIRE WEATHER
CONDITIONS OVER MUCH OF SOUTHEAST WYOMING WITH THE FOCUS ON AREAS
BELOW 8000 FEET. STARTED THE RFW SLIGHTLY EARLIER THAN PREVIOUS
ISSUANCE AS WINDS SHOULD INCREASE QUICKLY THROUGH THE LATE
MORNING...AND ADDED IN FWZ 302 TO ACCOUNT FOR THE LOWER ELEVATIONS
OF THIS ZONE WHICH SAW MARGINAL CRITICAL CONDITIONS YESTERDAY AND
WILL LIKELY BREACH CRITICAL THRESHOLDS AGAIN TODAY. REGARDING
STORM CHANCES ACROSS THE CWA...CONVECTION ASSOCIATED WITH THE
SHORTWAVE FEATURED APPEARED TO BE SOMEWHAT LIMITED OVER OREGON AND
IDAHO YESTERDAY WITHIN THE DRY AIRMASS. EXPECT A SIMILAR TREND FOR
OUR AREA TODAY WITH MINIMAL DEEP CONVECTION OVER THE CWA. LOOKING
INSTEAD AT SOME TOWERING CU AND PERHAPS A SHOWER OR TWO OVER THE
MOUNTAINS WHERE OROGRAPHIC EFFECTS WILL AIDE IN SOME CONVECTIVE
DEVELOPMENT. LACK OF DEEP LAYER MOISTURE SHOULD KEEP TSTORM
CHANCES MINIMAL THO.
A SURFACE FRONT WILL DROP SOUTH ACROSS THE PLAINS EARLY THIS
EVENING AND OVERNIGHT WITH AN INCREASE IN LLVL MOISTURE AND A
SFC WIND SHIFT TO THE NORTH THEN NORTHEAST WITH FROPA. MODELS
SUGGEST THAT MID LEVEL MOISTURE WILL INCREASE OVER THE ROCKIES
THROUGH THE DAY MONDAY WITH STRENGTHENING FLOW ALOFT. NORTHEAST
UPSLOPE FLOW IN PLACE ACROSS THE PLAINS COMBINED WITH INCREASING
MOISTURE WILL EASE FIRE WEATHER CONCERNS OVER THE FORECAST
AREA...WITH CHANCES FOR SHOWERS AND TSTORMS RETURNING TO THE
MOUNTAINS OF SOUTHEAST WYOMING AND NEARBY LOWER ELEVATIONS IN THE
AFTERNOON. MODELS HINT AT A WAA PATTERN DEVELOPING MONDAY NIGHT
AHEAD OF A SHORTWAVE MOVING UP FROM THE SOUTHWEST WITH
SOUTHWESTERLY H7 WINDS INCREASING TO 15 TO 20 KT OVERNIGHT. COULD
SEE CONVECTION CONTINUE THRU EARLY TUESDAY MORNING AS A
RESULT...WITH THE MAIN FOCUS ACROSS THE PANHANDLE WHERE WAA AND
DEEPEST MOISTURE WILL BE COLLOCATED WITH OROGRAPHIC LIFT OFF THE
PINE RIDGE.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 500 AM MDT SUN AUG 17 2014
MODELS VERY SIMILAR TUESDAY BRINGING A SHORTWAVE THROUGH THE RIDGE
OVER SOUTHERN WYOMING AND DEVELOPING SOME QPF OVER THE WESTERN
MOUNTAINS TUESDAY AFTERNOON. BOTH THE GFS AND ECMWF SPREAD THIS
MOISTURE OUT INTO THE PANHANDLE TUESDAY AFTERNOON...SO KEPT SLIGHT
CHANCE POPS GOING FOR MOST AREAS INTO TUESDAY EVENING. BEST CHANCES
FOR SHOWERS LOOKS TO BE WEST OF THE LARAMIE RANGE THOUGH AND THIS IS
WHERE HIGHEST POPS WERE PLACED.
DRIER AIR FOR WEDNESDAY...BUT STILL SOME CHANCES FOR THE SNOWY AND
SIERRA MADRE RANGES DURING THE AFTERNOON. MOST AREAS SHOULD STAY DRY
WITH WEST TO NORTHWEST DOWNSLOPING WINDS OFF THE LARAMIE RANGE.
A DIFFERENT STORY FOR FRIDAY AND MODELS BEGIN TO DIVERGE. THE GFS
SHOWING A POTENT SHORTWAVE MOVING INTO THE SOUTHEASTERN CWFA FRIDAY
MORNING WITH WIDESPREAD SHOWERS ACTIVITY ACROSS THE SOUTHERN
PANHANDLE BACK INTO EXTREME SOUTHEAST WYOMING. ECMWF MUCH WEAKER
WITH THIS SHORTWAVE AND KEEPS POPS MUCH LOWER THAN THE GFS. ECMWF
DOES EVENTUALLY BRING SOME QPF INTO THE AREA...MAINLY ACROSS OUR
NORTHERN AND EASTERN ZONES...SO DID KEEP SOME SLIGHT CHANCE TO LOW
CHANCE POPS GOING IN THE FORECAST FOR FRIDAY.
ENTERING SATURDAY...GFS SHOWING A 90KT UPPER LEVEL JET MOVING INTO
CENTRAL WYOMING SATURDAY MORNING. 700MB WINDS ON THE INCREASE AS
WELL...WITH 30KT DEVELOPING FRIDAY MORNING OUT WEST. ORIENTATION ON
ECMWF A LITTLE DIFFERENT WITH THE TROUGH MORE PRONOUNCED AND COLDER.
ECMWF 700MB TEMPERATURES SATURDAY AFTERNOON ACROSS NORTHERN WYOMING
DOWN TO 0 TO -2C. COULD BE A SIGNIFICANT COOL DOWN SHOULD THE ECMWF
FORECAST COME TRUE. FOR NOW...DID NOT COOL TEMPERATURES AS MUCH AS
WHAT THE ECMWF MIGHT GO FOR...BUT DID GO LOWER ON TEMPERATURES.
LARGE POSSIBILITIES FOR A TEMPERATURE BUST AS THERE IS A 10C
DIFFERENCE IN 700MB TEMPERATURES BETWEEN THE TWO MEDIUM RANGE MODELS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY MORNING)
ISSUED AT 1120 AM MDT SUN AUG 17 2014
VFR CONDITIONS THROUGH MONDAY WITH A RATHER DRY AIR MASS OVER THE
AREA. A WEAK SFC COOL FRONT WILL MOVE SOUTH ACROSS WY AND WRN
NEBRASKA TONIGHT SWITCHING WINDS TO LIGHT NORTHERLY OVER THE PLAINS.
&&
.FIRE WEATHER...
ISSUED AT 500 AM MDT SUN AUG 17 2014
RED FLAG WARNING REMAINS IN EFFECT FOR MUCH OF SOUTHEAST WYOMING
THIS AFTERNOON FOR NORTHWEST WIND GUSTS OF 25 TO 35 MPH COMBINING
WITH HUMIDITIES DROPPING TO THE LOW TEENS. THE HIGHEST THREAT FOR
CRITICAL CONDITIONS WILL BE IN AREAS BELOW 8000 FEET. INCREASING
MOISTURE AT THE SFC AND ALOFT WILL COMBINE WITH GENERALLY WEAKER
WINDS TO DIMINISH FIRE WEATHER CONCERNS FOR MONDAY AND TUESDAY.
CHANCES FOR SHOWERS AND THUNDERSTORMS WILL INCREASE EARLY NEXT
WEEK AS WELL.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...RED FLAG WARNING UNTIL 7 PM MDT THIS EVENING FOR WYZ301>304-306-
308>310.
NE...NONE.
&&
$$
UPDATE...JAMSKI
SHORT TERM...RJM
LONG TERM...CLAYCOMB
AVIATION...RE
FIRE WEATHER...RJM
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1109 AM MDT SUN AUG 17 2014
.UPDATE...
ISSUED AT 1050 AM MDT SUN AUG 17 2014
LATE MORNING WATER VAPOR LOOP SHOWED A CLOSED UPPER LOW DRIFTING
EAST ACROSS SOUTHERN SASKATCHEWAN PROVINCE WITH A TROUGH EXTENDING
INTO MT/NORTHERN WY. UPPER HIGH WAS SITUATED OVER THE DESERT SOUTHWEST
WITH ZONAL FLOW ALOFT OVER SOUTHEAST WY/WESTERN NE. 12Z RIW/DEN
SOUNDINGS INDICATED A VERY DRY LOW/MID LAYER WITH PRECIP WATER
VALUES OF .42/.52 INCH RESPECTIVELY. THE RIW SOUNDING DEPICTED 35
TO 45 KT WESTERLY WINDS JUST ABOVE 600MB. AS TEMPERATURES RISE TO
AROUND 90 THIS AFTERNOON...EFFICIENT MIXING OF MID LEVEL WINDS TO
THE SURFACE WILL RESULT IN GUSTS TO AROUND 30 KT FOR MUCH OF
SOUTHEAST WY. HUMIDITIES WILL DROP TO 10 TO 15 PERCENT BELOW 8000
FT. CURRENT RED FLAG WARNING FOR ALL WY ZONES EXCEPT THE SIERRA
MADRE AND SNOWY RANGES ON TRACK. WILL NEED TO CLOSELY MONITOR THE
WESTERN NE PANHANDLE FOR POTENTIAL CRITICAL FIRE WEATHER CONDITIONS
WITH WIND GUSTS OF 15 TO 20 MPH AND HUMIDITIES DROPPING TO AROUND
15 PERCENT...ESPECIALLY THOSE COUNTIES BORDERING WY.
LATEST HRRR MODEL KEEPS THE CWA DRY THIS AFTERNOON AND EARLY EVENING
AS SHOWER/TSTORM ACTIVITY WILL BE CONFINED TO CENTRAL/EASTERN CO
AND BLACK HILLS TO NORTHERN NE EASTWARD. THEREFORE...REMOVED SMALL
POPS FOR THE MOUNTAINS. RAISED MAX TEMPERATURES A FEW DEGREES FOR
THE PLAINS.
&&
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 500 AM MDT SUN AUG 17 2014
MAIN CONCERN FOR TODAY WILL ONCE AGAIN BE FIRE WEATHER AS CRITICAL
CONDITIONS ARE ANTICIPATED FOR MUCH OF SOUTHEAST WYOMING. AN
UPPER LEVEL SHORTWAVE CURRENTLY OVER IDAHO PER WATER VAPOR IMAGERY
WILL MOVE ACROSS NORTHERN WYOMING TODAY AND WILL SYNC UP WITH A
STRONGER UPPER TROUGH MOVING ALONG THE US/CANADIAN BORDER. THE
COMBINATION OF FEATURES WILL DEEPEN THE LEE SIDE SFC PRESSURE
TROUGH THROUGH THE DAY WITH BREEZY NORTHWEST WINDS DEVELOPING
ACROSS SOUTHEAST WYOMING AS THE SFC PRESSURE GRADIENT STRENGTHENS.
GUSTS OF 25 TO 35 MPH LOOK COMMON OVER THIS AREA THRU THE
AFTERNOON AS FORECAST SOUNDINGS SUGGEST THE TOP OF THE MIXING
LEVEL WILL BE UP BETWEEN 500 AND 600 MB WHERE WINDS WILL BE 30 TO
35 KT. THE ALREADY DRY BOUNDARY LAYER AIRMASS COMBINED WITH DRY
AND WARM DOWNSLOPE WINDS WILL TANK HUMIDITIES FAIRLY QUICKLY LATE
THIS MORNING OVER SOUTHEAST WYOMING...WITH HUMIDITIES EXPECTED TO
REMAIN IN THE LOW TEENS FOR MUCH OF THE AFTERNOON. THE COMBINATION
OF LOW RHS AND GUSTY WINDS WILL CREATE CRITICAL FIRE WEATHER
CONDITIONS OVER MUCH OF SOUTHEAST WYOMING WITH THE FOCUS ON AREAS
BELOW 8000 FEET. STARTED THE RFW SLIGHTLY EARLIER THAN PREVIOUS
ISSUANCE AS WINDS SHOULD INCREASE QUICKLY THROUGH THE LATE
MORNING...AND ADDED IN FWZ 302 TO ACCOUNT FOR THE LOWER ELEVATIONS
OF THIS ZONE WHICH SAW MARGINAL CRITICAL CONDITIONS YESTERDAY AND
WILL LIKELY BREACH CRITICAL THRESHOLDS AGAIN TODAY. REGARDING
STORM CHANCES ACROSS THE CWA...CONVECTION ASSOCIATED WITH THE
SHORTWAVE FEATURED APPEARED TO BE SOMEWHAT LIMITED OVER OREGON AND
IDAHO YESTERDAY WITHIN THE DRY AIRMASS. EXPECT A SIMILAR TREND FOR
OUR AREA TODAY WITH MINIMAL DEEP CONVECTION OVER THE CWA. LOOKING
INSTEAD AT SOME TOWERING CU AND PERHAPS A SHOWER OR TWO OVER THE
MOUNTAINS WHERE OROGRAPHIC EFFECTS WILL AIDE IN SOME CONVECTIVE
DEVELOPMENT. LACK OF DEEP LAYER MOISTURE SHOULD KEEP TSTORM
CHANCES MINIMAL THO.
A SURFACE FRONT WILL DROP SOUTH ACROSS THE PLAINS EARLY THIS
EVENING AND OVERNIGHT WITH AN INCREASE IN LLVL MOISTURE AND A
SFC WIND SHIFT TO THE NORTH THEN NORTHEAST WITH FROPA. MODELS
SUGGEST THAT MID LEVEL MOISTURE WILL INCREASE OVER THE ROCKIES
THROUGH THE DAY MONDAY WITH STRENGTHENING FLOW ALOFT. NORTHEAST
UPSLOPE FLOW IN PLACE ACROSS THE PLAINS COMBINED WITH INCREASING
MOISTURE WILL EASE FIRE WEATHER CONCERNS OVER THE FORECAST
AREA...WITH CHANCES FOR SHOWERS AND TSTORMS RETURNING TO THE
MOUNTAINS OF SOUTHEAST WYOMING AND NEARBY LOWER ELEVATIONS IN THE
AFTERNOON. MODELS HINT AT A WAA PATTERN DEVELOPING MONDAY NIGHT
AHEAD OF A SHORTWAVE MOVING UP FROM THE SOUTHWEST WITH
SOUTHWESTERLY H7 WINDS INCREASING TO 15 TO 20 KT OVERNIGHT. COULD
SEE CONVECTION CONTINUE THRU EARLY TUESDAY MORNING AS A
RESULT...WITH THE MAIN FOCUS ACROSS THE PANHANDLE WHERE WAA AND
DEEPEST MOISTURE WILL BE COLLOCATED WITH OROGRAPHIC LIFT OFF THE
PINE RIDGE.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 500 AM MDT SUN AUG 17 2014
MODELS VERY SIMILAR TUESDAY BRINGING A SHORTWAVE THROUGH THE RIDGE
OVER SOUTHERN WYOMING AND DEVELOPING SOME QPF OVER THE WESTERN
MOUNTAINS TUESDAY AFTERNOON. BOTH THE GFS AND ECMWF SPREAD THIS
MOISTURE OUT INTO THE PANHANDLE TUESDAY AFTERNOON...SO KEPT SLIGHT
CHANCE POPS GOING FOR MOST AREAS INTO TUESDAY EVENING. BEST CHANCES
FOR SHOWERS LOOKS TO BE WEST OF THE LARAMIE RANGE THOUGH AND THIS IS
WHERE HIGHEST POPS WERE PLACED.
DRIER AIR FOR WEDNESDAY...BUT STILL SOME CHANCES FOR THE SNOWY AND
SIERRA MADRE RANGES DURING THE AFTERNOON. MOST AREAS SHOULD STAY DRY
WITH WEST TO NORTHWEST DOWNSLOPING WINDS OFF THE LARAMIE RANGE.
A DIFFERENT STORY FOR FRIDAY AND MODELS BEGIN TO DIVERGE. THE GFS
SHOWING A POTENT SHORTWAVE MOVING INTO THE SOUTHEASTERN CWFA FRIDAY
MORNING WITH WIDESPREAD SHOWERS ACTIVITY ACROSS THE SOUTHERN
PANHANDLE BACK INTO EXTREME SOUTHEAST WYOMING. ECMWF MUCH WEAKER
WITH THIS SHORTWAVE AND KEEPS POPS MUCH LOWER THAN THE GFS. ECMWF
DOES EVENTUALLY BRING SOME QPF INTO THE AREA...MAINLY ACROSS OUR
NORTHERN AND EASTERN ZONES...SO DID KEEP SOME SLIGHT CHANCE TO LOW
CHANCE POPS GOING IN THE FORECAST FOR FRIDAY.
ENTERING SATURDAY...GFS SHOWING A 90KT UPPER LEVEL JET MOVING INTO
CENTRAL WYOMING SATURDAY MORNING. 700MB WINDS ON THE INCREASE AS
WELL...WITH 30KT DEVELOPING FRIDAY MORNING OUT WEST. ORIENTATION ON
ECMWF A LITTLE DIFFERENT WITH THE TROUGH MORE PRONOUNCED AND COLDER.
ECMWF 700MB TEMPERATURES SATURDAY AFTERNOON ACROSS NORTHERN WYOMING
DOWN TO 0 TO -2C. COULD BE A SIGNIFICANT COOL DOWN SHOULD THE ECMWF
FORECAST COME TRUE. FOR NOW...DID NOT COOL TEMPERATURES AS MUCH AS
WHAT THE ECMWF MIGHT GO FOR...BUT DID GO LOWER ON TEMPERATURES.
LARGE POSSIBILITIES FOR A TEMPERATURE BUST AS THERE IS A 10C
DIFFERENCE IN 700MB TEMPERATURES BETWEEN THE TWO MEDIUM RANGE MODELS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 500 AM MDT SUN AUG 17 2014
VFR CONDITIONS NEXT 24 HOURS FOR ALL SOUTHEAST WYOMING AND
NEBRASKA PANHANDLE AIRPORTS. MAIN CONCERN TODAY WILL BE GUSTY WEST
WINDS ACROSS SOUTHEAST WYOMING. COULD SEE GUSTS APPROACHING 30KT
AT KRWL AND KLAR THAT COULD PRODUCE SOME LOW LEVEL TURBULENCE ON
TAKEOFFS AND LANDINGS. SHOULD SEE MOSTLY CLEAR SKIES TODAY.
&&
.FIRE WEATHER...
ISSUED AT 500 AM MDT SUN AUG 17 2014
RED FLAG WARNING REMAINS IN EFFECT FOR MUCH OF SOUTHEAST WYOMING
THIS AFTERNOON FOR NORTHWEST WIND GUSTS OF 25 TO 35 MPH COMBINING
WITH HUMIDITIES DROPPING TO THE LOW TEENS. THE HIGHEST THREAT FOR
CRITICAL CONDITIONS WILL BE IN AREAS BELOW 8000 FEET. INCREASING
MOISTURE AT THE SFC AND ALOFT WILL COMBINE WITH GENERALLY WEAKER
WINDS TO DIMINISH FIRE WEATHER CONCERNS FOR MONDAY AND TUESDAY.
CHANCES FOR SHOWERS AND THUNDERSTORMS WILL INCREASE EARLY NEXT
WEEK AS WELL.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...RED FLAG WARNING UNTIL 7 PM MDT THIS EVENING FOR WYZ301>304-306-
308>310.
NE...NONE.
&&
$$
UPDATE...JAMSKI
SHORT TERM...RJM
LONG TERM...CLAYCOMB
AVIATION...CLAYCOMB
FIRE WEATHER...RJM
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1129 PM MDT MON AUG 18 2014
.UPDATE...
ISSUED AT 820 PM MDT MON AUG 18 2014
UPDATED MOST POP FORECASTS, REMOVING POPS OVER THE PLAINS AND
EASTERN MOUNTAINS, WHILE ADDING/EXTENDING PRECIP CHANCES OVER THE
SOUTHWEST MOUNTAINS AND SAN LUIS VALLEY...AS AREA OF TSRA OVER THE
SAN JUANS WILL MOVE EAST ACROSS LOWER ELEVATIONS BEFORE ENDING.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 259 PM MDT MON AUG 18 2014
THE UPR RIDGE IS STILL CENTERED NR THE FOUR CORNERS AREA TODAY
AND PRECIPITABLE WATER VALUES ARE SIMILAR TO WHAT THEY WERE
YESTERDAY. ISOLATED SHOWERS AND TSTMS HAVE DEVELOPED OVR SOME OF
THE MOUNTAIN AREAS AS OF 1930Z. SHOULD SEE COVERAGE OVR THE MTNS
INCREASE THIS AFTERNOON. HRRR AND RAP SHOW PCPN DEVELOPING/MOVING
OVR THE SERN PLAINS AND PORTIONS OF THE SAN LUIS VALLEY LATER THIS
AFTERNOON AND THIS EVENING. THE HRRR AND RAP HAVE PCPN ENDING IN
MOST LOCATIONS BY LATE EVENING...BUT SHOW THE POTENTIAL FOR SOME
CONTINUING OVR THE SAN JUAN MTNS INTO THE LATE NIGHT HOURS.
AS AN UPR TROF DIGS INTO SRN CA TONIGHT AND TUESDAY...THE UPR RIDGE
OVR OUR AREA SHIFTS EASTWARD. THIS PUSHES A LITTLE BETTER MSTR INTO
WRN CO FOR TUE...WITH PRECIPITABLE WATER VALUES INCREASING SLIGHTLY
OVR THE CONTDVD. AS A RESULT THERE SHOULD BE MORE WIDESPREAD SHOWER
AND TSTM ACTIVITY ALONG THE CONTDVD TOMORROW. THE ERN MTNS WL
LIKELY SEE SCT PCPN DEVELOPING IN THE AFTERNOON HOURS...WHILE THE
SERN PLAINS SHOULD JUST SEE A FEW SHOWERS OR STORMS DEVELOP. HIGH
TEMPS ON TUE SHOULD BE 5-8 DEGREES ABOVE AVERAGE OVR THE SERN
PLAINS...AND AROUND NORMAL IN THE SAN LUIS VALLEY AND UPR ARKANSAS
RIVER VALLEY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 259 PM MDT MON AUG 18 2014
...ACTIVE WEATHER FOR AT LEAST THE NEXT WEEK...
MODELS ARE NOW IN REASONABLE AGREEMENT THAT THE CUTOFF LOW
OFF THE CA COAST WILL PHASE WITH THE TROUGH MOVING INTO THE
PACNW...AND THIS WILL LEAD TO AN ENHANCED MONSOONAL PATTERN
FOR THE LATTER PART OF THIS WEEK AND BEYOND. A COUPLE OF
ADDITIONAL SHORTWAVES WILL MOVE THROUGH THE LONGWAVE TROUGH
PATTERN THAT IS OVER WRN CANADA...BRINGING THE THREAT FOR PERIODS
OF HEAVY RAIN TO OUR AREA.
TUE NIGHT...EXPECT ISOLD STORMS TO PERSIST OVER THE CONTDVD
AS THE PLUME BEGINS TO MOVE OVR WRN CO. BY LATE WED THE TROUGH
AND ABSORBED CUTOFF WILL MOVE INTO NW AZ/SW UT...AND THE THREAT
OF HEAVY BANDS OF CONVECTION WILL CONTINUE FOR THE SW MTS AND
CONTDVD. DEPENDING ON WHAT HAS ALREADY FALLEN OVR THE MTS
WE COULD SEE THE THREAT OF MORE FLASH FLOODING AND RISK OF
SLIDES FOR THE MT AREAS. TIMING FOR OUR CWA`S STAGES IN THE
PRO CYCLING CHALLENGE DOES NOT LOOK FAVORABLE AS THE STRONGEST
DYNAMICS FROM THIS SYSTEM MOVE THROUGH ON THURSDAY. THAT IS WHEN
THE CORE OF A 100 KT JET STREAK MOVES THROUGH CO. THIS IS PRETTY
ROBUST FOR AN AUGUST SYSTEM. WITH H6 TEMPS AT MINUS 2C OR LOWER IN
THE CORE OF THE LOW...COULD EASILY SEE SOME SNOW FOR ELEVS ABOVE
12K FEET BY FRI MORNING. THE GFS BRINGS US A BIT OF A BREAK IN THE
ACTION ON SATURDAY BEFORE ANOTHER FRONT COMES THROUGH SAT
NIGHT...FOLLOWED BY A THIRD SYSTEM SUN OR MON. THE ECMWF HAS SOME
OF THE HEAVIEST QPF ON FRI AND CONTINUES THE ONSLAUGHT THROUGH THE
WEEKEND. A BIT HARD TO SAY WHEN THE HEAVIEST RAIN WILL FALL...BUT
THE THREAT OF HEAVY PRECIP WILL CERTAINLY BE WITH US SO LONG AS
THIS PARADE OF SHORTWAVES CONTINUE...AT LEAST THROUGH THE FIRST
DAYS OF NEXT WEEK. ENSEMBLE POPS LOOKED MUCH TOO LOW SO HAVE
RAISED POPS BY AT LEAST 10 PERCENT OVER THIS TIME FRAME FOR BOTH
THE PLAINS AND MTS...WHILE THE MTS WILL SEE THE BEST SHOT AT HEAVY
PRECIP. TEMPS WILL TREND DOWNWARD THROUGH THE PERIOD...STARTING IN
THE NR 90 RANGE FOR TUE-THU...AND THEN FALLING INTO THE 80S AND
POSSIBLY LOWER FOR THE PLAINS NEXT WEEKEND. LOOKS LIKE THE
FORECAST WILL REMAIN CHALLENGING FOR THE REST OF THIS MONTH. ROSE
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1125 PM MDT MON AUG 18 2014
STILL SOME VERY ISOLATED TSRA LINGERING OVER THE SANGRES AND SAN
JUANS AS OF 0530Z...EXPECT THESE TO END BY 08Z WITH VFR CONDITIONS
ACROSS THE AREA...INCLUDING THE TAF SITES...FOR THE REMAINDER OF
THE NIGHT. ON TUESDAY...MOISTURE INCREASES ACROSS WESTERN COLORADO
AND EXPECT TSRA TO BE MORE NUMEROUS OVER THE HIGHER TERRAIN IN THE
AFTERNOON. HAVE INCLUDED A VCTS MENTION AT BOTH KALS AND KCOS FOR
LATE AFTERNOON INTO THE EVENING...THOUGH STORMS WILL BE FAIRLY
HIGH BASED WITH ONLY BRIEF MVFR CONDITIONS UNDER THE STRONGEST
CELLS. TSRA LESS LIKELY AT KPUB...THOUGH GUSTY OUTFLOW WINDS
CERTAINLY POSSIBLE...ESPECIALLY 22Z-02Z PERIOD.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...PETERSEN
SHORT TERM...28
LONG TERM...ROSE
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1102 PM MDT MON AUG 18 2014
.SHORT TERM...(TONIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 333 PM MDT MON AUG 18 2014
BIG CHANGES WILL OCCUR OVER THE NEXT 24 HOURS AS AN UNSEASONABLY
STRONG AND NEARLY VERTICALLY STACKED TROUGH...CURRENTLY OVER
CALIFORNIA...MOVES EAST INTO THE GREAT BASIN. THIS BRINGS EASTERN
UTAH AND WESTERN COLORADO INTO IDEAL POSITION FOR DEEP
SUBTROPICAL MOISTURE TO ADVECT INTO THE REGION. PRECIPITABLE
WATER VALUES OF 1 TO 1.3 INCH ARE EXPECTED TO COVER EASTERN UTAH
AND EVEN EXTREME WESTERN COLORADO BY LATE TUESDAY AFTERNOON. THIS
IS ALMOST 2 STANDARD DEVIATIONS ABOVE NORMAL FOR THIS TIME OF
YEAR.
MODELS ARE FORECASTING MULTIPLE VORT MAXES TO REACH THE UT/CO
BORDER THROUGHOUT THE DAY FROM NOON TO MIDNIGHT. THERE IS SOME
UNCERTAINTY ON THE TIMING OF H3 JET SUPPORT OF 60KTS REACHING THE
AREA...WHICH WILL HELP TO PROVIDE ASCENT IN THE UNIMPRESSIVE CAPE
AND SHEAR ENVIRONMENT. EXPECTING CLOUD COVER TO HINDER INSTABILITY
DURING THE DAY...HOWEVER THIS SCENARIO COULD CHANGE IF SUFFICIENT
CLEAR AIR IS ABOUND BY LATE MORNING. THE RAP SHOWS JET SUPPORT
INCHING INTO EASTERN UTAH AND SOUTHWEST COLORADO DURING THE
MORNING ON TUESDAY...HOWEVER THE NAM AND GFS SHOW THE BEST JET
SUPPORT ON TUESDAY NIGHT AND WEDNESDAY MORNING. STORM MOTION WILL
BE DECENT FOR TUESDAY - ABOUT 20 TO 30 KTS...SO COULD NOT JUSTIFY
A FLASH FLOOD WATCH AT THIS TIME. IT WILL RAIN IN MANY LOCATIONS
BY TUESDAY NIGHT...BUT ONLY EXPECTING MODERATE TO HEAVY RAIN
MULTICELLULAR STORMS CAUSING NUISANCE/SMALL STREAM FLOODING AT
THIS TIME. SEE HYDRO SECTION FOR MORE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 333 PM MDT MON AUG 18 2014
THE FORECAST AREA REMAINS UNDER SW FLOW WED-THU WITH THE JET AXIS
OVERHEAD. MONSOONAL MOISTURE PLUME WEAKENS WITH PRECIPITABLE WATER
VALUES DROPPING UNDER 1 INCH. NAM/GFS SHOW A WEAK 300 MB JET MAX
ARRIVING ON WED FOR POTENTIAL SUPPORT AND INCREASED VERTICAL
SHEAR....AND SHOULD IT ENTRAIN SOME DRIER MIDLEVEL AIR OVER HIGHER
MOISTURE NEAR THE SURFACE...IT COULD LEAD TO SOME STRONGER STORMS
WED AFTERNOON.
MODELS STILL HAVING TROUBLE HANDLING THE UPPER LOW THAT IS
CURRENTLY DROPPING SOUTH ALONG THE NRN CA COAST...WHICH LOWERS
FORECAST CONFIDENCE AFTER MIDWEEK. BUT AT LEAST THE GFS AND ECWMF
NOW BOTH BRING THE 500 MB LOW INLAND...JUST TIMING AND TRACK ARE
DIFFERENT. THE 12Z GFS SWINGS THE LOW INLAND ACROSS SRN CA WED AND
THEN LIFTS IT NE ACROSS UT AS AN OPEN WAVE ON THU. THIS COULD ADD
SOME DYNAMIC PUNCH TO STORM DEVELOPMENT ON THU. THE 12Z ECMWF IS
SLOWER BRINGING IT INLAND AND TRACKS IT FARTHER SOUTH ACROSS AZ
AND NWRN NM. THE 12Z CANADIAN HAS IT SHEARING OUT ALONG THE SRN CA
COAST THU-FRI. MODELS ALSO SHOW ENERGY DROPPING OUT OF THE GULF OF
AK LATE IN THE WEEK THAT SHOULD MAINTAIN TROUGHING OVER THE PAC
NW/NRN ROCKIES.
FOR NOW...WITH FOLLOW THE CONSENSUS MODEL TREND...WHICH SHOWS A
LESSENING OF STORM COVERAGE THE LAST HALF OF THE WEEK BUT NOT A
COMPLETE CESSATION. LOWER LEVEL MOISTURE LIKELY TO LINGER WITH SOME
SMALLER EMBEDDED WAVES IN THE FLOW THAT COULD TRIGGER ISOLATED-
SCATTERED ACTIVITY ABOUT EACH DAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1057 PM MDT MON AUG 18 2014
PLENTY OF CONVECTION CONTINUES THIS MORNING WITH SHOWERS AND OCCNL
RUMBLES OF THUNDER. THIS WILL LIKELY CONTINUE THROUGH 09Z WITH A
SLIGHT DOWNTICK AFTER THAT. SHOWERS AND STORMS WILL PICK UP AGAIN
WITH HEAVY RAIN...HAIL...AND GUSTY OUTFLOW WINDS OVERSPREADING THE
AREA FROM NOON ONWARDS WITH WIDEST COVERAGE FROM 21Z ONWARDS.
IFR/MVFR MAY OCCUR OVER AERODROMES DUE TO HEAVIER SHOWERS DROPPING
VIS AND ALSO DROPPING CIGS. MODELS CONTINUE PRECIP OVERNIGHT SO
EXPECT THESE CONDITIONS TO PERSIST THROUGH 06Z TOMORROW. MTN
OBSCURATIONS WILL ALSO BE COMMON.
&&
.HYDROLOGY...
ISSUED AT 333 PM MDT MON AUG 18 2014
MONSOONAL MOISTURE WILL RETURN TOMORROW AS AN UPPER LEVEL LOW OVER
CALIFORNIA PULLS DEEP SUBTROPICAL MOISTURE INTO THE REGION.
SHOWERS AND THUNDERSTORMS WILL INCREASE IN COVERAGE FROM WEST TO
EAST THROUGHOUT THE AFTERNOON AND PEAK DURING THE LATE HOURS OF
THE DAY AND OVERNIGHT INTO WEDNESDAY MORNING. EXPECTING TO HAVE
SMALL STREAM AND ARROYO FLOOD ISSUES BY WEDNESDAY MORNING IN THE
USUAL PROBLEM AREAS...BUT AT THIS NOT EXPECTING HIGH COVERAGE OF
TORRENTIAL DOWNPOURS DUE TO THUNDERSTORMS. THEREFORE...NO WATCHES
HAVE BEEN ISSUED AT THIS TIME.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...JAM
LONG TERM...JAD
AVIATION...TGR
HYDROLOGY...JAM
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
116 AM EDT TUE AUG 19 2014
.PREV DISCUSSION... /ISSUED 936 PM EDT MON AUG 18 2014/
UPDATE...
HAVE MADE SEVERAL CHANGES TO POPS THROUGH THE EVENING TO ACCOUNT
FOR TRENDS. MOST CONVECTION IS DYING OFF NOW...WITH ONLY LIGHT
RAIN REMAINING...BUT THE LEFTOVER MISSISSIPPI VALLEY MCV IS
WORKING ITS WAY ACROSS NORTHERN ALABAMA AT AFD TIME AND SHOULD
PUSH INTO NORTH GEORGIA IN THE NEXT FEW HOURS. AGAIN HAVE TRIED TO
ADJUST POPS TO ACCOUNT FOR THIS. AIRMASS IS PRETTY STABLE BEHIND
CONVECTION THIS EVENING SO THINK SEVERE POTENTIAL WITH ANY MCV
CONVECTION WOULD BE PRETTY LOW...HEAVY RAIN WOULD BE THE MORE
SIGNIFICANT THREAT.
UPDATED PRODUCTS OUT SHORTLY.
TDP
PREV DISCUSSION... /ISSUED 750 PM EDT MON AUG 18 2014/
PREV DISCUSSION... /ISSUED 320 PM EDT MON AUG 18 2014/
SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
STALLED FRONTAL BOUNDARY STRETCHES FROM THE TN VALLEY TO THE
SOUTHERN MID ATLANTIC STATES. A HIGH PRESSURE RIDGE IS SITUATED
ACROSS NORTHERN FL. 500MB ANALYSIS AND WV LOOP SHOWS A POTENT
SHORTWAVE MOVING EAST ACROSS NORTHERN MS. THIS FEATURE WILL BE THE
FOCUS FOR LATE AFTERNOON AND EVENING CONVECTION ACROSS THE CWFA.
THE 16Z HRRR HAS THE BEST HANDLE ON THE ONGOING CONVECTION THIS
AFTERNOON. HAVE TRIED TO ORIENT THE POPS ACCORDING TO CURRENT RADAR
TRENDS AND CLOSE TO THE HRRR SOLUTION. GOOD INSTABILITY DOES EXIST
AT THE SURFACE...BUT LAPSE RATES REMAIN POOR UNTIL THE COLD POOL
ALOFT MOVES OVERHEAD. BY THE TIME THE SHORTWAVE NEARS THE
CWFA...INSTABILITY HAS DECREASED WITH THE LOSS OF HEATING.
HOWEVER...WITH UNIDIRECTIONAL FLOW...STORMS MAY MOVE REPEATEDLY OVER
THE SAME AREAS...WITH LOCALLY HEAVY RAINFALL POSSIBLE. AREAS TO THE
NORTH RECEIVED ONE TO TWO INCHES OF RAINFALL OVERNIGHT/EARLY THIS
MORNING...SO ANY TRAINING STORMS OR HEAVY RAINFALL MAY CAUSE SOME
LOCALIZED FLOODING.
BY EARLY TUESDAY...THE POTENT EVENING/OVERNIGHT SHORTWAVE WILL HAVE
MOVED OFF TO THE EAST. MODELS ARE PROGGING ANOTHER...WEAKER...
SHORTWAVE TO MOVE EAST IN THE FLOW TOMORROW. CONFIDENCE IS LOW ON
EXACTLY WHERE CONVECTION WILL DEVELOP TOMORROW.
NLISTEMAA
LONG TERM /WEDNESDAY THROUGH MONDAY/...
LONG TERM FORECAST IS ON TRACK AND HAVE NOT MADE SIGNIFICANT
ADJUSTMENTS. ONE ADDITIONAL POINT TO NOTE IS THAT HEAT INDEX VALUES
ARE CREEPING ABOVE 100 DEGREES SOUTH OF AN ATLANTA TO ATHENS
LINE...WITH PORTIONS OF CENTRAL GEORGIA APPROACHING 105 DEGREES
DURING THE SECOND HALF OF THE WEEK. IF THIS TREND CONTINUES...MAY
NEED A HEAT ADVISORY FOR THESE 105-108 DEGREE VALUES ACROSS THE
SOUTHEAST PART OF THE CWA.
11/ATWELL
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
00Z GFS AND ECMWF ARE IN UNCOMMONLY GOOD AGREEMENT THROUGH THE
EXTENDED FORECAST PERIOD AND CONTINUE THE RECENT TREND OF BUILDING
UPPER-LEVEL HIGH PRESSURE INTO THE CENTRAL GULF COAST REGION AND
LOWER MISSISSIPPI VALLEY FROM MID-WEEK THROUGH NEXT WEEKEND. BY THE
WEEKEND THE UPPER RIDGE IS QUITE STRONG...BUT GEORGIA REMAINS ON THE
EASTERN PERIPHERY. THIS SHOULD ALLOW VERY WARM TEMPERATURES AND
INHIBIT DIURNAL CONVECTION SOMEWHAT...BUT I DO NOT BELIEVE THE
FORECAST AREA IS CLOSE ENOUGH TO THE CENTER OF THE RIDGE TO
ELIMINATE POPS ALTOGETHER.
20
&&
.AVIATION...
06Z UPDATE...
POTENTIAL FOR INCREASING LIFR-MVFR CEILINGS ACROSS THE TAF SITES
WITH SOME MVFR VSBYS DUE TO FOG. IMPROVEMENT EXPECTED TO VFR DURING
THE LATER MORNING. POTENTIAL FOR SHOWERS AND THUNDERSTORMS ALMOST
ANY TIME TODAY. SURFACE WINDS LIGHT WSW INCREASING TO MAINLY WEST
AROUND 10 KTS WITH SOME GUSTS AROUND 20 KTS.
//ATL CONFIDENCE...06Z UPDATE...
LOW CONFIDENCE ON CEILINGS/VSBYS AND IMPACTS OF THUNDERSTORMS TODAY.
HIGH CONFIDENCE ON WINDS.
BDL
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 91 72 97 72 / 40 30 10 5
ATLANTA 88 73 94 75 / 40 30 10 5
BLAIRSVILLE 84 67 90 68 / 40 30 20 10
CARTERSVILLE 89 71 94 71 / 40 30 10 5
COLUMBUS 92 73 96 75 / 40 30 10 5
GAINESVILLE 89 71 94 73 / 40 30 10 10
MACON 92 72 97 74 / 40 30 10 5
ROME 89 71 95 71 / 40 30 20 10
PEACHTREE CITY 89 71 94 72 / 40 30 10 5
VIDALIA 95 74 97 76 / 40 30 20 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BDL
LONG TERM....20
AVIATION...BDL
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
106 AM CDT TUE AUG 19 2014
.DISCUSSION...
650 PM...EARLY EVENING UPDATE...CONVECTION FIRING ACROSS CENTRAL
WI WILL CONTINUE THIS EVENING WITH ADDITIONAL THUNDERSTORMS
RAPIDLY DEVELOPING OVER FAR NORTHERN IA AND SOUTHERN MN. THIS
ACTIVITY WILL SLOWLY SAG SOUTH BUT PROBABLY NOT REACH NORTHERN IL
UNTIL AFTER 04Z-05Z. ACTIVITY WILL THEN SPREAD SOUTHEAST ACROSS
MAINLY THE NORTHERN TWO THIRDS OF THE CWA OVERNIGHT. SHORT TERM/
HI RES GUIDANCE IS IN FAIR AGREEMENT WITH MUCH OF THE AREA NOW
STAYING DRY THROUGH MIDNIGHT. HAVE UPDATED GRIDS/ZFP FOR THESE
TRENDS ALONG WITH MOSTLY CLEAR SKIES OVER MUCH OF THE AREA AS CU
FIELD DISSIPATES...THOUGH HIGH CLOUDS WILL LIKELY QUICKLY SPREAD
ACROSS THE AREA LATER THIS EVENING AS STORMS APPROACH. NO CHANGES
TO LIKELY POPS OVERNIGHT THOUGH POPS MAY NEED TO BE LOWERED ACROSS
THE FAR SOUTH AS TRENDS EMERGE. CMS
//PREV DISCUSSION...
239 PM CDT
SYNOPSIS...A WARMER AND NOTICEABLY MORE HUMID PATTERN WILL BE
DEVELOPING THROUGH MID WEEK. IN ADDITION TO THE WARMTH AN EVOLVING
UPPER AIR PATTERN WILL BRING PERIODIC CHANCES FOR SHOWERS AND
THUNDERSTORMS THROUGH THE WEEKEND. HIGH TEMPERATURES LATER IN THE
WEEK MAY BE DICTATED BY THE CONVECTION.
TONIGHT...
A LOW PRESSURE TROUGH IS OVER MINNESOTA AND IT WILL BECOME A CLOSED
LOW OVER WISCONSIN AND LAKE SUPERIOR TUESDAY EVENING. AT THE
SURFACE THERE IS A LOW PRESSURE TROUGH OVER MINNESOTA THAT WILL
BECOME A CLOSED LOW OVER WISCONSIN TOMORROW MORNING. THE LOW WILL
PUSH EAST OF THE LAKE WEDNESDAY.
EXPECTING THE FIRST ROUND OF STORMS TO MOVE INTO THE RFD AREA THIS
EVENING WITH THE MAJORITY OF CONVECTIVE ACTIVITY REMAINING OVER
WISCONSIN CLOSER TO THE LOW. THE FIRST WAVE WILL WEAKEN AS IT
PUSHES EAST. A SECOND WAVE FORMS AHEAD OF A VORT STREAMER OVERNIGHT
AND THINKING THIS WILL BE THE MAIN SHOW TONIGHT. EXPECTING ACTIVITY
TO REMAIN NORTH OF I-80 MOST OF THE NIGHT. ACTIVITY WILL THEN SPREAD
SOUTH AND EAST COVERING AREAS EAST OF I-39 EARLY TUESDAY MORNING.
THIS ACTIVITY WILL WEAKEN THROUGH THE MORNING AND CONTINUE SOUTHEAST
OUT OF THE WARNING AREA.
THE FIRST CONCERN OVERNIGHT IS HEAVY RAIN AS PWAT VALUES WILL BE
BETWEEN 1.5 AND 1.75 INCHES. CAPE VALUES WILL BE AROUND 1000 J/KG
THIS EVENING AND THEN DIMINISH OVERNIGHT. SHEAR VALUES ARE 20-30 KT
SO SEVERE WEATHER IS NOT EXPECTED...BUT SMALL HAIL MAY OCCUR WITH
THE STRONGEST STORMS. STEERING LEVEL FLOW IS ALSO WEAK SO STORMS
WILL BE SLOW MOVING WHICH COULD ENHANCE RAINFALL TOTALS.
THE OTHER CONCERN IS FOG TONIGHT. IF WE CLEAR OUT AT ALL EXPECTING
AREAS OF DENSE FOG TO DEVELOP. HAVE MEDIUM CONFIDENCE IN SKY COVER
SO ONLY HAVE PATCHY FOG IN THE FORECAST TONIGHT AFTER MIDNIGHT.
TUESDAY AND TUESDAY NIGHT...
MORE STORMS ARE EXPECTED AS THE LOW SHIFTS EAST OVER WISCONSIN.
EXPECTING FOG/LOW STRATUS/GENERAL CLOUD COVER TO THIN TUESDAY
MORNING. HEATING WILL RESULT IN DECENT CAPE VALUES. THE MOISTURE
RICH NAM FEATURES THE HIGHEST CAPE VALUES AROUND 3000 J/KG BUT THE
MORE CONSERVATIVE GFS ONLY SHOWS LESS THAN 1000 J/KG. SHEAR VALUES
STILL LOOK MARGINAL AROUND 35 KT. BUT PWAT VALUES WILL BE A BIT
LOWER AT 1.3 TO 1.5 INCHES. HEAVY RAIN IS STILL POSSIBLE BUT STORMS
SHOULD BE MOVING AT A BETTER PACE WITH STRONGER STEERING LEVEL
FLOW. THE FORCING WILL BE A COMBO OF THE LOWS FRONT THAT MOVES
THROUGH IN THE LATE AFTN/EVENING AND VORTICITY STREAMERS THAT ROTATE
AROUND THE LOW. HAVE MEDIUM CONFIDENCE IN WIDESPREAD TS
COVERAGE...BUT KEPT POPS IN THE CHANCE RANGE DUE TO LOW CONFIDENCE
IN WHEN AND WHERE STORMS WILL DEVELOP. HAIL AND STRONG WINDS ARE
POSSIBLE IN ADDITION TO THE HEAVY DOWNPOURS.
TEMPS REMAIN A CHALLENGE AS WE COULD BE WARMER IF SKY COVER IS ON
THE WEAKER SIDE. HOWEVER...HAVE MEDIUM CONFIDENCE IN WIDESPREAD TS
COVERAGE SO KEPT HIGH TEMPS IN THE LOW TO MID 80S.
JEE
WEDNESDAY THROUGH SUNDAY...
THE UPPER LOW OVER THE UPPER GREAT LAKES WILL START TO MOVE MORE
QUICKLY TO THE NORTHEAST WEDNESDAY MORNING AS NORTHERN PACIFIC
TROUGHING PUSHES INLAND OVER WESTERN CANADA. THIS HELPS TO PUSH
CUTOFF LOW PRESSURE ONTO THE CALIFORNIA COAST WITH BOTH OF THESE
FEATURES HELPING TO DRIVE UPPER RIDGE DEVELOPMENT OVER THE HIGH
PLAINS. THE LOCAL AREA WILL BE BETWEEN THE DEPARTING UPPER LOW AND
THE APPROACHING RIDGE WEDNESDAY MORNING WITH WEAK LOW LEVEL FLOW
IN PLACE AS WELL. THIS SHOULD RESULT IN DRY WEATHER FOR MUCH OF
WEDNESDAY BEFORE MID LEVEL BAROCLINICITY INCREASES LATE IN THE DAY
AND MORE SO IN THE EVENING AS THE RIDGE APPROACHES. PRECIPITABLE
WATER VALUES WILL INCREASE MARKEDLY WITH THE ARRIVAL OF THE MID
LEVEL WARM ADVECTION LEADING TO MOIST ASCENT WEDNESDAY EVENING AND
WEDNESDAY NIGHT. THIS LIFT ALONE MAY BE ENOUGH TO PRODUCE SHOWERS
AND THUNDERSTORMS AND MAY BE AIDED BY THE PASSAGE OF AN UPPER WAVE
WHICH GUIDANCE HAS BEEN HINTING AT. THIS IS CERTAINLY PLAUSIBLE
GIVEN THE PRESENCE OF THE DEEP TROUGH TO THE WEST AND THE TENDENCY
FOR WAVES TO EMANATE FROM IT. WILL CARRY HIGHEST POPS LATE
WEDNESDAY EVENING THROUGH THURSDAY MORNING. THE RIDGE AXIS WILL
SHIFT EASTWARD ACROSS THE AREA THROUGH FRIDAY. THE AMPLITUDE OF
THE RIDGE AND THEREFORE THE POSITIONING OF THE TRACK OF
SHORTWAVES/THUNDERSTORMS ALONG ITS NORTHERN PERIPHERY WILL BE
DRIVEN BY THE SPEED WITH WHICH THE LARGE WESTERN UPPER TROUGH
EVOLVES EASTWARD. THE GFS CONTINUES TO BE MORE PROGRESSIVE WITH
THE TROUGH AND THEREFORE SHARPER WITH THE RIDGE SUGGESTING THAT
THE MAIN STORM TRACK WILL BE NORTH OF THE LOCAL AREA FRIDAY
WHEREAS THE SLOWER AND LOWER AMPLITUDE ECMWF KEEPS THE FAVORED
TRACK ACROSS THE AREA INTO THE WEEKEND. THE UPPER TROUGH WILL
EVOLVE EASTWARD PUSHING THE RIDGE TO THE EAST AND BRINGING A COOL
FRONT INTO THE REGION LATE IN THE WEEKEND. THE BIGGEST UNCERTAINTY
IS THE TIMING. WITH PRECIPITABLE WATER VALUES OVER 2 INCHES FROM
THURSDAY ONWARD HEAVY RAINFALL WILL BE A CONCERN WITH ANY
STORMS...ESPECIALLY IF MULTIPLE ROUNDS ARE ABLE TO AFFECT THE AREA
THROUGH THE WEEKEND. HOWEVER A SHARPER RIDGE WOULD RESULT IN A
SHIFT IN THE TRACK TO THE NORTH AND STRONGER CAPPING LOCALLY.
TEMPERATURES WILL BE WARMING INTO THE MID 80S WEDNESDAY AND MOSTLY
MID AND UPPER 80S FROM THURSDAY INTO THE WEEKEND. LAKESHORE AREAS
WILL LIKELY BE COOLER MOST DAYS WITH LAKE INFLUENCES EXPECTED DUE TO
A RATHER LIGHT LOW LEVEL FLOW. THUNDERSTORMS AND ANY REMNANT
INFLUENCES MAY NEGATIVELY AFFECT HIGHS DEPENDING ON THEIR TIMING.
CANNOT RULE OUT SOME 90 DEGREE READINGS IN THE WEST AND SOUTH LATE
IN THE WEEK...ESPECIALLY IF THUNDERSTORM ACTIVITY KEEPS AT A
MINIMUM.
MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* A PERIOD OF SHRA/TSRA POSSIBLE SOMETIME BETWEEN 08Z-11Z.
* POTENTIAL FOR LOWER CIGS LATE TONIGHT INTO TUE MORNING.
* CHANCE FOR SCATTERED SHRA/TSRA MUCH OF TUE WITH A SLIGHTLY MORE
FAVORED TIME DURING THE AFTERNOON.
KREIN
//DISCUSSION...UPDATED 06Z...
A QUIET EVENING IS EXPECTED OVER LOCAL AIRPORTS BEFORE TSRA
CHANCES INCREASE OVERNIGHT.
AN UPPER LEVEL DISTURBANCE MOVING EAST THROUGH WISCONSIN CONTINUES
TO GENERATE A LINE OF THUNDERSTORMS EXTENDING FROM NEAR OSHKOSH
SOUTHWEST TO NEAR DES MOINES ALONG A WEAK COLD FRONT...WITH AN
ADDITIONAL CLUSTER OF SHOWERS AND EMBEDDED THUNDERSTORMS RIGHT
UNDER THE MAIN UPPER CIRCULATION CENTER. LATEST TRENDS INDICATE
THAT THE UPPER LEVEL SYSTEM IS TRACKING ALMOST DUE EAST WHILE THE
MAIN CONVECTIVE LINE SLOWLY SAGS SLIGHTLY SOUTH OF EAST. HAVE
DECREASING CONFIDENCE IN THE POTENTIAL FOR ANY OF THE TS TO REACH
ANY OF TERMINALS EXCEPT FOR ROCKFORD. ALSO...THE LATEST MODEL
GUIDANCE IS SHOWING THAT STEERING FLOW IS TURNING MORE DUE
WESTERLY AS THE UPPER SYSTEM MOVES EWD...WHICH WOULD THEN CAUSE
THE SOUTHERN END OF THE CONVECTIVE LINE TO STRETCH OUT IN A MORE
EAST-WEST ORIENTATION NEAR THE IL/WI BORDER. HOWEVER...THERE IS
STILL SOME DEVELOPMENT ALONG THE SRN END OF THE LINE OVER NERN IA
INTO CNTRL IA...SO CONFIDENCE IS NOT HIGH ENOUGH TO PULL THE TS
FROM THE TAFS FOR THE LATE NIGHT HOURS AS THERE IS STILL SOME
MOISTURE TRANSPORT AND BROAD SCALE LIFT OVER NRN IL WHERE 850MB
WINDS ARE STILL WSWLY. ANOTHER FACTOR POINTING TO A LOWER TS
POTENTIAL IS THE LACK OF STRONG SFC FORCING AND THAT THE SYSTEM IS
ALMOST ENTIRELY RELYING ON UPPER LEVEL FORCING. SO...TO MAKE A
SHORT STORY LONG...WILL MAINTAIN THE TS IN THE TAFS BTWN
08-11Z...AND REFINE THE FORECAST WHEN CONFIDENCE IS A LITTLE
HIGHER.
WHAT THUNDER THAT DOES MANAGE TO MOVE SOUTH OF THE WISCONSIN
BORDER SHOULD DISSIPATE BEFORE DAYBREAK...BUT WITH A MOIST AIRMASS
IN PLACE AND THE MAIN SYNOPTIC SCALE UPPER LOW MOVING OVER NRN
WISCONSIN BY MID DAY TUESDAY...THERE WILL STILL BE ADEQUATE
CYCLONIC FLOW ALOFT THAT SCT SHRA AND ISOLD TSRA COULD STILL
DEVELOP DURG THE DAYTIME HOURS. CHANCES FOR MORE ORGANIZED TS WILL
INCREASE THROUGH THE AFTERNOON AS ANOTHER MID LEVEL IMPULSE TRACKS
AROUND THE SRN PERIPHERY OF THE MAIN UPPER LOW.
AS FOR WINDS...LIGHT SWLY WINDS WILL CONTINUE IN ADVANCE OF THE
WEAK COLD FRONT...AND INCREASE THROUGH THE MORNING AS THE SFC
PRESSURE GRADIENT STRENGTHENS. BY LATE MORNING...SWLY WINDS SHOULD
INCREASE TO 10-15KT WITH OCNL GUSTS OF 15-20KT PERSISTING THROUGH
EARLY EVENING WHILE GRADUALLY VEERING TO WESTERLY BY LATE
AFTERNOON.
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* LOW CONFIDENCE IN TIMING AND COVERAGE OF TS ASSOCIATED WITH THE
COLD FRONT AND THE DIRECT IMPACT ON THE TERMINALS.
* MEDIUM TO HIGH CONFIDENCE IN WIND SPEED AND DIRECTION...THOUGH
THE WIND FIELD COULD BE LOCALLY DISRUPTED BY ANY TS THAT DO
DEVELOP.
* LOW IN MVFR CIGS OCCURRING LATE TONIGHT INTO TUE MORNING.
* LOW IN WHETHER TSRA OCCURS TUESDAY AND IN SPECIFIC TIMING.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...CHANCE OF TSRA AND LOWER CIGS DURING THE NIGHT.
THURSDAY-SATURDAY...PERIODS OF TSRA POSSIBLE.
SUNDAY...SLIGHT CHANCE OF TSRA.
MTF
&&
.MARINE...
239 PM CDT
LOW PRESSURE OVER MINNESOTA WILL MOVE OVER WISCONSIN TOMORROW AND
THEN OVER THE LAKE TOMORROW EVENING AND NIGHT. WINDS WILL BECOME
SOUTH ACROSS THE LAKE AND INCREASE TO 15 TO 25 KT OVERNIGHT. AS THE
LOW MOVES OVER THE LAKE TOMORROW...WINDS WILL DIMINISH SLOWLY OVER
THE SOUTH HALF AND BECOME SW. ON THE NORTH HALF...WINDS WILL ALSO
DIMINISH AND BECOME SE TO E AHEAD OF THE LOW. THE LOW SHIFTS EAST
OF THE LAKE TUESDAY NIGHT AND WINDS BECOME NW 10-15 KT.
THE LOW SHIFTING TO THE EAST WILL LEAVE A WEAK PRESSURE GRADIENT
IN ITS WAKE. THIS WILL RESULT IN LIGHT ONSHORE OR VARIABLE WINDS
WEDNESDAY WITH BEFORE A SOMEWHAT BETTER ORGANIZED PRESSURE
GRADIENT SPREADS IN WITH LOW PRESSURE FROM THE CENTRAL HIGH PLAINS
TO NORTHERN MANITOBA. THIS WILL BRING MAINLY SOUTH TO SOUTHEAST
WINDS ACROSS THE LAKE THURSDAY...WITH OCCASIONAL EAST WINDS OVER
THE FAR NORTH...BUT EVEN THEN THE FLOW MAY BE WEAK ENOUGH TO
SUPPORT A SHIFT TO ONSHORE WINDS THURSDAY AFTERNOON. SOUTH TO
SOUTHEAST WINDS ARE FAVORED THROUGH THE WEEKEND BUT THERE MAY BE
QUITE A BIT OF VARIABILITY IF THE LOW PRESSURE TO THE WEST EVOLVES
MORE SLOWLY AS SOME FORECAST GUIDANCE INDICATES. THE UPPER FLOW
PATTERN DOES LOOK TO SHIFT SUNDAY OR MONDAY BRINGING A COOL FRONT
ACROSS THE LAKE WITH A SHIFT TO NORTHERLY WINDS WHICH MAY BE
RATHER BREEZY.
JEE/MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1152 PM CDT Mon Aug 18 2014
.UPDATE...
ISSUED AT 900 PM CDT MON AUG 18 2014
Skies have become mostly clear across central and SE Illinois this
evening as diurnal heating ends. Although a few pockets of light
fog are possible early tonight, the next main forecast feature
will be the chance for thunderstorms overnight as an upper level
shortwave and cold front move into central IL. Have trimmed back
POPs before midnight as current radar and satellite indicate
storms are still several hours away. HRRR model simulated
reflectivity has been depicting movement of the system well in
northern IA, southern MN, southwest WI this evening and has been
used as a guide for timing through the first few hours of Tuesday.
Currently the system is associated with a slight risk (15% +) of
severe winds and hail to our northwest, but as it approaches
central IL, CAPE of 3000 J/kg should be diminishing to around 1500
or less with marginal 0-6 km bulk shear around 25-30 kts. This is
enough for only a 5% severe risk from the Illinois River
northwest. To the south, risk of severe storms is negligible, but
at least a slight chance for storms will reach as far as SE
Illinois by early morning. Have sent updates for
POP/Temp/Humidity/Wind trends this evening/early tonight.
&&
.SHORT TERM...(This evening through Tuesday)
ISSUED AT 311 PM CDT MON AUG 18 2014
Earlier stratus has given way to diurnal type clouds over central
and southeast Illinois early this afternoon, underneath a weak high
pressure axis. Leading edge of shortwave currently seen on water
vapor imagery pushing through Minnesota and northern Iowa, with a
more potent vorticity maximum moving out of North Dakota.
Convection ahead of the shortwave expected to begin over the next
couple hours over northern Iowa, where skies have been sunny and
CAPE`s are over 3000 J/kg per SPC mesoanalysis. High-resolution
models pushing the first wave of storms into Wisconsin with another
line forming in southern Minnesota/northern Iowa later this evening.
The second line is more of a concern for us as it will have a
southeast trajectory. However, most of the models show some fading
of the line with more of the energy staying to our north, and a
separate convective cluster developing over northwest Missouri
overnight. Have adjusted the PoP`s in our area to be primarily after
midnight, and largely eliminated them south of I-70.
Associated surface boundary expected to push into central Illinois
Tuesday afternoon as the upper wave arrives. Some concerns with
severe weather potential across east central and southeast Illinois,
as development takes place early afternoon and bulk shear increases
during the peak heating time. Latest Day2 SPC convective outlook
indicates a severe threat southeast of a Danville to Effingham line,
with NAM indicating a 2 pm to 7 pm time frame being the most
concern.
&&
.LONG TERM...(Tuesday night through Monday)
ISSUED AT 311 PM CDT MON AUG 18 2014
Tuesday evening will see decreasing storm chances from north to
south as a shortwave in the upper level trough over the Great Lakes
advances east of IL. We are in the day 2 slight risk in our
southeast counties, so we can`t rule out some lingering strong
storms into early evening, but the main threat should advance
southeast of IL by mid evening.
Additional storm chances re-develop across our far S-SW counties late
Tue night as a 300mb 75kt jet max in the back side of the trough
generates some lift in the left exit region. Minor rain/storm
chances will continue on Wednesday as the jet max progresses
eastward over Illinois, but only slight chances are expected.
Wednesday night, a warm front developing across our northern
counties oriented from NW to SE will become a focus for a round of
storms, with chances increasing to likely after midnight along and
north of I-74. Storms should progress northward with the warm front
on Thursday. However, storms chances are expected to linger north of
a line from Peoria to Paris Thursday and Thursday night.
Height rises and mid-level warming on Friday and Saturday should
help to keep provide a capping layer, and reduce storm chances
across central IL. The may be an isolated late afternoon or early
evening flare-up of a storm, but most areas should stay dry.
Rain-free conditions are forecast to continue into Sunday by the
ECMWF and GFS. They both show a cold front arriving later Sunday
night and wash-out as it passes across IL on Monday. The weakening
front is not expected to trigger much in the way of storms at this
point, but confidence is low on that scenario staying dry.
Heat and humidity will definitely dominate the last half of this
week, as highs climb into the upper 80s and lower 90s, with heat
index readings in the mid to upper 90s. Some relief will come on
Monday behind the cold front, with low to mid 80s for highs and
lowering dewpoints into the 60s.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
ISSUED AT 1152 PM CDT MON AUG 18 2014
Patchy fog resulting in VLIFR to MVFR conditions in place from
around K1H2-KAAA-KCMI eastward, with a line of thunderstorms
approaching northern IL from the northwest. Fog expected to
dissipate as light SSW winds ahead of the line of thunderstorms
promotes mixing. This line expected to weaken as it approaches and
mainly affect TAF sites from KPIA and KBMI northward. Have
included VCTS in central IL TAFs to address potential for
thunderstorms, but likelihood of MVFR conditions looks too low for
explicit mention at this time. A break in shower/thunderstorm
activity likely in the morning, then an upper level shortwave and
daytime heating should produce a re- intensification of storms
along the cold frontal boundary lingering over central Illinois.
Have brought VCTS and ceilings near MVFR thresholds for the
remainder of the afternoon to account for this. Starting around
00Z, conditions expected to improve as frontal boundary and upper
level shortwave moves east of the area.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ONTON
SHORT TERM...GEELHART
LONG TERM...SHIMON
AVIATION...ONTON
AREA FORECAST DISCUSSION...UPDATED
NWS DODGE CITY KS
1235 AM CDT Tue Aug 19 2014
...Updated for Aviation...
.SHORT TERM...(This evening through Tuesday)
ISSUED AT 1202 PM CDT MON AUG 18 2014
There is a high pressure ridge over Colorado south into New Mexico
late this afternoon. A lee side trough is near the Kansas and
Colorado border, and a warm front has been pushing northeast
through western Kansas this morning. The forecast is on track for
today, with highs just over 100F degrees likely somewhere across
southern and western Kansas, and upper 90s in our northern zones.
There could be a few and far between showers and isolated
thunderstorms just about anywhere late today. The HRRR model shows
a few thunderstorms across our south and southeast zones after
21z, but the NAM and NAMNG5 models are showing storms first over
our west and then moving across the northern CWA. Mid and high
clouds will be on the increase late this afternoon and evening.
So, the low Pops in the 17-20 percent range blanketing our
forecast area seem reasonable. Time will tell on which model is
more correct.
The same HRRR, NAM, and NAMNG5 models decrease the measurable
precip after 04Z, and then the clouds will slowly dissipate after
09Z or so. I plan to reduce 20 percent Pops rapidly between 06Z and
12Z. Not much precipitation will fall either, as any convection
will be high based. I used the QPF_from_PoP application, and it
only shows 0.01 to spotty 0.03 inches of rain overnight. With
clouds breaking late and perhaps a little rain, minimum temperatures
should end up in the middle 60s in Syracuse, Scott City, and
Wakeeney, while settling only to around 70F degrees in the Meade,
Coldwater and Medicine Lodge areas. Winds will continue to hover
at less than 10 MPH tonight.
On Tuesday, the surface low will advect into central Kansas, and the
front will sag south across part of our CWA. Thus, Max temps should
dip just a little north of the front, while south along the Oklahoma
border near Medicine Lodge, it should warm up to around 100F. Winds
on Tuesday will be breezy from the south in the 15 to 25 mph and
gusty range. I do not think there will any precipitation on
Tuesday, as the lower max temps will result in less instability than
today.
.LONG TERM...(Tuesday night through Monday)
ISSUED AT 225 PM CDT MON AUG 18 2014
Medium range models indicate an upper level ridge of high pressure
transitioning eastward out of the Western High Plains into the
Central Plains to begin the period Tuesday night. Combined with
a weak flow aloft, drier conditions are likely to prevail through
late Wednesday afternoon. Meanwhile, an upper level trough will dig
southeast across southern California Wednesday setting up a strong
southwest flow aloft across the Central and Southern Rockies,
including a +90kt jet core projected to lift northeast out of the
Desert Southwest into the Colorado Rockies. With a prevailing lee
side trough providing increased convergence in the lower levels,
thunderstorm development is likely across portions of eastern
Colorado Wednesday afternoon with a few storms potentially
drifting into western Kansas later in the evening through early
Thursday. However, the weaker flow aloft across western Kansas
will limit the strength and coverage of any storms. The upper
level shortwave will then lift northeast going into the weekend
while a large scale upper level high remains locked in across the
Deep South. Although precip chances will remain present virtually
each day into the weekend, the weaker flow aloft will limit storm
development, strength, and coverage.
Temperatures will remain above normal Wednesday as the
aforementioned upper level ridge shifts east across the Central
Plains. A prevailing southerly flow across western Kansas will
reinforce the warmer air mass already in place across the region
with H85 temperatures ranging from the upper 20s(C) in central
Kansas to around 30C closer to the Colorado border. As lower level
lapse rates steepen into the afternoon, look for highs well up
into the 90s(F) to near 100F Wednesday. Similar temperatures are
then expected each day through Saturday as the low level southerly
flow persists into the early part of the weekend.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
ISSUED AT 1232 AM CDT TUE AUG 19 2014
A few showers and isolated thunderstorms will dissipate by 07-09Z
this morning. A lee trough of low pressure will deepen with south
winds increasing to 15-25kt after 18Z. VFR conditions are expected.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 71 99 74 100 / 0 10 10 10
GCK 70 98 70 100 / 0 10 10 10
EHA 69 98 68 97 / 10 20 20 20
LBL 70 98 71 100 / 0 10 10 10
HYS 71 99 73 98 / 0 10 20 20
P28 74 99 76 100 / 0 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Burke
LONG TERM...JJohnson
AVIATION...Kruse
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1136 PM CDT Mon Aug 18 2014
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Tuesday)
Issued at 352 PM CDT MON AUG 18 2014
The center of an upper level trough was located across eastern ND
late this afternoon with an upper level trough axis extending
southwest across central SD. The numerical models show this upper
level trough digging southeast across southern MN and eastern NE
into northern MO. The southwest section of the upper trough will
move southeast across northeast KS between 6Z and 12Z. The NAM,
GFS and ECMWF forecast QPF across northeast and east central KS
later Tonight, with the ECMWF and NAM showing most of the CWA with
QPF. The NAM model shows weak isentropic lift at the 310K level
with LFCs around 700mb. The most intense isentropic lift at the
310K level will be across northern MO and IA.
The mesoscale models, consisting of the ARW, NMM and HRRR do not
forecast any QPF across the CWA tonight. I will probably keep slight
chance to chance pops across much of the CWA, since the ascent ahead
of the H5 trough combined with isentropic lift should allow elevated
thunderstorms to develop across the northeast counties of the CWA
around midnight, then building southwest across the central and
southwest counties of the CWA through the early morning hours before
spreading southeast across much of east central KS by 12Z TUE.
Any lingering elevated thunderstorms, if they do develop, will shift
southeast of the CWA during the mid morning hours. Skies should
clear through the late morning and early afternoon hours and
temperatures will warm into the lower to mid 90s. If there is a
leftover outflow boundary across the northeast counties, then
temperatures along the NE border may only reach into the upper 80s.
I placed in 14 pops in case there is enough surface convergence for
an isolated thunderstorm during the afternoon hours.
.LONG TERM...(Tuesday Night through Monday)
Issued at 352 PM CDT MON AUG 18 2014
Models are in agreement that heights rises and resulting warm air
advection will be situated across the northeast corner of the county
warning area Tuesday evening providing another chance for
thunderstorms. As this area focuses further northward through the
night...have removed pops this area after midnight. Will keep lows
mild in the low to middle 70s. This will then set the stage for
mostly sunny very warm...breezy day on Wednesday. Highs will
generally be 95 to 100 degrees with the warmest in the Abilene area
and the coolest near Hiawatha.
As the upper ridge builds across the southern plains...expect dry
weather across the cwa Wednesday night through Thursday. However...
with south winds continuing...highs Thursday will again be in the
middle to upper 90s.
As the cutoff upper trough in the desert southwest gets picked up by
Thursday and heads into the central and northern high plains into
the weekend...there will be better chances for thunderstorms across
the area...although the northern/northwest 1/2 of the cwa will be
the more likely areas to see rain. Do not expect a frontal passage
until during the day Sunday...so may not see highs temps below 90
degrees until Monday when readings in the middle to upper 80s should
be the rule.
&&
.AVIATION...(For the 06Z TAFs through 06Z Tuesday Night)
Issued at 1119 PM CDT MON AUG 18 2014
VFR prevails at KTOP/KFOE/KMHK with main concern being TSRA
potential. Cluster of TSRA over north central KS is progged to
gradually dissipate towards the southeast overnight. Short term
guidance maintains scattered TSRA aft 08Z so will leave VCTS
mention through 11Z at KMHK and 14Z at KTOP/KFOE.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Gargan
LONG TERM...63
AVIATION...Bowen
AREA FORECAST DISCUSSION
NWS JACKSON KY
1239 AM EDT TUE AUG 19 2014
.UPDATE...
ISSUED AT 1130 PM EDT MON AUG 18 2014
UPDATED THE FORECAST TO ISSUE A DENSE FOG ADVISORY FOR EASTERN
KENTUCKY. HAD REPORTS OF DENSE FOG MOST OF THE WAY FROM CLAY CITY TO
JACKSON. AT SIGNS POINT TO A WIDESPREAD FOG EVENT TONIGHT THAT IS
WORSE THAN THE NORMAL AUGUST VALLEY FOG.
UPDATE ISSUED AT 702 PM EDT MON AUG 18 2014
UPDATED THE FORECAST TO BETTER REFLECT CURRENT CONDITIONS AND MODEL
TRENDS. THE PRECIPITATION HAS BEEN TAPERING OFF AS THE SHORT WAVE
MOVES OFF TO THE EAST. LOWERED THE PROBABILITY OF PRECIPITATION
BASED ON CURRENT RADAR AND THE LATEST HRRR OUTPUT. ALSO TOOK OUT THE
CHANCE OF THUNDER OUT AS NONE HAS DEVELOPED ALL DAY AND THE MODELS
ARE NOT SUPPORTING THEIR DEVELOPMENT IN THE NEAR TERM. THE ONLY
THUNDER IS CURRENTLY OVER CENTRAL TENNESSEE. A WEAK FRONT IS STILL
QUASI STATIONARY OVER THE AREA. EXPECT TO SEE SOME FAIRLY DENSE FOG
TONIGHT...ESPECIALLY IN THE VALLEYS.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 255 PM EDT MON AUG 18 2014
THE LOW PRESSURE SYSTEM THAT BROUGHT THE WIDESPREAD RAIN LAST NIGHT
INTO THIS MORNING HAS MOVED INTO WV...TAKING THE DEEPER MOISTURE AND
BETTER LIFT WITH IT. A WEST EAST ORIENTED QUASI STATIONARY FRONT
REMAINS ACROSS KENTUCKY...AND SCATTERED LIGHT SHOWERS CONTINUE TO
MOVE FROM WEST TO EAST ACROSS THE AREA. ANOTHER WAVE OF LOW PRESSURE
EVIDENT ON SATELLITE AND RADAR IMAGERY WAS MOVING EAST ALONG THE TN MS
BORDER. THIS FEATURE...ALONG WITH THE BOUNDARY ACROSS KY WILL
NECESSITATE CONTINUING WITH A CHANCE OF RAIN OVERNIGHT. HOWEVER THE
BEST RAIN AND THUNDER CHANCES SHOULD BE SOUTH OF KY TONIGHT.
WITH VERY MOIST BOUNDARY LAYER AND SOME BREAKS EXPECTED IN THE CLOUDS
THIS EVENING...FOG AND LOW CLOUDS ARE EXPECTED TO DEVELOP DURING THE
NIGHT AND LINGER INTO THE MORNING ON TUESDAY. WILL INCLUDE FOG IN THE
FORECAST FOR TONIGHT. ON TUESDAY THE NEXT SHORT WAVE IN THIS VERY
ACTIVE PATTERN WILL BE PUSHING INTO THE WESTERN GREAT LAKES REGION. AT
THE SURFACE A VERY MOIST AND WARM AIR MASS WILL REMAIN IN PLACE
ACROSS EASTERN KY ON TUESDAY...WHILE A COLD FRONT DROPS SOUTHEAST ACROSS IL
AND INDIANA. THUNDERSTORMS ARE EXPECTED TO DEVELOP AHEAD OF THIS
FRONT TUESDAY AFTERNOON. CURRENT THINKING IS THAT SHOWERS AND
THUNDERSTORMS THAT DEVELOP TO OUR NORTHWEST ON TUESDAY WILL MOVE INTO
OUR AREA TUESDAY NIGHT. WITH THIS THOUGHT IN MIND WILL INTRODUCE
LIKELY PROBABILITIES FOR SHOWERS AND THUNDERSTORMS IN THE NORTHERN
PART OF OUR FORECAST AREA TUESDAY NIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 255 PM EDT MON AUG 18 2014
MODELS CONTINUE TO DISPLAY GOOD AGREEMENT THROUGH THE EXTENDED.
UPPER/MID LEVEL GREAT LAKES LOW WILL MAKE A BEE LINE TO THE MID
ATLANTIC COAST BY FRIDAY. MEANWHILE BURGEONING RIDGE TO OUR WEST
WILL EXERT ITS INFLUENCE FROM THE SOUTHERN PLAINS/MISSISSIPPI RIVER
DELTA NORTHWARD INTO THE UPPER MIDWEST. GREAT LAKES LOW WILL PASS TO
OUR NORTHEAST DURING ITS MARCH TO THE COAST AND DRAG A SURFACE
FRONTAL BOUNDARY ACROSS THE CENTER OF THE OHIO VALLEY REGION.
SHARPENING UPPER LEVEL RIDGE AXIS WILL SHIFT SOUTHEASTWARD OVER OUR
AREA TOWARDS THE END OF THE EXTENDED AS ENERGY ROUNDS ITS TOP ACROSS
THE NORTHERN TIER. DESPITE THE BUILDING RIDGE ALOFT...THE BY THEN
QUASI-STATIONARY SFC FRONTAL BOUNDARY WILL REMAIN IN OUR VICINITY AS
IT BECOMES ORIENTED PARALLEL TO THE UPPER LEVEL FLOW PATTERN. THUS
WITH LITTLE TO NO FORCING AT THE MID AND UPPER LEVELS...THIS
BOUNDARY WILL REMAIN CLOSE ENOUGH TO OUR AREA TO SERVE AS A FOCUS
FOR ADDITIONAL SHOWER AND THUNDERSTORM ACTIVITY THROUGH THE LATTER
HALF OF THE EXTENDED PERIOD. THE MAINLY DIURNAL SHOWER AND
THUNDERSTORM ACTIVITY MAY BE AUGMENTED BY ONE OR TWO ORGANIZED
THUNDERSTORM COMPLEXES DROPPING DOWN FROM THE NORTHWEST ON THE EAST
SIDE OF THE UPPER RIDGE.
FOR SENSIBLE WEATHER...WE WILL SEE THE RETURN OF TRUE SUMMER LIKE
WEATHER AS RIDGING TO OUR SOUTHWEST WILL BE STRONG ENOUGH TO SEND
TEMPERATURES INTO AND ABOVE SEASONABLE NORMS DESPITE THE INCREASED
HUMIDITY. THIS WILL ALSO HELP TO ENHANCE THE DIURNALLY DRIVEN
INSTABILITY ACROSS THE AREA RESULTING IN THE BEST CHANCES OF STORMS
EACH AFTERNOON AND EVENING. THE THREAT OF RAIN DECREASES BY NEXT
WEEKEND AS THE UPPER RIDGE AMPLIFIES AND SHIFTS EASTWARD A BIT...BUT
THE POTENTIAL CAN NOT BE TOTALLY REMOVED. IN ADDITION...SHOULD THE
RIDGE EXERT A STRONGER INFLUENCE BY SHIFTING JUST A BIT MORE EAST WE
MAY BE IN FOR EVEN HOTTER WEATHER BY NEXT WEEKEND. WITH THE 0Z ECMWF
ADVERTISING H850 TEMPS UP AROUND 22C TO 24C...THE POSSIBLY EXISTS
THAT WE MIGHT SEE SOME OF OUR HOTTEST WEATHER OF THE SUMMER THUS
FAR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1239 AM EDT TUE AUG 19 2014
THE MAIN CONCERN FOR THE FIRST 6 HOURS OF THE TAF PERIOD WILL BE LOW
CEILINGS AND FOG ACROSS EASTERN KENTUCKY. PARTLY CLOUD SKIES ALONG
WITH LIGHT WINDS AND PLENTY OF RAINFALL DURING THE PRIOR DAY HAS LEFT
A MOIST AND VERY STABLE BOUNDARY LAYER FOR FOG DEVELOPMENT. A FEW
SHOWERS MAY DEVELOP OVERNIGHT BUT WILL BE ISOLATED. HEADING INTO THE
DAY...SCATTERED SHOWERS AND A FEW THUNDERSTORMS WILL BE POSSIBLE AND
KSYM MAY NEED A VCTS MENTION AS THE BEST CHANCE FOR SHOWERS AND
STORMS WILL BE IN THE NORTH. OTHERWISE...EXPECT LIGHT WINDS AND
DECKS AROUND 5 KFT AFTER THE FOG LIFTS TODAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR KYZ044-
050>052-058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...JJ
SHORT TERM...SBH
LONG TERM...RAY
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
423 AM CDT TUE AUG 19 2014
.DISCUSSION...
THE MORNING WATER VAPOR IMAGERY INDICATES THAT THE MAIN SHORTWAVE
THAT PRODUCED EXTENSIVE CONVECTION JUST 24 HRS AGO OVER SW
AR/EXTREME NRN LA HAS SHIFTED E INTO NRN GA...WITH THE 00Z RAOB
500MB PLOT STILL REVEALING A WEAK SHEAR AXIS THAT EXTENDS FARTHER
W ACROSS NRN MS/N LA AND INTO NE TX. MEANWHILE...MOSAIC RADAR
IMAGERY ALSO INDICATES A WELL-DEFINED MCV SPINNING E OF
SJT...WHICH THE 00Z PROGS HAVE INITILIZED WELL ON AS CONVECTION
CONTINUES TO REGENERATE NEAR AND E OF THE CENTER OVER CNTRL TX.
THIS CONVECTION HAS PRODUCED A THICK AC CANOPY OVER NE TX/EXTREME
NW LA...ALTHOUGH IR IMAGERY DEPICTS WARMING CLOUD TOPS SUGGESTING
A WEAKENING TREND IS ONGOING ATTM. THIS MCV CENTER IS PROGGED TO
DRIFT NNE ACROSS NCNTRL TX TODAY...WHICH COULD MAINTAIN ELEVATED
CONVECTIVE DEBRIS OVER THE NRN HALF OF THE AREA THROUGH AT LEAST
THE FIRST HALF OF THE DAY...BEFORE POSSIBLY THINNING THIS
AFTERNOON. MY FORECAST MAX TEMPS MAY BE A BIT HIGH TODAY
ESPECIALLY IF THIS DEBRIS FIELD HANGS TOUGH TODAY...BUT HAVE
PLAYED THE PESSIMIST WITH IT THINNING LATER TODAY...ESPECIALLY AS
09Z TEMPS REMAIN IN THE MID/UPPER 70S. WHILE THE SHORT TERM PROGS
DO SUGGEST A WEAK SEABREEZE AFFECTING DEEP E TX/SRN SECTIONS OF
NCNTRL LA THIS AFTERNOON...ONLY THE LATEST HRRR RUN DEPICTS AT
LEAST ISOLATED CONVECTION DEVELOPING THIS AFTERNOON ALONG THE
RESIDUAL SHEAR AXIS...WHICH IS STILL WEAKLY REFLECTED IN THE OTHER
SHORT RANGE PROGS. IN ADDITION...THE 09Z SFC ANALYSIS INDICATES A
DISTINCT W-E GRADIENT IN SFC THETA-E FROM NEAR OSA TO ALONG THE
AR/LA LINE...INDICATIVE OF THE WEAK COLD POOL FROM CONVECTION THAT
AFFECTED THESE AREAS MONDAY AFTERNOON/EVENING. GIVEN THESE WEAK
SFC AND UPPER AIR FORCING MECHINISMS...AND THE FACT THAT THE CNTRL
TX MCV IS PROGGED TO LIFT NNE ACROSS THE STATE TODAY...HAVE
EXPANDED SLIGHT CHANCE POPS TO COVER MUCH OF THE REGION THIS
AFTERNOON...AND DID CARRY THEM THROUGH THE EVENING BEFORE THEY
DIMINISH WITH THE STABILIZING BNDRY LYR.
THE SHEAR AXIS IS EXPECTED TO WASH OUT OVERNIGHT WITH THE MCV
OPENING UP LATE...AS THE WRN ATLANTIC/CNTRL GULF OF MX UPPER RIDGE
EXPECTED TO BRIDGE NWD INTO THE LOWER MS VALLEY WEDNESDAY. STILL
SHOULD SEE A WEAK SEABREEZE AFFECTING THE SRN ZONES WEDNESDAY AND
THURSDAY AFTERNOONS/EARLY EVENINGS...BEFORE THE UPPER RIDGE CENTER
BECOMES ESTABLISHED OVER THE MID-SOUTH/LOWER MS VALLEY FRIDAY.
BOTH THE GFS AND ECMWF AMPLIFY THE RIDGE FARTHER N ACROSS THE SRN
PLAINS/MS VALLEY FRIDAY...AND KEEPS IT PERSISTENT THROUGH THE
WEEKEND INTO EARLY NEXT WEEK. INCREASED SUBSIDENCE WILL RESULT IN
MAX TEMPS CLIMBS INTO THE UPPER 90S AREAWIDE...WITH EVEN SOME
TRIPLE DIGITS POSSIBLE OVER SOME AREAS THIS WEEKEND/EARLY NEXT
WEEK. THE MEDIUM RANGE PROGS DO BEGIN TO SLOWLY NUDGE THE RIDGE E
INTO THE SE STATES BY TUESDAY/WEDNESDAY...WITH WEAKNESSES RIDING W
BENEATH THE RIDGE ACROSS S LA/SRN MS AS EARLY AS MONDAY.
THUS...ISOLATED CONVECTION WILL BE POSSIBLE OVER NCNTRL LA MONDAY
AFTERNOON...BEFORE SPREADING FARTHER WNW TO ENCOMPASS MUCH OF THE
REGION BY THE END OF THE EXTENDED.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 95 75 96 76 97 / 10 10 5 5 5
MLU 95 73 96 74 97 / 20 20 5 5 5
DEQ 94 71 94 71 95 / 20 20 0 0 0
TXK 94 74 96 74 96 / 20 20 0 0 0
ELD 95 72 96 74 97 / 20 20 0 0 0
TYR 94 75 96 76 97 / 10 20 5 5 5
GGG 95 74 96 75 97 / 10 10 5 5 5
LFK 96 75 96 76 97 / 20 20 20 20 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
15
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
122 AM EDT TUE AUG 19 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 322 PM EDT MON AUG 18 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A FAIRLY STRONG
SHRTWV OVER THE NRN PLAINS DRIFTING TO THE ESE INTO NW MN DOWNSTREAM
OF A RDG OVER WRN CANADA AND TOWARD A SHRTWV RDG STRETCHING FM
HUDSON BAY TOWARD THE SE GREAT LKS ON THE WRN FLANK OF A DEEP TROF
OVER THE CNDN MARITIMES. THERE IS ALSO A WEAKER SHRTWV MOVING E THRU
THE UPR LKS AHEAD OF THE MAIN DISTURBANCE APRCHG MN...AND THIS
FEATURE ALONG WITH ACCOMPANING AXIS OF GREATER H85 THETA E ADVCTN/A
FAIRLY MOIST 12Z GRB RAOB /KINX 36C AND PWAT 1.64 INCH OR ALMOST 175
PERCENT OF NORMAL/ HAS BEEN THE FOCUS FOR SOME SCT-NMRS SHOWERS
MAINLY OVER CENTRAL CWA TODAY. BUT QUITE A CONTRAST JUST TO THE E
WITH THE 12Z APX RAOB DISPLAYING A MUCH DRIER PROFILE...KINX -12C
AND PWAT 0.66 INCH OR ONLY 75 PERCENT OF NORMAL. THIS DRIER/STABLE
AIRMASS HAS SLOWED THE PROGRESS OF THE SHOWERS INTO THE AREA ARND
NEWBERRY SO FAR. THERE ARE MORE NMRS SHOWERS/A FEW TS MOVING INTO
WRN LK SUP CLOSER TO THE TRAILING SHRTWV. OTRW...QUITE A BIT OF CLD
COVER HAS LIMITED THE DIURNAL RISE OF TEMP AND DESTABILIZATION IN
THE ABSENCE OF STEEP LAPSE RATES SHOWN ON EVEN THE MOISTER 12Z GRB
RAOB...SO TS HAVE BEEN FEW AND FAR BTWN. BUT SOME HEAVY RAINS HAVE
FALLEN UNDER THE STRONGER SHOWERS WITH THE HIER PWAT/DEEPER MSTR.
MAIN FCST CONCERNS IN THE SHORT TERM ARE POPS RELATED TO THE TWO
DISTURBANCES THAT ARE MOVING THRU MN/THE UPR LKS.
LATE TODAY/TNGT...AS TROF OVER QUEBEC SLOWLY EXITS TO THE E...LEAD
SHRTWV MOVING THRU THE UPR LKS/ACCOMPANYING AXIS OF H85 THETA E
ADVCTN WL DRIFT TO THE E AND BRING SOME SHOWERS TO THE FAR ERN CWA
BY 00Z. ALTHOUGH THERE MAY BE ONLY SOME ISOLD/SCT SHOWERS OVER WRN
UPR MI WITH SOME H7-5 DRYING MOST OF TODAY...MORE NMRS SHOWERS/SOME
TS ASSOCIATED WITH THE STRONGER SHRTWV MOVING INTO MN WL ARRIVE OVER
THE FAR W ARND 00Z TOWARD AREA WHERE THE 12Z NAM/REGIONAL CNDN MODEL
SHOW HIER MUCAPE UP TO ABOUT 750 J/KG NEAR IWD. BUT SINCE THE MN
SHRTWV WL BE TENDING TO DIG ESEWD THRU THE NGT...THE 12Z NAM/
REGIONAL CNDN MODEL INDICATE THE MORE NMRS SHOWERS WL IMPACT WI
CLOSER TO MORE VIGOROUS H85-7 MSTR CNVGC/HIER MUCAPE IN THE 500-
1000J/KG THAT WL BE CONFINED TO WI. SO WL MAINTAIN THE HIEST LIKELY
POPS TOWARD THE WI BORDER... ALONG WITH THE TS CHANCES PER ABSENCE
OF FCST MUCAPE AOA 200 J/KG FARTHER N. BUT DEEP LYR QVECTOR CNVGC/
DEEP SATURATION ON FCST SDNGS ON THE CYC SIDE OF SHRTWV TRACK
JUSTIFIES AT LEAST 50-60 POPS OVER THE ENTIRE CWA EVEN IF THE BETTER
FORCING/INSTABILITY HOLD TO THE SW. EXPECT LTL DIURNAL TEMP DROP
WITH LOTS OF CLDS/LINGERING HIER PWAT IN THE 1.50-1.75 RANGE. ADDED
SOME PATCHY FOG...ESPECIALLY IN AREAS OVER THE CENTRAL THAT WL
EXPERIENCE UPSLOPE SE FLOW.
TUE...EXPECT CONTINUED SCT-NMRS SHOWERS AND A FEW TS AS THE SHRTWV/
SFC LO REFLECTION SLIDE ESEWD THRU NRN WI AND MAINTAINS DEEP MSTR...
CYC FLOW AND DEEP LYR QVECTOR CNVGC OVER UPR MI. FCST WL SHOW
DIMINISHING POPS IN THE AFTN OVER THE W WITH PASSAGE OF SHRTWV TO
THE E AND ARRIVAL OF SOME DNVA/DEEP LYR QVECTOR DVGC AFT 18Z. FOG IN
THE MRNG OVER MAINLY THE CENTRAL ZNS WL DSPT SLOWLY WITH DIURNAL
HEATING LIMITED BY EXTENSIVE CLD COVER.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 431 PM EDT MON AUG 18 2014
THE 500MB LOW CENTERED OVER UPPER MI AND LAKE SUPERIOR AT 00Z
WEDNESDAY WILL SHIFT ACROSS LAKE HURON WEDNESDAY NIGHT/THURSDAY
MORNING WITH A BRIEF RIDGE BUILDING ACROSS UPPER MI THURSDAY. THE
APEX OF THE RIDGE WILL SHIFT JUST TO OUR E THURSDAY NIGHT. A SIZABLE
TROUGH SET UP FROM FROM W AND CENTRAL CANADA THROUGH THE ENTIRE W
U.S. WEDNESDAY WILL SLOWLY SHIFT THE N CENTRAL U.S. FOR THE
WEEKEND...AND UPPER GREAT LAKES SUNDAY NIGHT/MONDAY.
AS FOR THE SFC FEATURES AND WX...THE EXITING SFC LOW OVER N LAKE MI
AT 00Z WEDNESDAY WILL LINGER THROUGH THE NIGHT BEFORE SHIFTING TO
LOWER MI THROUGH THE DAY WEDNESDAY. WITH WRAP AROUND/UPSLOPE
MOISTURE ACROSS THE AREA...EXPECT LIGHT SHOWERS TO LINGER THROUGH
MID DAY AT LEAST. THE BEST CHANCE OF THUNDERSTORMS WILL SINK SE WITH
THE SFC LOW.
IT LOOKS LIKE THE ONLY PERIOD OF MAINLY DRY WEATHER WILL BE LATE
WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING...DESPITE THE 500MB
RIDGE OVERHEAD THURSDAY THROUGH FRIDAY. THE LARGE HIGH PRESSURE OVER
QUEBEC...WITH A RIDGE EXTENDING OVER THE UPPER GREAT LAKES WILL EXIT
E ON FRIDAY. THERE STILL LOOKS TO BE PLENTY OF INCONSISTENCIES FOR
FRIDAY AFTERNOON ON. WILL CONTINUE TO RUN WITH A GENERAL CONSENSUS
FOR THIS PERIOD...WITH HAS AN ELONGATED SFC LOW FROM HUDSON BAY
THROUGH MN AND THE CENTRAL PLAINS AT 00Z SUNDAY. THE LOW WILL SLOWLY
SHIFT TO ONTARIO/FAR W LAKE SUPERIOR SATURDAY. THIS WOULD BRING WAA
TO THE AREA WITH HIGH TEMPS RETURNING TO NEAR NORMAL READINGS FRIDAY
AND SATURDAY. THE SFC TROUGH SHOULD BE OVER THE CWA SATURDAY
NIGHT/SUNDAY MORNING. HAVE SLOWLY DIMINISHING POPS FOR SUNDAY AND
MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 122 AM EDT TUE AUG 19 2014
ALTHOUGH THE SPECIFICS REMAIN UNCERTAIN...LIFR TO VLIFR CONDITIONS
SHOULD PREVAIL AT KCMX/KSAW THRU AT LEAST THE MORNING HRS UNDER
LIGHT UPSLOPE FLOW/DEEP MOISTURE AND SCT TO AT TIMES NMRS SHRA OVER
UPPER MI ASSOCIATED WITH DISTURBANCE MOVING SLOWLY ESEWD FROM MN. AT
KIWD...IFR CONDITIONS WILL FALL TO LIFR AND POTENTIALLY VLIFR AS
LIGHT UPSLOPE NORTHERLY WIND DEVELOPS LATER IN THE NIGHT. IFR
CONDITIONS SHOULD BE THE RULE THIS AFTN AT ALL TERMINALS...THOUGH
LOW MVFR CONDITIONS MAY OCCUR AT TIMES. ALL TERMINALS WILL FALL BACK
TO LIFR TONIGHT AS ABUNDANT MOISTURE LINGERS ON THE BACKSIDE OF
DISTURBANCE MOVING ACROSS THE UPPER LAKES.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 322 PM EDT MON AUG 18 2014
ADDED SOME FOG TO THE FORECAST THRU MUCH OF TUE OVER MAINLY THE
CENTRAL LAKE GIVEN ARRIVAL OF DEEPER MOISTURE AND EXPECTED AREA OF
LOWER TEMPERATURES NEAR THE LINGERING COOLEST DEEPER WATER.
OTHERWISE... EXPECT WINDS UNDER 20 KTS OVER THE NEXT WEEK AS A
RELATIVELY WEAK PRESSURE GRADIENT DOMINATES THE UPPER GREAT LAKES
ABOVE THE CHILLY WATERS OF LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1234 AM CDT TUE AUG 19 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 341 PM CDT MON AUG 18 2014
THE MAIN FORECAST ISSUE WILL BE THE POSSIBILITY OF SOME
THUNDERSTORM ACTIVITY IN THE FAR SOUTHERN CWA OVERNIGHT.
WEST NORTHWEST FLOW ALOFT IS FAIRLY WEAK AND A NEARLY STALLED
BOUNDARY ACROSS THE CWA CONTINUES TO DRIFT SOUTH TODAY. LITTLE IF
ANY DEVELOPMENT SHOULD DEVELOP ALONG THIS BOUNDARY TODAY INTO THIS
EVENING AS A FAIRLY HEALTHY CAP KEEPS THINGS QUIET...DESPITE
MODERATE INSTABILITY IN THE 1500 TO 2000 J/KG RANGE FOR CONVECTIVE
AVAILABLE POTENTIAL ENERGY. SOME SMALL POP-UPS ARE SHOWING UP JUST
NORTH OF THE CWA...BUT THERE SHOULD BE ENOUGH OF A CAP TO TAMP
MUCH FURTHER DEVELOPMENT IN THE NORTH.
LATER ON TONIGHT...A HEALTHY 40 TO 45 KT JET WILL DEVELOP OVER
KANSAS AND WILL CURVE EAST...MOSTLY LIKELY OVER NORTH CENTRAL
KANSAS. THIS WILL SET THE STAGE FOR SOME POTENTIAL LOW-LEVEL
CONVERGENCE ACROSS OUR SOUTHERN CWA IN NORTH CENTRAL KANSAS AND
FAR SOUTHERN NEBRASKA NEAR THE AFOREMENTIONED SURFACE BOUNDARY.
THIS COULD BE JUST ENOUGH SUPPORT FOR SOME SMALL HAIL AND GUSTY
WIND IN OUR FAR SOUTH AS WELL. THE HRRR IS TRENDING STRONGER WITH
SOME DEVELOPMENT OVER THE HIGH PLAINS THIS AFTERNOON...SUPPORTED
BY ANOTHER LOW-AMPLITUDE SHORTWAVE TROUGH. THIS COULD BE ENHANCED
BY THE DEVELOPING LOW-LEVEL JET IN KANSAS AS THIS POTENTIAL
CONVECTION HEADS SOUTH. THE NAM HAS BEEN ADVERTISING SOME ACTIVITY
IN THIS VICINITY FOR THE PAST COUPLE OF DAYS. THE PRUDENT ACTION
WOULD BE TO PUT A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS BACK
INTO THE FORECAST IN OUR SOUTH. OUR CHANCES OF RAIN ARE LARGELY
DEPENDENT ON INITIAL CONVECTION IN THE HIGH PLAINS WITHIN THE
STRONGLY UNSTABLE...YET STILL CAPPED ENVIRONMENT TO THE WEST AS
THE AFOREMENTIONED TROUGH ENTERS THE CENTRAL PLAINS. THE SREF
SOLUTIONS ARE ALSO COMING IN WITH STRONGER SIGNALS TOWARD
CONVECTION IN OUR SOUTH AS WELL.
FOR TUESDAY...KEEPING IT QUIET WITH THE THINKING THAT THERE
SHOULD BE ENOUGH OF A CAP FROM PRECLUDING DEVELOPMENT UNTIL THE
EVENING HOURS. HIGH PLAINS CONVECTION COULD DEVELOP DURING THE
DAY...BUT SHOULD HOLD OFF MAKING IT HERE UNTIL EVENING...WHEN A
LOW-LEVEL JET AXIS DEVELOPS JUST TO THE WEST OF THE CWA.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 341 PM CDT MON AUG 18 2014
GUIDANCE SUGGESTS UPPER TROPOSPHERIC RIDGING WILL EXIST OVER THE
CENTRAL CONUS TO START THE LONG TERM FORECAST PERIOD. THE RIDGE
AXIS IS EXPECTED TO SHIFT EAST SOMEWHAT BY THURSDAY OR FRIDAY
HOWEVER...ALLOWING FOR MORE OF A SOUTHWESTERLY UPPER TROPOSPHERIC
FLOW OVER OUR AREA LATE THIS WEEK INTO EARLY NEXT WEEK.
THE AXIS OF A 35-40KT LOWER TROPOSPHERIC JET STREAK...JUST ABOVE
THE BOUNDARY LAYER...IS EXPECTED DEVELOP FROM WESTERN KANSAS INTO
SOUTH CENTRAL NEBRASKA TUESDAY NIGHT INTO EARLY WEDNESDAY MORNING.
THERMAL ADVECTION ALONG THIS AXIS APPEARS AS THOUGH IT WILL BE
SUFFICIENT FOR PRECIPITATION PRODUCTION ACROSS NORTHEASTERN
PORTIONS OF OUR CWA...A SOLUTION SUPPORTED BY QPF FIELDS FROM THE
NAM...OPERATIONAL GFS AND EC. WENT AHEAD WITH 20-30% POPS ACROSS
OUR NORTHEAST TUESDAY NIGHT INTO EARLY WEDNESDAY MORNING AS A
RESULT.
ON OVERALL LACK IN OMEGA SHOULD THEN PROVIDE DRY CONDITIONS TO
OUR AREA THROUGH MUCH OF THE DAY WEDNESDAY. BY LATE WEDNESDAY
AFTERNOON HOWEVER...THE NAM AND OPERATIONAL GFS BOTH SUGGEST
CONVECTION WILL INITIATE OVER THE CENTRAL HIGH PLAINS...AND THEN
MOVE EAST INTO OUR AREA WEDNESDAY EVENING AND OVERNIGHT. GIVEN
THIS...WENT AHEAD WITH 20-30% POPS ACROSS MUCH OF THE CWA
WEDNESDAY EVENING AND NIGHT.
ALTHOUGH OMEGA IS EXPECTED TO REMAIN WEAK THROUGH THE DAY
THURSDAY AS WELL...FORECAST PROXIMITY SOUNDINGS FROM ACROSS THE
CWA...PER THE NAM AND OPERATIONAL GFS...SUGGEST A NEARLY DRY
ADIABATIC TEMPERATURE PROFILE WILL BE REALIZED FROM THE SURFACE TO
JUST ABOVE 700MB ACROSS MUCH OF THE CWA...THUS ALLOWING CONVECTIVE
TEMPERATURE READINGS TO BE REACH AND PROVIDING FOR ISOLATED
THUNDERSTORM DEVELOPMENT. THIS IS A SOLUTION ALSO SUPPORTED BY QPF
FIELDS FROM THE NAM...OPERATIONAL GFS AND EC. GIVEN ALL
THIS...WENT AHEAD WITH ~20% POPS ACROSS MUCH OF THE CWA THURSDAY
AFTERNOON AND EVENING.
HEADING INTO THURSDAY NIGHT AND BEYOND...GUIDANCE SUGGESTS
MULTIPLE UPPER TROPOSPHERIC PERTURBATIONS COULD MOVE OVER THE
CENTRAL PLAINS AS THE SOUTHWESTERLY UPPER TROPOSPHERIC FLOW
INTENSIFIES. ALLBLEND RESPONDED BY PROVIDING 20-50% POPS TO MANY
AREAS ACROSS THE CWA THURSDAY NIGHT THROUGH MONDAY...AND THESE
POPS WERE LEFT UNCHANGED FOR THE MOST PART.
FORECAST PROXIMITY SOUNDINGS FROM THE NORTHEASTERN CWA...PER THE
NAM AND OPERATIONAL GFS...SUGGEST STORM-ACCESSIBLE POTENTIAL
ENERGY WILL NOT EXCEED 200-300J/KG TUESDAY NIGHT INTO EARLY
WEDNESDAY MORNING AND THUS...WILL HOLD OFF FROM ANY MENTION OF
SEVERE WEATHER TUESDAY NIGHT INTO EARLY WEDNESDAY MORNING.
CONVECTION ALONG THE CENTRAL HIGH PLAINS WEDNESDAY AFTERNOON AND
EVENING WILL LIKELY HAVE THE CAPABILITY TO BE STRONG...BUT THERE
IS CONSIDERABLE UNCERTAINTY AS TO HOW LONG THIS CONVECTION WILL BE
ABLE TO MAINTAIN ITS INTENSITY AS IT MOVES EAST INTO OUR AREA.
GIVEN THIS UNCERTAINTY...WILL HOLD OFF FROM ANY MENTION OF SEVERE
WEATHER ACROSS OUR AREA WEDNESDAY EVENING AND LET FUTURE SHIFTS
REEVALUATE. BEYOND WEDNESDAY EVENING...AT THIS TIME THERE ARE NO
OVERWHELMING SIGNALS OF A SIGNIFICANT SEVERE WEATHER OUTBREAK.
ALTHOUGH A FEW HIT AND MISS STRONG TO SEVERE STORMS PROBABLY
CANNOT BE RULED OUT...DUE TO THE UNCERTAINTY WILL LEAVE OUT ANY
MENTION OF SEVERE WEATHER WEDNESDAY NIGHT AND BEYOND.
LITTLE CHANGE IN THE LOWER TROPOSPHERIC AIR MASS SHOULD PROMOTE
SIMILAR TEMPERATURE READINGS FROM DAY TO DAY WEDNESDAY THROUGH
SATURDAY...WITH AFTERNOON HIGHS IN THE UPPER 80S AND 90S AND
OVERNIGHT LOWS IN THE 60S AND LOWER 70S EXPECTED FOR THE MOST
PART. BEYOND SATURDAY...GUIDANCE DOES SUGGEST A LOWER TROPOSPHERIC
BAROCLINIC ZONE WILL MOVE ACROSS THE AREA...THUS ALLOWING A COOLER
LOWER TROPOSPHERIC AIR MASS INTO THE REGION. AFTERNOON HIGHS IN
THE UPPER 70S TO MID 80S AND LOWS GENERALLY IN THE 60S ARE
CURRENTLY EXPECTED TO FINISH THE LONG TERM FORECAST PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1230 AM CDT TUE AUG 19 2014
THUNDERSTORMS ARE WELL SOUTH OF THE TAF SITES EARLY THIS MORNING.
MOSTLY CLEAR SKIES ARE EXPECTED THROUGH THE PERIOD. LIGHT WINDS
WILL TURN TO THE SOUTHEAST DURING THE DAY AS A SURFACE HIGH MOVES
OFF TO THE EAST.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...HEINLEIN
LONG TERM...BRYANT
AVIATION...JCB
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1256 AM CDT TUE AUG 19 2014
.UPDATE...
ISSUED AT 1231 AM CDT TUE AUG 19 2014
OUT OF RESPECT FOR THE NAM...WHICH WAS UPGRADED LAST WEEK...AND
THE HIRES ARW...ISOLATED TO SCATTERED THUNDERSTORMS WERE EXPANDED
ON TUESDAY EVENING/NIGHT. THE MAIN FOCUS TONIGHT WILL BE ON
POSSIBLE FOG DEVELOPMENT THIS MORNING ALONG WITH THE POTENTIAL
FOR RAINFALL ON ALREADY SATURATED SOILS TUESDAY NIGHT THROUGH THE
WEEKEND.
UPDATE ISSUED AT 935 PM CDT MON AUG 18 2014
NO SIGNIFICANT UPDATES THIS EVENING. PRECIPITATION HAS ALL BUT
ENDED OVER EASTERN NORTH DAKOTA...THUS CLEAR TO PARTLY CLOUDY
SKIES EXPECTED TONIGHT WITH PATCHY FOG POSSIBLE AFTER MIDNIGHT.
CURRENT FORECAST LOWS IN THE 50S LOOK REASONABLE.
UPDATE ISSUED AT 638 PM CDT MON AUG 18 2014
ISOLATED THUNDERSHOWERS CONTINUE TO DISSIPATE ACROSS EASTERN
PORTIONS OF CENTRAL NORTH DAKOTA. HAVE REMOVED ALL EVENING POPS
EXCEPT FOR JUST A SLIGHT CHANCE FAR EAST THROUGH 9 PM. OTHERWISE
MOSTLY CLEAR SKIES TONIGHT WITH LIGHT WINDS. PREVIOUS FORECAST HAD
A MENTION OF PATCHY FOG AFTER MIDNIGHT...WHICH LOOKS GOOD.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 318 PM CDT MON AUG 18 2014
DIURNAL CONVECTION THROUGH SUNSET THIS EVENING AND FOG TONIGHT
HIGHLIGHT THE SHORT TERM.
DIURNAL SCATTERED CONVECTION IS EXPECTED TO REMAIN FOCUSED ACROSS
THE SOUTH CENTRAL AND JAMES RIVER VALLEY GIVEN RADAR AND SATELLITE
TRENDS THROUGH 1930 UTC...AND THE 16-17 UTC HRRR ITERATIONS.
MODEST INSTABILITY AND WEAK SHEAR ARE EXPECTED TO KEEP STORMS
BELOW SEVERE LIMITS. HOWEVER...THE NON SUPERCELL TORNADO OR
LANDSPOUT PARAMETER HAS A LOCAL MAXIMA ACROSS THE JAMES RIVER
VALLEY INTO THE SOUTHERN RED RIVER VALLEY WITH STEEP LOW LEVEL
LAPSE RATES AND ENVIRONMENTAL VORTICITY. THUS...WOULD NOT BE
SURPRISED BY A FUNNEL CLOUD REPORT.
FOR TONIGHT...WITH WEAK SURFACE HIGH PRESSURE IN PLACE...CLEAR
SKIES...LIGHT WINDS AND PLENTIFUL MOISTURE FROM WEEKEND RAINS...AREAS
OF FOG ARE POSSIBLE ACROSS MUCH OF THE AREA TONIGHT.
TUESDAY WILL BE THE ONLY DRY DAY IN THE FORECAST UNDER SHORTWAVE
RIDGING BEFORE A RETURN TO AN ACTIVE WEATHER PATTERN THROUGH THE
EXTENDED.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 318 PM CDT MON AUG 18 2014
A SLOW MOVING TROUGH EXTENDING FROM THE NORTHWEST TERRITORIES WILL
PRODUCE CHANCES FOR WIDESPREAD SHOWERS/THUNDERSTORMS FROM WEDNESDAY
INTO THE WEEKEND. CHANCES FOR PRECIPITATION WILL CONTINUE THROUGH
THE EXTENDED...AS UNSETTLED SOUTHWESTERLY FLOW REMAINS OVER THE
AREA.
HEAVY RAINFALL IS EXPECTED OVER WESTERN AND CENTRAL PORTIONS OF THE
STATE WEDNESDAY INTO THURSDAY...WITH ADDITIONAL RAINFALL THROUGH THE
WEEKEND. WESTERN AND CENTRAL AREAS HAVE ALREADY BEEN SATURATED WITH
ABUNDANT RAINFALL...FLOODING ISSUES REMAIN A CONCERN.
TEMPERATURES WILL NEAR AVERAGE FOR WEDNESDAY AND THURSDAY. A
COOLER AIRMASS BEGINS MOVING INTO THE AREA BY FRIDAY MORNING...HIGHS
WILL RANGE BETWEEN 10 AND 15 DEGREES BELOW AVERAGE THROUGH THE REST
OF THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1231 AM CDT TUE AUG 19 2014
AREAS OF FOG MAY DEVELOP THIS MORNING AND LAST UNTIL 13Z. KJMS HAS
THE BEST POTENTIAL FOR IFR BECAUSE OF RAINFALL THERE ON
MONDAY...SO VISIBILITY REDUCTIONS HELD TO MVFR AT KDIK/KISN WHERE
SOME REDUCTION HAS ALREADY BEEN OBSERVED. THUNDERSTORMS ARE
POSSIBLE AFTER 00Z AT KISN/KMOT/KDIK.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SCHECK
SHORT TERM...AYD
LONG TERM...AC
AVIATION...SCHECK
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
531 AM EDT TUE AUG 19 2014
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL DEVELOP AHEAD OF A WEAK FRONT WHICH
WILL APPROACH THIS AFTERNOON AND EVENING. THE FRONT WILL STALL
ALONG THE OHIO VALLEY WEDNESDAY...THEN GRADUALLY LIFT NORTHEAST
THROUGH THE END OF THE WEEK. DISTURBANCES TRACKING ALONG THE FRONT
WILL KEEP THE WEATHER UNSETTLED THROUGH AT LEAST FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED TO INCLUDE A DENSE FOG ADVISORY ACROSS THE SOUTHERN HALF
OF THE AREA WHERE THERE ARE QUITE A FEW OBSERVATIONS OF A QUARTER
MILE OR LESS. LIGHT FOG WILL EXIST ELSEWHERE.
PREVIOUS DISCUSSION...
FAIRLY WEAK FLOW PATTERN OVER THE EASTERN CONUS TODAY AS A
MID/UPPER LEVEL TROUGH DIGS INTO THE WESTERN GREAT LAKES. A WEAK
SURFACE BOUNDARY ALONG THE OHIO RIVER WILL LIFT NORTH IN RESPONSE
TO LOW PRESSURE ATTENDANT TO THE MID AND UPPER LEVEL FEATURE. A
FEW RUNS OF THE RAP AND HRRR TRIED TO DEVELOP A FEW SHOWERS WITH
THE BOUNDARY THIS MORNING...BUT HAVE KEPT THE FORECAST DRY BASED
ON LATEST OBSERVATIONS. AS DAYTIME HEATING BUILDS...SOME
CONVECTION MAY START DEVELOPING AROUND THE MIDDAY HOURS...BUT THIS
WILL BE ISOLATED AT BEST. THE MAIN FOCUS WILL BE TO OUR WEST...AS
SHOWERS AND STORMS FIRE ALONG A PREFRONTAL TROUGH. EXACT TIMING IS
STILL IN QUESTION...BUT SOME STORMS COULD ARRIVE IN WEST CENTRAL
OHIO BY LATE AFTERNOON. WILL DISCUSS THESE STORMS FURTHER IN THE
SHORT TERM SECTION. BASED ON THE TEMPERATURE TRENDS FROM
MONDAY...WE COULD WARM PRETTY NICELY WITH A LACK OF PRECIPITATION
DURING PEAK HEATING. WENT A LITTLE ABOVE GUIDANCE FOR MOST... IN
THE MID TO UPPER 80S AND INCREASING DEW POINTS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
AN AREA OF SCATTERED TO NUMEROUS STORMS WILL BE CROSSING THE AREA
DURING THE EVENING HOURS. MODERATE INSTABILITY...LIKELY BETWEEN
1-2K J/KG...WILL HAVE DEVELOPED DURING THE AFTERNOON. RICHER LOW
LEVEL MOISTURE LOOKS LIKE IT WILL STAY TO THE SOUTHWEST OF OUR
AREA. WHILE THERE IS SOME INCREASED MID LEVEL FLOW ASSOCIATED WITH
THE DIGGING TROUGH...THE HIGHEST BULK SHEAR VALUES ARE GENERALLY
TO OUR SOUTHWEST AS WELL. WITH THAT SAID...THERE ARE ENOUGH
INGREDIENTS IN PLACE FOR AT LEAST SOME STRONGER
STORMS...ESPECIALLY WEST OF I-75 WHERE SPC HAS HOISTED A SLIGHT
RISK. A WEAKENING TREND IS EXPECTED THROUGH THE EVENING AS
INSTABILITY IS LOST...BUT THE TIMING WILL BE IMPORTANT TO WHEN
THIS OCCURS. INTERESTINGLY...THE LATEST MODEL RUNS ARE FOCUSING
THE GREATEST COVERAGE NORTH OF THE OHIO RIVER...LIKELY CLOSEST TO
THE STRONGER FORCING...SO ADJUSTED THE POPS ACCORDINGLY. THE NAM
SEEMS A LITTLE TOO BULLISH IN DEVELOPING ADDITIONAL CONVECTION
ALONG THE WEAK SURFACE FRONT. BASED ON DEEP LAYER
MOISTURE...EXPECT A DRYING TREND TOWARD WEDNESDAY MORNING. MUGGY
LOWS IN THE UPPER 60S TO AROUND 70.
FORCING ASSOCIATED WITH THE UPPER LEVEL TROUGH WILL BE PUSHING
EAST ON WEDNESDAY...BUT THERE ARE SOME INDICATIONS THE SURFACE
FRONT COULD REACTIVATE IN CENTRAL OHIO AROUND MIDDAY BEFORE
PUSHING EAST. THE TAIL END OF THE FRONT WILL STALL ACROSS NORTHERN
KENTUCKY...WARRANTING CHANCE POPS THERE AS WELL. HIGH TEMPERATURES
IN THE MID 80S.
FROM WEDNESDAY NIGHT THROUGH FRIDAY...MID AND UPPER LEVEL RIDGING
WILL BEGIN BUILDING ACROSS THE CENTER OF THE COUNTRY AS TROUGHING
DIGS INTO THE PACIFIC NORTHWEST. THIS WILL PLACE THE OHIO VALLEY
UNDER INCREASING NORTHWEST FLOW WITH POTENTIAL FOR SOUTHEASTWARD
DIVING DISTURBANCES. A NW-SE LOW LEVEL BAROCLINIC ZONE WILL
TIGHTEN AS WELL WITH MOISTURE POOLED ALONG IT. THE CHANCE OF
STORMS WILL INCREASE WEDNESDAY NIGHT IN THE TRI STATE
AREA...OVERSPREADING THE REST OF THE REGION ON THURSDAY. FRIDAY
WILL REMAIN UNSETTLED AS THE CORRIDOR OF FORCING MOVES ONLY
SLIGHTLY NORTHEAST IN RESPONSE TO THE BUILDING RIDGE. EXPECT
INCREASINGLY MUGGY CONDITIONS WITH HIGHS GENERALLY IN THE MID TO
UPPER 80S AND LOWS ON EITHER SIDE OF 70.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
MID/UPPER LEVEL RIDGING OVER THE CENTRAL UNITED STATES WILL SHIFT
SLOWLY EAST TOWARD THE LOWER OHIO VALLEY THROUGH THE WEEKEND. PCPN
CHANCES SHOULD THEN BECOME MORE SUPPRESSED AS WE PROGRESS THROUGH
THE WEEKEND AS THE RIDGE BUILDS IN FROM THE SOUTHWEST. SHORT WAVE
ENERGY MOVING ACROSS THE GREAT LAKES WILL BEGIN TO WEAKEN THE
RIDGE FROM THE NORTH LATE IN THE PERIOD...EVENTUALLY HELPING TO
PUSH A COLD FRONT DOWN TOWARD OUR AREA. THIS MAY ALLOW FOR A
CHANCE OF PCPN TOWARD THE END OF THE PERIOD ON MONDAY...BUT GIVEN
THE MODEL DIFFERENCES WITH THE TIMING...WILL MAINTAIN A DRY
FORECAST AT THIS POINT.
TEMPERATURES WILL BE SOMEWHAT DEPENDENT ON THE TIMING AND DEGREE OF
THUNDERSTORM ACTIVITY THROUGH LATE IN THE WEEK. HOWEVER...WITH THE
HIGH BUILDING IN FROM THE SOUTHWEST...GENERALLY EXPECT A GRADUAL
WARMING TREND TO ABOVE NORMAL HIGH TEMPERATURES THROUGH THE WEEKEND.
OVERNIGHT LOWS WILL REMAIN ON THE WARM SIDE TOO WITH LOWS MOSTLY IN
THE UPPER 60S TO AROUND 70 DEGREES.
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
FIRST OF ALL...PARTLY CLOUDY TO MOSTLY CLEAR SKIES OVERNIGHT
ALONG WITH AMPLE LOW LEVEL MOISTURE AND LIGHT TO CALM WINDS WILL
RESULT IN PATCHY TO AREAS OF FOG AT THE TERMINALS. THE WORST
CONDITIONS ARE EXPECTED AT THE SOUTHERN TERMINALS WHERE MOISTURE
IS THE HIGHEST. HAVE IFR CONDITIONS AT KILN...KCVG AND KLUK...WITH
SOME LIFR/VLIFR POSSIBLE AT KILN AND AND KLUK. FOG SHOULD BURN OFF
BY 14Z.
A LOW PRESSURE SYSTEM WILL MOVE EAST ACROSS THE WESTERN GREAT
LAKES TODAY AND TONIGHT. FORECAST MODELS INDICATE THAT A
PREFRONTAL TROF AXIS WILL TRAIL SOUTH FROM THIS LOW AND WILL PUSH
EAST INTO OUR REGION LATE THIS AFTERNOON INTO THE EARLY MORNING
HOURS OF WEDNESDAY. THIS TROF AXIS WILL THEN BE FOLLOWED BY A
WEAK COLD FRONT LATE TONIGHT INTO WEDNESDAY MORNING.
FOR LATER TODAY AND TONIGHT...DAYTIME INSTABILITY AND ENOUGH
SHEAR/CONVERGENCE WITH THE PREFRONTAL TROF AXIS SHOULD BRING AT
LEAST SCATTERED SHOWERS AND THUNDERSTORMS TO THE TERMINALS THIS
EVENING INTO THE EARLY MORNING HOURS OF WEDNESDAY. HAVE PLACED
VCTS/CB DESCRIPTORS AT THE SITES WHEN THIS IS MOST
LIKELY TO OCCUR...BETWEEN 00Z AND 06Z. THE WEAK COLD FRONT WILL
FOLLOW BEHIND THE TROF LATE TONIGHT...BUT IT APPEARS CONVERGENCE
WILL BE WEAKER AND INSTABILITY WILL HAVE WANED SOME...SO COVERAGE
APPEARS LESS WITH THIS BOUNDARY.
OUTLOOK...THUNDERSTORMS POSSIBLE WEDNESDAY THROUGH SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR OHZ070>073-
077>082-088.
KY...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR KYZ089>100.
IN...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR INZ050-058-
059-066-073>075-080.
&&
$$
SYNOPSIS...SNYDER
NEAR TERM...SNYDER
SHORT TERM...SNYDER
LONG TERM...JGL
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
448 AM EDT TUE AUG 19 2014
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL DEVELOP AHEAD OF A WEAK FRONT WHICH
WILL APPROACH THIS AFTERNOON AND EVENING. THE FRONT WILL STALL
ALONG THE OHIO VALLEY WEDNESDAY...THEN GRADUALLY LIFT NORTHEAST
THROUGH THE END OF THE WEEK. DISTURBANCES TRACKING ALONG THE FRONT
WILL KEEP THE WEATHER UNSETTLED THROUGH AT LEAST FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FAIRLY WEAK FLOW PATTERN OVER THE EASTERN CONUS TODAY AS A MID/UPPER
LEVEL TROUGH DIGS INTO THE WESTERN GREAT LAKES. A WEAK SURFACE BOUNDARY
ALONG THE OHIO RIVER WILL LIFT NORTH IN RESPONSE TO LOW PRESSURE
ATTENDANT TO THE MID AND UPPER LEVEL FEATURE. A FEW RUNS OF THE
RAP AND HRRR TRIED TO DEVELOP A FEW SHOWERS WITH THE BOUNDARY THIS
MORNING...BUT HAVE KEPT THE FORECAST DRY BASED ON LATEST
OBSERVATIONS. AS DAYTIME HEATING BUILDS...SOME CONVECTION MAY
START DEVELOPING AROUND THE MIDDAY HOURS...BUT THIS WILL BE
ISOLATED AT BEST. THE MAIN FOCUS WILL BE TO OUR WEST...AS SHOWERS
AND STORMS FIRE ALONG A PREFRONTAL TROUGH. EXACT TIMING IS STILL
IN QUESTION...BUT SOME STORMS COULD ARRIVE IN WEST CENTRAL OHIO BY
LATE AFTERNOON. WILL DISCUSS THESE STORMS FURTHER IN THE SHORT
TERM SECTION. BASED ON THE TEMPERATURE TRENDS FROM MONDAY...WE
COULD WARM PRETTY NICELY WITH A LACK OF PRECIPITATION DURING PEAK
HEATING. WENT A LITTLE ABOVE GUIDANCE FOR MOST... IN THE MID TO
UPPER 80S AND INCREASING DEW POINTS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
AN AREA OF SCATTERED TO NUMEROUS STORMS WILL BE CROSSING THE AREA
DURING THE EVENING HOURS. MODERATE INSTABILITY...LIKELY BETWEEN
1-2K J/KG...WILL HAVE DEVELOPED DURING THE AFTERNOON. RICHER LOW
LEVEL MOISTURE LOOKS LIKE IT WILL STAY TO THE SOUTHWEST OF OUR
AREA. WHILE THERE IS SOME INCREASED MID LEVEL FLOW ASSOCIATED WITH
THE DIGGING TROUGH...THE HIGHEST BULK SHEAR VALUES ARE GENERALLY
TO OUR SOUTHWEST AS WELL. WITH THAT SAID...THERE ARE ENOUGH
INGREDIENTS IN PLACE FOR AT LEAST SOME STRONGER
STORMS...ESPECIALLY WEST OF I-75 WHERE SPC HAS HOISTED A SLIGHT
RISK. A WEAKENING TREND IS EXPECTED THROUGH THE EVENING AS
INSTABILITY IS LOST...BUT THE TIMING WILL BE IMPORTANT TO WHEN
THIS OCCURS. INTERESTINGLY...THE LATEST MODEL RUNS ARE FOCUSING
THE GREATEST COVERAGE NORTH OF THE OHIO RIVER...LIKELY CLOSEST TO
THE STRONGER FORCING...SO ADJUSTED THE POPS ACCORDINGLY. THE NAM
SEEMS A LITTLE TOO BULLISH IN DEVELOPING ADDITIONAL CONVECTION
ALONG THE WEAK SURFACE FRONT. BASED ON DEEP LAYER
MOISTURE...EXPECT A DRYING TREND TOWARD WEDNESDAY MORNING. MUGGY
LOWS IN THE UPPER 60S TO AROUND 70.
FORCING ASSOCIATED WITH THE UPPER LEVEL TROUGH WILL BE PUSHING
EAST ON WEDNESDAY...BUT THERE ARE SOME INDICATIONS THE SURFACE
FRONT COULD REACTIVATE IN CENTRAL OHIO AROUND MIDDAY BEFORE
PUSHING EAST. THE TAIL END OF THE FRONT WILL STALL ACROSS NORTHERN
KENTUCKY...WARRANTING CHANCE POPS THERE AS WELL. HIGH TEMPERATURES
IN THE MID 80S.
FROM WEDNESDAY NIGHT THROUGH FRIDAY...MID AND UPPER LEVEL RIDGING
WILL BEGIN BUILDING ACROSS THE CENTER OF THE COUNTRY AS TROUGHING
DIGS INTO THE PACIFIC NORTHWEST. THIS WILL PLACE THE OHIO VALLEY
UNDER INCREASING NORTHWEST FLOW WITH POTENTIAL FOR SOUTHEASTWARD
DIVING DISTURBANCES. A NW-SE LOW LEVEL BAROCLINIC ZONE WILL
TIGHTEN AS WELL WITH MOISTURE POOLED ALONG IT. THE CHANCE OF
STORMS WILL INCREASE WEDNESDAY NIGHT IN THE TRI STATE
AREA...OVERSPREADING THE REST OF THE REGION ON THURSDAY. FRIDAY
WILL REMAIN UNSETTLED AS THE CORRIDOR OF FORCING MOVES ONLY
SLIGHTLY NORTHEAST IN RESPONSE TO THE BUILDING RIDGE. EXPECT
INCREASINGLY MUGGY CONDITIONS WITH HIGHS GENERALLY IN THE MID TO
UPPER 80S AND LOWS ON EITHER SIDE OF 70.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
MID/UPPER LEVEL RIDGING OVER THE CENTRAL UNITED STATES WILL SHIFT
SLOWLY EAST TOWARD THE LOWER OHIO VALLEY THROUGH THE WEEKEND. PCPN
CHANCES SHOULD THEN BECOME MORE SUPPRESSED AS WE PROGRESS THROUGH
THE WEEKEND AS THE RIDGE BUILDS IN FROM THE SOUTHWEST. SHORT WAVE
ENERGY MOVING ACROSS THE GREAT LAKES WILL BEGIN TO WEAKEN THE
RIDGE FROM THE NORTH LATE IN THE PERIOD...EVENTUALLY HELPING TO
PUSH A COLD FRONT DOWN TOWARD OUR AREA. THIS MAY ALLOW FOR A
CHANCE OF PCPN TOWARD THE END OF THE PERIOD ON MONDAY...BUT GIVEN
THE MODEL DIFFERENCES WITH THE TIMING...WILL MAINTAIN A DRY
FORECAST AT THIS POINT.
TEMPERATURES WILL BE SOMEWHAT DEPENDENT ON THE TIMING AND DEGREE OF
THUNDERSTORM ACTIVITY THROUGH LATE IN THE WEEK. HOWEVER...WITH THE
HIGH BUILDING IN FROM THE SOUTHWEST...GENERALLY EXPECT A GRADUAL
WARMING TREND TO ABOVE NORMAL HIGH TEMPERATURES THROUGH THE WEEKEND.
OVERNIGHT LOWS WILL REMAIN ON THE WARM SIDE TOO WITH LOWS MOSTLY IN
THE UPPER 60S TO AROUND 70 DEGREES.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
FIRST OF ALL...PARTLY CLOUDY TO MOSTLY CLEAR SKIES OVERNIGHT
ALONG WITH AMPLE LOW LEVEL MOISTURE AND LIGHT TO CALM WINDS WILL
RESULT IN PATCHY TO AREAS OF FOG AT THE TERMINALS. THE WORST
CONDITIONS ARE EXPECTED AT THE SOUTHERN TERMINALS WHERE MOISTURE
IS THE HIGHEST. HAVE IFR CONDITIONS AT KILN...KCVG AND KLUK...WITH
SOME LIFR/VLIFR POSSIBLE AT KILN AND AND KLUK. FOG SHOULD BURN OFF
BY 14Z.
A LOW PRESSURE SYSTEM WILL MOVE EAST ACROSS THE WESTERN GREAT
LAKES TODAY AND TONIGHT. FORECAST MODELS INDICATE THAT A
PREFRONTAL TROF AXIS WILL TRAIL SOUTH FROM THIS LOW AND WILL PUSH
EAST INTO OUR REGION LATE THIS AFTERNOON INTO THE EARLY MORNING
HOURS OF WEDNESDAY. THIS TROF AXIS WILL THEN BE FOLLOWED BY A
WEAK COLD FRONT LATE TONIGHT INTO WEDNESDAY MORNING.
FOR LATER TODAY AND TONIGHT...DAYTIME INSTABILITY AND ENOUGH
SHEAR/CONVERGENCE WITH THE PREFRONTAL TROF AXIS SHOULD BRING AT
LEAST SCATTERED SHOWERS AND THUNDERSTORMS TO THE TERMINALS THIS
EVENING INTO THE EARLY MORNING HOURS OF WEDNESDAY. HAVE PLACED
VCTS/CB DESCRIPTORS AT THE SITES WHEN THIS IS MOST
LIKELY TO OCCUR...BETWEEN 00Z AND 06Z. THE WEAK COLD FRONT WILL
FOLLOW BEHIND THE TROF LATE TONIGHT...BUT IT APPEARS CONVERGENCE
WILL BE WEAKER AND INSTABILITY WILL HAVE WANED SOME...SO COVERAGE
APPEARS LESS WITH THIS BOUNDARY.
OUTLOOK...THUNDERSTORMS POSSIBLE WEDNESDAY THROUGH SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...SNYDER
NEAR TERM...SNYDER
SHORT TERM...SNYDER
LONG TERM...JGL
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
152 AM EDT TUE AUG 19 2014
.SYNOPSIS...
LOW PRESSURE OVER SOUTHERN OHIO WILL MOVE EAST TO THE VIRGINIA
COAST BY TUESDAY MORNING. A STATIONARY FRONT ACROSS CENTRAL OHIO
WILL BE DRAWN SOUTH IN THE WAKE OF THE LOW. ANOTHER LOW WILL MOVE
INTO THE WESTERN GREAT LAKES OVERNIGHT AND EXPAND ACROSS THE
CENTRAL LAKES TUESDAY BRINGING THE FRONT BACK NORTH INTO THE AREA
AS A WARM FRONT. THE LOW WILL REMAIN IN THE AREA THROUGH MID WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
OVERNIGHT WE ARE EXPECTING DRY CONDITIONS. NOT SURE WHY HRRR KEEPS
ON AND OFF LIGHT SHRA/SPRINKLES OVER THE EAST THRU THE NIGHT. THIS
AREA IS WHERE THE MODELS HAVE THE DRIEST AIR SO IT DOES NOT SEEM TO
MAKE SENSE...UNLESS ITS TRYING TO INDICATE MID LEVEL ATTEMPTS AT
PRECIP/VIRGA.
MORE CLOUDS ON THE WAY FROM THE WEST OVERNIGHT ASSOCIATED WITH THE
LOW MOVING INTO THE WESTERN LAKES. EXPECTING THOSE AFTER MIDNIGHT IN
THE WEST ALONG WITH A SLIGHT CHANCE OF SHOWERS OR A THUNDERSTORM
TOWARD DAYBREAK. LOWS SHOULD BE IN THE LOWER 60S WITH A FEW UPPER
50S EAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
THE SOUTHERN OHIO LOW WILL HAVE REACHED THE VIRGINIA COAST BY
MORNING WITH THE NEXT LOW MOVING INTO/ THROUGH THE WESTERN LAKES.
THIS LOW WILL DOMINATE THE SHORT TERM PERIOD AS IT ROTATES THROUGH
THE GREAT LAKES REGION THROUGH MID WEEK. ALSO THE FRONT TO OUR
SOUTH WILL BEGIN MOVING NORTHEAST AS A WARM FRONT AS THE LOW
APPROACHES AND BY MORNING IT SHOULD EXTEND FROM NEAR CHICAGO TO
CINCINNATI. FOLLOWED THE SREF FOR PRECIP TIMING TUESDAY WHICH
BRINGS CHANCE POPS INTO THE WEST DURING THE MORNING...INCREASING
TO LIKELY BY MID DAY AS THE REST OF THE AREA INCREASES TO CHANCE
POPS. BY EARLY EVENING SPREAD THE LIKELY POPS FURTHER EAST ACROSS
THE CENTRAL COUNTIES...EVENTUALLY EXPANDING ACROSS THE REMAINDER
OF THE EAST LATE EVENING TO OVERNIGHT. WEDNESDAY MORNING THE UPPER
LOW WILL REMAIN STUCK OVER NRN MI WITH CONTINUED DIVERGENCE ACROSS
NRN OHIO/NWRN PA. AXIS OF DEEPEST MOISTURE WILL BE NEGATIVELY
TILTED FROM THE WESTERN LAKES TO PA AND NY. WILL KEEP HIGHEST POPS
ACROSS NERN OHIO AND NWRN PA WITH DECREASING CHANCES WEST. THE LOW
WILL WEAKEN AND MOVE TO PA/NY THURSDAY AS AN UPPER RIDGE AXIS
BUILDS INTO THE UPPER MIDWEST. STILL WILL LIKELY SEE SHOWERS AND
THUNDERSTORMS DURING THE DAY GIVEN THE CONTINUED MOISTURE AND
DAYTIME HEATING SO WILL CONTINUE WITH CHANCE POPS. TEMPS NEAR
NORMAL.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
UPPER LEVEL LOW MOVES OFF THE EAST COAST ON FRIDAY WITH THE UPPER
LEVEL RIDGE OVER THE MISSISSIPPI VALLEY SLOWLY EXPANDING EASTWARD
OVER THE WEEKEND. FRIDAY LOOKS LIKE A TRANSITION DAY AND COULD BE
ACTIVE WITH SHOWERS AND THUNDERSTORMS AS ENERGY RIDES AROUND THE
BUILDING RIDGE. BOTH THE ECMWF AND GFS TRY TO BUILD A STRONG RIDGE
OVER THE GREAT LAKES THIS WEEKEND AND EXTENDING NORTHEAST INTO
QUEBEC. THIS SHOULD LEAD TO DECREASING CHANCES OF SHOWERS AND
THUNDERSTORMS BOTH SATURDAY AND SUNDAY AS MID LEVELS WARM AND WARM
FRONT SHIFTS NORTH OF THE AREA. MODELS DO INDICATE SOME LINGERING
MOISTURE AND SOMEWHAT OF A BOUNDARY IN PLACE THOUGH SO WILL HOLD
ONTO LOW CHANCES OF SHOWERS AND THUNDERSTORMS IN ALL BUT THE EAST
WHERE A DRIER EASTERLY FLOW ON THE PERIPHERY OF HIGH PRESSURE TO THE
EAST SHOULD LIKELY MAINTAIN DRY CONDITIONS. STILL EXPECT A WARMING
TREND OVER THE WEEKEND BUT HAVE BACKED OFF A FEW DEGREES FOR NOW
WITH UNCERTAINTY IN CLOUD COVER.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
FORECAST THIS MORNING ALL HINGES ON TIMING OF THE THUNDERSTORM
COMPLEX THAT IS CURRENTLY OVER WISCONSIN. POTENTIAL EXISTS THAT
THE BULK OF THE THUNDERSTORM ACTIVITY WILL SCOOT EAST ACROSS
MICHIGAN INTO ONTARIO. SOME INSTABILITY WILL DEVELOP ACROSS
NORTHERN OHIO AND NORTHWEST PENNSYLVANIA AND THIS COULD HELP SOME
OF THE THUNDERSTORM ACTIVITY TO DEVELOP FURTHER SOUTH. WILL
CONTINUE WITH CURRENT FORECAST OF TIMING PRECIPITATION INTO THE
FORECAST AREA DURING THE AFTERNOON AND EVENING FROM THE COMPLEX.
WILL ALSO KEEP A MENTION OF SHOWERS AND THUNDERSTORMS FOR TONIGHT
AS WARM FRONTAL BOUNDARY AND ASSOCIATED MOISTURE MOVE EAST INTO
THE REGION.
OUTLOOK...NON VFR POSSIBLE IN SHOWERS/THUNDERSTORMS THROUGH
FRIDAY.
&&
.MARINE...
LAKE ERIE IS LOCATED BETWEEN HIGH PRESSURE TO THE NORTH AND A WEAK
AREA OF LOW PRESSURE OVER THE OHIO VALLEY. NORTHEAST TO EAST WINDS
HAVE INCREASED TO AROUND 15 KNOTS OR SO ALONG MUCH OF THE SOUTH
SHORE OF THE LAKE...WITH WAVES OF 1 TO 3 FEET. THE HIGH WILL BUILD
TO THE EAST OVERNIGHT AND WINDS WILL DECREASE AS THE GRADIENT
RELAXES...SHIFTING TO EASTERLY AND THEN SOUTHEAST LATE.
AN AREA OF LOW PRESSURE WILL MOVE INTO THE WESTERN GREAT LAKES ON
TUESDAY THEN MOVE ACROSS LAKE ERIE ON WEDNESDAY BRINGING UNSETTLED
WEATHER. WINDS WILL GENERALLY REMAIN 15 KNOTS OR LESS AS THEY SHIFT
AROUND TO THE WEST BEHIND THIS SYSTEM. HIGH PRESSURE WILL RETURN ON
THURSDAY FOLLOWED BY A SLOW MOVING WARM FRONT THAT WILL LIFT NORTH
ACROSS THE LAKE OVER THE WEEKEND.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...ADAMS/TK
SHORT TERM...TK
LONG TERM...KEC
AVIATION...LOMBARDY
MARINE...KEC
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1111 PM MDT MON AUG 18 2014
.UPDATE...
ISSUED AT 806 PM MDT MON AUG 18 2014
00Z KUNR SOUNDING SHOWED A BIT OF MUCAPE. COUPLE OF WEAK
SHORTWAVES OVER SOUTH CENTRAL MT/NORTHWEST WY WILL MOVE EAST
THROUGH THE SOUTHWEST THIRD OF THE CWA OVERNIGHT BRINGING WITH IT
ISOLATED TSRA. LATEST HRRR SEEMS TO PICK UP ON THIS AS WELL AS
CURRENT RADAR TRENDS TO OUR WEST. WILL SPREAD POPS FROM CURRENT
RADAR RETURNS THROUGH SOUTHWEST THIRD OF CWA TO ACCOUNT WITH UPDATE.
&&
.SHORT TERM...THIS EVENING THROUGH TUESDAY NIGHT
ISSUED AT 300 PM MDT MON AUG 18 2014
CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE OVER FAR NORTHERN MN
WITH HIGH PRESSURE OVER CENTRAL MT. UPPER LEVEL ANALYSIS SHOWS
TROF OVER SOUTH CENTRAL CANADA...WITH NORTHWESTERLY FLOW OVER MOST
OF THE NORTHERN HIGH PLAINS. DRIER AIR IS IN PLACE ACROSS THE AREA
FOR TODAY...WITH DEWPOINTS MOSTLY IN THE UPPER 40S AND 50S.
SHOWERS AND STORMS THIS AFTERNOON HAVE STAYED TO THE NORTH AND
SOUTH OF THE CWA...WITH A FEW STRONG STORMS OVER THE NEB PANHANDLE
RIGHT NOW. TEMPS ARE IN THE UPPER 79S TO UPPER 80S WITH BRISK
NORTHWESTERLY WINDS ACROSS MUCH OF THE PLAINS. THESE WINDS WILL
BEGIN TO DIMINISH BY EARLY EVENING.
UNSETTLED WEATHER WILL RETURN LATER ON TUESDAY AND PERSIST AT TIMES
THROUGH THE END OF THE WEEK AS HIGH PRESSURE ALOFT MOVES INTO THE
SOUTHEASTERN CONUS AND A BROAD TROF DEVELOPS OVER THE WESTERN
STATES. DAILY CHANCES FOR SHOWERS AND STORMS CAN BE EXPECTED...
ESPECIALLY DURING THE AFTERNOON AND EVENING HOURS.
FOR TONIGHT...SKIES WILL BE CLEAR TO PARTLY CLOUDY. A WEAK
DISTURBANCE IN NORTHWEST FLOW COULD PRODUCE A FEW SHOWERS AND
POSSIBLY A STORM LATE TONIGHT INTO EARLY TUESDAY OVER THE BLACK
HILLS AREA. WINDS WILL BECOME LIGHT THIS EVENING AND THEN SWITCH TO
THE SOUTHEAST OVERNIGHT INTO TUESDAY MORNING AS HIGH PRESSURE PASSES
OVER AND EVENTUALLY EAST OF THE AREA.
WARMER AIR WILL RETURN ON TUESDAY AS SOUTH-SOUTHEAST WINDS INCREASE.
HIGHS WILL BE IN THE MID 80S TO AROUND 90 DEGREES ACROSS THE
PLAINS...MOSTLY 80S OVER THE BLACK HILLS. A MORE WIDESPREAD CHANCE
FOR STORMS WILL RETURN LATE TUESDAY AND ESPECIALLY TUESDAY NIGHT AS
FLOW ALOFT TURNS SOUTHWESTERLY OVER THE HIGH PLAINS. THE
SOUTH-SOUTHEAST WINDS WILL ALSO BRING LOW LEVEL MOISTURE BACK INTO
THE AREA...WITH INCREASING INSTABILITY INTO TUESDAY NIGHT. WILL
GENERALLY KEEP POPS AS IS LATE TUESDAY INTO TUESDAY NIGHT. THE
THREAT FOR SEVERE STORMS STILL LOOKS RELATIVELY LOW. HOWEVER...WITH
SUFFICIENT INSTABILITY AROUND...ISOLATED STRONG TO MARGINALLY SEVERE
STORMS WITH HAIL AND GUSTY WINDS ARE CERTAINLY POSSIBLE LATE IN THE
AFTERNOON INTO THE EVENING.
&&
.LONG TERM...WEDNESDAY THROUGH MONDAY
ISSUED AT 300 PM MDT MON AUG 18 2014
MEAN WESTERN NOAM TROUGHING WILL PERSIST IN THE PERIOD...WITH
MASSIVE EASTERN NOAM RIDGING ENSUING TOWARD THE END OF THE WEEK.
THIS WILL SUPPORT A LOCAL PATTERN CHANGE AS LOWER HEIGHTS AND MUCH
COOLER TEMPS SPREAD OVER THE NORTHERN PLAINS BY THIS WEEKEND...PER
THE WESTERN CONUS TROUGH PHASING WITH A LONG WAVE NORTHERN STREAM
TROUGH. ACTIVE SW FLOW CAN BE EXPECTED TO SUPPORT NEAR DAILY
CHANCES FOR PRECIP THROUGH THE PERIOD...WITH THE WESTERN CONUS
TROUGH SHIFTING EAST OVER THE NORTHERN PLAINS BY LATE THIS
WEEKEND.
HAVE RETAINED DAILY CHANCES FOR SHRA/TS WITH A WAVERING FRONTAL ZONE
OVER THE REGION THROUGH THUR. COLD FRONT WILL SHIFT SE TROUGH THE
REGION FRIDAY...WITH CAA SPREADING ACROSS THE REGION VIA GUSTY NW
WINDS. CYCLONIC DISTURBED SW FLOW WILL PERSIST THROUGH THE WEEKEND.
HOWEVER...GIVEN SIGNALS FOR THE BEST LSA BEING NW OF THE FA...WITH
MORE DIURNALLY DRIVEN CHANCES FOR CONVECTION...HAVE BIASED POPS MORE
TOWARD CLIMO NUMBERS THIS WEEKEND..ESP GIVEN CONVECTIVE NATURE TO
PRECIP.
AS FOR TEMPS...SEASONAL NUMBERS WILL PERSIST THROUGH THURS...WITH
COOLING CONDITIONS FRI-SUN. TEMPERATURES ARE PROGGED TO BE 5 TO 15
DEGREES BELOW SEASONAL NORMS BY SUNDAY AND MONDAY...ESP HIGH
TEMPERATURES. HAVE CONTINUED TO ADD A NEGATIVE BIAS PER HIGHS
SAT-MONDAY...WITH MANY PLACES LIKELY STRUGGLING TO REACH 70 ACROSS
THE NORTHERN HALF SUNDAY AND MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1109 PM MDT MON AUG 18 2014
MAINLY VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD. A
WARM FRONT WILL SHIFT NORTH TONIGHT AND POSSIBLY SUPPORT ISOLATED
TSRA. ADDITIONAL TSRA WILL DEVELOP LATER TUESDAY AFTERNOON INTO
TUESDAY NIGHT WITH LOCAL MVFR CIGS/VSBYS IN THE STRONGEST STORMS.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...HELGESON
SHORT TERM...26
LONG TERM...JC
AVIATION...HELGESON
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1131 PM CDT MON AUG 18 2014
.DISCUSSION...
UPDATED FOR 06Z AVIATION DISCUSSION
&&
.PREV DISCUSSION... /ISSUED 921 PM CDT MON AUG 18 2014/
UPDATE...
A CLUSTER OF SHOWERS AND THUNDERSTORMS ARE SKIRTING PHILLIPS
COUNTY ARKANSAS AND COAHOMA COUNTY MISSISSIPPI AT THIS TIME.
LATEST HRRR SHOWS THAT THE AREA FROM COAHOMA COUNTY TO MONROE
COUNTY MISSISSIPPI COULD CONTINUE SEE THIS ACTIVITY INTO THE
OVERNIGHT HOURS. OTHERWISE...EXPECT MAINLY DRY CONDITIONS. WILL
ADJUST POPS OTHERWISE REST OF THE FORECAST LOOKS GOOD.
KRM
DISCUSSION... /ISSUED 253 PM CDT MON AUG 18 2014/
SKIES ARE PARTLY CLOUDY OVER MUCH OF THE FORECAST AREA THIS
AFTERNOON WITH TEMPERATURES RANGING FROM THE LOWER 70S TO MID 80S.
SHOWERS AND A FEW THUNDERSTORMS CONTINUE TO MOVE ACROSS PORTIONS
OF THE FORECAST AREA. EARLIER THIS AFTERNOON WE HAD SOME HEAVY
RAINFALL OVER PORTIONS OF WEST TENNESSEE WITH 3 TO 5 INCHES OF
RAIN FALLING IN A FEW LOCATIONS. THE UPPER LEVEL DISTURBANCE WHICH
HELPED PRODUCE ALL THE THUNDERSTORM ACTIVITY WAS MOVING ACROSS
NORTH MISSISSIPPI THIS AFTERNOON. AS THIS DISTURBANCE CONTINUES TO
MOVE EAST INTO NORTH ALABAMA...THUNDERSTORMS WILL DECREASE IN
COVERAGE TONIGHT.
MEANWHILE...A WEAK FRONTAL BOUNDARY WAS LOCATED JUST NORTH OF THE
FORECAST AREA. AS IT BEGIN TO MOVE NORTH TONIGHT...SOME ADDITIONAL
THUNDERSTORMS MAY MOVE INTO NORTHWEST SECTIONS OF THE FORECAST
AREA OVERNIGHT. AS THE FRONT MOVES NORTH TUESDAY...THE CHANCE OF
THUNDERSTORMS WILL BE CONFINED TO MAINLY NORTHERN AND EASTERN
SECTIONS OF THE FORECAST AREA. TEMPERATURES WILL START TO BECOME
QUITE WARM ON TUESDAY WITH HIGHS IN THE LOW TO MID 90S.
BY WEDNESDAY...AN UPPER LEVEL RIDGE WILL START TO BUILD INTO THE
SOUTHEAST AND SOUTH CENTRAL U.S. THIS WILL BRING AN EXTENDED
PERIOD OF DRY WEATHER TO THE FORECAST AREA WITH NO RAIN EXPECTED
FROM WEDNESDAY THROUGH NEXT MONDAY. IN ADDITIONAL...TEMPERATURES
WILL BE AS HOT IF NOT HOTTER THAN WE HAVE SEEN THIS SUMMER WITH
HIGH TEMPERATURES IN THE MID TO UPPER 90S FROM WEDNESDAY THROUGH
NEXT MONDAY. HEAT INDEX VALUES MAY EXCEED 105 AT TIMES DURING THIS
PERIOD SO THERE MAY BE A NEED FOR A HEAT ADVISORY LATER THIS WEEK.
ARS
&&
.AVIATION...
VFR CONDS ACROSS THE REGION ATTM. PATCHY FOG WILL DEVELOP LATER
TONIGHT. LOW CLOUDS ARE POSSIBLE AT KMKL AND KTUP TUESDAY MORNING
THOUGH CONFIDENCE IS TOO LOW FOR A BKN DECK ATTM. UPPER RIDGE WILL
START BUILDING IN ON TUESDAY AND AREAL COVERAGE OF SHRAS/TSRAS
WILL BE TOO LOW TO MENTION VCTS. WINDS WILL BE LIGHT OVERNIGHT AND
WSW 7-10 KTS ON TUESDAY DIMINISHING AFTER SUNSET.
SJM
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1130 PM CDT MON AUG 18 2014
.AVIATION...
/06Z TAFS/
Convective activity has moved out of the area. VFR ceilings will
continue over all terminals through next 24 hours. Isolated
thunderstorms will be possible over the area through the next 24
hours, however the coverage does not warrant their inclusion in the
TAFs at this time. Due to the amount of rainfall that fell over the
southern terminals during the last 24 hours, MVFR visibilities are
likely to develop over the southern terminals before sunrise,
improving to VFR by mid-morning.
&&
.PREV DISCUSSION... /ISSUED 615 PM CDT MON AUG 18 2014/
.AVIATION...
/00Z TAFS/
As of 6 pm, there is an area of widespread rainfall with embedded
thunderstorms south of KABI and KSJT and affecting only the southern
terminals. VFR conditions are expected to continue through the next
24 hours at all terminals. Isolated to scattered thunderstorms are
possible through mid-evening over the southern terminal. Any
thunderstorms that occur will be capable of producing variable and
gusty winds. Thunderstorms are expected to occur again Tuesday
morning, mainly over the southern terminals.
&&
.PREV DISCUSSION... /ISSUED 350 PM CDT MON AUG 18 2014/
.SHORT TERM...
(Tonight and Tuesday)
Low confidence forecast across West Central Texas for the next 24
hours. Remnant Mesoscale Convective Vortex (MCV) continues to
remain nearly stationary across Sterling County early this
afternoon, and buried within a larger scale mid level shear axis
stretching across much of the area. Much like we saw on Sunday, as
the main morning area of showers and storms slowly winds down from
Abilene to Brownwood, more scattered convection is developing
along the periphery of the MCV where better heating is taking
place.
Biggest question in the forecast concerns tonight and Tuesday
rain chances. As the low level jet intensifies towards midnight,
expect to see another round of showers and storms form near the
center of the MCV and along its eastern flank. MCV is definitely
weaker today than it was yesterday, and should continue to slowly
wind down. How strong it remains tonight, where it ends up, and
what kind of storm coverage it can actually generate is highly
uncertain though. Models not a lot of help, with even the TTU WRF
and the HRRR models struggling in this highly mesoscale situation.
At this point, will bump pops to chance for most of the area,
knowing that some areas may miss out and others may see some
decent rainfall. Some of this area has seen rainfall totals in the
1 to 3 inch range, so if the rain can train over these areas, than
a flood threat becomes more pronounced. This will need to be
monitored through tonight.
07
.LONG TERM...
(Tuesday night through next Monday)
A mainly dry forecast expected for the extended period.
By Tuesday evening...the 500mb ridge that is currently centered
near Florida will expand farther west into Texas, pushing the
shear axis over the top of our CWA farther west as well. In
addition, by Tuesday night, 250mph ridging will move in over the
top of the region out of the southwest. These two factors point to
decreasing chances of precipitation overall for the area by
Tuesday night. However, we have left an area of slight chance PoPs
in for Tuesday evening. The combination of the previously
mentioned upper level shear axis and MCV is expected to result in
additional thunderstorm activity tomorrow afternoon. And although
these features are expected to be drifting to the west, there
could still be lingering activity for areas mainly south and west
of a Sterling City to San Angelo to Sonora line.
By Wednesday, upper level ridging will be in place across our
forecast area, effectively ending rain chances through the end of
the forecast period, and allowing temperatures to remain warm in
the mid to upper 90s for highs, and generally lower to mid 70s for
lows.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 72 94 71 97 74 / 30 30 5 5 5
San Angelo 71 93 72 95 74 / 30 30 10 5 5
Junction 73 92 73 93 73 / 30 30 10 5 5
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
411 AM CDT TUE AUG 19 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 411 AM CDT TUE AUG 19 2014
AREAS OF DENSE FOG HAVE DEVELOPED OVER PORTIONS OF CENTRAL WISCONSIN
EARLY THIS MORNING. A DENSE FOG ADVISORY HAS BEEN ISSUED FOR
JACKSON...CLARK...AND TAYLOR COUNTIES WHERE THE VISIBILITY HAS
FALLEN TO 1/4 MILE OR LESS. LOOK FOR THIS FOG TO DISSIPATE BETWEEN 8
AND 9 AM THIS MORNING.
LATEST WATER VAPOR IMAGERY SHOWED A VIGOROUS UPPER LEVEL TROUGH OVER
THE UPPER MISSISSIPPI RIVER VALLEY...PUSHING SOUTHEAST. SHOWERS
AND THUNDERSTORMS HAVE MOVED EAST OF THE FORECAST AREA EARLY THIS
MORNING. THE TROUGH WILL CONTINUE TO SWING ACROSS THE AREA TODAY
AND IS EXPECTED TO GENERATE SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS. NAM FORECAST SOUNDINGS SHOW TALL SKINNY CAPE
PROFILES TODAY WITH ONLY 400-500 J/KG OF SBCAPE NOTED. MESOSCALE
MODELS ARE REALLY NOT GENERATING MUCH CONVECTION THIS
AFTERNOON...MAINLY SHOWING SCATTERED SHOWERS FOR LOCATIONS NORTH
OF INTERSTATE 90. AFTER WE DESTABILIZE LATE THIS MORNING INTO THIS
AFTERNOON WE SHOULD SEE THE SCATTERED SHOWERS AND ISOLATED STORMS
DEVELOP. THIS ACTIVITY WILL THEN TAPER OFF LATE THIS AFTERNOON
INTO THIS EVENING WITH THE LOSS OF DAYTIME HEATING. PLAN ON HIGHS
TODAY RANGING FROM THE LOWER 70S OVER NORTH CENTRAL WISCONSIN TO
THE UPPER 70S ACROSS NORTHEAST IOWA. FOCUS TURNS TO DENSE FOG
POTENTIAL LATE TONIGHT INTO WEDNESDAY MORNING...ESPECIALLY ALONG
VALLEY LOCATIONS. SURFACE HIGH PRESSURE SETTLES OVER THE FORECAST
AREA LATE TONIGHT SETTING THE STAGE FOR LIGHT WINDS FROM THE
SURFACE THROUGH 4 KFT. WITH SKIES BECOMING MOSTLY CLEAR AND DEW
POINTS IN THE UPPER 50S TO LOWER 60S WE SHOULD SEE AREAS OF DENSE
FOG DEVELOP. ALSO...THE NAM FORECAST SOUNDING AT KLSE LOOKS VERY
FAVORABLE FOR A VALLEY FOG EVENT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 411 AM CDT TUE AUG 19 2014
AFTER SOME MORNING FOG...PARTLY TO MOSTLY SUNNY SKIES WILL BE THE
RULE ACROSS THE AREA ON WEDNESDAY AS LOW PRESSURE LIFTS NORTH OUT
OF THE CENTRAL PLAINS. THE LOW WILL PUSH A WARM FRONT INTO THE
FORECAST AREA WEDNESDAY NIGHT INTO THURSDAY MORNING...BRINGING A
VERY JUICY AIRMASS INTO THE REGION. PRECIPITABLE WATER VALUES
INCREASE TO 1.8 TO 2.1 INCHES AND WARM CLOUD DEPTH TO 4.4 KM. THE
STORMS DURING THIS TIMEFRAME. A BAND OF SHOWERS AND THUNDERSTORMS
LOOKS TO LIFT NORTHEAST ACROSS THE FORECAST AREA FROM LATE
WEDNESDAY NIGHT INTO THURSDAY MORNING. THE THUNDERSTORMS WILL BE
VERY EFFICIENT RAIN PRODUCERS AND COULD DROP 1 TO 2 INCHES OF
RAINFALL IN A SHORT AMOUNT OF TIME. THE WHOLE SYSTEM IS
PROGRESSIVE SO THIS SHOULD LIMIT FLOODING CONCERNS BUT GIVEN THE
AIRMASS CANNOT RULE OUT NEEDING SOME HYDROLOGY HEADLINES WEDNESDAY
NIGHT INTO TUESDAY MORNING. THE SHOWERS AND STORMS SHOULD LIFT
NORTHEAST THROUGH THE DAY ON THURSDAY LEAVING A VERY HUMID AIRMASS
ACROSS THE FORECAST AREA IN THE WAKE OF THIS ACTIVITY.
BEYOND THURSDAY THE FORECAST BECOMES CHALLENGING WITH MODELS IN
DISAGREEMENT ON HOW MUCH RIDGING BUILDS INTO THE FORECAST AREA.
THE ECMWF IS THE MOST AGGRESSIVE AND BUILDS HEAT ACROSS THE AREA
GOING INTO THIS WEEKEND. THE GFS KEEPS THE WARM FRONT LINGERING
OVER THE FORECAST AREA ON FRIDAY WITH CONTINUE CHANCES FOR HEAVY
RAINFALL. A HOT AIRMASS IS FOCUSED JUST SOUTH OF THE AREA GOING
INTO THIS WEEKEND AND IT WOULD TAKE MUCH TO GET THE STEAMY AIR
INTO NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN SO WILL HAVE TO
KEEP A VERY CLOSE EYE ON HOW MUCH RIDGING CAN BUILD OVER THE
AREA...AND WHERE THE FRONT SETS UP. CONVECTION WILL HAVE A HUGE
IMPACT ON TEMPERATURES AND THE LOCATION OF THE BOUNDARY. COOLER
AIR THEN LOOKS RETURN EARLY NEXT WEEK AS THE BOUNDARY IS PUSHED
TO THE SOUTH OF THE UPPER MISSISSIPPI RIVER VALLEY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1157 PM CDT MON AUG 18 2014
MAIN AREA OF CONVECTION HAS PASSED BY BOTH TAF SITES. THE WIND
SHIFT HAS YET TO COME THROUGH AND BASED ON THE 19.03Z RAP THIS
SHOULD PASS THROUGH LATE TONIGHT SWINGING THE WINDS AROUND TO THE
WEST AND THEN NORTHWEST. THE RAP BUFKIT SOUNDING ALSO NOW SHOWS
LITTLE POTENTIAL FOR SATURATION TO OCCUR BEHIND THE BOUNDARY
MAKING IT LOOK LESS LIKELY THAT FOG AND LOW LEVEL STRATUS WILL
FORM. GIVEN THAT BOTH SITES DID HAVE RAIN TONIGHT...WILL LEAVE
SOME MVFR VISIBILITIES IN THE FORECASTS IN THE EVENT THAT THE
WINDS DROP OFF SOME BEHIND THE FRONT. WITH ALL THE LOW LEVEL
MOISTURE FROM THE RAIN AND AS SOME HEATING STARTS AFTER
SUNRISE...DO EXPECT TO SEE SOME MVFR CEILINGS FORM BY MID MORNING
AND THE PERSIST INTO THE EARLY AFTERNOON BEFORE THESE LIFT TO VFR.
THESE CEILINGS SHOULD THEN REMAIN THROUGH THE AFTERNOON BEFORE
SCATTERING OUT LATE IN THE AFTERNOON OR EARLY EVENING.
&&
.HYDROLOGY...WEDNESDAY NIGHT INTO THURSDAY
ISSUED AT 411 AM CDT TUE AUG 19 2014
THERE IS THE POTENTIAL FOR THUNDERSTORMS WITH HEAVY RAINFALL
WEDNESDAY NIGHT INTO THURSDAY MORNING. THESE STORMS COULD PRODUCE 1
TO 2 INCHES OF RAINFALL WITH LOCALLY HIGHER AMOUNTS POSSIBLE. THIS
RAINFALL COMBINED WITH RECENT HEAVY RAINS ACROSS PORTIONS OF THE
FORECAST AREA COULD LEAD TO FLOODING CONCERNS. A FLASH FLOOD WATCH
MAY BE NEEDED WEDNESDAY NIGHT INTO THURSDAY MORNING ONCE CONFIDENCE
INCREASES ON EXACTLY WHERE THE HEAVIER RAINFALL WILL OCCUR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR WIZ017-029-
034.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...04
HYDROLOGY...WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1157 PM CDT MON AUG 18 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 315 PM CDT MON AUG 18 2014
FORECAST FOCUS IS ON RAIN TONIGHT AS UPPER SHORT WAVE PASSES
THROUGH THE REGION WITH A WARM AND HUMID AIRMASS IN PLACE. A
CLOSED LOW CUTS OFF OVER THE GREAT LAKES AS THIS WAVE ROUNDS THE
BASE OF THE LONG WAVE TROUGH. WITH WEAKER IMPULSES CIRCULATING
AROUND THE LOW...RAIN CHANCES LINGER INTO TUESDAY AS WELL.
19Z MESOANALYSIS SHOWS UPPER WAVE SPINNING INTO NORTHWEST MN...
HEADING SOUTHEAST. PLUME OF 70+ LOW LEVEL DEWPOINTS FROM EASTERN
IA UP INTO WESTERN WI AHEAD OF THE APPROACHING WAVE. ACTIVE
CONVECTION ONGOING FROM WEST CENTRAL INTO NORTHEAST WI...AND NEW
ACTIVITY GOING UP OVER NORTHEAST IA AND SOUTHEAST MN. ANTICIPATE
SCATTERED SHOWERS AND THUNDERSTORMS TONIGHT...WITH PERHAPS A BREAK
FOR A TIME EARLY THIS EVENING AFTER THIS FIRST INITIAL BAND.
PRECIPITABLE WATER SOMEWHAT ELEVATED AND WARM CLOUD DEPTH 3500+
METERS. ANY STORMS WILL BE PRODUCING HEAVY DOWNPOURS. DCAPE
SUGGESTS WIND POTENTIAL AS WELL.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 315 PM CDT MON AUG 18 2014
UPPER LEVEL LOW OVER THE GREAT LAKES SHIFTS EAST ON WEDNESDAY AS
UPPER RIDGING BUILDS INTO THE UPPER MIDWEST. A PATTERN SHIFT TO
MORE SOUTHWEST FLOW TAKES PLACE MID-WEEK WITH A LONG WAVE TROUGH
ESTABLISHING ITSELF OVER THE WESTERN CONUS. EVENTUAL RAIN CHANCES
LATER THIS WEEK...AND THE DEGREE OF WARMING...ARE TIED TO HOW THE
SHORT WAVE TROUGH ENERGY EJECTS NORTHEAST TOWARD OUR REGION.
MEDIUM RANGE MODELS DO SHOW SOME DIFFERENCES IN TIMING OF THESE
IMPULSES...SO CONFIDENCE NOT HIGH. BUT IT DOES APPEAR THE OVERALL
TREND OF WARM AND HUMID CONDITIONS WILL COME TO FRUITION. IT HAS
BEEN DRY LATELY...BUT THESE STORMS ONCE AGAIN LOOK TO HAVE
INGREDIENTS FOR HEAVY RAIN POTENTIAL. THIS WILL HAVE TO BE
MONITORED AS WE START TO ACCUMULATE SOME RAINFALL ON OUR RECENTLY
DRY SOILS...WILL A FLOOD WATCH EVENTUALLY BE NECESSARY?
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1157 PM CDT MON AUG 18 2014
MAIN AREA OF CONVECTION HAS PASSED BY BOTH TAF SITES. THE WIND
SHIFT HAS YET TO COME THROUGH AND BASED ON THE 19.03Z RAP THIS
SHOULD PASS THROUGH LATE TONIGHT SWINGING THE WINDS AROUND TO THE
WEST AND THEN NORTHWEST. THE RAP BUFKIT SOUNDING ALSO NOW SHOWS
LITTLE POTENTIAL FOR SATURATION TO OCCUR BEHIND THE BOUNDARY
MAKING IT LOOK LESS LIKELY THAT FOG AND LOW LEVEL STRATUS WILL
FORM. GIVEN THAT BOTH SITES DID HAVE RAIN TONIGHT...WILL LEAVE
SOME MVFR VISIBILITIES IN THE FORECASTS IN THE EVENT THAT THE
WINDS DROP OFF SOME BEHIND THE FRONT. WITH ALL THE LOW LEVEL
MOISTURE FROM THE RAIN AND AS SOME HEATING STARTS AFTER
SUNRISE...DO EXPECT TO SEE SOME MVFR CEILINGS FORM BY MID MORNING
AND THE PERSIST INTO THE EARLY AFTERNOON BEFORE THESE LIFT TO VFR.
THESE CEILINGS SHOULD THEN REMAIN THROUGH THE AFTERNOON BEFORE
SCATTERING OUT LATE IN THE AFTERNOON OR EARLY EVENING.
&&
.HYDROLOGY...
ISSUED AT 315 PM CDT MON AUG 18 2014
SO FAR IN AUGUST...OVERALL IT HAS BEEN QUITE DRY WITH MUCH OF THE
AREA ADDED TO THE ABNORMALLY DRY CATEGORY PER THE DROUGHT MONITOR.
BUT AS WE SAW LAST NIGHT...SLOW MOVING STORMS PRODUCING TORRENTIAL
DOWNPOURS CAN RESULT IN SOME LOCALIZED FLOODING ISSUES. ONCE AGAIN
TONIGHT...WARM CLOUD DEPTH AND ELEVATED PRECIPITABLE WATER
AMOUNTS POINT TO HEAVY RAINFALL POTENTIAL. THIS TREND LOOKS TO
CONTINUE THROUGH MUCH OF THE WEEK AS WELL. DRY CONDITIONS
INITIALLY WILL ALLOW FOR MUCH OF THIS WATER TO BE UTILIZED BY THE
SOIL AND REPLENISHING STORAGE AREAS. BUT WE WILL HAVE TO MONITOR
THE RAINFALL OVER THE COMING DAYS AND PERHAPS CONSIDER THE NEED
FOR A FLOOD WATCH FOR AREAS THAT SEE REPEATED RAINFALL.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...MW
LONG TERM...MW
AVIATION...04
HYDROLOGY...MW
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
940 AM EDT TUE AUG 19 2014
.SYNOPSIS...
AN UPPER TROUGH AND STRONG HEATING WILL SUPPORT SCATTERED
THUNDERSTORMS THIS AFTERNOON INTO THE EVENING. DRIER AIR AND A
BUILDING UPPER RIDGE JUST TO OUR WEST WILL REDUCE THUNDERSTORM
CHANCES WEDNESDAY AND THURSDAY...AND LEAD TO HOTTER HIGH
TEMPERATURES. AN APPROACHING COLD FRONT AND INCREASING MOISTURE
WILL INCREASE THE THUNDERSTORM CHANCE OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
TODAY...SCATTERED SHOWERS WERE MOVING INTO THE AREA THIS MORNING
ASSOCIATED WITH LIFT AHEAD OF A MID-LEVEL SHORTWAVE TROUGH. THE
TROUGH PLUS HEATING AND CONVERGENCE INTO THE LEE-SIDE SURFACE
TROUGH SHOULD HELP SUPPORT THUNDERSTORMS LATER TODAY. THE HIGH
RESOLUTION MODELS INDICATE SCATTERED COVERAGE. THE COVERAGE WILL
PROBABLY REMAIN LIMITED BECAUSE MUCH OF THE UPPER-LEVEL LIFT AHEAD
OF THE SHORTWAVE TROUGH WILL LIKELY OCCUR EARLY AND BEFORE MAXIMUM
HEATING. ALSO...CONVERGENCE INTO THE SURFACE FEATURE SHOULD REMAIN
WEAK AND FORECAST SOUNDINGS SHOW WESTERLY FLOW THROUGH A DEEP
LAYER WHICH SHOULD HELP KEEP MOISTURE SOMEWHAT SHALLOW.
SIGNIFICANT UNI-DIRECTIONAL WIND SHEAR WITH 5000-FOOT WINDS NEAR
30 KNOTS MAINLY IN THE SOUTH PART AND STEEP LOW-LEVEL LAPSE RATES
MAY HELP SUPPORT STRONG WIND GUSTS WITH ANY THUNDERSTORMS. STRONG
MIXING WILL BRING GUSTY WINDS. USED THE GFS LAMP AND NAM BUFKIT
MOMENTUM-TRANSFER TOOL FOR THE WIND GUST FORECAST. USED THE
WARMER TEMPERATURE GUIDANCE BECAUSE OF THE WESTERLY FLOW.
TONIGHT...THE MODELS MAINTAIN SURFACE TROUGHING. HOWEVER...BELIEVE
THE THUNDERSTORM CHANCE IS LOW BECAUSE OF SHALLOW MOISTURE IN THE
WAKE OF THE MID-LEVEL SHORTWAVE TROUGH AND NOCTURNAL COOLING. THE
NAM AND GFS MOS HAVE POPS 20 TO 30 PERCENT...MAINLY IN THE EVENING
CLOSER TO THE TIME OF HEATING. THE TEMPERATURE GUIDANCE WAS CLOSE.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
UPPER RIDGE WILL BUILD JUST TO OUR WEST WEDNESDAY AS THE UPPER
TROUGH MOVES OFF THE COAST. WARMING 850MB TEMPERATURES AND A LOW
LEVEL DOWNSLOPE FLOW WILL RESULT IN MAX TEMPERATURES PUSHING 100
DEGREES WEDNESDAY AND THURSDAY. GUIDANCE INDICATES DEW POINTS
MIXING DOWN INTO THE MID TO UPPER 60S ACROSS THE NORTHERN AND
WESTERN COUNTIES TO NEAR 70 ACROSS THE SOUTHEAST MIDLANDS. THIS
SHOULD KEEP HEAT INDICES JUST BELOW OUR HEAT ADVISORY CRITERIA OF
110F. ONLY SLIGHT CHANCE OF SHOWERS/TSTMS EXPECTED BOTH WEDNESDAY
AND THURSDAY DUE TO DRIER AIR AND BUILDING RIDGE ALOFT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
UPPER RIDGE TO OUR WEST WITH UPPER TROUGH AND CLOSED LOW TO OUR
NE...PROVIDING A NW FLOW ALOFT FOR OUR FA. SOME TIMING
UNCERTAINTIES...BUT MODELS SUGGEST A BACK DOOR FRONT WILL MOVE
DOWN THE EAST COAST...REACHING OUR FA SOME TIME THIS WEEKEND. THIS
WOULD INCREASE POPS ALONG AND SOUTH OF THE BOUNDARY...AND LEAD TO
COOLER TEMPS NORTH OF IT. WILL MAINTAIN TREND IN THE ONGOING
FORECAST OF POPS TRENDING HIGHER AND TEMPS TRENDING LOWER DURING
THAT TIME.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
EXPECT MAINLY VFR CONDITIONS DURING THE TAF PERIOD.
CLOUDINESS ASSOCIATED WITH A MID-LEVEL SHORTWAVE TROUGH AND H85
WIND SPEED CONVERGENCE MAY BRING A PERIOD OF MVFR CEILINGS AT
SOME OF THE TAF SITES. HEATING AND MIXING SHOULD HELP DIMINISH
THIS CLOUDINESS BY MIDDAY. SATELLITE TRENDS AND THE HRRR GUIDANCE
INDICATED A PERIOD OF MVFR AT AGS...DNL...CAE...AND CUB.
SCATTERED SHOWERS WERE MOVING INTO THE AREA THIS MORNING
ASSOCIATED WITH LIFT AHEAD OF THE MID-LEVEL SHORTWAVE TROUGH. THE
TROUGH PLUS HEATING AND CONVERGENCE INTO THE LEE-SIDE SURFACE
TROUGH SHOULD HELP SUPPORT THUNDERSTORMS LATER TODAY. THE HIGH
RESOLUTION MODELS INDICATE SCATTERED COVERAGE. THE COVERAGE WILL
PROBABLY REMAIN LIMITED BECAUSE MUCH OF THE UPPER-LEVEL LIFT AHEAD
OF THE SHORTWAVE TROUGH WILL LIKELY OCCUR EARLY AND BEFORE MAXIMUM
HEATING. ALSO...CONVERGENCE INTO THE SURFACE FEATURE SHOULD REMAIN
WEAK AND FORECAST SOUNDINGS SHOW WESTERLY FLOW THROUGH A DEEP
LAYER WHICH SHOULD HELP KEEP MOISTURE SOMEWHAT SHALLOW. THE
THUNDERSTORM CHANCE IS TOO LOW TO INCLUDE IN THE TERMINAL
FORECASTS AT THIS TIME BECAUSE OF THE SCATTERED COVERAGE AND
TIMING UNCERTAINTY. SIGNIFICANT UNI-DIRECTIONAL WIND SHEAR WITH
5000-FOOT WINDS NEAR 30 KNOTS MAINLY IN THE SOUTH PART AND STEEP
LOW-LEVEL LAPSE RATES MAY HELP SUPPORT STRONG WIND GUSTS NEAR ANY
THUNDERSTORMS. STRONG MIXING WILL BRING GUSTY WINDS. USED THE GFS
LAMP AND NAM BUFKIT MOMENTUM-TRANSFER TOOL FOR THE WIND GUST
FORECAST. DRYING ALOFT AND LINGERING LOW-LEVEL MOISTURE PLUS
NOCTURNAL COOLING MAY HELP SUPPORT FOG TONIGHT. MOST OF THE NAM
AND GFS MOS INDICATE MVFR FOG. FOG WILL LIKELY BE LIMITED BY SOME
MIXING.
EXTENDED AVIATION OUTLOOK...MVFR OR IFR CONDITIONS POSSIBLE IN LATE
NIGHT AND EARLY MORNING FOG THROUGH THE PERIOD. ISOLATED AFTERNOON
AND EVENING THUNDERSTORMS MAY ALSO BRING RESTRICTIONS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
808 AM EDT TUE AUG 19 2014
.SYNOPSIS...
AN UPPER TROUGH AND INCREASING MOISTURE WILL BRING THE CHANCE FOR
SHOWERS AND THUNDERSTORMS TODAY. DRIER AIR AND A BUILDING UPPER
RIDGE JUST TO OUR WEST WILL REDUCE AFTERNOON THUNDERSTORM CHANCES
WEDNESDAY AND THURSDAY...AND LEAD TO INCREASING HIGH TEMPERATURES.
AN APPROACHING BACKDOOR FRONT AND INCREASING MOISTURE WILL LEAD TO
GREATER THUNDERSTORM CHANCES OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
A SHORTWAVE TROUGH CROSSING NORTHERN GA IN NEAR ZONAL FLOW THIS
MORNING IS EXPECTED TO MOVE INTO WESTERN SC AROUND SUNRISE AND
CROSS THE FORECAST AREA TODAY. HAVE INCREASED POPS TO THE 40 TO 50
PERCENT RANGE. WEAK TO MODERATE INSTABILITY IS FORECAST ALONG WITH
PWAT INCREASING TO AROUND OR ABOVE 2.00 INCHES THIS AFTERNOON.
CANNOT RULE OUT AN ISOLATED STRONG TO SEVERE STORM THIS AFTERNOON
GIVEN INVERTED V SIGNATURE INDICATED IN FORECAST SOUNDINGS FOR THE
AFTERNOON. DAMAGING WIND GUSTS WOULD BE THE MAIN THREAT IF A
SEVERE STORM DEVELOPS WITH LARGE HAIL GENERALLY UNLIKELY DUE TO
FREEZING LEVEL HEIGHT OVER 15KFT. THE CENTRAL AND SOUTHEASTERN
MIDLANDS AND CSRA LOOK TO BE THE MOST FAVORABLE LOCATION FOR
STORMS TODAY. KEPT AFTERNOON HIGHS ON THE WARM SIDE OF GUIDANCE.
CONVECTION WILL DECREASE EARLY THIS EVENING AS THE SHORT WAVE
MOVES EAST OF THE AREA. OVERNIGHT LOWS ARE EXPECTED TO FALL INTO
THE LOWER 70S AS SKIES BECOME MOSTLY CLEAR.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
UPPER RIDGE WILL BUILD JUST TO OUR WEST WEDNESDAY AS THE UPPER
TROUGH MOVES OFF THE COAST. WARMING 850MB TEMPERATURES AND A LOW
LEVEL DOWNSLOPE FLOW WILL RESULT IN MAX TEMPERATURES PUSHING 100
DEGREES WEDNESDAY AND THURSDAY. GUIDANCE INDICATES DEWPOINTS
MIXING DOWN INTO THE MID TO UPPER 60S ACROSS THE NORTHERN AND
WESTERN COUNTIES TO NEAR 70 ACROSS THE SOUTHEAST MIDLANDS. THIS
SHOULD KEEP HEAT INDICES JUST BELOW OUR HEAT ADVISORY CRITERIA OF
110F. ONLY SLIGHT CHANCE OF SHOWERS/TSTMS EXPECTED BOTH WEDNESDAY
AND THURSDAY DUE TO DRIER AIR AND BUILDING RIDGE ALOFT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
NO SIGNIFICANT CHANGES MADE TO THE LONG TERM FORECAST.
PREVIOUS DISCUSSION:
UPPER RIDGE TO OUR WEST WITH UPPER TROUGH AND CLOSED LOW TO OUR
NE...PROVIDING A NW FLOW ALOFT FOR OUR FA. SOME TIMING
UNCERTAINTIES...BUT MODELS SUGGEST A BACK DOOR FRONT WILL MOVE
DOWN THE EAST COAST...REACHING OUR FA SOME TIME THIS WEEKEND. THIS
WOULD INCREASE POPS ALONG AND SOUTH OF THE BOUNDARY...AND LEAD TO
COOLER TEMPS NORTH OF IT. WILL MAINTAIN TREND IN THE ONGOING
FORECAST OF POPS TRENDING HIGHER AND TEMPS TRENDING LOWER DURING
THAT TIME.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
EXPECT MAINLY VFR CONDITIONS DURING THE TAF PERIOD.
H85 WIND SPEED CONVERGENCE MAY HELP SUPPORT A PERIOD OF MVFR
CEILINGS THIS MORNING. THE 08Z HRRR INDICATED MVFR CEILINGS FOR A
SHORT PERIOD OF TIME THIS MORNING AT AGS AND DNL. HEATING AND
MIXING SHOULD HELP DIMINISH THIS CLOUDINESS LATER THIS MORNING.
SCATTERED SHOWERS WERE MOVING INTO THE AREA THIS MORNING
ASSOCIATED WITH LIFT AHEAD OF A MID-LEVEL SHORTWAVE TROUGH.
THE TROUGH PLUS HEATING AND CONVERGENCE INTO THE LEE-SIDE SURFACE
TROUGH SHOULD HELP SUPPORT THUNDERSTORMS LATER TODAY. THE HIGH
RESOLUTION MODELS INDICATE SCATTERED COVERAGE. THE COVERAGE WILL
PROBABLY REMAIN LIMITED BECAUSE MUCH OF THE UPPER-LEVEL LIFT AHEAD
OF THE SHORTWAVE TROUGH WILL LIKELY OCCUR EARLY BEFORE MAXIMUM
HEATING. ALSO...CONVERGENCE INTO THE SURFACE FEATURE SHOULD REMAIN
WEAK AND FORECAST SOUNDINGS SHOW WESTERLY FLOW THROUGH A DEEP
LAYER WHICH SHOULD HELP KEEP MOISTURE SOMEWHAT SHALLOW. THE
THUNDERSTORM CHANCE IS TOO LOW TO INCLUDE IN THE TERMINAL
FORECASTS AT THIS TIME BECAUSE OF THE SCATTERED COVERAGE AND TIMING
UNCERTAINTY. SIGNIFICANT UNI-DIRECTIONAL WIND SHEAR WITH
5000-FOOT WINDS NEAR 30 KNOTS MAINLY IN THE SOUTH PART AND STEEP
LOW-LEVEL LAPSE RATES MAY HELP SUPPORT STRONG WIND GUSTS NEAR ANY
THUNDERSTORMS. STRONG MIXING WILL BRING GUSTY WINDS. USED THE GFS
LAMP AND NAM BUFKIT MOMENTUM-TRANSFER TOOL FOR THE WIND GUST
FORECAST.
EXTENDED AVIATION OUTLOOK...MVFR OR IFR CONDITIONS POSSIBLE IN LATE
NIGHT AND EARLY MORNING FOG THROUGH THE PERIOD. ISOLATED AFTERNOON
AND EVENING THUNDERSTORMS MAY ALSO BRING RESTRICTIONS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
923 AM CDT Tue Aug 19 2014
.UPDATE...
ISSUED AT 923 CDT TUE AUG 19 2014
Area of showers and thunderstorms associated with an upper-level
wave is currently crossing the Mississippi River into west-central
Illinois. 1417z radar imagery shows leading edge of precip extending
from Galesburg...to Rushville...to Bowling Green Missouri. Based
on timing tools, showers/thunder will arrive along the I-55
corridor by midday. HRRR and other high-res models generally show
the precip area weakening as it pushes eastward through the
morning, then potentially re-developing across east-central
Illinois later this afternoon. Made some adjustments to hourly
PoPs today, mainly to increase to categorical along/west of I-55
during the morning. Once the wave passes, rain chances will come
to an end across the Illinois River Valley by mid to late
afternoon, followed by a return to partly to mostly sunny skies.
Further east, rain chances will linger throughout the day before
coming to an end by evening.
&&
.SHORT TERM...(This afternoon through Wednesday)
ISSUED AT 336 AM CDT TUE AUG 19 2014
Short term models have trended slower with the front and precip that
is currently supposed to be moving into the area. But will still
have chance of precip starting in the northwest parts of the cwa
this morning. Then will progress the pcpn chances southeastward
across the cwa during the day. By this evening, most of the pcpn
will be in the eastern two thirds of the area with the highest pops
in the southeast. By overnight, the pcpn should have moved southeast
of the area so most of the area should be dry overnight, though will
keep a slight chance of pops in the southeast after midnight. Could
be some additional pcpn in the southwest late tonight, but models
keep most of pcpn west of the area through 12z.
Temps will begin the slow warming tomorrow, and am expecting mid to
upper 80s throughout the area today.
&&
.LONG TERM...(Wednesday night through Monday)
ISSUED AT 347 AM CDT TUE AUG 19 2014
Models still pretty consistent with the development and lift of a
boundary through the Midwest on Wednesday. Boundary will have little
reflection at the sfc with very weak flow/weak wind shift, and
thermal gradient is better represented in the mid levels. Boundary
will provide a weak focus for waves moving through the region as the
boundary lifts to the NE through the area for Wed/Wed night. Though
Wed is lacking signif pop for now, the timing of the progression is
better for early evening and into the overnight on Wednesday
night/shifting to the northeast for Thurs. Position of the boundary
or the remnants thereof will be where the majority of the precip
chances will be...increasing to the north, particularly north of
Interstate 74 from Thursday to Saturday. Ample sfc based instability
in the form of hot and humid conditions as the ridge over the
southwest opens and spreads signif heat into the Midwest. Models
have also shown consistency with 850 mb temps in the 19-25C range
from Wednesday through Sunday. This will drive the temps into the
upper 80s/lower 90s with heat indices in the upper 90s/approaching
100F. A far more summer-like pattern than much of the season so far,
and well above normal for this time of year...with breaks from the
heat provided by any thunderstorms that may have the chance to form
from more diurnal instability with any frontal forcing further to
the north. Into the extended, day 7/just into day 8, models diverge
in solutions with major difference in breaking down the upper ridge
for the Midwest.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
ISSUED AT 609 AM CDT TUE AUG 19 2014
Cold front is still back northwest of the area, but still
forecasted to move through the area, affecting all TAF sites this
through afternoon. However, radar loops show a complex of
thunderstorms in northern MO that could move into central IL this
morning and effect some of the TAF sites, possibly SPI and DEC.
Short term models do show some pcpn moving through the area this
morning, but appears it will diminish as it moves into the area.
Then the front drops into the area a few hours later and this will
bring a chance of thunderstorms to the TAF sites for the afternoon
and early evening. The early stuff could be just showers, but
since the front will be right on the heels of the current complex
coming out of MO, will opt to just have VCTS for all TAFs to cover
both events. Believe t-storms will be more scattered as well. Also
VCTS will be in the TAFs longer than necessary, but only because
of two events. Not expecting cigs to go down today, but having
some light fog issues at mainly CMI, with some very light fog at
PIA and BMI. This fog will burn off quickly, like yesterday
morning. Winds will be south to southwest through the morning and
then become southwest just ahead of the front, and then westerly
or light and variable after FROPA.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARNES
SHORT TERM...AUTEN
LONG TERM...HJS
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
651 AM CDT TUE AUG 19 2014
.AVIATION...
CONCERNING THE ARKLATEX...A LOT OF DEBRIS CIRRUS KEEPING STATION
AND MITIGATING MVFR BOTH CIGS/FG. CONVECTION TODAY MAY OCCUR OVER
THE SOUTH WITH RESPECT TO A WEAK SEA BREEZE PUSH AND OVER OUR
NORTH ALONG A WEAK SHEAR AXIS WITH SOMEWHAT BETTER CHANCES FROM
KTXK...TO KMLU AND MAY BRIEFLY AFFECT KELD AND KSHV THIS
MID AFTERNOON BASED ON THE HIGH RES MODEL. VCTS FOR THE AFTERNOON
HOURS WILL BE AMENDED WITH DEVELOPMENT. OTHERWISE S/SW WINDS ON
THE SFC ARE GENERALLY SW- NW ALOFT WITH NOT MUCH SPEED ANYWHERE.
/24/
&&
.PREV DISCUSSION... /ISSUED 423 AM CDT TUE AUG 19 2014/
DISCUSSION...
THE MORNING WATER VAPOR IMAGERY INDICATES THAT THE MAIN SHORTWAVE
THAT PRODUCED EXTENSIVE CONVECTION JUST 24 HRS AGO OVER SW
AR/EXTREME NRN LA HAS SHIFTED E INTO NRN GA...WITH THE 00Z RAOB
500MB PLOT STILL REVEALING A WEAK SHEAR AXIS THAT EXTENDS FARTHER
W ACROSS NRN MS/N LA AND INTO NE TX. MEANWHILE...MOSAIC RADAR
IMAGERY ALSO INDICATES A WELL-DEFINED MCV SPINNING E OF
SJT...WHICH THE 00Z PROGS HAVE INITILIZED WELL ON AS CONVECTION
CONTINUES TO REGENERATE NEAR AND E OF THE CENTER OVER CNTRL TX.
THIS CONVECTION HAS PRODUCED A THICK AC CANOPY OVER NE TX/EXTREME
NW LA...ALTHOUGH IR IMAGERY DEPICTS WARMING CLOUD TOPS SUGGESTING
A WEAKENING TREND IS ONGOING ATTM. THIS MCV CENTER IS PROGGED TO
DRIFT NNE ACROSS NCNTRL TX TODAY...WHICH COULD MAINTAIN ELEVATED
CONVECTIVE DEBRIS OVER THE NRN HALF OF THE AREA THROUGH AT LEAST
THE FIRST HALF OF THE DAY...BEFORE POSSIBLY THINNING THIS
AFTERNOON. MY FORECAST MAX TEMPS MAY BE A BIT HIGH TODAY
ESPECIALLY IF THIS DEBRIS FIELD HANGS TOUGH TODAY...BUT HAVE
PLAYED THE PESSIMIST WITH IT THINNING LATER TODAY...ESPECIALLY AS
09Z TEMPS REMAIN IN THE MID/UPPER 70S. WHILE THE SHORT TERM PROGS
DO SUGGEST A WEAK SEABREEZE AFFECTING DEEP E TX/SRN SECTIONS OF
NCNTRL LA THIS AFTERNOON...ONLY THE LATEST HRRR RUN DEPICTS AT
LEAST ISOLATED CONVECTION DEVELOPING THIS AFTERNOON ALONG THE
RESIDUAL SHEAR AXIS...WHICH IS STILL WEAKLY REFLECTED IN THE OTHER
SHORT RANGE PROGS. IN ADDITION...THE 09Z SFC ANALYSIS INDICATES A
DISTINCT W-E GRADIENT IN SFC THETA-E FROM NEAR OSA TO ALONG THE
AR/LA LINE...INDICATIVE OF THE WEAK COLD POOL FROM CONVECTION THAT
AFFECTED THESE AREAS MONDAY AFTERNOON/EVENING. GIVEN THESE WEAK
SFC AND UPPER AIR FORCING MECHINISMS...AND THE FACT THAT THE CNTRL
TX MCV IS PROGGED TO LIFT NNE ACROSS THE STATE TODAY...HAVE
EXPANDED SLIGHT CHANCE POPS TO COVER MUCH OF THE REGION THIS
AFTERNOON...AND DID CARRY THEM THROUGH THE EVENING BEFORE THEY
DIMINISH WITH THE STABILIZING BNDRY LYR.
THE SHEAR AXIS IS EXPECTED TO WASH OUT OVERNIGHT WITH THE MCV
OPENING UP LATE...AS THE WRN ATLANTIC/CNTRL GULF OF MX UPPER RIDGE
EXPECTED TO BRIDGE NWD INTO THE LOWER MS VALLEY WEDNESDAY. STILL
SHOULD SEE A WEAK SEABREEZE AFFECTING THE SRN ZONES WEDNESDAY AND
THURSDAY AFTERNOONS/EARLY EVENINGS...BEFORE THE UPPER RIDGE CENTER
BECOMES ESTABLISHED OVER THE MID-SOUTH/LOWER MS VALLEY FRIDAY.
BOTH THE GFS AND ECMWF AMPLIFY THE RIDGE FARTHER N ACROSS THE SRN
PLAINS/MS VALLEY FRIDAY...AND KEEPS IT PERSISTENT THROUGH THE
WEEKEND INTO EARLY NEXT WEEK. INCREASED SUBSIDENCE WILL RESULT IN
MAX TEMPS CLIMBS INTO THE UPPER 90S AREAWIDE...WITH EVEN SOME
TRIPLE DIGITS POSSIBLE OVER SOME AREAS THIS WEEKEND/EARLY NEXT
WEEK. THE MEDIUM RANGE PROGS DO BEGIN TO SLOWLY NUDGE THE RIDGE E
INTO THE SE STATES BY TUESDAY/WEDNESDAY...WITH WEAKNESSES RIDING W
BENEATH THE RIDGE ACROSS S LA/SRN MS AS EARLY AS MONDAY.
THUS...ISOLATED CONVECTION WILL BE POSSIBLE OVER NCNTRL LA MONDAY
AFTERNOON...BEFORE SPREADING FARTHER WNW TO ENCOMPASS MUCH OF THE
REGION BY THE END OF THE EXTENDED.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 95 75 96 76 97 / 10 10 10 10 10
MLU 95 73 96 74 97 / 20 20 10 10 10
DEQ 94 71 94 71 95 / 20 20 0 0 0
TXK 94 74 96 74 96 / 20 20 0 0 0
ELD 95 72 96 74 97 / 20 20 0 0 0
TYR 94 75 96 76 97 / 10 20 10 10 10
GGG 95 74 96 75 97 / 10 10 10 10 10
LFK 96 75 96 76 97 / 20 20 20 20 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
24
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1033 AM CDT TUE AUG 19 2014
.UPDATE...INCREASED POPS SLIGHTLY TO CARRY SLIGHT CHANCE
THUNDERSTORM WORDING ACROSS NW LOCATIONS THROUGH 1PM GIVEN CURRENT
RADAR TRENDS BUT ALSO CUT SOME FOR SW AREAS THROUGH THAT SAME TIME
PERIOD. HOURLY TEMP/DEWPOINTS WERE ALTERED SLIGHTLY BUT MAINLY ON
TRACK WITH LITTLE TO NO CHANGE IN EXPECTED HIGHS.
.DISCUSSION...A FEW THUNDERSTORMS ARE ONGOING IN AR/TN MOVING INTO
NORTH MS THIS HOUR. HI-RES MODELS ARE HAVING A HARD TIME RESOLVING
THIS ACTIVITY BUT THE RAP DOES INDICATE SOME LOWER CONDENSATION
PRESSURE DEFICITS IN CONJUNCTION WITH ISENTROPIC UPGLIDE AND
STEEPER LAPSE RATES IN THE VICINITY OF THE CURRENT ACTIVITY.
FOLLOWING THE RAP GUIDANCE, IT SUGGESTS A LOW-LVL CONVERGENCE AREA
TO PROPAGATE OUT OF THIS CLUSTER (LIKELY FROM AN OUTFLOW BOUNDARY)
THAT COULD ACT TO INITIATE NEW ACTIVITY THROUGH THE DAY AS
INSTABILITY BUILDS. MICROBURST RISK REVEALED SUBSTANTIAL SBCAPE
ABOVE 3000 J/KG BUT WITH PWATS UP NEAR 2" FEEL SCATTERED
SHOWERS/STORMS WILL BEGIN BY EARLY AFTN SOUTH OF THIS CLUSTER. SOME
STORMS COULD BECOME STRONG TO BRIEFLY SEVERE IF ORGANIZED ALONG A
COLD POOL BUT OVERALL COVERAGE OF THESE HAZARDS WILL BE ISOLATED.
WILL NOT INCLUDE ANY STRONG/SEVERE GRAPHIC UPDATES AT THIS TIME.
COVERAGE SHOULD DIMINISH THROUGH THE EVENING AS THE RIDGE
STRENGTHENS OVER THE REGION THROUGH THE NEXT SEVERAL DAYS.
AN UPDATED AVIATION DISCUSSION CAN BE FOUND BELOW. /ALLEN/
&&
.AVIATION...A MIX OF MVFR/VFR FLIGHT CATEGORIES ARE BEING OBSERVED
THIS MORNING AS LOW STRATUS HAS BEEN A LITTLE SLOWER TO ERODE THAN
PREVIOUSLY ANTICIPATED. STILL...VFR CONDITIONS ARE EXPECTED AS WE
MOVE INTO THE AFTERNOON HOURS WITH SCATTERED TO BROKEN CEILINGS
BETWEEN 3000-5000 FEET EXPECTED...ALONG WITH SOME MID AND HIGH
CLOUDS STREAMING OVERHEAD. SCATTERED CONVECTION IS AGAIN EXPECTED
THROUGH THE AFTERNOON TODAY. THIS COULD RESULT IN A BRIEF PERIOD OF
MVFR/IFR CEILINGS AND/OR VISIBILITIES IF CONVECTION IS OBSERVED
WITHIN A TAF SITES RESPECTED AERODROME. SHOWERS AND STORMS WILL
DISSIPATED THIS EVENING...WITH ANOTHER BOUT OF MVFR/IFR
CEILINGS/VISIBILITIES POSSIBLE EARLY WEDNESDAY MORNING DUE TO LOW
STRATUS AND/OR PATCHY FOG. WINDS TODAY WILL BE WEST SOUTHWESTERLY
BETWEEN 5-10 KNOTS...AND WILL GRADUALLY SUBSIDE TO LIGHT TO CALM
TONIGHT. /19/
&&
.PREV DISCUSSION... /ISSUED 403 AM CDT TUE AUG 19 2014/
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...AS RIDGING CONTINUES
OVER THE CENTER OF THE COUNTRY...THE ARKLAMISS REGION REMAINS UNDER
NORTHWEST FLOW ALOFT. A TROUGH AXIS IS LOCATED ACROSS EASTERN
MISSISSIPPI AND ALABAMA THIS MORNING AND WILL CONTINUE THERE TODAY.
THIS SHOULD COMBINE WITH ENOUGH MOISTURE TO BRING SOME ADDITIONAL
SHOWERS AND STORMS TODAY. WHILE SOME STORMS WILL BE POSSIBLE ACROSS
WESTERN ZONES...HEIGHTS WILL BE RISING IN THIS REGION AND SHOULD
WORK TO SUPPRESS CONVECTION A BIT MORE THERE. WHILE CONVECTION IN
THIS NORTHWEST FLOW REGIME HAS NOT BEEN DEPICTED TERRIBLY WELL ON
MODELS OF LATE...HI-RES MODELS AND EVEN THE LOCAL WRF SEEM TO
INDICATE THE BEST CHANCES OF RAIN TODAY WILL BE IN THE EAST AND HAVE
LEANED MORE TOWARD THE ECMWF WITH HIGHER RAIN CHANCES IN THIS
REGION. HIGHS TODAY ARE EXPECTED TO BE IN THE LOWER 90S BUT WITH
HUMIDITY...HEAT INDICES WILL NEAR 100 DEGREES.
THROUGH WEDNESDAY NIGHT...THE UPPER TROUGH WILL CONTINUE TO PUSH OFF
TO THE EAST AND UPPER RIDGING WILL MOVE INTO THE REGION FOR A WHILE.
THERE COULD BE SOME SMALL RAIN CHANCES IN THE FAR SOUTH ON WEDNESDAY
BUT IT APPEARS THAT MOST OF THE ARKLAMISS SHOULD BE DRY AS HEIGHTS
WILL CONTINUE TO BUILD. TEMPERATURES ON WEDNESDAY WILL BE A TAD
WARMER AND COULD FLIRT WITH THE 95-97 DEGREE RANGE. WEDNESDAY WILL
BE A BIT MORE MUGGY AS THE COMBINATION OF HEAT AND 70 DEGREE
DEWPOINTS WILL BRING HEAT INDICES NEAR 105 DEGREES. WILL CONTINUE
WITH THE LIMITED RISK CURRENTLY ADVERTISED IN THE HWO AND GRAPHICS
FOR HEAT INDICES DURING THIS TIME PERIOD. OVERNIGHT LOWS WILL DROP
LOW ENOUGH TO PRECLUDE ANY NEED FOR AN ADVISORY. /28/
LONG TERM...THURSDAY THROUGH MONDAY...HOTTER AND DRIER THROUGH THE
PERIOD. THURSDAY MORNING A LARGE 593DAM HIGH ATOP A 1019MB SURFACE
HIGH WILL BE CENTERED JUST SOUTHEAST OF OUR CWA. THE SURFACE HIGH
WILL BECOME CENTERED JUST SOUTH OF OUR CWA WHILE THE LARGE MID LEVEL
HIGH STRENGTHENS AND BECOMES CENTERED OVER OUR CWA BY THURSDAY
EVENING. A RATHER MOIST AIRMASS WILL BE IN PLACE WITH PWS OF 1.7-1.8
INCHES AND SURFACE DEW POINTS IN THE LOWER 70S. THE NORMAL AFTERNOON
HIGHS ARE AROUND 92F AND TEMPERATURES WILL TOP OUT THURSDAY ABOVE
NORMAL AT 95-97F AT MOST SITES. MODEL SOUNDINGS SUGGEST DRIER AIR
WILL MIX DOWN DURING THE AFTERNOON LOWERING DEW POINTS IN THE UPPER
60S. THIS WILL KNOCK THE HUMIDITY DOWN SOME BUT THE HEAT AND
HUMIDITY WILL COMBINE FOR MAXIMUM HEAT INDEX VALUES OF 100-103
THURSDAY. ISOLATED AFTERNOON STORMS WILL BE POSSIBLE IN THE
SOUTHWEST THURSDAY BUT RAIN CHANCES WILL REMAIN VERY LOW ELSEWHERE
THROUGH THE END OF THE WEEK. MODEL CONSENSUS IS A LITTLE SLOWER IN
BREAKING DOWN THE LARGE RIDGE OVER OUR AREA UNTIL IT BEGINS SHIFTING
EAST MONDAY. AS A RESULT HEAT AND HUMIDITY WILL REMAIN A CONCERN
THROUGH THE WEEKEND INTO MONDAY. ABOVE NORMAL TEMPERATURES TOPPING
OUT IN THE UPPER 90S EACH DAY WILL COMBINE WITH HIGH HUMIDITY TO
RESULT IN HEAT INDEX VALUES PEAKING AROUND 105 FOR SEVERAL HOURS
EACH AFTERNOON. A HEAT ADVISORY MAY BE NEEDED BY THE END OF THE WEEK
IF GREATER HUMIDITY CAN BE MAINTAINED INTO THE AFTERNOON HOURS. AS
THE MID LEVEL RIDGE SHIFTS EAST MONDAY OUR SOUTHERN ZONES WILL SEE A
SLIGHT CHANCE OF STORMS BY AFTERNOON AND EVENING DUE ALSO IN PART TO
THE SEA BREEZE FRONT PUSHING INTO THE AREA. /22/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 94 73 96 73 / 36 14 7 6
MERIDIAN 92 71 96 72 / 42 12 10 5
VICKSBURG 94 71 96 71 / 20 11 4 7
HATTIESBURG 95 74 97 74 / 44 14 25 9
NATCHEZ 93 73 94 73 / 25 11 14 10
GREENVILLE 94 74 96 74 / 21 9 3 6
GREENWOOD 94 73 97 73 / 29 10 4 5
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
ALLEN/19/28/22
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
651 AM EDT TUE AUG 19 2014
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL DEVELOP AHEAD OF A WEAK FRONT WHICH
WILL APPROACH THIS AFTERNOON AND EVENING. THE FRONT WILL STALL
ALONG THE OHIO VALLEY WEDNESDAY...THEN GRADUALLY LIFT NORTHEAST
THROUGH THE END OF THE WEEK. DISTURBANCES TRACKING ALONG THE FRONT
WILL KEEP THE WEATHER UNSETTLED THROUGH AT LEAST FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED TO INCLUDE A DENSE FOG ADVISORY ACROSS THE SOUTHERN HALF
OF THE AREA WHERE THERE ARE QUITE A FEW OBSERVATIONS OF A QUARTER
MILE OR LESS. LIGHT FOG WILL EXIST ELSEWHERE.
PREVIOUS DISCUSSION...
FAIRLY WEAK FLOW PATTERN OVER THE EASTERN CONUS TODAY AS A
MID/UPPER LEVEL TROUGH DIGS INTO THE WESTERN GREAT LAKES. A WEAK
SURFACE BOUNDARY ALONG THE OHIO RIVER WILL LIFT NORTH IN RESPONSE
TO LOW PRESSURE ATTENDANT TO THE MID AND UPPER LEVEL FEATURE. A
FEW RUNS OF THE RAP AND HRRR TRIED TO DEVELOP A FEW SHOWERS WITH
THE BOUNDARY THIS MORNING...BUT HAVE KEPT THE FORECAST DRY BASED
ON LATEST OBSERVATIONS. AS DAYTIME HEATING BUILDS...SOME
CONVECTION MAY START DEVELOPING AROUND THE MIDDAY HOURS...BUT THIS
WILL BE ISOLATED AT BEST. THE MAIN FOCUS WILL BE TO OUR WEST...AS
SHOWERS AND STORMS FIRE ALONG A PREFRONTAL TROUGH. EXACT TIMING IS
STILL IN QUESTION...BUT SOME STORMS COULD ARRIVE IN WEST CENTRAL
OHIO BY LATE AFTERNOON. WILL DISCUSS THESE STORMS FURTHER IN THE
SHORT TERM SECTION. BASED ON THE TEMPERATURE TRENDS FROM
MONDAY...WE COULD WARM PRETTY NICELY WITH A LACK OF PRECIPITATION
DURING PEAK HEATING. WENT A LITTLE ABOVE GUIDANCE FOR MOST... IN
THE MID TO UPPER 80S AND INCREASING DEW POINTS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
AN AREA OF SCATTERED TO NUMEROUS STORMS WILL BE CROSSING THE AREA
DURING THE EVENING HOURS. MODERATE INSTABILITY...LIKELY BETWEEN
1-2K J/KG...WILL HAVE DEVELOPED DURING THE AFTERNOON. RICHER LOW
LEVEL MOISTURE LOOKS LIKE IT WILL STAY TO THE SOUTHWEST OF OUR
AREA. WHILE THERE IS SOME INCREASED MID LEVEL FLOW ASSOCIATED WITH
THE DIGGING TROUGH...THE HIGHEST BULK SHEAR VALUES ARE GENERALLY
TO OUR SOUTHWEST AS WELL. WITH THAT SAID...THERE ARE ENOUGH
INGREDIENTS IN PLACE FOR AT LEAST SOME STRONGER
STORMS...ESPECIALLY WEST OF I-75 WHERE SPC HAS HOISTED A SLIGHT
RISK. A WEAKENING TREND IS EXPECTED THROUGH THE EVENING AS
INSTABILITY IS LOST...BUT THE TIMING WILL BE IMPORTANT TO WHEN
THIS OCCURS. INTERESTINGLY...THE LATEST MODEL RUNS ARE FOCUSING
THE GREATEST COVERAGE NORTH OF THE OHIO RIVER...LIKELY CLOSEST TO
THE STRONGER FORCING...SO ADJUSTED THE POPS ACCORDINGLY. THE NAM
SEEMS A LITTLE TOO BULLISH IN DEVELOPING ADDITIONAL CONVECTION
ALONG THE WEAK SURFACE FRONT. BASED ON DEEP LAYER
MOISTURE...EXPECT A DRYING TREND TOWARD WEDNESDAY MORNING. MUGGY
LOWS IN THE UPPER 60S TO AROUND 70.
FORCING ASSOCIATED WITH THE UPPER LEVEL TROUGH WILL BE PUSHING
EAST ON WEDNESDAY...BUT THERE ARE SOME INDICATIONS THE SURFACE
FRONT COULD REACTIVATE IN CENTRAL OHIO AROUND MIDDAY BEFORE
PUSHING EAST. THE TAIL END OF THE FRONT WILL STALL ACROSS NORTHERN
KENTUCKY...WARRANTING CHANCE POPS THERE AS WELL. HIGH TEMPERATURES
IN THE MID 80S.
FROM WEDNESDAY NIGHT THROUGH FRIDAY...MID AND UPPER LEVEL RIDGING
WILL BEGIN BUILDING ACROSS THE CENTER OF THE COUNTRY AS TROUGHING
DIGS INTO THE PACIFIC NORTHWEST. THIS WILL PLACE THE OHIO VALLEY
UNDER INCREASING NORTHWEST FLOW WITH POTENTIAL FOR SOUTHEASTWARD
DIVING DISTURBANCES. A NW-SE LOW LEVEL BAROCLINIC ZONE WILL
TIGHTEN AS WELL WITH MOISTURE POOLED ALONG IT. THE CHANCE OF
STORMS WILL INCREASE WEDNESDAY NIGHT IN THE TRI STATE
AREA...OVERSPREADING THE REST OF THE REGION ON THURSDAY. FRIDAY
WILL REMAIN UNSETTLED AS THE CORRIDOR OF FORCING MOVES ONLY
SLIGHTLY NORTHEAST IN RESPONSE TO THE BUILDING RIDGE. EXPECT
INCREASINGLY MUGGY CONDITIONS WITH HIGHS GENERALLY IN THE MID TO
UPPER 80S AND LOWS ON EITHER SIDE OF 70.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
MID/UPPER LEVEL RIDGING OVER THE CENTRAL UNITED STATES WILL SHIFT
SLOWLY EAST TOWARD THE LOWER OHIO VALLEY THROUGH THE WEEKEND. PCPN
CHANCES SHOULD THEN BECOME MORE SUPPRESSED AS WE PROGRESS THROUGH
THE WEEKEND AS THE RIDGE BUILDS IN FROM THE SOUTHWEST. SHORT WAVE
ENERGY MOVING ACROSS THE GREAT LAKES WILL BEGIN TO WEAKEN THE
RIDGE FROM THE NORTH LATE IN THE PERIOD...EVENTUALLY HELPING TO
PUSH A COLD FRONT DOWN TOWARD OUR AREA. THIS MAY ALLOW FOR A
CHANCE OF PCPN TOWARD THE END OF THE PERIOD ON MONDAY...BUT GIVEN
THE MODEL DIFFERENCES WITH THE TIMING...WILL MAINTAIN A DRY
FORECAST AT THIS POINT.
TEMPERATURES WILL BE SOMEWHAT DEPENDENT ON THE TIMING AND DEGREE OF
THUNDERSTORM ACTIVITY THROUGH LATE IN THE WEEK. HOWEVER...WITH THE
HIGH BUILDING IN FROM THE SOUTHWEST...GENERALLY EXPECT A GRADUAL
WARMING TREND TO ABOVE NORMAL HIGH TEMPERATURES THROUGH THE WEEKEND.
OVERNIGHT LOWS WILL REMAIN ON THE WARM SIDE TOO WITH LOWS MOSTLY IN
THE UPPER 60S TO AROUND 70 DEGREES.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
FOG AND STRATUS ARE PREVALENT AT THE SOUTHERN TERMINALS OF
KCVG...KLUK...AND KILN THIS MORNING. IFR/LIFR/VLIFR CONDITIONS
SHOULD IMPROVE BETWEEN 14Z AND 17Z AS THE FOG AND STRATUS BURN OFF
AND BECOME REPLACED BY BKN CUMULUS DECK.
OTHERWISE...A LOW PRESSURE SYSTEM WILL MOVE EAST ACROSS THE
WESTERN GREAT LAKES TODAY AND TONIGHT. FORECAST MODELS INDICATE
THAT PERHAPS A PREFRONTAL TROF AXIS WILL TRAIL SOUTH FROM THIS
LOW AND WILL PUSH EAST INTO OUR REGION LATE THIS AFTERNOON INTO
THE EARLY MORNING HOURS OF WEDNESDAY. THIS TROF AXIS WILL THEN BE
FOLLOWED BY A WEAK COLD FRONT LATE TONIGHT INTO WEDNESDAY MORNING.
DAYTIME INSTABILITY AND ENOUGH SHEAR/CONVERGENCE WITH THE
PREFRONTAL TROF AXIS SHOULD BRING AT LEAST SCATTERED SHOWERS AND
THUNDERSTORMS TO THE TERMINALS THIS EVENING INTO THE EARLY MORNING
HOURS OF WEDNESDAY. HAVE PLACED VCTS/CB DESCRIPTORS AT THE SITES
WHEN THIS IS MOST LIKELY TO OCCUR...BETWEEN 00Z AND 09Z. THE WEAK
COLD FRONT WILL FOLLOW BEHIND THE TROF LATE TONIGHT...BUT IT
APPEARS CONVERGENCE WILL BE WEAKER AND INSTABILITY WILL HAVE WANED
SOME...SO COVERAGE APPEARS LESS WITH THIS BOUNDARY.
OUTLOOK...THUNDERSTORMS POSSIBLE WEDNESDAY THROUGH SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR OHZ070>073-
077>082-088.
KY...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR KYZ089>100.
IN...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR INZ050-058-
059-066-073>075-080.
&&
$$
SYNOPSIS...SNYDER
NEAR TERM...SNYDER
SHORT TERM...SNYDER
LONG TERM...JGL
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1128 AM EDT TUE AUG 19 2014
.SYNOPSIS...
AN UPPER LOW OVR THE W GRT LKS WILL DRIFT SLOWLY SE ACROSS UPSTATE
NY AND NEW ENG BY LATE THIS WEEK. A LARGE SFC HIGH OVR THE CANADIAN
MARITIMES WILL RIDGE SOUTHWARD INTO PA DURING THE UPCOMING WEEKEND
AND EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
LOW CLOUDS SLOWLY LIFTING AND MOVING TO THE EAST. RADAR HAS
DETECTED SHOWERS WHICH DEVELOPED ON THE WESTERN EDGE OF THIS CLOUD
SHIELD AND HAS MOVED INTO CLEARFIELD COUNTY. SOME HINTS OF WEAK
CONVECTION IN THE HRRR AND 4KM NAM. USED THESE MODELS TO ADD
TEXTURE TO THE FORECAST SHOWING SHOWERS AND ISOLATED THUNDERSTORMS
DRIFTING ACROSS PENNSYLVANIA THIS MORNING AND AFTERNOON.
TRIED TO KEEP POPS IN CHANCE RANGE AS THERE IS LIMITED
ORGANIZATION TO THE CONVECTION. HOWEVER...3KM HRRR UPDATES FROM
NCEPS EXPERIMENTAL HRRR SHOW DIFFERENT AREAS OF SHOWERS IN CENTRAL
PA ALL AFTERNOON AND NOW IMPLY MORE ORGANIZED THUNDERSTORMS IN
S-SE COUNTIES IN LATE AFTERNOON EVENING. SEE HOW THIS EVOLVES.
SKIES SHOULD SLOWLY GET BETTER DURING DAY CENTRAL AREAS.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
SREF AND NAM CONTINUE TO SHOW CHANCE TO SLIGHT CHANCE OF SHOWERS
OVERNIGHT. THE SURGE OF CAPE AND PW INTO WESTERN PA IN THE SREF
AND NAM...SIMILAR TO OLDER GEFS/GFS IMPLY SOME MORE ORGANIZED RAIN
POSSIBLE ON WEDNESDAY. USED A BLEND TO GET THE POPS AND THE 12KM
NAM TO ADD SOME TEXTURE TO CONVECTION AND RAIN AREA THAT APPEARS
TO BE POISED TO MOVE WEST TO EAST ACROSS THE REGION WEDNESDAY.
THE SREF POPS/PDF IMPLIES SHOWERS COMING INTO WEST AROUND 1500 UTC
AND MOST OF CENTRAL TWO THIRDS OF REGION BY LATE EVENING. SREF IS
KIND OF OPTIMISTIC SOUTHEAST PA COULD HAVE YET ANOTHER MOSTLY
RAIN FREE DAY WEDNESDAY.
THE KEY FEATURES ARE THE RETROGRADING RIDGE OVER EASTERN CANADA
WHICH IS TAKING THE UMPH OUT OF THE SYSTEMS CUTTING UNDER THIS
FEATURE. IN MOST MODELS THE NEAR 1SD ABOVE NORMAL PW SURGES WEAKEN
AS THE MOVE INTO PA. THUS MORE OPTIMISTIC...SREF-LIKE IN THE WEST
THAN THE EAST WITH RAINFALL AND NOT REALLY CONFIDENT GOING LIKELY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THURSDAY LOOKS LIKE ANOTHER UNSETTLED DAY...AS UPPER LOW MAKES
IT/S CLOSEST PASS TO PA...TRACKING ACROSS UPSTATE NY. COOL TEMPS
ALOFT...COMBINED WITH DIURNAL HEATING...SHOULD YIELD NUMEROUS SHRA
AND TSRA BY AFTN. HAVE RAISED POPS TO THE LIKELY CATEGORY BASED ON
00Z OPER AND GEFS OUTPUT. SOUTHERLY LL JET AND PLUME OF HIGH
PWATS WILL HAVE PASSED NE OF THE AREA THURSDAY...LIMITING THE
THREAT OF ANY HVY RAINFALL. MDL BLENDED QPF IS IN THE QUARTER TO
HALF INCH RANGE THURSDAY. THE NUMEROUS SHOWERS AND COOLER TEMPS
ALOFT WILL RESULT IN HIGH TEMPS BLW NORMAL FOR AUGUST...WITH
MAXES MAINLY IN THE 70S.
LATEST MED RANGE GUIDANCE POINTING TOWARD DRIER WX FRIDAY INTO
EARLY NEXT WEEK...AS SUBTROPICAL HIGH IS PROGGED TO EDGE TOWARD
THE REGION FROM THE MIDWEST. DAILY RING OF FIRE CONVECTION ON NE
PERIPHERY OF THIS RIDGE WILL THREATEN WESTERN PA DURING THE
FRI-SUN TIME FRAME...WHILE EASTERN PA IS LIKELY TO REMAIN DRY.
DESPITE APPROACH OF UPPER RIDGE...NO BIG WARMUP EXPECTED...AS
LARGE SFC HIGH OVR THE CANADIAN MARITIMES WILL CIRCULATE AN
EASTERLY FLOW INTO CENTRAL PA. THERE MAY BE ISSUE WITH AM LOW
CLOUDS/FOG DUE TO THE EXPECTED MOISTLY SERLY FLOW OVR THE AREA.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
STILL LINGERING AREAS OF MVFR AND ISOLATED IFR AS THE LOW CLOUDS
AND PATCHY FOG FROM EARLY THIS MORNING AND LIFT AND SLOWLY DRIFT
TO THE EAST.
A LINE OF SHOWERS WITH ISOLATED THUNDER HAS DEVELOPED OVER THE
CENTRAL MOUNTAINS. THIS COULD BRING SHOWERS FROM KFIG SOUTH TO
KAOO AND KJST AND EVENTUALLY THE KUNV AREA. ADDED SHOWERS VICINITY
TO THESE SITES. THIS COULD MOVE FARTHER EAST.
MODELS SHOW ISOLATED TO SCATTERED SHOWERS RANDOMLY PLACED ABOUT
CENTRAL AND SOUTHERN PA OVER NEXT 12 HOURS.
THINGS SETTLE DOWN OVERNIGHT...MORE PATCHY FOG AND LOW CLOUDS.
RAIN AND SHOWERS LIKELY IN WESTERN PA BY MID-LATE MORNING SLOWLY
SPREADING EAST. VFR IN EAST BUT AREAS MVFR LIKELY IN AM FOG AND
THEN SHOWERS IN WESTERN AREAS.
OUTLOOK...
TUE...MAINLY VFR...WITH SHRA/TSRA POSSIBLE.
WED...MORNING FOG/LOW CLOUDS SHRA/TSRA LIKELY WEST CHANCE EAST.
THU-FRI...MORNING FOG CHANCES EACH DAY. OVERALL VFR...BUT
INCREASING CHANCES OF MAINLY AFTERNOON SHRA/TSRA AND ASSOCIATED
RESTRICTIONS. SAT...MAINLY VFR. STILL CHANCE OF SHRA...BUT
DECREASING CHANCES.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...GRUMM
SHORT TERM...GRUMM
LONG TERM...FITZGERALD
AVIATION...GRUMM
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1114 AM EDT TUE AUG 19 2014
.SYNOPSIS...
AN UPPER LOW OVR THE W GRT LKS WILL DRIFT SLOWLY SE ACROSS UPSTATE
NY AND NEW ENG BY LATE THIS WEEK. A LARGE SFC HIGH OVR THE CANADIAN
MARITIMES WILL RIDGE SOUTHWARD INTO PA DURING THE UPCOMING WEEKEND
AND EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
LOW CLOUDS SLOWLY LIFTING AND MOVING TO THE EAST. RADAR HAS
DETECTED SHOWERS WHICH DEVELOPED ON THE WESTERN EDGE OF THIS CLOUD
SHIELD AND HAS MOVED INTO CLEARFIELD COUNTY. SOME HINTS OF WEAK
CONVECTION IN THE HRRR AND 4KM NAM. USED THESE MODELS TO ADD
TEXTURE TO THE FORECAST SHOWING SHOWERS AND ISOLATED THUNDERSTORMS
DRIFTING ACROSS PENNSYLVANIA THIS MORNING AND AFTERNOON.
TRIED TO KEEP POPS IN CHANCE RANGE AS THERE IS LIMITED
ORGANIZATION TO THE CONVECTION. HOWEVER...3KM HRRR UPDATES FROM
NCEPS EXPERIMENTAL HRRR SHOW DIFFERENT AREAS OF SHOWERS IN CENTRAL
PA ALL AFTERNOON AND NOW IMPLY MORE ORGANIZED THUNDERSTORMS IN
S-SE COUNTIES IN LATE AFTERNOON EVENING. SEE HOW THIS EVOLVES.
SKIES SHOULD SLOWLY GET BETTER DURING DAY CENTRAL AREAS.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
SREF AND NAM CONTINUE TO SHOW CHANCE TO SLIGHT CHANCE OF SHOWERS
OVERNIGHT. THE SURGE OF CAPE AND PW INTO WESTERN PA IN THE SREF
AND NAM...SIMILAR TO OLDER GEFS/GFS IMPLY SOME MORE ORGANIZED RAIN
POSSIBLE ON WEDNESDAY. USED A BLEND TO GET THE POPS AND THE 12KM
NAM TO ADD SOME TEXTURE TO CONVECTION AND RAIN AREA THAT APPEARS
TO BE POISED TO MOVE WEST TO EAST ACROSS THE REGION WEDNESDAY.
THE SREF POPS/PDF IMPLIES SHOWERS COMING INTO WEST AROUND 1500 UTC
AND MOST OF CENTRAL TWO THIRDS OF REGION BY LATE EVENING. SREF IS
KIND OF OPTIMISTIC SOUTHEAST PA COULD HAVE YET ANOTHER MOSTLY
RAIN FREE DAY WEDNESDAY.
THE KEY FEATURES ARE THE RETROGRADING RIDGE OVER EASTERN CANADA
WHICH IS TAKING THE UMPH OUT OF THE SYSTEMS CUTTING UNDER THIS
FEATURE. IN MOST MODELS THE NEAR 1SD ABOVE NORMAL PW SURGES WEAKEN
AS THE MOVE INTO PA. THUS MORE OPTIMISTIC...SREF-LIKE IN THE WEST
THAN THE EAST WITH RAINFALL AND NOT REALLY CONFIDENT GOING LIKELY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THURSDAY LOOKS LIKE ANOTHER UNSETTLED DAY...AS UPPER LOW MAKES
IT/S CLOSEST PASS TO PA...TRACKING ACROSS UPSTATE NY. COOL TEMPS
ALOFT...COMBINED WITH DIURNAL HEATING...SHOULD YIELD NUMEROUS SHRA
AND TSRA BY AFTN. HAVE RAISED POPS TO THE LIKELY CATEGORY BASED ON
00Z OPER AND GEFS OUTPUT. SOUTHERLY LL JET AND PLUME OF HIGH
PWATS WILL HAVE PASSED NE OF THE AREA THURSDAY...LIMITING THE
THREAT OF ANY HVY RAINFALL. MDL BLENDED QPF IS IN THE QUARTER TO
HALF INCH RANGE THURSDAY. THE NUMEROUS SHOWERS AND COOLER TEMPS
ALOFT WILL RESULT IN HIGH TEMPS BLW NORMAL FOR AUGUST...WITH
MAXES MAINLY IN THE 70S.
LATEST MED RANGE GUIDANCE POINTING TOWARD DRIER WX FRIDAY INTO
EARLY NEXT WEEK...AS SUBTROPICAL HIGH IS PROGGED TO EDGE TOWARD
THE REGION FROM THE MIDWEST. DAILY RING OF FIRE CONVECTION ON NE
PERIPHERY OF THIS RIDGE WILL THREATEN WESTERN PA DURING THE
FRI-SUN TIME FRAME...WHILE EASTERN PA IS LIKELY TO REMAIN DRY.
DESPITE APPROACH OF UPPER RIDGE...NO BIG WARMUP EXPECTED...AS
LARGE SFC HIGH OVR THE CANADIAN MARITIMES WILL CIRCULATE AN
EASTERLY FLOW INTO CENTRAL PA. THERE MAY BE ISSUE WITH AM LOW
CLOUDS/FOG DUE TO THE EXPECTED MOISTLY SERLY FLOW OVR THE AREA.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS WILL GIVE WAY TO FOG AND LOWERING VSBYS OVERNIGHT
UNDER CLEAR SKIES AND LIGHT WINDS. EXPECT WIDESPREAD MVFR TO IFR
VSBYS AND CIGS TO DEVELOP OVERNIGHT AT MOST CENTRAL AND NORTHERN
AIRFIELDS. HOWEVER...HAVE NOT INCLUDED FOG IN THE LOWER
SUSQUEHANNA TAFS OF KMDT AND KLNS...AS CONFIDENCE OF FORMATION IS
LOWER. IF FOG DOES DEVELOP...LIKELY TO BE IN THE MVFR RANGE AT
THESE LOCATIONS.
CURRENT TIMING OF FOG IS FOR DEVELOPMENT AROUND 07Z IN MOST
LOCATIONS...WITH THE DENSEST FOG BETWEEN 09Z AND 12Z.
AFTER MORNING FOG...EXPECT GENERALLY VFR CONDITIONS. THERE IS A
THREAT FOR SHRA/TSRA...MOST LIKELY IN THE SOUTHWEST AND LEAST
LIKELY IN THE NORTHEAST.
A VERY SLOW APPROACHING UPPER LOW WILL SLOWLY INCREASE CHANCES FOR
DAILY SHOWERS AND POTENTIAL AFTERNOON TSRA FOR THE BALANCE OF THE
WEEK. CURRENTLY...LATER WEDNESDAY AND THURSDAY LOOK LIKE THE
HIGHEST LIKELIHOOD OF PRECIPITATION...WITH SURFACE FRONT CROSSING
THE REGION.
OUTLOOK...
TUE...MORNING FOG...THEN MAINLY VFR...WITH SHRA/TSRA POSSIBLE.
WED-FRI...MORNING FOG CHANCES EACH DAY. OVERALL VFR...BUT
INCREASING CHANCES OF MAINLY AFTERNOON SHRA/TSRA AND ASSOCIATED
RESTRICTIONS.
SAT...MAINLY VFR. STILL CHANCE OF SHRA...BUT DECREASING CHANCES.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...GRUMM
SHORT TERM...GRUMM
LONG TERM...FITZGERALD
AVIATION...GRUMM/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
756 AM EDT TUE AUG 19 2014
.SYNOPSIS...
AN UPPER LOW OVR THE W GRT LKS WILL DRIFT SLOWLY SE ACROSS UPSTATE
NY AND NEW ENG BY LATE THIS WEEK. A LARGE SFC HIGH OVR THE CANADIAN
MARITIMES WILL RIDGE SOUTHWARD INTO PA DURING THE UPCOMING WEEKEND
AND EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
WEAK UPPER-LEVEL LOWS ARE STRUGGLING TO MAKE IT UNDER THE
RETROGRADING UPPER LEVEL RIDGE. MODELS FOR DAYS NOW HAVE BEEN
WETTER THAN REALITY. THE SREF AND GEFS ARE MORE ROBUST WITH SHOWER
POTENTIAL TODAY THAN THE HIGH RESOLUTION CONVECTIVE FOLLOWING
MODELS.
LATEST 4KM NAM AND 3KM HRRR IMPLY SOME VERY ISOLATED CONVECTION
ABOUT CENTRAL PA THIS AFTERNOON AND EARLY EVENING. NOTHING
ORGANIZED OR SIGNIFICANT. SORT OF A QUANDARY HOW TO EFFECTIVELY
USE THESE DATA VERSE THE LARGER SCALE MODELS WHERE CONVECTION IS
GENERATED BY RELEASING INSTABILITY IN THE CONVECTIVE
PARAMETERIZATION SCHEMES (CPS). BIASED POPS LOWER TOWARD
CONVECTIVE ALLOWING MODELS THAT DO NOT USE CPS.
MODELS IMPLY PARTLY TO MOSTLY CLOUDY TODAY. FIRST BATCH OF LOW
CLOUDS IN SW PA WILL SHRINK AS IT ADVECTS ACROSS THE STATE.
TEMPERATURE WISE CLOSE TO NORMAL.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
ANY SHOWER ACTIVITY THAT DEVELOPS SHOULD FADE FAST AROUND SUNSET.
BUILDING 5940M RIDGE IN SOUTHERN US AND BLOCKING RIDGE TO OUR
NORTH. WE ARE STUCK IN THE SQUEEZE PLAY BETWEEN THEM. AN ANEMIC
FRONTAL SYSTEM TRIES TO PUSH THROUGH THE REGION. SREF LARGER SCALE
MODELS SHOW SOME SURGE OF SLIGHTLY ABOVE NORMAL PW AND SOME CAPE
INTO WESTERN PA. POPS SHOULD DROP OFF TO EAST AS THIS SYSTEM WILL
WEAKEN AS IT MOVES BENEATH THE BLOCK. BEST CHANCE...AS MENTIONED
BELOW FOR SEVERAL TENTHS WOULD BE IN WEST VERY LIGHT RAINFALL IN
EASTERN AREAS.
PREVIOUS: PASSAGE OF SHORTWAVE AND COOLING OF BLYR SHOULD CAUSE
ANY EARLY EVENING SHOWERS TO DIMINISH SHORTLY AFTER SUNSET.
HOWEVER...APPROACH OF UPPER LOW AND ASSOC LL JET/PLUME OF
ANOMALOUS PWATS COULD SPREAD SHRA/TSRA INTO THE NW MTNS TOWARD
DAWN WED.
HAVE RAISED POPS MARKEDLY ACROSS THE AREA WED...AS MDLS NOW IN
AGREEMENT WITH TIMING OF LL JET/PLUME OF ANOMALOUS PWATS. BLEND OF
OPER AND ENSEMBLE GUIDANCE SUGGESTS MOST LIKELY RAINFALL WED WILL
RANGE FROM LESS THAN 0.10 INCHES SE OF HARRISBURG...TO ARND A HALF
INCH ACROSS WARREN CO. HOWEVER...MUCH HIGHER LOCALIZED AMTS ARE
LIKELY ACROSS THE W MTNS...WHERE ENVIRONMENT OF MODERATE INSTABILITY
AND HIGH PWATS WILL MAKE LOCALLY HVY TSRA POSSIBLE. CONVECTION-
ALLOWING MDLS SUPPORT THIS SCENARIO WITH SPOT AMTS OF ARND 2
INCHES ON WED ACROSS THE W MTNS. A MORE STABLE MARITIME AIR MASS
OVR EASTERN PA WILL MAKE TSRA UNLIKELY THERE.
GEFS 925 TEMPS ARE SUPPORTIVE OF HIGH TEMPS WED FROM THE M70S OVR
THE ALLEGHENY PLATEAU...TO THE L80S OVR THE SUSQ VALLEY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THURSDAY LOOKS LIKE ANOTHER UNSETTLED DAY...AS UPPER LOW MAKES
IT/S CLOSEST PASS TO PA...TRACKING ACROSS UPSTATE NY. COOL TEMPS
ALOFT...COMBINED WITH DIURNAL HEATING...SHOULD YIELD NUMEROUS SHRA
AND TSRA BY AFTN. HAVE RAISED POPS TO THE LIKELY CATEGORY BASED ON
00Z OPER AND GEFS OUTPUT. SOUTHERLY LL JET AND PLUME OF HIGH
PWATS WILL HAVE PASSED NE OF THE AREA THURSDAY...LIMITING THE
THREAT OF ANY HVY RAINFALL. MDL BLENDED QPF IS IN THE QUARTER TO
HALF INCH RANGE THURSDAY. THE NUMEROUS SHOWERS AND COOLER TEMPS
ALOFT WILL RESULT IN HIGH TEMPS BLW NORMAL FOR AUGUST...WITH
MAXES MAINLY IN THE 70S.
LATEST MED RANGE GUIDANCE POINTING TOWARD DRIER WX FRIDAY INTO
EARLY NEXT WEEK...AS SUBTROPICAL HIGH IS PROGGED TO EDGE TOWARD
THE REGION FROM THE MIDWEST. DAILY RING OF FIRE CONVECTION ON NE
PERIPHERY OF THIS RIDGE WILL THREATEN WESTERN PA DURING THE
FRI-SUN TIME FRAME...WHILE EASTERN PA IS LIKELY TO REMAIN DRY.
DESPITE APPROACH OF UPPER RIDGE...NO BIG WARMUP EXPECTED...AS
LARGE SFC HIGH OVR THE CANADIAN MARITIMES WILL CIRCULATE AN
EASTERLY FLOW INTO CENTRAL PA. THERE MAY BE ISSUE WITH AM LOW
CLOUDS/FOG DUE TO THE EXPECTED MOISTLY SERLY FLOW OVR THE AREA.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS WILL GIVE WAY TO FOG AND LOWERING VSBYS OVERNIGHT
UNDER CLEAR SKIES AND LIGHT WINDS. EXPECT WIDESPREAD MVFR TO IFR
VSBYS AND CIGS TO DEVELOP OVERNIGHT AT MOST CENTRAL AND NORTHERN
AIRFIELDS. HOWEVER...HAVE NOT INCLUDED FOG IN THE LOWER
SUSQUEHANNA TAFS OF KMDT AND KLNS...AS CONFIDENCE OF FORMATION IS
LOWER. IF FOG DOES DEVELOP...LIKELY TO BE IN THE MVFR RANGE AT
THESE LOCATIONS.
CURRENT TIMING OF FOG IS FOR DEVELOPMENT AROUND 07Z IN MOST
LOCATIONS...WITH THE DENSEST FOG BETWEEN 09Z AND 12Z.
AFTER MORNING FOG...EXPECT GENERALLY VFR CONDITIONS. THERE IS A
THREAT FOR SHRA/TSRA...MOST LIKELY IN THE SOUTHWEST AND LEAST
LIKELY IN THE NORTHEAST.
A VERY SLOW APPROACHING UPPER LOW WILL SLOWLY INCREASE CHANCES FOR
DAILY SHOWERS AND POTENTIAL AFTERNOON TSRA FOR THE BALANCE OF THE
WEEK. CURRENTLY...LATER WEDNESDAY AND THURSDAY LOOK LIKE THE
HIGHEST LIKELIHOOD OF PRECIPITATION...WITH SURFACE FRONT CROSSING
THE REGION.
OUTLOOK...
TUE...MORNING FOG...THEN MAINLY VFR...WITH SHRA/TSRA POSSIBLE.
WED-FRI...MORNING FOG CHANCES EACH DAY. OVERALL VFR...BUT
INCREASING CHANCES OF MAINLY AFTERNOON SHRA/TSRA AND ASSOCIATED
RESTRICTIONS.
SAT...MAINLY VFR. STILL CHANCE OF SHRA...BUT DECREASING CHANCES.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...GRUMM
SHORT TERM...GRUMM/FITZGERALD
LONG TERM...FITZGERALD
AVIATION...JUNG/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
747 AM EDT TUE AUG 19 2014
.SYNOPSIS...
AN UPPER LOW OVR THE W GRT LKS WILL DRIFT SLOWLY SE ACROSS UPSTATE
NY AND NEW ENG BY LATE THIS WEEK. A LARGE SFC HIGH OVR THE CANADIAN
MARITIMES WILL RIDGE SOUTHWARD INTO PA DURING THE UPCOMING WEEKEND
AND EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
WEAK UPPER-LEVEL LOWS ARE STRUGGLING TO MAKE IT UNDER THE
RETROGRADING UPPER LEVEL RIDGE. MODELS FOR DAYS NOW HAVE BEEN
WETTER THAN REALITY. THE SREF AND GEFS ARE MORE ROBUST WITH SHOWER
POTENTIAL TODAY THAN THE HIGH RESOLUTION CONVECTIVE FOLLOWING
MODELS.
LATEST 4KM NAM AND 3KM HRRR IMPLY SOME VERY ISOLATED CONVECTION
ABOUT CENTRAL PA THIS AFTERNOON AND EARLY EVENING. NOTHING
ORGANIZED OR SIGNIFICANT. SORT OF A QUANDARY HOW TO EFFECTIVELY
USE THESE DATA VERSE THE LARGER SCALE MODELS WHERE CONVECTION IS
GENERATED BY RELEASING INSTABILITY IN THE CONVECTIVE
PARAMETERIZATION SCHEMES (CPS). BIASED POPS LOWER TOWARD
CONVECTIVE ALLOWING MODELS THAT DO NOT USE CPS.
MODELS IMPLY PARTLY TO MOSTLY CLOUDY TODAY. FIRST BATCH OF LOW
CLOUDS IN SW PA WILL SHRINK AS IT ADVECTS ACROSS THE STATE.
TEMPERATURE WISE CLOSE TO NORMAL.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
ANY SHOWER ACTIVITY THAT DEVELOPS SHOULD FADE FAST AROUND SUNSET.
BUILDING 5940M RIDGE IN SOUTHERN US AND BLOCKING RIDGE TO OUR
NORTH. WE ARE STUCK IN THE SQUEEZE PLAY BETWEEN THEM. AN ANEMIC
FRONTAL SYSTEM TRIES TO PUSH THROUGH THE REGION. SREF LARGER SCALE
MODELS SHOW SOME SURGE OF SLIGHTLY ABOVE NORMAL PW AND SOME CAPE
INTO WESTERN PA. POPS SHOULD DROP OFF TO EAST AS THIS SYSTEM WILL
WEAKEN AS IT MOVES BENEATH THE BLOCK. BEST CHANCE...AS MENTIONED
BELOW FOR SEVERAL TENTHS WOULD BE IN WEST VERY LIGHT RAINFALL IN
EASTERN AREAS.
PREVIOUS: PASSAGE OF SHORTWAVE AND COOLING OF BLYR SHOULD CAUSE
ANY EARLY EVENING SHOWERS TO DIMINISH SHORTLY AFTER SUNSET.
HOWEVER...APPROACH OF UPPER LOW AND ASSOC LL JET/PLUME OF
ANOMALOUS PWATS COULD SPREAD SHRA/TSRA INTO THE NW MTNS TOWARD
DAWN WED.
HAVE RAISED POPS MARKEDLY ACROSS THE AREA WED...AS MDLS NOW IN
AGREEMENT WITH TIMING OF LL JET/PLUME OF ANOMALOUS PWATS. BLEND OF
OPER AND ENSEMBLE GUIDANCE SUGGESTS MOST LIKELY RAINFALL WED WILL
RANGE FROM LESS THAN 0.10 INCHES SE OF HARRISBURG...TO ARND A HALF
INCH ACROSS WARREN CO. HOWEVER...MUCH HIGHER LOCALIZED AMTS ARE
LIKELY ACROSS THE W MTNS...WHERE ENVIRONMENT OF MODERATE INSTABILITY
AND HIGH PWATS WILL MAKE LOCALLY HVY TSRA POSSIBLE. CONVECTION-
ALLOWING MDLS SUPPORT THIS SCENARIO WITH SPOT AMTS OF ARND 2
INCHES ON WED ACROSS THE W MTNS. A MORE STABLE MARITIME AIR MASS
OVR EASTERN PA WILL MAKE TSRA UNLIKELY THERE.
GEFS 925 TEMPS ARE SUPPORTIVE OF HIGH TEMPS WED FROM THE M70S OVR
THE ALLEGHENY PLATEAU...TO THE L80S OVR THE SUSQ VALLEY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THURSDAY LOOKS LIKE ANOTHER UNSETTLED DAY...AS UPPER LOW MAKES
IT/S CLOSEST PASS TO PA...TRACKING ACROSS UPSTATE NY. COOL TEMPS
ALOFT...COMBINED WITH DIURNAL HEATING...SHOULD YIELD NUMEROUS SHRA
AND TSRA BY AFTN. HAVE RAISED POPS TO THE LIKELY CATEGORY BASED ON
00Z OPER AND GEFS OUTPUT. SOUTHERLY LL JET AND PLUME OF HIGH
PWATS WILL HAVE PASSED NE OF THE AREA THURSDAY...LIMITING THE
THREAT OF ANY HVY RAINFALL. MDL BLENDED QPF IS IN THE QUARTER TO
HALF INCH RANGE THURSDAY. THE NUMEROUS SHOWERS AND COOLER TEMPS
ALOFT WILL RESULT IN HIGH TEMPS BLW NORMAL FOR AUGUST...WITH
MAXES MAINLY IN THE 70S.
LATEST MED RANGE GUIDANCE POINTING TOWARD DRIER WX FRIDAY INTO
EARLY NEXT WEEK...AS SUBTROPICAL HIGH IS PROGGED TO EDGE TOWARD
THE REGION FROM THE MIDWEST. DAILY RING OF FIRE CONVECTION ON NE
PERIPHERY OF THIS RIDGE WILL THREATEN WESTERN PA DURING THE
FRI-SUN TIME FRAME...WHILE EASTERN PA IS LIKELY TO REMAIN DRY.
DESPITE APPROACH OF UPPER RIDGE...NO BIG WARMUP EXPECTED...AS
LARGE SFC HIGH OVR THE CANADIAN MARITIMES WILL CIRCULATE AN
EASTERLY FLOW INTO CENTRAL PA. THERE MAY BE ISSUE WITH AM LOW
CLOUDS/FOG DUE TO THE EXPECTED MOISTLY SERLY FLOW OVR THE AREA.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS WILL GIVE WAY TO FOG AND LOWERING VSBYS OVERNIGHT
UNDER CLEAR SKIES AND LIGHT WINDS. EXPECT WIDESPREAD MVFR TO IFR
VSBYS AND CIGS TO DEVELOP OVERNIGHT AT MOST CENTRAL AND NORTHERN
AIRFIELDS. HOWEVER...HAVE NOT INCLUDED FOG IN THE LOWER
SUSQUEHANNA TAFS OF KMDT AND KLNS...AS CONFIDENCE OF FORMATION IS
LOWER. IF FOG DOES DEVELOP...LIKELY TO BE IN THE MVFR RANGE AT
THESE LOCATIONS.
CURRENT TIMING OF FOG IS FOR DEVELOPMENT AROUND 07Z IN MOST
LOCATIONS...WITH THE DENSEST FOG BETWEEN 09Z AND 12Z.
AFTER MORNING FOG...EXPECT GENERALLY VFR CONDITIONS. THERE IS A
THREAT FOR SHRA/TSRA...MOST LIKELY IN THE SOUTHWEST AND LEAST
LIKELY IN THE NORTHEAST.
A VERY SLOW APPROACHING UPPER LOW WILL SLOWLY INCREASE CHANCES FOR
DAILY SHOWERS AND POTENTIAL AFTERNOON TSRA FOR THE BALANCE OF THE
WEEK. CURRENTLY...LATER WEDNESDAY AND THURSDAY LOOK LIKE THE
HIGHEST LIKELIHOOD OF PRECIPITATION...WITH SURFACE FRONT CROSSING
THE REGION.
OUTLOOK...
TUE...MORNING FOG...THEN MAINLY VFR...WITH SHRA/TSRA POSSIBLE.
WED-FRI...MORNING FOG CHANCES EACH DAY. OVERALL VFR...BUT
INCREASING CHANCES OF MAINLY AFTERNOON SHRA/TSRA AND ASSOCIATED
RESTRICTIONS.
SAT...MAINLY VFR. STILL CHANCE OF SHRA...BUT DECREASING CHANCES.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...GRUMM
SHORT TERM...GRUMM/FITZGERALD
LONG TERM...FITZGERALD
AVIATION...JUNG/GARTNER
AREA FORECAST DISCUSSION
NWS PUEBLO CO
320 PM MDT TUE AUG 19 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 249 PM MDT TUE AUG 19 2014
WV SATELLITE IMAGERY TODAY SHOWING THE MONSOON MSTR PLUME OVR
UT...BUT SLOWLY SHIFTING EASTWARD AS AN UPR LOW MOVES SOUTHWARD
ALONG THE CA COAST. SCATTERED SHOWERS AND TSTMS ARE EXPECTED THIS
EVENING OVR THE MTNS AND UPR ARKANSAS RIVER VALLEYS...WITH ISOLD
ACTIVITY OVR THE SERN PLAINS. BY 03Z THE HRRR AND RAP SHOW LITTLE IF
ANY PCPN OVR THE SERN PLAINS...WITH JUST SOME ISOLD PCPN OVR THE MTN
AREAS. OVERNIGHT THAT UPR LOW WL MOVE OVR SRN CA AND THE MONSOON
PLUME SHIFTS INTO WRN CO. AS A WX DISTURBANCE THE MSTR LIFTS
NORTHEASTWARD ACRS NWRN CO...SOME PCPN WL PROBABLY CONTINUE THRU THE
NIGHT ALONG THE CONTDVD...ESPECIALLY OVR THE CENTRAL CO MTNS WHICH
WL BE CLOSEST TO THE DISTURBANCE AND BETTER MSTR.
ON WED THE UPR LOW IS EXPECTED TO REMAIN OVR SRN CA. THE BEST MSTR
GOES NORTH OF THE AREA WITH THAT DISTURBANCE...AND MODELS ARE MAINLY
SHOWING SPOTTY PCPN FOR THE FORECAST AREA. WILL KEEP SCT POPS OVR
THE MTNS AREAS FOR WED AFTERNOON AND ISOLD POPS OVR THE SAN LUIS
VALLEY AND I-25 CORRIDOR. HIGH TEMPS ON WED SHOULD GENERALLY BE
AROUND TO A LITTLE ABOVE AVERAGE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 249 PM MDT TUE AUG 19 2014
THE UPPER LEVEL PATTERN IS FORECAST TO FEATURE A BROAD UPPER LEVEL
TROUGH OVER THE NORTHWEST TO NORTH-CENTRAL CONUS AND A HIGH
PRESSURE CENTER OVER THE SOUTHEAST STATES. THIS WILL PUT SOUTHERN
COLORADO UNDER SOUTHWESTERLY FLOW FOR MUCH OF THE EXTENDED. THERE
ARE MODEL DIFFERENCES IN HOW THEY WANT TO HANDLE UPPER LEVEL
DISTURBANCES IN THE FLOW...AND ENSEMBLES DEVELOP HIGH SPREADS BY
THIS WEEKEND LEADING TO LOWER CONFIDENCE IN THE LAST COUPLE OF
DAYS OF THE EXTENDED PERIOD.
THE GFS HAS REMAINED CONSISTENT FROM RUN TO RUN WITH AN UPPER
LEVEL LOW OVER SOUTHERN CALIFORNIA AND EJECTING IT NORTHEAST
ACROSS COLORADO ON THURSDAY NIGHT INTO FRIDAY. THE LATEST ECMWF IS
MORE IN LINE WITH THIS SOLUTION...HOWEVER IS ABOUT 24 HOURS SLOWER
IN EJECTING THE SYSTEM OUT. THE BIGGEST FORECAST CHANGE FOR THE
GFS IS WHERE THE SYSTEM DEVELOPS CONVECTION ON THURSDAY.
EXPECT ONGOING CONVECTION ACROSS THE MOUNTAINS WEDNESDAY EVENING
WITH MODELS BRINGING BAND EAST ACROSS THE PLAINS THROUGH THE
OVERNIGHT HOURS AS A WEAK DISTURBANCE LIFTS NORTHEAST. BY THURSDAY
MORNING...THE LOW PRESSURE CENTER OVER SOUTHERN CALIFORNIA IS
FORECAST TO OPEN UP AND LIFT NORTHEAST ACROSS COLORADO.
THUNDERSTORMS ARE FORECAST TO DEVELOP OVER THE MOUNTAINS BY LATE
THURSDAY MORNING. THUNDERSTORMS DEVELOPMENT IS THEN EXPECTED
EASTWARD ACROSS THE PALMER DIVIDE THROUGH THE AFTERNOON AND
EVENING HOURS. THE PREVIOUS RUN OF THE GFS HAD THIS THUNDERSTORM
DEVELOPMENT FURTHER SOUTH OVER SOUTHERN COLORADO...SO WHERE THIS
DISTURBANCE EJECTS WILL PLAY A ROLE IN WHAT AREAS SEEN THE
POTENTIAL FOR HEAVIER PRECIPITATION. THE ECMWF AND NAM SOLUTIONS
ARE A BIT SLOWER WITH THIS SYSTEM...WITH IT EJECTING ACROSS
SOUTHERN COLORADO ON FRIDAY AFTERNOON. IF THIS IS THE
CASE...THURSDAYS CONVECTION WILL LIKELY REMAIN TIED TO THE TERRAIN
AND PALMER DIVIDE...WITH NOT MUCH EXPECTED ON THE PLAINS. THE
HEAVY PRECIPITATION CHANCES WOULD THEN FOCUS ON FRIDAY AFTERNOON
AND NIGHT...WITH HEAVY RAINFALL AND THE POTENTIAL FOR FLASH
FLOODING. THE IMPORTANT THING TO REMEMBER...IS THAT SOME TIME
BETWEEN THURSDAY AND FRIDAY NIGHT...SOUTHERN COLORADO WILL LIKELY
SEE A PERIOD OF WIDESPREAD HEAVIER RAINFALL.
A BROAD TOUGH IS FORECAST TO REMAIN ENTRENCHED ACROSS THE PACIFIC
NORTHWEST INTO THE NORTHERN PLAINS SATURDAY THROUGH TUESDAY. THE
MAIN FORECAST ISSUE WILL BE HOW DEEP THE TROUGH GETS. THE GFS
SOLUTIONS DIGS IT THE FURTHEST SOUTH...WITH CONTINUED ACTIVE
WEATHER ACROSS THE AREA...WHILE THE ECMWF IS KEEP MOST OF THE
ENERGY CONFINED TO OUR NORTH WITH LESS CHANCES FOR PRECIPITATION.
A COLD FRONT IS FORECAST TO DROP SOUTH ACROSS THE PLAINS ON SUNDAY
WHICH MAY BE THE BEST OPPORTUNITY FOR WIDESPREAD PRECIPITATION
ACROSS THE AREA. OTHERWISE...CONVECTION WILL LIKELY REMAIN OVER
THE MOUNTAINS WITH LIMITED ACTIVITY OVER THE PLAINS. MOZLEY
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 249 PM MDT TUE AUG 19 2014
VFR CONDITIONS ARE EXPECTED THIS EVENING THROUGH WEDNESDAY AFTERNOON
AT KCOS...KPUB AND KALS. SOME TSTMS MAY MOVE INTO THE VCNTY OF THE
TERMINAL SITES THIS EVENING...AND THEN AGAIN ON WED AFTERNOON. THE
MAIN THREATS WITH TSTMS WILL BE GUSTY WINDS AND LIGHTNING...BUT SOME
LOCALLY HEAVY RAIN IS ALSO POSSIBLE.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...28
LONG TERM...MOZLEY
AVIATION...28
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
125 PM CDT TUE AUG 19 2014
.DISCUSSION...
1114 AM CDT
MAIN CONCERNS/CHALLENGES FOR MORNING UPDATE WERE MONITORING
SHOWER/THUNDERSTORM CHANCES THIS MORNING THROUGH THE AFTERNOON.
LATEST RADAR IMAGERY SHOWING THUNDERSTORM COMPLEX WHICH HAS MOVED
THROUGH NORTHERN MISSOURI AND WEST CENTRAL ILLINOIS THIS
MORNING...CONTINUING EAST AND CURRENTLY IMPACTING AREAS FROM LA
SALLE TO PONTIAC. EXPECT THIS COMPLEX TO CONTINUE EAST THROUGH THE
EARLY AFTERNOON...WITH THUNDERSTORMS LIKELY TO BUILD FURTHER TO
THE NORTHEAST TOWARDS THE CHICAGO METRO AREA OVER THE ONE TO TWO
HOURS...ALONG APPROACHING SURFACE TROUGH AND FRONT TO THE
NORTHWEST. FEEL FAIRLY CONFIDENT WITH THIS POSSIBILITY AS THIS
MID LEVEL WAVE AND SURFACE TROUGH/FRONT WILL MOVE THROUGH AN
ENVIRONMENT WITH LITTLE TO NO CIN AND MODERATE INSTABILITY.
CONFIDENCE IS LOWER WITH REGARD TO INTENSITY OF THESE STORMS AS
LARGE CLOUD SHIELD HAS LIMITED STEEPNESS OF LOW LEVEL LAPSE
RATES...AND WITH WESTERLIES/BULK SHEAR VALUES REMAINING ON THE
LOWER SIDE. COULD SEE THE STRONGEST DEVELOPMENT OCCURRING OVER
EAST CENTRAL ILLINOIS AND NORTHWEST INDIANA AS THIS BROKEN LINE OF
THUNDERSTORMS PUSHES EAST/SOUTHEAST THROUGH MID AFTERNOON...WITH
AN ISOLATED SEVERE THREAT STILL POSSIBLE. HIGH WIND GUSTS WOULD
BE THE MAIN THREAT...AS WELL AS HEAVY RAINFALL. SURFACE DEWPOINTS
RIGHT AROUND 70 DEG WITH AXIS OF HIGHEST PWATS RIGHT OVER THE
SOUTHEAST TWO THIRDS OF THE CWA SHOULD ALLOW FOR EFFICIENT RAIN
PRODUCERS TODAY...AND HAVE MADE MENTION OF THIS POTENTIAL FOR
LOCALLY HEAVY RAINFALL IN THE HWO.
RODRIGUEZ
//PREV DISCUSSION...
336 AM CDT
SHORT TERM...THROUGH TUESDAY NIGHT...
FOR THE REMAINDER OF THE OVERNIGHT HOURS...THE MAIN FOCUS WILL BE
THE PROGRESSION OF THUNDERSTORMS ALONG A WEAK COLD FRONT MOVING
THROUGH SRN WI/NERN IA AND PUSHING INTO NRN IL. THE MAIN SHORTWAVE
ASSOCIATED WITH THE ACTIVITY IS MOVING QUICKLY OVER ERN WI AND CNTRL
LAKE MICHIGAN. AS THE SHORTWAVE RACES RATHER QUICKLY TO THE
EAST...THE LINE OF THUNDERSTORMS IS TAKING ON A MORE EAST-WEST
ORIENTATION ALONG THE WISCONSIN BORDER...BUT IS SAGGING INTO
WINNEBAGO AND BOONE COUNTIES. SOME STRONG THUNDERSTORMS ALONG THIS
PORTION OF THE FRONT HAVE THE POTENTIAL TO PRODUCE SOME SMALL HAIL
AND LOCALIZED STRONGER WIND GUSTS. THERE IS STILL SOME CONCERN
ABOUT HOW FAR SOUTH THE ACTIVITY WILL REACH. CURRENTLY ANTICIPATE
THAT THE GREATEST THUNDERSTORM COVERAGE SHOULD BE OVER THE NORTHERN
TIER COUNTIES ALONG THE WISCONSIN BORDER. HOWEVER...THERE IS STILL
SOME SWLY FLOW ALOFT WITH WITH 850MB WINDS ARND 30KT...WHILE SFC
FLOW IS LIGHT AND GENERALLY SOUTHERLY. THERE IS PLENTY OF LOW
LEVEL MOISTURE IN PLACE AND WITH AT LEAST MODEST ISENTROPIC LIFT IN
THE WARM SECTOR WHICH COULD AT LEAST GENERATE SCT SHRA/TSRA. THE
LATEST HIGH RES GUIDANCE IS INDICATING A DIMINISHING TREND TO THE
CONVECTION ALONG THE SRN PORTION OF THE FRONT AS IT MOVES THROUGH
THE AREA THIS MORNING...SO HAVE BACKED OFF POPS TO SLIGHT
CHANCE...BUT WITH DAYTIME WARMING...THERE SHOULD BE AN UPTICK IN THE
CONVECTIVE ACTIVITY AD THE FRONT PUSHES THROUGH THE SRN PORTIONS OF
THE CHICAGO METRO AREA AND INTO ECNTRL IL AND NWRN INDIANA. PORTIONS
OF THE CWA. WITH INCREASING SLWY DEVELOPING WITH THE APPROACH OF
THE COLD FRONT AND VEERING TO WLY FOLLOWING THE FROPA...NO LAKE
BREEZE DEVELOPMENT IS EXPECTED TODAY AND THE WARM AIR SHOULD HAVE NO
TROUBLE REACHING RIGHT UP TO THE LAKEFRONT...WITH TEMPS IN THE LOWER
TO MIDDLE 80S EXPECTED FOR THE ENTIRE CWA.
ANY RESIDUAL PCPN ASSOCIATED WITH THE PASSING COLD FRONT SHOULD PUSH
TO THE EAST OF THE CWA BY LATE THIS EVENING. WEAK HIGH PRESSURE
SHOULD BUILD IN BEHIND THE FRONT WEDNESDAY EVENING AND OVERNIGHT.
WITH GENERALLY WLY FLOW BEHIND THE FRONT...AND NO SGFNT DRY AIR
UPSTREAM...THE LOW LEVELS SHOULD REMAIN VERY MOIST...SO FOG
DEVELOPMENT LATE TUESDAY NIGHT AND POSSIBLY INTO WEDNESDAY MORNING
IS A DISTINCT POSSIBILITY.
KREIN
WEDNESDAY THROUGH THURSDAY...
MAIN FEATURE IN THE MEDIUM TERM WILL BE THE DEPARTING MID-LVL VORT
FROM THE GREAT LAKES...STEADILY WEAKENING AND EJECTING EAST.
MEANWHILE A DEVELOPING 500MB RIDGE WILL TAKE SHAPE ACROSS THE
PLAINS...THEN LIFT NORTHEAST THUR. THE STALLED FRONTAL BOUNDARY WILL
REMAIN SOUTH OF THE FORECAST AREA THRU WED THEN AS THE RIDGE
STEADILY BUILDS AND EXPANDS NORTH WARM AIR ADVECTION WILL LIFT THE
BOUNDARY NORTH. THIS WILL LIKELY FEATURE MOISTENING LLVLS WITH
DECENT ISENTROPIC LIFT ALONG THE BOUNDARY...TO SUPPORT INCREASING
POPS LATE WED FROM SOUTH TO NORTH. WHILE IT APPEARS FAVORABLE FOR A
CHANNEL OF LIKELY POPS LATE WED-EARLY THUR...THERE IS SOME CONCERN
THAT WE COULD QUICKLY BECOME CAPPED WITH A STRONG PUSH OF VERY WARM
AIR ALOFT. SOME GUIDANCE IS SUGGESTING AFT 00Z 850MB THERMAL TEMPS
RISE TO ARND 19-20 DEG C...WHICH COULD BE ENOUGH TO LIMIT
COVERAGE/INTENSITY. HOWEVER IF THIS ENDS UP BEING SLIGHTLY COOLER
ANY PRECIP THAT DOES DEVELOP COULD EASILY PRODUCE LOCALLY HEAVY
RAINFALL...AS PWAT VALUES ARE EXPECTED TO RISE TO NEAR 1.7-2.0"
OVERNIGHT. TEMPS WED WILL PUSH INTO THE MID 80S...HOWEVER IT IS
PLAUSIBLE THAT A WEAK LK BREEZE COULD FORM EARLY IN THE AFTN AND
KEEP THE NEARSHORE AREAS COOLER.
WITH WARM AIR STEADILY ADVECTING NORTH INTO THE FORECAST
AREA...EXPECT TEMPS TO REMAIN MILD OVERNIGHT IN THE MID/UPR 60S. IF
CLOUDS AND PRECIP ARRIVE EARLIER WED EVE...THEN TEMPS MAY NOT DIP
BELOW 70.
THUR WILL FEATURE STEADILY RISING MID-LVL HEIGHTS AS THE ROBUST
RIDGE ESTABLISHES ITSELF ACROSS A BULK OF OF THE REGION. THIS POSES
CHALLENGES WITH PRECIP FOR THUR. GUIDANCE CONTINUES TO FAVOR A
SHORTWAVE LIFTING NORTHEAST INTO THE UPPER MIDWEST WITH BETTER
MID-LVL VORTICITY THEN SLIDING EAST ALONG THE NORTHERN PERIPHERY OF
THE RIDGE...BEFORE DIVING SOUTHEAST TOWARDS THE EASTERN GREAT LAKES.
THIS COUPLED WITH VERY WARM 850MB TEMPS NEARING 20 DEG C MAY RESULT
IN A CAPPED ENVIRONMENT. CONFIDENCE IS NOT YET STRONG ENOUGH TO
FURTHER REDUCE POPS THUR AFTN. DEPENDING ON CLOUDS/PRECIP THUR WILL
STEER HOW WARM SFC TEMPS BECOME. GUIDANCE CONTINUES TO POINT TOWARDS
MID/UPR 80S. DEW PTS WILL BE PUSHING INTO THE LOW 70S...WHICH THE
COMBINATION OF TEMP/DEW PT COULD BE SUPPORTIVE OF HEAT INDEX VALUES
NEARING THE MID 90S.
CONCERN REMAINS FOR THUR NGT ON POPS...BUT MORE IMPORTANTLY ON
POTENTIAL FOR HEAVY RAINFALL. PWAT VALUES CONTINUE TO HOVER ARND 2"
WITH VERY WARM DEW PTS BETWEEN 72-74 DEG. WITH THE LACK OF A STRONG
WIND FIELD...STORMS COULD BE SLOW MOVING AND EASILY PRODUCE LOCALLY
HEAVY RAINFALL. OVERNIGHT LOWS MAY NOT DIP BELOW THE MID/UPR
70S...WHICH SETS THE STAGE FOR A POTENTIALLY HOT/HUMID DAY FRI.
FRIDAY THROUGH EARLY NEXT WEEK...
MID-LVL RIDGING CONTINUES TO BE PROGGED FOR THE FRI-SUN
PERIODS...WHICH SETS THE STAGE FOR POTENTIALLY A VERY WARM STRETCH
ACROSS THE REGION WITH NUMEROUS AREAS REACHING 90 DEG IN THIS
TIMEFRAME. GUIDANCE CONTINUES TO FAVOR A HIGH PROBABILITY THAT DEW
PTS WILL EASILY REMAIN IN THE 72-74 DEG RANGE FRI/SAT...WHICH
COUPLED WITH TEMPS ARND 90 COULD EASILY PRODUCE 100 DEG HEAT INDEX
READINGS. THE CURRENT ECMWF SOLUTION PAINTS AN EVEN WARMER THERMAL
RIDGE AT 850MB FOR SUN AT 23-25 DEG C. CLOUDS/PRECIP WILL LIKELY
STEER HOW WARM SUN BECOMES.
THEN ENSEMBLES CONTINUE TO DEMONSTRATE SOME CONSISTENCY THAT THE
MID-LVL RIDGE WILL WEAKEN EARLY NEXT WEEK WITH A RETURN TO TROUGHING
ACROSS THE MIDDLE OF THE CONUS. CURRENT GUIDANCE SUGGESTS A FRONTAL
BOUNDARY WILL ARRIVE IN THE MON/TUE TIMEFRAME AND BRING TEMPS BACK
TO SEASONAL OR SLIGHTLY SUB-SEASONAL CONDS FOR THE MIDDLE OF NEXT
WEEK.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* ISOL SHRA/TSRA POSSIBLE THROUGH MID AFTERNOON.
* WESTERLY WINDS GUSTING TO AROUND 20 KT THROUGH EARLY EVENING.
* POTENTIAL FOR MVFR VIS IN BR LATE TONIGHT INTO WED MORNING.
RODRIGUEZ
//DISCUSSION...UPDATED 18Z...
LATEST RADAR IMAGERY SHOWING AREA OF THUNDERSTORMS EXITING TO THE
EAST OF THE TERMINALS...BUT WITH GYY THE ONLY TERMINAL BEING
IMPACTED AT THIS TIME. THIS WILL CONTINUE EAST OVER THE NEXT HOUR
WITH GENERALLY DRY CONDITIONS THEN EXPECTED OVER THE NEXT SEVERAL
HOURS. ISOL TO WIDELY SCATTERED SHOWERS ARE STILL DEVELOPING OVER
FAR NORTHERN ILLINOIS AND SOUTHERN WISCONSIN...OUT AHEAD OF FRONT
STRETCHED FROM SOUTHERN WISCONSIN TO EASTERN IOWA. THIS WILL
LIKELY CONTINUE INTO THE AFTERNOON AS THIS FRONT DROPS TO THE
SOUTHEAST...BUT EXPECT IT TO REMAIN LIMITED IN COVERAGE AS BETTER
LIFT ALOFT IS LOST. ONLY HAVE VCSH MENTIONED DUE TO ANTICIPATED
COVERAGE...BUT WILL NEED TO CONTINUE MONITORING THE POTENTIAL FOR
A STRAY SHOWER AND EVEN AN OUTSIDE POSSIBILITY FOR A BRIEF/ISOL
STORM TO MOVE OVER THE TERMINALS. CEILINGS STILL HOVERING AROUND
MVFR/VFR...BUT WITH VFR CEILINGS EXPECTED THIS AFTERNOON THROUGH
THE REST OF THE FORECAST PERIOD. FAIRLY MOIST CONDITIONS LINGERING
TONIGHT COULD ALLOW FOR FOG DEVELOPMENT...AND HAVE CONTINUED
MENTION OF THIS IN THE TAF.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM HIGH CONFIDENCE WITH ISOL SHRA/TSRA DEVELOPING AROUND THE
TERMINALS THIS AFTERNOON...LOW CONFIDENCE WITH THIS IMPACTING
THE TERMINALS.
* HIGH CONFIDENCE WITH WIND SPEED AND DIRECTION.
* MEDIUM CONFIDENCE WITH MVFR VIS OCCURRING LATE TONIGHT INTO
WEDNESDAY MORNING.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT THROUGH SUNDAY...PERIODIC CHANCES FOR TSRA AND
OCNL REDUCED CIGS/VIS.
SUNDAY NIGHT THROUGH MONDAY...VFR. WX NIL.
&&
.MARINE...
316 AM CDT
AN AREA OF LOW PRESSURE OVER CENTRAL WISC WILL CONTINUE TO DRIFT
NORTHEAST ACROSS THE NORTHERN PORTION OF THE LAKE MIDDAY...THEN
CONTINUE TO SLIDE EAST AND WEAKEN WEDNESDAY AFTERNOON ACROSS
SOUTHEAST ONTARIO. THE GRADIENT IS EXPECTED TO TIGHTEN SLIGHTLY
FROM THE SOUTH...WITH WINDS INCREASING THIS MORNING TO ARND 15 TO
25KT. THEN AS THE LOW SLIDES EAST WINDS WILL BECOME WEST AND
DIMINISH TO ARND 10 TO 20 KT LATE TONIGHT. WAVES SHUD BE ABLE TO
BRIEFLY BUILD ACROSS THE LAKE TO ARND 2-4FT...THEN WITH A LIGHTER
GRADIENT ARRIVING WED WAVES WILL SUBSIDE TO ARND 2 FT OR LESS. IN
THE DEPARTING SFC LOW WILL BE A MUCH WEAKER GRADIENT...WITH WINDS
GENERALLY LIGHT FROM THE NORTH ARND 5 TO 10 KT ACROSS THE NORTHERN
HALF OF THE LAKE AND AROUND 10 KT FROM THE SOUTH FOR THE SOUTHERN
HALF OF THE LAKE. A WARM FRONTAL BOUNDARY WILL LIFT NORTH ACROSS
THE SOUTHERN PORTION OF THE LAKE EARLY THUR...WITH MUCH WARMER AIR
LIFTING OVER THE LAKE. AT THIS TIME FEEL THAT FOG MAY NOT
DEVELOP...BUT COULD SEE SOME HAZY CONDITIONS DEVELOP LATE IN THE
WEEK. SOUTH/SOUTHEAST WINDS FOR THE WEEKEND. THE UPPER FLOW
PATTERN DOES LOOK TO SHIFT SUNDAY OR MONDAY BRINGING A COLD FRONT
ACROSS THE LAKE WITH A SHIFT TO NORTHERLY WINDS WHICH MAY BE
RATHER BREEZY EARLY NEXT WEEK.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1244 PM CDT Tue Aug 19 2014
.UPDATE...
ISSUED AT 923 CDT TUE AUG 19 2014
Area of showers and thunderstorms associated with an upper-level
wave is currently crossing the Mississippi River into west-central
Illinois. 1417z radar imagery shows leading edge of precip extending
from Galesburg...to Rushville...to Bowling Green Missouri. Based
on timing tools, showers/thunder will arrive along the I-55
corridor by midday. HRRR and other high-res models generally show
the precip area weakening as it pushes eastward through the
morning, then potentially re-developing across east-central
Illinois later this afternoon. Made some adjustments to hourly
PoPs today, mainly to increase to categorical along/west of I-55
during the morning. Once the wave passes, rain chances will come
to an end across the Illinois River Valley by mid to late
afternoon, followed by a return to partly to mostly sunny skies.
Further east, rain chances will linger throughout the day before
coming to an end by evening.
&&
.SHORT TERM...(This evening through Wednesday)
ISSUED AT 336 AM CDT TUE AUG 19 2014
Short term models have trended slower with the front and precip that
is currently supposed to be moving into the area. But will still
have chance of precip starting in the northwest parts of the cwa
this morning. Then will progress the pcpn chances southeastward
across the cwa during the day. By this evening, most of the pcpn
will be in the eastern two thirds of the area with the highest pops
in the southeast. By overnight, the pcpn should have moved southeast
of the area so most of the area should be dry overnight, though will
keep a slight chance of pops in the southeast after midnight. Could
be some additional pcpn in the southwest late tonight, but models
keep most of pcpn west of the area through 12z.
Temps will begin the slow warming tomorrow, and am expecting mid to
upper 80s throughout the area today.
&&
.LONG TERM...(Wednesday night through Tuesday)
ISSUED AT 347 AM CDT TUE AUG 19 2014
Models still pretty consistent with the development and lift of a
boundary through the Midwest on Wednesday. Boundary will have little
reflection at the sfc with very weak flow/weak wind shift, and
thermal gradient is better represented in the mid levels. Boundary
will provide a weak focus for waves moving through the region as the
boundary lifts to the NE through the area for Wed/Wed night. Though
Wed is lacking signif pop for now, the timing of the progression is
better for early evening and into the overnight on Wednesday
night/shifting to the northeast for Thurs. Position of the boundary
or the remnants thereof will be where the majority of the precip
chances will be...increasing to the north, particularly north of
Interstate 74 from Thursday to Saturday. Ample sfc based instability
in the form of hot and humid conditions as the ridge over the
southwest opens and spreads signif heat into the Midwest. Models
have also shown consistency with 850 mb temps in the 19-25C range
from Wednesday through Sunday. This will drive the temps into the
upper 80s/lower 90s with heat indices in the upper 90s/approaching
100F. A far more summer-like pattern than much of the season so far,
and well above normal for this time of year...with breaks from the
heat provided by any thunderstorms that may have the chance to form
from more diurnal instability with any frontal forcing further to
the north. Into the extended, day 7/just into day 8, models diverge
in solutions with major difference in breaking down the upper ridge
for the Midwest.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 1244 PM CDT TUE AUG 19 2014
17z surface analysis shows cold front across eastern Iowa
approaching the Mississippi River. Earlier convection that pushed
into the Illinois River Valley ahead of the front continues to
diminish as it tracks toward the I-57 corridor. Based on latest
satellite/radar trends, it appears chances for additional
convection at KPIA are slim to none, so have gone with a dry
forecast there. Further southeast at the remaining terminals, will
carry either VCTS or a TEMPO group for thunder this afternoon.
Atmosphere has been temporarily stabilized due to clouds/showers
this morning, but as skies partially clear, think scattered
showers/storms will develop east of the Illinois River through the
afternoon. Any convection that fires up will push into Indiana by
early evening, followed by clearing skies tonight. Given clear
skies and light winds, think areas of fog will once again develop.
Have dropped visbys lowest at KPIA where quite a bit of rain fell
earlier, but have gone with 2-3 miles everywhere between 07z and
14z. After that, mostly clear skies with a light W/SW wind will
prevail by Wednesday morning.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARNES
SHORT TERM...AUTEN
LONG TERM...HJS
AVIATION...BARNES
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1113 AM CDT TUE AUG 19 2014
.DISCUSSION...
336 AM CDT
SHORT TERM...THROUGH TUESDAY NIGHT...
FOR THE REMAINDER OF THE OVERNIGHT HOURS...THE MAIN FOCUS WILL BE
THE PROGRESSION OF THUNDERSTORMS ALONG A WEAK COLD FRONT MOVING
THROUGH SRN WI/NERN IA AND PUSHING INTO NRN IL. THE MAIN SHORTWAVE
ASSOCIATED WITH THE ACTIVITY IS MOVING QUICKLY OVER ERN WI AND CNTRL
LAKE MICHIGAN. AS THE SHORTWAVE RACES RATHER QUICKLY TO THE
EAST...THE LINE OF THUNDERSTORMS IS TAKING ON A MORE EAST-WEST
ORIENTATION ALONG THE WISCONSIN BORDER...BUT IS SAGGING INTO
WINNEBAGO AND BOONE COUNTIES. SOME STRONG THUNDERSTORMS ALONG THIS
PORTION OF THE FRONT HAVE THE POTENTIAL TO PRODUCE SOME SMALL HAIL
AND LOCALIZED STRONGER WIND GUSTS. THERE IS STILL SOME CONCERN
ABOUT HOW FAR SOUTH THE ACTIVITY WILL REACH. CURRENTLY ANTICIPATE
THAT THE GREATEST THUNDERSTORM COVERAGE SHOULD BE OVER THE NORTHERN
TIER COUNTIES ALONG THE WISCONSIN BORDER. HOWEVER...THERE IS STILL
SOME SWLY FLOW ALOFT WITH WITH 850MB WINDS ARND 30KT...WHILE SFC
FLOW IS LIGHT AND GENERALLY SOUTHERLY. THERE IS PLENTY OF LOW
LEVEL MOISTURE IN PLACE AND WITH AT LEAST MODEST ISENTROPIC LIFT IN
THE WARM SECTOR WHICH COULD AT LEAST GENERATE SCT SHRA/TSRA. THE
LATEST HIGH RES GUIDANCE IS INDICATING A DIMINISHING TREND TO THE
CONVECTION ALONG THE SRN PORTION OF THE FRONT AS IT MOVES THROUGH
THE AREA THIS MORNING...SO HAVE BACKED OFF POPS TO SLIGHT
CHANCE...BUT WITH DAYTIME WARMING...THERE SHOULD BE AN UPTICK IN THE
CONVECTIVE ACTIVITY AD THE FRONT PUSHES THROUGH THE SRN PORTIONS OF
THE CHICAGO METRO AREA AND INTO ECNTRL IL AND NWRN INDIANA. PORTIONS
OF THE CWA. WITH INCREASING SLWY DEVELOPING WITH THE APPROACH OF
THE COLD FRONT AND VEERING TO WLY FOLLOWING THE FROPA...NO LAKE
BREEZE DEVELOPMENT IS EXPECTED TODAY AND THE WARM AIR SHOULD HAVE NO
TROUBLE REACHING RIGHT UP TO THE LAKEFRONT...WITH TEMPS IN THE LOWER
TO MIDDLE 80S EXPECTED FOR THE ENTIRE CWA.
ANY RESIDUAL PCPN ASSOCIATED WITH THE PASSING COLD FRONT SHOULD PUSH
TO THE EAST OF THE CWA BY LATE THIS EVENING. WEAK HIGH PRESSURE
SHOULD BUILD IN BEHIND THE FRONT WEDNESDAY EVENING AND OVERNIGHT.
WITH GENERALLY WLY FLOW BEHIND THE FRONT...AND NO SGFNT DRY AIR
UPSTREAM...THE LOW LEVELS SHOULD REMAIN VERY MOIST...SO FOG
DEVELOPMENT LATE TUESDAY NIGHT AND POSSIBLY INTO WEDNESDAY MORNING
IS A DISTINCT POSSIBILITY.
KREIN
WEDNESDAY THROUGH THURSDAY...
MAIN FEATURE IN THE MEDIUM TERM WILL BE THE DEPARTING MID-LVL VORT
FROM THE GREAT LAKES...STEADILY WEAKENING AND EJECTING EAST.
MEANWHILE A DEVELOPING 500MB RIDGE WILL TAKE SHAPE ACROSS THE
PLAINS...THEN LIFT NORTHEAST THUR. THE STALLED FRONTAL BOUNDARY WILL
REMAIN SOUTH OF THE FORECAST AREA THRU WED THEN AS THE RIDGE
STEADILY BUILDS AND EXPANDS NORTH WARM AIR ADVECTION WILL LIFT THE
BOUNDARY NORTH. THIS WILL LIKELY FEATURE MOISTENING LLVLS WITH
DECENT ISENTROPIC LIFT ALONG THE BOUNDARY...TO SUPPORT INCREASING
POPS LATE WED FROM SOUTH TO NORTH. WHILE IT APPEARS FAVORABLE FOR A
CHANNEL OF LIKELY POPS LATE WED-EARLY THUR...THERE IS SOME CONCERN
THAT WE COULD QUICKLY BECOME CAPPED WITH A STRONG PUSH OF VERY WARM
AIR ALOFT. SOME GUIDANCE IS SUGGESTING AFT 00Z 850MB THERMAL TEMPS
RISE TO ARND 19-20 DEG C...WHICH COULD BE ENOUGH TO LIMIT
COVERAGE/INTENSITY. HOWEVER IF THIS ENDS UP BEING SLIGHTLY COOLER
ANY PRECIP THAT DOES DEVELOP COULD EASILY PRODUCE LOCALLY HEAVY
RAINFALL...AS PWAT VALUES ARE EXPECTED TO RISE TO NEAR 1.7-2.0"
OVERNIGHT. TEMPS WED WILL PUSH INTO THE MID 80S...HOWEVER IT IS
PLAUSIBLE THAT A WEAK LK BREEZE COULD FORM EARLY IN THE AFTN AND
KEEP THE NEARSHORE AREAS COOLER.
WITH WARM AIR STEADILY ADVECTING NORTH INTO THE FORECAST
AREA...EXPECT TEMPS TO REMAIN MILD OVERNIGHT IN THE MID/UPR 60S. IF
CLOUDS AND PRECIP ARRIVE EARLIER WED EVE...THEN TEMPS MAY NOT DIP
BELOW 70.
THUR WILL FEATURE STEADILY RISING MID-LVL HEIGHTS AS THE ROBUST
RIDGE ESTABLISHES ITSELF ACROSS A BULK OF OF THE REGION. THIS POSES
CHALLENGES WITH PRECIP FOR THUR. GUIDANCE CONTINUES TO FAVOR A
SHORTWAVE LIFTING NORTHEAST INTO THE UPPER MIDWEST WITH BETTER
MID-LVL VORTICITY THEN SLIDING EAST ALONG THE NORTHERN PERIPHERY OF
THE RIDGE...BEFORE DIVING SOUTHEAST TOWARDS THE EASTERN GREAT LAKES.
THIS COUPLED WITH VERY WARM 850MB TEMPS NEARING 20 DEG C MAY RESULT
IN A CAPPED ENVIRONMENT. CONFIDENCE IS NOT YET STRONG ENOUGH TO
FURTHER REDUCE POPS THUR AFTN. DEPENDING ON CLOUDS/PRECIP THUR WILL
STEER HOW WARM SFC TEMPS BECOME. GUIDANCE CONTINUES TO POINT TOWARDS
MID/UPR 80S. DEW PTS WILL BE PUSHING INTO THE LOW 70S...WHICH THE
COMBINATION OF TEMP/DEW PT COULD BE SUPPORTIVE OF HEAT INDEX VALUES
NEARING THE MID 90S.
CONCERN REMAINS FOR THUR NGT ON POPS...BUT MORE IMPORTANTLY ON
POTENTIAL FOR HEAVY RAINFALL. PWAT VALUES CONTINUE TO HOVER ARND 2"
WITH VERY WARM DEW PTS BETWEEN 72-74 DEG. WITH THE LACK OF A STRONG
WIND FIELD...STORMS COULD BE SLOW MOVING AND EASILY PRODUCE LOCALLY
HEAVY RAINFALL. OVERNIGHT LOWS MAY NOT DIP BELOW THE MID/UPR
70S...WHICH SETS THE STAGE FOR A POTENTIALLY HOT/HUMID DAY FRI.
FRIDAY THROUGH EARLY NEXT WEEK...
MID-LVL RIDGING CONTINUES TO BE PROGGED FOR THE FRI-SUN
PERIODS...WHICH SETS THE STAGE FOR POTENTIALLY A VERY WARM STRETCH
ACROSS THE REGION WITH NUMEROUS AREAS REACHING 90 DEG IN THIS
TIMEFRAME. GUIDANCE CONTINUES TO FAVOR A HIGH PROBABILITY THAT DEW
PTS WILL EASILY REMAIN IN THE 72-74 DEG RANGE FRI/SAT...WHICH
COUPLED WITH TEMPS ARND 90 COULD EASILY PRODUCE 100 DEG HEAT INDEX
READINGS. THE CURRENT ECMWF SOLUTION PAINTS AN EVEN WARMER THERMAL
RIDGE AT 850MB FOR SUN AT 23-25 DEG C. CLOUDS/PRECIP WILL LIKELY
STEER HOW WARM SUN BECOMES.
THEN ENSEMBLES CONTINUE TO DEMONSTRATE SOME CONSISTENCY THAT THE
MID-LVL RIDGE WILL WEAKEN EARLY NEXT WEEK WITH A RETURN TO TROUGHING
ACROSS THE MIDDLE OF THE CONUS. CURRENT GUIDANCE SUGGESTS A FRONTAL
BOUNDARY WILL ARRIVE IN THE MON/TUE TIMEFRAME AND BRING TEMPS BACK
TO SEASONAL OR SLIGHTLY SUB-SEASONAL CONDS FOR THE MIDDLE OF NEXT
WEEK.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* CHANCE FOR SHRA/TSRA MID DAY THROUGH EARLY AFTERNOON...WITH
BETTER CHANCES FOR MDW.
* SWLY-WLY WINDS GUSTING TO 20 KT THROUGH EARLY EVENING.
* POTENTIAL FOR MVFR VIS IN BR LATE TONIGHT INTO WED MORNING.
KREIN/RODRIGUEZ
//DISCUSSION...UPDATED 12Z...
THE UPPER LEVEL DISTURBANCE THAT BROUGHT THE SHRA/TSRA TO SRN WI
AND NRN IL HAS MOVED INTO LOWER MICHIGAN AND THAT PCPN HAS MOVED
AWAY FROM THE REGION. THE TRAILING COLD FRONT IS LAGGING SW ACROSS
THE AREA FROM NEAR UGN INTO SERN IA AT 12Z. SCT SHRA/TSRA HAVE
DEVELOPED ALONG THE FRONT...MOVING THROUGH THE ORD AREA BTWN
1100-1130Z. THIS ACTIVITY IS ALSO DISSIPATING AS IT MOVES EWD AND
EXPECT THAT THE TERMINALS...WITH THE EXCEPTION OF GYY SHOULD BE
DRY FOR THE REMAINDER OF THE MORNING. THERE IS STILL SOME CONCERN
THAT ADDITIONAL TSRA WILL IGNITE ALONG THE BOUNDARY BY LATE
MORNING OR EARLY AFTERNOON AS IT MOVES INTO NWRN IN-ECNTRL IL.
DIURNAL WARMING AND WEAK SFC CONVERGENCE SHOULD HELP ORGANIZE THE
DEVELOPMENT...BUT ANTICIPATE THAT IT SHOULD BE TO THE EAST OF THE
TERMINALS...WITH THE POSSIBLE EXCEPTION OF GYY BY THE TIME THE
ACTIVITY REDEVELOPS. AS FOR WINDS...LIGHT SWLY WINDS WILL
CONTINUE IN ADVANCE OF THE WEAK COLD FRONT...AND INCREASE THROUGH
THE MORNING AS THE SFC PRESSURE GRADIENT STRENGTHENS. BY LATE
MORNING...SWLY WINDS SHOULD INCREASE TO 10-15KT WITH OCNL GUSTS OF
20KT PERSISTING THROUGH EARLY EVENING WHILE GRADUALLY VEERING TO
WESTERLY BY LATE AFTERNOON UNTIL AROUND SUNSET. HIGH PRESSURE
BUILDING IN OVERNIGHT TONIGHT SHOULD BRING DECREASING CLOUD COVER
AND DIMINISHING WINDS. WITH AMPLE RESIDUAL MOISTURE EXPECT AT
LEAST PATCHY FOG TO DEVELOP AFTER MIDNIGHT. THERE IS THE POTENTIAL
FOR VIS TO DROP TO IFR...BUT THERE IS A CHANCE THAT THERE COULD BE
SOME RESIDUAL CLOUD COVER FROM CONVECTIVE ACTIVITY CURRENTLY
MOVING THROUGH MISSOURI COULD LIMIT THE VIS DROPPING...SO WILL
ONLY GO 3-4SM BR FOR NOW.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* LOW MEDIUM CONFIDENCE FOR TSRA/SHRA TO IMPACT ORD...MEDIUM HIGH
CONFIDENCE FOR TSRA/SHRA TO IMPACT MDW MID DAY THROUGH EARLY
AFTERNOON.
* MEDIUM TO HIGH CONFIDENCE IN WIND SPEED AND DIRECTION.
* MEDIUM CONFIDENCE IN MVFR VIS OCCURRING LATE TONIGHT INTO
WEDNESDAY MORNING. LOW CONFIDENCE IN CHANCES FOR IFR VIS.
KREIN/RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT THROUGH SUNDAY...PERIODIC CHANCES FOR TSRA AND
OCNL REDUCED CIGS/VIS.
SUNDAY NIGHT THROUGH MONDAY...VFR. WX NIL.
&&
.MARINE...
316 AM CDT
AN AREA OF LOW PRESSURE OVER CENTRAL WISC WILL CONTINUE TO DRIFT
NORTHEAST ACROSS THE NORTHERN PORTION OF THE LAKE MIDDAY...THEN
CONTINUE TO SLIDE EAST AND WEAKEN WEDNESDAY AFTERNOON ACROSS
SOUTHEAST ONTARIO. THE GRADIENT IS EXPECTED TO TIGHTEN SLIGHTLY
FROM THE SOUTH...WITH WINDS INCREASING THIS MORNING TO ARND 15 TO
25KT. THEN AS THE LOW SLIDES EAST WINDS WILL BECOME WEST AND
DIMINISH TO ARND 10 TO 20 KT LATE TONIGHT. WAVES SHUD BE ABLE TO
BRIEFLY BUILD ACROSS THE LAKE TO ARND 2-4FT...THEN WITH A LIGHTER
GRADIENT ARRIVING WED WAVES WILL SUBSIDE TO ARND 2 FT OR LESS. IN
THE DEPARTING SFC LOW WILL BE A MUCH WEAKER GRADIENT...WITH WINDS
GENERALLY LIGHT FROM THE NORTH ARND 5 TO 10 KT ACROSS THE NORTHERN
HALF OF THE LAKE AND AROUND 10 KT FROM THE SOUTH FOR THE SOUTHERN
HALF OF THE LAKE. A WARM FRONTAL BOUNDARY WILL LIFT NORTH ACROSS
THE SOUTHERN PORTION OF THE LAKE EARLY THUR...WITH MUCH WARMER AIR
LIFTING OVER THE LAKE. AT THIS TIME FEEL THAT FOG MAY NOT
DEVELOP...BUT COULD SEE SOME HAZY CONDITIONS DEVELOP LATE IN THE
WEEK. SOUTH/SOUTHEAST WINDS FOR THE WEEKEND. THE UPPER FLOW
PATTERN DOES LOOK TO SHIFT SUNDAY OR MONDAY BRINGING A COLD FRONT
ACROSS THE LAKE WITH A SHIFT TO NORTHERLY WINDS WHICH MAY BE
RATHER BREEZY EARLY NEXT WEEK.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
923 AM CDT Tue Aug 19 2014
.UPDATE...
ISSUED AT 923 CDT TUE AUG 19 2014
Area of showers and thunderstorms associated with an upper-level
wave is currently crossing the Mississippi River into west-central
Illinois. 1417z radar imagery shows leading edge of precip extending
from Galesburg...to Rushville...to Bowling Green Missouri. Based
on timing tools, showers/thunder will arrive along the I-55
corridor by midday. HRRR and other high-res models generally show
the precip area weakening as it pushes eastward through the
morning, then potentially re-developing across east-central
Illinois later this afternoon. Made some adjustments to hourly
PoPs today, mainly to increase to categorical along/west of I-55
during the morning. Once the wave passes, rain chances will come
to an end across the Illinois River Valley by mid to late
afternoon, followed by a return to partly to mostly sunny skies.
Further east, rain chances will linger throughout the day before
coming to an end by evening.
&&
.SHORT TERM...(This afternoon through Wednesday)
ISSUED AT 336 AM CDT TUE AUG 19 2014
Short term models have trended slower with the front and precip that
is currently supposed to be moving into the area. But will still
have chance of precip starting in the northwest parts of the cwa
this morning. Then will progress the pcpn chances southeastward
across the cwa during the day. By this evening, most of the pcpn
will be in the eastern two thirds of the area with the highest pops
in the southeast. By overnight, the pcpn should have moved southeast
of the area so most of the area should be dry overnight, though will
keep a slight chance of pops in the southeast after midnight. Could
be some additional pcpn in the southwest late tonight, but models
keep most of pcpn west of the area through 12z.
Temps will begin the slow warming tomorrow, and am expecting mid to
upper 80s throughout the area today.
&&
.LONG TERM...(Wednesday night through Monday)
ISSUED AT 347 AM CDT TUE AUG 19 2014
Models still pretty consistent with the development and lift of a
boundary through the Midwest on Wednesday. Boundary will have little
reflection at the sfc with very weak flow/weak wind shift, and
thermal gradient is better represented in the mid levels. Boundary
will provide a weak focus for waves moving through the region as the
boundary lifts to the NE through the area for Wed/Wed night. Though
Wed is lacking signif pop for now, the timing of the progression is
better for early evening and into the overnight on Wednesday
night/shifting to the northeast for Thurs. Position of the boundary
or the remnants thereof will be where the majority of the precip
chances will be...increasing to the north, particularly north of
Interstate 74 from Thursday to Saturday. Ample sfc based instability
in the form of hot and humid conditions as the ridge over the
southwest opens and spreads signif heat into the Midwest. Models
have also shown consistency with 850 mb temps in the 19-25C range
from Wednesday through Sunday. This will drive the temps into the
upper 80s/lower 90s with heat indices in the upper 90s/approaching
100F. A far more summer-like pattern than much of the season so far,
and well above normal for this time of year...with breaks from the
heat provided by any thunderstorms that may have the chance to form
from more diurnal instability with any frontal forcing further to
the north. Into the extended, day 7/just into day 8, models diverge
in solutions with major difference in breaking down the upper ridge
for the Midwest.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
ISSUED AT 609 AM CDT TUE AUG 19 2014
Cold front is still back northwest of the area, but still
forecasted to move through the area, affecting all TAF sites this
through afternoon. However, radar loops show a complex of
thunderstorms in northern MO that could move into central IL this
morning and effect some of the TAF sites, possibly SPI and DEC.
Short term models do show some pcpn moving through the area this
morning, but appears it will diminish as it moves into the area.
Then the front drops into the area a few hours later and this will
bring a chance of thunderstorms to the TAF sites for the afternoon
and early evening. The early stuff could be just showers, but
since the front will be right on the heels of the current complex
coming out of MO, will opt to just have VCTS for all TAFs to cover
both events. Believe t-storms will be more scattered as well. Also
VCTS will be in the TAFs longer than necessary, but only because
of two events. Not expecting cigs to go down today, but having
some light fog issues at mainly CMI, with some very light fog at
PIA and BMI. This fog will burn off quickly, like yesterday
morning. Winds will be south to southwest through the morning and
then become southwest just ahead of the front, and then westerly
or light and variable after FROPA.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARNES
SHORT TERM...AUTEN
LONG TERM...HJS
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS DES MOINES IA
604 PM CDT TUE AUG 19 2014
.SYNOPSIS...
ISSUED AT 305 PM CDT TUE AUG 19 2014
WEAK HIGH PRESSURE OVER IOWA WILL MOVE EAST AS A WARM FRONT
DEVELOPS TO THE SOUTH AND BEGINS TO LIFT NORTH TONIGHT. THE FRONT
WILL LIFT NORTH OF THE STATE ON WEDNESDAY NIGHT. STRONG S/WV WILL
MOVE UP THE BACK SIDE OF THE UPPER LEVEL RIDGE AND PUSH A COLD
FRONT ACROSS THE STATE THIS WEEKEND.
&&
.SHORT TERM /TONIGHT/...
ISSUED AT 305 PM CDT TUE AUG 19 2014
A SURFACE LOW DEVELOPING OVER NORTHEAST COLORADO WILL SHIFT INTO
NORTHWEST NEBRASKA OVERNIGHT. AN ASSOCIATED WARM FRONT WILL EXTEND
FROM THE LOW THROUGH EASTERN NEBRASKA AND INTO SOUTHWEST IOWA AND
NORTHERN MISSOURI BY 12Z WEDNESDAY BEFORE SURGING NORTH THROUGH THE
DAY WEDNESDAY. STRONG THETA-E ADVECTION IS FORECAST TO LIFT ACROSS
CENTRAL IOWA DURING THE OVERNIGHT HOURS...ESPECIALLY AFTER 06Z.
FORCING IS WEAK BUT DOES IMPROVE OVERNIGHT AS A LOW LEVEL JET
FOCUSES INTO SOUTHWEST IOWA. ALOFT A WEAK SHORTWAVE IS PROGGED TO
MOVE ACROSS EASTERN NEBRASKA/SOUTHWEST IOWA. THIS SHOULD BE ENOUGH
TO PRODUCE SHOWERS AND THUNDERSTORMS ACROSS SOUTHWEST INTO CENTRAL
IOWA. STORMS SHOULD MAINLY BE ELEVATED AS LOW LEVEL CONVERGENCE IS
WEAK TO NON EXISTENT. THERE IS ALSO SOME WEAK SHEAR...PERHAPS
ENOUGH FOR AN ISOLATED STORM TO BRIEFLY PRODUCE SOME MARGINALLY
SEVERE TO SEVERE HAIL. THE HIGH RES AND NAM12 MODELS ARE NOT AS
IMPRESSIVE WITH DEVELOPING STORMS ACROSS THE AREA BUT THE SREF DOES
AS DOES PREVIOUS RUN OF THE HI-RES MODELS. THE HRRR IN PARTICULAR
IS FAIRLY BULLISH ON BRINING PRECIP INTO THE SW WHILE THE MEMBERS OF
THE HOPWRF ARE A LITTLE MORE RESERVED...AT LEAST THROUGH 09Z.
SOME POTENTIAL FOR FOG ACROSS THE NORTHEAST OVERNIGHT AS REMAINING
CLOUDS ACROSS THE AREA DISSIPATE WITH SUNSET AND SURFACE RIDGING
MOVES OVERHEAD PRODUCING LIGHT WIND. NOT LOOKING AT DENSE FOG AT
THIS POINT GIVEN THE VERY SHALLOW NATURE OF THE MOISTURE MOVING IN.
GENERALLY WENT WITH PATCHY FOG WORDING HOWEVER ALO/MCW WILL BE EAST
OF THE RIDGE AXIS AND MOISTURE COULD BE ENOUGH FOR A LITTLE MORE
WIDESPREAD FOG SO I MENTION AREAS OF FOG OVER THESE LOCATIONS.
.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
ISSUED AT 305 PM CDT TUE AUG 19 2014
A BREAK IN THE CONVECTION IS EXPECTED ON WED AS THE FIRST ROUND OF
THETA-E ADVECTON LIFTS OUT OF THE STATE. A RENEWED THREAT OF
THUNDERSTORMS WILL COME AS THE WARM FRONT LIFTS NORTH AND STRONG
THETA-E ADVECTION TAKES PLACE WED NIGHT. THE H8 SHOWS GOOD SPEED
CONVERGENCE AND THERE IS DIVERGENCE ALOFT...THE FLY IN THE
OINTMENT WILL BE IF THE ATMOSPHERE CAPS OFF OR NOT. AN EML IS IN
PLACE...BUT IT IS NOT ALL THAT STRONG.
WARM AND HUMID WEATHER WILL HOLD INTO THE WEEKEND WITH AFTERNOON
HEAT INDICES IN THE LOW TO MID 90S NORTH...AND 95 TO 105 SOUTH
TUE-THU AFTERNOON. BELOW CRITERIA...BUT WILL MENTION IN THE HWO
WITH ALL THE SCHOOL ACTIVITIES GOING ON.
COOLER WEATHER WILL MOVE IN OVER THE WEEKEND...FIRST DUE TO THE
INCREASED CLOUD COVER...THEN DUE TO THE FRONTAL PASSAGE SAT. COOL
AIR WILL SETTLE IN SLOWLY WITH TEMPS FALLING BELOW NORMAL; FOR MON
AND TUE.
&&
.AVIATION...20/00Z
ISSUED AT 601 PM CDT TUE AUG 19 2014
BOUNDARY LIFTING NORTH ACROSS CENTRAL IOWA MAY AFFECT SITES WITH
SHRA/TSRA AT TIMES NEAR 12Z. CONDITIONS MAY DROP TO MVFR OR IFR AT
TIMES WITH TSRA AT SITES...HAVE ONLY INCLUDED AT SOUTHERN
SITES...KFOD/KDSM/KOTM ATTM. IN ADDITION...BR OR FG MAY DEVELOP
WITH LIGHT WINDS AT NORTHERN SITES NEAR 12Z BRINGING CONDITIONS
DOWN TO MVFR OR IFR. CONDITIONS WILL IMPROVE QUICKLY BEYOND 12Z
WITH WINDS BECOMING SOUTHERLY AND VFR CONDITIONS EXPECTED AGAIN.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MS AUG 14
SHORT TERM...FAB
LONG TERM...MS AUG 14
AVIATION...AWB
AREA FORECAST DISCUSSION
NWS DES MOINES IA
330 PM CDT TUE AUG 19 2014
.SYNOPSIS...
ISSUED AT 305 PM CDT TUE AUG 19 2014
WEAK HIGH PRESSURE OVER IOWA WILL MOVE EAST AS A WARM FRONT
DEVELOPS TO THE SOUTH AND BEGINS TO LIFT NORTH TONIGHT. THE FRONT
WILL LIFT NORTH OF THE STATE ON WEDNESDAY NIGHT. STRONG S/WV WILL
MOVE UP THE BACK SIDE OF THE UPPER LEVEL RIDGE AND PUSH A COLD
FRONT ACROSS THE STATE THIS WEEKEND.
&&
.SHORT TERM /TONIGHT/...
ISSUED AT 305 PM CDT TUE AUG 19 2014
A SURFACE LOW DEVELOPING OVER NORTHEAST COLORADO WILL SHIFT INTO
NORTHWEST NEBRASKA OVERNIGHT. AN ASSOCIATED WARM FRONT WILL EXTEND
FROM THE LOW THROUGH EASTERN NEBRASKA AND INTO SOUTHWEST IOWA AND
NORTHERN MISSOURI BY 12Z WEDNESDAY BEFORE SURGING NORTH THROUGH THE
DAY WEDNESDAY. STRONG THETA-E ADVECTION IS FORECAST TO LIFT ACROSS
CENTRAL IOWA DURING THE OVERNIGHT HOURS...ESPECIALLY AFTER 06Z.
FORCING IS WEAK BUT DOES IMPROVE OVERNIGHT AS A LOW LEVEL JET
FOCUSES INTO SOUTHWEST IOWA. ALOFT A WEAK SHORTWAVE IS PROGGED TO
MOVE ACROSS EASTERN NEBRASKA/SOUTHWEST IOWA. THIS SHOULD BE ENOUGH
TO PRODUCE SHOWERS AND THUNDERSTORMS ACROSS SOUTHWEST INTO CENTRAL
IOWA. STORMS SHOULD MAINLY BE ELEVATED AS LOW LEVEL CONVERGENCE IS
WEAK TO NON EXISTENT. THERE IS ALSO SOME WEAK SHEAR...PERHAPS
ENOUGH FOR AN ISOLATED STORM TO BRIEFLY PRODUCE SOME MARGINALLY
SEVERE TO SEVERE HAIL. THE HIGH RES AND NAM12 MODELS ARE NOT AS
IMPRESSIVE WITH DEVELOPING STORMS ACROSS THE AREA BUT THE SREF DOES
AS DOES PREVIOUS RUN OF THE HI-RES MODELS. THE HRRR IN PARTICULAR
IS FAIRLY BULLISH ON BRINING PRECIP INTO THE SW WHILE THE MEMBERS OF
THE HOPWRF ARE A LITTLE MORE RESERVED...AT LEAST THROUGH 09Z.
SOME POTENTIAL FOR FOG ACROSS THE NORTHEAST OVERNIGHT AS REMAINING
CLOUDS ACROSS THE AREA DISSIPATE WITH SUNSET AND SURFACE RIDGING
MOVES OVERHEAD PRODUCING LIGHT WIND. NOT LOOKING AT DENSE FOG AT
THIS POINT GIVEN THE VERY SHALLOW NATURE OF THE MOISTURE MOVING IN.
GENERALLY WENT WITH PATCHY FOG WORDING HOWEVER ALO/MCW WILL BE EAST
OF THE RIDGE AXIS AND MOISTURE COULD BE ENOUGH FOR A LITTLE MORE
WIDESPREAD FOG SO I MENTION AREAS OF FOG OVER THESE LOCATIONS.
.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
ISSUED AT 305 PM CDT TUE AUG 19 2014
A BREAK IN THE CONVECTION IS EXPECTED ON WED AS THE FIRST ROUND OF
THETA-E ADVECTON LIFTS OUT OF THE STATE. A RENEWED THREAT OF
THUNDERSTORMS WILL COME AS THE WARM FRONT LIFTS NORTH AND STRONG
THETA-E ADVECTION TAKES PLACE WED NIGHT. THE H8 SHOWS GOOD SPEED
CONVERGENCE AND THERE IS DIVERGENCE ALOFT...THE FLY IN THE
OINTMENT WILL BE IF THE ATMOSPHERE CAPS OFF OR NOT. AN EML IS IN
PLACE...BUT IT IS NOT ALL THAT STRONG.
WARM AND HUMID WEATHER WILL HOLD INTO THE WEEKEND WITH AFTERNOON
HEAT INDICES IN THE LOW TO MID 90S NORTH...AND 95 TO 105 SOUTH
TUE-THU AFTERNOON. BELOW CRITERIA...BUT WILL MENTION IN THE HWO
WITH ALL THE SCHOOL ACTIVITIES GOING ON.
COOLER WEATHER WILL MOVE IN OVER THE WEEKEND...FIRST DUE TO THE
INCREASED CLOUD COVER...THEN DUE TO THE FRONTAL PASSAGE SAT. COOL
AIR WILL SETTLE IN SLOWLY WITH TEMPS FALLING BELOW NORMAL; FOR MON
AND TUE.
&&
.AVIATION...19/18Z
ISSUED AT 1247 PM CDT TUE AUG 19 2014
WARMER AIR WILL MOVE INTO CENTRAL IOWA FROM THE SW...ALONG WITH SOME
MOISTURE AND INSTABILITY AS A WARM FRONT TRIES TO ESTABLISH ITSELF
OVER NEB AND KS THEN LIFT INTO IA LATER THIS EVENING/OVERNIGHT.
SOME SHOWERS/TSRA ARE POSSIBLE MAINLY FM KDSM-KOTM BUT MAY MAKE IT
AS FAR NORTH AS KFOD. WITH LOW LEVEL MOISTURE INCREASING...COULD
ALSO SEE SOME FOG...ESPECIALLY NORTHEAST AFT 08Z. MVFR VSBYS
POSSIBLE IN THE FOG. VFR CONDITIONS SHOULD AGAIN PREVAIL AFTER 13-
15Z.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MS AUG 14
SHORT TERM...FAB
LONG TERM...MS AUG 14
AVIATION...FAB
AREA FORECAST DISCUSSION
NWS PADUCAH KY
ISSUED BY NATIONAL WEATHER SERVICE LOUISVILLE KY
1250 PM CDT Tue Aug 19 2014
.UPDATE...
Issued at 1250 PM CDT TUE AUG 19 2014
The AVIATION section has been updated for the 18Z TAF issuance.
UPDATE Issued at 1121 AM CDT TUE AUG 19 2014
The fog and low clouds have dissipate, leaving behind just a
scattered cu deck late this morning.
An area of convection has weakened significantly since 15Z as it
moved eastward into the KSTL area. However, it did push an outflow
boundary eastward and it is only a county or so northwest of our
area as of 16Z. Not sure whether the boundary will survive as it
moves into the strong mixing in our region or not, but figure it
or just a differential heating boundary may focus thunderstorm
development possibly by 18Z in the KMVN and KMDH areas.
The latest HRRR and 12Z NAM runs develop convection over much of
southern Illinois and push it southeast through southwest Indiana
and much of west Kentucky through the late afternoon and early
evening hours. The southwestward extent of development is in doubt
due to a very strong capping inversion noted on the 12Z KSGF RAOB.
The forecast has been updated to account for these convective
trends. Capped PoPs in the northeast at 50% due to the potential
for the cap to hold even up there. Also, kept a slight chance in
the far west just in case the cap does not hold. The NAM soundings
indicate that there will be some fairly steep mid-level lapse
rates for storms to feed on, if the cap can be broken. Wind fields
will be increasing, but the best winds may lag the convection
through the area. Given the instability alone, figure that a few
storms will reach severe criteria with winds and hail the primary
concerns.
&&
.SHORT TERM...(Today through Thursday night)
Issued at 214 AM CDT TUE AUG 19 2014
Short term weather continues to be somewhat active.
Aside from patchy/areas of dense fog early this morning, only a few
high clouds are expected to track across the region. An MCS located
over north central Kansas at the time of this writing should weaken
considerably on its southeast trek, and should there be anything
left of it later this morning, it should pass by to our south and
west.
Precipitation chances are expected to make their way into the
forecast this afternoon as a short wave pushes a weak cold front
toward the lower Ohio valley. Due to lack of deeper moisture models
not showing much in the way of convection before 18Z, but after that
precipitation chances should begin to increase from the northwest
with the approach of the aforementioned boundary. With decent flow
aloft over a moderately unstable airmass in place, a few storms
could become strong to severe Tuesday afternoon into the evening
hours, especially over most of southern Illinois and northwest
Kentucky, and all of southwest Indiana. Large hail and damaging
winds will be the primary threats.
Models show the short wave outrunning the surface boundary late
Tuesday night, and with H5 heights beginning to increase at that
point, the boundary never quite makes it into our CWA and gets
pushed back to the north and east as a warm front.
Precipitation chances will begin to diminish from southwest to
northeast on Wednesday as an upper ridge over the southern plains
begins to build northeast across our region . This trend will
continue through Thursday as the ridge continues to overspread the
area. At this time it looks like Thursday night will be dry as the
upper ridge takes control.
Unfortunately with the approach of the ridge, the resultant
compression/warming of the air will raise temperatures to near
normal levels (mid 90s) the latter half of the short term period.
This combined with dewpoints around 70 degrees will produce heat
indices near the century mark for most if not all of our CWA both
Wednesday and Thursday afternoon.
.LONG TERM...(Friday through Monday)
Issued at 214 AM CDT TUE AUG 19 2014
The long term will be dominated by an upper level ridge over the
Lower and Middle Mississippi Valley. This will help to stabilize the
atmosphere as the tropospheric profile undergoes a drying trend.
Consequently, any slight chance for showers and thunderstorms will
likely be shunted north and east of the immediate forecast area
through the weekend.
The main concern during this time will be the heat and humidity as
the hottest weather of the year takes hold. Highs in the mid to
upper 90s will combine with relatively high humidity to push heat
index readings to the 100 to 105 degree range each afternoon. Given
the anticipated prolonged nature of this event, I see little reason
why a Heat Advisory will not be issued later this week for peak
afternoon heat indices between 100 and 105 for at least four
consecutive days. Will continue to monitor and adjust forecast as
necessary.
&&
.AVIATION...
Issued at 1250 PM CDT TUE AUG 19 2014
An outflow boundary is expected to provide a focus for
thunderstorm development over southern Illinois this afternoon.
Best guess is that the storms would impact KEVV and KOWB around
00Z. With plentiful low-level moisture, fog development will be
possible again tonight, but with some southwest wind expected,
LIFR/VLIFR conditions are less likely. If they occur it would most
likely be at KCGI. Just a few cu expected by midday Wednesday,
along with modest west southwest to west winds.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...JP
LONG TERM...RJP
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
106 PM CDT TUE AUG 19 2014
.AVIATION...
FOR THE 19/18Z TAFS...SCATTERED CONVECTION BEGINNING TO DEVELOP IN
ASSOCIATION WITH A WEAK SHEAR AXIS AND MID LVL TROUGH OVER CNTRL
TX. HAVE VCTS AREAWIDE THIS AFTERNOON BUT SHWRS/TSTMS SHOULD BE
MOSTLY UNORGANIZED AND SPOTTY. WITH THE EXCEPTION OF KLFK...DIRECT
IMPACTS ON THE TAF SITES ARE TOO UNCERTAIN TO PREVAIL OR TEMPO PRECIP
SO AMENDMENTS MAY BE NEEDED LATER THIS AFTERNOON. VFR CONDITIONS
SHOULD PREVAIL ALTHOUGH MVFR OR LOWER CONDITIONS WILL BE POSSIBLE
WHERE CONVECTION IS ONGOING. SHWRS/TSTMS EXPECTED TO SLOWLY
DISSIPATE AFTER SUNSET WITH THE LOSS OF DAYTIME HEATING. MOIST SLY
FLOW SHOULD RESULT IN A BRIEF WINDOW OF LOW STRATUS AROUND SUNRISE
WEDNESDAY MORNING MAINLY ALONG AND SOUTH OF I-20 WITH CIGS LIFTING
LATE IN THE PERIOD. /09/
&&
.PREV DISCUSSION... /ISSUED 1109 AM CDT TUE AUG 19 2014/
DISCUSSION...
HAVE BUMPED UP THE DAYTIME HIGHS FOR MUCH OF THE FOUR STATE AREA
TODAY GIVEN THE CURRENT TREND SHOWS WARMING ABOUT 2 TO 3 DEGREES
FASTER TODAY THAN YESTERDAY. MINOR ADJUSTMENTS TO THE DEW POINTS AND
WINDS. NO OTHER SIGNIFICANT CHANGES TO THE FORECAST. /06/
PREV DISCUSSION... /ISSUED 423 AM CDT TUE AUG 19 2014/
DISCUSSION...
THE MORNING WATER VAPOR IMAGERY INDICATES THAT THE MAIN SHORTWAVE
THAT PRODUCED EXTENSIVE CONVECTION JUST 24 HRS AGO OVER SW
AR/EXTREME NRN LA HAS SHIFTED E INTO NRN GA...WITH THE 00Z RAOB
500MB PLOT STILL REVEALING A WEAK SHEAR AXIS THAT EXTENDS FARTHER
W ACROSS NRN MS/N LA AND INTO NE TX. MEANWHILE...MOSAIC RADAR
IMAGERY ALSO INDICATES A WELL-DEFINED MCV SPINNING E OF
SJT...WHICH THE 00Z PROGS HAVE INITILIZED WELL ON AS CONVECTION
CONTINUES TO REGENERATE NEAR AND E OF THE CENTER OVER CNTRL TX.
THIS CONVECTION HAS PRODUCED A THICK AC CANOPY OVER NE TX/EXTREME
NW LA...ALTHOUGH IR IMAGERY DEPICTS WARMING CLOUD TOPS SUGGESTING
A WEAKENING TREND IS ONGOING ATTM. THIS MCV CENTER IS PROGGED TO
DRIFT NNE ACROSS NCNTRL TX TODAY...WHICH COULD MAINTAIN ELEVATED
CONVECTIVE DEBRIS OVER THE NRN HALF OF THE AREA THROUGH AT LEAST
THE FIRST HALF OF THE DAY...BEFORE POSSIBLY THINNING THIS
AFTERNOON. MY FORECAST MAX TEMPS MAY BE A BIT HIGH TODAY
ESPECIALLY IF THIS DEBRIS FIELD HANGS TOUGH TODAY...BUT HAVE
PLAYED THE PESSIMIST WITH IT THINNING LATER TODAY...ESPECIALLY AS
09Z TEMPS REMAIN IN THE MID/UPPER 70S. WHILE THE SHORT TERM PROGS
DO SUGGEST A WEAK SEABREEZE AFFECTING DEEP E TX/SRN SECTIONS OF
NCNTRL LA THIS AFTERNOON...ONLY THE LATEST HRRR RUN DEPICTS AT
LEAST ISOLATED CONVECTION DEVELOPING THIS AFTERNOON ALONG THE
RESIDUAL SHEAR AXIS...WHICH IS STILL WEAKLY REFLECTED IN THE OTHER
SHORT RANGE PROGS. IN ADDITION...THE 09Z SFC ANALYSIS INDICATES A
DISTINCT W-E GRADIENT IN SFC THETA-E FROM NEAR OSA TO ALONG THE
AR/LA LINE...INDICATIVE OF THE WEAK COLD POOL FROM CONVECTION THAT
AFFECTED THESE AREAS MONDAY AFTERNOON/EVENING. GIVEN THESE WEAK
SFC AND UPPER AIR FORCING MECHINISMS...AND THE FACT THAT THE CNTRL
TX MCV IS PROGGED TO LIFT NNE ACROSS THE STATE TODAY...HAVE
EXPANDED SLIGHT CHANCE POPS TO COVER MUCH OF THE REGION THIS
AFTERNOON...AND DID CARRY THEM THROUGH THE EVENING BEFORE THEY
DIMINISH WITH THE STABILIZING BNDRY LYR.
THE SHEAR AXIS IS EXPECTED TO WASH OUT OVERNIGHT WITH THE MCV
OPENING UP LATE...AS THE WRN ATLANTIC/CNTRL GULF OF MX UPPER RIDGE
EXPECTED TO BRIDGE NWD INTO THE LOWER MS VALLEY WEDNESDAY. STILL
SHOULD SEE A WEAK SEABREEZE AFFECTING THE SRN ZONES WEDNESDAY AND
THURSDAY AFTERNOONS/EARLY EVENINGS...BEFORE THE UPPER RIDGE CENTER
BECOMES ESTABLISHED OVER THE MID-SOUTH/LOWER MS VALLEY FRIDAY.
BOTH THE GFS AND ECMWF AMPLIFY THE RIDGE FARTHER N ACROSS THE SRN
PLAINS/MS VALLEY FRIDAY...AND KEEPS IT PERSISTENT THROUGH THE
WEEKEND INTO EARLY NEXT WEEK. INCREASED SUBSIDENCE WILL RESULT IN
MAX TEMPS CLIMBS INTO THE UPPER 90S AREAWIDE...WITH EVEN SOME
TRIPLE DIGITS POSSIBLE OVER SOME AREAS THIS WEEKEND/EARLY NEXT
WEEK. THE MEDIUM RANGE PROGS DO BEGIN TO SLOWLY NUDGE THE RIDGE E
INTO THE SE STATES BY TUESDAY/WEDNESDAY...WITH WEAKNESSES RIDING W
BENEATH THE RIDGE ACROSS S LA/SRN MS AS EARLY AS MONDAY.
THUS...ISOLATED CONVECTION WILL BE POSSIBLE OVER NCNTRL LA MONDAY
AFTERNOON...BEFORE SPREADING FARTHER WNW TO ENCOMPASS MUCH OF THE
REGION BY THE END OF THE EXTENDED.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 95 75 96 76 97 / 10 10 10 10 10
MLU 95 73 96 74 97 / 20 20 10 10 10
DEQ 94 71 94 71 95 / 20 20 0 0 0
TXK 94 74 96 74 96 / 20 20 0 0 0
ELD 95 72 96 74 97 / 20 20 0 0 0
TYR 95 75 96 76 97 / 10 20 10 10 10
GGG 95 74 96 75 97 / 10 10 10 10 10
LFK 96 75 96 76 97 / 20 20 20 20 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
09
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1109 AM CDT TUE AUG 19 2014
.DISCUSSION...
HAVE BUMPED UP THE DAYTIME HIGHS FOR MUCH OF THE FOUR STATE AREA
TODAY GIVEN THE CURRENT TREND SHOWS WARMING ABOUT 2 TO 3 DEGREES
FASTER TODAY THAN YESTERDAY. MINOR ADJUSTMENTS TO THE DEW POINTS AND
WINDS. NO OTHER SIGNIFICANT CHANGES TO THE FORECAST. /06/
&&
.PREV DISCUSSION... /ISSUED 651 AM CDT TUE AUG 19 2014/
AVIATION...
CONCERNING THE ARKLATEX...A LOT OF DEBRIS CIRRUS KEEPING STATION
AND MITIGATING MVFR BOTH CIGS/FG. CONVECTION TODAY MAY OCCUR OVER
THE SOUTH WITH RESPECT TO A WEAK SEA BREEZE PUSH AND OVER OUR
NORTH ALONG A WEAK SHEAR AXIS WITH SOMEWHAT BETTER CHANCES FROM
KTXK...TO KMLU AND MAY BRIEFLY AFFECT KELD AND KSHV THIS
MID AFTERNOON BASED ON THE HIGH RES MODEL. VCTS FOR THE AFTERNOON
HOURS WILL BE AMENDED WITH DEVELOPMENT. OTHERWISE S/SW WINDS ON
THE SFC ARE GENERALLY SW- NW ALOFT WITH NOT MUCH SPEED ANYWHERE.
/24/
PREV DISCUSSION... /ISSUED 423 AM CDT TUE AUG 19 2014/
DISCUSSION...
THE MORNING WATER VAPOR IMAGERY INDICATES THAT THE MAIN SHORTWAVE
THAT PRODUCED EXTENSIVE CONVECTION JUST 24 HRS AGO OVER SW
AR/EXTREME NRN LA HAS SHIFTED E INTO NRN GA...WITH THE 00Z RAOB
500MB PLOT STILL REVEALING A WEAK SHEAR AXIS THAT EXTENDS FARTHER
W ACROSS NRN MS/N LA AND INTO NE TX. MEANWHILE...MOSAIC RADAR
IMAGERY ALSO INDICATES A WELL-DEFINED MCV SPINNING E OF
SJT...WHICH THE 00Z PROGS HAVE INITILIZED WELL ON AS CONVECTION
CONTINUES TO REGENERATE NEAR AND E OF THE CENTER OVER CNTRL TX.
THIS CONVECTION HAS PRODUCED A THICK AC CANOPY OVER NE TX/EXTREME
NW LA...ALTHOUGH IR IMAGERY DEPICTS WARMING CLOUD TOPS SUGGESTING
A WEAKENING TREND IS ONGOING ATTM. THIS MCV CENTER IS PROGGED TO
DRIFT NNE ACROSS NCNTRL TX TODAY...WHICH COULD MAINTAIN ELEVATED
CONVECTIVE DEBRIS OVER THE NRN HALF OF THE AREA THROUGH AT LEAST
THE FIRST HALF OF THE DAY...BEFORE POSSIBLY THINNING THIS
AFTERNOON. MY FORECAST MAX TEMPS MAY BE A BIT HIGH TODAY
ESPECIALLY IF THIS DEBRIS FIELD HANGS TOUGH TODAY...BUT HAVE
PLAYED THE PESSIMIST WITH IT THINNING LATER TODAY...ESPECIALLY AS
09Z TEMPS REMAIN IN THE MID/UPPER 70S. WHILE THE SHORT TERM PROGS
DO SUGGEST A WEAK SEABREEZE AFFECTING DEEP E TX/SRN SECTIONS OF
NCNTRL LA THIS AFTERNOON...ONLY THE LATEST HRRR RUN DEPICTS AT
LEAST ISOLATED CONVECTION DEVELOPING THIS AFTERNOON ALONG THE
RESIDUAL SHEAR AXIS...WHICH IS STILL WEAKLY REFLECTED IN THE OTHER
SHORT RANGE PROGS. IN ADDITION...THE 09Z SFC ANALYSIS INDICATES A
DISTINCT W-E GRADIENT IN SFC THETA-E FROM NEAR OSA TO ALONG THE
AR/LA LINE...INDICATIVE OF THE WEAK COLD POOL FROM CONVECTION THAT
AFFECTED THESE AREAS MONDAY AFTERNOON/EVENING. GIVEN THESE WEAK
SFC AND UPPER AIR FORCING MECHINISMS...AND THE FACT THAT THE CNTRL
TX MCV IS PROGGED TO LIFT NNE ACROSS THE STATE TODAY...HAVE
EXPANDED SLIGHT CHANCE POPS TO COVER MUCH OF THE REGION THIS
AFTERNOON...AND DID CARRY THEM THROUGH THE EVENING BEFORE THEY
DIMINISH WITH THE STABILIZING BNDRY LYR.
THE SHEAR AXIS IS EXPECTED TO WASH OUT OVERNIGHT WITH THE MCV
OPENING UP LATE...AS THE WRN ATLANTIC/CNTRL GULF OF MX UPPER RIDGE
EXPECTED TO BRIDGE NWD INTO THE LOWER MS VALLEY WEDNESDAY. STILL
SHOULD SEE A WEAK SEABREEZE AFFECTING THE SRN ZONES WEDNESDAY AND
THURSDAY AFTERNOONS/EARLY EVENINGS...BEFORE THE UPPER RIDGE CENTER
BECOMES ESTABLISHED OVER THE MID-SOUTH/LOWER MS VALLEY FRIDAY.
BOTH THE GFS AND ECMWF AMPLIFY THE RIDGE FARTHER N ACROSS THE SRN
PLAINS/MS VALLEY FRIDAY...AND KEEPS IT PERSISTENT THROUGH THE
WEEKEND INTO EARLY NEXT WEEK. INCREASED SUBSIDENCE WILL RESULT IN
MAX TEMPS CLIMBS INTO THE UPPER 90S AREAWIDE...WITH EVEN SOME
TRIPLE DIGITS POSSIBLE OVER SOME AREAS THIS WEEKEND/EARLY NEXT
WEEK. THE MEDIUM RANGE PROGS DO BEGIN TO SLOWLY NUDGE THE RIDGE E
INTO THE SE STATES BY TUESDAY/WEDNESDAY...WITH WEAKNESSES RIDING W
BENEATH THE RIDGE ACROSS S LA/SRN MS AS EARLY AS MONDAY.
THUS...ISOLATED CONVECTION WILL BE POSSIBLE OVER NCNTRL LA MONDAY
AFTERNOON...BEFORE SPREADING FARTHER WNW TO ENCOMPASS MUCH OF THE
REGION BY THE END OF THE EXTENDED.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 95 75 96 76 97 / 10 10 10 10 10
MLU 95 73 96 74 97 / 20 20 10 10 10
DEQ 94 71 94 71 95 / 20 20 0 0 0
TXK 94 74 96 74 96 / 20 20 0 0 0
ELD 95 72 96 74 97 / 20 20 0 0 0
TYR 95 75 96 76 97 / 10 20 10 10 10
GGG 95 74 96 75 97 / 10 10 10 10 10
LFK 96 75 96 76 97 / 20 20 20 20 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
06
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
424 PM EDT TUE AUG 19 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 422 PM EDT TUE AUG 19 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW FROM WRN
LAKE SUPERIOR INTO W UPPER MI. A SHORTWAVE NEAR THE LOW CENTER
SUPPORTED AN AREA OF SHOWERS...SOME LOCALLY HEAVY...THROUGH CNTRL
UPPER MI. WITH THE SLOW FORWARD MOVEMENT...PWAT AROUND 1.5
INCHES...AND EFFICIENT WARM RAIN PROCESSES...NEARLY 2.0 INCHES OF
RAIN FELL AT THE NWS OFFICE BTWN 1915Z-1945Z. AN FLS WAS ISSUED TO
HIGHLIGHT THREAT FOR MINOR FLOODING WITH SMALL STREAMS AND LOW-LYING
AREAS. AT THE SFC...LOW PRES WAS LOCATED OVER NW UPPER MI.
EXPECT THE VERTICALLY STACKED LOW TO ONLY SLOWLY WOBBLE TO THE EAST
TO CNTRL/EAST UPPER MI BY 12Z/WED AND TO NEAR THE STRAITS BY 00Z/THU.
THERE WILL BE A CONTINUED THREAT FOR SOME LOCALLY HEAVY RAIN WITH
THE SHRTWV MOVING THROUGH CNTRL UPPER MI THIS EVENING.
ONLY ISOLD TSRA ARE EXPECTED...GIVEN AFTERNOON TRENDS AND MUCAPE BLO
1K J/KG.
OTHERWISE...HIGH RES MODELS AND UPSTREAM RADAR TRENDS SUGGEST RAIN
WILL BECOME MORE SCATTERED THIS EVENING AND DIMINISH FURTHER
OVERNIGHT. WITH ABUNDANT DEEP MOISTURE REMAINING OVER THE REGION
THROUGH WED MORNING...SOME SCT LIGHT SHOWERS OR DRIZZLE WILL REMAIN
POSSIBLE THROUGH THE MORNING...ESPECIALLY OVER THE N CNTRL AND EAST
EVEN WITH WEAK FORCING NEAR THE LOW. HOWEVER...ANY ADDITIONAL
RAINFALL AMOUNTS SHOULD BE LIGHT...LESS THAN A TENTH OF AN INCH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 402 PM EDT TUE AUG 19 2014
THE UPPER LEVEL WAVE AND ASSOCIATED WEAK LOW PRESSURE SYSTEM THAT
ARE CURRENTLY OVER THE AREA WILL CONTINUE TO INFLUENCE THE UPPER
GREAT LAKES REGION INTO WEDNESDAY BEFORE PULLING OUT ON WEDNESDAY
NIGHT. AS THIS WAVE PULLS OUT...SHOULD SEE A DRY PERIOD OVER MUCH
OF THE U.P. FOR WEDNESDAY NIGHT INTO THURSDAY MORNING (ALTHOUGH
THERE COULD BE SOME LINGERING SHOWERS OVER THE NORTHEAST ON
WEDNESDAY EVENING) BEFORE THE NEXT WAVE ARRIVES THURSDAY AFTERNOON
AND REMAINS INTO FRIDAY. THE DRY PERIOD WILL BE AIDED BY THE WEAK
RIDGING ALOFT THAT WILL MOVE INTO THE UPPER GREAT LAKES REGION AND
ATTEMPT TO BUILD INTO THE GREAT LAKES REGION THROUGH THE WEEKEND.
AS THAT RIDGING OCCURS...AN UPPER TROUGH WILL ESTABLISH ITSELF
OVER THE NORTHERN ROCKIES AND EJECT OUT A COUPLE PIECES OF ENERGY
THROUGH THE REST OF THE EXTENDED PERIOD. THE FIRST WAVE WILL
MOVE INTO THE NORTHERN PLAINS ON WEDNESDAY AND THEN SHIFT NORTHEAST
ACROSS THE MINNESOTA ARROWHEAD THURSDAY EVENING AND INTO ONTARIO ON
FRIDAY. THERE ARE STILL SOME MODEL DIFFERENCES WITH HOW PROGRESSIVE
THIS SHORTWAVE AND ASSOCIATED WEAK LOW (AND WARM FRONT) ARE...AND IT
IS LARGELY TIED INTO THE STRENGTH OF THE SHORTWAVE. AT THIS
POINT...THE 12Z GFS APPEARS TO BE THE OUTLIER (KEEPS THE WARM FRONT
SOUTH OF THE CWA DUE TO WEAKER SHORTWAVE UNTIL THE NEXT WAVE
ARRIVES ON SATURDAY) WHILE THE 00Z ECMWF AND ITS ENSEMBLE
MEMBERS...ALONG WITH THE 12Z GEM/NAM...BRING THE WARM FRONT INTO THE
AREA LATE THURSDAY AFTERNOON AND PUSHING NORTHEAST OF THE AREA ON
FRIDAY NIGHT INTO SATURDAY. THINK THE NON GFS CONSENSUS IS THE WAY
TO GO AT THIS POINT AND FOLLOWS THE GENERAL IDEA FROM THE PREVIOUS
SHIFT. THEREFORE...WILL INCREASE PRECIP CHANCES FROM SOUTHWEST TO
NORTHEAST THURSDAY AFTERNOON INTO THURSDAY NIGHT AND THEN KEEP
CHANCE POPS INTO THE FIRST PART OF THE WEEKEND. WILL NEED TO KEEP
AN EYE ON CONVECTION FIRING IN EAST CENTRAL MINNESOTA AND NORTHWEST
WISCONSIN THURSDAY AFTERNOON ALONG THE WARM FRONT AND LOW LEVEL
MOISTURE TRANSPORT MAXIMUM IS LOCATED. COULD SEE SOME STRONG TO
POTENTIAL SEVERE STORMS IN THAT AREA...WHICH BASED OFF STORM MOTION
VECTORS WOULD TRY TO LIFT THEM EAST-NORTHEAST ALONG WITH THE FRONT
WHILE BUILDING TO THE SOUTHEAST. FAR WESTERN UPPER MICHIGAN WOULD
HAVE THE BEST OPPORTUNITY FOR SEEING THESE STRONGER STORMS HEADING
INTO THE EVENING HOURS.
ONCE THAT WAVE DECAYS AND SLIDES NORTHEAST OF THE
CWA...PRECIPITATION CHANCES WILL DEPEND ON OTHER WAVES EJECTING OUT
OF THE UPPER TROUGH OVER THE NORTHERN ROCKIES. RIDGE AXIS WILL BE
RIGHT OVER THE U.P. THROUGH SUNDAY AND THEN SHIFT EAST FOR THE
BEGINNING OF NEXT WEEK AS THE UPPER TROUGH GRADUALLY SHIFTS EAST.
WITH THAT RIDGE AXIS...IT APPEARS THAT SUNDAY WILL BE THE BEST
OPPORTUNITY FOR DRIER WEATHER BEFORE THE NEXT WAVE SLIDES NORTHEAST
OVER THE WESTERN HALF OF THE CWA SUNDAY NIGHT INTO MONDAY MORNING.
EXPECT IT TO BE FAIRLY MUGGY OVER THE AREA FRIDAY INTO THE
WEEKEND....ESPECIALLY WHEN COMPARED TO WHAT HAS BEEN SEEN IN THIS
REGION FOR MUCH OF THE SUMMER. AFTER THE NORMAL TO SLIGHTLY ABOVE
NORMAL TEMPERATURES VALUES THURSDAY THROUGH SUNDAY...THEY ARE
EXPECTED TO FALL BACK BELOW NORMAL FOR MONDAY AND TUESDAY BEHIND THE
COLD FRONT ASSOCIATED WITH THE WAVE THAT MOVES THROUGH ON SUNDAY
NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 203 PM EDT TUE AUG 19 2014
WITH A LOW PRESSURE SYSTEM REMAINING IN THE AREA WITH ABUNDANT LOW
LEVEL MOISTURE...LIFR TO VLIFR CONDITIONS SHOULD PREVAIL AT ALL
SITES THIS PERIOD WITH NRLY UPSLOPE FLOW AND OCCASIONAL LIGHT
SHOWERS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 422 PM EDT TUE AUG 19 2014
SOME FOG IS EXPECTED TO PERSIST OVER THE CNTRL AND ERN LAKE TONIGHT
GIVEN ABUNDANT LOW LEVEL MOISTURE AND LIGHT WINDS. EXPECT WINDS
UNDER 20 KTS THROUGH SATURDAY AS A RELATIVELY WEAK PRESSURE GRADIENT
DOMINATES THE UPPER GREAT LAKES ABOVE THE RELATIVELY COLD WATERS OF
LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
521 PM CDT TUE AUG 19 2014
.UPDATE...
ISSUED AT 521 PM CDT TUE AUG 19 2014
UPDATED TO INCLUDE A SLIGHT CHANCE FOR THUNDERSTORMS FROM SWRN
NEBR INTO CENTRAL NEBRASKA AS THIS EVENING PROGRESSES. LATEST
REGIONAL RADAR MOSAIC SHOWS SCATTERED THUNDERSTORMS FROM NEAR
SCOTTSBLUFF THROUGH FORT MORGAN AND LAST CHANCE COLORADO. THE
LATEST HRRR AND RAP13 INDICATE THIS TO PUSH NORTHEAST AND INCREASE
IN COVERAGE INTO WRN NEBR THIS EVENING. RECENT ISOLATED
DEVELOPMENT NOW IN SHERIDAN AND CHERRY COUNTY ATTM.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 337 PM CDT TUE AUG 19 2014
SHORTWAVE RIDGING ALOFT CURRENTLY RESIDES OVER THE AREA...WITH VERY
LITTLE IN THE WAY OF CLOUD COVER EXCEPT FOR SOME HIGH CIRRUS CLOUDS.
SHORT TERM HRRR MODEL SUGGESTS THUNDERSTORMS WILL DEVELOP OVER THE
HIGHER TERRAIN TO THE WEST LATE THIS AFTERNOON...AND THEN DRIFT EAST
INTO WESTERN NEBRASKA THIS EVENING. LATEST VISIBLE SATELLITE TRENDS
CONFIRMS THIS THINKING...WITH QUITE A BIT IN THE WAY OF TOWERING
CUMULUS FROM CHEYENNE DOWN THROUGH THE DENVER METRO. SOUTHERLY LOW
LEVEL JET WILL INCREASE TO AROUND 35 KTS THIS EVENING...WHICH MAY
HELP SUPPORT STORMS AS THEY TRACK EAST. NOT EXPECTING COVERAGE TO BE
WIDESPREAD...AND DUE TO THE RIDGING ALOFT...NOT REAL CONFIDENT ON
HOW FAR EAST STORMS WILL MAKE IT. LATER TONIGHT...DECENT MID LEVEL
INSTABILITY DEVELOPS ACROSS NORTH CENTRAL INTO NORTHEAST
NEBRASKA...AND EXPECT AT LEAST SCATTERED COVERAGE OF ELEVATED
THUNDERSTORMS TO DEVELOP WITHIN AREA OF ISENTROPIC ASCENT.
A SURFACE TROUGH WILL EXTEND FROM NORTHEAST TO SOUTHWEST WEDNESDAY
AFTERNOON...AND SHOULD BE THE FOCUS FOR SCATTERED LATE AFTERNOON
THUNDERSTORMS. THE NAM MODEL IS THE FARTHEST EAST WITH THE
TROUGH...WHILE THE NMM...ARW AND GEM REGIONAL HOLD THE TROUGH BACK
FROM ROUGHLY AINSWORTH TO IMPERIAL. DECENT INSTABILITY DEVELOPS BY
AFTERNOON ALONG AND EAST OF THE TROUGH...WITH SURFACE BASED CAPES
APPROACHING 4000 J/KG. A BELT OF STRONGER MID LEVEL WINDS WILL ALSO
BE PRESENT BY AFTERNOON ON THE SOUTHERN FLANK OF A SHORTWAVE
CROSSING THE NORTHERN PLAINS. THE SYNOPTIC SET UP APPEARS SIMILAR TO
THE SUNDAY SEVERE EVENT...AND AGREE WITH THE STORM PREDICTION CENTER
SLIGHT RISK FOR SEVERE STORMS EAST OF HIGHWAY 83.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 337 PM CDT TUE AUG 19 2014
THE WEAK FRONT WILL CROSS CENTRAL NEBRASKA WEDNESDAY NIGHT AND
GENERATE A BAND OF THUNDERSTORMS...ESPECIALLY IN CENTRAL AND NORTH
CENTRAL NEBRASKA. MODEL OUTPUT STATISTICS INDICATE PROBABILITY/
COVERAGE OF 20-30 PERCENT IN THE SANDHILLS AND 30-40 PERCENT IN
CENTRAL AND NORTH CENTRAL NEBRASKA. THAT SEEMS REASONABLE. SURFACE
BASED CAPE IN CENTRAL AND NORTH CENTRAL NEBRASKA IS PRETTY HIGH AT
3500-4000J/KG WITH BULK SHEAR (0-6KM) AROUND 30KT. WITH STORM MOTION
240-260 AT 15-25KT...STORM RELATIVE HELICITY IS EXPECTED TO BE
110-200. SEVERE STORMS ARE POSSIBLE INTO THE EVENING...THOUGH WE
WILL NOT INCLUDE THE MENTION IN THE FORECAST FOR WEDNESDAY NIGHT.
A BOUNDARY LIFTING NORTH INTO SOUTHERN NEBRASKA WILL BRING THE
POSSIBILITY OF THUNDERSTORMS TO SOUTH CENTRAL AND SOUTHWEST NEBRASKA
THURSDAY NIGHT. AS THE BOUNDARY MAKES ITS WAY A LITTLE FARTHER NORTH
FRIDAY...THERE IS A POSSIBILITY OF THUNDERSTORMS IN CENTRAL AND
NORTHERN NEBRASKA.
FINALLY...SATURDAY NIGHT AND SUNDAY...A COOL FRONT COMES ACROSS
NEBRASKA AND THE PATTERN IS NOT AS FAVORABLE FOR STRONG CONVECTION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1239 PM CDT TUE AUG 19 2014
VFR CONDITIONS WILL PREVAIL ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA THROUGH TONIGHT. ISOLATED THUNDERSTORMS MAY MOVE EASTWARD
INTO FAR WESTERN NEBRASKA THIS EVENING...AND SOME ISOLATED
DEVELOPMENT IS ALSO POSSIBLE LATE TONIGHT ACROSS NORTH CENTRAL
NEBRASKA. DUE TO THE ISOLATED NATURE...NO MENTION IS WARRANTED IN
THE OFFICIAL TAF FORECAST. WINDS WILL GENERALLY BE SOUTHEAST
AROUND 10 KTS THROUGH TONIGHT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ROBERG
SHORT TERM...TAYLOR
LONG TERM...SPRINGER
AVIATION...TAYLOR
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
338 PM CDT TUE AUG 19 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 337 PM CDT TUE AUG 19 2014
SHORTWAVE RIDGING ALOFT CURRENTLY RESIDES OVER THE AREA...WITH VERY
LITTLE IN THE WAY OF CLOUD COVER EXCEPT FOR SOME HIGH CIRRUS CLOUDS.
SHORT TERM HRRR MODEL SUGGESTS THUNDERSTORMS WILL DEVELOP OVER THE
HIGHER TERRAIN TO THE WEST LATE THIS AFTERNOON...AND THEN DRIFT EAST
INTO WESTERN NEBRASKA THIS EVENING. LATEST VISIBLE SATELLITE TRENDS
CONFIRMS THIS THINKING...WITH QUITE A BIT IN THE WAY OF TOWERING
CUMULUS FROM CHEYENNE DOWN THROUGH THE DENVER METRO. SOUTHERLY LOW
LEVEL JET WILL INCREASE TO AROUND 35 KTS THIS EVENING...WHICH MAY
HELP SUPPORT STORMS AS THEY TRACK EAST. NOT EXPECTING COVERAGE TO BE
WIDESPREAD...AND DUE TO THE RIDGING ALOFT...NOT REAL CONFIDENT ON
HOW FAR EAST STORMS WILL MAKE IT. LATER TONIGHT...DECENT MID LEVEL
INSTABILITY DEVELOPS ACROSS NORTH CENTRAL INTO NORTHEAST
NEBRASKA...AND EXPECT AT LEAST SCATTERED COVERAGE OF ELEVATED
THUNDERSTORMS TO DEVELOP WITHIN AREA OF ISENTROPIC ASCENT.
A SURFACE TROUGH WILL EXTEND FROM NORTHEAST TO SOUTHWEST WEDNESDAY
AFTERNOON...AND SHOULD BE THE FOCUS FOR SCATTERED LATE AFTERNOON
THUNDERSTORMS. THE NAM MODEL IS THE FARTHEST EAST WITH THE
TROUGH...WHILE THE NMM...ARW AND GEM REGIONAL HOLD THE TROUGH BACK
FROM ROUGHLY AINSWORTH TO IMPERIAL. DECENT INSTABILITY DEVELOPS BY
AFTERNOON ALONG AND EAST OF THE TROUGH...WITH SURFACE BASED CAPES
APPROACHING 4000 J/KG. A BELT OF STRONGER MID LEVEL WINDS WILL ALSO
BE PRESENT BY AFTERNOON ON THE SOUTHERN FLANK OF A SHORTWAVE
CROSSING THE NORTHERN PLAINS. THE SYNOPTIC SET UP APPEARS SIMILAR TO
THE SUNDAY SEVERE EVENT...AND AGREE WITH THE STORM PREDICTION CENTER
SLIGHT RISK FOR SEVERE STORMS EAST OF HIGHWAY 83.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 337 PM CDT TUE AUG 19 2014
THE WEAK FRONT WILL CROSS CENTRAL NEBRASKA WEDNESDAY NIGHT AND
GENERATE A BAND OF THUNDERSTORMS...ESPECIALLY IN CENTRAL AND NORTH
CENTRAL NEBRASKA. MODEL OUTPUT STATISTICS INDICATE PROBABILITY/
COVERAGE OF 20-30 PERCENT IN THE SANDHILLS AND 30-40 PERCENT IN
CENTRAL AND NORTH CENTRAL NEBRASKA. THAT SEEMS REASONABLE. SURFACE
BASED CAPE IN CENTRAL AND NORTH CENTRAL NEBRASKA IS PRETTY HIGH AT
3500-4000J/KG WITH BULK SHEAR (0-6KM) AROUND 30KT. WITH STORM MOTION
240-260 AT 15-25KT...STORM RELATIVE HELICITY IS EXPECTED TO BE
110-200. SEVERE STORMS ARE POSSIBLE INTO THE EVENING...THOUGH WE
WILL NOT INCLUDE THE MENTION IN THE FORECAST FOR WEDNESDAY NIGHT.
A BOUNDARY LIFTING NORTH INTO SOUTHERN NEBRASKA WILL BRING THE
POSSIBILITY OF THUNDERSTORMS TO SOUTH CENTRAL AND SOUTHWEST NEBRASKA
THURSDAY NIGHT. AS THE BOUNDARY MAKES ITS WAY A LITTLE FARTHER NORTH
FRIDAY...THERE IS A POSSIBILITY OF THUNDERSTORMS IN CENTRAL AND
NORTHERN NEBRASKA.
FINALLY...SATURDAY NIGHT AND SUNDAY...A COOL FRONT COMES ACROSS
NEBRASKA AND THE PATTERN IS NOT AS FAVORABLE FOR STRONG CONVECTION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1239 PM CDT TUE AUG 19 2014
VFR CONDITIONS WILL PREVAIL ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA THROUGH TONIGHT. ISOLATED THUNDERSTORMS MAY MOVE EASTWARD
INTO FAR WESTERN NEBRASKA THIS EVENING...AND SOME ISOLATED
DEVELOPMENT IS ALSO POSSIBLE LATE TONIGHT ACROSS NORTH CENTRAL
NEBRASKA. DUE TO THE ISOLATED NATURE...NO MENTION IS WARRANTED IN
THE OFFICIAL TAF FORECAST. WINDS WILL GENERALLY BE SOUTHEAST
AROUND 10 KTS THROUGH TONIGHT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...TAYLOR
LONG TERM...SPRINGER
AVIATION...TAYLOR
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
359 PM EDT TUE AUG 19 2014
.SYNOPSIS...
LOW PRESSURE OVER LAKE MICHIGAN WILL SLOWLY MOVE TO THE EASTERN
GREAT LAKES THROUGH THURSDAY...PUSHING A WEAK COLD FRONT SOUTH
ACROSS THE AREA. HIGH PRESSURE WILL BUILD OVER LAKE ERIE BEHIND THIS
SYSTEM THURSDAY NIGHT...SHIFTING TO THE EASTERN GREAT LAKES ON
FRIDAY. A WARM FRONT WILL LIFT NORTH ACROSS THE AREA ON FRIDAY AND
SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
SHOWERS AND THUNDERSTORMS CONTINUE TO FILL IN ACROSS SW LOWER
MICHIGAN INTO INDIANA AHEAD OF A LOW PRESSURE SYSTEM LOCATED OVER
LAKE MICHIGAN. THIS REGION IS ALSO LOCATED AHEAD OF AN UPPER LEVEL
LOW SPINNING OVER THE WESTERN GREAT LAKES. THE SOUTHERN PORTION OF
THIS COMPLEX IS THE REMNANTS OF A LONG LIVED MCS THAT TRACKED OUT OF
MISSOURI THIS MORNING AND IS NOW MERGING WITH THE CONVECTION
DEVELOPING ALONG THE FRONT. STORM MOTION THIS AFTERNOON IS TO THE
NORTHEAST...ALTHOUGH THE CLUSTER OVER MICHIGAN IS SHOWING A TENDANCY
TO SLOWLY SINK SOUTH WITH TIME. IT LOOKS LIKE THE CLUSTER MOVING OUT
OF INDIANA WILL APPROACH THE TOLEDO AREA TOWARDS 6 PM. A SEVERE
THUNDERSTORM WATCH IS IN EFFECT FOR AREAS JUST WEST AND NORTH OF
TOLEDO AND THE WATCH MAY NEED TO BE EXPANDED IN NW OHIO IF
THUNDERSTORMS CAN MAINTAIN STRENGTH. THUS FAR THE GREATEST THREAT
HAS BEEN HEAVY RAIN WHERE STORMS HAVE BEEN TRAINING IN MICHIGAN WITH
NO REPORTS OF SEVERE WEATHER. AS OF 330 PM...NO WARNINGS HAVE BEEN
ISSUED WITH THE CONVECTION IN NRN INDIANA WHICH IS STARTING TO
OUTPACE THE FRONT. THERE IS SUFFICIENT INSTABILITY WITH ML CAPES
AROUND 1500 J/KG FOR STRONG TO SEVERE STORMS BUT SHEAR IS LACKING.
CORRIDOR OF DEEPER MOISTURE WILL CONTINUE TO MOVE NORTHEAST AHEAD OF
THE SURACE AND UPPER LEVEL LOW OVERNIGHT AND SHOWERS AND
THUNDERSTORMS ARE EXPECTED MOST AREAS. STORMS SHOULD WEAKEN AS WE
LOSE DIURNAL HEATING OVERNIGHT AND MAY BE MAINLY SHOWERS EAST OF
I-77 BY MORNING. DEWPOINTS/HUMIDITY WILL CONTINUE TO INCREASE
OVERNIGHT WHICH WILL KEEP TEMPERATURES MILD TONIGHT. LOWS ARE
FORECAST TO DROP INTO THE MID 60S.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY NIGHT/...
NEARLY VERTICALLY STACKED UPPER LEVEL AND SURFACE LOW WILL BE OVER
THE CENTRAL GREAT LAKES ON WEDNESDAY. A MOIST AND UNSTABLE AIRMASS
WILL RESIDE WITHIN THE AREA OF SOUTHERLY FLOW AHEAD OF THE SURFACE
LOW ACROSS MAINLY NE OHIO AND NW PA. CAPES ARE EXPECTED TO INCREASE
TO AROUND 2500 J/KG WITH SEVERAL MECHANISMS FOR CONVECTIVE INITIATION
DURING THE AFTERNOON. STORMS WILL FIRE DURING THE AFTERNOON AS THE
LOW SLOWLY MOVES EASTWARD. HIGHER RESOLUTION MODELS ALSO SHOW SOME
CONVERGENCE DOWNWIND OF LAKE ERIE THAT WILL SET UP SOUTH OF I-90.
LARGE SCALE FORCING WILL ALSO INCREASE DURING THE LATE AFTERNOON AS
A 35 KNOT MID-LEVEL JET STREAK MOVES THROUGH THE NORTHWESTERLY FLOW
ON THE BACK SIDE OF THE TROUGH. ALL OF THIS COMBINES TO MAKE
THUNDERSTORMS LIKELY ON THURSDAY ACROSS AT LEAST THE EASTERN HALF OF
THE FORECAST AREA. LESS CERTAIN IS IF ANYTHING CAN FIRE ACROSS NW
OHIO AHEAD OF THE JET STREAK WHICH CAN NOT BE ENTIRELY RULED OUT SO
WILL LEAVE A LOW POP IN THE NW OHIO. WHATEVER BREAKS EXIST IN THE
CLOUDS TO START THE DAY IN NE OHIO/NW PA WILL FILL IN QUICKLY AS
DIURNAL HEATING INCREASES...WHILE A GOOD DEAL OF SUN IS EXPECTED IN
THE DRIER AIR IN NW OHIO. HIGHS WILL RANGE FROM 77-85 AND WILL BE
HIGHEST IN THE WEST WHERE THEY WILL RECEIVE MORE SUN.
WEDNESDAY NIGHT WILL BE MOSTLY DRY AS WEAK COLD FRONT PUSHES SOUTH
WITH NEGATIVE THETA-E ADVECTION THROUGH THE COLUMN. WEAK HIGH
PRESSURE ALSO BUILDS IN BEHIND THE DEPARTING SURFACE LOW WHICH
SHOULD REDUCE CHANCES FOR PRECIPITATION DOWNWIND OF LAKE ERIE IN NE
OH/NW PA ON THURSDAY.
FARTHER SOUTH...SCATTERED THUNDERSTORMS ARE EXPECTED TO FIRE ALONG
STALLED BOUNDARY ON THURSDAY. THURSDAY NIGHT COULD ALSO BE ACTIVE
ACROSS THE SW HALF OF THE FORECAST AREA AS ENERGY MOVES AROUND THE
BUILDING RIDGE THURSDAY NIGHT. THIS WILL BE FOLLOWED BY A WARM FRONT
STARTING TO LIFT BACK NORTH ON FRIDAY. THIS WILL BE THE BEGINNING OF
THE WARMING TREND FOR THE WEEKEND...WITH HIGHS REACHING THE MID TO
UPPER 80S IN THE WEST ON FRIDAY.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THE LONG TERM BEGINS ON SATURDAY WITH BOTH THE GFS AND ECMWF SHOWING
AN UPPER LEVEL HIGH CENTERED OVER THE SOUTHEASTERN STATES. A RIDGE
WILL EXTEND NORTH INTO THE CENTRAL LAKES. NOT MUCH CHANGES THROUGH
SUNDAY INTO MONDAY EXCEPT THAT LOW PRESSURE MOVING THROUGH SOUTHERN
CANADA WILL TILT THE AXIS OF THE RIDGE EAST A BIT HOWEVER IT SHOULD
STILL REMAIN WEST OF THE AREA. TUESDAY THE LOW MOVES TO NORTHERN
ONTARIO FLATTENING THE RIDGE ACROSS THE LAKES. GIVEN THE RIDGE
POSITION...WOULD EXPECT THAT ANY CONVECTION THAT GOES OVER THE TOP
OF THE RIDGE WILL DESCEND ON THE REGION FROM THE NORTH. FOR NOW
THOUGH IT WOULD BE FAIRLY DIFFICULT TO ANTICIPATE TIMING OTHER THAT
A SMALL CHANCE POP FOR AFTERNOON AND EARLY EVENING CONVECTION. WILL
HAVE A SLIGHT CHANCE POP IN FOR THE OVERNIGHT AND EARLY MORNING
PERIODS. ALSO...GUIDANCE SUGGESTS MORE CLOUD COVER THEN SEEMS
REASONABLE GIVEN THE RIDGE SO LOWERED CLOUD PERCENTAGES TO GET
PARTLY CLOUDY THROUGH MOST OF THE PERIOD. TEMPS AT OR ABOVE
NORMAL.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
LOW PRESSURE MOVING INTO THE CENTRAL LAKES THIS AFTERNOON WITH
CONVECTION NOW FROM SRN/CENTRAL LWR MI ACRS SRN LAKE MI INTO NRN
INDIANA. ACTIVITY TIMES INTO NWRN OHIO 22Z-24Z. USING TIMING FROM
THE HRRR AS WELL AS SPC MODELS...CONVECTION TIMES INTO KCLE AROUND
00Z AND KERI/KCAK/YNG 02Z-04Z. OVERNIGHT AFTER THE CONVECTION
EXPECT CONDITIONS WILL DROP TO MVFR/IFR IN LOWER CIGS AND MIST/FOG
GIVEN THE ADDED LOW LEVEL MOISTURE AS WELL AS MOISTURE ASSOCIATED
WITH THE LOW AFFECTING THE REGION.
OUTLOOK...NON VFR POSSIBLE IN SHOWERS/THUNDERSTORMS THROUGH
FRIDAY.
&&
.MARINE...
LOW PRESSURE OVER THE GREAT LAKES WILL CONTINUE THROUGH TONIGHT AND
TUESDAY INTO MID WEEK...EVENTUALLY REACHING WESTERN NEW YORK BY
THURSDAY MORNING. FLOW AROUND THE LOW IS NOT PARTICULARLY STRONG SO
AM EXPECTING VARIABLE BUT GENERALLY LIGHT WINDS THROUGH THE PERIOD
RESULTING IN WAVES OF 2 FEET OR LESS ON THE LAKE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KEC
NEAR TERM...KEC
SHORT TERM...KEC
LONG TERM...TK
AVIATION...TK
MARINE...TK
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
151 PM EDT TUE AUG 19 2014
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTHWARD INTO NORTHERN OHIO TODAY AS LOW
PRESSURE TRACKS INTO NORTHERN MICHIGAN TONIGHT. AS THE LOW
PROGRESSES SLOWLY EASTWARD INTO THURSDAY IT WILL DRAG A COLD FRONT
ACROSS THE REGION. THIS FRONTAL BOUNDARY WILL REMAIN A FACTOR INTO
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DEWPOINTS ARE INCREASING INTO THE UPPER 60S ACROSS WESTERN OHIO.
SHOWERS AND THUNDERSTORMS ARE FILLING IN ALONG THE WARM FRONT IN
WESTERN MICHIGAN...EXTENDING WESTWARD ACROSS LAKE MICHIGAN TOWARDS
THE MCS IN ILLINOIS. IT WILL TAKE SEVERAL HOURS YET FOR THIS
ACTIVITY TO REACH NORTHWEST OHIO. SLOWED DOWN THE CHANCE OF
THUNDERSTORMS A LITTLE BIT MORE FOR LATER TODAY AND REMOVED THE
SLIGHT CHANCE OF THUNDERSTORMS FROM NORTHEAST OHIO. INSTABILITY IS
INCREASING ACROSS INDIANA WITH ML CAPE VALUES NEAR 2000 J/KG. AT
THIS TIME THERE STILL APPEARS TO BE A SEVERE WEATHER THREAT FOR
NW OHIO INTO THIS EVENING AS THIS ACTIVITY APPROACHES. THE CIRRUS
SHIELD IS STARTING TO OUTPACE THE CONVECTION THOUGH SO WE WILL
HAVE TO SEE WHAT EFFECT THAT HAS ON INSTABILITY LATER TODAY.
PREVIOUS DISCUSSION...WE WILL CONTINUE TO WATCH THE UPSTREAM
CLUSTER OF THUNDERSTORMS MOVING INTO ILLINOIS. THIS ACTIVITY IS
ONGOING IN AN AREA OF BETTER INSTABILITY WITH A WEAK JET STREAK IN
THE MID-LEVEL FLOW NEAR 500MB. MID-LEVEL LAPSE RATES ARE FAIRLY
STEEP ACROSS ILLINOIS AHEAD OF THIS FEATURE SO COULD SEE THIS
ACTIVITY HOLD TOGETHER AND STRENGTHEN AS IT CONTINUES EASTWARD.
CONVECTION WILL LIKELY ALSO DEVELOP ACROSS SW MICHIGAN/INDIANA IN
THE VICINITY OF THE OUTFLOW BOUNDARY FROM THIS MORNING AND IT WILL
BE INTERESTING TO SEE HOW THIS INTERACTS WITH THE LARGER COMPLEX
TO THE WEST. CHANCES FOR SHOWERS AND THUNDERSTORMS ACROSS NW OHIO
WILL INCREASE LATE THIS AFTERNOON...LIKELY AFTER 4 PM...THEN
SPREAD EASTWARD TONIGHT. NW OHIO REMAINS IN THE SLIGHT RISK FOR
SEVERE STORMS AS INSTABILITY AND LARGE SCALE ASCENT INCREASES
AHEAD OF THE UPPER LOW APPROACHING LAKE MICHIGAN.
ORIGINAL DISCUSSION... A WARM FRONT WILL SLOWLY LIFT NORTHWARD ACROSS
OHIO TODAY. LIFT OVER THIS BOUNDARY...AFTERNOON HEATING AND
INCREASING SHEAR ASSOCIATED WITH A 5H 40 KNOT JET WILL HELP TO
DEVELOP THUNDERSTORMS OVER SOUTHERN MICHIGAN SOUTHWARD INTO
INDIANA THIS AFTERNOON. A FEW OF THESE THUNDERSTORMS WILL BE
CAPABLE OF PRODUCING STRONG DAMAGING WINDS AND LARGE HAIL AS THEY
MOVE TOWARD NW OHIO LATE THIS AFTERNOON INTO THE EVENING. EASTERN
AREAS WILL TAKE MOST OF THE DAY TO MOISTEN UP SO THE THREAT OF
THUNDERSTORMS IS MINIMAL.
IT WILL BE ANOTHER WARM DAY WITH HIGHS SIMILAR TO YESTERDAYS.
ACTUALLY IT WILL PROBABLY BE A DEGREE OR TWO WARMER AT MOST
LOCATIONS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
THERE WILL BE A THREAT OF SEVERE THUNDERSTORMS UNTIL SHORTLY AFTER
SUNSET THIS EVENING. BEYOND THAT IT APPEARS THERE WILL BE AN AREA
OF SHOWERS AND THUNDERSTORMS THAT MOVE FROM WEST TO EAST ACROSS
THE REGION WITH A WEAKENING COLD FRONT. IT WILL LIKELY TAKE UNTIL AFTER
MIDNIGHT FOR THE RAIN TO REACH EXTREME NE OHIO INTO NW PA. THIS
WEAK FRONT WILL END UP BEING A FACTOR IN THE WEATHER THROUGH THE
SECOND HALF OF THE WEEK. IT IS DIFFICULT TO SAY WHERE THIS
BOUNDARY WILL BE LOCATED EACH DAY WITH IT POTENTIALLY BEING PUSHED
SOUTH OF THE COUNTY WARNING AREA BY THURSDAY. SINCE THERE IS SO
MUCH UNCERTAINTY WE WILL KEEP LOW CHANCES GOING IN THE FORECAST AT
THIS TIME. HOWEVER WITH INCREASING HEIGHTS OVER THE REGION WE MAY
BE ABLE TO SHUT THE RAIN CHANCES OFF FASTER THAN WHAT THE CURRENT
FORECAST INDICATES.
IT WILL REMAIN WARM THROUGH THE SHORT TERM WITH HIGHS REMAINING
SLIGHTLY ABOVE SEASONAL AVERAGES.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
UPPER LEVEL HIGH PRESSURE WILL ENCOMPASS THE ENTIRE EASTERN UNITED
STATES BY SATURDAY AND BUILD GRADUALLY EAST THROUGH THE PERIOD.
HOWEVER...ATMOSPHERE IS A BIT ACTIVE AS SMALL WEAK SHORTWAVE TROUGHS
ROTATE OVER THE NORTH SIDE OF THE HIGH INTO THE FORECAST AREA
THROUGH MUCH OF THE EXTENDED PERIOD. EXPECTING SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS JUST ABOUT EACH DAY. THIS IS ALSO IN
RESPONSE TO SOME WARM AIR ADVECTION TAKING PLACE AND THE CLOSE
PROXIMITY OF A STATIONARY FRONT. SO...THE TEMPERATURES AND
PRECIPITATION THREAT IS ALL DEPENDENT ON WHERE THE STATIONARY
FRONT IS AT...AT ANY GIVEN MOMENT. SOME PLACES IN THE WEST COULD
HIT 90 DEGREES FOR HIGHS ON SATURDAY WHILE COOLER TEMPERATURES
OCCUR THE FURTHER EAST ONE GOES.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
LOW PRESSURE MOVING INTO THE CENTRAL LAKES THIS AFTERNOON WITH
CONVECTION NOW FROM SRN/CENTRAL LWR MI ACRS SRN LAKE MI INTO NRN
INDIANA. ACTIVITY TIMES INTO NWRN OHIO 22Z-24Z. USING TIMING FROM
THE HRRR AS WELL AS SPC MODELS...CONVECTION TIMES INTO KCLE AROUND
00Z AND KERI/KCAK/YNG 02Z-04Z. OVERNIGHT AFTER THE CONVECTION
EXPECT CONDITIONS WILL DROP TO MVFR/IFR IN LOWER CIGS AND MIST/FOG
GIVEN THE ADDED LOW LEVEL MOISTURE AS WELL AS MOISTURE ASSOCIATED
WITH THE LOW AFFECTING THE REGION.
OUTLOOK...NON VFR POSSIBLE IN SHOWERS/THUNDERSTORMS THROUGH
FRIDAY.
&&
.MARINE...
NOT MUCH TO TALK ABOUT ON THE LAKE OVER THE NEXT 5 DAYS. WINDS ARE
EXPECTED TO BE RELATIVELY LIGHT AND THEREFORE TRANSLATE TO WAVES OF
GENERALLY ONE FOOT OR LESS THROUGH THE PERIOD.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MULLEN
NEAR TERM...KEC/MULLEN
SHORT TERM...MULLEN
LONG TERM...LOMBARDY
AVIATION...TK
MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1225 PM EDT TUE AUG 19 2014
.SYNOPSIS...
A VERY WARM...HUMID AND ACTIVE WEATHER PATTERN CONTINUES. AN UPPER
LEVEL DISTURBANCE CROSSES TONIGHT. A WARM FRONT SETS UP TO THE WEST
OF THE AREA WEDNESDAY NIGHT...AND THEN MOVES INTO THE AREA ON FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
SENT A QUICK UPDATE TO ADJUST POPS PER LATEST RADAR IMAGES SHOWING
WEAK CONVECTION ACROSS THE SOUTH AND WESTERN SLOPES OF WV AROUND
NOON. EXPECT THIS ACTIVITY TO INCREASE IN COVERAGE AND INTENSITY
PER HIGH RESOLUTION MODELS INDICATING INCREASE IN SFC BASED CAPE
FROM 1600-2000 J/KG BY THE RAP AND NAM MODELS. THESE VALUES LOOKS
REASONABLE COMPARED WITH DEWPOINTS IN THE LOWER 70S ACROSS THE
AREA. PWATS IN THE ORDER OF 1.4 INCHES...ACCORDING WITH
SATELLITE DERIVED PRODUCTS...AND DIFFERENTIAL HEATING FROM BREAKS
IN THE SKY WILL ALLOW CONVECTION TO STRENGTHEN INTO ISOLATED
THUNDERSTORMS THIS AFTERNOON AND TONIGHT. MODELS ALSO SHOW A
SHORTWAVE AT 5 BRINGING A VORTICITY MAXIMA ACROSS THE AREA BY 06Z
WEDNESDAY. THIS FEATURE WILL ENHANCE CONVECTION TONIGHT. INCREASED
POPS TO LIKELY WITH THIS LATEST FEATURE.
HOURLY TEMPERATURES ADJUSTED AS WELL PER LATEST SFC OBS.
PREVIOUS DISCUSSION BELOW...
630 AM UPDATE...
FCST ON TRACK.
PREV DISCN...
ISOLATED SHOWERS WITH PINHEAD DOWNPOURS CONTINUE OVER SE PORTIONS OF
THE FCST AREA IN THE WAKE OF AN UPPER LEVEL S/W TROUGH AND SFC LOW
THAT CROSSED MON. LOW LEVEL WNW UPSLOPE FLOW AND HIGH PW VALUES ARE
LIKELY HELPING TO MAINTAIN THIS ACTIVITY...WHICH SHOULD WANE A BIT
FURTHER BUT PERHAPS NOT ALTOGETHER DISAPPEAR LATER THIS MORNING.
OTHERWISE LOW CLOUDS WILL BE SLOW TO MIX OUT THIS MORNING...AS THE
FOG SLOWLY THINS.
THE AREA REMAINS IN A VERY MOIST AND HUMID AIR MASS TODAY WITH
INSTABILITY LEADING TO DIURNAL CONVECTION THIS AFTERNOON. THE LACK
OF FORCING SUGGESTS THERE WILL NOT BE MUCH COVERAGE...BUT THE LIGHT
FLOW THROUGH H5 SPELLS SLOW MOVEMENT ON ANYTHING THAT DOES STAND UP.
UPPER LEVEL S/W TROUGH CROSSES TONIGHT...ITS TIMING SLOWER COMPARED
WITH PREVIOUS RUNS. ANY SEVERE POTENTIAL WITH IT WILL BE MAINLY W
OF THE AREA BECAUSE OF THIS...ALTHOUGH STRONG STORMS CAN MAKE IT
INTO THE MIDDLE OHIO VALLEY BEFORE SUNSET. STRATUS AND FOG WILL
LIKELY FOLLOW THE SHOWERS AND THUNDERSTORMS LATE TONIGHT.
MINOR CHANGES TO TEMPERATURES IN LIGHT OF LATEST BIAS CORRECTED
GUIDANCE...A LITTLE WARMER TODAY WITH THE SLOWER SYSTEM...AND
ANOTHER VERY WARM AND MUGGY NT TONIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
UNSETTLED WEATHER IN THE SHORT TERM PERIOD. UPPER LOW/TROUGH MOVING
EAST...WITH A MAINLY NWLY FLOW ALOFT...WITH SEVERAL UPPER
DISTURBANCES MOVING INTO THE REGION. THIS...COMBINED WITH THE HUMID
AIRMASS IN PLACE...WILL KEEP A MENTION OF SHOWERS AND THUNDERSTORMS
IN THE FORECAST. PW VALUES DURING THE PERIOD WILL REMAIN RATHER
HIGH...GENERALLY 1.5 INCHES OR HIGHER...THUS CONTINUING THE THREAT
FOR HEAVY DOWNPOURS. IN ADDITION...COULD BE STORMS ON THE STRONGER
SIDE WEDNESDAY/WEDNESDAY NIGHT...PARTICULARLY SOUTHEAST OHIO AND
EASTERN KY WHERE BETTER CAPE/SHEAR WILL EXIST.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
USED WPC THINKING WITH SOME TWEAKS. NORTHWEST UPPER LEVEL FLOW IS
ANTICIPATED THROUGH MUCH OF THE PERIOD...WITH HIGH PRESSURE TRYING
TO BUILD IN LATE. AT THE SURFACE...A NW-SE ORIENTED FRONT SHOULD
BE LOCATED NEARBY THROUGH MUCH OF THE PERIOD.
WPC TEMPS LOOKED GOOD AND WERE GENERALLY USED.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
LOW STRATUS DOMINATES EARLY THIS MORNING. IT TOOK THE LOWERING OF
IT TO REALIZE DENSE FOG AT HTS AND IT LOOKED LIKE THE SAME THING
WAS HAPPENING AT EKN AS 11Z APPROACHED. THE SAME MAY HAPPEN AT
OTHER SITES AS WE NEAR AND CROSS THE START OF THE 1912/2012 TAF
PERIOD. THE FOG WILL THIN INTO AN MVFR MIST BY MID MORNING BEFORE
DISAPPEARING ALTOGETHER...BUT IT WILL TAKE MUCH OF NOT ALL OF THE
MORNING FOR THE STRATUS TO LIFT THROUGH AND THEN ABOVE THE MVFR
RANGE. MVFR STRATOCU MAY HANG ON INTO THE AFTERNOON IN THE
MOUNTAINS.
THE PROBLEM TONIGHT WILL BE THUNDERSTORMS...ALTHOUGH THIS FCST IS
ALSO A BIT UNCERTAIN. THE STORMS SHOULD FIRE UP IN THE MIDDLE OHIO
VALLY AS A SYSTEM APPROACHES FROM THE NW LATER TODAY. THE STORMS
WILL MOVE QUICKLY SEWD THROUGH THE MIDDLE OHIO VALLEY AND THEN THE
CENTRAL APPALACHIANS TONIGHT.
POST RAIN STRATUS AND FOG ARE LIKELY TO FORM IN THE WAKE OF THE
SHOWERS AND THUNDERSTORMS BY DAWN WED.
LIGHT AND VARIABLE SFC FLOW WILL BECOME LIGHT SW TONIGHT...WHILE
LIGHT NW FLOW ALOFT BECOMES LIGHT W THIS AFTERNOON AND THEN LIGHT SW
TONIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE: LOW TO MEDIUM.
ALTERNATE SCENARIOS: TIMING OF LIFTING AND DISSIPATION OF LOW
STRATOCU...STRATUS AND FOG THIS MORNING MAY VARY. TIMING OF AND
CONDITIONS IN THUNDERSTORMS LATE TODAY AND TONIGHT MAY VARY. IFR IS
POSSIBLE RIGHT BENEATH ANY THUNDERSTORM LATE TODAY AND TONIGHT. THE
THUNDERSTORMS MAY ALSO PRODUCE STRONG WIND GUSTS IN THE MIDDLE OHIO
VALLEY THIS EVENING. TIMING AND EXTENT OF FOG AND STRATUS LATE
OVERNIGHT TONIGHT MAY ALSO VARY FROM FCST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY L H M M M H H H H H H H
HTS CONSISTENCY M H H H H H H H H H H H
BKW CONSISTENCY H H H H H H M H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H M M M H H H H H H H H
AFTER 18Z WEDNESDAY...
IFR POSSIBLE IN ANY ROUND OF CONVECTION WED NT THROUGH FRI NT...AND
IN LATE NT/EARLY MORNING POST RAIN FOG AND STRATUS THROUGH SAT
MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/SL
NEAR TERM...ARJ/TRM
SHORT TERM...SL
LONG TERM...JSH
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
633 PM EDT TUE AUG 19 2014
.SYNOPSIS...
A MASSIVE RIDGE WILL BUILD OVER EAST-CENTRAL CANADA FOR THE NEXT
WEEK. ANOTHER STRONG RIDGE WILL BUILD OVER THE SOUTHERN UNITED
STATES. SHORT-WAVES EMBEDDED IN THE WEAK FLOW MOVING UNDER THE
CANADIAN BLOCK WILL SLOW DOWN AND WEAKEN AS THEY MOVE THROUGH OUR
REGION. THIS WILL LEAD TO A POTENTIALLY PROLONGED PERIOD OF
UNSETTLED WEATHER. BUT IT SHOULD PROTECT US FROM THE LATE SEASON
HEAT BUILDING TO OUR SOUTH.
&&
.NEAR TERM /UNTIL MIDNIGHT TONIGHT/...
A PLEASANT EVENING IS IN STORE FOR MOST OF THE REGION AS A NEARLY
N/S RIBBON OF RELATIVELY LOWER PWAT AIR /AROUND 1.0/ SLIDES EAST.
CLOUDS...AND ISOLATED TO SCATTERED SHOWERS WILL AFFECT MAINLY THE
LOWER SUSQ VALLEY THROUGH ABOUT 01Z WED.
PRECIP CHCS WILL BE ESSENTIALLY ZERO ACROSS MUCH OF CENTRAL AND
WESTERN PORTIONS OF THE CWA THROUGH 04-06Z...BEFORE A SHIELD OF
ANVIL CIRRUS...THEN PRECIP ENTERS OUR NW ZONES IN ASSOCIATION
WITH AN AREA TSRA MOVING ACROSS EXTREME SE MICH ATTM.
TEMPS WILL SLOWLY COOL OFF FROM THE LOWER TO MID 70S THIS
EVENING...BUT WILL LINGER AROUND 80F ACROSS THE FAR SE ZONES
THROUGH 00Z.
&&
.SHORT TERM /MIDNIGHT THROUGH 6 PM WEDNESDAY/...
THE HIGH RES WRF ARW AND HRRR SHOWS CONVECTION MOVING ACROSS LAKE
ERIE THIS EVENING AND INTO OUR FAR NW ZONES TWD 06Z /THOUGH THE
HRRR HAS TRENDED TWD A FEW-SEVERAL HOUR LATER ONSET OF THE
CONVECTION/. THIS AREA OF SHRA/TSRA SHOULD STEADILY
WEAKEN/FRAGMENT AS IT ENCOUNTERS LOWER PWATS AND A COOLER/MORE
STABLE LLVL ENVIRONMENT RESIDING OVER CENTRAL PENN.
POPS AFTER 06Z WILL INCREASE GRADUALLY TO ABOUT 30-40 PERCENT
BY DAYBREAK ACROSS THE WESTERN HALF OF THE CWA...BUT WILL REMIAN
AOB 15 PERCENT FURTHER EAST ACROSS THE ENTIRE SUSQ VALLEY.
PERVIOUS DISC BELOW...
A SURGE OF CAPE AND PW INTO WESTERN PA IN THE SREF AND
NAM...SIMILAR TO OLDER GEFS/GFS IMPLY SOME MORE ORGANIZED RAIN
POSSIBLE ON WEDNESDAY. USED A BLEND TO GET THE POPS AND THE 12KM
NAM TO ADD SOME TEXTURE TO CONVECTION AND RAIN AREA THAT APPEARS
TO BE POISED TO MOVE WEST TO EAST ACROSS THE REGION WEDNESDAY.
THE SREF POPS/PDF IMPLIES SHOWERS COMING INTO WEST AROUND 1500 UTC
AND MOST OF CENTRAL TWO THIRDS OF REGION BY LATE EVENING. SREF IS
KIND OF OPTIMISTIC SOUTHEAST PA COULD HAVE YET ANOTHER MOSTLY
RAIN FREE DAY WEDNESDAY.
THE KEY FEATURES ARE THE RETROGRADING RIDGE OVER EASTERN CANADA
WHICH IS TAKING THE UMPH OUT OF THE SYSTEMS CUTTING UNDER THIS
FEATURE. IN MOST MODELS THE NEAR 1SD ABOVE NORMAL PW SURGES WEAKEN
AS THE MOVE INTO PA. THUS MORE OPTIMISTIC...SREF-LIKE IN THE WEST
THAN THE EAST WITH RAINFALL AND NOT REALLY CONFIDENT GOING LIKELY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
THE WEAKENING RIDGE OVER EASTERN CANADA WILL ALLOW FOR DIVERGENT
FLOW AS THE UPPER LEVEL LOW SLOWLY MOVES EASTWARD. DAYTIME
HEATING...DECREASING PRESSURE...MOIST SOUTHEASTERLY SFC FLOW...AND
WEST TO NORTHWESTERLY FLOW ALOFT SHOULD ALLOW FOR ENOUGH
SHEAR...FOR CHANCE TO LIKELY POPS EARLY WEDNESDAY EVENING. CAPE
VALUES ARE LOW...WITH AN AVG OF 500-1K J/KG THROUGHOUT MOST OF
CENTRAL PA. SO SCATTERED SHOWERS AND THUNDERSTORMS REMAIN POSSIBLE
EARLY WEDNESDAY EVENING. THESE WILL SLOWLY FADE AS THE EVENING
CONTINUES.
THURSDAY LOOKS LIKE ANOTHER UNSETTLED DAY...AS UPPER LOW MAKES
IT/S CLOSEST PASS TO PA...TRACKING ACROSS UPSTATE NY...WITH THE
850MB LOW MOVING THROUGH PA. COOL TEMPS ALOFT...COMBINED WITH
DIURNAL HEATING...SHOULD YIELD NUMEROUS SHRA AND TSRA BY THE
AFTERNOON. HAVE CONTINUED POPS IN THE LIKELY CATEGORY BASED ON 12Z
OPERATIONAL AND GEFS OUTPUT. DUE TO THE CHANGING POSITION AND
TIMING OF THE LOW...HAVE SLIGHTLY LOWERED POPS ALONG THE SOUTHERN
HALF OF THE CWA. THE SOUTHERLY LL JET AND PLUME OF HIGH PWATS WILL
HAVE PASSED NE OF THE AREA THURSDAY...LIMITING THE THREAT OF ANY
HVY RAINFALL. MODEL BLENDED QPF IS IN THE QUARTER TO HALF INCH
RANGE THURSDAY. BEFORE THE LOW PASSES...TEMPS COULD REACH UP TO
THE LOW 80S. AFTER THURSDAY/S NUMEROUS SHOWERS AND THE ADVECTION
OF COOLER TEMPS ALOFT...HIGH TEMPS SHOULD DROP BELOW NORMAL FOR
AUGUST...WITH MAXES MAINLY IN THE 70S THROUGH THE END OF THE WORK
WEEK INTO THE WEEKEND.
LATEST MED RANGE GUIDANCE POINTING TOWARD DRIER WX FRIDAY INTO
EARLY NEXT WEEK...AS SUBTROPICAL HIGH IS PROGGED TO EDGE TOWARD
THE REGION FROM THE MIDWEST. DAILY RING OF FIRE CONVECTION ON NE
PERIPHERY OF THIS RIDGE WILL THREATEN WESTERN PA DURING THE
FRI-SUN TIME FRAME...WHILE EASTERN PA IS LIKELY TO REMAIN DRY.
DESPITE APPROACH OF UPPER RIDGE...NO BIG WARM UP EXPECTED...AS
LARGE SFC HIGH OVR THE CANADIAN MARITIMES WILL CIRCULATE AN
EASTERLY FLOW INTO CENTRAL PA. THERE MAY BE ISSUE WITH AM LOW
CLOUDS/FOG DUE TO THE EXPECTED MOISTLY SERLY FLOW OVR THE AREA.
&&
.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
BULK OF SHOWERS AND STORMS OVER WITH...JUST A FEW ACROSS THE
FAR SOUTH. 21Z TAFS ADJUSTED FOR THIS.
EARLIER DISCUSSION BELOW.
THINGS SETTLE DOWN OVERNIGHT...MORE PATCHY FOG AND LOW CLOUDS.
SO MORE AREAS OF MVFR AND IFR.
WEDNESDAY WILL SEE RAIN AND SHOWERS LIKELY IN WESTERN PA BY
MID TO LATE MORNING SLOWLY SPREADING EAST. VFR IN EAST BUT AREAS
MVFR LIKELY IN AM FOG AND THEN SHOWERS IN WESTERN AREAS.
OUTLOOK...
THU-SAT...MORNING FOG CHANCES EACH DAY. OVERALL VFR...BUT CHC OF
MAINLY AFTERNOON SHRA/TSRA AND ASSOCIATED RESTRICTIONS.
SUN...MAINLY VFR. STILL CHANCE OF SHRA IN THE MORNING.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT/GRUMM
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT/GRUMM
LONG TERM...FITZGERALD/CERU
AVIATION...GRUMM/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
523 PM EDT TUE AUG 19 2014
.SYNOPSIS...
A MASSIVE RIDGE WILL BUILD OVER EAST-CENTRAL CANADA FOR THE NEXT
WEEK. ANOTHER STRONG RIDGE WILL BUILD OVER THE SOUTHERN UNITED
STATES. SHORT-WAVES IN THE WEAK FLOW MOVING UNDER THE CANADIAN
BLOCK WILL SLOW DOWN AND WEAKEN AS THEY MOVE THROUGH OUR REGION.
THIS WILL LEAD TO A POTENTIALLY PROLONGED PERIOD OF UNSETTLED
WEATHER. BUT IT SHOULD PROTECT US FROM THE LATE SEASON HEAT
BUILDING TO OUR SOUTH.
&&
.NEAR TERM /UNTIL 9 PM THIS EVENING/...
A WEAKLY ORGANIZED BROKEN LINE OF SHOWERS AND ISOLATED
THUNDERSTORMS IS TRYING TO WORK ITS AWAY ACROSS OUR WEST-CENTRAL
COUNTIES FROM CENTRE COUNTY DOWN TO THE MARYLAND BORDER. BUMPED
UP POPS AND ADDED TEXTURE TO THE GRIDS WITH 3KM HRRR AND 4KM NAM
ESTIMATED POPS/QPF.
RADAR SHOWS VERY LIGHT RAIN. LOCAL GAGES SHOW ABOUT 0.10 IN
WESTERN AREAS OF STATE COLLEGE. BUT SOME STREAKS ON RADAR OF 0.1
TO 0.4 INCHES. IN SOMERSET COUNTY...STRONGER CELLS SHOWS CLOSE TO
AN INCH OF ESTIMATED RAINFALL. RADAR AND HRRR IMPLY BEST CHANCE
RAIN WILL BE FROM CAMBRIA AND SOMERSET COUNTIES EASTWARD TO
HUNTINGTON AND FRANKLIN COUNTY AS THE STRONGEST ELEMENTS HEAD
SLOWLY EAST.
THE 3KM AND 4KM MODELS IMPLY MOST OF THIS CONVECTION DIES OFF A
FEW HOURS EITHER SIDE 6 PM.
&&
.SHORT TERM /9 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
SREF AND NAM CONTINUE TO SHOW CHANCE TO SLIGHT CHANCE OF SHOWERS
OVERNIGHT. MOST AREAS RAIN FREE IN HRRR AFTER 0000 UTC TONIGHT
THROUGH 0600 UTC.
BUT THE HRRR DOES SHOW OVERNIGHT CONVECTION IN THE MIDWEST MOVING
INTO WESTERN PA AFTER 0600 UTC. CHANCE RAIN WILL CLEARER INCREASE
BEFORE SUNRISE IN WESTERN AREAS.
THE SURGE OF CAPE AND PW INTO WESTERN PA IN THE SREF AND
NAM...SIMILAR TO OLDER GEFS/GFS IMPLY SOME MORE ORGANIZED RAIN
POSSIBLE ON WEDNESDAY. USED A BLEND TO GET THE POPS AND THE 12KM
NAM TO ADD SOME TEXTURE TO CONVECTION AND RAIN AREA THAT APPEARS
TO BE POISED TO MOVE WEST TO EAST ACROSS THE REGION WEDNESDAY.
THE SREF POPS/PDF IMPLIES SHOWERS COMING INTO WEST AROUND 1500 UTC
AND MOST OF CENTRAL TWO THIRDS OF REGION BY LATE EVENING. SREF IS
KIND OF OPTIMISTIC SOUTHEAST PA COULD HAVE YET ANOTHER MOSTLY
RAIN FREE DAY WEDNESDAY.
THE KEY FEATURES ARE THE RETROGRADING RIDGE OVER EASTERN CANADA
WHICH IS TAKING THE UMPH OUT OF THE SYSTEMS CUTTING UNDER THIS
FEATURE. IN MOST MODELS THE NEAR 1SD ABOVE NORMAL PW SURGES WEAKEN
AS THE MOVE INTO PA. THUS MORE OPTIMISTIC...SREF-LIKE IN THE WEST
THAN THE EAST WITH RAINFALL AND NOT REALLY CONFIDENT GOING LIKELY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
THE WEAKENING RIDGE OVER EASTERN CANADA WILL ALLOW FOR DIVERGENT
FLOW AS THE UPPER LEVEL LOW SLOWLY MOVES EASTWARD. DAYTIME
HEATING...DECREASING PRESSURE...MOIST SOUTHEASTERLY SFC FLOW...AND
WEST TO NORTHWESTERLY FLOW ALOFT SHOULD ALLOW FOR ENOUGH
SHEAR...FOR CHANCE TO LIKELY POPS EARLY WEDNESDAY EVENING. CAPE
VALUES ARE LOW...WITH AN AVG OF 500-1K J/KG THROUGHOUT MOST OF
CENTRAL PA. SO SCATTERED SHOWERS AND THUNDERSTORMS REMAIN POSSIBLE
EARLY WEDNESDAY EVENING. THESE WILL SLOWLY FADE AS THE EVENING
CONTINUES.
THURSDAY LOOKS LIKE ANOTHER UNSETTLED DAY...AS UPPER LOW MAKES
IT/S CLOSEST PASS TO PA...TRACKING ACROSS UPSTATE NY...WITH THE
850MB LOW MOVING THROUGH PA. COOL TEMPS ALOFT...COMBINED WITH
DIURNAL HEATING...SHOULD YIELD NUMEROUS SHRA AND TSRA BY THE
AFTERNOON. HAVE CONTINUED POPS IN THE LIKELY CATEGORY BASED ON 12Z
OPERATIONAL AND GEFS OUTPUT. DUE TO THE CHANGING POSITION AND
TIMING OF THE LOW...HAVE SLIGHTLY LOWERED POPS ALONG THE SOUTHERN
HALF OF THE CWA. THE SOUTHERLY LL JET AND PLUME OF HIGH PWATS WILL
HAVE PASSED NE OF THE AREA THURSDAY...LIMITING THE THREAT OF ANY
HVY RAINFALL. MODEL BLENDED QPF IS IN THE QUARTER TO HALF INCH
RANGE THURSDAY. BEFORE THE LOW PASSES...TEMPS COULD REACH UP TO
THE LOW 80S. AFTER THURSDAY/S NUMEROUS SHOWERS AND THE ADVECTION
OF COOLER TEMPS ALOFT...HIGH TEMPS SHOULD DROP BELOW NORMAL FOR
AUGUST...WITH MAXES MAINLY IN THE 70S THROUGH THE END OF THE WORK
WEEK INTO THE WEEKEND.
LATEST MED RANGE GUIDANCE POINTING TOWARD DRIER WX FRIDAY INTO
EARLY NEXT WEEK...AS SUBTROPICAL HIGH IS PROGGED TO EDGE TOWARD
THE REGION FROM THE MIDWEST. DAILY RING OF FIRE CONVECTION ON NE
PERIPHERY OF THIS RIDGE WILL THREATEN WESTERN PA DURING THE
FRI-SUN TIME FRAME...WHILE EASTERN PA IS LIKELY TO REMAIN DRY.
DESPITE APPROACH OF UPPER RIDGE...NO BIG WARM UP EXPECTED...AS
LARGE SFC HIGH OVR THE CANADIAN MARITIMES WILL CIRCULATE AN
EASTERLY FLOW INTO CENTRAL PA. THERE MAY BE ISSUE WITH AM LOW
CLOUDS/FOG DUE TO THE EXPECTED MOISTLY SERLY FLOW OVR THE AREA.
&&
.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
BULK OF SHOWERS AND STORMS OVER WITH...JUST A FEW ACROSS THE
FAR SOUTH. 21Z TAFS ADJUSTED FOR THIS.
EARLIER DISCUSSION BELOW.
THINGS SETTLE DOWN OVERNIGHT...MORE PATCHY FOG AND LOW CLOUDS.
SO MORE AREAS OF MVFR AND IFR.
WEDNESDAY WILL SEE RAIN AND SHOWERS LIKELY IN WESTERN PA BY
MID TO LATE MORNING SLOWLY SPREADING EAST. VFR IN EAST BUT AREAS
MVFR LIKELY IN AM FOG AND THEN SHOWERS IN WESTERN AREAS.
OUTLOOK...
THU-SAT...MORNING FOG CHANCES EACH DAY. OVERALL VFR...BUT CHC OF
MAINLY AFTERNOON SHRA/TSRA AND ASSOCIATED RESTRICTIONS.
SUN...MAINLY VFR. STILL CHANCE OF SHRA IN THE MORNING.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...
NEAR TERM...GRUMM
SHORT TERM...GRUMM
LONG TERM...FITZGERALD/CERU
AVIATION...GRUMM/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
351 PM EDT TUE AUG 19 2014
.SYNOPSIS...
A MASSIVE RIDGE WILL BUILD OVER EAST-CENTRAL CANADA FOR THE NEXT
WEEK. ANOTHER STRONG RIDGE WILL BUILD OVER THE SOUTHERN UNITED
STATES. SHORT-WAVES IN THE WEAK FLOW MOVING UNDER THE CANADIAN
BLOCK WILL SLOW DOWN AND WEAKEN AS THEY MOVE THROUGH OUR REGION.
THIS WILL LEAD TO A POTENTIALLY PROLONGED PERIOD OF UNSETTLED
WEATHER. BUT IT SHOULD PROTECT US FROM THE LATE SEASON HEAT
BUILDING TO OUR SOUTH.
&&
.NEAR TERM /UNTIL 9 PM THIS EVENING/...
A WEAKLY ORGANIZED BROKEN LINE OF SHOWERS AND ISOLATED
THUNDERSTORMS IS TRYING TO WORK ITS AWAY ACROSS OUR WEST-CENTRAL
COUNTIES FROM CENTRE COUNTY DOWN TO THE MARYLAND BORDER. BUMPED UP
POPS AND ADDED TEXTURE TO THE GRIDS WITH 3KM HRRR AND 4KM NAM
ESTIMATED POPS/QPF.
RADAR SHOWS VERY LIGHT RAIN. LOCAL GAGES SHOW ABOUT 0.10 IN
WESTERN AREAS OF STATE COLLEGE. BUT SOME STREAKS ON RADAR OF 0.1
TO 0.4 INCHES. IN SOMERSET COUNTY...STRONGER CELLS SHOWS CLOSE TO
AN INCH OF ESTIMATED RAINFALL. RADAR AND HRRR IMPLY BEST CHANCE
RAIN WILL BE FROM CAMBRIA AND SOMERSET COUNTIES EASTWARD TO
HUNTINGTON AND FRANKLIN COUNTY AS THE STRONGEST ELEMENTS HEAD
SLOWLY EAST.
THE 3KM AND 4KM MODELS IMPLY MOST OF THIS CONVECTION DIES OFF A
FEW HOURS EITHER SIDE 6 PM.
&&
.SHORT TERM /9 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
SREF AND NAM CONTINUE TO SHOW CHANCE TO SLIGHT CHANCE OF SHOWERS
OVERNIGHT. MOST AREAS RAIN FREE IN HRRR AFTER 0000 UTC TONIGHT
THROUGH 0600 UTC.
BUT THE HRRR DOES SHOW OVERNIGHT CONVECTION IN THE MIDWEST MOVING
INTO WESTERN PA AFTER 0600 UTC. CHANCE RAIN WILL CLEARER INCREASE
BEFORE SUNRISE IN WESTERN AREAS.
THE SURGE OF CAPE AND PW INTO WESTERN PA IN THE SREF AND
NAM...SIMILAR TO OLDER GEFS/GFS IMPLY SOME MORE ORGANIZED RAIN
POSSIBLE ON WEDNESDAY. USED A BLEND TO GET THE POPS AND THE 12KM
NAM TO ADD SOME TEXTURE TO CONVECTION AND RAIN AREA THAT APPEARS
TO BE POISED TO MOVE WEST TO EAST ACROSS THE REGION WEDNESDAY.
THE SREF POPS/PDF IMPLIES SHOWERS COMING INTO WEST AROUND 1500 UTC
AND MOST OF CENTRAL TWO THIRDS OF REGION BY LATE EVENING. SREF IS
KIND OF OPTIMISTIC SOUTHEAST PA COULD HAVE YET ANOTHER MOSTLY
RAIN FREE DAY WEDNESDAY.
THE KEY FEATURES ARE THE RETROGRADING RIDGE OVER EASTERN CANADA
WHICH IS TAKING THE UMPH OUT OF THE SYSTEMS CUTTING UNDER THIS
FEATURE. IN MOST MODELS THE NEAR 1SD ABOVE NORMAL PW SURGES WEAKEN
AS THE MOVE INTO PA. THUS MORE OPTIMISTIC...SREF-LIKE IN THE WEST
THAN THE EAST WITH RAINFALL AND NOT REALLY CONFIDENT GOING LIKELY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
THE WEAKENING RIDGE OVER EASTERN CANADA WILL ALLOW FOR DIVERGENT
FLOW AS THE UPPER LEVEL LOW SLOWLY MOVES EASTWARD. DAYTIME
HEATING...DECREASING PRESSURE...MOIST SOUTHEASTERLY SFC FLOW...AND
WEST TO NORTHWESTERLY FLOW ALOFT SHOULD ALLOW FOR ENOUGH
SHEAR...FOR CHANCE TO LIKELY POPS EARLY WEDNESDAY EVENING. CAPE
VALUES ARE LOW...WITH AN AVG OF 500-1K J/KG THROUGHOUT MOST OF
CENTRAL PA. SO SCATTERED SHOWERS AND THUNDERSTORMS REMAIN POSSIBLE
EARLY WEDNESDAY EVENING. THESE WILL SLOWLY FADE AS THE EVENING
CONTINUES.
THURSDAY LOOKS LIKE ANOTHER UNSETTLED DAY...AS UPPER LOW MAKES
IT/S CLOSEST PASS TO PA...TRACKING ACROSS UPSTATE NY...WITH THE
850MB LOW MOVING THROUGH PA. COOL TEMPS ALOFT...COMBINED WITH
DIURNAL HEATING...SHOULD YIELD NUMEROUS SHRA AND TSRA BY THE
AFTERNOON. HAVE CONTINUED POPS IN THE LIKELY CATEGORY BASED ON 12Z
OPERATIONAL AND GEFS OUTPUT. DUE TO THE CHANGING POSITION AND
TIMING OF THE LOW...HAVE SLIGHTLY LOWERED POPS ALONG THE SOUTHERN
HALF OF THE CWA. THE SOUTHERLY LL JET AND PLUME OF HIGH PWATS WILL
HAVE PASSED NE OF THE AREA THURSDAY...LIMITING THE THREAT OF ANY
HVY RAINFALL. MODEL BLENDED QPF IS IN THE QUARTER TO HALF INCH
RANGE THURSDAY. BEFORE THE LOW PASSES...TEMPS COULD REACH UP TO
THE LOW 80S. AFTER THURSDAY/S NUMEROUS SHOWERS AND THE ADVECTION
OF COOLER TEMPS ALOFT...HIGH TEMPS SHOULD DROP BELOW NORMAL FOR
AUGUST...WITH MAXES MAINLY IN THE 70S THROUGH THE END OF THE WORK
WEEK INTO THE WEEKEND.
LATEST MED RANGE GUIDANCE POINTING TOWARD DRIER WX FRIDAY INTO
EARLY NEXT WEEK...AS SUBTROPICAL HIGH IS PROGGED TO EDGE TOWARD
THE REGION FROM THE MIDWEST. DAILY RING OF FIRE CONVECTION ON NE
PERIPHERY OF THIS RIDGE WILL THREATEN WESTERN PA DURING THE
FRI-SUN TIME FRAME...WHILE EASTERN PA IS LIKELY TO REMAIN DRY.
DESPITE APPROACH OF UPPER RIDGE...NO BIG WARM UP EXPECTED...AS
LARGE SFC HIGH OVR THE CANADIAN MARITIMES WILL CIRCULATE AN
EASTERLY FLOW INTO CENTRAL PA. THERE MAY BE ISSUE WITH AM LOW
CLOUDS/FOG DUE TO THE EXPECTED MOISTLY SERLY FLOW OVR THE AREA.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
RADAR SHOWS SOME ORGANIZED SHOWERS AND THUNDERSTORMS FROM NEAR
KFIG SOUTH TO THE MARYLAND BORDER. THESE SHOWERS AND STORMS WILL
SLOWLY MOVE EASTWARD THIS AFTERNOON. AREAS OF MVFR AND LOCALLY IFR
ARE POSSIBLE ALONG THE LINE AND WITHIN THE SHOWERS AND
THUNDERSTORMS.
MODELS ALL SUGGEST POPCORN SHOWERS POSSIBLE OVER MOST OF CENTRAL
PA AND THE MORE ORGANIZED ACTIVITY OVER THE SOUTHERN HALF OF THE
STATE THROUGH THIS EVENING.
THINGS SETTLE DOWN OVERNIGHT...MORE PATCHY FOG AND LOW CLOUDS.SO
MORE AREAS OF MVFR AND IFR.
WEDNESDAY WILL SEE RAIN AND SHOWERS LIKELY IN WESTERN PA BY MID-
LATE MORNING SLOWLY SPREADING EAST. VFR IN EAST BUT AREAS MVFR
LIKELY IN AM FOG AND THEN SHOWERS IN WESTERN AREAS.
OUTLOOK...
TUE...MAINLY VFR...WITH SHRA/TSRA POSSIBLE.
WED...MORNING FOG/LOW CLOUDS SHRA/TSRA LIKELY WEST CHANCE EAST.
THU-FRI...MORNING FOG CHANCES EACH DAY. OVERALL VFR...BUT
INCREASING CHANCES OF MAINLY AFTERNOON SHRA/TSRA AND ASSOCIATED
RESTRICTIONS. SAT...MAINLY VFR. STILL CHANCE OF SHRA...BUT
DECREASING CHANCES.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...
NEAR TERM...GRUMM
SHORT TERM...GRUMM
LONG TERM...CERU/FITZGERALD
AVIATION...GRUMM
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
206 PM EDT TUE AUG 19 2014
.SYNOPSIS...
A MASSIVE RIDGE WILL BUILD OVER EAST-CENTRAL CANADA FOR THE NEXT
WEEK. ANOTHER STRONG RIDGE WILL BUILD OVER THE SOUTHERN UNITED
STATES. SHORT-WAVES IN THE WEAK FLOW MOVING UNDER THE CANADIAN
BLOCK WILL SLOW DOWN AND WEAKEN AS THEY MOVE THROUGH OUR REGION.
THIS WILL LEAD TO A POTENTIALLY PROLONGED PERIOD OF UNSETTLED
WEATHER. BUT IT SHOULD PROTECT US FROM THE LATE SEASON HEAT
BUILDING TO OUR SOUTH.
&&
.NEAR TERM /UNTIL 9 PM THIS EVENING/...
A WEAKLY ORGANIZED BROKEN LINE OF SHOWERS AND ISOLATED
THUNDERSTORMS IS TRYING TO WORK ITS AWAY ACROSS OUR WEST-CENTRAL
COUNTIES FROM CENTRE COUNTY DOWN TO THE MARYLAND BORDER. BUMPED UP
POPS AND ADDED TEXTURE TO THE GRIDS WITH 3KM HRRR AND 4KM NAM
ESTIMATED POPS/QPF.
RADAR SHOWS VERY LIGHT RAIN. LOCAL GAGES SHOW ABOUT 0.10 IN
WESTERN AREAS OF STATE COLLEGE. BUT SOME STREAKS ON RADAR OF 0.1
TO 0.4 INCHES. IN SOMERSET COUNTY...STRONGER CELLS SHOWS CLOSE TO
AN INCH OF ESTIMATED RAINFALL. RADAR AND HRRR IMPLY BEST CHANCE
RAIN WILL BE FROM CAMBRIA AND SOMERSET COUNTIES EASTWARD TO
HUNTINGTON AND FRANKLIN COUNTY AS THE STRONGEST ELEMENTS HEAD
SLOWLY EAST.
THE 3KM AND 4KM MODELS IMPLY MOST OF THIS CONVECTION DIES OFF A
FEW HOURS EITHER SIDE 6 PM.
&&
.SHORT TERM /9 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
SREF AND NAM CONTINUE TO SHOW CHANCE TO SLIGHT CHANCE OF SHOWERS
OVERNIGHT. MOST AREAS RAINFREE IN HRRR AFTER 0000 UTC TONIGHT
THROUGH 0600 UTC.
BUT THE HRRR DOES SHOW OVERNIGHT CONVECTION IN THE MIDWEST MOVING
INTO WESTERN PA AFTER 0600 UTC. CHANCE RAIN WILL CLEARER INCREASE
BEFORE SUNRISE IN WESTERN AREAS.
THE SURGE OF CAPE AND PW INTO WESTERN PA IN THE SREF AND
NAM...SIMILAR TO OLDER GEFS/GFS IMPLY SOME MORE ORGANIZED RAIN
POSSIBLE ON WEDNESDAY. USED A BLEND TO GET THE POPS AND THE 12KM
NAM TO ADD SOME TEXTURE TO CONVECTION AND RAIN AREA THAT APPEARS
TO BE POISED TO MOVE WEST TO EAST ACROSS THE REGION WEDNESDAY.
THE SREF POPS/PDF IMPLIES SHOWERS COMING INTO WEST AROUND 1500 UTC
AND MOST OF CENTRAL TWO THIRDS OF REGION BY LATE EVENING. SREF IS
KIND OF OPTIMISTIC SOUTHEAST PA COULD HAVE YET ANOTHER MOSTLY
RAIN FREE DAY WEDNESDAY.
THE KEY FEATURES ARE THE RETROGRADING RIDGE OVER EASTERN CANADA
WHICH IS TAKING THE UMPH OUT OF THE SYSTEMS CUTTING UNDER THIS
FEATURE. IN MOST MODELS THE NEAR 1SD ABOVE NORMAL PW SURGES WEAKEN
AS THE MOVE INTO PA. THUS MORE OPTIMISTIC...SREF-LIKE IN THE WEST
THAN THE EAST WITH RAINFALL AND NOT REALLY CONFIDENT GOING LIKELY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THURSDAY LOOKS LIKE ANOTHER UNSETTLED DAY...AS UPPER LOW MAKES
IT/S CLOSEST PASS TO PA...TRACKING ACROSS UPSTATE NY. COOL TEMPS
ALOFT...COMBINED WITH DIURNAL HEATING...SHOULD YIELD NUMEROUS SHRA
AND TSRA BY AFTN. HAVE RAISED POPS TO THE LIKELY CATEGORY BASED ON
00Z OPER AND GEFS OUTPUT. SOUTHERLY LL JET AND PLUME OF HIGH
PWATS WILL HAVE PASSED NE OF THE AREA THURSDAY...LIMITING THE
THREAT OF ANY HVY RAINFALL. MDL BLENDED QPF IS IN THE QUARTER TO
HALF INCH RANGE THURSDAY. THE NUMEROUS SHOWERS AND COOLER TEMPS
ALOFT WILL RESULT IN HIGH TEMPS BLW NORMAL FOR AUGUST...WITH
MAXES MAINLY IN THE 70S.
LATEST MED RANGE GUIDANCE POINTING TOWARD DRIER WX FRIDAY INTO
EARLY NEXT WEEK...AS SUBTROPICAL HIGH IS PROGGED TO EDGE TOWARD
THE REGION FROM THE MIDWEST. DAILY RING OF FIRE CONVECTION ON NE
PERIPHERY OF THIS RIDGE WILL THREATEN WESTERN PA DURING THE
FRI-SUN TIME FRAME...WHILE EASTERN PA IS LIKELY TO REMAIN DRY.
DESPITE APPROACH OF UPPER RIDGE...NO BIG WARMUP EXPECTED...AS
LARGE SFC HIGH OVR THE CANADIAN MARITIMES WILL CIRCULATE AN
EASTERLY FLOW INTO CENTRAL PA. THERE MAY BE ISSUE WITH AM LOW
CLOUDS/FOG DUE TO THE EXPECTED MOISTLY SERLY FLOW OVR THE AREA.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
RADAR SHOWS SOME ORGANIZED SHOWERS AND THUNDERSTORMS FROM NEAR
KFIG SOUTH TO THE MARYLAND BORDER. THESE SHOWERS AND STORMS WILL
SLOWLY MOVE EASTWARD THIS AFTERNOON. AREAS OF MVFR AND LOCALLY IFR
ARE POSSIBLE ALONG THE LINE AND WITHIN THE SHOWERS AND
THUNDERSTORMS.
MODELS ALL SUGGEST POPCORN SHOWERS POSSIBLE OVER MOST OF CENTRAL
PA AND THE MORE ORGANIZED ACTIVITY OVER THE SOUTHERN HALF OF THE
STATE THROUGH THIS EVENING.
THINGS SETTLE DOWN OVERNIGHT...MORE PATCHY FOG AND LOW CLOUDS.SO
MORE AREAS OF MVFR AND IFR.
WEDNESDAY WILL SEE RAIN AND SHOWERS LIKELY IN WESTERN PA BY MID-
LATE MORNING SLOWLY SPREADING EAST. VFR IN EAST BUT AREAS MVFR
LIKELY IN AM FOG AND THEN SHOWERS IN WESTERN AREAS.
OUTLOOK...
TUE...MAINLY VFR...WITH SHRA/TSRA POSSIBLE.
WED...MORNING FOG/LOW CLOUDS SHRA/TSRA LIKELY WEST CHANCE EAST.
THU-FRI...MORNING FOG CHANCES EACH DAY. OVERALL VFR...BUT
INCREASING CHANCES OF MAINLY AFTERNOON SHRA/TSRA AND ASSOCIATED
RESTRICTIONS. SAT...MAINLY VFR. STILL CHANCE OF SHRA...BUT
DECREASING CHANCES.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...
NEAR TERM...GRUMM
SHORT TERM...GRUMM
LONG TERM...FITZGERALD
AVIATION...GRUMM
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
201 PM EDT TUE AUG 19 2014
.SYNOPSIS...
AN UPPER LOW OVR THE W GRT LKS WILL DRIFT SLOWLY SE ACROSS UPSTATE
NY AND NEW ENG BY LATE THIS WEEK. A LARGE SFC HIGH OVR THE CANADIAN
MARITIMES WILL RIDGE SOUTHWARD INTO PA DURING THE UPCOMING WEEKEND
AND EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 9 PM THIS EVENING/...
A WEAKLY ORGANIZED BROKEN LINE OF SHOWERS AND ISOLATED
THUNDERSTORMS IS TRYING TO WORK ITS AWAY ACROSS OUR WEST-CENTRAL
COUNTIES FROM CENTRE COUNTY DOWN TO THE MARYLAND BORDER. BUMPED UP
POPS AND ADDED TEXTURE TO THE GRIDS WITH 3KM HRRR AND 4KM NAM
ESTIMATED POPS/QPF.
RADAR SHOWS VERY LIGHT RAIN. LOCAL GAGES SHOW ABOUT 0.10 IN
WESTERN AREAS OF STATE COLLEGE. BUT SOME STREAKS ON RADAR OF 0.1
TO 0.4 INCHES. IN SOMERSET COUNTY...STRONGER CELLS SHOWS CLOSE TO
AN INCH OF ESTIMATED RAINFALL. RADAR AND HRRR IMPLY BEST CHANCE
RAIN WILL BE FROM CAMBRIA AND SOMERSET COUNTIES EASTWARD TO
HUNTINGTON AND FRANKLIN COUNTY AS THE STRONGEST ELEMENTS HEAD
SLOWLY EAST.
THE 3KM AND 4KM MODELS IMPLY MOST OF THIS CONVECTION DIES OFF A
FEW HOURS EITHER SIDE 6 PM.
&&
.SHORT TERM /9 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
SREF AND NAM CONTINUE TO SHOW CHANCE TO SLIGHT CHANCE OF SHOWERS
OVERNIGHT. MOST AREAS RAINFREE IN HRRR AFTER 0000 UTC TONIGHT
THROUGH 0600 UTC.
BUT THE HRRR DOES SHOW OVERNIGHT CONVECTION IN THE MIDWEST MOVING
INTO WESTERN PA AFTER 0600 UTC. CHANCE RAIN WILL CLEARER INCREASE
BEFORE SUNRISE IN WESTERN AREAS.
THE SURGE OF CAPE AND PW INTO WESTERN PA IN THE SREF AND
NAM...SIMILAR TO OLDER GEFS/GFS IMPLY SOME MORE ORGANIZED RAIN
POSSIBLE ON WEDNESDAY. USED A BLEND TO GET THE POPS AND THE 12KM
NAM TO ADD SOME TEXTURE TO CONVECTION AND RAIN AREA THAT APPEARS
TO BE POISED TO MOVE WEST TO EAST ACROSS THE REGION WEDNESDAY.
THE SREF POPS/PDF IMPLIES SHOWERS COMING INTO WEST AROUND 1500 UTC
AND MOST OF CENTRAL TWO THIRDS OF REGION BY LATE EVENING. SREF IS
KIND OF OPTIMISTIC SOUTHEAST PA COULD HAVE YET ANOTHER MOSTLY
RAIN FREE DAY WEDNESDAY.
THE KEY FEATURES ARE THE RETROGRADING RIDGE OVER EASTERN CANADA
WHICH IS TAKING THE UMPH OUT OF THE SYSTEMS CUTTING UNDER THIS
FEATURE. IN MOST MODELS THE NEAR 1SD ABOVE NORMAL PW SURGES WEAKEN
AS THE MOVE INTO PA. THUS MORE OPTIMISTIC...SREF-LIKE IN THE WEST
THAN THE EAST WITH RAINFALL AND NOT REALLY CONFIDENT GOING LIKELY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THURSDAY LOOKS LIKE ANOTHER UNSETTLED DAY...AS UPPER LOW MAKES
IT/S CLOSEST PASS TO PA...TRACKING ACROSS UPSTATE NY. COOL TEMPS
ALOFT...COMBINED WITH DIURNAL HEATING...SHOULD YIELD NUMEROUS SHRA
AND TSRA BY AFTN. HAVE RAISED POPS TO THE LIKELY CATEGORY BASED ON
00Z OPER AND GEFS OUTPUT. SOUTHERLY LL JET AND PLUME OF HIGH
PWATS WILL HAVE PASSED NE OF THE AREA THURSDAY...LIMITING THE
THREAT OF ANY HVY RAINFALL. MDL BLENDED QPF IS IN THE QUARTER TO
HALF INCH RANGE THURSDAY. THE NUMEROUS SHOWERS AND COOLER TEMPS
ALOFT WILL RESULT IN HIGH TEMPS BLW NORMAL FOR AUGUST...WITH
MAXES MAINLY IN THE 70S.
LATEST MED RANGE GUIDANCE POINTING TOWARD DRIER WX FRIDAY INTO
EARLY NEXT WEEK...AS SUBTROPICAL HIGH IS PROGGED TO EDGE TOWARD
THE REGION FROM THE MIDWEST. DAILY RING OF FIRE CONVECTION ON NE
PERIPHERY OF THIS RIDGE WILL THREATEN WESTERN PA DURING THE
FRI-SUN TIME FRAME...WHILE EASTERN PA IS LIKELY TO REMAIN DRY.
DESPITE APPROACH OF UPPER RIDGE...NO BIG WARMUP EXPECTED...AS
LARGE SFC HIGH OVR THE CANADIAN MARITIMES WILL CIRCULATE AN
EASTERLY FLOW INTO CENTRAL PA. THERE MAY BE ISSUE WITH AM LOW
CLOUDS/FOG DUE TO THE EXPECTED MOISTLY SERLY FLOW OVR THE AREA.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
RADAR SHOWS SOME ORGANIZED SHOWERS AND THUNDERSTORMS FROM NEAR
KFIG SOUTH TO THE MARYLAND BORDER. THESE SHOWERS AND STORMS WILL
SLOWLY MOVE EASTWARD THIS AFTERNOON. AREAS OF MVFR AND LOCALLY IFR
ARE POSSIBLE ALONG THE LINE AND WITHIN THE SHOWERS AND
THUNDERSTORMS.
MODELS ALL SUGGEST POPCORN SHOWERS POSSIBLE OVER MOST OF CENTRAL
PA AND THE MORE ORGANIZED ACTIVITY OVER THE SOUTHERN HALF OF THE
STATE THROUGH THIS EVENING.
THINGS SETTLE DOWN OVERNIGHT...MORE PATCHY FOG AND LOW CLOUDS.SO
MORE AREAS OF MVFR AND IFR.
WEDNESDAY WILL SEE RAIN AND SHOWERS LIKELY IN WESTERN PA BY MID-
LATE MORNING SLOWLY SPREADING EAST. VFR IN EAST BUT AREAS MVFR
LIKELY IN AM FOG AND THEN SHOWERS IN WESTERN AREAS.
OUTLOOK...
TUE...MAINLY VFR...WITH SHRA/TSRA POSSIBLE.
WED...MORNING FOG/LOW CLOUDS SHRA/TSRA LIKELY WEST CHANCE EAST.
THU-FRI...MORNING FOG CHANCES EACH DAY. OVERALL VFR...BUT
INCREASING CHANCES OF MAINLY AFTERNOON SHRA/TSRA AND ASSOCIATED
RESTRICTIONS. SAT...MAINLY VFR. STILL CHANCE OF SHRA...BUT
DECREASING CHANCES.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...GRUMM
SHORT TERM...GRUMM
LONG TERM...FITZGERALD
AVIATION...GRUMM
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
128 PM EDT TUE AUG 19 2014
.SYNOPSIS...
AN UPPER LOW OVR THE W GRT LKS WILL DRIFT SLOWLY SE ACROSS UPSTATE
NY AND NEW ENG BY LATE THIS WEEK. A LARGE SFC HIGH OVR THE CANADIAN
MARITIMES WILL RIDGE SOUTHWARD INTO PA DURING THE UPCOMING WEEKEND
AND EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
LOW CLOUDS SLOWLY LIFTING AND MOVING TO THE EAST. RADAR HAS
DETECTED SHOWERS WHICH DEVELOPED ON THE WESTERN EDGE OF THIS CLOUD
SHIELD AND HAS MOVED INTO CLEARFIELD COUNTY. SOME HINTS OF WEAK
CONVECTION IN THE HRRR AND 4KM NAM. USED THESE MODELS TO ADD
TEXTURE TO THE FORECAST SHOWING SHOWERS AND ISOLATED THUNDERSTORMS
DRIFTING ACROSS PENNSYLVANIA THIS MORNING AND AFTERNOON.
TRIED TO KEEP POPS IN CHANCE RANGE AS THERE IS LIMITED
ORGANIZATION TO THE CONVECTION. HOWEVER...3KM HRRR UPDATES FROM
NCEPS EXPERIMENTAL HRRR SHOW DIFFERENT AREAS OF SHOWERS IN CENTRAL
PA ALL AFTERNOON AND NOW IMPLY MORE ORGANIZED THUNDERSTORMS IN
S-SE COUNTIES IN LATE AFTERNOON EVENING. SEE HOW THIS EVOLVES.
SKIES SHOULD SLOWLY GET BETTER DURING DAY CENTRAL AREAS.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
SREF AND NAM CONTINUE TO SHOW CHANCE TO SLIGHT CHANCE OF SHOWERS
OVERNIGHT. THE SURGE OF CAPE AND PW INTO WESTERN PA IN THE SREF
AND NAM...SIMILAR TO OLDER GEFS/GFS IMPLY SOME MORE ORGANIZED RAIN
POSSIBLE ON WEDNESDAY. USED A BLEND TO GET THE POPS AND THE 12KM
NAM TO ADD SOME TEXTURE TO CONVECTION AND RAIN AREA THAT APPEARS
TO BE POISED TO MOVE WEST TO EAST ACROSS THE REGION WEDNESDAY.
THE SREF POPS/PDF IMPLIES SHOWERS COMING INTO WEST AROUND 1500 UTC
AND MOST OF CENTRAL TWO THIRDS OF REGION BY LATE EVENING. SREF IS
KIND OF OPTIMISTIC SOUTHEAST PA COULD HAVE YET ANOTHER MOSTLY
RAIN FREE DAY WEDNESDAY.
THE KEY FEATURES ARE THE RETROGRADING RIDGE OVER EASTERN CANADA
WHICH IS TAKING THE UMPH OUT OF THE SYSTEMS CUTTING UNDER THIS
FEATURE. IN MOST MODELS THE NEAR 1SD ABOVE NORMAL PW SURGES WEAKEN
AS THE MOVE INTO PA. THUS MORE OPTIMISTIC...SREF-LIKE IN THE WEST
THAN THE EAST WITH RAINFALL AND NOT REALLY CONFIDENT GOING LIKELY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THURSDAY LOOKS LIKE ANOTHER UNSETTLED DAY...AS UPPER LOW MAKES
IT/S CLOSEST PASS TO PA...TRACKING ACROSS UPSTATE NY. COOL TEMPS
ALOFT...COMBINED WITH DIURNAL HEATING...SHOULD YIELD NUMEROUS SHRA
AND TSRA BY AFTN. HAVE RAISED POPS TO THE LIKELY CATEGORY BASED ON
00Z OPER AND GEFS OUTPUT. SOUTHERLY LL JET AND PLUME OF HIGH
PWATS WILL HAVE PASSED NE OF THE AREA THURSDAY...LIMITING THE
THREAT OF ANY HVY RAINFALL. MDL BLENDED QPF IS IN THE QUARTER TO
HALF INCH RANGE THURSDAY. THE NUMEROUS SHOWERS AND COOLER TEMPS
ALOFT WILL RESULT IN HIGH TEMPS BLW NORMAL FOR AUGUST...WITH
MAXES MAINLY IN THE 70S.
LATEST MED RANGE GUIDANCE POINTING TOWARD DRIER WX FRIDAY INTO
EARLY NEXT WEEK...AS SUBTROPICAL HIGH IS PROGGED TO EDGE TOWARD
THE REGION FROM THE MIDWEST. DAILY RING OF FIRE CONVECTION ON NE
PERIPHERY OF THIS RIDGE WILL THREATEN WESTERN PA DURING THE
FRI-SUN TIME FRAME...WHILE EASTERN PA IS LIKELY TO REMAIN DRY.
DESPITE APPROACH OF UPPER RIDGE...NO BIG WARMUP EXPECTED...AS
LARGE SFC HIGH OVR THE CANADIAN MARITIMES WILL CIRCULATE AN
EASTERLY FLOW INTO CENTRAL PA. THERE MAY BE ISSUE WITH AM LOW
CLOUDS/FOG DUE TO THE EXPECTED MOISTLY SERLY FLOW OVR THE AREA.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
RADAR SHOWS SOME ORGANIZED SHOWERS AND THUNDERSTORMS FROM NEAR
KFIG SOUTH TO THE MARYLAND BORDER. THESE SHOWERS AND STORMS WILL
SLOWLY MOVE EASTWARD THIS AFTERNOON. AREAS OF MVFR AND LOCALLY IFR
ARE POSSIBLE ALONG THE LINE AND WITHIN THE SHOWERS AND
THUNDERSTORMS.
MODELS ALL SUGGEST POPCORN SHOWERS POSSIBLE OVER MOST OF CENTRAL
PA AND THE MORE ORGANIZED ACTIVITY OVER THE SOUTHERN HALF OF THE
STATE THROUGH THIS EVENING.
THINGS SETTLE DOWN OVERNIGHT...MORE PATCHY FOG AND LOW CLOUDS.SO
MORE AREAS OF MVFR AND IFR.
WEDNESDAY WILL SEE RAIN AND SHOWERS LIKELY IN WESTERN PA BY MID-
LATE MORNING SLOWLY SPREADING EAST. VFR IN EAST BUT AREAS MVFR
LIKELY IN AM FOG AND THEN SHOWERS IN WESTERN AREAS.
OUTLOOK...
TUE...MAINLY VFR...WITH SHRA/TSRA POSSIBLE.
WED...MORNING FOG/LOW CLOUDS SHRA/TSRA LIKELY WEST CHANCE EAST.
THU-FRI...MORNING FOG CHANCES EACH DAY. OVERALL VFR...BUT
INCREASING CHANCES OF MAINLY AFTERNOON SHRA/TSRA AND ASSOCIATED
RESTRICTIONS. SAT...MAINLY VFR. STILL CHANCE OF SHRA...BUT
DECREASING CHANCES.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...GRUMM
SHORT TERM...GRUMM
LONG TERM...FITZGERALD
AVIATION...GRUMM
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
319 PM CDT TUE AUG 19 2014
.DISCUSSION...
UPPER FLOW IS NORTHWESTERLY THIS AFTERNOON WITH A SHORTWAVE AXIS IN
PLACE FROM LAKE SUPERIOR SW THROUGH IO. AFTERNOON RADAR DEPICTS AN
IMPULSE TO OUR NW WHICH WILL SWING OUR WAY OVERNIGHT. MID LEVEL
RIDGING THIS AFTERNOON IS EXPECTED TO VACATE THE AREA BY EVENING.
THIS WILL ACT TO PROMOTE A LITTLE EXTRA INSTABILITY OVERNIGHT.
LATEST HRRR SHOWS THAT AN AREA OF CONVECTION WILL ENTER OUR
NORTHWESTERN COUNTIES BETWEEN 01Z AND 03Z THIS EVENING. THE
CONVECTION WILL THEN SPREAD SOUTHEAST BUT WILL FRAGMENT AND
WEAKEN. WILL GO AHEAD AND INCLUDE 30-40 POPS FOR TONIGHT. A FEW
OF THE STORMS COULD BECOME STRONG...PARTICULARLY ACROSS WESTERN
AREAS THIS EVENING. OTW...WARM AND HUMID CONDITIONS TO CONTINUE
OVERNIGHT. LOWS WILL GENERALLY BE IN THE LOWER 70S...UPPER 60S
PLATEAU.
NORTHWESTERLY FLOW WILL CONTINUE THROUGH WEDNESDAY. ASSOCIATED
IMPULSES LOOK WEAK WITH THE LIMITED ENGAGEMENT OF APPRECIABLE
MOISTURE. STILL THOUGH...CAP TO WEAKEN DURING THE AFTERNOON AND
WILL THEREFORE INCLUDE SLIGHT POPS.
FOR THURSDAY AND BEYOND THE PATTERN WILL CHANGE AND MORPH INTO A
STRENGTHENING UPPER LEVEL RIDGING REGIME. BY THE WEEKEND...THE UPPER
RIDGING WILL EXPAND OVER THE SOUTHEASTERN U.S. WITH THE UPPER HIGH
CENTERED SOMEWHERE NEAR THE MS DELTA. THERMAL RIDGING TO
STRENGTHEN AS WELL WITH SEPARATION OCCURRING ACROSS THE
SOUTHEASTERN U.S. BY EARLY NEXT WEEK. THIS ALL EQUATES TO THE
HOTTEST WEATHER WE HAVE SEEN ALL SUMMER. A MARKED INCREASE IN
HUMIDITY LEVELS LOOKS SOMEWHAT QUESTIONABLE. MODELS HANG ON TO
UPPER 60S AFTERNOON DEWPOINTS. THE LOWER LEVEL WIND FETCH LOOKS TO
BE A BIT MORE LAND BASED AND THE HEIGHTENED LOWER LEVEL MOISTURE
RETURNS LOOK RATHER SHALLOW IN DEPTH. THIS WILL ALLOW SOME
AFTERNOON MIXING OF LOWER UPPER 60S DEWPOINTS DOWNWARD.
THEREFORE...THE HEAT INDEX INFLUENCE WILL BE IN PLACE BUT WILL BE
KEPT AT A RESPECTABLE AND NON-HIDEOUS LEVEL.
AS FOR CONVECTION CHANCES DURING THE EXTENDED...MRH FIELDS LOOK TO
BE IN THE 40-50% RANGE. 18Z CAP EROSION LOOKS LIKE IT WILL BE HARD
PRESSED TO HAPPEN AS THE MID LEVELS WARM UNDERNEATH THE STRONG
RIDGE. WILL THEREFORE BE LEAVING POPS OUT OF THE FCST...FOR THE MOST
PART.
FOR TEMPERATURES...HIGHS IN THE LOWER TO MID 90S FOR THE NEXT FEW
DAYS. THEN...WE WILL SEE MID TO UPPER 90S FOR THE WEEKEND AND NEXT
WEEK. OVERNIGHT LOWS WILL GENERALLY BE IN THE LOWER 70S FOR THE NEXT
FEW DAYS...MID 70S FOR THE WEEKEND AND NEXT WEEK. OF COURSE...A
LITTLE COOLER THROUGHOUT THE FCST FOR THE PLATEAU AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 73 93 74 95 / 30 20 20 05
CLARKSVILLE 71 94 72 95 / 40 20 20 05
CROSSVILLE 67 88 68 90 / 30 30 20 20
COLUMBIA 72 94 73 95 / 30 20 10 0
LAWRENCEBURG 71 95 71 95 / 30 20 10 0
WAVERLY 71 94 72 95 / 40 20 10 05
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
252 PM CDT TUE AUG 19 2014
.SHORT TERM...(TONIGHT THROUGH WEDNESDAY NIGHT)
ISSUED AT 252 PM CDT TUE AUG 19 2014
WATER VAPOR IMAGERY COUPLED WITH RAP 500MB ANALYSIS SHOWING A MID-
LEVEL LOW OVER WESTERN UPPER MICHIGAN. COLD POOL ALOFT ASSOCIATED
WITH THE LOW PRODUCING WIDESPREAD CUMULUS/STRATOCUMULUS FIELD ACROSS
THE FORECAST AREA WITH RADAR EVEN SHOWING A FEW SHOWERS POPPING UP
ACROSS NORTHERN MN INTO NORTHERN WI. OTHERWISE...TEMPERATURE ACROSS
THE ARX FORECAST AREA WERE IN THE 70-80 DEGREE RANGE.
FOR TONIGHT...COULD SEE A FEW SHOWERS NORTHEAST OF I-94 THIS EVENING
BUT THEN EXPECTING CLOUDS TO DIMINISH LATE IN THE EVENING AND
THROUGH THE OVERNIGHT HOURS AS A RIDGE OF HIGH PRESSURE MOVES
OVERHEAD. THIS WILL SET UP FAVORABLE FOG POTENTIAL OVERNIGHT/EARLY
WEDNESDAY MORNING...ESPECIALLY FAVORED RIVER VALLEY LOCATIONS.
THINKING AREAS SOUTHWEST OF I-94 WILL BE MOST IMPACTED WHERE
CONFIDENCE IS HIGHER FOR CLEARING SKY CONDITIONS EXISTS. HELD OFF ON
DENSE FOG ADVISORY FOR NOW BASED ON INPUT FROM SURROUNDING
OFFICES...BUT EVENING FORECASTER WILL HAVE TO MONITOR CLOSELY FOR
POSSIBLE FOG HEADLINE. LOOK FOR LOWS TONIGHT IN THE MIDDLE 50S TO
THE LOWER 60S.
AFTER AREAS OF MORNING FOG...PLAN ON THE RIDGE OF HIGH PRESSURE TO
KEEP THE FORECAST AREA DRY THROUGH WEDNESDAY. AN APPROACHING WARM
FRONT FROM THE CENTRAL PLAINS/MID-MISSISSIPPI RIVER VALLEY WILL
LIKELY SPARK A FEW SHOWERS AND THUNDERSTORMS...BUT PRETTY CONFIDENT
THESE WILL REMAIN SOUTH OF THE AREA. OTHERWISE...EXPECTING HIGH
TEMPERATURES TO TOP OFF IN THE MID 70S TO THE LOWER 80S.
LOOK FOR SHOWERS AND THUNDERSTORMS TO BECOME LIKELY BY LATE
WEDNESDAY NIGHT AS THE WARM FRONT CONTINUES TO APPROACH THE REGION.
ALL MODELS SHOW 850MB MOISTURE TRANSPORT INCREASING INTO/OVER THE
FRONT...WITH BEST AXIS OF MOISTURE PLUME REMAINING JUST WEST OF THE
FORECAST AREA. IN FACT...THE GFS/NAM SHOWING PRECIPITABLE WATER
VALUES SURGING INTO THE 1.5-2 INCH RANGE. THIS COULD LEAD TO SOME
LOCALIZED HEAVIER RAINFALL AS WARM CLOUD LAYER DEPTH INCREASE TO
AROUND 4KM BY MORNING. MAY NEED TO MONITOR THE POTENTIAL FOR A FEW
SEVERE THUNDERSTORMS WITH LARGE HAIL INITIALLY WITH THE INCOMING
CONVECTION AS NAM INDICATING 1-6KM MUCAPE IN THE 2500-3500J/KG RANGE
COUPLED WITH 25-35KT BULK SHEAR.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 252 PM CDT TUE AUG 19 2014
MODELS SHOWING THE WARM FRONT PUSHING NORTHEAST THROUGH THE AREA ON
THURSDAY FOR THE CONTINUED LIKELIHOOD OF SHOWERS AND THUNDERSTORMS.
MODELS ALSO SHOWING 850MB MOISTURE TRANSPORT WANING THROUGH THE
MORNING HOURS AND EVENTUAL CAPPING ALONG AND WEST OF THE MISSISSIPPI
DURING THE AFTERNOON HOURS. AS SUCH...DIVIDED POPS INTO
MORNING/AFTERNOON TIME PERIODS. STILL LOOKING AT THE POTENTIAL FOR
SOME LOCALIZED HEAVY RAINFALL THROUGH THE MORNING HOURS WITH
PRECIPITABLE WATER VALUES LINGERING IN THE 1.5 TO 2 INCH RANGE.
OTHERWISE...LOOK FOR SUBSTANTIALLY MORE HUMID CONDITIONS AS DEW
POINTS CREEP UP INTO THE LOWER 70S. THESE DEW POINTS COMBINED WITH
DAYTIME HIGHS WELL INTO THE 80S FOR MOST OF THE AREA ARE EXPECTED
TO PRODUCE HEAT INDICES IN THE 90 TO 100 DEGREE...HIGHEST ALONG AND
WEST/SOUTH OF THE MISSISSIPPI/WISCONSIN RIVERS.
FOR THURSDAY NIGHT THROUGH THE REST OF THE PERIOD...FORECAST
CONFIDENCE WANES FAIRLY RAPIDLY. MODEL CONSENSUS SHOWS A MID-LEVEL
RIDGE TRYING TO ESTABLISH ITSELF OVER THE CENTRAL CONUS.
HOWEVER...MESSY FLOW WITH MONSOONAL TAP WILL BE IN PLACE ACROSS THE
INTERMOUNTAIN/PLAINS REGION. TIMING OF THESE WAVES PRETTY UNCERTAIN
AT THIS TIME. AS SUCH...WILL KEEP LOW-MEDIUM RANGE
SHOWER/THUNDERSTORM CHANCES IN THROUGH THE PERIOD. TEMPERATURES
THROUGH THE PERIOD LOOK TO STAY AT OR A FEW DEGREES ABOVE NORMAL
THROUGH THE WEEKEND...WITH PERHAPS SOME COOLING EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1222 PM CDT TUE AUG 19 2014
LOW STRATUS THIS MORNING AT KLSE AND KRST HAS LIFTED TO ABOVE 3000
FT AGL AND EXPECT VFR CONDITIONS TO PERSIST THROUGH THIS AFTERNOON
AND EVENING. OVERNIGHT SET-UP STILL VERY FAVORABLE FOR FOG WITH HIGH
PRESSURE BUILDING ACROSS THE REGION RESULTING IN CLEARING SKIES AND
CALM WIND. BASED ON LATEST MODEL GUIDANCE...BEGAN LIFR CONDITIONS AT
KLSE AT 08Z WITH IMPROVEMENT EXPECTED AFTER 15Z. FOG EXTENT AT KRST
A BIT LESS CERTAIN...SO WILL KEEP WITH THE IDEA OF VISIBILITY
REDUCTIONS TO 1 SM AT 10Z WITH THE POTENTIAL FOR FURTHER
RESTRICTIONS.
&&
.HYDROLOGY...WEDNESDAY NIGHT INTO THURSDAY
ISSUED AT 252 PM CDT TUE AUG 19 2014
THERE IS THE LIKELIHOOD FOR SHOWERS AND THUNDERSTORMS WITH THE
POTENTIAL FOR HEAVY RAINFALL WEDNESDAY NIGHT INTO THURSDAY MORNING.
EXPECTING FAIRLY WIDESPREAD 1/4 TO 3/4 INCH RAINFALL WITH LOCALIZED
GREATER THAN 1 INCH AMOUNTS. THIS RAINFALL COMBINED WITH RECENT
POCKETS OF HEAVY RAINS ACROSS PORTIONS OF THE FORECAST AREA COULD
LEAD TO SOME LOCALIZED FLOODING CONCERNS. WILL KEEP A CLOSE EYE ON
LOCALIZED FLOODING CONCERN AND THE POTENTIAL FOR A FLASH FLOOD WATCH
HEADLINE WEDNESDAY NIGHT INTO THURSDAY MORNING ONCE CONFIDENCE
INCREASES ON EXACTLY WHERE THE HEAVIER RAINFALL WILL OCCUR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...ROGERS
HYDROLOGY...DAS
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
250 PM MDT TUE AUG 19 2014
.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 250 PM MDT TUE AUG 19 2014
THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS WHERE THE
CONVECTION WILL BREAK OUT THIS AFTERNOON AND HOW MUCH CONVECTION
WILL BREAK OUT AHEAD OF THE JET STREAK MOVING ACROSS THE ROCKIES
TONIGHT.
LATEST VISIBLE IMAGERY WAS SHOWING SOME ACCAS DEVELOPING ACROSS NORTHEAST
COLORADO NEAR THE SURFACE TROF. THIS AREA MAY END UP BEING THE
FIRST AREA TO FIRE UP THIS AFTERNOON. HOWEVER...IT MAY TRY TO
IGNITE JUST EAST OF THE LARAMIE AND FRONT RANGES AS WELL WHERE WE
HAVE HAD QUITE A BIT OF SUNSHINE. IN FACT...WE ARE STARTING TO SEE
A LITTLE BIT OF ACCAS OVERHEAD AND CONVECTION DEVELOPING ALONG THE
FRONT RANGE. MODELS ARE PROJECTING MIXED LAYER CAPES TO APPROACH 1500
J/KG THIS AFTERNOON WITH VERY LIMITED CAP. 0-6KM SHEAR VALUES
(~30KTS) MAY ALSO BE FAVORABLE FOR A FEW STRONG TO SEVERE STORMS.
AT THIS POINT...IT LOOKS THE HRRR IS STARTING TO BREAK OUT
CONVECTION JUST EAST OF CHEYENNE AFTER 21Z WITH THE BULK OF THIS
CONVECTION PUSHING GENERALLY EAST AT AROUND 20KTS. A FEW OF THESE
STORMS MAY HAVE THE POTENTIAL TO PRODUCING STRONG WINDS AND HAIL IN THE
PANHANDLE THIS AFTERNOON. LATEST SURFACE ANALYSIS WAS ALSO SHOWING
SOME WINDS BACKING TO THE SOUTHEAST IN THE PANHANDLE. WE WILL ALSO
NEED TO WATCH THAT AS THE AFTERNOON WEARS ON...ESPECIALLY IF THE
STORMS GET GOING IN THAT REGION.
ANOTHER CONCERN IS THE NAM IS SHOWING A 500MB JET STREAK MOVING
OUT OF NORTHEAST COLORADO EARLY THIS EVENING WHICH MAY HELP
ENHANCE THE SHEAR ACROSS THE PANHANDLE. IF CONVECTION IS ON GOING
IN THAT REGION AS THIS JET STREAK MOVES ACROSS WE MAY HAVE MORE OF
A SEVERE POTENTIAL. THEREFORE...IT WILL BE A MATTER OF TIMING ON
HOW THINGS COME TOGETHER LATE THIS AFTERNOON AND EVENING.
TONIGHT THE MODELS ARE SHOWING A FAIRLY STRONG UPPER LEVEL JET
MOVING THROUGH NORTHERN COLORADO AND LIFTING NORTHEAST INTO
NORTHEAST WYOMING BY DAYBREAK WHICH WILL HELP ENHANCE UPPER LEVEL
DIFFLUENCE. THE MODELS ARE EVEN IN FAIRLY GOOD AGREEMENT IN
SHOWING A MID LEVEL CIRCULATION WITH THIS JET STREAK. AS A
RESULT... WE WOULD NOT SURPRISED TO SEE A COMPLEX OF SHOWERS AND
THUNDERSTORMS DEVELOP ACROSS THE WESTERN HALF OF THE FORECAST AREA
OVERNIGHT ALONG WITH THE POTENTIAL FOR HEAVY RAINFALL DUE TO PRECIPITABLE
WATER VALUES AROUND 1 INCH. NOT EXPECTING MUCH IN THE WAY OF
FLOODING SINCE THIS COMPLEX SHOULD BE FAIRLY PROGRESSIVE. WE DID
BUMP UP POPS ACROSS THE NORTHERN HALF OF THE AREA TONIGHT TO
REFLECT THIS POTENTIAL.
WEDNESDAY-THURSDAY NIGHT:
THE MID LEVEL CIRCULATION IS PROGGED TO CONTINUE LIFTING NORTHEAST
WHICH WILL TAKE THE BULK OF THE CONVECTION NORTHEAST OF THE
FORECAST AREA BY MID MORNING. THIS WILL LEAVE A FAIRLY BROAD AREA OF
SUBSIDENCE IN THE MORNING IN THE WAKE OF THE CONVECTION...BUT WE
MAY MORE CONVECTION DEVELOP IN THE AFTERNOON ACROSS THE MOUNTAINS
AS UPSLOPE FLOW COMMENCES WITH LEFTOVER RESIDUAL MOISTURE.
OTHERWISE...THE REMAINDER OF THE AREA EAST OF THE LARAMIE RANGE
SHOULD REMAIN FAIRLY DRY WITH HIGHS GENERALLY IN THE 80S. THE
NEXT CHANCE OF SHOWERS AND THUNDERSTORMS IS PROGGED TO TAKE PLACE
ON THURSDAY AFTERNOON AS ANOTHER UPPER LEVEL WAVE LIFTS NORTHEAST
OUT OF COLORADO AND PUSHES THROUGH AREAS EAST OF THE LARAMIE RANGE
THURSDAY AFTERNOON INTO THURSDAY NIGHT.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 250 PM MDT TUE AUG 19 2014
AN UPPER LOW AND ASSOCIATED TROUGH OVER THE PACIFIC NW FRIDAY WILL
MOVE SLOWLY EAST TOWARDS THE AREA FRIDAY THROUGH SATURDAY...
SWINGING BY THE AREA ON SUNDAY. THIS WILL COMBINE WITH AT LEAST
RESIDUAL MONSOONAL MOISTURE TO KEEP CHANCES FOR SHOWERS AND TSTMS
GOING OVER MOST AREAS THROUGH SATURDAY NIGHT. WILL CONTINUE TO
LEAN TOWARDS THE EC SOLUTION AS IT HAS BEEN FAIRLY CONSISTENT WITH
THIS FEATURE. WARM TEMPS WILL CONTINUE THROUGH SATURDAY THEN A
DECENT COOL FRONT WILL PASS ACROSS SAT NIGHT LEAVING A DRIER AND
MILD DAY FOR THE CWA SUNDAY. CONTINUED MILD ON MONDAY WITH THE CWA
ON THE SOUTHERN PORTION OF BROAD CYCLONIC UPPER FLOW THAT WILL BE
OVER THE NORTHERN PART OF THE COUNTRY. A SECOND UPPER SHORTWAVE
SHOULD PASS BY TUESDAY BRINGING A REINFORCING SHOT OF COOLER AIR
AND A CHANCE FOR SOME PRECIPITATION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY MORNING)
ISSUED AT 1123 AM MDT TUE AUG 19 2014
MID/HIGH CLOUDS WILL SPREAD ACROSS THE AREA THIS AFTERNOON AS A
SURGE OF MONSOONAL MOISTURE MOVES IN FROM THE SW. WDLY SCTD SHWRS
AND TSTMS DEVELOPING THIS AFTERNOON OVER AND NR THE SE WY MTNS WITH SOME
SHOWERS CONTINUING TONIGHT MAINLY OVER WESTERN TERMINALS. BRIEF MVFR
CIGS WITH ANY ACTIVITY.
&&
.FIRE WEATHER...
ISSUED AT 1056 AM MDT TUE AUG 19 2014
FIRE WEATHER CONCERNS TO REMAIN MINIMAL FOR THE REST OF THE WEEK
WITH NON-CRITICAL WEATHER CONDITIONS EXPECTED. SOME WETTING RAINS
SHOULD OCCUR OVER AT LEAST PARTS OF THE AREA OVER THE NEXT COUPLE
DAYS AS A SURGE OF MONSOONAL MOISTURE PASSES OVER THE REGION AND
INCREASES PRECIPITATION.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...REC
LONG TERM...RE
AVIATION...RE
FIRE WEATHER...RE