RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Tue Jul 22 18:59:02 UTC 2014.
No Mesoscale Discussions are in effect as of Tue Jul 22 18:59:02 UTC 2014.
SPC 1730Z Day 2 Outlook
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1209 PM CDT TUE JUL 22 2014
VALID 231200Z - 241200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE NRN
ROCKIES...
...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN WY INTO WRN SD AND THE
NEB PANHANDLE...
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF NEW ENGLAND...
...SUMMARY...
SEVERE STORMS ARE POSSIBLE ACROSS PARTS OF THE NORTHERN ROCKIES FROM
NORTHERN IDAHO INTO WESTERN AND CENTRAL MONTANA AS WELL AS ACROSS
NEW ENGLAND WEDNESDAY AFTERNOON AND EVENING. ADDITIONAL SEVERE
THUNDERSTORMS ARE POSSIBLE FROM EASTERN WYOMING INTO WESTERN SOUTH
DAKOTA AND NEBRASKA LATE IN THE AFTERNOON INTO WEDNESDAY NIGHT.
ELSEWHERE...STRONG TO LOCALLY SEVERE STORMS ARE POSSIBLE OVER THE
NORTHERN HIGH PLAINS AND FROM THE OHIO VALLEY TO THE OZARKS AREA.
...SYNOPSIS...
THE UPPER RIDGE SPREADING NORTHWARD FROM THE CNTRL/SRN ROCKIES INTO
THE NRN HIGH PLAINS WILL SHIFT SLIGHTLY EWD WHILE MARGINALLY
DEAMPLIFYING AS THE PACIFIC NORTHWEST SHORTWAVE TROUGH MOVES INLAND.
AT THE SFC...A LEE TROUGH WILL EXTEND SWD FROM A WEAK SFC LOW OVER
S-CNTRL MT ACROSS ERN WY INTO NE CO. FURTHER EAST...A TROUGH OVER SE
CANADA AND THE GREAT LAKES WILL DEEPEN ALONG THE APPALACHIANS WHILE
A SFC COLD FRONT TRACK E/SE FROM NEW ENGLAND INTO THE OH/TN VALLEYS
AND SOUTHERN PLAINS.
...NRN ROCKIES...
ENHANCED S/SWLY FLOW WILL OVERSPREAD THE NRN ROCKIES AS INTENSE
SHORTWAVE TROUGH MOVES INLAND THROUGH THE FORECAST PERIOD. THE
RESULTING FALLING HEIGHTS/COOLING ALOFT WILL AID IN SCATTERED
THUNDERSTORM DEVELOPMENT DURING THE AFTERNOON AND EVENING AHEAD OF
AN EWD ADVANCING SFC COLD FRONT FROM FAR ERN WA INTO WRN/CNTRL MT.
S/SELY LOW LEVEL WINDS WILL MAINTAIN UPPER 40S/LOWER 50S DEWPOINTS.
AS TEMPERATURES WARM INTO THE 80S...WEAK TO MODERATE INSTABILITY
WILL DEVELOP BENEATH STEEP LAPSE RATES. INVERTED-V THERMODYNAMIC
PROFILES COUPLED WITH FAST STORM MOTION WILL FURTHER ENHANCE STRONG
WIND THREAT. SOME INSTANCES OF LARGE HAIL WILL BE POSSIBLE AS WELL.
...NRN HIGH PLAINS/BLACK HILLS...
ISOLATED TO SCATTERED THUNDERSTORM DEVELOPMENT IS EXPECTED NEAR
HIGHER TERRAIN ALONG THE LEE TROUGH BY MID/LATE AFTERNOON AND WILL
SPREAD EWD ACROSS THE HIGH PLAINS AS A SHORTWAVE IMPULSE MIGRATES
AROUND THE UPPER ANTICYCLONE FROM THE GREAT BASIN THROUGH THE CNTRL
ROCKIES OF WY. S/SELY LOW LEVEL FLOW WILL MAINTAIN MID 50S TO LOW
60S DEWPOINTS TO THE EAST OF THE LEE TROUGH AND AS TEMPERATURES WARM
INTO THE 90S...MODERATE TO STRONG INSTABILITY WILL DEVELOP BENEATH
STEEP LAPSE RATES. LARGE HAIL AND STRONG WINDS WILL BE THE MAIN
THREATS. LATER DURING THE EVENING/OVERNIGHT...WAA REGIME SHOULD
RESULT IN AN ARC OF THUNDERSTORMS FROM ERN MT INTO THE CNTRL
DAKOTAS. THE ELEVATED NATURE OF THIS CONVECTION SHOULD LIMIT
DAMAGING WIND THREAT...BUT SOME MARGINALLY SEVERE HAIL WILL BE
POSSIBLE.
...NEW ENGLAND...
HEIGHT FALLS/COOLING ALOFT ASSOCIATED WITH DEEPENING TROUGH OVER THE
REGION WILL AID IN THUNDERSTORM DEVELOPMENT BY LATE MORNING/EARLY
AFTERNOON AHEAD OF AN EWD ADVANCING COLD FRONT. A MOIST AIRMASS WITH
SFC DEWPOINTS IN THE MID/UPPER 60S WILL BE PRESENT WITH TEMPERATURES
WARMING INTO THE 80S TO NEAR 90 DEGREES...RESULTING IN MODERATE
DESTABILIZATION. MIDLEVEL LAPSE RATES WILL GENERALLY BE POOR...BUT
NEAR 30 KT DEEP LAYER SHEAR AND STEEP LOW LEVEL LAPSE RATES SHOULD
RESULT IN A STRONG/LOCALLY DAMAGING WIND THREAT. MARGINALLY SEVERE
HAIL MAY BE POSSIBLE AS WELL GIVEN DEGREE OF INSTABILITY.
...OH/TN VALLEY INTO CNTRL APPALACHIANS...
A WARM/MOIST AIRMASS CHARACTERIZED BY MID 60S TO NEAR 70 DEWPOINTS
AND HIGH TEMPERATURES NEAR 90 DEGREES WILL BE IN PLACE...WITH STEEP
LOW LEVEL LAPSE RATES DEVELOPING BY LATE MORNING/EARLY AFTERNOON. AS
A RESULT...STRONG INSTABILITY WILL BE PRESENT AND SCATTERED
THUNDERSTORMS ARE EXPECTED AHEAD OF THE COLD FRONT. HOWEVER...THREAT
SHOULD REMAIN RELATIVELY UNORGANIZED AS DEEP LAYER SHEAR WILL BE
WEAKER THAN THAT EXPECTED FURTHER TO THE NE ACROSS NEW ENGLAND.
ADDITIONALLY...STRONGER FORCING FOR ASCENT WILL NOT BE TIMED WELL
WITH DIURNAL PEAK HEATING FURTHER SE ACROSS THE CNTRL
APPALACHIANS...ARRIVING LATER DURING THE OVERNIGHT PERIOD. AS
SUCH...MARGINAL WIND/HAIL THREAT WILL EXIST DURING THE AFTERNOON
WITH PERHAPS A LOCALLY SEVERE STORM POSSIBLE.
...OZARKS...
ISOLATED THUNDERSTORMS ARE EXPECTED TO DEVELOP IN THE VICINITY OF
THE COLD FRONT FROM SRN MO INTO FAR ERN OK EWD ACROSS AR IN A
WARM/MOIST AND STRONGLY UNSTABLE ENVIRONMENT. THIS AREA WILL BE ON
THE PERIPHERY OF BAND OF STRONGER FLOW ALOFT BETWEEN THE RIDGE TO
THE WEST AND TROUGH TO THE EAST...RESULTING IN 20-30 KT 0-6 KM
SHEAR. FORCING FOR ASCENT WILL REMAIN WEAK...LIMITING OPPORTUNITY
FOR A BETTER ORGANIZED THREAT. A MARGINAL WIND THREAT /PERHAPS A FEW
LOCALLY DAMAGING GUSTS/ WILL EXIST WITH STRONGER STORM CLUSTERS AS
THEY TRACK SWD ACROSS THE REGION.
..LEITMAN.. 07/22/2014
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SPC 1630Z Day 1 Outlook
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1121 AM CDT TUE JUL 22 2014
VALID 221630Z - 231200Z
...THERE IS A SLGT RISK OF SVR TSTMS FROM KS/MO INTO SOUTHWEST LOWER
MI...
...THERE IS A SLGT RISK OF SVR TSTMS OVER THE BLACK HILLS AND
ADJACENT REGIONS...
...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF CNTRL ORE...
...SUMMARY...
SCATTERED SEVERE STORMS WITH WIND AND HAIL WILL OCCUR LATER TODAY
AND TONIGHT FROM THE CENTRAL PLAINS EAST-NORTHEAST TO SOUTHERN LAKE
MICHIGAN. A CLUSTER OF SEVERE STORMS IS POSSIBLE OVER THE BLACK
HILLS REGION...AND MORE ISOLATED WIND AND HAIL STORMS MAY OCCUR OVER
INTERIOR PORTIONS OF THE PACIFIC NORTHWEST.
...KS/MO INTO SOUTHERN LAKE MI REGION...
WATER VAPOR LOOPS SHOW A LARGE UPPER RIDGE IN PLACE OVER MOST OF THE
U.S. TODAY. A STRONG SHORTWAVE TROUGH IS MOVING ACROSS THE GREAT
LAKES STATES...WITH ITS ASSOCIATED COLD FRONT SAGGING SOUTHEASTWARD
ACROSS PARTS OF WI/IA/NEB. A MOIST AND VERY UNSTABLE AIR MASS IS
FORECAST TO DEVELOP AHEAD OF THE FRONT LATER THIS AFTERNOON WITH
DEWPOINTS IN THE 70S AND MLCAPE VALUES OVER 2500 J/KG. DESPITE THE
STRONG CAPE AND APPROACHING FRONT...WARM TEMPERATURES ALOFT AND ONLY
SUBTLE FORCING ALOFT RESULTS IN CONSIDERABLE UNCERTAINTY WHEN/WHERE
STORMS MAY DEVELOP OVER THE MS VALLEY LATER TODAY. MODEL GUIDANCE
IS VERY DIVERSE...WITH THE HRRR/NSSL SOLUTIONS MOST BULLISH ON
STORMS LATE THIS AFTERNOON AND EVENING FROM NORTHERN IL INTO MO.
ANY STORMS THAT FORM WILL POSE A RISK OF HAIL AND DAMAGING WINDS.
DESPITE THE UNCERTAINTY...WILL MAINTAIN THE ONGOING SLIGHT RISK AND
FURTHER REFINE IN LATER OUTLOOKS.
...WESTERN HIGH PLAINS...
THE UPPER RIDGE WILL BUILD THROUGHOUT THE FORECAST PERIOD OVER THE
HIGH PLAINS. DESPITE THIS PROCESS...MODELS ARE IN RELATIVELY GOOD
AGREEMENT THAT SUFFICIENT INSTABILITY AND EFFECTIVE SHEAR WILL BE
PRESENT FOR THE DEVELOPMENT OF ORGANIZED/SUPERCELLULAR STORMS OVER
PARTS OF SOUTHEAST MT/EASTERN WY BY EARLY EVENING. THE STORMS THAT
FORM WILL MOVE WITH THE NORTHWESTERLY STEERING FLOW INTO PARTS OF
SD/NEB. THE STRONGEST CELLS WILL BE CAPABLE OF HAIL AND GUSTY
WINDS.
...CENTRAL MT INTO THE PACIFIC NORTHWEST REGION...
A BAND OF STRONGER WESTERLY FLOW EXTENDS AROUND THE RIDGE FROM
NORTHERN CA INTO ORE/ID AND MT. MARGINAL AFTERNOON INSTABILITY WILL
DEVELOP ACROSS MUCH OF THIS REGION...LEADING TO WIDELY SCATTERED
SHOWERS AND THUNDERSTORMS. SUFFICIENT FLOW ALOFT AND INVERTED-V
PROFILES WILL PROMOTE A RISK OF GUSTY/LOCALLY DAMAGING WINDS AND
HAIL IN THE STRONGER CELLS. A WELL-DEFINED EMBEDDED VORTICITY MAX
OVER NORTHERN CA MAY RESULT IN A SLIGHTLY MORE CONCENTRATED AREA OF
STRONG STORMS OVER PARTS OF CENTRAL ORE LATER TODAY.
..HART/ROGERS.. 07/22/2014
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SPC Day 1 Fire Weather Outlook
DAY 1 FIRE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1140 AM CDT TUE JUL 22 2014
VALID 221700Z - 231200Z
THE ONLY CHANGE THIS FORECAST UPDATE IS MODIFY THE AREAL BOUNDS OF
THE ISOLATED DRY THUNDERSTORM AREA FROM CA NEWD INTO ID/MT.
...NERN CA / SERN ORE / NWRN AND N-CNTRL NV / CNTRL AND SWRN ID /
FAR SWRN MT...
BASED ON MORNING AREA RAOBS AND OBSERVED PW SENSOR DATA...HAVE
REMOVED THE NWRN PORTIONS OF THE ISOLATED DRY THUNDERSTORM AREA DUE
TO THE PROPENSITY FOR WETTING RAINS WITH SHOWER/THUNDERSTORM
ACTIVITY THIS AFTERNOON/TONIGHT. HAVE INCLUDED AREAS OF NWRN NV
NEWD INTO SWRN ID INTO THE DRY THUNDERSTORM AREA. ISOLATED TO
SCATTERED THUNDERSTORM COVERAGE IS FORECAST AND SOME OF THE STORMS
MAY BE DRIER...ESPECIALLY IN THE NWRN GREAT BASIN WHERE BOUNDARY
LAYER TEMP/DEWPOINT SPREADS WILL BE GREATEST.
..SMITH.. 07/22/2014
.PREV DISCUSSION... /ISSUED 0314 AM CDT TUE JUL 22 2014/
...SYNOPSIS...
UPPER HIGH CENTERED OVER THE CNTRL ROCKIES WILL BUILD NWD /INTO THE
NRN HIGH PLAINS/ AND WWD /INTO THE WRN GREAT BASIN/ THROUGHOUT THE
DAY. SHORTWAVE TROUGH MOVING FROM THE UPPER MS VALLEY EWD ACROSS THE
GREAT LAKES WILL DAMPEN THE NERN PORTION OF THIS UPPER HIGH WHILE AN
UPPER LOW MOVING WWD ALONG THE GULF COAST IMPINGES ON THE HIGH/S
SEWD EXTENT. A DEEP UPPER LOW WILL SLOWLY PROGRESS SEWD TOWARDS THE
SRN BC/NRN WA COAST. ENHANCED SWLY FLOW ALOFT IS EXPECTED BETWEEN
THIS UPPER LOW AND THE UPPER HIGH FARTHER SE...ROUGHLY FROM CNTRL CA
NEWD INTO NWRN MT.
...EXTREME E-CNTRL CA...CNTRL/NE NV...FAR WRN UT...
DESPITE TEMPERATURES ACROSS THE REGION IN THE MID 80S TO LOW 90S /AT
OR A FEW DEGREES BELOW NORMAL/...DEEP BOUNDARY LAYER MIXING AMIDST A
RELATIVELY DRY AIRMASS WILL ALLOW RH VALUES TO DROP INTO THE UPPER
SINGLE DIGITS TO LOW TEENS BY THE MID-AFTERNOON. AFOREMENTIONED
ENHANCED SWLY FLOW ALOFT OVER THE REGION WILL AID IN THE DEVELOPMENT
OF SUSTAINED SWLY WINDS AROUND 20 MPH /GUSTS UP TO 30 MPH/ AS THE
BOUNDARY LAYER MIXES. THESE CONDITIONS COMBINED WITH DRY FUELS WILL
RESULT IN AN ELEVATED TO LOCALLY CRITICAL FIRE WEATHER THREAT.
...FAR N-CNTRL CA...CNTRL/NE ORE...FAR SE WA...CNTRL/SW ID...
TWO DIFFERENT MECHANISMS ARE EXPECTED TO RESULT IN ISOLATED TO
SCATTERED TSTM COVERAGE FROM FAR N-CNTRL CA NEWD THROUGH CNTRL MT
FROM TUESDAY AFTERNOON THROUGH EARLY WEDNESDAY MORNING. AFTERNOON
TSTM ACTIVITY...FORCED MAINLY BY DIURNAL HEATING AND OROGRAPHIC
LIFT...WILL LIKELY BE ISOLATED TO WIDELY SCATTERED. HIGHEST COVERAGE
IS EXPECTED ACROSS CNTRL ORE. MOST STORMS ARE EXPECTED TO BE WET BUT
FAST STORM MOTIONS /OVER 25 KT/ AND DRY SURFACE CONDITIONS WILL
RESULT IN ISOLATED DRY TSTMS. EVEN IF STORMS ARE WET...COVERAGE OF
WETTING RAINS WILL BE LOW AND LIGHTNING AMIDST DRY TO VERY DRY FUELS
WILL POSE A RISK FOR LIGHTNING-CAUSED IGNITIONS. IN ADDITION TO THE
FIRE WEATHER THREAT...SHEARED ENVIRONMENT WILL LIKELY SUPPORT SOME
ROTATING TSTMS WITH THE POTENTIAL TO PRODUCE ISOLATED SVR WIND AND
HAIL -- SEE DAY 1 CONVECTIVE OUTLOOK FOR MORE DETAILS.
A SECOND ROUND OF TSTMS IS POSSIBLE OVERNIGHT...MAINLY OVER ERN ORE
AND CNTRL/SRN ID...AS A SHORTWAVE TROUGH PROGRESSES THROUGH THE
REGION WITHIN THE ENHANCED SWLY FLOW ALOFT. MOSTLY WET TSTMS ARE
AGAIN ANTICIPATED BUT SOME DRY TSTMS ARE POSSIBLE. LIGHTNING AMIDST
DRY FUELS WILL AGAIN RESULT IN A FIRE WEATHER THREAT.
...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT...
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SPC Day 2 Fire Weather Outlook
DAY 2 FIRE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0156 PM CDT TUE JUL 22 2014
VALID 231200Z - 241200Z
NO CHANGE HAS BEEN MADE TO THE PREVIOUS FORECAST.
..SMITH.. 07/22/2014
.PREV DISCUSSION... /ISSUED 0316 AM CDT TUE JUL 22 2014/
...SYNOPSIS...
DEEP UPPER LOW WILL MOVE EWD ACROSS THE PACIFIC NW TOWARDS THE NRN
ROCKIES. UPPER HIGH CENTERED OVER THE CNTRL ROCKIES AND COVERING
MUCH OF THE PLAINS AND SOUTHWEST STATES WILL REMAIN LARGELY IN PLACE
WITH SOME DAMPENING OF ITS NRN EXTENT EXPECTED AS THE PACIFIC NW
UPPER LOW PROGRESSES EWD. FARTHER E...TROUGHING WILL DEEPEN OVER
WITH ERN CONUS WHILE A WEAK UPPER LOW CONTINUES WWD ALONG THE WRN
GULF COAST. AT THE SURFACE...A LEE TROUGH IS ANTICIPATED ACROSS THE
NRN AND CNTRL HIGH PLAINS WITH A COLD FRONT LIKELY EXTENDING FROM
NEW ENGLAND SWWD ACROSS THE OH AND MID MS VALLEYS BY WEDNESDAY
EVENING.
...MUCH OF NV...FAR WRN UT...ERN WA/ORE...SRN ID...SWRN WY...
SWLY FLOW ALOFT BETWEEN THE CNTRL ROCKIES HIGH AND THE PACIFIC NW
UPPER LOW /FROM NE CA NEWD INTO SRN ALBERTA/ WILL INCREASE
THROUGHOUT THE DAY AS THE UPPER LOW PROGRESSES EWD...SUPPORTING
SUSTAINED SWLY AROUND 15 MPH ACROSS MUCH OF THE GREAT BASIN.
TEMPERATURES ACROSS THE REGION WILL NOT BE PARTICULARLY WARM BUT THE
AIRMASS WILL BE DRY ENOUGH TO SUPPORT MIN RH VALUES AROUND 20
PERCENT ACROSS SE ORE...NRN NV...SRN ID..AND SWRN WY. SLIGHTLY LOWER
RH VALUES ARE POSSIBLE ACROSS CNTRL NV. THESE CONDITIONS ARE
CONSISTENT WITH AN ELEVATED FIRE WEATHER THREAT.
ACROSS E-CNTRL/NE ORE AND ERN WA...DOWNSLOPE EFFECTS WILL SUPPORT
SUSTAINED WLY WIND FROM 20 TO 30 MPH. THE AIRMASS HERE WILL NOT BE
PARTICULARLY DRY /RH VALUES ABOVE 3O PERCENT/ BUT THE STRENGTH OF
THE WINDS AMIDST DRY TO VERY DRY FUELS WILL STILL PROMOTE AN
ELEVATED FIRE WEATHER THREAT.
...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT...
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