Showing posts with label Kansas weather. Show all posts
Showing posts with label Kansas weather. Show all posts

Friday, April 13, 2012

TWIN HIGH RISKS OF SEVERE WEATHER ON SATURDAY,ADDITIONAL THREAT TODAY

METD WEATHER
AKSHAY DEORAS
SEVERE WEATHER FORECASTER

*** SEVERE WEATHER WITH SOME TORNADOES TODAY ( FRIDAY) ACROSS LOWER OKLAHOMA***

*** EXTREMELY DANGEROUS WEATHER EXPECTED ON SATURDAY IN CENTRAL US****

*** LIKELY HOOD OF LONG TRACK DANGEROUS TORNADOES****


*** MOST SEVERE WEATHER WILL TAKE PLACE AT LATE EVENING INTO NIGHT HOURS***


***NIGHT-TIME TORNADOES ARE VERY LIKELY FOR CENTRAL USA***



The Large Positively tilted trough presently over California is all set to produce A HISTORIC TORNADO OUTBREAK ON SATURDAY IN CENTRAL USA. As was expected, Storm Prediction Center has UPGRADED the Moderate Risk to a High Risk for Saturday



THE HIGH RISK AREA IS FROM SALINA,KS TO OKLAHOMA CITY,OK .




WEATHER FORECASTS- 

FRIDAY- 

Update as of 1830z GMT

Tornado Watch issued for SW OK across NW Texas- 




""" 

  

   URGENT - IMMEDIATE BROADCAST REQUESTED
   TORNADO WATCH NUMBER 160
   NWS STORM PREDICTION CENTER NORMAN OK
   130 PM CDT FRI APR 13 2012
   
   THE NWS STORM PREDICTION CENTER HAS ISSUED A
   TORNADO WATCH FOR PORTIONS OF 
   
          OKLAHOMA
          A SMALL PART OF NORTHWEST TEXAS
   
   EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 130 PM UNTIL 900
   PM CDT.
   
   TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND
   GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
   AREAS.
   
   THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE
   MILES EAST AND WEST OF A LINE FROM 35 MILES WEST OF WICHITA FALLS
   TEXAS TO 20 MILES NORTH NORTHWEST OF PONCA CITY OKLAHOMA.  FOR A
   COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
   UPDATE (WOUS64 KWNS WOU0).
   
   REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
   TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
   AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
   THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
   AND POSSIBLE WARNINGS.
   
   DISCUSSION...STORMS ARE BEGINNING TO DEVELOP OVER SWRN OK AS THE CAP
   HAS WEAKENED WITHIN A STRONGLY UNSTABLE ENVIRONMENT WITH MLCAPE OF
   2000-2500 J/KG.  ALTHOUGH DYNAMIC FORCING FOR LARGE SCALE ASCENT IS
   SUBTLE...NUMERICAL GUIDANCE INDICATES THAT STORMS WILL CONTINUE TO
   DEVELOP TOWARD NRN OK THIS AFTERNOON...WITH CONVECTIVE POTENTIAL
   ALSO INCREASING ALONG THE NWRN EDGE OF MOISTURE AS IT RETREATS NWWD
   LATER THIS AFTERNOON AND EVENING.  DEEP LAYER SHEAR OF 40 KT IN THE
   LOWEST 6 KM WILL FAVOR FORMATION OF SUPERCELL STRUCTURES...WITH AN
   INITIAL THREAT FOR LARGE HAIL AND STRONG WIND GUSTS.  WITH
   TIME...LOW LEVEL WINDS/SHEAR WILL STRENGTHEN WITH A SUBSEQUENT
   INCREASE IN TORNADO POTENTIAL LATER THIS AFTERNOON AND EVENING.
   
   AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
   SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE
   WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
   550. MEAN STORM MOTION VECTOR 23025.

Thunderstorms are expected to fire today in Oklahoma area East of the dryline. Convective inhibition or CIN shall prevent storms from firing till late afternoon period. With sufficient day time heat, the CAP will break and storms will fire in the presence of Moderately Destabilized atmosphere of CAPE values over 2000J/Kg across Oklahoma and SFC Dewpoint over 70F for convection. Supported by Steep Lapse rates from late afternoon into evening and the best lifted indices of -7 at Oklahoma, developing storms shall strengthen and become capable of producing large size hails into the afternoon hours. Lack of supporting wind shear for afternoon hours coupled with lesser intensified LLJ shall prevent tornadoes developing till early evening portion. 
After the evening initiates, presence of improvised shears and LLJ for moisture shall elevate the potentials for tornadoes across SW Oklahoma,Central OK,SW Texas Oklahoma Border ( around Wichita Falls,). The Hodographs are indicating extremely good curvatures and in agreement with tornadoes especially close to SW OK..

*** SINCE MOST OF THE TORNADOES ARE EXPECTED IN NIGHT PERIOD WITH STORM INITIATING AROUND 19Z-20Z WITH SUPERCELLS PEOPLE MUST PAY ATTENTION TO THE WEATHER AS NIGHT TIME TORNADOES ARE VERY DANGEROUS ***

*** SOUTH WEST OK,CENTRAL OK AND NW TEXAS-OKLAHOMA BORDER I.E CLOSE TO WICHITA FALLS,TX SHALL PAY SPECIAL ATTENTION FOR TORNADOES AT NIGHT PERIOD ***

----------------------


HIGH RISK: SATURDAY 
*** LIFE THREATENING SITUATION EXPECTED***
*** TWIN HIGH RISK AREAS***

 DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1231 PM CDT FRI APR 13 2012
   
   VALID 141200Z - 151200Z
   
   ...THERE IS A HIGH RISK OF SVR TSTMS OVER ERN NEB AND FAR WRN IA...
   
   ...THERE IS A HIGH RISK OF SVR TSTMS FROM S CNTRL KS INTO W CNTRL
   OK...
   
   ...THERE IS A MDT RISK OF SVR TSTMS FROM WRN OK INTO NEB AND IA...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM NW TX NWD INTO SRN MN AND
   WRN IL...





As the positive tilted trough digs further, the severe weather threat will shift Eastwards and become widespread on Saturday. 
The Surface analysis depicts intensifying surface low to settle over KS-NE border on Saturday. The Surface Low shall be a driving factor for the low level jets and the moisture incursion from the Gulf of Mexico. 

Above- Valid 0000z,Sun SFC analysis shows the L at NW KS

As the upper air jet surges further, it shall drive a pocket of cool air from West Central US into the plains which eventually will collide with the warm moist air from the south creating instability over a wedge area for convection. Morning period appears to have a capped environment across the warm sector east of the dryline. With enough day time heat after some showers at places like Oklahoma, capping shall break into afternoon as per the GFS and expect storm initiation robustly across western to central OK in CAPE over 2000J/Kg and upto 2000 J/Kg across Eastern Nebraska as per the GFS.. 

Moisture shall be abundant across the warm sector all due to the LLJ which maintains the 40-50kt strength till around 00z,GMT (15th April) and exploding to over 60kt after 03z thus adding to more severe weather threat! 

Initially,the wind shears shall be limited across OK-KS area and pretty favorable for areas such as NE-IA and hence the primary tornado threat shall apply for Eastern NE and Western IA.. With the increase period, shears will also improve and lack of convergence across OK-KS shall produce discrete supercells capable of producing tornadoes particularly stronger at night period... Threat of Large hails persists as well 

The Hodographs are much impressive for the NE-IA area than OK-KS which may imply stronger tornado likelyhood there... However the SPC has issued a "RARE TWIN HIGH RISK AREA" 

KANSAS-OKLAHOMA HIGH RISK COVERS CITIES FROM SALINA,KS TO OKC,OK AND NE-IA HIGH RISK COVERS MAJOR CITIES LIKE NORFOLK,OMAHA,LINCOLN ( NE)

THIS IS GOING TO BE A HISTORIC TORNADO OUTBREAK***

STAY TUNED FOR UPDATES!!

Thursday, April 12, 2012

Severe Weather expected in Central US,Moderate Risk Saturday

METD WEATHER
Akshay Deoras
Severe Weather Forecaster




Multiple rounds of severe weather are happening in the US prominently Central parts. The above 300mb GFS 09z shows exiting trough from East Central US. The trough had provided some thunderstorms in recent at Central parts. The plot also shows the approaching short wave trough currently over the Western US. The shortwave trough is expected to dig in the central US by Friday evening hours into Saturday with large amplified flow exceeding 120kt.



THURSDAY-




The pressure gradient over Gulf of Mexico and Central US  is forcing the winds to carry moisture inwards. The RUC 05hr shows dewpoint over 65F across Western Oklahoma,Western Kansas and Western parts of Texas. As the day time heat coupled with instability adds up Severe Thunderstorms shall fire East of the dryline in Texas,Oklahoma and stretching upto Kansas. During the afternoon period, large hails shall be likely across Western Kansas and Western Oklahoma. By evening hours, ground helicity will be favored over 200-300 units across a region particularly Eastern Texas Panhandle-Western,North-Western Oklahoma where the Hodographs are indicating nice curvatures favoring for tornadoes. Its very likely that isolated supercells will form and shall be capable to produce tornado*** NIGHT TIME TORNADOES ARE LIKELY AFTER 21Z ESPECIALLY ACROSS NW OK,WEST OK,EASTERN TX PANHANDLE AND WRN KS******






FRIDAY


The Upper level pattern combined with surface level analysis indicates the second round of severe weather across the same area stretching more North East wards.

The Instability shall be Moderate i.e over 3000 J/Kg across Southern,Central Oklahoma prominently with very good lifting depicted by LI over -7 to -8 in southern and central OK. However the Wind shears shall be a bit limited as per the NAM models. The 0-1km Hel and EHI shows weak values supporting not very strong tornadoes. However the models keep changing and hence its mandatory to keep an eye on the weather

***MODERATE RISK : SATURDAY***

Possible HIGH RISK?




With more Eastward progression of the trough, the energy required for strong weather avails on Saturday. 
The Warm moist sector shall be a widespread as the SFC low over Western Kansas by 14/12z amplifies the LLJ stretching over 60kt at peak and causing a Robust incursion of moisture from the Gulf of Mexico into the Texas,Oklahoma,Kansas particularly causing elevated dewpoint over 70F favoring for strong convection. The best lifted indices shall be across a region stretching from North Central TX to SRN,Cent OK amidst CAPE values over 2000J/Kg. 




Supercells are likely in the areas as being depicted by the GFS Bulk Shear over 50kt. Not much of Severe Weather is expected by mid or late afternoon as the trough will take some time before it reaches the concerned area. Also the developing wind shear shall blast in a period stretching from late afternoon into night hours across the region. Considering the favored combination of instability and powered by steep lapse rates and overall curvatures in the Hodograph, the mentioned Moderate Risk AREA will witness strong thunderstorms and some capable of producing tornadoes and hails prominently with strong winds and localized flooding due to heavy rains. 

Considering the status of LLJ, it might not be wrong to see if the MDT area or slightly East of it is upgraded to High Risk area till Saturday. 

So Stay TUNED FOR UPDATES

Saturday, April 2, 2011

Severe Weather likely across SE KS,MO - DEPENDING ON CAP





METD WEATHER
Akshay Deoras
Severe Weather Forecaster

**UPGRADE TO MODERATE RISK**
...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF ERN KS AND NW    MO...        ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MID-MO    VALLEY...CNTRL PLAINS...SRN PLAINS...WRN OZARKS AND WRN GREAT    LAKES...        ...SEVERE WEATHER EVENT EXPECTED FROM ERN KS NEWD ACROSS NRN MO INTO    WRN AND NRN IL THIS AFTERNOON AND EVENING...

A possible severe weather outbreak is likely in US across a major area covering from Illinois to South Central states.

A positively tilted trough currently in the Pacific will amplify over the rockies ejecting in the West- Central US by Sunday morning along with the cold front

As the trough shits Eastwards, Convection is likely to be inhibited due to presence of very strong Capping Inversion in the south central states.

With some day time heating expected, the strong CAP over MO is expected to break some by late evening hours Sunday. Thus for entire afternoon,convection shall be inhibited.

With the minor breaking of CAP, Severe storms are expected to fire and in Moderate Instability across Eastern KS,Much of MO during evening hours in the surface dewpoints of 65-70F

Once the convection initiates, the thunderstorms embeded in the squall line and some isolated storms w'd modify into supercells as there is a presence of nice Vertical shears ( Helicity) at the ground (0-1km) height.
Supercells shall explode into Missouri and particularly expected in Eastern Kansas if the CAP breaks on time.

Primary target-

Tornado threat persists for evening - night tornadoes specially for SE Kansas to extreme SW MO where the EHI values are peaking around 5 as CAPE is really strong there and excellent low level curvature in the hodographs but all depends on the CAP breaking


The second target remains Central MO-
West of Coloumbia,MO where some tornadoes are possible

SPC Outlooks 10% Tornado risk in NE Missouri,SE IA,Western IL
SPC Day 1 1200Z Tornado Prob Outlook


Rest-
Thunderstorms capable of damaging wind gust and large hails to appear from NRN OK,MO,East-SE IA,Western IL


MORE TO COME-
SEVERE WEATHER IS AGAIN GOING TO HAMMER SOUTHERN AND EAST CENTRAL STATES ON MONDAY