[SWODY2] SWODY2

[SWODY2 at goshenarc.org]

ACUS02 KWNS 210741
SWODY2
SPC AC 210740

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0240 AM CDT MON JUN 21 2004

VALID 221200Z - 231200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 10 NE
HSE 25 WSW RDU 55 NNW AHN 15 WSW GWO 40 SE PGO 10 ENE HRO 30 SSW SDF
35 E PKB 40 S UCA 15 NW PSF 15 E ISP.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 65 SSW GBN 40 WNW PHX
INW 30 ENE GUP 25 WSW ALS 35 W COS 35 W LAR 35 NNW BPI 55 S 27U 40
SSW BKE 45 NE 4LW 50 ENE SVE 45 S NFL 60 NE MER 15 E SAC 25 WNW RBL
30 WNW MFR 10 S SLE 25 ESE OLM 20 ENE BLI ...CONT... 25 NNW ANJ 15 W
OSH 25 E ALO 30 ENE OMA 40 NE MCK 50 E LAA 60 NE AMA 30 E OKC 30 WNW
JLN 20 NNW BMG 25 ENE MFD 20 NW BUF ...CONT... 40 ENE CRP 10 SSW
LRD.

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE TN VLY/LWR MS VLY E/NE
TO THE MID ATLANTIC STATES...

...SYNOPSIS...
AN UNUSUALLY BLOCKY PATTERN WILL PREVAIL ACROSS NOAM THIS
PERIOD...AS UPPER RIDGES PERSIST OVER BOTH WRN CANADA AND THE DAVIS
STRAIT.  SLIGHT RETROGRESSION OF THE LATTER BLOCK WILL DRIVE STRONG
POLAR IMPULSE NOW IN NUNAVUT SWD ACROSS SASKATCHEWAN/ MANITOBA LATER
TODAY. THE SYSTEM SHOULD CONTINUE E/SE ACROSS WRN ONTARIO AND NRN
MN ON TUESDAY...WHERE IT WILL SERVE TO MAINTAIN A BROAD SWATH OF
CYCLONIC FLOW OVER MUCH OF THE NRN AND ERN U.S.

FARTHER S...THE LAST IN A SERIES OF SRN STREAM DISTURBANCES
ORIGINATING IN THE NRN GRT BASIN WILL TRACK E ACROSS THE TN
VLY...AND PARTIALLY PHASE WITH NRN STREAM SHORTWAVE IMPULSE NOW
ENTERING THE NRN PLNS. THE COMBINED SYSTEM SHOULD REACH THE
NRN/CNTRL APPALACHIANS BY 12Z WEDNESDAY.

...LWR MS/TN VLYS E/NE TO THE MID ATLANTIC STATES...
A CLUSTER OR TWO OF STRONG THUNDERSTORMS MAY BE ONGOING AT THE START
OF THE PERIOD OVER PARTS OF OK AND AR...IN WARM ADVECTION AREA
DOWNSTREAM FROM AFOREMENTIONED SRN STREAM IMPULSE.  WHILE LARGE
SCALE FORCING FOR ASCENT SHOULD WEAKEN AS UPPER IMPULSE IS ABSORBED
IN CONFLUENT FLOW ALOFT...THE STORMS SHOULD MOVE/DEVELOP EWD INTO
THE TN VLY LATER IN THE DAY...BEING DRIVEN LARGELY BY SURFACE
HEATING AND CONVERGENCE ALONG CONVECTIVE OUTFLOW.  COMBINATION OF
FAIRLY STEEP MID LEVEL LAPSE RATES /APCHG 7 DEG C PER KM/...RICH
BOUNDARY LAYER MOISTURE INFLOW /DEWPOINTS IN THE LOW 70S/ AND
MODERATE /30 KT/ UNIDIRECTIONAL WSWLY MEAN FLOW SHOULD SUPPORT
ORGANIZED BANDS OF STORMS WITH BOWING SEGMENTS/LOCALLY DAMAGING WIND
THROUGH EARLY TUESDAY NIGHT.

FARTHER NE...EXPECT THAT LOW TO MID LEVEL LAPSE RATES ON THE WHOLE
WILL BE SOMEWHAT WEAKER FROM THE CNTRL APPALACHIANS TO THE MID
ATLANTIC CST...WHERE LARGE SCALE ASCENT AND CONTINUED LOW LEVEL WARM
ADVECTION WILL LIKELY CONTRIBUTE TO ABUNDANT CLOUDS.  ONE EXCEPTION
MIGHT BE IN THE LEE OF THE BLUE RIDGE MOUNTAINS ACROSS CNTRL
PORTIONS OF MD/VA...WHERE MEAN WLY FLOW SHOULD TEND TO SCOUR
RESIDUAL LOW LEVEL CLOUDS.

SURFACE HEATING...CONVERGENCE ALONG COLD FRONT ASSOCIATED WITH
PHASING UPPER LEVEL DISTURBANCES...AND WEAK LARGE SCALE ASCENT MAY
SUFFICIENTLY DESTABILIZE REGION TO SUPPORT STORM DEVELOPMENT BY MID
AFTERNOON FROM WRN PARTS OF NC NWD INTO SRN/ERN PA.  BAND OF 40-50
KT WSWLY MID LEVEL FLOW WILL CONTRIBUTE TO AMPLE DEEP SHEAR FOR
ORGANIZED STORMS/SUPERCELLS...IF SUSTAINED ACTIVITY DOES INDEED
DEVELOP.  LOW LEVEL SHEAR WILL EVEN BE FAVORABLE FOR TORNADOES ALONG
LEE TROUGH FROM ERN VA NEWD INTO ERN PA/NJ... ASSUMING STORMS ARE
ABLE TO REMAIN DISCRETE.  WHILE IT APPEARS ATTM THAT WEAK
INSTABILITY WILL LIKELY LIMIT COVERAGE/INTENSITY OF  SEVERE THREAT
IN THE EAST...ESPECIALLY N OF MD...THERE WILL EXIST AT LEAST A
CONDITIONAL THREAT FOR HIGH WIND AND POSSIBLY A TORNADO OR TWO IF
SUSTAINED STORMS DO INDEED FORM.  GIVEN LIMITED INSTABILITY...ANY
SEVERE THREAT SHOULD DIMINISH WITH SUNSET.

...UPR MS VLY/UPR GRT LKS...
STRONG LARGE SCALE FORCING FOR ASCENT AHEAD OF POTENT IMPULSE
DROPPING S FROM MANITOBA...COUPLED WITH CONVERGENCE ALONG ASSOCIATED
COLD FRONT AND PREFRONTAL TROUGH...MAY YIELD A BAND OF LOW-TOPPED
STORMS IN AXIS OF STEEP LOW LEVEL LAPSE RATES FROM ERN SD INTO
MN/NRN WI. LIMITED MOISTURE AVAILABILITY /DEWPOINTS AROUND 50/ WILL
PROBABLY PRECLUDE A WIDESPREAD SEVERE THREAT...BUT ISOLATED STORMS
COULD YIELD HIGH WIND AND MARGINALLY SEVERE HAIL TUESDAY AFTERNOON.

..CORFIDI.. 06/21/2004

...NOTICE...
FOR USERS DECODING THE POINTS PARAGRAPH HEREIN...LATITUDE AND
LONGITUDE POINTS FOR THE CATEGORICAL AND PROBABILISTIC OUTLOOK
GRAPHICS ALSO ARE LOCATED IN A SEPARATE PRODUCT UNDER THE WMO
HEADINGS WUUS01 PTSDY1...WUUS02 PTSDY2...AND WUUS03 PTSDY3.  THE
INCLUSION OF POINTS IN THIS PRODUCT WILL EVENTUALLY BE DISCONTINUED.