From mcd at goshenarc.org Tue Feb 20 00:35:34 2007 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 19 Feb 2007 19:35:34 -0500 Subject: [MCD] Notice/update regarding email weather bulletins Message-ID: <20070220003559.40E423A004E@mail.goshen.edu> As many of you have noticed there have not been a lot of weather bulletins coming to you by email in the last month or so. The cold weather has exposed the slow failure of the LNB (low-noise block down-converter) on my Ku-band EMWIN satellite downlink. When LNBs get old, their center-frequencies become very temperature dependent. In other words, the colder outside it gets, the futher off-frequency it drifts, until the signal drops to below the noise threshhold. At that point the ingest engines locks up and no more message get parsed. So as long as the temperature stays above the mid-twenties, the data will keep flowing. A new LNB has been ordered, and hopefully the four-foot snow drift around the dish will melt about the same time the new LNB shows up. That's the update...it appears to be running smoothly right now with the temperatures mild, so we'll see what happens in the next week. If you are on more that one list, you have received one message for each list that you are on. Apologies for any duplicates. ---------------------------------------------------------- Calvin F. Swartzendruber calvinfs at goshen.edu From mcd at goshenarc.org Wed Feb 21 00:23:04 2007 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Tue, 20 Feb 2007 19:23:04 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 210027 SWOMCD SPC MCD 210027 TNZ000-KYZ000-ILZ000-MOZ000-ARZ000-210200- MESOSCALE DISCUSSION 0173 NWS STORM PREDICTION CENTER NORMAN OK 0627 PM CST TUE FEB 20 2007 AREAS AFFECTED...SRN IL...SERN MO....NERN AR....WRN KY...WRN TN CONCERNING...SEVERE THUNDERSTORM WATCH 26... VALID 210027Z - 210200Z SEVERE STORMS WITH HAIL WILL CONTINUE TO DEVELOP GENERALLY EWD ACROSS NRN/NWRN PORTIONS OF WATCH 26. SEVERE TSTMS CONTINUE TO INCREASE NEAR SURFACE WAVE AND FRONTAL ZONE FROM EXTREME NRN AR ACROSS THE MO BOOTHEEL REGION THIS EVENING. LARGE HAIL HAS BEEN REPORTED WITH ACTIVITY ACROSS SCOTT COUNTY MO OVER THE PAST HOUR. DEEP CONVECTION APPEARS TO BE DEVELOPING WITHIN AN AXIS OF STRONG LOW LEVEL CONVERGENCE ASSOCIATED WITH THE FRONTAL WAVE. AN INTENSE LEFT-MOVING STORM WAS TRACKING ENEWD TOWARD EXTREME SRN IL ATTM...AND ADDITIONAL CELLS WERE STRENGTHENING WWD AND SWWD ACROSS STODDARD...BUTLER...AND RIPLEY COUNTIES. AIR MASS IN THE VICINITY OF THESE STORMS SHOULD REMAIN SUFFICIENTLY UNSTABLE TO MAINTAIN ROBUST UPDRAFTS WITHIN A STRONGLY SHEARED ENVIRONMENT. RECENT STORM TRENDS AND LATEST LITTLE ROCK SOUNDING INDICATED INTENSE UNIDIRECTIONAL EFFECTIVE SHEAR...ON THE ORDER OF 50-70KT...WAS RESULTING IN SPLITTING SUPERCELLS. GREATEST THREAT WITH THIS ACTIVITY WILL CONTINUE TO BE LARGE HAIL FROM BOTH LEFT AND RIGHT MOVING UPDRAFTS GIVEN STEEP MID LEVEL LAPSE RATES AND MODERATE FORCING FOR ASCENT. IF RIGHT-MOVING CELLS CAN REMAIN DISCRETE WHILE DEVELOPING INTO LOW LEVEL MOIST AXIS ALIGNED WITH MS RIVER OVER NEXT HOUR OR SO...A BRIEF TORNADO CANNOT BE RULED OUT. ..CARBIN.. 02/21/2007 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LMK...OHX...PAH...MEG...LZK...SGF... 35508738 35439121 36779111 37288947 37288823 37008699  From mcd at goshenarc.org Wed Feb 21 02:39:03 2007 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Tue, 20 Feb 2007 21:39:03 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 210243 SWOMCD SPC MCD 210243 TNZ000-KYZ000-ILZ000-MOZ000-ARZ000-210415- MESOSCALE DISCUSSION 0174 NWS STORM PREDICTION CENTER NORMAN OK 0843 PM CST TUE FEB 20 2007 AREAS AFFECTED...SERN MO...NERN AR...SRN IL...WRN KY/TN CONCERNING...SEVERE THUNDERSTORM WATCH 26... VALID 210243Z - 210415Z SCATTERED SEVERE STORMS WITH THE POTENTIAL TO PRODUCE HAIL WILL REMAIN A POSSIBILITY ACROSS PARTS OF THE LOWER OH VALLEY/MID MS VALLEY FOR THE NEXT COUPLE OF HOURS. DESPITE MODEST FORCING FOR ASCENT ACROSS THE REGION...RELATIVELY LIMITED INSTABILITY SHOULD PRECLUDE THE NEED FOR ADDITIONAL WATCHES. NUMEROUS SPLITTING SUPERCELLS CONTINUE TO SPREAD EWD TONIGHT FROM THE BOOTHEEL OF MO TO SRN IL AND WRN KY. THIS CONVECTION WAS OCCURRING AHEAD OF A WEAK FRONTAL WAVE CYCLONE TRACKING EAST ALONG THE MO/AR BORDER. LOW LEVEL CONVERGENCE AHEAD OF THE LOW...AND ALONG THE FRONTAL ZONE EXTENDING EAST TO THE LOWER OH VALLEY...SHOULD CONTINUE TO SUPPORT SCATTERED SEVERE TSTMS OVER THE NEXT 1-2 HOURS. A PLUME OF STEEP MID LEVEL LAPSE RATES ASSOCIATED WITH POSITIVE TILT LARGE SCALE MID/UPPER LEVEL TROUGH SHEARING EAST ACROSS THE REGION WILL ALSO LEND SUPPORT TO ROBUST BUT PRIMARILY ELEVATED CONVECTION. WHILE VERY STRONG SHEAR AND MODEST NEAR SURFACE-BASED INSTABILITY EXIST ACROSS SRN PORTIONS OF THE WATCH...MOSTLY WRN TN...LATEST GUIDANCE AND RADAR TRENDS SUGGEST LITTLE DEVELOPMENT OVER THIS AREA IN THE NEXT FEW HOURS. HOWEVER...ENVIRONMENT OVER THE LARGER AREA WILL REMAIN SUPPORTIVE OF ROTATING/PERSISTENT UPDRAFTS CAPABLE OF PRODUCING LARGE HAIL FOR AT LEAST ANOTHER 1-2 HOURS. AFTER THAT TIME...STRONGER FORCING BEGINS TO DECOUPLE FROM WEAKENING INSTABILITY AND ADDITIONAL WATCHES ARE NOT ANTICIPATED. ..CARBIN.. 02/21/2007 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LMK...OHX...PAH...MEG... 35498727 35449097 36879106 37118983 37618942 37608805 37168773 37048703 36198711 WWWW From mcd at goshenarc.org Wed Feb 21 07:33:13 2007 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 21 Feb 2007 02:33:13 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 210737 SWOMCD SPC MCD 210737 NCZ000-TNZ000-GAZ000-ALZ000-211000- MESOSCALE DISCUSSION 0175 NWS STORM PREDICTION CENTER NORMAN OK 0137 AM CST WED FEB 21 2007 AREAS AFFECTED...PORTIONS MIDDLE-ERN TN...NRN AL...EXTREME NRN GA...WRN NC. CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 210737Z - 211000Z WIDELY SCATTERED TSTMS MAY DEVELOP ACROSS DISCUSSION AREA THROUGH REMAINDER PRE-DAWN HOURS...BOTH WITHIN REMAINS OF ONGOING MCS AND TO ITS S AND E FROM NRN AL TO WRN NC. MRGL SVR HAIL THREAT STILL MAY EXIST WITH STRONGEST CELLS. OVERALL POTENTIAL APPEARS TOO WEAK AND SPORADIC TO WARRANT WW. ALL ACTIVITY SHOULD REMAIN WELL AHEAD OF WEAK SFC COLD FRONT...WHICH WAS ANALYZED AT 7Z FROM E-CENTRAL KY WSWWD ACROSS MO BOOTHEEL TO W-CENTRAL AR. STRONG LOW LEVEL WAA REGIME IS EVIDENT JUST ABOVE SFC...WITH 40-50 KT LLJ EVIDENT IN VWP ACROSS REGION...AND PATCHY AREAS OF ENHANCED ISENTROPIC ASCENT IN 800-900 MB LAYER PROGGED BY RUC. 850 MB FLOW IS FCST TO MAINTAIN INTENSITY AND BECOME MORE CONFLUENT ACROSS THIS REGION THROUGH 12Z. AS PARCELS REACH LFC...MUCAPES AROUND 500 J/KG ARE EXPECTED WITH EFFECTIVE BULK SHEARS 40-50 KT...BASED ON MODIFIED RAOBS AND RUC FCST SOUNDINGS. LACK OF MORE ROBUST BUOYANCY...AND OF STRONGER LOW LEVEL FORCING AHEAD OF FRONT -- SHOULD PRECLUDE BETTER ORGANIZED SVR POTENTIAL. ..EDWARDS.. 02/21/2007 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...GSP...MRX...FFC...OHX...BMX...HUN... 35878721 36478451 36428263 36108184 35418244 34728388 34128559 33708713 34358797 35778722  From mcd at goshenarc.org Tue Feb 20 00:35:34 2007 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 19 Feb 2007 19:35:34 -0500 Subject: [MCD] Notice/update regarding email weather bulletins Message-ID: <20070220003559.40E423A004E@mail.goshen.edu> As many of you have noticed there have not been a lot of weather bulletins coming to you by email in the last month or so. The cold weather has exposed the slow failure of the LNB (low-noise block down-converter) on my Ku-band EMWIN satellite downlink. When LNBs get old, their center-frequencies become very temperature dependent. In other words, the colder outside it gets, the futher off-frequency it drifts, until the signal drops to below the noise threshhold. At that point the ingest engines locks up and no more message get parsed. So as long as the temperature stays above the mid-twenties, the data will keep flowing. A new LNB has been ordered, and hopefully the four-foot snow drift around the dish will melt about the same time the new LNB shows up. That's the update...it appears to be running smoothly right now with the temperatures mild, so we'll see what happens in the next week. If you are on more that one list, you have received one message for each list that you are on. Apologies for any duplicates. ---------------------------------------------------------- Calvin F. Swartzendruber calvinfs at goshen.edu From mcd at goshenarc.org Wed Feb 21 00:23:04 2007 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Tue, 20 Feb 2007 19:23:04 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 210027 SWOMCD SPC MCD 210027 TNZ000-KYZ000-ILZ000-MOZ000-ARZ000-210200- MESOSCALE DISCUSSION 0173 NWS STORM PREDICTION CENTER NORMAN OK 0627 PM CST TUE FEB 20 2007 AREAS AFFECTED...SRN IL...SERN MO....NERN AR....WRN KY...WRN TN CONCERNING...SEVERE THUNDERSTORM WATCH 26... VALID 210027Z - 210200Z SEVERE STORMS WITH HAIL WILL CONTINUE TO DEVELOP GENERALLY EWD ACROSS NRN/NWRN PORTIONS OF WATCH 26. SEVERE TSTMS CONTINUE TO INCREASE NEAR SURFACE WAVE AND FRONTAL ZONE FROM EXTREME NRN AR ACROSS THE MO BOOTHEEL REGION THIS EVENING. LARGE HAIL HAS BEEN REPORTED WITH ACTIVITY ACROSS SCOTT COUNTY MO OVER THE PAST HOUR. DEEP CONVECTION APPEARS TO BE DEVELOPING WITHIN AN AXIS OF STRONG LOW LEVEL CONVERGENCE ASSOCIATED WITH THE FRONTAL WAVE. AN INTENSE LEFT-MOVING STORM WAS TRACKING ENEWD TOWARD EXTREME SRN IL ATTM...AND ADDITIONAL CELLS WERE STRENGTHENING WWD AND SWWD ACROSS STODDARD...BUTLER...AND RIPLEY COUNTIES. AIR MASS IN THE VICINITY OF THESE STORMS SHOULD REMAIN SUFFICIENTLY UNSTABLE TO MAINTAIN ROBUST UPDRAFTS WITHIN A STRONGLY SHEARED ENVIRONMENT. RECENT STORM TRENDS AND LATEST LITTLE ROCK SOUNDING INDICATED INTENSE UNIDIRECTIONAL EFFECTIVE SHEAR...ON THE ORDER OF 50-70KT...WAS RESULTING IN SPLITTING SUPERCELLS. GREATEST THREAT WITH THIS ACTIVITY WILL CONTINUE TO BE LARGE HAIL FROM BOTH LEFT AND RIGHT MOVING UPDRAFTS GIVEN STEEP MID LEVEL LAPSE RATES AND MODERATE FORCING FOR ASCENT. IF RIGHT-MOVING CELLS CAN REMAIN DISCRETE WHILE DEVELOPING INTO LOW LEVEL MOIST AXIS ALIGNED WITH MS RIVER OVER NEXT HOUR OR SO...A BRIEF TORNADO CANNOT BE RULED OUT. ..CARBIN.. 02/21/2007 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LMK...OHX...PAH...MEG...LZK...SGF... 35508738 35439121 36779111 37288947 37288823 37008699  From mcd at goshenarc.org Wed Feb 21 02:39:03 2007 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Tue, 20 Feb 2007 21:39:03 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 210243 SWOMCD SPC MCD 210243 TNZ000-KYZ000-ILZ000-MOZ000-ARZ000-210415- MESOSCALE DISCUSSION 0174 NWS STORM PREDICTION CENTER NORMAN OK 0843 PM CST TUE FEB 20 2007 AREAS AFFECTED...SERN MO...NERN AR...SRN IL...WRN KY/TN CONCERNING...SEVERE THUNDERSTORM WATCH 26... VALID 210243Z - 210415Z SCATTERED SEVERE STORMS WITH THE POTENTIAL TO PRODUCE HAIL WILL REMAIN A POSSIBILITY ACROSS PARTS OF THE LOWER OH VALLEY/MID MS VALLEY FOR THE NEXT COUPLE OF HOURS. DESPITE MODEST FORCING FOR ASCENT ACROSS THE REGION...RELATIVELY LIMITED INSTABILITY SHOULD PRECLUDE THE NEED FOR ADDITIONAL WATCHES. NUMEROUS SPLITTING SUPERCELLS CONTINUE TO SPREAD EWD TONIGHT FROM THE BOOTHEEL OF MO TO SRN IL AND WRN KY. THIS CONVECTION WAS OCCURRING AHEAD OF A WEAK FRONTAL WAVE CYCLONE TRACKING EAST ALONG THE MO/AR BORDER. LOW LEVEL CONVERGENCE AHEAD OF THE LOW...AND ALONG THE FRONTAL ZONE EXTENDING EAST TO THE LOWER OH VALLEY...SHOULD CONTINUE TO SUPPORT SCATTERED SEVERE TSTMS OVER THE NEXT 1-2 HOURS. A PLUME OF STEEP MID LEVEL LAPSE RATES ASSOCIATED WITH POSITIVE TILT LARGE SCALE MID/UPPER LEVEL TROUGH SHEARING EAST ACROSS THE REGION WILL ALSO LEND SUPPORT TO ROBUST BUT PRIMARILY ELEVATED CONVECTION. WHILE VERY STRONG SHEAR AND MODEST NEAR SURFACE-BASED INSTABILITY EXIST ACROSS SRN PORTIONS OF THE WATCH...MOSTLY WRN TN...LATEST GUIDANCE AND RADAR TRENDS SUGGEST LITTLE DEVELOPMENT OVER THIS AREA IN THE NEXT FEW HOURS. HOWEVER...ENVIRONMENT OVER THE LARGER AREA WILL REMAIN SUPPORTIVE OF ROTATING/PERSISTENT UPDRAFTS CAPABLE OF PRODUCING LARGE HAIL FOR AT LEAST ANOTHER 1-2 HOURS. AFTER THAT TIME...STRONGER FORCING BEGINS TO DECOUPLE FROM WEAKENING INSTABILITY AND ADDITIONAL WATCHES ARE NOT ANTICIPATED. ..CARBIN.. 02/21/2007 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LMK...OHX...PAH...MEG... 35498727 35449097 36879106 37118983 37618942 37608805 37168773 37048703 36198711 WWWW From mcd at goshenarc.org Wed Feb 21 07:33:13 2007 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 21 Feb 2007 02:33:13 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 210737 SWOMCD SPC MCD 210737 NCZ000-TNZ000-GAZ000-ALZ000-211000- MESOSCALE DISCUSSION 0175 NWS STORM PREDICTION CENTER NORMAN OK 0137 AM CST WED FEB 21 2007 AREAS AFFECTED...PORTIONS MIDDLE-ERN TN...NRN AL...EXTREME NRN GA...WRN NC. CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 210737Z - 211000Z WIDELY SCATTERED TSTMS MAY DEVELOP ACROSS DISCUSSION AREA THROUGH REMAINDER PRE-DAWN HOURS...BOTH WITHIN REMAINS OF ONGOING MCS AND TO ITS S AND E FROM NRN AL TO WRN NC. MRGL SVR HAIL THREAT STILL MAY EXIST WITH STRONGEST CELLS. OVERALL POTENTIAL APPEARS TOO WEAK AND SPORADIC TO WARRANT WW. ALL ACTIVITY SHOULD REMAIN WELL AHEAD OF WEAK SFC COLD FRONT...WHICH WAS ANALYZED AT 7Z FROM E-CENTRAL KY WSWWD ACROSS MO BOOTHEEL TO W-CENTRAL AR. STRONG LOW LEVEL WAA REGIME IS EVIDENT JUST ABOVE SFC...WITH 40-50 KT LLJ EVIDENT IN VWP ACROSS REGION...AND PATCHY AREAS OF ENHANCED ISENTROPIC ASCENT IN 800-900 MB LAYER PROGGED BY RUC. 850 MB FLOW IS FCST TO MAINTAIN INTENSITY AND BECOME MORE CONFLUENT ACROSS THIS REGION THROUGH 12Z. AS PARCELS REACH LFC...MUCAPES AROUND 500 J/KG ARE EXPECTED WITH EFFECTIVE BULK SHEARS 40-50 KT...BASED ON MODIFIED RAOBS AND RUC FCST SOUNDINGS. LACK OF MORE ROBUST BUOYANCY...AND OF STRONGER LOW LEVEL FORCING AHEAD OF FRONT -- SHOULD PRECLUDE BETTER ORGANIZED SVR POTENTIAL. ..EDWARDS.. 02/21/2007 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...GSP...MRX...FFC...OHX...BMX...HUN... 35878721 36478451 36428263 36108184 35418244 34728388 34128559 33708713 34358797 35778722