SUBVORTEX STATUS MESSAGE DATE: 5/17/98 STATUS: LIKELY GO...ANOTHER STATUS MESSAGE WILL BE ISSUED BY 945 AM SYNOPSIS: Morning surface data and soundings indicate that a plume of moisture has advected northward in W TX, TX Panhandle, WRN OK, and SW KS. Morning soundings at DDC and AMA show moisture already sufficient to produce significant CAPE and attainable convective temperatures during late afternoon. 12Z profiler and rawinsonde data also reveal 80-90 kt jet streak entering SW KS from NE NM. DAY 1 FORECAST: Vertical shear should support supercells in the TX Panhandle and SW KS. At this time, we are on standby for another hour to better assess the jet position and evaluate the possibility of overnight stay, depending on today's target to be chosen and the future outlook. Today will be a likely go to either the TX Panhandle or SW KS. DAY 2 FORECAST: We are currently assessing Day 2. DAY n FORECAST: Latest MRF is considerably different from past runs and appears to be converging toward NOGAPS solution, which would yield several very favorable days for the southern half of the Plains this week. MISCELLANEOUS: Status will be reissued at 945 AM. Markowski/Rasmussen --------------------------------------------------------- ----------------------- UPDATE -------------------------- --------------------------------------------------------- SUBVORTEX STATUS MESSAGE DATE: 5/17/98 STATUS: STANDBY UNTIL 12 PM CDT FOR POSSIBLE 1245 DEPARTURE SYNOPSIS: Morning surface data and soundings indicate that a plume of moisture has advected northward in W TX, TX Panhandle, WRN OK, and SW KS. Morning soundings at DDC and AMA show moisture already sufficient to produce significant CAPE and attainable convective temperatures during late afternoon. 12Z profiler and rawinsonde data also reveal 80-90 kt jet streak entering SW KS from NE NM. DAY 1 FORECAST: Vertical shear should support supercells in the TX Panhandle and SW KS. Big question is initiation. Eta forecasts warming aloft at 700 mb during the day...this is in question because upstream temps are colder (thus advection cannot accomplish the warming) and lapse rates are neutral from around 550 mb to 780 mb on AMA 12Z sounding (thus, subsudence could not warm temps unless parcels descend to 700 mb from above 550 mb...quite a vertical displacement). Initiation on low terrain will be difficult to impossible...but if moisture remains on high terrain, convective temperatures will be approached or attained. Any storm that is initiated will have a high probability of becoming a supercell. CAPE will be high (on the order of 3-4 kJ/kg). Forecast problem is western edge of moisture. Model data have been scarce this morning...SAMEX data and 12Z RUC are still unavailable. Therefore we will remain on standby until 12 pm. If the dryline is on low terrain at that time, we will not depart. If the dryline is on the elevated terrain, departure will be at 1245 pm. DAY 2 FORECAST: We suspect that adequate flow for supercells may continue to be ejected from massive jet offshore SW US, despite progs' display of weaker flow. Flow aloft will have to be monitored daily. DAY n FORECAST: Latest MRF is considerably different from past runs and appears to be converging toward NOGAPS solution, which would yield several very favorable days for the southern half of the Plains this week. MISCELLANEOUS: Overnight stay is still being considered. Markowski/Rasmussen --------------------------------------------------------- ----------------------- UPDATE -------------------------- --------------------------------------------------------- SUBVORTEX STATUS MESSAGE DATE: 5/17/98 STATUS: GO...1245 PM DEPARTURE EQUIPMENT STATUS: Mobile Mesonets: operational DOWS: unavailable UMASS Radar: down indefinitely Rockets: not operational Turtles: operational RALPH: operational NOAA P-3: operational SYNOPSIS: Dryline is expected to move little throughout the afternoon. Cap strength trend is uncertain. Dryline is presently located from near CVS to just west of AMA, although confluence zone currently is about 40 miles farther east. Initiation is probably only likely on terrain above 2800 feet. 12 pm update: AMA is now 83 F...6-7 F from convective temp. Cu abound along and north of I-40 in western OK and eastern TX Panhandle. Winds have also backed at AMA to 170 deg. DAY 1 FORECAST: Convective initiation question remains unanswered. We put the probability of initiation around 30%...but CAPE is high and shear north of about I-40 is expected to support classic supercells. Conditional probability of a supercell given initiation is from 60-75%. DAY 2 FORECAST: Similar scenario to today. DAY n FORECAST: MRF shows more promise, appears to be converging toward favorable NOGAPS solution. MISCELLANEOUS: No overnight stay tonight. Rasmussen/Markowski