Forecasters: Michael Skipper (NWS/GLD) and Bruce Entwistle (NWS/GLD)

12Z data indicated an outflow boundary from southeast Colorado through southwest Kansas into western Oklahoma. Satellite imagery and morning sounding showed a 50 to 60 kt subtropical jet from eastern New Mexico through central Kansas into the eastern Dakotas. A weak vort max was noted over northeast New Mexico. A strong jet (100 kts at Spokane) was diving southward through the intermountain west and a SW-NE oriented cold front approaching the northwest corner of Colorado. The dry line was up against the Colorado Front Range.

The dry line is expected to intensify and push east toward the Colorado/Kansas border. The dewpoint gradient should reach 35F. Towering cumulus could develop along the dry line around 19Z with convection firing about 20 miles west of Highway 385 by 22Z. The progression of convective activity should be similar to Sunday with separate cells early with cloud bases around 675 mb. With mid level flow expected to be weak, storms are most likely to become outflow dominated and quickly organize into a line. Motion will be east around 12.5 m/s.

Winds up to 30 m/s are possible with the strongest convection as well as hailstones up to 45 mm.

Synoptic situation is favorable for our area once again, for MCS development anyway. Radars will come up in surveillance at 1 PM. NSSL5 will hold in Goodland and receive hourly updates starting at 1 PM. Mobile mesonet will probably deploy to eastern Colorado to monitor expected dryline formation there, and expected convective initiation. T-28 will receive updates starting at 1 PM for possible late afternoon-early evening flight. Mobile soundings at 18Z/21Z at Limon and Goodland are requested.

Since four EFM's were used in yesterday's MCS, we will likely repeat that number today only if significant positive CG lightning is occurring. Otherwise we expect to use fewer EFM's (in an MCS situation) and will target the convective line rearward into the stratiform region.

[Radar images]

Although conditions seemed favorable in the morning for afternoon convection, nothing developed early in the STEPS domain of any significance. A well defined dryline was present to the west of the domain by late morning. A few weak storms went up on the northern and southern portion of the dryline, but were short lived and weak. These storms did produce some electrification, with normal polarity fields.

The southern end of the bowed boundary produced the storm that ended up being our target for the T-28, NSSL5 and the intercept team. All units were all well positioned but the storm died extremely rapidly, as it was undercut by a major outflow boundary. This latter feature was oriented east-west and was generated by convection in extreme SE Colorado. The cell that did form SE of CHILL near 2300 UTC produced some IC lightning, but very few, if any CG's. This storm was reported having an inverted charge structure, positive underlying negative. Polarimetric radar indicated a brief period of large drops with this precipitation shaft. The T-28 made two passes in the rapidly decaying convection. One EFM was launched into the decaying storm but the quality of the data on this flight was unclear at the time of this writing. The mobile mesonet worked the dryline prior to convective development. All facilities performed well in this case.