Forecasters: Bruce Entwistle (NWS) and Morris Weisman (NCAR/MMM)
Today:
A surface trough line has moved to the vicinity of Goodland this morning with nothwesterly flow and drier conditions to its west and moister southerly flow to its east. A warm frontal boundary is also in place northeast of Goodland, with southeasterly surface flow and dew points from 65-70 F evident in southern Nebraska from Imperial to Benkleman and McCook. A weak upper-level disturbance is also in place in Northeast Colorado, producing some enhanced cloudiness in northeast Colorado and southwest Nebraska. Winds alift have increased significantly, with 20-30 kt southwesterlies at 500 mb, increasing to 50-70 kts at 300 mb. The surface warm frontal boundary is forecast to remain stationary during the day, with very large CAPES (2000-3000) forecast to its north and east over the Benkleman-McCook region. Upper level flow is forecast to increase further over this region during the day, and is expected to be sufficient for supercellular activity. However, over the standard STEPS research domain, surface dew points are forecast to decrease to the upper 40's and low 50's F, only offering the possibility of weak, high based convection.
Day 2:
For Wednesday, strong upper-level flow and shear remains in place, but surface moisture is forecast to remain low over the STEPS region, only offering the continued possibility for weak, high-based convection.
Day 3:
For Thursday, temperatures warm aloft, upper-level winds decrease, and surface moisture remains low, offerring little chance for significant convection.
| VARIABLE | Day 1: 1-4 pm | Day 1: 4-9 pm | Day 2 | Day 3 |
|---|---|---|---|---|
| Convective Potential |
1 | 1 | 1 | 1 |
| Storm Type | 2 | 2 | 2 | 1 |
| Triggering | 1 | 1 | 1 | 1 |
| Intuition | 0 | 0 | 0 | -1 |
| Total | 4 | 4 | 4 | 2 |
| SYSTEM | STATUS |
|---|---|
| Ops Center | Operational. |
| CHILL | Operational. |
| S-Pol | Operational. |
| LMA | Operational. |
| MGLASS | Operational. Prior to any soundings today, there are about 14-17 remaining sondes. |
| T-28 | Engine failure, no longer available to the project. |
| Storm ballooning | Operational. There are 6 EFMs available. |
| Mobile mesonet | Recalled to Norman, no longer available to the project. |
| Storm chase van | Operational as the primary precipitation verification vehicle, but no one available to staff it. |
| YRFS | Operational. |
| NWS | Operational. |
Radars will be on standby at noon. Electric ballooning units are on standby at noon for possible travel to Benkleman-McCook Nebraska area for possible supercell intercept. The chances of local convection are low; however, some convection might develop in the Sterling CO area provided the winds turn more northeasterly. An 18 UTC sounding will be taken at Goodland.
The electrical ballooning unit deployed to the Benkelman-McCook Nebraska area with the expectation of severe convection, including the potential for supercellular activity. Although CAPE was high, the region was strongly capped so that no significant organized convection ever developed. We secured operations at 0100Z, July 5.