Forecasters: ? (NWS) and Morris Weisman (NCAR/MMM)
A surface cold front is forecast to propagate from northwest to southeast through the STEPS domain this afternoon, offering strong convective triggering. Ahead of the cold front, surface dew points this morning range from the low-to-mid 50's to the west to low 60's to the southeast. Surface winds are light and variable ahead of the front, with 10-20 kts from the N-NW behind the front. During the day, 10-20 kt S-SE flow is expected to develop ahead of the front, which, along with 20-30 kt flow at 500 mb from the W, is expected to produce minimal shear values for supercellular convection. CAPEs are expected to range from 500-1000 j/kg behind the front to over 2000 j/kg ahead of the front. The best chances for severe convection will be in the southern and eastern portions of the STEPS domain today.
For tomorrow (Monday), the surface front continues to move southeast, reducing CAPE values and chances of significant convection.
More stable conditions are also forecast for Tuesday, with little chance of significant convection.
| VARIABLE | Day 1: 1-4 pm | Day 1: 4-9 pm | Day 2 | Day 3 |
|---|---|---|---|---|
| Convective Potential |
3 | 3 | 1 | 1 |
| Storm Type | 2 | 2 | 3 | 3 |
| Triggering | 3 | 3 | 1 | 0 |
| Intuition | 1 | 1 | -1 | -1 |
| Total | 9 | 9 | 4 | 3 |
| SYSTEM | STATUS |
|---|---|
| Ops Center | Operational. |
| CHILL | Operational. |
| S-Pol | Operational. |
| LMA | Operational. |
| MGLASS | Operational. |
| T-28 | Operational. |
| Storm ballooning | Operational, but only seven EFMs remain with the possibility of refurbishing an additional five. |
| Mobile mesonet | Five vehicles are available. |
| Storm chase van | Operational as the primary precipitation verification vehicle. |
| YRFS | Operational. |
| NWS | Operational. |
Radars and mobile platforms will be on standby as of 12:00 pm for probable severe convection primarily in the southern and eastern regions of the STEPS domain. All facilities are available for operations. MGLASS soundings will be taken at 18 UTC at Stratton CO and Colby KS, with a high probability of additional soundings being requested for 21 and 00 UTC.
The cold front passed to the eastern and southern edges of the STEPS domain by mid-afternoon, which was 2-3 hours quicker than forecast. Convection triggered along an arc from Tribune to Hoxie KS. Mobile units were sent to the Tribune area early afternoon for possible operations, but convection moved out of the research region and teams returned back to Goodland. Operations were called down at 5:30 pm.