Valid 012000Z – 021200Z
…THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF
EASTERN AND NORTHEAST COLORADO…NORTHWEST KANSAS…WESTERN
NEBRASKA…AND FAR SOUTHEAST WYOMING…
…SUMMARY…
Severe thunderstorms capable of large hail and strong wind gusts are
possible across parts of the central Plains this afternoon and
evening.
…Discussion…
Only two changes were made to the previous outlook.
1) Expanded the Slight Risk northward into the NE Panhandle and
southeast WY for associated hail/wind probabilities.
2) Added a small 5-percent hail/wind area in the upper Chesapeake
Bay for strong to locally severe storms for the next few hours.
KDOX VAD shows slightly stronger flow (0-6km around 20kt) compared
to KLWX and coupled with around 2000 J/kg MLCAPE, a couple of the
stronger storms may yield marginally severe hail and/or localized
damaging gusts.
Elsewhere, the forecast remains unchanged.
..Smith.. 08/01/2019
.PREV DISCUSSION… /ISSUED 1127 AM CDT Thu Aug 01 2019/
…CO/NE/KS…
A large upper ridge remains centered over the southern Rockies
today, with anticyclonic flow aloft present from the northern Great
Basin into the northern Plains. Ample low-level moisture is in
place over eastern CO and adjacent parts of WY/NE/KS with dewpoints
in the mid/upper 60s. Visible satellite imagery shows considerable
cloud cover over WY which will limit northward destabilization. But
parts of eastern CO should become quite warm/unstable this afternoon
with MLCAPE values over 2000 J/kg. Thunderstorms are expected to
develop over the foothills of CO during the early afternoon and
intensify as they move into the greater instability farther east.
Midlevel westerly flow is relatively weak, but backed low-level
winds over eastern CO will provide sufficient vertical shear for a
few supercell structures as well as bowing segments. Damaging winds
and large hail will be possible in the strongest cells. Activity
will track eastward into northwest KS and southwest NE this evening
before weakening.
…Northern High Plains…
Isolated strong to severe storms will be possible along a rather
diffuse axis from eastern MT and the western Dakotas southward into
WY and the NE Panhandle. Hail and gusty winds will be possible in
the strongest cells throughout this area. A combination of clouds
and uncertain forcing mechanisms limit forecast confidence in
initiation and timing of these storms.
..KS/NE/OK…
A long-lived region of elevated convection continues over eastern
KS, with areas of showers extending westward into central KS and
northern OK. Moderate to strong instability will be present
throughout this area, but convective initiation will be dependent on
remnant outflow boundaries and other very subtle forcing mechanisms.
Any severe risk in this region should be quite isolated, but the
strongest cells could produce gusty winds.
Later tonight, elevated convection will re-develop over parts of
NE/KS with perhaps a renewed risk of hail and gusty winds.
$$