Area Forecast Discussion
Issued by NWS North Platte, NE
Issued by NWS North Platte, NE
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
855 FXUS63 KLBF 132323 AFDLBF Area Forecast Discussion National Weather Service North Platte NE 623 PM CDT Mon May 13 2024 .KEY MESSAGES... - Thunderstorms return to the area tomorrow afternoon into Wednesday ahead of a frontal boundary, some of which could be strong. - Warm and drier conditions then round out the workweek, with highs well above average (mid/upper 80s) Friday and Saturday. - More active weather (thunderstorms and precipitation) could return by late weekend and persist into early next week, though confidence in this remains low for now. && .SHORT TERM /THROUGH TUESDAY NIGHT/... Issued at 335 PM CDT Mon May 13 2024 Currently, the area sits in a post-frontal airmass, on the northwestern periphery of an upper low centered over eastern KS/western MO. Temperatures have climbed into the 70s across the area, with diurnal cumulus development noted across much of western and north central Nebraska. Lapse rates remain steep enough in the lowest few kilometers aloft to squeeze out at least some CAPE across the area this afternoon. That said, very nebulous surface features and limited convergence has largely precluded any widely isolated thunderstorm development thus far. Cannot completely rule out a thunderstorm across north central Nebraska (where an outflow boundary is sliding westward into Holt/Wheeler counties as I type this) though confidence is too low to add precipitation mention for now. By tonight, a quick moving shortwave will begin to push eastward across WY, with an associated surface low gradually deepening across eastern WY overnight. This will transition low level flow back southward, and lead to increasing warm advection through the overnight hours. That said, the warm advection does look somewhat meager, and should only boost lows into the middle/upper 40s (to near 50 in northwest Nebraska) across the area tonight. The aforementioned shortwave will then begin to eject eastward across the northern Plains tomorrow afternoon, reaching eastern SD by tomorrow night. The associated broad surface low will eject eastward across the Dakotas tomorrow afternoon as well, dragging a trough axis to near the HWY 83 corridor by late afternoon. At the same time, a cold front will begin to enter northwest Nebraska, approaching the meandering trough axis by late evening. Ahead of the surface trough, dewpoints will climb into the lower 50s, and will promote at least some MLCAPE, though lapse rates look to remain somewhat meager (H7-H5 lapse rates of 6.5-7.5 degC/km) aloft. That said, hodographs do lengthen with height into the afternoon hours as mid-level flow increases in response to the approaching shortwave. Deep layer shear of 30-40kts is anticipated tomorrow afternoon, with largely straight line hodographs on forecast soundings. Scattered thunderstorm development is possible ahead of the encroaching surface trough by late tomorrow afternoon, primarily near/east of HWY 83. Another regime of convective initiation is possible across the higher terrain of WY, which could push east with time into northwest Nebraska. With both regimes, cannot rule out a strong to briefly severe storm, as the increasing deep layer shear could support some updraft organization. Hail would be possible amid the aforementioned straight-line hodographs, though the meager lapse rates aloft/meager instability put this somewhat in question. Any organized convection would support a strong wind threat however, with high LCLs and very steep lapse rates in the lowest few kilometers. This activity should push east of the area after sunset, while also weakening with the loss of diurnal heating. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Issued at 335 PM CDT Mon May 13 2024 Another shortwave, on the southwestern periphery of tomorrow`s system, will push southeast across CO Wednesday, with a renewed threat for shower and thunderstorm development during the afternoon hours. As with tomorrow`s thunderstorm activity, meager instability will primarily hold back any strong storm threat, though this remains a little uncertain for now. Heights rise in the wake of the Wednesday shortwave across the central Plains, and shortwave ridging translates across the area through Friday. This will lead to drier conditions and quickly warming temperatures, as low level flow turns southwesterly and increases warm advection. In fact, highs look to climb into the middle to upper 80s (even approaching 90 across southwest Nebraska) Friday afternoon. Guidance continues to hint at a return to a more active weather regime as we head into the weekend and early next week, as southwesterly flow attempts to establish aloft. This will need to be monitored closely, as this could lead to increasing precipitation chances and a returning threat for rounds of severe weather into next week. && .AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/... Issued at 622 PM CDT Mon May 13 2024 VFR conditions will continue into Tuesday morning as clear to mostly clear skies prevail. Increasing clouds and lowering ceilings are expected Tuesday afternoon with increasing winds as well. Gusts up to 25 to 30 knots are possible across northern Nebraska with lesser gusts further to the south. Thunderstorm potential also returns on Tuesday, but confidence in any convective development before 00Z Wednesday is low. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Brown LONG TERM...Brown AVIATION...Kulik