Area Forecast Discussion
Issued by NWS Medford, OR
Issued by NWS Medford, OR
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
038 FXUS66 KMFR 071143 AFDMFR Area Forecast Discussion National Weather Service Medford OR 443 AM PDT Fri Jun 7 2024 Updated AVIATION Section .DISCUSSION...Skies are clear across the region this morning per satellite imagery, with the exception of patchy stratus just over Coos Bay and the Coquille Basin. High pressure will remain in control today as a ridge pushes east into the region and amplifies along the West Coast. This will maintain hot temperatures today, with most areas (away from the immediate coast) seeing the hottest day of the forecast period and of the year so far. High temperatures this afternoon will peak around 15 to 20 degrees above normal for this time of year. Mid to upper 90s are expected for many of the West Side Valleys, except low 90s for the Umpqua Basin. Upper 80s and even local areas of low 90s are expected for areas east of the Cascades. Some records will be challenged this afternoon: Klamath Falls (91/1996), Alturas (93/1996) and Mount Shasta City (92/2015). Heat Risk values do show these temperatures will affect most individuals sensitive to heat, especially those without adequate cooling and hydration, so be sure to take it easy if outside during the peak heating hours today. Thunderstorms will again be possible this afternoon and evening. Aside from the additional energy from daytime heating, the atmosphere remains fairly similar to Thursday`s conditions. Isolated thunderstorms are possible (15-20% chance) across portions of the East Side and southwestward across the Medicine Lakes region, Shasta Valley and the southwest portion of Siskiyou County. Tonight into Saturday morning, models show a shortwave coming through the area, which in a convective pattern, raises the concern for overnight thunderstorms. Right now, it looks like moisture and stability are not optimal for elevated convection, and we`ll most likely see an influx of mid to high level clouds with some isolated showers possible over the marine waters/coastal locations. The ridge axis shifts east of the Cascades on Saturday, and this will result in about a 7 to 10 degree cooldown for West Side locations. For the East Side, however, temperatures may be cooler by a few degrees, but for the most part, Saturday looks to be similar to today`s high temperatures. Regarding thunderstorm potential on Saturday, this looks like the best day in terms of coverage for showers and thunderstorms. Chances still remain east of the Cascades and across western Siskiyou County, but instability and moisture parameters increase on Saturday and we could see scattered thunderstorms over portions of Klamath and Lake Counties. The limiting factor, however, will be the amount of cloud cover around on Saturday. Models do show quite a bit of mid and high level cloud cover in advance of an approaching weak trough, so this could hinder thunderstorm development. This weak trough passes through the region late Saturday night into Sunday, and guidance indicates the potential for showers to continue across northern Klamath/Lake Counties during this time. The cooling trend continues on Sunday as the weak trough passes through with the most notable cooling expected east of the Cascades where high temperatures are expected to be about 7 to 10 degrees cooler. West Side will cool further as well, but only by a few degrees. We`ll see yet another day of thunderstorm potential Sunday afternoon for the same areas, but again the amount of cloud cover could extensively limit thunderstorm development. Late Sunday into Monday, energy from this week trough gets cut off from main flow and forms a cut off low off the coast of southern California. The flow will become more zonal over the PacNW through about mid-week, resulting in a stabilizing atmosphere and losing the daily thunderstorm potential. With zonal flow, we don`t anticipate a big warm up, but temperatures will remain about 10 degrees above normal for the first half of the week. /BR-y && .AVIATION...07/12Z TAFs...Widespread VFR conditions prevail this morning. The exception is in the Coquille River Valley and along the coast from Cape Arago to near Bandon where stratus is causing IFR/LIFR ceilings. The sky is clear at North Bend as of 5 am, but the terminal has been in and out of lower ceilings since about midnight. Confidence is low on how much stratus will fill in near KOTH this morning, so we`ve gone with a TEMPO for IFR ceilings from 13-16Z. Otherwise, expect VFR there. Gusty north winds are expected along the Oregon coast and at Roseburg this afternoon. While VFR will mostly continue for the remainder of the TAF period, isolated to scattered showers and thunderstorms are expected to redevelop this afternoon/evening and could cause brief MVFR. These will be in much the same areas as on Thursday -- from this Trinity Alps and Mt. Shasta region of Siskiyou County eastward across Modoc and Lake Counties. Portions of Klamath and Lake counties will also have isolated thunderstorms, perhaps even at Klamath Falls. However, confidence is too low to include in the TAF at this time. -Spilde && .MARINE...Updated 200 AM Friday, June 7, 2024...A thermal trough will maintain gusty north winds and steep wind-driven seas over the coastal waters today, with very steep and hazardous seas south of Gold Beach and beyond 5 NM from shore. Winds and seas will gradually decrease later today, but will lower even more tonight into Saturday. The break will be short-lived, however, as a moderate west swell moves in late Saturday through Sunday. At the same time, the thermal trough will restrengthen, bringing increasing north winds and steep seas to all waters Sunday into early next week. -Spilde && .MFR WATCHES/WARNINGS/ADVISORIES... OR...CA...None. PACIFIC COASTAL WATERS...Small Craft Advisory until 5 AM PDT Saturday for PZZ350-356-370-376. Hazardous Seas Warning until 5 PM PDT this afternoon for PZZ356- 376. && $$ MNF/MAS