WRAPPING IT UP...
The final numbers are in on summer and the big take away is that it was warm and dry areawide. Of the six major reporting stations at the NWS office in Davenport, all registered above normal temperatures and below normal rainfall. Dubuque was the warmest with a summer temperature departure of 1.3 degrees. Burlington was by far the driest with a 6.71 rainfall deficit. That makes it the 10th driest summer there with a total of just 5.95 inches. Iowa City and Cedar Rapids were also well be normal.
Here are the summer temperature departures around the region. Far more warmer departures than negatives.
Precipitation outside of the 6 major reporting stations did reach above normal levels over much of the NE third of the area. NE Iowa and NW Illinois were especially wet with 6-8 inch surpluses . That's the area which fell within the dominant summer storm track and its generous rains, a region where the ring of fire was active from late June to early August.
As you would expect, with such large rainfall deficits southwest of the Quad Cities, moderate to severe drought now covers much of the SW half of Iowa extending into WC Illinois.
At least in the short term, prospects for drought busting rains are not encouraging as the projected 16 day rainfall anomalies are significant in virtually all of the central Midwest.
NOAA'S long range seasonal drought outlook through November 1st shows a tendency for dry conditions to continue to plague the same general areas. On a positive note, NOAA is not indicating any expansion into my central and northern counties the next 2 months. Here's the seasonal drought outlook through October.
THE HOLIDAY WEEKEND REPORT:
No doubt about it, the holiday weekend gets off to toasty start Friday with southwesterly flow bringing higher temperatures and a bit more humidity. Highs are likely to hit the mid to upper 80s with a 90 on the table, especially in SE Iowa. While an isolated shower or storm is possible chances are so low its hardly worth the mention.
Friday night the front slowly approaches but the best forcing remains to the northwest and for that reason I would expect a dry night. The exception would be in the far north where a late night shower or storm is low threat.
Saturday the front ever so slowly creeps southward. The slow movement should allow for a fair amount of heating, especially over the southern half of my area. Some models like the 3k NAM build up a very warm muggy day with dew points reaching the upper 60s to near 70. Ahead of the front instability would attain significant levels if such conditions are realized. The 3k NAM shows CAPE reaching 3,000 j/kg near I-80 late in the day. That fuel combined with the front could generate at least scattered thunderstorms near and south of the advancing forcing.
Again, the lift is not impressive and shear is negligible so even if some storms go up severe weather is unlikely. That said, for my money Saturday is the period best suited to bring the potential for any meaningful rain over the holiday weekend. What occurs should be hit and miss and is most likely to be found near or slightly beyond peak heating. My central counties near and north of I-80 would be most favored, Highs could range quite a bit with readings in the upper 70s far north to about 90 in the far south. The model blend shows this for highs Saturday.
Saturday night the front slowly advances into Missouri allowing winds to turn to the east for the rest of the holiday weekend. It also means the rain threat is basically over Sunday and Monday with high pressure building into the Great Lakes. Highs both days should remain in the upper 70s to low 80s but some passing clouds will be noted from time to time. In essence, the wetter solutions that some models were indicating in this time frame yesterday have been eradicated, (as I indicated was likely to happen). Here is what models are suggesting for rainfall totals Friday through Monday. Keep in mind most of this occurs Saturday. The EURO is the outlier with its heavier amounts. It's probably over done but I cant say that with confidence.
The EURO
The GFS
The NBM (national model blend)
The WPC (Weather Prediction Center)
That sets us up for the dry quiet period models have been indicating in the longer range. Here's the rainfall departures the EURO depicts through September 16th.
Additionally, temperatures will average above normal next week. The warm EURO departures Saturday through next Friday September 9th show no signs of the fall season that is lurking ahead of us.
So there you have it as we dive into a holiday weekend. Here's hoping you all have the opportunity to enjoy it in some way, shape, or form. Roll weather...TS
