After 3 straight nights of below freezing temperatures, the map on the right shows the cumulative number of hours that temperatures have been at or below the freezing mark. Needless to say, this is unusual; particularly when you consider that our normal first freeze date here in Tulsa is Nov 3. Couple that with the earliest freeze on record which occurred the morning of Oct 7, and this month is proving to be quite an anomaly from what we have experienced so far this year. In fact, this October will be the first month in which temperatures have averaged cooler than normal since Sep of 2011.
Also, last fall when we got a break in temperature, we also got a break in the drought and picked up some significant rainfall. That has not happened this time around and the drought just continues to worsen. At least, we are getting into the cooler time of year when evaporation rates are greatly reduced and with the recent freezing temperatures, the growing season is all but over as well.
As far as our prospects for any significant rainfall, they are rather meager at best. The rest of this week will be dry with no mention of rain and the next chance of rain is not till late Saturday or into the morning hours of Sunday. The longer range guidance still has some timing and intensity issues with this particular system, so will not get too excited about the rain chances till we see better consistency and am holding the chance to 30% for now.
At least this means we will have some very pleasant fall weather for this week with a gradual warming trend in store for us. This is at least partly due to the circulation around mega storm Sandy on the E coast keeping the flow pattern aloft blocked which is preventing any significant systems from coming our way. We are far enough west that we will have a rather weak pressure pattern at the surface and therefore relatively light winds.
What winds we do have will be southerly through tonight and into Tuesday so it will not be quite as cold to start the day. After making it back into the 60s this afternoon, some lower 70s are expected for Tuesday afternoon and the morning lows should be in the 30s to near 40. Would not be surprised if there is also some patchy frost to start the day.
A weak pressure pattern should also result in light winds for Halloween and a very pleasant evening for the trick or treaters. Thursday is somewhat questionable as one of the computer models tries to bring a cold front through with brisk northerly winds and cooler conditions. Am currently thinking that the system is being overplayed so will keep the wind rather light and the wind shift should have little effect on temperatures.
Brisk southerly winds and even warmer conditions are then expected for Friday and into the day Saturday and hopefully some showers and storms before the weekend is over.
So, stay tuned and check back for updates.