Indian Summer Arrives This Week

The much advertised warm up started Sunday.  Sunshine and southerly wind produced highs of 65°-70° across Central Indiana…which was a good 15°-20° warmer than Saturday.

This is merely an appetizer to the main course of warmth that’s lurking downstream.  Highs in southwest Indiana and back through the Central US topped-out in the upper 70s & 80s.  This air mass is on the move and will claim real estate in the viewing area by Monday afternoon.

This will lead to a warmer start Monday morning in the mid 50s.  Though kids at the bus stop will need a light coat, they’ll be shedding layers quickly tomorrow with the arrival of Indian Summer conditions.

This stretch of much warmer than normal days will be considered an Indian Summer…since most of the state has had a heavy frost and first freeze (Indianapolis’ occurred on Oct. 8th – 31°).  Average high is 64° and this warm spell produces temperatures 15° to nearly 20° above normal.

The warmth should peak-out on Wednesday and Thursday…when the record highs of 81° and 82° respectively will be challenged.  I was always told never to forecast a record high that far out, but it’s hard to ignore that model guidance actually suggests mid 80s for both days.  Stay tuned.  You’ll notice we’re back to reality next weekend, with all eyes on a potential tropical system impacting the eastern seaboard… and possibly interacting with a strong cold front diving southward into the Midwest.  MUCH can change between now and then.  But I have a hunch this becomes a big weather story as the week plays.

The image above is from the 12z (7am) Sunday run of the trusted ECMWF (European) model.  That bulls eye in the northeast might become Tropical/Hurricane Sandy this week.  If this model verifies I’d anticipate BIG travel problems in Megalopolis.  But again it’s way too far out to put much stock into this output.  Definitely stay on top of the forecast if you have travel plans in that direction.

With or without a possible Sandy… ALL long-range guidance suggest large temperature anomalies building across the Great Lakes, Ohio Valley and southeastern US late next weekend and into the first week of November.  If accurate, this would suggest a rather chilly Halloween.  But plenty of time to iron-out details.

Have a great evening and even better work week!

Sean Ash and