Frame Challenge
You don't supply every bit of information needed to complete the analysis, but it's close enough to say that you overestimate the effect of such an impact.
You supply a volume of 1.887e6 m^3, this means a diameter of 153.317 m. And a density of 2450 kg/m^3
You don't specify the angle of impact, so I'll assume worst case of 90 degrees.
Plugging these into the Purdue / University College of London Impact Simulator yields the following result at a distance of 50 km from the impact site.
Crater Dimensions:
What does this mean?
Crater shape is normal in spite of atmospheric crushing; fragments are not significantly dispersed.
Transient Crater Diameter: 2.57 km ( = 1.59 miles )
Transient Crater Depth: 907 meters ( = 2980 feet )
Final Crater Diameter: 2.92 km ( = 1.81 miles )
Final Crater Depth: 408 meters ( = 1340 feet )
The crater formed is a simple crater
The floor of the crater is underlain by a lens of broken rock debris (breccia) with a maximum thickness of 0 microns ( = 0 thousandths of an inch ).
The volume of the target melted or vaporized is 0.0059 km3 = 0.00141 miles3
Roughly half the melt remains in the crater
Thermal Radiation:
What does this mean?
Time for maximum radiation: 103 milliseconds after impact
Visible fireball radius: 1.55 km ( = 0.961 miles )
The fireball appears 7.03 times larger than the sun
Thermal Exposure: 1.08 x 105 Joules/m2
Duration of Irradiation: 22.7 seconds
Radiant flux (relative to the sun): 4.79
Seismic Effects:
What does this mean?
The major seismic shaking will arrive approximately 10 seconds after impact.
Richter Scale Magnitude: 6.1
Mercalli Scale Intensity at a distance of 50 km:
VII. Damage negligible in buildings of good design and construction; slight to moderate in well-built ordinary structures; considerable damage in poorly built or badly designed structures; some chimneys broken.
VIII. Damage slight in specially designed structures; considerable damage in ordinary substantial buildings with partial collapse. Damage great in poorly built structures. Fall of chimneys, factory stacks, columns, monuments, walls. Heavy furniture overturned.
Ejecta:
What does this mean?
The ejecta will arrive approximately 1.69 minutes after the impact.
At your position there is a fine dusting of ejecta with occasional larger fragments
Average Ejecta Thickness: 3.1 mm ( = 1.22 tenths of an inch )
Mean Fragment Diameter: 11.1 cm ( = 4.39 inches )
Air Blast:
What does this mean?
The air blast will arrive approximately 2.53 minutes after impact.
Peak Overpressure: 9790 Pa = 0.0979 bars = 1.39 psi
Max wind velocity: 22.2 m/s = 49.6 mph
Sound Intensity: 80 dB (Loud as heavy traffic)
Damage Description:
Glass windows will shatter.
Assuming that the impact location can be accurately estimated (and it should be quite accurate if they have had the time and accuracy needed to nuke it), at a distance of 50 km from ground zero the only prep needed would be to board up windows. If the point of impact is in a major city, evacuation will still be quite challenging, and people will die from the evacuation as well as not being evacuated. But, this would be in no way as problematic as evacuating Florida.
Outside of 25 km, shelter in place measures would often be sufficient to avoid significant personal harm. A true regional disaster that will be the lead story for quite a while, but no need to evacuate the whole state.
At the time of the Fukishima disaster, 51 people died as a result of the evacuation - given the much more challenging, it is safe to assume a much larger number of people would die by attempting to evacuate Florida.
Changing the meteor characteristics to make it match the destructiveness you want to achieve can run into another problem, the bigger the rock, the sooner it will be detected. If you decide that is what you want, I suggest you user a higher speed impact (one going counter to the Earth path around the sun is a good option since that is around 30 km/s), - but the same rock hitting at 50 km/s is still has a long way to get to require evacuating the entire state.